Federal National Mortgage Association (FNMA) 10-Q 29 Oct 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 15, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
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	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents	$ 37,472	$ 21,184
Restricted Cash and Cash Equivalents	73,516	40,223
Federal funds sold and securities purchased under agreements to resell or similar arrangements	12,700	13,578
Investments in securities:
Debt Securities, Trading	142,472	48,123
Total fair value	1,895	2,404
Total investments in securities	144,367	50,527
Mortgage loans:
Loans held for sale, at lower of cost or fair value	8,312	6,773
Financing Receivable, before Allowance for Credit Loss	3,550,734	3,336,405
Allowance for loan losses	(11,703)	(9,016)
Total loans held for investment, net of allowance	3,539,031	3,327,389
Total mortgage loans	3,547,343	3,334,162
Advance to Lender	10,228	6,453
Deferred tax assets, net	12,808	11,910
Interest Receivable	(9,748)	(8,604)
Acquired property, net	1,462	2,366
Other assets	14,959	14,312
Total assets	3,864,603	3,503,319
Liabilities:
Accrued interest payable (includes $9,133 and $9,361, respectively, related to consolidated trusts)	9,982	10,228
Other Liabilities	14,124	11,097
Total liabilities	3,843,910	3,488,711
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	(112,680)	(118,776)
Accumulated other comprehensive income	120	131
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)	20,693	14,608
Total liabilities and equity	$ 3,864,603	$ 3,503,319
Senior preferred stock liquidation preference	137,976	131,178
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
Mortgage loans:
Interest Receivable	$ (569)
Fannie Mae [Member]
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	111,056	$ 94,911
Liabilities:
Debt (includes $3,986 and $5,687, respectively, of debt of Fannie Mae at fair value and $24,741 and $21,880, respectively, of debt of consolidated trusts, at fair value)	289,423	182,247
Consolidated Trusts [Member]
Assets:
Restricted Cash and Cash Equivalents	65,431	33,294
Investments in securities:
Debt Securities, Trading	850	896
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	3,439,678	3,241,494
Interest Receivable	(9,867)	(8,172)
Liabilities:
Accrued interest payable (includes $9,133 and $9,361, respectively, related to consolidated trusts)	9,133	9,361
Debt (includes $3,986 and $5,687, respectively, of debt of Fannie Mae at fair value and $24,741 and $21,880, respectively, of debt of consolidated trusts, at fair value)	3,530,381	3,285,139
Other Liabilities	$ 1,813	$ 376

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets:
Restricted Cash and Cash Equivalents	$ 73,516	$ 40,223
Investments in securities:
Investments in securities, pledged as collateral	6,237	3,037
Amortized cost of investments in securities	1,780	2,281
Allowance for credit losses	3
Mortgage loans:
Mortgage loans held for investment, at fair value	6,968	7,825
Interest Receivable	9,748	8,604
Liabilities:
Interest Payable	9,982	10,228
Other Liabilities	$ 14,124	$ 11,097
Fannie Mae stockholders’ equity:
Senior preferred stock liquidation preference	137,976,000,000	131,178,000,000
Preferred stock, 700,000,000 shares are authorized	700,000,000	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 $3,986 and $5,687, respectively, of debt of Fannie Mae at fair value and $24,741 and $21,880, respectively, of debt of consolidated trusts, at fair value)	$ 3,986	$ 5,687
Consolidated Trusts [Member]
Assets:
Restricted Cash and Cash Equivalents	65,431	33,294
Mortgage loans:
Interest Receivable	9,867	8,172
Liabilities:
Interest Payable	9,133	9,361
Debt (includes $3,986 and $5,687, respectively, of debt of Fannie Mae at fair value and $24,741 and $21,880, respectively, of debt of consolidated trusts, at fair value)	24,741	21,880
Other Liabilities	$ 1,813	$ 376

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Trading securities	$ 177	$ 418	$ 712	$ 1,277
Available-for-sale securities	19	40	76	138
Mortgage loans	25,810	29,072	81,755	88,445
Federal funds sold and securities purchased under agreements to resell or similar arrangements	14	178	135	698
Other	33	47	92	120
Total interest income	26,053	29,755	82,770	90,678
Interest expense:
Short-term debt	(19)	(125)	(175)	(369)
Long-term debt	(19,378)	(24,282)	(64,815)	(74,938)
Total interest expense	(19,397)	(24,407)	(64,990)	(75,307)
Net interest income	6,656	5,348	17,780	15,371
Benefit (provision) for credit losses	501	1,857	(2,094)	3,732
Net interest income after benefit (provision) for credit losses	7,157	7,205	15,686	19,103
Non-interest income (loss):
Investment gains, net	653	253	644	847
Fair value losses, net	(327)	(713)	(1,621)	(2,298)
Fee and other income	93	188	303	435
Non-interest income (loss)	419	(272)	(674)	(1,016)
Administrative expenses:
Salaries and employee benefits	(386)	(361)	(1,161)	(1,123)
Professional services	(230)	(241)	(673)	(699)
Other administrative expenses	(146)	(147)	(431)	(415)
Total administrative expenses	(762)	(749)	(2,265)	(2,237)
Foreclosed property expense	(71)	(96)	(161)	(364)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(679)	(613)	(1,976)	(1,806)
Credit enhancement expense	(325)	(290)	(1,061)	(782)
Change in expected credit enhancement recoveries	(48)	0	413	0
Other expenses, net	(313)	(186)	(792)	(551)
Total expenses	(2,198)	(1,934)	(5,842)	(5,740)
Income before federal income taxes	5,378	4,999	9,170	12,347
Provision for federal income taxes	(1,149)	(1,036)	(1,935)	(2,552)
Other comprehensive income (loss):
Changes in unrealized gains (losses) on available-for-sale securities, net of reclassification adjustments and taxes	(11)	16	(4)	(85)
Other, net of taxes	(2)	(2)	(7)	(7)
Total other comprehensive income (loss)	(13)	14	(11)	(92)
Total comprehensive income	4,216	3,977	7,224	9,703
Net income	4,229	3,963	7,235	9,795
Dividends distributed or amounts attributable to senior preferred stock	(4,216)	(3,977)	(7,224)	(9,703)
Net income (loss) attributable to common stockholders	$ 13	$ (14)	$ 11	$ 92
Earnings per share, Basic	$ 0	$ 0	$ 0	$ 0.02
Earnings per share, Diluted	$ 0	$ 0	$ 0	$ 0.02
Weighted-average common shares outstanding, Basic	5,867	5,762	5,867	5,762
Weighted-average common shares outstanding, Diluted	5,893	5,762	5,893	5,893

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Net cash provided by (used in) operating activities
Net cash provided by (used in) operating activities	$ (76,994)	$ 3,176
Cash flows provided by (used in) investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	35	46
Proceeds from sales of trading securities held for investment	44	49
Proceeds from maturities and paydowns of available-for-sale securities	275	364
Proceeds from sales of available-for-sale securities	258	376
Purchases of loans held for investment	(519,133)	(181,898)
Advances to lenders	(223,007)	(95,636)
Proceeds from disposition of acquired property and preforeclosure sales	4,694	5,644
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	878	9,762
Other, net	(576)	(74)
Net cash provided by investing activities	46,583	134,747
Cash flows provided by (used in) financing activities:
Payments of cash dividends on senior preferred stock to Treasury	0	(5,601)
Other, net	(461)	1,129
Net cash provided by (used in) financing activities	79,992	(122,848)
Net increase in cash, cash equivalents and restricted cash	49,581	15,075
Cash, cash equivalents and restricted cash at beginning of period	61,407	49,423
Cash, cash equivalents and restricted cash at end of period	110,988	64,498
Cash paid during the period for:
Interest	86,035	86,699
Income taxes	2,750	1,250
Fannie Mae [Member]
Cash flows provided by (used in) investing activities:
Proceeds from repayments of loans acquired as held for investment	7,711	9,338
Proceeds from sales of loans acquired as held for investment of Fannie Mae	4,422	8,987
Cash flows provided by (used in) financing activities:
Proceeds from issuance of debt	501,627	587,659
Payments to redeem debt	(394,187)	(606,665)
Consolidated Trusts [Member]
Cash flows provided by (used in) investing activities:
Proceeds from repayments of loans acquired as held for investment	770,982	377,789
Cash flows provided by (used in) financing activities:
Proceeds from issuance of debt	716,591	286,126
Payments to redeem debt	$ (743,578)	$ (385,496)

Condensed Consolidated Statem_3

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	Balance as of January 1, 2020, adjusted	Balance as of January 1, 2020, adjustedSenior Preferred Stock	Balance as of January 1, 2020, adjustedPreferred Stock	Balance as of January 1, 2020, adjustedCommon Stock	Balance as of January 1, 2020, adjustedAccumulated Deficit	Balance as of January 1, 2020, adjustedAccumulated Other Comprehensive Income	Balance as of January 1, 2020, adjustedTreasury Stock	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]Accumulated Deficit
Balance (shares) at Dec. 31, 2018		1	556	1,158
Balance at Dec. 31, 2018	$ 6,240	$ 120,836	$ 19,130	$ 687	$ (127,335)	$ 322	$ (7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Senior preferred stock dividends paid	(5,601)				(5,601)
Comprehensive income:
Net income	9,795				9,795
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $5 and $2, respectively)	27					27
Reclassification adjustment for gains included in net income (net of tax of $- and $12, respectively)	(112)					(112)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $1 and $1, respectively)	(7)					(7)
Total comprehensive income	9,703
Balance at Sep. 30, 2019	10,342	$ 120,836	$ 19,130	$ 687	(123,141)	230	(7,400)
Balance (shares) at Sep. 30, 2019		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	(7)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	30
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	2
Balance (shares) at Jun. 30, 2019		1	556	1,158
Balance at Jun. 30, 2019	6,365	$ 120,836	$ 19,130	$ 687	(127,104)	216	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Senior preferred stock dividends paid	0				0
Comprehensive income:
Net income	3,963				3,963
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $5 and $2, respectively)	10					10
Reclassification adjustment for gains included in net income (net of tax of $- and $12, respectively)	6					6
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $1 and $1, respectively)	(2)					(2)
Total comprehensive income	3,977
Balance at Sep. 30, 2019	10,342	$ 120,836	$ 19,130	$ 687	(123,141)	230	(7,400)
Balance (shares) at Sep. 30, 2019		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	(2)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(1)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	1
Accumulated deficit	(118,776)
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)	$ (1,139)	$ (1,139)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Senior preferred stock dividends paid	0				0
Comprehensive income:
Net income	7,235				7,235
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $5 and $2, respectively)	2					2
Reclassification adjustment for gains included in net income (net of tax of $- and $12, respectively)	(6)					(6)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $1 and $1, respectively)	(7)					(7)
Total comprehensive income	7,224
Balance at Sep. 30, 2020	20,693	$ 120,836	$ 19,130	$ 687	(112,680)	120	(7,400)
Balance (shares) at Sep. 30, 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	1
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(2)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	2
Balance (shares) at Jun. 30, 2020		1	556	1,158
Balance at Jun. 30, 2020	16,477	$ 120,836	$ 19,130	$ 687	(116,909)	133	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Senior preferred stock dividends paid	0				0
Comprehensive income:
Net income	4,229				4,229
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $5 and $2, respectively)	1					1
Reclassification adjustment for gains included in net income (net of tax of $- and $12, respectively)	(12)					(12)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax of $1 and $1, respectively)	(2)					(2)
Total comprehensive income	4,216
Balance at Sep. 30, 2020	20,693	$ 120,836	$ 19,130	$ 687	$ (112,680)	$ 120	$ (7,400)
Balance (shares) at Sep. 30, 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	0
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	$ (112,680)

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Deficit) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 0	$ (2)	$ 1	$ (7)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(3)	(1)	(2)	30
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	$ 1	$ 1	$ 2	$ 2

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies We are a stockholder-owned corporation organized and existing under the Federal National Mortgage Association Charter Act (the “Charter Act” or our “charter”). We are a government-sponsored enterprise (“GSE”), and 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, 2019 (“2019 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 and nine months ended September 30, 2020 and related notes, should be read in conjunction with our audited consolidated financial statements and related notes included in our 2019 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 and nine months ended September 30, 2020 may not necessarily be indicative of the results for the year ending December 31, 2020. Presentation of Advances to Lenders Advances to lenders represent our payments of cash in exchange for the receipt of mortgage loans from lenders in a transfer that is accounted for as a secured lending arrangement. These transfers primarily occur when we provide early funding to lenders for loans that they will subsequently either sell to us or securitize into a Fannie Mae MBS that they will deliver to us. Early lender funding advances have terms up to 60 days and earn a short-term market rate of interest. Advances to lenders has been presented as a separate line item for all periods presented as increased mortgage refinance activity resulted in a higher balance at period end. In prior periods, advances to lenders were recorded in “Other assets.” Presentation of Freestanding Credit Enhancement Expense and Recoveries Freestanding credit enhancements primarily include our Connecticut Avenue Securities ® (“CAS”) and Credit Insurance Risk Transfer TM (“CIRT TM ”) programs, enterprise-paid mortgage insurance (“EPMI”), and certain lender risk-sharing arrangements, including our multifamily Delegated Underwriting and Servicing (“DUS ® ”) program. We have revised our presentation of the expenses and recoveries associated with these programs as described below. Credit Enhancement Expense Credit enhancement expense consists of costs associated with our freestanding credit enhancements. We exclude from this expense costs related to our CAS transactions accounted for as debt instruments and credit risk transfer programs accounted for as derivative instruments. Credit enhancement expense has been presented as a separate line item for all periods presented as these expenses have become a more significant driver of our results of operations. In prior periods, credit enhancement expenses were recorded in “Other expenses, net.” Change in Expected Credit Enhancement Recoveries Change in expected credit enhancement recoveries consists of the change in benefits recognized from our freestanding credit enhancements, including any realized amounts. Benefits, if any, from our CAS, CIRT and EPMI programs previously recorded in “Fee and other income” have been reclassified to “Change in expected credit enhancement recoveries” for all periods presented. Benefits from other lender risk-sharing programs, including our multifamily DUS program, were recorded as a reduction of credit-related expense in periods prior to 2020. However, with our adoption of the CECL standard on January 1, 2020, benefits from freestanding credit enhancements are no longer recorded as a reduction of credit-related expenses. These benefits from lender risk-sharing have been reclassified into “Change in expected credit enhancement recoveries” on a prospective basis beginning January 1, 2020. Presentation of Yield Maintenance Fees Prior period multifamily yield maintenance fees have been reclassified to conform to the current period presentation. Multifamily yield maintenance fees, or prepayment premiums, are fees that a borrower pays when they prepay their loan. For multifamily loans held in a consolidated trust, a portion of the yield maintenance fee is typically passed through to the holders of the trust certificate. As of January 1, 2020, we classify all yield maintenance fees as interest income. For consolidated loans, the portion of the fee passed through to the certificate holders of the trust is classified as interest expense. Previously, we classified multifamily yield maintenance fees as interest income only when the fee was associated with a loan refinancing, otherwise the fee was classified as fee and other income. The portion of the fees passed through to the certificate holders of the trust were previously classified as interest expense only when the fee was associated with a loan refinancing, otherwise the fee was classified as other expense. The changes in presentation have been applied retrospectively to all periods presented and were immaterial for prior periods. 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, 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 September 30, 2020. Actual results could differ 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 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. On September 5, 2019, Treasury released a plan to reform the housing finance system. The Treasury Housing Reform Plan (the “Treasury plan”) is far-reaching in scope and could have a significant impact on our structure, our role in the secondary mortgage market, our capitalization, our business and our competitive environment. The Treasury plan includes recommendations relating to ending our conservatorship, amending our senior preferred stock purchase agreement with Treasury, considering additional restrictions and requirements on our business, and many other matters. The Treasury plan recommends that Treasury’s commitment to provide funding under the senior preferred stock purchase agreement should be replaced with legislation that authorizes an explicit, paid-for guarantee backed by the full faith and credit of the Federal Government that is limited to the timely payment of principal and interest on qualifying MBS. The Treasury plan further recommends that, pending legislation, even after conservatorship Treasury should maintain its ongoing commitment to support our single-family and multifamily mortgage-backed securities through the senior preferred stock purchase agreement, as amended as contemplated by the plan. 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 Senior Preferred Stock Purchase Agreement and 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 September 30, 2020, and the amount of remaining funding available to us under the agreement was $113.9 billion. Pursuant to the senior preferred stock purchase agreement, we issued shares of senior preferred stock in 2008. The current dividend provisions of the senior preferred stock provide for quarterly dividends consisting of the amount, if any, by which our net worth as of the end of the immediately preceding fiscal quarter exceeds a $25 billion capital reserve amount. We refer to this as a “net worth sweep” dividend. Because we had a net worth of $16.5 billion as of June 30, 2020, no dividends were payable for the third quarter of 2020. And because we had a net worth of $20.7 billion as of September 30, 2020, no dividends are payable for the fourth quarter of 2020. The aggregate liquidation preference of the senior preferred stock increased from $135.4 billion as of June 30, 2020 to $138.0 billion as of September 30, 2020 due to the $2.5 billion increase in our net worth during the second quarter of 2020. The aggregate liquidation preference of the senior preferred stock will increase to $142.2 billion as of December 31, 2020 due to the $4.2 billion increase in our net worth during the third quarter of 2020. See “Note 11, Equity” in our 2019 Form 10-K for additional information about the senior preferred stock purchase agreement and the senior preferred stock. Regulatory Capital We submit capital reports to FHFA, which monitors our capital levels. The deficit of core capital over statutory minimum capital was $128.1 billion as of September 30, 2020 and $128.8 billion as of December 31, 2019. 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 September 30, 2020, Treasury held an investment in our senior preferred stock with an aggregate liquidation preference of $138.0 billion. See “Senior Preferred Stock Purchase Agreement and Senior Preferred Stock” above for additional information on transactions under this 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 such, 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. With our implementation of the Single Security Initiative in June 2019, some of the structured securities we issue are backed in whole or in part by Freddie Mac 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 $5 million for the three months ended September 30, 2020 and 2019, and $14 million and $15 million for the nine months ended September 30, 2020 and 2019, 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. The resulting fee revenue and expense are recorded in “Mortgage loans interest income” 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 $679 million and $613 million in TCCA fees during the three months ended September 30, 2020 and 2019, respectively, and $2.0 billion and $1.8 billion for the nine months ended September 30, 2020 and 2019, respectively, of which $679 million had not been remitted to Treasury as of September 30, 2020. 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, are 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 a total of $59 million and $32 million in “Other expenses, net” for the three months ended September 30, 2020 and 2019, respectively, and $144 million and $68 million for the nine months ended September 30, 2020 and 2019, respectively, in connection with Treasury’s Capital Magnet Fund, of which $144 million has not been remitted as of September 30, 2020. 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 $35 million and $30 million for the three months ended September 30, 2020 and 2019, respectively, and $102 million and $89 million for the nine months ended September 30, 2020 and 2019, respectively. Transactions with CSS and Freddie Mac We contributed capital to CSS, the company we jointly own with Freddie Mac, of $19 million and $22 million for the three months ended September 30, 2020 and 2019, respectively, and $67 million and $84 million for the nine months ended September 30, 2020 and 2019, respectively. Principles of Consolidation Our condensed consolidated financial statements include our accounts as well as the accounts of the other entities in which we have a controlling financial interest. All intercompany balances and transactions have been eliminated. The typical condition for a controlling financial interest is ownership of a majority of the voting interests of an entity. A controlling financial interest may also exist in entities through arrangements that do not involve voting interests, such as a variable interest entity (“VIE”). Investments in Securities Impairment of Available-for-Sale Debt Securities An available-for-sale (“AFS”) debt security is impaired if the fair value of the investment is less than its amortized cost basis. Credit losses (benefits) on impaired AFS debt securities are recognized through an allowance for credit losses. Credit losses are evaluated on an individual security basis and are limited to the difference between the fair value of the debt security and its amortized cost basis. If we intend to sell a debt security or it is more likely than not that we will be required to sell the debt security before recovery, any allowance for credit losses on the debt security is reversed and the amortized cost basis of the debt security is written down to its fair value. Mortgage Loans Loans Held for Sale When we acquire mortgage loans that we intend to sell or securitize via trusts that will not be consolidated, we classify the loans as held for sale (“HFS”). We report the carrying value of HFS loans at the lower of cost or fair value. Any excess of an HFS loan’s cost over its fair value is recognized as a valuation allowance, with changes in the valuation allowance recognized as “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. We recognize interest income on HFS loans on an accrual basis, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. Purchased premiums, discounts and other cost basis adjustments on HFS loans are deferred upon loan acquisition, included in the cost basis of the loan, and not amortized. We determine any lower of cost or fair value adjustment on HFS loans at an individual loan level. For nonperforming loans transferred from held for investment (“HFI”) to HFS, based upon a change in our intent, we record the loans at the lower of cost or fair value on the date of transfer. When the fair value of the nonperforming loan is less than its amortized cost, we record a write-off against the allowance for loan losses in an amount equal to the difference between the amortized cost basis and the fair value of the loan. If the amount written off upon transfer exceeds the allowance related to the transferred loan, we record the excess in provision for credit losses. If the amounts written off are less than the allowance related to the loans, we recognize a benefit for credit losses. Nonperforming loans include both seriously delinquent and reperforming loans, which are loans that were previously delinquent but are performing again because payments on the mortgage loan have become current with or without the use of a loan modification plan. 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. In the event that we reclassify a performing loan from HFI to HFS, based upon a change in our intent, the allowance for loan losses previously recorded on the HFI mortgage loan is reversed through earnings at the time of reclassification. The mortgage loan is reclassified into HFS at its amortized cost basis and a valuation allowance is established to the extent that the amortized cost basis of the loan exceeds its fair value. The initial recognition of the valuation allowance and any subsequent changes are recorded as a gain or loss in “Investment gains, net.” Loans Held for Investment When we acquire mortgage loans that we have the ability and the intent to hold for the foreseeable future or until maturity, we classify the loans as HFI. When we consolidate a securitization trust, we recognize the loans underlying the trust in our condensed consolidated balance sheets. The trusts do not have the ability to sell mortgage loans and the use of such loans is limited exclusively to the settlement of obligations of the trusts. Therefore, mortgage loans acquired when we have the intent to securitize via consolidated trusts are generally classified as HFI in our condensed consolidated balance sheets both prior to and subsequent to their securitization. We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and allowance for loan losses. We define the amortized cost of HFI loans as unpaid principal balance and accrued interest receivable, net, including any unamortized premiums, discounts, and other cost basis adjustments. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable separately from the amortized cost of our loans held for investment. We recognize interest income on HFI loans on an accrual basis using the effective yield method over the contractual life of the loan, including the amortization of any deferred cost basis adjustments, such as the premium or discount at acquisition, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. Nonaccrual Loans F or loans that were current as of March 1, 2020 and subsequently became delinquent or entered into forbearance during the COVID-19 pandemic, see the changes to our application of our nonaccrual guidance in the section on New Accounting Guidance below. For loans not subject to the COVID-19-related nonaccrual guidance, we discontinue accruing interest on loans when we believe collectability of principal or 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 loans is reversed through interest income at the date a 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 that the borrower brings the loan current. We return a modified single-family loan to accrual status at the point that the borrower successfully makes all required payments during the trial period (generally three to four months) and the modification is made permanent. As of January 1, 2020, 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. Transactions related to the multifamily nonaccrual policy have been immaterial historically. 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. Allowance for Loan Losses Our allowance for loan losses is a valuation account that is deducted from the amortized cost basis of HFI loans to present the net amount expected to be collected on the loans. The allowance for loan losses reflects an estimate of expected credit losses on single-family and multifamily HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts. Estimates of credit losses are based on expected cash flows derived from internal models that estimate loan performance under simulated ranges of economic environments. Our modeled loan performance is based on our historical experience of loans with similar risk characteristics adjusted to reflect current conditions and reasonable and supportable forecasts. Our historical loss experience and our credit loss estimates capture the possibility of remote events that could result in credit losses on loans that are considered low risk. The allowance for loan losses does not consider benefits from freestanding credit enhancements, such as our CAS and CIRT programs and multifamily DUS lender risk-sharing arrangements, which are recorded in “Other assets” in our condensed consolidated balance sheets. For loans that were current as of March 1, 2020 and subsequently became delinquent or entered into forbearance during the COVID-19 pandemic, see changes to our allowance for loan losses in the section on New Accounting Guidance below. For loans not subject to the COVID-19 related guidance, we have elected not to measure an allowance for credit losses on accrued interest receivable balances as we have a nonaccrual policy to ensure the timely reversal of unpaid accrued interest. See “Note 4, Allowance for Loan Losses” for additional information about our current period provision for loan losses, including a discussion of the estimates used in measuring the impact of the COVID-19 pandemic on our allowance. Changes to our estimate of expected credit losses, including changes due to the passage of time, are recorded through the benefit (provision) for credit losses. When calculating our allowance for loan losses, we consider only our amortized cost in the loans at the balance sheet date. We record write-offs as a reduction to the allowance for loan losses when losses are confirmed through the receipt of assets in satisfaction of a loan, such as the underlying collateral upon foreclosure or cash upon completion of a short sale. Additionally, we record write-offs as a reduction to our allowance for loan losses when a loan is determined to be uncollectible and upon the transfer of a nonperforming loan from HFI to HFS. We include expected recoveries of amounts previously written off and expected to be written off in determining our allowance for loan losses. Single-Family Loans We estimate the amount expected to be collected on our single-family loans using a discounted cash flow approach. Our allowance for loan losses is calculated as the difference between the amortized cost basis of the loan and the present value of expected cash flows on the loan. Expected cash flows include payments from the borrower, net of servicing fees, contractually attached credit enhancements and proceeds from the sale of the underlying collateral, net of selling costs. When foreclosure of a single-family loan is probable, the allowance for loan losses is calculated as the difference between the amortized cost basis of the loan and the fair value of the collateral as of the reporting date, adjusted for the estimated costs to sell the property and the amount of expected recoveries from contractually attached credit enhancements or other proceeds we expect to receive. Expected cash flows are developed using internal models that capture market and loan characteristic inputs. Market inputs include information such as actual and forecasted home prices, interest rates, volatility, and spreads, while loan characteristic inputs include information such as mark-to-market loan-to-value (“LTV”) ratios, delinquency status, geography, and borrower FICO credit scores. The model assigns a probability to borrower events including contractual payment, loan payoff and default under various economic environments based on historical data, current conditions, and reasonable and supportable forecasts. The two primary drivers of our forecasted economic environments are interest rates and home prices. Our model projects the range of possible interest rate scenarios over the life of the loan based on actual interest rates and observed option pricing volatility in the capital markets. We develop regional forecasts based on Metropolitan Statistical Area data for single-family home prices using a multi-path simulation that captures home price projections over a five-year period, the period for which we can develop reasonable and supportable forecasts. After the five-year period, the home price forecast immediately reverts to a historical long-term growth rate. Expected cash flows on the loan are discounted at the effective interest rate on the loan, adjusted for expected prepayments. For single-family loans that have not been modified in a troubled debt restructuring (“TDR”), the discount rate is updated each reporting period to reflect changes in expected prepayments. Expected cash flows do not include expected extensions of the contractual term unless such extension is the result of a reasonably expected TDR. We consider the effects of actual and reasonably expected TDRs in our estimate of credit losses. These effects include any economic concession provided or expected to be provided to a borrower experiencing financial difficulty. We consider our current servicing practices and our historical experience to estimate reasonably expected TDRs. When a loan is contractually modified in a TDR, to capture the concession, the discount rate on the loan is locked to the rate in effect just prior to the modification and is no longer updated for changes in expected prepayments. Multifamily Loans Our allowance for loan losses on multifamily loans is calculated based on estimated probabilities of default and loss severities to derive expected loss ratios, which are then applied to the amortized cost basis of the loans. Our probabilities of default and severity are estimated using internal models based on historical loss experience of loans with similar risk characteristics that affect credit performance, such as debt service coverage ratio (“DSCR”), mark-to-market LTV ratio, collateral type, age, loan size, geo

Consolidations and Transfers of

Consolidations and Transfers of Financial Assets	9 Months Ended
	Sep. 30, 2020
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 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 September 30, 2020 December 31, 2019 (Dollars in millions) Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts: Assets: Trading securities: Fannie Mae $ 1,900 $ 2,543 Non-Fannie Mae 3,676 5,100 Total trading securities 5,576 7,643 Available-for-sale securities: Fannie Mae 1,284 1,524 Non-Fannie Mae 361 574 Total available-for-sale securities 1,645 2,098 Other assets 42 56 Other liabilities (68) (78) Net carrying amount $ 7,195 $ 9,719 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 was approximately $127 billion and $62 billion as of September 30, 2020 and December 31, 2019, respectively. Our total exposure to Freddie Mac securities backing Fannie Mae-issued REMICs disclosed as of December 31, 2019 may have been lower because a portion of the Freddie Mac securities backing these Fannie Mae-issued REMICS may have been backed by Fannie Mae MBS. To the extent that these Freddie Mac securities are backed by Fannie Mae MBS, our guarantee to the resecuritization trust does not subject us to any additional exposure to credit risk. The total assets of our unconsolidated securitization and resecuritization trusts were approximately $190 billion and $130 billion as of September 30, 2020 and December 31, 2019, 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 $107 million and the related net carrying value was $99 million as of September 30, 2020. As of December 31, 2019, the maximum exposure to loss was $98 million and the related net carrying value was $79 million. The total assets of these limited partnership investments were $2.3 billion as of September 30, 2020 and $2.0 billion as of December 31, 2019. 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 CAS and Multifamily Connecticut Avenue Securities (“MCAS”) SPVs. The maximum exposure to loss related to these unconsolidated SPVs was $10.1 billion and $9.5 billion as of September 30, 2020 and December 31, 2019, respectively. The total assets related to these unconsolidated SPVs were $10.1 billion and $9.5 billion as of September 30, 2020 and December 31, 2019, respectively. 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 September 30, 2020 and 2019, the unpaid principal balance of portfolio securitizations was $213.0 billion and $89.0 billion, respectively. For the nine months ended September 30, 2020 and 2019, the unpaid principal balance of portfolio securitizations was $504.9 billion and $187.7 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 September 30, 2020, the unpaid principal balance of retained interests was $2.0 billion and its related fair value was $3.3 billion. As of December 31, 2019, the unpaid principal balance of retained interests was $2.9 billion and its related fair value was $4.0 billion. For the three months ended September 30, 2020 and 2019, the principal, interest and other fees received on retained interests was $166 million and $187 million, respectively. For the nine months ended September 30, 2020 and 2019, the principal, interest and other fees received on retained interests was $517 million and $425 million, respectively. Qualifying Sales of Portfolio Securitizations We consolidate the substantial majority of our single-class MBS trusts; therefore, these portfolio securitization transactions do not qualify for sale treatment. The assets and liabilities of consolidated trusts created via portfolio securitization transactions that do not qualify as sales are reported in our consolidated balance sheets. We recognize assets obtained and liabilities incurred in qualifying sales of portfolio securitizations at fair value. Proceeds from the initial sale of securities from portfolio securitizations were $416 million and $538 million for three and nine months ended September 30, 2020, respectively. There were no proceeds from the initial sale of securities from portfolio securitizations for three and nine months ended September 30, 2019. Our continuing involvement in the form of guaranty assets and guaranty liabilities with assets that were transferred into unconsolidated trusts is not material to our consolidated financial statements.

Mortgage Loans

Mortgage Loans	9 Months Ended
	Sep. 30, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Mortgage Loans	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 HFI or 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, other cost basis adjustments, and accrued interest receivable, net. For purposes of our condensed consolidated balance sheet, 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, net” in our condensed consolidated statements of operations and comprehensive income. For purposes of the single-family mortgage loan disclosures below, we display loans by class of financing receivable type. In the current period, we revised the financing receivable classes used for disclosure to 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. We believe the revised classifications are more aligned with how we assess and manage the credit risk of our loans. We have revised the presentation of certain loan disclosures for prior periods to conform with the revised current period classes of financing receivables. The following table displays the carrying value of mortgage loans and our allowance for loan losses. As of September 30, 2020 December 31, 2019 (Dollars in millions) Single-family $ 3,137,726 $ 2,972,361 Multifamily 355,950 327,593 Total unpaid principal balance of mortgage loans 3,493,676 3,299,954 Cost basis and fair value adjustments, net 65,370 43,224 Allowance for loan losses (11,703) (9,016) Total mortgage loans (1) $ 3,547,343 $ 3,334,162 (1) Excludes $9.6 billion and $8.4 billion of accrued interest receivable, net of allowance on mortgage loans as of September 30, 2020 and December 31, 2019, 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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Single family loans redesignated from HFI to HFS: Amortized cost $ 5,305 $ 5,154 $ 6,942 $ 15,287 Lower of cost or fair value adjustment at time of redesignation (1) (227) (227) (236) (946) Allowance reversed at time of redesignation 737 780 921 2,149 Single-family loans sold: Unpaid principal balance $ 4,593 $ 3,941 $ 5,088 $ 10,497 Realized gains, net 424 184 464 504 (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 $6.0 billion and $7.6 billion as of September 30, 2020 and December 31, 2019, 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 December 31, 2020, 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. The increase in loans classified as delinquent as of September 30, 2020 compared with December 31, 2019 was primarily attributable to the economic dislocation caused by the COVID-19 pandemic. As of September 30, 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 $ 27,339 $ 13,584 $ 99,491 $ 140,414 $ 2,529,879 $ 2,670,293 $ 81,405 $ 7,156 15-year or less, amortizing fixed-rate 2,084 965 6,170 9,219 420,848 430,067 5,533 393 Adjustable-rate 309 172 1,363 1,844 33,461 35,305 1,160 135 Other (2) 1,267 606 5,355 7,228 51,276 58,504 3,271 785 Total single-family 30,999 15,327 112,379 158,705 3,035,464 3,194,169 91,369 8,469 Multifamily (3) 512 N/A 4,074 4,586 355,131 359,717 3,729 44 Total $ 31,511 $ 15,327 $ 116,453 $ 163,291 $ 3,390,595 $ 3,553,886 $ 95,098 $ 8,513 As of December 31, 2019 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Loans 90 Days or More Delinquent and Accruing Interest (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate $ 26,882 $ 7,126 $ 13,082 $ 47,090 $ 2,470,457 $ 2,517,547 $ 28 15-year or less, amortizing fixed-rate 1,616 286 445 2,347 371,740 374,087 — Adjustable-rate 412 85 167 664 44,244 44,908 — Other (2) 2,323 829 1,891 5,043 64,726 69,769 136 Total single-family 31,233 8,326 15,585 55,144 2,951,167 3,006,311 164 Multifamily (3) 7 N/A 115 122 330,496 330,618 — Total $ 31,240 $ 8,326 $ 15,700 $ 55,266 $ 3,281,663 $ 3,336,929 $ 164 (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 table displays 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 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 September 30, 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% $ 533,538 $ 261,595 $ 148,609 $ 210,619 $ 255,376 $ 868,596 $ 2,278,333 Greater than 80% and less than or equal to 90% 105,147 105,917 40,296 11,281 2,789 7,711 273,141 Greater than 90% and less than or equal to 100% 94,975 16,605 1,542 432 171 2,603 116,328 Greater than 100% 17 21 41 101 103 2,208 2,491 Total 20 and 30-year or more, amortizing fixed-rate 733,677 384,138 190,488 222,433 258,439 881,118 2,670,293 15-year or less, amortizing fixed-rate: Less than or equal to 80% 124,783 46,988 18,095 35,192 50,610 146,127 421,795 Greater than 80% and less than or equal to 90% 5,020 1,627 100 18 11 25 6,801 Greater than 90% and less than or equal to 100% 1,379 38 4 5 3 12 1,441 Greater than 100% — — 4 6 4 16 30 Total 15-year or less, amortizing fixed-rate 131,182 48,653 18,203 35,221 50,628 146,180 430,067 Adjustable-rate: Less than or equal to 80% 2,542 2,102 2,853 5,696 3,169 18,138 34,500 Greater than 80% and less than or equal to 90% 233 233 179 42 4 18 709 Greater than 90% and less than or equal to 100% 72 16 2 2 — 3 95 Greater than 100% — — — — — 1 1 Total adjustable-rate 2,847 2,351 3,034 5,740 3,173 18,160 35,305 Other: Less than or equal to 80% — 42 341 839 1,076 37,973 40,271 Greater than 80% and less than or equal to 90% — 3 25 54 37 1,590 1,709 Greater than 90% and less than or equal to 100% — 1 11 22 16 736 786 Greater than 100% — 1 5 11 11 782 810 Total other — 47 382 926 1,140 41,081 43,576 Total $ 867,706 $ 435,189 $ 212,107 $ 264,320 $ 313,380 $ 1,086,539 $ 3,179,241 Total for all classes by LTV ratio: (2) Less than or equal to 80% $ 660,863 $ 310,727 $ 169,898 $ 252,346 $ 310,231 $ 1,070,834 $ 2,774,899 Greater than 80% and less than or equal to 90% 110,400 107,780 40,600 11,395 2,841 9,344 282,360 Greater than 90% and less than or equal to 100% 96,426 16,660 1,559 461 190 3,354 118,650 Greater than 100% 17 22 50 118 118 3,007 3,332 Total $ 867,706 $ 435,189 $ 212,107 $ 264,320 $ 313,380 $ 1,086,539 $ 3,179,241 As of December 31, 2019 (1) 20- and 30-Year or More, Amortizing Fixed-Rate 15-Year or Less, Amortizing Fixed-Rate Adjustable-Rate Other Total (Dollars in millions) Estimated mark-to-market LTV ratio: (2) Less than or equal to 80% $ 2,145,018 $ 368,181 $ 43,415 $ 47,005 $ 2,603,619 Greater than 80% and less than or equal to 90% 237,623 4,556 1,275 2,872 246,326 Greater than 90% and less than or equal to 100% 130,152 1,284 215 1,398 133,049 Greater than 100% 4,754 66 3 1,365 6,188 Total $ 2,517,547 $ 374,087 $ 44,908 $ 52,640 $ 2,989,182 (1) Excludes $14.9 billion and $17.1 billion as of September 30, 2020 and December 31, 2019, 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 table displays the total amortized cost of 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 September 30, 2020, by Year of Origination 2020 2019 2018 2017 2016 Prior Total (Dollars in millions) Internally assigned credit risk rating: Non-classified (1) $ 45,240 $ 68,698 $ 62,601 $ 51,824 $ 44,804 $ 76,825 $ 349,992 Classified (2) 8 848 1,448 2,559 1,489 3,373 9,725 Total $ 45,248 $ 69,546 $ 64,049 $ 54,383 $ 46,293 $ 80,198 $ 359,717 As of December 31, 2019 (Dollars in millions) Internally assigned credit risk rating: Non-classified (1) $ 323,773 Classified (2) 6,845 Total $ 330,618 (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. We had no loans classified as doubtful as of September 30, 2020 and loans with an amortized cost of $5 million classified as doubtful as of December 31, 2019. 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 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. See “Note 1, Summary of Significant Accounting Policies” for more information on the impact of the CARES Act. The substantial majority of the loan modifications accounted for as a TDR result in term extensions, interest rate reductions or a combination of both. The average term extension of a single-family modified loan was 159 months and 164 months for the three months ended September 30, 2020 and 2019, respectively. The average interest rate reduction was 0.42 and 0.15 percentage points, for the three months ended September 30, 2020 and 2019, respectively. During the nine months ended September 30, 2020 and 2019, the average term extension of a single-family modified loan was 166 months and 160 months, respectively, and the average interest rate reduction was 0.35 and 0.11 percentage points, respectively. The following tables display the number of loans and amortized cost in loans classified as a TDR. For the Three Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 5,993 $ 1,006 10,113 $ 1,694 15-year or less, amortizing fixed-rate 579 50 1,078 97 Adjustable-rate 109 16 182 28 Other 371 47 648 87 Total single-family 7,052 1,119 12,021 1,906 Multifamily — — 3 4 Total TDRs 7,052 $ 1,119 12,024 $ 1,910 For the Nine Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 25,360 $ 4,412 31,960 $ 5,226 15-year or less, amortizing fixed-rate 2,448 216 3,554 317 Adjustable-rate 395 62 612 91 Other 1,464 185 2,383 323 Total single-family 29,667 4,875 38,509 5,957 Multifamily — — 9 37 Total TDRs 29,667 $ 4,875 38,518 $ 5,994 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 September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 2,956 $ 532 3,582 $ 567 15-year or less, amortizing fixed-rate 21 1 164 12 Adjustable-rate 3 — 34 5 Other 219 35 422 62 Total single-family 3,199 568 4,202 646 Multifamily — — 1 13 Total TDRs that subsequently defaulted 3,199 $ 568 4,203 $ 659 For the Nine Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 11,529 $ 2,119 11,871 $ 1,825 15-year or less, amortizing fixed-rate 106 7 415 30 Adjustable-rate 15 2 57 8 Other 1,094 180 1,564 247 Total single-family 12,744 2,308 13,907 2,110 Multifamily 4 16 2 19 Total TDRs that subsequently defaulted 12,748 $ 2,324 13,909 $ 2,129 Nonaccrual Loans The table below displays the forgone interest and the accrued interest receivable written off through the reversal of interest income for nonaccrual loans. For updates to our application of our nonaccrual policy for loans negatively impacted by the COVID-19 pandemic, see “Note 1, Summary of Significant Accounting Policies.” For the Three Months Ended September 30, 2020 For the Nine Months Ended September 30, 2020 (Dollars in millions) Single-family: Interest income forgone (1) $ 219 $ 573 Accrued interest receivable written off through the reversal of interest income 33 165 Multifamily: Interest income forgone (1) $ 8 $ 9 Accrued interest receivable written off through the reversal of interest income 5 7 (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 September 30, 2020 For the Nine Months Ended September 30, 2020 September 30, 2020 June 30, 2020 December 31, 2019 Amortized Cost Total Interest Income Recognized (1) (Dollars in millions) Single-family: 20- and 30-year or more, $ 21,902 $ 23,783 $ 23,427 $ 68 $ 309 15-year or less, amortizing fixed-rate 780 844 858 2 9 Adjustable-rate 247 275 288 1 3 Other 2,438 2,851 2,973 5 31 Total single-family 25,367 27,753 27,546 76 352 Multifamily 347 316 435 — 3 Total nonaccrual loans $ 25,714 $ 28,069 $ 27,981 $ 76 $ 355 (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. Individually Impaired Loans Prior to the adoption of the CECL standard, we recorded a specific loss reserve for individually impaired loans and a collective loss reserve for all other loans. Individually impaired loans include TDRs, acquired credit-impaired loans and multifamily loans that we have assessed as probable that we will not collect all contractual amounts due, regardless of whether we are currently accruing interest, excluding loans classified as HFS and loans for which we have elected the fair value option. The following tables display the unpaid principal balance, total amortized cost and related allowance for loan losses as of December 31, 2019 and average amortized cost, total interest income recognized and interest income recognized on a cash basis for individually impaired loans for the three and nine months ended September 30, 2019. As of December 31, 2019 Unpaid Principal Balance Total Amortized Cost Related Allowance for Loan Losses (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 63,091 $ 61,033 $ (5,851) 15-year or less, amortizing fixed-rate 954 960 (24) Adjustable-rate 156 157 (9) Other 15,181 14,078 (2,291) Total single-family 79,382 76,228 (8,175) Multifamily 314 315 (45) Total individually impaired loans with related allowance recorded 79,696 76,543 (8,220) With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 18,372 17,578 — 15-year or less, amortizing fixed-rate 410 407 — Adjustable-rate 265 265 — Other 3,014 2,718 — Total single-family 22,061 20,968 — Multifamily 363 365 — Total individually impaired loans with no related allowance recorded 22,424 21,333 — Total individually impaired loans (2) $ 102,120 $ 97,876 $ (8,220) (1) The discounted cash flows or collateral value equals or exceeds the carrying value of the loan and, as such, no valuation allowance is required. (2) Includes single-family loans restructured in a TDR with an amortized cost of $96.9 billion as of December 31, 2019. Includes multifamily loans restructured in a TDR with an amortized cost of $102 million as of December 31, 2019. For the Three Months Ended September 30, 2019 Average Amortized Cost Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 67,788 $ 702 $ 61 15-year or less, amortizing fixed-rate 1,141 10 1 Adjustable-rate 155 1 1 Other 16,011 164 11 Total single-family 85,095 877 74 Multifamily 313 2 — Total individually impaired loans with related allowance recorded 85,408 879 74 With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 15,787 255 37 15-year or less, amortizing fixed-rate 329 4 1 Adjustable-rate 300 3 1 Other 2,767 55 5 Total single-family 19,183 317 44 Multifamily 401 8 — Total individually impaired loans with no related allowance recorded 19,584 325 44 Total individually impaired loans $ 104,992 $ 1,204 $ 118 For the Nine Months Ended September 30, 2019 Average Amortized Cost Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 72,229 $ 2,268 $ 210 15-year or less, amortizing fixed-rate 1,237 32 3 Adjustable-rate 135 4 1 Other 17,995 557 41 Total single-family 91,596 2,861 255 Multifamily 280 7 — Total individually impaired loans with related allowance recorded 91,876 2,868 255 With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 15,041 708 98 15-year or less, amortizing fixed-rate 320 11 3 Adjustable-rate 352 12 2 Other 2,875 158 14 Total single-family 18,588 889 117 Multifamily 377 16 — Total individually impaired loans with no related allowance recorded 18,965 905 117 Total individually impaired loans $ 110,841 $ 3,773 $ 372 (1) The discounted cash flows or collateral value equals or exceeds the carrying value of the loan and, as such, no valuation allowance is required.

Allowance for Loan Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Allowance for Loan Losses	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. See “Note 1, Summary of Significant Accounting Policies” for additional information and accounting policies on loans held for sale and changes resulting from our adoption of the CECL standard. 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 the CECL standard. For the Three Months Ended September 30, 2020 For the Nine Months Ended September 30, 2020 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,598) $ (8,759) Transition impact of the adoption of the CECL standard — (1,229) Benefit (provision) for loan losses 931 (857) Write-offs 261 377 Recoveries (4) (10) Other 23 91 Ending Balance $ (10,387) $ (10,387) Multifamily allowance for loan losses: Beginning balance $ (1,368) $ (257) Transition impact of the adoption of the CECL standard — (493) Provision for loan losses (34) (669) Write-offs 86 104 Recoveries — (1) Ending Balance $ (1,316) $ (1,316) Total allowance for loan losses: Beginning balance $ (12,966) $ (9,016) Transition impact of the adoption of the CECL standard — (1,722) Benefit (provision) for loan losses 897 (1,526) Write-offs 347 481 Recoveries (4) (11) Other 23 91 Ending Balance $ (11,703) $ (11,703) 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, during 2020, 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 provision for loan losses for the nine months ended September 30, 2020 were: • Provision from change in actual and expected loan delinquencies and change in assumptions regarding COVID-19 forbearance, which includes adjustments to modeled results . Our single-family provision for loan losses for the nine months ended September 30, 2020 was driven by the economic dislocation caused by the COVID-19 pandemic, with the majority of the provision recognized in the first quarter of 2020. Estimating expected loan losses as a result of the COVID-19 pandemic continues to require significant management judgment regarding a number of matters, including our expectations surrounding borrower participation in a COVID-19-related forbearance, the type and extent of loss mitigation that may be needed when the loan exits forbearance, the high degree of uncertainty regarding the future course of the pandemic and its effect on the economy, and expectations regarding the impact of fiscal stimulus to support borrowers. As a result, the model used to estimate single-family loan losses does not capture the entirety of losses we expect to incur relating to COVID-19. The model has consumed data from the initial months of the pandemic, including loan delinquencies, and updated credit profile data for loans in forbearance. As more of this data was consumed by our credit loss model, we reduced the non-modeled adjustment initially recorded in the first quarter. In the third quarter of 2020, management continued to apply its judgment and supplement model results as of September 30, 2020, taking into account the continued high degree of uncertainty regarding the future impact of the pandemic and its effect on the economy, future economic and housing policy, and extended foreclosure moratoriums. These factors, combined with higher loan delinquencies, led to an increase in provision attributable to these COVD-19-related factors, which was partially offset by a decrease in our estimated single-family cumulative forbearance take-up, based on recent economic data and actual forbearance activity observed through the third quarter of 2020. The factors discussed above were offset by the factors below, which contributed to a single-family benefit for loan losses for the three months ended September 30, 2020 and reduced the amount of single-family provision for loan losses recognized for the nine months ended September 30, 2020: • Benefit from lower actual and projected interest rates. For much of 2020, we continued to be in a historically low interest rate environment. As mortgage interest rates decline, we expect an increase in future prepayments on single-family loans, including modified loans. Higher expected prepayments shorten the expected lives of modified loans, which decreases the expected impairment relating to term and interest-rate concessions provided on these loans and results in a benefit for loan losses. Most of this benefit from lower actual and projected mortgage interest rates was recognized in the first half of 2020. • Benefit from the redesignation of certain reperforming single-family loans from HFI to HFS. In the third quarter of 2020, we resumed sales of reperforming loans after our suspension of new loan sales in the second quarter of 2020. As a result, we redesignated certain reperforming single-family loans from HFI to HFS in the third quarter of 2020, 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, which contributed to a net benefit for loan losses for the three and nine months ended September 30, 2020. • Benefit from actual and expected home price growth . In the first quarter of 2020, we significantly reduced our expectations for home price growth to near-zero for 2020. However, the negative impact from the first quarter of 2020 was more than offset by an increase in actual home price growth in the second and third quarters due to better-than-expected housing demand and continued low levels of supply. Higher home prices decrease the likelihood that loans will default and decrease the amount of credit loss on loans that do default, which impacts our estimate of losses and ultimately decreases our loss reserves and provision for loan losses. The primary factor that contributed to a decrease in single-family write-offs for the nine months ended September 30, 2020 compared with the nine months ended September 30, 2019 was a reduction in the volume of reperforming loans redesignated from HFI to HFS. Our multifamily provision for loan losses for the nine months ended September 30, 2020 was driven by higher expected losses as a result of the economic dislocation caused by the COVID-19 pandemic and heightened economic uncertainty, driven by elevated unemployment which we expect will result in a decrease of multifamily property income and property values. In addition, the multifamily provision for loan losses includes increased expected loan losses on seniors housing loans as these properties have been disproportionately impacted by the pandemic. The vast majority of these expenses were recognized in the first half of 2020. Consistent with the single-family discussion above, the model we use to estimate multifamily loan losses does not capture the entirety of losses we expect to incur relating to COVID-19. The model has consumed data from the initial months of the pandemic, but we continue to apply management judgment and supplement model results as of September 30, 2020, taking into account the continued high degree of uncertainty that remains relating to the impact of the pandemic. In the third quarter of 2020, our provision for expected multifamily loan losses as a result of the COVID-19 pandemic was relatively flat. In September 2020, we decreased our estimate for loan losses due to a downward revision of our estimated multifamily cumulative forbearance take-up rate, as well as an improved forecasted unemployment rate. These benefits were offset by continued economic uncertainty, forbearance arrangements that were extended beyond the initial term, and overall increased delinquencies. These factors, inclusive of the other components of the multifamily provision for loan losses, resulted in a modest expense for the third quarter of 2020. The primary factor that contributed to multifamily write-offs for the three and nine months ended September 30, 2020 was a write down in the value of a seniors housing portfolio during the third quarter of 2020 following its default on its forbearance agreement. Allowance for Accrued Interest Receivable As a result of our update to the application of our nonaccrual policy in the second quarter of 2020, we continue to accrue interest for single-family and multifamily loans that were negatively impacted by the COVID-19 pandemic. This update resulted in a significant portion of delinquent loans, that were current as of March 1, 2020 and subsequently became delinquent, remaining on accrual status. Accordingly, we established a valuation allowance for expected credit losses on the accrued interest receivable balance based on our evaluation of collectability. This contributed to the provision for credit losses for the three and nine months ended September 30, 2020. We recorded a valuation allowance of $569 million, as a component of “Accrued interest receivable, net” in our condensed consolidated balance sheet as of September 30, 2020. We recognized the related provision as a component of “Benefit (provision) for credit losses” in our condensed consolidated statements of operations and comprehensive income. See “Note 1, Summary of Significant Accounting Policies” for more information about our nonaccrual policy. The following tables display prior period changes in single-family and multifamily allowance for loan losses and the prior period amortized cost in our HFI loans by impairment or allowance methodology and portfolio segment prior to the adoption of the CECL standard. For a description of our previous allowance and impairment methodology refer to “Note 1, Summary of Significant Accounting Policies” in our 2019 Form 10-K. For the Three Months Ended September 30, 2019 For the Nine Months Ended September 30, 2019 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,210) $ (13,969) Benefit for loan losses 1,826 3,712 Write-offs 270 1,209 Recoveries (8) (68) Other — (6) Ending Balance $ (9,122) $ (9,122) Multifamily allowance for loan losses: Beginning balance $ (272) $ (234) Benefit (provision) for loan losses 17 (23) Write-offs 2 6 Recoveries (1) (3) Ending Balance $ (254) $ (254) Total allowance for loan losses: Beginning balance $ (11,482) $ (14,203) Benefit for loan losses 1,843 3,689 Write-offs 272 1,215 Recoveries (9) (71) Other — (6) Ending Balance $ (9,376) $ (9,376) As of December 31, 2019 Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans $ (8,175) $ (45) $ (8,220) Collectively reserved loans (584) (212) (796) Total allowance for loan losses $ (8,759) $ (257) $ (9,016) Amortized cost in loans by segment: Individually impaired loans $ 97,196 $ 680 $ 97,876 Collectively reserved loans 2,909,115 329,938 3,239,053 Total amortized cost in loans $ 3,006,311 $ 330,618 $ 3,336,929

Investments in Securities

Investments in Securities	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Investments in Securities	Investments in Securities Trading Securities Trading securities are recorded at fair value with subsequent changes in fair value recorded as “Fair value losses, net” in our condensed consolidated statements of operations and comprehensive income. The following table displays our investments in trading securities. As of September 30, 2020 December 31, 2019 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 2,750 $ 3,424 Other agency (1) 3,518 4,490 Private-label and other mortgage securities 158 629 Total mortgage-related securities (includes $850 million and $896 million, respectively, related to consolidated trusts) 6,426 8,543 Non-mortgage-related securities: U.S. Treasury securities 135,972 39,501 Other securities 74 79 Total non-mortgage-related securities 136,046 39,580 Total trading securities $ 142,472 $ 48,123 (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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Net trading gains (losses) $ (91) $ 95 $ 691 $ 370 Net trading gains (losses) recognized in the period related to securities still held at period end (71) 82 448 298 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, 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. Pursuant to the CECL standard, 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 September 30, 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 $ 1,195 $ — $ 102 $ (14) $ 1,283 Other agency (2) 85 — 11 — 96 Alt-A and subprime private-label securities 4 — 2 — 6 Mortgage revenue bonds 249 (3) 9 — 255 Other mortgage-related securities 247 — 8 — 255 Total $ 1,780 $ (3) $ 132 $ (14) $ 1,895 As of December 31, 2019 Total Amortized Cost (1)(3) Gross Unrealized Gains Gross Unrealized Losses Total Fair Value (1) (Dollars in millions) Fannie Mae $ 1,445 $ 85 $ (10) $ 1,520 Other agency (2) 183 15 — 198 Alt-A and subprime private-label securities 34 23 — 57 Mortgage revenue bonds 309 9 (3) 315 Other mortgage-related securities 310 5 (1) 314 Total $ 2,281 $ 137 $ (14) $ 2,404 (1) We exclude from amortized cost and fair value accrued interest of $7 million and $10 million as of September 30, 2020 and December 31, 2019 , 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. (3) Prior to our adoption of the CECL standard, total amortized cost represented the unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, as well as temporary impairments recognized in “Investment gains, net” in our consolidated statements of operations and comprehensive income. 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 September 30, 2020, 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 September 30, 2020 Less Than 12 Consecutive Months 12 Consecutive Months or Longer Gross Unrealized Losses in AOCI Fair Value Gross Unrealized Losses in AOCI Fair Value (Dollars in millions) Fannie Mae $ (2) $ 72 $ (12) $ 90 Mortgage revenue bonds — — — — Other mortgage-related securities — — — — Total $ (2) $ 72 $ (12) $ 90 As of December 31, 2019 Less Than 12 Consecutive Months 12 Consecutive Months or Longer Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (Dollars in millions) Fannie Mae $ — $ — $ (10) $ 337 Mortgage revenue bonds — — (3) 3 Other mortgage-related securities (1) 130 — — Total $ (1) $ 130 $ (13) $ 340 The following table displays the gross realized gains and proceeds on sales of AFS securities. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Gross realized gains $ 15 $ — $ 45 $ 171 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 137 — 258 376 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 September 30, 2020 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded an allowance for credit losses $ 93 Other 27 Accumulated other comprehensive income $ 120 As of December 31, 2019 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 97 Other 34 Accumulated other comprehensive income $ 131 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 September 30, 2020 Total Carrying Amount (1) Total 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 $ 1,195 $ 1,283 $ — $ — $ 6 $ 6 $ 88 $ 100 $ 1,101 $ 1,177 Other agency 85 96 — — — — 10 11 75 85 Alt-A and subprime private-label securities 4 6 — — — — 2 3 2 3 Mortgage revenue bonds 246 255 1 1 28 30 24 24 193 200 Other mortgage-related securities 247 255 — — — — 20 21 227 234 Total $ 1,777 $ 1,895 $ 1 $ 1 $ 34 $ 36 $ 144 $ 159 $ 1,598 $ 1,699 (1) Net carrying amount consists of book value, net of allowance for credit losses on AFS debt securities.

Financial Guarantees

Financial Guarantees	9 Months Ended
	Sep. 30, 2020
Guarantees [Abstract]
Financial Guarantees	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. With our adoption of the CECL standard on January 1, 2020, 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. As such, we exclude from the following table Freddie Mac securities backing unconsolidated Fannie Mae-issued structured securities of approximately $117.7 billion and $50.1 billion as of September 30, 2020 and December 31, 2019, 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 September 30, 2020 December 31, 2019 Maximum Exposure Guaranty Obligation Maximum Recovery (1) Maximum Exposure Guaranty Obligation Maximum Recovery (1) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 4,880 $ 18 $ 4,666 $ 5,801 $ 26 $ 5,545 Other guaranty arrangements (2) 11,950 110 2,424 12,670 128 2,553 Total $ 16,830 $ 128 $ 7,090 $ 18,471 $ 154 $ 8,098 (1) Recoverability of such credit enhancements and recourse is subject to, among other factors, our mortgage insurers’ and financial guarantors’ ability to meet their obligations to us. For information on our mortgage insurers, see “Note 10, Concentrations of Credit Risk.” (2) Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt

Short-Term and Long-Term Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Short-Term and Long-Term Debt	Short-Term and Long-Term Debt 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 September 30, 2020 December 31, 2019 Outstanding Weighted- Average Interest Rate (1) Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Federal funds purchased and securities sold under agreements to repurchase (2) $ — — % $ 478 1.67 % Short-term debt of Fannie Mae 23,526 0.23 26,662 1.56 (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Represents agreements to repurchase securities for a specified price, with repayment generally occurring on the following day, reported as “Other liabilities” in our condensed consolidated balance sheets. Intraday Lines of Credit We use secured and unsecured intraday funding lines of credit provided by large financial institutions. As these lines of credit are uncommitted intraday loan facilities, we may be unable to draw on them if and when needed. The lines of credit under these facilities was up to $15.0 billion as of September 30, 2020 and December 31, 2019. 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 September 30, 2020 December 31, 2019 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2020 - 2030 $ 104,323 2.26 % 2020 - 2030 $ 86,114 2.66 % Medium-term notes (2) 2020 - 2030 37,983 0.73 2020 - 2026 32,590 1.57 Other (3) 2020 - 2038 5,214 4.63 2020 - 2038 5,254 5.01 Total senior fixed 147,520 1.95 123,958 2.47 Senior floating: Medium-term notes (2) 2020 - 2022 102,585 0.35 2020 - 2021 9,774 1.66 Connecticut Avenue Securities (4) 2023 - 2031 15,336 4.34 2023 - 2031 21,424 5.61 Other (5) 2037 435 5.14 2020 - 2037 398 6.27 Total senior floating 118,356 0.89 31,596 4.40 Secured borrowings (6) 2021 - 2022 21 3.00 2021 - 2022 31 2.31 Total long-term debt of Fannie Mae (7) 265,897 1.48 155,585 2.86 Debt of consolidated trusts 2020 - 2059 3,530,381 2.09 2020 - 2059 3,285,139 2.78 Total long-term debt $ 3,796,278 2.04 % $ 3,440,724 2.78 % (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Includes long-term debt with an original contractual maturity of greater than 1 year and up to 10 years, excluding zero-coupon debt. (3) Includes other long-term debt with an original contractual maturity of greater than 10 years and foreign exchange bonds. (4) 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 2019 Form 10-K for more information about our CAS structures issued beginning November 2018. (5) Consists of structured debt instruments that are reported at fair value. (6) Represents our remaining liability resulting from the transfer of financial assets from our condensed consolidated balance sheets that did not qualify as a sale under the accounting guidance for the transfer of financial instruments. (7) Includes unamortized discounts and premiums, other cost basis adjustments and fair value adjustments in a net discount position of $491 million and $2 million as of September 30, 2020 and December 31, 2019, respectively.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	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 2019 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. 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. As of September 30, 2020 As of December 31, 2019 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: Swaps: Pay-fixed $ 110,215 $ — $ 25,728 $ (1,297) $ 41,052 $ — $ 29,178 $ (970) Receive-fixed 109,774 1,082 19,213 (54) 73,579 816 26,382 (62) Basis 250 218 — — 273 149 — — Foreign currency 224 41 226 (78) 229 39 232 (65) Swaptions: Pay-fixed 5,400 10 5,525 (341) 4,600 18 6,375 (219) Receive-fixed 6,625 591 800 (138) 2,875 106 4,600 (232) Futures (1) 55,004 — — — 20,507 — — — Total gross risk management derivatives 287,492 1,942 51,492 (1,908) 143,115 1,128 66,767 (1,548) Accrued interest receivable — 111 — (230) — 226 — (250) Netting adjustment (2) — (2,037) — 2,053 — (1,288) — 1,694 Total net risk management derivatives $ 287,492 $ 16 $ 51,492 $ (85) $ 143,115 $ 66 $ 66,767 $ (104) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 36,756 $ 93 $ 9,180 $ (13) $ 7,115 $ 15 $ 1,787 $ (1) Forward contracts to purchase mortgage-related securities 122,096 402 37,607 (70) 55,531 137 9,560 (28) Forward contracts to sell mortgage-related securities 45,165 68 232,148 (759) 9,282 13 109,066 (277) Total mortgage commitment derivatives 204,017 563 278,935 (842) 71,928 165 120,413 (306) Credit enhancement derivatives 20,804 459 10,060 (38) 28,432 40 9,486 (25) Derivatives at fair value $ 512,313 $ 1,038 $ 340,487 $ (965) $ 243,475 $ 271 $ 196,666 $ (435) (1) Futures have no ascribable fair value because the positions are settled daily. We record all derivative gains and losses, including accrued interest, in “Fair value 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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ 634 $ (1,414) $ (3,489) $ (4,913) Receive-fixed (550) 966 2,984 4,131 Basis (5) 24 68 75 Foreign currency 23 (11) (11) (9) Swaptions: Pay-fixed 2 (110) (159) (430) Receive-fixed (60) 209 597 309 Futures — 42 (75) 296 Net contractual interest expense on interest-rate swaps (46) (190) (216) (698) Total risk management derivatives fair value losses, net (2) (484) (301) (1,239) Mortgage commitment derivatives fair value losses, net (672) (177) (2,327) (946) Credit enhancement derivatives fair value gains (losses), net 380 (7) 400 (31) Total derivatives fair value losses, net $ (294) $ (668) $ (2,228) $ (2,216) 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 September 30, 2020 and December 31, 2019.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2020
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 2019 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 are allocated to our Single-Family business segment. The following tables display our segment results. For the Three Months Ended September 30, 2020 2019 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 5,870 $ 786 $ 6,656 $ 4,484 $ 864 $ 5,348 Fee and other income (2) 73 20 93 156 32 188 Net revenues 5,943 806 6,749 4,640 896 5,536 Investment gains, net (3) 583 70 653 198 55 253 Fair value gains (losses), net (4) (244) (83) (327) (719) 6 (713) Administrative expenses (634) (128) (762) (634) (115) (749) Credit-related income (expense): (5) Benefit (provision) for credit losses 542 (41) 501 1,840 17 1,857 Foreclosed property expense (64) (7) (71) (93) (3) (96) Total credit-related income (expense) 478 (48) 430 1,747 14 1,761 TCCA fees (6) (679) — (679) (613) — (613) Credit enhancement expense (7) (274) (51) (325) (240) (50) (290) Change in expected credit enhancement recoveries (8) (48) — (48) — — — Other expenses, net (307) (6) (313) (184) (2) (186) Income before federal income taxes 4,818 560 5,378 4,195 804 4,999 Provision for federal income taxes (1,049) (100) (1,149) (872) (164) (1,036) Net income $ 3,769 $ 460 $ 4,229 $ 3,323 $ 640 $ 3,963 For the Nine Months Ended September 30, 2020 2019 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 15,350 $ 2,430 $ 17,780 $ 12,942 $ 2,429 $ 15,371 Fee and other income (2) 238 65 303 350 85 435 Net revenues 15,588 2,495 18,083 13,292 2,514 15,806 Investment gains, net (3) 527 117 644 709 138 847 Fair value gains (losses), net (4) (1,734) 113 (1,621) (2,364) 66 (2,298) Administrative expenses (1,888) (377) (2,265) (1,899) (338) (2,237) Credit-related income (expense): (5) Benefit (provision) for credit losses (1,411) (683) (2,094) 3,753 (21) 3,732 Foreclosed property expense (145) (16) (161) (362) (2) (364) Total credit-related income (expense) (1,556) (699) (2,255) 3,391 (23) 3,368 TCCA fees (6) (1,976) — (1,976) (1,806) — (1,806) Credit enhancement expense (7) (897) (164) (1,061) (639) (143) (782) Change in expected credit enhancement recoveries (8) 218 195 413 — — — Other expenses, net (722) (70) (792) (540) (11) (551) Income before federal income taxes 7,560 1,610 9,170 10,144 2,203 12,347 Provision for federal income taxes (1,623) (312) (1,935) (2,125) (427) (2,552) Net income $ 5,937 $ 1,298 $ 7,235 $ 8,019 $ 1,776 $ 9,795 (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. (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. The presentation of our credit-related income or expense for the three and nine months ended September 30, 2019 represents amounts recognized prior to our transition to the lifetime loss model prescribed by the CECL standard. (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 CIRT, CAS and EPMI programs. Multifamily credit enhancement expense primarily consists of costs associated with our MCIRT and 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. (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” for more information about our change in presentation.

Concentrations of Credit Risk

Concentrations of Credit Risk	9 Months Ended
	Sep. 30, 2020
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	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 economic conditions, 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 September 30, 2020 December 31, 2019 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 1.00 % 0.49 % 3.61 % 1.07 % 0.29 % 0.59 % Percentage of single-family conventional loans based on loan count 1.11 0.50 3.20 1.27 0.35 0.66 As of September 30, 2020 December 31, 2019 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% * 21.74 % * 10.14 % Geographical distribution: California 19 % 3.04 19 % 0.32 Florida 6 4.76 6 0.84 Illinois 3 3.46 4 0.91 New Jersey 3 5.31 3 1.13 New York 5 5.39 5 1.18 All other states 64 2.85 63 0.64 Product distribution: Alt-A 1 9.46 2 2.95 Vintages: 2004 and prior 2 5.81 2 2.48 2005-2008 3 9.84 4 4.11 2009-2020 95 2.74 94 0.35 * 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 September 30, 2020 or December 31, 2019. 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 other loans that have higher risk characteristics, to assess 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 September 30, 2020 (1) December 31, 2019 (1) 30 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent Seriously Delinquent (2) Percentage of multifamily guaranty book of business 0.14 % 1.12 % 0.02 % 0.04 % As of September 30, 2020 December 31, 2019 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 % 1.24 % 1 % — % Less than or equal to 80% 99 1.12 99 0.04 Current DSCR below 1.0 (4) 2 22.07 2 0.48 (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 only reflect the initial impact 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 September 30, 2020 December 31, 2019 Risk in Force Percentage of Single-Family Guaranty Book of Business Risk in Force Percentage of Single-Family Guaranty Book of Business (Dollars in millions) Mortgage insurance risk in force: Primary mortgage insurance $ 169,011 $ 162,855 Pool mortgage insurance 296 339 Total mortgage insurance risk in force $ 169,307 5% $ 163,194 6% 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 default 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 September 30, 2020 December 31, 2019 Counterparty: (1) Arch Capital Group Ltd. 21 % 23 % Radian Guaranty, Inc. 19 20 Mortgage Guaranty Insurance Corp. 18 18 Genworth Mortgage Insurance Corp. (2) 17 15 Essent Guaranty, Inc. 15 14 Others 10 10 Total 100 % 100 % (1) Insurance coverage amounts provided for each counterparty may include coverage provided by affiliates and subsidiaries of the counterparty. (2) Genworth Financial, Inc., the ultimate parent company of Genworth Mortgage Insurance Corp., is in the process of being acquired by China Oceanwide Holdings Group Co., Ltd. Upon acquisition, Genworth Mortgage Insurance Corp. will continue to be subject to our ongoing review of financial and operational eligibility requirements. Three of our mortgage insurer counterparties that are currently not approved to write new business are in run-off: PMI Mortgage Insurance Co. (“PMI”), Triad Guaranty Insurance Corporation (“Triad”) and Republic Mortgage Insurance Company (”RMIC”). Entering run-off may close off a source of profits and liquidity that may have otherwise assisted a mortgage insurer in paying claims under insurance policies, and could also cause the quality and speed of its claims processing to deteriorate. These three mortgage insurers provided a combined $2.7 billion, or 2%, of the risk-in-force mortgage insurance coverage of our single-family conventional guaranty book of business as of September 30, 2020. PMI and Triad have been paying only a portion of policyholder claims and deferring the remaining portion. PMI is currently paying 76.5% of claims under its mortgage insurance policies in cash and is deferring the remaining 23.5%, 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 any remaining deferred policyholder claims and/or increase or decrease the amount of cash they pay on claims. RMIC is no longer deferring payments on policyholder claims and has paid us its previously outstanding deferred payment obligations as well as interest on those obligations; however, RMIC 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 September 30, 2020 and December 31, 2019, our estimated benefit from mortgage insurance, which is based on estimated credit losses as of period end, reduced our loss reserves by $1.7 billion and $410 million, respectively. As of September 30, 2020 and December 31, 2019, we had outstanding receivables of $569 million and $654 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 September 30, 2020 and December 31, 2019, we assessed these outstanding receivables for collectability, and established a valuation allowance of $499 million and $541 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 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 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 September 30, 2020 December 31, 2019 Wells Fargo Bank, N.A. (together with its affiliates) 15 % 17 % Remaining top five depository servicers 12 15 Top five non-depository servicers 25 27 Total 52 % 59 % 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 September 30, 2020 December 31, 2019 Wells Fargo Bank, N.A. (together with its affiliates) 13 % 13 % Walker & Dunlop, Inc. 12 12 Remaining top five servicers 23 23 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. Derivative 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

Netting Arrangements	9 Months Ended
	Sep. 30, 2020
Offsetting [Abstract]
Netting Arrangements	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 September 30, 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 $ 2,053 $ (2,052) $ 1 $ — $ — $ 1 Cleared risk management derivatives — 15 15 — — 15 Mortgage commitment derivatives 563 — 563 (289) (23) 251 Total derivative assets 2,616 (2,037) 579 (4) (289) (23) 267 Securities purchased under agreements to resell or similar arrangements (5) 27,100 — 27,100 — (27,100) — Total assets $ 29,716 $ (2,037) $ 27,679 $ (289) $ (27,123) $ 267 Liabilities: OTC risk management derivatives $ (2,138) $ 2,056 $ (82) $ — $ — $ (82) Cleared risk management derivatives — (3) (3) — 3 — Mortgage commitment derivatives (842) — (842) 289 529 (24) Total derivative liabilities (2,980) 2,053 (927) (4) 289 532 (106) Total liabilities $ (2,980) $ 2,053 $ (927) $ 289 $ 532 $ (106) As of December 31, 2019 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 $ 1,354 $ (1,334) $ 20 $ — $ — $ 20 Cleared risk management derivatives — 46 46 — — 46 Mortgage commitment derivatives 165 — 165 (101) (1) 63 Total derivative assets 1,519 (1,288) 231 (4) (101) (1) 129 Securities purchased under agreements to resell or similar arrangements (5) 24,928 — 24,928 — (24,928) — Total assets $ 26,447 $ (1,288) $ 25,159 $ (101) $ (24,929) $ 129 Liabilities: OTC risk management derivatives $ (1,798) $ 1,695 $ (103) $ — $ — $ (103) Cleared risk management derivatives — (1) (1) — 1 — Mortgage commitment derivatives (306) — (306) 101 181 (24) Total derivative liabilities (2,104) 1,694 (410) (4) 101 182 (127) Securities sold under agreements to repurchase or similar arrangements (478) — (478) — 475 (3) Total liabilities $ (2,582) $ 1,694 $ (888) $ 101 $ 657 $ (130) (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 $4.8 billion and $2.3 billion as of September 30, 2020 and December 31, 2019, respectively. The fair value of non-cash collateral received was $27.0 billion and $24.7 billion, of which $25.8 billion and $23.8 billion could be sold or repledged as of September 30, 2020 and December 31, 2019, respectively. None of the underlying collateral was sold or repledged as of September 30, 2020 or December 31, 2019. (4) Excludes derivative assets of $459 million and $40 million as of September 30, 2020 and December 31, 2019, respectively, and derivative liabilities of $38 million and $25 million recognized in our condensed consolidated balance sheets as of September 30, 2020 and December 31, 2019, respectively, that are not subject to enforceable master netting arrangements. (5) Includes $14.4 billion and $11.4 billion in securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of September 30, 2020 and December 31, 2019, respectively. 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 2019 Form 10-K.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value	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 September 30, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ 3,443 $ — $ — $ — $ 3,443 Trading securities: Mortgage-related securities: Fannie Mae — 2,690 60 — 2,750 Other agency — 3,517 1 — 3,518 Private-label and other mortgage securities — 158 — — 158 Non-mortgage-related securities: U.S. Treasury securities 135,972 — — — 135,972 Other securities — 74 — — 74 Total trading securities 135,972 6,439 61 — 142,472 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,061 222 — 1,283 Other agency — 96 — — 96 Alt-A and subprime private-label securities — 4 2 — 6 Mortgage revenue bonds — — 255 — 255 Other — 7 248 — 255 Total available-for-sale securities — 1,168 727 — 1,895 Mortgage loans — 6,090 878 — 6,968 Other assets: Risk management derivatives: Swaps — 1,231 221 — 1,452 Swaptions — 601 — — 601 Netting adjustment — — — (2,037) (2,037) Mortgage commitment derivatives — 563 — — 563 Credit enhancement derivatives — — 459 — 459 Total other assets — 2,395 680 (2,037) 1,038 Total assets at fair value $ 139,415 $ 16,092 $ 2,346 $ (2,037) $ 155,816 Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 3,551 $ 435 $ — $ 3,986 Total of Fannie Mae — 3,551 435 — 3,986 Of consolidated trusts — 24,656 85 — 24,741 Total long-term debt — 28,207 520 — 28,727 Other liabilities: Risk management derivatives: Swaps — 1,659 — — 1,659 Swaptions — 479 — — 479 Netting adjustment — — — (2,053) (2,053) Mortgage commitment derivatives — 842 — — 842 Credit enhancement derivatives — — 38 — 38 Total other liabilities — 2,980 38 (2,053) 965 Total liabilities at fair value $ — $ 31,187 $ 558 $ (2,053) $ 29,692 Fair Value Measurements as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 3,379 $ 45 $ — $ 3,424 Other agency — 4,489 1 — 4,490 Private-label and other mortgage securities — 629 — — 629 Non-mortgage-related securities: U.S. Treasury securities 39,501 — — — 39,501 Other securities — 79 — — 79 Total trading securities 39,501 8,576 46 — 48,123 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,349 171 — 1,520 Other agency — 198 — — 198 Alt-A and subprime private-label securities — 57 — — 57 Mortgage revenue bonds — — 315 — 315 Other — 8 306 — 314 Total available-for-sale securities — 1,612 792 — 2,404 Mortgage loans — 7,137 688 — 7,825 Other assets: Risk management derivatives: Swaps — 1,071 159 — 1,230 Swaptions — 124 — — 124 Netting adjustment — — — (1,288) (1,288) Mortgage commitment derivatives — 165 — — 165 Credit enhancement derivatives — — 40 — 40 Total other assets — 1,360 199 (1,288) 271 Total assets at fair value $ 39,501 $ 18,685 $ 1,725 $ (1,288) $ 58,623 Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 5,289 $ 398 $ — $ 5,687 Total of Fannie Mae — 5,289 398 — 5,687 Of consolidated trusts — 21,805 75 — 21,880 Total long-term debt — 27,094 473 — 27,567 Other liabilities: Risk management derivatives: Swaps — 1,346 1 — 1,347 Swaptions — 440 11 — 451 Netting adjustment — — — (1,694) (1,694) Mortgage commitment derivatives — 306 — — 306 Credit enhancement derivatives — — 25 — 25 Total other liabilities — 2,092 37 (1,694) 435 Total liabilities at fair value $ — $ 29,186 $ 510 $ (1,694) $ 28,002 (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 September 30, 2020 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2020 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2020 (1) Balance, June 30, 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 Balance, September 30, 2020 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 38 $ — $ — $ — $ (1) $ — $ — $ (3) $ 26 $ 60 $ — $ — Other agency — — — — — — — — 1 1 — — Private-label and other mortgage securities 98 (4) — — (94) — — — — — — — Total trading securities $ 136 $ (4) (5)(6) $ — $ — $ (95) $ — $ — $ (3) $ 27 $ 61 $ — $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 446 $ 1 $ 2 $ — $ — $ — $ (9) $ (218) $ — $ 222 $ — $ — Alt-A and subprime private-label securities 2 — — — — — — — — 2 — — Mortgage revenue bonds 278 — — — — — (23) — — 255 — — Other 254 5 5 — — — (16) — — 248 — 4 Total available-for-sale securities $ 980 $ 6 (5)(6) $ 7 $ — $ — $ — $ (48) $ (218) $ — $ 727 $ — $ 4 Mortgage loans $ 797 $ 41 (5)(6) $ — $ — $ (11) $ — $ (39) $ (31) $ 121 $ 878 $ 36 $ — Net derivatives 269 380 (5) — — — — (7) — — 642 372 — Long-term debt: Of Fannie Mae: Senior floating (433) (3) (5) — — — — 1 — — (435) (3) — Of consolidated trusts (89) (1) (5)(6) — — — — 5 1 (1) (85) (1) — Total long-term debt $ (522) $ (4) $ — $ — $ — $ — $ 6 $ 1 $ (1) $ (520) $ (4) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2020 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2020 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 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 Balance, September 30, 2020 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 45 $ (9) $ — $ — $ (1) $ — $ — $ (48) $ 73 $ 60 $ (8) $ — Other agency 1 — — — — — — (1) 1 1 — — Private-label and other mortgage securities — 3 — — (94) — (3) — 94 — — — Total trading securities $ 46 $ (6) (5)(6) $ — $ — $ (95) $ — $ (3) $ (49) $ 168 $ 61 $ (8) $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 171 $ 1 $ 2 $ — $ — $ — $ (12) $ (218) $ 278 $ 222 $ — $ — Alt-A and subprime private-label securities — — — — — — — — 2 2 — — Mortgage revenue bonds 315 (3) 3 74 (74) — (60) — — 255 — 5 Other 306 (9) 4 268 (268) — (53) — — 248 — 3 Total available-for-sale securities $ 792 $ (11) (6)(7) $ 9 $ 342 $ (342) $ — $ (125) $ (218) $ 280 $ 727 $ — $ 8 Mortgage loans $ 688 $ 32 (5)(6) $ — $ — $ (11) $ — $ (93) $ (75) $ 337 $ 878 $ 5 $ — Net derivatives 162 470 (5) — — — — (8) 18 — 642 468 — Long-term debt: Of Fannie Mae: Senior floating (398) (61) (5) — — — — 24 — — (435) (61) — Of consolidated trusts (75) — (5)(6) — — — — 12 2 (24) (85) 1 — Total long-term debt $ (473) $ (61) $ — $ — $ — $ — $ 36 $ 2 $ (24) $ (520) $ (60) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2019 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, June 30, 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 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 74 $ 2 $ — $ 77 $ — $ — $ — $ (31) $ — $ 122 $ 1 $ — Other agency — — — — — — — — 2 2 — — Total trading securities $ 74 $ 2 (5)(6) $ — $ 77 $ — $ — $ — $ (31) $ 2 $ 124 $ 1 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 132 $ — $ 3 $ — $ — $ — $ (1) $ — $ 40 $ 174 $ — $ 3 Mortgage revenue bonds 364 1 (1) — — — (18) — — 346 — — Other 326 (1) (1) — — — (9) — — 315 — (2) Total available-for-sale securities $ 822 $ — (6)(7) $ 1 $ — $ — $ — $ (28) $ — $ 40 $ 835 $ — $ 1 Mortgage loans $ 770 $ 14 (5)(6) $ — $ — $ (27) $ — $ (35) $ (41) $ 45 $ 726 $ 10 $ — Net derivatives 183 21 (5) — — — — (6) — — 198 15 — Long-term debt: Of Fannie Mae: Senior floating (398) (24) (5) — — — — — — — (422) (24) — Of consolidated trusts (102) (3) (5)(6) — — — (2) 6 20 (7) (88) (1) — Total long-term debt $ (500) $ (27) $ — $ — $ — $ (2) $ 6 $ 20 $ (7) $ (510) $ (25) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2019 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, December 31, 2018 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 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 5 $ — $ 77 $ (14) $ — $ (16) $ (31) $ 69 $ 122 $ 4 $ — Other agency — — — — — — — — 2 2 — — Private-label and other mortgage securities 1 — — — — — (1) — — — — — Total trading securities $ 33 $ 5 (5)(6) $ — $ 77 $ (14) $ — $ (17) $ (31) $ 71 $ 124 $ 4 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 9 $ — $ — $ — $ (8) $ (103) $ 124 $ 174 $ — $ 8 Alt-A and subprime private-label securities 24 5 (5) — (23) — (1) — — — — — Mortgage revenue bonds 434 1 (2) — (4) — (83) — — 346 — (1) Other 342 11 (11) — — — (26) (2) 1 315 — (9) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (9) $ — $ (27) $ — $ (118) $ (105) $ 125 $ 835 $ — $ (2) Mortgage loans $ 937 $ 45 (5)(6) $ — $ — $ (40) $ — $ (105) $ (228) $ 117 $ 726 $ 28 $ — Net derivatives 194 139 (5) — — — — (126) (9) — 198 39 — Long-term debt: Of Fannie Mae: Senior floating (351) (71) (5) — — — — — — — (422) (71) — Of consolidated trusts (201) (7) (5)(6) — — — (2) 16 189 (83) (88) (3) — Total long-term debt $ (552) $ (78) $ — $ — $ — $ (2) $ 16 $ 189 $ (83) $ (510) $ (74) $ — (1) Gains (losses) included in other comprehensive 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 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, 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 September 30, 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) $ 61 Various Available-for-sale securities: Mortgage-related securities: Agency (3) 124 Consensus 98 Various Total agency 222 Alt-A and subprime private-label securities 2 Various Mortgage revenue bonds 177 Single Vendor Spreads (bps) 35.5 — 318.8 100.0 78 Various Total mortgage revenue bonds 255 Other 216 Discounted Cash Flow Spreads (bps) 406.0 — 431.0 418.8 32 Various Total other 248 Total available-for-sale securities $ 727 Net derivatives $ 221 Dealer Mark 421 Discounted Cash Flow Total net derivatives $ 642 Fair Value Measurements as of December 31, 2019 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) $ 46 Various Available-for-sale securities: Mortgage-related securities: Agency (3) 107 Consensus 64 Various Total agency 171 Available-for-sale securities: Mortgage-related securities: Mortgage revenue bonds 222 Single Vendor Spreads(bps) 23.0 - 205.1 76.1 93 Various Total mortgage revenue bonds 315 Other 267 Discounted Cash Flow Spreads(bps) 300.0 300.0 39 Various Total other 306 Total available-for-sale securities $ 792 Net derivatives $ 147 Dealer Mark 15 Various Total net derivatives $ 162 (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 September 30, 2020 or December 31, 2019 that were measured at fair value on a nonrecurring basis. We held $127 million and $274 million in Level 2 assets as of September 30, 2020 and December 31, 2019, respectively, comprised of mortgage loans held for sale and mortgage loans held for investment that were impaired. We had no Level 2 liabilities that were measured at fair value on a nonrecurring basis as of September 30, 2020 or December 31, 2019. The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis. The significant unobservable inputs related to these techniques primarily relate to collateral dependent valuations. The related ranges and weighted averages are not meaningful when aggregated as they vary significantly from property to property. Fair Value Measurements as of Valuation Techniques September 30, 2020 December 31, 2019 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,113 $ 471 Single Vendor 767 605 Total mortgage loans held for sale, at lower of cost or fair value 1,880 1,076 Single-family mortgage loans held for investment, at amortized cost Internal Model 855 555 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate — 24 Various 232 16 Total multifamily mortgage loans held for investment, at amortized cost 232 40 Acquired property, net: Single-family Accepted Offers 60 101 Appraisals 115 362 Walk Forwards 111 240 Internal Model 55 164 Various 15 51 Total single-family 356 918 Multifamily Various 27 9 Total nonrecurring assets at fair value $ 3,350 $ 2,598 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 September 30, 2020 Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Netting Adjustment Estimated Fair Value (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 110,988 $ 96,588 $ 14,400 $ — $ — $ 110,988 Federal funds sold and securities purchased under agreements to resell or similar arrangements 12,700 — 12,700 — — 12,700 Trading securities 142,472 135,972 6,439 61 — 142,472 Available-for-sale securities 1,895 — 1,168 727 — 1,895 Mortgage loans held for sale 8,312 — 679 8,297 — 8,976 Mortgage loans held for investment, net of allowance for loan losses 3,539,031 — 3,414,104 257,448 — 3,671,552 Advances to lenders 10,228 — 10,227 1 — 10,228 Derivative assets at fair value 1,038 — 2,395 680 (2,037) 1,038 Guaranty assets and buy-ups 115 — — 270 — 270 Total financial assets $ 3,826,779 $ 232,560 $ 3,462,112 $ 267,484 $ (2,037) $ 3,960,119 Financial liabilities: Short-term debt: Of Fannie Mae $ 23,526 $ — $ 23,536 $ — $ — $ 23,536 Long-term debt: Of Fannie Mae 265,897 — 277,190 878 — 278,068 Of consolidated trusts 3,530,381 — 3,648,508 31,618 — 3,680,126 Derivative liabilities at fair value 965 — 2,980 38 (2,053) 965 Guaranty obligations 128 — — 78 — 78 Total financial liabilities $ 3,820,897 $ — $ 3,952,214 $ 32,612 $ (2,053) $ 3,982,773 As of December 31, 2019 Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Netting Adjustment Estimated Fair Value (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 61,407 $ 50,057 $ 11,350 $ — $ — $ 61,407 Federal funds sold and securities purchased under agreements to resell or similar arrangements 13,578 — 13,578 — — 13,578 Trading securities 48,123 39,501 8,576 46 — 48,123 Available-for-sale securities 2,404 — 1,612 792 — 2,404 Mortgage loans held for sale 6,773 — 229 7,054 — 7,283 Mortgage loans held for investment, net of allowance for loan losses 3,327,389 — 3,270,535 127,650 — 3,398,185 Advances to lenders 6,453 — 6,451 2 — 6,453 Derivative liabilities at fair value 271 — 1,360 199 (1,288) 271 Guaranty assets and buy-ups 142 — — 305 — 305 Total financial assets $ 3,466,540 $ 89,558 $ 3,313,691 $ 136,048 $ (1,288) $ 3,538,009 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 478 $ — $ 478 $ — $ — $ 478 Short-term debt: Of Fannie Mae 26,662 — 26,667 — — 26,667 Long-term debt: Of Fannie Mae 155,585 — 164,144 401 — 164,545 Of consolidated trusts 3,285,139 — 3,312,763 31,827 — 3,344,590 Derivative liabilities at fair value 435 — 2,092 37 (1,694) 435 Guaranty obligations 154 — — 97 — 97 Total financial liabilities $ 3,468,453 $ — $ 3,506,144 $ 32,362 $ (1,694) $ 3,536,812 For a detailed description and classification of our financial instruments, see “Note 15, Fair Value” in our 2019 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 September 30, 2020 December 31, 2019 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 $ 6,968 $ 3,986 $ 24,741 $ 7,825 $ 5,687 $ 21,880 Unpaid principal balance 6,501 3,895 21,521 7,514 5,200 19,653 (1) Includes nonaccrual loans with a fair value of $140 million and $129 million as of September 30, 2020 and December 31, 2019, respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of September 30, 2020 and December 31, 2019 was $9 million and $11 million, respectively. Includes loans that are 90 days or more past due with a fair value of $297 million and $80 million as of September 30, 2020 and December 31, 2019, respectively. The difference between unpaid principal balance and the fair value of these 90 or more days past due loans as of September 30, 2020 and December 31, 2019 was $16 million and $10 million, respectively. Changes in Fair Value under the Fair Value Option Election We recorded gains of $107 million and $248 million for the three and nine months ended September 30, 2020, respectively, and gains of $95 million and $334 million for the three and nine months ended September 30, 2019, respectively, from changes in the fair value of loans recorded at fair value in “Fair value losses, net” in our condensed consolidated statements of operations and comprehensive income. We recorded losses of $32 million and $344 million for the three and nine months ended September 30, 2020 respectively, and losses of $245 million and $797 million for the three and nine months ended September 30, 2019, respectively, from changes in the fair value of long-term debt recorded at fair value in “Fair value losses, net” in our condensed consolidated statements of operations and comprehensive income.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
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 Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
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 and nine months ended September 30, 2020 may not necessarily be indicative of the results for the year ending December 31, 2020. Presentation of Advances to Lenders Advances to lenders represent our payments of cash in exchange for the receipt of mortgage loans from lenders in a transfer that is accounted for as a secured lending arrangement. These transfers primarily occur when we provide early funding to lenders for loans that they will subsequently either sell to us or securitize into a Fannie Mae MBS that they will deliver to us. Early lender funding advances have terms up to 60 days and earn a short-term market rate of interest. Advances to lenders has been presented as a separate line item for all periods presented as increased mortgage refinance activity resulted in a higher balance at period end. In prior periods, advances to lenders were recorded in “Other assets.” Presentation of Freestanding Credit Enhancement Expense and Recoveries Freestanding credit enhancements primarily include our Connecticut Avenue Securities ® (“CAS”) and Credit Insurance Risk Transfer TM (“CIRT TM ”) programs, enterprise-paid mortgage insurance (“EPMI”), and certain lender risk-sharing arrangements, including our multifamily Delegated Underwriting and Servicing (“DUS ® ”) program. We have revised our presentation of the expenses and recoveries associated with these programs as described below. Credit Enhancement Expense Credit enhancement expense consists of costs associated with our freestanding credit enhancements. We exclude from this expense costs related to our CAS transactions accounted for as debt instruments and credit risk transfer programs accounted for as derivative instruments. Credit enhancement expense has been presented as a separate line item for all periods presented as these expenses have become a more significant driver of our results of operations. In prior periods, credit enhancement expenses were recorded in “Other expenses, net.” Change in Expected Credit Enhancement Recoveries Change in expected credit enhancement recoveries consists of the change in benefits recognized from our freestanding credit enhancements, including any realized amounts. Benefits, if any, from our CAS, CIRT and EPMI programs previously recorded in “Fee and other income” have been reclassified to “Change in expected credit enhancement recoveries” for all periods presented. Benefits from other lender risk-sharing programs, including our multifamily DUS program, were recorded as a reduction of credit-related expense in periods prior to 2020. However, with our adoption of the CECL standard on January 1, 2020, benefits from freestanding credit enhancements are no longer recorded as a reduction of credit-related expenses. These benefits from lender risk-sharing have been reclassified into “Change in expected credit enhancement recoveries” on a prospective basis beginning January 1, 2020. Presentation of Yield Maintenance Fees Prior period multifamily yield maintenance fees have been reclassified to conform to the current period presentation. Multifamily yield maintenance fees, or prepayment premiums, are fees that a borrower pays when they prepay their loan. For multifamily loans held in a consolidated trust, a portion of the yield maintenance fee is typically passed through to the holders of the trust certificate. As of January 1, 2020, we classify all yield maintenance fees as interest income. For consolidated loans, the portion of the fee passed through to the certificate holders of the trust is classified as interest expense. Previously, we classified multifamily yield maintenance fees as interest income only when the fee was associated with a loan refinancing, otherwise the fee was classified as fee and other income. The portion of the fees passed through to the certificate holders of the trust were previously classified as interest expense only when the fee was associated with a loan refinancing, otherwise the fee was classified as other expense. The changes in presentation have been applied retrospectively to all periods presented and were immaterial for prior periods.
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, 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 September 30, 2020. Actual results could differ from these estimates.
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
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Guidance The CARES Act and Interagency Regulatory Guidance Section 4013 of the Coronavirus Aid, Relief, and Economic Security Act, referred to as the CARES Act, which was enacted in March 2020, provides temporary relief from the accounting and reporting requirements for TDRs regarding certain loan modifications related to COVID-19. The CARES Act provides that a financial institution may elect to suspend the TDR requirements under GAAP for loan modifications related to the COVID-19 pandemic that occur between March 1, 2020 through the earlier of December 31, 2020 or 60 days after the date on which the COVID-19 national emergency terminates (the “Applicable Period”), as long as the loan was not more than 30 days delinquent as of December 31, 2019. Loan modifications are defined in this section of the CARES Act to include forbearance arrangements, repayment plans, interest rate modifications, and any similar arrangement that defer or delay the payment of principal or interest. We have elected to account for eligible loan modifications under Section 4013 of the CARES Act. Therefore, the initial relief (i.e., the forbearance arrangement) and the subsequent agreements (i.e., repayment plans, payment deferrals and loan modifications) that are necessary to allow the borrower to repay the past due amounts (collectively, the “COVID-19 Relief”), will not be subject to the specialized accounting or disclosures that are required for TDRs if the initial relief related to COVID-19 is granted during the Applicable Period and the borrower was no more than 30 days past due as of December 31, 2019. In addition to the CARES Act, the Board of Governors of the Federal Reserve System, the Federal Deposit Insurance Corporation, National Credit Union Administration, Office of the Comptroller of the Currency, Consumer Financial Protection Bureau and the State Banking Regulators (collectively, the “Banking Agencies”) issued an Interagency Statement on Loan Modifications and Reporting for Financial Institutions Working with Customers Affected by the Coronavirus (the “Interagency Statement”) in April 2020. The Interagency Statement primarily provides incremental guidance related to the nonaccrual of interest income. It indicates that financial institutions may continue to accrue interest income on loans that are granted short-term payment delays, such as forbearance, if the delay is in response to COVID-19 and the loan was less than 30 days past due at the time the delay was granted. Pursuant to the Interagency Statement, we continue to recognize interest income at the current contractual yield for up to six months on loans that were current at March 1, 2020 and have been negatively impacted by COVID-19. For loans that are in a forbearance plan beyond six months of delinquency, we continue to accrue interest income provided collection of principal and interest continues to be reasonably assured. Our evaluation of whether the collection of principal and interest is reasonably assured will consider the probability of default, the current value of the collateral, and any proceeds that are expected from contractually attached mortgage insurance. Once the forbearance period has ended, we will also consider the extent to which the borrower and the servicer have agreed to any of the loss mitigation options that are available. For single-family loans placed on nonaccrual status, cash payments are applied as a reduction of accrued interest receivable until the receivable has been reduced to zero, and then we recognize income on a cash basis when payments are received. For multifamily loans on nonaccrual status, we apply any payment received on a cost recovery basis to reduce accrued interest receivable to zero and then reduce principal on the mortgage loan. Multifamily loans will not be placed on nonaccrual status while the loan is well secured and in the process of collection. For loans that have been negatively impacted by COVID-19, we establish a valuation allowance for expected credit losses on the accrued interest receivable balance applying the process that we have established for both single-family and multifamily loans. The credit expense related to this valuation allowance is classified as a component of the provision for credit losses. This receivable is written off when the amount is deemed to be uncollectible, in accordance with our write-off policy for mortgage loans. As a result of this update to the application of our nonaccrual policy for loans negatively impacted by COVID-19, we recognized $763 million and $2.2 billion in interest income for the three and nine months ended September 30, 2020, respectively. We also recognized $569 million of provision for loan losses on the related accrued interest receivable for the nine months ended September 30, 2020. The Current Expected Credit Loss Standard The Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments in June 2016, which was later amended by ASU 2019-04, ASU 2019-05 and ASU 2019-11. These ASUs (the “CECL standard”) replaced the existing incurred loss impairment methodology for loans that are collectively evaluated for impairment with a methodology that reflects lifetime expected credit losses and requires consideration of a broader range of reasonable and supportable forecast information to develop a lifetime credit loss estimate. The CECL standard also requires credit losses related to AFS debt securities to be recorded through an allowance for credit losses. Our adoption of this standard on January 1, 2020 did not have a material impact on our portfolio of AFS debt securities. The CECL standard became effective for our fiscal year beginning January 1, 2020. We have changed our accounting policies as described above and implemented system, model and process changes to adopt the standard. Upon adoption, we used a discounted cash flow method to measure expected credit losses on our single-family mortgage loans and an undiscounted loss method to measure expected credit losses on our multifamily mortgage loans. The models used to estimate credit losses incorporated our historical credit loss experience, adjusted for current economic forecasts and the current credit profile of our loan book of business. The models used reasonable and supportable forecasts for key economic drivers, such as home prices (single-family), rental income (multifamily) and capitalization rates (multifamily). The adoption of the CECL standard on January 1, 2020 reduced our retained earnings by $1.1 billion on an after-tax basis. The adoption of this guidance increased our overall credit loss reserves primarily as the result of an increase in our single-family loan loss reserves that were previously evaluated on a collective basis for impairment. This increase was partially offset by a decrease in estimated credit losses on loans that were previously considered individually impaired (our TDRs). The increase in our single-family loan loss reserves that were previously evaluated on a collective basis was primarily driven by the migration from an incurred-loss approach, which allowed us to consider only default events and economic conditions that already existed as of each financial reporting date, to an estimate that incorporates both expected default events over the expected life of each mortgage loan and a forecast of home prices in different economic environments over a reasonable and supportable period. The increase in loss reserves for this portion of our book was low relative to its size due to the credit quality of these loans and because as of the date of adoption our current model forecasted home price growth. The allowance for loan losses on the TDR book was already measured using an expected lifetime credit loss estimate. The credit losses on this portion of our single-family book decreased upon the adoption of the CECL standard because the new guidance required us to exclude from our estimate of credit losses all pre-foreclosure and post-foreclosure costs that are expected to be advanced after the balance sheet date. Prior to the adoption of the CECL standard, we incorporated these costs in our estimate of credit losses for this book. Impacts on Key Balance Sheet Line Items upon Implementation of the CECL Standard The following table discloses the impact of adopting the CECL standard on key balance sheet line items. Balance as of Transition Impact of Adoption of the Balance as of (Dollars in millions) Mortgage loans held for sale $ 6,773 $ 50 $ 6,823 Allowance for loan losses (9,016) (1,722) (10,738) Other assets (1) 14,312 230 14,542 Deferred tax assets, net 11,910 303 12,213 Accumulated deficit (beginning retained earnings) (118,776) (1,139) (119,915) (1) Transition adjustment primarily represents the reclassification and recognition of freestanding credit enhancements not contractually attached to the loan. For a discussion of the current period measurement of our allowance for loan losses under the CECL standard, including the expected impact of the COVID-19 pandemic, see “Note 4, Allowance for Loan Losses.” Reference Rate Reform In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”), which provides optional temporary relief to ease the potential burden of transitioning away from LIBOR and other discontinued interest rates. Specifically, ASU 2020-04 provides optional practical expedients and exceptions under GAAP related to contract modifications and hedging relationships that reference LIBOR or another reference rate expected to be discontinued. Qualifying for the accounting relief provided by ASU 2020-04 is subject to meeting certain criteria and is generally only available to contract modifications made and hedging relationships entered into or evaluated prospectively from March 12, 2020 through December 31, 2022. In May 2020, we modified trust agreements governing our Fannie Mae REMIC and other multi-class transactions issued prior to July 2013 that are backed by floating rate or reverse floating rate securities to include fallback provisions in order to ease the potential burden of transitioning away from LIBOR. The update to the fallback language in the Omnibus Trust Supplement qualified for the accounting relief provided by ASU 2020-04, and we accounted for the update as a modification to the existing agreements. The impact of the May 2020 agreement modifications governing Fannie Mae REMIC and multi-class transactions issued prior to July 2013 was not material to Fannie Mae. We had no hedge accounting relationships between March 12, 2020 and September 30, 2020. We will continue to evaluate ASU 2020-04 to determine the timing and extent to which we will apply the provided accounting relief.
Consolidations, Policy [Policy Text Block]	Principles of Consolidation Our condensed consolidated financial statements include our accounts as well as the accounts of the other entities in which we have a controlling financial interest. All intercompany balances and transactions have been eliminated. The typical condition for a controlling financial interest is ownership of a majority of the voting interests of an entity. A controlling financial interest may also exist in entities through arrangements that do not involve voting interests, such as a variable interest entity (“VIE”).
Marketable Securities, Policy [Policy Text Block]	Investments in Securities Impairment of Available-for-Sale Debt Securities An available-for-sale (“AFS”) debt security is impaired if the fair value of the investment is less than its amortized cost basis. Credit losses (benefits) on impaired AFS debt securities are recognized through an allowance for credit losses. Credit losses are evaluated on an individual security basis and are limited to the difference between the fair value of the debt security and its amortized cost basis. If we intend to sell a debt security or it is more likely than not that we will be required to sell the debt security before recovery, any allowance for credit losses on the debt security is reversed and the amortized cost basis of the debt security is written down to its fair value. 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, 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. Pursuant to the CECL standard, 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.
Financing Receivable, Held-for-sale [Policy Text Block]	Loans Held for Sale When we acquire mortgage loans that we intend to sell or securitize via trusts that will not be consolidated, we classify the loans as held for sale (“HFS”). We report the carrying value of HFS loans at the lower of cost or fair value. Any excess of an HFS loan’s cost over its fair value is recognized as a valuation allowance, with changes in the valuation allowance recognized as “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. We recognize interest income on HFS loans on an accrual basis, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. Purchased premiums, discounts and other cost basis adjustments on HFS loans are deferred upon loan acquisition, included in the cost basis of the loan, and not amortized. We determine any lower of cost or fair value adjustment on HFS loans at an individual loan level. For nonperforming loans transferred from held for investment (“HFI”) to HFS, based upon a change in our intent, we record the loans at the lower of cost or fair value on the date of transfer. When the fair value of the nonperforming loan is less than its amortized cost, we record a write-off against the allowance for loan losses in an amount equal to the difference between the amortized cost basis and the fair value of the loan. If the amount written off upon transfer exceeds the allowance related to the transferred loan, we record the excess in provision for credit losses. If the amounts written off are less than the allowance related to the loans, we recognize a benefit for credit losses. Nonperforming loans include both seriously delinquent and reperforming loans, which are loans that were previously delinquent but are performing again because payments on the mortgage loan have become current with or without the use of a loan modification plan. 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. In the event that we reclassify a performing loan from HFI to HFS, based upon a change in our intent, the allowance for loan losses previously recorded on the HFI mortgage loan is reversed through earnings at the time of reclassification. The mortgage loan is reclassified into HFS at its amortized cost basis and a valuation allowance is established to the extent that the amortized cost basis of the loan exceeds its fair value. The initial recognition of the valuation allowance and any subsequent changes are recorded as a gain or loss in “Investment gains, net.”
Financing Receivable, Held-for-investment [Policy Text Block]	Loans Held for Investment When we acquire mortgage loans that we have the ability and the intent to hold for the foreseeable future or until maturity, we classify the loans as HFI. When we consolidate a securitization trust, we recognize the loans underlying the trust in our condensed consolidated balance sheets. The trusts do not have the ability to sell mortgage loans and the use of such loans is limited exclusively to the settlement of obligations of the trusts. Therefore, mortgage loans acquired when we have the intent to securitize via consolidated trusts are generally classified as HFI in our condensed consolidated balance sheets both prior to and subsequent to their securitization. We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and allowance for loan losses. We define the amortized cost of HFI loans as unpaid principal balance and accrued interest receivable, net, including any unamortized premiums, discounts, and other cost basis adjustments. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable separately from the amortized cost of our loans held for investment. We recognize interest income on HFI loans on an accrual basis using the effective yield method over the contractual life of the loan, including the amortization of any deferred cost basis adjustments, such as the premium or discount at acquisition, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured.
Nonaccrual Loans [Policy Text Block]	Nonaccrual Loans F or loans that were current as of March 1, 2020 and subsequently became delinquent or entered into forbearance during the COVID-19 pandemic, see the changes to our application of our nonaccrual guidance in the section on New Accounting Guidance below. For loans not subject to the COVID-19-related nonaccrual guidance, we discontinue accruing interest on loans when we believe collectability of principal or 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 loans is reversed through interest income at the date a 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 that the borrower brings the loan current. We return a modified single-family loan to accrual status at the point that the borrower successfully makes all required payments during the trial period (generally three to four months) and the modification is made permanent. As of January 1, 2020, 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. Transactions related to the
Allowance for Loan Losses [Policy Text Block]	Allowance for Loan Losses Our allowance for loan losses is a valuation account that is deducted from the amortized cost basis of HFI loans to present the net amount expected to be collected on the loans. The allowance for loan losses reflects an estimate of expected credit losses on single-family and multifamily HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts. Estimates of credit losses are based on expected cash flows derived from internal models that estimate loan performance under simulated ranges of economic environments. Our modeled loan performance is based on our historical experience of loans with similar risk characteristics adjusted to reflect current conditions and reasonable and supportable forecasts. Our historical loss experience and our credit loss estimates capture the possibility of remote events that could result in credit losses on loans that are considered low risk. The allowance for loan losses does not consider benefits from freestanding credit enhancements, such as our CAS and CIRT programs and multifamily DUS lender risk-sharing arrangements, which are recorded in “Other assets” in our condensed consolidated balance sheets. For loans that were current as of March 1, 2020 and subsequently became delinquent or entered into forbearance during the COVID-19 pandemic, see changes to our allowance for loan losses in the section on New Accounting Guidance below. For loans not subject to the COVID-19 related guidance, we have elected not to measure an allowance for credit losses on accrued interest receivable balances as we have a nonaccrual policy to ensure the timely reversal of unpaid accrued interest. See “Note 4, Allowance for Loan Losses” for additional information about our current period provision for loan losses, including a discussion of the estimates used in measuring the impact of the COVID-19 pandemic on our allowance. 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, during 2020, 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.
Impaired Financing Receivable, Policy	Single-Family Loans We estimate the amount expected to be collected on our single-family loans using a discounted cash flow approach. Our allowance for loan losses is calculated as the difference between the amortized cost basis of the loan and the present value of expected cash flows on the loan. Expected cash flows include payments from the borrower, net of servicing fees, contractually attached credit enhancements and proceeds from the sale of the underlying collateral, net of selling costs. When foreclosure of a single-family loan is probable, the allowance for loan losses is calculated as the difference between the amortized cost basis of the loan and the fair value of the collateral as of the reporting date, adjusted for the estimated costs to sell the property and the amount of expected recoveries from contractually attached credit enhancements or other proceeds we expect to receive. Expected cash flows are developed using internal models that capture market and loan characteristic inputs. Market inputs include information such as actual and forecasted home prices, interest rates, volatility, and spreads, while loan characteristic inputs include information such as mark-to-market loan-to-value (“LTV”) ratios, delinquency status, geography, and borrower FICO credit scores. The model assigns a probability to borrower events including contractual payment, loan payoff and default under various economic environments based on historical data, current conditions, and reasonable and supportable forecasts. The two primary drivers of our forecasted economic environments are interest rates and home prices. Our model projects the range of possible interest rate scenarios over the life of the loan based on actual interest rates and observed option pricing volatility in the capital markets. We develop regional forecasts based on Metropolitan Statistical Area data for single-family home prices using a multi-path simulation that captures home price projections over a five-year period, the period for which we can develop reasonable and supportable forecasts. After the five-year period, the home price forecast immediately reverts to a historical long-term growth rate. Expected cash flows on the loan are discounted at the effective interest rate on the loan, adjusted for expected prepayments. For single-family loans that have not been modified in a troubled debt restructuring (“TDR”), the discount rate is updated each reporting period to reflect changes in expected prepayments. Expected cash flows do not include expected extensions of the contractual term unless such extension is the result of a reasonably expected TDR. We consider the effects of actual and reasonably expected TDRs in our estimate of credit losses. These effects include any economic concession provided or expected to be provided to a borrower experiencing financial difficulty. We consider our current servicing practices and our historical experience to estimate reasonably expected TDRs. When a loan is contractually modified in a TDR, to capture the concession, the discount rate on the loan is locked to the rate in effect just prior to the modification and is no longer updated for changes in expected prepayments. Multifamily Loans Our allowance for loan losses on multifamily loans is calculated based on estimated probabilities of default and loss severities to derive expected loss ratios, which are then applied to the amortized cost basis of the loans. Our probabilities of default and severity are estimated using internal models based on historical loss experience of loans with similar risk characteristics that affect credit performance, such as debt service coverage ratio (“DSCR”), mark-to-market LTV ratio, collateral type, age, loan size, geography, prepayment penalty term, and note type. Our models simulate a range of possible future economic scenarios, which are used to estimate probabilities of default and loss severities. Key inputs to our models include rental income, which drives expected DSCRs for our loans, and capitalization rates, which project future property values. Our reasonable and supportable forecasts for multifamily rental income and capitalization rates, which are projected based on Metropolitan Statistical Area data, extend through the contractual maturity of the loans. For TDRs, we use a discounted cash flow approach to estimate expected credit losses.
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.We consolidate the substantial majority of our single-class MBS trusts; therefore, these portfolio securitization transactions do not qualify for sale treatment. The assets and liabilities of consolidated trusts created via portfolio securitization transactions that do not qualify as sales are reported in our consolidated balance sheets.We recognize assets obtained and liabilities incurred in qualifying sales of portfolio securitizations at fair value.
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.With our adoption of the CECL standard on January 1, 2020, 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.
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 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.
Derivatives, Policy [Policy Text Block]	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 flowsWe record all derivative gains and losses, including accrued interest, in “Fair value losses, net” in our condensed consolidated statements of operations and comprehensive income.
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.
Derivatives, Offsetting Policy [Policy Text Block]	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.
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. 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

Organization, Consolidation and Presentation of Financial Statements (Policies)	9 Months Ended
	Sep. 30, 2020
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.We consolidate the substantial majority of our single-class MBS trusts; therefore, these portfolio securitization transactions do not qualify for sale treatment. The assets and liabilities of consolidated trusts created via portfolio securitization transactions that do not qualify as sales are reported in our consolidated balance sheets.We recognize assets obtained and liabilities incurred in qualifying sales of portfolio securitizations at fair value.

Comprehensive Text Block List (

Comprehensive Text Block List (Policies)	9 Months Ended
	Sep. 30, 2020
Text Block [Abstract]
Allowance for Loan Losses [Policy Text Block]	Allowance for Loan Losses Our allowance for loan losses is a valuation account that is deducted from the amortized cost basis of HFI loans to present the net amount expected to be collected on the loans. The allowance for loan losses reflects an estimate of expected credit losses on single-family and multifamily HFI loans held by Fannie Mae and by consolidated Fannie Mae MBS trusts. Estimates of credit losses are based on expected cash flows derived from internal models that estimate loan performance under simulated ranges of economic environments. Our modeled loan performance is based on our historical experience of loans with similar risk characteristics adjusted to reflect current conditions and reasonable and supportable forecasts. Our historical loss experience and our credit loss estimates capture the possibility of remote events that could result in credit losses on loans that are considered low risk. The allowance for loan losses does not consider benefits from freestanding credit enhancements, such as our CAS and CIRT programs and multifamily DUS lender risk-sharing arrangements, which are recorded in “Other assets” in our condensed consolidated balance sheets. For loans that were current as of March 1, 2020 and subsequently became delinquent or entered into forbearance during the COVID-19 pandemic, see changes to our allowance for loan losses in the section on New Accounting Guidance below. For loans not subject to the COVID-19 related guidance, we have elected not to measure an allowance for credit losses on accrued interest receivable balances as we have a nonaccrual policy to ensure the timely reversal of unpaid accrued interest. See “Note 4, Allowance for Loan Losses” for additional information about our current period provision for loan losses, including a discussion of the estimates used in measuring the impact of the COVID-19 pandemic on our allowance. 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, during 2020, 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 Se

Investments, Debt and Equity Securities (Policies)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Marketable Securities, Policy [Policy Text Block]	Investments in Securities Impairment of Available-for-Sale Debt Securities An available-for-sale (“AFS”) debt security is impaired if the fair value of the investment is less than its amortized cost basis. Credit losses (benefits) on impaired AFS debt securities are recognized through an allowance for credit losses. Credit losses are evaluated on an individual security basis and are limited to the difference between the fair value of the debt security and its amortized cost basis. If we intend to sell a debt security or it is more likely than not that we will be required to sell the debt security before recovery, any allowance for credit losses on the debt security is reversed and the amortized cost basis of the debt security is written down to its fair value. 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, 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. Pursuant to the CECL standard, 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.

Accounting Policies (Tables)

Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table discloses the impact of adopting the CECL standard on key balance sheet line items. Balance as of Transition Impact of Adoption of the Balance as of (Dollars in millions) Mortgage loans held for sale $ 6,773 $ 50 $ 6,823 Allowance for loan losses (9,016) (1,722) (10,738) Other assets (1) 14,312 230 14,542 Deferred tax assets, net 11,910 303 12,213 Accumulated deficit (beginning retained earnings) (118,776) (1,139) (119,915) (1) Transition adjustment primarily represents the reclassification and recognition of freestanding credit enhancements not contractually attached to the loan.

Consolidations and Transfers _2

Consolidations and Transfers of Financial Assets (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 December 31, 2019 (Dollars in millions) Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts: Assets: Trading securities: Fannie Mae $ 1,900 $ 2,543 Non-Fannie Mae 3,676 5,100 Total trading securities 5,576 7,643 Available-for-sale securities: Fannie Mae 1,284 1,524 Non-Fannie Mae 361 574 Total available-for-sale securities 1,645 2,098 Other assets 42 56 Other liabilities (68) (78) Net carrying amount $ 7,195 $ 9,719

Mortgage Loans (Tables)

Mortgage Loans (Tables)	9 Months Ended
	Sep. 30, 2020
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 mortgage loans and our allowance for loan losses. As of September 30, 2020 December 31, 2019 (Dollars in millions) Single-family $ 3,137,726 $ 2,972,361 Multifamily 355,950 327,593 Total unpaid principal balance of mortgage loans 3,493,676 3,299,954 Cost basis and fair value adjustments, net 65,370 43,224 Allowance for loan losses (11,703) (9,016) Total mortgage loans (1) $ 3,547,343 $ 3,334,162 (1) Excludes $9.6 billion and $8.4 billion of accrued interest receivable, net of allowance on mortgage loans as of September 30, 2020 and December 31, 2019, 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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Single family loans redesignated from HFI to HFS: Amortized cost $ 5,305 $ 5,154 $ 6,942 $ 15,287 Lower of cost or fair value adjustment at time of redesignation (1) (227) (227) (236) (946) Allowance reversed at time of redesignation 737 780 921 2,149 Single-family loans sold: Unpaid principal balance $ 4,593 $ 3,941 $ 5,088 $ 10,497 Realized gains, net 424 184 464 504 (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. 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. The increase in loans classified as delinquent as of September 30, 2020 compared with December 31, 2019 was primarily attributable to the economic dislocation caused by the COVID-19 pandemic. As of September 30, 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 $ 27,339 $ 13,584 $ 99,491 $ 140,414 $ 2,529,879 $ 2,670,293 $ 81,405 $ 7,156 15-year or less, amortizing fixed-rate 2,084 965 6,170 9,219 420,848 430,067 5,533 393 Adjustable-rate 309 172 1,363 1,844 33,461 35,305 1,160 135 Other (2) 1,267 606 5,355 7,228 51,276 58,504 3,271 785 Total single-family 30,999 15,327 112,379 158,705 3,035,464 3,194,169 91,369 8,469 Multifamily (3) 512 N/A 4,074 4,586 355,131 359,717 3,729 44 Total $ 31,511 $ 15,327 $ 116,453 $ 163,291 $ 3,390,595 $ 3,553,886 $ 95,098 $ 8,513 As of December 31, 2019 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Loans 90 Days or More Delinquent and Accruing Interest (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate $ 26,882 $ 7,126 $ 13,082 $ 47,090 $ 2,470,457 $ 2,517,547 $ 28 15-year or less, amortizing fixed-rate 1,616 286 445 2,347 371,740 374,087 — Adjustable-rate 412 85 167 664 44,244 44,908 — Other (2) 2,323 829 1,891 5,043 64,726 69,769 136 Total single-family 31,233 8,326 15,585 55,144 2,951,167 3,006,311 164 Multifamily (3) 7 N/A 115 122 330,496 330,618 — Total $ 31,240 $ 8,326 $ 15,700 $ 55,266 $ 3,281,663 $ 3,336,929 $ 164 (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.
Troubled Debt Restructurings Activity [Table Text Block]	The following tables display the number of loans and amortized cost in loans classified as a TDR. For the Three Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 5,993 $ 1,006 10,113 $ 1,694 15-year or less, amortizing fixed-rate 579 50 1,078 97 Adjustable-rate 109 16 182 28 Other 371 47 648 87 Total single-family 7,052 1,119 12,021 1,906 Multifamily — — 3 4 Total TDRs 7,052 $ 1,119 12,024 $ 1,910 For the Nine Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 25,360 $ 4,412 31,960 $ 5,226 15-year or less, amortizing fixed-rate 2,448 216 3,554 317 Adjustable-rate 395 62 612 91 Other 1,464 185 2,383 323 Total single-family 29,667 4,875 38,509 5,957 Multifamily — — 9 37 Total TDRs 29,667 $ 4,875 38,518 $ 5,994 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 September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 2,956 $ 532 3,582 $ 567 15-year or less, amortizing fixed-rate 21 1 164 12 Adjustable-rate 3 — 34 5 Other 219 35 422 62 Total single-family 3,199 568 4,202 646 Multifamily — — 1 13 Total TDRs that subsequently defaulted 3,199 $ 568 4,203 $ 659 For the Nine Months Ended September 30, 2020 2019 Number of Loans Amortized Cost Number of Loans Amortized Cost (Dollars in millions) Single-family: 20- and 30-year or more, amortizing fixed-rate 11,529 $ 2,119 11,871 $ 1,825 15-year or less, amortizing fixed-rate 106 7 415 30 Adjustable-rate 15 2 57 8 Other 1,094 180 1,564 247 Total single-family 12,744 2,308 13,907 2,110 Multifamily 4 16 2 19 Total TDRs that subsequently defaulted 12,748 $ 2,324 13,909 $ 2,129
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 updates to our application of our nonaccrual policy for loans negatively impacted by the COVID-19 pandemic, see “Note 1, Summary of Significant Accounting Policies.” For the Three Months Ended September 30, 2020 For the Nine Months Ended September 30, 2020 (Dollars in millions) Single-family: Interest income forgone (1) $ 219 $ 573 Accrued interest receivable written off through the reversal of interest income 33 165 Multifamily: Interest income forgone (1) $ 8 $ 9 Accrued interest receivable written off through the reversal of interest income 5 7 (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 September 30, 2020 For the Nine Months Ended September 30, 2020 September 30, 2020 June 30, 2020 December 31, 2019 Amortized Cost Total Interest Income Recognized (1) (Dollars in millions) Single-family: 20- and 30-year or more, $ 21,902 $ 23,783 $ 23,427 $ 68 $ 309 15-year or less, amortizing fixed-rate 780 844 858 2 9 Adjustable-rate 247 275 288 1 3 Other 2,438 2,851 2,973 5 31 Total single-family 25,367 27,753 27,546 76 352 Multifamily 347 316 435 — 3 Total nonaccrual loans $ 25,714 $ 28,069 $ 27,981 $ 76 $ 355 (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.
Individually Impaired Loans [Table Text Block]	The following tables display the unpaid principal balance, total amortized cost and related allowance for loan losses as of December 31, 2019 and average amortized cost, total interest income recognized and interest income recognized on a cash basis for individually impaired loans for the three and nine months ended September 30, 2019. As of December 31, 2019 Unpaid Principal Balance Total Amortized Cost Related Allowance for Loan Losses (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 63,091 $ 61,033 $ (5,851) 15-year or less, amortizing fixed-rate 954 960 (24) Adjustable-rate 156 157 (9) Other 15,181 14,078 (2,291) Total single-family 79,382 76,228 (8,175) Multifamily 314 315 (45) Total individually impaired loans with related allowance recorded 79,696 76,543 (8,220) With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 18,372 17,578 — 15-year or less, amortizing fixed-rate 410 407 — Adjustable-rate 265 265 — Other 3,014 2,718 — Total single-family 22,061 20,968 — Multifamily 363 365 — Total individually impaired loans with no related allowance recorded 22,424 21,333 — Total individually impaired loans (2) $ 102,120 $ 97,876 $ (8,220) (1) The discounted cash flows or collateral value equals or exceeds the carrying value of the loan and, as such, no valuation allowance is required. (2) Includes single-family loans restructured in a TDR with an amortized cost of $96.9 billion as of December 31, 2019. Includes multifamily loans restructured in a TDR with an amortized cost of $102 million as of December 31, 2019. For the Three Months Ended September 30, 2019 Average Amortized Cost Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 67,788 $ 702 $ 61 15-year or less, amortizing fixed-rate 1,141 10 1 Adjustable-rate 155 1 1 Other 16,011 164 11 Total single-family 85,095 877 74 Multifamily 313 2 — Total individually impaired loans with related allowance recorded 85,408 879 74 With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 15,787 255 37 15-year or less, amortizing fixed-rate 329 4 1 Adjustable-rate 300 3 1 Other 2,767 55 5 Total single-family 19,183 317 44 Multifamily 401 8 — Total individually impaired loans with no related allowance recorded 19,584 325 44 Total individually impaired loans $ 104,992 $ 1,204 $ 118 For the Nine Months Ended September 30, 2019 Average Amortized Cost Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: 20- and 30-year or more, amortizing fixed-rate $ 72,229 $ 2,268 $ 210 15-year or less, amortizing fixed-rate 1,237 32 3 Adjustable-rate 135 4 1 Other 17,995 557 41 Total single-family 91,596 2,861 255 Multifamily 280 7 — Total individually impaired loans with related allowance recorded 91,876 2,868 255 With no related allowance recorded: (1) Single-family: 20- and 30-year or more, amortizing fixed-rate 15,041 708 98 15-year or less, amortizing fixed-rate 320 11 3 Adjustable-rate 352 12 2 Other 2,875 158 14 Total single-family 18,588 889 117 Multifamily 377 16 — Total individually impaired loans with no related allowance recorded 18,965 905 117 Total individually impaired loans $ 110,841 $ 3,773 $ 372 (1) The discounted cash flows or collateral value equals or exceeds the carrying value of the loan and, as such, no valuation allowance is required.
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]	The following table displays 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 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 September 30, 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% $ 533,538 $ 261,595 $ 148,609 $ 210,619 $ 255,376 $ 868,596 $ 2,278,333 Greater than 80% and less than or equal to 90% 105,147 105,917 40,296 11,281 2,789 7,711 273,141 Greater than 90% and less than or equal to 100% 94,975 16,605 1,542 432 171 2,603 116,328 Greater than 100% 17 21 41 101 103 2,208 2,491 Total 20 and 30-year or more, amortizing fixed-rate 733,677 384,138 190,488 222,433 258,439 881,118 2,670,293 15-year or less, amortizing fixed-rate: Less than or equal to 80% 124,783 46,988 18,095 35,192 50,610 146,127 421,795 Greater than 80% and less than or equal to 90% 5,020 1,627 100 18 11 25 6,801 Greater than 90% and less than or equal to 100% 1,379 38 4 5 3 12 1,441 Greater than 100% — — 4 6 4 16 30 Total 15-year or less, amortizing fixed-rate 131,182 48,653 18,203 35,221 50,628 146,180 430,067 Adjustable-rate: Less than or equal to 80% 2,542 2,102 2,853 5,696 3,169 18,138 34,500 Greater than 80% and less than or equal to 90% 233 233 179 42 4 18 709 Greater than 90% and less than or equal to 100% 72 16 2 2 — 3 95 Greater than 100% — — — — — 1 1 Total adjustable-rate 2,847 2,351 3,034 5,740 3,173 18,160 35,305 Other: Less than or equal to 80% — 42 341 839 1,076 37,973 40,271 Greater than 80% and less than or equal to 90% — 3 25 54 37 1,590 1,709 Greater than 90% and less than or equal to 100% — 1 11 22 16 736 786 Greater than 100% — 1 5 11 11 782 810 Total other — 47 382 926 1,140 41,081 43,576 Total $ 867,706 $ 435,189 $ 212,107 $ 264,320 $ 313,380 $ 1,086,539 $ 3,179,241 Total for all classes by LTV ratio: (2) Less than or equal to 80% $ 660,863 $ 310,727 $ 169,898 $ 252,346 $ 310,231 $ 1,070,834 $ 2,774,899 Greater than 80% and less than or equal to 90% 110,400 107,780 40,600 11,395 2,841 9,344 282,360 Greater than 90% and less than or equal to 100% 96,426 16,660 1,559 461 190 3,354 118,650 Greater than 100% 17 22 50 118 118 3,007 3,332 Total $ 867,706 $ 435,189 $ 212,107 $ 264,320 $ 313,380 $ 1,086,539 $ 3,179,241 As of December 31, 2019 (1) 20- and 30-Year or More, Amortizing Fixed-Rate 15-Year or Less, Amortizing Fixed-Rate Adjustable-Rate Other Total (Dollars in millions) Estimated mark-to-market LTV ratio: (2) Less than or equal to 80% $ 2,145,018 $ 368,181 $ 43,415 $ 47,005 $ 2,603,619 Greater than 80% and less than or equal to 90% 237,623 4,556 1,275 2,872 246,326 Greater than 90% and less than or equal to 100% 130,152 1,284 215 1,398 133,049 Greater than 100% 4,754 66 3 1,365 6,188 Total $ 2,517,547 $ 374,087 $ 44,908 $ 52,640 $ 2,989,182 (1) Excludes $14.9 billion and $17.1 billion as of September 30, 2020 and December 31, 2019, 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.
Multifamily [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Credit Quality Indicators [Table Text Block]	The following table displays the total amortized cost of 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 September 30, 2020, by Year of Origination 2020 2019 2018 2017 2016 Prior Total (Dollars in millions) Internally assigned credit risk rating: Non-classified (1) $ 45,240 $ 68,698 $ 62,601 $ 51,824 $ 44,804 $ 76,825 $ 349,992 Classified (2) 8 848 1,448 2,559 1,489 3,373 9,725 Total $ 45,248 $ 69,546 $ 64,049 $ 54,383 $ 46,293 $ 80,198 $ 359,717 As of December 31, 2019 (Dollars in millions) Internally assigned credit risk rating: Non-classified (1) $ 323,773 Classified (2) 6,845 Total $ 330,618 (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. We had no loans classified as doubtful as of September 30, 2020 and loans with an amortized cost of $5 million classified as doubtful as of December 31, 2019.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Financing Receivable, Allowance for Credit Loss	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 the CECL standard. For the Three Months Ended September 30, 2020 For the Nine Months Ended September 30, 2020 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,598) $ (8,759) Transition impact of the adoption of the CECL standard — (1,229) Benefit (provision) for loan losses 931 (857) Write-offs 261 377 Recoveries (4) (10) Other 23 91 Ending Balance $ (10,387) $ (10,387) Multifamily allowance for loan losses: Beginning balance $ (1,368) $ (257) Transition impact of the adoption of the CECL standard — (493) Provision for loan losses (34) (669) Write-offs 86 104 Recoveries — (1) Ending Balance $ (1,316) $ (1,316) Total allowance for loan losses: Beginning balance $ (12,966) $ (9,016) Transition impact of the adoption of the CECL standard — (1,722) Benefit (provision) for loan losses 897 (1,526) Write-offs 347 481 Recoveries (4) (11) Other 23 91 Ending Balance $ (11,703) $ (11,703) The following tables display prior period changes in single-family and multifamily allowance for loan losses and the prior period amortized cost in our HFI loans by impairment or allowance methodology and portfolio segment prior to the adoption of the CECL standard. For a description of our previous allowance and impairment methodology refer to “Note 1, Summary of Significant Accounting Policies” in our 2019 Form 10-K. For the Three Months Ended September 30, 2019 For the Nine Months Ended September 30, 2019 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,210) $ (13,969) Benefit for loan losses 1,826 3,712 Write-offs 270 1,209 Recoveries (8) (68) Other — (6) Ending Balance $ (9,122) $ (9,122) Multifamily allowance for loan losses: Beginning balance $ (272) $ (234) Benefit (provision) for loan losses 17 (23) Write-offs 2 6 Recoveries (1) (3) Ending Balance $ (254) $ (254) Total allowance for loan losses: Beginning balance $ (11,482) $ (14,203) Benefit for loan losses 1,843 3,689 Write-offs 272 1,215 Recoveries (9) (71) Other — (6) Ending Balance $ (9,376) $ (9,376) As of December 31, 2019 Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans $ (8,175) $ (45) $ (8,220) Collectively reserved loans (584) (212) (796) Total allowance for loan losses $ (8,759) $ (257) $ (9,016) Amortized cost in loans by segment: Individually impaired loans $ 97,196 $ 680 $ 97,876 Collectively reserved loans 2,909,115 329,938 3,239,053 Total amortized cost in loans $ 3,006,311 $ 330,618 $ 3,336,929

Investments in Securities (Tabl

Investments in Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Investments In Trading Securities [Table Text Block]	The following table displays our investments in trading securities. As of September 30, 2020 December 31, 2019 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 2,750 $ 3,424 Other agency (1) 3,518 4,490 Private-label and other mortgage securities 158 629 Total mortgage-related securities (includes $850 million and $896 million, respectively, related to consolidated trusts) 6,426 8,543 Non-mortgage-related securities: U.S. Treasury securities 135,972 39,501 Other securities 74 79 Total non-mortgage-related securities 136,046 39,580 Total trading securities $ 142,472 $ 48,123 (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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Net trading gains (losses) $ (91) $ 95 $ 691 $ 370 Net trading gains (losses) recognized in the period related to securities still held at period end (71) 82 448 298
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	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 September 30, 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 $ 1,195 $ — $ 102 $ (14) $ 1,283 Other agency (2) 85 — 11 — 96 Alt-A and subprime private-label securities 4 — 2 — 6 Mortgage revenue bonds 249 (3) 9 — 255 Other mortgage-related securities 247 — 8 — 255 Total $ 1,780 $ (3) $ 132 $ (14) $ 1,895 As of December 31, 2019 Total Amortized Cost (1)(3) Gross Unrealized Gains Gross Unrealized Losses Total Fair Value (1) (Dollars in millions) Fannie Mae $ 1,445 $ 85 $ (10) $ 1,520 Other agency (2) 183 15 — 198 Alt-A and subprime private-label securities 34 23 — 57 Mortgage revenue bonds 309 9 (3) 315 Other mortgage-related securities 310 5 (1) 314 Total $ 2,281 $ 137 $ (14) $ 2,404 (1) We exclude from amortized cost and fair value accrued interest of $7 million and $10 million as of September 30, 2020 and December 31, 2019 , 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. (3) Prior to our adoption of the CECL standard, total amortized cost represented the unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, as well as temporary impairments recognized in “Investment gains, net” in our consolidated statements of operations and comprehensive income.
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	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 September 30, 2020 Less Than 12 Consecutive Months 12 Consecutive Months or Longer Gross Unrealized Losses in AOCI Fair Value Gross Unrealized Losses in AOCI Fair Value (Dollars in millions) Fannie Mae $ (2) $ 72 $ (12) $ 90 Mortgage revenue bonds — — — — Other mortgage-related securities — — — — Total $ (2) $ 72 $ (12) $ 90 As of December 31, 2019 Less Than 12 Consecutive Months 12 Consecutive Months or Longer Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (Dollars in millions) Fannie Mae $ — $ — $ (10) $ 337 Mortgage revenue bonds — — (3) 3 Other mortgage-related securities (1) 130 — — Total $ (1) $ 130 $ (13) $ 340
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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Gross realized gains $ 15 $ — $ 45 $ 171 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 137 — 258 376
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 September 30, 2020 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded an allowance for credit losses $ 93 Other 27 Accumulated other comprehensive income $ 120 As of December 31, 2019 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 97 Other 34 Accumulated other comprehensive income $ 131
Investments Classified by Contractual Maturity Date [Table Text Block]	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 September 30, 2020 Total Carrying Amount (1) Total 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 $ 1,195 $ 1,283 $ — $ — $ 6 $ 6 $ 88 $ 100 $ 1,101 $ 1,177 Other agency 85 96 — — — — 10 11 75 85 Alt-A and subprime private-label securities 4 6 — — — — 2 3 2 3 Mortgage revenue bonds 246 255 1 1 28 30 24 24 193 200 Other mortgage-related securities 247 255 — — — — 20 21 227 234 Total $ 1,777 $ 1,895 $ 1 $ 1 $ 34 $ 36 $ 144 $ 159 $ 1,598 $ 1,699 (1) Net carrying amount consists of book value, net of allowance for credit losses on AFS debt securities.

Financial Guarantees (Tables)

Financial Guarantees (Tables)	9 Months Ended
	Sep. 30, 2020
Guarantees [Abstract]
Financial Guarantees and Maximum Recovery [Table Text Block]	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 September 30, 2020 December 31, 2019 Maximum Exposure Guaranty Obligation Maximum Recovery (1) Maximum Exposure Guaranty Obligation Maximum Recovery (1) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 4,880 $ 18 $ 4,666 $ 5,801 $ 26 $ 5,545 Other guaranty arrangements (2) 11,950 110 2,424 12,670 128 2,553 Total $ 16,830 $ 128 $ 7,090 $ 18,471 $ 154 $ 8,098 (1) Recoverability of such credit enhancements and recourse is subject to, among other factors, our mortgage insurers’ and financial guarantors’ ability to meet their obligations to us. For information on our mortgage insurers, see “Note 10, Concentrations of Credit Risk.” (2) Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt (

Short-Term and Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 December 31, 2019 Outstanding Weighted- Average Interest Rate (1) Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Federal funds purchased and securities sold under agreements to repurchase (2) $ — — % $ 478 1.67 % Short-term debt of Fannie Mae 23,526 0.23 26,662 1.56 (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Represents agreements to repurchase securities for a specified price, with repayment generally occurring on the following day, reported as “Other liabilities” in our condensed consolidated balance sheets.
Long-Term Debt [Table Text Block]	The following table displays our outstanding long-term debt. As of September 30, 2020 December 31, 2019 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2020 - 2030 $ 104,323 2.26 % 2020 - 2030 $ 86,114 2.66 % Medium-term notes (2) 2020 - 2030 37,983 0.73 2020 - 2026 32,590 1.57 Other (3) 2020 - 2038 5,214 4.63 2020 - 2038 5,254 5.01 Total senior fixed 147,520 1.95 123,958 2.47 Senior floating: Medium-term notes (2) 2020 - 2022 102,585 0.35 2020 - 2021 9,774 1.66 Connecticut Avenue Securities (4) 2023 - 2031 15,336 4.34 2023 - 2031 21,424 5.61 Other (5) 2037 435 5.14 2020 - 2037 398 6.27 Total senior floating 118,356 0.89 31,596 4.40 Secured borrowings (6) 2021 - 2022 21 3.00 2021 - 2022 31 2.31 Total long-term debt of Fannie Mae (7) 265,897 1.48 155,585 2.86 Debt of consolidated trusts 2020 - 2059 3,530,381 2.09 2020 - 2059 3,285,139 2.78 Total long-term debt $ 3,796,278 2.04 % $ 3,440,724 2.78 % (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Includes long-term debt with an original contractual maturity of greater than 1 year and up to 10 years, excluding zero-coupon debt. (3) Includes other long-term debt with an original contractual maturity of greater than 10 years and foreign exchange bonds. (4) 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 2019 Form 10-K for more information about our CAS structures issued beginning November 2018. (5) Consists of structured debt instruments that are reported at fair value. (6) Represents our remaining liability resulting from the transfer of financial assets from our condensed consolidated balance sheets that did not qualify as a sale under the accounting guidance for the transfer of financial instruments. (7) Includes unamortized discounts and premiums, other cost basis adjustments and fair value adjustments in a net discount position of $491 million and $2 million as of September 30, 2020 and December 31, 2019, respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2020
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. As of September 30, 2020 As of December 31, 2019 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: Swaps: Pay-fixed $ 110,215 $ — $ 25,728 $ (1,297) $ 41,052 $ — $ 29,178 $ (970) Receive-fixed 109,774 1,082 19,213 (54) 73,579 816 26,382 (62) Basis 250 218 — — 273 149 — — Foreign currency 224 41 226 (78) 229 39 232 (65) Swaptions: Pay-fixed 5,400 10 5,525 (341) 4,600 18 6,375 (219) Receive-fixed 6,625 591 800 (138) 2,875 106 4,600 (232) Futures (1) 55,004 — — — 20,507 — — — Total gross risk management derivatives 287,492 1,942 51,492 (1,908) 143,115 1,128 66,767 (1,548) Accrued interest receivable — 111 — (230) — 226 — (250) Netting adjustment (2) — (2,037) — 2,053 — (1,288) — 1,694 Total net risk management derivatives $ 287,492 $ 16 $ 51,492 $ (85) $ 143,115 $ 66 $ 66,767 $ (104) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 36,756 $ 93 $ 9,180 $ (13) $ 7,115 $ 15 $ 1,787 $ (1) Forward contracts to purchase mortgage-related securities 122,096 402 37,607 (70) 55,531 137 9,560 (28) Forward contracts to sell mortgage-related securities 45,165 68 232,148 (759) 9,282 13 109,066 (277) Total mortgage commitment derivatives 204,017 563 278,935 (842) 71,928 165 120,413 (306) Credit enhancement derivatives 20,804 459 10,060 (38) 28,432 40 9,486 (25) Derivatives at fair value $ 512,313 $ 1,038 $ 340,487 $ (965) $ 243,475 $ 271 $ 196,666 $ (435) (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 September 30, For the Nine Months Ended September 30, 2020 2019 2020 2019 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ 634 $ (1,414) $ (3,489) $ (4,913) Receive-fixed (550) 966 2,984 4,131 Basis (5) 24 68 75 Foreign currency 23 (11) (11) (9) Swaptions: Pay-fixed 2 (110) (159) (430) Receive-fixed (60) 209 597 309 Futures — 42 (75) 296 Net contractual interest expense on interest-rate swaps (46) (190) (216) (698) Total risk management derivatives fair value losses, net (2) (484) (301) (1,239) Mortgage commitment derivatives fair value losses, net (672) (177) (2,327) (946) Credit enhancement derivatives fair value gains (losses), net 380 (7) 400 (31) Total derivatives fair value losses, net $ (294) $ (668) $ (2,228) $ (2,216)

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Segment results [Table Text Block]	The following tables display our segment results. For the Three Months Ended September 30, 2020 2019 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 5,870 $ 786 $ 6,656 $ 4,484 $ 864 $ 5,348 Fee and other income (2) 73 20 93 156 32 188 Net revenues 5,943 806 6,749 4,640 896 5,536 Investment gains, net (3) 583 70 653 198 55 253 Fair value gains (losses), net (4) (244) (83) (327) (719) 6 (713) Administrative expenses (634) (128) (762) (634) (115) (749) Credit-related income (expense): (5) Benefit (provision) for credit losses 542 (41) 501 1,840 17 1,857 Foreclosed property expense (64) (7) (71) (93) (3) (96) Total credit-related income (expense) 478 (48) 430 1,747 14 1,761 TCCA fees (6) (679) — (679) (613) — (613) Credit enhancement expense (7) (274) (51) (325) (240) (50) (290) Change in expected credit enhancement recoveries (8) (48) — (48) — — — Other expenses, net (307) (6) (313) (184) (2) (186) Income before federal income taxes 4,818 560 5,378 4,195 804 4,999 Provision for federal income taxes (1,049) (100) (1,149) (872) (164) (1,036) Net income $ 3,769 $ 460 $ 4,229 $ 3,323 $ 640 $ 3,963 For the Nine Months Ended September 30, 2020 2019 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 15,350 $ 2,430 $ 17,780 $ 12,942 $ 2,429 $ 15,371 Fee and other income (2) 238 65 303 350 85 435 Net revenues 15,588 2,495 18,083 13,292 2,514 15,806 Investment gains, net (3) 527 117 644 709 138 847 Fair value gains (losses), net (4) (1,734) 113 (1,621) (2,364) 66 (2,298) Administrative expenses (1,888) (377) (2,265) (1,899) (338) (2,237) Credit-related income (expense): (5) Benefit (provision) for credit losses (1,411) (683) (2,094) 3,753 (21) 3,732 Foreclosed property expense (145) (16) (161) (362) (2) (364) Total credit-related income (expense) (1,556) (699) (2,255) 3,391 (23) 3,368 TCCA fees (6) (1,976) — (1,976) (1,806) — (1,806) Credit enhancement expense (7) (897) (164) (1,061) (639) (143) (782) Change in expected credit enhancement recoveries (8) 218 195 413 — — — Other expenses, net (722) (70) (792) (540) (11) (551) Income before federal income taxes 7,560 1,610 9,170 10,144 2,203 12,347 Provision for federal income taxes (1,623) (312) (1,935) (2,125) (427) (2,552) Net income $ 5,937 $ 1,298 $ 7,235 $ 8,019 $ 1,776 $ 9,795 (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. (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. The presentation of our credit-related income or expense for the three and nine months ended September 30, 2019 represents amounts recognized prior to our transition to the lifetime loss model prescribed by the CECL standard. (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 CIRT, CAS and EPMI programs. Multifamily credit enhancement expense primarily consists of costs associated with our MCIRT and 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. (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” for more information about our change in presentation.

Concentrations of Credit Risk (

Concentrations of Credit Risk (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 December 31, 2019 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 1.00 % 0.49 % 3.61 % 1.07 % 0.29 % 0.59 % Percentage of single-family conventional loans based on loan count 1.11 0.50 3.20 1.27 0.35 0.66
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of September 30, 2020 December 31, 2019 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% * 21.74 % * 10.14 % Geographical distribution: California 19 % 3.04 19 % 0.32 Florida 6 4.76 6 0.84 Illinois 3 3.46 4 0.91 New Jersey 3 5.31 3 1.13 New York 5 5.39 5 1.18 All other states 64 2.85 63 0.64 Product distribution: Alt-A 1 9.46 2 2.95 Vintages: 2004 and prior 2 5.81 2 2.48 2005-2008 3 9.84 4 4.11 2009-2020 95 2.74 94 0.35 * Represents less than 0.5% of single-family conventional guaranty book of business.
Schedule of Risk in Force Mortgage Insurance Coverage [Table Text Block]	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 September 30, 2020 December 31, 2019 Risk in Force Percentage of Single-Family Guaranty Book of Business Risk in Force Percentage of Single-Family Guaranty Book of Business (Dollars in millions) Mortgage insurance risk in force: Primary mortgage insurance $ 169,011 $ 162,855 Pool mortgage insurance 296 339 Total mortgage insurance risk in force $ 169,307 5% $ 163,194 6%
Schedule of Risk in Force Mortgage Insurance Coverage, by Counterparty [Table Text Block]	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 September 30, 2020 December 31, 2019 Counterparty: (1) Arch Capital Group Ltd. 21 % 23 % Radian Guaranty, Inc. 19 20 Mortgage Guaranty Insurance Corp. 18 18 Genworth Mortgage Insurance Corp. (2) 17 15 Essent Guaranty, Inc. 15 14 Others 10 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 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 September 30, 2020 December 31, 2019 Wells Fargo Bank, N.A. (together with its affiliates) 15 % 17 % Remaining top five depository servicers 12 15 Top five non-depository servicers 25 27 Total 52 % 59 %
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 September 30, 2020 (1) December 31, 2019 (1) 30 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent Seriously Delinquent (2) Percentage of multifamily guaranty book of business 0.14 % 1.12 % 0.02 % 0.04 % (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 September 30, 2020 December 31, 2019 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 % 1.24 % 1 % — % Less than or equal to 80% 99 1.12 99 0.04 Current DSCR below 1.0 (4) 2 22.07 2 0.48 (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.
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	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 September 30, 2020 December 31, 2019 Wells Fargo Bank, N.A. (together with its affiliates) 13 % 13 % Walker & Dunlop, Inc. 12 12 Remaining top five servicers 23 23 Total 48 % 48 %

Netting Arrangements (Tables)

Netting Arrangements (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 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 $ 2,053 $ (2,052) $ 1 $ — $ — $ 1 Cleared risk management derivatives — 15 15 — — 15 Mortgage commitment derivatives 563 — 563 (289) (23) 251 Total derivative assets 2,616 (2,037) 579 (4) (289) (23) 267 Securities purchased under agreements to resell or similar arrangements (5) 27,100 — 27,100 — (27,100) — Total assets $ 29,716 $ (2,037) $ 27,679 $ (289) $ (27,123) $ 267 Liabilities: OTC risk management derivatives $ (2,138) $ 2,056 $ (82) $ — $ — $ (82) Cleared risk management derivatives — (3) (3) — 3 — Mortgage commitment derivatives (842) — (842) 289 529 (24) Total derivative liabilities (2,980) 2,053 (927) (4) 289 532 (106) Total liabilities $ (2,980) $ 2,053 $ (927) $ 289 $ 532 $ (106) As of December 31, 2019 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 $ 1,354 $ (1,334) $ 20 $ — $ — $ 20 Cleared risk management derivatives — 46 46 — — 46 Mortgage commitment derivatives 165 — 165 (101) (1) 63 Total derivative assets 1,519 (1,288) 231 (4) (101) (1) 129 Securities purchased under agreements to resell or similar arrangements (5) 24,928 — 24,928 — (24,928) — Total assets $ 26,447 $ (1,288) $ 25,159 $ (101) $ (24,929) $ 129 Liabilities: OTC risk management derivatives $ (1,798) $ 1,695 $ (103) $ — $ — $ (103) Cleared risk management derivatives — (1) (1) — 1 — Mortgage commitment derivatives (306) — (306) 101 181 (24) Total derivative liabilities (2,104) 1,694 (410) (4) 101 182 (127) Securities sold under agreements to repurchase or similar arrangements (478) — (478) — 475 (3) Total liabilities $ (2,582) $ 1,694 $ (888) $ 101 $ 657 $ (130) (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 $4.8 billion and $2.3 billion as of September 30, 2020 and December 31, 2019, respectively. The fair value of non-cash collateral received was $27.0 billion and $24.7 billion, of which $25.8 billion and $23.8 billion could be sold or repledged as of September 30, 2020 and December 31, 2019, respectively. None of the underlying collateral was sold or repledged as of September 30, 2020 or December 31, 2019. (4) Excludes derivative assets of $459 million and $40 million as of September 30, 2020 and December 31, 2019, respectively, and derivative liabilities of $38 million and $25 million recognized in our condensed consolidated balance sheets as of September 30, 2020 and December 31, 2019, respectively, that are not subject to enforceable master netting arrangements. (5) Includes $14.4 billion and $11.4 billion in securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of September 30, 2020 and December 31, 2019, respectively.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Recurring Changes in Fair Value [Table Text Block]	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 September 30, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ 3,443 $ — $ — $ — $ 3,443 Trading securities: Mortgage-related securities: Fannie Mae — 2,690 60 — 2,750 Other agency — 3,517 1 — 3,518 Private-label and other mortgage securities — 158 — — 158 Non-mortgage-related securities: U.S. Treasury securities 135,972 — — — 135,972 Other securities — 74 — — 74 Total trading securities 135,972 6,439 61 — 142,472 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,061 222 — 1,283 Other agency — 96 — — 96 Alt-A and subprime private-label securities — 4 2 — 6 Mortgage revenue bonds — — 255 — 255 Other — 7 248 — 255 Total available-for-sale securities — 1,168 727 — 1,895 Mortgage loans — 6,090 878 — 6,968 Other assets: Risk management derivatives: Swaps — 1,231 221 — 1,452 Swaptions — 601 — — 601 Netting adjustment — — — (2,037) (2,037) Mortgage commitment derivatives — 563 — — 563 Credit enhancement derivatives — — 459 — 459 Total other assets — 2,395 680 (2,037) 1,038 Total assets at fair value $ 139,415 $ 16,092 $ 2,346 $ (2,037) $ 155,816 Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 3,551 $ 435 $ — $ 3,986 Total of Fannie Mae — 3,551 435 — 3,986 Of consolidated trusts — 24,656 85 — 24,741 Total long-term debt — 28,207 520 — 28,727 Other liabilities: Risk management derivatives: Swaps — 1,659 — — 1,659 Swaptions — 479 — — 479 Netting adjustment — — — (2,053) (2,053) Mortgage commitment derivatives — 842 — — 842 Credit enhancement derivatives — — 38 — 38 Total other liabilities — 2,980 38 (2,053) 965 Total liabilities at fair value $ — $ 31,187 $ 558 $ (2,053) $ 29,692 Fair Value Measurements as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 3,379 $ 45 $ — $ 3,424 Other agency — 4,489 1 — 4,490 Private-label and other mortgage securities — 629 — — 629 Non-mortgage-related securities: U.S. Treasury securities 39,501 — — — 39,501 Other securities — 79 — — 79 Total trading securities 39,501 8,576 46 — 48,123 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,349 171 — 1,520 Other agency — 198 — — 198 Alt-A and subprime private-label securities — 57 — — 57 Mortgage revenue bonds — — 315 — 315 Other — 8 306 — 314 Total available-for-sale securities — 1,612 792 — 2,404 Mortgage loans — 7,137 688 — 7,825 Other assets: Risk management derivatives: Swaps — 1,071 159 — 1,230 Swaptions — 124 — — 124 Netting adjustment — — — (1,288) (1,288) Mortgage commitment derivatives — 165 — — 165 Credit enhancement derivatives — — 40 — 40 Total other assets — 1,360 199 (1,288) 271 Total assets at fair value $ 39,501 $ 18,685 $ 1,725 $ (1,288) $ 58,623 Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 5,289 $ 398 $ — $ 5,687 Total of Fannie Mae — 5,289 398 — 5,687 Of consolidated trusts — 21,805 75 — 21,880 Total long-term debt — 27,094 473 — 27,567 Other liabilities: Risk management derivatives: Swaps — 1,346 1 — 1,347 Swaptions — 440 11 — 451 Netting adjustment — — — (1,694) (1,694) Mortgage commitment derivatives — 306 — — 306 Credit enhancement derivatives — — 25 — 25 Total other liabilities — 2,092 37 (1,694) 435 Total liabilities at fair value $ — $ 29,186 $ 510 $ (1,694) $ 28,002 (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.
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Table Text Block]	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 September 30, 2020 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2020 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2020 (1) Balance, June 30, 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 Balance, September 30, 2020 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 38 $ — $ — $ — $ (1) $ — $ — $ (3) $ 26 $ 60 $ — $ — Other agency — — — — — — — — 1 1 — — Private-label and other mortgage securities 98 (4) — — (94) — — — — — — — Total trading securities $ 136 $ (4) (5)(6) $ — $ — $ (95) $ — $ — $ (3) $ 27 $ 61 $ — $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 446 $ 1 $ 2 $ — $ — $ — $ (9) $ (218) $ — $ 222 $ — $ — Alt-A and subprime private-label securities 2 — — — — — — — — 2 — — Mortgage revenue bonds 278 — — — — — (23) — — 255 — — Other 254 5 5 — — — (16) — — 248 — 4 Total available-for-sale securities $ 980 $ 6 (5)(6) $ 7 $ — $ — $ — $ (48) $ (218) $ — $ 727 $ — $ 4 Mortgage loans $ 797 $ 41 (5)(6) $ — $ — $ (11) $ — $ (39) $ (31) $ 121 $ 878 $ 36 $ — Net derivatives 269 380 (5) — — — — (7) — — 642 372 — Long-term debt: Of Fannie Mae: Senior floating (433) (3) (5) — — — — 1 — — (435) (3) — Of consolidated trusts (89) (1) (5)(6) — — — — 5 1 (1) (85) (1) — Total long-term debt $ (522) $ (4) $ — $ — $ — $ — $ 6 $ 1 $ (1) $ (520) $ (4) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2020 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2020 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 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 Balance, September 30, 2020 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 45 $ (9) $ — $ — $ (1) $ — $ — $ (48) $ 73 $ 60 $ (8) $ — Other agency 1 — — — — — — (1) 1 1 — — Private-label and other mortgage securities — 3 — — (94) — (3) — 94 — — — Total trading securities $ 46 $ (6) (5)(6) $ — $ — $ (95) $ — $ (3) $ (49) $ 168 $ 61 $ (8) $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 171 $ 1 $ 2 $ — $ — $ — $ (12) $ (218) $ 278 $ 222 $ — $ — Alt-A and subprime private-label securities — — — — — — — — 2 2 — — Mortgage revenue bonds 315 (3) 3 74 (74) — (60) — — 255 — 5 Other 306 (9) 4 268 (268) — (53) — — 248 — 3 Total available-for-sale securities $ 792 $ (11) (6)(7) $ 9 $ 342 $ (342) $ — $ (125) $ (218) $ 280 $ 727 $ — $ 8 Mortgage loans $ 688 $ 32 (5)(6) $ — $ — $ (11) $ — $ (93) $ (75) $ 337 $ 878 $ 5 $ — Net derivatives 162 470 (5) — — — — (8) 18 — 642 468 — Long-term debt: Of Fannie Mae: Senior floating (398) (61) (5) — — — — 24 — — (435) (61) — Of consolidated trusts (75) — (5)(6) — — — — 12 2 (24) (85) 1 — Total long-term debt $ (473) $ (61) $ — $ — $ — $ — $ 36 $ 2 $ (24) $ (520) $ (60) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2019 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, June 30, 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 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 74 $ 2 $ — $ 77 $ — $ — $ — $ (31) $ — $ 122 $ 1 $ — Other agency — — — — — — — — 2 2 — — Total trading securities $ 74 $ 2 (5)(6) $ — $ 77 $ — $ — $ — $ (31) $ 2 $ 124 $ 1 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 132 $ — $ 3 $ — $ — $ — $ (1) $ — $ 40 $ 174 $ — $ 3 Mortgage revenue bonds 364 1 (1) — — — (18) — — 346 — — Other 326 (1) (1) — — — (9) — — 315 — (2) Total available-for-sale securities $ 822 $ — (6)(7) $ 1 $ — $ — $ — $ (28) $ — $ 40 $ 835 $ — $ 1 Mortgage loans $ 770 $ 14 (5)(6) $ — $ — $ (27) $ — $ (35) $ (41) $ 45 $ 726 $ 10 $ — Net derivatives 183 21 (5) — — — — (6) — — 198 15 — Long-term debt: Of Fannie Mae: Senior floating (398) (24) (5) — — — — — — — (422) (24) — Of consolidated trusts (102) (3) (5)(6) — — — (2) 6 20 (7) (88) (1) — Total long-term debt $ (500) $ (27) $ — $ — $ — $ (2) $ 6 $ 20 $ (7) $ (510) $ (25) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2019 Total Gains (Losses) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, December 31, 2018 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 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 5 $ — $ 77 $ (14) $ — $ (16) $ (31) $ 69 $ 122 $ 4 $ — Other agency — — — — — — — — 2 2 — — Private-label and other mortgage securities 1 — — — — — (1) — — — — — Total trading securities $ 33 $ 5 (5)(6) $ — $ 77 $ (14) $ — $ (17) $ (31) $ 71 $ 124 $ 4 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 9 $ — $ — $ — $ (8) $ (103) $ 124 $ 174 $ — $ 8 Alt-A and subprime private-label securities 24 5 (5) — (23) — (1) — — — — — Mortgage revenue bonds 434 1 (2) — (4) — (83) — — 346 — (1) Other 342 11 (11) — — — (26) (2) 1 315 — (9) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (9) $ — $ (27) $ — $ (118) $ (105) $ 125 $ 835 $ — $ (2) Mortgage loans $ 937 $ 45 (5)(6) $ — $ — $ (40) $ — $ (105) $ (228) $ 117 $ 726 $ 28 $ — Net derivatives 194 139 (5) — — — — (126) (9) — 198 39 — Long-term debt: Of Fannie Mae: Senior floating (351) (71) (5) — — — — — — — (422) (71) — Of consolidated trusts (201) (7) (5)(6) — — — (2) 16 189 (83) (88) (3) — Total long-term debt $ (552) $ (78) $ — $ — $ — $ (2) $ 16 $ 189 $ (83) $ (510) $ (74) $ — (1) Gains (losses) included in other comprehensive 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 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, 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]	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 September 30, 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) $ 61 Various Available-for-sale securities: Mortgage-related securities: Agency (3) 124 Consensus 98 Various Total agency 222 Alt-A and subprime private-label securities 2 Various Mortgage revenue bonds 177 Single Vendor Spreads (bps) 35.5 — 318.8 100.0 78 Various Total mortgage revenue bonds 255 Other 216 Discounted Cash Flow Spreads (bps) 406.0 — 431.0 418.8 32 Various Total other 248 Total available-for-sale securities $ 727 Net derivatives $ 221 Dealer Mark 421 Discounted Cash Flow Total net derivatives $ 642 Fair Value Measurements as of December 31, 2019 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) $ 46 Various Available-for-sale securities: Mortgage-related securities: Agency (3) 107 Consensus 64 Various Total agency 171 Available-for-sale securities: Mortgage-related securities: Mortgage revenue bonds 222 Single Vendor Spreads(bps) 23.0 - 205.1 76.1 93 Various Total mortgage revenue bonds 315 Other 267 Discounted Cash Flow Spreads(bps) 300.0 300.0 39 Various Total other 306 Total available-for-sale securities $ 792 Net derivatives $ 147 Dealer Mark 15 Various Total net derivatives $ 162 (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.
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. The significant unobservable inputs related to these techniques primarily relate to collateral dependent valuations. The related ranges and weighted averages are not meaningful when aggregated as they vary significantly from property to property. Fair Value Measurements as of Valuation Techniques September 30, 2020 December 31, 2019 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,113 $ 471 Single Vendor 767 605 Total mortgage loans held for sale, at lower of cost or fair value 1,880 1,076 Single-family mortgage loans held for investment, at amortized cost Internal Model 855 555 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate — 24 Various 232 16 Total multifamily mortgage loans held for investment, at amortized cost 232 40 Acquired property, net: Single-family Accepted Offers 60 101 Appraisals 115 362 Walk Forwards 111 240 Internal Model 55 164 Various 15 51 Total single-family 356 918 Multifamily Various 27 9 Total nonrecurring assets at fair value $ 3,350 $ 2,598
Fair Value of Financial Instruments [Table Text Block]	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 September 30, 2020 Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Netting Adjustment Estimated Fair Value (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 110,988 $ 96,588 $ 14,400 $ — $ — $ 110,988 Federal funds sold and securities purchased under agreements to resell or similar arrangements 12,700 — 12,700 — — 12,700 Trading securities 142,472 135,972 6,439 61 — 142,472 Available-for-sale securities 1,895 — 1,168 727 — 1,895 Mortgage loans held for sale 8,312 — 679 8,297 — 8,976 Mortgage loans held for investment, net of allowance for loan losses 3,539,031 — 3,414,104 257,448 — 3,671,552 Advances to lenders 10,228 — 10,227 1 — 10,228 Derivative assets at fair value 1,038 — 2,395 680 (2,037) 1,038 Guaranty assets and buy-ups 115 — — 270 — 270 Total financial assets $ 3,826,779 $ 232,560 $ 3,462,112 $ 267,484 $ (2,037) $ 3,960,119 Financial liabilities: Short-term debt: Of Fannie Mae $ 23,526 $ — $ 23,536 $ — $ — $ 23,536 Long-term debt: Of Fannie Mae 265,897 — 277,190 878 — 278,068 Of consolidated trusts 3,530,381 — 3,648,508 31,618 — 3,680,126 Derivative liabilities at fair value 965 — 2,980 38 (2,053) 965 Guaranty obligations 128 — — 78 — 78 Total financial liabilities $ 3,820,897 $ — $ 3,952,214 $ 32,612 $ (2,053) $ 3,982,773 As of December 31, 2019 Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Netting Adjustment Estimated Fair Value (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 61,407 $ 50,057 $ 11,350 $ — $ — $ 61,407 Federal funds sold and securities purchased under agreements to resell or similar arrangements 13,578 — 13,578 — — 13,578 Trading securities 48,123 39,501 8,576 46 — 48,123 Available-for-sale securities 2,404 — 1,612 792 — 2,404 Mortgage loans held for sale 6,773 — 229 7,054 — 7,283 Mortgage loans held for investment, net of allowance for loan losses 3,327,389 — 3,270,535 127,650 — 3,398,185 Advances to lenders 6,453 — 6,451 2 — 6,453 Derivative liabilities at fair value 271 — 1,360 199 (1,288) 271 Guaranty assets and buy-ups 142 — — 305 — 305 Total financial assets $ 3,466,540 $ 89,558 $ 3,313,691 $ 136,048 $ (1,288) $ 3,538,009 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 478 $ — $ 478 $ — $ — $ 478 Short-term debt: Of Fannie Mae 26,662 — 26,667 — — 26,667 Long-term debt: Of Fannie Mae 155,585 — 164,144 401 — 164,545 Of consolidated trusts 3,285,139 — 3,312,763 31,827 — 3,344,590 Derivative liabilities at fair value 435 — 2,092 37 (1,694) 435 Guaranty obligations 154 — — 97 — 97 Total financial liabilities $ 3,468,453 $ — $ 3,506,144 $ 32,362 $ (1,694) $ 3,536,812
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 September 30, 2020 December 31, 2019 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 $ 6,968 $ 3,986 $ 24,741 $ 7,825 $ 5,687 $ 21,880 Unpaid principal balance 6,501 3,895 21,521 7,514 5,200 19,653

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, September 2019 Amendment [Line Items]
Deficit of core capital over statutory minimum capital requirement	$ (128,100)		$ (128,800)
Weighted Average Number of Shares, Contingently Issuable	4,700,000	4,600,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Related Parties [Line Items]
Deficit Of Core Capital Over Statutory Minimum Capital Requirement	$ (128,100,000,000)		$ (128,100,000,000)					$ (128,800,000,000)
Net worth	20,693,000,000		20,693,000,000			$ 16,500,000,000		14,608,000,000
Aggregate liquidation preference of senior preferred stock	138,000,000,000		138,000,000,000
Payments of cash dividends on senior preferred stock to Treasury	0	$ 0	0	$ 5,601,000,000
Income Taxes Paid			2,750,000,000	1,250,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	$ 679,000,000	613,000,000	$ 1,976,000,000	1,806,000,000
Basis Points of Each Dollar of Unpaid Principal Balance	420.00%		420.00%
Debt Securities, Trading	$ 142,472,000,000		$ 142,472,000,000					48,123,000,000
Interest Receivable	9,748,000,000		9,748,000,000					8,604,000,000
Interest income recognized on Treasury securities	177,000,000	418,000,000	712,000,000	1,277,000,000
Affordable Housing Program Obligation	0.35		0.35
Loans held for sale, at lower of cost or fair value	8,312,000,000		8,312,000,000				$ 6,823,000,000	6,773,000,000
Accumulated deficit	(112,680,000,000)		(112,680,000,000)				(119,915,000,000)	(118,776,000,000)
Allowance for Loan and Lease Losses, Real Estate	11,703,000,000		11,703,000,000				10,738,000,000	9,016,000,000
Other assets	14,959,000,000		14,959,000,000				14,542,000,000	14,312,000,000
Deferred Tax Assets, Net							12,213,000,000	$ 11,910,000,000
Accounting Standards Update 2016-13 [Member]
Related Parties [Line Items]
Loans held for sale, at lower of cost or fair value							50,000,000
Accumulated deficit							(1,139,000,000)
Allowance for Loan and Lease Losses, Real Estate							1,722,000,000
Other assets							230,000,000
Deferred Tax Assets, Net							$ 303,000,000
US Treasury [Member]
Related Parties [Line Items]
Capital Reserve Amount, current year, Senior Preferred Stock Purchase Agreement, Amendment	$ 25,000,000,000		$ 25,000,000,000
Aggregate liquidation preference of senior preferred stock						$ 135,400,000,000
Percentage of common shares attributable to warrants issued to US Treasury as percentage to total diluted common shares	79.90%		79.90%
Home Affordable Modification Program administrative expense reimbursements from Treasury and Freddie Mac	$ 5,000,000	5,000,000	$ 14,000,000	15,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	679,000,000	613,000,000	1,976,000,000	1,806,000,000
Total available funding from US Treasury pursuant to the senior preferred stock agreement	113,900,000,000		113,900,000,000
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement	119,800,000,000		119,800,000,000
US Treasury [Member] | Forecast [Member]
Related Parties [Line Items]
Aggregate liquidation preference of senior preferred stock					$ 142,200,000,000
US Treasury [Member] | Single-family [Member]
Related Parties [Line Items]
Recognized TCCA fees that had not been remitted to Treasury as of period end	679,000,000		679,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees	35,000,000	30,000,000	102,000,000	89,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments	19,000,000	22,000,000	67,000,000	84,000,000
Other Expense [Member] | US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments	$ 59,000,000	$ 32,000,000	$ 144,000,000	$ 68,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details) - USD ($) shares in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Related Parties [Line Items]
Other assets	$ 14,959,000,000			$ 14,959,000,000		$ 14,542,000,000	$ 14,312,000,000
Deferred Tax Assets, Net						12,213,000,000	11,910,000,000
Loans held for sale, at lower of cost or fair value	8,312,000,000			8,312,000,000		6,823,000,000	6,773,000,000
Allowance for Loan and Lease Losses, Real Estate	11,703,000,000			11,703,000,000		10,738,000,000	9,016,000,000
Accumulated deficit	(112,680,000,000)			(112,680,000,000)		(119,915,000,000)	$ (118,776,000,000)
Interest and Fee Income, Loans and Leases	$ 25,810,000,000		$ 29,072,000,000	$ 81,755,000,000	$ 88,445,000,000
Convertible Preferred Stock, Shares Issued upon Conversion	26,000		131,000	26,000	131,000
Provision for Loan and Lease Losses				$ 569,000,000
Net income	$ 4,229,000,000	$ 2,500,000,000	$ 3,963,000,000	7,235,000,000	$ 9,795,000,000
Aggregate liquidation preference of senior preferred stock	138,000,000,000			138,000,000,000
Non Accrual Loans [Member]
Related Parties [Line Items]
Interest and Fee Income, Loans and Leases	$ 763,000,000			$ 2,200,000,000
Accounting Standards Update 2016-13 [Member]
Related Parties [Line Items]
Other assets						230,000,000
Deferred Tax Assets, Net						303,000,000
Loans held for sale, at lower of cost or fair value						50,000,000
Allowance for Loan and Lease Losses, Real Estate						1,722,000,000
Accumulated deficit						$ (1,139,000,000)

Consolidations and Transfers _3

Consolidations and Transfers of Financial Assets Unconsolidated VIEs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Assets	$ 3,864,603		$ 3,864,603			$ 3,503,319
Trading, at fair value	142,472		142,472			48,123
Available-for-sale, at fair value	1,895		1,895			2,404
Other assets	14,959		14,959		$ 14,542	14,312
Other liabilities	(14,124)		(14,124)			(11,097)
Unpaid principal balance of mortgage loans	3,493,676		3,493,676			3,299,954
Portfolio securitizations: unpaid principal balance	213,000	$ 89,000	504,900	$ 187,700
Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Retained interests: principal and interest received	166	$ 187	517	$ 425
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	355,950		355,950			327,593
Multifamily [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	356,000		356,000
Single-family [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	3,137,726		3,137,726			2,972,361
Mortgage-related securities [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	190,000		190,000			130,000
Trading, at fair value	5,576		5,576			7,643
Available-for-sale, at fair value	1,645		1,645			2,098
Other assets	42		42			56
Other liabilities	(68)		(68)			(78)
Maximum exposure to loss	127,000		127,000			62,000
Net carrying amount	7,195		7,195			9,719
Partnership interest LIHTC [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	2,300		2,300			2,000
Maximum exposure to loss	107		107			98
Net carrying amount	99		99			79
Debt Securities [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Assets	10,100		10,100			9,500
Maximum exposure to loss	10,100		10,100			9,500
Fannie Mae Securities [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	1,900		1,900			2,543
Available-for-sale, at fair value	1,284		1,284			1,524
Non-Fannie Mae Securities [Member] | Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	3,676		3,676			5,100
Available-for-sale, at fair value	$ 361		$ 361			$ 574

Consolidations and Transfers _4

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Transfers of Financial Assets [Line Items]
Portfolio securitizations: unpaid principal balance	$ 213,000	$ 89,000	$ 504,900	$ 187,700
Maximum Exposure	16,830		16,830		$ 18,471
Guaranty Obligation	128		128		154
Maximum Recovery	7,090		7,090		8,098
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	416		538
Unconsolidated Fannie Mae MBS [Member] | Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Maximum Exposure	4,880		4,880		5,801
Guaranty Obligation	18		18		26
Maximum Recovery	4,666		4,666		5,545
Other guaranty arrangements [Member] | Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Maximum Exposure	11,950		11,950		12,670
Guaranty Obligation	110		110		128
Maximum Recovery	2,424		2,424		2,553
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	166	$ 187	517	$ 425
Unconsolidated VIEs [Member] | Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	2,000		2,000		2,900
Retained interests: fair value	$ 3,300		$ 3,300		$ 4,000

Mortgage Loans Loans in Mortgag

Mortgage Loans Loans in Mortgage Portfolio (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,493,676		$ 3,493,676			$ 3,299,954
Total Loan, Cost Basis and Fair Value Adjustments, Net	65,370		65,370			43,224
Allowance for Loan and Lease Losses, Real Estate	11,703		11,703		$ 10,738	9,016
Total mortgage loans	3,547,343		3,547,343			3,334,162
Interest Receivable	9,748		9,748			8,604
Financing Receivable, before Allowance for Credit Loss	3,550,734		3,550,734			3,336,405
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	3,137,726		3,137,726			2,972,361
Financing Receivable, Reclassification to Held-for-sale	5,305	$ 5,154	6,942	$ 15,287
Financing Receivable, Sale	4,593	3,941	5,088	10,497
Gain (Loss) on Sale of Mortgage Loans	424	184	464	504
Mortgage Loans in Process of Foreclosure, Amount	6,000		6,000			7,600
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	219		573
Financing Receivable, before Allowance for Credit Loss	3,179,241		3,179,241
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)	(227)	(227)	(236)	(946)
Charge-offs	737	$ 780	921	$ 2,149
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	355,950		355,950			327,593
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	8		9
Mortgage loans [Member]
Loans in Mortgage Portfolio [Line Items]
Interest Receivable	$ 9,600		$ 9,600			$ 8,400

Mortgage Loans Aging (Details)

Mortgage Loans Aging (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 163,291		$ 55,266
Current	3,390,595		3,281,663
Total recorded investment in loans	3,553,886		3,336,929
Recorded investment in loans 90 days or more delinquent and accruing interest	95,098		164
Recorded investment in nonaccrual loans	25,714	$ 28,069	27,981
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	8,513
Financing Receivable, before Allowance for Credit Loss	3,550,734		3,336,405
30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	31,511		31,240
60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	15,327		8,326
Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	116,453		15,700
Single-family [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	158,705		55,144
Current	3,035,464		2,951,167
Total recorded investment in loans	3,194,169		3,006,311
Recorded investment in loans 90 days or more delinquent and accruing interest	91,369		164
Recorded investment in nonaccrual loans	25,367	27,753	27,546
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	8,469
Financing Receivable, before Allowance for Credit Loss	$ 3,179,241
Single-family [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days
Single-family [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 30,999		31,233
Single-family [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	15,327		8,326
Single-family [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	112,379		15,585
Single-family [Member] | FixedRateResidentialMortgage15yearMember
Financing Receivable, Past Due [Line Items]
Days delinquent	9,219		2,347
Current	420,848		371,740
Total recorded investment in loans	430,067		374,087
Recorded investment in loans 90 days or more delinquent and accruing interest	5,533		0
Recorded investment in nonaccrual loans	780	844	858
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	393
Financing Receivable, before Allowance for Credit Loss	430,067
Single-family [Member] | FixedRateResidentialMortgage15yearMember | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	2,084		1,616
Single-family [Member] | FixedRateResidentialMortgage15yearMember | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	965		286
Single-family [Member] | FixedRateResidentialMortgage15yearMember | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	6,170		445
Single-family [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	7,228		5,043
Current	51,276		64,726
Total recorded investment in loans	58,504		69,769
Recorded investment in loans 90 days or more delinquent and accruing interest	3,271		136
Recorded investment in nonaccrual loans	2,438	2,851	2,973
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	785
Financing Receivable, before Allowance for Credit Loss	43,576
Single-family [Member] | Other [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,267		2,323
Single-family [Member] | Other [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	606		829
Single-family [Member] | Other [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	5,355		1,891
Single-family [Member] | Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,844		664
Current	33,461		44,244
Total recorded investment in loans	35,305		44,908
Recorded investment in loans 90 days or more delinquent and accruing interest	1,160		0
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	135
Financing Receivable, before Allowance for Credit Loss	35,305
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	309		412
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	172		85
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,363		167
Single-family [Member] | Fixed Rate Residential Mortgage
Financing Receivable, Past Due [Line Items]
Days delinquent	140,414		47,090
Current	2,529,879		2,470,457
Total recorded investment in loans	2,670,293		2,517,547
Recorded investment in loans 90 days or more delinquent and accruing interest	81,405		28
Recorded investment in nonaccrual loans	21,902	23,783	23,427
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	7,156
Financing Receivable, before Allowance for Credit Loss	2,670,293
Single-family [Member] | Fixed Rate Residential Mortgage | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	27,339		26,882
Single-family [Member] | Fixed Rate Residential Mortgage | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	13,584		7,126
Single-family [Member] | Fixed Rate Residential Mortgage | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	99,491		13,082
Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	4,586		122
Current	355,131		330,496
Total recorded investment in loans	359,717		330,618
Recorded investment in loans 90 days or more delinquent and accruing interest	3,729		0
Recorded investment in nonaccrual loans	347	$ 316	435
Table Footnote [Abstract]
Financing Receivable, Nonaccrual, No Allowance	$ 44
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	$ 512		7
Multifamily [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 4,074		$ 115

Mortgage Loans Credit Quality I

Mortgage Loans Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 3,553,886	$ 3,336,929
Financing Receivable, before Allowance for Credit Loss	3,550,734	3,336,405
Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,989,182
Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,603,619
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		246,326
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		133,049
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		6,188
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	45,248
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	69,546
Financing Receivable, Originated Two Years before Latest Fiscal Year	64,049
Financing Receivable, Originated Three Years before Latest Fiscal Year	54,383
Financing Receivable, Originated Four Years before Latest Fiscal Year	46,293
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	80,198
Financing Receivable, before Allowance for Credit Loss	359,717
FixedRateResidentialMortgage15yearMember | Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		374,087
FixedRateResidentialMortgage15yearMember | Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		368,181
FixedRateResidentialMortgage15yearMember | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,556
FixedRateResidentialMortgage15yearMember | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,284
FixedRateResidentialMortgage15yearMember | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		66
Other [Member] | Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		52,640
Other [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		47,005
Other [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,872
Other [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,398
Other [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,365
Adjustable Rate Residential Mortgage [Member] | Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		44,908
Adjustable Rate Residential Mortgage [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		43,415
Adjustable Rate Residential Mortgage [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,275
Adjustable Rate Residential Mortgage [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		215
Adjustable Rate Residential Mortgage [Member] | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		3
Fixed Rate Residential Mortgage | Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,517,547
Fixed Rate Residential Mortgage | Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,145,018
Fixed Rate Residential Mortgage | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		237,623
Fixed Rate Residential Mortgage | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		130,152
Fixed Rate Residential Mortgage | Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,754
Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	3,194,169	3,006,311
Financing Receivable, Originated in Current Fiscal Year	867,706
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	435,189
Financing Receivable, Originated Two Years before Latest Fiscal Year	212,107
Financing Receivable, Originated Three Years before Latest Fiscal Year	264,320
Financing Receivable, Originated Four Years before Latest Fiscal Year	313,380
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,086,539
Financing Receivable, before Allowance for Credit Loss	3,179,241
Single-family [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	660,863
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	310,727
Financing Receivable, Originated Two Years before Latest Fiscal Year	169,898
Financing Receivable, Originated Three Years before Latest Fiscal Year	252,346
Financing Receivable, Originated Four Years before Latest Fiscal Year	310,231
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,070,834
Financing Receivable, before Allowance for Credit Loss	2,774,899
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	110,400
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	107,780
Financing Receivable, Originated Two Years before Latest Fiscal Year	40,600
Financing Receivable, Originated Three Years before Latest Fiscal Year	11,395
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,841
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	9,344
Financing Receivable, before Allowance for Credit Loss	282,360
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	96,426
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	16,660
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,559
Financing Receivable, Originated Three Years before Latest Fiscal Year	461
Financing Receivable, Originated Four Years before Latest Fiscal Year	190
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3,354
Financing Receivable, before Allowance for Credit Loss	118,650
Single-family [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	17
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	22
Financing Receivable, Originated Two Years before Latest Fiscal Year	50
Financing Receivable, Originated Three Years before Latest Fiscal Year	118
Financing Receivable, Originated Four Years before Latest Fiscal Year	118
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3,007
Financing Receivable, before Allowance for Credit Loss	3,332
Single-family [Member] | FixedRateResidentialMortgage15yearMember
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	430,067	374,087
Financing Receivable, Originated in Current Fiscal Year	131,182
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	48,653
Financing Receivable, Originated Two Years before Latest Fiscal Year	18,203
Financing Receivable, Originated Three Years before Latest Fiscal Year	35,221
Financing Receivable, Originated Four Years before Latest Fiscal Year	50,628
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	146,180
Financing Receivable, before Allowance for Credit Loss	430,067
Single-family [Member] | FixedRateResidentialMortgage15yearMember | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	124,783
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	46,988
Financing Receivable, Originated Two Years before Latest Fiscal Year	18,095
Financing Receivable, Originated Three Years before Latest Fiscal Year	35,192
Financing Receivable, Originated Four Years before Latest Fiscal Year	50,610
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	146,127
Financing Receivable, before Allowance for Credit Loss	421,795
Single-family [Member] | FixedRateResidentialMortgage15yearMember | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	5,020
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,627
Financing Receivable, Originated Two Years before Latest Fiscal Year	100
Financing Receivable, Originated Three Years before Latest Fiscal Year	18
Financing Receivable, Originated Four Years before Latest Fiscal Year	11
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	25
Financing Receivable, before Allowance for Credit Loss	6,801
Single-family [Member] | FixedRateResidentialMortgage15yearMember | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,379
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	38
Financing Receivable, Originated Two Years before Latest Fiscal Year	4
Financing Receivable, Originated Three Years before Latest Fiscal Year	5
Financing Receivable, Originated Four Years before Latest Fiscal Year	3
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	12
Financing Receivable, before Allowance for Credit Loss	1,441
Single-family [Member] | FixedRateResidentialMortgage15yearMember | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	4
Financing Receivable, Originated Three Years before Latest Fiscal Year	6
Financing Receivable, Originated Four Years before Latest Fiscal Year	4
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	16
Financing Receivable, before Allowance for Credit Loss	30
Single-family [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	58,504	69,769
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	47
Financing Receivable, Originated Two Years before Latest Fiscal Year	382
Financing Receivable, Originated Three Years before Latest Fiscal Year	926
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,140
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	41,081
Financing Receivable, before Allowance for Credit Loss	43,576
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	42
Financing Receivable, Originated Two Years before Latest Fiscal Year	341
Financing Receivable, Originated Three Years before Latest Fiscal Year	839
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,076
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	37,973
Financing Receivable, before Allowance for Credit Loss	40,271
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	3
Financing Receivable, Originated Two Years before Latest Fiscal Year	25
Financing Receivable, Originated Three Years before Latest Fiscal Year	54
Financing Receivable, Originated Four Years before Latest Fiscal Year	37
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,590
Financing Receivable, before Allowance for Credit Loss	1,709
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1
Financing Receivable, Originated Two Years before Latest Fiscal Year	11
Financing Receivable, Originated Three Years before Latest Fiscal Year	22
Financing Receivable, Originated Four Years before Latest Fiscal Year	16
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	736
Financing Receivable, before Allowance for Credit Loss	786
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1
Financing Receivable, Originated Two Years before Latest Fiscal Year	5
Financing Receivable, Originated Three Years before Latest Fiscal Year	11
Financing Receivable, Originated Four Years before Latest Fiscal Year	11
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	782
Financing Receivable, before Allowance for Credit Loss	810
Single-family [Member] | Government [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	14,900	17,100
Single-family [Member] | Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	35,305	44,908
Financing Receivable, Originated in Current Fiscal Year	2,847
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,351
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,034
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,740
Financing Receivable, Originated Four Years before Latest Fiscal Year	3,173
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	18,160
Financing Receivable, before Allowance for Credit Loss	35,305
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,542
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,102
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,853
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,696
Financing Receivable, Originated Four Years before Latest Fiscal Year	3,169
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	18,138
Financing Receivable, before Allowance for Credit Loss	34,500
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	233
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	233
Financing Receivable, Originated Two Years before Latest Fiscal Year	179
Financing Receivable, Originated Three Years before Latest Fiscal Year	42
Financing Receivable, Originated Four Years before Latest Fiscal Year	4
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	18
Financing Receivable, before Allowance for Credit Loss	709
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	72
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	16
Financing Receivable, Originated Two Years before Latest Fiscal Year	2
Financing Receivable, Originated Three Years before Latest Fiscal Year	2
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3
Financing Receivable, before Allowance for Credit Loss	95
Single-family [Member] | Adjustable Rate Residential Mortgage [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1
Financing Receivable, before Allowance for Credit Loss	1
Single-family [Member] | Fixed Rate Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	2,670,293	$ 2,517,547
Financing Receivable, Originated in Current Fiscal Year	733,677
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	384,138
Financing Receivable, Originated Two Years before Latest Fiscal Year	190,488
Financing Receivable, Originated Three Years before Latest Fiscal Year	222,433
Financing Receivable, Originated Four Years before Latest Fiscal Year	258,439
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	881,118
Financing Receivable, before Allowance for Credit Loss	2,670,293
Single-family [Member] | Fixed Rate Residential Mortgage | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	533,538
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	261,595
Financing Receivable, Originated Two Years before Latest Fiscal Year	148,609
Financing Receivable, Originated Three Years before Latest Fiscal Year	210,619
Financing Receivable, Originated Four Years before Latest Fiscal Year	255,376
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	868,596
Financing Receivable, before Allowance for Credit Loss	2,278,333
Single-family [Member] | Fixed Rate Residential Mortgage | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	105,147
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	105,917
Financing Receivable, Originated Two Years before Latest Fiscal Year	40,296
Financing Receivable, Originated Three Years before Latest Fiscal Year	11,281
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,789
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,711
Financing Receivable, before Allowance for Credit Loss	273,141
Single-family [Member] | Fixed Rate Residential Mortgage | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	94,975
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	16,605
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,542
Financing Receivable, Originated Three Years before Latest Fiscal Year	432
Financing Receivable, Originated Four Years before Latest Fiscal Year	171
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,603
Financing Receivable, before Allowance for Credit Loss	116,328
Single-family [Member] | Fixed Rate Residential Mortgage | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	17
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	21
Financing Receivable, Originated Two Years before Latest Fiscal Year	41
Financing Receivable, Originated Three Years before Latest Fiscal Year	101
Financing Receivable, Originated Four Years before Latest Fiscal Year	103
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,208
Financing Receivable, before Allowance for Credit Loss	$ 2,491

Mortgage Loans Credit Quality_2

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 3,553,886	$ 3,336,929
Financing Receivable, before Allowance for Credit Loss	3,550,734	3,336,405
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	359,717
Financing Receivable, Originated in Current Fiscal Year	45,248
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	69,546
Financing Receivable, Originated Two Years before Latest Fiscal Year	64,049
Financing Receivable, Originated Three Years before Latest Fiscal Year	54,383
Financing Receivable, Originated Four Years before Latest Fiscal Year	46,293
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	80,198
Doubtful [Member] | Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	5
Non-Classified [Member] | Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	349,992	323,773
Financing Receivable, Originated in Current Fiscal Year	45,240
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	68,698
Financing Receivable, Originated Two Years before Latest Fiscal Year	62,601
Financing Receivable, Originated Three Years before Latest Fiscal Year	51,824
Financing Receivable, Originated Four Years before Latest Fiscal Year	44,804
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	76,825
Classified | Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,725	6,845
Financing Receivable, Originated in Current Fiscal Year	8
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	848
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,448
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,559
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,489
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3,373
Internal Credit Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		330,618
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 359,717	$ 330,618

Mortgage Loans TDRs (Details)

Mortgage Loans TDRs (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)contracts	Sep. 30, 2019USD ($)contracts	Sep. 30, 2020USD ($)contracts	Sep. 30, 2019USD ($)contracts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Average term extension of a single-family modified loan	159 months	164 months	166 months	160 months
Average interest rate reduction of a single-family modified loan	0.42%	0.15%	0.35%	0.11%
Number of loans troubled debt restructurings activity | contracts	7,052	12,024	29,667	38,518
Recorded investment troubled debt restructurings activity | $	$ 1,119	$ 1,910	$ 4,875	$ 5,994
Number of loans troubled debt restructurings subsequent default | contracts	3,199	4,203	12,748	13,909
Recorded investment troubled debt restructurings subsequent default | $	$ 568	$ 659	$ 2,324	$ 2,129
Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	7,052	12,021	29,667	38,509
Recorded investment troubled debt restructurings activity | $	$ 1,119	$ 1,906	$ 4,875	$ 5,957
Number of loans troubled debt restructurings subsequent default | contracts	3,199	4,202	12,744	13,907
Recorded investment troubled debt restructurings subsequent default | $	$ 568	$ 646	$ 2,308	$ 2,110
Multifamily [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	0	3	0	9
Recorded investment troubled debt restructurings activity | $	$ 0	$ 4	$ 0	$ 37
Number of loans troubled debt restructurings subsequent default | contracts	0	1	4	2
Recorded investment troubled debt restructurings subsequent default | $	$ 0	$ 13	$ 16	$ 19
FixedRateResidentialMortgage15yearMember | Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	579	1,078	2,448	3,554
Recorded investment troubled debt restructurings activity | $	$ 50	$ 97	$ 216	$ 317
Number of loans troubled debt restructurings subsequent default | contracts	21	164	106	415
Recorded investment troubled debt restructurings subsequent default | $	$ 1	$ 12	$ 7	$ 30
Other [Member] | Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	371	648	1,464	2,383
Recorded investment troubled debt restructurings activity | $	$ 47	$ 87	$ 185	$ 323
Number of loans troubled debt restructurings subsequent default | contracts	219	422	1,094	1,564
Recorded investment troubled debt restructurings subsequent default | $	$ 35	$ 62	$ 180	$ 247
Adjustable Rate Residential Mortgage [Member] | Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	109	182	395	612
Recorded investment troubled debt restructurings activity | $	$ 16	$ 28	$ 62	$ 91
Number of loans troubled debt restructurings subsequent default | contracts	3	34	15	57
Recorded investment troubled debt restructurings subsequent default | $	$ 0	$ 5	$ 2	$ 8
Fixed Rate Residential Mortgage | Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	5,993	10,113	25,360	31,960
Recorded investment troubled debt restructurings activity | $	$ 1,006	$ 1,694	$ 4,412	$ 5,226
Number of loans troubled debt restructurings subsequent default | contracts	2,956	3,582	11,529	11,871
Recorded investment troubled debt restructurings subsequent default | $	$ 532	$ 567	$ 2,119	$ 1,825

Mortgage Loans Non-accrual Loan

Mortgage Loans Non-accrual Loans (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	$ 25,714	$ 25,714	$ 28,069	$ 27,981
Financing Receivable, Nonaccrual, Interest Income	76	355
Single-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	219	573
Recorded investment in nonaccrual loans	25,367	25,367	27,753	27,546
Financing Receivable, Nonaccrual, Interest Income	76	352
Financing Receivable, Accrued Interest, Writeoff	33	165
Single-family [Member] | FixedRateResidentialMortgage15yearMember
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	780	780	844	858
Financing Receivable, Nonaccrual, Interest Income	2	9
Single-family [Member] | Other [Member]
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	2,438	2,438	2,851	2,973
Financing Receivable, Nonaccrual, Interest Income	5	31
Single-family [Member] | Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	1	3
Single-family [Member] | Adjustable Rate Loans
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	247	247	275	288
Single-family [Member] | Fixed Rate Residential Mortgage
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	21,902	21,902	23,783	23,427
Financing Receivable, Nonaccrual, Interest Income	68	309
Multifamily [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	8	9
Recorded investment in nonaccrual loans	347	347	$ 316	$ 435
Financing Receivable, Nonaccrual, Interest Income	0	3
Financing Receivable, Accrued Interest, Writeoff	$ 5	$ 7

Mortgage Loans Individually Imp

Mortgage Loans Individually Impaired Loans (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance			$ 79,696
Individually impaired loans with related allowance recorded: total recorded investment			76,543
Related allowance for loan losses			(8,220)
Individually impaired loans with no related allowance recorded: unpaid principal balance			22,424
Total individually impaired loans: total recorded investment			97,876
Individually impaired loans with no related allowance recorded: total recorded investment			21,333
Impaired Financing Receivable, Unpaid Principal Balance			102,120
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 118	$ 372
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	117
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment			96,900
Individually impaired loans with related allowance recorded: unpaid principal balance			79,382
Individually impaired loans with related allowance recorded: total recorded investment			76,228
Related allowance for loan losses			(8,175)
Individually impaired loans with no related allowance recorded: unpaid principal balance			22,061
Individually impaired loans with no related allowance recorded: total recorded investment			20,968
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	117
Single-family [Member] | FixedRateResidentialMortgage15yearMember
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance			954
Individually impaired loans with related allowance recorded: total recorded investment			960
Related allowance for loan losses			(24)
Individually impaired loans with no related allowance recorded: unpaid principal balance			410
Individually impaired loans with no related allowance recorded: total recorded investment			407
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	3
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance			15,181
Individually impaired loans with related allowance recorded: total recorded investment			14,078
Related allowance for loan losses			(2,291)
Individually impaired loans with no related allowance recorded: unpaid principal balance			3,014
Individually impaired loans with no related allowance recorded: total recorded investment			2,718
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	5	14
Single-family [Member] | Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance			156
Individually impaired loans with related allowance recorded: total recorded investment			157
Related allowance for loan losses			(9)
Individually impaired loans with no related allowance recorded: unpaid principal balance			265
Individually impaired loans with no related allowance recorded: total recorded investment			265
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	2
Single-family [Member] | Fixed Rate Residential Mortgage
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance			63,091
Individually impaired loans with related allowance recorded: total recorded investment			61,033
Related allowance for loan losses			(5,851)
Individually impaired loans with no related allowance recorded: unpaid principal balance			18,372
Individually impaired loans with no related allowance recorded: total recorded investment			17,578
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	37	98
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment			102
Individually impaired loans with related allowance recorded: unpaid principal balance			314
Individually impaired loans with related allowance recorded: total recorded investment			315
Related allowance for loan losses			(45)
Individually impaired loans with no related allowance recorded: unpaid principal balance			363
Individually impaired loans with no related allowance recorded: total recorded investment			$ 365
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	$ 0	$ 0

Mortgage Loans Individually I_2

Mortgage Loans Individually Impaired Loans - 2 (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	$ 85,408	$ 91,876
Individually impaired loans with no related allowance recorded: total interest income recognized	325	905
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	879	2,868
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	74	255
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	117
Individually impaired loans with no related allowance recorded: average recorded investment	19,584	18,965
Impaired Financing Receivable, Average Recorded Investment	104,992	110,841
Individually impaired loans: total interest income recognized	1,204	3,773
Impaired Financing Receivable, Interest Income, Cash Basis Method	118	372
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	85,095	91,596
Individually impaired loans with no related allowance recorded: total interest income recognized	317	889
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	877	2,861
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	74	255
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	117
Individually impaired loans with no related allowance recorded: average recorded investment	19,183	18,588
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	16,011	17,995
Individually impaired loans with no related allowance recorded: total interest income recognized	55	158
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	164	557
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	11	41
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	5	14
Individually impaired loans with no related allowance recorded: average recorded investment	2,767	2,875
Single-family [Member] | FixedRateResidentialMortgage15yearMember
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	1,141	1,237
Individually impaired loans with no related allowance recorded: total interest income recognized	4	11
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	10	32
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	1	3
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	3
Individually impaired loans with no related allowance recorded: average recorded investment	329	320
Single-family [Member] | Adjustable Rate Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	155	135
Individually impaired loans with no related allowance recorded: total interest income recognized	3	12
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	1	4
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	1	1
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	2
Individually impaired loans with no related allowance recorded: average recorded investment	300	352
Single-family [Member] | Fixed Rate Residential Mortgage
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	67,788	72,229
Individually impaired loans with no related allowance recorded: total interest income recognized	255	708
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	702	2,268
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	61	210
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	37	98
Individually impaired loans with no related allowance recorded: average recorded investment	15,787	15,041
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	313	280
Individually impaired loans with no related allowance recorded: total interest income recognized	8	16
Table Footnote [Abstract]
Individually impaired loans with related allowance recorded: total interest income recognized	2	7
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	0	0
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	0
Individually impaired loans with no related allowance recorded: average recorded investment	$ 401	$ 377

Allowance for Loan Losses Rollf

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	$ (12,966)	$ (11,482)	$ (9,016)	$ (14,203)
Transition impact of the adoption of the CECL standard	(11,703)		(11,703)
Allowance for loan losses for loans held for investment	(11,703)		(11,703)		$ (10,738)	$ (9,016)
Benefit (provision) for loan losses	897	1,843	(1,526)	3,689
Write-offs	347	272	481	1,215
Recoveries	(4)	(9)	(11)	(71)
Other	23	0	91	(6)
Ending Balance	(11,703)	(9,376)	(11,703)	(9,376)
Single-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	(11,598)	(11,210)	(8,759)	(13,969)
Allowance for loan losses for loans held for investment						(8,759)
Benefit (provision) for loan losses	931	1,826	(857)	3,712
Write-offs	261	270	377	1,209
Recoveries	(4)	(8)	(10)	(68)
Other	23	0	91	(6)
Ending Balance	(10,387)	(9,122)	(10,387)	(9,122)
Multifamily [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	(1,368)	(272)	(257)	(234)
Allowance for loan losses for loans held for investment						$ (257)
Benefit (provision) for loan losses	(34)	17	(669)	(23)
Write-offs	86	2	104	6
Recoveries	0	(1)	(1)	(3)
Ending Balance	$ (1,316)	$ (254)	$ (1,316)	$ (254)
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)

Allowance for Loan Losses and T

Allowance for Loan Losses and Total Recorded Investment in HFI Loans (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans			$ (8,220)
Allowance for loan losses for collectively reserved loans			(796)
Total allowance for loan losses	$ (11,703)	$ (10,738)	(9,016)
Recorded investment in individually impaired loans			97,876
Recorded investment in collectively reserved loans			3,239,053
Total recorded investment in loans	$ 3,553,886		3,336,929
Single-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans			(8,175)
Allowance for loan losses for collectively reserved loans			(584)
Total allowance for loan losses			(8,759)
Recorded investment in individually impaired loans			97,196
Recorded investment in collectively reserved loans			2,909,115
Total recorded investment in loans			3,006,311
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans			(45)
Allowance for loan losses for collectively reserved loans			(212)
Total allowance for loan losses			(257)
Recorded investment in individually impaired loans			680
Recorded investment in collectively reserved loans			329,938
Total recorded investment in loans			$ 330,618

Investments in Securities Tradi

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 142,472	$ 48,123
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	6,426	8,543
Fannie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	2,750	3,424
Other agency [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	3,518	4,490
Private-label and other mortgage securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	158	629
Non-mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	136,046	39,580
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	135,972	39,501
Other securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	74	79
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 850	$ 896

Investments in Securities Tra_2

Investments in Securities Trading 2 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt and Equity Securities, FV-NI [Line Items]
Net trading gains (losses)	$ (91)	$ 95	$ 691	$ 370
Net trading gains (losses) recognized in the period related to securities still held at period end	$ (71)	$ 82	$ 448	$ 298

Investments in Securities Avail

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 15	$ 0	$ 45	$ 171
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 137	$ 0	$ 258	$ 376

Investments in Securities Ava_2

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	$ 1,780	$ 2,281
Allowance for credit losses	(3)
Gross unrealized gains	132	137
Gross unrealized losses	(14)	(14)
Total fair value	1,895	2,404
Interest excluded from amortized cost and fair value	7	10
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	1,195	1,445
Allowance for credit losses	0
Gross unrealized gains	102	85
Gross unrealized losses	(14)	(10)
Total fair value	1,283	1,520
Other agency [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	85	183
Allowance for credit losses	0
Gross unrealized gains	11	15
Gross unrealized losses	0	0
Total fair value	96	198
Alt-A and subprime private-label securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	4	34
Allowance for credit losses	0
Gross unrealized gains	2	23
Gross unrealized losses	0	0
Total fair value	6	57
Mortgage revenue bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	249	309
Allowance for credit losses	(3)
Gross unrealized gains	9	9
Gross unrealized losses	0	(3)
Total fair value	255	315
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	247	310
Allowance for credit losses	0
Gross unrealized gains	8	5
Gross unrealized losses	0	(1)
Total fair value	$ 255	$ 314

Investments in Securities Ava_3

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	$ 2	$ 1
Less than 12 Consecutive Months, Fair Value	72	130
12 Consecutive Months or Longer, Gross Unrealized Losses	(12)	(13)
12 Consecutive Months or Longer, Fair Value	90	340
AOCI, Debt Securities, Available-for-sale without Allowance for Credit Loss, Cumulative Gain (Loss), after Tax	93
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	90	340
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	72	130
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	12	13
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(27)	(34)
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	2	0
Less than 12 Consecutive Months, Fair Value	72	0
12 Consecutive Months or Longer, Gross Unrealized Losses	(12)	(10)
12 Consecutive Months or Longer, Fair Value	90	337
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	90	337
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	72	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	12	10
Mortgage revenue bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	0	0
Less than 12 Consecutive Months, Fair Value	0	0
12 Consecutive Months or Longer, Gross Unrealized Losses	0	(3)
12 Consecutive Months or Longer, Fair Value	0	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	3
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	0	1
Less than 12 Consecutive Months, Fair Value	0	130
12 Consecutive Months or Longer, Gross Unrealized Losses	0	0
12 Consecutive Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	130
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0	$ 0

Investments in Securities Other

Investments in Securities Other-than-temporary Impairments (Details) $ in Millions	Dec. 31, 2019USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 36

Investments in Securities Sched

Investments in Securities Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income [Line Items]
Accumulated Other Comprehensive Income , Net of Tax, Available-for-sale Securities, Other-than-temporary Impairment not Recorded		$ 97
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	$ 27	34
Accumulated other comprehensive income	$ 120	131
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held		$ 36

Investments in Securities Matur

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 1,780	$ 2,281
Total fair value	1,895	2,404
Amortized cost of investments in securities	1,780	2,281
Total fair value	1,895	2,404
Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,895
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	36
After Five Years through Ten Years, Fair Value	159
After Ten Years, Fair Value	1,699
Total fair value	1,895
Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,777
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	34
After Five Years through Ten Years, Fair Value	144
After Ten Years, Fair Value	1,598
Total fair value	1,777
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,195	1,445
Total fair value	1,283	1,520
Amortized cost of investments in securities	1,195	1,445
Total fair value	1,283	1,520
Fannie Mae [Member] | Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,283
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	6
After Five Years through Ten Years, Fair Value	100
After Ten Years, Fair Value	1,177
Total fair value	1,283
Fannie Mae [Member] | Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	1,195
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	6
After Five Years through Ten Years, Fair Value	88
After Ten Years, Fair Value	1,101
Total fair value	1,195
Other agency [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	85	183
Total fair value	96	198
Amortized cost of investments in securities	85	183
Total fair value	96	198
Other agency [Member] | Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	96
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	11
After Ten Years, Fair Value	85
Total fair value	96
Other agency [Member] | Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	85
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	10
After Ten Years, Fair Value	75
Total fair value	85
Alt-A and subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	4	34
Total fair value	6	57
Amortized cost of investments in securities	4	34
Total fair value	6	57
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	6
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	3
After Ten Years, Fair Value	3
Total fair value	6
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	4
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	2
Total fair value	4
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	249	309
Total fair value	255	315
Amortized cost of investments in securities	249	309
Total fair value	255	315
Mortgage revenue bonds [Member] | Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	255
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	30
After Five Years through Ten Years, Fair Value	24
After Ten Years, Fair Value	200
Total fair value	255
Mortgage revenue bonds [Member] | Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	246
One Year or Less, Fair Value	1
After One Year through Five Years, Fair Value	28
After Five Years through Ten Years, Fair Value	24
After Ten Years, Fair Value	193
Total fair value	246
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	247	310
Total fair value	255	314
Amortized cost of investments in securities	247	310
Total fair value	255	$ 314
Other mortgage-related securities [Member] | Estimated of Fair Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	255
One Year or Less, Fair Value	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Fair Value	21
After Ten Years, Fair Value	234
Total fair value	255
Other mortgage-related securities [Member] | Carrying Value [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total fair value	247
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	227
Total fair value	$ 247

Financial Guarantees Financial

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Financial Guarantees and Maximum Recovery [Line Items]
Contractual terms of our guarantees	32 years
Maximum Exposure	$ 16,830	$ 18,471
Guaranty Obligation	128	154
Maximum Recovery	7,090	8,098
Unconsolidated Fannie Mae MBS [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	4,880	5,801
Guaranty Obligation	18	26
Maximum Recovery	4,666	5,545
Other guaranty arrangements [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	11,950	12,670
Guaranty Obligation	110	128
Maximum Recovery	2,424	2,553
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	$ 117,700	$ 50,100

Short-Term and Long-Term Debt S

Short-Term and Long-Term Debt Short-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Short-Term Debt [Line Items]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	$ 0	$ 478
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Short-Term Debt [Line Items]
Debt, Weighted Average Interest Rate	0.00%	1.67%
Intraday line of credit [Member]
Short-Term Debt [Line Items]
Line of credit maximum borrowing capacity	$ 15,000	$ 15,000
Fannie Mae [Member]
Short-Term Debt [Line Items]
Short-term debt, outstanding	$ 23,526	$ 26,662
Short-term debt, weighted-average interest rate	0.23%	1.56%

Short-Term and Long-Term Debt L

Short-Term and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,796,278	$ 3,440,724
Long-term debt, weighted-average interest rate	2.04%	2.78%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,530,381	$ 3,285,139
Long-term debt, weighted-average interest rate	2.09%	2.78%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 265,897	$ 155,585
Long-term debt, weighted-average interest rate	1.48%	2.86%
Unamortized discounts and premiums, other cost basis adjustments and fair value adjustments	$ 491	$ 2
Fannie Mae [Member] | Senior Fixed [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 147,520	$ 123,958
Long-term debt, weighted-average interest rate	1.95%	2.47%
Fannie Mae [Member] | Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 104,323	$ 86,114
Long-term debt, weighted-average interest rate	2.26%	2.66%
Fannie Mae [Member] | Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 37,983	$ 32,590
Long-term debt, weighted-average interest rate	0.73%	1.57%
Fannie Mae [Member] | Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 5,214	$ 5,254
Long-term debt, weighted-average interest rate	4.63%	5.01%
Fannie Mae [Member] | Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 118,356	$ 31,596
Long-term debt, weighted-average interest rate	0.89%	4.40%
Fannie Mae [Member] | Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 102,585	$ 9,774
Long-term debt, weighted-average interest rate	0.35%	1.66%
Fannie Mae [Member] | Senior floating Connecticut Avenue Securities [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 15,336	$ 21,424
Long-term debt, weighted-average interest rate	4.34%	5.61%
Fannie Mae [Member] | Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 435	$ 398
Long-term debt, weighted-average interest rate	5.14%	6.27%
Fannie Mae [Member] | Secured borrowings [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 21	$ 31
Long-term debt, weighted-average interest rate	3.00%	2.31%

Derivative Instruments Derivati

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Asset Derivatives [Abstract]
Notional amount	$ 512,313	$ 243,475
Derivative asset, estimated fair value	1,038	271
Netting adjustment	(2,037)	(1,288)
Liability Derivatives [Abstract]
Notional amount	340,487	196,666
Derivative liability, estimated fair value	(965)	(435)
Netting adjustment	2,053	1,694
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	991	1,000
Cash collateral received for derivative instruments	975	635
Pay-fixed Swap
Asset Derivatives [Abstract]
Notional amount	110,215	41,052
Derivative asset, estimated fair value	0	0
Liability Derivatives [Abstract]
Notional amount	25,728	29,178
Derivative liability, estimated fair value	(1,297)	(970)
Receive-fixed Swap
Asset Derivatives [Abstract]
Notional amount	109,774	73,579
Derivative asset, estimated fair value	1,082	816
Liability Derivatives [Abstract]
Notional amount	19,213	26,382
Derivative liability, estimated fair value	(54)	(62)
Basis Swap
Asset Derivatives [Abstract]
Notional amount	250	273
Derivative asset, estimated fair value	218	149
Liability Derivatives [Abstract]
Notional amount	0	0
Derivative liability, estimated fair value	0	0
Foreign Currency Swap
Asset Derivatives [Abstract]
Notional amount	224	229
Derivative asset, estimated fair value	41	39
Liability Derivatives [Abstract]
Notional amount	226	232
Derivative liability, estimated fair value	(78)	(65)
Pay-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	5,400	4,600
Derivative asset, estimated fair value	10	18
Liability Derivatives [Abstract]
Notional amount	5,525	6,375
Derivative liability, estimated fair value	(341)	(219)
Receive-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	6,625	2,875
Derivative asset, estimated fair value	591	106
Liability Derivatives [Abstract]
Notional amount	800	4,600
Derivative liability, estimated fair value	(138)	(232)
Future [Member]
Asset Derivatives [Abstract]
Notional amount	55,004	20,507
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	287,492	143,115
Derivative asset, estimated fair value	1,942	1,128
Accrued interest receivable (payable)	111	226
Netting adjustment	(2,037)	(1,288)
Total net risk management derivatives	16	66
Liability Derivatives [Abstract]
Notional amount	51,492	66,767
Derivative liability, estimated fair value	(1,908)	(1,548)
Accrued interest receivable (payable)	(230)	(250)
Netting adjustment	2,053	1,694
Total net risk management derivatives	(85)	(104)
Mortgage commitments to purchase whole loans
Asset Derivatives [Abstract]
Notional amount	36,756	7,115
Derivative asset, estimated fair value	93	15
Liability Derivatives [Abstract]
Notional amount	9,180	1,787
Derivative liability, estimated fair value	(13)	(1)
Forward contracts to purchase mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	122,096	55,531
Derivative asset, estimated fair value	402	137
Liability Derivatives [Abstract]
Notional amount	37,607	9,560
Derivative liability, estimated fair value	(70)	(28)
Forward contracts to sell mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	45,165	9,282
Derivative asset, estimated fair value	68	13
Liability Derivatives [Abstract]
Notional amount	232,148	109,066
Derivative liability, estimated fair value	(759)	(277)
Mortgage commitment derivatives
Asset Derivatives [Abstract]
Notional amount	204,017	71,928
Derivative asset, estimated fair value	563	165
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	278,935	120,413
Derivative liability, estimated fair value	(842)	(306)
Netting adjustment	0	0
Other
Asset Derivatives [Abstract]
Notional amount	20,804	28,432
Derivative asset, estimated fair value	459	40
Liability Derivatives [Abstract]
Notional amount	10,060	9,486
Derivative liability, estimated fair value	$ (38)	$ (25)

Derivative Instruments Deriva_2

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ (294)	$ (668)	$ (2,228)	$ (2,216)
Net contractual interest expense on interest-rate swaps	6,656	5,348	17,780	15,371
Pay-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	634	(1,414)	(3,489)	(4,913)
Receive-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(550)	966	2,984	4,131
Basis Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(5)	24	68	75
Foreign Currency Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	23	(11)	(11)	(9)
Pay-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	2	(110)	(159)	(430)
Receive-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(60)	209	597	309
Future [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	0	42	(75)	296
Risk Management Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(2)	(484)	(301)	(1,239)
Net contractual interest expense on interest-rate swaps	(46)	(190)	(216)	(698)
Mortgage commitment derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(672)	(177)	(2,327)	(946)
Other
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ 380	$ (7)	$ 400	$ (31)

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net interest income	$ 6,656	$ 5,348	$ 17,780	$ 15,371
Fee and other income	93	188	303	435
Net revenues	6,749	5,536	18,083	15,806
Investment gains, net	653	253	644	847
Fair value gains (losses), net	(327)	(713)	(1,621)	(2,298)
Administrative expenses	(762)	(749)	(2,265)	(2,237)
Benefit (provision) for credit losses	501	1,857	(2,094)	3,732
Foreclosed property income (expense)	(71)	(96)	(161)	(364)
Credit-related income (expense)	430	1,761	(2,255)	3,368
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(679)	(613)	(1,976)	(1,806)
Credit enhancement expense	(325)	(290)	(1,061)	(782)
Change in expected credit enhancement recoveries	(48)	0	413	0
Other expenses, net	(313)	(186)	(792)	(551)
Income before federal income taxes	5,378	4,999	9,170	12,347
Provision for federal income taxes	(1,149)	(1,036)	(1,935)	(2,552)
Net income	4,229	3,963	7,235	9,795
US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(679)	(613)	(1,976)	(1,806)
Business Segments [Member] | Single-family [Member]
Segment Reporting Information [Line Items]
Net interest income	5,870	4,484	15,350	12,942
Fee and other income	73	156	238	350
Net revenues	5,943	4,640	15,588	13,292
Investment gains, net	583	198	527	709
Fair value gains (losses), net	(244)	(719)	(1,734)	(2,364)
Administrative expenses	(634)	(634)	(1,888)	(1,899)
Benefit (provision) for credit losses	542	1,840	(1,411)	3,753
Foreclosed property income (expense)	(64)	(93)	(145)	(362)
Credit-related income (expense)	478	1,747	(1,556)	3,391
Credit enhancement expense	(274)	(240)	(897)	(639)
Change in expected credit enhancement recoveries	(48)	0	218	0
Other expenses, net	(307)	(184)	(722)	(540)
Income before federal income taxes	4,818	4,195	7,560	10,144
Provision for federal income taxes	(1,049)	(872)	(1,623)	(2,125)
Net income	3,769	3,323	5,937	8,019
Business Segments [Member] | Single-family [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(679)	(613)	(1,976)	(1,806)
Business Segments [Member] | Multifamily [Member]
Segment Reporting Information [Line Items]
Net interest income	786	864	2,430	2,429
Fee and other income	20	32	65	85
Net revenues	806	896	2,495	2,514
Investment gains, net	70	55	117	138
Fair value gains (losses), net	(83)	6	113	66
Administrative expenses	(128)	(115)	(377)	(338)
Benefit (provision) for credit losses	(41)	17	(683)	(21)
Foreclosed property income (expense)	(7)	(3)	(16)	(2)
Credit-related income (expense)	(48)	14	(699)	(23)
Credit enhancement expense	(51)	(50)	(164)	(143)
Change in expected credit enhancement recoveries	0	0	195	0
Other expenses, net	(6)	(2)	(70)	(11)
Income before federal income taxes	560	804	1,610	2,203
Provision for federal income taxes	(100)	(164)	(312)	(427)
Net income	460	640	1,298	1,776
Business Segments [Member] | Multifamily [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	$ 0	$ 0	$ 0	$ 0

Concentrations of Credit Risk S

Concentrations of Credit Risk SF Risk Characteristics (Details) - Single-family [Member]	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Guaranty Book of Business [Member] | Conventional Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	1.00%	1.07%
60 days delinquent (percentage of book of business)	0.49%	0.29%
Seriously delinquent (percentage of book of business)	3.61%	0.59%
30 days delinquent (percentage of conventional loans)	1.11%	1.27%
60 days delinquent (percentage of conventional loans)	0.50%	0.35%
Seriously delinquent (percentage of conventional loans)	3.20%	0.66%
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)	21.74%	10.14%
Guaranty Book of Business [Member] | Conventional Loan [Member] | Alt-A
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	9.46%	2.95%
Percentage of Unpaid Principal Balance of Loans	1.00%	2.00%
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)	5.81%	2.48%
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)	9.84%	4.11%
Percentage of Unpaid Principal Balance of Loans	3.00%	4.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2009-2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.74%	0.35%
Percentage of Unpaid Principal Balance of Loans	95.00%	94.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	3.04%	0.32%
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)	4.76%	0.84%
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)	3.46%	0.91%
Percentage of Unpaid Principal Balance of Loans	3.00%	4.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	5.31%	1.13%
Percentage of Unpaid Principal Balance of Loans	3.00%	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)	5.39%	1.18%
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)	2.85%	0.64%
Percentage of Unpaid Principal Balance of Loans	64.00%	63.00%
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	90 days

Concentrations of Credit Risk M

Concentrations of Credit Risk MF Risk Characteristics (Details) - Multifamily [Member]	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
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
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)	0.14%	0.02%
Seriously delinquent (percentage of book of business)	1.12%	0.04%
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	1.24%	0.00%
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	1.12%	0.04%
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	22.07%	0.48%

Concentrations of Credit Risk O

Concentrations of Credit Risk Other Concentrations (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)contracts	Dec. 31, 2019USD ($)
Concentration Risk [Line Items]
Estimated benefit included in loss reserves	$ 1,700	$ 410
Receivable from claims on insured, defaulted loans excluding government insured loans	569	654
Allowance for mortgage insurance receivable	$ 499	541
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	76.50%
Mortgage insurance coverage risk in force percentage to be deferred	23.50%
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	$ 169,011	162,855
Pool mortgage insurance	296	339
Mortgage insurance coverage risk in force	$ 169,307	$ 163,194
Mortgage insurance coverage risk in force as percentage	5.00%	6.00%
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	52.00%	59.00%
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	25.00%	27.00%
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	15.00%	17.00%
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	12.00%	15.00%
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	$ 2,700
Percentage of Concentration Risk	2.00%
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	21.00%	23.00%
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	19.00%	20.00%
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] | Genworth Mortgage Insurance Corp.(2)
Concentration Risk [Line Items]
Percentage of Risk-in-Force Coverage by Mortgage Insurer	17.00%	15.00%
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	15.00%	14.00%
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	10.00%	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%	13.00%
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	12.00%	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	23.00%	23.00%

Netting Arrangements (Details)

Netting Arrangements (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Fair Value of Securities Received as Collateral that Have Been Resold or Repledged	$ 0	$ 0	$ 0
Derivative Liability, Not Subject to Master Netting Arrangement	38	38	25
Assets:
Derivative assets, gross amount	2,616	2,616	1,519
Derivative assets, gross amount offset	(2,037)	(2,037)	(1,288)
Derivative assets, net amount presented in our condensed consolidated balance sheets	579	579	231
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(289)	(289)	(101)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(23)	(23)	(1)
Derivative assets, net amount	267	267	129
Securities purchased under agreements to resell or similar arrangements, gross amount	27,100	27,100	24,928
Securities purchased under agreements to resell or similar arrangements, gross amount offset	0	0	0
Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement	27,100	27,100	24,928
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	0
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(27,100)	(27,100)	(24,928)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0	0
Total assets, gross amount	29,716	29,716	26,447
Total assets, gross amount offset	(2,037)	(2,037)	(1,288)
Total assets, net amount presented in our condensed consolidated balance sheets	27,679	27,679	25,159
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(289)	(289)	(101)
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(27,123)	(27,123)	(24,929)
Total assets, net amount	267	267	129
Liabilities:
Derivative liabilities, gross amount	(2,980)	(2,980)	(2,104)
Derivative liabilities, gross amount offset	2,053	2,053	1,694
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(927)	(927)	(410)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	289	289	101
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	532	532	182
Derivative liabilities, net amount	(106)	(106)	(127)
Total liabilities, gross amount	(2,980)	(2,980)	(2,582)
Total liabilities, gross amount offset	2,053	2,053	1,694
Total liabilities, net amount presented in our condensed consolidated balance sheets	(927)	(927)	(888)
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	289	289	101
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	532	532	657
Total liabilities, net amount	(106)	(106)	(130)
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral			3
Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement			478
Securities Sold under Agreements to Repurchase, Gross			478
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities			475
Single-family [Member]
Liabilities:
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	219	573
Risk Management Derivatives
Assets:
Derivative assets, gross amount offset	(2,037)	(2,037)	(1,288)
Liabilities:
Derivative liabilities, gross amount offset	2,053	2,053	1,694
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	563	563	165
Derivative assets, gross amount offset	0	0	0
Derivative assets, net amount presented in our condensed consolidated balance sheets	563	563	165
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(289)	(289)	(101)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(23)	(23)	(1)
Derivative assets, net amount	251	251	63
Liabilities:
Derivative liabilities, gross amount	(842)	(842)	(306)
Derivative liabilities, gross amount offset	0	0	0
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(842)	(842)	(306)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	289	289	101
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	529	529	181
Derivative liabilities, net amount	(24)	(24)	(24)
Over the Counter [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	2,053	2,053	1,354
Derivative assets, gross amount offset	(2,052)	(2,052)	(1,334)
Derivative assets, net amount presented in our condensed consolidated balance sheets	1	1	20
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0	0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0	0
Derivative assets, net amount	1	1	20
Liabilities:
Derivative liabilities, gross amount	(2,138)	(2,138)	(1,798)
Derivative liabilities, gross amount offset	2,056	2,056	1,695
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(82)	(82)	(103)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0	0
Derivative liabilities, net amount	(82)	(82)	(103)
Exchange Cleared [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	0	0	0
Derivative assets, gross amount offset	15	15	46
Derivative assets, net amount presented in our condensed consolidated balance sheets	15	15	46
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0	0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0	0
Derivative assets, net amount	15	15	46
Liabilities:
Derivative liabilities, gross amount	0	0	0
Derivative liabilities, gross amount offset	(3)	(3)	(1)
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(3)	(3)	(1)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	3	3	1
Derivative liabilities, net amount	$ 0	$ 0	$ 0

Netting Arrangements Narratives

Netting Arrangements Narratives (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Fair value of non-cash collateral we pledged	$ 4,800	$ 2,300
Fair value of non-cash collateral received	27,000	24,700
Fair value of non-cash collateral received that can be resold or repledged	25,800	23,800
Fair value of securities received as collateral that have been resold or repledge	0	0
Derivative assets not subject to enforceable master netting arrangements	459	40
Derivative liabilities not subject to enforceable master netting arrangements	(38)	(25)
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Securities purchased under agreements to resell	$ 14,400	$ 11,400

Fair Value Levels Hierarchy (De

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 6,968	$ 7,825
Other assets [Abstract]
Derivative assets, gross amount offset	(2,037)	(1,288)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,053)	(1,694)
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	3,986	5,687
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	24,741	21,880
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	135,972	39,501
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	232,560	89,558
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	6,439	8,576
Available-for-sale securities	1,168	1,612
Mortgage loans held for investment, at fair value	3,414,104	3,270,535
Other assets [Abstract]
Derivatives assets at fair value	2,395	1,360
Total assets at fair value	3,462,112	3,313,691
Other liabilities [Abstract]
Derivative liabilities at fair value	2,980	2,092
Total liabilities at fair value	3,952,214	3,506,144
Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	277,190	164,144
Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,648,508	3,312,763
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	61	46
Available-for-sale securities	727	792
Mortgage loans held for investment, at fair value	257,448	127,650
Other assets [Abstract]
Derivatives assets at fair value	680	199
Total assets at fair value	267,484	136,048
Other liabilities [Abstract]
Derivative liabilities at fair value	38	37
Total liabilities at fair value	32,612	32,362
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	878	401
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	31,618	31,827
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Trading securities	142,472	48,123
Available-for-sale securities	1,895	2,404
Mortgage loans held for investment, at fair value	6,968	7,825
Other assets [Abstract]
Derivatives assets at fair value	1,038	271
Derivative assets, gross amount offset	(2,037)	(1,288)
Total assets at fair value	155,816	58,623
Liabilities [Abstract]
Long-term debt, fair value	28,727	27,567
Other liabilities [Abstract]
Derivative liabilities at fair value	965	435
Derivative liabilities, gross amount offset	(2,053)	(1,694)
Total liabilities at fair value	29,692	28,002
Cash and Cash Equivalents, Fair Value Disclosure	3,443
Recurring Fair Value Measurements [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,452	1,230
Other liabilities [Abstract]
Derivative liabilities at fair value	1,659	1,347
Recurring Fair Value Measurements [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	601	124
Other liabilities [Abstract]
Derivative liabilities at fair value	479	451
Recurring Fair Value Measurements [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	563	165
Other liabilities [Abstract]
Derivative liabilities at fair value	842	306
Recurring Fair Value Measurements [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	459	40
Other liabilities [Abstract]
Derivative liabilities at fair value	38	25
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,986	5,687
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,986	5,687
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	24,741	21,880
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	2,750	3,424
Available-for-sale securities	1,283	1,520
Recurring Fair Value Measurements [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,518	4,490
Available-for-sale securities	96	198
Recurring Fair Value Measurements [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	158	629
Available-for-sale securities	6	57
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	255	315
Recurring Fair Value Measurements [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	255	314
Recurring Fair Value Measurements [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	135,972	39,501
Recurring Fair Value Measurements [Member] | Other securities [Member]
Assets [Abstract]
Trading securities	74	79
Recurring Fair Value Measurements [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	135,972	39,501
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	139,415	39,501
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	3,443
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	135,972	39,501
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	6,439	8,576
Available-for-sale securities	1,168	1,612
Mortgage loans held for investment, at fair value	6,090	7,137
Other assets [Abstract]
Derivatives assets at fair value	2,395	1,360
Total assets at fair value	16,092	18,685
Liabilities [Abstract]
Long-term debt, fair value	28,207	27,094
Other liabilities [Abstract]
Derivative liabilities at fair value	2,980	2,092
Total liabilities at fair value	31,187	29,186
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,231	1,071
Other liabilities [Abstract]
Derivative liabilities at fair value	1,659	1,346
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	601	124
Other liabilities [Abstract]
Derivative liabilities at fair value	479	440
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	563	165
Other liabilities [Abstract]
Derivative liabilities at fair value	842	306
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	3,551	5,289
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	3,551	5,289
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	24,656	21,805
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	2,690	3,379
Available-for-sale securities	1,061	1,349
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,517	4,489
Available-for-sale securities	96	198
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	158	629
Available-for-sale securities	4	57
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	7	8
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	74	79
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	61	171
Available-for-sale securities	727	792
Mortgage loans held for investment, at fair value	878	688
Other assets [Abstract]
Derivatives assets at fair value	680	199
Total assets at fair value	2,346	1,725
Liabilities [Abstract]
Long-term debt, fair value	520	473
Other liabilities [Abstract]
Derivative liabilities at fair value	38	37
Total liabilities at fair value	558	510
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	221	159
Other liabilities [Abstract]
Derivative liabilities at fair value	0	1
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	11
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	459	40
Other liabilities [Abstract]
Derivative liabilities at fair value	38	25
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	435	398
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	435	398
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	85	75
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	60	45
Available-for-sale securities	222	171
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	1	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	2	0
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	255	315
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	248	306
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		$ 46

Fair Value Level 3 Rollforward

Fair Value Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	$ 0	$ 1	$ (8)	$ 4
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	136	74	46	33
Total gains (losses) (realized/unrealized) Included in Net Income	(4)	2	(6)	5
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	77	0	77
Sales	(95)	0	(95)	(14)
Issues	0	0	0	0
Settlements	0	0	(3)	(17)
Transfers out of Level 3	(3)	(31)	(49)	(31)
Transfers into Level 3	27	2	168	71
Ending Balance	61	124	61	124
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	1	(8)	4
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	38	74	45	32
Total gains (losses) (realized/unrealized) Included in Net Income	0	2	(9)	5
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	77	0	77
Sales	(1)	0	(1)	(14)
Issues	0	0	0	0
Settlements	0	0	0	(16)
Transfers out of Level 3	(3)	(31)	(48)	(31)
Transfers into Level 3	26	0	73	69
Ending Balance	60	122	60	122
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	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	0	1	0
Total gains (losses) (realized/unrealized) Included in Net Income	0	0	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	0	0	0	0
Transfers out of Level 3	0	0	(1)	0
Transfers into Level 3	1	2	1	2
Ending Balance	1	2	1	2
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	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	98		0	1
Total gains (losses) (realized/unrealized) Included in Net Income	(4)		3	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0		0	0
Purchases	0		0	0
Sales	(94)		(94)	0
Issues	0		0	0
Settlements	0		(3)	(1)
Transfers out of Level 3	0		0	0
Transfers into Level 3	0		94	0
Ending Balance	0	0	0	0
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	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	980	822	792	952
Total gains (losses) (realized/unrealized) Included in Net Income	6	0	(11)	17
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	7	1	9	(9)
Purchases	0	0	342	0
Sales	0	0	(342)	(27)
Issues	0	0	0	0
Settlements	(48)	(28)	(125)	(118)
Transfers out of Level 3	(218)	0	(218)	(105)
Transfers into Level 3	0	40	280	125
Ending Balance	727	835	727	835
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	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	446	132	171	152
Total gains (losses) (realized/unrealized) Included in Net Income	1	0	1	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	2	3	2	9
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(9)	(1)	(12)	(8)
Transfers out of Level 3	(218)	0	(218)	(103)
Transfers into Level 3	0	40	278	124
Ending Balance	222	174	222	174
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		0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2		0	24
Total gains (losses) (realized/unrealized) Included in Net Income	0		0	5
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0		0	(5)
Purchases	0		0	0
Sales	0		0	(23)
Issues	0		0	0
Settlements	0		0	(1)
Transfers out of Level 3	0		0	0
Transfers into Level 3	0		2	0
Ending Balance	2	0	2	0
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	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	278	364	315	434
Total gains (losses) (realized/unrealized) Included in Net Income	0	1	(3)	1
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	(1)	3	(2)
Purchases	0	0	74	0
Sales	0	0	(74)	(4)
Issues	0	0	0	0
Settlements	(23)	(18)	(60)	(83)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	255	346	255	346
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	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	254	326	306	342
Total gains (losses) (realized/unrealized) Included in Net Income	5	(1)	(9)	11
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	5	(1)	4	(11)
Purchases	0	0	268	0
Sales	0	0	(268)	0
Issues	0	0	0	0
Settlements	(16)	(9)	(53)	(26)
Transfers out of Level 3	0	0	0	(2)
Transfers into Level 3	0	0	0	1
Ending Balance	248	315	248	315
Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	36	10	5	28
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	797	770	688	937
Total gains (losses) (realized/unrealized) Included in Net Income	41	14	32	45
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	(11)	(27)	(11)	(40)
Issues	0	0	0	0
Settlements	(39)	(35)	(93)	(105)
Transfers out of Level 3	(31)	(41)	(75)	(228)
Transfers into Level 3	121	45	337	117
Ending Balance	878	726	878	726
Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	372	15	468	39
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	269	183	162	194
Total gains (losses) (realized/unrealized) Included in Net Income	380	21	470	139
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(7)	(6)	(8)	(126)
Transfers out of Level 3	0	0	18	(9)
Transfers into Level 3	0	0	0	0
Ending Balance	642	198	642	198
Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	(4)	(25)	(60)	(74)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(522)	(500)	(473)	(552)
Total gains (losses) (realized/unrealized) Included in Net Income	(4)	27	(61)	78
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	(2)	0	(2)
Settlements	6	6	36	16
Transfers out of Level 3	1	20	2	189
Transfers into Level 3	(1)	(7)	(24)	(83)
Ending Balance	(520)	(510)	(520)	(510)
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	(1)	(1)	1	(3)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(89)	(102)	(75)	(201)
Total gains (losses) (realized/unrealized) Included in Net Income	1	3	0	7
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	(2)	0	(2)
Settlements	5	6	12	16
Transfers out of Level 3	1	20	2	189
Transfers into Level 3	(1)	(7)	(24)	(83)
Ending Balance	(85)	(88)	(85)	(88)
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	(3)	(24)	(61)	(71)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(433)	(398)	(398)	(351)
Total gains (losses) (realized/unrealized) Included in Net Income	3	(24)	61	(71)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances	0	0	0	0
Settlements	1	0	24	0
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	(435)	(422)	(435)	(422)
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	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	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	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	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	4	1	8	(2)
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	0	3	0	8
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		0	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	0	5	(1)
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	4	(2)	3	(9)
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	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	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	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	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	$ 0	$ 0

Fair Value Level 3 Valuation In

Fair Value Level 3 Valuation Inputs (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 579	$ 231
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	142,472	48,123
Available-for-sale securities	1,895	2,404
Assets, Fair Value Disclosure	155,816	58,623
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	135,972	39,501
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	232,560	89,558
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	135,972	39,501
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	139,415	39,501
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	6,439	8,576
Available-for-sale securities	1,168	1,612
Assets, Fair Value Disclosure	3,462,112	3,313,691
Mortgage loans held-for-sale, at lower of cost or fair value	679	229
Significant Other Observable Inputs (Level 2) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	6,439	8,576
Available-for-sale securities	1,168	1,612
Assets, Fair Value Disclosure	16,092	18,685
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	127	274
Liabilities, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	61	46
Available-for-sale securities	727	792
Assets, Fair Value Disclosure	267,484	136,048
Mortgage loans held-for-sale, at lower of cost or fair value	8,297	7,054
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	61	171
Available-for-sale securities	727	792
Derivatives	642	162
Assets, Fair Value Disclosure	2,346	1,725
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	421	15
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	221	147
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	3,350	2,598
Mortgage loans held-for-sale, at lower of cost or fair value	1,880	1,076
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	767	605
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	1,113	471
Agency | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	222
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	61	46
Available-for-sale securities	98
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	124	107
Private-label and other mortgage securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	158	629
Available-for-sale securities	6	57
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	158	629
Available-for-sale securities	4	57
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	2	0
Mortgage revenue bonds [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	255	315
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	255	315
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	177	222
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		64
Available-for-sale securities	78	93
Other [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	255	314
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	7	8
Other [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	248	306
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	32	39
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	$ 216	$ 267
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 (%)	35.50%	23.00%
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 (%)	4.060	3
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 (%)	318.80%	2.051%
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 (%)	4.310	3
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 (%)	100.00%	0.761%
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 (%)	4.188	3
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	$ 2

Fair Value Level 3 Valuation -

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 6,968	$ 7,825
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	679	229
Mortgage loans held for investment, at fair value	3,414,104	3,270,535
Total assets at fair value	3,462,112	3,313,691
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	8,297	7,054
Mortgage loans held for investment, at fair value	257,448	127,650
Total assets at fair value	267,484	136,048
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	127	274
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	1,880	1,076
Total assets at fair value	3,350	2,598
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	767	605
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	1,113	471
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	356	918
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	15	51
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	855	555
Acquired property, net	55	164
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	60	101
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	115	362
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Walk Forwards [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	111	240
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	232	40
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	232	16
Acquired property, net	27	9
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Asset Manager Estimate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 0	$ 24

Fair Value Fair Value of Financ

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (2,037)	$ (1,288)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,053)	(1,694)
Mortgage loans held for investment, at fair value	6,968	7,825
Derivative assets, gross amount offset	(2,037)	(1,288)
Derivative liabilities, gross amount offset	(2,053)	(1,694)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	96,588	50,057
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	135,972	39,501
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	232,560	89,558
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	14,400	11,350
Federal funds sold and securities purchased under agreements to resell or similar arrangements	12,700	13,578
Trading securities	6,439	8,576
Available-for-sale securities	1,168	1,612
Mortgage loans held for sale	679	229
Mortgage loans held for investment, at fair value	3,414,104	3,270,535
Advances to lenders	10,227	6,451
Derivatives assets at fair value	2,395	1,360
Guaranty assets and buy-ups	0	0
Total financial assets	3,462,112	3,313,691
Financial liabilities [Abstract]
Derivative liabilities at fair value	2,980	2,092
Guaranty obligations	0	0
Total financial liabilities	3,952,214	3,506,144
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		478
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	61	46
Available-for-sale securities	727	792
Mortgage loans held for sale	8,297	7,054
Mortgage loans held for investment, at fair value	257,448	127,650
Advances to lenders	1	2
Derivatives assets at fair value	680	199
Guaranty assets and buy-ups	270	305
Total financial assets	267,484	136,048
Financial liabilities [Abstract]
Derivative liabilities at fair value	38	37
Guaranty obligations	78	97
Total financial liabilities	32,612	32,362
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	3,986	5,687
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	23,536	26,667
Long-term debt	277,190	164,144
Fannie Mae [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	878	401
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	24,741	21,880
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	3,648,508	3,312,763
Consolidated Trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Long-term debt	31,618	31,827
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	110,988	61,407
Federal funds sold and securities purchased under agreements to resell or similar arrangements	12,700	13,578
Trading securities	142,472	48,123
Available-for-sale securities	1,895	2,404
Mortgage loans held for sale	8,312	6,773
Mortgage loans held for investment, at fair value	3,539,031	3,327,389
Advances to lenders	10,228	6,453
Derivatives assets at fair value	1,038	271
Guaranty assets and buy-ups	115	142
Total financial assets	3,826,779	3,466,540
Financial liabilities [Abstract]
Derivative liabilities at fair value	965	435
Guaranty obligations	128	154
Total financial liabilities	3,820,897	3,468,453
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		478
Carrying Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	23,526	26,662
Long-term debt	265,897	155,585
Carrying Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	3,530,381	3,285,139
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	110,988	61,407
Federal funds sold and securities purchased under agreements to resell or similar arrangements	12,700	13,578
Trading securities	142,472	48,123
Available-for-sale securities	1,895	2,404
Mortgage loans held for sale	8,976	7,283
Mortgage loans held for investment, at fair value	3,671,552	3,398,185
Advances to lenders	10,228	6,453
Derivatives assets at fair value	1,038	271
Guaranty assets and buy-ups	270	305
Total financial assets	3,960,119	3,538,009
Financial liabilities [Abstract]
Derivative liabilities at fair value	965	435
Guaranty obligations	78	97
Total financial liabilities	3,982,773	3,536,812
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		478
Estimated of Fair Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	23,536	26,667
Long-term debt	278,068	164,545
Estimated of Fair Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	$ 3,680,126	$ 3,344,590

Fair Value Fair Value Option (D

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Option, Quantitative Disclosures [Line Items]
Document Period End Date			Sep. 30, 2020
Mortgage loans held for investment, at fair value	$ 6,968		$ 6,968		$ 7,825
Difference between unpaid principal balance and the fair value of nonaccrual loans	9		9		11
Fair value of nonaccrual loans	140		140		129
Fair value of loans that are 90 days or more past due	297		297		80
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	16		$ 16		10
Single-family [Member] | 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	3,986		$ 3,986		5,687
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	24,741		24,741		21,880
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	6,968		6,968		7,825
Loans, unpaid principal balance	6,501		6,501		7,514
Fair Value, Option, Changes in Fair Value, Gain (Loss)	107	$ 95	248	$ 334
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(32)	$ (245)	(344)	$ (797)
Long-term debt [Member] | Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	3,986		3,986		5,687
Long-term debt, unpaid principal balance	3,895		3,895		5,200
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	24,741		24,741		21,880
Long-term debt, unpaid principal balance	$ 21,521		$ 21,521		$ 19,653

Fair Value Changes in FV under

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ (107)	$ (95)	$ (248)	$ (334)
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ 32	$ 245	$ 344	$ 797