Federal National Mortgage Association (FNMA) 10-Q 1 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page	6 Months Ended
	Jun. 30, 2019shares
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
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 Shell Company	false
Entity Central Index Key	0000310522
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding	1,158,087,567
Entity Small Business	false
Entity Emerging Growth Company	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets:
Cash and cash equivalents	$ 30,791	$ 25,557
Restricted cash (includes $24,765 and $17,849, respectively, related to consolidated trusts)	30,179	23,866
Federal funds sold and securities purchased under agreements to resell or similar arrangements	19,562	32,938
Investments in securities:
Trading, at fair value (includes $2,775 and $3,061, respectively, pledged as collateral)	42,866	41,867
Available-for-sale, at fair value	2,761	3,429
Total investments in securities	45,627	45,296
Mortgage loans:
Loans held for sale, at lower of cost or fair value	11,220	7,701
Loans held for investment, at amortized cost	3,273,494	3,255,897
Allowance for loan losses	(11,482)	(14,203)
Total loans held for investment, net of allowance	3,262,012	3,241,694
Total mortgage loans	3,273,232	3,249,395
Deferred tax assets, net	12,521	13,188
Accrued interest receivable, net (includes $8,543 and $7,928, respectively, related to consolidated trusts)	9,089	8,490
Acquired property, net	2,398	2,584
Other assets	19,888	17,004
Total assets	3,443,287	3,418,318
Liabilities:
Accrued interest payable (includes $9,277 and $9,133, respectively, related to consolidated trusts)	10,342	10,211
Other liabilities (includes $369 and $356, respectively, related to consolidated trusts)	10,001	9,947
Total liabilities	3,436,922	3,412,078
Commitments and contingencies (Note 13)	0	0
Fannie Mae stockholders’ equity:
Senior preferred stock, 1,000,000 shares issued and outstanding	120,836	120,836
Preferred stock, 700,000,000 shares are authorized—555,374,922 shares issued and outstanding	19,130	19,130
Common stock, no par value, no maximum authorization—1,308,762,703 shares issued and 1,158,087,567 shares outstanding	687	687
Accumulated deficit	(127,104)	(127,335)
Accumulated other comprehensive income	216	322
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 our dividend obligation to Treasury)	6,365	6,240
Total liabilities and equity	3,443,287	3,418,318
Fannie Mae [Member]
Mortgage loans:
Loans held for investment, at amortized cost	105,580	113,039
Liabilities:
Debt (includes $6,370 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,771 and $23,753, respectively, of debt of consolidated trusts, at fair value)	216,814	232,074
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $24,765 and $17,849, respectively, related to consolidated trusts)	24,765	17,849
Investments in securities:
Trading, at fair value (includes $2,775 and $3,061, respectively, pledged as collateral)	983	32
Mortgage loans:
Loans held for investment, at amortized cost	3,167,914	3,142,858
Accrued interest receivable, net (includes $8,543 and $7,928, respectively, related to consolidated trusts)	8,543	7,928
Liabilities:
Accrued interest payable (includes $9,277 and $9,133, respectively, related to consolidated trusts)	9,277	9,133
Debt (includes $6,370 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,771 and $23,753, respectively, of debt of consolidated trusts, at fair value)	3,199,765	3,159,846
Other liabilities (includes $369 and $356, respectively, related to consolidated trusts)	$ 369	$ 356

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest income:
Trading securities	$ 432	$ 318	$ 859	$ 554
Available-for-sale securities	45	50	98	121
Mortgage loans (includes $28,102 and $26,521, respectively, for the three months ended and $56,547 and $52,819, respectively, for the six months ended related to consolidated trusts)	29,379	28,307	59,147	56,341
Federal funds sold and securities purchased under agreements to resell or similar arrangements	257	149	520	291
Other	41	33	73	64
Total interest income	30,154	28,857	60,697	57,371
Interest expense:
Short-term debt	(119)	(110)	(244)	(217)
Long-term debt (includes $23,407 and $21,896, respectively, for the three months ended and $47,596 and $43,611, respectively, for the six months ended related to consolidated trusts)	(24,885)	(23,370)	(50,570)	(46,545)
Total interest expense	(25,004)	(23,480)	(50,814)	(46,762)
Net interest income	5,150	5,377	9,883	10,609
Benefit for credit losses	1,225	1,296	1,875	1,513
Net interest income after benefit for credit losses	6,375	6,673	11,758	12,122
Non-interest income (loss):
Investment gains, net	461	277	594	527
Fair value gains (losses), net	(754)	229	(1,585)	1,274
Fee and other income	246	239	473	559
Non-interest income (loss)	(47)	745	(518)	2,360
Administrative expenses:
Salaries and employee benefits	(376)	(365)	(762)	(746)
Professional services	(233)	(254)	(458)	(497)
Other administrative expenses	(135)	(136)	(268)	(262)
Total administrative expenses	(744)	(755)	(1,488)	(1,505)
Foreclosed property expense	(128)	(139)	(268)	(301)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(600)	(565)	(1,193)	(1,122)
Other expenses, net	(535)	(366)	(943)	(569)
Total expenses	(2,007)	(1,825)	(3,892)	(3,497)
Income before federal income taxes	4,321	5,593	7,348	10,985
Provision for federal income taxes	(889)	(1,136)	(1,516)	(2,267)
Other comprehensive income (loss):
Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes	(65)	4	(101)	(316)
Other, net of taxes	(2)	(2)	(5)	(5)
Total other comprehensive income (loss)	(67)	2	(106)	(321)
Total comprehensive income	3,365	4,459	5,726	8,397
Net income	3,432	4,457	5,832	8,718
Dividends distributed or available for distribution to senior preferred stockholder	(3,365)	(4,459)	(5,726)	(5,397)
Net income (loss) attributable to common stockholders	$ 67	$ (2)	$ 106	$ 3,321
Earnings per share, Basic	$ 0.01	$ 0	$ 0.02	$ 0.58
Earnings per share, Diluted	$ 0.01	$ 0	$ 0.02	$ 0.56
Weighted-average common shares outstanding, Basic	5,762	5,762	5,762	5,762
Weighted-average common shares outstanding, Diluted	5,893	5,762	5,893	5,893

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets:
Restricted cash (includes $24,765 and $17,849, respectively, related to consolidated trusts)	$ 30,179	$ 23,866
Investments in securities:
Trading, at fair value (includes $2,977 and $3,061, respectively, pledged as collateral)	2,775	3,061
Available-for-sale, at fair value	2,761	3,429
Accrued interest receivable, net (includes $8,543 and $7,928, respectively, related to consolidated trusts)	9,089	8,490
Mortgage loans:
Total loans held for investment (includes $8,479 and $8,922, respectively, at fair value)	8,479	8,922
Liabilities:
Accrued interest payable (includes $9,277 and $9,133, respectively, related to consolidated trusts)	10,342	10,211
Other liabilities (includes $369 and $356, respectively, related to consolidated trusts)	$ 10,001	$ 9,947
Fannie Mae stockholders’ equity:
Senior preferred stock, 1,000,000 shares issued	1,000,000	1,000,000
Senior preferred stock, 1,000,000 shares outstanding	1,000,000	1,000,000
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
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $24,765 and $17,849, respectively, related to consolidated trusts)	$ 24,765	$ 17,849
Investments in securities:
Accrued interest receivable, net (includes $8,543 and $7,928, respectively, related to consolidated trusts)	8,543	7,928
Liabilities:
Accrued interest payable (includes $9,277 and $9,133, respectively, related to consolidated trusts)	9,277	9,133
Debt (includes $6,370 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,771 and $23,753, respectively, of debt of consolidated trusts, at fair value)	22,771	23,753
Other liabilities (includes $369 and $356, respectively, related to consolidated trusts)	369	356
Fannie Mae [Member]
Liabilities:
Debt (includes $6,370 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,771 and $23,753, respectively, of debt of consolidated trusts, at fair value)	$ 6,370	$ 6,826

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Mortgage loans (includes $28,102 and $26,521, respectively, for the three months ended and $56,547 and $52,819, respectively, for the six months ended related to consolidated trusts)	$ 29,379	$ 28,307	$ 59,147	$ 56,341
Long-term debt (includes $23,407 and $21,896, respectively, for the three months ended and $47,596 and $43,611, respectively, for the six months ended related to consolidated trusts)	24,885	23,370	50,570	46,545
Consolidated Trusts [Member]
Mortgage loans (includes $28,102 and $26,521, respectively, for the three months ended and $56,547 and $52,819, respectively, for the six months ended related to consolidated trusts)	28,102	26,521	56,547	52,819
Long-term debt (includes $23,407 and $21,896, respectively, for the three months ended and $47,596 and $43,611, respectively, for the six months ended related to consolidated trusts)	$ 23,407	$ 21,896	$ 47,596	$ 43,611

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Net cash provided by (used in) operating activities
Net cash provided by (used in) operating activities	$ 2,180	$ (1,675)
Cash flows provided by investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	28	141
Proceeds from sales of trading securities held for investment	49	96
Proceeds from maturities and paydowns of available-for-sale securities	268	417
Proceeds from sales of available-for-sale securities	376	672
Purchases of loans held for investment	(90,612)	(86,615)
Advances to lenders	(54,440)	(55,151)
Proceeds from disposition of acquired property and preforeclosure sales	3,870	4,848
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	13,376	3,170
Other, net	(743)	(495)
Net cash provided by investing activities	95,506	80,506
Cash flows used in financing activities:
Payments of cash dividends on senior preferred stock to Treasury	5,601	938
Proceeds from senior preferred stock purchase agreement with Treasury	0	3,687
Other, net	132	(20)
Net cash used in financing activities	(86,139)	(90,362)
Net increase (decrease) in cash, cash equivalents and restricted cash	11,547	(11,531)
Cash, cash equivalents and restricted cash at beginning of period	49,423	60,260
Cash, cash equivalents and restricted cash at end of period	60,970	48,729
Cash paid during the period for:
Interest	57,637	54,408
Income taxes	700	460
Fannie Mae [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	5,557	7,945
Proceeds from sales of loans acquired as held for investment of Fannie Mae	5,821	2,555
Cash flows used in financing activities:
Proceeds from issuance of debt	374,284	473,373
Payments to redeem debt	(389,779)	(499,674)
Consolidated Trusts [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	211,956	202,923
Cash flows used in financing activities:
Proceeds from issuance of debt	158,970	172,507
Payments to redeem debt	$ (224,145)	$ (239,297)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity (Deficit) - USD ($) $ in Millions	Total	Senior Preferred Stock	Preferred Stock	Common Stock	Accumulated Deficit	Accumulated Other Comprehensive Income	Treasury Stock
Proceeds From Senior Preferred Stock Agreement With Us Treasury	$ 3,687	$ 3,687
Balance (shares) at Dec. 31, 2017		1,000,000	556,000,000	1,158,000,000
Balance at Dec. 31, 2017	(3,686)	$ 117,149	$ 19,130	$ 687	$ (133,805)	$ 553	$ (7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	(938)				(938)
Increase to senior preferred stock		3,687
Comprehensive income:
Net income	8,718				8,718
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3, $5, $1 and $14, respectively)	(53)					(53)
Reclassification adjustment for gains included in net income (net of tax of $19, $31, $0 and $70, respectively)	(263)					(263)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax)	(5)					(5)
Total comprehensive income	8,397
Reclassification related to Tax Cuts and Jobs Act					(117)	117
Other	(1)				(1)
Balance at Jun. 30, 2018	7,459	$ 120,836	$ 19,130	$ 687	(126,143)	349	(7,400)
Balance (shares) at Jun. 30, 2018		1,000,000	556,000,000	1,158,000,000
Proceeds From Senior Preferred Stock Agreement With Us Treasury		$ 0
Balance (shares) at Mar. 31, 2018		1,000,000	556,000,000	1,158,000,000
Balance at Mar. 31, 2018	3,938	$ 120,836	$ 19,130	$ 687	(129,662)	347	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	(938)				(938)
Increase to senior preferred stock		0
Comprehensive income:
Net income	4,457				4,457
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3, $5, $1 and $14, respectively)	4					4
Reclassification adjustment for gains included in net income (net of tax of $19, $31, $0 and $70, respectively)	0					0
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax)	(2)					(2)
Total comprehensive income	4,459
Reclassification related to Tax Cuts and Jobs Act					0	0
Other	0				0
Balance at Jun. 30, 2018	$ 7,459	$ 120,836	$ 19,130	$ 687	(126,143)	349	(7,400)
Balance (shares) at Jun. 30, 2018		1,000,000	556,000,000	1,158,000,000
Other comprehensive income (loss), net of tax effect:
Senior preferred stock issued, shares	1,000,000
Proceeds From Senior Preferred Stock Agreement With Us Treasury	$ 0
Balance (shares) at Dec. 31, 2018		1,000,000	556,000,000	1,158,000,000
Balance at Dec. 31, 2018	6,240	$ 120,836	$ 19,130	$ 687	(127,335)	322	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	(5,601)				(5,601)
Comprehensive income:
Net income	5,832				5,832
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3, $5, $1 and $14, respectively)	17					17
Reclassification adjustment for gains included in net income (net of tax of $19, $31, $0 and $70, respectively)	(118)					(118)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax)	(5)					(5)
Total comprehensive income	5,726
Balance at Jun. 30, 2019	6,365	$ 120,836	$ 19,130	$ 687	(127,104)	216	(7,400)
Balance (shares) at Jun. 30, 2019		1,000,000	556,000,000	1,158,000,000
Balance (shares) at Mar. 31, 2019		1,000,000	556,000,000	1,158,000,000
Balance at Mar. 31, 2019	5,361	$ 120,836	$ 19,130	$ 687	(128,175)	283	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	(2,361)				(2,361)
Comprehensive income:
Net income	3,432				3,432
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $3, $5, $1 and $14, respectively)	9					9
Reclassification adjustment for gains included in net income (net of tax of $19, $31, $0 and $70, respectively)	(74)					(74)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax)	(2)					(2)
Total comprehensive income	3,365
Balance at Jun. 30, 2019	$ 6,365	$ 120,836	$ 19,130	$ 687	$ (127,104)	$ 216	$ (7,400)
Balance (shares) at Jun. 30, 2019		1,000,000	556,000,000	1,158,000,000
Other comprehensive income (loss), net of tax effect:
Senior preferred stock issued, shares	1,000,000

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Deficit) (Parenthetical) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 3,000,000	$ 1,000,000	$ 5,000,000	$ 14,000,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	19,000,000	$ 0	31,000,000	$ 70,000,000
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	$ 0		$ 1,000,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
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, 2018 (“ 2018 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 six months ended June 30, 2019 and related notes, should be read in conjunction with our audited consolidated financial statements and related notes included in our 2018 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 six months ended June 30, 2019 may not necessarily be indicative of the results for the year ending December 31, 2019 . 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. Actual results could be different from these estimates. Conservatorship On September 7, 2008, the Secretary of the Treasury and the Director of FHFA announced several actions taken by Treasury and FHFA regarding Fannie Mae, which included: (1) placing us in conservatorship 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. 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, how long we will be in conservatorship, what form we will have and what ownership interest, if any, our current common and preferred stockholders will hold in us after the conservatorship is terminated and whether we will continue to exist following conservatorship. Treasury has made a commitment under the senior preferred stock purchase agreement to provide funding to us under certain circumstances if we have a net worth deficit. We are not aware of any plans of FHFA to fundamentally change our business model or reduce the aggregate amount available to or held by the company under our capital structure, which includes the senior preferred stock purchase agreement, in the near term. 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 June 30, 2019 , 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 to Treasury in 2008. Acting as successor to the rights, titles, powers and privileges of the Board, our conservator has declared and directed us to pay dividends to Treasury on the senior preferred stock on a quarterly basis for every dividend period for which dividends were payable since we entered conservatorship 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 $3.0 billion capital reserve amount. We refer to this as a “net worth sweep” dividend. On June 28, 2019 , we paid Treasury a dividend of $2.4 billion based on our net worth of $5.4 billion as of March 31, 2019 , less the applicable capital reserve amount of $3.0 billion . Because we had a net worth of $6.4 billion as of June 30, 2019 , we expect to pay Treasury a dividend of $3.4 billion for the third quarter of 2019 by September 30, 2019 . The liquidation preference of the senior preferred stock is subject to adjustment. The aggregate liquidation preference of the senior preferred stock was $123.8 billion as of June 30, 2019 . See “ Note 11, Equity (Deficit) ” in our 2018 Form 10-K for additional information about the senior preferred stock purchase agreement and the senior preferred stock. 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”). Single Security Initiative The Single Security Initiative is a joint initiative among Fannie Mae, Freddie Mac, and our jointly owned limited liability company, Common Securitization Solutions, LLC (“CSS”), under the direction of FHFA, to develop a single common mortgage-backed security issued by both Fannie Mae and Freddie Mac to finance fixed-rate mortgage loans backed by one- to four-unit single-family properties. The objective of the Single Security Initiative is to enhance the overall liquidity of Fannie Mae and Freddie Mac mortgage-backed securities eligible for trading in the to-be-announced (“TBA”) market by supporting their fungibility without regard to which company is the issuer. We and Freddie Mac began issuing uniform mortgage-backed securities (“UMBS”) pursuant to the Single Security Initiative in June 2019. We and Freddie Mac also began resecuritizing UMBS certificates into structured securities in June 2019. The structured securities backed by UMBS that we may issue include Supers, which are single-class resecuritization transactions, and Real Estate Mortgage Investment Conduit securities (“REMICs”) and interest-only and principal-only strip securities (“SMBS”), which are multi-class resecuritization transactions. Beginning in June 2019 and going forward, we may include UMBS, Supers and other structured securities issued by Freddie Mac in our resecuritization trusts. The mortgage loans that serve as collateral for Freddie Mac-issued UMBS are not held in trusts that are consolidated by Fannie Mae. When we include Freddie Mac securities in our structured securities we are subject to additional credit risk because we guarantee securities that were not previously guaranteed by Fannie Mae. However, Freddie Mac continues to guarantee the payment of principal and interest on the underlying Freddie Mac securities that we have resecuritized. As such, we have concluded that this additional credit risk is negligible because of the funding commitment available to Freddie Mac through its senior preferred stock purchase agreement with Treasury. Prior to the implementation of the Single Security Initiative, 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. Single-Class Resecuritization Trusts Fannie Mae single-class resecuritization trusts are created by depositing mortgage-backed securities (“MBS”) into a new securitization trust for the purpose of aggregating multiple mortgage-related securities into a single security. Single-class resecuritization securities pass through directly to the holders of the securities all of the cash flows of the underlying mortgage-backed securities held in the resecuritization trust. As a result of the Single Security Initiative, these securities can now be collateralized directly or indirectly by cash flows from underlying securities issued by Fannie Mae, Freddie Mac, or a combination of both. Resecuritization trusts backed directly or indirectly only by Fannie Mae MBS are non-commingled resecuritization trusts. Resecuritization trusts collateralized directly or indirectly by cash flows either in part or in whole from Freddie Mac securities are commingled resecuritization trusts. Securities issued by our non-commingled single-class resecuritization trusts are backed solely by Fannie Mae MBS and the guarantee we provide on the trust does not subject us to additional credit risk because we have already provided a guarantee on the underlying securities. Further, the securities issued by our non-commingled single-class resecuritization trusts pass through all of the cash flows of the underlying Fannie Mae MBS directly to the holders of the securities. Accordingly, these securities are deemed to be substantially the same as the underlying Fannie Mae MBS collateral. Additionally, our involvement with these trusts does not provide us with any incremental rights or powers that would enable us to direct any activities of the trusts. As a result, we have concluded that we are not the primary beneficiaries of, and as a result, we do not consolidate, our non-commingled single-class resecuritization trusts. Therefore, we account for purchases and sales of securities issued by non-commingled single-class resecuritization trusts as extinguishments and issuances of the underlying MBS debt, respectively. Securities issued by our commingled single-class resecuritization trusts are backed in whole or in part by Freddie Mac securities. The guaranty we provide to the commingled single-class resecuritization trust subjects us to additional credit risk because we are providing a guaranty for the timely payment of principal and interest on the underlying Freddie Mac securities that we have not previously guaranteed. Accordingly, securities issued by our commingled resecuritization trusts are not deemed to be substantially the same as the underlying collateral. We do not have any incremental rights or powers related to commingled single-class resecuritization trusts that would enable us to direct any activities of the underlying trusts. As a result, we have concluded that we are not the primary beneficiary of, and therefore do not consolidate, our commingled single-class resecuritization trusts unless we have the unilateral right to dissolve the trust. We have this right when we hold 100% of the beneficial interests issued by the resecuritization trust. Therefore, we account for purchases and sales of these securities as purchases and sales of investment securities. Multi-Class Resecuritization Trusts Multi-class resecuritization trusts are trusts we create to issue multi-class Fannie Mae structured securities, including REMICs and SMBS, in which the cash flows of the underlying mortgage assets are divided, creating several classes of securities, each of which represents a beneficial ownership interest in a separate portion of cash flows. We guarantee to each multi-class resecuritization trust that we will supplement amounts received by the trusts as required to permit timely payments of principal and interest, as applicable, on the related Fannie Mae structured securities. As a result of the Single Security Initiative, these multi-class structured securities can now be collateralized, directly or indirectly, by securities issued by Fannie Mae, Freddie Mac, or a combination of both. The guaranty we provide to our non-commingled multi-class resecuritization trusts does not subject us to additional credit risk , because the underlying assets are Fannie Mae-issued securities for which we have already provided a guaranty. However, for commingled multi-class structured securities, we are subject to additional credit risk because we are providing a guaranty for the timely payment of principal and interest on the underlying Freddie Mac securities that we have not previously guaranteed. For both commingled and non-commingled multi-class resecuritization trusts, we may also be exposed to prepayment risk via our ownership of securities issued by these trusts. We do not have the ability via our involvement with a multi-class resecuritization trust to impact either the credit risk or prepayment risk to which we are exposed. Therefore, we have concluded that we do not have the characteristics of a controlling financial interest and do not consolidate multi-class resecuritization trusts unless we have the unilateral right to dissolve the trust as noted below. Securities issued by multi-class resecuritization trusts do not directly pass through all of the cash flows of the underlying securities and therefore the issued and underlying securities are not considered substantially the same. Accordingly, if a multi-class resecuritization trust is not consolidated, we account for purchases and sales of securities issued by the trust as purchases and sales of investment securities. Beginning June 2019, in connection with the Single Security Initiative, we may now include UMBS, Supers and other structured securities backed by securities issued by Freddie Mac in our resecuritization trusts. As a result, we adopted a consolidation threshold for multi-class resecuritization trusts that is based on our ability to unilaterally dissolve the resecuritization trust. This ability exists only when we hold 100% of the outstanding beneficial interests issued by the resecuritization trust. This new consolidation threshold was applied prospectively upon implementation of the Single Security Initiative in the second quarter of 2019 and prior period amounts were not recast. Prior to the implementation of the Single Security Initiative, we consolidated multi-class resecuritization trusts when we held a substantial portion of the outstanding beneficial interests issued by the trust. Our adoption of the new consolidation threshold did not have a material impact on our condensed consolidated financial statements for the second quarter or first half of 2019. Regulatory Capital We submit capital reports to FHFA, which monitors our capital levels. The deficit of core capital over statutory minimum capital was $137.0 billion as of June 30, 2019 and $137.1 billion as of December 31, 2018 . Due to the terms of our senior preferred stock, we do not expect to eliminate our deficit of core capital over statutory minimum capital. 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 June 30, 2019 , Treasury held an investment in our senior preferred stock with an aggregate liquidation preference of $123.8 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 CSS, a limited liability company created to operate a common securitization platform; as such, CSS is deemed a related party. 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 and $6 million for the three months ended June 30, 2019 and 2018 , respectively, and $10 million and $13 million for the six months ended June 30, 2019 and 2018 , 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. FHFA and Treasury advised us to remit this fee increase to Treasury with respect to all loans acquired by us on or after April 1, 2012 and before January 1, 2022, and to continue to remit these amounts to Treasury on and after January 1, 2022 with respect to loans we acquired before this date until those loans are paid off or otherwise liquidated. The resulting fee revenue and expense are recorded in “Mortgage loans interest income” and “TCCA fees,” respectively, in our condensed consolidated statements of operations and comprehensive income. We recognized $600 million and $565 million in TCCA fees during the three months ended June 30, 2019 and 2018 , respectively, and $1.2 billion and $1.1 billion for the six months ended June 30, 2019 and 2018 , respectively, of which $600 million had not been remitted to Treasury as of June 30, 2019 . 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”), we are required 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 $21 million and $19 million in “Other expenses, net” for the three months ended June 30, 2019 and 2018 , respectively, and $36 million and $37 million for the six months ended June 30, 2019 and 2018 , respectively, relating to amounts payable to Treasury’s Capital Magnet Fund. In 2020, we expect to pay the $36 million recognized for the six months ended June 30, 2019 to Treasury’s Capital Magnet Fund, along with additional amounts based on our new business purchases in the second half of 2019. In April 2019, we paid $75 million to Treasury’s Capital Magnet Fund based on our new business purchases in 2018. 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 $29 million and $26 million for the three months ended June 30, 2019 and 2018 , respectively, and $59 million and $55 million for the six months ended June 30, 2019 and 2018 , respectively. Transactions with CSS and Freddie Mac We contributed capital to CSS, the company we jointly own with Freddie Mac, of $26 million and $35 million for the three months ended June 30, 2019 and 2018 , respectively, and $62 million and $76 million for the six months ended June 30, 2019 and 2018 , respectively. In the second quarter of 2019, Fannie Mae, Freddie Mac and CSS entered into an amendment to the customer services agreement that sets forth the terms under which CSS provides mortgage securitization services to us and Freddie Mac. In June 2019, we entered into an indemnification agreement with Freddie Mac relating to the commingled structured securities that we and Freddie Mac issue. Under the indemnification agreement, Fannie Mae and Freddie Mac each have agreed to indemnify the other party for losses caused by: its failure to meet its payment or other specified obligations under the trust agreements pursuant to which the underlying resecuritized securities were issued; its failure to meet its obligations under the customer services agreement; its violations of laws; or with respect to material misstatements or omissions in offering documents, ongoing disclosures and related materials relating to the underlying resecuritized securities. 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). Weighted average common shares includes 4.6 billion shares for the periods ended June 30, 2019 and 2018 that would be issued upon the full exercise of the warrant issued to Treasury from the date the warrant was issued through June 30, 2019 and 2018 . 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. For the three months ended June 30, 2019 and six months ended June 30, 2019 and 2018 , our diluted EPS weighted average shares outstanding includes shares of common stock that would be issuable upon the conversion of 131 million shares of convertible preferred stock. For the three months ended June 30, 2018 , convertible preferred stock is not included in the calculation because a net loss attributable to common shareholders was incurred and it would have an anti-dilutive effect. New Accounting Guidance T he following updates information about our significant accounting policies that have recently been adopted or yet to be adopted from the information included in “Note 1, Summary of Significant Accounting Policies” in our 2018 Form 10-K. T he 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 (“CECL”) in June 2016. It was amended by ASU 2019-04, Codification Improvements (to Topic 326), Financial Instruments—Credit Losses in April 2019. The standard replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects lifetime expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this standard also require credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses. We do not expect a material impact for establishing an allowance for credit losses related to our available-for-sale debt securities. CECL will become effective for our fiscal year beginning January 1, 2020. We are continuing to update the allowance models and accounting systems that will be used to estimate credit losses and record accounting impacts under CECL, and we are in the process of validating their results. All updates to our allowance models are subject to our model oversight and review governance process. We expect model and system testing to continue in 2019, followed by full integrated testing across all affected systems and processes. We are managing the implementation of this guidance in accordance with our change management governance standards, which are designed to ensure compliance with GAAP as well as operational readiness at adoption. Senior management and the Audit Committee receive regular updates regarding the status of our implementation plan, results of modeled impacts and any identified key risks. We will use a discounted cash flow method to measure credit impairment on our single-family mortgage loans and an undiscounted loss method to measure credit impairment on our multifamily mortgage loans. The models we will use to estimate credit losses will incorporate our historical credit loss experience, adjusted for current economic forecasts and the current credit profile of our loan book of business. The models will use reasonable and supportable forecasts for key economic drivers, such as home prices (Single-Family), rental income (Multifamily) and capitalization rates (Multifamily). Based on the composition of the loans in our book of business as of June 30, 2019 and our current expectations of future economic conditions, we estimate that our adoption of CECL will result in a reduction in our retained earnings of up to $4 billion on an after-tax basis in the first quarter of 2020. We are still assessing the impact of various implementation issues as well as the FASB’s recently proposed guidance relating to the standard. The resolution of these items may reduce CECL’s impact on our retained earnings upon adoption. In addition, we continue to evaluate the results of our modeled loss estimates and may make refinements to our approach and assumptions. The impact of our adoption of CECL on our retained earnings will be further influenced by the credit risk profile of the loans in our book of business as of the January 1, 2020 adoption date, as well as economic conditions and forecasts of future economic conditions at that time.

Consolidations and Transfers of

Consolidations and Transfers of Financial Assets	6 Months Ended
	Jun. 30, 2019
Consolidations and Transfers of Financial Assets [Abstract]
Consolidations and Transfers of Financial Assets	Consolidations and Transfers of Financial Assets We have interests in various entities that are considered to be variable interest entities (“VIEs”). The primary types of entities are securitization and resecuritization trusts, limited partnerships and special purpose vehicles (“SPVs”). These interests include investments in securities issued by VIEs, such as Fannie Mae MBS created pursuant to our securitization transactions and our guaranty to the entity. We consolidate the substantial majority of our single-class securitization trusts because our role as guarantor and master servicer provides us with the power to direct matters (primarily the servicing of mortgage loans) that impact the credit risk to which we are exposed. In contrast, we do not consolidate single-class securitization trusts when other organizations have the power to direct these activities. 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, beginning with the implementation of the Single Security Initiative in June 2019, we include securities issued by Freddie Mac in some of our resecuritization trusts. The mortgage loans that serve as collateral for Freddie Mac-issued UMBS 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 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 June 30, 2019 December 31, 2018 Assets and liabilities recorded in our condensed consolidated balance sheets related to mortgage-backed trusts: (Dollars in millions) Assets: Trading securities: Fannie Mae $ 2,173 $ 1,422 Non-Fannie Mae 4,352 4,809 Total trading securities 6,525 6,231 Available-for-sale securities: Fannie Mae 1,615 1,704 Non-Fannie Mae 791 1,207 Total available-for-sale securities 2,406 2,911 Other assets 60 66 Other liabilities (90 ) (101 ) Net carrying amount $ 8,901 $ 9,107 Our maximum exposure to loss generally represents the greater of our recorded investment 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 refers to our resecuritization trusts that are backed entirely by Fannie Mae MBS. These non-commingled single-class and multi-class resecuritization trusts that are not consolidated do not give rise to any additional exposure to loss as we already consolidate the underlying collateral. Fannie Mae commingled resecuritization trusts refers to our resecuritization trusts that are backed in whole or in part by Freddie Mac securities. The guaranty that we provide to these commingled resecuritization trusts increases our exposure to loss relating to the Freddie Mac securities that serve as the underlying collateral. Our maximum exposure to loss for these unconsolidated trusts is measured by the amount of Freddie Mac securities that back these resecuritization trusts. However a portion of these Freddie Mac securities may be backed in whole or in part by Fannie Mae MBS. Therefore, to the extent that these Freddie Mac securities are backed by Fannie Mae MBS, it would not give rise to any additional exposure and our total exposure to collateral that is ultimately guaranteed by Freddie Mac may be lower than the disclosed maximum exposure to loss. Our maximum exposure to loss related to unconsolidated securitization and resecuritization trusts was approximately $20 billion and $14 billion as of June 30, 2019 and December 31, 2018 , respectively. The total assets of our unconsolidated securitization and resecuritization trusts were approximately $110 billion and $80 billion as of June 30, 2019 and December 31, 2018 , 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 $96 million and the related carrying value was $75 million as of June 30, 2019 . As of December 31, 2018 , the maximum exposure to loss was $111 million and the related carrying value was $89 million . The total assets of these limited partnership investments were $2.1 billion and $2.3 billion as of June 30, 2019 and December 31, 2018 , respectively. The maximum exposure to loss related to our involvement with unconsolidated SPVs that transfer credit risk represents the unpaid principal balance and accrued interest payable of obligations issued by the Connecticut Avenue Securities (“CAS”) SPVs. The maximum exposure to loss related to these unconsolidated SPVs was $4.6 billion and $920 million as of June 30, 2019 and December 31, 2018 , respectively. The total assets related to these unconsolidated SPVs were $4.7 billion and $931 million as of June 30, 2019 and December 31, 2018 , respectively. The unpaid principal balance of our multifamily loan portfolio was $310.9 billion as of June 30, 2019 . As our lending relationship does not provide us with a controlling financial interest in the borrower entity, we do not consolidate these borrowers regardless of their status as either a VIE or a voting interest entity. We have excluded these entities from our VIE disclosures. However, the disclosures we have provided in “ Note 3, Mortgage Loans ,” “ Note 4, Allowance for Loan Losses ” and “ Note 6, Financial Guarantees ” with respect to this population are consistent with the FASB’s stated objectives for the disclosures related to unconsolidated VIEs. Transfers of Financial Assets We issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the transferor when we transfer assets from our own retained mortgage portfolio in a portfolio securitization transaction. For the three months ended June 30, 2019 and 2018 , the unpaid principal balance of portfolio securitizations was $57.3 billion and $51.6 billion , respectively. For the six months ended June 30, 2019 and 2018 , the unpaid principal balance of portfolio securitizations was $98.7 billion and $115.9 billion , respectively. We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts. As of June 30, 2019 , the unpaid principal balance of retained interests was $2.7 billion and its related fair value was $3.7 billion . As of December 31, 2018 , the unpaid principal balance of retained interests was $1.5 billion and its related fair value was $2.2 billion . For the three months ended June 30, 2019 and 2018 , the principal, interest and other fees received on retained interests was $122 million and $128 million , respectively. For the six months ended June 30, 2019 and 2018 , the principal, interest and other fees received on retained interests was $238 million and $354 million , respectively. Managed Loans Managed loans include primarily loans that are guaranteed or insured, in whole or in part, by the U.S. government. For those loans that we have securitized in unconsolidated portfolio securitization trusts, the outstanding unpaid principal balance was $1.1 billion as of June 30, 2019 and $1.2 billion as of December 31, 2018 . For information regarding on-balance sheet managed loans, see “ Note 3, Mortgage Loans .”

Mortgage Loans

Mortgage Loans	6 Months Ended
	Jun. 30, 2019
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 held for investment (“HFI”) or held for sale (“HFS”). We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and an allowance for loan losses. 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. We define the recorded investment of HFI loans as unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable. For purposes of the single-family mortgage loan disclosures below, we define “primary” class as mortgage loans that are not included in other loan classes; “government” class as mortgage loans that are guaranteed or insured, in whole or in part, by the U.S. government, and that are not Alt-A; and “other” class as loans with certain higher-risk characteristics, such as interest-only loans and negative-amortizing loans, that are neither government nor Alt-A. The following table displays the carrying value of our mortgage loans. As of June 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,932,553 $ 2,929,925 Multifamily 310,899 293,858 Total unpaid principal balance of mortgage loans 3,243,452 3,223,783 Cost basis and fair value adjustments, net 41,262 39,815 Allowance for loan losses for loans held for investment (11,482 ) (14,203 ) Total mortgage loans $ 3,273,232 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 6,759 $ 6,235 $ 9,370 $ 13,602 Carrying value of loans redesignated from HFS to HFI (1) 3 12 12 30 Loans sold - unpaid principal balance 6,498 3,710 6,556 4,458 Realized gains on sale of mortgage loans 284 210 320 208 (1) Represents the carrying value of the loans after redesignation, excluding allowance. The recorded investment of single-family mortgage loans for which formal foreclosure proceedings are in process was $9.0 billion and $10.1 billion as of June 30, 2019 and December 31, 2018 , 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. Nonaccrual Loans We discontinue accruing interest on loans when we believe collectibility 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 is reversed through interest income at the date a loan is placed on nonaccrual status. 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. We place a multifamily loan on nonaccrual status when the loan becomes three months or more past due according to its contractual terms or is deemed to be individually impaired, unless the loan is well secured such that collectibility of principal and accrued interest is reasonably assured. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan or we otherwise determine that the loan is well secured such that collectibility is reasonably assured. Aging Analysis The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of June 30, 2019 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Recorded Investment in Loans 90 Days or More Delinquent and Accruing Interest Recorded Investment in Nonaccrual Loans (Dollars in millions) Single-family: Primary $ 33,030 $ 7,308 $ 13,547 $ 53,885 $ 2,827,424 $ 2,881,309 $ 22 $ 24,035 Government (2) 46 18 152 216 18,691 18,907 152 — Alt-A 2,228 645 1,533 4,406 43,083 47,489 1 2,528 Other 733 236 590 1,559 10,986 12,545 2 944 Total single-family 36,037 8,207 15,822 60,066 2,900,184 2,960,250 177 27,507 Multifamily (3) 24 N/A 187 211 313,334 313,545 — 513 Total $ 36,061 $ 8,207 $ 16,009 $ 60,277 $ 3,213,518 $ 3,273,795 $ 177 $ 28,020 As of December 31, 2018 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Recorded Investment in Loans 90 Days or More Delinquent and Accruing Interest Recorded Investment in Nonaccrual Loans (Dollars in millions) Single-family: Primary $ 30,471 $ 7,881 $ 14,866 $ 53,218 $ 2,816,047 $ 2,869,265 $ 22 $ 26,170 Government (2) 57 17 169 243 21,887 22,130 169 — Alt-A 2,332 821 1,844 4,997 48,274 53,271 2 3,082 Other 804 283 713 1,800 13,038 14,838 2 1,128 Total single-family 33,664 9,002 17,592 60,258 2,899,246 2,959,504 195 30,380 Multifamily (3) 56 N/A 171 227 295,437 295,664 — 492 Total $ 33,720 $ 9,002 $ 17,763 $ 60,485 $ 3,194,683 $ 3,255,168 $ 195 $ 30,872 (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) Primarily consists of reverse mortgages, which due to their nature, are not aged 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 recorded investment in our single-family HFI loans by class and credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, 2019 (1) December 31, 2018 (1) Primary Alt-A Other Primary Alt-A Other (Dollars in millions) Estimated mark-to-market loan-to-value (“LTV”) ratio: (2) Less than or equal to 80% $ 2,551,443 $ 41,960 $ 10,773 $ 2,521,766 $ 45,476 $ 12,291 Greater than 80% and less than or equal to 90% 221,190 2,819 874 228,614 3,804 1,195 Greater than 90% and less than or equal to 100% 102,585 1,383 435 109,548 1,997 645 Greater than 100% 6,091 1,327 463 9,337 1,994 707 Total $ 2,881,309 $ 47,489 $ 12,545 $ 2,869,265 $ 53,271 $ 14,838 (1) Excludes $18.9 billion and $22.1 billion as of June 30, 2019 and December 31, 2018 , respectively, of mortgage loans guaranteed or insured, in whole or in part, by the U.S. government or one of its agencies, that are not Alt-A loans. The class is 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 recorded investment in our multifamily HFI loans by credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, December 31, 2019 2018 (Dollars in millions) Credit risk profile by internally assigned grade: Non-classified $ 306,257 $ 289,231 Classified (1) 7,288 6,433 Total $ 313,545 $ 295,664 (1) Includes loans classified as “Substandard” or “Doubtful.” Loans classified as “Substandard” have a well-defined weakness that jeopardizes the timely full repayment. Loans classified as “Doubtful” have weakness that makes collection or liquidation in full highly questionable and improbable based on existing conditions and values. As of June 30, 2019 , we had loans with recorded investment of less than $0.5 million classified as doubtful, compared with $1 million as of December 31, 2018 . Individually Impaired Loans Individually impaired loans include troubled debt restructurings (“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 total unpaid principal balance, recorded investment, related allowance, average recorded investment and interest income recognized for individually impaired loans. As of June 30, 2019 December 31, 2018 Unpaid Principal Balance Total Recorded Investment Related Allowance for Loan Losses Unpaid Principal Balance Total Recorded Investment Related Allowance for Loan Losses (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 74,143 $ 71,549 $ (7,615 ) $ 81,791 $ 78,688 $ (9,406 ) Government 261 267 (54 ) 264 270 (55 ) Alt-A 13,703 12,554 (2,129 ) 16,576 15,158 (2,793 ) Other 4,520 4,268 (774 ) 5,482 5,169 (1,001 ) Total single-family 92,627 88,638 (10,572 ) 104,113 99,285 (13,255 ) Multifamily 340 343 (55 ) 197 196 (40 ) Total individually impaired loans with related allowance recorded 92,967 88,981 (10,627 ) 104,310 99,481 (13,295 ) With no related allowance recorded: (1) Single-family: Primary 16,638 15,866 — 15,939 15,191 — Government 59 55 — 61 56 — Alt-A 2,445 2,193 — 2,628 2,363 — Other 654 602 — 718 666 — Total single-family 19,796 18,716 — 19,346 18,276 — Multifamily 431 433 — 343 346 — Total individually impaired loans with no related allowance recorded 20,227 19,149 — 19,689 18,622 — Total individually impaired loans (2) $ 113,194 $ 108,130 $ (10,627 ) $ 123,999 $ 118,103 $ (13,295 ) (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 a recorded investment of $107.0 billion and $117.2 billion as of June 30, 2019 and December 31, 2018 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $188 million and $187 million as of June 30, 2019 and December 31, 2018 , respectively. For the Three Months Ended June 30, 2019 2018 Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 74,162 $ 774 $ 72 $ 88,526 $ 915 $ 109 Government 269 3 — 279 9 — Alt-A 13,399 145 11 19,349 219 16 Other 4,471 41 3 7,265 73 6 Total single-family 92,301 963 86 115,419 1,216 131 Multifamily 321 3 — 232 1 — Total individually impaired loans with related allowance recorded 92,622 966 86 115,651 1,217 131 With no related allowance recorded: (1) Single-family: Primary 15,474 249 36 14,942 243 32 Government 55 1 — 57 2 — Alt-A 2,196 44 5 2,723 61 5 Other 615 10 1 857 15 1 Total single-family 18,340 304 42 18,579 321 38 Multifamily 397 6 — 355 1 — Total individually impaired loans with no related allowance recorded 18,737 310 42 18,934 322 38 Total individually impaired loans $ 111,359 $ 1,276 $ 128 $ 134,585 $ 1,539 $ 169 For the Six Months Ended June 30, 2019 2018 Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 75,888 $ 1,591 $ 152 $ 88,342 $ 1,826 $ 216 Government 270 6 — 278 12 — Alt-A 14,023 301 22 20,020 431 32 Other 4,706 86 7 7,556 144 11 Total single-family 94,887 1,984 181 116,196 2,413 259 Multifamily 279 5 — 248 1 — Total individually impaired loans with related allowance recorded 95,166 1,989 181 116,444 2,414 259 With no related allowance recorded: (1) Single-family: Primary 15,336 469 64 14,988 486 58 Government 55 2 — 58 2 — Alt-A 2,244 83 7 2,781 119 9 Other 631 18 2 878 31 2 Total single-family 18,266 572 73 18,705 638 69 Multifamily 380 8 — 340 3 — Total individually impaired loans with no related allowance recorded 18,646 580 73 19,045 641 69 Total individually impaired loans $ 113,812 $ 2,569 $ 254 $ 135,489 $ 3,055 $ 328 (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. 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, including those modifications in a trial period, 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. The substantial majority of the loan modifications we complete result in term extensions, interest rate reductions or a combination of both. The average term extension of a single-family modified loan was 160 months and 128 months for the three months ended June 30, 2019 and 2018 , respectively. The average interest rate reduction was 0.10 and 0.13 percentage points, for the three months ended June 30, 2019 and 2018 , respectively. During the six months ended June 30, 2019 and 2018 , the average term extension of a single-family modified loan was 158 months and 133 months, respectively, and the average interest rate reduction was 0.10 and 0.18 percentage points, respectively. The following tables display the number of loans and recorded investment in loans classified as a TDR. For the Three Months Ended June 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 11,796 $ 1,844 21,820 $ 3,148 Government 22 2 26 2 Alt-A 639 81 1,538 200 Other 138 25 285 52 Total single-family 12,595 1,952 23,669 3,402 Multifamily 3 20 2 19 Total TDRs 12,598 $ 1,972 23,671 $ 3,421 For the Six Months Ended June 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 24,753 $ 3,815 63,499 $ 9,672 Government 45 6 74 6 Alt-A 1,405 178 3,720 483 Other 285 52 730 136 Total single-family 26,488 4,051 68,023 10,297 Multifamily 6 33 10 61 Total TDRs 26,494 $ 4,084 68,033 $ 10,358 (1) Based on the nature of our modification programs, which do not include principal or past-due interest forgiveness, there is not a material difference between the recorded investment in our loans pre- and post- modification. Therefore, these amounts represent recorded investment post-modification. The decrease in loans classified as a TDR for the three and six months ended June 30, 2019 compared with the three and six months ended June 30, 2018 For loans that had a payment default in the period presented and that were classified as a TDR in the twelve months prior to the payment default, the following tables display the number of loans and our recorded investment in these loans at the time of payment default. For the 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 June 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 4,047 $ 606 3,834 $ 554 Government 10 2 15 2 Alt-A 379 58 588 92 Other 110 21 131 26 Total single-family 4,546 687 4,568 674 Multifamily 1 6 — — Total TDRs that subsequently defaulted 4,547 $ 693 4,568 $ 674 For the Six Months Ended June 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 8,563 $ 1,279 8,652 $ 1,255 Government 28 5 29 4 Alt-A 850 131 1,265 201 Other 264 49 326 64 Total single-family 9,705 1,464 10,272 1,524 Multifamily 1 6 1 2 Total TDRs that subsequently defaulted 9,706 $ 1,470 10,273 $ 1,526

Allowance for Loan Losses

Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2019
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 amortized premiums and discounts, and other cost basis adjustments of HFI loans at the balance sheet date. We record charge-offs as a reduction to our allowance for loan losses at the point of foreclosure, completion of a short sale, upon the redesignation of loans from HFI to HFS or when a loan is determined to be uncollectible. We aggregate single-family HFI loans that are not individually impaired based on similar risk characteristics, for purposes of estimating incurred credit losses and establishing a collective single-family loss reserve using an econometric model that derives an overall loss reserve estimate. We base our allowance methodology on historical events and trends, such as loss severity (in event of default), default rates, and recoveries from mortgage insurance contracts and other credit enhancements that provide loan-level loss coverage and are either contractually attached to a loan or that were entered into contemporaneously with and in contemplation of a guaranty or loan purchase transaction. We use recent regional historical sales and appraisal information, including the sales of our own foreclosed properties, to develop our loss severity estimates for all loan categories. Our allowance calculation also incorporates a loss confirmation period (the anticipated time lag between a credit loss event and the confirmation of the credit loss resulting from that event) to ensure our allowance estimate captures credit losses that have been incurred as of the balance sheet date but have not been confirmed. In addition, management performs a review of the observable data used in its estimate to ensure it is representative of prevailing economic conditions and other events existing as of the balance sheet date. Individually impaired single-family loans currently include those classified as a TDR and acquired credit-impaired loans. We consider a loan to be impaired when, based on current information, it is probable that we will not receive all amounts due, including interest, in accordance with the contractual terms of the loan agreement. When a loan has been restructured, we measure impairment using a cash flow analysis discounted at the loan’s original effective interest rate. If we expect to recover our recorded investment in an individually impaired loan through probable foreclosure of the underlying collateral, we measure impairment based on the difference between our recorded investment in the loan and the fair value of the underlying property, adjusted for the estimated costs to sell the property and estimated insurance or other proceeds we expect to receive. We establish a collective allowance for all loans in our multifamily guaranty book of business that are not individually measured for impairment using an internal model that applies loss factors to loans in similar risk categories. Our loss factors are developed based on our historical default and loss severity experience. We identify multifamily loans for evaluation for impairment through a credit risk assessment process. If we determine that a multifamily loan is individually impaired, we generally measure impairment on that loan based on the fair value of the underlying collateral less estimated costs to sell the property, as we have concluded that such loans are collateral dependent. We evaluate collectively for impairment smaller-balance homogeneous multifamily loans. The following table displays changes in single-family, multifamily and total allowance for loan losses. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (12,985 ) $ (18,523 ) $ (13,969 ) $ (18,849 ) Benefit (provision) for loan losses (1) 1,239 1,270 1,886 1,192 Charge-offs 558 731 939 1,196 Recoveries (15 ) (64 ) (60 ) (124 ) Other (7 ) (16 ) (6 ) (17 ) Ending balance $ (11,210 ) $ (16,602 ) $ (11,210 ) $ (16,602 ) Multifamily allowance for loan losses: Beginning balance $ (247 ) $ (211 ) $ (234 ) $ (235 ) Benefit (provision) for loan losses (1) (27 ) — (40 ) 20 Charge-offs 4 1 4 5 Recoveries (2 ) — (2 ) — Ending balance $ (272 ) $ (210 ) $ (272 ) $ (210 ) Total allowance for loan losses: Beginning balance $ (13,232 ) $ (18,734 ) $ (14,203 ) $ (19,084 ) Benefit (provision) for loan losses (1) 1,212 1,270 1,846 1,212 Charge-offs 562 732 943 1,201 Recoveries (17 ) (64 ) (62 ) (124 ) Other (7 ) (16 ) (6 ) (17 ) Ending balance $ (11,482 ) $ (16,812 ) $ (11,482 ) $ (16,812 ) (1) Benefit (provision) for loan losses is included in “ Benefit for credit losses ” in our condensed consolidated statements of operations and comprehensive income. The following table displays the allowance for loan losses and recorded investment in our HFI loans by impairment or allowance methodology and portfolio segment, excluding loans for which we have elected the fair value option. As of June 30, 2019 December 31, 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans (1) $ (10,572 ) $ (55 ) $ (10,627 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (638 ) (217 ) (855 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (11,210 ) $ (272 ) $ (11,482 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 107,354 $ 776 $ 108,130 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,852,896 312,769 3,165,665 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,960,250 $ 313,545 $ 3,273,795 $ 2,959,504 $ 295,664 $ 3,255,168 (1) Includes acquired credit-impaired loans.

Investments in Securities

Investments in Securities	6 Months Ended
	Jun. 30, 2019
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 gains (losses), net ” in our condensed consolidated statements of operations and comprehensive income. The following table displays our investments in trading securities. As of June 30, 2019 December 31, 2018 (Dollars in millions) Mortgage-related securities: Fannie Mae (1) $ 3,151 $ 1,467 Other agency (2) 3,629 3,503 Private-label and other mortgage securities 736 1,306 Total mortgage-related securities (includes $983 and $32, respectively, related to consolidated trusts) 7,516 6,276 Non-mortgage-related securities: U.S. Treasury securities 35,266 35,502 Other securities 84 89 Total non-mortgage-related securities 35,350 35,591 Total trading securities $ 42,866 $ 41,867 (1) In connection with the implementation of the Single Security Initiative in the second quarter of 2019, we recognized $1.4 billion in mortgage-related securities that had previously been consolidated. (2) Consists of Freddie Mac and Ginnie Mae mortgage-related securities. The following table displays information about our net trading gains. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Net trading gains $ 183 $ 21 $ 275 $ 119 Net trading gains recognized in the period related to securities still held at period end 147 1 227 48 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. The following table displays the gross realized gains and proceeds on sales of AFS securities. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Gross realized gains $ 110 $ — $ 171 $ 363 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 245 6 376 641 The following tables display the amortized cost, gross unrealized gains and losses, and fair value by major security type for AFS securities. As of June 30, 2019 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,536 $ 90 $ (11 ) $ 1,615 Other agency 209 19 — 228 Alt-A and subprime private-label securities 109 111 — 220 Mortgage revenue bonds 356 11 (3 ) 364 Other mortgage-related securities 329 5 — 334 Total $ 2,539 $ 236 $ (14 ) $ 2,761 As of December 31, 2018 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,754 $ 69 $ (26 ) $ 1,797 Other agency 239 17 — 256 Alt-A and subprime private-label securities 325 267 — 592 Mortgage revenue bonds 425 13 (4 ) 434 Other mortgage-related securities 336 14 — 350 Total $ 3,079 $ 380 $ (30 ) $ 3,429 (1) Amortized cost consists of unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, as well as net other-than-temporary impairments (“OTTI”) recognized in “ Investment gains, net ” in our condensed consolidated statements of operations and comprehensive income. (2) Represents the gross unrealized losses on securities for which we have not recognized OTTI, as well as the noncredit component of OTTI and cumulative changes in fair value of securities for which we previously recognized the credit component of OTTI in “ Accumulated other comprehensive income ” in our condensed consolidated balance sheets. 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. As of June 30, 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 $ — $ — $ (11 ) $ 366 Mortgage revenue bonds — — (3 ) 5 Total $ — $ — $ (14 ) $ 371 As of December 31, 2018 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 $ — $ — $ (26 ) $ 487 Mortgage revenue bonds (1 ) 24 (3 ) 19 Total $ (1 ) $ 24 $ (29 ) $ 506 Other-Than-Temporary Impairments The cumulative outstanding balance related to other-than-temporary-impairment (OTTI) credit loss amounts previously recognized in our condensed consolidated statements of operations and comprehensive income throughout the life of AFS debt securities held in portfolio were $57 million and $635 million as of June 30, 2019 and December 31, 2018 , respectively. Those amounts were $733 million and $1.1 billion as of June 30, 2018 and December 31, 2017 , respectively. The decrease in the cumulative outstanding balance in the first six months of 2019 and 2018 was primarily driven by securities that we no longer hold in portfolio. The following table displays net unrealized gains on AFS securities and other amounts within accumulated other comprehensive income (“AOCI”), net of tax, by major categories. As of June 30, December 31, 2019 2018 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 80 $ 52 Net unrealized gains on AFS securities for which we have recorded OTTI 95 224 Other 41 46 Accumulated other comprehensive income $ 216 $ 322 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 June 30, 2019 Total Amortized Cost Total Fair Value One Year or Less After One Year Through Five Years After Five Years Through Ten Years After Ten Years Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in millions) Fannie Mae $ 1,536 $ 1,615 $ — $ — $ 15 $ 15 $ 104 $ 115 $ 1,417 $ 1,485 Other agency 209 228 — — 22 24 25 28 162 176 Alt-A and subprime private-label securities 109 220 — — — — 1 1 108 219 Mortgage revenue bonds 356 364 2 2 24 24 43 45 287 293 Other mortgage-related securities 329 334 — — — — 26 28 303 306 Total $ 2,539 $ 2,761 $ 2 $ 2 $ 61 $ 63 $ 199 $ 217 $ 2,277 $ 2,479

Financial Guarantees

Financial Guarantees	6 Months Ended
	Jun. 30, 2019
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 remaining contractual terms of our guarantees range from 1 day to 33 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. As the guarantor of commingled structured securities issued pursuant to the Single Security Initiative, 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. 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 approximately $7.7 billion of Freddie Mac securities backing unconsolidated Fannie Mae-issued structured securities as of June 30, 2019. 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 June 30, 2019 December 31, 2018 Maximum Exposure Guaranty Obligation Maximum Recovery (1) Maximum Exposure Guaranty Obligation Maximum Recovery (1) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 6,761 $ 26 $ 6,440 $ 7,278 $ 30 $ 6,811 Other guaranty arrangements (2) 13,420 140 2,645 13,847 130 2,711 Total $ 20,181 $ 166 $ 9,085 $ 21,125 $ 160 $ 9,522 (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 and financial guarantors, see “Note 13, Concentrations of Credit Risk” in our 2018 Form 10-K and “ Note 10, Concentrations of Credit Risk ” in this report. (2) Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt

Short-Term and Long-Term Debt	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 December 31, 2018 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) $ 131 2.25 % $ — — % Short-term debt of Fannie Mae $ 22,901 2.39 % $ 24,896 2.29 % (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. Intraday Line of Credit We use a secured intraday funding line of credit provided by a large financial institution. We post collateral which, in some circumstances, the secured party has the right to repledge to third parties. As this line of credit is an uncommitted intraday loan facility, we may be unable to draw on it if and when needed. The line of credit under this facility was $15.0 billion as of June 30, 2019 and December 31, 2018 . 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 June 30, 2019 December 31, 2018 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2019 - 2030 $ 97,884 2.56 % 2019 - 2030 $ 103,206 2.36 % Medium-term notes (2) 2019 - 2026 51,345 1.53 2019 - 2026 61,455 1.48 Other (3) 2019 - 2038 6,621 4.80 2019 - 2038 6,683 4.62 Total senior fixed 155,850 2.31 171,344 2.13 Senior floating: Medium-term notes (2) 2020 7,773 2.50 2019 - 2020 4,174 2.36 Connecticut Avenue Securities (4) 2023 - 2031 24,210 6.12 2023 - 2031 25,641 5.97 Other (5) 2020 - 2037 398 6.37 2020 - 2037 351 10.19 Total senior floating 32,381 5.25 30,166 5.52 Subordinated debentures 2019 5,641 9.99 2019 5,617 9.64 Secured borrowings (6) 2021 - 2022 41 2.06 2021 - 2022 51 1.96 Total long-term debt of Fannie Mae (7) 193,913 3.03 207,178 2.83 Debt of consolidated trusts 2019 - 2058 3,199,765 2.90 2019 - 2058 3,159,846 3.03 Total long-term debt $ 3,393,678 2.91 % $ 3,367,024 3.02 % (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 Connecticut Avenue Securities issued prior to the implementation of our CAS REMIC structure in November 2018. See “Note 2, Consolidations and Transfers of Financial Assets” in our 2018 Form 10-K for more information about our CAS REMIC structure. (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 of $151 million and $413 million as of June 30, 2019 and December 31, 2018 , respectively.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2019
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. We enter into various forms of credit risk-sharing agreements that we account for as derivatives, including some of our credit risk transfer transactions and swap credit enhancements. The majority of our credit-related derivatives are credit risk transfer transactions, whereby a portion of the credit risk associated with losses on a reference pool of mortgage loans is transferred to a third party. Additionally, we enter into derivative transactions that are associated with some of our other 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 netted to the extent a legal right of offset exists and is enforceable by law at the counterparty level and are 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 June 30, 2019 As of December 31, 2018 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 $ 58,357 $ 4 $ 31,468 $ (1,327 ) $ 71,416 $ 438 $ 21,253 $ (740 ) Receive-fixed 91,919 1,096 47,254 (210 ) 88,799 1,113 58,399 (860 ) Basis 273 155 — — 250 104 624 — Foreign currency 220 30 222 (77 ) 221 22 223 (72 ) Swaptions: Pay-fixed 4,600 29 6,375 (172 ) 10,375 191 1,000 (4 ) Receive-fixed 2,125 90 5,350 (232 ) 500 20 7,375 (338 ) Futures (1) 19,537 — — — 16,631 — — — Total gross risk management derivatives 177,031 1,404 90,669 (2,018 ) 188,192 1,888 88,874 (2,014 ) Accrued interest receivable (payable) — 360 — (359 ) — 400 — (419 ) Netting adjustment (2) — (1,709 ) — 2,297 — (2,266 ) — 2,315 Total net risk management derivatives $ 177,031 $ 55 $ 90,669 $ (80 ) $ 188,192 $ 22 $ 88,874 $ (118 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 9,767 $ 54 $ 2,417 $ (2 ) $ 4,370 $ 29 $ 57 $ — Forward contracts to purchase mortgage-related securities 78,510 389 10,000 (11 ) 40,650 349 1,045 (3 ) Forward contracts to sell mortgage-related securities 10,230 12 131,017 (675 ) 292 1 70,593 (645 ) Total mortgage commitment derivatives 98,507 455 143,434 (688 ) 45,312 379 71,695 (648 ) Credit enhancement derivatives 31,809 51 4,647 (31 ) 33,431 57 919 (11 ) Derivatives at fair value $ 307,347 $ 561 $ 238,750 $ (799 ) $ 266,935 $ 458 $ 161,488 $ (777 ) (1) Futures have no ascribable fair value because the positions are settled daily. (2) The netting adjustment represents the effect of the legal right to offset under legally enforceable master netting arrangements to settle with the same counterparty on a net basis, including cash collateral posted and received. Cash collateral posted was $1.2 billion and $713 million as of June 30, 2019 and December 31, 2018 , respectively. Cash collateral received was $573 million and $664 million as of June 30, 2019 and December 31, 2018 We record all derivative gains and losses, including accrued interest, in “ Fair value gains (losses), net ” in our condensed consolidated statements of operations and comprehensive income. The following table displays, by type of derivative instrument, the fair value gains and losses, net on our derivatives. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (2,164 ) $ 967 $ (3,499 ) $ 3,750 Receive-fixed 1,884 (597 ) 3,165 (2,984 ) Basis 27 (3 ) 51 (26 ) Foreign currency (17 ) (41 ) 2 (25 ) Swaptions: Pay-fixed (143 ) 36 (320 ) 165 Receive-fixed 93 (22 ) 100 (38 ) Futures 195 (11 ) 254 (3 ) Net accrual of periodic settlements (242 ) (286 ) (508 ) (501 ) Total risk management derivatives fair value gains (losses), net (367 ) 43 (755 ) 338 Mortgage commitment derivatives fair value gains (losses), net (469 ) (76 ) (769 ) 488 Credit enhancement derivatives fair value losses, net (17 ) (5 ) (24 ) (1 ) Total derivatives fair value gains (losses), net $ (853 ) $ (38 ) $ (1,548 ) $ 825 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.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting We have two reportable business segments: 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. Segment Allocations and Results The majority of our revenues and expenses are directly associated with either our single-family or our multifamily business segment and are included in determining that segment’s operating results. Other revenues and expenses, including administrative 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 table displays our segment results. For the Three Months Ended June 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 4,419 $ 731 $ 5,150 $ 4,723 $ 654 $ 5,377 Fee and other income (2) 88 158 246 69 170 239 Net revenues 4,507 889 5,396 4,792 824 5,616 Investment gains, net (3) 417 44 461 252 25 277 Fair value gains (losses), net (4) (758 ) 4 (754 ) 278 (49 ) 229 Administrative expenses (634 ) (110 ) (744 ) (649 ) (106 ) (755 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,252 (27 ) 1,225 1,295 1 1,296 Foreclosed property expense (126 ) (2 ) (128 ) (136 ) (3 ) (139 ) Total credit-related income (expense) 1,126 (29 ) 1,097 1,159 (2 ) 1,157 TCCA fees (6) (600 ) — (600 ) (565 ) — (565 ) Other expenses, net (418 ) (117 ) (535 ) (270 ) (96 ) (366 ) Income before federal income taxes 3,640 681 4,321 4,997 596 5,593 Provision for federal income taxes (769 ) (120 ) (889 ) (1,044 ) (92 ) (1,136 ) Net income $ 2,871 $ 561 $ 3,432 $ 3,953 $ 504 $ 4,457 For the Six Months Ended June 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 8,458 $ 1,425 $ 9,883 $ 9,284 $ 1,325 $ 10,609 Fee and other income (2) 194 279 473 227 332 559 Net revenues 8,652 1,704 10,356 9,511 1,657 11,168 Investment gains, net (3) 511 83 594 494 33 527 Fair value gains (losses), net (4) (1,645 ) 60 (1,585 ) 1,312 (38 ) 1,274 Administrative expenses (1,265 ) (223 ) (1,488 ) (1,292 ) (213 ) (1,505 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,913 (38 ) 1,875 1,491 22 1,513 Foreclosed property income (expense) (269 ) 1 (268 ) (298 ) (3 ) (301 ) Total credit-related income (expense) 1,644 (37 ) 1,607 1,193 19 1,212 TCCA fees (6) (1,193 ) — (1,193 ) (1,122 ) — (1,122 ) Other expenses, net (755 ) (188 ) (943 ) (402 ) (167 ) (569 ) Income before federal income taxes 5,949 1,399 7,348 9,694 1,291 10,985 Provision for federal income taxes (1,253 ) (263 ) (1,516 ) (2,060 ) (207 ) (2,267 ) Net income $ 4,696 $ 1,136 $ 5,832 $ 7,634 $ 1,084 $ 8,718 (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, and income resulting from settlement agreements resolving certain claims relating to private-label securities we purchased or that we have guaranteed. Multifamily fee and other income consists of fees associated with Multifamily business activities, including yield maintenance income. (3) Investment gains and losses primarily consist of gains and losses on the sale of mortgage assets for the respective business segment. (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 and other financial instruments associated with our single-family guaranty book of business. Multifamily fair value gains and losses primarily consist of fair value gains and losses on MBS commitment derivatives, trading securities and other financial instruments associated with our multifamily guaranty book of business. (5) Credit-related income or expense is based on the guaranty book of business of the respective business segment and consists of the applicable segment’s benefit or provision for credit losses and foreclosed property income or expense on loans underlying the segment’s guaranty book of business. (6) Consists of the portion of our single-family guaranty fees that is remitted to Treasury pursuant to the TCCA.

Concentrations of Credit Risk

Concentrations of Credit Risk	6 Months Ended
	Jun. 30, 2019
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	Concentrations of Credit Risk Risk Characteristics of our Guaranty Book of Business One of the key measures by which we gauge our performance 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 these 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. 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 June 30, 2019 (1) December 31, 2018 (1) 30 Days Delinquent 60 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent 60 Days Delinquent Seriously Delinquent (2) Percentage of single-family conventional guaranty book of business (3) 1.27 % 0.30 % 0.64 % 1.17 % 0.32 % 0.69 % Percentage of single-family conventional loans (4) 1.47 0.35 0.70 1.37 0.38 0.76 As of June 30, 2019 (1) December 31, 2018 (1) Percentage of Single-Family Conventional Guaranty Book of Business (3) Seriously Delinquent Rate (2) Percentage of Single-Family Conventional Guaranty Book of Business (3) Seriously Delinquent Rate (2) Estimated mark-to-market LTV ratio: Greater than 100% * 10.63 % * 9.85 % Geographical distribution: California 19 0.33 19 0.34 Florida 6 0.94 6 1.16 New Jersey 4 1.28 4 1.38 New York 5 1.32 5 1.40 All other states 66 0.69 66 0.75 Product distribution: Alt-A 2 3.25 2 3.35 Vintages: 2004 and prior 3 2.61 3 2.69 2005-2008 4 4.45 5 4.61 2009-2019 93 0.32 92 0.34 * Represents less than 0.5% of single-family conventional business volume or book of business. (1) Consists of the portion of our single-family conventional guaranty book of business for which we have detailed loan-level information, which constituted approximately 99% of our single-family conventional guaranty book of business as of June 30, 2019 and December 31, 2018 . (2) Consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of June 30, 2019 or December 31, 2018 . (3) Calculated based on the aggregate unpaid principal balance of single-family conventional loans for each category divided by the aggregate unpaid principal balance of loans in our single-family conventional guaranty book of business. (4) Calculated based on the number of single-family conventional loans that were delinquent divided by the total number of loans in our single-family conventional guaranty book of business. 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 determine our overall credit quality indicator. Higher risk characteristics include, but are not limited to, current debt service coverage ratio (“DSCR”) below 1.0 and high original LTV ratios. 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 June 30, 2019 (1) December 31, 2018 (1) 30 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent Seriously Delinquent (2) Percentage of multifamily guaranty book of business 0.04 % 0.05 % 0.02 % 0.06 % As of June 30, 2019 December 31, 2018 Percentage of Multifamily Guaranty Book of Business (1) Percentage Seriously Delinquent (2)(3) Percentage of Multifamily Guaranty Book of Business (1) Percentage Seriously Delinquent (2)(3) Original LTV ratio: Greater than 80% 1 % — % 1 % — % Less than or equal to 80% 99 0.05 99 0.06 Current DSCR below 1.0 (4) 2 1.11 2 1.38 (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. 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 guaranty book of business. As of June 30, 2019 December 31, 2018 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 $ 158,191 $ 152,379 Pool mortgage insurance 391 409 Total mortgage insurance risk in force $ 158,582 5% $ 152,788 5% 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 guaranty book of business. Percentage of Risk in Force Coverage by Mortgage Insurer As of June 30, 2019 December 31, 2018 Counterparty: (1) Arch Capital Group Ltd. 24 % 25 % Radian Guaranty, Inc. 20 21 Mortgage Guaranty Insurance Corp. 18 18 Genworth Mortgage Insurance Corp. (2) 15 15 Essent Guaranty, Inc. 13 12 Others 10 9 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. We have approved the acquisition subject to specified conditions, including Genworth Financial, Inc. receiving all required and outstanding regulatory approvals. 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 $4.0 billion , or 3% , of our risk in force mortgage insurance coverage of our single-family guaranty book of business as of June 30, 2019 . PMI and Triad have been paying only a portion of policyholder claims and deferring the remaining portion. PMI is currently paying 74.5% of claims under its mortgage insurance policies in cash and is deferring the remaining 25.5% , 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, 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. 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 only probable 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 June 30, 2019 and December 31, 2018 , our estimated benefit from mortgage insurance reduced our loss reserves by $563 million and $691 million , respectively. As of June 30, 2019 and December 31, 2018 , we had outstanding receivables of $685 million and $745 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 June 30, 2019 and December 31, 2018 , we assessed these outstanding receivables for collectibility, and established a valuation allowance of $546 million and $564 million , respectively, which reduces 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, 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 June 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 18 % 18 % Remaining top five depository servicers 15 16 Top five non-depository servicers 25 22 Total 58 % 56 % There was an increase in the portion of our single-family guaranty book serviced by our top five non-depository servicers, particularly for our delinquent single-family loans. Compared with depository financial institutions, these institutions pose additional risks to us because they may not have the same financial strength or operational capacity, or be subject to the same level of regulatory oversight, as our largest mortgage servicer counterparties, which are mostly depository 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 June 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 13 % 14 % Walker & Dunlop, Inc. 12 12 Remaining top five servicers 23 22 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 on-site and 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 on-site 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	6 Months Ended
	Jun. 30, 2019
Offsetting [Abstract]
Netting Arrangements	We use master netting arrangements, which allow us to offset certain financial instruments and collateral with the same counterparty, to minimize counterparty credit exposure. The tables below display information related to derivatives, securities purchased under agreements to resell or similar arrangements, and securities sold under agreements to repurchase or similar arrangements, which are subject to an enforceable master netting arrangement or similar agreement that are either offset or not offset in our condensed consolidated balance sheets. As of June 30, 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 $ 1,764 $ (1,716 ) $ 48 $ — $ — $ 48 Cleared risk management derivatives — 7 7 — — 7 Mortgage commitment derivatives 455 — 455 (159 ) (22 ) 274 Total derivative assets 2,219 (1,709 ) 510 (4) (159 ) (22 ) 329 Securities purchased under agreements to resell or similar arrangements (5) 40,362 — 40,362 — (40,362 ) — Total assets $ 42,581 $ (1,709 ) $ 40,872 $ (159 ) $ (40,384 ) $ 329 Liabilities: OTC risk management derivatives $ (2,377 ) $ 2,301 $ (76 ) $ — $ — $ (76 ) Cleared risk management derivatives — (4 ) (4 ) — 2 (2 ) Mortgage commitment derivatives (688 ) — (688 ) 159 510 (19 ) Total derivative liabilities (3,065 ) 2,297 (768 ) (4) 159 512 (97 ) Securities sold under agreements to repurchase or similar arrangements (131 ) — (131 ) — 130 (1 ) Total liabilities $ (3,196 ) $ 2,297 $ (899 ) $ 159 $ 642 $ (98 ) As of December 31, 2018 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 $ 2,288 $ (2,273 ) $ 15 $ — $ — $ 15 Cleared risk management derivatives — 7 7 — — 7 Mortgage commitment derivatives 379 — 379 (153 ) (7 ) 219 Total derivative assets 2,667 (2,266 ) 401 (4) (153 ) (7 ) 241 Securities purchased under agreements to resell or similar arrangements (5) 48,288 — 48,288 — (48,288 ) — Total assets $ 50,955 $ (2,266 ) $ 48,689 $ (153 ) $ (48,295 ) $ 241 Liabilities: OTC risk management derivatives $ (2,433 ) $ 2,342 $ (91 ) $ — $ — $ (91 ) Cleared risk management derivatives — (27 ) (27 ) — 23 (4 ) Mortgage commitment derivatives (648 ) — (648 ) 153 466 (29 ) Total derivative liabilities (3,081 ) 2,315 (766 ) (4) 153 489 (124 ) Total liabilities $ (3,081 ) $ 2,315 $ (766 ) $ 153 $ 489 $ (124 ) (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 is 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. The fair value of non-cash collateral we pledged was $1.6 billion and $1.9 billion as of June 30, 2019 and December 31, 2018 , respectively, which the counterparty was permitted to sell or repledge. The fair value of non-cash collateral received was $40.4 billion and $48.4 billion , of which $37.9 billion and $45.7 billion could be sold or repledged as of June 30, 2019 and December 31, 2018 , respectively. None of the underlying collateral was sold or repledged as of June 30, 2019 or December 31, 2018 . (4) Excludes derivative assets of $51 million and $57 million as of June 30, 2019 and December 31, 2018 , respectively, and derivative liabilities of $31 million and $11 million recognized in our condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $20.8 billion and $15.4 billion in securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , 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 2018 Form 10-K.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2019
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 fair value 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 June 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ — $ — $ — $ — $ — Trading securities: Mortgage-related securities: Fannie Mae — 3,077 74 — 3,151 Other agency — 3,629 — — 3,629 Private-label and other mortgage securities — 736 — — 736 Non-mortgage-related securities: U.S. Treasury securities 35,266 — — — 35,266 Other securities — 84 — — 84 Total trading securities 35,266 7,526 74 — 42,866 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,483 132 — 1,615 Other agency — 228 — — 228 Alt-A and subprime private-label securities — 220 — — 220 Mortgage revenue bonds — — 364 — 364 Other — 8 326 — 334 Total available-for-sale securities — 1,939 822 — 2,761 Mortgage loans — 7,709 770 — 8,479 Other assets: Risk management derivatives: Swaps — 1,480 165 — 1,645 Swaptions — 119 — — 119 Netting adjustment — — — (1,709 ) (1,709 ) Mortgage commitment derivatives — 455 — — 455 Credit enhancement derivatives — — 51 — 51 Total other assets — 2,054 216 (1,709 ) 561 Total assets at fair value $ 35,266 $ 19,228 $ 1,882 $ (1,709 ) $ 54,667 Fair Value Measurements as of June 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 5,972 $ 398 $ — $ 6,370 Total of Fannie Mae — 5,972 398 — 6,370 Of consolidated trusts — 22,669 102 — 22,771 Total long-term debt — 28,641 500 — 29,141 Other liabilities: Risk management derivatives: Swaps — 1,971 2 — 1,973 Swaptions — 404 — — 404 Netting adjustment — — — (2,297 ) (2,297 ) Mortgage commitment derivatives — 688 — — 688 Credit enhancement derivatives — — 31 — 31 Total other liabilities — 3,063 33 (2,297 ) 799 Total liabilities at fair value $ — $ 31,704 $ 533 $ (2,297 ) $ 29,940 Fair Value Measurements as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ 748 $ — $ — $ — $ 748 Trading securities: Mortgage-related securities: Fannie Mae — 1,435 32 — 1,467 Other agency — 3,503 — — 3,503 Private-label and other mortgage securities — 1,305 1 — 1,306 Non-mortgage-related securities: U.S. Treasury securities 35,502 — — — 35,502 Other Securities — 89 — — 89 Total trading securities 35,502 6,332 33 — 41,867 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,645 152 — 1,797 Other agency — 256 — — 256 Alt-A and subprime private-label securities — 568 24 — 592 Mortgage revenue bonds — — 434 — 434 Other — 8 342 — 350 Total available-for-sale securities — 2,477 952 — 3,429 Mortgage loans — 7,985 937 — 8,922 Other assets: Risk management derivatives: Swaps — 1,962 115 — 2,077 Swaptions — 211 — — 211 Netting adjustment — — — (2,266 ) (2,266 ) Mortgage commitment derivatives — 342 37 — 379 Credit enhancement derivatives — — 57 — 57 Total other assets — 2,515 209 (2,266 ) 458 Total assets at fair value $ 36,250 $ 19,309 $ 2,131 $ (2,266 ) $ 55,424 Fair Value Measurements as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 6,475 $ 351 $ — $ 6,826 Total of Fannie Mae — 6,475 351 — 6,826 Of consolidated trusts — 23,552 201 — 23,753 Total long-term debt — 30,027 552 — 30,579 Other liabilities: Risk management derivatives: Swaps — 2,089 2 — 2,091 Swaptions — 342 — — 342 Netting adjustment — — — (2,315 ) (2,315 ) Mortgage commitment derivatives — 646 2 — 648 Credit enhancement derivatives — — 11 — 11 Total other liabilities — 3,077 15 (2,315 ) 777 Total liabilities at fair value $ — $ 33,104 $ 567 $ (2,315 ) $ 31,356 (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 June 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2019 (1) Balance, March 31, 2019 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 67 $ 1 $ — $ — $ (14 ) $ — $ (16 ) $ — $ 36 $ 74 $ 2 $ — Total trading securities $ 67 $ 1 (5)(6) $ — $ — $ (14 ) $ — $ (16 ) $ — $ 36 $ 74 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 199 $ — $ 2 $ — $ — $ — $ (7 ) $ (62 ) $ — $ 132 $ — $ 3 Alt-A and subprime private-label securities 23 5 (5 ) — (23 ) — — — — — — — Mortgage revenue bonds 425 — (1 ) — (4 ) — (56 ) — — 364 — — Other 337 5 (5 ) — — — (9 ) (2 ) — 326 — (3 ) Total available-for-sale securities $ 984 $ 10 (6)(7) $ (9 ) $ — $ (27 ) $ — $ (72 ) $ (64 ) $ — $ 822 $ — $ — Mortgage loans $ 934 $ 17 (5)(6) $ — $ — $ (13 ) $ — $ (36 ) $ (159 ) $ 27 $ 770 $ 14 $ — Net derivatives 203 20 (5) — — — — (31 ) (9 ) — 183 18 — Long-term debt: Of Fannie Mae: Senior floating (376 ) (22 ) — — — — — — — (398 ) (22 ) — Of consolidated trusts (224 ) (1 ) — — — — 5 120 (2 ) (102 ) (1 ) — Total long-term debt $ (600 ) $ (23 ) (5) $ — $ — $ — $ — $ 5 $ 120 $ (2 ) $ (500 ) $ (23 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 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 Level 3 Balance, June 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 3 $ — $ — $ (14 ) $ — $ (16 ) $ — $ 69 $ 74 $ 3 $ — Private-label and other mortgage securities 1 — — — — — (1 ) — — — — — Total trading securities $ 33 $ 3 (5)(6) $ — $ — $ (14 ) $ — $ (17 ) $ — $ 69 $ 74 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 6 $ — $ — $ — $ (7 ) $ (103 ) $ 84 $ 132 $ — $ 5 Alt-A and subprime private-label securities 24 5 (5 ) — (23 ) — (1 ) — — — — — Mortgage revenue bonds 434 — (1 ) — (4 ) — (65 ) — — 364 — (1 ) Other 342 12 (10 ) — — — (17 ) (2 ) 1 326 — (7 ) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (10 ) $ — $ (27 ) $ — $ (90 ) $ (105 ) $ 85 $ 822 $ — $ (3 ) Mortgage loans $ 937 $ 31 (5)(6) $ — $ — $ (13 ) $ — $ (70 ) $ (187 ) $ 72 $ 770 $ 22 $ — Net derivatives 194 118 (5) — — — — (120 ) (9 ) — 183 24 — Long-term debt: Of Fannie Mae: Senior floating (351 ) (47 ) — — — — — — — (398 ) (47 ) — Of consolidated trusts (201 ) (4 ) — — — — 10 169 (76 ) (102 ) (2 ) — Total long-term debt $ (552 ) $ (51 ) (5) $ — $ — $ — $ — $ 10 $ 169 $ (76 ) $ (500 ) $ (49 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2018 (1) Balance, March 31, 2018 Included in Net Income Included in Total OCI (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 83 $ (5 ) $ — $ — $ — $ — $ — $ — $ 1 $ 79 $ 3 $ — Private-label and other mortgage securities 1 — — — — — — — — 1 — — Total trading securities $ 84 $ (5 ) (5)(6) $ — $ — $ — $ — $ — $ — $ 1 $ 80 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 202 $ 1 $ 4 $ — $ — $ — $ (3 ) $ — $ — $ 204 $ — $ 3 Alt-A and subprime private-label securities 27 — — — — — (1 ) — — 26 — — Mortgage revenue bonds 539 (11 ) 10 — (7 ) — (25 ) — — 506 — 8 Other 351 7 10 — — — (11 ) — — 357 — 8 Total available-for-sale securities $ 1,119 $ (3 ) (6)(7) $ 24 $ — $ (7 ) $ — $ (40 ) $ — $ — $ 1,093 $ — $ 19 Mortgage loans $ 1,102 $ 11 (5)(6) $ — $ — $ — $ — $ (79 ) $ (51 ) $ 35 $ 1,018 $ 8 $ — Net derivatives 133 (28 ) (5) — — — — 12 — — 117 (14 ) — Long-term debt: Of Fannie Mae: Senior floating (357 ) 3 — — — — — — — (354 ) 3 — Of consolidated trusts (462 ) 4 — — — — 21 177 (59 ) (319 ) (1 ) — Total long-term debt $ (819 ) $ 7 (5) $ — $ — $ — $ — $ 21 $ 177 $ (59 ) $ (673 ) $ 2 $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2018 (1) Balance, December 31, 2017 Included in Net Income Included in Total OCI (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 971 $ 166 $ — $ 1 $ (1,060 ) $ — $ — $ — $ 1 $ 79 $ 3 $ — Other agency 35 (1 ) — — — — (1 ) (33 ) — — — — Private-label and other mortgage securities 195 (85 ) — — — — (5 ) (104 ) — 1 — — Total trading securities $ 1,201 $ 80 (5)(6) $ — $ 1 $ (1,060 ) $ — $ (6 ) $ (137 ) $ 1 $ 80 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 208 $ 1 $ — $ — $ — $ — $ (5 ) $ — $ — $ 204 $ — $ — Alt-A and subprime private-label securities 77 — (45 ) — — — (2 ) (4 ) — 26 — 1 Mortgage revenue bonds 671 — (3 ) — (18 ) — (144 ) — — 506 — — Other 357 14 8 — — — (22 ) — — 357 — 8 Total available-for-sale securities $ 1,313 $ 15 (6)(7) $ (40 ) $ — $ (18 ) $ — $ (173 ) $ (4 ) $ — $ 1,093 $ — $ 9 Mortgage loans $ 1,116 $ 28 (5)(6) $ — $ — $ — $ — $ (127 ) $ (87 ) $ 88 $ 1,018 $ 16 $ — Net derivatives 134 (86 ) (5) — — — — 16 53 — 117 (37 ) — Long-term debt: Of Fannie Mae: Senior floating (376 ) 22 — — — — — — — (354 ) 22 — Of consolidated trusts (582 ) 7 — — — 1 31 331 (107 ) (319 ) (1 ) — Total long-term debt $ (958 ) $ 29 (5) $ — $ — $ — $ 1 $ 31 $ 331 $ (107 ) $ (673 ) $ 21 $ — (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on AFS 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. For the first half of 2018 , includes the dissolution of a Fannie Mae-wrapped private-label securities trust. (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 OTTI are not considered unrealized and are not included in this amount. (5) Gains (losses) are included in “ Fair value gains (losses), net ” in our condensed consolidated statements of operations and comprehensive income. (6) Gains (losses) are included in “ Net interest income ” in our condensed consolidated statements of operations and comprehensive income. (7) Gains (losses) are included in “ Investment gains, 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 June 30, 2019 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Agency (2) $ 74 Various Available-for-sale securities: Mortgage-related securities: Agency (2) $ 106 Consensus 26 Various Total agency 132 Mortgage revenue bonds 250 Single Vendor Spreads(bps) 16.5 - 193.3 66.1 114 Various Total mortgage revenue bonds 364 Other 283 Discounted Cash Flow Default Rate(%) 5.5 5.5 Prepayment Speed(%) 5.5 5.5 Severity(%) 95.0 95.0 Spreads(bps) 59.3 - 294.0 292.4 43 Various Total other 326 Total available-for-sale securities $ 822 Net derivatives $ 163 Dealer Mark 20 Various Total net derivatives $ 183 Fair Value Measurements as of December 31, 2018 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 (2) $ 32 Various Private-label securities and other mortgage securities 1 Various Total trading securities $ 33 Available-for-sale securities: Mortgage-related securities: Agency (2) $ 152 Various Alt-A and subprime private-label securities 24 Various Mortgage revenue bonds 349 Single Vendor Spreads(bps) (0.5 ) - 332.8 59.0 85 Various Total mortgage revenue bonds 434 Other 294 Discounted Cash Flow Default Rate(%) 4.7 4.7 Prepayment Speed(%) 8.2 8.2 Severity(%) 70.0 70.0 Spreads(bps) 75.4 - 390.0 389.1 48 Various Total other 342 Total available-for-sale securities $ 952 Net derivatives $ 113 Dealers Mark 81 Various Total net derivatives $ 194 (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. 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 June 30, 2019 or December 31, 2018 that were measured at fair value on a nonrecurring basis. We held $247 million and $91 million in Level 2 assets, comprised of mortgage loans held for sale, and no Level 2 liabilities that were measured at fair value on a nonrecurring basis as of June 30, 2019 and December 31, 2018 , respectively. 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 June 30, 2019 December 31, 2018 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,772 $ 631 Single Vendor 1,448 1,119 Total mortgage loans held for sale, at lower of cost or fair value 3,220 1,750 Single-family mortgage loans held for investment, at amortized cost Internal Model 571 818 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate 218 102 Various 13 40 Total multifamily mortgage loans held for investment, at amortized cost 231 142 Acquired property, net: (1) Single-family Accepted Offers 118 151 Appraisals 337 419 Walk Forwards 198 181 Internal Model 150 219 Various 33 41 Total single-family 836 1,011 Multifamily Various — 50 Total nonrecurring assets at fair value $ 4,858 $ 3,771 (1) The most commonly used techniques in our valuation of acquired property are proprietary home price model and third-party valuations (both current and walk forward). Based on the number of properties measured as of June 30, 2019 and December 31, 2018 , these methodologies comprised approximately 82% of our valuations, while accepted offers comprised approximately 15% of our valuations. We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. See “ Note 15, Fair Value ” in our 2018 Form 10-K for information on the valuation control processes and the valuation techniques we use for fair value measurement and disclosure as well as our basis for classifying these measurements as Level 1, Level 2 or Level 3 of the valuation hierarchy in more specific situations. We made no material changes to the valuation control processes or the valuation techniques for the six months ended June 30, 2019 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 June 30, 2019 Carrying Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment Estimated (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 60,970 $ 40,170 $ 20,800 $ — $ — $ 60,970 Federal funds sold and securities purchased under agreements to resell or similar arrangements 19,562 — 19,562 — — 19,562 Trading securities 42,866 35,266 7,526 74 — 42,866 Available-for-sale securities 2,761 — 1,939 822 — 2,761 Mortgage loans held for sale 11,220 — 826 11,112 — 11,938 Mortgage loans held for investment, net of allowance for loan losses 3,262,012 — 3,175,207 142,889 — 3,318,096 Advances to lenders 5,395 — 5,393 2 — 5,395 Derivative assets at fair value 561 — 2,054 216 (1,709 ) 561 Guaranty assets and buy-ups 152 — — 352 — 352 Total financial assets $ 3,405,499 $ 75,436 $ 3,233,307 $ 155,467 $ (1,709 ) $ 3,462,501 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 131 $ — $ 131 $ — $ — $ 131 Short-term debt: Of Fannie Mae 22,901 — 22,907 — — 22,907 Long-term debt: Of Fannie Mae 193,913 — 201,775 826 — 202,601 Of consolidated trusts 3,199,765 — 3,195,793 36,368 — 3,232,161 Derivative liabilities at fair value 799 — 3,063 33 (2,297 ) 799 Guaranty obligations 166 — — 109 — 109 Total financial liabilities $ 3,417,675 $ — $ 3,423,669 $ 37,336 $ (2,297 ) $ 3,458,708 As of December 31, 2018 Carrying Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment Estimated (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 49,423 $ 34,073 $ 15,350 $ — $ — $ 49,423 Federal funds sold and securities purchased under agreements to resell or similar arrangements 32,938 — 32,938 — — 32,938 Trading securities 41,867 35,502 6,332 33 — 41,867 Available-for-sale securities 3,429 — 2,477 952 — 3,429 Mortgage loans held for sale 7,701 — 238 7,856 — 8,094 Mortgage loans held for investment, net of allowance for loan losses 3,241,694 — 2,990,104 216,404 — 3,206,508 Advances to lenders 3,356 — 3,354 2 — 3,356 Derivative assets at fair value 458 — 2,515 209 (2,266 ) 458 Guaranty assets and buy-ups 147 — — 356 — 356 Total financial assets $ 3,381,013 $ 69,575 $ 3,053,308 $ 225,812 $ (2,266 ) $ 3,346,429 Financial liabilities: Short-term debt: Of Fannie Mae $ 24,896 $ — $ 24,901 $ — $ — $ 24,901 Long-term debt: Of Fannie Mae 207,178 — 211,403 771 — 212,174 Of consolidated trusts 3,159,846 — 3,064,239 39,043 — 3,103,282 Derivative liabilities at fair value 777 — 3,077 15 (2,315 ) 777 Guaranty obligations 160 — — 121 — 121 Total financial liabilities $ 3,392,857 $ — $ 3,303,620 $ 39,950 $ (2,315 ) $ 3,341,255 For a detailed description and classification of our financial instruments, see “ Note 15, Fair Value ” in our 2018 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 June 30, 2019 December 31, 2018 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 $ 8,479 $ 6,370 $ 22,771 $ 8,922 $ 6,826 $ 23,753 Unpaid principal balance 8,221 5,835 20,687 8,832 6,241 22,080 (1) Includes nonaccrual loans with a fair value of $141 million and $161 million as of June 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of June 30, 2019 and December 31, 2018 was $13 million and $19 million , respectively. Includes loans that are 90 days or more past due with a fair value of $87 million and $102 million as of June 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these 90 or more days past due loans as of June 30, 2019 and December 31, 2018 was $10 million and $14 million , respectively. Changes in Fair Value under the Fair Value Option Election We recorded gains of $126 million and $239 million for the three and six months ended June 30, 2019 , respectively, and losses of $27 million and $176 million for the three and six months ended June 30, 2018 , respectively, from changes in the fair value of loans recorded at fair value in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We recorded losses of $222 million and $552 million for the three and six months ended June 30, 2019 , respectively, and gains of $247 million and $501 million for the three and six months ended June 30, 2018 , respectively, from changes in the fair value of long-term debt recorded at fair value in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
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 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. In the consolidated class action and two of the non-class action suits, Arrowood Indemnity Company v. Fannie Mae and Fairholme Funds v. FHFA, plaintiffs filed amended complaints 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. On October 15, 2018, defendants filed a motion for partial reconsideration. On May 16, 2019, the court denied this motion. On May 21, 2018, a pro se plaintiff in a non-class action case, Angel v. Federal Home Loan Mortgage Corporation, filed a complaint for declaratory relief and compensatory damages against Fannie Mae (including certain members of its Board of Directors), Freddie Mac (including certain members of its Board of Directors) and FHFA, as conservator, in the U.S. District Court for the District of Columbia. Plaintiff in that case asserts claims for breach of contract, breach of implied covenants of good faith and fair dealing, and aiding and abetting the federal government in avoiding an alleged implicit guarantee of dividend payments. On March 6, 2019, the court granted defendants’ motion to dismiss and on March 18, 2019, plaintiff moved to alter or amend the judgment and to file an amended complaint. On May 24, 2019, the court denied this motion. On June 19, 2019, plaintiff filed a notice of appeal of the court’s dismissal and related orders with the U.S. Court of Appeals for the District of Columbia Circuit. 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)	6 Months Ended
	Jun. 30, 2019
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 six months ended June 30, 2019 may not necessarily be indicative of the results for the year ending December 31, 2019 .
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. Actual results could be different from these estimates.
Earnings Per Share, Policy [Policy Text Block]	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). Weighted average common shares includes 4.6 billion shares for the periods ended June 30, 2019 and 2018 that would be issued upon the full exercise of the warrant issued to Treasury from the date the warrant was issued through June 30, 2019 and 2018 . 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. For the three months ended June 30, 2019 and six months ended June 30, 2019 and 2018 , our diluted EPS weighted average shares outstanding includes shares of common stock that would be issuable upon the conversion of 131 million shares of convertible preferred stock. For the three months ended June 30, 2018 , convertible preferred stock is not included in the calculation because a net loss attributable to common shareholders was incurred and it would have an anti-dilutive effect.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Guidance T he following updates information about our significant accounting policies that have recently been adopted or yet to be adopted from the information included in “Note 1, Summary of Significant Accounting Policies” in our 2018 Form 10-K. T he 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 (“CECL”) in June 2016. It was amended by ASU 2019-04, Codification Improvements (to Topic 326), Financial Instruments—Credit Losses in April 2019. The standard replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects lifetime expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this standard also require credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses. We do not expect a material impact for establishing an allowance for credit losses related to our available-for-sale debt securities. CECL will become effective for our fiscal year beginning January 1, 2020. We are continuing to update the allowance models and accounting systems that will be used to estimate credit losses and record accounting impacts under CECL, and we are in the process of validating their results. All updates to our allowance models are subject to our model oversight and review governance process. We expect model and system testing to continue in 2019, followed by full integrated testing across all affected systems and processes. We are managing the implementation of this guidance in accordance with our change management governance standards, which are designed to ensure compliance with GAAP as well as operational readiness at adoption. Senior management and the Audit Committee receive regular updates regarding the status of our implementation plan, results of modeled impacts and any identified key risks. We will use a discounted cash flow method to measure credit impairment on our single-family mortgage loans and an undiscounted loss method to measure credit impairment on our multifamily mortgage loans. The models we will use to estimate credit losses will incorporate our historical credit loss experience, adjusted for current economic forecasts and the current credit profile of our loan book of business. The models will use reasonable and supportable forecasts for key economic drivers, such as home prices (Single-Family), rental income (Multifamily) and capitalization rates (Multifamily). Based on the composition of the loans in our book of business as of June 30, 2019 and our current expectations of future economic conditions, we estimate that our adoption of CECL will result in a reduction in our retained earnings of up to $4 billion on an after-tax basis in the first quarter of 2020. We are still assessing the impact of various implementation issues as well as the FASB’s recently proposed guidance relating to the standard. The resolution of these items may reduce CECL’s impact on our retained earnings upon adoption. In addition, we continue to evaluate the results of our modeled loss estimates and may make refinements to our approach and assumptions. The impact of our adoption of CECL on our retained earnings will be further influenced by the credit risk profile of the loans in our book of business as of the January 1, 2020 adoption date, as well as economic conditions and forecasts of future economic conditions at that time.

Consolidations and Transfers _2

Consolidations and Transfers of Financial Assets (Policies)	6 Months Ended
	Jun. 30, 2019
Consolidations and Transfers of Financial Assets [Abstract]
Consolidations, Policy [Policy Text Block]	We have interests in various entities that are considered to be variable interest entities (“VIEs”). The primary types of entities are securitization and resecuritization trusts, limited partnerships and special purpose vehicles (“SPVs”). These interests include investments in securities issued by VIEs, such as Fannie Mae MBS created pursuant to our securitization transactions and our guaranty to the entity. We consolidate the substantial majority of our single-class securitization trusts because our role as guarantor and master servicer provides us with the power to direct matters (primarily the servicing of mortgage loans) that impact the credit risk to which we are exposed. In contrast, we do not consolidate single-class securitization trusts when other organizations have the power to direct these activities. 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, beginning with the implementation of the Single Security Initiative in June 2019, we include securities issued by Freddie Mac in some of our resecuritization trusts. The mortgage loans that serve as collateral for Freddie Mac-issued UMBS are not held in trusts that are consolidated by Fannie Mae.
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]	Transfers of Financial Assets

Mortgage Loans (Policies)

Mortgage Loans (Policies)	6 Months Ended
	Jun. 30, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block]	We define the recorded investment of HFI loans as unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable.We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and an allowance for loan losses.
Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block]	We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “ Investment gains, net
Nonaccrual Loans [Policy Text Block]	We discontinue accruing interest on loans when we believe collectibility 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 is reversed through interest income at the date a loan is placed on nonaccrual status. 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. We place a multifamily loan on nonaccrual status when the loan becomes three months or more past due according to its contractual terms or is deemed to be individually impaired, unless the loan is well secured such that collectibility of principal and accrued interest is reasonably assured. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan or we otherwise determine that the loan is well secured such that collectibility is reasonably assured.
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.

Allowance for Loan Losses (Poli

Allowance for Loan Losses (Policies)	6 Months Ended
	Jun. 30, 2019
Receivables [Abstract]
Allowance for Loan Losses [Policy Text Block]	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 amortized premiums and discounts, and other cost basis adjustments of HFI loans at the balance sheet date. We record charge-offs as a reduction to our allowance for loan losses at the point of foreclosure, completion of a short sale, upon the redesignation of loans from HFI to HFS or when a loan is determined to be uncollectible. We aggregate single-family HFI loans that are not individually impaired based on similar risk characteristics, for purposes of estimating incurred credit losses and establishing a collective single-family loss reserve using an econometric model that derives an overall loss reserve estimate. We base our allowance methodology on historical events and trends, such as loss severity (in event of default), default rates, and recoveries from mortgage insurance contracts and other credit enhancements that provide loan-level loss coverage and are either contractually attached to a loan or that were entered into contemporaneously with and in contemplation of a guaranty or loan purchase transaction. We use recent regional historical sales and appraisal information, including the sales of our own foreclosed properties, to develop our loss severity estimates for all loan categories. Our allowance calculation also incorporates a loss confirmation period (the anticipated time lag between a credit loss event and the confirmation of the credit loss resulting from that event) to ensure our allowance estimate captures credit losses that have been incurred as of the balance sheet date but have not been confirmed. In addition, management performs a review of the observable data used in its estimate to ensure it is representative of prevailing economic conditions and other events existing as of the balance sheet date. Individually impaired single-family loans currently include those classified as a TDR and acquired credit-impaired loans. We consider a loan to be impaired when, based on current information, it is probable that we will not receive all amounts due, including interest, in accordance with the contractual terms of the loan agreement. When a loan has been restructured, we measure impairment using a cash flow analysis discounted at the loan’s original effective interest rate. If we expect to recover our recorded investment in an individually impaired loan through probable foreclosure of the underlying collateral, we measure impairment based on the difference between our recorded investment in the loan and the fair value of the underlying property, adjusted for the estimated costs to sell the property and estimated insurance or other proceeds we expect to receive. We establish a collective allowance for all loans in our multifamily guaranty book of business that are not individually measured for impairment using an internal model that applies loss factors to loans in similar risk categories. Our loss factors are developed based on our historical default and loss severity experience. We identify multifamily loans for evaluation for impairment through a credit risk assessment process. If we determine that a multifamily loan is individually impaired, we generally measure impairment on that loan based on the fair value of the underlying collateral less estimated costs to sell the property, as we have concluded that such loans are collateral dependent. We evaluate collectively for impairment smaller-balance homogeneous multifamily loans.

Investment in Securities (Polic

Investment in Securities (Policies)	6 Months Ended
	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Policy [Policy Text Block]	Trading Securities Trading securities are recorded at fair value with subsequent changes in fair value recorded as “ Fair value gains (losses), net 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.

Derivative Instruments (Policie

Derivative Instruments (Policies)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
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 netted to the extent a legal right of offset exists and is enforceable by law at the counterparty level and are 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.

Segment Reporting (Policies)

Segment Reporting (Policies)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Reporting, Policy [Policy Text Block]	We have two reportable business segments: Single-Family and Multifamily. Results of our two

Netting Arrangements (Policies)

Netting Arrangements (Policies)	6 Months Ended
	Jun. 30, 2019
Offsetting [Abstract]
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. 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 2018 Form 10-K.

Fair Value (Policies)

Fair Value (Policies)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
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 fair value 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.

Commitments and Contingencies (

Commitments and Contingencies (Policies)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
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.

Consolidations and Transfers _3

Consolidations and Transfers of Financial Assets (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 December 31, 2018 Assets and liabilities recorded in our condensed consolidated balance sheets related to mortgage-backed trusts: (Dollars in millions) Assets: Trading securities: Fannie Mae $ 2,173 $ 1,422 Non-Fannie Mae 4,352 4,809 Total trading securities 6,525 6,231 Available-for-sale securities: Fannie Mae 1,615 1,704 Non-Fannie Mae 791 1,207 Total available-for-sale securities 2,406 2,911 Other assets 60 66 Other liabilities (90 ) (101 ) Net carrying amount $ 8,901 $ 9,107

Mortgage Loans (Tables)

Mortgage Loans (Tables)	6 Months Ended
	Jun. 30, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans in Mortgage Portfolio [Table Text Block]	The following table displays the carrying value of our mortgage loans. As of June 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,932,553 $ 2,929,925 Multifamily 310,899 293,858 Total unpaid principal balance of mortgage loans 3,243,452 3,223,783 Cost basis and fair value adjustments, net 41,262 39,815 Allowance for loan losses for loans held for investment (11,482 ) (14,203 ) Total mortgage loans $ 3,273,232 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 6,759 $ 6,235 $ 9,370 $ 13,602 Carrying value of loans redesignated from HFS to HFI (1) 3 12 12 30 Loans sold - unpaid principal balance 6,498 3,710 6,556 4,458 Realized gains on sale of mortgage loans 284 210 320 208 The following table displays the allowance for loan losses and recorded investment in our HFI loans by impairment or allowance methodology and portfolio segment, excluding loans for which we have elected the fair value option. As of June 30, 2019 December 31, 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans (1) $ (10,572 ) $ (55 ) $ (10,627 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (638 ) (217 ) (855 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (11,210 ) $ (272 ) $ (11,482 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 107,354 $ 776 $ 108,130 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,852,896 312,769 3,165,665 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,960,250 $ 313,545 $ 3,273,795 $ 2,959,504 $ 295,664 $ 3,255,168 (1) Includes acquired credit-impaired loans.
Aging Analysis [Table Text Block]	The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of June 30, 2019 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Recorded Investment in Loans 90 Days or More Delinquent and Accruing Interest Recorded Investment in Nonaccrual Loans (Dollars in millions) Single-family: Primary $ 33,030 $ 7,308 $ 13,547 $ 53,885 $ 2,827,424 $ 2,881,309 $ 22 $ 24,035 Government (2) 46 18 152 216 18,691 18,907 152 — Alt-A 2,228 645 1,533 4,406 43,083 47,489 1 2,528 Other 733 236 590 1,559 10,986 12,545 2 944 Total single-family 36,037 8,207 15,822 60,066 2,900,184 2,960,250 177 27,507 Multifamily (3) 24 N/A 187 211 313,334 313,545 — 513 Total $ 36,061 $ 8,207 $ 16,009 $ 60,277 $ 3,213,518 $ 3,273,795 $ 177 $ 28,020 As of December 31, 2018 30 - 59 Days Delinquent 60 - 89 Days Delinquent Seriously Delinquent (1) Total Delinquent Current Total Recorded Investment in Loans 90 Days or More Delinquent and Accruing Interest Recorded Investment in Nonaccrual Loans (Dollars in millions) Single-family: Primary $ 30,471 $ 7,881 $ 14,866 $ 53,218 $ 2,816,047 $ 2,869,265 $ 22 $ 26,170 Government (2) 57 17 169 243 21,887 22,130 169 — Alt-A 2,332 821 1,844 4,997 48,274 53,271 2 3,082 Other 804 283 713 1,800 13,038 14,838 2 1,128 Total single-family 33,664 9,002 17,592 60,258 2,899,246 2,959,504 195 30,380 Multifamily (3) 56 N/A 171 227 295,437 295,664 — 492 Total $ 33,720 $ 9,002 $ 17,763 $ 60,485 $ 3,194,683 $ 3,255,168 $ 195 $ 30,872 (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) Primarily consists of reverse mortgages, which due to their nature, are not aged and are included in the current column. (3) Multifamily loans 60 - 89 days delinquent are included in the seriously delinquent column.
Individually Impaired Loans [Table Text Block]	The following tables display the total unpaid principal balance, recorded investment, related allowance, average recorded investment and interest income recognized for individually impaired loans. As of June 30, 2019 December 31, 2018 Unpaid Principal Balance Total Recorded Investment Related Allowance for Loan Losses Unpaid Principal Balance Total Recorded Investment Related Allowance for Loan Losses (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 74,143 $ 71,549 $ (7,615 ) $ 81,791 $ 78,688 $ (9,406 ) Government 261 267 (54 ) 264 270 (55 ) Alt-A 13,703 12,554 (2,129 ) 16,576 15,158 (2,793 ) Other 4,520 4,268 (774 ) 5,482 5,169 (1,001 ) Total single-family 92,627 88,638 (10,572 ) 104,113 99,285 (13,255 ) Multifamily 340 343 (55 ) 197 196 (40 ) Total individually impaired loans with related allowance recorded 92,967 88,981 (10,627 ) 104,310 99,481 (13,295 ) With no related allowance recorded: (1) Single-family: Primary 16,638 15,866 — 15,939 15,191 — Government 59 55 — 61 56 — Alt-A 2,445 2,193 — 2,628 2,363 — Other 654 602 — 718 666 — Total single-family 19,796 18,716 — 19,346 18,276 — Multifamily 431 433 — 343 346 — Total individually impaired loans with no related allowance recorded 20,227 19,149 — 19,689 18,622 — Total individually impaired loans (2) $ 113,194 $ 108,130 $ (10,627 ) $ 123,999 $ 118,103 $ (13,295 ) (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 a recorded investment of $107.0 billion and $117.2 billion as of June 30, 2019 and December 31, 2018 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $188 million and $187 million as of June 30, 2019 and December 31, 2018 , respectively. For the Three Months Ended June 30, 2019 2018 Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 74,162 $ 774 $ 72 $ 88,526 $ 915 $ 109 Government 269 3 — 279 9 — Alt-A 13,399 145 11 19,349 219 16 Other 4,471 41 3 7,265 73 6 Total single-family 92,301 963 86 115,419 1,216 131 Multifamily 321 3 — 232 1 — Total individually impaired loans with related allowance recorded 92,622 966 86 115,651 1,217 131 With no related allowance recorded: (1) Single-family: Primary 15,474 249 36 14,942 243 32 Government 55 1 — 57 2 — Alt-A 2,196 44 5 2,723 61 5 Other 615 10 1 857 15 1 Total single-family 18,340 304 42 18,579 321 38 Multifamily 397 6 — 355 1 — Total individually impaired loans with no related allowance recorded 18,737 310 42 18,934 322 38 Total individually impaired loans $ 111,359 $ 1,276 $ 128 $ 134,585 $ 1,539 $ 169 For the Six Months Ended June 30, 2019 2018 Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 75,888 $ 1,591 $ 152 $ 88,342 $ 1,826 $ 216 Government 270 6 — 278 12 — Alt-A 14,023 301 22 20,020 431 32 Other 4,706 86 7 7,556 144 11 Total single-family 94,887 1,984 181 116,196 2,413 259 Multifamily 279 5 — 248 1 — Total individually impaired loans with related allowance recorded 95,166 1,989 181 116,444 2,414 259 With no related allowance recorded: (1) Single-family: Primary 15,336 469 64 14,988 486 58 Government 55 2 — 58 2 — Alt-A 2,244 83 7 2,781 119 9 Other 631 18 2 878 31 2 Total single-family 18,266 572 73 18,705 638 69 Multifamily 380 8 — 340 3 — Total individually impaired loans with no related allowance recorded 18,646 580 73 19,045 641 69 Total individually impaired loans $ 113,812 $ 2,569 $ 254 $ 135,489 $ 3,055 $ 328 (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.
Troubled Debt Restructurings Activity [Table Text Block]	The following tables display the number of loans and recorded investment in loans classified as a TDR. For the Three Months Ended June 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 11,796 $ 1,844 21,820 $ 3,148 Government 22 2 26 2 Alt-A 639 81 1,538 200 Other 138 25 285 52 Total single-family 12,595 1,952 23,669 3,402 Multifamily 3 20 2 19 Total TDRs 12,598 $ 1,972 23,671 $ 3,421 For the Six Months Ended June 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 24,753 $ 3,815 63,499 $ 9,672 Government 45 6 74 6 Alt-A 1,405 178 3,720 483 Other 285 52 730 136 Total single-family 26,488 4,051 68,023 10,297 Multifamily 6 33 10 61 Total TDRs 26,494 $ 4,084 68,033 $ 10,358 (1) Based on the nature of our modification programs, which do not include principal or past-due interest forgiveness, there is not a material difference between the recorded investment in our loans pre- and post- modification. Therefore, these amounts represent recorded investment post-modification. For the Three Months Ended June 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 4,047 $ 606 3,834 $ 554 Government 10 2 15 2 Alt-A 379 58 588 92 Other 110 21 131 26 Total single-family 4,546 687 4,568 674 Multifamily 1 6 — — Total TDRs that subsequently defaulted 4,547 $ 693 4,568 $ 674 For the Six Months Ended June 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 8,563 $ 1,279 8,652 $ 1,255 Government 28 5 29 4 Alt-A 850 131 1,265 201 Other 264 49 326 64 Total single-family 9,705 1,464 10,272 1,524 Multifamily 1 6 1 2 Total TDRs that subsequently defaulted 9,706 $ 1,470 10,273 $ 1,526
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 recorded investment in our single-family HFI loans by class and credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, 2019 (1) December 31, 2018 (1) Primary Alt-A Other Primary Alt-A Other (Dollars in millions) Estimated mark-to-market loan-to-value (“LTV”) ratio: (2) Less than or equal to 80% $ 2,551,443 $ 41,960 $ 10,773 $ 2,521,766 $ 45,476 $ 12,291 Greater than 80% and less than or equal to 90% 221,190 2,819 874 228,614 3,804 1,195 Greater than 90% and less than or equal to 100% 102,585 1,383 435 109,548 1,997 645 Greater than 100% 6,091 1,327 463 9,337 1,994 707 Total $ 2,881,309 $ 47,489 $ 12,545 $ 2,869,265 $ 53,271 $ 14,838 (1) Excludes $18.9 billion and $22.1 billion as of June 30, 2019 and December 31, 2018 , respectively, of mortgage loans guaranteed or insured, in whole or in part, by the U.S. government or one of its agencies, that are not Alt-A loans. The class is 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.
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 recorded investment in our multifamily HFI loans by credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, December 31, 2019 2018 (Dollars in millions) Credit risk profile by internally assigned grade: Non-classified $ 306,257 $ 289,231 Classified (1) 7,288 6,433 Total $ 313,545 $ 295,664 (1) Includes loans classified as “Substandard” or “Doubtful.” Loans classified as “Substandard” have a well-defined weakness that jeopardizes the timely full repayment. Loans classified as “Doubtful” have weakness that makes collection or liquidation in full highly questionable and improbable based on existing conditions and values. As of June 30, 2019 , we had loans with recorded investment of less than $0.5 million classified as doubtful, compared with $1 million as of December 31, 2018 .

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2019
Receivables [Abstract]
Allowance for Loan Losses Rollforward by Segment [Table Text Block]	The following table displays changes in single-family, multifamily and total allowance for loan losses. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (12,985 ) $ (18,523 ) $ (13,969 ) $ (18,849 ) Benefit (provision) for loan losses (1) 1,239 1,270 1,886 1,192 Charge-offs 558 731 939 1,196 Recoveries (15 ) (64 ) (60 ) (124 ) Other (7 ) (16 ) (6 ) (17 ) Ending balance $ (11,210 ) $ (16,602 ) $ (11,210 ) $ (16,602 ) Multifamily allowance for loan losses: Beginning balance $ (247 ) $ (211 ) $ (234 ) $ (235 ) Benefit (provision) for loan losses (1) (27 ) — (40 ) 20 Charge-offs 4 1 4 5 Recoveries (2 ) — (2 ) — Ending balance $ (272 ) $ (210 ) $ (272 ) $ (210 ) Total allowance for loan losses: Beginning balance $ (13,232 ) $ (18,734 ) $ (14,203 ) $ (19,084 ) Benefit (provision) for loan losses (1) 1,212 1,270 1,846 1,212 Charge-offs 562 732 943 1,201 Recoveries (17 ) (64 ) (62 ) (124 ) Other (7 ) (16 ) (6 ) (17 ) Ending balance $ (11,482 ) $ (16,812 ) $ (11,482 ) $ (16,812 ) (1) Benefit (provision) for loan losses is included in “ Benefit for credit losses ” in our condensed consolidated statements of operations and comprehensive income.
Allowance for Loan Losses and Total Recorded Investment in HFI Loans [Table Text Block]	The following table displays the carrying value of our mortgage loans. As of June 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,932,553 $ 2,929,925 Multifamily 310,899 293,858 Total unpaid principal balance of mortgage loans 3,243,452 3,223,783 Cost basis and fair value adjustments, net 41,262 39,815 Allowance for loan losses for loans held for investment (11,482 ) (14,203 ) Total mortgage loans $ 3,273,232 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 6,759 $ 6,235 $ 9,370 $ 13,602 Carrying value of loans redesignated from HFS to HFI (1) 3 12 12 30 Loans sold - unpaid principal balance 6,498 3,710 6,556 4,458 Realized gains on sale of mortgage loans 284 210 320 208 The following table displays the allowance for loan losses and recorded investment in our HFI loans by impairment or allowance methodology and portfolio segment, excluding loans for which we have elected the fair value option. As of June 30, 2019 December 31, 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans (1) $ (10,572 ) $ (55 ) $ (10,627 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (638 ) (217 ) (855 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (11,210 ) $ (272 ) $ (11,482 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 107,354 $ 776 $ 108,130 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,852,896 312,769 3,165,665 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,960,250 $ 313,545 $ 3,273,795 $ 2,959,504 $ 295,664 $ 3,255,168 (1) Includes acquired credit-impaired loans.

Investments in Securities (Tabl

Investments in Securities (Tables)	6 Months Ended
	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Investments In Trading Securities [Table Text Block]	The following table displays our investments in trading securities. As of June 30, 2019 December 31, 2018 (Dollars in millions) Mortgage-related securities: Fannie Mae (1) $ 3,151 $ 1,467 Other agency (2) 3,629 3,503 Private-label and other mortgage securities 736 1,306 Total mortgage-related securities (includes $983 and $32, respectively, related to consolidated trusts) 7,516 6,276 Non-mortgage-related securities: U.S. Treasury securities 35,266 35,502 Other securities 84 89 Total non-mortgage-related securities 35,350 35,591 Total trading securities $ 42,866 $ 41,867 (1) In connection with the implementation of the Single Security Initiative in the second quarter of 2019, we recognized $1.4 billion in mortgage-related securities that had previously been consolidated. (2) 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. For the Three Months Ended June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Net trading gains $ 183 $ 21 $ 275 $ 119 Net trading gains recognized in the period related to securities still held at period end 147 1 227 48
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 June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Gross realized gains $ 110 $ — $ 171 $ 363 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 245 6 376 641
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	The following tables display the amortized cost, gross unrealized gains and losses, and fair value by major security type for AFS securities. As of June 30, 2019 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,536 $ 90 $ (11 ) $ 1,615 Other agency 209 19 — 228 Alt-A and subprime private-label securities 109 111 — 220 Mortgage revenue bonds 356 11 (3 ) 364 Other mortgage-related securities 329 5 — 334 Total $ 2,539 $ 236 $ (14 ) $ 2,761 As of December 31, 2018 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,754 $ 69 $ (26 ) $ 1,797 Other agency 239 17 — 256 Alt-A and subprime private-label securities 325 267 — 592 Mortgage revenue bonds 425 13 (4 ) 434 Other mortgage-related securities 336 14 — 350 Total $ 3,079 $ 380 $ (30 ) $ 3,429 (1) Amortized cost consists of unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, as well as net other-than-temporary impairments (“OTTI”) recognized in “ Investment gains, net ” in our condensed consolidated statements of operations and comprehensive income. (2) Represents the gross unrealized losses on securities for which we have not recognized OTTI, as well as the noncredit component of OTTI and cumulative changes in fair value of securities for which we previously recognized the credit component of OTTI in “ Accumulated other comprehensive income ” in our condensed consolidated balance sheets.
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. As of June 30, 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 $ — $ — $ (11 ) $ 366 Mortgage revenue bonds — — (3 ) 5 Total $ — $ — $ (14 ) $ 371 As of December 31, 2018 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 $ — $ — $ (26 ) $ 487 Mortgage revenue bonds (1 ) 24 (3 ) 19 Total $ (1 ) $ 24 $ (29 ) $ 506
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table displays net unrealized gains on AFS securities and other amounts within accumulated other comprehensive income (“AOCI”), net of tax, by major categories. As of June 30, December 31, 2019 2018 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 80 $ 52 Net unrealized gains on AFS securities for which we have recorded OTTI 95 224 Other 41 46 Accumulated other comprehensive income $ 216 $ 322
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 June 30, 2019 Total Amortized Cost Total Fair Value One Year or Less After One Year Through Five Years After Five Years Through Ten Years After Ten Years Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in millions) Fannie Mae $ 1,536 $ 1,615 $ — $ — $ 15 $ 15 $ 104 $ 115 $ 1,417 $ 1,485 Other agency 209 228 — — 22 24 25 28 162 176 Alt-A and subprime private-label securities 109 220 — — — — 1 1 108 219 Mortgage revenue bonds 356 364 2 2 24 24 43 45 287 293 Other mortgage-related securities 329 334 — — — — 26 28 303 306 Total $ 2,539 $ 2,761 $ 2 $ 2 $ 61 $ 63 $ 199 $ 217 $ 2,277 $ 2,479

Financial Guarantees (Tables)

Financial Guarantees (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 December 31, 2018 Maximum Exposure Guaranty Obligation Maximum Recovery (1) Maximum Exposure Guaranty Obligation Maximum Recovery (1) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 6,761 $ 26 $ 6,440 $ 7,278 $ 30 $ 6,811 Other guaranty arrangements (2) 13,420 140 2,645 13,847 130 2,711 Total $ 20,181 $ 166 $ 9,085 $ 21,125 $ 160 $ 9,522 (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 and financial guarantors, see “Note 13, Concentrations of Credit Risk” in our 2018 Form 10-K and “ Note 10, Concentrations of Credit Risk ” in this report. (2) Primarily consists of credit enhancements and long-term standby commitments.

Short-Term and Long-Term Debt (

Short-Term and Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 December 31, 2018 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) $ 131 2.25 % $ — — % Short-term debt of Fannie Mae $ 22,901 2.39 % $ 24,896 2.29 % (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.
Long-Term Debt [Table Text Block]	The following table displays our outstanding long-term debt. As of June 30, 2019 December 31, 2018 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2019 - 2030 $ 97,884 2.56 % 2019 - 2030 $ 103,206 2.36 % Medium-term notes (2) 2019 - 2026 51,345 1.53 2019 - 2026 61,455 1.48 Other (3) 2019 - 2038 6,621 4.80 2019 - 2038 6,683 4.62 Total senior fixed 155,850 2.31 171,344 2.13 Senior floating: Medium-term notes (2) 2020 7,773 2.50 2019 - 2020 4,174 2.36 Connecticut Avenue Securities (4) 2023 - 2031 24,210 6.12 2023 - 2031 25,641 5.97 Other (5) 2020 - 2037 398 6.37 2020 - 2037 351 10.19 Total senior floating 32,381 5.25 30,166 5.52 Subordinated debentures 2019 5,641 9.99 2019 5,617 9.64 Secured borrowings (6) 2021 - 2022 41 2.06 2021 - 2022 51 1.96 Total long-term debt of Fannie Mae (7) 193,913 3.03 207,178 2.83 Debt of consolidated trusts 2019 - 2058 3,199,765 2.90 2019 - 2058 3,159,846 3.03 Total long-term debt $ 3,393,678 2.91 % $ 3,367,024 3.02 % (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 Connecticut Avenue Securities issued prior to the implementation of our CAS REMIC structure in November 2018. See “Note 2, Consolidations and Transfers of Financial Assets” in our 2018 Form 10-K for more information about our CAS REMIC structure. (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 of $151 million and $413 million as of June 30, 2019 and December 31, 2018 , respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 As of December 31, 2018 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 $ 58,357 $ 4 $ 31,468 $ (1,327 ) $ 71,416 $ 438 $ 21,253 $ (740 ) Receive-fixed 91,919 1,096 47,254 (210 ) 88,799 1,113 58,399 (860 ) Basis 273 155 — — 250 104 624 — Foreign currency 220 30 222 (77 ) 221 22 223 (72 ) Swaptions: Pay-fixed 4,600 29 6,375 (172 ) 10,375 191 1,000 (4 ) Receive-fixed 2,125 90 5,350 (232 ) 500 20 7,375 (338 ) Futures (1) 19,537 — — — 16,631 — — — Total gross risk management derivatives 177,031 1,404 90,669 (2,018 ) 188,192 1,888 88,874 (2,014 ) Accrued interest receivable (payable) — 360 — (359 ) — 400 — (419 ) Netting adjustment (2) — (1,709 ) — 2,297 — (2,266 ) — 2,315 Total net risk management derivatives $ 177,031 $ 55 $ 90,669 $ (80 ) $ 188,192 $ 22 $ 88,874 $ (118 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 9,767 $ 54 $ 2,417 $ (2 ) $ 4,370 $ 29 $ 57 $ — Forward contracts to purchase mortgage-related securities 78,510 389 10,000 (11 ) 40,650 349 1,045 (3 ) Forward contracts to sell mortgage-related securities 10,230 12 131,017 (675 ) 292 1 70,593 (645 ) Total mortgage commitment derivatives 98,507 455 143,434 (688 ) 45,312 379 71,695 (648 ) Credit enhancement derivatives 31,809 51 4,647 (31 ) 33,431 57 919 (11 ) Derivatives at fair value $ 307,347 $ 561 $ 238,750 $ (799 ) $ 266,935 $ 458 $ 161,488 $ (777 ) (1) Futures have no ascribable fair value because the positions are settled daily. (2) The netting adjustment represents the effect of the legal right to offset under legally enforceable master netting arrangements to settle with the same counterparty on a net basis, including cash collateral posted and received. Cash collateral posted was $1.2 billion and $713 million as of June 30, 2019 and December 31, 2018 , respectively. Cash collateral received was $573 million and $664 million as of June 30, 2019 and December 31, 2018 , respectively.
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 June 30, For the Six Months Ended June 30, 2019 2018 2019 2018 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (2,164 ) $ 967 $ (3,499 ) $ 3,750 Receive-fixed 1,884 (597 ) 3,165 (2,984 ) Basis 27 (3 ) 51 (26 ) Foreign currency (17 ) (41 ) 2 (25 ) Swaptions: Pay-fixed (143 ) 36 (320 ) 165 Receive-fixed 93 (22 ) 100 (38 ) Futures 195 (11 ) 254 (3 ) Net accrual of periodic settlements (242 ) (286 ) (508 ) (501 ) Total risk management derivatives fair value gains (losses), net (367 ) 43 (755 ) 338 Mortgage commitment derivatives fair value gains (losses), net (469 ) (76 ) (769 ) 488 Credit enhancement derivatives fair value losses, net (17 ) (5 ) (24 ) (1 ) Total derivatives fair value gains (losses), net $ (853 ) $ (38 ) $ (1,548 ) $ 825

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment results [Table Text Block]	The following table displays our segment results. For the Three Months Ended June 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 4,419 $ 731 $ 5,150 $ 4,723 $ 654 $ 5,377 Fee and other income (2) 88 158 246 69 170 239 Net revenues 4,507 889 5,396 4,792 824 5,616 Investment gains, net (3) 417 44 461 252 25 277 Fair value gains (losses), net (4) (758 ) 4 (754 ) 278 (49 ) 229 Administrative expenses (634 ) (110 ) (744 ) (649 ) (106 ) (755 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,252 (27 ) 1,225 1,295 1 1,296 Foreclosed property expense (126 ) (2 ) (128 ) (136 ) (3 ) (139 ) Total credit-related income (expense) 1,126 (29 ) 1,097 1,159 (2 ) 1,157 TCCA fees (6) (600 ) — (600 ) (565 ) — (565 ) Other expenses, net (418 ) (117 ) (535 ) (270 ) (96 ) (366 ) Income before federal income taxes 3,640 681 4,321 4,997 596 5,593 Provision for federal income taxes (769 ) (120 ) (889 ) (1,044 ) (92 ) (1,136 ) Net income $ 2,871 $ 561 $ 3,432 $ 3,953 $ 504 $ 4,457 For the Six Months Ended June 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 8,458 $ 1,425 $ 9,883 $ 9,284 $ 1,325 $ 10,609 Fee and other income (2) 194 279 473 227 332 559 Net revenues 8,652 1,704 10,356 9,511 1,657 11,168 Investment gains, net (3) 511 83 594 494 33 527 Fair value gains (losses), net (4) (1,645 ) 60 (1,585 ) 1,312 (38 ) 1,274 Administrative expenses (1,265 ) (223 ) (1,488 ) (1,292 ) (213 ) (1,505 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,913 (38 ) 1,875 1,491 22 1,513 Foreclosed property income (expense) (269 ) 1 (268 ) (298 ) (3 ) (301 ) Total credit-related income (expense) 1,644 (37 ) 1,607 1,193 19 1,212 TCCA fees (6) (1,193 ) — (1,193 ) (1,122 ) — (1,122 ) Other expenses, net (755 ) (188 ) (943 ) (402 ) (167 ) (569 ) Income before federal income taxes 5,949 1,399 7,348 9,694 1,291 10,985 Provision for federal income taxes (1,253 ) (263 ) (1,516 ) (2,060 ) (207 ) (2,267 ) Net income $ 4,696 $ 1,136 $ 5,832 $ 7,634 $ 1,084 $ 8,718 (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, and income resulting from settlement agreements resolving certain claims relating to private-label securities we purchased or that we have guaranteed. Multifamily fee and other income consists of fees associated with Multifamily business activities, including yield maintenance income. (3) Investment gains and losses primarily consist of gains and losses on the sale of mortgage assets for the respective business segment. (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 and other financial instruments associated with our single-family guaranty book of business. Multifamily fair value gains and losses primarily consist of fair value gains and losses on MBS commitment derivatives, trading securities and other financial instruments associated with our multifamily guaranty book of business. (5) Credit-related income or expense is based on the guaranty book of business of the respective business segment and consists of the applicable segment’s benefit or provision for credit losses and foreclosed property income or expense on loans underlying the segment’s guaranty book of business. (6) Consists of the portion of our single-family guaranty fees that is remitted to Treasury pursuant to the TCCA.

Concentrations of Credit Risk (

Concentrations of Credit Risk (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 (1) December 31, 2018 (1) 30 Days Delinquent 60 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent 60 Days Delinquent Seriously Delinquent (2) Percentage of single-family conventional guaranty book of business (3) 1.27 % 0.30 % 0.64 % 1.17 % 0.32 % 0.69 % Percentage of single-family conventional loans (4) 1.47 0.35 0.70 1.37 0.38 0.76
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of June 30, 2019 (1) December 31, 2018 (1) Percentage of Single-Family Conventional Guaranty Book of Business (3) Seriously Delinquent Rate (2) Percentage of Single-Family Conventional Guaranty Book of Business (3) Seriously Delinquent Rate (2) Estimated mark-to-market LTV ratio: Greater than 100% * 10.63 % * 9.85 % Geographical distribution: California 19 0.33 19 0.34 Florida 6 0.94 6 1.16 New Jersey 4 1.28 4 1.38 New York 5 1.32 5 1.40 All other states 66 0.69 66 0.75 Product distribution: Alt-A 2 3.25 2 3.35 Vintages: 2004 and prior 3 2.61 3 2.69 2005-2008 4 4.45 5 4.61 2009-2019 93 0.32 92 0.34 * Represents less than 0.5% of single-family conventional business volume or book of business. (1) Consists of the portion of our single-family conventional guaranty book of business for which we have detailed loan-level information, which constituted approximately 99% of our single-family conventional guaranty book of business as of June 30, 2019 and December 31, 2018 . (2) Consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of June 30, 2019 or December 31, 2018 . (3) Calculated based on the aggregate unpaid principal balance of single-family conventional loans for each category divided by the aggregate unpaid principal balance of loans in our single-family conventional guaranty book of business. (4) Calculated based on the number of single-family conventional loans that were delinquent divided by the total number of loans in our 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 guaranty book of business. As of June 30, 2019 December 31, 2018 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 $ 158,191 $ 152,379 Pool mortgage insurance 391 409 Total mortgage insurance risk in force $ 158,582 5% $ 152,788 5%
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 guaranty book of business. Percentage of Risk in Force Coverage by Mortgage Insurer As of June 30, 2019 December 31, 2018 Counterparty: (1) Arch Capital Group Ltd. 24 % 25 % Radian Guaranty, Inc. 20 21 Mortgage Guaranty Insurance Corp. 18 18 Genworth Mortgage Insurance Corp. (2) 15 15 Essent Guaranty, Inc. 13 12 Others 10 9 Total 100 % 100 % (1) Insurance coverage amounts provided for each counterparty may include coverage provided by affiliates and subsidiaries of the counterparty. (2)
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, 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 June 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 18 % 18 % Remaining top five depository servicers 15 16 Top five non-depository servicers 25 22 Total 58 % 56 %
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 June 30, 2019 (1) December 31, 2018 (1) 30 Days Delinquent Seriously Delinquent (2) 30 Days Delinquent Seriously Delinquent (2) Percentage of multifamily guaranty book of business 0.04 % 0.05 % 0.02 % 0.06 %
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of June 30, 2019 December 31, 2018 Percentage of Multifamily Guaranty Book of Business (1) Percentage Seriously Delinquent (2)(3) Percentage of Multifamily Guaranty Book of Business (1) Percentage Seriously Delinquent (2)(3) Original LTV ratio: Greater than 80% 1 % — % 1 % — % Less than or equal to 80% 99 0.05 99 0.06 Current DSCR below 1.0 (4) 2 1.11 2 1.38 (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.
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 June 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 13 % 14 % Walker & Dunlop, Inc. 12 12 Remaining top five servicers 23 22 Total 48 % 48 %

Netting Arrangements (Tables)

Netting Arrangements (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 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 $ 1,764 $ (1,716 ) $ 48 $ — $ — $ 48 Cleared risk management derivatives — 7 7 — — 7 Mortgage commitment derivatives 455 — 455 (159 ) (22 ) 274 Total derivative assets 2,219 (1,709 ) 510 (4) (159 ) (22 ) 329 Securities purchased under agreements to resell or similar arrangements (5) 40,362 — 40,362 — (40,362 ) — Total assets $ 42,581 $ (1,709 ) $ 40,872 $ (159 ) $ (40,384 ) $ 329 Liabilities: OTC risk management derivatives $ (2,377 ) $ 2,301 $ (76 ) $ — $ — $ (76 ) Cleared risk management derivatives — (4 ) (4 ) — 2 (2 ) Mortgage commitment derivatives (688 ) — (688 ) 159 510 (19 ) Total derivative liabilities (3,065 ) 2,297 (768 ) (4) 159 512 (97 ) Securities sold under agreements to repurchase or similar arrangements (131 ) — (131 ) — 130 (1 ) Total liabilities $ (3,196 ) $ 2,297 $ (899 ) $ 159 $ 642 $ (98 ) As of December 31, 2018 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 $ 2,288 $ (2,273 ) $ 15 $ — $ — $ 15 Cleared risk management derivatives — 7 7 — — 7 Mortgage commitment derivatives 379 — 379 (153 ) (7 ) 219 Total derivative assets 2,667 (2,266 ) 401 (4) (153 ) (7 ) 241 Securities purchased under agreements to resell or similar arrangements (5) 48,288 — 48,288 — (48,288 ) — Total assets $ 50,955 $ (2,266 ) $ 48,689 $ (153 ) $ (48,295 ) $ 241 Liabilities: OTC risk management derivatives $ (2,433 ) $ 2,342 $ (91 ) $ — $ — $ (91 ) Cleared risk management derivatives — (27 ) (27 ) — 23 (4 ) Mortgage commitment derivatives (648 ) — (648 ) 153 466 (29 ) Total derivative liabilities (3,081 ) 2,315 (766 ) (4) 153 489 (124 ) Total liabilities $ (3,081 ) $ 2,315 $ (766 ) $ 153 $ 489 $ (124 ) (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 is 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. The fair value of non-cash collateral we pledged was $1.6 billion and $1.9 billion as of June 30, 2019 and December 31, 2018 , respectively, which the counterparty was permitted to sell or repledge. The fair value of non-cash collateral received was $40.4 billion and $48.4 billion , of which $37.9 billion and $45.7 billion could be sold or repledged as of June 30, 2019 and December 31, 2018 , respectively. None of the underlying collateral was sold or repledged as of June 30, 2019 or December 31, 2018 . (4) Excludes derivative assets of $51 million and $57 million as of June 30, 2019 and December 31, 2018 , respectively, and derivative liabilities of $31 million and $11 million recognized in our condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $20.8 billion and $15.4 billion in securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , respectively.

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ — $ — $ — $ — $ — Trading securities: Mortgage-related securities: Fannie Mae — 3,077 74 — 3,151 Other agency — 3,629 — — 3,629 Private-label and other mortgage securities — 736 — — 736 Non-mortgage-related securities: U.S. Treasury securities 35,266 — — — 35,266 Other securities — 84 — — 84 Total trading securities 35,266 7,526 74 — 42,866 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,483 132 — 1,615 Other agency — 228 — — 228 Alt-A and subprime private-label securities — 220 — — 220 Mortgage revenue bonds — — 364 — 364 Other — 8 326 — 334 Total available-for-sale securities — 1,939 822 — 2,761 Mortgage loans — 7,709 770 — 8,479 Other assets: Risk management derivatives: Swaps — 1,480 165 — 1,645 Swaptions — 119 — — 119 Netting adjustment — — — (1,709 ) (1,709 ) Mortgage commitment derivatives — 455 — — 455 Credit enhancement derivatives — — 51 — 51 Total other assets — 2,054 216 (1,709 ) 561 Total assets at fair value $ 35,266 $ 19,228 $ 1,882 $ (1,709 ) $ 54,667 Fair Value Measurements as of June 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 5,972 $ 398 $ — $ 6,370 Total of Fannie Mae — 5,972 398 — 6,370 Of consolidated trusts — 22,669 102 — 22,771 Total long-term debt — 28,641 500 — 29,141 Other liabilities: Risk management derivatives: Swaps — 1,971 2 — 1,973 Swaptions — 404 — — 404 Netting adjustment — — — (2,297 ) (2,297 ) Mortgage commitment derivatives — 688 — — 688 Credit enhancement derivatives — — 31 — 31 Total other liabilities — 3,063 33 (2,297 ) 799 Total liabilities at fair value $ — $ 31,704 $ 533 $ (2,297 ) $ 29,940 Fair Value Measurements as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Recurring fair value measurements: Assets: Cash equivalents (2) $ 748 $ — $ — $ — $ 748 Trading securities: Mortgage-related securities: Fannie Mae — 1,435 32 — 1,467 Other agency — 3,503 — — 3,503 Private-label and other mortgage securities — 1,305 1 — 1,306 Non-mortgage-related securities: U.S. Treasury securities 35,502 — — — 35,502 Other Securities — 89 — — 89 Total trading securities 35,502 6,332 33 — 41,867 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,645 152 — 1,797 Other agency — 256 — — 256 Alt-A and subprime private-label securities — 568 24 — 592 Mortgage revenue bonds — — 434 — 434 Other — 8 342 — 350 Total available-for-sale securities — 2,477 952 — 3,429 Mortgage loans — 7,985 937 — 8,922 Other assets: Risk management derivatives: Swaps — 1,962 115 — 2,077 Swaptions — 211 — — 211 Netting adjustment — — — (2,266 ) (2,266 ) Mortgage commitment derivatives — 342 37 — 379 Credit enhancement derivatives — — 57 — 57 Total other assets — 2,515 209 (2,266 ) 458 Total assets at fair value $ 36,250 $ 19,309 $ 2,131 $ (2,266 ) $ 55,424 Fair Value Measurements as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustment (1) Estimated Fair Value (Dollars in millions) Liabilities: Long-term debt: Of Fannie Mae: Senior floating $ — $ 6,475 $ 351 $ — $ 6,826 Total of Fannie Mae — 6,475 351 — 6,826 Of consolidated trusts — 23,552 201 — 23,753 Total long-term debt — 30,027 552 — 30,579 Other liabilities: Risk management derivatives: Swaps — 2,089 2 — 2,091 Swaptions — 342 — — 342 Netting adjustment — — — (2,315 ) (2,315 ) Mortgage commitment derivatives — 646 2 — 648 Credit enhancement derivatives — — 11 — 11 Total other liabilities — 3,077 15 (2,315 ) 777 Total liabilities at fair value $ — $ 33,104 $ 567 $ (2,315 ) $ 31,356 (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 June 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2019 (1) Balance, March 31, 2019 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 67 $ 1 $ — $ — $ (14 ) $ — $ (16 ) $ — $ 36 $ 74 $ 2 $ — Total trading securities $ 67 $ 1 (5)(6) $ — $ — $ (14 ) $ — $ (16 ) $ — $ 36 $ 74 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 199 $ — $ 2 $ — $ — $ — $ (7 ) $ (62 ) $ — $ 132 $ — $ 3 Alt-A and subprime private-label securities 23 5 (5 ) — (23 ) — — — — — — — Mortgage revenue bonds 425 — (1 ) — (4 ) — (56 ) — — 364 — — Other 337 5 (5 ) — — — (9 ) (2 ) — 326 — (3 ) Total available-for-sale securities $ 984 $ 10 (6)(7) $ (9 ) $ — $ (27 ) $ — $ (72 ) $ (64 ) $ — $ 822 $ — $ — Mortgage loans $ 934 $ 17 (5)(6) $ — $ — $ (13 ) $ — $ (36 ) $ (159 ) $ 27 $ 770 $ 14 $ — Net derivatives 203 20 (5) — — — — (31 ) (9 ) — 183 18 — Long-term debt: Of Fannie Mae: Senior floating (376 ) (22 ) — — — — — — — (398 ) (22 ) — Of consolidated trusts (224 ) (1 ) — — — — 5 120 (2 ) (102 ) (1 ) — Total long-term debt $ (600 ) $ (23 ) (5) $ — $ — $ — $ — $ 5 $ 120 $ (2 ) $ (500 ) $ (23 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 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 Level 3 Balance, June 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 3 $ — $ — $ (14 ) $ — $ (16 ) $ — $ 69 $ 74 $ 3 $ — Private-label and other mortgage securities 1 — — — — — (1 ) — — — — — Total trading securities $ 33 $ 3 (5)(6) $ — $ — $ (14 ) $ — $ (17 ) $ — $ 69 $ 74 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 6 $ — $ — $ — $ (7 ) $ (103 ) $ 84 $ 132 $ — $ 5 Alt-A and subprime private-label securities 24 5 (5 ) — (23 ) — (1 ) — — — — — Mortgage revenue bonds 434 — (1 ) — (4 ) — (65 ) — — 364 — (1 ) Other 342 12 (10 ) — — — (17 ) (2 ) 1 326 — (7 ) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (10 ) $ — $ (27 ) $ — $ (90 ) $ (105 ) $ 85 $ 822 $ — $ (3 ) Mortgage loans $ 937 $ 31 (5)(6) $ — $ — $ (13 ) $ — $ (70 ) $ (187 ) $ 72 $ 770 $ 22 $ — Net derivatives 194 118 (5) — — — — (120 ) (9 ) — 183 24 — Long-term debt: Of Fannie Mae: Senior floating (351 ) (47 ) — — — — — — — (398 ) (47 ) — Of consolidated trusts (201 ) (4 ) — — — — 10 169 (76 ) (102 ) (2 ) — Total long-term debt $ (552 ) $ (51 ) (5) $ — $ — $ — $ — $ 10 $ 169 $ (76 ) $ (500 ) $ (49 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2018 (1) Balance, March 31, 2018 Included in Net Income Included in Total OCI (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 83 $ (5 ) $ — $ — $ — $ — $ — $ — $ 1 $ 79 $ 3 $ — Private-label and other mortgage securities 1 — — — — — — — — 1 — — Total trading securities $ 84 $ (5 ) (5)(6) $ — $ — $ — $ — $ — $ — $ 1 $ 80 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 202 $ 1 $ 4 $ — $ — $ — $ (3 ) $ — $ — $ 204 $ — $ 3 Alt-A and subprime private-label securities 27 — — — — — (1 ) — — 26 — — Mortgage revenue bonds 539 (11 ) 10 — (7 ) — (25 ) — — 506 — 8 Other 351 7 10 — — — (11 ) — — 357 — 8 Total available-for-sale securities $ 1,119 $ (3 ) (6)(7) $ 24 $ — $ (7 ) $ — $ (40 ) $ — $ — $ 1,093 $ — $ 19 Mortgage loans $ 1,102 $ 11 (5)(6) $ — $ — $ — $ — $ (79 ) $ (51 ) $ 35 $ 1,018 $ 8 $ — Net derivatives 133 (28 ) (5) — — — — 12 — — 117 (14 ) — Long-term debt: Of Fannie Mae: Senior floating (357 ) 3 — — — — — — — (354 ) 3 — Of consolidated trusts (462 ) 4 — — — — 21 177 (59 ) (319 ) (1 ) — Total long-term debt $ (819 ) $ 7 (5) $ — $ — $ — $ — $ 21 $ 177 $ (59 ) $ (673 ) $ 2 $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of June 30, 2018 (1) Balance, December 31, 2017 Included in Net Income Included in Total OCI (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, June 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 971 $ 166 $ — $ 1 $ (1,060 ) $ — $ — $ — $ 1 $ 79 $ 3 $ — Other agency 35 (1 ) — — — — (1 ) (33 ) — — — — Private-label and other mortgage securities 195 (85 ) — — — — (5 ) (104 ) — 1 — — Total trading securities $ 1,201 $ 80 (5)(6) $ — $ 1 $ (1,060 ) $ — $ (6 ) $ (137 ) $ 1 $ 80 $ 3 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 208 $ 1 $ — $ — $ — $ — $ (5 ) $ — $ — $ 204 $ — $ — Alt-A and subprime private-label securities 77 — (45 ) — — — (2 ) (4 ) — 26 — 1 Mortgage revenue bonds 671 — (3 ) — (18 ) — (144 ) — — 506 — — Other 357 14 8 — — — (22 ) — — 357 — 8 Total available-for-sale securities $ 1,313 $ 15 (6)(7) $ (40 ) $ — $ (18 ) $ — $ (173 ) $ (4 ) $ — $ 1,093 $ — $ 9 Mortgage loans $ 1,116 $ 28 (5)(6) $ — $ — $ — $ — $ (127 ) $ (87 ) $ 88 $ 1,018 $ 16 $ — Net derivatives 134 (86 ) (5) — — — — 16 53 — 117 (37 ) — Long-term debt: Of Fannie Mae: Senior floating (376 ) 22 — — — — — — — (354 ) 22 — Of consolidated trusts (582 ) 7 — — — 1 31 331 (107 ) (319 ) (1 ) — Total long-term debt $ (958 ) $ 29 (5) $ — $ — $ — $ 1 $ 31 $ 331 $ (107 ) $ (673 ) $ 21 $ — (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on AFS 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. For the first half of 2018 , includes the dissolution of a Fannie Mae-wrapped private-label securities trust. (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 OTTI are not considered unrealized and are not included in this amount. (5) Gains (losses) are included in “ Fair value gains (losses), net ” in our condensed consolidated statements of operations and comprehensive income. (6) Gains (losses) are included in “ Net interest income ” in our condensed consolidated statements of operations and comprehensive income. (7) Gains (losses) are included in “ Investment gains, 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 June 30, 2019 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Agency (2) $ 74 Various Available-for-sale securities: Mortgage-related securities: Agency (2) $ 106 Consensus 26 Various Total agency 132 Mortgage revenue bonds 250 Single Vendor Spreads(bps) 16.5 - 193.3 66.1 114 Various Total mortgage revenue bonds 364 Other 283 Discounted Cash Flow Default Rate(%) 5.5 5.5 Prepayment Speed(%) 5.5 5.5 Severity(%) 95.0 95.0 Spreads(bps) 59.3 - 294.0 292.4 43 Various Total other 326 Total available-for-sale securities $ 822 Net derivatives $ 163 Dealer Mark 20 Various Total net derivatives $ 183 Fair Value Measurements as of December 31, 2018 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 (2) $ 32 Various Private-label securities and other mortgage securities 1 Various Total trading securities $ 33 Available-for-sale securities: Mortgage-related securities: Agency (2) $ 152 Various Alt-A and subprime private-label securities 24 Various Mortgage revenue bonds 349 Single Vendor Spreads(bps) (0.5 ) - 332.8 59.0 85 Various Total mortgage revenue bonds 434 Other 294 Discounted Cash Flow Default Rate(%) 4.7 4.7 Prepayment Speed(%) 8.2 8.2 Severity(%) 70.0 70.0 Spreads(bps) 75.4 - 390.0 389.1 48 Various Total other 342 Total available-for-sale securities $ 952 Net derivatives $ 113 Dealers Mark 81 Various Total net derivatives $ 194 (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.
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 June 30, 2019 December 31, 2018 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,772 $ 631 Single Vendor 1,448 1,119 Total mortgage loans held for sale, at lower of cost or fair value 3,220 1,750 Single-family mortgage loans held for investment, at amortized cost Internal Model 571 818 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate 218 102 Various 13 40 Total multifamily mortgage loans held for investment, at amortized cost 231 142 Acquired property, net: (1) Single-family Accepted Offers 118 151 Appraisals 337 419 Walk Forwards 198 181 Internal Model 150 219 Various 33 41 Total single-family 836 1,011 Multifamily Various — 50 Total nonrecurring assets at fair value $ 4,858 $ 3,771 (1) The most commonly used techniques in our valuation of acquired property are proprietary home price model and third-party valuations (both current and walk forward). Based on the number of properties measured as of June 30, 2019 and December 31, 2018 , these methodologies comprised approximately 82% of our valuations, while accepted offers comprised approximately 15% of our valuations.
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 June 30, 2019 Carrying Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment Estimated (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 60,970 $ 40,170 $ 20,800 $ — $ — $ 60,970 Federal funds sold and securities purchased under agreements to resell or similar arrangements 19,562 — 19,562 — — 19,562 Trading securities 42,866 35,266 7,526 74 — 42,866 Available-for-sale securities 2,761 — 1,939 822 — 2,761 Mortgage loans held for sale 11,220 — 826 11,112 — 11,938 Mortgage loans held for investment, net of allowance for loan losses 3,262,012 — 3,175,207 142,889 — 3,318,096 Advances to lenders 5,395 — 5,393 2 — 5,395 Derivative assets at fair value 561 — 2,054 216 (1,709 ) 561 Guaranty assets and buy-ups 152 — — 352 — 352 Total financial assets $ 3,405,499 $ 75,436 $ 3,233,307 $ 155,467 $ (1,709 ) $ 3,462,501 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 131 $ — $ 131 $ — $ — $ 131 Short-term debt: Of Fannie Mae 22,901 — 22,907 — — 22,907 Long-term debt: Of Fannie Mae 193,913 — 201,775 826 — 202,601 Of consolidated trusts 3,199,765 — 3,195,793 36,368 — 3,232,161 Derivative liabilities at fair value 799 — 3,063 33 (2,297 ) 799 Guaranty obligations 166 — — 109 — 109 Total financial liabilities $ 3,417,675 $ — $ 3,423,669 $ 37,336 $ (2,297 ) $ 3,458,708 As of December 31, 2018 Carrying Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Netting Adjustment Estimated (Dollars in millions) Financial assets: Cash and cash equivalents and restricted cash $ 49,423 $ 34,073 $ 15,350 $ — $ — $ 49,423 Federal funds sold and securities purchased under agreements to resell or similar arrangements 32,938 — 32,938 — — 32,938 Trading securities 41,867 35,502 6,332 33 — 41,867 Available-for-sale securities 3,429 — 2,477 952 — 3,429 Mortgage loans held for sale 7,701 — 238 7,856 — 8,094 Mortgage loans held for investment, net of allowance for loan losses 3,241,694 — 2,990,104 216,404 — 3,206,508 Advances to lenders 3,356 — 3,354 2 — 3,356 Derivative assets at fair value 458 — 2,515 209 (2,266 ) 458 Guaranty assets and buy-ups 147 — — 356 — 356 Total financial assets $ 3,381,013 $ 69,575 $ 3,053,308 $ 225,812 $ (2,266 ) $ 3,346,429 Financial liabilities: Short-term debt: Of Fannie Mae $ 24,896 $ — $ 24,901 $ — $ — $ 24,901 Long-term debt: Of Fannie Mae 207,178 — 211,403 771 — 212,174 Of consolidated trusts 3,159,846 — 3,064,239 39,043 — 3,103,282 Derivative liabilities at fair value 777 — 3,077 15 (2,315 ) 777 Guaranty obligations 160 — — 121 — 121 Total financial liabilities $ 3,392,857 $ — $ 3,303,620 $ 39,950 $ (2,315 ) $ 3,341,255
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 June 30, 2019 December 31, 2018 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 $ 8,479 $ 6,370 $ 22,771 $ 8,922 $ 6,826 $ 23,753 Unpaid principal balance 8,221 5,835 20,687 8,832 6,241 22,080 (1) Includes nonaccrual loans with a fair value of $141 million and $161 million as of June 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of June 30, 2019 and December 31, 2018 was $13 million and $19 million , respectively. Includes loans that are 90 days or more past due with a fair value of $87 million and $102 million as of June 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these 90 or more days past due loans as of June 30, 2019 and December 31, 2018 was $10 million and $14 million , respectively.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Deficit of core capital over statutory minimum capital requirement	$ (137,000)	$ (137,100)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2020	Mar. 31, 2019	Dec. 31, 2018
Related Parties [Line Items]
Deficit Of Core Capital Over Statutory Minimum Capital Requirement		$ (137,000,000,000)	$ (137,000,000,000)		$ (137,000,000,000)				$ (137,100,000,000)
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement		119,800,000,000	119,800,000,000		119,800,000,000
Net worth		6,365,000,000	6,365,000,000		6,365,000,000			$ 5,400,000,000	6,240,000,000
Payments of cash dividends on senior preferred stock to Treasury		$ 2,400,000,000	2,361,000,000	$ 938,000,000	5,601,000,000	$ 938,000,000
Income Taxes Paid			0		$ 700,000,000	$ 460,000,000
Weighted Average Number of Shares, Contingently Issuable					4,600,000,000	4,600,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			$ 600,000,000	565,000,000	$ 1,193,000,000	$ 1,122,000,000
Basis Points of Each Dollar of Unpaid Principal Balance		0.042%	0.042%		0.042%
Trading, at fair value (includes $2,775 and $3,061, respectively, pledged as collateral)		$ 42,866,000,000	$ 42,866,000,000		$ 42,866,000,000				41,867,000,000
Interest Receivable		9,089,000,000	9,089,000,000		9,089,000,000				$ 8,490,000,000
Interest income recognized on Treasury securities			432,000,000	318,000,000	$ 859,000,000	$ 554,000,000
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock					131,000,000	131,000,000
Affordable Housing Program Obligation		0.35	0.35		$ 0.35
Scenario, Forecast [Member]
Related Parties [Line Items]
Cumulative Effect Of New Accounting Principle In Period Of Adoption							$ 4,000,000,000
Payments of cash dividends on senior preferred stock to Treasury	$ 3,400,000,000
US Treasury [Member]
Related Parties [Line Items]
Total available funding from US Treasury pursuant to the senior preferred stock agreement		113,900,000,000	113,900,000,000		113,900,000,000
Capital Reserve Amount, current year, Senior Preferred Stock Purchase Agreement, Amendment		3,000,000,000	3,000,000,000		3,000,000,000
Aggregate liquidation preference of senior preferred stock		$ 123,800,000,000	$ 123,800,000,000		$ 123,800,000,000
Percentage of common shares attributable to warrants issued to US Treasury as percentage to total diluted common shares		79.90%	79.90%		79.90%
Home Affordable Modification Program administrative expense reimbursements from Treasury and Freddie Mac			$ 5,000,000	6,000,000	$ 10,000,000	$ 13,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			600,000,000	565,000,000	1,193,000,000	1,122,000,000
Affordable Housing Program Obligation		$ 75,000,000	75,000,000		75,000,000
US Treasury [Member] | Single-family [Member]
Related Parties [Line Items]
Recognized TCCA fees that had not been remitted to Treasury as of period end		600,000,000	600,000,000		600,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees			29,000,000	26,000,000	59,000,000	55,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments			26,000,000	35,000,000	62,000,000	76,000,000
Other Expense [Member] | US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments		$ 75,000,000	$ 21,000,000	$ 19,000,000	$ 36,000,000	$ 37,000,000

Consolidations and Transfers _4

Consolidations and Transfers of Financial Assets Unconsolidated VIEs (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entities [Line Items]
Trading, at fair value	$ 42,866	$ 41,867
Available-for-sale, at fair value	2,761	3,429
Other assets	19,888	17,004
Other liabilities	$ (10,001)	(9,947)
Document Period End Date	Jun. 30, 2019
Unpaid principal balance of mortgage loans	$ 3,243,452	3,223,783
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement	1,100	1,200
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	310,899	293,858
Unconsolidated VIEs [Member] | Multifamily [Member]
Variable Interest Entities [Line Items]
Total unconsolidated assets	4,700	931
Unpaid principal balance of mortgage loans	310,900
Unconsolidated VIEs [Member] | Mortgage-related securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	6,525	6,231
Available-for-sale, at fair value	2,406	2,911
Other assets	60	66
Other liabilities	(90)	(101)
Net carrying amount	8,901	9,107
Maximum exposure to loss	20,000	14,000
Total unconsolidated assets	110,000	80,000
Unconsolidated VIEs [Member] | Partnership interest [Member]
Variable Interest Entities [Line Items]
Net carrying amount	75	89
Maximum exposure to loss	96	111
Total unconsolidated assets	2,100	2,300
Unconsolidated VIEs [Member] | Debt Securities [Member]
Variable Interest Entities [Line Items]
Maximum exposure to loss	4,600	920
Unconsolidated VIEs [Member] | Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	2,173	1,422
Available-for-sale, at fair value	1,615	1,704
Unconsolidated VIEs [Member] | Non-Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	4,352	4,809
Available-for-sale, at fair value	$ 791	$ 1,207

Consolidations and Transfers _5

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Transfers of Financial Assets [Line Items]
Document Period End Date			Jun. 30, 2019
Portfolio securitizations: unpaid principal balance	$ 57,300	$ 51,600	$ 98,700	$ 115,900
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	122	$ 128	238	$ 354
Unconsolidated VIEs [Member] | Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	2,700		2,700		$ 1,500
Retained interests: fair value	$ 3,700		$ 3,700		$ 2,200

Consolidations and Transfers _6

Consolidations and Transfers of Financial Assets Managed Loans (Details) - USD ($) $ in Billions	Jun. 30, 2019	Dec. 31, 2018
Consolidations and Transfers of Financial Assets [Abstract]
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement	$ 1.1	$ 1.2

Mortgage Loans Loans in Mortgag

Mortgage Loans Loans in Mortgage Portfolio (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,243,452		$ 3,243,452			$ 3,223,783
Cost basis and fair value adjustments, net	41,262		41,262			39,815
Allowance for loan losses for loans held for investment	(11,482)	$ (16,812)	(11,482)	$ (16,812)	$ (13,232)	(14,203)	$ (18,734)	$ (19,084)
Total mortgage loans	3,273,232		3,273,232			3,249,395
Carrying value of loans redesignated from HFI to HFS	6,759	6,235	9,370	13,602
Carrying value of loans redesignated from HFS to HFI	3	12	12	30
Loans sold - unpaid principal balance	6,498	3,710	6,556	4,458
Realized gains on sale of mortgage loans	284	$ 210	320	$ 208
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,932,553		2,932,553			2,929,925
Mortgage Loans in Process of Foreclosure, Amount	9,000		9,000			10,100
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 310,899		$ 310,899			$ 293,858

Mortgage Loans Aging (Details)

Mortgage Loans Aging (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 60,277	$ 60,485
Current	3,213,518	3,194,683
Total recorded investment in loans	3,273,795	3,255,168
Recorded investment in loans 90 days or more delinquent and accruing interest	177	195
Recorded investment in nonaccrual loans	28,020	30,872
30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	36,061	33,720
60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	8,207	9,002
Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	16,009	17,763
Single-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	60,066	60,258
Current	2,900,184	2,899,246
Total recorded investment in loans	2,960,250	2,959,504
Recorded investment in loans 90 days or more delinquent and accruing interest	177	195
Recorded investment in nonaccrual loans	27,507	30,380
Table Footnote [Abstract]
Mortgage Loans in Process of Foreclosure, Amount	$ 9,000	$ 10,100
Single-family [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days	90 days
Single-family [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 36,037	$ 33,664
Single-family [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	8,207	9,002
Single-family [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	15,822	17,592
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	53,885	53,218
Current	2,827,424	2,816,047
Total recorded investment in loans	2,881,309	2,869,265
Recorded investment in loans 90 days or more delinquent and accruing interest	22	22
Recorded investment in nonaccrual loans	24,035	26,170
Single-family [Member] | Primary [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	33,030	30,471
Single-family [Member] | Primary [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	7,308	7,881
Single-family [Member] | Primary [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	13,547	14,866
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	216	243
Current	18,691	21,887
Total recorded investment in loans	18,907	22,130
Recorded investment in loans 90 days or more delinquent and accruing interest	152	169
Recorded investment in nonaccrual loans	0	0
Single-family [Member] | Government [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	46	57
Single-family [Member] | Government [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	18	17
Single-family [Member] | Government [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	152	169
Single-family [Member] | Alt-A
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	4,406	4,997
Current	43,083	48,274
Total recorded investment in loans	47,489	53,271
Recorded investment in loans 90 days or more delinquent and accruing interest	1	2
Recorded investment in nonaccrual loans	2,528	3,082
Single-family [Member] | Alt-A | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	2,228	2,332
Single-family [Member] | Alt-A | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	645	821
Single-family [Member] | Alt-A | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	1,533	1,844
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	1,559	1,800
Current	10,986	13,038
Total recorded investment in loans	12,545	14,838
Recorded investment in loans 90 days or more delinquent and accruing interest	2	2
Recorded investment in nonaccrual loans	944	1,128
Single-family [Member] | Other [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	733	804
Single-family [Member] | Other [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	236	283
Single-family [Member] | Other [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	590	713
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	211	227
Current	313,334	295,437
Total recorded investment in loans	313,545	295,664
Recorded investment in loans 90 days or more delinquent and accruing interest	0	0
Recorded investment in nonaccrual loans	$ 513	$ 492
Multifamily [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	60 days	60 days
Multifamily [Member] | Maximum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	89 days	89 days
Multifamily [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 24	$ 56
Multifamily [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 187	$ 171

Mortgage Loans Credit Quality I

Mortgage Loans Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,273,795	$ 3,255,168
Single-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,960,250	2,959,504
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,881,309	2,869,265
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,551,443	2,521,766
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	221,190	228,614
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	102,585	109,548
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	6,091	9,337
Single-family [Member] | Alt-A
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	47,489	53,271
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	41,960	45,476
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,819	3,804
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,383	1,997
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,327	1,994
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	12,545	14,838
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	10,773	12,291
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, Recorded Investment [Line Items]
Total recorded investment in loans	874	1,195
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, Recorded Investment [Line Items]
Total recorded investment in loans	435	645
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	463	707
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 18,907	$ 22,130

Mortgage Loans Credit Quality_2

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,273,795	$ 3,255,168
Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	313,545	295,664
Multifamily [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0.5	1
Multifamily [Member] | Non-Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	306,257	289,231
Multifamily [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 7,288	$ 6,433

Mortgage Loans Individually Imp

Mortgage Loans Individually Impaired Loans (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	$ 92,967	$ 104,310
Individually impaired loans with related allowance recorded: total recorded investment	88,981	99,481
Related allowance for loan losses	(10,627)	(13,295)
Individually impaired loans with no related allowance recorded: unpaid principal balance	20,227	19,689
Individually impaired loans with no related allowance recorded: total recorded investment	19,149	18,622
Total individually impaired loans: unpaid principal balance	113,194	123,999
Total individually impaired loans: total recorded investment	108,130	118,103
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	107,000	117,200
Individually impaired loans with related allowance recorded: unpaid principal balance	92,627	104,113
Individually impaired loans with related allowance recorded: total recorded investment	88,638	99,285
Related allowance for loan losses	(10,572)	(13,255)
Individually impaired loans with no related allowance recorded: unpaid principal balance	19,796	19,346
Individually impaired loans with no related allowance recorded: total recorded investment	18,716	18,276
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	74,143	81,791
Individually impaired loans with related allowance recorded: total recorded investment	71,549	78,688
Related allowance for loan losses	(7,615)	(9,406)
Individually impaired loans with no related allowance recorded: unpaid principal balance	16,638	15,939
Individually impaired loans with no related allowance recorded: total recorded investment	15,866	15,191
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	261	264
Individually impaired loans with related allowance recorded: total recorded investment	267	270
Related allowance for loan losses	(54)	(55)
Individually impaired loans with no related allowance recorded: unpaid principal balance	59	61
Individually impaired loans with no related allowance recorded: total recorded investment	55	56
Single-family [Member] | Alt-A
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	13,703	16,576
Individually impaired loans with related allowance recorded: total recorded investment	12,554	15,158
Related allowance for loan losses	(2,129)	(2,793)
Individually impaired loans with no related allowance recorded: unpaid principal balance	2,445	2,628
Individually impaired loans with no related allowance recorded: total recorded investment	2,193	2,363
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	4,520	5,482
Individually impaired loans with related allowance recorded: total recorded investment	4,268	5,169
Related allowance for loan losses	(774)	(1,001)
Individually impaired loans with no related allowance recorded: unpaid principal balance	654	718
Individually impaired loans with no related allowance recorded: total recorded investment	602	666
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	188	187
Individually impaired loans with related allowance recorded: unpaid principal balance	340	197
Individually impaired loans with related allowance recorded: total recorded investment	343	196
Related allowance for loan losses	(55)	(40)
Individually impaired loans with no related allowance recorded: unpaid principal balance	431	343
Individually impaired loans with no related allowance recorded: total recorded investment	$ 433	$ 346

Mortgage Loans Individually I_2

Mortgage Loans Individually Impaired Loans - 2 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	$ 92,622	$ 115,651	$ 95,166	$ 116,444
Individually impaired loans with related allowance recorded: total interest income recognized	966	1,217	1,989	2,414
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	86	131	181	259
Individually impaired loans with no related allowance recorded: average recorded investment	18,737	18,934	18,646	19,045
Individually impaired loans with no related allowance recorded: total interest income recognized	310	322	580	641
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	42	38	73	69
Individually impaired loans: average recorded investment	111,359	134,585	113,812	135,489
Individually impaired loans: total interest income recognized	1,276	1,539	2,569	3,055
Individually impaired loans: interest income recognized on a cash basis	128	169	254	328
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	92,301	115,419	94,887	116,196
Individually impaired loans with related allowance recorded: total interest income recognized	963	1,216	1,984	2,413
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	86	131	181	259
Individually impaired loans with no related allowance recorded: average recorded investment	18,340	18,579	18,266	18,705
Individually impaired loans with no related allowance recorded: total interest income recognized	304	321	572	638
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	42	38	73	69
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	74,162	88,526	75,888	88,342
Individually impaired loans with related allowance recorded: total interest income recognized	774	915	1,591	1,826
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	72	109	152	216
Individually impaired loans with no related allowance recorded: average recorded investment	15,474	14,942	15,336	14,988
Individually impaired loans with no related allowance recorded: total interest income recognized	249	243	469	486
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	36	32	64	58
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	269	279	270	278
Individually impaired loans with related allowance recorded: total interest income recognized	3	9	6	12
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Individually impaired loans with no related allowance recorded: average recorded investment	55	57	55	58
Individually impaired loans with no related allowance recorded: total interest income recognized	1	2	2	2
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Single-family [Member] | Alt-A
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	13,399	19,349	14,023	20,020
Individually impaired loans with related allowance recorded: total interest income recognized	145	219	301	431
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	11	16	22	32
Individually impaired loans with no related allowance recorded: average recorded investment	2,196	2,723	2,244	2,781
Individually impaired loans with no related allowance recorded: total interest income recognized	44	61	83	119
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	5	5	7	9
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	4,471	7,265	4,706	7,556
Individually impaired loans with related allowance recorded: total interest income recognized	41	73	86	144
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	3	6	7	11
Individually impaired loans with no related allowance recorded: average recorded investment	615	857	631	878
Individually impaired loans with no related allowance recorded: total interest income recognized	10	15	18	31
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	1	2	2
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	321	232	279	248
Individually impaired loans with related allowance recorded: total interest income recognized	3	1	5	1
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Individually impaired loans with no related allowance recorded: average recorded investment	397	355	380	340
Individually impaired loans with no related allowance recorded: total interest income recognized	6	1	8	3
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	$ 0	$ 0	$ 0	$ 0

Mortgage Loans TDRs (Details)

Mortgage Loans TDRs (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019USD ($)contracts	Jun. 30, 2018USD ($)contracts	Jun. 30, 2019USD ($)contracts	Jun. 30, 2018USD ($)contracts	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Average term extension of a single-family modified loan	160 months	128 months	158 months		133 months
Document Period End Date			Jun. 30, 2019
Average interest rate reduction of a single-family modified loan	0.10%	0.13%	0.10%		0.18%
Number of loans troubled debt restructurings activity | contracts	12,598	23,671	26,494	68,033
Recorded investment troubled debt restructurings activity | $	$ 1,972	$ 3,421	$ 4,084	$ 10,358
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	12,595	23,669	26,488	68,023
Recorded investment troubled debt restructurings activity | $	$ 1,952	$ 3,402	$ 4,051	$ 10,297
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	11,796	21,820	24,753	63,499
Recorded investment troubled debt restructurings activity | $	$ 1,844	$ 3,148	$ 3,815	$ 9,672
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	22	26	45	74
Recorded investment troubled debt restructurings activity | $	$ 2	$ 2	$ 6	$ 6
Single-family [Member] | Alt-A
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	639	1,538	1,405	3,720
Recorded investment troubled debt restructurings activity | $	$ 81	$ 200	$ 178	$ 483
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	138	285	285	730
Recorded investment troubled debt restructurings activity | $	$ 25	$ 52	$ 52	$ 136
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	3	2	6	10
Recorded investment troubled debt restructurings activity | $	$ 20	$ 19	$ 33	$ 61

Mortgage Loans TDRs with Sub De

Mortgage Loans TDRs with Sub Defaults (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)contracts	Jun. 30, 2018USD ($)contracts	Jun. 30, 2019USD ($)contracts	Jun. 30, 2018USD ($)contracts
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,547	4,568	9,706	10,273
Recorded investment troubled debt restructurings subsequent default | $	$ 693	$ 674	$ 1,470	$ 1,526
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,546	4,568	9,705	10,272
Recorded investment troubled debt restructurings subsequent default | $	$ 687	$ 674	$ 1,464	$ 1,524
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,047	3,834	8,563	8,652
Recorded investment troubled debt restructurings subsequent default | $	$ 606	$ 554	$ 1,279	$ 1,255
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	10	15	28	29
Recorded investment troubled debt restructurings subsequent default | $	$ 2	$ 2	$ 5	$ 4
Single-family [Member] | Alt-A
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	379	588	850	1,265
Recorded investment troubled debt restructurings subsequent default | $	$ 58	$ 92	$ 131	$ 201
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	110	131	264	326
Recorded investment troubled debt restructurings subsequent default | $	$ 21	$ 26	$ 49	$ 64
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	1	0	1	1
Recorded investment troubled debt restructurings subsequent default | $	$ 6	$ 0	$ 6	$ 2

Allowance for Loan Losses Rollf

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Allowance for Loan Losses [Roll Forward]
Beginning balance	$ (13,232)	$ (18,734)	$ (14,203)	$ (19,084)
Benefit (provision) for loan losses	1,212	1,270	1,846	1,212
Charge-offs	562	732	943	1,201
Recoveries	(17)	(64)	(62)	(124)
Other	(7)	(16)	(6)	(17)
Ending balance	(11,482)	(16,812)	(11,482)	(16,812)
Single-family [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	(12,985)	(18,523)	(13,969)	(18,849)
Benefit (provision) for loan losses	1,239	1,270	1,886	1,192
Charge-offs	558	731	939	1,196
Recoveries	(15)	(64)	(60)	(124)
Other	(7)	(16)	(6)	(17)
Ending balance	(11,210)	(16,602)	(11,210)	(16,602)
Multifamily [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	(247)	(211)	(234)	(235)
Benefit (provision) for loan losses	(27)	0	(40)	20
Charge-offs	4	1	4	5
Recoveries	(2)	0	(2)	0
Ending balance	$ (272)	$ (210)	$ (272)	$ (210)

Allowance for Loan Losses and T

Allowance for Loan Losses and Total Recorded Investment in HFI Loans (Details) - USD ($) $ in Millions	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	$ (10,627)		$ (13,295)
Allowance for loan losses for collectively reserved loans	(855)		(908)
Total allowance for loan losses	(11,482)	$ (13,232)	(14,203)	$ (16,812)	$ (18,734)	$ (19,084)
Recorded investment in individually impaired loans	108,130		118,103
Recorded investment in collectively reserved loans	3,165,665		3,137,065
Total recorded investment in loans	3,273,795		3,255,168
Single-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	(10,572)		(13,255)
Allowance for loan losses for collectively reserved loans	(638)		(714)
Total allowance for loan losses	(11,210)	(12,985)	(13,969)	(16,602)	(18,523)	(18,849)
Recorded investment in individually impaired loans	107,354		117,561
Recorded investment in collectively reserved loans	2,852,896		2,841,943
Total recorded investment in loans	2,960,250		2,959,504
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	(55)		(40)
Allowance for loan losses for collectively reserved loans	(217)		(194)
Total allowance for loan losses	(272)	$ (247)	(234)	$ (210)	$ (211)	$ (235)
Recorded investment in individually impaired loans	776		542
Recorded investment in collectively reserved loans	312,769		295,122
Total recorded investment in loans	$ 313,545		$ 295,664

Investments in Securities Tradi

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 42,866	$ 41,867
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	7,516	6,276
Fannie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Single Security recognized mortgage related securities	1,400
Trading, at fair value	3,151	1,467
Other agency [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	3,629	3,503
Private-label and other mortgage securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	736	1,306
Non-mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	35,350	35,591
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	35,266	35,502
Other securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	84	89
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 983	$ 32

Investments in Securities Tra_2

Investments in Securities Trading 2 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt and Equity Securities, FV-NI [Line Items]
Net trading gains	$ 183	$ 21	$ 275	$ 119
Net trading gains recognized in the period related to securities still held at period end	$ 147	$ 1	$ 227	$ 48

Investments in Securities Avail

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 110	$ 0	$ 171	$ 363
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 245	$ 6	$ 376	$ 641

Investments in Securities Ava_2

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	$ 2,539	$ 3,079
Gross unrealized gains	236	380
Gross unrealized losses	(14)	(30)
Total fair value	2,761	3,429
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	1,536	1,754
Gross unrealized gains	90	69
Gross unrealized losses	(11)	(26)
Total fair value	1,615	1,797
Other agency [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	209	239
Gross unrealized gains	19	17
Gross unrealized losses	0	0
Total fair value	228	256
Alt-A and subprime private-label securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	109	325
Gross unrealized gains	111	267
Gross unrealized losses	0	0
Total fair value	220	592
Mortgage revenue bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	356	425
Gross unrealized gains	11	13
Gross unrealized losses	(3)	(4)
Total fair value	364	434
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	329	336
Gross unrealized gains	5	14
Gross unrealized losses	0	0
Total fair value	$ 334	$ 350

Investments in Securities Ava_3

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
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	24
12 Consecutive Months or Longer, Gross Unrealized Losses	(14)	(29)
12 Consecutive Months or Longer, Fair Value	371	506
Fannie Mae [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	(11)	(26)
12 Consecutive Months or Longer, Fair Value	366	487
Mortgage revenue bonds [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	24
12 Consecutive Months or Longer, Gross Unrealized Losses	(3)	(3)
12 Consecutive Months or Longer, Fair Value	$ 5	$ 19

Investments in Securities Other

Investments in Securities Other-than-temporary Impairments (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Balance of the unrealized credit loss component of AFS debt securities held by us	$ 57	$ 635	$ 733	$ 1,100

Investments in Securities Sched

Investments in Securities Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Available-for-sale Securities, Other-than-temporary Impairment not Recorded	$ 80	$ 52
Accumulated Other Comprehensive Income (Loss), Net of Tax, Available-for-sale Gain (Loss), Other-than-temporary Impairment Recorded	95	224
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	41	46
Accumulated other comprehensive income	216	322
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 57	$ 635	$ 733	$ 1,100

Investments in Securities Matur

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 2,539	$ 3,079
Total fair value	2,761	3,429
One Year or Less, Amortized Cost	2
One Year or Less, Fair Value	2
After One Year through Five Years, Amortized Cost	61
After One Year through Five Years, Fair Value	63
After Five Years through Ten Years, Amortized Cost	199
After Five Years through Ten Years, Fair Value	217
After Ten Years, Amortized Cost	2,277
After Ten Years, Fair Value	2,479
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,536	1,754
Total fair value	1,615	1,797
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	15
After One Year through Five Years, Fair Value	15
After Five Years through Ten Years, Amortized Cost	104
After Five Years through Ten Years, Fair Value	115
After Ten Years, Amortized Cost	1,417
After Ten Years, Fair Value	1,485
Other agency [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	209	239
Total fair value	228	256
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	22
After One Year through Five Years, Fair Value	24
After Five Years through Ten Years, Amortized Cost	25
After Five Years through Ten Years, Fair Value	28
After Ten Years, Amortized Cost	162
After Ten Years, Fair Value	176
Alt-A and subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	109	325
Total fair value	220	592
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Amortized Cost	1
After Five Years through Ten Years, Fair Value	1
After Ten Years, Amortized Cost	108
After Ten Years, Fair Value	219
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	356	425
Total fair value	364	434
One Year or Less, Amortized Cost	2
One Year or Less, Fair Value	2
After One Year through Five Years, Amortized Cost	24
After One Year through Five Years, Fair Value	24
After Five Years through Ten Years, Amortized Cost	43
After Five Years through Ten Years, Fair Value	45
After Ten Years, Amortized Cost	287
After Ten Years, Fair Value	293
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	329	336
Total fair value	334	$ 350
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	0
After One Year through Five Years, Fair Value	0
After Five Years through Ten Years, Amortized Cost	26
After Five Years through Ten Years, Fair Value	28
After Ten Years, Amortized Cost	303
After Ten Years, Fair Value	$ 306

Financial Guarantees Financial

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	$ 20,181	$ 21,125
Guaranty Obligation	166	160
Maximum Recovery	9,085	9,522
Unconsolidated VIEs [Member] | Unconsolidated Fannie Mae MBS [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	6,761	7,278
Guaranty Obligation	26	30
Maximum Recovery	6,440	6,811
Unconsolidated VIEs [Member] | Other guaranty arrangements [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	13,420	13,847
Guaranty Obligation	140	130
Maximum Recovery	2,645	$ 2,711
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Single security, exclusion of Freddie Mac issued securities backing unconsolidated Fannie Mae securities	$ 7,700
Minimum [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Contractual terms of our guarantees	1 day
Maximum [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Contractual terms of our guarantees	33 years

Short-Term and Long-Term Debt S

Short-Term and Long-Term Debt Short-Term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Short-Term Debt [Line Items]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	$ 131	$ 0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Short-Term Debt [Line Items]
Debt, Weighted Average Interest Rate	2.25%	0.00%
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	$ 22,901	$ 24,896
Short-term debt, weighted-average interest rate	2.39%	2.29%

Short-Term and Long-Term Debt L

Short-Term and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,393,678	$ 3,367,024
Long-term debt, weighted-average interest rate	2.91%	3.02%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,199,765	$ 3,159,846
Long-term debt, weighted-average interest rate	2.90%	3.03%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 193,913	$ 207,178
Long-term debt, weighted-average interest rate	3.03%	2.83%
Unamortized discounts and premiums, other cost basis adjustments and fair value adjustments	$ 151	$ 413
Fannie Mae [Member] | Minimum [Member]
Long-Term Debt [Line Items]
Medium-term notes original contractual maturity	1 year	1 year
Long-term debt original contractual maturity greater than 10 years	10 years	10 years
Fannie Mae [Member] | Maximum [Member]
Long-Term Debt [Line Items]
Medium-term notes original contractual maturity	10 years	10 years
Fannie Mae [Member] | Senior Fixed [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 155,850	$ 171,344
Long-term debt, weighted-average interest rate	2.31%	2.13%
Fannie Mae [Member] | Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 97,884	$ 103,206
Long-term debt, weighted-average interest rate	2.56%	2.36%
Fannie Mae [Member] | Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 51,345	$ 61,455
Long-term debt, weighted-average interest rate	1.53%	1.48%
Fannie Mae [Member] | Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 6,621	$ 6,683
Long-term debt, weighted-average interest rate	4.80%	4.62%
Fannie Mae [Member] | Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 32,381	$ 30,166
Long-term debt, weighted-average interest rate	5.25%	5.52%
Fannie Mae [Member] | Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 7,773	$ 4,174
Long-term debt, weighted-average interest rate	2.50%	2.36%
Fannie Mae [Member] | Senior floating Connecticut Avenue Securities [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 24,210	$ 25,641
Long-term debt, weighted-average interest rate	6.12%	5.97%
Fannie Mae [Member] | Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 398	$ 351
Long-term debt, weighted-average interest rate	6.37%	10.19%
Fannie Mae [Member] | Subordinated debentures [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 5,641	$ 5,617
Long-term debt, weighted-average interest rate	9.99%	9.64%
Fannie Mae [Member] | Secured borrowings [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 41	$ 51
Long-term debt, weighted-average interest rate	2.06%	1.96%

Derivative Instruments Derivati

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Asset Derivatives [Abstract]
Notional amount	$ 307,347	$ 266,935
Derivative asset, estimated fair value	561	458
Netting adjustment	(1,709)	(2,266)
Liability Derivatives [Abstract]
Notional amount	238,750	161,488
Derivative liability, estimated fair value	(799)	(777)
Netting adjustment	2,297	2,315
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	1,200	713
Cash collateral received for derivative instruments	573	664
Pay-fixed Swap
Asset Derivatives [Abstract]
Notional amount	58,357	71,416
Derivative asset, estimated fair value	4	438
Liability Derivatives [Abstract]
Notional amount	31,468	21,253
Derivative liability, estimated fair value	(1,327)	(740)
Receive-fixed Swap
Asset Derivatives [Abstract]
Notional amount	91,919	88,799
Derivative asset, estimated fair value	1,096	1,113
Liability Derivatives [Abstract]
Notional amount	47,254	58,399
Derivative liability, estimated fair value	(210)	(860)
Basis Swap
Asset Derivatives [Abstract]
Notional amount	273	250
Derivative asset, estimated fair value	155	104
Liability Derivatives [Abstract]
Notional amount	0	624
Derivative liability, estimated fair value	0	0
Foreign Currency Swap
Asset Derivatives [Abstract]
Notional amount	220	221
Derivative asset, estimated fair value	30	22
Liability Derivatives [Abstract]
Notional amount	222	223
Derivative liability, estimated fair value	(77)	(72)
Pay-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	4,600	10,375
Derivative asset, estimated fair value	29	191
Liability Derivatives [Abstract]
Notional amount	6,375	1,000
Derivative liability, estimated fair value	(172)	(4)
Receive-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	2,125	500
Derivative asset, estimated fair value	90	20
Liability Derivatives [Abstract]
Notional amount	5,350	7,375
Derivative liability, estimated fair value	(232)	(338)
Future [Member]
Asset Derivatives [Abstract]
Notional amount	19,537	16,631
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	177,031	188,192
Derivative asset, estimated fair value	1,404	1,888
Accrued interest receivable (payable)	360	400
Netting adjustment	(1,709)	(2,266)
Total net risk management derivatives	55	22
Liability Derivatives [Abstract]
Notional amount	90,669	88,874
Derivative liability, estimated fair value	(2,018)	(2,014)
Accrued interest receivable (payable)	(359)	(419)
Netting adjustment	2,297	2,315
Total net risk management derivatives	(80)	(118)
Mortgage commitments to purchase whole loans
Asset Derivatives [Abstract]
Notional amount	9,767	4,370
Derivative asset, estimated fair value	54	29
Liability Derivatives [Abstract]
Notional amount	2,417	57
Derivative liability, estimated fair value	(2)	0
Forward contracts to purchase mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	78,510	40,650
Derivative asset, estimated fair value	389	349
Liability Derivatives [Abstract]
Notional amount	10,000	1,045
Derivative liability, estimated fair value	(11)	(3)
Forward contracts to sell mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	10,230	292
Derivative asset, estimated fair value	12	1
Liability Derivatives [Abstract]
Notional amount	131,017	70,593
Derivative liability, estimated fair value	(675)	(645)
Mortgage commitment derivatives
Asset Derivatives [Abstract]
Notional amount	98,507	45,312
Derivative asset, estimated fair value	455	379
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	143,434	71,695
Derivative liability, estimated fair value	(688)	(648)
Netting adjustment	0	0
Other
Asset Derivatives [Abstract]
Notional amount	31,809	33,431
Derivative asset, estimated fair value	51	57
Liability Derivatives [Abstract]
Notional amount	4,647	919
Derivative liability, estimated fair value	$ (31)	$ (11)

Derivative Instruments Deriva_2

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ (853)	$ (38)	$ (1,548)	$ 825
Net accrual of periodic settlements	5,150	5,377	9,883	10,609
Pay-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(2,164)	967	(3,499)	3,750
Receive-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	1,884	(597)	3,165	(2,984)
Basis Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	27	(3)	51	(26)
Foreign Currency Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(17)	(41)	2	(25)
Pay-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(143)	36	(320)	165
Receive-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	93	(22)	100	(38)
Future [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	195	(11)	254	(3)
Risk Management Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(367)	43	(755)	338
Net accrual of periodic settlements	(242)	(286)	(508)	(501)
Mortgage commitment derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(469)	(76)	(769)	488
Other
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ (17)	$ (5)	$ (24)	$ (1)

Segment Reporting Narrative (De

Segment Reporting Narrative (Details)	6 Months Ended
	Jun. 30, 2019segments
Segment Reporting [Abstract]
Number of Reportable Segments	2

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Net interest income	$ 5,150	$ 5,377	$ 9,883	$ 10,609
Fee and other income	246	239	473	559
Net revenues	5,396	5,616	10,356	11,168
Investment gains, net	461	277	594	527
Fair value gains (losses), net	(754)	229	(1,585)	1,274
Administrative expenses	(744)	(755)	(1,488)	(1,505)
Benefit (provision) for credit losses	1,225	1,296	1,875	1,513
Foreclosed property income (expense)	(128)	(139)	(268)	(301)
Total credit-related income (expense)	1,097	1,157	1,607	1,212
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(600)	(565)	(1,193)	(1,122)
Other expenses, net	(535)	(366)	(943)	(569)
Income before federal income taxes	4,321	5,593	7,348	10,985
Provision for federal income taxes	(889)	(1,136)	(1,516)	(2,267)
Net income	3,432	4,457	5,832	8,718
US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(600)	(565)	(1,193)	(1,122)
Business Segments [Member] | Single-family [Member]
Segment Reporting Information [Line Items]
Net interest income	4,419	4,723	8,458	9,284
Fee and other income	88	69	194	227
Net revenues	4,507	4,792	8,652	9,511
Investment gains, net	417	252	511	494
Fair value gains (losses), net	(758)	278	(1,645)	1,312
Administrative expenses	(634)	(649)	(1,265)	(1,292)
Benefit (provision) for credit losses	1,252	1,295	1,913	1,491
Foreclosed property income (expense)	(126)	(136)	(269)	(298)
Total credit-related income (expense)	1,126	1,159	1,644	1,193
Other expenses, net	(418)	(270)	(755)	(402)
Income before federal income taxes	3,640	4,997	5,949	9,694
Provision for federal income taxes	(769)	(1,044)	(1,253)	(2,060)
Net income	2,871	3,953	4,696	7,634
Business Segments [Member] | Single-family [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(600)	(565)	(1,193)	(1,122)
Business Segments [Member] | Multifamily [Member]
Segment Reporting Information [Line Items]
Net interest income	731	654	1,425	1,325
Fee and other income	158	170	279	332
Net revenues	889	824	1,704	1,657
Investment gains, net	44	25	83	33
Fair value gains (losses), net	4	(49)	60	(38)
Administrative expenses	(110)	(106)	(223)	(213)
Benefit (provision) for credit losses	(27)	1	(38)	22
Foreclosed property income (expense)	(2)	(3)	1	(3)
Total credit-related income (expense)	(29)	(2)	(37)	19
Other expenses, net	(117)	(96)	(188)	(167)
Income before federal income taxes	681	596	1,399	1,291
Provision for federal income taxes	(120)	(92)	(263)	(207)
Net income	561	504	1,136	1,084
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)	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Multifamily [Member] | Guaranty Book of Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	0.04%	0.02%
Seriously delinquent (percentage of book of business)	0.05%	0.06%
Multifamily [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	60 days	60 days
Multifamily [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	89 days	89 days
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	1.27%	1.17%
60 days delinquent (percentage of book of business)	0.30%	0.32%
Seriously delinquent (percentage of book of business)	0.64%	0.69%
30 days delinquent (percentage of conventional loans)	1.47%	1.37%
60 days delinquent (percentage of conventional loans)	0.35%	0.38%
Seriously delinquent (percentage of conventional loans)	0.70%	0.76%
Percentage of loans with detailed loan level information	99.00%	99.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.33%	0.34%
Percentage of Unpaid Principal Balance of Loans	19.00%	19.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.94%	1.16%
Percentage of Unpaid Principal Balance of Loans	6.00%	6.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	1.28%	1.38%
Percentage of Unpaid Principal Balance of Loans	4.00%	4.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	1.32%	1.40%
Percentage of Unpaid Principal Balance of Loans	5.00%	5.00%
Single-family [Member] | 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)	0.69%	0.75%
Percentage of Unpaid Principal Balance of Loans	66.00%	66.00%
Single-family [Member] | 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)	10.63%	9.85%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | Alt-A
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	3.25%	3.35%
Percentage of Unpaid Principal Balance of Loans	2.00%	2.00%
Single-family [Member] | 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)	2.61%	2.69%
Percentage of Unpaid Principal Balance of Loans	3.00%	3.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | 2005-2008
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	4.45%	4.61%
Percentage of Unpaid Principal Balance of Loans	4.00%	5.00%
Single-family [Member] | Guaranty Book of Business [Member] | Conventional Loan [Member] | 2009-2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.32%	0.34%
Percentage of Unpaid Principal Balance of Loans	93.00%	92.00%
Single-family [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	90 days	90 days

Concentrations of Credit Risk M

Concentrations of Credit Risk MF Risk Characteristics (Details) - Multifamily [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	60 days	60 days
Current debt service coverage ratio reporting lag	3 months	3 months
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	89 days	89 days
Current debt service coverage ratio (higher risk loans)	1	1
Current debt service coverage ratio reporting lag	6 months	6 months
Guaranty Book of Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	0.04%	0.02%
Seriously delinquent (percentage of book of business)	0.05%	0.06%
Guaranty Book of Business [Member] | Original LTV ratio greater than 80% [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of book of business	1.00%	1.00%
Loans seriously delinquent, percentage by unpaid principal balance	0.00%	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	0.05%	0.06%
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	1.11%	1.38%

Concentrations of Credit Risk O

Concentrations of Credit Risk Other Concentrations (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Document Period End Date	Jun. 30, 2019
Estimated benefit included in loss reserves	$ 563	$ 691
Receivable from claims on insured, defaulted loans excluding government insured loans	685	745
Allowance for mortgage insurance receivable	$ 546	564
PMI Mortgage Insurance Company [Member]
Concentration Risk [Line Items]
Mortgage insurance coverage risk in force percentage to be paid in cash	74.50%
Mortgage insurance coverage risk in force percentage to be deferred	25.50%
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]
Mortgage insurance coverage risk in force	$ 158,582	$ 152,788
Mortgage insurance coverage risk in force as percentage	5.00%	5.00%
Primary mortgage insurance	$ 158,191	$ 152,379
Pool mortgage insurance	$ 391	$ 409
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	58.00%	56.00%
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%	22.00%
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	18.00%	18.00%
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	15.00%	16.00%
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	$ 4,000
Percentage of Concentration Risk	3.00%
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	24.00%	25.00%
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	20.00%	21.00%
Single-family [Member] | Guaranty Book of Business [Member] | Insurance Service Provider Concentration Risk [Member] | Mortgage Guaranty Insurance Corp.
Concentration Risk [Line Items]
Percentage of Risk in Force Coverage by Mortgage Insurer	18.00%	18.00%
Single-family [Member] | Guaranty Book of Business [Member] | Insurance Service Provider Concentration Risk [Member] | Genworth Mortgage Insurance Corp.(2)
Concentration Risk [Line Items]
Percentage of Risk in Force Coverage by Mortgage Insurer	15.00%	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	13.00%	12.00%
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%	9.00%
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%	14.00%
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%	22.00%

Netting Arrangements (Details)

Netting Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Offsetting Assets [Line Items]
Fair Value of Securities Received as Collateral that Have Been Resold or Repledged	$ 0	$ 0
Derivative Liability, Not Subject to Master Netting Arrangement	31	11
Assets:
Derivative assets, gross amount	2,219	2,667
Derivative assets, gross amount offset	(1,709)	(2,266)
Derivative assets, net amount presented in our condensed consolidated balance sheets	510	401
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(159)	(153)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(22)	(7)
Derivative assets, net amount	329	241
Securities purchased under agreements to resell or similar arrangements, gross amount	40,362	48,288
Securities purchased under agreements to resell or similar arrangements, gross amount offset	0	0
Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement	40,362	48,288
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(40,362)	(48,288)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	42,581	50,955
Total assets, gross amount offset	(1,709)	(2,266)
Total assets, net amount presented in our condensed consolidated balance sheets	40,872	48,689
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(159)	(153)
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(40,384)	(48,295)
Total assets, net amount	329	241
Liabilities:
Derivative liabilities, gross amount	(3,065)	(3,081)
Derivative liabilities, gross amount offset	2,297	2,315
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(768)	(766)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	159	153
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	512	489
Derivative liabilities, net amount	(97)	(124)
Total liabilities, gross amount	(3,196)	(3,081)
Total liabilities, gross amount offset	2,297	2,315
Total liabilities, net amount presented in our condensed consolidated balance sheets	(899)	(766)
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	159	153
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	642	489
Total liabilities, net amount	(98)	(124)
Fair Value of Securities Received as Collateral that Can be Resold or Repledged	37,900	45,700
Securities Sold under Agreements to Repurchase, Gross	(131)
Securities Sold under Agreements to Repurchase, Asset	0
Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement	(131)
Securities Sold under Agreements to Repurchase, Not Offset, Policy Election Deduction	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	130
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	1
Risk Management Derivatives
Assets:
Derivative assets, gross amount offset	(1,709)	(2,266)
Liabilities:
Derivative liabilities, gross amount offset	2,297	2,315
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	455	379
Derivative assets, gross amount offset	0	0
Derivative assets, net amount presented in our condensed consolidated balance sheets	455	379
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(159)	(153)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(22)	(7)
Derivative assets, net amount	274	219
Liabilities:
Derivative liabilities, gross amount	(688)	(648)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(688)	(648)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	159	153
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	510	466
Derivative liabilities, net amount	(19)	(29)
Over the Counter [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	1,764	2,288
Derivative assets, gross amount offset	(1,716)	(2,273)
Derivative assets, net amount presented in our condensed consolidated balance sheets	48	15
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0
Derivative assets, net amount	48	15
Liabilities:
Derivative liabilities, gross amount	(2,377)	(2,433)
Derivative liabilities, gross amount offset	2,301	2,342
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(76)	(91)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0
Derivative liabilities, net amount	(76)	(91)
Exchange Cleared [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	0	0
Derivative assets, gross amount offset	7	7
Derivative assets, net amount presented in our condensed consolidated balance sheets	7	7
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	0	0
Derivative assets, net amount	7	7
Liabilities:
Derivative liabilities, gross amount	0	0
Derivative liabilities, gross amount offset	(4)	(27)
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(4)	(27)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	2	23
Derivative liabilities, net amount	$ (2)	$ (4)

Netting Arrangements Narratives

Netting Arrangements Narratives (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Fair value of non-cash collateral we pledged	$ 1,600	$ 1,900
Fair value of non-cash collateral received	40,400	48,400
Fair value of non-cash collateral received that can be resold or repledged	37,900	45,700
Fair value of securities received as collateral that have been resold or repledge	0	0
Derivative assets not subject to enforceable master netting arrangements	51	57
Derivative liabilities not subject to enforceable master netting arrangements	(31)	(11)
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Securities purchased under agreements to resell	$ 20,800	$ 15,400

Fair Value Levels Hierarchy (De

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 8,479	$ 8,922
Other assets [Abstract]
Derivative assets, gross amount offset	(1,709)	(2,266)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,297)	(2,315)
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	6,370	6,826
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,771	23,753
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	35,266	35,502
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	75,436	69,575
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	7,526	6,332
Available-for-sale securities	1,939	2,477
Mortgage loans held for investment, at fair value	3,175,207	2,990,104
Other assets [Abstract]
Derivatives assets at fair value	2,054	2,515
Total assets at fair value	3,233,307	3,053,308
Other liabilities [Abstract]
Derivative liabilities at fair value	3,063	3,077
Total liabilities at fair value	3,423,669	3,303,620
Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	201,775	211,403
Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,195,793	3,064,239
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	74	33
Available-for-sale securities	822	952
Mortgage loans held for investment, at fair value	142,889	216,404
Other assets [Abstract]
Derivatives assets at fair value	216	209
Total assets at fair value	155,467	225,812
Other liabilities [Abstract]
Derivative liabilities at fair value	33	15
Total liabilities at fair value	37,336	39,950
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	826	771
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	36,368	39,043
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Cash equivalents	0	748
Trading securities	42,866	41,867
Available-for-sale securities	2,761	3,429
Mortgage loans held for investment, at fair value	8,479	8,922
Other assets [Abstract]
Derivatives assets at fair value	561	458
Derivative assets, gross amount offset	(1,709)	(2,266)
Total assets at fair value	54,667	55,424
Liabilities [Abstract]
Long-term debt, fair value	29,141	30,579
Other liabilities [Abstract]
Derivative liabilities at fair value	799	777
Derivative liabilities, gross amount offset	(2,297)	(2,315)
Total liabilities at fair value	29,940	31,356
Recurring Fair Value Measurements [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,645	2,077
Other liabilities [Abstract]
Derivative liabilities at fair value	1,973	2,091
Recurring Fair Value Measurements [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	119	211
Other liabilities [Abstract]
Derivative liabilities at fair value	404	342
Recurring Fair Value Measurements [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	455	379
Other liabilities [Abstract]
Derivative liabilities at fair value	688	648
Recurring Fair Value Measurements [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	51	57
Other liabilities [Abstract]
Derivative liabilities at fair value	31	11
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	6,370	6,826
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	6,370	6,826
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,771	23,753
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	3,151	1,467
Available-for-sale securities	1,615	1,797
Recurring Fair Value Measurements [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,629	3,503
Available-for-sale securities	228	256
Recurring Fair Value Measurements [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	736	1,306
Available-for-sale securities	220	592
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	364	434
Recurring Fair Value Measurements [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	334	350
Recurring Fair Value Measurements [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	35,266	35,502
Recurring Fair Value Measurements [Member] | Other securities [Member]
Assets [Abstract]
Trading securities	84	89
Recurring Fair Value Measurements [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash equivalents	0	748
Trading securities	35,266	35,502
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	35,266	36,250
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
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	35,266	35,502
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]
Cash equivalents	0	0
Trading securities	7,526	6,332
Available-for-sale securities	1,939	2,477
Mortgage loans held for investment, at fair value	7,709	7,985
Other assets [Abstract]
Derivatives assets at fair value	2,054	2,515
Total assets at fair value	19,228	19,309
Liabilities [Abstract]
Long-term debt, fair value	28,641	30,027
Other liabilities [Abstract]
Derivative liabilities at fair value	3,063	3,077
Total liabilities at fair value	31,704	33,104
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,480	1,962
Other liabilities [Abstract]
Derivative liabilities at fair value	1,971	2,089
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	119	211
Other liabilities [Abstract]
Derivative liabilities at fair value	404	342
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	455	342
Other liabilities [Abstract]
Derivative liabilities at fair value	688	646
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	5,972	6,475
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	5,972	6,475
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,669	23,552
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	3,077	1,435
Available-for-sale securities	1,483	1,645
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,629	3,503
Available-for-sale securities	228	256
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	736	1,305
Available-for-sale securities	220	568
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	8	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	84	89
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Cash equivalents	0	0
Trading securities	74	33
Available-for-sale securities	822	952
Mortgage loans held for investment, at fair value	770	937
Other assets [Abstract]
Derivatives assets at fair value	216	209
Total assets at fair value	1,882	2,131
Liabilities [Abstract]
Long-term debt, fair value	500	552
Other liabilities [Abstract]
Derivative liabilities at fair value	33	15
Total liabilities at fair value	533	567
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	165	115
Other liabilities [Abstract]
Derivative liabilities at fair value	2	2
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	0	37
Other liabilities [Abstract]
Derivative liabilities at fair value	0	2
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	51	57
Other liabilities [Abstract]
Derivative liabilities at fair value	31	11
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	398	351
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	398	351
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	102	201
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	74	32
Available-for-sale securities	132	152
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	0	0
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	1
Available-for-sale securities	0	24
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	364	434
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	326	342
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

Fair Value Level 3 Rollforward

Fair Value Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	$ 2	$ 3	$ 3	$ 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	67	84	33	1,201
Total gains (losses) (realized/unrealized) Included in Net Income	1	(5)	3	80
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	1
Sales	(14)	0	(14)	(1,060)
Issues	0	0	0	0
Settlements	(16)	0	(17)	(6)
Transfers out of Level 3	0	0	0	(137)
Transfers into Level 3	36	1	69	1
Ending Balance	74	80	74	80
Trading securities [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	2	3	3	3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	67	83	32	971
Total gains (losses) (realized/unrealized) Included in Net Income	1	(5)	3	166
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	1
Sales	(14)	0	(14)	(1,060)
Issues	0	0	0	0
Settlements	(16)	0	(16)	0
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	36	1	69	1
Ending Balance	74	79	74	79
Trading securities [Member] | Other agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets				0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance				35
Total gains (losses) (realized/unrealized) Included in Net Income		0		(1)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)				0
Purchases				0
Sales				0
Issues				0
Settlements				(1)
Transfers out of Level 3				(33)
Transfers into Level 3				0
Ending Balance		0		0
Trading securities [Member] | Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets		0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		1	1	195
Total gains (losses) (realized/unrealized) Included in Net Income			0	(85)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)		0	0	0
Purchases		0	0	0
Sales		0	0	0
Issues		0	0	0
Settlements		0	(1)	(5)
Transfers out of Level 3		0	0	(104)
Transfers into Level 3		0	0	0
Ending Balance	0	1	0	1
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	984	1,119	952	1,313
Total gains (losses) (realized/unrealized) Included in Net Income	10	(3)	17	15
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(9)	24	(10)	(40)
Purchases	0	0	0	0
Sales	(27)	(7)	(27)	(18)
Issues	0	0	0	0
Settlements	(72)	(40)	(90)	(173)
Transfers out of Level 3	(64)	0	(105)	(4)
Transfers into Level 3	0	0	85	0
Ending Balance	822	1,093	822	1,093
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	199	202	152	208
Total gains (losses) (realized/unrealized) Included in Net Income	0	1	0	1
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	2	4	6	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(7)	(3)	(7)	(5)
Transfers out of Level 3	(62)	0	(103)	0
Transfers into Level 3	0	0	84	0
Ending Balance	132	204	132	204
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	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	23	27	24	77
Total gains (losses) (realized/unrealized) Included in Net Income	5	0	5	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(5)	0	(5)	(45)
Purchases	0	0	0	0
Sales	(23)	0	(23)	0
Issues	0	0	0	0
Settlements	0	(1)	(1)	(2)
Transfers out of Level 3	0	0	0	(4)
Transfers into Level 3	0	0	0	0
Ending Balance	0	26	0	26
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	425	539	434	671
Total gains (losses) (realized/unrealized) Included in Net Income	0	(11)	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(1)	10	(1)	(3)
Purchases	0	0	0	0
Sales	(4)	(7)	(4)	(18)
Issues	0	0	0	0
Settlements	(56)	(25)	(65)	(144)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	364	506	364	506
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	337	351	342	357
Total gains (losses) (realized/unrealized) Included in Net Income	5	7	12	14
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(5)	10	(10)	8
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(9)	(11)	(17)	(22)
Transfers out of Level 3	(2)	0	(2)	0
Transfers into Level 3	0	0	1	0
Ending Balance	326	357	326	357
Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	14	8	22	16
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	934	1,102	937	1,116
Total gains (losses) (realized/unrealized) Included in Net Income	17	11	31	28
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	(13)	0	(13)	0
Issues	0	0	0	0
Settlements	(36)	(79)	(70)	(127)
Transfers out of Level 3	(159)	(51)	(187)	(87)
Transfers into Level 3	27	35	72	88
Ending Balance	770	1,018	770	1,018
Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	18	(14)	24	(37)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	203	133	194	134
Total gains (losses) (realized/unrealized) Included in Net Income	20	(28)	118	(86)
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	(31)	(12)	(120)	16
Transfers out of Level 3	(9)	0	(9)	53
Transfers into Level 3	0	0	0	0
Ending Balance	183	117	183	117
Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	(23)	2	(49)	21
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(600)	(819)	(552)	(958)
Total gains (losses) (realized/unrealized) Included in Net Income	(23)	(7)	(51)	(29)
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	(1)
Settlements	5	21	10	31
Transfers out of Level 3	120	177	169	331
Transfers into Level 3	(2)	(59)	(76)	(107)
Ending Balance	(500)	(673)	(500)	(673)
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)	(2)	(1)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(224)	(462)	(201)	(582)
Total gains (losses) (realized/unrealized) Included in Net Income	1	(4)	4	(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	0	0	(1)
Settlements	5	21	10	31
Transfers out of Level 3	120	177	169	331
Transfers into Level 3	(2)	(59)	(76)	(107)
Ending Balance	(102)	(319)	(102)	(319)
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	(22)	3	(47)	22
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(376)	(357)	(351)	(376)
Total gains (losses) (realized/unrealized) Included in Net Income	22	3	47	22
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	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	(398)	(354)	(398)	(354)
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] | Other agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets				0
Other Comprehensive Income (Loss) [Member] | 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	0	19	(3)	9
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	3	3	5	0
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	1
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	8	(1)	0
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	(3)	8	(7)	8
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	Jun. 30, 2019	Dec. 31, 2018
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 510	$ 401
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	42,866	41,867
Available-for-sale securities	2,761	3,429
Assets, Fair Value Disclosure	54,667	55,424
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	35,266	35,502
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	75,436	69,575
Mortgage loans held-for-sale, at lower of cost or fair value	0	0
Liabilities, Fair Value Disclosure		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	35,266	35,502
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	35,266	36,250
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, 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	7,526	6,332
Available-for-sale securities	1,939	2,477
Assets, Fair Value Disclosure	3,233,307	3,053,308
Mortgage loans held-for-sale, at lower of cost or fair value	826	238
Significant Other Observable Inputs (Level 2) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	7,526	6,332
Available-for-sale securities	1,939	2,477
Assets, Fair Value Disclosure	19,228	19,309
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	247	91
Liabilities, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	74	33
Available-for-sale securities	822	952
Assets, Fair Value Disclosure	155,467	225,812
Mortgage loans held-for-sale, at lower of cost or fair value	11,112	7,856
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	74	33
Available-for-sale securities	822	952
Derivatives	183	194
Assets, Fair Value Disclosure	1,882	2,131
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	20	81
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	163	113
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	4,858	3,771
Mortgage loans held-for-sale, at lower of cost or fair value	3,220	1,750
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, 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	1,448	1,119
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, 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	1,772	631
Agency | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	132
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	74	32
Available-for-sale securities	26	152
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	106
Private-label and other mortgage securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	736	1,306
Available-for-sale securities	220	592
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	736	1,305
Available-for-sale securities	220	568
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	1
Available-for-sale securities	0	24
Private-label and other mortgage securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities		24
Mortgage revenue bonds [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	364	434
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	364	434
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	$ 250	$ 349
Mortgage revenue bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Available-for-sale Securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.165%	0.005%
Mortgage revenue bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Available-for-sale Securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	1.933%	3.333%
Mortgage revenue bonds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Available-for-sale Securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.661%	0.59%
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		$ 1
Available-for-sale securities	$ 114	85
Other [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	334	350
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	8	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	326	342
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	43	48
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	$ 283	$ 294
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 (%)	0.593%	0.754%
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 (%)	5.5	4.7
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, Constant Prepayment Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	5.5	8.2
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, Loss Severity [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	0.950	0.700
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 (%)	2.94%	3.90%
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 (%)	2.924%	3.891%
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 (%)	5.5	4.7
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, Constant Prepayment Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	5.5	8.2
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, Loss Severity [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	0.950	0.700

Fair Value Level 3 Valuation -

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 8,479	$ 8,922
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	826	238
Mortgage loans held for investment, at fair value	3,175,207	2,990,104
Total assets at fair value	3,233,307	3,053,308
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	11,112	7,856
Mortgage loans held for investment, at fair value	142,889	216,404
Total assets at fair value	155,467	225,812
Fair Value, Measurements, 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	247	91
Fair Value, Measurements, 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	3,220	1,750
Total assets at fair value	4,858	3,771
Fair Value, Measurements, 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	1,448	1,119
Fair Value, Measurements, 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	$ 1,772	$ 631
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Number of Acquired Properties Valuated, Percentage	15.00%	15.00%
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Proprietary Home Price Model and Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Number of Acquired Properties Valuated, Percentage	82.00%	82.00%
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	$ 836	$ 1,011
Fair Value, Measurements, 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	33	41
Fair Value, Measurements, 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	571	818
Acquired property, net	150	219
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	118	151
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	337	419
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Walk Forwards [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	198	181
Fair Value, Measurements, 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	231	142
Fair Value, Measurements, 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	13	40
Acquired property, net	0	50
Fair Value, Measurements, 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	$ 218	$ 102

Fair Value Fair Value of Financ

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (1,709)	$ (2,266)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,297)	(2,315)
Mortgage loans held for investment, at fair value	8,479	8,922
Derivative assets, gross amount offset	(1,709)	(2,266)
Derivative liabilities, gross amount offset	(2,297)	(2,315)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	40,170	34,073
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	35,266	35,502
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	75,436	69,575
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0
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	20,800	15,350
Federal funds sold and securities purchased under agreements to resell or similar arrangements	19,562	32,938
Trading securities	7,526	6,332
Available-for-sale securities	1,939	2,477
Mortgage loans held for sale	826	238
Mortgage loans held for investment, at fair value	3,175,207	2,990,104
Advances to lenders	5,393	3,354
Derivatives assets at fair value	2,054	2,515
Guaranty assets and buy-ups	0	0
Total financial assets	3,233,307	3,053,308
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	131
Derivative liabilities at fair value	3,063	3,077
Guaranty obligations	0	0
Total financial liabilities	3,423,669	3,303,620
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	74	33
Available-for-sale securities	822	952
Mortgage loans held for sale	11,112	7,856
Mortgage loans held for investment, at fair value	142,889	216,404
Advances to lenders	2	2
Derivatives assets at fair value	216	209
Guaranty assets and buy-ups	352	356
Total financial assets	155,467	225,812
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0
Derivative liabilities at fair value	33	15
Guaranty obligations	109	121
Total financial liabilities	37,336	39,950
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	6,370	6,826
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	22,907	24,901
Long-term debt	201,775	211,403
Fannie Mae [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	826	771
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	22,771	23,753
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	3,195,793	3,064,239
Consolidated Trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Long-term debt	36,368	39,043
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	60,970	49,423
Federal funds sold and securities purchased under agreements to resell or similar arrangements	19,562	32,938
Trading securities	42,866	41,867
Available-for-sale securities	2,761	3,429
Mortgage loans held for sale	11,220	7,701
Mortgage loans held for investment, at fair value	3,262,012	3,241,694
Advances to lenders	5,395	3,356
Derivatives assets at fair value	561	458
Guaranty assets and buy-ups	152	147
Total financial assets	3,405,499	3,381,013
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	131
Derivative liabilities at fair value	799	777
Guaranty obligations	166	160
Total financial liabilities	3,417,675	3,392,857
Carrying Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	22,901	24,896
Long-term debt	193,913	207,178
Carrying Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	3,199,765	3,159,846
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	60,970	49,423
Federal funds sold and securities purchased under agreements to resell or similar arrangements	19,562	32,938
Trading securities	42,866	41,867
Available-for-sale securities	2,761	3,429
Mortgage loans held for sale	11,938	8,094
Mortgage loans held for investment, at fair value	3,318,096	3,206,508
Advances to lenders	5,395	3,356
Derivatives assets at fair value	561	458
Guaranty assets and buy-ups	352	356
Total financial assets	3,462,501	3,346,429
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	131
Derivative liabilities at fair value	799	777
Guaranty obligations	109	121
Total financial liabilities	3,458,708	3,341,255
Estimated of Fair Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	22,907	24,901
Long-term debt	202,601	212,174
Estimated of Fair Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	$ 3,232,161	$ 3,103,282

Fair Value Fair Value Option (D

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Fair Value, Option, Quantitative Disclosures [Line Items]
Document Period End Date			Jun. 30, 2019
Mortgage loans held for investment, at fair value	$ 8,479		$ 8,479		$ 8,922
Fair value of nonaccrual loans	141		141		161
Difference between unpaid principal balance and the fair value of nonaccrual loans	13		13		19
Fair value of loans that are 90 days or more past due	87		87		102
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	10		$ 10		$ 14
Single-family [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Serious delinquency, days past due			90 days		90 days
Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	6,370		$ 6,370		$ 6,826
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	22,771		22,771		23,753
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	8,479		8,479		8,922
Loans, unpaid principal balance	8,221		8,221		8,832
Fair Value, Option, Changes in Fair Value, Gain (Loss)	126	$ (27)	239	$ (176)
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(222)	$ 247	(552)	$ 501
Long-term debt [Member] | Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	6,370		6,370		6,826
Long-term debt, unpaid principal balance	5,835		5,835		6,241
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	22,771		22,771		23,753
Long-term debt, unpaid principal balance	$ 20,687		$ 20,687		$ 22,080

Fair Value Changes in FV under

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ (126)	$ 27	$ (239)	$ 176
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ 222	$ (247)	$ 552	$ (501)