0000310522-21-000192 | 10-Q | XBRL Viewer | Federal National Mortgage Association Fannie MAE

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2021	Apr. 15, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	0-50231
Entity Registrant Name	FEDERAL NATIONAL MORTGAGE ASSOCIATION FANNIE MAE
Entity Incorporation, State or Country Code	X1
Entity Tax Identification Number	52-0883107
Entity Address, Address Line One	1100 15th Street, NW
Entity Address, City or Town	Washington,
Entity Address, State or Province	DC
Entity Address, Postal Zip Code	20005
City Area Code	800
Local Phone Number	232-6643
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,158,087,567
Entity Central Index Key	0000310522
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets:
Cash and cash equivalents	$ 26,538	$ 38,337
Restricted Cash and Cash Equivalents (includes $80,899 and $68,308, respectively, related to consolidated trusts)	87,803	77,286
Federal funds sold and securities purchased under agreements to resell or similar arrangements (includes $40,837 and $0, respectively, related to consolidated trusts)	54,937	28,200
Investments in securities:
Debt Securities, Trading	111,256	136,542
Total fair value	1,502	1,697
Total investments in securities	112,758	138,239
Mortgage loans:
Loans held for sale, at lower of cost or fair value	7,824	5,197
Financing Receivable, before Allowance for Credit Loss	3,741,684	3,659,247
Allowance for loan losses	(9,628)	(10,552)
Total loans held for investment, net of allowance	3,732,056	3,648,695
Total mortgage loans	3,739,880	3,653,892
Advance to Lender	10,572	10,449
Deferred tax assets, net	12,516	12,947
Interest Receivable (includes $9,732 and $9,635, respectively, related to consolidated trusts and net of an allowance of $226, and $216)	(9,993)	(9,937)
Acquired property, net	1,183	1,261
Other assets	13,923	15,201
Total assets	4,070,103	3,985,749
Liabilities:
Interest Payable (includes $8,768 and $8,955, respectively, related to consolidated trusts)	9,585	9,719
Other Liabilities (includes $1,375 and $1,523, respectively, related to consolidated trusts)	16,313	15,035
Total liabilities	4,039,878	3,960,490
Commitments and contingencies (Note 13)	0	0
Fannie Mae stockholders’ equity:
Senior Preferred Stock Value	120,836	120,836
Preferred Stock, Value, Issued	19,130	19,130
Common Stock, Value, Issued	687	687
Accumulated deficit	(103,117)	(108,110)
Accumulated other comprehensive income	89	116
Treasury stock, at cost, 150,675,136 shares	(7,400)	(7,400)
Total stockholders’ equity (See Note 1: Senior Preferred Stock Purchase Agreement and Senior Preferred Stock for information on the related dividend obligation and liquidation preference)	30,225	25,259
Total liabilities and equity	4,070,103	3,985,749
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
Mortgage loans:
Interest Receivable (includes $9,732 and $9,635, respectively, related to consolidated trusts and net of an allowance of $226, and $216)	(226)	(216)
Fannie Mae [Member]
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	103,310	112,726
Liabilities:
Debt (includes $3,336 and $3,728, respectively, of debt of Fannie Mae at fair value and $23,601 and $24,586 respectively, of debt of consolidated trusts, at fair value)	273,442	289,572
Consolidated Trusts [Member]
Assets:
Restricted Cash and Cash Equivalents (includes $80,899 and $68,308, respectively, related to consolidated trusts)	80,899	68,308
Federal funds sold and securities purchased under agreements to resell or similar arrangements (includes $40,837 and $0, respectively, related to consolidated trusts)	40,837	0
Investments in securities:
Debt Securities, Trading	741	793
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	3,638,374	3,546,521
Interest Receivable (includes $9,732 and $9,635, respectively, related to consolidated trusts and net of an allowance of $226, and $216)	(9,732)	(9,635)
Liabilities:
Interest Payable (includes $8,768 and $8,955, respectively, related to consolidated trusts)	8,768	8,955
Debt (includes $3,336 and $3,728, respectively, of debt of Fannie Mae at fair value and $23,601 and $24,586 respectively, of debt of consolidated trusts, at fair value)	3,740,538	3,646,164
Other Liabilities (includes $1,375 and $1,523, respectively, related to consolidated trusts)	$ 1,375	$ 1,523

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets:
Restricted Cash and Cash Equivalents (includes $80,899 and $68,308, respectively, related to consolidated trusts)	$ 87,803	$ 77,286
Federal funds sold and securities purchased under agreements to resell or similar arrangements (includes $40,837 and $0, respectively, related to consolidated trusts)	54,937	28,200
Investments in securities:
Trading, at fair value (includes $6,658 and $6,544, respectively, pledged as collateral)	6,658	6,544
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	1,440	1,606
Allowance for credit losses	3
Mortgage loans:
Mortgage loans held for investment, at fair value	6,048	6,490
Interest Receivable	9,993	9,937
Liabilities:
Interest Payable (includes $8,768 and $8,955, respectively, related to consolidated trusts)	9,585	9,719
Other Liabilities	$ 16,313	$ 15,035
Fannie Mae stockholders’ equity:
Senior preferred stock liquidation preference	146,758,000,000	142,192,000,000
Preferred stock, 700,000,000 shares are authorized	700,000,000
Preferred stock, 555,374,922 shares issued	555,374,922	555,374,922
Preferred stock, 555,374,922 shares outstanding	555,374,922	555,374,922
Common stock, 1,308,762,703 shares issued	1,308,762,703	1,308,762,703
Common stock, 1,158,087,567 shares outstanding	1,158,087,567	1,158,087,567
Treasury stock, at cost, 150,675,136 shares	150,675,136	150,675,136
Fannie Mae [Member]
Liabilities:
Debt (includes $3,336 and $3,728, respectively, of debt of Fannie Mae at fair value and $23,601 and $24,586, respectively, of debt of consolidated trusts, at fair value)	$ 3,336	$ 3,728
Consolidated Trusts [Member]
Assets:
Restricted Cash and Cash Equivalents (includes $80,899 and $68,308, respectively, related to consolidated trusts)	80,899	68,308
Federal funds sold and securities purchased under agreements to resell or similar arrangements (includes $40,837 and $0, respectively, related to consolidated trusts)	40,837	0
Mortgage loans:
Interest Receivable	9,732	9,635
Liabilities:
Interest Payable (includes $8,768 and $8,955, respectively, related to consolidated trusts)	8,768	8,955
Debt (includes $3,336 and $3,728, respectively, of debt of Fannie Mae at fair value and $23,601 and $24,586, respectively, of debt of consolidated trusts, at fair value)	23,601	24,586
Other Liabilities	$ 1,375	$ 1,523

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income:
Trading securities	$ 140	$ 316
Available-for-sale securities	19	31
Mortgage loans	23,353	28,938
Federal funds sold and securities purchased under agreements to resell or similar arrangements	8	107
Other	42	34
Total interest income	23,562	29,426
Interest expense:
Short-term debt	(3)	(102)
Long-term debt	(16,817)	(23,977)
Total interest expense	(16,820)	(24,079)
Net interest income	6,742	5,347
Benefit (provision) for credit losses	765	(2,583)
Net interest income after benefit (provision) for credit losses	7,507	2,764
Non-interest income (loss):
Investment gains (losses), net	45	(158)
Fair value gains (losses), net	784	(276)
Fee and other income	87	120
Non-interest income (loss)	916	(314)
Administrative expenses:
Salaries and employee benefits	(387)	(393)
Professional services	(214)	(212)
Other administrative expenses	(147)	(144)
Total administrative expenses	(748)	(749)
Foreclosed Real Estate Income (Expense)	5	(80)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(731)	(637)
Credit enhancement expense	(284)	(376)
Change in expected credit enhancement recoveries	(31)	188
Other expenses, net	(319)	(218)
Total expenses	(2,108)	(1,872)
Income before federal income taxes	6,315	578
Provision for federal income taxes	(1,322)	(117)
Other comprehensive income (loss):
Changes in unrealized gains (losses) on available-for-sale securities, net of reclassification adjustments and taxes	(23)	18
Other, net of taxes	(4)	(3)
Total other comprehensive income (loss)	(27)	15
Total comprehensive income	4,966	476
Net income	4,993	461
Dividends distributed or amounts attributable to senior preferred stock	(4,966)	(476)
Net income (loss) attributable to common stockholders	$ 27	$ (15)
Earnings per share, Basic	$ 0.00	$ (0.00)
Earnings per share, Diluted	$ 0.00	$ (0.00)
Weighted-average common shares outstanding, Basic	5,867	5,867
Weighted-average common shares outstanding, Diluted	5,893	5,867

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net cash provided by operating activities
Net cash provided by operating activities	$ 24,883	$ 2,174
Cash flows provided by (used in) investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	13	13
Proceeds from sales of trading securities held for investment	97	0
Proceeds from maturities and paydowns of available-for-sale securities	69	96
Proceeds from sales of available-for-sale securities	115	50
Purchases of loans held for investment	(214,402)	(86,307)
Advances to lenders	(114,805)	(45,248)
Proceeds from disposition of acquired property and preforeclosure sales	1,064	1,832
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	(26,737)	5,803
Other, net	228	(539)
Net cash provided by (used in) investing activities	(14,441)	47,664
Cash flows provided by (used in) financing activities:
Other, net	71	(470)
Net cash provided by (used in) financing activities	(11,724)	17,463
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	(1,282)	67,301
Cash, cash equivalents and restricted cash and cash equivalents at beginning of period	115,623	61,407
Cash, cash equivalents and restricted cash and cash equivalents at end of period	114,341	128,708
Cash paid during the period for:
Interest	27,019	28,867
Income taxes	0	0
Fannie Mae [Member]
Cash flows provided by (used in) investing activities:
Proceeds from repayments of loans acquired as held for investment	2,889	2,308
Cash flows provided by (used in) financing activities:
Proceeds from issuance of debt	54,780	254,559
Payments to redeem debt	(69,735)	(207,818)
Consolidated Trusts [Member]
Cash flows provided by (used in) investing activities:
Proceeds from repayments of loans acquired as held for investment	337,028	169,656
Cash flows provided by (used in) financing activities:
Proceeds from issuance of debt	339,056	135,918
Payments to redeem debt	$ (335,896)	$ (164,726)

Condensed Consolidated Statements of Changes in Equity (Deficit) - USD ($) shares in Millions, $ in Millions	Total	Senior Preferred Stock	Preferred Stock	Common Stock	Accumulated Deficit	Accumulated Other Comprehensive Income	Treasury Stock	Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Senior Preferred Stock	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Preferred Stock	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Common Stock	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Accumulated Deficit	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Accumulated Other Comprehensive Income	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Treasury Stock	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Deficit
Balance (shares) at Dec. 31, 2019		1	556	1,158					1	556	1,158
Balance at Dec. 31, 2019	$ 14,608	$ 120,836	$ 19,130	$ 687	$ (118,776)	$ 131	$ (7,400)	$ 13,469	$ 120,836	$ 19,130	$ 687	$ (119,915)	$ 131	$ (7,400)
Comprehensive income:
Net income	461				461
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3 and $5, respectively)	18					18
Reclassification adjustment for gains included in net income (net of tax of $3 and $-, respectively)	0					0
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $3 and $-, respectively)	(3)					(3)
Total comprehensive income	476
Balance at Mar. 31, 2020	13,945	$ 120,836	$ 19,130	$ 687	(119,454)	146	(7,400)
Balance (shares) at Mar. 31, 2020		1	556	1,158
Other comprehensive income (loss), net of tax effect:
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	5
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	1
Accumulated deficit	(108,110)
Balance (shares) at Dec. 31, 2020		1	556	1,158
Balance at Dec. 31, 2020	25,259	$ 120,836	$ 19,130	$ 687	(108,110)	116	(7,400)								$ (1,139)	$ (1,139)
Comprehensive income:
Net income	4,993				4,993
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3 and $5, respectively)	(12)					(12)
Reclassification adjustment for gains included in net income (net of tax of $3 and $-, respectively)	(11)					(11)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $3 and $-, respectively)	(4)					(4)
Total comprehensive income	4,966
Balance at Mar. 31, 2021	30,225	$ 120,836	$ 19,130	$ 687	$ (103,117)	$ 89	$ (7,400)
Balance (shares) at Mar. 31, 2021		1	556	1,158
Other comprehensive income (loss), net of tax effect:
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	3
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(3)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	(1)
Accumulated deficit	$ (103,117)

Consolidated Statements of Changes in Equity (Deficit) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 3	$ 5
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(3)	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	$ (1)	$ 1

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Fannie Mae is a leading source of financing for mortgages in the United States. We are a shareholder-owned corporation organized as a government-sponsored entity (“GSE”) and existing under the Federal National Mortgage Association Charter Act (the “Charter Act” or our “charter”). Our charter is an act of Congress, and we have a mission under that charter to provide liquidity and stability to the residential mortgage market and to promote access to mortgage credit. As a result, we are subject to government oversight and regulation. Our regulators include the Federal Housing Finance Agency (“FHFA”), the U.S. Department of Housing and Urban Development (“HUD”), the U.S. Securities and Exchange Commission (“SEC”) and the U.S. Department of the Treasury (“Treasury”). The U.S. government does not guarantee our securities or other obligations. We have been under conservatorship, with FHFA acting as conservator, since September 6, 2008. See below and “Note 1, Summary of Significant Accounting Policies” in our annual report on Form 10-K for the year ended December 31, 2020 (“2020 Form 10-K”) for additional information on our conservatorship and the impact of U.S. government support of our business. The unaudited interim condensed consolidated financial statements as of and for the three months ended March 31, 2021 and related notes should be read in conjunction with our audited consolidated financial statements and related notes included in our 2020 Form 10-K. Basis of Presentation The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and with the SEC’s instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and note disclosures required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments of a normal recurring nature considered necessary for a fair presentation have been included. The accompanying condensed consolidated financial statements include our accounts as well as the accounts of other entities in which we have a controlling financial interest. All intercompany accounts and transactions have been eliminated. To conform to our current period presentation, we have reclassified certain amounts reported in our prior period condensed consolidated financial statements. Results for the three months ended March 31, 2021 may not necessarily be indicative of the results for the year ending December 31, 2021. Presentation of Restricted Cash and Cash Equivalents Restricted cash and cash equivalents includes funds held by consolidated MBS trusts that have not yet been remitted to MBS certificateholders under the terms of our servicing guide and the related trust agreements. In the first quarter of 2021, Fannie Mae, in its role as trustee, began to invest funds held by consolidated trusts directly in eligible short-term third-party investments, which may include investments in cash equivalents that are comprised of overnight repurchase agreements and U.S. Treasuries that have a maturity at the date of acquisition of three months or less. The funds underlying these short-term investments are restricted per the trust agreements. Accordingly, any investment in cash equivalents should be classified as restricted and is presented as “Restricted cash and cash equivalents” in our condensed consolidated balance sheets to reflect the investment of funds related to MBS trusts. Use of Estimates Preparing condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect our reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the dates of our condensed consolidated financial statements, as well as our reported amounts of revenues and expenses during the reporting periods. Management has made significant estimates in a variety of areas including, but not limited to, the allowance for loan losses. For example, significant uncertainty regarding the expected impacts of the COVID-19 pandemic required substantial management judgment in assessing our allowance for loan losses as of March 31, 2021. Actual results could be different from these estimates. Conservatorship On September 7, 2008, the Secretary of the Treasury and the Director of FHFA announced several actions taken by Treasury and FHFA regarding Fannie Mae, which included: (1) placing us in conservatorship, with FHFA acting as our conservator, and (2) the execution of a senior preferred stock purchase agreement by our conservator, on our behalf, and Treasury, pursuant to which we issued to Treasury both senior preferred stock and a warrant to purchase common stock. Under the Federal Housing Enterprises Financial Safety and Soundness Act of 1992, as amended, including by the Federal Housing Finance Regulatory Reform Act of 2008 (together, the “GSE Act”), the conservator immediately succeeded to (1) all rights, titles, powers and privileges of Fannie Mae, and of any stockholder, officer or director of Fannie Mae with respect to Fannie Mae and its assets, and (2) title to the books, records and assets of any other legal custodian of Fannie Mae. The conservator subsequently issued an order that provided for our Board of Directors to exercise specified authorities. The conservator also provided instructions regarding matters for which conservator decision or notification is required. The conservator retains the authority to amend or withdraw its order and instructions at any time. The conservator has the power to transfer or sell any asset or liability of Fannie Mae (subject to limitations and post-transfer notice provisions for transfers of qualified financial contracts) without any approval, assignment of rights or consent of any party. However, mortgage loans and mortgage-related assets that have been transferred to a Fannie Mae MBS trust must be held by the conservator for the beneficial owners of the Fannie Mae MBS and cannot be used to satisfy the general creditors of Fannie Mae. Neither the conservatorship nor the terms of our agreements with Treasury change our obligation to make required payments on our debt securities or perform under our mortgage guaranty obligations. The conservatorship has no specified termination date and there continues to be significant uncertainty regarding our future, including how long we will continue to exist in our current form, the extent of our role in the market, the level of government support of our business, how long we will be in conservatorship, what form we will have and what ownership interest, if any, our current common and preferred stockholders will hold in us after the conservatorship is terminated and whether we will continue to exist following conservatorship. Under the GSE Act, FHFA must place us into receivership if the Director of FHFA makes a written determination that our assets are less than our obligations or if we have not been paying our debts, in either case, for a period of 60 days. In addition, the Director of FHFA may place us into receivership at his discretion at any time for other reasons set forth in the GSE Act, including if we are critically undercapitalized or if we are undercapitalized and have no reasonable prospect of becoming adequately capitalized. Should we be placed into receivership, different assumptions would be required to determine the carrying value of our assets, which could lead to substantially different financial results. Treasury has made a commitment under the senior preferred stock purchase agreement to provide funding to us under certain circumstances if we have a net worth deficit. We are not aware of any plans of FHFA (1) to fundamentally change our business model, or (2) to reduce the aggregate amount available to or held by the company under our capital structure, which includes the senior preferred stock purchase agreement. Senior Preferred Stock Purchase Agreement and Senior Preferred Stock Under our senior preferred stock purchase agreement with Treasury, in September 2008 we issued Treasury one million shares of senior preferred stock and a warrant to purchase shares of our common stock. The senior preferred stock purchase agreement and the dividend and liquidation provisions of the senior preferred stock were amended in January 2021 pursuant to a letter agreement between us, through FHFA in its capacity as conservator, and Treasury. These changes included the following: •The dividend provisions of the senior preferred stock were amended to permit us to retain increases in our net worth until our net worth exceeds the amount of adjusted total capital necessary for us to meet the capital requirements and buffers under the enterprise regulatory capital framework discussed in “Note 12, Regulatory Capital Requirements” in our 2020 Form 10-K. After the “capital reserve end date,” which is defined as the last day of the second consecutive fiscal quarter during which we have maintained capital equal to, or in excess of, all of the capital requirements and buffers under the enterprise regulatory capital framework, the amount of quarterly dividends to Treasury will be equal to the lesser of any quarterly increase in our net worth and a 10% annual rate on the then-current liquidation preference of the senior preferred stock. •At the end of each fiscal quarter, through and including the capital reserve end date, the liquidation preference of the senior preferred stock will be increased by an amount equal to the increase in our net worth, if any, during the immediately prior fiscal quarter. •We may issue and retain up to $70 billion in proceeds from the sale of common stock without Treasury’s prior consent, provided that (1) Treasury has already exercised its warrant in full, and (2) all currently pending significant litigation relating to the conservatorship and to an amendment to the senior preferred stock purchase agreement made in August 2012 has been resolved, which may require Treasury’s assent. •FHFA may release us from conservatorship without Treasury’s consent after (1) all currently pending significant litigation relating to the conservatorship and to the August 2012 amendment to the senior preferred stock purchase agreement has been resolved, and (2) our common equity tier 1 capital, together with any other common stock that we may issue in a public offering, equals or exceeds 3% of our “adjusted total assets” under our enterprise regulatory capital framework. •New restrictive covenants were added that will impact both our single-family and multifamily business activities. The amendment has been accounted for as a modification of the existing arrangement. As a result, there is no change in the carrying value of the senior preferred stock. Treasury has made a commitment under the senior preferred stock purchase agreement to provide funding to us under certain circumstances if we have a net worth deficit. Pursuant to the senior preferred stock purchase agreement, we have received a total of $119.8 billion from Treasury as of March 31, 2021, and the amount of remaining funding available to us under the agreement is $113.9 billion. We have not received any funding from Treasury under this commitment since the first quarter of 2018. Dividend provisions of the senior preferred stock permit us to retain increases in our net worth until our net worth exceeds the amount of adjusted total capital necessary for us to meet the capital requirements and buffers under the enterprise regulatory capital framework established by FHFA in November 2020. The aggregate liquidation preference of the senior preferred stock increased to $146.8 billion as of March 31, 2021 and will further increase to $151.7 billion as of June 30, 2021 due to the $5.0 billion increase in our net worth during the first quarter of 2021. See “Note 11, Equity” in our 2020 Form 10-K for additional information about the senior preferred stock purchase agreement and the senior preferred stock. Statutory Capital We submit capital reports to FHFA, which monitors our capital levels. The deficit of core capital over statutory minimum capital was $119.5 billion as of March 31, 2021 and $124.3 billion as of December 31, 2020. Related Parties Because Treasury holds a warrant to purchase shares of Fannie Mae common stock equal to 79.9% of the total number of shares of Fannie Mae common stock, we and Treasury are deemed related parties. As of March 31, 2021, Treasury held an investment in our senior preferred stock with an aggregate liquidation preference of $146.8 billion. See “Senior Preferred Stock Purchase Agreement and Senior Preferred Stock” above for additional information on transactions under this agreement and the modifications made in the January 2021 letter agreement. FHFA’s control of both Fannie Mae and Freddie Mac has caused Fannie Mae, FHFA and Freddie Mac to be deemed related parties. Additionally, Fannie Mae and Freddie Mac jointly own Common Securitization Solutions, LLC (“CSS”), a limited liability company created to operate a common securitization platform; as a result, CSS is deemed a related party. As a part of our joint ownership, Fannie Mae, Freddie Mac and CSS are parties to a limited liability company agreement that sets forth the overall framework for the joint venture, including Fannie Mae’s and Freddie Mac’s rights and responsibilities as members of CSS. Fannie Mae, Freddie Mac and CSS are also parties to a customer services agreement that sets forth the terms under which CSS provides mortgage securitization services to us and Freddie Mac, including the operation of the common securitization platform as well as an administrative services agreement. CSS operates as a separate company from us and Freddie Mac, with all funding and limited administrative support services and other resources provided to it by us and Freddie Mac through our capital contributions. In the ordinary course of business, Fannie Mae may purchase and sell securities issued by Treasury and Freddie Mac. These transactions occur on the same terms as those prevailing at the time for comparable transactions with unrelated parties. Some of the structured securities we issue are backed in whole or in part by Freddie Mac securities. Fannie Mae and Freddie Mac each have agreed to indemnify the other party for losses caused by: its failure to meet its payment or other specified obligations under the trust agreements pursuant to which the underlying resecuritized securities were issued; its failure to meet its obligations under the customer services agreement; its violations of laws; or with respect to material misstatements or omissions in offering documents, ongoing disclosures and related materials relating to the underlying resecuritized securities. Additionally, we make regular income tax payments to and receive tax refunds from the Internal Revenue Service (“IRS”), a bureau of Treasury. Transactions with Treasury Our administrative expenses were reduced by $4 million and $5 million for the three months ended March 31, 2021 and 2020, respectively, due to reimbursements from Treasury and Freddie Mac for expenses incurred as program administrator for Treasury’s Home Affordable Modification Program and other initiatives under Treasury’s Making Home Affordable Program. In December 2011, Congress enacted the Temporary Payroll Cut Continuation Act of 2011 (“TCCA”) which, among other provisions, required that we increase our single-family guaranty fees by at least 10 basis points and remit this increase to Treasury. Effective April 1, 2012, we increased the guaranty fee on all single-family residential mortgages delivered to us by 10 basis points. In 2012, FHFA and Treasury advised us to remit this fee increase to Treasury with respect to all loans acquired by us on or after April 1, 2012 and before January 1, 2022, and to continue to remit these amounts to Treasury on and after January 1, 2022 with respect to loans we acquired before this date until those loans are paid off or otherwise liquidated. The resulting fee revenue and expense are recorded in “Interest income: Mortgage loans” and “TCCA fees,” respectively, in our condensed consolidated statements of operations and comprehensive income. In 2020, FHFA provided guidance that we are not required to accrue or remit TCCA fees to Treasury with respect to loans backing MBS trusts that have been delinquent for four months or longer. Once payments on such loans resume, we will resume accrual and remittance to Treasury of the associated TCCA fees on the loans. We recognized $731 million and $637 million in TCCA fees during the three months ended March 31, 2021 and 2020, respectively, of which $727 million had not been remitted to Treasury as of March 31, 2021. The GSE Act requires us to set aside certain funding obligations, a portion of which is attributable to Treasury’s Capital Magnet Fund. These funding obligations, recognized in “Other expenses, net” in our condensed consolidated statements of operations and comprehensive income, were measured as the product of 4.2 basis points and the unpaid principal balance of our total new business purchases for the respective period, and 35% of this amount is payable to Treasury’s Capital Magnet Fund. We recognized $62 million and $30 million in “Other expenses, net” in connection with Treasury’s Capital Magnet Fund for the three months ended March 31, 2021 and 2020, respectively, of which $62 million has not been remitted as of March 31, 2021. Transactions with FHFA The GSE Act authorizes FHFA to establish an annual assessment for regulated entities, including Fannie Mae, which is payable on a semi-annual basis (April and October), for FHFA’s costs and expenses, as well as to maintain FHFA’s working capital. We recognized FHFA assessment fees, which are recorded in “Administrative expenses” in our condensed consolidated statements of operations and comprehensive income, of $37 million and $32 million for the three months ended March 31, 2021 and 2020, respectively. Transactions with CSS and Freddie Mac We contributed capital to CSS, the company we jointly own with Freddie Mac, of $27 million and $29 million for the three months ended March 31, 2021 and 2020, respectively. Derivatives We recognize our derivatives as either assets or liabilities in our condensed consolidated balance sheets at their fair value on a trade date basis. Changes in fair value and interest accruals on derivatives not in qualifying fair value hedging relationships are recorded as “fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We offset the carrying amounts of certain derivatives that are in gain positions and loss positions as well as cash collateral receivables and payables associated with derivative positions pursuant to the terms of enforceable master netting arrangements. We offset these amounts only when we have the legal right to offset under the contract and we have met all the offsetting conditions. For our over-the-counter (“OTC”) derivative positions, our master netting arrangements allow us to net derivative assets and liabilities with the same counterparty. For our cleared derivative contracts, our master netting arrangements allow us to net our exposure by clearing organization and by clearing member. After offsetting, we report derivatives in a gain position in “Other assets” and derivatives in a loss position in “Other liabilities” in our condensed consolidated balance sheets. We evaluate financial instruments that we purchase or issue and other financial and non-financial contracts for embedded derivatives. To identify embedded derivatives that we must account for separately, we determine whether: (1) the economic characteristics of the embedded derivative are not clearly and closely related to the economic characteristics of the financial instrument or other contract (i.e., the host contract); (2) the financial instrument or other contract itself is not already measured at fair value with changes in fair value included in earnings; and (3) a separate instrument with the same terms as the embedded derivative would meet the definition of a derivative. If the embedded derivative meets all three of these conditions, we elect to carry the hybrid contract in its entirety at fair value with changes in fair value recorded in earnings. Fair value hedge accounting In January 2021, to reduce earnings volatility related to changes in benchmark interest rates, we began applying fair value hedge accounting to certain pools of single-family mortgage loans and certain issuances of our funding debt by designating such instruments as the hedged item in hedging relationships with interest-rate swaps. In these relationships, we have designated the change in the benchmark interest rate, either the London Inter-bank Offered Rate (“LIBOR”) or Secured Overnight Financing Rate (“SOFR”), as the risk being hedged. We have elected to use the last-of-layer method to hedge certain pools of single-family mortgage loans. This election involves establishing fair value hedging relationships on the portion of each loan pool that is not expected to be affected by prepayments, defaults and other events that affect the timing and amount of cash flows. The term of each hedging relationship is generally one business day and we establish hedging relationships daily to align our hedge accounting with our risk management practices. We apply hedge accounting to qualifying hedging relationships. A qualifying hedging relationship exists when changes in the fair value of a derivative hedging instrument are expected to be highly effective in offsetting changes in the fair value of the hedged item attributable to the risk being hedged during the term of the hedging relationship. We assess hedge effectiveness using statistical regression analysis. A hedging relationship is considered highly effective if the total change in fair value of the hedging instrument and the change in the fair value of the hedged item due to changes in the benchmark interest rate offset each other within a range of 80% to 125% and certain other statistical tests are met. If a hedging relationship qualifies for hedge accounting, the change in the fair value of the interest-rate swaps and the change in the fair value of the hedged item for the risk being hedged are recorded through net interest income. A corresponding basis adjustment is recorded against the hedged item, either the pool of mortgage loans or the debt, for the changes in the fair value attributable to the risk being hedged. For hedging relationships that hedge pools of single-family mortgage loans, basis adjustments are allocated to individual single-family loans based on the relative unpaid principal balance of each loan at the termination of the hedging relationship. The cumulative basis adjustments on the hedged item are amortized into earnings using the effective interest method over the contractual life of the hedged item, with amortization beginning upon termination of the hedging relationship. All changes in fair value of the designated portion of the derivative hedging instrument (i.e., interest-rate swap), including interest accruals, are recorded in the same line item in the condensed consolidated statements of operations and comprehensive income used to record the earnings effect of the hedged item. Therefore, changes in the fair value of the hedged mortgage loans and debt attributable to the risk being hedged are recognized in “Interest income” or “Interest expense,” along with the changes in the fair value of the respective derivative hedging instruments. The recognition of basis adjustments on the hedged item and the subsequent amortization are noncash activities and are reported in “Net cash provided by operating activities” in our condensed consolidated statements of cash flows. Cash on derivative instruments paid or received while the derivative is designated in a hedging relationship is reported as “Net cash provided by operating activities” in the condensed consolidated statement of cash flows. See “Note 3, Mortgage Loans,” “Note 7, Short-Term and Long-Term Debt” and “Note 8, Derivative Instruments” for additional information on our fair value hedge accounting policy and related disclosures. Earnings per Share Earnings per share (“EPS”) is presented for basic and diluted EPS. We compute basic EPS by dividing net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. However, as a result of our conservatorship status and the terms of the senior preferred stock, no amounts would be available to distribute as dividends to common or preferred stockholders (other than to Treasury as the holder of the senior preferred stock). Net income (loss) attributable to common stockholders excludes amounts attributable to the senior preferred stock. Weighted average common shares include 4.7 billion shares for the periods ended March 31, 2021 and 2020 that would have been issued upon the full exercise of the warrant issued to Treasury from the date the warrant was issued through March 31, 2021 and 2020. The calculation of diluted EPS includes all the components of basic earnings per share, plus the dilutive effect of common stock equivalents such as convertible securities and stock options. Weighted average shares outstanding is increased to include the number of additional common shares that would have been outstanding if the dilutive potential common shares had been issued. Our diluted EPS weighted-average shares outstanding includes 26 million shares issuable upon the conversion of convertible preferred stock as of March 31, 2021. For the three months ended March 31, 2020, convertible preferred stock is not included in the calculation because a net loss attributable to common shareholders was incurred and it would have an anti-dilutive effect.

Consolidations and Transfers of Financial Assets

3 Months Ended

Mar. 31, 2021

Consolidations and Transfers of Financial Assets [Abstract]

Consolidations and Transfers of Financial Assets

2. Consolidations and Transfers of Financial AssetsWe have interests in various entities that are considered to be variable interest entities (“VIEs”). The primary types of entities are securitization and resecuritization trusts, limited partnerships and special purpose vehicles (“SPVs”). These interests include investments in securities issued by VIEs, such as Fannie Mae MBS created pursuant to our securitization transactions and our guaranty to the entity. We consolidate the substantial majority of our single-class securitization trusts because our role as guarantor and master servicer provides us with the power to direct matters (primarily the servicing of mortgage loans) that impact the credit risk to which we are exposed. In contrast, we do not consolidate single-class securitization trusts when other organizations have the power to direct these activities unless we have the unilateral ability to dissolve the trust. We also do not consolidate our resecuritization trusts unless we have the unilateral ability to dissolve the trust. Historically, the vast majority of underlying assets of our resecuritization trusts were limited to Fannie Mae securities that were collateralized by mortgage loans held in consolidated trusts. However, with our issuance of uniform mortgage-backed securities (“UMBS®”), we include securities issued by Freddie Mac in some of our resecuritization trusts. The mortgage loans that serve as collateral for Freddie Mac-issued securities are not held in trusts that are consolidated by Fannie Mae.

Unconsolidated VIEs

We do not consolidate VIEs when we are not deemed to be the primary beneficiary. Our unconsolidated VIEs include securitization and resecuritization trusts, limited partnerships, and certain SPVs designed to transfer credit risk. The following table displays the carrying amount and classification of our assets and liabilities that relate to our involvement with unconsolidated securitization and resecuritization trusts.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts:
Assets:
Trading securities:
Fannie Mae	$	1,243	$	1,611
Non-Fannie Mae	3,598		3,608
Total trading securities	4,841		5,219
Available-for-sale securities:
Fannie Mae	1,036		1,168
Non-Fannie Mae	279		318
Total available-for-sale securities	1,315		1,486
Other assets	39		41
Other liabilities	(65)		(67)
Net carrying amount	$	6,130	$	6,679

Our maximum exposure to loss generally represents the greater of our carrying value in the entity or the unpaid principal balance of the assets covered by our guaranty. Our involvement in unconsolidated resecuritization trusts may give rise to additional exposure to loss depending on the type of resecuritization trust. Fannie Mae non-commingled resecuritization trusts are backed entirely by Fannie Mae MBS. These non-commingled single-class and multi-class resecuritization trusts are not consolidated and do not give rise to any additional exposure to loss as we already consolidate the underlying collateral.

Fannie Mae commingled resecuritization trusts are backed in whole or in part by Freddie Mac securities. The guaranty that we provide to these commingled resecuritization trusts may increase our exposure to loss to the extent that we are providing a guaranty for the timely payment and interest on the underlying Freddie Mac securities that we have not previously guaranteed. Our maximum exposure to loss for these unconsolidated trusts is measured by the amount of Freddie Mac securities that are held in these resecuritization trusts. Our maximum exposure to loss related to

unconsolidated securitization and resecuritization trusts, which includes but is not limited to our exposure to these Freddie Mac securities, was approximately $164 billion and $146 billion as of March 31, 2021 and December 31, 2020, respectively. The total assets of our unconsolidated securitization and resecuritization trusts were approximately $230 billion and $180 billion as of March 31, 2021 and December 31, 2020, respectively.

The maximum exposure to loss for our unconsolidated limited partnerships and similar legal entities, which consist of low-income housing tax credit investments (“LIHTC”), community investments and other entities, was $169 million and the related net carrying value was $163 million as of March 31, 2021. As of December 31, 2020, the maximum exposure to loss was $126 million and the related net carrying value was $121 million. The total assets of these limited partnership investments were $2.5 billion as of March 31, 2021 and $2.6 billion as of December 31, 2020.

The maximum exposure to loss related to our involvement with unconsolidated SPVs that transfer credit risk represents the unpaid principal balance and accrued interest payable of obligations issued by the Connecticut Avenue Securities® (“CAS”) and Multifamily Connecticut Avenue Securities (“MCAS”) SPVs. The maximum exposure to loss related to these unconsolidated SPVs was $10.4 billion and $11.4 billion as of March 31, 2021 and December 31, 2020, respectively. The total assets related to these unconsolidated SPVs were $10.5 billion and $11.4 billion as of March 31, 2021 and December 31, 2020, respectively.

The unpaid principal balance of our multifamily loan portfolio was $388.6 billion as of March 31, 2021. As our lending relationship does not provide us with a controlling financial interest in the borrower entity, we do not consolidate these borrowers regardless of their status as either a VIE or a voting interest entity. We have excluded these entities from our VIE disclosures. However, the disclosures we have provided in “Note 3, Mortgage Loans,” “Note 4, Allowance for Loan Losses” and “Note 6, Financial Guarantees” with respect to this population are consistent with the FASB’s stated objectives for the disclosures related to unconsolidated VIEs

Transfers of Financial Assets

We issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the transferor when we transfer assets from our own retained mortgage portfolio in a portfolio securitization transaction. For the three months ended March 31, 2021 and 2020, the unpaid principal balance of portfolio securitizations was $216.7 billion and $89.0 billion, respectively. The substantial majority of these portfolio securitization transactions generally do not qualify for sale treatment. Portfolio securitization trusts that do qualify for sale treatment primarily consist of loans that are guaranteed or insured, in whole or in part, by the U.S. government.

We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts. As of March 31, 2021, the unpaid principal balance of retained interests was $1.4 billion and its related fair value was $2.5 billion. As of December 31, 2020, the unpaid principal balance of retained interests was $1.7 billion and its related fair value was $2.9 billion. For the three months ended March 31, 2021 and 2020, the principal, interest and other fees received on retained interests was $143 million and $181 million, respectively.

Mortgage Loans

3 Months Ended

Mar. 31, 2021

SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]

Mortgage Loans

We own single-family mortgage loans, which are secured by four or fewer residential dwelling units, and multifamily mortgage loans, which are secured by five or more residential dwelling units. We classify these loans as either held for investment (“HFI”) or held for sale (“HFS”). We report the amortized cost of HFI loans for which we have not elected the fair value option at the unpaid principal balance, net of unamortized premiums and discounts, hedge-related basis adjustments, other cost basis adjustments, and accrued interest receivable, net. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable, net separately from the amortized cost of our loans held for investment. We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. See “Note 1, Summary of Significant Accounting Policies” and “Note 8, Derivative Instruments” for additional information on hedge-related basis adjustments and on implementation of our fair value hedge accounting program in January 2021.

For purposes of the single-family mortgage loan disclosures below, we display loans by class of financing receivable type. Financing receivable classes used for disclosure consist of: “20- and 30-year or more, amortizing fixed-rate,” “15-year or less, amortizing fixed-rate,” “Adjustable-rate,” and “Other.” The “Other” class primarily consists of reverse mortgage loans, interest-only loans, negative-amortizing loans and second liens.

The following table displays the carrying value of our mortgage loans and allowance for loan losses.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Single-family	$	3,286,381	$	3,216,146
Multifamily	388,591		373,722
Total unpaid principal balance of mortgage loans	3,674,972		3,589,868
Cost basis and fair value adjustments, net	74,536		74,576
Allowance for loan losses for HFI loans	(9,628)		(10,552)
Total mortgage loans(1)	$	3,739,880	$	3,653,892

(1)Excludes $9.9 billion and $9.8 billion of accrued interest receivable, net of allowance as of March 31, 2021 and December 31, 2020, respectively.

The following tables display information about our redesignation of loans from HFI to HFS and the sales of mortgage loans during the period.


		For the Three Months Ended March 31,

			2021		2020
	(Dollars in millions)
Single-family loans redesignated from HFI to HFS:
Amortized cost			$	3,112	$	1,637
Lower of cost or fair value adjustment at time of redesignation(1)			(54)		(9)
Allowance reversed at time of redesignation			361		184

Single-family loans sold:
Unpaid principal balance			$	208	$	—
Realized gains, net			2		—

(1)Consists of the write-off against the allowance at the time of redesignation.

The amortized cost of single-family mortgage loans for which formal foreclosure proceedings were in process was $4.7 billion and $5.0 billion as of March 31, 2021 and December 31, 2020, respectively. As a result of our various loss mitigation and foreclosure prevention efforts, we expect that a portion of the loans in the process of formal foreclosure proceedings will not ultimately foreclose. In addition, in response to the COVID-19 pandemic, we have prohibited our servicers from completing foreclosures on our single-family loans through at least June 30, 2021, except in the case of vacant or abandoned properties.

Aging Analysis

The following tables display an aging analysis of the total amortized cost of our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option.

Pursuant to the CARES Act, for purposes of reporting to the credit bureaus, servicers must report a borrower receiving a COVID-19-related payment accommodation during the covered period, such as a forbearance plan or loan modification, as current if the borrower was current prior to receiving the accommodation and the borrower makes all required payments in accordance with the accommodation. For purposes of our disclosures regarding delinquency status, we report loans receiving COVID-19-related payment forbearance as delinquent according to the contractual terms of the loan.


	As of March 31, 2021
	30 - 59 Days Delinquent		60 - 89 Days Delinquent		Seriously Delinquent(1)		Total Delinquent		Current		Total		Loans 90 Days or More Delinquent and Accruing Interest		Nonaccrual Loans with No Allowance
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate	$	17,400	$	7,024	$	79,349	$	103,773	$	2,688,967	$	2,792,740	$	51,671	$	6,461
15-year or less, amortizing fixed-rate	1,742		492		4,275		6,509		475,960		482,469		3,424		210
Adjustable-rate	180		63		993		1,236		26,549		27,785		735		116
Other(2)	801		317		4,494		5,612		45,188		50,800		2,132		860
Total single-family	20,123		7,896		89,111		117,130		3,236,664		3,353,794		57,962		7,647
Multifamily(3)	1,495		N/A		2,531		4,026		387,841		391,867		404		183
Total	$	21,618	$	7,896	$	91,642	$	121,156	$	3,624,505	$	3,745,661	$	58,366	$	7,830


	As of December 31, 2020
	30 - 59 Days Delinquent		60 - 89 Days Delinquent		Seriously Delinquent(1)		Total Delinquent		Current		Total		Loans 90 Days or More Delinquent and Accruing Interest		Nonaccrual Loans with No Allowance
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate	$	24,928	$	9,414	$	88,276	$	122,618	$	2,619,585	$	2,742,203	$	68,526	$	6,028
15-year or less, amortizing fixed-rate	1,987		601		5,028		7,616		449,443		457,059		4,292		240
Adjustable-rate	268		97		1,143		1,508		29,933		31,441		907		114
Other(2)	1,150		458		5,037		6,645		47,937		54,582		2,861		771
Total single-family	28,333		10,570		99,484		138,387		3,146,898		3,285,285		76,586		7,153
Multifamily(3)	1,140		N/A		3,688		4,828		372,598		377,426		610		302
Total	$	29,473	$	10,570	$	103,172	$	143,215	$	3,519,496	$	3,662,711	$	77,196	$	7,455

(1)Single-family seriously delinquent loans are loans that are 90 days or more past due or in the foreclosure process. Multifamily seriously delinquent loans are loans that are 60 days or more past due.

(2)Reverse mortgage loans included in “Other” are not aged due to their nature and are included in the current column.

(3)Multifamily loans 60-89 days delinquent are included in the seriously delinquent column.

Credit Quality Indicators

The following tables display the total amortized cost of our single-family HFI loans by class, year of origination and credit quality indicator, excluding loans for which we have elected the fair value option. The estimated mark-to-market loan-to-value (“LTV”) ratio is a primary factor we consider when estimating our allowance for loan losses for single-family loans. As LTV ratios increase, the borrower's equity in the home decreases, which may negatively affect the borrower's ability to refinance or to sell the property for an amount at or above the outstanding balance of the loan.


	As of March 31, 2021, by Year of Origination(1)
	2021		2020		2019		2018		2017		Prior		Total
	(Dollars in millions)
Estimated mark-to-market LTV ratio:(2)
20- and 30-year or more, amortizing fixed-rate:
Less than or equal to 80%	$	187,046	$	848,710	$	216,806	$	124,252	$	158,591	$	885,994	$	2,421,399
Greater than 80% and less than or equal to 90%	23,830		180,295		51,499		10,692		2,706		5,552		274,574
Greater than 90% and less than or equal to 100%	25,159		66,092		1,710		578		157		1,556		95,252
Greater than 100%	—		25		6		24		58		1,402		1,515
Total 20- and 30-year or more, amortizing fixed-rate	236,035		1,095,122		270,021		135,546		161,512		894,504		2,792,740
15-year or less, amortizing fixed-rate:
Less than or equal to 80%	48,003		187,390		35,975		13,779		28,112		161,802		475,061
Greater than 80% and less than or equal to 90%	1,137		4,953		292		19		9		19		6,429
Greater than 90% and less than or equal to 100%	356		587		4		2		3		9		961
Greater than 100%	—		—		—		2		3		13		18
Total 15-year or less, amortizing fixed-rate	49,496		192,930		36,271		13,802		28,127		161,843		482,469
Adjustable-rate:
Less than or equal to 80%	111		2,757		1,608		2,006		3,982		16,940		27,404
Greater than 80% and less than or equal to 90%	11		189		79		35		15		13		342
Greater than 90% and less than or equal to 100%	6		29		2		—		—		1		38
Greater than 100%	—		—		—		—		—		1		1
Total adjustable-rate	128		2,975		1,689		2,041		3,997		16,955		27,785
Other:
Less than or equal to 80%	—		—		39		318		779		34,761		35,897
Greater than 80% and less than or equal to 90%	—		—		1		15		31		1,000		1,047
Greater than 90% and less than or equal to 100%	—		—		2		5		11		456		474
Greater than 100%	—		—		—		3		5		485		493
Total other	—		—		42		341		826		36,702		37,911
Total	$	285,659	$	1,291,027	$	308,023	$	151,730	$	194,462	$	1,110,004	$	3,340,905

Total for all classes by LTV ratio:(2)
Less than or equal to 80%	$	235,160	$	1,038,857	$	254,428	$	140,355	$	191,464	$	1,099,497	$	2,959,761
Greater than 80% and less than or equal to 90%	24,978		185,437		51,871		10,761		2,761		6,584		282,392
Greater than 90% and less than or equal to 100%	25,521		66,708		1,718		585		171		2,022		96,725
Greater than 100%	—		25		6		29		66		1,901		2,027
Total	$	285,659	$	1,291,027	$	308,023	$	151,730	$	194,462	$	1,110,004	$	3,340,905


	As of December 31, 2020, by Year of Origination(1)
	2020		2019		2018		2017		2016		Prior		Total
	(Dollars in millions)
Estimated mark-to-market LTV ratio:(2)
20- and 30-year or more, amortizing fixed-rate:
Less than or equal to 80%	$	794,156	$	233,994	$	135,849	$	183,315	$	221,172	$	775,636	$	2,344,122
Greater than 80% and less than or equal to 90%	157,500		85,227		23,440		5,270		1,592		5,958		278,987
Greater than 90% and less than or equal to 100%	109,743		4,186		820		250		124		1,994		117,117
Greater than 100%	28		7		28		77		81		1,756		1,977
Total 20- and 30-year or more, amortizing fixed-rate	1,061,427		323,414		160,137		188,912		222,969		785,344		2,742,203
15-year or less, amortizing fixed-rate:
Less than or equal to 80%	181,418		41,374		15,768		31,497		46,088		132,596		448,741
Greater than 80% and less than or equal to 90%	6,105		811		35		14		8		20		6,993
Greater than 90% and less than or equal to 100%	1,274		9		3		4		3		10		1,303
Greater than 100%	—		—		3		3		3		13		22
Total 15-year or less, amortizing fixed-rate	188,797		42,194		15,809		31,518		46,102		132,639		457,059
Adjustable-rate:
Less than or equal to 80%	2,935		1,839		2,412		4,765		2,678		16,248		30,877
Greater than 80% and less than or equal to 90%	234		152		79		19		5		12		501
Greater than 90% and less than or equal to 100%	56		3		1		—		—		2		62
Greater than 100%	—		—		—		—		—		1		1
Total adjustable-rate	3,225		1,994		2,492		4,784		2,683		16,263		31,441
Other:
Less than or equal to 80%	—		41		328		811		1,028		36,216		38,424
Greater than 80% and less than or equal to 90%	—		2		20		43		30		1,298		1,393
Greater than 90% and less than or equal to 100%	—		2		8		16		10		602		638
Greater than 100%	—		—		4		8		9		631		652
Total other	—		45		360		878		1,077		38,747		41,107
Total	$	1,253,449	$	367,647	$	178,798	$	226,092	$	272,831	$	972,993	$	3,271,810

Total for all classes by LTV ratio:(2)
Less than or equal to 80%	$	978,509	$	277,248	$	154,357	$	220,388	$	270,966	$	960,696	$	2,862,164
Greater than 80% and less than or equal to 90%	163,839		86,192		23,574		5,346		1,635		7,288		287,874
Greater than 90% and less than or equal to 100%	111,073		4,200		832		270		137		2,608		119,120
Greater than 100%	28		7		35		88		93		2,401		2,652
Total	$	1,253,449	$	367,647	$	178,798	$	226,092	$	272,831	$	972,993	$	3,271,810

(1)Excludes $12.9 billion and $13.5 billion as of March 31, 2021 and December 31, 2020, respectively, of mortgage loans guaranteed or insured, in whole or in part, by the U.S. government or one of its agencies, which represents primarily reverse mortgages for which we do not calculate an estimated mark-to-market LTV ratio.

(2)The aggregate estimated mark-to-market LTV ratio is based on the unpaid principal balance of the loan divided by the estimated current value of the property as of the end of each reported period, which we calculate using an internal valuation model that estimates periodic changes in home value.

The following tables display the total amortized cost in our multifamily HFI loans by year of origination and credit-risk rating, excluding loans for which we have elected the fair value option. Property rental income and property valuations are key inputs to our internally assigned credit risk ratings.


	As of March 31, 2021, by Year of Origination
	2021		2020		2019		2018		2017		Prior		Total
	(Dollars in millions)
Internally assigned credit risk rating:
Non-classified(1)	$	11,295	$	81,647	$	67,630	$	61,280	$	49,903	$	108,429	$	380,184
Classified(2)	—		204		1,185		1,673		2,882		5,739		11,683
Total	$	11,295	$	81,851	$	68,815	$	62,953	$	52,785	$	114,168	$	391,867


	As of December 31, 2020, by Year of Origination
	2020		2019		2018		2017		2016		Prior		Total
	(Dollars in millions)
Internally assigned credit risk rating:
Non-classified(1)	$	71,977	$	68,296	$	62,087	$	50,907	$	43,174	$	70,933	$	367,374
Classified(2)	37		1,041		1,529		2,616		1,579		3,250		10,052
Total	$	72,014	$	69,337	$	63,616	$	53,523	$	44,753	$	74,183	$	377,426

(1)A loan categorized as “Non-classified” is current or adequately protected by the current financial strength and debt service capability of the borrower.

(2)Represents loans classified as “Substandard” or “Doubtful.” Loans classified as “Substandard” have a well-defined weakness that jeopardizes the timely full repayment. “Doubtful” refers to a loan with a weakness that makes collection or liquidation in full highly questionable and improbable based on existing conditions and values. As of March 31, 2021 and December 31, 2020, we had loans with an amortized cost of $4 million and less than $1 million, respectively, classified as doubtful.

Troubled Debt Restructurings

A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a troubled debt restructuring (“TDR”). In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for these informal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs. However, our current TDR accounting described herein is temporarily impacted by our election to account for certain eligible loss mitigation activities under the COVID-19 Relief granted pursuant to the CARES Act and the Consolidated Appropriations Act of 2021. See “Note 1, Summary of Significant Accounting Policies” in our 2020 Form 10-K for more information on the relief from TDR accounting and disclosure requirements.

The substantial majority of the loan modifications accounted for as a TDR result in term extensions, interest rate reductions or a combination of both. During the three months ended March 31, 2021 and 2020, the average term extension of a single-family modified loan was 138 months and 168 months, respectively, and the average interest rate reduction was 0.52 and 0.32 percentage points, respectively.

The following table displays the number of loans and amortized cost of loans classified as a TDR during the period.


	For the Three Months Ended March 31,
	2021				2020
		Number of Loans	Amortized Cost			Number of Loans	Amortized Cost
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		2,989	$	471		10,856	$	1,909
15-year or less, amortizing fixed-rate		369	28			1,073	98
Adjustable-rate		41	6			144	24
Other		154	18			537	68
Total single-family		3,553	523			12,610	2,099
Multifamily		—	—			—	—
Total TDRs		3,553	$	523		12,610	$	2,099

For loans that defaulted in the period presented and that were classified as a TDR in the twelve months prior to the default, the following table displays the number of loans and the amortized cost of these loans at the time of payment default. For purposes of this disclosure, we define loans that had a payment default as: single-family and multifamily loans with completed TDRs that liquidated during the period, either through foreclosure, deed-in-lieu of foreclosure, or a short sale; single-family loans with completed modifications that are two or more months delinquent during the period; or multifamily loans with completed modifications that are one or more months delinquent during the period.


		For the Three Months Ended March 31,
	2021				2020
		Number of Loans	Amortized Cost			Number of Loans	Amortized Cost
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		7,172	$	1,327		3,175	$	521
15-year or less, amortizing fixed-rate		152	11			50	3
Adjustable-rate		11	2			7	1
Other		633	112			327	51
Total single-family		7,968	1,452			3,559	576
Multifamily		—	—			2	2
Total TDRs that subsequently defaulted		7,968	$	1,452		3,561	$	578

Nonaccrual Loans

For loans not subject to the COVID-19-related nonaccrual policy, we discontinue accruing interest when we believe collectability of principal and interest is not reasonably assured, which for a single-family loan we have determined, based on our historical experience, to be when the loan becomes two months or more past due according to its contractual terms. Interest previously accrued but not collected on such loans is reversed through interest income at the date the loan is placed on nonaccrual status. For single-family loans on nonaccrual status, we recognize income when cash payments are received. We return a non-modified single-family loan to accrual status at the point when the borrower brings the loan current. We return a modified single-family loan to accrual status at the point when the borrower has successfully made all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes two months or more past due according to its contractual terms unless the loan is well secured such that collectability of principal and accrued interest is reasonably assured. For multifamily loans on nonaccrual status, we apply any payment received on a cost recovery basis to reduce principal on the mortgage loan. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan. Single-family and multifamily loans are reported past due if a full payment of principal and interest is not received within one month of its due date.

For loans negatively impacted by the COVID-19 pandemic, we continue to recognize interest income at the current contractual yield for up to six months of delinquency provided that the loan was either current at March 1, 2020 or originated after March 1, 2020, and collection of principal and interest is reasonably assured. For single-family loans where we have provided relief beyond six months of delinquency, we continue to accrue interest income provided that the loan remains in a forbearance arrangement and collection of principal and interest continues to be reasonably assured. Multifamily loans that are in a forbearance arrangement are placed on nonaccrual status when the borrower is six months past due unless the loan is both well secured and in the process of collection. Loans that have been placed in a repayment plan or that have been brought current through a modification or a payment deferral are returned to accrual status once the borrower has made six consecutive contractual payments under the terms of the repayment plan or the modified loan. For loans in a forbearance arrangement that are placed on nonaccrual status, cash payments for interest are applied as a reduction of accrued interest receivable until the receivable has been reduced to zero, and then recognized as interest income. If a loan is modified, any capitalized interest that has not been previously recognized as interest income is recorded as a discount to the loan and amortized over the life of the loan. See “Note 1, Summary of Significant Accounting Policies” in our 2020 Form 10-K for more information on our nonaccrual policy, including a discussion of regulatory guidance on interest income issued in response to COVID-19, and additional information on our policies for determining if the collection of principal and interest is reasonably assured, as well as our policy for establishing a valuation allowance for expected credit losses on the accrued interest receivable balance for loans negatively impacted by COVID-19.

The table below displays the forgone interest and the accrued interest receivable written off through the reversal of interest income for nonaccrual loans.


		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Single-family:
Interest income forgone(1)		$	307	$	182
Accrued interest receivable written off through the reversal of interest income		108		87

Multifamily:
Interest income forgone(1)		$	14	$	1
Accrued interest receivable written off through the reversal of interest income		—		—

(1)For loans on nonaccrual status held as of period end, represents the amount of interest income we did not recognize but would have recognized if the loans had performed in accordance with their original contractual terms.

The table below includes the amortized cost of and interest income recognized on our HFI single-family and multifamily loans on nonaccrual status by class, excluding loans for which we have elected the fair value option.


		As of				For the Three Months Ended March 31,
		March 31, 2021		December 31, 2020			2021			2020
		Amortized Cost				Total Interest Income Recognized(1)
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		$	30,173	$	22,907			$	64		$	101
15-year or less, amortizing fixed-rate		945		853				2			2
Adjustable-rate		284		270				1			1
Other		2,583		2,475				4			13
Total single-family		33,985		26,505				71			117
Multifamily		2,153		2,069				8			—
Total nonaccrual loans		$	36,138	$	28,574			$	79		$	117

(1)Single-family interest income recognized includes amounts accrued while the loans were performing, including the amortization of any deferred cost basis adjustments, as well as payments received on nonaccrual loans for nonaccrual loans held as of period end. Multifamily interest income recognized includes amounts accrued while the loans were performing and the amortization of any deferred cost basis adjustments for nonaccrual loans held as of period end.

Allowance for Loan Losses

3 Months Ended

Mar. 31, 2021

Receivables [Abstract]

Allowance for Loan Losses

We maintain an allowance for loan losses for HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts, excluding loans for which we have elected the fair value option. When calculating our allowance for loan losses, we consider the unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments of HFI loans at the balance sheet date. We record write-offs as a reduction to our allowance for loan losses at the point of foreclosure, completion of a short sale, upon the redesignation of nonperforming and reperforming loans from HFI to HFS or when a loan is determined to be uncollectible.

The following table displays changes in our allowance for single-family loans, multifamily loans and total allowance for loan losses, including the transition impact of adopting Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments,” which was later amended by ASU 2019-04, ASU 2019-05 and ASU 2019-1 (collectively, the “CECL standard”), on January 1, 2020. See “Note 1, Summary of Significant Accounting Policies” in our 2020 Form 10-K for additional information on changes to our allowance for loan losses resulting from our adoption of the CECL standard.

The benefit or provision for loan losses excludes provision for accrued interest receivable losses, guaranty loss reserves and credit losses on available-for-sale (“AFS”) debt securities. Cumulatively, these expenses are recognized as “Benefit (provision) for credit losses” in our condensed consolidated statements of operations and comprehensive income.


		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Single-family allowance for loan losses:
Beginning balance		$	(9,344)	$	(8,759)
Transition impact of the adoption of the CECL standard		—		(1,229)
Benefit (provision) for loan losses		671		(2,177)
Write-offs		71		70
Recoveries		(2)		(3)
Other		57		28
Ending Balance		$	(8,547)	$	(12,070)
Multifamily allowance for loan losses:
Beginning balance		$	(1,208)	$	(257)
Transition impact of the adoption of the CECL standard		—		(493)
Benefit (provision) for loan losses		95		(407)
Write-offs		33		19
Recoveries		(1)		(1)

Ending Balance		$	(1,081)	$	(1,139)
Total allowance for loan losses:
Beginning balance		$	(10,552)	$	(9,016)
Transition impact of the adoption of the CECL standard		—		(1,722)
Benefit (provision) for loan losses		766		(2,584)
Write-offs		104		89
Recoveries		(3)		(4)
Other		57		28
Ending Balance		$	(9,628)	$	(13,209)

Our benefit or provision for loan losses can vary substantially from period to period based on a number of factors, such as changes in actual and forecasted home prices or property valuations, fluctuations in actual and forecasted interest rates, borrower payment behavior, events such as natural disasters or pandemics, the types and volume of our loss mitigation activities, including forbearance and loan modifications, the volume of foreclosures completed, and the redesignation of loans from HFI to HFS. Our benefit or provision can also be impacted by updates to the models, assumptions, and data used in determining our allowance for loan losses. As described below, our benefit or provision for loan losses and our loss reserves have been significantly affected by our estimates of the impact of the COVID-19

pandemic, which require significant management judgment. Changes in our estimates of borrowers that will ultimately receive forbearance and even more significantly, the loss mitigation outcomes of affected borrowers after the forbearance period ends, remain uncertain and can affect the amount of benefit or provision for loan losses we recognize.

The primary factors that contributed to our single-family benefit for loan losses in the first quarter of 2021 were:

•Benefit from actual and expected home price growth. During the first quarter of 2021, home price growth was unseasonably strong. We also increased our expectations for home price growth on a national basis for full year 2021. Higher home prices decrease the likelihood that loans will default and reduce the amount of credit loss on loans that do default, which impacts our estimate of losses and ultimately reduces our loss reserves and provision for loan losses.

•Benefit from the redesignation of certain reperforming single-family loans from HFI to HFS. After a temporary pause in sales of nonperforming and reperforming loans, we resumed our plans for sales late in the first quarter of 2021. As a result, we redesignated certain reperforming single-family loans from HFI to HFS, as we no longer intend to hold them for the foreseeable future or to maturity. Upon redesignation of these loans, we recorded the loans at the lower of cost or fair value with a write-off against the allowance for loan losses. Amounts recorded in the allowance related to these loans exceeded the amounts written off, resulting in a benefit for loan losses.

•Benefit from changes in assumptions regarding COVID-19 forbearance and change in actual and expected loan delinquencies. Management continues to apply its judgment and supplement model results as of March 31, 2021, due to continued uncertainty regarding the loss mitigation outcomes of borrowers in forbearance, and uncertainty regarding the future impact of the pandemic, including the efficacy of the COVID-19 vaccines on new strains of the virus and its effect on the economy. Although uncertainty remains, our expected loan losses as a result of the COVID-19 pandemic decreased in the first quarter of 2021, driven by the passage of the American Rescue Plan, which provides additional economic stimulus and helps support the continued economic recovery. In addition, decreased political uncertainty compared with the end of 2020 combined with the increased progression of the COVID-19 vaccines rollout lessened expectations of loan losses. Based on these factors in the first quarter of 2021, management used its judgment to reduce the non-modeled adjustment that was previously applied to the loss projections developed by our credit loss model.

The impact of these factors was partially offset by the impact of the following factor which reduced our single-family benefit for loan losses recognized in the first quarter of 2021.

•Provision from higher actual and projected interest rates. Although we continue to be in a historically low interest-rate environment, actual and projected interest rates rose in the first quarter of 2021. As mortgage interest rates increase, we expect a decrease in future prepayments on single-family loans, including modified loans. Lower expected prepayments extend the expected lives of modified loans, which increases the expected impairment relating to term and interest-rate concessions provided on these loans resulting in a provision for loan losses.

The primary factors that impacted our single-family provision for loan losses in the first quarter of 2020 were:

•Expected loan losses as a result of the COVID-19 pandemic. Given the rapidly changing and deteriorating market conditions in the first quarter of 2020 as a result of the unprecedented COVID-19 pandemic, we believed our model used to estimate single-family credit losses as of March 31, 2020 did not capture the entirety of losses we expected to incur relating to COVID-19. As a result, management used its judgment to increase the loss projections developed by our credit loss model to reflect our expectations at that time relating to COVID-19’s impact. These judgments included adjusting our modeled results for (1) the expected impact of widespread forbearance programs, including the rate of borrower participation, and the volume and type of loan modifications as a result thereof, (2) the effect of TDR accounting relief from the CARES Act, and (3) lower expected prepayment volumes given the sharp rise in unemployment rates that were expected to stay elevated over the near term. In developing this model adjustment, management considered the credit risk profile of our single-family loan book of business at that time, as well as relevant historical credit loss experience during rare or stressful economic environments.

•A decrease in our expectations for home price growth. In the first quarter of 2020, we revised our forecast to reflect near zero home price appreciation on a national basis for 2020 due to COVID-19 market disruptions. Lower home prices increase the likelihood that loans will default and increase the amount of credit loss on loans that do default, which impacts our estimate of losses and ultimately increases our loss reserves and provision for credit losses.

•These factors were partially offset by lower actual and projected mortgage interest rates. As mortgage interest rates declined, we expected an increase in future prepayments on single-family loans, including modified loans. As noted above, we adjusted downward our modeled expectation of prepayment volumes due to the COVID-19 pandemic, which reduced this modeled benefit from interest rates.

The primary factors that impacted our multifamily benefit for loan losses in the first quarter of 2021 were:

•Benefit from actual and projected economic data. In the first quarter of 2021, property value forecasts increased due to continued demand for multifamily housing. In addition, improved job growth led to an increase in projected average property net operating income, which reduced the probability of loan default, resulting in a benefit for loan losses for the quarter.

•Benefit from changes in expected loan losses as a result of the COVID-19 pandemic. Similar to our single-family provision for loan losses described above, management continues to apply its judgment and supplement model results as of March 31, 2021, due to continued uncertainty regarding the future impact of the pandemic, including the efficacy of the COVID-19 vaccines on new strains of the virus and its effect on the economy. Although uncertainty remains, our expected loan losses as a result of the COVID-19 pandemic decreased in the first quarter of 2021 driven by positive economic growth and the passage of the American Rescue Plan, which provided additional economic stimulus. Based on these factors in the first quarter of 2021, management used its judgment to reduce the non-modeled adjustment that was previously applied to the loss projections developed by our credit loss model.

Our multifamily provision for loan losses in the first quarter 2020 was primarily driven by higher expected losses as a result of the economic dislocation caused by the COVID-19 pandemic. Consistent with the 2020 single-family provision for loan losses discussed above, we believed our model used to estimate multifamily loan losses as of March 31, 2020 did not capture the entirety of losses we expected to incur relating to COVID-19. As a result, management used its judgment to increase the loss projections developed by our credit loss model to reflect our expectations at that time relating to COVID-19’s impact. Accordingly, our multifamily provision for loan losses was primarily driven by higher expected unemployment rates, which we expected would increase the number of loans in forbearance and reduce property net operating income in the near term, thereby decreasing forecasted property values and increasing the probability of loan default. In developing these adjustments, management considered the credit risk profile of our multifamily loan book of business at that time, as well as relevant historical credit loss experience during rare or stressful economic environments.

Investments in Securities

3 Months Ended

Mar. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Investments in Securities

Trading Securities

Trading securities are recorded at fair value with subsequent changes in fair value recorded as “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. The following table displays our investments in trading securities.


	As of
	March 31, 2021			December 31, 2020
	(Dollars in millions)
Mortgage-related securities:
Fannie Mae		$	1,985		$	2,404
Other agency(1)		3,440			3,451
Private-label and other mortgage securities		157			158
Total mortgage-related securities (includes $741 million and $793 million, respectively, related to consolidated trusts)		5,582			6,013
Non-mortgage-related securities:
U.S. Treasury securities		105,601			130,456
Other securities		73			73
Total non-mortgage-related securities		105,674			130,529
Total trading securities		$	111,256		$	136,542

(1)Consists of Freddie Mac and Ginnie Mae mortgage-related securities.

The following table displays information about our net trading gains (losses).


		For the Three Months Ended March 31,

			2021		2020
	(Dollars in millions)
Net trading gains (losses)			$	(758)	$	647
Net trading gains (losses) recognized in the period related to securities still held at period end			(759)		591

Available-for-Sale Securities

We record AFS securities at fair value with unrealized gains and losses, recorded net of tax, as a component of “Other comprehensive income (loss)” and we recognize realized gains and losses from the sale of AFS securities in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We define the amortized cost basis of our AFS securities as unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments. We record an allowance for credit losses for AFS securities that reflects the impairment for credit losses, which are limited to the amount that fair value is less than the amortized cost. Impairment due to non-credit losses are recorded as unrealized losses within other comprehensive income.

The following tables display the amortized cost, allowance for credit losses, gross unrealized gains and losses in accumulated other comprehensive income (loss) (“AOCI”), and fair value by major security type for AFS securities.


	As of March 31, 2021
	Total Amortized Cost(1)			Allowance for Credit Losses		Gross Unrealized Gains in AOCI		Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	988	$	—	$	59		$	(11)	$	1,036
Other agency(2)		32		—		2			—		34
Alt-A and subprime private-label securities		3		—		2			—		5

Mortgage revenue bonds		187		(3)		7			—		191
Other mortgage-related securities		230		—		6			—		236
Total		$	1,440	$	(3)	$	76		$	(11)	$	1,502


	As of December 31, 2020
	Total Amortized Cost(1)			Allowance for Credit Losses			Gross Unrealized Gains in AOCI			Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	1,094		$	—		$	86		$	(12)	$	1,168
Other agency(2)		59			—			6			—		65
Alt-A and subprime private-label securities		4			—			2			—		6
Mortgage revenue bonds		211			(3)			8			—		216
Other mortgage-related securities		238			—			4			—		242
Total		$	1,606		$	(3)		$	106		$	(12)	$	1,697

(1)We exclude from amortized cost and fair value accrued interest of $5 million and $6 million as of March 31, 2021 and December 31, 2020, respectively, which we record in “Other assets” in our condensed consolidated balance sheets.

(2)Other agency securities consist of securities issued by Freddie Mac and Ginnie Mae.

Fannie Mae and Other Agency Securities

Our Fannie Mae and other agency AFS securities consist of securities issued by us, Freddie Mac, or Ginnie Mae. The principal and interest on these securities are guaranteed by the issuing agency. We believe that the guaranty provided by the issuing agency, the support provided to the agencies by the U.S. government, the importance of the agencies to the liquidity and stability in the secondary mortgage market, and the long history of zero credit losses on agency

mortgage-related securities are all indicators that there are currently no credit losses on these securities, even if the security is in an unrealized loss position. In addition, we generally hold these securities that are in an unrealized loss position to recovery. As a result, unless we intend to sell the security, we do not recognize an allowance for credit losses on agency mortgage-related securities.

Non-Agency Mortgage-Related Securities

As of March 31, 2021, substantially all of our non-agency mortgage-related securities were in an unrealized gain position. As a result, we have not recognized an allowance for credit losses on these securities.

The following tables display additional information regarding gross unrealized losses and fair value by major security type for AFS securities in an unrealized loss position, excluding allowance for credit losses.


	As of
	March 31, 2021										December 31, 2020
	Less Than 12 Consecutive Months					12 Consecutive Months or Longer					Less Than 12 Consecutive Months					12 Consecutive Months or Longer
	Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value
	(Dollars in millions)
Fannie Mae		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94


Total		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94

The following table displays the gross realized gains and proceeds on sales of AFS securities.


	For the Three Months Ended March 31,

			2021		2020
		(Dollars in millions)
Gross realized gains			$	13	$	21

Total proceeds (excludes initial sale of securities from new portfolio securitizations)			115		50

The following tables display net unrealized gains on AFS securities and other amounts accumulated within our accumulated other comprehensive income, net of tax.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Net unrealized gains on AFS securities for which we have not recorded an allowance for credit losses	$	51	$	74

Other	38		42
Accumulated other comprehensive income	$	89	$	116

Maturity Information

The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time.


	As of March 31, 2021
	Total Carrying Amount(1)			Total Fair Value		One Year or Less					After One Year Through Five Years					After Five Years Through Ten Years					After Ten Years
						Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value
	(Dollars in millions)
Fannie Mae		$	988	$	1,036		$	—	$	—		$	4	$	4		$	98	$	109		$	886	$	923
Other agency		32		34			—		—			—		—			1		1			31		33
Alt-A and subprime private-label securities		3		5			—		—			—		—			2		2			1		3

Mortgage revenue bonds		184		191			1		1			26		27			18		19			139		144
Other mortgage-related securities		230		236			—		—			—		—			18		20			212		216
Total		$	1,437	$	1,502		$	1	$	1		$	30	$	31		$	137	$	151		$	1,269	$	1,319

(1) Net carrying amount consists of book value, net of allowance for credit losses on AFS debt securities.

Financial Guarantees

3 Months Ended

Mar. 31, 2021

Guarantees [Abstract]

Financial Guarantees

We recognize a guaranty obligation for our obligation to stand ready to perform on our guarantees to unconsolidated trusts and other guaranty arrangements. These off-balance sheet guarantees expose us to credit losses primarily relating to the unpaid principal balance of our unconsolidated Fannie Mae MBS and other financial guarantees. The maximum remaining contractual term of our guarantees is 32 years; however, the actual term of each guaranty may be significantly less than the contractual term based on the prepayment characteristics of the related mortgage loans. We measure our guaranty reserve for estimated credit losses for off-balance sheet exposures over the contractual period for which they are exposed to the credit risk, unless that obligation is unconditionally cancellable by the issuer.

As the guarantor of structured securities backed in whole or in part by Freddie Mac-issued securities, we extend our guaranty to the underlying Freddie Mac securities in our resecuritization trusts. However, Freddie Mac continues to guarantee the payment of principal and interest on the underlying Freddie Mac securities that we have resecuritized. We do not charge an incremental guaranty fee to include Freddie Mac securities in the structured securities that we issue. When we began issuing UMBS in June 2019, we entered into an indemnification agreement under which Freddie Mac agreed to indemnify us for losses caused by its failure to meet its payment or other specified obligations under the trust agreements pursuant to which the underlying resecuritized securities were issued. As a result, and due to the funding commitment available to Freddie Mac through its senior preferred stock purchase agreement with Treasury, we have concluded that the associated credit risk is negligible. Accordingly, we exclude from the following table Freddie Mac securities backing unconsolidated Fannie Mae-issued structured securities of approximately $154.6 billion and $137.3 billion as of March 31, 2021 and December 31, 2020, respectively.

The following table displays our off-balance sheet maximum exposure, guaranty obligation recognized in our condensed consolidated balance sheets and the potential maximum recovery from third parties through available credit enhancements and recourse related to our financial guarantees.


	As of
	March 31, 2021						December 31, 2020
	Maximum Exposure		Guaranty Obligation		Maximum Recovery(1)		Maximum Exposure		Guaranty Obligation		Maximum Recovery(1)
	(Dollars in millions)
Unconsolidated Fannie Mae MBS	$	4,232	$	17	$	4,047	$	4,424	$	18	$	4,226
Other guaranty arrangements(2)	11,392		103		2,295		11,828		109		2,438
Total	$	15,624	$	120	$	6,342	$	16,252	$	127	$	6,664

(1)Recoverability of such credit enhancements and recourse is subject to, among other factors, the ability of our mortgage insurers and the U.S. government, as a financial guarantor, to meet their obligations to us. For information on our mortgage insurers, “Note 10, Concentrations of Credit Risk.”

(2)Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt

3 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Short-Term and Long-Term Debt

Short-Term and Long-Term Debt In January 2021, we began applying fair value hedge accounting to certain debt issuances. The objective of our fair value hedges is to reduce GAAP earnings volatility related to changes in benchmark interest rates. See “Note 1, Summary of Significant Accounting Policies” and “Note 8, Derivative Instruments” for additional information on our fair value hedge accounting policy and related disclosures.

Short-Term Debt

The following table displays our outstanding short-term debt (debt with an original contractual maturity of one year or less) and weighted-average interest rates of this debt.


	As of
	March 31, 2021				December 31, 2020
	Outstanding		Weighted- Average Interest Rate(1)		Outstanding		Weighted- Average Interest Rate(1)
	(Dollars in millions)

Short-term debt of Fannie Mae	$	2,857	0.06	%	$	12,173	0.18	%

(1)Includes the effects of discounts, premiums and other cost basis adjustments.

Long-Term Debt

Long-term debt represents debt with an original contractual maturity of greater than one year. The following table displays our outstanding long-term debt.


	As of
	March 31, 2021					December 31, 2020
	Maturities	Outstanding(1)		Weighted- Average Interest Rate(2)		Maturities	Outstanding		Weighted- Average Interest Rate(2)
	(Dollars in millions)
Senior fixed:
Benchmark notes and bonds	2021 - 2030	$	102,683	2.09	%	2021 - 2030	$	106,691	2.03	%
Medium-term notes(3)	2021 - 2031	47,693		0.61		2021 - 2030	48,524		0.63
Other(4)	2021 - 2038	7,195		3.77		2021 - 2038	6,701		3.90
Total senior fixed		157,571		1.72			161,916		1.69
Senior floating:
Medium-term notes(3)	2021 - 2022	98,095		0.28		2021 - 2022	100,089		0.35
Connecticut Avenue Securities(5)	2023 - 2031	14,537		4.13		2023 - 2031	14,978		4.16
Other(6)	2037	382		7.69		2037	416		7.75
Total senior floating		113,014		0.79			115,483		0.86


Total long-term debt of Fannie Mae(7)		270,585		1.34			277,399		1.34
Debt of consolidated trusts	2021 - 2060	3,740,538		1.72		2021 - 2060	3,646,164		1.88
Total long-term debt		$	4,011,123	1.70	%		$	3,923,563	1.85	%

(1)Outstanding debt balance consists of the unpaid principal balance, premiums and discounts, fair value adjustments, hedge-related basis adjustments, and other cost basis adjustments.

(2)Excludes the effects of fair value adjustments and hedge-related basis adjustments.

(3)Includes long-term debt with an original contractual maturity of greater than 1 year and up to 10 years, excluding zero-coupon debt.

(4)Includes other long-term debt with an original contractual maturity of greater than 10 years and foreign exchange bonds.

(5)Credit risk-sharing securities that transfer a portion of the credit risk on specified pools of single-family mortgage loans to the investors in these securities, a portion of which is reported at fair value. Represents CAS issued prior to November 2018. See “Note 2, Consolidations and Transfers of Financial Assets” in our 2020 Form 10-K for more information about our CAS structures issued beginning November 2018.

(6)Consists of structured debt instruments that are reported at fair value.

(7)Includes unamortized discounts and premiums, fair value adjustments, hedge-related cost basis adjustments, and other cost basis adjustments in a net discount position of $1.6 billion and $392 million as of March 31, 2021 and December 31, 2020, respectively.

Derivative Instruments

3 Months Ended

Mar. 31, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments

Derivative instruments are an integral part of our strategy in managing interest-rate risk. Derivative instruments may be privately-negotiated, bilateral contracts, or they may be listed and traded on an exchange. We refer to our derivative transactions made pursuant to bilateral contracts as our over-the-counter (“OTC”) derivative transactions and our derivative transactions accepted for clearing by a derivatives clearing organization as our cleared derivative transactions. We typically do not settle the notional amount of our risk management derivatives; rather, notional amounts provide the basis for calculating actual payments or settlement amounts. The derivative contracts we use for interest-rate risk management purposes consist primarily of interest-rate swaps and interest-rate options. See “Note 8, Derivative Instruments” in our 2020 Form 10-K for additional information on interest-rate risk management.

We account for certain forms of credit risk transfer transactions as derivatives. In our credit risk transfer transactions, a portion of the credit risk associated with losses on a reference pool of mortgage loans is transferred to a third party. We enter into derivative transactions that are associated with some of our credit risk transfer transactions, whereby we manage investment risk to guarantee that certain unconsolidated VIEs have sufficient cash flows to pay their contractual obligations.

We enter into forward purchase and sale commitments that lock in the future delivery of mortgage loans and mortgage-related securities at a fixed price or yield. Certain commitments to purchase mortgage loans and purchase or sell mortgage-related securities meet the criteria of a derivative. We typically settle the notional amount of our mortgage commitments that are accounted for as derivatives.

We recognize all derivatives as either assets or liabilities in our condensed consolidated balance sheets at their fair value on a trade date basis. Fair value amounts, which are (1) netted to the extent a legal right of offset exists and is enforceable by law at the counterparty level and (2) inclusive of the right or obligation associated with the cash collateral posted or received, are recorded in “Other assets” or “Other liabilities” in our condensed consolidated balance sheets. See “Note 12, Fair Value” for additional information on derivatives recorded at fair value. We present cash flows from derivatives as operating activities in our condensed consolidated statements of cash flows.

Fair Value Hedge Accounting

As discussed in “Note 1, Summary of Significant Accounting Policies,” we implemented a fair value hedge accounting program in January 2021. Pursuant to this program, we may designate certain interest-rate swaps as hedging instruments in hedges of the change in fair value attributable to the designated benchmark interest rate for certain closed pools of fixed-rate, single-family mortgage loans or our funding debt. For hedged items in qualifying fair value hedging relationships, changes in fair value attributable to the designated risk are recognized as a basis adjustment to the hedged item. We also report changes in the fair value of the derivative hedging instrument in the same condensed consolidated statements of operations and comprehensive income line item used to recognize the earnings effect of the hedged item’s basis adjustment. The objective of our fair value hedges is to reduce GAAP earnings volatility related to changes in benchmark interest rates.

Notional and Fair Value Position of our Derivatives

The following table displays the notional amount and estimated fair value of our asset and liability derivative instruments, including derivative instruments designated as hedges.


	As of March 31, 2021								As of December 31, 2020
	Asset Derivatives				Liability Derivatives				Asset Derivatives				Liability Derivatives
	Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value
	(Dollars in millions)
Risk management derivatives designated as fair value hedges:
Swaps:
Pay-fixed	$	2,804	$	—	$	75	$	(7)	$	—	$	—	$	—	$	—
Receive-fixed	39,754		2		—		—		—		—		—		—
Accrued interest receivable	—		1		—		—		—		—		—		—
Total risk management derivatives designated as hedges	42,558		3		75		(7)		—		—		—		—
Risk management derivatives not designated as fair value hedges:
Swaps:
Pay-fixed	68,674		—		9,636		(482)		88,361		—		11,461		(595)
Receive-fixed	45,635		167		46,039		(1,035)		92,315		233		33,919		(123)
Basis	250		146		—		—		250		192		—		—
Foreign currency	238		43		241		(52)		237		57		239		(58)
Swaptions:
Pay-fixed	5,690		124		375		(16)		5,530		37		2,025		(118)
Receive-fixed	1,455		96		1,110		(42)		3,355		346		700		(16)
Futures(1)	1,602		—		—		—		64,398		—		—		—
Total gross risk management derivatives	123,544		576		57,401		(1,627)		254,446		865		48,344		(910)
Accrued interest receivable (payable)	—		91		—		(86)		—		97		—		(105)
Total risk management derivatives not designated as hedges	123,544		667		57,401		(1,713)		254,446		962		48,344		(1,015)
Netting adjustment(2)	—		(655)		—		1,632		—		(905)		—		995
Total risk management derivatives portfolio	166,102		15		57,476		(88)		254,446		57		48,344		(20)
Mortgage commitment derivatives:
Mortgage commitments to purchase whole loans	9,456		5		22,709		(237)		35,292		145		51		—
Forward contracts to purchase mortgage-related securities	26,155		57		145,335		(1,689)		144,215		844		607		—
Forward contracts to sell mortgage-related securities	220,063		2,534		31,765		(46)		199		—		227,828		(1,426)
Total mortgage commitment derivatives	255,674		2,596		199,809		(1,972)		179,706		989		228,486		(1,426)
Credit enhancement derivatives	14,079		61		10,410		(46)		16,829		179		11,368		(49)
Derivatives at fair value	$	435,855	$	2,672	$	267,695	$	(2,106)	$	450,981	$	1,225	$	288,198	$	(1,495)

(1)Futures have no ascribable fair value because the positions are settled daily.

(2)The netting adjustment represents the effect of the legal right to offset under legally enforceable master netting arrangements to settle with the same counterparty on a net basis, including cash collateral posted and received. Cash collateral posted was $1.0 billion and $658 million as of March 31, 2021 and December 31, 2020, respectively. Cash collateral received was $35 million and $568 million as of March 31, 2021 and December 31, 2020, respectively.

We record all gains and losses, including accrued interest, on derivatives while they are not in a qualifying designated hedging relationship in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. The following table displays, by type of derivative instrument, the fair value gains and losses, net on our derivatives.


	For the Three Months Ended March 31,

			2021		2020
		(Dollars in millions)
Risk management derivatives:
Swaps:
Pay-fixed			$	2,207	$	(4,029)
Receive-fixed			(1,855)		3,343
Basis			(46)		56
Foreign currency			(8)		(38)
Swaptions:
Pay-fixed			107		(148)
Receive-fixed			(239)		632
Futures			1		(71)
Net contractual interest expense on interest-rate swaps			(11)		(106)
Total risk management derivatives fair value gains (losses), net			156		(361)
Mortgage commitment derivatives fair value gains (losses), net			1,082		(993)
Credit enhancement derivatives fair value losses, net			(90)		(11)
Total derivatives fair value gains (losses), net			$	1,148	$	(1,365)

The following table displays the effect of fair value hedge accounting on our condensed consolidated statements of operations and comprehensive income, including gains and losses recognized on fair value hedging relationships.


	For the Three Months Ended March 31, 2021
	Interest Income: Mortgage Loans		Interest Expense: Long-Term Debt
	(Dollars in millions)
Total amounts presented in our condensed consolidated statements of operations and comprehensive income	$	23,353	$	(16,817)




Gains (losses) from fair value hedging relationships:
Mortgage loans HFI and related interest-rate contracts:
Hedged items	(36)		—



Derivatives designated as hedging instruments	36		—

Debt of Fannie Mae and related interest-rate contracts:
Hedged items	—		1,195
Discontinued hedge-related basis adjustment amortization	—		(13)
Derivatives designated as hedging instruments	—		(1,214)
Interest accruals on derivative hedging instruments	—		54
Total effect of fair value hedges	$	—	$	22

Hedged Items in Fair Value Hedging Relationships

The following table displays the carrying amounts of the hedged items that have been in qualifying fair value hedges recorded in our condensed consolidated balance sheets, including the hedged item's cumulative basis adjustments and the closed portfolio balances under the last-of-layer method. The hedged item carrying amounts and total basis adjustments include both open and discontinued hedges. The amortized cost and designated UPB consists of open hedges only.


	As of March 31, 2021
	Carrying Amount Assets (Liabilities)		Cumulative Amount of Fair Value Hedging Basis Adjustments Included in the Carrying Amount				Closed Portfolio of Mortgage Loans Under Last-of-Layer Method
			Total Basis Adjustments(1)		Remaining Adjustments - Discontinued Hedge		Total Amortized Cost		Designated UPB
	(Dollars in millions)
Mortgage loans HFI	$	83,521	$	(36)	$	(36)	$	55,819	$	2,879

Debt of Fannie Mae	(55,345)		1,182		1,182		—		—

(1) Based on the unamortized balance of the hedge-related cost basis.

Derivative Counterparty Credit Exposure

Our derivative counterparty credit exposure relates principally to interest-rate derivative contracts. We are exposed to the risk that a counterparty in a derivative transaction will default on payments due to us, which may require us to seek a replacement derivative from a different counterparty. This replacement may be at a higher cost, or we may be unable to find a suitable replacement. We manage our derivative counterparty credit exposure relating to our risk management derivative transactions mainly through enforceable master netting arrangements, which allow us to net derivative assets and liabilities with the same counterparty or clearing organization and clearing member. For our OTC derivative transactions, we require counterparties to post collateral, which may include cash, U.S. Treasury securities, agency debt and agency mortgage-related securities.

See “Note 11, Netting Arrangements” for information on our rights to offset assets and liabilities as of March 31, 2021 and December 31, 2020

Segment Reporting

3 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Segment Reporting

9. Segment Reporting

We have two reportable business segments, which are based on the type of business activities each perform: Single-Family and Multifamily. Results of our two business segments are intended to reflect each segment as if it were a stand-alone business. The sum of the results for our two business segments equals our condensed consolidated results of operations. For additional information related to our business segments, including basis of organization and other segment activities, see “Note 10, Segment Reporting” in our 2020 Form 10-K.

Segment Allocations and Results

The majority of our revenues and expenses are directly associated with each respective business segment and are included in determining its operating results. Those revenues and expenses that are not directly attributable to a particular business segment are allocated based on the size of each segment’s guaranty book of business. The substantial majority of the gains and losses associated with our risk management derivatives, including the impact of hedge accounting, are allocated to our Single-Family business segment.

The following table displays our segment results.


	For the Three Months Ended March 31,
	2021						2020
	Single-Family		Multifamily		Total		Single-Family		Multifamily		Total
	(Dollars in millions)
Net interest income(1)	$	5,894	$	848	$	6,742	$	4,541	$	806	$	5,347
Fee and other income(2)	62		25		87		94		26		120
Net revenues	5,956		873		6,829		4,635		832		5,467
Investment gains (losses), net(3)	64		(19)		45		(152)		(6)		(158)
Fair value gains (losses), net(4)	740		44		784		(460)		184		(276)
Administrative expenses	(623)		(125)		(748)		(629)		(120)		(749)
Credit-related income (expense):(5)
Benefit (provision) for credit losses	662		103		765		(2,172)		(411)		(2,583)
Foreclosed property income (expense)	17		(12)		5		(78)		(2)		(80)
Total credit-related income (expense)	679		91		770		(2,250)		(413)		(2,663)
TCCA fees(6)	(731)		—		(731)		(637)		—		(637)
Credit enhancement expense(7)	(226)		(58)		(284)		(316)		(60)		(376)
Change in expected credit enhancement recoveries(8)	(16)		(15)		(31)		58		130		188
Other expenses, net	(287)		(32)		(319)		(163)		(55)		(218)
Income before federal income taxes	5,556		759		6,315		86		492		578
Provision for federal income taxes	(1,162)		(160)		(1,322)		(18)		(99)		(117)
Net income	$	4,394	$	599	$	4,993	$	68	$	393	$	461

(1)Net interest income primarily consists of guaranty fees received as compensation for assuming and managing the credit risk on loans underlying Fannie Mae MBS held by third parties for the respective business segment, and the difference between the interest income earned on the respective business segment’s mortgage assets in our retained mortgage portfolio and the interest expense associated with the debt funding those assets. Revenues from single-family guaranty fees include revenues generated by the 10 basis point increase in guaranty fees pursuant to the TCCA, the incremental revenue from which is remitted to Treasury and not retained by us. Also includes yield maintenance fees we recognized on the prepayment of multifamily loans.

(2)Single-family fee and other income primarily consists of compensation for engaging in structured transactions and providing other lender services. Multifamily fee and other income consists of fees associated with Multifamily business activities.

(3)Single-family investment gains and losses primarily consist of gains and losses on the sale of mortgage assets. Multifamily investment gains and losses primarily consists of gains and losses on resecuritization activity.

(4)Single-family fair value gains and losses primarily consist of fair value gains and losses on risk management and mortgage commitment derivatives, trading securities, fair value option debt, and other financial instruments associated with our single-family guaranty book of business. Multifamily fair value gains and losses primarily consist of fair value gains and losses on MBS commitment derivatives, trading securities and other financial instruments associated with our multifamily guaranty book of business.

(5)Credit-related income or expense is based on the guaranty book of business of the respective business segment and consists of the applicable segment’s benefit or provision for credit losses and foreclosed property income or expense on loans underlying the segment’s guaranty book of business.

(6)Consists of the portion of our single-family guaranty fees that is remitted to Treasury pursuant to the TCCA.

(7)Single-family credit enhancement expense consists of costs associated with our freestanding credit enhancements, which include primarily costs associated with our Credit Insurance Risk TransferTM (“CIRTTM”), Connecticut Avenue Securities® (“CAS”) and enterprise-paid mortgage insurance (“EPMI”) programs. Multifamily credit enhancement expense primarily consists of costs associated with our Multifamily CIRTTM (“MCIRTTM”) and Multifamily Connecticut Avenue SecuritiesTM (“MCAS”) programs as well as amortization expense for certain lender risk-sharing programs. Excludes CAS transactions accounted for as debt instruments and credit risk transfer programs accounted for as derivative instruments.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Concentrations of Credit Risk

3 Months Ended

Mar. 31, 2021

Risks and Uncertainties [Abstract]

Concentrations of Credit Risk

Risk Characteristics of our Guaranty Book of Business

One of the measures by which we gauge our credit risk is the delinquency status of the mortgage loans in our guaranty book of business.

For single-family and multifamily loans, we use this information, in conjunction with housing market and other economic data, to structure our pricing and our eligibility and underwriting criteria to reflect the current risk of loans with higher-risk characteristics, and in some cases we decide to significantly reduce our participation in riskier loan product categories. Management also uses this data together with other credit risk measures to identify key trends that guide the development of our loss mitigation strategies.

We report the delinquency status of our single-family and multifamily guaranty book of business below. We report loans receiving COVID-19-related payment forbearance as delinquent according to the contractual terms of the loans.

Single-Family Credit Risk Characteristics

For single-family loans, management monitors the serious delinquency rate, which is the percentage of single-family loans, based on the number of loans that are 90 days or more past due or in the foreclosure process, and loans that have higher risk characteristics, such as high mark-to-market LTV ratios.

The following tables display the delinquency status and serious delinquency rates for specified loan categories of our single-family conventional guaranty book of business.


	As of
	March 31, 2021						December 31, 2020
	30 Days Delinquent		60 Days Delinquent		Seriously Delinquent(1)		30 Days Delinquent		60 Days Delinquent		Seriously Delinquent(1)
Percentage of single-family conventional guaranty book of business based on UPB	0.62	%	0.24	%	2.72	%	0.88	%	0.33	%	3.10	%
Percentage of single-family conventional loans based on loan count	0.71		0.26		2.58		1.02		0.36		2.87


	As of
	March 31, 2021				December 31, 2020
	Percentage of Single-Family Conventional Guaranty Book of Business Based on UPB		Serious Delinquency Rate(1)		Percentage of Single-Family Conventional Guaranty Book of Business Based on UPB		Serious Delinquency Rate(1)
Estimated mark-to-market LTV ratio:
Greater than 100%	*		21.81	%	*		22.43	%
Geographical distribution:
California	19	%	2.31		19	%	2.62
Florida	6		3.60		6		4.17
Illinois	3		3.02		3		3.10
New Jersey	4		4.04		3		4.57
New York	5		4.34		5		4.79
All other states	63		2.34		64		2.59
Product distribution:
Alt-A	1		8.85		1		9.32
Vintages:
2004 and prior	2		5.66		2		5.88
2005-2008	2		9.65		2		9.98
2009-2021	96		2.13		96		2.39

* Represents less than 0.5% of single-family conventional guaranty book of business.

(1)Based on loan count, consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of March 31, 2021 or December 31, 2020.

Multifamily Credit Risk Characteristics

For multifamily loans, management monitors the serious delinquency rate, which is the percentage of multifamily loans, based on unpaid principal balance, that are 60 days or more past due, and loans with other higher risk characteristics to determine the overall credit quality of our multifamily book of business. Higher risk characteristics include, but are not limited to, current DSCR below 1.0 and original LTV ratios greater than 80%. We stratify multifamily loans into different internal risk categories based on the credit risk inherent in each individual loan.

The following tables display the delinquency status and serious delinquency rates for specified loan categories of our multifamily guaranty book of business.


	As of
	March 31, 2021(1)				December 31, 2020(1)
	30 Days Delinquent		Seriously Delinquent(2)		30 Days Delinquent		Seriously Delinquent(2)
Percentage of multifamily guaranty book of business	0.37	%	0.66	%	0.29	%	0.98	%


	As of
	March 31, 2021				December 31, 2020
	Percentage of Multifamily Guaranty Book of Business(1)		Serious Delinquency Rate(2)(3)		Percentage of Multifamily Guaranty Book of Business(1)		Serious Delinquency Rate(2)(3)
Original LTV ratio:
Greater than 80%	1	%	0.86	%	1	%	1.04	%
Less than or equal to 80%	99		0.66		99		0.98
Current DSCR below 1.0(4)	2		18.51		2		21.19

(1)Calculated based on the aggregate unpaid principal balance of multifamily loans for each category divided by the aggregate unpaid principal balance of loans in our multifamily guaranty book of business.

(2)Consists of multifamily loans that were 60 days or more past due as of the dates indicated.

(3)Calculated based on the unpaid principal balance of multifamily loans that were seriously delinquent divided by the aggregate unpaid principal balance of multifamily loans for each category included in our multifamily guaranty book of business.

(4)Our estimates of current DSCRs are based on the latest available income information for these properties. Although we use the most recently available results of our multifamily borrowers, there is a lag in reporting, which typically can range from 3 to 6 months but in some cases may be longer. As a result, the financial information we have received from borrowers to date may not reflect the most recent impacts of COVID-19. For certain properties, we do not receive updated financial information.

Other Concentrations

Mortgage Insurers. Mortgage insurance “risk in force” refers to our maximum potential loss recovery under the applicable mortgage insurance policies in force and is generally based on the loan-level insurance coverage percentage and, if applicable, any aggregate pool loss limit, as specified in the policy.

The following table displays our total mortgage insurance risk in force by primary and pool insurance, as well as the total risk-in-force mortgage insurance coverage as a percentage of the single-family conventional guaranty book of business.


	As of
	March 31, 2021			December 31, 2020
	Risk in Force		Percentage of Single-Family Conventional Guaranty Book of Business	Risk in Force		Percentage of Single-Family Conventional Guaranty Book of Business
	(Dollars in millions)
Mortgage insurance risk in force:
Primary mortgage insurance	$	169,582		$	170,890
Pool mortgage insurance	285			291
Total mortgage insurance risk in force	$	169,867	5%	$	171,181	5%

Mortgage insurance does not protect us from all losses on covered loans. For example, mortgage insurance does not cover property damage that is not covered by the hazard insurance we require, and such damage may result in a reduction to, or a denial of, mortgage insurance benefits. Specifically, a property damaged by a flood that was outside a Federal Emergency Management Agency (“FEMA”)-identified Special Flood Hazard Area, where we require coverage, or a property damaged by an earthquake are the most likely scenarios where property damage may result in a loss event not covered by hazard insurance.

The table below displays our mortgage insurer counterparties that provided approximately 10% or more of the risk-in-force mortgage insurance coverage on mortgage loans in our single-family conventional guaranty book of business.


	Percentage of Risk-in-Force Coverage by Mortgage Insurer
	As of
	March 31, 2021		December 31, 2020

Counterparty:(1)
Arch Capital Group Ltd.	20	%	21	%
Mortgage Guaranty Insurance Corp.	18		18
Radian Guaranty, Inc.	18		19
Genworth Mortgage Insurance Corp.	17		16
Essent Guaranty, Inc.	16		16
Others	11		10
Total	100	%	100	%

(1)Insurance coverage amounts provided for each counterparty may include coverage provided by affiliates and subsidiaries of the counterparty.

Three of our mortgage insurer counterparties that are currently not approved to write new business—PMI Mortgage Insurance Co. (“PMI”), Triad Guaranty Insurance Corporation (“Triad”) and Republic Mortgage Insurance Company (“RMIC”)—are currently in run-off. A mortgage insurer that is in run-off continues to collect renewal premiums and process claims on its existing insurance business, but no longer writes new insurance, which increases the risk that the mortgage insurer will fail to pay claims fully. Entering run-off may limit sources of profits and liquidity for the mortgage insurer and could also cause the quality and speed of its claims processing to deteriorate. These three mortgage insurers provided a combined $2.2 billion, or 1%, of the risk-in-force mortgage insurance coverage of our single-family conventional guaranty book of business as of March 31, 2021.

PMI and Triad have been paying only a portion of policyholder claims and deferring the remaining portion. PMI is currently paying 77.5% of claims under its mortgage insurance policies in cash and is deferring the remaining 22.5%, and Triad is currently paying 75% of claims in cash and deferring the remaining 25%. It is uncertain whether PMI or Triad will be permitted in the future to pay their deferred policyholder claims or increase or decrease the amount of cash they pay on claims. RMIC is no longer deferring payments on policyholder claims, but remains in run-off.

We have counterparty credit risk relating to the potential insolvency of, or non-performance by, monoline mortgage insurers that insure single-family loans we purchase or guarantee. There is risk that these counterparties may fail to fulfill their obligations to pay our claims under insurance policies. On at least a quarterly basis, we assess our mortgage insurer counterparties’ respective abilities to fulfill their obligations to us. Our assessment includes financial reviews and analyses of the insurers’ portfolios and capital adequacy. If we determine that it is probable that we will not collect all of our claims from one or more of our mortgage insurer counterparties, it could increase our loss reserves, which could adversely affect our results of operations, liquidity, financial condition and net worth.

When we estimate the credit losses that are inherent in our mortgage loans and under the terms of our guaranty obligations, we also consider the recoveries that we will receive on primary mortgage insurance, as mortgage insurance recoveries would reduce the severity of the loss associated with defaulted loans. We evaluate the financial condition of our mortgage insurer counterparties and adjust the contractually due recovery amounts to ensure that expected credit losses as of the balance sheet date are included in our loss reserve estimate. As a result, if our assessment of one or more of our mortgage insurer counterparties’ ability to fulfill their respective obligations to us worsens, it could increase our loss reserves. As of March 31, 2021 and December 31, 2020, our estimated benefit from mortgage insurance, which is based on estimated credit losses as of period end, reduced our loss reserves by $1.2 billion and $1.4 billion, respectively.

As of March 31, 2021 and December 31, 2020, we had outstanding receivables of $542 million and $560 million, respectively, recorded in “Other assets” in our condensed consolidated balance sheets related to amounts claimed on insured, defaulted loans excluding government-insured loans. As of March 31, 2021 and December 31, 2020, we assessed these outstanding receivables for collectability, and established a valuation allowance of $480 million and $497 million, respectively, which reduced our claim receivable to the amount considered probable of collection.

Mortgage Servicers and Sellers. Mortgage servicers collect mortgage and escrow payments from borrowers, pay taxes and insurance costs from escrow accounts, monitor and report delinquencies, and perform other required activities, including loss mitigation, on our behalf. Our mortgage servicers and sellers may also be obligated to repurchase loans or foreclosed properties, reimburse us for losses or provide other remedies under certain circumstances, such as if it is determined that the mortgage loan did not meet our underwriting or eligibility requirements, if certain loan representations and warranties are violated or if mortgage insurers rescind coverage. Our representation and warranty framework does not require repurchase for loans that have breaches of certain selling representations and warranties if they have met specified criteria for relief.

Our business with mortgage servicers is concentrated. The table below displays the percentage of our single-family guaranty book of business serviced by our top five depository single-family mortgage servicers and top five non-depository single-family mortgage servicers (i.e., servicers that are not insured depository institutions), and identifies one depository servicer that serviced more than 10% of our single-family guaranty book of business based on unpaid principal balance.


	Percentage of Single-Family Guaranty Book of Business
	As of
	March 31, 2021		December 31, 2020
Wells Fargo Bank, N.A. (together with its affiliates)	12	%	13	%
Remaining top five depository servicers	10		11
Top five non-depository servicers	23		24
Total	45	%	48	%

Compared with depository financial institutions, our non-depository servicers pose additional risks because they may not have the same financial strength or operational capacity, or be subject to the same level of regulatory oversight as depository financial institutions.

The table below displays the percentage of our multifamily guaranty book of business serviced by our top five multifamily mortgage servicers, and identifies two servicers that serviced 10% or more of our multifamily guaranty book of business based on unpaid principal balance.


	Percentage of Multifamily Guaranty Book of Business
	As of
	March 31, 2021		December 31, 2020
Walker & Dunlop, Inc.	13	%	12	%
Wells Fargo Bank, N.A. (together with its affiliates)	11		12
Remaining top five servicers	24		24
Total	48	%	48	%

If a significant mortgage servicer or seller counterparty, or a number of mortgage servicers or sellers, fails to meet their obligations to us, it could adversely affect our results of operations and financial condition. We mitigate these risks in several ways, including:

•establishing minimum standards and financial requirements for our servicers;

•monitoring financial and portfolio performance as compared with peers and internal benchmarks; and

•for our largest mortgage servicers, conducting periodic financial reviews to confirm compliance with servicing guidelines and servicing performance expectations.

We may take one or more of the following actions to mitigate our credit exposure to mortgage servicers that present a higher risk:

•require a guaranty of obligations by higher-rated entities;

•transfer exposure to third parties;

•require collateral;

•establish more stringent financial requirements;

•work with underperforming major servicers to improve operational processes; and

•suspend or terminate the selling and servicing relationship if deemed necessary.

Derivatives Counterparties. For information on credit risk associated with our derivative transactions and repurchase agreements see “Note 8, Derivative Instruments” and “Note 11, Netting Arrangements.”

Netting Arrangements

3 Months Ended

Mar. 31, 2021

Offsetting [Abstract]

Netting Arrangements

We use master netting arrangements, which allow us to offset certain financial instruments and collateral with the same counterparty, to minimize counterparty credit exposure. The tables below display information related to derivatives, securities purchased under agreements to resell or similar arrangements, and securities sold under agreements to repurchase or similar arrangements, which are subject to an enforceable master netting arrangement or similar agreement that are either offset or not offset in our condensed consolidated balance sheets.


	As of March 31, 2021
			Gross Amount Offset(1)		Net Amount Presented in our Condensed Consolidated Balance Sheets				Amounts Not Offset in our Condensed Consolidated Balance Sheets
	Gross Amount								Financial Instruments(2)			Collateral(3)			Net Amount
	(Dollars in millions)
Assets:
OTC risk management derivatives	$	670	$	(661)		$	9			$	—		$	—	$	9
Cleared risk management derivatives	—		6			6				—			—		6
Mortgage commitment derivatives	2,596		—			2,596				(801)			(85)		1,710
Total derivative assets	3,266		(655)			2,611		(4)		(801)			(85)		1,725
Securities purchased under agreements to resell or similar arrangements(5)	66,437		—			66,437				—			(66,437)		—
Total assets	$	69,703	$	(655)		$	69,048			$	(801)		$	(66,522)	$	1,725
Liabilities:
OTC risk management derivatives	$	(1,720)	$	1,646		$	(74)			$	—		$	—	$	(74)
Cleared risk management derivatives	—		(14)			(14)				—			14		—
Mortgage commitment derivatives	(1,972)		—			(1,972)				801			159		(1,012)
Total derivative liabilities	(3,692)		1,632			(2,060)		(4)		801			173		(1,086)

Total liabilities	$	(3,692)	$	1,632		$	(2,060)			$	801		$	173	$	(1,086)


	As of December 31, 2020
			Gross Amount Offset(1)		Net Amount Presented in our Condensed Consolidated Balance Sheets					Amounts Not Offset in our Condensed Consolidated Balance Sheets
	Gross Amount								Financial Instruments(2)				Collateral(3)			Net Amount
	(Dollars in millions)
Assets:
OTC risk management derivatives	$	962	$	(952)		$	10				$	—		$	—		$	10
Cleared risk management derivatives	—		47			47					—			—			47
Mortgage commitment derivatives	989		—			989					(406)			(53)			530
Total derivative assets	1,951		(905)			1,046		(4)			(406)			(53)			587
Securities purchased under agreements to resell or similar arrangements(5)	46,644		—			46,644					—			(46,644)			—
Total assets	$	48,595	$	(905)		$	47,690				$	(406)		$	(46,697)		$	587
Liabilities:
OTC risk management derivatives	$	(1,015)	$	999		$	(16)				$	—		$	—		$	(16)
Cleared risk management derivatives	—		(4)			(4)					—			2			(2)
Mortgage commitment derivatives	(1,426)		—			(1,426)					406			1,017			(3)
Total derivative liabilities	(2,441)		995			(1,446)		(4)			406			1,019			(21)

Total liabilities	$	(2,441)	$	995		$	(1,446)				$	406		$	1,019		$	(21)

(1)Represents the effect of the right to offset under legally enforceable master netting arrangements to settle with the same counterparty on a net basis, including cash collateral posted and received and accrued interest.

(2)Mortgage commitment derivative amounts reflect where we have recognized both an asset and a liability with the same counterparty under an enforceable master netting arrangement but we have not elected to offset the related amounts in our condensed consolidated balance sheets.

(3)Represents collateral received that has not been recognized and not offset in our condensed consolidated balance sheets as well as collateral posted which has been recognized but not offset in our condensed consolidated balance sheets. Does not include collateral held or posted in excess of our exposure. The fair value of non-cash collateral we pledged which the counterparty was permitted to sell or repledge was $4.7 billion as of March 31, 2021 and December 31, 2020. The fair value of non-cash collateral received was $66.5 billion and $46.6 billion, of which $65.4 billion and $46.6 billion could be sold or repledged as of March 31, 2021 and December 31, 2020, respectively. None of the underlying collateral was sold or repledged as of March 31, 2021 or December 31, 2020.

(4)Excludes derivative assets of $61 million and $179 million as of March 31, 2021 and December 31, 2020, respectively, and derivative liabilities of $46 million and $49 million recognized in our condensed consolidated balance sheets as of March 31, 2021 and December 31, 2020, respectively, that are not subject to enforceable master netting arrangements.

(5)Includes $6.1 billion and $18.4 billion in securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of March 31, 2021 and December 31, 2020, respectively. Includes $5.4 billion in securities purchased under agreements to resell classified as “Restricted cash and cash equivalents” in our condensed consolidated balance sheets as of March 31, 2021. There were no securities purchased under agreements to resell classified as “Restricted cash and cash equivalents” as of December 31, 2020.

Derivative instruments are recorded at fair value and securities purchased under agreements to resell or similar arrangements are recorded at amortized cost in our condensed consolidated balance sheets. For how we determine our rights to offset the assets and liabilities presented above with the same counterparty, including collateral posted or received, see “Note 14, Netting Arrangements” in our 2020 Form 10-K.

Fair Value

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value

We use fair value measurements for the initial recording of certain assets and liabilities and periodic remeasurement of certain assets and liabilities on a recurring or nonrecurring basis.

Fair Value Measurement

Fair value measurement guidance defines fair value, establishes a framework for measuring fair value, and sets forth disclosures around fair value measurements. This guidance applies whenever other accounting guidance requires or permits assets or liabilities to be measured at fair value. The guidance establishes a three-level fair value hierarchy that prioritizes the inputs into the valuation techniques used to measure fair value. The hierarchy gives the highest priority, Level 1, to measurements based on unadjusted quoted prices in active markets for identical assets or liabilities. The next highest priority, Level 2, is given to measurements of assets and liabilities based on limited observable inputs or observable inputs for similar assets and liabilities. The lowest priority, Level 3, is given to measurements based on unobservable inputs.

Recurring Changes in Fair Value

The following tables display our assets and liabilities measured in our condensed consolidated balance sheets at fair value on a recurring basis subsequent to initial recognition, including instruments for which we have elected the fair value option.


	Fair Value Measurements as of March 31, 2021
	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment(1)			Estimated Fair Value
	(Dollars in millions)
Recurring fair value measurements:
Assets:
Cash equivalents(2)		$	4,050		$	—		$	—		$	—		$	4,050
Trading securities:
Mortgage-related securities:
Fannie Mae		—			1,876			109			—			1,985
Other agency		—			3,440			—			—			3,440
Private-label and other mortgage securities		—			157			—			—			157
Non-mortgage-related securities:
U.S. Treasury securities		105,601			—			—			—			105,601
Other securities		—			73			—			—			73
Total trading securities		105,601			5,546			109			—			111,256
Available-for-sale securities:
Mortgage-related securities:
Fannie Mae		—			847			189			—			1,036
Other agency		—			34			—			—			34
Alt-A and subprime private-label securities		—			4			1			—			5
Mortgage revenue bonds		—			—			191			—			191
Other		—			6			230			—			236
Total available-for-sale securities		—			891			611			—			1,502
Mortgage loans		—			5,228			820			—			6,048
Other assets:
Risk management derivatives:
Swaps		—			299			151			—			450
Swaptions		—			220			—			—			220
Netting adjustment		—			—			—			(655)			(655)
Mortgage commitment derivatives		—			2,596			—			—			2,596
Credit enhancement derivatives		—			—			61			—			61
Total other assets		—			3,115			212			(655)			2,672
Total assets at fair value		$	109,651		$	14,780		$	1,752		$	(655)		$	125,528

Liabilities:
Long-term debt:
Of Fannie Mae:

Senior floating		$	—		$	2,954		$	382		$	—		$	3,336
Total of Fannie Mae		—			2,954			382			—			3,336
Of consolidated trusts		—			23,543			58			—			23,601
Total long-term debt		—			26,497			440			—			26,937
Other liabilities:
Risk management derivatives:
Swaps		—			1,662			—			—			1,662
Swaptions		—			58			—			—			58
Netting adjustment		—			—			—			(1,632)			(1,632)
Mortgage commitment derivatives		—			1,972			—			—			1,972
Credit enhancement derivatives		—			—			46			—			46
Total other liabilities		—			3,692			46			(1,632)			2,106
Total liabilities at fair value		$	—		$	30,189		$	486		$	(1,632)		$	29,043


	Fair Value Measurements as of December 31, 2020
	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment(1)			Estimated Fair Value
		(Dollars in millions)
Recurring fair value measurements:
Assets:
Cash equivalents(2)		$	1,120		$	—		$	—		$	—		$	1,120
Trading securities:
Mortgage-related securities:
Fannie Mae		—			2,310			94			—			2,404
Other agency		—			3,450			1			—			3,451
Private-label and other mortgage securities		—			158			—			—			158
Non-mortgage-related securities:
U.S. Treasury securities		130,456			—			—			—			130,456
Other securities		—			73			—			—			73
Total trading securities		130,456			5,991			95			—			136,542
Available-for-sale securities:
Mortgage-related securities:
Fannie Mae		—			973			195			—			1,168
Other agency		—			65			—			—			65
Alt-A and subprime private-label securities		—			4			2			—			6
Mortgage revenue bonds		—			—			216			—			216
Other		—			7			235			—			242
Total available-for-sale securities		—			1,049			648			—			1,697
Mortgage loans		—			5,629			861			—			6,490
Other assets:
Risk management derivatives:
Swaps		—			376			203			—			579
Swaptions		—			383			—			—			383
Netting adjustment		—			—			—			(905)			(905)
Mortgage commitment derivatives		—			989			—			—			989
Credit enhancement derivatives		—			—			179			—			179
Total other assets		—			1,748			382			(905)			1,225
Total assets at fair value		$	131,576		$	14,417		$	1,986		$	(905)		$	147,074

Liabilities:
Long-term debt:
Of Fannie Mae:

Senior floating		$	—		$	3,312		$	416		$	—		$	3,728
Total of Fannie Mae		—			3,312			416			—			3,728
Of consolidated trusts		—			24,503			83			—			24,586
Total long-term debt		—			27,815			499			—			28,314
Other liabilities:
Risk management derivatives:
Swaps		—			881			—			—			881
Swaptions		—			134			—			—			134
Netting adjustment		—			—			—			(995)			(995)
Mortgage commitment derivatives		—			1,426			—			—			1,426
Credit enhancement derivatives		—			—			49			—			49
Total other liabilities		—			2,441			49			(995)			1,495
Total liabilities at fair value		$	—		$	30,256		$	548		$	(995)		$	29,809

(1)Derivative contracts are reported on a gross basis by level. The netting adjustment represents the effect of the legal right to offset under legally enforceable master netting arrangements to settle with the same counterparty on a net basis, including cash collateral posted and received.

(2)Cash equivalents are comprised of U.S. Treasuries that have a maturity at the date of acquisition of three months or less.

The following tables display a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3). The tables also display gains and losses due to changes in fair value, including realized and unrealized gains and losses, recognized in our condensed consolidated statements of operations and comprehensive income for Level 3 assets and liabilities.


	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	For the Three Months Ended March 31, 2021
			Total Gains (Losses) (Realized/Unrealized)																			Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of March 31, 2021(4)(5)		Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of March 31, 2021(1)
	Balance, December 31, 2020		Included in Net Income			Included in Total OCI Gain/(Loss)(1)		Purchases(2)		Sales(2)		Issues(3)		Settlements(3)		Transfers out of Level 3		Transfers into Level 3		Balance, March 31, 2021
	(Dollars in millions)
Trading securities:
Mortgage-related:
Fannie Mae	$	94	$	(1)		$	—	$	—	$	—	$	—	$	—	$	(7)	$	23	$	109	$	2	$	—
Other agency	1		—			—		—		—		—		—		(1)		—		—		—		—
Private-label and other mortgage securities	—		—			—		—		—		—		—		—		—		—		—		—
Total trading securities	$	95	$	(1)	(5)(6)	$	—	$	—	$	—	$	—	$	—	$	(8)	$	23	$	109	$	2	$	—

Available-for-sale securities:
Mortgage-related:
Fannie Mae	$	195	$	—		$	(3)	$	—	$	—	$	—	$	(3)	$	—	$	—	$	189	$	—	$	(2)
Alt-A and subprime private-label securities	2		—			(1)		—		—		—		—		—		—		1		—		—
Mortgage revenue bonds	216		—			(1)		—		—		—		(24)		—		—		191		—		—
Other	235		3			3		—		—		—		(11)		—		—		230		—		2
Total available-for-sale securities	$	648	$	3	(6)(7)	$	(2)	$	—	$	—	$	—	$	(38)	$	—	$	—	$	611	$	—	$	—

Mortgage loans	$	861	$	8	(5)(6)	$	—	$	—	$	—	$	—	$	(47)	$	(23)	$	21	$	820	$	9	$	—
Net derivatives	333		(132)		(5)	—		—		—		—		(35)		—		—		166		(167)		—

Long-term debt:
Of Fannie Mae:
Senior floating	$	(416)	$	34	(5)	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	(382)	$	34	$	—
Of consolidated trusts	(83)		1		(5)(6)	—		—		—		—		4		20		—		(58)		—		—
Total long-term debt	$	(499)	$	35		$	—	$	—	$	—	$	—	$	4	$	20	$	—	$	(440)	$	34	$	—


	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	For the Three Months Ended March 31, 2020
			Total Gains (Losses) (Realized/Unrealized)																			Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of March 31, 2020(4)(5)		Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of March 31, 2020(1)
	Balance, December 31, 2019		Included in Net Income			Included in Total OCI Gain/(Loss)(1)		Purchases(2)		Sales(2)		Issues(3)		Settlements(3)		Transfers out of Level 3		Transfers into Level 3		Balance, March 31, 2020
	(Dollars in millions)
Trading securities:
Mortgage-related:
Fannie Mae	$	45	$	(9)		$	—	$	—	$	—	$	—	$	—	$	(11)	$	43	$	68	$	(10)	$	—
Other agency	1		—			—		—		—		—		—		(1)		—		—		—		—
Private-label and other mortgage securities	—		—			—		—		—		—		—		—		94		94		—		—
Total trading securities	$	46	$	(9)	(5)(6)	$	—	$	—	$	—	$	—	$	—	$	(12)	$	137	$	162	$	(10)	$	—

Available-for-sale securities:
Mortgage-related:
Fannie Mae	$	171	$	—		$	4	$	—	$	—	$	—	$	(1)	$	—	$	14	$	188	$	—	$	3

Mortgage revenue bonds	315		(3)			2		74		(74)		—		(18)		—		—		296		—		4
Other	306		(11)			(1)		268		(268)		—		(10)		—		—		284		—		(1)
Total available-for-sale securities	$	792	$	(14)	(6)(7)	$	5	$	342	$	(342)	$	—	$	(29)	$	—	$	14	$	768	$	—	$	6


Mortgage loans	$	688	$	(24)	(5)(6)	$	—	$	—	$	—	$	—	$	(29)	$	(23)	$	26	$	638	$	(26)	$	—
Net derivatives	162		41		(5)	—		—		—		—		(4)		18		—		217		44		—

Long-term debt:
Of Fannie Mae:
Senior floating	$	(398)	$	(34)	(5)	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	(432)	$	(34)	$	—
Of consolidated trusts	(75)		4		(5)(6)	—		—		—		—		3		—		(15)		(83)		4		—
Total long-term debt	$	(473)	$	(30)		$	—	$	—	$	—	$	—	$	3	$	—	$	(15)	$	(515)	$	(30)	$	—

(1)Gains (losses) included in other comprehensive income (loss) are included in “Changes in unrealized gains (losses) on available-for-sale securities, net of reclassification adjustments and taxes” in our condensed consolidated statements of operations and comprehensive income.

(2)Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts.

(3)Issues and settlements include activity related to the consolidation and deconsolidation of liabilities of securitization trusts.

(4)Amount represents temporary changes in fair value. Amortization, accretion and the impairment of credit losses are not considered unrealized and are not included in this amount.

(5)Gains (losses) are included in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

(6)Gains (losses) are included in “Net interest income” in our condensed consolidated statements of operations and comprehensive income.

(7)Gains (losses) are included in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

The following tables display valuation techniques and the range and the weighted average of significant unobservable inputs for our Level 3 assets and liabilities measured at fair value on a recurring basis, excluding instruments for which we have elected the fair value option. Changes in these unobservable inputs can result in significantly higher or lower fair value measurements of these assets and liabilities as of the reporting date.


	Fair Value Measurements as of March 31, 2021
	Fair Value		Significant Valuation Techniques	Significant Unobservable Inputs(1)	Range(1)			Weighted - Average(1)(2)
	(Dollars in millions)
Recurring fair value measurements:
Trading securities:
Mortgage-related securities:
Agency(3)	$	109	Various



Available-for-sale securities:
Mortgage-related securities:
Agency(3)	93		Consensus
	96		Various

Total agency	189

Alt-A and subprime private-label securities	1		Various

Mortgage revenue bonds	119		Single Vendor	Spreads (bps)	32.5	-	188.5	78.4
	72		Various
Total mortgage revenue bonds	191

Other	202		Discounted Cash Flow	Spreads (bps)	405.0	-	406.0	405.5



	28		Various
Total other	230
Total available-for-sale securities	$	611

Net derivatives	$	151	Dealer Mark
	15		Discounted Cash Flow
Total net derivatives	$	166


	Fair Value Measurements as of December 31, 2020
	Fair Value		Significant Valuation Techniques	Significant Unobservable Inputs(1)	Range(1)			Weighted - Average(1)(2)
	(Dollars in millions)
Recurring fair value measurements:
Trading securities:
Mortgage-related securities:
Agency(3)	$	95	Various

Available-for-sale securities:
Mortgage-related securities:
Agency(3)	97		Consensus
	98		Various
Total agency	195





Alt-A and subprime private-label securities	2		Various

Mortgage revenue bonds	144		Single Vendor	Spreads (bps)	32.0	-	315.3	93.4
	72		Various
Total mortgage revenue bonds	216

Other	206		Discounted Cash Flow	Spreads (bps)	425.0	-	443.0	434.2



	29		Various
Total other	235
Total available-for-sale securities	$	648

Net derivatives	$	203	Dealer Mark
	130		Discounted Cash Flow
Total net derivatives	$	333

(1)Valuation techniques for which no unobservable inputs are disclosed generally reflect the use of third-party pricing services or dealers, and the range of unobservable inputs applied by these sources is not readily available or cannot be reasonably estimated. Where we have disclosed unobservable inputs for consensus and single vendor techniques, those inputs are based on our validations performed at the security level using discounted cash flows.

(2)Unobservable inputs were weighted by the relative fair value of the instruments.

(3)Includes Fannie Mae and Freddie Mac securities.

In our condensed consolidated balance sheets, certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when we evaluate loans for impairment). We had no Level 1 assets or liabilities held as of March 31, 2021 or December 31, 2020 that were measured at fair value on a nonrecurring basis. We held $672 million and $25 million in Level 2 assets as of March 31, 2021 and December 31, 2020, respectively, comprised of mortgage loans held for sale that were impaired. We had no Level 2 liabilities that were measured at fair value on a nonrecurring basis as of March 31, 2021 or December 31, 2020.

The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis.


		Fair Value Measurements as of
	Valuation Techniques	March 31, 2021		December 31, 2020
	(Dollars in millions)
Nonrecurring fair value measurements:
Mortgage loans held for sale, at lower of cost or fair value	Consensus	$	212	$	754
	Single Vendor	394		333

Total mortgage loans held for sale, at lower of cost or fair value		606		1,087

Single-family mortgage loans held for investment, at amortized cost	Internal Model	614		979


Multifamily mortgage loans held for investment, at amortized cost	Appraisals	166		225

	Internal Model	122		125
	Various	75		40
Total multifamily mortgage loans held for investment, at amortized cost		363		390
Acquired property, net:
Single-family	Accepted Offers	16		35
	Appraisals	63		89
	Internal Model	26		41
	Walk Forwards	56		85
	Various	10		11
Total single-family		171		261

Multifamily	Various	5		25

Total nonrecurring assets at fair value		$	1,759	$	2,742

We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. See “Note 15, Fair Value” in our 2020 Form 10-K for information on the valuation control processes and the valuation techniques we use for fair value measurement and disclosure as well as our basis for classifying these measurements as Level 1, Level 2 or Level 3 of the valuation hierarchy in more specific situations. We made no material changes to the valuation control processes or the valuation techniques for the three months ended March 31, 2021.

Fair Value of Financial Instruments

The following table displays the carrying value and estimated fair value of our financial instruments. The fair value of financial instruments we disclose includes commitments to purchase multifamily and single-family mortgage loans that we do not record in our condensed consolidated balance sheets. The fair values of these commitments are included as “Mortgage loans held for investment, net of allowance for loan losses.” The disclosure excludes all non-financial instruments; therefore, the fair value of our financial assets and liabilities does not represent the underlying fair value of our total consolidated assets and liabilities.


	As of March 31, 2021
	Carrying Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment			Estimated Fair Value
	(Dollars in millions)
Financial assets:
Cash and cash equivalents, including restricted cash and cash equivalents	$	114,341	$	102,841		$	11,500		$	—		$	—		$	114,341
Federal funds sold and securities purchased under agreements to resell or similar arrangements	54,937		—			54,937			—			—			54,937
Trading securities	111,256		105,601			5,546			109			—			111,256
Available-for-sale securities	1,502		—			891			611			—			1,502
Mortgage loans held for sale	7,824		—			3,511			5,122			—			8,633
Mortgage loans held for investment, net of allowance for loan losses	3,732,056		—			3,549,337			245,916			—			3,795,253
Advances to lenders	10,572		—			10,571			1			—			10,572
Derivative assets at fair value	2,672		—			3,115			212			(655)			2,672
Guaranty assets and buy-ups	109		—			—			242			—			242
Total financial assets	$	4,035,269	$	208,442		$	3,639,408		$	252,213		$	(655)		$	4,099,408

Financial liabilities:

Short-term debt:
Of Fannie Mae	$	2,857	$	—		$	2,857		$	—		$	—		$	2,857

Long-term debt:
Of Fannie Mae	270,585		—			279,208			828			—			280,036
Of consolidated trusts	3,740,538		—			3,777,011			30,990			—			3,808,001
Derivative liabilities at fair value	2,106		—			3,692			46			(1,632)			2,106
Guaranty obligations	120		—			—			75			—			75
Total financial liabilities	$	4,016,206	$	—		$	4,062,768		$	31,939		$	(1,632)		$	4,093,075


	As of December 31, 2020
	Carrying Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment	Estimated Fair Value
	(Dollars in millions)
Financial assets:
Cash and cash equivalents and restricted cash	$	115,623	$	97,179		$	18,444		$	—			$	—	$	115,623
Federal funds sold and securities purchased under agreements to resell or similar arrangements	28,200		—			28,200			—				—		28,200
Trading securities	136,542		130,456			5,991			95				—		136,542
Available-for-sale securities	1,697		—			1,049			648				—		1,697
Mortgage loans held for sale	5,197		—			116			5,502				—		5,618
Mortgage loans held for investment, net of allowance for loan losses	3,648,695		—			3,512,672			255,556				—		3,768,228
Advances to lenders	10,449		—			10,448			1				—		10,449
Derivative assets at fair value	1,225		—			1,748			382				(905)		1,225
Guaranty assets and buy-ups	115		—			—			258				—		258
Total financial assets	$	3,947,743	$	227,635		$	3,578,668		$	262,442			$	(905)	$	4,067,840

Financial liabilities:

Short-term debt:
Of Fannie Mae	$	12,173	$	—		$	12,177		$	—			$	—	$	12,177

Long-term debt:
Of Fannie Mae	277,399		—			288,414			878				—		289,292
Of consolidated trusts	3,646,164		—			3,756,673			31,584				—		3,788,257
Derivative liabilities at fair value	1,495		—			2,441			49				(995)		1,495
Guaranty obligations	127		—			—			82				—		82
Total financial liabilities	$	3,937,358	$	—		$	4,059,705		$	32,593			$	(995)	$	4,091,303

For a detailed description and classification of our financial instruments, see “Note 15, Fair Value” in our 2020 Form 10-K.

Fair Value Option

We elected the fair value option for loans and debt that contain embedded derivatives that would otherwise require bifurcation. Additionally, we elected the fair value option for our credit risk-sharing securities accounted for as debt of Fannie Mae issued under our CAS series prior to January 1, 2016. Under the fair value option, we elected to carry these instruments at fair value instead of bifurcating the embedded derivative from such instruments.

Interest income for the mortgage loans is recorded in “Interest income—Mortgage loans” and interest expense for the debt instruments is recorded in “Interest expense—Long-term debt” in our condensed consolidated statements of operations and comprehensive income.

The following table displays the fair value and unpaid principal balance of the financial instruments for which we have made fair value elections.


	As of
	March 31, 2021									December 31, 2020
	Loans(1)			Long-Term Debt of Fannie Mae			Long-Term Debt of Consolidated Trusts			Loans(1)			Long-Term Debt of Fannie Mae			Long-Term Debt of Consolidated Trusts
	(Dollars in millions)
Fair value		$	6,048		$	3,336		$	23,601		$	6,490		$	3,728		$	24,586
Unpaid principal balance		5,618			3,158			20,828			6,046			3,518			21,408

(1)Includes nonaccrual loans with a fair value of $144 million and $139 million as of March 31, 2021 and December 31, 2020, respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of March 31, 2021 and December 31, 2020 was $9 million and $8 million, respectively. Includes loans that are 90 days or more past due with a fair value of $228 million and $257 million as of March 31, 2021 and December 31, 2020, respectively. The difference between unpaid principal balance and the fair value of these 90 or more days past due loans as of March 31, 2021 and December 31, 2020 was $10 million and $14 million, respectively.

Changes in Fair Value under the Fair Value Option Election

We recorded gains of $25 million and $151 million for the three months ended March 31, 2021 and March 31, 2020, respectively, from changes in the fair value of loans recorded at fair value in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

We recorded gains of $373 million and $262 million for the three months ended March 31, 2021 and March 31, 2020, respectively, from changes in the fair value of long-term debt recorded at fair value in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We are party to various types of legal actions and proceedings, including actions brought on behalf of various classes of claimants. We also are subject to regulatory examinations, inquiries and investigations, and other information gathering requests. In some of the matters, indeterminate amounts are sought. Modern pleading practice in the U.S. permits considerable variation in the assertion of monetary damages or other relief. Jurisdictions may permit claimants not to specify the monetary damages sought or may permit claimants to state only that the amount sought is sufficient to invoke the jurisdiction of the trial court. This variability in pleadings, together with our and our counsel’s actual experience in litigating or settling claims, leads us to conclude that the monetary relief that may be sought by plaintiffs bears little relevance to the merits or disposition value of claims. We have substantial and valid defenses to the claims in the proceedings described below and intend to defend these matters vigorously. However, legal actions and proceedings of all types are subject to many uncertain factors that generally cannot be predicted with assurance. Accordingly, the outcome of any given matter and the amount or range of potential loss at particular points in time is frequently difficult to ascertain. Uncertainties can include how fact finders will evaluate documentary evidence and the credibility and effectiveness of witness testimony, and how courts will apply the law. Disposition valuations are also subject to the uncertainty of how opposing parties and their counsel may view the evidence and applicable law. On a quarterly basis, we review relevant information about all pending legal actions and proceedings for the purpose of evaluating and revising our contingencies, accruals and disclosures. We establish an accrual only for matters when a loss is probable and we can reasonably estimate the amount of such loss. We are often unable to estimate the possible losses or ranges of losses, particularly for proceedings that are in their early stages of development, where plaintiffs seek indeterminate or unspecified damages, where there may be novel or unsettled legal questions relevant to the proceedings, or where settlement negotiations have not occurred or progressed. Given the uncertainties involved in any action or proceeding, regardless of whether we have established an accrual, the ultimate resolution of certain of these matters may be material to our operating results for a particular period, depending on, among other factors, the size of the loss or liability imposed and the level of our net income or loss for that period. In addition to the matters specifically described below, we are involved in a number of legal and regulatory proceedings that arise in the ordinary course of business that we do not expect will have a material impact on our business or financial condition. We have also advanced fees and expenses of certain current and former officers and directors in connection with various legal proceedings pursuant to our bylaws and indemnification agreements. Senior Preferred Stock Purchase Agreements Litigation A consolidated putative class action (“In re Fannie Mae/Freddie Mac Senior Preferred Stock Purchase Agreement Class Action Litigations”) and two non-class action lawsuits, Arrowood Indemnity Company v. Fannie Mae and Fairholme Funds v. FHFA, filed by Fannie Mae and Freddie Mac shareholders against us, FHFA as our conservator, and Freddie Mac are pending in the U.S. District Court for the District of Columbia. The lawsuits challenge the August 2012 amendment to each company’s senior preferred stock purchase agreement with Treasury. Plaintiffs filed amended complaints in all three lawsuits on November 1, 2017 alleging that the net worth sweep dividend provisions of the senior preferred stock that were implemented pursuant to the August 2012 amendments nullified certain of the shareholders’ rights, particularly the right to receive dividends. Plaintiffs seek unspecified damages, equitable and injunctive relief, and costs and expenses, including attorneys’ fees. Plaintiffs in the class action seek to represent several classes of preferred and/or common shareholders of Fannie Mae and/or Freddie Mac who held stock as of the public announcement of the August 2012 amendments. On September 28, 2018, the court dismissed all of the plaintiffs’ claims except for their claims for breach of an implied covenant of good faith and fair dealing. Given the stage of these lawsuits, the substantial and novel legal questions that remain, and our substantial defenses, we are currently unable to estimate the reasonably possible loss or range of loss arising from this litigation.

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation [Policy Text Block]	Basis of Presentation The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and with the SEC’s instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and note disclosures required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments of a normal recurring nature considered necessary for a fair presentation have been included. The accompanying condensed consolidated financial statements include our accounts as well as the accounts of other entities in which we have a controlling financial interest. All intercompany accounts and transactions have been eliminated. To conform to our current period presentation, we have reclassified certain amounts reported in our prior period condensed consolidated financial statements. Results for the three months ended March 31, 2021 may not necessarily be indicative of the results for the year ending December 31, 2021. Presentation of Restricted Cash and Cash Equivalents Restricted cash and cash equivalents includes funds held by consolidated MBS trusts that have not yet been remitted to MBS certificateholders under the terms of our servicing guide and the related trust agreements. In the first quarter of 2021, Fannie Mae, in its role as trustee, began to invest funds held by consolidated trusts directly in eligible short-term third-party investments, which may include investments in cash equivalents that are comprised of overnight repurchase agreements and U.S. Treasuries that have a maturity at the date of acquisition of three months or less. The funds underlying these short-term investments are restricted per the trust agreements. Accordingly, any investment in cash equivalents should be classified as restricted and is presented as “Restricted cash and cash equivalents” in our condensed consolidated balance sheets to reflect the investment of funds related to MBS trusts.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates Preparing condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect our reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the dates of our condensed consolidated financial statements, as well as our reported amounts of revenues and expenses during the reporting periods. Management has made significant estimates in a variety of areas including, but not limited to, the allowance for loan losses. For example, significant uncertainty regarding the expected impacts of the COVID-19 pandemic required substantial management judgment in assessing our allowance for loan losses as of March 31, 2021. Actual results could be different from these estimates.
Single-Family Guaranty Fees 10 Basis Points Increase due to a provision stated in the Temporary Payroll Tax Cut Continuation Act of 2011	Effective April 1, 2012, we increased the guaranty fee on all single-family residential mortgages delivered to us by 10 basis points. In 2012, FHFA and Treasury advised us to remit this fee increase to Treasury with respect to all loans acquired by us on or after April 1, 2012 and before January 1, 2022, and to continue to remit these amounts to Treasury on and after January 1, 2022 with respect to loans we acquired before this date until those loans are paid off or otherwise liquidated. The resulting fee revenue and expense are recorded in “Interest income: Mortgage loans” and “TCCA fees,” respectively, in our condensed consolidated statements of operations and comprehensive income. In 2020, FHFA provided guidance that we are not required to accrue or remit TCCA fees to Treasury with respect to loans backing MBS trusts that have been delinquent for four months or longer. Once payments on such loans resume, we will resume accrual and remittance to Treasury of the associated TCCA fees on the loans.
Derivatives, Policy [Policy Text Block]	DerivativesWe recognize our derivatives as either assets or liabilities in our condensed consolidated balance sheets at their fair value on a trade date basis. Changes in fair value and interest accruals on derivatives not in qualifying fair value hedging relationships are recorded as “fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.We recognize all derivatives as either assets or liabilities in our condensed consolidated balance sheets at their fair value on a trade date basis. Fair value amounts, which are (1) netted to the extent a legal right of offset exists and is enforceable by law at the counterparty level and (2) inclusive of the right or obligation associated with the cash collateral posted or received, are recorded in “Other assets” or “Other liabilities” in our condensed consolidated balance sheets.We present cash flows from derivatives as operating activities in our condensed consolidated statements of cash flows.We record all gains and losses, including accrued interest, on derivatives while they are not in a qualifying designated hedging relationship in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.
Derivatives, Offsetting Policy [Policy Text Block]	We offset the carrying amounts of certain derivatives that are in gain positions and loss positions as well as cash collateral receivables and payables associated with derivative positions pursuant to the terms of enforceable master netting arrangements. We offset these amounts only when we have the legal right to offset under the contract and we have met all the offsetting conditions. For our over-the-counter (“OTC”) derivative positions, our master netting arrangements allow us to net derivative assets and liabilities with the same counterparty. For our cleared derivative contracts, our master netting arrangements allow us to net our exposure by clearing organization and by clearing member.After offsetting, we report derivatives in a gain position in “Other assets” and derivatives in a loss position in “Other liabilities” in our condensed consolidated balance sheets.Derivative instruments are recorded at fair value and securities purchased under agreements to resell or similar arrangements are recorded at amortized cost in our condensed consolidated balance sheets.
Derivatives, Embedded Derivatives	We evaluate financial instruments that we purchase or issue and other financial and non-financial contracts for embedded derivatives. To identify embedded derivatives that we must account for separately, we determine whether: (1) the economic characteristics of the embedded derivative are not clearly and closely related to the economic characteristics of the financial instrument or other contract (i.e., the host contract); (2) the financial instrument or other contract itself is not already measured at fair value with changes in fair value included in earnings; and (3) a separate instrument with the same terms as the embedded derivative would meet the definition of a derivative. If the embedded derivative meets all three of these conditions, we elect to carry the hybrid contract in its entirety at fair value with changes in fair value recorded in earnings.
Derivatives, Methods of Accounting, Hedging Derivatives	Fair value hedge accounting In January 2021, to reduce earnings volatility related to changes in benchmark interest rates, we began applying fair value hedge accounting to certain pools of single-family mortgage loans and certain issuances of our funding debt by designating such instruments as the hedged item in hedging relationships with interest-rate swaps. In these relationships, we have designated the change in the benchmark interest rate, either the London Inter-bank Offered Rate (“LIBOR”) or Secured Overnight Financing Rate (“SOFR”), as the risk being hedged. We have elected to use the last-of-layer method to hedge certain pools of single-family mortgage loans. This election involves establishing fair value hedging relationships on the portion of each loan pool that is not expected to be affected by prepayments, defaults and other events that affect the timing and amount of cash flows. The term of each hedging relationship is generally one business day and we establish hedging relationships daily to align our hedge accounting with our risk management practices. If a hedging relationship qualifies for hedge accounting, the change in the fair value of the interest-rate swaps and the change in the fair value of the hedged item for the risk being hedged are recorded through net interest income. A corresponding basis adjustment is recorded against the hedged item, either the pool of mortgage loans or the debt, for the changes in the fair value attributable to the risk being hedged. For hedging relationships that hedge pools of single-family mortgage loans, basis adjustments are allocated to individual single-family loans based on the relative unpaid principal balance of each loan at the termination of the hedging relationship. The cumulative basis adjustments on the hedged item are amortized into earnings using the effective interest method over the contractual life of the hedged item, with amortization beginning upon termination of the hedging relationship. All changes in fair value of the designated portion of the derivative hedging instrument (i.e., interest-rate swap), including interest accruals, are recorded in the same line item in the condensed consolidated statements of operations and comprehensive income used to record the earnings effect of the hedged item. Therefore, changes in the fair value of the hedged mortgage loans and debt attributable to the risk being hedged are recognized in “Interest income” or “Interest expense,” along with the changes in the fair value of the respective derivative hedging instruments. The recognition of basis adjustments on the hedged item and the subsequent amortization are noncash activities and are reported in “Net cash provided by operating activities” in our condensed consolidated statements of cash flows. Cash on derivative instruments paid or received while the derivative is designated in a hedging relationship is reported as “Net cash provided by operating activities” in the condensed consolidated statement of cash flows. Pursuant to this program, we may designate certain interest-rate swaps as hedging instruments in hedges of the change in fair value attributable to the designated benchmark interest rate for certain closed pools of fixed-rate, single-family mortgage loans or our funding debt. For hedged items in qualifying fair value hedging relationships, changes in fair value attributable to the designated risk are recognized as a basis adjustment to the hedged item. We also report changes in the fair value of the derivative hedging instrument in the same condensed consolidated statements of operations and comprehensive income line item used to recognize the earnings effect of the hedged item’s basis adjustment.
Derivatives, Methods of Accounting, Hedge Effectiveness	We apply hedge accounting to qualifying hedging relationships. A qualifying hedging relationship exists when changes in the fair value of a derivative hedging instrument are expected to be highly effective in offsetting changes in the fair value of the hedged item attributable to the risk being hedged during the term of the hedging relationship. We assess hedge effectiveness using statistical regression analysis. A hedging relationship is considered highly effective if the total change in fair value of the hedging instrument and the change in the fair value of the hedged item due to changes in the benchmark interest rate offset each other within a range of 80% to 125% and certain other statistical tests are met.
Earnings Per Share, Policy [Policy Text Block]	Earnings per Share Earnings per share (“EPS”) is presented for basic and diluted EPS. We compute basic EPS by dividing net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. However, as a result of our conservatorship status and the terms of the senior preferred stock, no amounts would be available to distribute as dividends to common or preferred stockholders (other than to Treasury as the holder of the senior preferred stock).The calculation of diluted EPS includes all the components of basic earnings per share, plus the dilutive effect of common stock equivalents such as convertible securities and stock options. Weighted average shares outstanding is increased to include the number of additional common shares that would have been outstanding if the dilutive potential common shares had been issued.
Consolidations, Policy [Policy Text Block]	We have interests in various entities that are considered to be variable interest entities (“VIEs”). The primary types of entities are securitization and resecuritization trusts, limited partnerships and special purpose vehicles (“SPVs”). These interests include investments in securities issued by VIEs, such as Fannie Mae MBS created pursuant to our securitization transactions and our guaranty to the entity. We consolidate the substantial majority of our single-class securitization trusts because our role as guarantor and master servicer provides us with the power to direct matters (primarily the servicing of mortgage loans) that impact the credit risk to which we are exposed. In contrast, we do not consolidate single-class securitization trusts when other organizations have the power to direct these activities unless we have the unilateral ability to dissolve the trust. We also do not consolidate our resecuritization trusts unless we have the unilateral ability to dissolve the trust. Historically, the vast majority of underlying assets of our resecuritization trusts were limited to Fannie Mae securities that were collateralized by mortgage loans held in consolidated trusts. However, with our issuance of uniform mortgage-backed securities (“UMBS®”), we include securities issued by Freddie Mac in some of our resecuritization trusts. The mortgage loans that serve as collateral for Freddie Mac-issued securities are not held in trusts that are consolidated by Fannie Mae.Unconsolidated VIEsWe do not consolidate VIEs when we are not deemed to be the primary beneficiary. Our unconsolidated VIEs include securitization and resecuritization trusts, limited partnerships, and certain SPVs designed to transfer credit risk.
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]	Transfers of Financial AssetsWe issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the transferor when we transfer assets from our own retained mortgage portfolio in a portfolio securitization transaction.We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts.
Financing Receivable, Held-for-investment [Policy Text Block]	We report the amortized cost of HFI loans for which we have not elected the fair value option at the unpaid principal balance, net of unamortized premiums and discounts, hedge-related basis adjustments, other cost basis adjustments, and accrued interest receivable, net. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable, net separately from the amortized cost of our loans held for investment.
Financing Receivable, Held-for-sale [Policy Text Block]	We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.
New Accounting Pronouncements, Policy [Policy Text Block]	Pursuant to the CARES Act, for purposes of reporting to the credit bureaus, servicers must report a borrower receiving a COVID-19-related payment accommodation during the covered period, such as a forbearance plan or loan modification, as current if the borrower was current prior to receiving the accommodation and the borrower makes all required payments in accordance with the accommodation. For purposes of our disclosures regarding delinquency status, we report loans receiving COVID-19-related payment forbearance as delinquent according to the contractual terms of the loan.
Troubled Debt Restructurings [Policy Text Block]	A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a troubled debt restructuring (“TDR”). In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for these informal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs. However, our current TDR accounting described herein is temporarily impacted by our election to account for certain eligible loss mitigation activities under the COVID-19 Relief granted pursuant to the CARES Act and the Consolidated Appropriations Act of 2021.
Finance, Loan and Lease Receivables, Held-for-investment, Allowance and Nonperforming Loans, Policy	For loans not subject to the COVID-19-related nonaccrual policy, we discontinue accruing interest when we believe collectability of principal and interest is not reasonably assured, which for a single-family loan we have determined, based on our historical experience, to be when the loan becomes two months or more past due according to its contractual terms. Interest previously accrued but not collected on such loans is reversed through interest income at the date the loan is placed on nonaccrual status. For single-family loans on nonaccrual status, we recognize income when cash payments are received. We return a non-modified single-family loan to accrual status at the point when the borrower brings the loan current. We return a modified single-family loan to accrual status at the point when the borrower has successfully made all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes two months or more past due according to its contractual terms unless the loan is well secured such that collectability of principal and accrued interest is reasonably assured. For multifamily loans on nonaccrual status, we apply any payment received on a cost recovery basis to reduce principal on the mortgage loan. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan. Single-family and multifamily loans are reported past due if a full payment of principal and interest is not received within one month of its due date.For loans negatively impacted by the COVID-19 pandemic, we continue to recognize interest income at the current contractual yield for up to six months of delinquency provided that the loan was either current at March 1, 2020 or originated after March 1, 2020, and collection of principal and interest is reasonably assured. For single-family loans where we have provided relief beyond six months of delinquency, we continue to accrue interest income provided that the loan remains in a forbearance arrangement and collection of principal and interest continues to be reasonably assured. Multifamily loans that are in a forbearance arrangement are placed on nonaccrual status when the borrower is six months past due unless the loan is both well secured and in the process of collection. Loans that have been placed in a repayment plan or that have been brought current through a modification or a payment deferral are returned to accrual status once the borrower has made six consecutive contractual payments under the terms of the repayment plan or the modified loan. For loans in a forbearance arrangement that are placed on nonaccrual status, cash payments for interest are applied as a reduction of accrued interest receivable until the receivable has been reduced to zero, and then recognized as interest income. If a loan is modified, any capitalized interest that has not been previously recognized as interest income is recorded as a discount to the loan and amortized over the life of the loan.
Allowance for Loan Losses [Policy Text Block]	The estimated mark-to-market loan-to-value (“LTV”) ratio is a primary factor we consider when estimating our allowance for loan losses for single-family loans. As LTV ratios increase, the borrower's equity in the home decreases, which may negatively affect the borrower's ability to refinance or to sell the property for an amount at or above the outstanding balance of the loan.Property rental income and property valuations are key inputs to our internally assigned credit risk ratings.We maintain an allowance for loan losses for HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts, excluding loans for which we have elected the fair value option. When calculating our allowance for loan losses, we consider the unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments of HFI loans at the balance sheet date. We record write-offs as a reduction to our allowance for loan losses at the point of foreclosure, completion of a short sale, upon the redesignation of nonperforming and reperforming loans from HFI to HFS or when a loan is determined to be uncollectible.Our benefit or provision for loan losses can vary substantially from period to period based on a number of factors, such as changes in actual and forecasted home prices or property valuations, fluctuations in actual and forecasted interest rates, borrower payment behavior, events such as natural disasters or pandemics, the types and volume of our loss mitigation activities, including forbearance and loan modifications, the volume of foreclosures completed, and the redesignation of loans from HFI to HFS. Our benefit or provision can also be impacted by updates to the models, assumptions, and data used in determining our allowance for loan losses. As described below, our benefit or provision for loan losses and our loss reserves have been significantly affected by our estimates of the impact of the COVID-19 pandemic, which require significant management judgment. Changes in our estimates of borrowers that will ultimately receive forbearance and even more significantly, the loss mitigation outcomes of affected borrowers after the forbearance period ends, remain uncertain and can affect the amount of benefit or provision for loan losses we recognize.
Marketable Securities, Policy [Policy Text Block]	Trading SecuritiesTrading securities are recorded at fair value with subsequent changes in fair value recorded as “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. Available-for-Sale Securities We record AFS securities at fair value with unrealized gains and losses, recorded net of tax, as a component of “Other comprehensive income (loss)” and we recognize realized gains and losses from the sale of AFS securities in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We define the amortized cost basis of our AFS securities as unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments. We record an allowance for credit losses for AFS securities that reflects the impairment for credit losses, which are limited to the amount that fair value is less than the amortized cost. Impairment due to non-credit losses are recorded as unrealized losses within other comprehensive income.
Off-Balance-Sheet Credit Exposure, Policy	We recognize a guaranty obligation for our obligation to stand ready to perform on our guarantees to unconsolidated trusts and other guaranty arrangements. These off-balance sheet guarantees expose us to credit losses primarily relating to the unpaid principal balance of our unconsolidated Fannie Mae MBS and other financial guarantees.We measure our guaranty reserve for estimated credit losses for off-balance sheet exposures over the contractual period for which they are exposed to the credit risk, unless that obligation is unconditionally cancellable by the issuer.
Segment Reporting, Policy [Policy Text Block]	We have two reportable business segments, which are based on the type of business activities each perform: Single-Family and Multifamily. Results of our two business segments are intended to reflect each segment as if it were a stand-alone business. The sum of the results for our two business segments equals our condensed consolidated results of operations.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Measurement Fair value measurement guidance defines fair value, establishes a framework for measuring fair value, and sets forth disclosures around fair value measurements. This guidance applies whenever other accounting guidance requires or permits assets or liabilities to be measured at fair value. The guidance establishes a three-level fair value hierarchy that prioritizes the inputs into the valuation techniques used to measure fair value. The hierarchy gives the highest priority, Level 1, to measurements based on unadjusted quoted prices in active markets for identical assets or liabilities. The next highest priority, Level 2, is given to measurements of assets and liabilities based on limited observable inputs or observable inputs for similar assets and liabilities. The lowest priority, Level 3, is given to measurements based on unobservable inputs. The fair value of financial instruments we disclose includes commitments to purchase multifamily and single-family mortgage loans that we do not record in our condensed consolidated balance sheets. The fair values of these commitments are included as “Mortgage loans held for investment, net of allowance for loan losses.” The disclosure excludes all non-financial instruments; therefore, the fair value of our financial assets and liabilities does not represent the underlying fair value of our total consolidated assets and liabilities. Fair Value Option We elected the fair value option for loans and debt that contain embedded derivatives that would otherwise require bifurcation. Additionally, we elected the fair value option for our credit risk-sharing securities accounted for as debt of Fannie Mae issued under our CAS series prior to January 1, 2016. Under the fair value option, we elected to carry these instruments at fair value instead of bifurcating the embedded derivative from such instruments. Interest income for the mortgage loans is recorded in “Interest income—Mortgage loans” and interest expense for the debt instruments is recorded in “Interest expense—Long-term debt” in our condensed consolidated statements of operations and comprehensive income.
Fair Value of Financial Instruments, Policy	In our condensed consolidated balance sheets, certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when we evaluate loans for impairment).
Commitments and Contingencies, Policy [Policy Text Block]	On a quarterly basis, we review relevant information about all pending legal actions and proceedings for the purpose of evaluating and revising our contingencies, accruals and disclosures. We establish an accrual only for matters when a loss is probable and we can reasonably estimate the amount of such loss.

Organization, Consolidation and Presentation of Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]	Transfers of Financial AssetsWe issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the transferor when we transfer assets from our own retained mortgage portfolio in a portfolio securitization transaction.We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts.

- Definition

Disclosure of accounting policy for transfers and servicing financial assets, including securitization transactions as well as repurchase and resale agreements. This disclosure may include how the entity (1) determines whether a transaction is accounted for as a sale; (2) accounts for a sale transaction, including the initial and subsequent accounting for any interests that the entity obtains or continues to hold in the transaction, how such interests are valued, and the significant assumptions used in the valuation; (3) accounts for a transaction that does not qualify for sale treatment (that is, a financing); and (4) accounts for its servicing assets and liabilities ("servicing"), including how such servicing is measured initially and subsequently, and the methodology and significant assumptions used to value such servicing.

+ References + Details

SEC Schedule, Article 12-29, Mortgage Loans on Real Estate (Policies)	3 Months Ended
	Mar. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Finance, Loan and Lease Receivables, Held-for-investment, Allowance and Nonperforming Loans, Policy	For loans not subject to the COVID-19-related nonaccrual policy, we discontinue accruing interest when we believe collectability of principal and interest is not reasonably assured, which for a single-family loan we have determined, based on our historical experience, to be when the loan becomes two months or more past due according to its contractual terms. Interest previously accrued but not collected on such loans is reversed through interest income at the date the loan is placed on nonaccrual status. For single-family loans on nonaccrual status, we recognize income when cash payments are received. We return a non-modified single-family loan to accrual status at the point when the borrower brings the loan current. We return a modified single-family loan to accrual status at the point when the borrower has successfully made all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes two months or more past due according to its contractual terms unless the loan is well secured such that collectability of principal and accrued interest is reasonably assured. For multifamily loans on nonaccrual status, we apply any payment received on a cost recovery basis to reduce principal on the mortgage loan. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan. Single-family and multifamily loans are reported past due if a full payment of principal and interest is not received within one month of its due date.For loans negatively impacted by the COVID-19 pandemic, we continue to recognize interest income at the current contractual yield for up to six months of delinquency provided that the loan was either current at March 1, 2020 or originated after March 1, 2020, and collection of principal and interest is reasonably assured. For single-family loans where we have provided relief beyond six months of delinquency, we continue to accrue interest income provided that the loan remains in a forbearance arrangement and collection of principal and interest continues to be reasonably assured. Multifamily loans that are in a forbearance arrangement are placed on nonaccrual status when the borrower is six months past due unless the loan is both well secured and in the process of collection. Loans that have been placed in a repayment plan or that have been brought current through a modification or a payment deferral are returned to accrual status once the borrower has made six consecutive contractual payments under the terms of the repayment plan or the modified loan. For loans in a forbearance arrangement that are placed on nonaccrual status, cash payments for interest are applied as a reduction of accrued interest receivable until the receivable has been reduced to zero, and then recognized as interest income. If a loan is modified, any capitalized interest that has not been previously recognized as interest income is recorded as a discount to the loan and amortized over the life of the loan.

- Definition

Describes an entity's accounting policy and methodology for estimating its allowance for loan and lease losses, and its accounting policy for nonperforming loans. The description identifies the factors that influenced management of the entity in establishing the level of the allowance (for example, historical losses and existing economic conditions) and also may include discussion of the risk elements relevant to particular categories of receivables. The disclosure also may describe any liability the entity has recorded for off-balance sheet credit losses and may include the basis for determining each element of the allowance for loan and lease losses. The disclosure also could discuss the entity's policy for (1) placing loans on nonaccrual status (or discontinuing accrual of interest) and recording payments received on nonaccrual loans, and the policy for resuming accrual of interest, (2) charging-off uncollectible loans, and (3) determining past due or delinquency status (that is, whether past due status is based on how recently payments have been received or contractual terms).

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Comprehensive Text Block List (Policies)	3 Months Ended
Comprehensive Text Block List (Policies)	Mar. 31, 2021
Text Block [Abstract]
Allowance for Loan Losses [Policy Text Block]	The estimated mark-to-market loan-to-value (“LTV”) ratio is a primary factor we consider when estimating our allowance for loan losses for single-family loans. As LTV ratios increase, the borrower's equity in the home decreases, which may negatively affect the borrower's ability to refinance or to sell the property for an amount at or above the outstanding balance of the loan.Property rental income and property valuations are key inputs to our internally assigned credit risk ratings.We maintain an allowance for loan losses for HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts, excluding loans for which we have elected the fair value option. When calculating our allowance for loan losses, we consider the unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments of HFI loans at the balance sheet date. We record write-offs as a reduction to our allowance for loan losses at the point of foreclosure, completion of a short sale, upon the redesignation of nonperforming and reperforming loans from HFI to HFS or when a loan is determined to be uncollectible.Our benefit or provision for loan losses can vary substantially from period to period based on a number of factors, such as changes in actual and forecasted home prices or property valuations, fluctuations in actual and forecasted interest rates, borrower payment behavior, events such as natural disasters or pandemics, the types and volume of our loss mitigation activities, including forbearance and loan modifications, the volume of foreclosures completed, and the redesignation of loans from HFI to HFS. Our benefit or provision can also be impacted by updates to the models, assumptions, and data used in determining our allowance for loan losses. As described below, our benefit or provision for loan losses and our loss reserves have been significantly affected by our estimates of the impact of the COVID-19 pandemic, which require significant management judgment. Changes in our estimates of borrowers that will ultimately receive forbearance and even more significantly, the loss mitigation outcomes of affected borrowers after the forbearance period ends, remain uncertain and can affect the amount of benefit or provision for loan losses we recognize.

Investments, Debt and Equity Securities (Policies)	3 Months Ended
Investments, Debt and Equity Securities (Policies)	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities, Policy [Policy Text Block]	Trading SecuritiesTrading securities are recorded at fair value with subsequent changes in fair value recorded as “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. Available-for-Sale Securities We record AFS securities at fair value with unrealized gains and losses, recorded net of tax, as a component of “Other comprehensive income (loss)” and we recognize realized gains and losses from the sale of AFS securities in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We define the amortized cost basis of our AFS securities as unpaid principal balance, net of unamortized premiums and discounts, and other cost basis adjustments. We record an allowance for credit losses for AFS securities that reflects the impairment for credit losses, which are limited to the amount that fair value is less than the amortized cost. Impairment due to non-credit losses are recorded as unrealized losses within other comprehensive income.

Derivative Instruments and Hedging Activities (Policies)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives, Methods of Accounting, Hedging Derivatives	Fair value hedge accounting In January 2021, to reduce earnings volatility related to changes in benchmark interest rates, we began applying fair value hedge accounting to certain pools of single-family mortgage loans and certain issuances of our funding debt by designating such instruments as the hedged item in hedging relationships with interest-rate swaps. In these relationships, we have designated the change in the benchmark interest rate, either the London Inter-bank Offered Rate (“LIBOR”) or Secured Overnight Financing Rate (“SOFR”), as the risk being hedged. We have elected to use the last-of-layer method to hedge certain pools of single-family mortgage loans. This election involves establishing fair value hedging relationships on the portion of each loan pool that is not expected to be affected by prepayments, defaults and other events that affect the timing and amount of cash flows. The term of each hedging relationship is generally one business day and we establish hedging relationships daily to align our hedge accounting with our risk management practices. If a hedging relationship qualifies for hedge accounting, the change in the fair value of the interest-rate swaps and the change in the fair value of the hedged item for the risk being hedged are recorded through net interest income. A corresponding basis adjustment is recorded against the hedged item, either the pool of mortgage loans or the debt, for the changes in the fair value attributable to the risk being hedged. For hedging relationships that hedge pools of single-family mortgage loans, basis adjustments are allocated to individual single-family loans based on the relative unpaid principal balance of each loan at the termination of the hedging relationship. The cumulative basis adjustments on the hedged item are amortized into earnings using the effective interest method over the contractual life of the hedged item, with amortization beginning upon termination of the hedging relationship. All changes in fair value of the designated portion of the derivative hedging instrument (i.e., interest-rate swap), including interest accruals, are recorded in the same line item in the condensed consolidated statements of operations and comprehensive income used to record the earnings effect of the hedged item. Therefore, changes in the fair value of the hedged mortgage loans and debt attributable to the risk being hedged are recognized in “Interest income” or “Interest expense,” along with the changes in the fair value of the respective derivative hedging instruments. The recognition of basis adjustments on the hedged item and the subsequent amortization are noncash activities and are reported in “Net cash provided by operating activities” in our condensed consolidated statements of cash flows. Cash on derivative instruments paid or received while the derivative is designated in a hedging relationship is reported as “Net cash provided by operating activities” in the condensed consolidated statement of cash flows. Pursuant to this program, we may designate certain interest-rate swaps as hedging instruments in hedges of the change in fair value attributable to the designated benchmark interest rate for certain closed pools of fixed-rate, single-family mortgage loans or our funding debt. For hedged items in qualifying fair value hedging relationships, changes in fair value attributable to the designated risk are recognized as a basis adjustment to the hedged item. We also report changes in the fair value of the derivative hedging instrument in the same condensed consolidated statements of operations and comprehensive income line item used to recognize the earnings effect of the hedged item’s basis adjustment.

Consolidations and Transfers of Financial Assets (Tables)

3 Months Ended

Mar. 31, 2021

Consolidations and Transfers of Financial Assets [Abstract]

Unconsolidated Variable Interest Entities [Table Text Block]

The following table displays the carrying amount and classification of our assets and liabilities that relate to our involvement with unconsolidated securitization and resecuritization trusts.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts:
Assets:
Trading securities:
Fannie Mae	$	1,243	$	1,611
Non-Fannie Mae	3,598		3,608
Total trading securities	4,841		5,219
Available-for-sale securities:
Fannie Mae	1,036		1,168
Non-Fannie Mae	279		318
Total available-for-sale securities	1,315		1,486
Other assets	39		41
Other liabilities	(65)		(67)
Net carrying amount	$	6,130	$	6,679

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Mortgage Loans (Tables)

3 Months Ended

Mar. 31, 2021

SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]

Loans in Mortgage Portfolio [Table Text Block]

The following table displays the carrying value of our mortgage loans and allowance for loan losses.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Single-family	$	3,286,381	$	3,216,146
Multifamily	388,591		373,722
Total unpaid principal balance of mortgage loans	3,674,972		3,589,868
Cost basis and fair value adjustments, net	74,536		74,576
Allowance for loan losses for HFI loans	(9,628)		(10,552)
Total mortgage loans(1)	$	3,739,880	$	3,653,892

(1)Excludes $9.9 billion and $9.8 billion of accrued interest receivable, net of allowance as of March 31, 2021 and December 31, 2020, respectively.

The following tables display information about our redesignation of loans from HFI to HFS and the sales of mortgage loans during the period.


		For the Three Months Ended March 31,

			2021		2020
	(Dollars in millions)
Single-family loans redesignated from HFI to HFS:
Amortized cost			$	3,112	$	1,637
Lower of cost or fair value adjustment at time of redesignation(1)			(54)		(9)
Allowance reversed at time of redesignation			361		184

Single-family loans sold:
Unpaid principal balance			$	208	$	—
Realized gains, net			2		—

(1)Consists of the write-off against the allowance at the time of redesignation.

Aging Analysis [Table Text Block]

The following tables display an aging analysis of the total amortized cost of our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option.


	As of March 31, 2021
	30 - 59 Days Delinquent		60 - 89 Days Delinquent		Seriously Delinquent(1)		Total Delinquent		Current		Total		Loans 90 Days or More Delinquent and Accruing Interest		Nonaccrual Loans with No Allowance
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate	$	17,400	$	7,024	$	79,349	$	103,773	$	2,688,967	$	2,792,740	$	51,671	$	6,461
15-year or less, amortizing fixed-rate	1,742		492		4,275		6,509		475,960		482,469		3,424		210
Adjustable-rate	180		63		993		1,236		26,549		27,785		735		116
Other(2)	801		317		4,494		5,612		45,188		50,800		2,132		860
Total single-family	20,123		7,896		89,111		117,130		3,236,664		3,353,794		57,962		7,647
Multifamily(3)	1,495		N/A		2,531		4,026		387,841		391,867		404		183
Total	$	21,618	$	7,896	$	91,642	$	121,156	$	3,624,505	$	3,745,661	$	58,366	$	7,830


	As of December 31, 2020
	30 - 59 Days Delinquent		60 - 89 Days Delinquent		Seriously Delinquent(1)		Total Delinquent		Current		Total		Loans 90 Days or More Delinquent and Accruing Interest		Nonaccrual Loans with No Allowance
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate	$	24,928	$	9,414	$	88,276	$	122,618	$	2,619,585	$	2,742,203	$	68,526	$	6,028
15-year or less, amortizing fixed-rate	1,987		601		5,028		7,616		449,443		457,059		4,292		240
Adjustable-rate	268		97		1,143		1,508		29,933		31,441		907		114
Other(2)	1,150		458		5,037		6,645		47,937		54,582		2,861		771
Total single-family	28,333		10,570		99,484		138,387		3,146,898		3,285,285		76,586		7,153
Multifamily(3)	1,140		N/A		3,688		4,828		372,598		377,426		610		302
Total	$	29,473	$	10,570	$	103,172	$	143,215	$	3,519,496	$	3,662,711	$	77,196	$	7,455

(2)Reverse mortgage loans included in “Other” are not aged due to their nature and are included in the current column.

(3)Multifamily loans 60-89 days delinquent are included in the seriously delinquent column.

Troubled Debt Restructurings Activity [Table Text Block]

The following table displays the number of loans and amortized cost of loans classified as a TDR during the period.


	For the Three Months Ended March 31,
	2021				2020
		Number of Loans	Amortized Cost			Number of Loans	Amortized Cost
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		2,989	$	471		10,856	$	1,909
15-year or less, amortizing fixed-rate		369	28			1,073	98
Adjustable-rate		41	6			144	24
Other		154	18			537	68
Total single-family		3,553	523			12,610	2,099
Multifamily		—	—			—	—
Total TDRs		3,553	$	523		12,610	$	2,099


		For the Three Months Ended March 31,
	2021				2020
		Number of Loans	Amortized Cost			Number of Loans	Amortized Cost
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		7,172	$	1,327		3,175	$	521
15-year or less, amortizing fixed-rate		152	11			50	3
Adjustable-rate		11	2			7	1
Other		633	112			327	51
Total single-family		7,968	1,452			3,559	576
Multifamily		—	—			2	2
Total TDRs that subsequently defaulted		7,968	$	1,452		3,561	$	578

Financing Receivable, Nonaccrual

The table below displays the forgone interest and the accrued interest receivable written off through the reversal of interest income for nonaccrual loans.


		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Single-family:
Interest income forgone(1)		$	307	$	182
Accrued interest receivable written off through the reversal of interest income		108		87

Multifamily:
Interest income forgone(1)		$	14	$	1
Accrued interest receivable written off through the reversal of interest income		—		—


		As of				For the Three Months Ended March 31,
		March 31, 2021		December 31, 2020			2021			2020
		Amortized Cost				Total Interest Income Recognized(1)
	(Dollars in millions)
Single-family:
20- and 30-year or more, amortizing fixed-rate		$	30,173	$	22,907			$	64		$	101
15-year or less, amortizing fixed-rate		945		853				2			2
Adjustable-rate		284		270				1			1
Other		2,583		2,475				4			13
Total single-family		33,985		26,505				71			117
Multifamily		2,153		2,069				8			—
Total nonaccrual loans		$	36,138	$	28,574			$	79		$	117

Single-family [Member]

SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]

Credit Quality Indicators [Table Text Block]


	As of March 31, 2021, by Year of Origination(1)
	2021		2020		2019		2018		2017		Prior		Total
	(Dollars in millions)
Estimated mark-to-market LTV ratio:(2)
20- and 30-year or more, amortizing fixed-rate:
Less than or equal to 80%	$	187,046	$	848,710	$	216,806	$	124,252	$	158,591	$	885,994	$	2,421,399
Greater than 80% and less than or equal to 90%	23,830		180,295		51,499		10,692		2,706		5,552		274,574
Greater than 90% and less than or equal to 100%	25,159		66,092		1,710		578		157		1,556		95,252
Greater than 100%	—		25		6		24		58		1,402		1,515
Total 20- and 30-year or more, amortizing fixed-rate	236,035		1,095,122		270,021		135,546		161,512		894,504		2,792,740
15-year or less, amortizing fixed-rate:
Less than or equal to 80%	48,003		187,390		35,975		13,779		28,112		161,802		475,061
Greater than 80% and less than or equal to 90%	1,137		4,953		292		19		9		19		6,429
Greater than 90% and less than or equal to 100%	356		587		4		2		3		9		961
Greater than 100%	—		—		—		2		3		13		18
Total 15-year or less, amortizing fixed-rate	49,496		192,930		36,271		13,802		28,127		161,843		482,469
Adjustable-rate:
Less than or equal to 80%	111		2,757		1,608		2,006		3,982		16,940		27,404
Greater than 80% and less than or equal to 90%	11		189		79		35		15		13		342
Greater than 90% and less than or equal to 100%	6		29		2		—		—		1		38
Greater than 100%	—		—		—		—		—		1		1
Total adjustable-rate	128		2,975		1,689		2,041		3,997		16,955		27,785
Other:
Less than or equal to 80%	—		—		39		318		779		34,761		35,897
Greater than 80% and less than or equal to 90%	—		—		1		15		31		1,000		1,047
Greater than 90% and less than or equal to 100%	—		—		2		5		11		456		474
Greater than 100%	—		—		—		3		5		485		493
Total other	—		—		42		341		826		36,702		37,911
Total	$	285,659	$	1,291,027	$	308,023	$	151,730	$	194,462	$	1,110,004	$	3,340,905

Total for all classes by LTV ratio:(2)
Less than or equal to 80%	$	235,160	$	1,038,857	$	254,428	$	140,355	$	191,464	$	1,099,497	$	2,959,761
Greater than 80% and less than or equal to 90%	24,978		185,437		51,871		10,761		2,761		6,584		282,392
Greater than 90% and less than or equal to 100%	25,521		66,708		1,718		585		171		2,022		96,725
Greater than 100%	—		25		6		29		66		1,901		2,027
Total	$	285,659	$	1,291,027	$	308,023	$	151,730	$	194,462	$	1,110,004	$	3,340,905


	As of December 31, 2020, by Year of Origination(1)
	2020		2019		2018		2017		2016		Prior		Total
	(Dollars in millions)
Estimated mark-to-market LTV ratio:(2)
20- and 30-year or more, amortizing fixed-rate:
Less than or equal to 80%	$	794,156	$	233,994	$	135,849	$	183,315	$	221,172	$	775,636	$	2,344,122
Greater than 80% and less than or equal to 90%	157,500		85,227		23,440		5,270		1,592		5,958		278,987
Greater than 90% and less than or equal to 100%	109,743		4,186		820		250		124		1,994		117,117
Greater than 100%	28		7		28		77		81		1,756		1,977
Total 20- and 30-year or more, amortizing fixed-rate	1,061,427		323,414		160,137		188,912		222,969		785,344		2,742,203
15-year or less, amortizing fixed-rate:
Less than or equal to 80%	181,418		41,374		15,768		31,497		46,088		132,596		448,741
Greater than 80% and less than or equal to 90%	6,105		811		35		14		8		20		6,993
Greater than 90% and less than or equal to 100%	1,274		9		3		4		3		10		1,303
Greater than 100%	—		—		3		3		3		13		22
Total 15-year or less, amortizing fixed-rate	188,797		42,194		15,809		31,518		46,102		132,639		457,059
Adjustable-rate:
Less than or equal to 80%	2,935		1,839		2,412		4,765		2,678		16,248		30,877
Greater than 80% and less than or equal to 90%	234		152		79		19		5		12		501
Greater than 90% and less than or equal to 100%	56		3		1		—		—		2		62
Greater than 100%	—		—		—		—		—		1		1
Total adjustable-rate	3,225		1,994		2,492		4,784		2,683		16,263		31,441
Other:
Less than or equal to 80%	—		41		328		811		1,028		36,216		38,424
Greater than 80% and less than or equal to 90%	—		2		20		43		30		1,298		1,393
Greater than 90% and less than or equal to 100%	—		2		8		16		10		602		638
Greater than 100%	—		—		4		8		9		631		652
Total other	—		45		360		878		1,077		38,747		41,107
Total	$	1,253,449	$	367,647	$	178,798	$	226,092	$	272,831	$	972,993	$	3,271,810

Total for all classes by LTV ratio:(2)
Less than or equal to 80%	$	978,509	$	277,248	$	154,357	$	220,388	$	270,966	$	960,696	$	2,862,164
Greater than 80% and less than or equal to 90%	163,839		86,192		23,574		5,346		1,635		7,288		287,874
Greater than 90% and less than or equal to 100%	111,073		4,200		832		270		137		2,608		119,120
Greater than 100%	28		7		35		88		93		2,401		2,652
Total	$	1,253,449	$	367,647	$	178,798	$	226,092	$	272,831	$	972,993	$	3,271,810

Multifamily [Member]

SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]

Credit Quality Indicators [Table Text Block]


	As of March 31, 2021, by Year of Origination
	2021		2020		2019		2018		2017		Prior		Total
	(Dollars in millions)
Internally assigned credit risk rating:
Non-classified(1)	$	11,295	$	81,647	$	67,630	$	61,280	$	49,903	$	108,429	$	380,184
Classified(2)	—		204		1,185		1,673		2,882		5,739		11,683
Total	$	11,295	$	81,851	$	68,815	$	62,953	$	52,785	$	114,168	$	391,867


	As of December 31, 2020, by Year of Origination
	2020		2019		2018		2017		2016		Prior		Total
	(Dollars in millions)
Internally assigned credit risk rating:
Non-classified(1)	$	71,977	$	68,296	$	62,087	$	50,907	$	43,174	$	70,933	$	367,374
Classified(2)	37		1,041		1,529		2,616		1,579		3,250		10,052
Total	$	72,014	$	69,337	$	63,616	$	53,523	$	44,753	$	74,183	$	377,426

(1)A loan categorized as “Non-classified” is current or adequately protected by the current financial strength and debt service capability of the borrower.

Allowance for Loan Losses (Tables)

3 Months Ended

Mar. 31, 2021

Receivables [Abstract]

Financing Receivable, Allowance for Credit Loss


		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Single-family allowance for loan losses:
Beginning balance		$	(9,344)	$	(8,759)
Transition impact of the adoption of the CECL standard		—		(1,229)
Benefit (provision) for loan losses		671		(2,177)
Write-offs		71		70
Recoveries		(2)		(3)
Other		57		28
Ending Balance		$	(8,547)	$	(12,070)
Multifamily allowance for loan losses:
Beginning balance		$	(1,208)	$	(257)
Transition impact of the adoption of the CECL standard		—		(493)
Benefit (provision) for loan losses		95		(407)
Write-offs		33		19
Recoveries		(1)		(1)

Ending Balance		$	(1,081)	$	(1,139)
Total allowance for loan losses:
Beginning balance		$	(10,552)	$	(9,016)
Transition impact of the adoption of the CECL standard		—		(1,722)
Benefit (provision) for loan losses		766		(2,584)
Write-offs		104		89
Recoveries		(3)		(4)
Other		57		28
Ending Balance		$	(9,628)	$	(13,209)

Investments in Securities (Tables)

3 Months Ended

Mar. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Investments In Trading Securities [Table Text Block]

The following table displays our investments in trading securities.


	As of
	March 31, 2021			December 31, 2020
	(Dollars in millions)
Mortgage-related securities:
Fannie Mae		$	1,985		$	2,404
Other agency(1)		3,440			3,451
Private-label and other mortgage securities		157			158
Total mortgage-related securities (includes $741 million and $793 million, respectively, related to consolidated trusts)		5,582			6,013
Non-mortgage-related securities:
U.S. Treasury securities		105,601			130,456
Other securities		73			73
Total non-mortgage-related securities		105,674			130,529
Total trading securities		$	111,256		$	136,542

(1)Consists of Freddie Mac and Ginnie Mae mortgage-related securities.

Schedule of Trading Securities Gains (Losses), Net [Table Text Block]

The following table displays information about our net trading gains (losses).


		For the Three Months Ended March 31,

			2021		2020
	(Dollars in millions)
Net trading gains (losses)			$	(758)	$	647
Net trading gains (losses) recognized in the period related to securities still held at period end			(759)		591

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]


	As of March 31, 2021
	Total Amortized Cost(1)			Allowance for Credit Losses		Gross Unrealized Gains in AOCI		Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	988	$	—	$	59		$	(11)	$	1,036
Other agency(2)		32		—		2			—		34
Alt-A and subprime private-label securities		3		—		2			—		5

Mortgage revenue bonds		187		(3)		7			—		191
Other mortgage-related securities		230		—		6			—		236
Total		$	1,440	$	(3)	$	76		$	(11)	$	1,502


	As of December 31, 2020
	Total Amortized Cost(1)			Allowance for Credit Losses			Gross Unrealized Gains in AOCI			Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	1,094		$	—		$	86		$	(12)	$	1,168
Other agency(2)		59			—			6			—		65
Alt-A and subprime private-label securities		4			—			2			—		6
Mortgage revenue bonds		211			(3)			8			—		216
Other mortgage-related securities		238			—			4			—		242
Total		$	1,606		$	(3)		$	106		$	(12)	$	1,697

(2)Other agency securities consist of securities issued by Freddie Mac and Ginnie Mae.

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]


	As of
	March 31, 2021										December 31, 2020
	Less Than 12 Consecutive Months					12 Consecutive Months or Longer					Less Than 12 Consecutive Months					12 Consecutive Months or Longer
	Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value
	(Dollars in millions)
Fannie Mae		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94


Total		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94

Schedule of Realized Gain (Loss) [Table Text Block]

The following table displays the gross realized gains and proceeds on sales of AFS securities.


	For the Three Months Ended March 31,

			2021		2020
		(Dollars in millions)
Gross realized gains			$	13	$	21

Total proceeds (excludes initial sale of securities from new portfolio securitizations)			115		50

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following tables display net unrealized gains on AFS securities and other amounts accumulated within our accumulated other comprehensive income, net of tax.


	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Net unrealized gains on AFS securities for which we have not recorded an allowance for credit losses	$	51	$	74

Other	38		42
Accumulated other comprehensive income	$	89	$	116

Investments Classified by Contractual Maturity Date [Table Text Block]


	As of March 31, 2021
	Total Carrying Amount(1)			Total Fair Value		One Year or Less					After One Year Through Five Years					After Five Years Through Ten Years					After Ten Years
						Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value
	(Dollars in millions)
Fannie Mae		$	988	$	1,036		$	—	$	—		$	4	$	4		$	98	$	109		$	886	$	923
Other agency		32		34			—		—			—		—			1		1			31		33
Alt-A and subprime private-label securities		3		5			—		—			—		—			2		2			1		3

Mortgage revenue bonds		184		191			1		1			26		27			18		19			139		144
Other mortgage-related securities		230		236			—		—			—		—			18		20			212		216
Total		$	1,437	$	1,502		$	1	$	1		$	30	$	31		$	137	$	151		$	1,269	$	1,319

(1) Net carrying amount consists of book value, net of allowance for credit losses on AFS debt securities.

Financial Guarantees (Tables)

3 Months Ended

Mar. 31, 2021

Guarantees [Abstract]

Financial Guarantees and Maximum Recovery [Table Text Block]


	As of
	March 31, 2021						December 31, 2020
	Maximum Exposure		Guaranty Obligation		Maximum Recovery(1)		Maximum Exposure		Guaranty Obligation		Maximum Recovery(1)
	(Dollars in millions)
Unconsolidated Fannie Mae MBS	$	4,232	$	17	$	4,047	$	4,424	$	18	$	4,226
Other guaranty arrangements(2)	11,392		103		2,295		11,828		109		2,438
Total	$	15,624	$	120	$	6,342	$	16,252	$	127	$	6,664

(2)Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Short-Term Debt [Table Text Block]

The following table displays our outstanding short-term debt (debt with an original contractual maturity of one year or less) and weighted-average interest rates of this debt.


	As of
	March 31, 2021				December 31, 2020
	Outstanding		Weighted- Average Interest Rate(1)		Outstanding		Weighted- Average Interest Rate(1)
	(Dollars in millions)

Short-term debt of Fannie Mae	$	2,857	0.06	%	$	12,173	0.18	%

(1)Includes the effects of discounts, premiums and other cost basis adjustments.

Long-Term Debt [Table Text Block]

The following table displays our outstanding long-term debt.


	As of
	March 31, 2021					December 31, 2020
	Maturities	Outstanding(1)		Weighted- Average Interest Rate(2)		Maturities	Outstanding		Weighted- Average Interest Rate(2)
	(Dollars in millions)
Senior fixed:
Benchmark notes and bonds	2021 - 2030	$	102,683	2.09	%	2021 - 2030	$	106,691	2.03	%
Medium-term notes(3)	2021 - 2031	47,693		0.61		2021 - 2030	48,524		0.63
Other(4)	2021 - 2038	7,195		3.77		2021 - 2038	6,701		3.90
Total senior fixed		157,571		1.72			161,916		1.69
Senior floating:
Medium-term notes(3)	2021 - 2022	98,095		0.28		2021 - 2022	100,089		0.35
Connecticut Avenue Securities(5)	2023 - 2031	14,537		4.13		2023 - 2031	14,978		4.16
Other(6)	2037	382		7.69		2037	416		7.75
Total senior floating		113,014		0.79			115,483		0.86


Total long-term debt of Fannie Mae(7)		270,585		1.34			277,399		1.34
Debt of consolidated trusts	2021 - 2060	3,740,538		1.72		2021 - 2060	3,646,164		1.88
Total long-term debt		$	4,011,123	1.70	%		$	3,923,563	1.85	%

(1)Outstanding debt balance consists of the unpaid principal balance, premiums and discounts, fair value adjustments, hedge-related basis adjustments, and other cost basis adjustments.

(2)Excludes the effects of fair value adjustments and hedge-related basis adjustments.

(3)Includes long-term debt with an original contractual maturity of greater than 1 year and up to 10 years, excluding zero-coupon debt.

(4)Includes other long-term debt with an original contractual maturity of greater than 10 years and foreign exchange bonds.

(6)Consists of structured debt instruments that are reported at fair value.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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+ Details

Derivative Instruments (Tables)

3 Months Ended

Mar. 31, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Notional and Fair Value Position [Table Text Block]

The following table displays the notional amount and estimated fair value of our asset and liability derivative instruments, including derivative instruments designated as hedges.


	As of March 31, 2021								As of December 31, 2020
	Asset Derivatives				Liability Derivatives				Asset Derivatives				Liability Derivatives
	Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value		Notional Amount		Estimated Fair Value
	(Dollars in millions)
Risk management derivatives designated as fair value hedges:
Swaps:
Pay-fixed	$	2,804	$	—	$	75	$	(7)	$	—	$	—	$	—	$	—
Receive-fixed	39,754		2		—		—		—		—		—		—
Accrued interest receivable	—		1		—		—		—		—		—		—
Total risk management derivatives designated as hedges	42,558		3		75		(7)		—		—		—		—
Risk management derivatives not designated as fair value hedges:
Swaps:
Pay-fixed	68,674		—		9,636		(482)		88,361		—		11,461		(595)
Receive-fixed	45,635		167		46,039		(1,035)		92,315		233		33,919		(123)
Basis	250		146		—		—		250		192		—		—
Foreign currency	238		43		241		(52)		237		57		239		(58)
Swaptions:
Pay-fixed	5,690		124		375		(16)		5,530		37		2,025		(118)
Receive-fixed	1,455		96		1,110		(42)		3,355		346		700		(16)
Futures(1)	1,602		—		—		—		64,398		—		—		—
Total gross risk management derivatives	123,544		576		57,401		(1,627)		254,446		865		48,344		(910)
Accrued interest receivable (payable)	—		91		—		(86)		—		97		—		(105)
Total risk management derivatives not designated as hedges	123,544		667		57,401		(1,713)		254,446		962		48,344		(1,015)
Netting adjustment(2)	—		(655)		—		1,632		—		(905)		—		995
Total risk management derivatives portfolio	166,102		15		57,476		(88)		254,446		57		48,344		(20)
Mortgage commitment derivatives:
Mortgage commitments to purchase whole loans	9,456		5		22,709		(237)		35,292		145		51		—
Forward contracts to purchase mortgage-related securities	26,155		57		145,335		(1,689)		144,215		844		607		—
Forward contracts to sell mortgage-related securities	220,063		2,534		31,765		(46)		199		—		227,828		(1,426)
Total mortgage commitment derivatives	255,674		2,596		199,809		(1,972)		179,706		989		228,486		(1,426)
Credit enhancement derivatives	14,079		61		10,410		(46)		16,829		179		11,368		(49)
Derivatives at fair value	$	435,855	$	2,672	$	267,695	$	(2,106)	$	450,981	$	1,225	$	288,198	$	(1,495)

(1)Futures have no ascribable fair value because the positions are settled daily.

Fair Value Gain (Loss), Net [Table Text Block]

The following table displays, by type of derivative instrument, the fair value gains and losses, net on our derivatives.


	For the Three Months Ended March 31,

			2021		2020
		(Dollars in millions)
Risk management derivatives:
Swaps:
Pay-fixed			$	2,207	$	(4,029)
Receive-fixed			(1,855)		3,343
Basis			(46)		56
Foreign currency			(8)		(38)
Swaptions:
Pay-fixed			107		(148)
Receive-fixed			(239)		632
Futures			1		(71)
Net contractual interest expense on interest-rate swaps			(11)		(106)
Total risk management derivatives fair value gains (losses), net			156		(361)
Mortgage commitment derivatives fair value gains (losses), net			1,082		(993)
Credit enhancement derivatives fair value losses, net			(90)		(11)
Total derivatives fair value gains (losses), net			$	1,148	$	(1,365)

Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location


	For the Three Months Ended March 31, 2021
	Interest Income: Mortgage Loans		Interest Expense: Long-Term Debt
	(Dollars in millions)
Total amounts presented in our condensed consolidated statements of operations and comprehensive income	$	23,353	$	(16,817)




Gains (losses) from fair value hedging relationships:
Mortgage loans HFI and related interest-rate contracts:
Hedged items	(36)		—



Derivatives designated as hedging instruments	36		—

Debt of Fannie Mae and related interest-rate contracts:
Hedged items	—		1,195
Discontinued hedge-related basis adjustment amortization	—		(13)
Derivatives designated as hedging instruments	—		(1,214)
Interest accruals on derivative hedging instruments	—		54
Total effect of fair value hedges	$	—	$	22

Hedged Items in Fair Value Hedging Relationships


	As of March 31, 2021
	Carrying Amount Assets (Liabilities)		Cumulative Amount of Fair Value Hedging Basis Adjustments Included in the Carrying Amount				Closed Portfolio of Mortgage Loans Under Last-of-Layer Method
			Total Basis Adjustments(1)		Remaining Adjustments - Discontinued Hedge		Total Amortized Cost		Designated UPB
	(Dollars in millions)
Mortgage loans HFI	$	83,521	$	(36)	$	(36)	$	55,819	$	2,879

Debt of Fannie Mae	(55,345)		1,182		1,182		—		—

(1) Based on the unamortized balance of the hedge-related cost basis.

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

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+ Details

Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Segment results [Table Text Block]

The following table displays our segment results.


	For the Three Months Ended March 31,
	2021						2020
	Single-Family		Multifamily		Total		Single-Family		Multifamily		Total
	(Dollars in millions)
Net interest income(1)	$	5,894	$	848	$	6,742	$	4,541	$	806	$	5,347
Fee and other income(2)	62		25		87		94		26		120
Net revenues	5,956		873		6,829		4,635		832		5,467
Investment gains (losses), net(3)	64		(19)		45		(152)		(6)		(158)
Fair value gains (losses), net(4)	740		44		784		(460)		184		(276)
Administrative expenses	(623)		(125)		(748)		(629)		(120)		(749)
Credit-related income (expense):(5)
Benefit (provision) for credit losses	662		103		765		(2,172)		(411)		(2,583)
Foreclosed property income (expense)	17		(12)		5		(78)		(2)		(80)
Total credit-related income (expense)	679		91		770		(2,250)		(413)		(2,663)
TCCA fees(6)	(731)		—		(731)		(637)		—		(637)
Credit enhancement expense(7)	(226)		(58)		(284)		(316)		(60)		(376)
Change in expected credit enhancement recoveries(8)	(16)		(15)		(31)		58		130		188
Other expenses, net	(287)		(32)		(319)		(163)		(55)		(218)
Income before federal income taxes	5,556		759		6,315		86		492		578
Provision for federal income taxes	(1,162)		(160)		(1,322)		(18)		(99)		(117)
Net income	$	4,394	$	599	$	4,993	$	68	$	393	$	461

(6)Consists of the portion of our single-family guaranty fees that is remitted to Treasury pursuant to the TCCA.

(8)Consists of change in benefits recognized from our freestanding credit enhancements, primarily from our CAS and CIRT programs as well as certain lender risk-sharing arrangements, including our multifamily DUS program. See “Note 1, Summary of Significant Accounting Policies” in our 2020 Form 10-K for more information on our change in presentation.

Concentrations of Credit Risk (Tables)

3 Months Ended

Mar. 31, 2021

Single-family [Member]

Concentration Risk [Line Items]

Schedule of Delinquency Status Guaranty Book of Business [Table Text Block]

The following tables display the delinquency status and serious delinquency rates for specified loan categories of our single-family conventional guaranty book of business.


	As of
	March 31, 2021						December 31, 2020
	30 Days Delinquent		60 Days Delinquent		Seriously Delinquent(1)		30 Days Delinquent		60 Days Delinquent		Seriously Delinquent(1)
Percentage of single-family conventional guaranty book of business based on UPB	0.62	%	0.24	%	2.72	%	0.88	%	0.33	%	3.10	%
Percentage of single-family conventional loans based on loan count	0.71		0.26		2.58		1.02		0.36		2.87

Based on loan count, consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of March 31, 2021 or December 31, 2020

Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]


	As of
	March 31, 2021				December 31, 2020
	Percentage of Single-Family Conventional Guaranty Book of Business Based on UPB		Serious Delinquency Rate(1)		Percentage of Single-Family Conventional Guaranty Book of Business Based on UPB		Serious Delinquency Rate(1)
Estimated mark-to-market LTV ratio:
Greater than 100%	*		21.81	%	*		22.43	%
Geographical distribution:
California	19	%	2.31		19	%	2.62
Florida	6		3.60		6		4.17
Illinois	3		3.02		3		3.10
New Jersey	4		4.04		3		4.57
New York	5		4.34		5		4.79
All other states	63		2.34		64		2.59
Product distribution:
Alt-A	1		8.85		1		9.32
Vintages:
2004 and prior	2		5.66		2		5.88
2005-2008	2		9.65		2		9.98
2009-2021	96		2.13		96		2.39

* Represents less than 0.5% of single-family conventional guaranty book of business.

(1)Based on loan count, consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of March 31, 2021 or December 31, 2020.

Schedule of Risk in Force Mortgage Insurance Coverage [Table Text Block]


	As of
	March 31, 2021			December 31, 2020
	Risk in Force		Percentage of Single-Family Conventional Guaranty Book of Business	Risk in Force		Percentage of Single-Family Conventional Guaranty Book of Business
	(Dollars in millions)
Mortgage insurance risk in force:
Primary mortgage insurance	$	169,582		$	170,890
Pool mortgage insurance	285			291
Total mortgage insurance risk in force	$	169,867	5%	$	171,181	5%

Schedule of Risk in Force Mortgage Insurance Coverage, by Counterparty [Table Text Block]


	Percentage of Risk-in-Force Coverage by Mortgage Insurer
	As of
	March 31, 2021		December 31, 2020

Counterparty:(1)
Arch Capital Group Ltd.	20	%	21	%
Mortgage Guaranty Insurance Corp.	18		18
Radian Guaranty, Inc.	18		19
Genworth Mortgage Insurance Corp.	17		16
Essent Guaranty, Inc.	16		16
Others	11		10
Total	100	%	100	%

(1)Insurance coverage amounts provided for each counterparty may include coverage provided by affiliates and subsidiaries of the counterparty.

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

The table below displays the percentage of our single-family guaranty book of business serviced by our top five depository single-family mortgage servicers and top five non-depository single-family mortgage servicers (i.e., servicers that are not insured depository institutions), and identifies one depository servicer that serviced more than 10% of our single-family guaranty book of business based on unpaid principal balance.


	Percentage of Single-Family Guaranty Book of Business
	As of
	March 31, 2021		December 31, 2020
Wells Fargo Bank, N.A. (together with its affiliates)	12	%	13	%
Remaining top five depository servicers	10		11
Top five non-depository servicers	23		24
Total	45	%	48	%

Multifamily [Member]

Concentration Risk [Line Items]

Schedule of Delinquency Status Guaranty Book of Business [Table Text Block]

The following tables display the delinquency status and serious delinquency rates for specified loan categories of our multifamily guaranty book of business.


	As of
	March 31, 2021(1)				December 31, 2020(1)
	30 Days Delinquent		Seriously Delinquent(2)		30 Days Delinquent		Seriously Delinquent(2)
Percentage of multifamily guaranty book of business	0.37	%	0.66	%	0.29	%	0.98	%

Calculated based on the aggregate unpaid principal balance of multifamily loans for each category divided by the aggregate unpaid principal balance of loans in our multifamily guaranty book of business.(2)Consists of multifamily loans that were 60 days or more past due as of the dates indicated.

Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]


	As of
	March 31, 2021				December 31, 2020
	Percentage of Multifamily Guaranty Book of Business(1)		Serious Delinquency Rate(2)(3)		Percentage of Multifamily Guaranty Book of Business(1)		Serious Delinquency Rate(2)(3)
Original LTV ratio:
Greater than 80%	1	%	0.86	%	1	%	1.04	%
Less than or equal to 80%	99		0.66		99		0.98
Current DSCR below 1.0(4)	2		18.51		2		21.19

(2)Consists of multifamily loans that were 60 days or more past due as of the dates indicated.

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]


	Percentage of Multifamily Guaranty Book of Business
	As of
	March 31, 2021		December 31, 2020
Walker & Dunlop, Inc.	13	%	12	%
Wells Fargo Bank, N.A. (together with its affiliates)	11		12
Remaining top five servicers	24		24
Total	48	%	48	%

Netting Arrangements (Tables)

3 Months Ended

Mar. 31, 2021

Offsetting [Abstract]

Offsetting [Table Text Block]

The tables below display information related to derivatives, securities purchased under agreements to resell or similar arrangements, and securities sold under agreements to repurchase or similar arrangements, which are subject to an enforceable master netting arrangement or similar agreement that are either offset or not offset in our condensed consolidated balance sheets.


	As of March 31, 2021
			Gross Amount Offset(1)		Net Amount Presented in our Condensed Consolidated Balance Sheets				Amounts Not Offset in our Condensed Consolidated Balance Sheets
	Gross Amount								Financial Instruments(2)			Collateral(3)			Net Amount
	(Dollars in millions)
Assets:
OTC risk management derivatives	$	670	$	(661)		$	9			$	—		$	—	$	9
Cleared risk management derivatives	—		6			6				—			—		6
Mortgage commitment derivatives	2,596		—			2,596				(801)			(85)		1,710
Total derivative assets	3,266		(655)			2,611		(4)		(801)			(85)		1,725
Securities purchased under agreements to resell or similar arrangements(5)	66,437		—			66,437				—			(66,437)		—
Total assets	$	69,703	$	(655)		$	69,048			$	(801)		$	(66,522)	$	1,725
Liabilities:
OTC risk management derivatives	$	(1,720)	$	1,646		$	(74)			$	—		$	—	$	(74)
Cleared risk management derivatives	—		(14)			(14)				—			14		—
Mortgage commitment derivatives	(1,972)		—			(1,972)				801			159		(1,012)
Total derivative liabilities	(3,692)		1,632			(2,060)		(4)		801			173		(1,086)

Total liabilities	$	(3,692)	$	1,632		$	(2,060)			$	801		$	173	$	(1,086)


	As of December 31, 2020
			Gross Amount Offset(1)		Net Amount Presented in our Condensed Consolidated Balance Sheets					Amounts Not Offset in our Condensed Consolidated Balance Sheets
	Gross Amount								Financial Instruments(2)				Collateral(3)			Net Amount
	(Dollars in millions)
Assets:
OTC risk management derivatives	$	962	$	(952)		$	10				$	—		$	—		$	10
Cleared risk management derivatives	—		47			47					—			—			47
Mortgage commitment derivatives	989		—			989					(406)			(53)			530
Total derivative assets	1,951		(905)			1,046		(4)			(406)			(53)			587
Securities purchased under agreements to resell or similar arrangements(5)	46,644		—			46,644					—			(46,644)			—
Total assets	$	48,595	$	(905)		$	47,690				$	(406)		$	(46,697)		$	587
Liabilities:
OTC risk management derivatives	$	(1,015)	$	999		$	(16)				$	—		$	—		$	(16)
Cleared risk management derivatives	—		(4)			(4)					—			2			(2)
Mortgage commitment derivatives	(1,426)		—			(1,426)					406			1,017			(3)
Total derivative liabilities	(2,441)		995			(1,446)		(4)			406			1,019			(21)

Total liabilities	$	(2,441)	$	995		$	(1,446)				$	406		$	1,019		$	(21)

Fair Value (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Recurring Changes in Fair Value [Table Text Block]


	Fair Value Measurements as of March 31, 2021
	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment(1)			Estimated Fair Value
	(Dollars in millions)
Recurring fair value measurements:
Assets:
Cash equivalents(2)		$	4,050		$	—		$	—		$	—		$	4,050
Trading securities:
Mortgage-related securities:
Fannie Mae		—			1,876			109			—			1,985
Other agency		—			3,440			—			—			3,440
Private-label and other mortgage securities		—			157			—			—			157
Non-mortgage-related securities:
U.S. Treasury securities		105,601			—			—			—			105,601
Other securities		—			73			—			—			73
Total trading securities		105,601			5,546			109			—			111,256
Available-for-sale securities:
Mortgage-related securities:
Fannie Mae		—			847			189			—			1,036
Other agency		—			34			—			—			34
Alt-A and subprime private-label securities		—			4			1			—			5
Mortgage revenue bonds		—			—			191			—			191
Other		—			6			230			—			236
Total available-for-sale securities		—			891			611			—			1,502
Mortgage loans		—			5,228			820			—			6,048
Other assets:
Risk management derivatives:
Swaps		—			299			151			—			450
Swaptions		—			220			—			—			220
Netting adjustment		—			—			—			(655)			(655)
Mortgage commitment derivatives		—			2,596			—			—			2,596
Credit enhancement derivatives		—			—			61			—			61
Total other assets		—			3,115			212			(655)			2,672
Total assets at fair value		$	109,651		$	14,780		$	1,752		$	(655)		$	125,528

Liabilities:
Long-term debt:
Of Fannie Mae:

Senior floating		$	—		$	2,954		$	382		$	—		$	3,336
Total of Fannie Mae		—			2,954			382			—			3,336
Of consolidated trusts		—			23,543			58			—			23,601
Total long-term debt		—			26,497			440			—			26,937
Other liabilities:
Risk management derivatives:
Swaps		—			1,662			—			—			1,662
Swaptions		—			58			—			—			58
Netting adjustment		—			—			—			(1,632)			(1,632)
Mortgage commitment derivatives		—			1,972			—			—			1,972
Credit enhancement derivatives		—			—			46			—			46
Total other liabilities		—			3,692			46			(1,632)			2,106
Total liabilities at fair value		$	—		$	30,189		$	486		$	(1,632)		$	29,043


	Fair Value Measurements as of December 31, 2020
	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment(1)			Estimated Fair Value
		(Dollars in millions)
Recurring fair value measurements:
Assets:
Cash equivalents(2)		$	1,120		$	—		$	—		$	—		$	1,120
Trading securities:
Mortgage-related securities:
Fannie Mae		—			2,310			94			—			2,404
Other agency		—			3,450			1			—			3,451
Private-label and other mortgage securities		—			158			—			—			158
Non-mortgage-related securities:
U.S. Treasury securities		130,456			—			—			—			130,456
Other securities		—			73			—			—			73
Total trading securities		130,456			5,991			95			—			136,542
Available-for-sale securities:
Mortgage-related securities:
Fannie Mae		—			973			195			—			1,168
Other agency		—			65			—			—			65
Alt-A and subprime private-label securities		—			4			2			—			6
Mortgage revenue bonds		—			—			216			—			216
Other		—			7			235			—			242
Total available-for-sale securities		—			1,049			648			—			1,697
Mortgage loans		—			5,629			861			—			6,490
Other assets:
Risk management derivatives:
Swaps		—			376			203			—			579
Swaptions		—			383			—			—			383
Netting adjustment		—			—			—			(905)			(905)
Mortgage commitment derivatives		—			989			—			—			989
Credit enhancement derivatives		—			—			179			—			179
Total other assets		—			1,748			382			(905)			1,225
Total assets at fair value		$	131,576		$	14,417		$	1,986		$	(905)		$	147,074

Liabilities:
Long-term debt:
Of Fannie Mae:

Senior floating		$	—		$	3,312		$	416		$	—		$	3,728
Total of Fannie Mae		—			3,312			416			—			3,728
Of consolidated trusts		—			24,503			83			—			24,586
Total long-term debt		—			27,815			499			—			28,314
Other liabilities:
Risk management derivatives:
Swaps		—			881			—			—			881
Swaptions		—			134			—			—			134
Netting adjustment		—			—			—			(995)			(995)
Mortgage commitment derivatives		—			1,426			—			—			1,426
Credit enhancement derivatives		—			—			49			—			49
Total other liabilities		—			2,441			49			(995)			1,495
Total liabilities at fair value		$	—		$	30,256		$	548		$	(995)		$	29,809

(2)Cash equivalents are comprised of U.S. Treasuries that have a maturity at the date of acquisition of three months or less.

Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Table Text Block]


	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	For the Three Months Ended March 31, 2021
			Total Gains (Losses) (Realized/Unrealized)																			Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of March 31, 2021(4)(5)		Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of March 31, 2021(1)
	Balance, December 31, 2020		Included in Net Income			Included in Total OCI Gain/(Loss)(1)		Purchases(2)		Sales(2)		Issues(3)		Settlements(3)		Transfers out of Level 3		Transfers into Level 3		Balance, March 31, 2021
	(Dollars in millions)
Trading securities:
Mortgage-related:
Fannie Mae	$	94	$	(1)		$	—	$	—	$	—	$	—	$	—	$	(7)	$	23	$	109	$	2	$	—
Other agency	1		—			—		—		—		—		—		(1)		—		—		—		—
Private-label and other mortgage securities	—		—			—		—		—		—		—		—		—		—		—		—
Total trading securities	$	95	$	(1)	(5)(6)	$	—	$	—	$	—	$	—	$	—	$	(8)	$	23	$	109	$	2	$	—

Available-for-sale securities:
Mortgage-related:
Fannie Mae	$	195	$	—		$	(3)	$	—	$	—	$	—	$	(3)	$	—	$	—	$	189	$	—	$	(2)
Alt-A and subprime private-label securities	2		—			(1)		—		—		—		—		—		—		1		—		—
Mortgage revenue bonds	216		—			(1)		—		—		—		(24)		—		—		191		—		—
Other	235		3			3		—		—		—		(11)		—		—		230		—		2
Total available-for-sale securities	$	648	$	3	(6)(7)	$	(2)	$	—	$	—	$	—	$	(38)	$	—	$	—	$	611	$	—	$	—

Mortgage loans	$	861	$	8	(5)(6)	$	—	$	—	$	—	$	—	$	(47)	$	(23)	$	21	$	820	$	9	$	—
Net derivatives	333		(132)		(5)	—		—		—		—		(35)		—		—		166		(167)		—

Long-term debt:
Of Fannie Mae:
Senior floating	$	(416)	$	34	(5)	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	(382)	$	34	$	—
Of consolidated trusts	(83)		1		(5)(6)	—		—		—		—		4		20		—		(58)		—		—
Total long-term debt	$	(499)	$	35		$	—	$	—	$	—	$	—	$	4	$	20	$	—	$	(440)	$	34	$	—


	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	For the Three Months Ended March 31, 2020
			Total Gains (Losses) (Realized/Unrealized)																			Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of March 31, 2020(4)(5)		Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of March 31, 2020(1)
	Balance, December 31, 2019		Included in Net Income			Included in Total OCI Gain/(Loss)(1)		Purchases(2)		Sales(2)		Issues(3)		Settlements(3)		Transfers out of Level 3		Transfers into Level 3		Balance, March 31, 2020
	(Dollars in millions)
Trading securities:
Mortgage-related:
Fannie Mae	$	45	$	(9)		$	—	$	—	$	—	$	—	$	—	$	(11)	$	43	$	68	$	(10)	$	—
Other agency	1		—			—		—		—		—		—		(1)		—		—		—		—
Private-label and other mortgage securities	—		—			—		—		—		—		—		—		94		94		—		—
Total trading securities	$	46	$	(9)	(5)(6)	$	—	$	—	$	—	$	—	$	—	$	(12)	$	137	$	162	$	(10)	$	—

Available-for-sale securities:
Mortgage-related:
Fannie Mae	$	171	$	—		$	4	$	—	$	—	$	—	$	(1)	$	—	$	14	$	188	$	—	$	3

Mortgage revenue bonds	315		(3)			2		74		(74)		—		(18)		—		—		296		—		4
Other	306		(11)			(1)		268		(268)		—		(10)		—		—		284		—		(1)
Total available-for-sale securities	$	792	$	(14)	(6)(7)	$	5	$	342	$	(342)	$	—	$	(29)	$	—	$	14	$	768	$	—	$	6


Mortgage loans	$	688	$	(24)	(5)(6)	$	—	$	—	$	—	$	—	$	(29)	$	(23)	$	26	$	638	$	(26)	$	—
Net derivatives	162		41		(5)	—		—		—		—		(4)		18		—		217		44		—

Long-term debt:
Of Fannie Mae:
Senior floating	$	(398)	$	(34)	(5)	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	(432)	$	(34)	$	—
Of consolidated trusts	(75)		4		(5)(6)	—		—		—		—		3		—		(15)		(83)		4		—
Total long-term debt	$	(473)	$	(30)		$	—	$	—	$	—	$	—	$	3	$	—	$	(15)	$	(515)	$	(30)	$	—

(2)Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts.

(3)Issues and settlements include activity related to the consolidation and deconsolidation of liabilities of securitization trusts.

(4)Amount represents temporary changes in fair value. Amortization, accretion and the impairment of credit losses are not considered unrealized and are not included in this amount.

(5)Gains (losses) are included in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

(6)Gains (losses) are included in “Net interest income” in our condensed consolidated statements of operations and comprehensive income.

(7)Gains (losses) are included in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

Valuation Techniques and Significant Unobservable Inputs for Level 3 Assets and Liabilities [Table Text Block]


	Fair Value Measurements as of March 31, 2021
	Fair Value		Significant Valuation Techniques	Significant Unobservable Inputs(1)	Range(1)			Weighted - Average(1)(2)
	(Dollars in millions)
Recurring fair value measurements:
Trading securities:
Mortgage-related securities:
Agency(3)	$	109	Various



Available-for-sale securities:
Mortgage-related securities:
Agency(3)	93		Consensus
	96		Various

Total agency	189

Alt-A and subprime private-label securities	1		Various

Mortgage revenue bonds	119		Single Vendor	Spreads (bps)	32.5	-	188.5	78.4
	72		Various
Total mortgage revenue bonds	191

Other	202		Discounted Cash Flow	Spreads (bps)	405.0	-	406.0	405.5



	28		Various
Total other	230
Total available-for-sale securities	$	611

Net derivatives	$	151	Dealer Mark
	15		Discounted Cash Flow
Total net derivatives	$	166


	Fair Value Measurements as of December 31, 2020
	Fair Value		Significant Valuation Techniques	Significant Unobservable Inputs(1)	Range(1)			Weighted - Average(1)(2)
	(Dollars in millions)
Recurring fair value measurements:
Trading securities:
Mortgage-related securities:
Agency(3)	$	95	Various

Available-for-sale securities:
Mortgage-related securities:
Agency(3)	97		Consensus
	98		Various
Total agency	195





Alt-A and subprime private-label securities	2		Various

Mortgage revenue bonds	144		Single Vendor	Spreads (bps)	32.0	-	315.3	93.4
	72		Various
Total mortgage revenue bonds	216

Other	206		Discounted Cash Flow	Spreads (bps)	425.0	-	443.0	434.2



	29		Various
Total other	235
Total available-for-sale securities	$	648

Net derivatives	$	203	Dealer Mark
	130		Discounted Cash Flow
Total net derivatives	$	333

(2)Unobservable inputs were weighted by the relative fair value of the instruments.

(3)Includes Fannie Mae and Freddie Mac securities.

Level 3 Assets Measured on Nonrecurring Basis [Table Text Block]

The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis.


		Fair Value Measurements as of
	Valuation Techniques	March 31, 2021		December 31, 2020
	(Dollars in millions)
Nonrecurring fair value measurements:
Mortgage loans held for sale, at lower of cost or fair value	Consensus	$	212	$	754
	Single Vendor	394		333

Total mortgage loans held for sale, at lower of cost or fair value		606		1,087

Single-family mortgage loans held for investment, at amortized cost	Internal Model	614		979


Multifamily mortgage loans held for investment, at amortized cost	Appraisals	166		225

	Internal Model	122		125
	Various	75		40
Total multifamily mortgage loans held for investment, at amortized cost		363		390
Acquired property, net:
Single-family	Accepted Offers	16		35
	Appraisals	63		89
	Internal Model	26		41
	Walk Forwards	56		85
	Various	10		11
Total single-family		171		261

Multifamily	Various	5		25

Total nonrecurring assets at fair value		$	1,759	$	2,742

Fair Value of Financial Instruments [Table Text Block]


	As of March 31, 2021
	Carrying Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment			Estimated Fair Value
	(Dollars in millions)
Financial assets:
Cash and cash equivalents, including restricted cash and cash equivalents	$	114,341	$	102,841		$	11,500		$	—		$	—		$	114,341
Federal funds sold and securities purchased under agreements to resell or similar arrangements	54,937		—			54,937			—			—			54,937
Trading securities	111,256		105,601			5,546			109			—			111,256
Available-for-sale securities	1,502		—			891			611			—			1,502
Mortgage loans held for sale	7,824		—			3,511			5,122			—			8,633
Mortgage loans held for investment, net of allowance for loan losses	3,732,056		—			3,549,337			245,916			—			3,795,253
Advances to lenders	10,572		—			10,571			1			—			10,572
Derivative assets at fair value	2,672		—			3,115			212			(655)			2,672
Guaranty assets and buy-ups	109		—			—			242			—			242
Total financial assets	$	4,035,269	$	208,442		$	3,639,408		$	252,213		$	(655)		$	4,099,408

Financial liabilities:

Short-term debt:
Of Fannie Mae	$	2,857	$	—		$	2,857		$	—		$	—		$	2,857

Long-term debt:
Of Fannie Mae	270,585		—			279,208			828			—			280,036
Of consolidated trusts	3,740,538		—			3,777,011			30,990			—			3,808,001
Derivative liabilities at fair value	2,106		—			3,692			46			(1,632)			2,106
Guaranty obligations	120		—			—			75			—			75
Total financial liabilities	$	4,016,206	$	—		$	4,062,768		$	31,939		$	(1,632)		$	4,093,075


	As of December 31, 2020
	Carrying Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Netting Adjustment	Estimated Fair Value
	(Dollars in millions)
Financial assets:
Cash and cash equivalents and restricted cash	$	115,623	$	97,179		$	18,444		$	—			$	—	$	115,623
Federal funds sold and securities purchased under agreements to resell or similar arrangements	28,200		—			28,200			—				—		28,200
Trading securities	136,542		130,456			5,991			95				—		136,542
Available-for-sale securities	1,697		—			1,049			648				—		1,697
Mortgage loans held for sale	5,197		—			116			5,502				—		5,618
Mortgage loans held for investment, net of allowance for loan losses	3,648,695		—			3,512,672			255,556				—		3,768,228
Advances to lenders	10,449		—			10,448			1				—		10,449
Derivative assets at fair value	1,225		—			1,748			382				(905)		1,225
Guaranty assets and buy-ups	115		—			—			258				—		258
Total financial assets	$	3,947,743	$	227,635		$	3,578,668		$	262,442			$	(905)	$	4,067,840

Financial liabilities:

Short-term debt:
Of Fannie Mae	$	12,173	$	—		$	12,177		$	—			$	—	$	12,177

Long-term debt:
Of Fannie Mae	277,399		—			288,414			878				—		289,292
Of consolidated trusts	3,646,164		—			3,756,673			31,584				—		3,788,257
Derivative liabilities at fair value	1,495		—			2,441			49				(995)		1,495
Guaranty obligations	127		—			—			82				—		82
Total financial liabilities	$	3,937,358	$	—		$	4,059,705		$	32,593			$	(995)	$	4,091,303

Fair Value Option [Table Text Block]

The following table displays the fair value and unpaid principal balance of the financial instruments for which we have made fair value elections.


	As of
	March 31, 2021									December 31, 2020
	Loans(1)			Long-Term Debt of Fannie Mae			Long-Term Debt of Consolidated Trusts			Loans(1)			Long-Term Debt of Fannie Mae			Long-Term Debt of Consolidated Trusts
	(Dollars in millions)
Fair value		$	6,048		$	3,336		$	23,601		$	6,490		$	3,728		$	24,586
Unpaid principal balance		5,618			3,158			20,828			6,046			3,518			21,408

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions		3 Months Ended
	Sep. 08, 2008	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020
Related Parties [Line Items]
Proceeds from Issuance of Common Stock		$ 70,000
Net income		4,993	$ 461
Other assets		13,923		$ 15,201
Loans held for sale, at lower of cost or fair value		7,824		5,197
Allowance for Loan and Lease Losses, Real Estate		9,628		10,552
Accumulated deficit		(103,117)		$ (108,110)
Interest and Fee Income, Loans and Leases		$ 23,353	28,938
Convertible Preferred Stock, Shares Issued upon Conversion		26,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees		$ 731	637
Series 2008-2 Senior Preferred Stock
Related Parties [Line Items]
Shares issued (shares)	1,000,000
US Treasury [Member]
Related Parties [Line Items]
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement		119,800
Total available funding from US Treasury pursuant to the senior preferred stock agreement		113,900
Aggregate liquidation preference of senior preferred stock		146,800
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees		$ 731	$ 637
Accounting Standards Update 2016-13 [Member]
Related Parties [Line Items]
Allowance for Loan and Lease Losses, Real Estate					$ 1,722

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) shares in Billions, $ in Billions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, September 2019 Amendment [Line Items]
Deficit of core capital over statutory minimum capital requirement	$ (119.5)		$ (124.3)
Weighted Average Number of Shares, Contingently Issuable	4.7	4.7
US Treasury [Member]
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, September 2019 Amendment [Line Items]
Increase of Guarantee Fee Rate Resulting from the Temporary Payroll Tax Cut Continuation Act of 2011.	1000.00%

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2021
Related Parties [Line Items]
Basis Points of Each Dollar of Unpaid Principal Balance	420.00%
Affordable Housing Program Obligation	$ 0.35
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	731,000,000	$ 637,000,000
Net income	4,993,000,000	461,000,000
US Treasury [Member]
Related Parties [Line Items]
Home Affordable Modification Program administrative expense reimbursements from Treasury and Freddie Mac	$ 4,000,000	5,000,000
Percentage of common shares attributable to warrants issued to US Treasury as percentage to total diluted common shares	79.90%
Increase of Guarantee Fee Rate Resulting from the Temporary Payroll Tax Cut Continuation Act of 2011.	1000.00%
Aggregate liquidation preference of senior preferred stock	$ 146,800,000,000
Total available funding from US Treasury pursuant to the senior preferred stock agreement	113,900,000,000
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement	119,800,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	731,000,000	637,000,000
US Treasury [Member] \| Forecast [Member]
Related Parties [Line Items]
Aggregate liquidation preference of senior preferred stock			$ 151,700,000,000
US Treasury [Member] \| FNM_SingleFamily
Related Parties [Line Items]
Recognized TCCA fees that had not been remitted to Treasury as of period end	727,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees	37,000,000	32,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments	27,000,000	29,000,000
Other Expense [Member] \| US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments	62,000,000	$ 30,000,000
Affordable housing program assessments not remitted	$ 62,000,000

Consolidations and Transfers of Financial Assets Unconsolidated VIEs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Variable Interest Entities [Line Items]
Assets	$ 4,070,103		$ 3,985,749
Trading, at fair value	111,256		136,542
Available-for-sale, at fair value	1,502		1,697
Other assets	13,923		15,201
Other liabilities	(16,313)		(15,035)
Unpaid principal balance of mortgage loans	3,674,972		3,589,868
Portfolio securitizations: unpaid principal balance	216,700	$ 89,000
Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Retained interests: principal and interest received	143	$ 181
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	388,591		373,722
Multifamily [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	388,600
Single-family [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	3,286,381		3,216,146
Mortgage-related securities [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	230,000		180,000
Trading, at fair value	4,841		5,219
Available-for-sale, at fair value	1,315		1,486
Other assets	39		41
Other liabilities	(65)		(67)
Maximum exposure to loss	164,000		146,000
Net carrying amount	6,130		6,679
Partnership interest LIHTC [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	2,500		2,600
Maximum exposure to loss	169		126
Net carrying amount	163		121
Debt Securities [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	10,500		11,400
Maximum exposure to loss	10,400		11,400
Fannie Mae Securities [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	1,243		1,611
Available-for-sale, at fair value	1,036		1,168
Non-Fannie Mae Securities [Member] \| Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	3,598		3,608
Available-for-sale, at fair value	$ 279		$ 318

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Transfers of Financial Assets [Line Items]
Portfolio securitizations: unpaid principal balance	$ 216,700	$ 89,000
Maximum Exposure	15,624		$ 16,252
Guaranty Obligation	120		127
Maximum Recovery	6,342		6,664
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	143	$ 181
Unconsolidated VIEs [Member] \| Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	1,400		1,700
Retained interests: fair value	$ 2,500		$ 2,900

Mortgage Loans Loans in Mortgage Portfolio (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,674,972		$ 3,589,868
Total Loan, Cost Basis and Fair Value Adjustments, Net	74,536		74,576
Allowance for Loan and Lease Losses, Real Estate	9,628		10,552
Total mortgage loans	3,739,880		3,653,892
Interest Receivable	9,993		9,937
Financing Receivable, before Allowance for Credit Loss	3,741,684		3,659,247
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	3,286,381		3,216,146
Financing Receivable, Reclassification to Held-for-sale	3,112	$ 1,637
Financing Receivable, Sale	208	0
Gain (Loss) on Sale of Mortgage Loans	2	0
Mortgage Loans in Process of Foreclosure, Amount	4,700		5,000
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	307	182
Financing Receivable, before Allowance for Credit Loss	3,340,905		3,271,810
Single-family [Member] \| allowance for the redesignated from HFI to HFS
Loans in Mortgage Portfolio [Line Items]
Allowance for Loan and Lease Losses, Period Increase (Decrease)	(54)	(9)
Charge-offs	361	184
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	388,591		373,722
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	14	$ 1
Mortgage loans [Member]
Loans in Mortgage Portfolio [Line Items]
Interest Receivable	$ 9,900		$ 9,800

Mortgage Loans Aging (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mortgage Loans Aging (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 121,156	$ 143,215
Current	3,624,505	3,519,496
Total recorded investment in loans	3,745,661	3,662,711
Recorded investment in loans 90 days or more delinquent and accruing interest	58,366	77,196
Recorded investment in nonaccrual loans	36,138	28,574
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	7,830	7,455
Financing Receivable, before Allowance for Credit Loss	3,741,684	3,659,247
30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	21,618	29,473
60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	7,896	10,570
Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	91,642	103,172
Single-family [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	117,130	138,387
Current	3,236,664	3,146,898
Total recorded investment in loans	3,353,794	3,285,285
Recorded investment in loans 90 days or more delinquent and accruing interest	57,962	76,586
Recorded investment in nonaccrual loans	33,985	26,505
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	7,647	7,153
Financing Receivable, before Allowance for Credit Loss	$ 3,340,905	$ 3,271,810
Single-family [Member] \| Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days	90 days
Single-family [Member] \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 20,123	$ 28,333
Single-family [Member] \| 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	7,896	10,570
Single-family [Member] \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	89,111	99,484
Single-family [Member] \| FixedRateResidentialMortgage15yearMember
Financing Receivable, Past Due [Line Items]
Days delinquent	6,509	7,616
Current	475,960	449,443
Total recorded investment in loans	482,469	457,059
Recorded investment in loans 90 days or more delinquent and accruing interest	3,424	4,292
Recorded investment in nonaccrual loans	945	853
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	210	240
Financing Receivable, before Allowance for Credit Loss	482,469	457,059
Single-family [Member] \| FixedRateResidentialMortgage15yearMember \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,742	1,987
Single-family [Member] \| FixedRateResidentialMortgage15yearMember \| 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	492	601
Single-family [Member] \| FixedRateResidentialMortgage15yearMember \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	4,275	5,028
Single-family [Member] \| Other [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	5,612	6,645
Current	45,188	47,937
Total recorded investment in loans	50,800	54,582
Recorded investment in loans 90 days or more delinquent and accruing interest	2,132	2,861
Recorded investment in nonaccrual loans	2,583	2,475
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	860	771
Financing Receivable, before Allowance for Credit Loss	37,911	41,107
Single-family [Member] \| Other [Member] \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	801	1,150
Single-family [Member] \| Other [Member] \| 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	317	458
Single-family [Member] \| Other [Member] \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	4,494	5,037
Single-family [Member] \| Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,236	1,508
Current	26,549	29,933
Total recorded investment in loans	27,785	31,441
Recorded investment in loans 90 days or more delinquent and accruing interest	735	907
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	116	114
Financing Receivable, before Allowance for Credit Loss	27,785	31,441
Single-family [Member] \| Adjustable Rate Residential Mortgage [Member] \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	180	268
Single-family [Member] \| Adjustable Rate Residential Mortgage [Member] \| 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	63	97
Single-family [Member] \| Adjustable Rate Residential Mortgage [Member] \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	993	1,143
Single-family [Member] \| Fixed Rate Residential Mortgage
Financing Receivable, Past Due [Line Items]
Days delinquent	103,773	122,618
Current	2,688,967	2,619,585
Total recorded investment in loans	2,792,740	2,742,203
Recorded investment in loans 90 days or more delinquent and accruing interest	51,671	68,526
Recorded investment in nonaccrual loans	30,173	22,907
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	6,461	6,028
Financing Receivable, before Allowance for Credit Loss	2,792,740	2,742,203
Single-family [Member] \| Fixed Rate Residential Mortgage \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	17,400	24,928
Single-family [Member] \| Fixed Rate Residential Mortgage \| 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	7,024	9,414
Single-family [Member] \| Fixed Rate Residential Mortgage \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	79,349	88,276
Single-family [Member] \| Government [Member]
Table Footnote [Abstract]
Financing Receivable, before Allowance for Credit Loss	12,900	13,500
Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	4,026	4,828
Current	387,841	372,598
Total recorded investment in loans	391,867	377,426
Recorded investment in loans 90 days or more delinquent and accruing interest	404	610
Recorded investment in nonaccrual loans	2,153	2,069
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	$ 183	302
Multifamily [Member] \| Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	60 days
Multifamily [Member] \| Maximum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	89 days
Multifamily [Member] \| 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 1,495	1,140
Multifamily [Member] \| Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 2,531	$ 3,688

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 3,745,661	$ 3,662,711
Financing Receivable, before Allowance for Credit Loss	3,741,684	3,659,247
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	391,867	377,426
Financing Receivable, Originated in Current Fiscal Year	11,295	72,014
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,851	69,337
Financing Receivable, Originated Two Years before Latest Fiscal Year	68,815	63,616
Financing Receivable, Originated Three Years before Latest Fiscal Year	62,953	53,523
Financing Receivable, Originated Four Years before Latest Fiscal Year	52,785	44,753
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	114,168	74,183
Doubtful [Member] \| Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	4	1
Pass \| Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	380,184	367,374
Financing Receivable, Originated in Current Fiscal Year	11,295	71,977
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	81,647	68,296
Financing Receivable, Originated Two Years before Latest Fiscal Year	67,630	62,087
Financing Receivable, Originated Three Years before Latest Fiscal Year	61,280	50,907
Financing Receivable, Originated Four Years before Latest Fiscal Year	49,903	43,174
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	108,429	70,933
Criticized \| Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	11,683	10,052
Financing Receivable, Originated in Current Fiscal Year	0	37
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	204	1,041
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,185	1,529
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,673	2,616
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,882	1,579
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	5,739	3,250
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 391,867	$ 377,426

Mortgage Loans TDRs (Details) $ in Millions	3 Months Ended
Mortgage Loans TDRs (Details) $ in Millions	Mar. 31, 2021 USD ($) contracts	Mar. 31, 2020 USD ($) contracts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Average term extension of a single-family modified loan	138 months	168 months
Average interest rate reduction of a single-family modified loan	0.52%	0.32%
Number of loans troubled debt restructurings activity \| contracts	3,553	12,610
Recorded investment troubled debt restructurings activity \| $	$ 523	$ 2,099
Number of loans troubled debt restructurings subsequent default \| contracts	7,968	3,561
Recorded investment troubled debt restructurings subsequent default \| $	$ 1,452	$ 578
Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	3,553	12,610
Recorded investment troubled debt restructurings activity \| $	$ 523	$ 2,099
Number of loans troubled debt restructurings subsequent default \| contracts	7,968	3,559
Recorded investment troubled debt restructurings subsequent default \| $	$ 1,452	$ 576
Multifamily [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	0	0
Recorded investment troubled debt restructurings activity \| $	$ 0	$ 0
Number of loans troubled debt restructurings subsequent default \| contracts	0	2
Recorded investment troubled debt restructurings subsequent default \| $	$ 0	$ 2
FixedRateResidentialMortgage15yearMember \| Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	369	1,073
Recorded investment troubled debt restructurings activity \| $	$ 28	$ 98
Number of loans troubled debt restructurings subsequent default \| contracts	152	50
Recorded investment troubled debt restructurings subsequent default \| $	$ 11	$ 3
Other [Member] \| Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	154	537
Recorded investment troubled debt restructurings activity \| $	$ 18	$ 68
Number of loans troubled debt restructurings subsequent default \| contracts	633	327
Recorded investment troubled debt restructurings subsequent default \| $	$ 112	$ 51
Adjustable Rate Residential Mortgage [Member] \| Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	41	144
Recorded investment troubled debt restructurings activity \| $	$ 6	$ 24
Number of loans troubled debt restructurings subsequent default \| contracts	11	7
Recorded investment troubled debt restructurings subsequent default \| $	$ 2	$ 1
Fixed Rate Residential Mortgage \| Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity \| contracts	2,989	10,856
Recorded investment troubled debt restructurings activity \| $	$ 471	$ 1,909
Number of loans troubled debt restructurings subsequent default \| contracts	7,172	3,175
Recorded investment troubled debt restructurings subsequent default \| $	$ 1,327	$ 521

Mortgage Loans Non-accrual Loans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	$ 36,138		$ 28,574
Financing Receivable, Nonaccrual, Interest Income	79	$ 117
Single-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	307	182
Recorded investment in nonaccrual loans	33,985		26,505
Financing Receivable, Nonaccrual, Interest Income	71	117
Financing Receivable, Accrued Interest, Writeoff	108	87
Single-family [Member] \| FixedRateResidentialMortgage15yearMember
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	945		853
Financing Receivable, Nonaccrual, Interest Income	2	2
Single-family [Member] \| Other [Member]
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	2,583		2,475
Financing Receivable, Nonaccrual, Interest Income	4	13
Single-family [Member] \| Adjustable Rate Loans
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	284		270
Financing Receivable, Nonaccrual, Interest Income	1	1
Single-family [Member] \| Fixed Rate Residential Mortgage
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	30,173		22,907
Financing Receivable, Nonaccrual, Interest Income	64	101
Multifamily [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	14	1
Recorded investment in nonaccrual loans	2,153		$ 2,069
Financing Receivable, Nonaccrual, Interest Income	8	0
Financing Receivable, Accrued Interest, Writeoff	$ 0	$ 0

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	$ (10,552)	$ (9,016)
Transition impact of the adoption of the CECL standard	(9,628)
Allowance for loan losses for loans held for investment	(9,628)		$ (10,552)
Benefit (provision) for loan losses	766	(2,584)
Write-offs	104	89
Recoveries	(3)	(4)
Allowance for Loan and Lease Losses, Adjustments, Other	57	28
Ending Balance	(9,628)	(13,209)
Single-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	(9,344)	(8,759)
Benefit (provision) for loan losses	671	(2,177)
Write-offs	71	70
Recoveries	(2)	(3)
Allowance for Loan and Lease Losses, Adjustments, Other	57	28
Ending Balance	(8,547)	(12,070)
Multifamily [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	(1,208)	(257)
Benefit (provision) for loan losses	95	(407)
Write-offs	33	19
Recoveries	(1)	(1)
Ending Balance	$ (1,081)	$ (1,139)
Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses for loans held for investment				$ (1,722)
Accounting Standards Update 2016-13 [Member] \| Single-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses for loans held for investment				(1,229)
Accounting Standards Update 2016-13 [Member] \| Multifamily [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses for loans held for investment				$ (493)

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 111,256	$ 136,542
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	5,582	6,013
Fannie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,985	2,404
Other agency [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	3,440	3,451
Private-label and other mortgage securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	157	158
Non-mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	105,674	130,529
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	105,601	130,456
Other securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	73	73
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 741	$ 793

Investments in Securities Trading 2 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Net trading gains (losses)	$ (758)	$ 647
Net trading gains (losses) recognized in the period related to securities still held at period end	$ (759)	$ 591

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 13	$ 21
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 115	$ 50

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	$ 1,440	$ 1,606
Allowance for credit losses	(3)
Gross unrealized gains	76	106
Gross unrealized losses	(11)	(12)
Total fair value	1,502	1,697
Interest excluded from amortized cost and fair value	5	6
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	988	1,094
Allowance for credit losses	0	0
Gross unrealized gains	59	86
Gross unrealized losses	(11)	(12)
Total fair value	1,036	1,168
Other agency [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	32	59
Allowance for credit losses	0	0
Gross unrealized gains	2	6
Gross unrealized losses	0	0
Total fair value	34	65
Alt-A and subprime private-label securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	3	4
Allowance for credit losses	0	0
Gross unrealized gains	2	2
Gross unrealized losses	0	0
Total fair value	5	6
Mortgage revenue bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	187	211
Allowance for credit losses	(3)
Gross unrealized gains	7	8
Gross unrealized losses	0	0
Total fair value	191	216
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	230	238
Allowance for credit losses	0
Gross unrealized gains	6	4
Gross unrealized losses	0	0
Total fair value	$ 236	$ 242

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ (1)
Less than 12 Consecutive Months, Fair Value	0	40
12 Consecutive Months or Longer, Gross Unrealized Losses	(11)	(11)
12 Consecutive Months or Longer, Fair Value	131	94
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	131	94
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	40
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(11)	(11)
Accumulated Other Comprehensive Income , Net of Tax, Available-for-sale Securities, Other-than-temporary Impairment not Recorded	51	74
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	38	42
Accumulated other comprehensive income	89	116
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(1)
Less than 12 Consecutive Months, Fair Value	0	40
12 Consecutive Months or Longer, Gross Unrealized Losses	(11)	(11)
12 Consecutive Months or Longer, Fair Value	131	94
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	131	94
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	40
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (11)	$ (11)

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References + Details

Investments in Securities Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income [Line Items]
Accumulated Other Comprehensive Income , Net of Tax, Available-for-sale Securities, Other-than-temporary Impairment not Recorded	$ 51	$ 74
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	38	42
Accumulated other comprehensive income	$ 89	$ 116

- Definition

+ References + Details

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 1,440	$ 1,606
Total fair value	1,502	1,697
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	1,440	1,606
Total fair value	1,502	1,697
Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,502
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	31
After Five Years through Ten Years, Fair Value	151
After Ten Years, Fair Value	1,319
Total fair value	1,502
Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,437
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	30
After Five Years through Ten Years, Fair Value	137
After Ten Years, Fair Value	1,269
Total fair value	1,437
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	988	1,094
Total fair value	1,036	1,168
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	988	1,094
Total fair value	1,036	1,168
Fannie Mae [Member] \| Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,036
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	4
After Five Years through Ten Years, Fair Value	109
After Ten Years, Fair Value	923
Total fair value	1,036
Fannie Mae [Member] \| Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	988
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	4
After Five Years through Ten Years, Fair Value	98
After Ten Years, Fair Value	886
Total fair value	988
Other agency [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	32	59
Total fair value	34	65
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	32	59
Total fair value	34	65
Other agency [Member] \| Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	34
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	1
After Ten Years, Fair Value	33
Total fair value	34
Other agency [Member] \| Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	32
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	1
After Ten Years, Fair Value	31
Total fair value	32
Alt-A and subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	3	4
Total fair value	5	6
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	3	4
Total fair value	5	6
Alt-A and subprime private-label securities [Member] \| Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	5
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	2
After Ten Years, Fair Value	3
Total fair value	5
Alt-A and subprime private-label securities [Member] \| Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	3
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	2
After Ten Years, Fair Value	1
Total fair value	3
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	187	211
Total fair value	191	216
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	187	211
Total fair value	191	216
Mortgage revenue bonds [Member] \| Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	191
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	27
After Five Years through Ten Years, Fair Value	19
After Ten Years, Fair Value	144
Total fair value	191
Mortgage revenue bonds [Member] \| Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	184
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	26
After Five Years through Ten Years, Fair Value	18
After Ten Years, Fair Value	139
Total fair value	184
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	230	238
Total fair value	236	242
Available-for-sale, at fair value (with an amortized cost of $1,440 and $1,606, net of allowance of credit losses of $3)	230	238
Total fair value	236	$ 242
Other mortgage-related securities [Member] \| Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	236
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	20
After Ten Years, Fair Value	216
Total fair value	236
Other mortgage-related securities [Member] \| Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	230
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	18
After Ten Years, Fair Value	212
Total fair value	$ 230

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Financial Guarantees and Maximum Recovery [Line Items]
Contractual terms of our guarantees	32 years
Maximum Exposure	$ 15,624	$ 16,252
Guaranty Obligation	120	127
Maximum Recovery	6,342	6,664
Unconsolidated Fannie Mae MBS [Member] \| Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	4,232	4,424
Guaranty Obligation	17	18
Maximum Recovery	4,047	4,226
Other guaranty arrangements [Member] \| Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	11,392	11,828
Guaranty Obligation	103	109
Maximum Recovery	2,295	2,438
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] \| Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Single security, Freddie Mac issued securities backing unconsolidated Fannie Mae securities	$ 154,600	$ 137,300

Short-Term and Long-Term Debt Short-Term Debt (Details) - Fannie Mae [Member] - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Short-Term Debt [Line Items]
Short-term debt, weighted-average interest rate	0.06%	0.18%
Short-term debt, outstanding	$ 2,857	$ 12,173

Short-Term and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 4,011,123	$ 3,923,563
Long-term debt, weighted-average interest rate	1.70%	1.85%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 270,585	$ 277,399
Long-term debt, weighted-average interest rate	1.34%	1.34%
Unamortized discounts and premiums, fair value adjustments, hedge-related cost basis adjustments, and other cost basis adjustments	$ 1,600	$ 392
Fannie Mae [Member] \| Senior Fixed [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 157,571	$ 161,916
Long-term debt, weighted-average interest rate	1.72%	1.69%
Fannie Mae [Member] \| Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 102,683	$ 106,691
Long-term debt, weighted-average interest rate	2.09%	2.03%
Fannie Mae [Member] \| Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 47,693	$ 48,524
Long-term debt, weighted-average interest rate	0.61%	0.63%
Fannie Mae [Member] \| Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 7,195	$ 6,701
Long-term debt, weighted-average interest rate	3.77%	3.90%
Fannie Mae [Member] \| Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 113,014	$ 115,483
Long-term debt, weighted-average interest rate	0.79%	0.86%
Fannie Mae [Member] \| Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 98,095	$ 100,089
Long-term debt, weighted-average interest rate	0.28%	0.35%
Fannie Mae [Member] \| Senior floating Connecticut Avenue Securities [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 14,537	$ 14,978
Long-term debt, weighted-average interest rate	4.13%	4.16%
Fannie Mae [Member] \| Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 382	$ 416
Long-term debt, weighted-average interest rate	7.69%	7.75%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,740,538	$ 3,646,164
Long-term debt, weighted-average interest rate	1.72%	1.88%

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Asset Derivatives [Abstract]
Notional amount	$ 435,855	$ 450,981
Derivative asset, estimated fair value	2,672	1,225
Netting adjustment	(655)	(905)
Liability Derivatives [Abstract]
Notional amount	267,695	288,198
Derivative liability, estimated fair value	(2,106)	(1,495)
Netting adjustment	1,632	995
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	1,000	658
Cash collateral received for derivative instruments	35	568
Pay-fixed Swap
Asset Derivatives [Abstract]
Notional amount	68,674	88,361
Derivative asset, estimated fair value	0	0
Liability Derivatives [Abstract]
Notional amount	9,636	11,461
Derivative liability, estimated fair value	(482)	(595)
Pay-fixed Swap \| Fair Value Hedging \| Designated as Hedging Instrument
Asset Derivatives [Abstract]
Notional amount	2,804	0
Derivative asset, estimated fair value	0	0
Liability Derivatives [Abstract]
Notional amount	75	0
Derivative liability, estimated fair value	(7)	0
Receive-fixed Swap
Asset Derivatives [Abstract]
Notional amount	45,635	92,315
Derivative asset, estimated fair value	167	233
Liability Derivatives [Abstract]
Notional amount	46,039	33,919
Derivative liability, estimated fair value	(1,035)	(123)
Receive-fixed Swap \| Fair Value Hedging \| Designated as Hedging Instrument
Asset Derivatives [Abstract]
Notional amount	39,754	0
Derivative asset, estimated fair value	2	0
Liability Derivatives [Abstract]
Notional amount	0	0
Derivative liability, estimated fair value	0	0
Basis Swap
Asset Derivatives [Abstract]
Notional amount	250	250
Derivative asset, estimated fair value	146	192
Liability Derivatives [Abstract]
Notional amount	0	0
Derivative liability, estimated fair value	0	0
Foreign Currency Swap
Asset Derivatives [Abstract]
Notional amount	238	237
Derivative asset, estimated fair value	43	57
Liability Derivatives [Abstract]
Notional amount	241	239
Derivative liability, estimated fair value	(52)	(58)
Pay-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	5,690	5,530
Derivative asset, estimated fair value	124	37
Liability Derivatives [Abstract]
Notional amount	375	2,025
Derivative liability, estimated fair value	(16)	(118)
Receive-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	1,455	3,355
Derivative asset, estimated fair value	96	346
Liability Derivatives [Abstract]
Notional amount	1,110	700
Derivative liability, estimated fair value	(42)	(16)
Future [Member]
Asset Derivatives [Abstract]
Notional amount	1,602	64,398
Derivative asset, estimated fair value	0	0
Liability Derivatives [Abstract]
Notional amount	0	0
Derivative liability, estimated fair value	0	0
Risk Management Derivatives
Asset Derivatives [Abstract]
Notional amount	123,544	254,446
Derivative asset, estimated fair value	576	865
Accrued interest receivable (payable)	91	97
Netting adjustment	(655)	(905)
Liability Derivatives [Abstract]
Notional amount	57,401	48,344
Derivative liability, estimated fair value	(1,627)	(910)
Accrued interest (receivable) payable	(86)	(105)
Netting adjustment	1,632	995
Risk Management Derivatives \| Not Designated as Hedging Instrument, Economic Hedge
Asset Derivatives [Abstract]
Notional amount	123,544	254,446
Total net risk management derivatives	667	962
Liability Derivatives [Abstract]
Notional amount	57,401	48,344
Total net risk management derivatives	(1,713)	(1,015)
Risk Management Derivatives \| Fair Value Hedging \| Designated as Hedging Instrument
Asset Derivatives [Abstract]
Accrued interest receivable (payable)	1	0
Liability Derivatives [Abstract]
Accrued interest (receivable) payable	0	0
Mortgage commitments to purchase whole loans
Asset Derivatives [Abstract]
Notional amount	9,456	35,292
Derivative asset, estimated fair value	5	145
Liability Derivatives [Abstract]
Notional amount	22,709	51
Derivative liability, estimated fair value	(237)	0
Forward contracts to purchase mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	26,155	144,215
Derivative asset, estimated fair value	57	844
Liability Derivatives [Abstract]
Notional amount	145,335	607
Derivative liability, estimated fair value	(1,689)	0
Forward contracts to sell mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	220,063	199
Derivative asset, estimated fair value	2,534	0
Liability Derivatives [Abstract]
Notional amount	31,765	227,828
Derivative liability, estimated fair value	(46)	(1,426)
Mortgage commitment derivatives
Asset Derivatives [Abstract]
Notional amount	255,674	179,706
Derivative asset, estimated fair value	2,596	989
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	199,809	228,486
Derivative liability, estimated fair value	(1,972)	(1,426)
Netting adjustment	0	0
Other
Asset Derivatives [Abstract]
Notional amount	14,079	16,829
Derivative asset, estimated fair value	61	179
Liability Derivatives [Abstract]
Notional amount	10,410	11,368
Derivative liability, estimated fair value	(46)	(49)
Fair Value Hedging \| Designated as Hedging Instrument
Asset Derivatives [Abstract]
Notional amount	42,558	0
Derivative asset, estimated fair value	3	0
Liability Derivatives [Abstract]
Notional amount	75	0
Derivative liability, estimated fair value	(7)	0
Total risk management derivatives portfolio
Asset Derivatives [Abstract]
Notional amount	166,102	254,446
Total net risk management derivatives	15	57
Liability Derivatives [Abstract]
Notional amount	57,476	48,344
Total net risk management derivatives	$ (88)	$ (20)

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ 1,148	$ (1,365)
Net contractual interest expense on interest-rate swaps	6,742	5,347
Interest and Dividend Income, Operating	23,562	29,426
Long-term debt	(16,817)	(23,977)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	0	22
Hedged Asset, Fair Value Hedge	83,521
Hedged Liability, Fair Value Hedge	(55,345)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	1,182
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(36)
Interest and Fee Income, Loans and Leases	23,353	28,938
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(36)
Hedged Asset, Fair Value Hedge, Last-of-Layer, Cumulative Increase (Decrease)	55,819
Hedged Asset, Fair Value Hedge, Last-of-Layer, Amount	2,879
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	1,182
Pay-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	2,207	(4,029)
Receive-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(1,855)	3,343
Basis Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(46)	56
Foreign Currency Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(8)	(38)
Pay-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	107	(148)
Receive-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(239)	632
Future [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	1	(71)
Risk Management Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	156	(361)
Net contractual interest expense on interest-rate swaps	(11)	(106)
Mortgage commitment derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	1,082	(993)
Other
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(90)	$ (11)
Interestrateriskonheldforinvestmentmortgageloantrust \| Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(36)
Interestrateriskonheldforinvestmentmortgageloan \| Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	36
Interestrateriskondebt \| Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	1,195
Discontinued hedge related basis adjustment amortization	(13)
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(1,214)
Interest accruals on hedging instruments	$ 54

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended
Segment Reporting (Details) - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net interest income	$ 6,742	$ 5,347
Fee and other income	87	120
Net revenues	6,829	5,467
Investment gains, net	45	(158)
Fair value gains (losses), net	784	(276)
Administrative expenses	(748)	(749)
Benefit (provision) for credit losses	765	(2,583)
Foreclosed property income (expense)	5	(80)
Credit-related income (expense)	770	(2,663)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(731)	(637)
Credit enhancement expense	(284)	(376)
Change in expected credit enhancement recoveries	(31)	188
Other expenses, net	(319)	(218)
Income before federal income taxes	6,315	578
Provision for federal income taxes	(1,322)	(117)
Net income	4,993	461
US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(731)	(637)
Business Segments [Member] \| FNM_SingleFamily
Segment Reporting Information [Line Items]
Net interest income	5,894	4,541
Fee and other income	62	94
Net revenues	5,956	4,635
Investment gains, net	64	(152)
Fair value gains (losses), net	740	(460)
Administrative expenses	(623)	(629)
Benefit (provision) for credit losses	662	(2,172)
Foreclosed property income (expense)	17	(78)
Credit-related income (expense)	679	(2,250)
Credit enhancement expense	(226)	(316)
Change in expected credit enhancement recoveries	(16)	58
Other expenses, net	(287)	(163)
Income before federal income taxes	5,556	86
Provision for federal income taxes	(1,162)	(18)
Net income	4,394	68
Business Segments [Member] \| FNM_SingleFamily \| US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(731)	(637)
Business Segments [Member] \| fnm_MultifamilyMember
Segment Reporting Information [Line Items]
Net interest income	848	806
Fee and other income	25	26
Net revenues	873	832
Investment gains, net	(19)	(6)
Fair value gains (losses), net	44	184
Administrative expenses	(125)	(120)
Benefit (provision) for credit losses	103	(411)
Foreclosed property income (expense)	(12)	(2)
Credit-related income (expense)	91	(413)
Credit enhancement expense	(58)	(60)
Change in expected credit enhancement recoveries	(15)	130
Other expenses, net	(32)	(55)
Income before federal income taxes	759	492
Provision for federal income taxes	(160)	(99)
Net income	599	393
Business Segments [Member] \| fnm_MultifamilyMember \| US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	$ 0	$ 0

Concentrations of Credit Risk SF Risk Characteristics (Details) - Single-family [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Guaranty Book of Business [Member] \| Conventional Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	0.62%	0.88%
60 days delinquent (percentage of book of business)	0.24%	0.33%
Seriously delinquent (percentage of book of business)	2.72%	3.10%
30 days delinquent (percentage of conventional loans)	0.71%	1.02%
60 days delinquent (percentage of conventional loans)	0.26%	0.36%
Seriously delinquent (percentage of conventional loans)	2.58%	2.87%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| Estimated mark-to-market loan-to-value ratio greater than 100%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	21.81%	22.43%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| Alt-A
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	8.85%	9.32%
Percentage of Unpaid Principal Balance of Loans	1.00%	1.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| 2004 and prior
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	5.66%	5.88%
Percentage of Unpaid Principal Balance of Loans	2.00%	2.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| 2005-2008
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	9.65%	9.98%
Percentage of Unpaid Principal Balance of Loans	2.00%	2.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| 2009-2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.13%	2.39%
Percentage of Unpaid Principal Balance of Loans	96.00%	96.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.31%	2.62%
Percentage of Unpaid Principal Balance of Loans	19.00%	19.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	3.60%	4.17%
Percentage of Unpaid Principal Balance of Loans	6.00%	6.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| Illinois
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	3.02%	3.10%
Percentage of Unpaid Principal Balance of Loans	3.00%	3.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	4.04%	4.57%
Percentage of Unpaid Principal Balance of Loans	4.00%	3.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	4.34%	4.79%
Percentage of Unpaid Principal Balance of Loans	5.00%	5.00%
Guaranty Book of Business [Member] \| Conventional Loan [Member] \| All other states
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.34%	2.59%
Percentage of Unpaid Principal Balance of Loans	63.00%	64.00%
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	90 days	90 days

Concentrations of Credit Risk MF Risk Characteristics (Details) - Multifamily [Member]	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	60 days
Current debt service coverage ratio reporting lag	3 months
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	89 days
Current debt service coverage ratio (higher risk loans)	1.0
Current debt service coverage ratio reporting lag	6 months
Guaranty Book of Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	0.37%	0.29%
Seriously delinquent (percentage of book of business)	0.66%	0.98%
Guaranty Book of Business [Member] \| Original LTV ratio greater than 80% [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of book of business	1.00%	1.00%
Loans seriously delinquent, percentage by unpaid principal balance	0.86%	1.04%
Guaranty Book of Business [Member] \| Original LTV ratio less than or equal to 80% [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of book of business	99.00%	99.00%
Loans seriously delinquent, percentage by unpaid principal balance	0.66%	0.98%
Guaranty Book of Business [Member] \| Current DSCR below 1.0 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of book of business	2.00%	2.00%
Loans seriously delinquent, percentage by unpaid principal balance	18.51%	21.19%

Concentrations of Credit Risk Other Concentrations (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($) contracts	Dec. 31, 2020 USD ($)
Concentration Risk [Line Items]
Estimated benefit included in loss reserves	$ 1,200	$ 1,400
Receivable from claims on insured, defaulted loans excluding government insured loans	542	560
Allowance for mortgage insurance receivable	$ 480	497
nm_NumberOfMortgageInsurersPubliclyDisclosedCreditQualityDeterioration \| contracts	3
PMI Mortgage Insurance Company [Member]
Concentration Risk [Line Items]
Mortgage insurance coverage risk in force percentage to be paid in cash	77.50%
Mortgage insurance coverage risk in force percentage to be deferred	22.50%
Triad Guaranty Insurance Corporation 1 [Member]
Concentration Risk [Line Items]
Mortgage insurance coverage risk in force percentage to be paid in cash	75.00%
Mortgage insurance coverage risk in force percentage to be deferred	25.00%
Single-family [Member] \| Guaranty Book of Business [Member]
Concentration Risk [Line Items]
Primary mortgage insurance	$ 169,582	170,890
Pool mortgage insurance	285	291
Mortgage insurance coverage risk in force	$ 169,867	$ 171,181
Mortgage insurance coverage risk in force as percentage	5.00%	5.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Group of Largest Mortgage Servicers including Affiliates [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	45.00%	48.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Group of Largest Mortgage Servicers including Affiliates [Member] \| Non-Depository Servicer [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	23.00%	24.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Wells Fargo Bank N.A. [Member] \| Depository Servicer [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	12.00%	13.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Other Servicers [Member] \| Depository Servicer [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	10.00%	11.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	100.00%	100.00%
Mortgage insurance coverage risk in force for insurers with credit quality deterioration	$ 2,200
Percentage of Concentration Risk	1.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Arch Capital Group Ltd.
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	20.00%	21.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Mortgage Guaranty Insurance Corp.
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	18.00%	18.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Radian Guaranty, Inc.
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	18.00%	19.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Genworth Mortgage Insurance Corp.
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	17.00%	16.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Essent Guaranty, Inc.
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	16.00%	16.00%
Single-family [Member] \| Guaranty Book of Business [Member] \| Insurance Service Provider Concentration Risk [Member] \| Others
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	11.00%	10.00%
Multifamily [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Group of Largest Mortgage Servicers including Affiliates [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	48.00%	48.00%
Multifamily [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Wells Fargo Bank N.A. [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	13.00%	12.00%
Multifamily [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Walker & Dunlop, LLC [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	11.00%	12.00%
Multifamily [Member] \| Guaranty Book of Business [Member] \| Credit Concentration Risk [Member] \| Other Servicers [Member]
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	24.00%	24.00%

Netting Arrangements (Details) - USD ($) $ in Millions	3 Months Ended
Netting Arrangements (Details) - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Offsetting Assets [Line Items]
Fair Value of Securities Received as Collateral that Have Been Resold or Repledged	$ 0		$ 0
Derivative Liability, Not Subject to Master Netting Arrangement	46		49
Assets:
Derivative assets, gross amount	3,266		1,951
Derivative assets, gross amount offset	(655)		(905)
Derivative assets, net amount presented in our condensed consolidated balance sheets	2,611		1,046
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(801)		(406)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(85)		(53)
Derivative assets, net amount	1,725		587
Securities purchased under agreements to resell or similar arrangements, gross amount	66,437		46,644
Securities purchased under agreements to resell or similar arrangements, gross amount offset	0		0
Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement	66,437		46,644
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0		0
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(66,437)		(46,644)
Securities purchased under agreements to resell or similar arrangements, net amount	0		0
Total assets, gross amount	69,703		48,595
Total assets, gross amount offset	(655)		(905)
Total assets, net amount presented in our condensed consolidated balance sheets	69,048		47,690
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(801)		(406)
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(66,522)		(46,697)
Total assets, net amount	1,725		587
Liabilities:
Derivative liabilities, gross amount	(3,692)		(2,441)
Derivative liabilities, gross amount offset	1,632		995
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(2,060)		(1,446)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	801		406
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	173		1,019
Derivative liabilities, net amount	(1,086)		(21)
Total liabilities, gross amount	(3,692)		(2,441)
Total liabilities, gross amount offset	1,632		995
Total liabilities, net amount presented in our condensed consolidated balance sheets	(2,060)		(1,446)
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	801		406
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	173		1,019
Total liabilities, net amount	(1,086)		(21)
Fair value of non-cash collateral we pledged	4,700		4,700
Cash and Cash Equivalents [Member]
Liabilities:
Securities purchased under agreements to resell	6,100		18,400
Restricted Cash and Cash Equivalent
Liabilities:
Securities purchased under agreements to resell	5,400
Single-family [Member]
Liabilities:
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	307	$ 182
Risk Management Derivatives
Assets:
Derivative assets, gross amount offset	(655)		(905)
Liabilities:
Derivative liabilities, gross amount offset	1,632		995
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	2,596		989
Derivative assets, gross amount offset	0		0
Derivative assets, net amount presented in our condensed consolidated balance sheets	2,596		989
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(801)		(406)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(85)		(53)
Derivative assets, net amount	1,710		530
Liabilities:
Derivative liabilities, gross amount	(1,972)		(1,426)
Derivative liabilities, gross amount offset	0		0
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(1,972)		(1,426)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	801		406
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	159		1,017
Derivative liabilities, net amount	(1,012)		(3)
Over the Counter [Member] \| Risk Management Derivatives
Assets:
Derivative assets, gross amount	670		962
Derivative assets, gross amount offset	(661)		(952)
Derivative assets, net amount presented in our condensed consolidated balance sheets	9		10
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0		0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0		0
Derivative assets, net amount	9		10
Liabilities:
Derivative liabilities, gross amount	(1,720)		(1,015)
Derivative liabilities, gross amount offset	1,646		999
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(74)		(16)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0		0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0		0
Derivative liabilities, net amount	(74)		(16)
Exchange Cleared [Member] \| Risk Management Derivatives
Assets:
Derivative assets, gross amount	0		0
Derivative assets, gross amount offset	6		47
Derivative assets, net amount presented in our condensed consolidated balance sheets	6		47
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0		0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0		0
Derivative assets, net amount	6		47
Liabilities:
Derivative liabilities, gross amount	0		0
Derivative liabilities, gross amount offset	(14)		(4)
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(14)		(4)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0		0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	14		2
Derivative liabilities, net amount	$ 0		$ (2)

Netting Arrangements Narratives (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Fair value of non-cash collateral we pledged	$ 4,700	$ 4,700
Fair value of non-cash collateral received	66,500	46,600
Fair value of non-cash collateral received that can be resold or repledged	65,400	46,600
Fair value of securities received as collateral that have been resold or repledge	0	0
Derivative assets not subject to enforceable master netting arrangements	61	179
Derivative liabilities not subject to enforceable master netting arrangements	(46)	(49)
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Securities purchased under agreements to resell	$ 6,100	$ 18,400

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 6,048	$ 6,490
Other assets [Abstract]
Derivative assets, gross amount offset	(655)	(905)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(1,632)	(995)
Mortgage commitment derivatives
Other assets [Abstract]
Derivative assets, gross amount offset	0	0
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	0	0
Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,336	3,728
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	23,601	24,586
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	105,601	130,456
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Other assets [Abstract]
Derivatives assets at fair value	0	0
Total assets at fair value	208,442	227,635
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Total liabilities at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Trading securities	5,546	5,991
Available-for-sale securities	891	1,049
Mortgage loans held for investment, at fair value	3,549,337	3,512,672
Other assets [Abstract]
Derivatives assets at fair value	3,115	1,748
Total assets at fair value	3,639,408	3,578,668
Other liabilities [Abstract]
Derivative liabilities at fair value	3,692	2,441
Total liabilities at fair value	4,062,768	4,059,705
Significant Other Observable Inputs (Level 2) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	279,208	288,414
Significant Other Observable Inputs (Level 2) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,777,011	3,756,673
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	109	95
Available-for-sale securities	611	648
Mortgage loans held for investment, at fair value	245,916	255,556
Other assets [Abstract]
Derivatives assets at fair value	212	382
Total assets at fair value	252,213	262,442
Other liabilities [Abstract]
Derivative liabilities at fair value	46	49
Total liabilities at fair value	31,939	32,593
Significant Unobservable Inputs (Level 3) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	828	878
Significant Unobservable Inputs (Level 3) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	30,990	31,584
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Trading securities	111,256	136,542
Available-for-sale securities	1,502	1,697
Mortgage loans held for investment, at fair value	6,048	6,490
Other assets [Abstract]
Derivatives assets at fair value	2,672	1,225
Derivative assets, gross amount offset	(655)	(905)
Total assets at fair value	125,528	147,074
Liabilities [Abstract]
Long-term debt, fair value	26,937	28,314
Other liabilities [Abstract]
Derivative liabilities at fair value	2,106	1,495
Derivative liabilities, gross amount offset	(1,632)	(995)
Total liabilities at fair value	29,043	29,809
Cash and Cash Equivalents, Fair Value Disclosure	4,050	1,120
Recurring Fair Value Measurements [Member] \| Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	450	579
Other liabilities [Abstract]
Derivative liabilities at fair value	1,662	881
Recurring Fair Value Measurements [Member] \| Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	220	383
Other liabilities [Abstract]
Derivative liabilities at fair value	58	134
Recurring Fair Value Measurements [Member] \| Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	2,596	989
Other liabilities [Abstract]
Derivative liabilities at fair value	1,972	1,426
Recurring Fair Value Measurements [Member] \| Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	61	179
Other liabilities [Abstract]
Derivative liabilities at fair value	46	49
Recurring Fair Value Measurements [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,336	3,728
Recurring Fair Value Measurements [Member] \| Fannie Mae [Member] \| Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,336	3,728
Recurring Fair Value Measurements [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	23,601	24,586
Recurring Fair Value Measurements [Member] \| Fannie Mae [Member]
Assets [Abstract]
Trading securities	1,985	2,404
Available-for-sale securities	1,036	1,168
Recurring Fair Value Measurements [Member] \| Other agency [Member]
Assets [Abstract]
Trading securities	3,440	3,451
Available-for-sale securities	34	65
Recurring Fair Value Measurements [Member] \| Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	157	158
Available-for-sale securities	5	6
Recurring Fair Value Measurements [Member] \| Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	191	216
Recurring Fair Value Measurements [Member] \| Other [Member]
Assets [Abstract]
Available-for-sale securities	236	242
Recurring Fair Value Measurements [Member] \| U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	105,601	130,456
Recurring Fair Value Measurements [Member] \| Other securities [Member]
Assets [Abstract]
Trading securities	73	73
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	105,601	130,456
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Other assets [Abstract]
Derivatives assets at fair value	0	0
Total assets at fair value	109,651	131,576
Liabilities [Abstract]
Long-term debt, fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Total liabilities at fair value	0	0
Cash and Cash Equivalents, Fair Value Disclosure	4,050	1,120
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fannie Mae [Member] \| Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fannie Mae [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Other agency [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Other [Member]
Assets [Abstract]
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	105,601	130,456
Recurring Fair Value Measurements [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Other securities [Member]
Assets [Abstract]
Trading securities	0	0
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Trading securities	5,546	5,991
Available-for-sale securities	891	1,049
Mortgage loans held for investment, at fair value	5,228	5,629
Other assets [Abstract]
Derivatives assets at fair value	3,115	1,748
Total assets at fair value	14,780	14,417
Liabilities [Abstract]
Long-term debt, fair value	26,497	27,815
Other liabilities [Abstract]
Derivative liabilities at fair value	3,692	2,441
Total liabilities at fair value	30,189	30,256
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	299	376
Other liabilities [Abstract]
Derivative liabilities at fair value	1,662	881
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	220	383
Other liabilities [Abstract]
Derivative liabilities at fair value	58	134
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	2,596	989
Other liabilities [Abstract]
Derivative liabilities at fair value	1,972	1,426
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	2,954	3,312
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Fannie Mae [Member] \| Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	2,954	3,312
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	23,543	24,503
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Fannie Mae [Member]
Assets [Abstract]
Trading securities	1,876	2,310
Available-for-sale securities	847	973
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Other agency [Member]
Assets [Abstract]
Trading securities	3,440	3,450
Available-for-sale securities	34	65
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	157	158
Available-for-sale securities	4	4
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Other [Member]
Assets [Abstract]
Available-for-sale securities	6	7
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	0	0
Recurring Fair Value Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Other securities [Member]
Assets [Abstract]
Trading securities	73	73
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	109	195
Available-for-sale securities	611	648
Mortgage loans held for investment, at fair value	820	861
Other assets [Abstract]
Derivatives assets at fair value	212	382
Total assets at fair value	1,752	1,986
Liabilities [Abstract]
Long-term debt, fair value	440	499
Other liabilities [Abstract]
Derivative liabilities at fair value	46	49
Total liabilities at fair value	486	548
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	151	203
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	61	179
Other liabilities [Abstract]
Derivative liabilities at fair value	46	49
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	382	416
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Fannie Mae [Member] \| Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	382	416
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	58	83
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Fannie Mae [Member]
Assets [Abstract]
Trading securities	109	94
Available-for-sale securities	189	195
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other agency [Member]
Assets [Abstract]
Trading securities	0	1
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	1	2
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	191	216
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other [Member]
Assets [Abstract]
Available-for-sale securities	230	235
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other securities [Member]
Assets [Abstract]
Trading securities	$ 0	0
Recurring Fair Value Measurements [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Trading Securities
Assets [Abstract]
Trading securities		$ 95

Fair Value Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	$ 2	$ (10)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	95	46
Total gains (losses) (realized/unrealized) Included in Net Income	(1)	(9)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	0	0
Transfers out of Level 3	(8)	(12)
Transfers into Level 3	23	137
Ending Balance	109	162
Trading securities [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	2	(10)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	94	45
Total gains (losses) (realized/unrealized) Included in Net Income	(1)	(9)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	0	0
Transfers out of Level 3	(7)	(11)
Transfers into Level 3	23	43
Ending Balance	109	68
Trading securities [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1	1
Total gains (losses) (realized/unrealized) Included in Net Income	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	0	0
Transfers out of Level 3	(1)	(1)
Transfers into Level 3	0	0
Ending Balance	0	0
Trading securities [Member] \| Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	0
Total gains (losses) (realized/unrealized) Included in Net Income	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	0	0
Transfers out of Level 3	0	0
Transfers into Level 3	0	94
Ending Balance	0	94
Available-for-sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	648	792
Total gains (losses) (realized/unrealized) Included in Net Income	3	(14)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(2)	5
Purchases	0	342
Sales	0	(342)
Issues	0	0
Settlements	(38)	(29)
Transfers out of Level 3	0	0
Transfers into Level 3	0	14
Ending Balance	611	768
Available-for-sale Securities [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	195	171
Total gains (losses) (realized/unrealized) Included in Net Income	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(3)	4
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	(3)	(1)
Transfers out of Level 3	0	0
Transfers into Level 3	0	14
Ending Balance	189	188
Available-for-sale Securities [Member] \| Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2
Total gains (losses) (realized/unrealized) Included in Net Income	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(1)
Purchases	0
Sales	0
Issues	0
Settlements	0
Transfers out of Level 3	0
Transfers into Level 3	0
Ending Balance	1
Available-for-sale Securities [Member] \| Mortgage revenue bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	216	315
Total gains (losses) (realized/unrealized) Included in Net Income	0	(3)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(1)	2
Purchases	0	74
Sales	0	(74)
Issues	0	0
Settlements	(24)	(18)
Transfers out of Level 3	0	0
Transfers into Level 3	0	0
Ending Balance	191	296
Available-for-sale Securities [Member] \| Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	235	306
Total gains (losses) (realized/unrealized) Included in Net Income	3	(11)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	3	(1)
Purchases	0	268
Sales	0	(268)
Issues	0	0
Settlements	(11)	(10)
Transfers out of Level 3	0	0
Transfers into Level 3	0	0
Ending Balance	230	284
Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	9	(26)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	861	688
Total gains (losses) (realized/unrealized) Included in Net Income	8	(24)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	(47)	(29)
Transfers out of Level 3	(23)	(23)
Transfers into Level 3	21	26
Ending Balance	820	638
Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	(167)	44
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	333	162
Total gains (losses) (realized/unrealized) Included in Net Income	(132)	41
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Issues	0	0
Settlements	(35)	(4)
Transfers out of Level 3	0	18
Transfers into Level 3	0	0
Ending Balance	166	217
Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	34	(30)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(499)	(473)
Total gains (losses) (realized/unrealized) Included in Net Income	35	30
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	0
Settlements	4	3
Transfers out of Level 3	20	0
Transfers into Level 3	0	(15)
Ending Balance	(440)	(515)
Long-term debt [Member] \| Consolidated Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	0	4
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(83)	(75)
Total gains (losses) (realized/unrealized) Included in Net Income	(1)	(4)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	0
Settlements	4	3
Transfers out of Level 3	20	0
Transfers into Level 3	0	(15)
Ending Balance	(58)	(83)
Long-term debt [Member] \| Senior floating [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	34	(34)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(416)	(398)
Total gains (losses) (realized/unrealized) Included in Net Income	(34)	(34)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	0
Sales	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	0
Settlements	0	0
Transfers out of Level 3	0	0
Transfers into Level 3	0	0
Ending Balance	(382)	(432)
Other Comprehensive Income (Loss) [Member] \| Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Trading securities [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Trading securities [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Trading securities [Member] \| Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Available-for-sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	6
Other Comprehensive Income (Loss) [Member] \| Available-for-sale Securities [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	(2)	3
Other Comprehensive Income (Loss) [Member] \| Available-for-sale Securities [Member] \| Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0
Other Comprehensive Income (Loss) [Member] \| Available-for-sale Securities [Member] \| Mortgage revenue bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	4
Other Comprehensive Income (Loss) [Member] \| Available-for-sale Securities [Member] \| Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	2	(1)
Other Comprehensive Income (Loss) [Member] \| Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0
Other Comprehensive Income (Loss) [Member] \| Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	0	0
Other Comprehensive Income (Loss) [Member] \| Long-term debt [Member] \| Consolidated Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	0	0
Other Comprehensive Income (Loss) [Member] \| Long-term debt [Member] \| Senior floating [Member] \| Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	$ 0	$ 0

Fair Value Level 3 Valuation Inputs (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 2,611	$ 1,046
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	111,256	136,542
Available-for-sale securities	1,502	1,697
Assets, Fair Value Disclosure	125,528	147,074
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	105,601	130,456
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	208,442	227,635
Mortgage loans held-for-sale, at lower of cost or fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	105,601	130,456
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	109,651	131,576
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	5,546	5,991
Available-for-sale securities	891	1,049
Assets, Fair Value Disclosure	3,639,408	3,578,668
Mortgage loans held-for-sale, at lower of cost or fair value	3,511	116
Significant Other Observable Inputs (Level 2) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	5,546	5,991
Available-for-sale securities	891	1,049
Assets, Fair Value Disclosure	14,780	14,417
Significant Other Observable Inputs (Level 2) [Member] \| Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	672	25
Liabilities, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	109	95
Available-for-sale securities	611	648
Assets, Fair Value Disclosure	252,213	262,442
Mortgage loans held-for-sale, at lower of cost or fair value	5,122	5,502
Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	109	195
Available-for-sale securities	611	648
Derivatives	166	333
Assets, Fair Value Disclosure	1,752	1,986
Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	15	130
Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Dealer Mark [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	151	203
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	1,759	2,742
Mortgage loans held-for-sale, at lower of cost or fair value	606	1,087
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Nonrecurring [Member] \| Single Vendor Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	394	333
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Nonrecurring [Member] \| Consensus Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	212	754
Agency \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	189
Agency \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	109	95
Available-for-sale securities	96
Agency \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Consensus Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	93	97
Private-label and other mortgage securities [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	157	158
Available-for-sale securities	5	6
Private-label and other mortgage securities [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	0	0
Available-for-sale securities	0	0
Private-label and other mortgage securities [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	157	158
Available-for-sale securities	4	4
Private-label and other mortgage securities [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	0	0
Available-for-sale securities	1	2
Private-label and other mortgage securities [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities		2
Mortgage revenue bonds [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	191	216
Mortgage revenue bonds [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	0	0
Mortgage revenue bonds [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	0	0
Mortgage revenue bonds [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	191	216
Mortgage revenue bonds [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Single Vendor With Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	119	144
Mortgage revenue bonds [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities		98
Available-for-sale securities	72	72
Other [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	236	242
Other [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	0	0
Other [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	6	7
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	230	235
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	28	29
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 202	$ 206
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	3250.00%	32.00%
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Minimum [Member] \| Measurement Input, Default Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	405.0	4.250
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	18850.00%	315.30%
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Maximum [Member] \| Measurement Input, Default Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	406.0	4.430
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	7840.00%	0.934%
Other [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Discounted Cash Flow with Inputs [Member] \| Available-for-sale Securities [Member] \| Weighted Average [Member] \| Measurement Input, Default Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	405.5	4.342
Subprime \| Significant Unobservable Inputs (Level 3) [Member] \| Recurring Fair Value Measurements [Member] \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 1

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 6,048	$ 6,490
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	3,511	116
Mortgage loans held for investment, at fair value	3,549,337	3,512,672
Total assets at fair value	3,639,408	3,578,668
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	5,122	5,502
Mortgage loans held for investment, at fair value	245,916	255,556
Total assets at fair value	252,213	262,442
Fair Value, Nonrecurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	672	25
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	606	1,087
Total assets at fair value	1,759	2,742
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Single Vendor Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	394	333
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Consensus Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	212	754
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	171	261
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	10	11
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily \| Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	614	979
Acquired property, net	26	41
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily \| Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	16	35
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily \| Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	63	89
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| FNM_SingleFamily \| Walk Forwards [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	56	85
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| fnm_MultifamilyMember
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	363	390
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| fnm_MultifamilyMember \| Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	75	40
Acquired property, net	5	25
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| fnm_MultifamilyMember \| Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	122	125
Fair Value, Nonrecurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| fnm_MultifamilyMember \| Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 166	$ 225

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (655)	$ (905)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(1,632)	(995)
Mortgage loans held for investment, at fair value	6,048	6,490
Derivative assets, gross amount offset	(655)	(905)
Derivative liabilities, gross amount offset	(1,632)	(995)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	102,841	97,179
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	105,601	130,456
Available-for-sale securities	0	0
Mortgage loans held for sale	0	0
Mortgage loans held for investment, at fair value	0	0
Advances to lenders	0	0
Derivatives assets at fair value	0	0
Guaranty assets and buy-ups	0	0
Total financial assets	208,442	227,635
Financial liabilities [Abstract]
Derivative liabilities at fair value	0	0
Guaranty obligations	0	0
Total financial liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	11,500	18,444
Federal funds sold and securities purchased under agreements to resell or similar arrangements	54,937	28,200
Trading securities	5,546	5,991
Available-for-sale securities	891	1,049
Mortgage loans held for sale	3,511	116
Mortgage loans held for investment, at fair value	3,549,337	3,512,672
Advances to lenders	10,571	10,448
Derivatives assets at fair value	3,115	1,748
Guaranty assets and buy-ups	0	0
Total financial assets	3,639,408	3,578,668
Financial liabilities [Abstract]
Derivative liabilities at fair value	3,692	2,441
Guaranty obligations	0	0
Total financial liabilities	4,062,768	4,059,705
Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	0	0
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	109	95
Available-for-sale securities	611	648
Mortgage loans held for sale	5,122	5,502
Mortgage loans held for investment, at fair value	245,916	255,556
Advances to lenders	1	1
Derivatives assets at fair value	212	382
Guaranty assets and buy-ups	242	258
Total financial assets	252,213	262,442
Financial liabilities [Abstract]
Derivative liabilities at fair value	46	49
Guaranty obligations	75	82
Total financial liabilities	31,939	32,593
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	3,336	3,728
Fannie Mae [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	0	0
Fannie Mae [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial liabilities [Abstract]
Short-term debt	2,857	12,177
Long-term debt	279,208	288,414
Fannie Mae [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	828	878
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	23,601	24,586
Consolidated Trusts [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial liabilities [Abstract]
Long-term debt	0	0
Consolidated Trusts [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial liabilities [Abstract]
Long-term debt	3,777,011	3,756,673
Consolidated Trusts [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Long-term debt	30,990	31,584
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	114,341	115,623
Federal funds sold and securities purchased under agreements to resell or similar arrangements	54,937	28,200
Trading securities	111,256	136,542
Available-for-sale securities	1,502	1,697
Mortgage loans held for sale	7,824	5,197
Mortgage loans held for investment, at fair value	3,732,056	3,648,695
Advances to lenders	10,572	10,449
Derivatives assets at fair value	2,672	1,225
Guaranty assets and buy-ups	109	115
Total financial assets	4,035,269	3,947,743
Financial liabilities [Abstract]
Derivative liabilities at fair value	2,106	1,495
Guaranty obligations	120	127
Total financial liabilities	4,016,206	3,937,358
Carrying Value [Member] \| Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	2,857	12,173
Long-term debt	270,585	277,399
Carrying Value [Member] \| Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	3,740,538	3,646,164
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	114,341	115,623
Federal funds sold and securities purchased under agreements to resell or similar arrangements	54,937	28,200
Trading securities	111,256	136,542
Available-for-sale securities	1,502	1,697
Mortgage loans held for sale	8,633	5,618
Mortgage loans held for investment, at fair value	3,795,253	3,768,228
Advances to lenders	10,572	10,449
Derivatives assets at fair value	2,672	1,225
Guaranty assets and buy-ups	242	258
Total financial assets	4,099,408	4,067,840
Financial liabilities [Abstract]
Derivative liabilities at fair value	2,106	1,495
Guaranty obligations	75	82
Total financial liabilities	4,093,075	4,091,303
Estimated of Fair Value [Member] \| Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	2,857	12,177
Long-term debt	280,036	289,292
Estimated of Fair Value [Member] \| Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	$ 3,808,001	$ 3,788,257

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures [Line Items]
Document Period End Date	Mar. 31, 2021
Mortgage loans held for investment, at fair value	$ 6,048		$ 6,490
Difference between unpaid principal balance and the fair value of nonaccrual loans	9		8
Fair value of nonaccrual loans	144		139
Fair value of loans that are 90 days or more past due	228		257
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	$ 10		14
FNM_SingleFamily \| Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Serious delinquency, days past due	90 days
Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	$ 3,336		3,728
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	23,601		24,586
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	6,048		6,490
Loans, unpaid principal balance	5,618		6,046
Fair Value, Option, Changes in Fair Value, Gain (Loss)	25	$ 151
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	373	$ 262
Long-term debt [Member] \| Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	3,336		3,728
Long-term debt, unpaid principal balance	3,158		3,518
Long-term debt [Member] \| Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	23,601		24,586
Long-term debt, unpaid principal balance	$ 20,828		$ 21,408

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ (25)	$ (151)
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ (373)	$ (262)