Federal National Mortgage Association (FNMA) 10-Q 31 Oct 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page	9 Months Ended
	Sep. 30, 2019shares
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 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	Q3
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	Sep. 30, 2019	Dec. 31, 2018
Assets:
Cash and cash equivalents	$ 22,592	$ 25,557
Restricted cash (includes $35,496 and $17,849, respectively, related to consolidated trusts)	41,906	23,866
Federal funds sold and securities purchased under agreements to resell or similar arrangements	23,176	32,938
Investments in securities:
Trading, at fair value (includes $4,304 and $3,061, respectively, pledged as collateral)	44,206	41,867
Available-for-sale, at fair value	2,690	3,429
Total investments in securities	46,896	45,296
Mortgage loans:
Loans held for sale, at lower of cost or fair value	12,289	7,701
Financing Receivable, before Allowance for Credit Loss	3,311,223	3,255,897
Allowance for loan losses	(9,376)	(14,203)
Total loans held for investment, net of allowance	3,301,847	3,241,694
Total mortgage loans	3,314,136	3,249,395
Deferred tax assets, net	11,994	13,188
Accrued interest receivable, net (includes $8,450 and $7,928, respectively, related to consolidated trusts)	8,923	8,490
Acquired property, net	2,452	2,584
Other assets	22,361	17,004
Total assets	3,494,436	3,418,318
Liabilities:
Accrued interest payable (includes $9,348 and $9,133, respectively, related to consolidated trusts)	10,400	10,211
Other liabilities (includes $359 and $356, respectively, related to consolidated trusts)	11,836	9,947
Total liabilities	3,484,094	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	(123,141)	(127,335)
Accumulated other comprehensive income	230	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)	10,342	6,240
Total liabilities and equity	3,494,436	3,418,318
Fannie Mae [Member]
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	104,367	113,039
Liabilities:
Debt (includes $6,041 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,719 and $23,753, respectively, of debt of consolidated trusts, at fair value)	213,522	232,074
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $35,496 and $17,849, respectively, related to consolidated trusts)	35,496	17,849
Investments in securities:
Trading, at fair value (includes $4,304 and $3,061, respectively, pledged as collateral)	922	32
Mortgage loans:
Financing Receivable, before Allowance for Credit Loss	3,206,856	3,142,858
Accrued interest receivable, net (includes $8,450 and $7,928, respectively, related to consolidated trusts)	8,450	7,928
Liabilities:
Accrued interest payable (includes $9,348 and $9,133, respectively, related to consolidated trusts)	9,348	9,133
Debt (includes $6,041 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,719 and $23,753, respectively, of debt of consolidated trusts, at fair value)	3,248,336	3,159,846
Other liabilities (includes $359 and $356, respectively, related to consolidated trusts)	$ 359	$ 356

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income:
Trading securities	$ 418	$ 363	$ 1,277	$ 917
Available-for-sale securities	40	54	138	175
Mortgage loans (includes $27,610 and $27,058, respectively, for the three months ended and $84,157 and $79,877, respectively, for the nine months ended related to consolidated trusts)	28,858	28,723	88,005	85,064
Federal funds sold and securities purchased under agreements to resell or similar arrangements	178	166	698	457
Other	47	38	120	102
Total interest income	29,541	29,344	90,238	86,715
Interest expense:
Short-term debt	(125)	(114)	(369)	(331)
Long-term debt (includes $22,775 and $22,361, respectively, for the three months ended and $70,371 and $65,972, respectively, for the nine months ended related to consolidated trusts)	(24,187)	(23,861)	(74,757)	(70,406)
Total interest expense	(24,312)	(23,975)	(75,126)	(70,737)
Net interest income	5,229	5,369	15,112	15,978
Benefit for credit losses	1,857	716	3,732	2,229
Net interest income after benefit for credit losses	7,086	6,085	18,844	18,207
Non-interest income (loss):
Investment gains, net	253	166	847	693
Fair value gains (losses), net	(713)	386	(2,298)	1,660
Fee and other income	402	271	875	830
Non-interest income (loss)	(58)	(823)	576	(3,183)
Administrative expenses:
Salaries and employee benefits	(361)	(355)	(1,123)	(1,101)
Professional services	(241)	(247)	(699)	(744)
Other administrative expenses	(147)	(138)	(415)	(400)
Total administrative expenses	(749)	(740)	(2,237)	(2,245)
Foreclosed property expense	(96)	(159)	(364)	(460)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(613)	(576)	(1,806)	(1,698)
Other expenses, net	(571)	(377)	(1,514)	(946)
Total expenses	(2,029)	(1,852)	(5,921)	(5,349)
Income before federal income taxes	4,999	5,056	12,347	16,041
Provision for federal income taxes	(1,036)	(1,045)	(2,552)	(3,312)
Other comprehensive income (loss):
Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes	16	(33)	(85)	(349)
Other, net of taxes	(2)	(3)	(7)	(8)
Total other comprehensive income (loss)	14	(36)	(92)	(357)
Total comprehensive income	3,977	3,975	9,703	12,372
Net income	3,963	4,011	9,795	12,729
Dividends distributed or comprehensive income attributable to an increase in the senior preferred stock liquidation preference	(3,977)	(3,975)	(9,703)	(9,372)
Net income (loss) attributable to common stockholders	$ (14)	$ 36	$ 92	$ 3,357
Earnings per share, Basic	$ 0	$ 0.01	$ 0.02	$ 0.58
Earnings per share, Diluted	$ 0	$ 0.01	$ 0.02	$ 0.57
Weighted-average common shares outstanding, Basic	5,762	5,762	5,762	5,762
Weighted-average common shares outstanding, Diluted	5,762	5,893		5,893

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets:
Restricted cash (includes $35,496 and $17,849, respectively, related to consolidated trusts)	$ 41,906	$ 23,866
Investments in securities:
Trading, at fair value (includes $4,304 and $3,061, respectively, pledged as collateral)	4,304	3,061
Available-for-sale, at fair value	2,690	3,429
Accrued interest receivable, net (includes $8,450 and $7,928, respectively, related to consolidated trusts)	8,923	8,490
Mortgage loans:
Total loans held for investment (includes $8,183 and $8,922, respectively, at fair value)	8,183	8,922
Liabilities:
Accrued interest payable (includes $9,348 and $9,133, respectively, related to consolidated trusts)	10,400	10,211
Other liabilities (includes $359 and $356, respectively, related to consolidated trusts)	$ 11,836	$ 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 $35,496 and $17,849, respectively, related to consolidated trusts)	$ 35,496	$ 17,849
Investments in securities:
Accrued interest receivable, net (includes $8,450 and $7,928, respectively, related to consolidated trusts)	8,450	7,928
Liabilities:
Accrued interest payable (includes $9,348 and $9,133, respectively, related to consolidated trusts)	9,348	9,133
Debt (includes $6,041 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,719 and $23,753, respectively, of debt of consolidated trusts, at fair value)	22,719	23,753
Other liabilities (includes $359 and $356, respectively, related to consolidated trusts)	359	356
Fannie Mae [Member]
Liabilities:
Debt (includes $6,041 and $6,826, respectively, of debt of Fannie Mae at fair value and $22,719 and $23,753, respectively, of debt of consolidated trusts, at fair value)	$ 6,041	$ 6,826

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Mortgage loans (includes $27,610 and $27,058, respectively, for the three months ended and $84,157 and $79,877, respectively, for the nine months ended related to consolidated trusts)	$ 28,858	$ 28,723	$ 88,005	$ 85,064
Long-term debt (includes $22,775 and $22,361, respectively, for the three months ended and $70,371 and $65,972, respectively, for the nine months ended related to consolidated trusts)	24,187	23,861	74,757	70,406
Consolidated Trusts [Member]
Mortgage loans (includes $27,610 and $27,058, respectively, for the three months ended and $84,157 and $79,877, respectively, for the nine months ended related to consolidated trusts)	27,610	27,058	84,157	79,877
Long-term debt (includes $22,775 and $22,361, respectively, for the three months ended and $70,371 and $65,972, respectively, for the nine months ended related to consolidated trusts)	$ 22,775	$ 22,361	$ 70,371	$ 65,972

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net cash provided by (used in) operating activities
Net cash provided by (used in) operating activities	$ 3,176	$ (1,796)
Cash flows provided by investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	46	163
Proceeds from sales of trading securities held for investment	49	96
Proceeds from maturities and paydowns of available-for-sale securities	364	564
Proceeds from sales of available-for-sale securities	376	729
Purchases of loans held for investment	(181,898)	(135,913)
Advances to lenders	(95,636)	(83,643)
Proceeds from disposition of acquired property and preforeclosure sales	5,644	7,090
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	9,762	(7,128)
Other, net	(74)	(56)
Net cash provided by investing activities	134,747	110,564
Cash flows used in financing activities:
Payments of cash dividends on senior preferred stock to Treasury	(5,601)	(5,397)
Proceeds from senior preferred stock purchase agreement with Treasury	0	3,687
Other, net	1,129	720
Net cash used in financing activities	(122,848)	(117,997)
Net increase (decrease) in cash, cash equivalents and restricted cash	15,075	(9,229)
Cash, cash equivalents and restricted cash at beginning of period	49,423	60,260
Cash, cash equivalents and restricted cash at end of period	64,498	51,031
Cash paid during the period for:
Interest	86,699	82,010
Income taxes	1,250	460
Fannie Mae [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	9,338	11,651
Proceeds from sales of loans acquired as held for investment of Fannie Mae	8,987	10,637
Cash flows used in financing activities:
Proceeds from issuance of debt	587,659	636,466
Payments to redeem debt	(606,665)	(666,888)
Consolidated Trusts [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	377,789	306,374
Cash flows used in financing activities:
Proceeds from issuance of debt	286,126	278,357
Payments to redeem debt	$ (385,496)	$ (364,942)

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	(5,397)				(5,397)
Increase to senior preferred stock		3,687
Comprehensive income:
Net income	12,729				12,729
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $2, $8, $7 and $22, respectively)	(84)					(84)
Reclassification adjustment for gains included in net income (net of tax of $1, $1, $30 and $71, respectively)	(265)					(265)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax 1,0,2,0)	(8)					(8)
Total comprehensive income	12,372
Reclassification related to Tax Cuts and Jobs Act					(117)	117
Other	(1)				(1)
Balance at Sep. 30, 2018	6,975	$ 120,836	$ 19,130	$ 687	(126,591)	313	(7,400)
Balance (shares) at Sep. 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 Jun. 30, 2018		1,000,000	556,000,000	1,158,000,000
Balance at Jun. 30, 2018	7,459	$ 120,836	$ 19,130	$ 687	(126,143)	349	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	(4,459)				(4,459)
Increase to senior preferred stock		0
Comprehensive income:
Net income	4,011				4,011
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $2, $8, $7 and $22, respectively)	(31)					(31)
Reclassification adjustment for gains included in net income (net of tax of $1, $1, $30 and $71, respectively)	(2)					(2)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax 1,0,2,0)	(3)					(3)
Total comprehensive income	3,975
Reclassification related to Tax Cuts and Jobs Act					0	0
Other	0				0
Balance at Sep. 30, 2018	$ 6,975	$ 120,836	$ 19,130	$ 687	(126,591)	313	(7,400)
Balance (shares) at Sep. 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	9,795				9,795
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $2, $8, $7 and $22, respectively)	27					27
Reclassification adjustment for gains included in net income (net of tax of $1, $1, $30 and $71, respectively)	(112)					(112)
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax 1,0,2,0)	(7)					(7)
Total comprehensive income	9,703
Balance at Sep. 30, 2019	10,342	$ 120,836	$ 19,130	$ 687	(123,141)	230	(7,400)
Balance (shares) at Sep. 30, 2019		1,000,000	556,000,000	1,158,000,000
Balance (shares) at Jun. 30, 2019		1,000,000	556,000,000	1,158,000,000
Balance at Jun. 30, 2019	6,365	$ 120,836	$ 19,130	$ 687	(127,104)	216	(7,400)
Increase (Decrease) in Stockholders' Equity [Rollforward]
Preferred Stock, Dividends, Per Share, Cash Paid	0				0
Comprehensive income:
Net income	3,963				3,963
Other comprehensive income (loss), net of tax effect:
Changes in net unrealized gains on available-for-sale securities (net of tax of $2, $8, $7 and $22, respectively)	10					10
Reclassification adjustment for gains included in net income (net of tax of $1, $1, $30 and $71, respectively)	6					6
Prior service cost and actuarial gains, net of amortization for defined benefit plans (net of tax 1,0,2,0)	(2)					(2)
Total comprehensive income	3,977
Balance at Sep. 30, 2019	$ 10,342	$ 120,836	$ 19,130	$ 687	$ (123,141)	$ 230	$ (7,400)
Balance (shares) at Sep. 30, 2019		1,000,000	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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 2,000,000	$ 8,000,000	$ 7,000,000	$ 22,000,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	1,000,000	1,000,000	30,000,000	71,000,000
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	$ 1,000,000	$ 0	$ 2,000,000	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 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 nine months ended September 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 nine months ended September 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. On September 5, 2019, Treasury released its plan to reform the housing finance system. The Treasury Housing Reform Plan (the “Treasury plan”) is far-reaching in scope and could have a significant impact on our structure, our role in the secondary mortgage market, our capitalization, our business and our competitive environment. The Treasury plan includes recommendations relating to ending our conservatorship, amending our senior preferred stock purchase agreement with Treasury, considering additional restrictions and requirements on our business, and many other matters. The Treasury plan recommends that Treasury’s commitment to provide funding under the senior preferred stock purchase agreement should be replaced with legislation that authorizes an explicit, paid-for guarantee backed by the full faith and credit of the Federal Government that is limited to the timely payment of principal and interest on qualifying MBS. The Treasury plan further recommends that, pending legislation, even after conservatorship Treasury should maintain its ongoing commitment to support our single-family and multifamily mortgage-backed securities through the senior preferred stock purchase agreement, as amended as contemplated by the plan. 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 (1) to fundamentally change our business model, other than changes that might result from recommendations in the Treasury plan, if implemented, or (2) to reduce the aggregate amount available to or held by the company under our capital structure, which includes the senior preferred stock purchase agreement. Senior Preferred Stock Purchase Agreement and Senior Preferred Stock Treasury has made a commitment under the senior preferred stock purchase agreement to provide funding to us under certain circumstances if we have a net worth deficit. Pursuant to the senior preferred stock purchase agreement, we have received a total of $119.8 billion from Treasury as of September 30, 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 in 2008. On September 27, 2019, we, through FHFA acting on our behalf in its capacity as our conservator, and Treasury entered into a letter agreement modifying the dividend and liquidation preference provisions of the senior preferred stock . These modifications and other specified provisions of the letter agreement are described below. • Modification to Dividend Provisions — Increase in Applicable Capital Reserve Amount. The terms of the senior preferred stock provide for dividends each quarter in the amount, if any, by which our net worth as of the end of the immediately preceding fiscal quarter exceeds the applicable capital reserve amount. The letter agreement modified the dividend provisions of the senior preferred stock to increase the applicable capital reserve amount from $3 billion to $25 billion , effective for dividend periods beginning July 1, 2019. As a result of this change to the senior preferred stock dividend provisions: ◦ No dividends were payable on the senior preferred stock for the third quarter of 2019 , as our net worth of $6.4 billion as of June 30, 2019 was lower than the $25 billion capital reserve amount. ◦ No dividends will be payable on the senior preferred stock for the fourth quarter of 2019 , as our net worth of $10.3 billion as of September 30, 2019 is lower than the $25 billion capital reserve amount. • Modification to Liquidation Preference Provisions — Increase in Liquidation Preference. The letter agreement provides that, on September 30, 2019, and at the end of each fiscal quarter thereafter, the liquidation preference of the senior preferred stock will increase by an amount equal to the increase in our net worth, if any, during the immediately prior fiscal quarter, until such time as the liquidation preference has increased by $22 billion . As a result of this change to the senior preferred stock liquidation preference provisions: ◦ The aggregate liquidation preference of the senior preferred stock increased from $123.8 billion as of June 30, 2019 to $127.2 billion as of September 30, 2019 , due to the $3.4 billion increase in our net worth during the second quarter of 2019 . ◦ The aggregate liquidation preference of the senior preferred stock will increase from $127.2 billion as of September 30, 2019 to $131.2 billion as of December 31, 2019 , due to the $4.0 billion increase in our net worth during the third quarter of 2019 . • Agreement to Amend Senior Preferred Stock Purchase Agreement to Enhance Taxpayer Protections. The letter agreement provides that we and Treasury agree to negotiate and execute an additional amendment to the senior preferred stock purchase agreement that further enhances taxpayer protections by adopting covenants broadly consistent with recommendations for administrative reform contained in the Treasury plan. 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 and UMBS The Single Security Initiative was 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. 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. Since the implementation of the Single Security Initiative in June 2019, we have been able to include UMBS, Supers and other structured 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. 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. 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. With the implementation 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. With the implementation 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. Since the implementation of the Single Security Initiative in June 2019, 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. Regulatory Capital We submit capital reports to FHFA, which monitors our capital levels. The deficit of core capital over statutory minimum capital was $133.8 billion as of September 30, 2019 and $137.1 billion as of December 31, 2018 . Related Parties Because Treasury holds a warrant to purchase shares of Fannie Mae common stock equal to 79.9% of the total number of shares of Fannie Mae common stock, we and Treasury are deemed related parties. As of September 30, 2019 , Treasury held an investment in our senior preferred stock with an aggregate liquidation preference of $127.2 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 September 30, 2019 and 2018 , respectively, and $15 million and $19 million for the nine months ended September 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 $613 million and $576 million in TCCA fees during the three months ended September 30, 2019 and 2018 , respectively, and $1.8 billion and $1.7 billion for the nine months ended September 30, 2019 and 2018 , respectively, of which $613 million had not been remitted to Treasury as of September 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 $32 million and $20 million in “Other expenses, net” for the three months ended September 30, 2019 and 2018 , respectively, and $68 million and $57 million for the nine months ended September 30, 2019 and 2018 , respectively, relating to amounts payable to Treasury’s Capital Magnet Fund. In 2020, we expect to pay the $68 million recognized for the nine months ended September 30, 2019 to Treasury’s Capital Magnet Fund, along with additional amounts based on our new business purchases in the fourth quarter of 2019. In April 2019, we paid $75 million to Treasury’s Capital Magnet Fund based on our new business purchases in 2018. On September 27, 2019, we, through FHFA acting on our behalf in its capacity as our conservator, and Treasury entered into a letter agreement modifying the dividend and liquidation preference provisions of the senior preferred stock held by Treasury. These modifications and other specified provisions of the letter agreement are described under “Senior Preferred Stock Purchase Agreement and Senior Preferred Stock” above. 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 $30 million and $26 million for the three months ended September 30, 2019 and 2018 , respectively, and $89 million and $81 million for the nine months ended September 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 $22 million and $33 million for the three months ended September 30, 2019 and 2018 , respectively, and $84 million and $109 million for the nine months ended September 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). Net income (loss) attributable to common stockholders excludes amounts attributable to the senior preferred stock, which increase the liquidation preference as described above in “ Senior Preferred Stock Purchase Agreement and Senior Preferred Stock .” Weighted average common shares includes 4.6 billion shares for the periods ended September 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 September 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 September 30, 2019 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. For the nine months ended September 30, 2019 and 2018 and the three months ended September 30, 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. New Accounting Guidance T he following updates information about our significant accounting policies that have recently been adopted or are 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 in June 2016. It was amended by ASU 2019-04, Codification Improvements (to Topic 326), Financial Instruments—Credit Losses in April 2019. These ASUs (the “CECL standard”) replace 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 develop credit loss estimates. The amendments in this standard also require credit losses related to available-for-sale (“AFS”) 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 AFS debt securities. The CECL standard will become effective for our fiscal year beginning January 1, 2020. We are currently performing full integrated testing across all models, accounting systems and processes that will be used to estimate credit losses and record accounting impacts under the CECL standard. All updates to our credit loss models are subject to our model oversight and review governance process. 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 expected credit losses on our single-family mortgage loans and an undiscounted loss method to measure expected credit losses on our multifamily mortgage loans. The models 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 September 30, 2019 and our current expectations of future economic conditions, we estimate that our adoption of the CECL standard will result in a reduction in our retained earnings of up to $2 billion on an after-tax basis in the first quarter of 2020. Our estimated impact upon adoption has been refined over the last quarter to incorporate updated economic conditions and the resolution of various implementation items, including the exclusion of certain pre-foreclosure costs from our estimated allowance for credit losses. We continue to monitor and will assess the impact of further implementation guidance that may be issued. In addition, we continue to evaluate our modeled loss estimates and may make refinements to our approach and assumptions as a part of our overall integrated testing efforts. The impact of our adoption of the CECL standard 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 changes in economic conditions and our forecasts of future economic conditions at that time.

Consolidations and Transfers of

Consolidations and Transfers of Financial Assets	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts: (Dollars in millions) Assets: Trading securities: Fannie Mae $ 2,733 $ 1,422 Non-Fannie Mae 4,445 4,809 Total trading securities 7,178 6,231 Available-for-sale securities: Fannie Mae 1,581 1,704 Non-Fannie Mae 771 1,207 Total available-for-sale securities 2,352 2,911 Other assets 57 66 Other liabilities (82 ) (101 ) Net carrying amount $ 9,505 $ 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 $41 billion and $14 billion as of September 30, 2019 and December 31, 2018 , respectively. The total assets of our unconsolidated securitization and resecuritization trusts were approximately $100 billion and $80 billion as of September 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 $93 million and the related carrying value was $70 million as of September 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 $2.3 billion as of September 30, 2019 and December 31, 2018 . 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 $6.5 billion and $920 million as of September 30, 2019 and December 31, 2018 , respectively. The total assets related to these unconsolidated SPVs were $6.5 billion and $931 million as of September 30, 2019 and December 31, 2018 , respectively. The unpaid principal balance of our multifamily loan portfolio was $318.1 billion as of September 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 September 30, 2019 and 2018 , the unpaid principal balance of portfolio securitizations was $89.0 billion and $64.9 billion , respectively. For the nine months ended September 30, 2019 and 2018 , the unpaid principal balance of portfolio securitizations was $187.7 billion and $180.8 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 September 30, 2019 , the unpaid principal balance of retained interests was $3.1 billion and its related fair value was $4.2 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 September 30, 2019 and 2018 , the principal, interest and other fees received on retained interests was $187 million and $114 million , respectively. For the nine months ended September 30, 2019 and 2018 , the principal, interest and other fees received on retained interests was $425 million and $468 million , respectively. Managed Loans Managed loans primarily include 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 September 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	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,962,083 $ 2,929,925 Multifamily 318,106 293,858 Total unpaid principal balance of mortgage loans 3,280,189 3,223,783 Cost basis and fair value adjustments, net 43,323 39,815 Allowance for loan losses for loans held for investment (9,376 ) (14,203 ) Total mortgage loans $ 3,314,136 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 4,882 $ 4,249 $ 14,252 $ 17,851 Carrying value of loans redesignated from HFS to HFI (1) 10 6 22 36 Loans sold - unpaid principal balance 3,941 9,373 10,497 13,831 Realized gains on sale of mortgage loans 184 93 504 301 (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 $8.2 billion and $10.1 billion as of September 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 September 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 $ 29,211 $ 7,188 $ 13,291 $ 49,690 $ 2,867,330 $ 2,917,020 $ 26 $ 23,840 Government (2) 44 20 144 208 17,881 18,089 144 — Alt-A 1,717 591 1,316 3,624 40,663 44,287 1 2,228 Other 572 212 485 1,269 9,836 11,105 2 800 Total single-family 31,544 8,011 15,236 54,791 2,935,710 2,990,501 173 26,868 Multifamily (3) 32 N/A 181 213 320,984 321,197 — 604 Total $ 31,576 $ 8,011 $ 15,417 $ 55,004 $ 3,256,694 $ 3,311,698 $ 173 $ 27,472 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 September 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% $ 2,569,771 $ 39,710 $ 9,694 $ 2,521,766 $ 45,476 $ 12,291 Greater than 80% and less than or equal to 90% 228,868 2,365 709 228,614 3,804 1,195 Greater than 90% and less than or equal to 100% 113,424 1,131 337 109,548 1,997 645 Greater than 100% 4,957 1,081 365 9,337 1,994 707 Total $ 2,917,020 $ 44,287 $ 11,105 $ 2,869,265 $ 53,271 $ 14,838 (1) Excludes $18.1 billion and $22.1 billion as of September 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 September 30, December 31, 2019 2018 (Dollars in millions) Credit risk profile by internally assigned grade: Non-classified $ 314,458 $ 289,231 Classified (1) 6,739 6,433 Total $ 321,197 $ 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 September 30, 2019 , we had loans with recorded investment of less than $0.1 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 September 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 $ 67,175 $ 64,987 $ (6,141 ) $ 81,791 $ 78,688 $ (9,406 ) Government 250 255 (50 ) 264 270 (55 ) Alt-A 11,956 11,008 (1,726 ) 16,576 15,158 (2,793 ) Other 3,703 3,505 (590 ) 5,482 5,169 (1,001 ) Total single-family 83,084 79,755 (8,507 ) 104,113 99,285 (13,255 ) Multifamily 281 283 (45 ) 197 196 (40 ) Total individually impaired loans with related allowance recorded 83,365 80,038 (8,552 ) 104,310 99,481 (13,295 ) With no related allowance recorded: (1) Single-family: Primary 19,326 18,463 — 15,939 15,191 — Government 65 61 — 61 56 — Alt-A 2,391 2,141 — 2,628 2,363 — Other 624 571 — 718 666 — Total single-family 22,406 21,236 — 19,346 18,276 — Multifamily 368 369 — 343 346 — Total individually impaired loans with no related allowance recorded 22,774 21,605 — 19,689 18,622 — Total individually impaired loans (2) $ 106,139 $ 101,643 $ (8,552 ) $ 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 $100.7 billion and $117.2 billion as of September 30, 2019 and December 31, 2018 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $126 million and $187 million as of September 30, 2019 and December 31, 2018 , respectively. For the Three Months Ended September 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 $ 69,084 $ 713 $ 62 $ 84,043 $ 871 $ 86 Government 262 2 — 276 3 — Alt-A 11,845 125 8 17,034 179 13 Other 3,904 37 4 6,254 57 4 Total single-family 85,095 877 74 107,607 1,110 103 Multifamily 313 2 — 231 1 — Total individually impaired loans with related allowance recorded 85,408 879 74 107,838 1,111 103 With no related allowance recorded: (1) Single-family: Primary 16,422 262 39 15,140 254 30 Government 56 1 — 57 1 — Alt-A 2,130 44 4 2,562 54 4 Other 575 10 1 784 13 2 Total single-family 19,183 317 44 18,543 322 36 Multifamily 401 8 — 335 8 — Total individually impaired loans with no related allowance recorded 19,584 325 44 18,878 330 36 Total individually impaired loans $ 104,992 $ 1,204 $ 118 $ 126,716 $ 1,441 $ 139 For the Nine Months Ended September 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 $ 73,601 $ 2,304 $ 214 $ 86,842 $ 2,697 $ 302 Government 267 8 — 277 15 — Alt-A 13,299 426 30 19,081 610 45 Other 4,429 123 11 7,140 201 15 Total single-family 91,596 2,861 255 113,340 3,523 362 Multifamily 280 7 — 244 2 — Total individually impaired loans with related allowance recorded 91,876 2,868 255 113,584 3,525 362 With no related allowance recorded: (1) Single-family: Primary 15,718 731 103 15,039 740 88 Government 56 3 — 58 3 — Alt-A 2,203 127 11 2,710 173 13 Other 611 28 3 848 44 4 Total single-family 18,588 889 117 18,655 960 105 Multifamily 377 16 — 333 11 — Total individually impaired loans with no related allowance recorded 18,965 905 117 18,988 971 105 Total individually impaired loans $ 110,841 $ 3,773 $ 372 $ 132,572 $ 4,496 $ 467 (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 164 months and 98 months for the three months ended September 30, 2019 and 2018 , respectively. The average interest rate reduction was 0.15 and 0.14 percentage points, for the three months ended September 30, 2019 and 2018 , respectively. During the nine months ended September 30, 2019 and 2018 , the average term extension of a single-family modified loan was 160 months and 104 months, respectively, and the average interest rate reduction was 0.11 and 0.23 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 September 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 11,373 $ 1,819 12,291 $ 1,797 Government 16 1 21 3 Alt-A 543 70 779 100 Other 89 16 207 37 Total single-family 12,021 1,906 13,298 1,937 Multifamily 3 4 2 7 Total TDRs 12,024 $ 1,910 13,300 $ 1,944 For the Nine Months Ended September 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 36,126 $ 5,634 75,790 $ 11,469 Government 61 7 95 9 Alt-A 1,948 248 4,499 583 Other 374 68 937 173 Total single-family 38,509 5,957 81,321 12,234 Multifamily 9 37 12 68 Total TDRs 38,518 $ 5,994 81,333 $ 12,302 (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 nine months ended September 30, 2019 compared with the three and nine months ended September 30, 2018 was primarily attributable to a significantly higher number of single-family loan modifications and other forms of loss mitigation in the areas affected by Hurricanes Harvey, Irma and Maria that resulted in a restructuring of the terms of those loans during the first nine months of 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 September 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 3,780 $ 585 3,720 $ 519 Government 28 2 8 — Alt-A 307 43 438 74 Other 87 16 143 29 Total single-family 4,202 646 4,309 622 Multifamily 1 13 1 2 Total TDRs that subsequently defaulted 4,203 $ 659 4,310 $ 624 For the Nine Months Ended September 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 12,343 $ 1,864 12,372 $ 1,774 Government 56 7 37 4 Alt-A 1,157 174 1,703 275 Other 351 65 469 93 Total single-family 13,907 2,110 14,581 2,146 Multifamily 2 19 2 4 Total TDRs that subsequently defaulted 13,909 $ 2,129 14,583 $ 2,150

Allowance for Loan Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 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. During the three months ended September 30, 2019 , we enhanced the model used to estimate cash flows for individually impaired single-family loans within our allowance for loan losses. This enhancement was performed as a part of management’s routine model performance review process. In addition to incorporating recent loan performance data, this model enhancement better captures recent prepayment activity, default rates, and loss severity in the event of default. The enhancement resulted in a decrease to our allowance for loan losses and an incremental benefit for credit losses of approximately $850 million and is included in “Benefit (provision) for loan losses” in the table below. 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 September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,210 ) $ (16,602 ) $ (13,969 ) $ (18,849 ) Benefit (provision) for loan losses (1) 1,826 724 3,712 1,916 Charge-offs 270 509 1,209 1,705 Recoveries (8 ) (65 ) (68 ) (189 ) Other — (2 ) (6 ) (19 ) Ending balance $ (9,122 ) $ (15,436 ) $ (9,122 ) $ (15,436 ) Multifamily allowance for loan losses: Beginning balance $ (272 ) $ (210 ) $ (234 ) $ (235 ) Benefit (provision) for loan losses (1) 17 (14 ) (23 ) 6 Charge-offs 2 — 6 5 Recoveries (1 ) (3 ) (3 ) (3 ) Ending balance $ (254 ) $ (227 ) $ (254 ) $ (227 ) Total allowance for loan losses: Beginning balance $ (11,482 ) $ (16,812 ) $ (14,203 ) $ (19,084 ) Benefit (provision) for loan losses (1) 1,843 710 3,689 1,922 Charge-offs 272 509 1,215 1,710 Recoveries (9 ) (68 ) (71 ) (192 ) Other — (2 ) (6 ) (19 ) Ending balance $ (9,376 ) $ (15,663 ) $ (9,376 ) $ (15,663 ) (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 September 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) $ (8,507 ) $ (45 ) $ (8,552 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (615 ) (209 ) (824 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (9,122 ) $ (254 ) $ (9,376 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 100,991 $ 652 $ 101,643 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,889,510 320,545 3,210,055 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,990,501 $ 321,197 $ 3,311,698 $ 2,959,504 $ 295,664 $ 3,255,168 (1) Includes acquired credit-impaired loans.

Investments in Securities

Investments in Securities	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 (Dollars in millions) Mortgage-related securities: Fannie Mae (1) $ 3,661 $ 1,467 Other agency (2) 3,704 3,503 Private-label and other mortgage securities 741 1,306 Total mortgage-related securities (includes $922 and $32, respectively, related to consolidated trusts) 8,106 6,276 Non-mortgage-related securities: U.S. Treasury securities 36,016 35,502 Other securities 84 89 Total non-mortgage-related securities 36,100 35,591 Total trading securities $ 44,206 $ 41,867 (1) In the second quarter of 2019, we implemented the Single Security Initiative and 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 (losses). For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Net trading gains (losses) $ 95 $ (40 ) $ 370 $ 79 Net trading gains (losses) recognized in the period related to securities still held at period end 82 (27 ) 298 20 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 September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Gross realized gains $ — $ 12 $ 171 $ 375 Total proceeds (excludes initial sale of securities from new portfolio securitizations) — 21 376 662 The following tables display the amortized cost, gross unrealized gains and losses, and fair value by major security type for AFS securities. As of September 30, 2019 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,492 $ 98 $ (8 ) $ 1,582 Other agency 195 18 — 213 Alt-A and subprime private-label securities 102 124 — 226 Mortgage revenue bonds 339 10 (3 ) 346 Other mortgage-related securities 320 5 (2 ) 323 Total $ 2,448 $ 255 $ (13 ) $ 2,690 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 September 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 $ — $ — $ (8 ) $ 348 Mortgage revenue bonds — — (3 ) 5 Other mortgage-related securities (2 ) 273 — — Total $ (2 ) $ 273 $ (11 ) $ 353 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 $37 million and $635 million as of September 30, 2019 and December 31, 2018 , respectively. Those amounts were $718 million and $1.1 billion as of September 30, 2018 and December 31, 2017 , respectively. The decrease in the cumulative outstanding balance in the first nine 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 September 30, December 31, 2019 2018 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 191 $ 52 Net unrealized gains on AFS securities for which we have recorded OTTI — 224 Other 39 46 Accumulated other comprehensive income $ 230 $ 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 September 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 $ 1,492 $ 1,582 $ — $ — $ 14 $ 15 $ 101 $ 111 $ 1,377 $ 1,456 Other agency 195 213 — — 20 21 26 29 149 163 Alt-A and subprime private-label securities 102 226 — — — — 1 1 101 225 Mortgage revenue bonds 339 346 2 2 26 27 36 37 275 280 Other mortgage-related securities 320 323 — — 2 1 24 27 294 295 Total $ 2,448 $ 2,690 $ 2 $ 2 $ 62 $ 64 $ 188 $ 205 $ 2,196 $ 2,419

Financial Guarantees

Financial Guarantees	9 Months Ended
	Sep. 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 structured securities backed in whole or in part by Freddie Mac-issued securities, we extend our guaranty to the underlying Freddie Mac securities in our resecuritization trusts. However, Freddie Mac continues to guarantee the payment of principal and interest on the underlying Freddie Mac securities that we have resecuritized. We do not charge an incremental guaranty fee to include Freddie Mac securities in the structured securities that we issue. 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 $28.9 billion of Freddie Mac securities backing unconsolidated Fannie Mae-issued structured securities as of September 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 September 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 $ 6,603 $ 26 $ 6,354 $ 7,278 $ 30 $ 6,811 Other guaranty arrangements (2) 12,981 135 2,609 13,847 130 2,711 Total $ 19,584 $ 161 $ 8,963 $ 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	9 Months Ended
	Sep. 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 September 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) $ 1,125 2.15 % $ — — % Short-term debt of Fannie Mae $ 35,812 2.04 % $ 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 up to $15.0 billion as of September 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 September 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 $ 91,603 2.66 % 2019 - 2030 $ 103,206 2.36 % Medium-term notes (2) 2019 - 2026 40,973 1.60 2019 - 2026 61,455 1.48 Other (3) 2019 - 2038 6,142 4.84 2019 - 2038 6,683 4.62 Total senior fixed 138,718 2.44 171,344 2.13 Senior floating: Medium-term notes (2) 2020 - 2021 9,773 2.28 2019 - 2020 4,174 2.36 Connecticut Avenue Securities (4) 2023 - 2031 22,977 5.90 2023 - 2031 25,641 5.97 Other (5) 2020 - 2037 422 7.79 2020 - 2037 351 10.19 Total senior floating 33,172 4.86 30,166 5.52 Subordinated debentures 2019 5,783 9.99 2019 5,617 9.64 Secured borrowings (6) 2021 - 2022 37 2.24 2021 - 2022 51 1.96 Total long-term debt of Fannie Mae (7) 177,710 3.14 207,178 2.83 Debt of consolidated trusts 2019 - 2058 3,248,336 2.79 2019 - 2058 3,159,846 3.03 Total long-term debt $ 3,426,046 2.81 % $ 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 $30 million and $413 million as of September 30, 2019 and December 31, 2018 , respectively.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 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. See “ Note 8, Derivative Instruments ” in our 2018 Form 10-K for additional information on interest rate risk management. 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 September 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 $ 35,550 $ — $ 32,893 $ (1,481 ) $ 71,416 $ 438 $ 21,253 $ (740 ) Receive-fixed 71,372 958 34,986 (103 ) 88,799 1,113 58,399 (860 ) Basis 273 179 — — 250 104 624 — Foreign currency 213 27 215 (86 ) 221 22 223 (72 ) Swaptions: Pay-fixed 4,600 18 6,375 (270 ) 10,375 191 1,000 (4 ) Receive-fixed 2,875 203 4,600 (137 ) 500 20 7,375 (338 ) Futures (1) 47,069 — — — 16,631 — — — Total gross risk management derivatives 161,952 1,385 79,069 (2,077 ) 188,192 1,888 88,874 (2,014 ) Accrued interest receivable (payable) — 287 — (374 ) — 400 — (419 ) Netting adjustment (2) — (1,663 ) — 2,299 — (2,266 ) — 2,315 Total net risk management derivatives $ 161,952 $ 9 $ 79,069 $ (152 ) $ 188,192 $ 22 $ 88,874 $ (118 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 7,812 $ 20 $ 6,258 $ (26 ) $ 4,370 $ 29 $ 57 $ — Forward contracts to purchase mortgage-related securities 70,120 231 28,853 (85 ) 40,650 349 1,045 (3 ) Forward contracts to sell mortgage-related securities 57,048 170 109,229 (305 ) 292 1 70,593 (645 ) Total mortgage commitment derivatives 134,980 421 144,340 (416 ) 45,312 379 71,695 (648 ) Credit enhancement derivatives 30,407 42 6,509 (27 ) 33,431 57 919 (11 ) Derivatives at fair value $ 327,339 $ 472 $ 229,918 $ (595 ) $ 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 $1.3 billion and $713 million as of September 30, 2019 and December 31, 2018 , respectively. Cash collateral received was $684 million and $664 million as of September 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 September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (1,414 ) $ 1,034 $ (4,913 ) $ 4,784 Receive-fixed 966 (524 ) 4,131 (3,508 ) Basis 24 (5 ) 75 (31 ) Foreign currency (11 ) (10 ) (9 ) (35 ) Swaptions: Pay-fixed (110 ) 67 (430 ) 232 Receive-fixed 209 (34 ) 309 (72 ) Futures 42 — 296 (3 ) Net accrual of periodic settlements (190 ) (285 ) (698 ) (786 ) Total risk management derivatives fair value gains (losses), net (484 ) 243 (1,239 ) 581 Mortgage commitment derivatives fair value gains (losses), net (177 ) 118 (946 ) 606 Credit enhancement derivatives fair value losses, net (7 ) (1 ) (31 ) (2 ) Total derivatives fair value gains (losses), net $ (668 ) $ 360 $ (2,216 ) $ 1,185 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	9 Months Ended
	Sep. 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 September 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 4,484 $ 745 $ 5,229 $ 4,670 $ 699 $ 5,369 Fee and other income (2) 156 246 402 79 192 271 Net revenues 4,640 991 5,631 4,749 891 5,640 Investment gains, net (3) 198 55 253 146 20 166 Fair value gains (losses), net (4) (719 ) 6 (713 ) 417 (31 ) 386 Administrative expenses (634 ) (115 ) (749 ) (636 ) (104 ) (740 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,840 17 1,857 732 (16 ) 716 Foreclosed property expense (93 ) (3 ) (96 ) (150 ) (9 ) (159 ) Total credit-related income (expense) 1,747 14 1,761 582 (25 ) 557 TCCA fees (6) (613 ) — (613 ) (576 ) — (576 ) Other expenses, net (424 ) (147 ) (571 ) (282 ) (95 ) (377 ) Income before federal income taxes 4,195 804 4,999 4,400 656 5,056 Provision for federal income taxes (872 ) (164 ) (1,036 ) (938 ) (107 ) (1,045 ) Net income $ 3,323 $ 640 $ 3,963 $ 3,462 $ 549 $ 4,011 For the Nine Months Ended September 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 12,942 $ 2,170 $ 15,112 $ 13,954 $ 2,024 $ 15,978 Fee and other income (2) 350 525 875 306 524 830 Net revenues 13,292 2,695 15,987 14,260 2,548 16,808 Investment gains, net (3) 709 138 847 640 53 693 Fair value gains (losses), net (4) (2,364 ) 66 (2,298 ) 1,729 (69 ) 1,660 Administrative expenses (1,899 ) (338 ) (2,237 ) (1,928 ) (317 ) (2,245 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 3,753 (21 ) 3,732 2,223 6 2,229 Foreclosed property expense (362 ) (2 ) (364 ) (448 ) (12 ) (460 ) Total credit-related income (expense) 3,391 (23 ) 3,368 1,775 (6 ) 1,769 TCCA fees (6) (1,806 ) — (1,806 ) (1,698 ) — (1,698 ) Other expenses, net (1,179 ) (335 ) (1,514 ) (684 ) (262 ) (946 ) Income before federal income taxes 10,144 2,203 12,347 14,094 1,947 16,041 Provision for federal income taxes (2,125 ) (427 ) (2,552 ) (2,998 ) (314 ) (3,312 ) Net income $ 8,019 $ 1,776 $ 9,795 $ 11,096 $ 1,633 $ 12,729 (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	9 Months Ended
	Sep. 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 September 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) 1.11 % 0.29 % 0.61 % 1.17 % 0.32 % 0.69 % Percentage of single-family conventional loans (4) 1.28 0.35 0.68 1.37 0.38 0.76 As of September 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% * 10.62 % * 9.85 % Geographical distribution: California 19 0.32 19 0.34 Florida 6 0.87 6 1.16 New Jersey 3 1.21 4 1.38 New York 5 1.24 5 1.40 All other states 67 0.67 66 0.75 Product distribution: Alt-A 2 3.09 2 3.35 Vintages: 2004 and prior 2 2.53 3 2.69 2005-2008 4 4.24 5 4.61 2009-2019 94 0.33 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 more than 99% of our single-family conventional guaranty book of business as of September 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 September 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 original LTV ratios greater than 80%. We stratify multifamily loans into different internal risk categories based on the credit risk inherent in each individual loan. The following tables display the delinquency status and serious delinquency rates for specified loan categories of our multifamily guaranty book of business. As of September 30, 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 * 0.06 % 0.02 % 0.06 % As of September 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 0.06 99 0.06 Current DSCR below 1.0 (4) 2 0.44 2 1.38 * Represents less than 0.01% of multifamily business volume or book of business. (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 September 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 $ 162,339 $ 152,379 Pool mortgage insurance 379 409 Total mortgage insurance risk in force $ 162,718 6% $ 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 September 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 $3.7 billion , or 2% , of our risk in force mortgage insurance coverage of our single-family guaranty book of business as of September 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. On at least a quarterly basis, we assess our mortgage insurer counterparties’ respective abilities to fulfill their obligations to us. Our assessment includes financial reviews and analyses of the insurers’ portfolios and capital adequacy. If we determine that it is probable that we will not collect all of our claims from one or more of our mortgage insurer counterparties, it could increase our loss reserves, which could adversely affect our results of operations, liquidity, financial condition and net worth. When we estimate the credit losses that are inherent in our mortgage loans and under the terms of our guaranty obligations, we also consider the recoveries that we will receive on primary mortgage insurance, as mortgage insurance recoveries would reduce the severity of the loss associated with defaulted loans. We evaluate the financial condition of our mortgage insurer counterparties and adjust the contractually due recovery amounts to ensure that 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 September 30, 2019 and December 31, 2018 , our estimated benefit from mortgage insurance reduced our loss reserves by $398 million and $691 million , respectively. As of September 30, 2019 and December 31, 2018 , we had outstanding receivables of $669 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 September 30, 2019 and December 31, 2018 , we assessed these outstanding receivables for collectibility, and established a valuation allowance of $545 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 September 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 17 % 18 % Remaining top five depository servicers 15 16 Top five non-depository servicers 25 22 Total 57 % 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 September 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	9 Months Ended
	Sep. 30, 2019
Offsetting [Abstract]
Netting Arrangements	Netting Arrangements We use master netting arrangements, which allow us to offset certain financial instruments and collateral with the same counterparty, to minimize counterparty credit exposure. The tables below display information related to derivatives, securities purchased under agreements to resell or similar arrangements, and securities sold under agreements to repurchase or similar arrangements, which are subject to an enforceable master netting arrangement or similar agreement that are either offset or not offset in our condensed consolidated balance sheets. As of September 30, 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 $ 1,672 $ (1,667 ) $ 5 $ — $ — $ 5 Cleared risk management derivatives — 4 4 — — 4 Mortgage commitment derivatives 421 — 421 (368 ) (7 ) 46 Total derivative assets 2,093 (1,663 ) 430 (4) (368 ) (7 ) 55 Securities purchased under agreements to resell or similar arrangements (5) 36,051 — 36,051 — (36,051 ) — Total assets $ 38,144 $ (1,663 ) $ 36,481 $ (368 ) $ (36,058 ) $ 55 Liabilities: OTC risk management derivatives $ (2,451 ) $ 2,332 $ (119 ) $ — $ — $ (119 ) Cleared risk management derivatives — (33 ) (33 ) — 33 — Mortgage commitment derivatives (416 ) — (416 ) 368 4 (44 ) Total derivative liabilities (2,867 ) 2,299 (568 ) (4) 368 37 (163 ) Securities sold under agreements to repurchase or similar arrangements (1,125 ) — (1,125 ) — 1,123 (2 ) Total liabilities $ (3,992 ) $ 2,299 $ (1,693 ) $ 368 $ 1,160 $ (165 ) 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 $3.1 billion and $1.9 billion as of September 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 $36.1 billion and $48.4 billion , of which $34.3 billion and $45.7 billion could be sold or repledged as of September 30, 2019 and December 31, 2018 , respectively. None of the underlying collateral was sold or repledged as of September 30, 2019 or December 31, 2018 . (4) Excludes derivative assets of $42 million and $57 million as of September 30, 2019 and December 31, 2018 , respectively, and derivative liabilities of $27 million and $11 million recognized in our condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $12.9 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 September 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	9 Months Ended
	Sep. 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 September 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: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 3,539 $ 122 $ — $ 3,661 Other agency — 3,702 2 — 3,704 Private-label and other mortgage securities — 741 — — 741 Non-mortgage-related securities: U.S. Treasury securities 36,016 — — — 36,016 Other securities — 84 — — 84 Total trading securities 36,016 8,066 124 — 44,206 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,408 174 — 1,582 Other agency — 213 — — 213 Alt-A and subprime private-label securities — 226 — — 226 Mortgage revenue bonds — — 346 — 346 Other — 8 315 — 323 Total available-for-sale securities — 1,855 835 — 2,690 Mortgage loans — 7,457 726 — 8,183 Other assets: Risk management derivatives: Swaps — 1,267 184 — 1,451 Swaptions — 221 — — 221 Netting adjustment — — — (1,663 ) (1,663 ) Mortgage commitment derivatives — 421 — — 421 Credit enhancement derivatives — — 42 — 42 Total other assets — 1,909 226 (1,663 ) 472 Total assets at fair value $ 36,016 $ 19,287 $ 1,911 $ (1,663 ) $ 55,551 Fair Value Measurements as of September 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 $ — $ 5,619 $ 422 $ — $ 6,041 Total of Fannie Mae — 5,619 422 — 6,041 Of consolidated trusts — 22,631 88 — 22,719 Total long-term debt — 28,250 510 — 28,760 Other liabilities: Risk management derivatives: Swaps — 2,043 1 — 2,044 Swaptions — 407 — — 407 Netting adjustment — — — (2,299 ) (2,299 ) Mortgage commitment derivatives — 416 — — 416 Credit enhancement derivatives — — 27 — 27 Total other liabilities — 2,866 28 (2,299 ) 595 Total liabilities at fair value $ — $ 31,116 $ 538 $ (2,299 ) $ 29,355 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 September 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, June 30, 2019 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 74 $ 2 $ — $ 77 $ — $ — $ — $ (31 ) $ — $ 122 $ 1 $ — Other agency — — — — — — — — 2 2 — — Total trading securities $ 74 $ 2 (5)(6) $ — $ 77 $ — $ — $ — $ (31 ) $ 2 $ 124 $ 1 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 132 $ — $ 3 $ — $ — $ — $ (1 ) $ — $ 40 $ 174 $ — $ 3 Mortgage revenue bonds 364 1 (1 ) — — — (18 ) — — 346 — — Other 326 (1 ) (1 ) — — — (9 ) — — 315 — (2 ) Total available-for-sale securities $ 822 $ — (6)(7) $ 1 $ — $ — $ — $ (28 ) $ — $ 40 $ 835 $ — $ 1 Mortgage loans $ 770 $ 14 (5)(6) $ — $ — $ (27 ) $ — $ (35 ) $ (41 ) $ 45 $ 726 $ 10 $ — Net derivatives 183 21 (5) — — — — (6 ) — — 198 15 — Long-term debt: Of Fannie Mae: Senior floating (398 ) (24 ) — — — — — — — (422 ) (24 ) — Of consolidated trusts (102 ) (3 ) — — — (2 ) 6 20 (7 ) (88 ) (1 ) — Total long-term debt $ (500 ) $ (27 ) (5) $ — $ — $ — $ (2 ) $ 6 $ 20 $ (7 ) $ (510 ) $ (25 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, December 31, 2018 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 5 $ — $ 77 $ (14 ) $ — $ (16 ) $ (31 ) $ 69 $ 122 $ 4 $ — Other agency — — — — — — — — 2 2 — — Private-label and other mortgage securities 1 — — — — — (1 ) — — — — — Total trading securities $ 33 $ 5 (5)(6) $ — $ 77 $ (14 ) $ — $ (17 ) $ (31 ) $ 71 $ 124 $ 4 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 9 $ — $ — $ — $ (8 ) $ (103 ) $ 124 $ 174 $ — $ 8 Alt-A and subprime private-label securities 24 5 (5 ) — (23 ) — (1 ) — — — — — Mortgage revenue bonds 434 1 (2 ) — (4 ) — (83 ) — — 346 — (1 ) Other 342 11 (11 ) — — — (26 ) (2 ) 1 315 — (9 ) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (9 ) $ — $ (27 ) $ — $ (118 ) $ (105 ) $ 125 $ 835 $ — $ (2 ) Mortgage loans $ 937 $ 45 (5)(6) $ — $ — $ (40 ) $ — $ (105 ) $ (228 ) $ 117 $ 726 $ 28 $ — Net derivatives 194 139 (5) — — — — (126 ) (9 ) — 198 39 — Long-term debt: Of Fannie Mae: Senior floating (351 ) (71 ) — — — — — — — (422 ) (71 ) — Of consolidated trusts (201 ) (7 ) — — — (2 ) 16 189 (83 ) (88 ) (3 ) — Total long-term debt $ (552 ) $ (78 ) (5) $ — $ — $ — $ (2 ) $ 16 $ 189 $ (83 ) $ (510 ) $ (74 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2018 (1) Balance, June 30, 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, September 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 79 $ (3 ) $ — $ — $ — $ — $ — $ — $ — $ 76 $ 2 $ — Private-label and other mortgage securities 1 — — — — — — — — 1 — — Total trading securities $ 80 $ (3 ) (5)(6) $ — $ — $ — $ — $ — $ — $ — $ 77 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 204 $ — $ (1 ) $ — $ — $ — $ (3 ) $ — $ — $ 200 $ — $ (1 ) Alt-A and subprime private-label securities 26 — — — — — (2 ) — — 24 — — Mortgage revenue bonds 506 1 (3 ) — (4 ) — (36 ) — — 464 — (2 ) Other 357 7 (7 ) — — — (9 ) — — 348 — (6 ) Total available-for-sale securities $ 1,093 $ 8 (6)(7) $ (11 ) $ — $ (4 ) $ — $ (50 ) $ — $ — $ 1,036 $ — $ (9 ) Mortgage loans $ 1,018 $ 7 (5)(6) $ — $ — $ — $ — $ (47 ) $ (44 ) $ 31 $ 965 $ 2 $ — Net derivatives 117 (18 ) (5) — — — — (1 ) — — 98 (27 ) — Long-term debt: Of Fannie Mae: Senior floating (354 ) 7 — — — — — — — (347 ) 7 — Of consolidated trusts (319 ) 2 — — — — 4 172 (22 ) (163 ) — — Total long-term debt $ (673 ) $ 9 (5) $ — $ — $ — $ — $ 4 $ 172 $ (22 ) $ (510 ) $ 7 $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 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, September 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 971 $ 163 $ — $ 1 $ (1,060 ) $ — $ — $ — $ 1 $ 76 $ 2 $ — Other agency 35 (1 ) — — — — (1 ) (33 ) — — — — Private-label and other mortgage securities 195 (85 ) — — — — (5 ) (104 ) — 1 — — Total trading securities $ 1,201 $ 77 (5)(6) $ — $ 1 $ (1,060 ) $ — $ (6 ) $ (137 ) $ 1 $ 77 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 208 $ 1 $ (1 ) $ — $ — $ — $ (8 ) $ — $ — $ 200 $ — $ (1 ) Alt-A and subprime private-label securities 77 — (45 ) — — — (4 ) (4 ) — 24 — 1 Mortgage revenue bonds 671 1 (6 ) — (22 ) — (180 ) — — 464 — (3 ) Other 357 21 1 — — — (31 ) — — 348 — 3 Total available-for-sale securities $ 1,313 $ 23 (6)(7) $ (51 ) $ — $ (22 ) $ — $ (223 ) $ (4 ) $ — $ 1,036 $ — $ — Mortgage loans $ 1,116 $ 35 (5)(6) $ — $ — $ — $ — $ (174 ) $ (131 ) $ 119 $ 965 $ 17 $ — Net derivatives 134 (104 ) (5) — — — — 15 53 — 98 (56 ) — Long-term debt: Of Fannie Mae: Senior floating (376 ) 29 — — — — — — — (347 ) 29 — Of consolidated trusts (582 ) 9 — — — 1 35 503 (129 ) (163 ) (3 ) — Total long-term debt $ (958 ) $ 38 (5) $ — $ — $ — $ 1 $ 35 $ 503 $ (129 ) $ (510 ) $ 26 $ — (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes” in our condensed consolidated statements of operations and comprehensive income. (2) Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts. For the nine months ended September 30, 2018 , this 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 September 30, 2019 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1)(2) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Agency (3) $ 124 Various Available-for-sale securities: Mortgage-related securities: Agency (3) $ 118 Consensus 56 Various Total agency 174 Mortgage revenue bonds 232 Single Vendor Spreads(bps) 22.5 - 204.5 70.3 114 Various Total mortgage revenue bonds 346 Other 274 Discounted Cash Flow Default Rate(%) 0.8 0.8 Prepayment Speed(%) 8.7 8.7 Severity(%) 84.0 84.0 Spreads(bps) 77.5 - 300.0 299.4 41 Various Total other 315 Total available-for-sale securities $ 835 Net derivatives $ 183 Dealer Mark 15 Various Total net derivatives $ 198 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 (3) $ 32 Various Private-label securities and other mortgage securities 1 Various Total trading securities $ 33 Available-for-sale securities: Mortgage-related securities: Agency (3) $ 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. (3) Includes Fannie Mae and Freddie Mac securities. In our condensed consolidated balance sheets, certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when we evaluate loans for impairment). We had no Level 1 assets or liabilities held as of September 30, 2019 or December 31, 2018 that were measured at fair value on a nonrecurring basis. We held $620 million and $91 million in Level 2 assets as of September 30, 2019 and December 31, 2018 , respectively, comprised of mortgage loans held for sale and mortgage loans held for investment that were individually impaired. We had no Level 2 liabilities that were measured at fair value on a nonrecurring basis as of September 30, 2019 and December 31, 2018 . The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis. The significant unobservable inputs related to these techniques primarily relate to collateral dependent valuations. The related ranges and weighted averages are not meaningful when aggregated as they vary significantly from property to property. Fair Value Measurements as of Valuation Techniques September 30, 2019 December 31, 2018 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 2,067 $ 631 Single Vendor 780 1,119 Various 1 — Total mortgage loans held for sale, at lower of cost or fair value 2,848 1,750 Single-family mortgage loans held for investment, at amortized cost Internal Model 543 818 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate 70 102 Various 13 40 Total multifamily mortgage loans held for investment, at amortized cost 83 142 Acquired property, net: (1) Single-family Accepted Offers 100 151 Appraisals 386 419 Walk Forwards 190 181 Internal Model 152 219 Various 32 41 Total single-family 860 1,011 Multifamily Various — 50 Total nonrecurring assets at fair value $ 4,334 $ 3,771 (1) The most commonly used techniques in our valuation of acquired property are a proprietary home price model and third-party valuations (both current and walk forward). Based on the number of properties measured as of September 30, 2019 , these methodologies comprised approximately 83% of our valuations, while accepted offers comprised approximately 13% of our valuations. Based on the number of properties measured as of 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 nine months ended September 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 September 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 $ 64,498 $ 51,623 $ 12,875 $ — $ — $ 64,498 Federal funds sold and securities purchased under agreements to resell or similar arrangements 23,176 — 23,176 — — 23,176 Trading securities 44,206 36,016 8,066 124 — 44,206 Available-for-sale securities 2,690 — 1,855 835 — 2,690 Mortgage loans held for sale 12,289 — 4,783 8,672 — 13,455 Mortgage loans held for investment, net of allowance for loan losses 3,301,847 — 3,241,129 134,732 — 3,375,861 Advances to lenders 6,937 — 6,935 2 — 6,937 Derivative assets at fair value 472 — 1,909 226 (1,663 ) 472 Guaranty assets and buy-ups 149 — — 319 — 319 Total financial assets $ 3,456,264 $ 87,639 $ 3,300,728 $ 144,910 $ (1,663 ) $ 3,531,614 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 1,125 $ — $ 1,125 $ — $ — $ 1,125 Short-term debt: Of Fannie Mae 35,812 — 35,818 — — 35,818 Long-term debt: Of Fannie Mae 177,710 — 186,489 847 — 187,336 Of consolidated trusts 3,248,336 — 3,273,846 33,667 — 3,307,513 Derivative liabilities at fair value 595 — 2,866 28 (2,299 ) 595 Guaranty obligations 161 — — 102 — 102 Total financial liabilities $ 3,463,739 $ — $ 3,500,144 $ 34,644 $ (2,299 ) $ 3,532,489 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 September 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 $ 8,183 $ 6,041 $ 22,719 $ 8,922 $ 6,826 $ 23,753 Unpaid principal balance 7,866 5,541 20,380 8,832 6,241 22,080 (1) Includes nonaccrual loans with a fair value of $127 million and $161 million as of September 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of September 30, 2019 and December 31, 2018 was $11 million and $19 million , respectively. Includes loans that are 90 days or more past due with a fair value of $76 million and $102 million as of September 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 September 30, 2019 and December 31, 2018 was $9 million and $14 million , respectively. Changes in Fair Value under the Fair Value Option Election We recorded gains of $95 million and $334 million for the three and nine months ended September 30, 2019 , respectively, and losses of $63 million and $239 million for the three and nine months ended September 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 $245 million and $797 million for the three and nine months ended September 30, 2019 , respectively, and gains of $128 million and $629 million for the three and nine months ended September 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	9 Months Ended
	Sep. 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 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)	9 Months Ended
	Sep. 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 nine months ended September 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). Net income (loss) attributable to common stockholders excludes amounts attributable to the senior preferred stock, which increase the liquidation preference as described above in “ Senior Preferred Stock Purchase Agreement and Senior Preferred Stock .” Weighted average common shares includes 4.6 billion shares for the periods ended September 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 September 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 September 30, 2019 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. For the nine months ended September 30, 2019 and 2018 and the three months ended September 30, 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.
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 are 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 in June 2016. It was amended by ASU 2019-04, Codification Improvements (to Topic 326), Financial Instruments—Credit Losses in April 2019. These ASUs (the “CECL standard”) replace 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 develop credit loss estimates. The amendments in this standard also require credit losses related to available-for-sale (“AFS”) 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 AFS debt securities. The CECL standard will become effective for our fiscal year beginning January 1, 2020. We are currently performing full integrated testing across all models, accounting systems and processes that will be used to estimate credit losses and record accounting impacts under the CECL standard. All updates to our credit loss models are subject to our model oversight and review governance process. 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 expected credit losses on our single-family mortgage loans and an undiscounted loss method to measure expected credit losses on our multifamily mortgage loans. The models 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 September 30, 2019 and our current expectations of future economic conditions, we estimate that our adoption of the CECL standard will result in a reduction in our retained earnings of up to $2 billion on an after-tax basis in the first quarter of 2020. Our estimated impact upon adoption has been refined over the last quarter to incorporate updated economic conditions and the resolution of various implementation items, including the exclusion of certain pre-foreclosure costs from our estimated allowance for credit losses. We continue to monitor and will assess the impact of further implementation guidance that may be issued. In addition, we continue to evaluate our modeled loss estimates and may make refinements to our approach and assumptions as a part of our overall integrated testing efforts. The impact of our adoption of the CECL standard 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 changes in economic conditions and our forecasts of future economic conditions at that time.

Consolidations and Transfers _2

Consolidations and Transfers of Financial Assets (Policies)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 30, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Financing Receivable, Held-for-investment [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.
Financing Receivable, Held-for-sale [Policy Text Block]	We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “ Investment gains, 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)	9 Months Ended
	Sep. 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. During the three months ended September 30, 2019 , we enhanced the model used to estimate cash flows for individually impaired single-family loans within our allowance for loan losses. This enhancement was performed as a part of management’s routine model performance review process. In addition to incorporating recent loan performance data, this model enhancement better captures recent prepayment activity, default rates, and loss severity in the event of default. The enhancement resulted in a decrease to our allowance for loan losses and an incremental benefit for credit losses of approximately $850 million and is included in “Benefit (provision) for loan losses” in the table below. 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.
Change In Accounting Estimate [Policy Text Block]	During the three months ended September 30, 2019

Investment in Securities (Polic

Investment in Securities (Policies)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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

Segment Reporting (Policies)

Segment Reporting (Policies)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 Assets and liabilities recorded in our condensed consolidated balance sheets related to unconsolidated mortgage-backed trusts: (Dollars in millions) Assets: Trading securities: Fannie Mae $ 2,733 $ 1,422 Non-Fannie Mae 4,445 4,809 Total trading securities 7,178 6,231 Available-for-sale securities: Fannie Mae 1,581 1,704 Non-Fannie Mae 771 1,207 Total available-for-sale securities 2,352 2,911 Other assets 57 66 Other liabilities (82 ) (101 ) Net carrying amount $ 9,505 $ 9,107

Mortgage Loans (Tables)

Mortgage Loans (Tables)	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,962,083 $ 2,929,925 Multifamily 318,106 293,858 Total unpaid principal balance of mortgage loans 3,280,189 3,223,783 Cost basis and fair value adjustments, net 43,323 39,815 Allowance for loan losses for loans held for investment (9,376 ) (14,203 ) Total mortgage loans $ 3,314,136 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 4,882 $ 4,249 $ 14,252 $ 17,851 Carrying value of loans redesignated from HFS to HFI (1) 10 6 22 36 Loans sold - unpaid principal balance 3,941 9,373 10,497 13,831 Realized gains on sale of mortgage loans 184 93 504 301 (1) Represents the carrying value of the loans after redesignation, excluding allowance. 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 September 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) $ (8,507 ) $ (45 ) $ (8,552 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (615 ) (209 ) (824 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (9,122 ) $ (254 ) $ (9,376 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 100,991 $ 652 $ 101,643 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,889,510 320,545 3,210,055 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,990,501 $ 321,197 $ 3,311,698 $ 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 September 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 $ 29,211 $ 7,188 $ 13,291 $ 49,690 $ 2,867,330 $ 2,917,020 $ 26 $ 23,840 Government (2) 44 20 144 208 17,881 18,089 144 — Alt-A 1,717 591 1,316 3,624 40,663 44,287 1 2,228 Other 572 212 485 1,269 9,836 11,105 2 800 Total single-family 31,544 8,011 15,236 54,791 2,935,710 2,990,501 173 26,868 Multifamily (3) 32 N/A 181 213 320,984 321,197 — 604 Total $ 31,576 $ 8,011 $ 15,417 $ 55,004 $ 3,256,694 $ 3,311,698 $ 173 $ 27,472 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 September 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 $ 67,175 $ 64,987 $ (6,141 ) $ 81,791 $ 78,688 $ (9,406 ) Government 250 255 (50 ) 264 270 (55 ) Alt-A 11,956 11,008 (1,726 ) 16,576 15,158 (2,793 ) Other 3,703 3,505 (590 ) 5,482 5,169 (1,001 ) Total single-family 83,084 79,755 (8,507 ) 104,113 99,285 (13,255 ) Multifamily 281 283 (45 ) 197 196 (40 ) Total individually impaired loans with related allowance recorded 83,365 80,038 (8,552 ) 104,310 99,481 (13,295 ) With no related allowance recorded: (1) Single-family: Primary 19,326 18,463 — 15,939 15,191 — Government 65 61 — 61 56 — Alt-A 2,391 2,141 — 2,628 2,363 — Other 624 571 — 718 666 — Total single-family 22,406 21,236 — 19,346 18,276 — Multifamily 368 369 — 343 346 — Total individually impaired loans with no related allowance recorded 22,774 21,605 — 19,689 18,622 — Total individually impaired loans (2) $ 106,139 $ 101,643 $ (8,552 ) $ 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 $100.7 billion and $117.2 billion as of September 30, 2019 and December 31, 2018 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $126 million and $187 million as of September 30, 2019 and December 31, 2018 , respectively. For the Three Months Ended September 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 $ 69,084 $ 713 $ 62 $ 84,043 $ 871 $ 86 Government 262 2 — 276 3 — Alt-A 11,845 125 8 17,034 179 13 Other 3,904 37 4 6,254 57 4 Total single-family 85,095 877 74 107,607 1,110 103 Multifamily 313 2 — 231 1 — Total individually impaired loans with related allowance recorded 85,408 879 74 107,838 1,111 103 With no related allowance recorded: (1) Single-family: Primary 16,422 262 39 15,140 254 30 Government 56 1 — 57 1 — Alt-A 2,130 44 4 2,562 54 4 Other 575 10 1 784 13 2 Total single-family 19,183 317 44 18,543 322 36 Multifamily 401 8 — 335 8 — Total individually impaired loans with no related allowance recorded 19,584 325 44 18,878 330 36 Total individually impaired loans $ 104,992 $ 1,204 $ 118 $ 126,716 $ 1,441 $ 139 For the Nine Months Ended September 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 $ 73,601 $ 2,304 $ 214 $ 86,842 $ 2,697 $ 302 Government 267 8 — 277 15 — Alt-A 13,299 426 30 19,081 610 45 Other 4,429 123 11 7,140 201 15 Total single-family 91,596 2,861 255 113,340 3,523 362 Multifamily 280 7 — 244 2 — Total individually impaired loans with related allowance recorded 91,876 2,868 255 113,584 3,525 362 With no related allowance recorded: (1) Single-family: Primary 15,718 731 103 15,039 740 88 Government 56 3 — 58 3 — Alt-A 2,203 127 11 2,710 173 13 Other 611 28 3 848 44 4 Total single-family 18,588 889 117 18,655 960 105 Multifamily 377 16 — 333 11 — Total individually impaired loans with no related allowance recorded 18,965 905 117 18,988 971 105 Total individually impaired loans $ 110,841 $ 3,773 $ 372 $ 132,572 $ 4,496 $ 467 (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 September 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 11,373 $ 1,819 12,291 $ 1,797 Government 16 1 21 3 Alt-A 543 70 779 100 Other 89 16 207 37 Total single-family 12,021 1,906 13,298 1,937 Multifamily 3 4 2 7 Total TDRs 12,024 $ 1,910 13,300 $ 1,944 For the Nine Months Ended September 30, 2019 2018 Number of Loans Recorded Investment (1) Number of Loans Recorded Investment (1) (Dollars in millions) Single-family: Primary 36,126 $ 5,634 75,790 $ 11,469 Government 61 7 95 9 Alt-A 1,948 248 4,499 583 Other 374 68 937 173 Total single-family 38,509 5,957 81,321 12,234 Multifamily 9 37 12 68 Total TDRs 38,518 $ 5,994 81,333 $ 12,302 (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 September 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 3,780 $ 585 3,720 $ 519 Government 28 2 8 — Alt-A 307 43 438 74 Other 87 16 143 29 Total single-family 4,202 646 4,309 622 Multifamily 1 13 1 2 Total TDRs that subsequently defaulted 4,203 $ 659 4,310 $ 624 For the Nine Months Ended September 30, 2019 2018 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 12,343 $ 1,864 12,372 $ 1,774 Government 56 7 37 4 Alt-A 1,157 174 1,703 275 Other 351 65 469 93 Total single-family 13,907 2,110 14,581 2,146 Multifamily 2 19 2 4 Total TDRs that subsequently defaulted 13,909 $ 2,129 14,583 $ 2,150
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 September 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% $ 2,569,771 $ 39,710 $ 9,694 $ 2,521,766 $ 45,476 $ 12,291 Greater than 80% and less than or equal to 90% 228,868 2,365 709 228,614 3,804 1,195 Greater than 90% and less than or equal to 100% 113,424 1,131 337 109,548 1,997 645 Greater than 100% 4,957 1,081 365 9,337 1,994 707 Total $ 2,917,020 $ 44,287 $ 11,105 $ 2,869,265 $ 53,271 $ 14,838 (1) Excludes $18.1 billion and $22.1 billion as of September 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 September 30, December 31, 2019 2018 (Dollars in millions) Credit risk profile by internally assigned grade: Non-classified $ 314,458 $ 289,231 Classified (1) 6,739 6,433 Total $ 321,197 $ 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 September 30, 2019 , we had loans with recorded investment of less than $0.1 million classified as doubtful, compared with $1 million as of December 31, 2018 .

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 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 September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ (11,210 ) $ (16,602 ) $ (13,969 ) $ (18,849 ) Benefit (provision) for loan losses (1) 1,826 724 3,712 1,916 Charge-offs 270 509 1,209 1,705 Recoveries (8 ) (65 ) (68 ) (189 ) Other — (2 ) (6 ) (19 ) Ending balance $ (9,122 ) $ (15,436 ) $ (9,122 ) $ (15,436 ) Multifamily allowance for loan losses: Beginning balance $ (272 ) $ (210 ) $ (234 ) $ (235 ) Benefit (provision) for loan losses (1) 17 (14 ) (23 ) 6 Charge-offs 2 — 6 5 Recoveries (1 ) (3 ) (3 ) (3 ) Ending balance $ (254 ) $ (227 ) $ (254 ) $ (227 ) Total allowance for loan losses: Beginning balance $ (11,482 ) $ (16,812 ) $ (14,203 ) $ (19,084 ) Benefit (provision) for loan losses (1) 1,843 710 3,689 1,922 Charge-offs 272 509 1,215 1,710 Recoveries (9 ) (68 ) (71 ) (192 ) Other — (2 ) (6 ) (19 ) Ending balance $ (9,376 ) $ (15,663 ) $ (9,376 ) $ (15,663 ) (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 September 30, 2019 December 31, 2018 (Dollars in millions) Single-family $ 2,962,083 $ 2,929,925 Multifamily 318,106 293,858 Total unpaid principal balance of mortgage loans 3,280,189 3,223,783 Cost basis and fair value adjustments, net 43,323 39,815 Allowance for loan losses for loans held for investment (9,376 ) (14,203 ) Total mortgage loans $ 3,314,136 $ 3,249,395 The following table displays information about our redesignated mortgage loans. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Carrying value of loans redesignated from HFI to HFS (1) $ 4,882 $ 4,249 $ 14,252 $ 17,851 Carrying value of loans redesignated from HFS to HFI (1) 10 6 22 36 Loans sold - unpaid principal balance 3,941 9,373 10,497 13,831 Realized gains on sale of mortgage loans 184 93 504 301 (1) Represents the carrying value of the loans after redesignation, excluding allowance. 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 September 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) $ (8,507 ) $ (45 ) $ (8,552 ) $ (13,255 ) $ (40 ) $ (13,295 ) Collectively reserved loans (615 ) (209 ) (824 ) (714 ) (194 ) (908 ) Total allowance for loan losses $ (9,122 ) $ (254 ) $ (9,376 ) $ (13,969 ) $ (234 ) $ (14,203 ) Recorded investment in loans by segment: Individually impaired loans (1) $ 100,991 $ 652 $ 101,643 $ 117,561 $ 542 $ 118,103 Collectively reserved loans 2,889,510 320,545 3,210,055 2,841,943 295,122 3,137,065 Total recorded investment in loans $ 2,990,501 $ 321,197 $ 3,311,698 $ 2,959,504 $ 295,664 $ 3,255,168 (1) Includes acquired credit-impaired loans.

Investments in Securities (Tabl

Investments in Securities (Tables)	9 Months Ended
	Sep. 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 September 30, 2019 December 31, 2018 (Dollars in millions) Mortgage-related securities: Fannie Mae (1) $ 3,661 $ 1,467 Other agency (2) 3,704 3,503 Private-label and other mortgage securities 741 1,306 Total mortgage-related securities (includes $922 and $32, respectively, related to consolidated trusts) 8,106 6,276 Non-mortgage-related securities: U.S. Treasury securities 36,016 35,502 Other securities 84 89 Total non-mortgage-related securities 36,100 35,591 Total trading securities $ 44,206 $ 41,867 (1) In the second quarter of 2019, we implemented the Single Security Initiative and 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 (losses). For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Net trading gains (losses) $ 95 $ (40 ) $ 370 $ 79 Net trading gains (losses) recognized in the period related to securities still held at period end 82 (27 ) 298 20
Schedule of Realized Gain (Loss) [Table Text Block]	The following table displays the gross realized gains and proceeds on sales of AFS securities. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Gross realized gains $ — $ 12 $ 171 $ 375 Total proceeds (excludes initial sale of securities from new portfolio securitizations) — 21 376 662
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 September 30, 2019 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 1,492 $ 98 $ (8 ) $ 1,582 Other agency 195 18 — 213 Alt-A and subprime private-label securities 102 124 — 226 Mortgage revenue bonds 339 10 (3 ) 346 Other mortgage-related securities 320 5 (2 ) 323 Total $ 2,448 $ 255 $ (13 ) $ 2,690 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 September 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 $ — $ — $ (8 ) $ 348 Mortgage revenue bonds — — (3 ) 5 Other mortgage-related securities (2 ) 273 — — Total $ (2 ) $ 273 $ (11 ) $ 353 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 September 30, December 31, 2019 2018 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI $ 191 $ 52 Net unrealized gains on AFS securities for which we have recorded OTTI — 224 Other 39 46 Accumulated other comprehensive income $ 230 $ 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 September 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 $ 1,492 $ 1,582 $ — $ — $ 14 $ 15 $ 101 $ 111 $ 1,377 $ 1,456 Other agency 195 213 — — 20 21 26 29 149 163 Alt-A and subprime private-label securities 102 226 — — — — 1 1 101 225 Mortgage revenue bonds 339 346 2 2 26 27 36 37 275 280 Other mortgage-related securities 320 323 — — 2 1 24 27 294 295 Total $ 2,448 $ 2,690 $ 2 $ 2 $ 62 $ 64 $ 188 $ 205 $ 2,196 $ 2,419

Financial Guarantees (Tables)

Financial Guarantees (Tables)	9 Months Ended
	Sep. 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 September 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 $ 6,603 $ 26 $ 6,354 $ 7,278 $ 30 $ 6,811 Other guaranty arrangements (2) 12,981 135 2,609 13,847 130 2,711 Total $ 19,584 $ 161 $ 8,963 $ 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)	9 Months Ended
	Sep. 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 September 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) $ 1,125 2.15 % $ — — % Short-term debt of Fannie Mae $ 35,812 2.04 % $ 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 September 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 $ 91,603 2.66 % 2019 - 2030 $ 103,206 2.36 % Medium-term notes (2) 2019 - 2026 40,973 1.60 2019 - 2026 61,455 1.48 Other (3) 2019 - 2038 6,142 4.84 2019 - 2038 6,683 4.62 Total senior fixed 138,718 2.44 171,344 2.13 Senior floating: Medium-term notes (2) 2020 - 2021 9,773 2.28 2019 - 2020 4,174 2.36 Connecticut Avenue Securities (4) 2023 - 2031 22,977 5.90 2023 - 2031 25,641 5.97 Other (5) 2020 - 2037 422 7.79 2020 - 2037 351 10.19 Total senior floating 33,172 4.86 30,166 5.52 Subordinated debentures 2019 5,783 9.99 2019 5,617 9.64 Secured borrowings (6) 2021 - 2022 37 2.24 2021 - 2022 51 1.96 Total long-term debt of Fannie Mae (7) 177,710 3.14 207,178 2.83 Debt of consolidated trusts 2019 - 2058 3,248,336 2.79 2019 - 2058 3,159,846 3.03 Total long-term debt $ 3,426,046 2.81 % $ 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 $30 million and $413 million as of September 30, 2019 and December 31, 2018 , respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 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 September 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 $ 35,550 $ — $ 32,893 $ (1,481 ) $ 71,416 $ 438 $ 21,253 $ (740 ) Receive-fixed 71,372 958 34,986 (103 ) 88,799 1,113 58,399 (860 ) Basis 273 179 — — 250 104 624 — Foreign currency 213 27 215 (86 ) 221 22 223 (72 ) Swaptions: Pay-fixed 4,600 18 6,375 (270 ) 10,375 191 1,000 (4 ) Receive-fixed 2,875 203 4,600 (137 ) 500 20 7,375 (338 ) Futures (1) 47,069 — — — 16,631 — — — Total gross risk management derivatives 161,952 1,385 79,069 (2,077 ) 188,192 1,888 88,874 (2,014 ) Accrued interest receivable (payable) — 287 — (374 ) — 400 — (419 ) Netting adjustment (2) — (1,663 ) — 2,299 — (2,266 ) — 2,315 Total net risk management derivatives $ 161,952 $ 9 $ 79,069 $ (152 ) $ 188,192 $ 22 $ 88,874 $ (118 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 7,812 $ 20 $ 6,258 $ (26 ) $ 4,370 $ 29 $ 57 $ — Forward contracts to purchase mortgage-related securities 70,120 231 28,853 (85 ) 40,650 349 1,045 (3 ) Forward contracts to sell mortgage-related securities 57,048 170 109,229 (305 ) 292 1 70,593 (645 ) Total mortgage commitment derivatives 134,980 421 144,340 (416 ) 45,312 379 71,695 (648 ) Credit enhancement derivatives 30,407 42 6,509 (27 ) 33,431 57 919 (11 ) Derivatives at fair value $ 327,339 $ 472 $ 229,918 $ (595 ) $ 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 $1.3 billion and $713 million as of September 30, 2019 and December 31, 2018 , respectively. Cash collateral received was $684 million and $664 million as of September 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 September 30, For the Nine Months Ended September 30, 2019 2018 2019 2018 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (1,414 ) $ 1,034 $ (4,913 ) $ 4,784 Receive-fixed 966 (524 ) 4,131 (3,508 ) Basis 24 (5 ) 75 (31 ) Foreign currency (11 ) (10 ) (9 ) (35 ) Swaptions: Pay-fixed (110 ) 67 (430 ) 232 Receive-fixed 209 (34 ) 309 (72 ) Futures 42 — 296 (3 ) Net accrual of periodic settlements (190 ) (285 ) (698 ) (786 ) Total risk management derivatives fair value gains (losses), net (484 ) 243 (1,239 ) 581 Mortgage commitment derivatives fair value gains (losses), net (177 ) 118 (946 ) 606 Credit enhancement derivatives fair value losses, net (7 ) (1 ) (31 ) (2 ) Total derivatives fair value gains (losses), net $ (668 ) $ 360 $ (2,216 ) $ 1,185

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment results [Table Text Block]	The following table displays our segment results. For the Three Months Ended September 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 4,484 $ 745 $ 5,229 $ 4,670 $ 699 $ 5,369 Fee and other income (2) 156 246 402 79 192 271 Net revenues 4,640 991 5,631 4,749 891 5,640 Investment gains, net (3) 198 55 253 146 20 166 Fair value gains (losses), net (4) (719 ) 6 (713 ) 417 (31 ) 386 Administrative expenses (634 ) (115 ) (749 ) (636 ) (104 ) (740 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 1,840 17 1,857 732 (16 ) 716 Foreclosed property expense (93 ) (3 ) (96 ) (150 ) (9 ) (159 ) Total credit-related income (expense) 1,747 14 1,761 582 (25 ) 557 TCCA fees (6) (613 ) — (613 ) (576 ) — (576 ) Other expenses, net (424 ) (147 ) (571 ) (282 ) (95 ) (377 ) Income before federal income taxes 4,195 804 4,999 4,400 656 5,056 Provision for federal income taxes (872 ) (164 ) (1,036 ) (938 ) (107 ) (1,045 ) Net income $ 3,323 $ 640 $ 3,963 $ 3,462 $ 549 $ 4,011 For the Nine Months Ended September 30, 2019 2018 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Net interest income (1) $ 12,942 $ 2,170 $ 15,112 $ 13,954 $ 2,024 $ 15,978 Fee and other income (2) 350 525 875 306 524 830 Net revenues 13,292 2,695 15,987 14,260 2,548 16,808 Investment gains, net (3) 709 138 847 640 53 693 Fair value gains (losses), net (4) (2,364 ) 66 (2,298 ) 1,729 (69 ) 1,660 Administrative expenses (1,899 ) (338 ) (2,237 ) (1,928 ) (317 ) (2,245 ) Credit-related income (expense) (5) Benefit (provision) for credit losses 3,753 (21 ) 3,732 2,223 6 2,229 Foreclosed property expense (362 ) (2 ) (364 ) (448 ) (12 ) (460 ) Total credit-related income (expense) 3,391 (23 ) 3,368 1,775 (6 ) 1,769 TCCA fees (6) (1,806 ) — (1,806 ) (1,698 ) — (1,698 ) Other expenses, net (1,179 ) (335 ) (1,514 ) (684 ) (262 ) (946 ) Income before federal income taxes 10,144 2,203 12,347 14,094 1,947 16,041 Provision for federal income taxes (2,125 ) (427 ) (2,552 ) (2,998 ) (314 ) (3,312 ) Net income $ 8,019 $ 1,776 $ 9,795 $ 11,096 $ 1,633 $ 12,729 (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)	9 Months Ended
	Sep. 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 September 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) 1.11 % 0.29 % 0.61 % 1.17 % 0.32 % 0.69 % Percentage of single-family conventional loans (4) 1.28 0.35 0.68 1.37 0.38 0.76
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of September 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% * 10.62 % * 9.85 % Geographical distribution: California 19 0.32 19 0.34 Florida 6 0.87 6 1.16 New Jersey 3 1.21 4 1.38 New York 5 1.24 5 1.40 All other states 67 0.67 66 0.75 Product distribution: Alt-A 2 3.09 2 3.35 Vintages: 2004 and prior 2 2.53 3 2.69 2005-2008 4 4.24 5 4.61 2009-2019 94 0.33 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 more than 99% of our single-family conventional guaranty book of business as of September 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 September 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 September 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 $ 162,339 $ 152,379 Pool mortgage insurance 379 409 Total mortgage insurance risk in force $ 162,718 6% $ 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 September 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 September 30, 2019 December 31, 2018 Wells Fargo Bank, N.A. (together with its affiliates) 17 % 18 % Remaining top five depository servicers 15 16 Top five non-depository servicers 25 22 Total 57 % 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 September 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 * 0.06 % 0.02 % 0.06 %
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of September 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 0.06 99 0.06 Current DSCR below 1.0 (4) 2 0.44 2 1.38 * Represents less than 0.01% of multifamily business volume or book of business. (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 September 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)	9 Months Ended
	Sep. 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 September 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 $ 1,672 $ (1,667 ) $ 5 $ — $ — $ 5 Cleared risk management derivatives — 4 4 — — 4 Mortgage commitment derivatives 421 — 421 (368 ) (7 ) 46 Total derivative assets 2,093 (1,663 ) 430 (4) (368 ) (7 ) 55 Securities purchased under agreements to resell or similar arrangements (5) 36,051 — 36,051 — (36,051 ) — Total assets $ 38,144 $ (1,663 ) $ 36,481 $ (368 ) $ (36,058 ) $ 55 Liabilities: OTC risk management derivatives $ (2,451 ) $ 2,332 $ (119 ) $ — $ — $ (119 ) Cleared risk management derivatives — (33 ) (33 ) — 33 — Mortgage commitment derivatives (416 ) — (416 ) 368 4 (44 ) Total derivative liabilities (2,867 ) 2,299 (568 ) (4) 368 37 (163 ) Securities sold under agreements to repurchase or similar arrangements (1,125 ) — (1,125 ) — 1,123 (2 ) Total liabilities $ (3,992 ) $ 2,299 $ (1,693 ) $ 368 $ 1,160 $ (165 ) 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 $3.1 billion and $1.9 billion as of September 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 $36.1 billion and $48.4 billion , of which $34.3 billion and $45.7 billion could be sold or repledged as of September 30, 2019 and December 31, 2018 , respectively. None of the underlying collateral was sold or repledged as of September 30, 2019 or December 31, 2018 . (4) Excludes derivative assets of $42 million and $57 million as of September 30, 2019 and December 31, 2018 , respectively, and derivative liabilities of $27 million and $11 million recognized in our condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $12.9 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 September 30, 2019 and December 31, 2018 , respectively.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 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 September 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: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 3,539 $ 122 $ — $ 3,661 Other agency — 3,702 2 — 3,704 Private-label and other mortgage securities — 741 — — 741 Non-mortgage-related securities: U.S. Treasury securities 36,016 — — — 36,016 Other securities — 84 — — 84 Total trading securities 36,016 8,066 124 — 44,206 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 1,408 174 — 1,582 Other agency — 213 — — 213 Alt-A and subprime private-label securities — 226 — — 226 Mortgage revenue bonds — — 346 — 346 Other — 8 315 — 323 Total available-for-sale securities — 1,855 835 — 2,690 Mortgage loans — 7,457 726 — 8,183 Other assets: Risk management derivatives: Swaps — 1,267 184 — 1,451 Swaptions — 221 — — 221 Netting adjustment — — — (1,663 ) (1,663 ) Mortgage commitment derivatives — 421 — — 421 Credit enhancement derivatives — — 42 — 42 Total other assets — 1,909 226 (1,663 ) 472 Total assets at fair value $ 36,016 $ 19,287 $ 1,911 $ (1,663 ) $ 55,551 Fair Value Measurements as of September 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 $ — $ 5,619 $ 422 $ — $ 6,041 Total of Fannie Mae — 5,619 422 — 6,041 Of consolidated trusts — 22,631 88 — 22,719 Total long-term debt — 28,250 510 — 28,760 Other liabilities: Risk management derivatives: Swaps — 2,043 1 — 2,044 Swaptions — 407 — — 407 Netting adjustment — — — (2,299 ) (2,299 ) Mortgage commitment derivatives — 416 — — 416 Credit enhancement derivatives — — 27 — 27 Total other liabilities — 2,866 28 (2,299 ) 595 Total liabilities at fair value $ — $ 31,116 $ 538 $ (2,299 ) $ 29,355 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 September 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, June 30, 2019 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 74 $ 2 $ — $ 77 $ — $ — $ — $ (31 ) $ — $ 122 $ 1 $ — Other agency — — — — — — — — 2 2 — — Total trading securities $ 74 $ 2 (5)(6) $ — $ 77 $ — $ — $ — $ (31 ) $ 2 $ 124 $ 1 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 132 $ — $ 3 $ — $ — $ — $ (1 ) $ — $ 40 $ 174 $ — $ 3 Mortgage revenue bonds 364 1 (1 ) — — — (18 ) — — 346 — — Other 326 (1 ) (1 ) — — — (9 ) — — 315 — (2 ) Total available-for-sale securities $ 822 $ — (6)(7) $ 1 $ — $ — $ — $ (28 ) $ — $ 40 $ 835 $ — $ 1 Mortgage loans $ 770 $ 14 (5)(6) $ — $ — $ (27 ) $ — $ (35 ) $ (41 ) $ 45 $ 726 $ 10 $ — Net derivatives 183 21 (5) — — — — (6 ) — — 198 15 — Long-term debt: Of Fannie Mae: Senior floating (398 ) (24 ) — — — — — — — (422 ) (24 ) — Of consolidated trusts (102 ) (3 ) — — — (2 ) 6 20 (7 ) (88 ) (1 ) — Total long-term debt $ (500 ) $ (27 ) (5) $ — $ — $ — $ (2 ) $ 6 $ 20 $ (7 ) $ (510 ) $ (25 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2019 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2019 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2019 (1) Balance, December 31, 2018 Included in Net Income Included in Total OCI Gain/(Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 Transfers into Level 3 Balance, September 30, 2019 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 32 $ 5 $ — $ 77 $ (14 ) $ — $ (16 ) $ (31 ) $ 69 $ 122 $ 4 $ — Other agency — — — — — — — — 2 2 — — Private-label and other mortgage securities 1 — — — — — (1 ) — — — — — Total trading securities $ 33 $ 5 (5)(6) $ — $ 77 $ (14 ) $ — $ (17 ) $ (31 ) $ 71 $ 124 $ 4 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 152 $ — $ 9 $ — $ — $ — $ (8 ) $ (103 ) $ 124 $ 174 $ — $ 8 Alt-A and subprime private-label securities 24 5 (5 ) — (23 ) — (1 ) — — — — — Mortgage revenue bonds 434 1 (2 ) — (4 ) — (83 ) — — 346 — (1 ) Other 342 11 (11 ) — — — (26 ) (2 ) 1 315 — (9 ) Total available-for-sale securities $ 952 $ 17 (6)(7) $ (9 ) $ — $ (27 ) $ — $ (118 ) $ (105 ) $ 125 $ 835 $ — $ (2 ) Mortgage loans $ 937 $ 45 (5)(6) $ — $ — $ (40 ) $ — $ (105 ) $ (228 ) $ 117 $ 726 $ 28 $ — Net derivatives 194 139 (5) — — — — (126 ) (9 ) — 198 39 — Long-term debt: Of Fannie Mae: Senior floating (351 ) (71 ) — — — — — — — (422 ) (71 ) — Of consolidated trusts (201 ) (7 ) — — — (2 ) 16 189 (83 ) (88 ) (3 ) — Total long-term debt $ (552 ) $ (78 ) (5) $ — $ — $ — $ (2 ) $ 16 $ 189 $ (83 ) $ (510 ) $ (74 ) $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 30, 2018 (1) Balance, June 30, 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, September 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 79 $ (3 ) $ — $ — $ — $ — $ — $ — $ — $ 76 $ 2 $ — Private-label and other mortgage securities 1 — — — — — — — — 1 — — Total trading securities $ 80 $ (3 ) (5)(6) $ — $ — $ — $ — $ — $ — $ — $ 77 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 204 $ — $ (1 ) $ — $ — $ — $ (3 ) $ — $ — $ 200 $ — $ (1 ) Alt-A and subprime private-label securities 26 — — — — — (2 ) — — 24 — — Mortgage revenue bonds 506 1 (3 ) — (4 ) — (36 ) — — 464 — (2 ) Other 357 7 (7 ) — — — (9 ) — — 348 — (6 ) Total available-for-sale securities $ 1,093 $ 8 (6)(7) $ (11 ) $ — $ (4 ) $ — $ (50 ) $ — $ — $ 1,036 $ — $ (9 ) Mortgage loans $ 1,018 $ 7 (5)(6) $ — $ — $ — $ — $ (47 ) $ (44 ) $ 31 $ 965 $ 2 $ — Net derivatives 117 (18 ) (5) — — — — (1 ) — — 98 (27 ) — Long-term debt: Of Fannie Mae: Senior floating (354 ) 7 — — — — — — — (347 ) 7 — Of consolidated trusts (319 ) 2 — — — — 4 172 (22 ) (163 ) — — Total long-term debt $ (673 ) $ 9 (5) $ — $ — $ — $ — $ 4 $ 172 $ (22 ) $ (510 ) $ 7 $ — Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2018 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2018 (4)(5) Net Unrealized Gains (Losses) Included in OCI Related to Assets and Liabilities Still Held as of September 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, September 30, 2018 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 971 $ 163 $ — $ 1 $ (1,060 ) $ — $ — $ — $ 1 $ 76 $ 2 $ — Other agency 35 (1 ) — — — — (1 ) (33 ) — — — — Private-label and other mortgage securities 195 (85 ) — — — — (5 ) (104 ) — 1 — — Total trading securities $ 1,201 $ 77 (5)(6) $ — $ 1 $ (1,060 ) $ — $ (6 ) $ (137 ) $ 1 $ 77 $ 2 $ — Available-for-sale securities: Mortgage-related: Fannie Mae $ 208 $ 1 $ (1 ) $ — $ — $ — $ (8 ) $ — $ — $ 200 $ — $ (1 ) Alt-A and subprime private-label securities 77 — (45 ) — — — (4 ) (4 ) — 24 — 1 Mortgage revenue bonds 671 1 (6 ) — (22 ) — (180 ) — — 464 — (3 ) Other 357 21 1 — — — (31 ) — — 348 — 3 Total available-for-sale securities $ 1,313 $ 23 (6)(7) $ (51 ) $ — $ (22 ) $ — $ (223 ) $ (4 ) $ — $ 1,036 $ — $ — Mortgage loans $ 1,116 $ 35 (5)(6) $ — $ — $ — $ — $ (174 ) $ (131 ) $ 119 $ 965 $ 17 $ — Net derivatives 134 (104 ) (5) — — — — 15 53 — 98 (56 ) — Long-term debt: Of Fannie Mae: Senior floating (376 ) 29 — — — — — — — (347 ) 29 — Of consolidated trusts (582 ) 9 — — — 1 35 503 (129 ) (163 ) (3 ) — Total long-term debt $ (958 ) $ 38 (5) $ — $ — $ — $ 1 $ 35 $ 503 $ (129 ) $ (510 ) $ 26 $ — (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes” in our condensed consolidated statements of operations and comprehensive income. (2) Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts. For the nine months ended September 30, 2018 , this 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 September 30, 2019 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1)(2) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Agency (3) $ 124 Various Available-for-sale securities: Mortgage-related securities: Agency (3) $ 118 Consensus 56 Various Total agency 174 Mortgage revenue bonds 232 Single Vendor Spreads(bps) 22.5 - 204.5 70.3 114 Various Total mortgage revenue bonds 346 Other 274 Discounted Cash Flow Default Rate(%) 0.8 0.8 Prepayment Speed(%) 8.7 8.7 Severity(%) 84.0 84.0 Spreads(bps) 77.5 - 300.0 299.4 41 Various Total other 315 Total available-for-sale securities $ 835 Net derivatives $ 183 Dealer Mark 15 Various Total net derivatives $ 198 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 (3) $ 32 Various Private-label securities and other mortgage securities 1 Various Total trading securities $ 33 Available-for-sale securities: Mortgage-related securities: Agency (3) $ 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. (3) Includes Fannie Mae and Freddie Mac securities.
Level 3 Assets Measured on Nonrecurring Basis [Table Text Block]	The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis. The significant unobservable inputs related to these techniques primarily relate to collateral dependent valuations. The related ranges and weighted averages are not meaningful when aggregated as they vary significantly from property to property. Fair Value Measurements as of Valuation Techniques September 30, 2019 December 31, 2018 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 2,067 $ 631 Single Vendor 780 1,119 Various 1 — Total mortgage loans held for sale, at lower of cost or fair value 2,848 1,750 Single-family mortgage loans held for investment, at amortized cost Internal Model 543 818 Multifamily mortgage loans held for investment, at amortized cost Asset Manager Estimate 70 102 Various 13 40 Total multifamily mortgage loans held for investment, at amortized cost 83 142 Acquired property, net: (1) Single-family Accepted Offers 100 151 Appraisals 386 419 Walk Forwards 190 181 Internal Model 152 219 Various 32 41 Total single-family 860 1,011 Multifamily Various — 50 Total nonrecurring assets at fair value $ 4,334 $ 3,771 (1) The most commonly used techniques in our valuation of acquired property are a proprietary home price model and third-party valuations (both current and walk forward). Based on the number of properties measured as of September 30, 2019 , these methodologies comprised approximately 83% of our valuations, while accepted offers comprised approximately 13% of our valuations. Based on the number of properties measured as of 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 September 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 $ 64,498 $ 51,623 $ 12,875 $ — $ — $ 64,498 Federal funds sold and securities purchased under agreements to resell or similar arrangements 23,176 — 23,176 — — 23,176 Trading securities 44,206 36,016 8,066 124 — 44,206 Available-for-sale securities 2,690 — 1,855 835 — 2,690 Mortgage loans held for sale 12,289 — 4,783 8,672 — 13,455 Mortgage loans held for investment, net of allowance for loan losses 3,301,847 — 3,241,129 134,732 — 3,375,861 Advances to lenders 6,937 — 6,935 2 — 6,937 Derivative assets at fair value 472 — 1,909 226 (1,663 ) 472 Guaranty assets and buy-ups 149 — — 319 — 319 Total financial assets $ 3,456,264 $ 87,639 $ 3,300,728 $ 144,910 $ (1,663 ) $ 3,531,614 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 1,125 $ — $ 1,125 $ — $ — $ 1,125 Short-term debt: Of Fannie Mae 35,812 — 35,818 — — 35,818 Long-term debt: Of Fannie Mae 177,710 — 186,489 847 — 187,336 Of consolidated trusts 3,248,336 — 3,273,846 33,667 — 3,307,513 Derivative liabilities at fair value 595 — 2,866 28 (2,299 ) 595 Guaranty obligations 161 — — 102 — 102 Total financial liabilities $ 3,463,739 $ — $ 3,500,144 $ 34,644 $ (2,299 ) $ 3,532,489 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 September 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 $ 8,183 $ 6,041 $ 22,719 $ 8,922 $ 6,826 $ 23,753 Unpaid principal balance 7,866 5,541 20,380 8,832 6,241 22,080 (1) Includes nonaccrual loans with a fair value of $127 million and $161 million as of September 30, 2019 and December 31, 2018 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of September 30, 2019 and December 31, 2018 was $11 million and $19 million , respectively. Includes loans that are 90 days or more past due with a fair value of $76 million and $102 million as of September 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 September 30, 2019 and December 31, 2018 was $9 million and $14 million , respectively.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, September 2019 Amendment [Line Items]
Deficit of core capital over statutory minimum capital requirement	$ (133,800)	$ (137,100)
US Treasury [Member]
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, September 2019 Amendment [Line Items]
Capital Reserve Amount Fiscal Year Senior Preferred Stock Purchase Agreement September 2019 Amendment	$ 22,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2020	Dec. 31, 2018
Related Parties [Line Items]
Deficit Of Core Capital Over Statutory Minimum Capital Requirement		$ (133,800,000,000)		$ (133,800,000,000)			$ (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
Net worth	$ 6,400,000,000	10,342,000,000		10,342,000,000			6,240,000,000
Payments of cash dividends on senior preferred stock to Treasury		0	$ 4,459,000,000	5,601,000,000	$ 5,397,000,000
Income Taxes Paid		0		$ 1,250,000,000	$ 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		$ 613,000,000	576,000,000	$ 1,806,000,000	$ 1,698,000,000
Basis Points of Each Dollar of Unpaid Principal Balance		0.042%		0.042%
Trading, at fair value (includes $4,304 and $3,061, respectively, pledged as collateral)		$ 44,206,000,000		$ 44,206,000,000			41,867,000,000
Interest Receivable		8,923,000,000		8,923,000,000			8,490,000,000
Interest income recognized on Treasury securities		418,000,000	363,000,000	$ 1,277,000,000	$ 917,000,000
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
Forecast [Member]
Related Parties [Line Items]
Cumulative Effect Of New Accounting Principle In Period Of Adoption						$ 2,000,000,000
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
Capital Reserve Amount, Fiscal Year, Senior Preferred Stock Purchase Agreement, Amendment	3,000,000,000
Capital Reserve Amount, current year, Senior Preferred Stock Purchase Agreement, Amendment		25,000,000,000		25,000,000,000
Aggregate liquidation preference of senior preferred stock	123,800,000,000	127,200,000,000		127,200,000,000			$ 131,200,000,000
Increase in Aggregate Liquidation Preference of Senior Preferred Stock	3,400,000,000	$ 4,000,000,000		$ 4,000,000,000
Percentage of common shares attributable to warrants issued to US Treasury as percentage to total diluted common shares		79.90%		79.90%
Home Affordable Modification Program administrative expense reimbursements from Treasury and Freddie Mac		$ 5,000,000	6,000,000	$ 15,000,000	$ 19,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees		613,000,000	576,000,000	1,806,000,000	1,698,000,000
Affordable Housing Program Obligation		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		613,000,000		613,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees		30,000,000	26,000,000	89,000,000	81,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments		22,000,000	33,000,000	84,000,000	109,000,000
Other Expense [Member] | US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments	$ 75,000,000	$ 32,000,000	$ 20,000,000	$ 68,000,000	$ 57,000,000

Consolidations and Transfers _4

Consolidations and Transfers of Financial Assets Unconsolidated VIEs (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Variable Interest Entities [Line Items]
Trading, at fair value	$ 44,206	$ 41,867
Available-for-sale, at fair value	2,690	3,429
Other assets	22,361	17,004
Other liabilities	$ (11,836)	(9,947)
Document Period End Date	Sep. 30, 2019
Unpaid principal balance of mortgage loans	$ 3,280,189	3,223,783
Unpaid Principal Balance of Loans Securitized in Unconsolidated Portfolio Securitization Trusts	1,100	1,200
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	318,106	293,858
Unconsolidated VIEs [Member] | Multifamily [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	6,500	931
Unpaid principal balance of mortgage loans	318,100
Unconsolidated VIEs [Member] | Mortgage-related securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	7,178	6,231
Available-for-sale, at fair value	2,352	2,911
Other assets	57	66
Other liabilities	(82)	(101)
Net carrying amount	9,505	9,107
Maximum exposure to loss	41,000	14,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	100,000	80,000
Unconsolidated VIEs [Member] | Partnership interest LIHTC [Member]
Variable Interest Entities [Line Items]
Net carrying amount	70	89
Maximum exposure to loss	93
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	2,300	2,300
Unconsolidated VIEs [Member] | Debt Securities [Member]
Variable Interest Entities [Line Items]
Maximum exposure to loss	6,500	920
Unconsolidated VIEs [Member] | Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	2,733	1,422
Available-for-sale, at fair value	1,581	1,704
Unconsolidated VIEs [Member] | Non-Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	4,445	4,809
Available-for-sale, at fair value	$ 771	$ 1,207

Consolidations and Transfers _5

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Transfers of Financial Assets [Line Items]
Document Period End Date			Sep. 30, 2019
Portfolio securitizations: unpaid principal balance	$ 89,000	$ 64,900	$ 187,700	$ 180,800
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	187	$ 114	425	$ 468
Unconsolidated VIEs [Member] | Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	3,100		3,100		$ 1,500
Retained interests: fair value	$ 4,200		$ 4,200		$ 2,200

Consolidations and Transfers _6

Consolidations and Transfers of Financial Assets Managed Loans (Details) - USD ($) $ in Billions	Sep. 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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,280,189		$ 3,280,189			$ 3,223,783
Cost basis and fair value adjustments, net	43,323		43,323			39,815
Allowance for loan losses for loans held for investment	(9,376)	$ (15,663)	(9,376)	$ (15,663)	$ (11,482)	(14,203)	$ (16,812)	$ (19,084)
Total mortgage loans	3,314,136		3,314,136			3,249,395
Carrying value of loans redesignated from HFI to HFS(1)	4,882	4,249	14,252	17,851
Carrying value of loans redesignated from HFS to HFI(1)	10	6	22	36
Loans sold - unpaid principal balance	3,941	9,373	10,497	13,831
Realized gains on sale of mortgage loans	184	$ 93	504	$ 301
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,962,083		2,962,083			2,929,925
Mortgage Loans in Process of Foreclosure, Amount	8,200		8,200			10,100
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 318,106		$ 318,106			$ 293,858

Mortgage Loans Aging (Details)

Mortgage Loans Aging (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 55,004	$ 60,485
Current	3,256,694	3,194,683
Total recorded investment in loans	3,311,698	3,255,168
Recorded investment in loans 90 days or more delinquent and accruing interest	173	195
Recorded investment in nonaccrual loans	27,472	30,872
30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	31,576	33,720
60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	8,011	9,002
Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	15,417	17,763
Single-family [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	54,791	60,258
Current	2,935,710	2,899,246
Total recorded investment in loans	2,990,501	2,959,504
Recorded investment in loans 90 days or more delinquent and accruing interest	173	195
Recorded investment in nonaccrual loans	26,868	30,380
Table Footnote [Abstract]
Mortgage Loans in Process of Foreclosure, Amount	$ 8,200	$ 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, Past Due [Line Items]
Days delinquent	$ 31,544	$ 33,664
Single-family [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	8,011	9,002
Single-family [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	15,236	17,592
Single-family [Member] | Primary [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	49,690	53,218
Current	2,867,330	2,816,047
Total recorded investment in loans	2,917,020	2,869,265
Recorded investment in loans 90 days or more delinquent and accruing interest	26	22
Recorded investment in nonaccrual loans	23,840	26,170
Single-family [Member] | Primary [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	29,211	30,471
Single-family [Member] | Primary [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	7,188	7,881
Single-family [Member] | Primary [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	13,291	14,866
Single-family [Member] | Government [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	208	243
Current	17,881	21,887
Total recorded investment in loans	18,089	22,130
Recorded investment in loans 90 days or more delinquent and accruing interest	144	169
Recorded investment in nonaccrual loans	0	0
Single-family [Member] | Government [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	44	57
Single-family [Member] | Government [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	20	17
Single-family [Member] | Government [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	144	169
Single-family [Member] | Alt-A
Financing Receivable, Past Due [Line Items]
Days delinquent	3,624	4,997
Current	40,663	48,274
Total recorded investment in loans	44,287	53,271
Recorded investment in loans 90 days or more delinquent and accruing interest	1	2
Recorded investment in nonaccrual loans	2,228	3,082
Single-family [Member] | Alt-A | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,717	2,332
Single-family [Member] | Alt-A | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	591	821
Single-family [Member] | Alt-A | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,316	1,844
Single-family [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	1,269	1,800
Current	9,836	13,038
Total recorded investment in loans	11,105	14,838
Recorded investment in loans 90 days or more delinquent and accruing interest	2	2
Recorded investment in nonaccrual loans	800	1,128
Single-family [Member] | Other [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	572	804
Single-family [Member] | Other [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	212	283
Single-family [Member] | Other [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	485	713
Multifamily [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	213	227
Current	320,984	295,437
Total recorded investment in loans	321,197	295,664
Recorded investment in loans 90 days or more delinquent and accruing interest	0	0
Recorded investment in nonaccrual loans	$ 604	$ 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, Past Due [Line Items]
Days delinquent	$ 32	$ 56
Multifamily [Member] | Seriously Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Days delinquent	$ 181	$ 171

Mortgage Loans Credit Quality I

Mortgage Loans Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 3,311,698	$ 3,255,168
Single-family [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	2,990,501	2,959,504
Single-family [Member] | Primary [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	2,917,020	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	2,569,771	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	228,868	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	113,424	109,548
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	4,957	9,337
Single-family [Member] | Alt-A
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	44,287	53,271
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	39,710	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	2,365	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	1,131	1,997
Single-family [Member] | Alt-A | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	1,081	1,994
Single-family [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	11,105	14,838
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	9,694	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	709	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, Credit Quality Indicator [Line Items]
Total recorded investment in loans	337	645
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	365	707
Single-family [Member] | Government [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 18,089	$ 22,130

Mortgage Loans Credit Quality_2

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 3,311,698	$ 3,255,168
Multifamily [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	321,197	295,664
Multifamily [Member] | Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	0.1	1
Multifamily [Member] | Non-Classified [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	314,458	289,231
Multifamily [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total recorded investment in loans	$ 6,739	$ 6,433

Mortgage Loans Individually Imp

Mortgage Loans Individually Impaired Loans (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	$ 83,365	$ 104,310
Individually impaired loans with related allowance recorded: total recorded investment	80,038	99,481
Related allowance for loan losses	(8,552)	(13,295)
Individually impaired loans with no related allowance recorded: unpaid principal balance	22,774	19,689
Individually impaired loans with no related allowance recorded: total recorded investment	21,605	18,622
Total individually impaired loans: unpaid principal balance	106,139	123,999
Total individually impaired loans: total recorded investment	101,643	118,103
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	100,700	117,200
Individually impaired loans with related allowance recorded: unpaid principal balance	83,084	104,113
Individually impaired loans with related allowance recorded: total recorded investment	79,755	99,285
Related allowance for loan losses	(8,507)	(13,255)
Individually impaired loans with no related allowance recorded: unpaid principal balance	22,406	19,346
Individually impaired loans with no related allowance recorded: total recorded investment	21,236	18,276
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	67,175	81,791
Individually impaired loans with related allowance recorded: total recorded investment	64,987	78,688
Related allowance for loan losses	(6,141)	(9,406)
Individually impaired loans with no related allowance recorded: unpaid principal balance	19,326	15,939
Individually impaired loans with no related allowance recorded: total recorded investment	18,463	15,191
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	250	264
Individually impaired loans with related allowance recorded: total recorded investment	255	270
Related allowance for loan losses	(50)	(55)
Individually impaired loans with no related allowance recorded: unpaid principal balance	65	61
Individually impaired loans with no related allowance recorded: total recorded investment	61	56
Single-family [Member] | Alt-A
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	11,956	16,576
Individually impaired loans with related allowance recorded: total recorded investment	11,008	15,158
Related allowance for loan losses	(1,726)	(2,793)
Individually impaired loans with no related allowance recorded: unpaid principal balance	2,391	2,628
Individually impaired loans with no related allowance recorded: total recorded investment	2,141	2,363
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	3,703	5,482
Individually impaired loans with related allowance recorded: total recorded investment	3,505	5,169
Related allowance for loan losses	(590)	(1,001)
Individually impaired loans with no related allowance recorded: unpaid principal balance	624	718
Individually impaired loans with no related allowance recorded: total recorded investment	571	666
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	126	187
Individually impaired loans with related allowance recorded: unpaid principal balance	281	197
Individually impaired loans with related allowance recorded: total recorded investment	283	196
Related allowance for loan losses	(45)	(40)
Individually impaired loans with no related allowance recorded: unpaid principal balance	368	343
Individually impaired loans with no related allowance recorded: total recorded investment	$ 369	$ 346

Mortgage Loans Individually I_2

Mortgage Loans Individually Impaired Loans - 2 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	$ 85,408	$ 107,838	$ 91,876	$ 113,584
Individually impaired loans with related allowance recorded: total interest income recognized	879	1,111	2,868	3,525
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	74	103	255	362
Individually impaired loans with no related allowance recorded: average recorded investment	19,584	18,878	18,965	18,988
Individually impaired loans with no related allowance recorded: total interest income recognized	325	330	905	971
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	36	117	105
Individually impaired loans: average recorded investment	104,992	126,716	110,841	132,572
Individually impaired loans: total interest income recognized	1,204	1,441	3,773	4,496
Individually impaired loans: interest income recognized on a cash basis	118	139	372	467
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	85,095	107,607	91,596	113,340
Individually impaired loans with related allowance recorded: total interest income recognized	877	1,110	2,861	3,523
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	74	103	255	362
Individually impaired loans with no related allowance recorded: average recorded investment	19,183	18,543	18,588	18,655
Individually impaired loans with no related allowance recorded: total interest income recognized	317	322	889	960
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	44	36	117	105
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	69,084	84,043	73,601	86,842
Individually impaired loans with related allowance recorded: total interest income recognized	713	871	2,304	2,697
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	62	86	214	302
Individually impaired loans with no related allowance recorded: average recorded investment	16,422	15,140	15,718	15,039
Individually impaired loans with no related allowance recorded: total interest income recognized	262	254	731	740
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	39	30	103	88
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	262	276	267	277
Individually impaired loans with related allowance recorded: total interest income recognized	2	3	8	15
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	56	57	56	58
Individually impaired loans with no related allowance recorded: total interest income recognized	1	1	3	3
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	11,845	17,034	13,299	19,081
Individually impaired loans with related allowance recorded: total interest income recognized	125	179	426	610
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	8	13	30	45
Individually impaired loans with no related allowance recorded: average recorded investment	2,130	2,562	2,203	2,710
Individually impaired loans with no related allowance recorded: total interest income recognized	44	54	127	173
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	4	4	11	13
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	3,904	6,254	4,429	7,140
Individually impaired loans with related allowance recorded: total interest income recognized	37	57	123	201
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	4	4	11	15
Individually impaired loans with no related allowance recorded: average recorded investment	575	784	611	848
Individually impaired loans with no related allowance recorded: total interest income recognized	10	13	28	44
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	1	2	3	4
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	313	231	280	244
Individually impaired loans with related allowance recorded: total interest income recognized	2	1	7	2
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	401	335	377	333
Individually impaired loans with no related allowance recorded: total interest income recognized	8	8	16	11
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		9 Months Ended
	Sep. 30, 2019USD ($)contracts	Sep. 30, 2018USD ($)contracts	Sep. 30, 2019USD ($)contracts	Sep. 30, 2018USD ($)contracts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Average term extension of a single-family modified loan	164 months	98 months	160 months	104 months
Document Period End Date			Sep. 30, 2019
Average interest rate reduction of a single-family modified loan	0.15%	0.14%	0.11%	0.23%
Number of loans troubled debt restructurings activity | contracts	12,024	13,300	38,518	81,333
Recorded investment troubled debt restructurings activity | $	$ 1,910	$ 1,944	$ 5,994	$ 12,302
Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	12,021	13,298	38,509	81,321
Recorded investment troubled debt restructurings activity | $	$ 1,906	$ 1,937	$ 5,957	$ 12,234
Single-family [Member] | Primary [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	11,373	12,291	36,126	75,790
Recorded investment troubled debt restructurings activity | $	$ 1,819	$ 1,797	$ 5,634	$ 11,469
Single-family [Member] | Government [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	16	21	61	95
Recorded investment troubled debt restructurings activity | $	$ 1	$ 3	$ 7	$ 9
Single-family [Member] | Alt-A
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	543	779	1,948	4,499
Recorded investment troubled debt restructurings activity | $	$ 70	$ 100	$ 248	$ 583
Single-family [Member] | Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	89	207	374	937
Recorded investment troubled debt restructurings activity | $	$ 16	$ 37	$ 68	$ 173
Multifamily [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings activity | contracts	3	2	9	12
Recorded investment troubled debt restructurings activity | $	$ 4	$ 7	$ 37	$ 68

Mortgage Loans TDRs with Sub De

Mortgage Loans TDRs with Sub Defaults (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)contracts	Sep. 30, 2018USD ($)contracts	Sep. 30, 2019USD ($)contracts	Sep. 30, 2018USD ($)contracts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,203	4,310	13,909	14,583
Recorded investment troubled debt restructurings subsequent default | $	$ 659	$ 624	$ 2,129	$ 2,150
Single-family [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,202	4,309	13,907	14,581
Recorded investment troubled debt restructurings subsequent default | $	$ 646	$ 622	$ 2,110	$ 2,146
Single-family [Member] | Primary [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	3,780	3,720	12,343	12,372
Recorded investment troubled debt restructurings subsequent default | $	$ 585	$ 519	$ 1,864	$ 1,774
Single-family [Member] | Government [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	28	8	56	37
Recorded investment troubled debt restructurings subsequent default | $	$ 2	$ 0	$ 7	$ 4
Single-family [Member] | Alt-A
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	307	438	1,157	1,703
Recorded investment troubled debt restructurings subsequent default | $	$ 43	$ 74	$ 174	$ 275
Single-family [Member] | Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	87	143	351	469
Recorded investment troubled debt restructurings subsequent default | $	$ 16	$ 29	$ 65	$ 93
Multifamily [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	1	1	2	2
Recorded investment troubled debt restructurings subsequent default | $	$ 13	$ 2	$ 19	$ 4

Allowance for Loan Losses Rollf

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Allowance for Loan Losses [Roll Forward]
Beginning balance	$ (11,482)	$ (16,812)	$ (14,203)	$ (19,084)
Benefit (provision) for loan losses	(1,843)	(710)	(3,689)	(1,922)
Charge-offs	272	509	1,215	1,710
Recoveries	(9)	(68)	(71)	(192)
Other	0	(2)	(6)	(19)
Ending balance	(9,376)	(15,663)	(9,376)	(15,663)
Single-family [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	(11,210)	(16,602)	(13,969)	(18,849)
Benefit (provision) for loan losses	(1,826)	(724)	(3,712)	(1,916)
Charge-offs	270	509	1,209	1,705
Recoveries	(8)	(65)	(68)	(189)
Other	0	(2)	(6)	(19)
Ending balance	(9,122)	(15,436)	(9,122)	(15,436)
Multifamily [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	(272)	(210)	(234)	(235)
Benefit (provision) for loan losses	(17)	14	23	(6)
Charge-offs	2	0	6	5
Recoveries	(1)	(3)	(3)	(3)
Ending balance	(254)	$ (227)	$ (254)	$ (227)
Change in Accounting Estimate, Type [Domain]
Allowance for Loan Losses [Roll Forward]
Benefit (provision) for loan losses	$ 850

Allowance for Loan Losses and T

Allowance for Loan Losses and Total Recorded Investment in HFI Loans (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	$ (8,552)		$ (13,295)
Allowance for loan losses for collectively reserved loans	(824)		(908)
Total allowance for loan losses	(9,376)	$ (11,482)	(14,203)	$ (15,663)	$ (16,812)	$ (19,084)
Recorded investment in individually impaired loans	101,643		118,103
Recorded investment in collectively reserved loans	3,210,055		3,137,065
Total recorded investment in loans	3,311,698		3,255,168
Single-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	(8,507)		(13,255)
Allowance for loan losses for collectively reserved loans	(615)		(714)
Total allowance for loan losses	(9,122)	(11,210)	(13,969)	(15,436)	(16,602)	(18,849)
Recorded investment in individually impaired loans	100,991		117,561
Recorded investment in collectively reserved loans	2,889,510		2,841,943
Total recorded investment in loans	2,990,501		2,959,504
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	(45)		(40)
Allowance for loan losses for collectively reserved loans	(209)		(194)
Total allowance for loan losses	(254)	$ (272)	(234)	$ (227)	$ (210)	$ (235)
Recorded investment in individually impaired loans	652		542
Recorded investment in collectively reserved loans	320,545		295,122
Total recorded investment in loans	$ 321,197		$ 295,664

Investments in Securities Tradi

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 44,206		$ 41,867
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2)		(1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	273		24
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	11		29
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	353		506
Other [Member]
Schedule of Investments in Trading Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	273		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	8,106		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	3,661		1,467
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	8		26
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	348		487
Other agency [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	3,704		3,503
Private-label and other mortgage securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	741		1,306
Non-mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	36,100		35,591
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	36,016		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	$ 922		$ 32

Investments in Securities Tra_2

Investments in Securities Trading 2 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt and Equity Securities, FV-NI [Line Items]
Net trading gains (losses)	$ 95	$ (40)	$ 370	$ 79
Net trading gains (losses) recognized in the period related to securities still held at period end	$ 82	$ (27)	$ 298	$ 20

Investments in Securities Avail

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 0	$ 12	$ 171	$ 375
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 0	$ 21	$ 376	$ 662

Investments in Securities Ava_2

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	$ 2,448	$ 3,079
Gross unrealized gains	255	380
Gross unrealized losses	(13)	(30)
Total fair value	2,690	3,429
Fannie Mae [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	1,492	1,754
Gross unrealized gains	98	69
Gross unrealized losses	(8)	(26)
Total fair value	1,582	1,797
Other agency [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	195	239
Gross unrealized gains	18	17
Gross unrealized losses	0	0
Total fair value	213	256
Alt-A and subprime private-label securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	102	325
Gross unrealized gains	124	267
Gross unrealized losses	0	0
Total fair value	226	592
Mortgage revenue bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	339	425
Gross unrealized gains	10	13
Gross unrealized losses	(3)	(4)
Total fair value	346	434
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	320	336
Gross unrealized gains	5	14
Gross unrealized losses	(2)	0
Total fair value	$ 323	$ 350

Investments in Securities Ava_3

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	$ 2	$ 1
Less than 12 Consecutive Months, Fair Value	273	24
12 Consecutive Months or Longer, Gross Unrealized Losses	(11)	(29)
12 Consecutive Months or Longer, Fair Value	353	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	(8)	(26)
12 Consecutive Months or Longer, Fair Value	348	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
Other mortgage-related securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	2	0
Less than 12 Consecutive Months, Fair Value	273	0
12 Consecutive Months or Longer, Gross Unrealized Losses	0	0
12 Consecutive Months or Longer, Fair Value	$ 0	$ 0

Investments in Securities Other

Investments in Securities Other-than-temporary Impairments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 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	$ 37	$ 635	$ 718	$ 1,100

Investments in Securities Sched

Investments in Securities Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 37	$ 635	$ 718	$ 1,100
Accumulated Other Comprehensive Income , Net of Tax, Available-for-sale Securities, Other-than-temporary Impairment not Recorded	191	52
Accumulated Other Comprehensive Income , Net of Tax, Available-for-sale Gain, Other-than-temporary Impairment Recorded	0	224
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	39	46
Accumulated other comprehensive income	$ 230	$ 322

Investments in Securities Matur

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 2,448	$ 3,079
Total fair value	2,690	3,429
One Year or Less, Amortized Cost	2
One Year or Less, Fair Value	2
After One Year through Five Years, Amortized Cost	62
After One Year through Five Years, Fair Value	64
After Five Years through Ten Years, Amortized Cost	188
After Five Years through Ten Years, Fair Value	205
After Ten Years, Amortized Cost	2,196
After Ten Years, Fair Value	2,419
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,492	1,754
Total fair value	1,582	1,797
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	14
After One Year through Five Years, Fair Value	15
After Five Years through Ten Years, Amortized Cost	101
After Five Years through Ten Years, Fair Value	111
After Ten Years, Amortized Cost	1,377
After Ten Years, Fair Value	1,456
Other agency [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	195	239
Total fair value	213	256
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	20
After One Year through Five Years, Fair Value	21
After Five Years through Ten Years, Amortized Cost	26
After Five Years through Ten Years, Fair Value	29
After Ten Years, Amortized Cost	149
After Ten Years, Fair Value	163
Alt-A and subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	102	325
Total fair value	226	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	101
After Ten Years, Fair Value	225
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	339	425
Total fair value	346	434
One Year or Less, Amortized Cost	2
One Year or Less, Fair Value	2
After One Year through Five Years, Amortized Cost	26
After One Year through Five Years, Fair Value	27
After Five Years through Ten Years, Amortized Cost	36
After Five Years through Ten Years, Fair Value	37
After Ten Years, Amortized Cost	275
After Ten Years, Fair Value	280
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	320	336
Total fair value	323	$ 350
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	2
After One Year through Five Years, Fair Value	1
After Five Years through Ten Years, Amortized Cost	24
After Five Years through Ten Years, Fair Value	27
After Ten Years, Amortized Cost	294
After Ten Years, Fair Value	$ 295

Financial Guarantees Financial

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	$ 19,584	$ 21,125
Guaranty Obligation	161	160
Maximum Recovery	8,963	9,522
Unconsolidated VIEs [Member] | Unconsolidated Fannie Mae MBS [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	6,603	7,278
Guaranty Obligation	26	30
Maximum Recovery	6,354	6,811
Unconsolidated VIEs [Member] | Other guaranty arrangements [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	12,981	13,847
Guaranty Obligation	135	130
Maximum Recovery	2,609	$ 2,711
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Unconsolidated VIEs [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Single security, Freddie Mac issued securities backing unconsolidated Fannie Mae securities	$ 28,900
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	Sep. 30, 2019	Dec. 31, 2018
Short-Term Debt [Line Items]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	$ 1,125	$ 0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Short-Term Debt [Line Items]
Debt, Weighted Average Interest Rate	2.15%	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	$ 35,812	$ 24,896
Short-term debt, weighted-average interest rate	2.04%	2.29%

Short-Term and Long-Term Debt L

Short-Term and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,426,046	$ 3,367,024
Long-term debt, weighted-average interest rate	2.81%	3.02%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,248,336	$ 3,159,846
Long-term debt, weighted-average interest rate	2.79%	3.03%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 177,710	$ 207,178
Long-term debt, weighted-average interest rate	3.14%	2.83%
Unamortized discounts and premiums, other cost basis adjustments and fair value adjustments	$ 30	$ 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	$ 138,718	$ 171,344
Long-term debt, weighted-average interest rate	2.44%	2.13%
Fannie Mae [Member] | Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 91,603	$ 103,206
Long-term debt, weighted-average interest rate	2.66%	2.36%
Fannie Mae [Member] | Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 40,973	$ 61,455
Long-term debt, weighted-average interest rate	1.60%	1.48%
Fannie Mae [Member] | Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 6,142	$ 6,683
Long-term debt, weighted-average interest rate	4.84%	4.62%
Fannie Mae [Member] | Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 33,172	$ 30,166
Long-term debt, weighted-average interest rate	4.86%	5.52%
Fannie Mae [Member] | Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 9,773	$ 4,174
Long-term debt, weighted-average interest rate	2.28%	2.36%
Fannie Mae [Member] | Senior floating Connecticut Avenue Securities [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 22,977	$ 25,641
Long-term debt, weighted-average interest rate	5.90%	5.97%
Fannie Mae [Member] | Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 422	$ 351
Long-term debt, weighted-average interest rate	7.79%	10.19%
Fannie Mae [Member] | Subordinated debentures [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 5,783	$ 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	$ 37	$ 51
Long-term debt, weighted-average interest rate	2.24%	1.96%

Derivative Instruments Derivati

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Asset Derivatives [Abstract]
Notional amount	$ 327,339	$ 266,935
Derivative asset, estimated fair value	472	458
Netting adjustment	(1,663)	(2,266)
Liability Derivatives [Abstract]
Notional amount	229,918	161,488
Derivative liability, estimated fair value	(595)	(777)
Netting adjustment	2,299	2,315
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	1,300	713
Cash collateral received for derivative instruments	684	664
Pay-fixed Swap
Asset Derivatives [Abstract]
Notional amount	35,550	71,416
Derivative asset, estimated fair value	0	438
Liability Derivatives [Abstract]
Notional amount	32,893	21,253
Derivative liability, estimated fair value	(1,481)	(740)
Receive-fixed Swap
Asset Derivatives [Abstract]
Notional amount	71,372	88,799
Derivative asset, estimated fair value	958	1,113
Liability Derivatives [Abstract]
Notional amount	34,986	58,399
Derivative liability, estimated fair value	(103)	(860)
Basis Swap
Asset Derivatives [Abstract]
Notional amount	273	250
Derivative asset, estimated fair value	179	104
Liability Derivatives [Abstract]
Notional amount	0	624
Derivative liability, estimated fair value	0	0
Foreign Currency Swap
Asset Derivatives [Abstract]
Notional amount	213	221
Derivative asset, estimated fair value	27	22
Liability Derivatives [Abstract]
Notional amount	215	223
Derivative liability, estimated fair value	(86)	(72)
Pay-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	4,600	10,375
Derivative asset, estimated fair value	18	191
Liability Derivatives [Abstract]
Notional amount	6,375	1,000
Derivative liability, estimated fair value	(270)	(4)
Receive-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	2,875	500
Derivative asset, estimated fair value	203	20
Liability Derivatives [Abstract]
Notional amount	4,600	7,375
Derivative liability, estimated fair value	(137)	(338)
Future [Member]
Asset Derivatives [Abstract]
Notional amount	47,069	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	161,952	188,192
Derivative asset, estimated fair value	1,385	1,888
Accrued interest receivable (payable)	287	400
Netting adjustment	(1,663)	(2,266)
Total net risk management derivatives	9	22
Liability Derivatives [Abstract]
Notional amount	79,069	88,874
Derivative liability, estimated fair value	(2,077)	(2,014)
Accrued interest receivable (payable)	(374)	(419)
Netting adjustment	2,299	2,315
Total net risk management derivatives	(152)	(118)
Mortgage commitments to purchase whole loans
Asset Derivatives [Abstract]
Notional amount	7,812	4,370
Derivative asset, estimated fair value	20	29
Liability Derivatives [Abstract]
Notional amount	6,258	57
Derivative liability, estimated fair value	(26)	0
Forward contracts to purchase mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	70,120	40,650
Derivative asset, estimated fair value	231	349
Liability Derivatives [Abstract]
Notional amount	28,853	1,045
Derivative liability, estimated fair value	(85)	(3)
Forward contracts to sell mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	57,048	292
Derivative asset, estimated fair value	170	1
Liability Derivatives [Abstract]
Notional amount	109,229	70,593
Derivative liability, estimated fair value	(305)	(645)
Mortgage commitment derivatives
Asset Derivatives [Abstract]
Notional amount	134,980	45,312
Derivative asset, estimated fair value	421	379
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	144,340	71,695
Derivative liability, estimated fair value	(416)	(648)
Netting adjustment	0	0
Other
Asset Derivatives [Abstract]
Notional amount	30,407	33,431
Derivative asset, estimated fair value	42	57
Liability Derivatives [Abstract]
Notional amount	6,509	919
Derivative liability, estimated fair value	$ (27)	$ (11)

Derivative Instruments Deriva_2

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ (668)	$ 360	$ (2,216)	$ 1,185
Net accrual of periodic settlements	5,229	5,369	15,112	15,978
Pay-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(1,414)	1,034	(4,913)	4,784
Receive-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	966	(524)	4,131	(3,508)
Basis Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	24	(5)	75	(31)
Foreign Currency Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(11)	(10)	(9)	(35)
Pay-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(110)	67	(430)	232
Receive-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	209	(34)	309	(72)
Future [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	42	0	296	(3)
Risk Management Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(484)	243	(1,239)	581
Net accrual of periodic settlements	(190)	(285)	(698)	(786)
Mortgage commitment derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	(177)	118	(946)	606
Other
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Fair Value Gain (Loss) on Derivative, Net	$ (7)	$ (1)	$ (31)	$ (2)

Segment Reporting Narrative (De

Segment Reporting Narrative (Details)	9 Months Ended
	Sep. 30, 2019segments
Segment Reporting [Abstract]
Number of Reportable Segments	2

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net interest income	$ 5,229	$ 5,369	$ 15,112	$ 15,978
Fee and other income	402	271	875	830
Net revenues	5,631	5,640	15,987	16,808
Investment gains, net	253	166	847	693
Fair value gains (losses), net	(713)	386	(2,298)	1,660
Administrative expenses	(749)	(740)	(2,237)	(2,245)
Benefit (provision) for credit losses	1,857	716	3,732	2,229
Foreclosed property income (expense)	(96)	(159)	(364)	(460)
Total credit-related income (expense)	(1,761)	(557)	(3,368)	(1,769)
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(613)	(576)	(1,806)	(1,698)
Other expenses, net	(571)	(377)	(1,514)	(946)
Income before federal income taxes	4,999	5,056	12,347	16,041
Provision for federal income taxes	(1,036)	(1,045)	(2,552)	(3,312)
Net income	3,963	4,011	9,795	12,729
US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(613)	(576)	(1,806)	(1,698)
Business Segments [Member] | Single-family [Member]
Segment Reporting Information [Line Items]
Net interest income	4,484	4,670	12,942	13,954
Fee and other income	156	79	350	306
Net revenues	4,640	4,749	13,292	14,260
Investment gains, net	198	146	709	640
Fair value gains (losses), net	(719)	417	(2,364)	1,729
Administrative expenses	(634)	(636)	(1,899)	(1,928)
Benefit (provision) for credit losses	(1,840)	(732)	(3,753)	(2,223)
Foreclosed property income (expense)	(93)	(150)	(362)	(448)
Total credit-related income (expense)	(1,747)	(582)	(3,391)	(1,775)
Other expenses, net	(424)	(282)	(1,179)	(684)
Income before federal income taxes	4,195	4,400	10,144	14,094
Provision for federal income taxes	(872)	(938)	(2,125)	(2,998)
Net income	3,323	3,462	8,019	11,096
Business Segments [Member] | Single-family [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	(613)	(576)	(1,806)	(1,698)
Business Segments [Member] | Multifamily [Member]
Segment Reporting Information [Line Items]
Net interest income	745	699	2,170	2,024
Fee and other income	246	192	525	524
Net revenues	991	891	2,695	2,548
Investment gains, net	55	20	138	53
Fair value gains (losses), net	6	(31)	66	(69)
Administrative expenses	(115)	(104)	(338)	(317)
Benefit (provision) for credit losses	(17)	(16)	(21)	(6)
Foreclosed property income (expense)	(3)	(9)	(2)	(12)
Total credit-related income (expense)	(14)	(25)	(23)	(6)
Other expenses, net	(147)	(95)	(335)	(262)
Income before federal income taxes	804	656	2,203	1,947
Provision for federal income taxes	(164)	(107)	(427)	(314)
Net income	640	549	1,776	1,633
Business Segments [Member] | Multifamily [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	$ 0	$ 0	$ 0	$ 0

Concentrations of Credit Risk S

Concentrations of Credit Risk SF Risk Characteristics (Details) - Single-family [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Guaranty Book of Business [Member] | Conventional Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	1.11%	1.17%
60 days delinquent (percentage of book of business)	0.29%	0.32%
Seriously delinquent (percentage of book of business)	0.61%	0.69%
30 days delinquent (percentage of conventional loans)	1.28%	1.37%
60 days delinquent (percentage of conventional loans)	0.35%	0.38%
Seriously delinquent (percentage of conventional loans)	0.68%	0.76%
Percentage of loans with detailed loan level information	99.00%
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)	10.62%	9.85%
Guaranty Book of Business [Member] | Conventional Loan [Member] | Alt-A
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	3.09%	3.35%
Percentage of Unpaid Principal Balance of Loans	2.00%	2.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2004 and prior
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.53%	2.69%
Percentage of Unpaid Principal Balance of Loans	2.00%	3.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2005-2008
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	4.24%	4.61%
Percentage of Unpaid Principal Balance of Loans	4.00%	5.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2009-2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.33%	0.34%
Percentage of Unpaid Principal Balance of Loans	94.00%	92.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | California
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	19.00%	19.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.87%	1.16%
Percentage of Unpaid Principal Balance of Loans	6.00%	6.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	1.21%	1.38%
Percentage of Unpaid Principal Balance of Loans	3.00%	4.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	1.24%	1.40%
Percentage of Unpaid Principal Balance of Loans	5.00%	5.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | All other states
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.67%	0.75%
Percentage of Unpaid Principal Balance of Loans	67.00%	66.00%
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]	9 Months Ended	12 Months Ended
	Sep. 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
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
Current debt service coverage ratio reporting lag	6 months
Guaranty Book of Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)		0.02%
Seriously delinquent (percentage of book of business)	0.06%	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	0.06%	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	0.44%	1.38%

Concentrations of Credit Risk O

Concentrations of Credit Risk Other Concentrations (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Estimated benefit included in loss reserves	$ 398	$ 691
Receivable from claims on insured, defaulted loans excluding government insured loans	669	745
Allowance for mortgage insurance receivable	$ 545	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	$ 162,718	$ 152,788
Mortgage insurance coverage risk in force as percentage	6.00%	5.00%
Primary mortgage insurance	$ 162,339	$ 152,379
Pool mortgage insurance	$ 379	$ 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	57.00%	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	17.00%	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	$ 3,700
Percentage of Concentration Risk	2.00%
Single-family [Member] | Guaranty Book of Business [Member] | Insurance Service Provider Concentration Risk [Member] | Arch Capital Group Ltd.
Concentration Risk [Line Items]
Percentage of Risk in Force Coverage by Mortgage Insurer	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	Sep. 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	27	11
Assets:
Derivative assets, gross amount	2,093	2,667
Derivative assets, gross amount offset	(1,663)	(2,266)
Derivative assets, net amount presented in our condensed consolidated balance sheets	430	401
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(368)	(153)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(7)	(7)
Derivative assets, net amount	55	241
Securities purchased under agreements to resell or similar arrangements, gross amount	36,051	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	36,051	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	(36,051)	(48,288)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	38,144	50,955
Total assets, gross amount offset	(1,663)	(2,266)
Total assets, net amount presented in our condensed consolidated balance sheets	36,481	48,689
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(368)	(153)
Total assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(36,058)	(48,295)
Total assets, net amount	55	241
Liabilities:
Derivative liabilities, gross amount	(2,867)	(3,081)
Derivative liabilities, gross amount offset	2,299	2,315
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(568)	(766)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	368	153
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	37	489
Derivative liabilities, net amount	(163)	(124)
Total liabilities, gross amount	(3,992)	(3,081)
Total liabilities, gross amount offset	2,299	2,315
Total liabilities, net amount presented in our condensed consolidated balance sheets	(1,693)	(766)
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	368	153
Total liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	1,160	489
Total liabilities, net amount	(165)	(124)
Fair Value of Securities Received as Collateral that Can be Resold or Repledged	34,300	45,700
Securities Sold under Agreements to Repurchase, Gross	(1,125)
Securities Sold under Agreements to Repurchase, Asset	0
Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement	(1,125)
Securities Sold under Agreements to Repurchase, Not Offset, Policy Election Deduction	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	1,123
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	2
Risk Management Derivatives
Assets:
Derivative assets, gross amount offset	(1,663)	(2,266)
Liabilities:
Derivative liabilities, gross amount offset	2,299	2,315
Mortgage commitment derivatives
Assets:
Derivative assets, gross amount	421	379
Derivative assets, gross amount offset	0	0
Derivative assets, net amount presented in our condensed consolidated balance sheets	421	379
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	(368)	(153)
Derivative assets, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	(7)	(7)
Derivative assets, net amount	46	219
Liabilities:
Derivative liabilities, gross amount	(416)	(648)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(416)	(648)
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, financial instruments	368	153
Derivative liabilities, under master netting arrangements, amounts not offset in our condensed consolidated balance sheets, collateral	4	466
Derivative liabilities, net amount	(44)	(29)
Over the Counter [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	1,672	2,288
Derivative assets, gross amount offset	(1,667)	(2,273)
Derivative assets, net amount presented in our condensed consolidated balance sheets	5	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	5	15
Liabilities:
Derivative liabilities, gross amount	(2,451)	(2,433)
Derivative liabilities, gross amount offset	2,332	2,342
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(119)	(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	(119)	(91)
Exchange Cleared [Member] | Risk Management Derivatives
Assets:
Derivative assets, gross amount	0	0
Derivative assets, gross amount offset	4	7
Derivative assets, net amount presented in our condensed consolidated balance sheets	4	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	4	7
Liabilities:
Derivative liabilities, gross amount	0	0
Derivative liabilities, gross amount offset	(33)	(27)
Derivative liabilities, net amount presented in our condensed consolidated balance sheets	(33)	(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	33	23
Derivative liabilities, net amount	$ 0	$ (4)

Netting Arrangements Narratives

Netting Arrangements Narratives (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Fair value of non-cash collateral we pledged	$ 3,100	$ 1,900
Fair value of non-cash collateral received	36,100	48,400
Fair value of non-cash collateral received that can be resold or repledged	34,300	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	42	57
Derivative liabilities not subject to enforceable master netting arrangements	(27)	(11)
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Securities purchased under agreements to resell	$ 12,900	$ 15,400

Fair Value Levels Hierarchy (De

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 8,183	$ 8,922
Other assets [Abstract]
Derivative assets, gross amount offset	(1,663)	(2,266)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,299)	(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	6,041	6,826
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,719	23,753
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	36,016	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	87,639	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	8,066	6,332
Available-for-sale securities	1,855	2,477
Mortgage loans held for investment, at fair value	3,241,129	2,990,104
Other assets [Abstract]
Derivatives assets at fair value	1,909	2,515
Total assets at fair value	3,300,728	3,053,308
Other liabilities [Abstract]
Derivative liabilities at fair value	2,866	3,077
Total liabilities at fair value	3,500,144	3,303,620
Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	186,489	211,403
Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	3,273,846	3,064,239
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	124	33
Available-for-sale securities	835	952
Mortgage loans held for investment, at fair value	134,732	216,404
Other assets [Abstract]
Derivatives assets at fair value	226	209
Total assets at fair value	144,910	225,812
Other liabilities [Abstract]
Derivative liabilities at fair value	28	15
Total liabilities at fair value	34,644	39,950
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	847	771
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	33,667	39,043
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Cash equivalents		748
Trading securities	44,206	41,867
Available-for-sale securities	2,690	3,429
Mortgage loans held for investment, at fair value	8,183	8,922
Other assets [Abstract]
Derivatives assets at fair value	472	458
Derivative assets, gross amount offset	(1,663)	(2,266)
Total assets at fair value	55,551	55,424
Liabilities [Abstract]
Long-term debt, fair value	28,760	30,579
Other liabilities [Abstract]
Derivative liabilities at fair value	595	777
Derivative liabilities, gross amount offset	(2,299)	(2,315)
Total liabilities at fair value	29,355	31,356
Recurring Fair Value Measurements [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,451	2,077
Other liabilities [Abstract]
Derivative liabilities at fair value	2,044	2,091
Recurring Fair Value Measurements [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	221	211
Other liabilities [Abstract]
Derivative liabilities at fair value	407	342
Recurring Fair Value Measurements [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	421	379
Other liabilities [Abstract]
Derivative liabilities at fair value	416	648
Recurring Fair Value Measurements [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	42	57
Other liabilities [Abstract]
Derivative liabilities at fair value	27	11
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	6,041	6,826
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	6,041	6,826
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,719	23,753
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	3,661	1,467
Available-for-sale securities	1,582	1,797
Recurring Fair Value Measurements [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,704	3,503
Available-for-sale securities	213	256
Recurring Fair Value Measurements [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	741	1,306
Available-for-sale securities	226	592
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Available-for-sale securities	346	434
Recurring Fair Value Measurements [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	323	350
Recurring Fair Value Measurements [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	36,016	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		748
Trading securities	36,016	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	36,016	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	36,016	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
Trading securities	8,066	6,332
Available-for-sale securities	1,855	2,477
Mortgage loans held for investment, at fair value	7,457	7,985
Other assets [Abstract]
Derivatives assets at fair value	1,909	2,515
Total assets at fair value	19,287	19,309
Liabilities [Abstract]
Long-term debt, fair value	28,250	30,027
Other liabilities [Abstract]
Derivative liabilities at fair value	2,866	3,077
Total liabilities at fair value	31,116	33,104
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	1,267	1,962
Other liabilities [Abstract]
Derivative liabilities at fair value	2,043	2,089
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	221	211
Other liabilities [Abstract]
Derivative liabilities at fair value	407	342
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage commitment derivatives
Other assets [Abstract]
Derivatives assets at fair value	421	342
Other liabilities [Abstract]
Derivative liabilities at fair value	416	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	5,619	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	5,619	6,475
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	22,631	23,552
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	3,539	1,435
Available-for-sale securities	1,408	1,645
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	3,702	3,503
Available-for-sale securities	213	256
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private-label and other mortgage securities [Member]
Assets [Abstract]
Trading securities	741	1,305
Available-for-sale securities	226	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
Trading securities	124	33
Available-for-sale securities	835	952
Mortgage loans held for investment, at fair value	726	937
Other assets [Abstract]
Derivatives assets at fair value	226	209
Total assets at fair value	1,911	2,131
Liabilities [Abstract]
Long-term debt, fair value	510	552
Other liabilities [Abstract]
Derivative liabilities at fair value	28	15
Total liabilities at fair value	538	567
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Swaps [Member]
Other assets [Abstract]
Derivatives assets at fair value	184	115
Other liabilities [Abstract]
Derivative liabilities at fair value	1	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	42	57
Other liabilities [Abstract]
Derivative liabilities at fair value	27	11
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	422	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	422	351
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	88	201
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	122	32
Available-for-sale securities	174	152
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other agency [Member]
Assets [Abstract]
Trading securities	2	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	346	434
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	315	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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 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	$ 1	$ 2	$ 4	$ 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	74	80	33	1,201
Total gains (losses) (realized/unrealized) Included in Net Income	2	(3)	5	77
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	77	0	77	1
Sales	0	0	(14)	(1,060)
Issues	0	0	0	0
Settlements	0	0	(17)	(6)
Transfers out of Level 3	(31)	0	(31)	(137)
Transfers into Level 3	2	0	71	1
Ending Balance	124	77	124	77
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	1	2	4	2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	74	79	32	971
Total gains (losses) (realized/unrealized) Included in Net Income	2	(3)	5	163
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	77	0	77	1
Sales	0	0	(14)	(1,060)
Issues	0	0	0	0
Settlements	0	0	(16)	0
Transfers out of Level 3	(31)	0	(31)	0
Transfers into Level 3	0	0	69	1
Ending Balance	122	76	122	76
Trading securities [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0		0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0		0	35
Total gains (losses) (realized/unrealized) Included in Net Income	0		0	(1)
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		0	(1)
Transfers out of Level 3	0		0	(33)
Transfers into Level 3	2		2	0
Ending Balance	2	0	2	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	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	822	1,093	952	1,313
Total gains (losses) (realized/unrealized) Included in Net Income	0	8	17	23
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	1	(11)	(9)	(51)
Purchases	0	0	0	0
Sales	0	(4)	(27)	(22)
Issues	0	0	0	0
Settlements	(28)	(50)	(118)	(223)
Transfers out of Level 3	0	0	(105)	(4)
Transfers into Level 3	40	0	125	0
Ending Balance	835	1,036	835	1,036
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	132	204	152	208
Total gains (losses) (realized/unrealized) Included in Net Income	0	0	0	1
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	3	(1)	9	(1)
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(1)	(3)	(8)	(8)
Transfers out of Level 3	0	0	(103)	0
Transfers into Level 3	40	0	124	0
Ending Balance	174	200	174	200
Available-for-sale Securities [Member] | Private-label and other mortgage securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets		0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		26	24	77
Total gains (losses) (realized/unrealized) Included in Net Income		0	5	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)		0	(5)	(45)
Purchases		0	0	0
Sales		0	(23)	0
Issues		0	0	0
Settlements		(2)	(1)	(4)
Transfers out of Level 3		0	0	(4)
Transfers into Level 3		0	0	0
Ending Balance	0	24	0	24
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	364	506	434	671
Total gains (losses) (realized/unrealized) Included in Net Income	1	1	1	1
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(1)	(3)	(2)	(6)
Purchases	0	0	0	0
Sales	0	(4)	(4)	(22)
Issues	0	0	0	0
Settlements	(18)	(36)	(83)	(180)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	346	464	346	464
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	326	357	342	357
Total gains (losses) (realized/unrealized) Included in Net Income	(1)	7	11	21
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(1)	(7)	(11)	1
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	(9)	(9)	(26)	(31)
Transfers out of Level 3	0	0	(2)	0
Transfers into Level 3	0	0	1	0
Ending Balance	315	348	315	348
Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	10	2	28	17
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	770	1,018	937	1,116
Total gains (losses) (realized/unrealized) Included in Net Income	14	7	45	35
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	(27)	0	(40)	0
Issues	0	0	0	0
Settlements	(35)	(47)	(105)	(174)
Transfers out of Level 3	(41)	(44)	(228)	(131)
Transfers into Level 3	45	31	117	119
Ending Balance	726	965	726	965
Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	15	(27)	39	(56)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	183	117	194	134
Total gains (losses) (realized/unrealized) Included in Net Income	21	(18)	139	(104)
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	(6)	(1)	(126)	(15)
Transfers out of Level 3	0	0	(9)	53
Transfers into Level 3	0	0	0	0
Ending Balance	198	98	198	98
Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	(25)	7	(74)	26
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(500)	(673)	(552)	(958)
Total gains (losses) (realized/unrealized) Included in Net Income	(27)	(9)	(78)	(38)
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	(2)	0	(2)	(1)
Settlements	6	4	16	35
Transfers out of Level 3	20	172	189	503
Transfers into Level 3	(7)	(22)	(83)	(129)
Ending Balance	(510)	(510)	(510)	(510)
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	(1)	0	(3)	(3)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(102)	(319)	(201)	(582)
Total gains (losses) (realized/unrealized) Included in Net Income	3	(2)	7	(9)
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	(2)	0	(2)	(1)
Settlements	6	4	16	35
Transfers out of Level 3	20	172	189	503
Transfers into Level 3	(7)	(22)	(83)	(129)
Ending Balance	(88)	(163)	(88)	(163)
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	(24)	7	(71)	29
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(398)	(354)	(351)	(376)
Total gains (losses) (realized/unrealized) Included in Net Income	24	7	71	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	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	(422)	(347)	(422)	(347)
Other Comprehensive Income (Loss) [Member] | Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Trading securities [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Trading securities [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0		0	0
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	1	(9)	(2)	0
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	(1)	8	(1)
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	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	(2)	(1)	(3)
Other Comprehensive Income (Loss) [Member] | Available-for-sale Securities [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	(2)	(6)	(9)	3
Other Comprehensive Income (Loss) [Member] | Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Assets	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	0	0	0	0
Other Comprehensive Income (Loss) [Member] | Long-term debt [Member] | Senior floating [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Unrealized Gain (Losses) Related to Liabilities	$ 0	$ 0	$ 0	$ 0

Fair Value Level 3 Valuation In

Fair Value Level 3 Valuation Inputs (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 430	$ 401
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	44,206	41,867
Available-for-sale securities	2,690	3,429
Assets, Fair Value Disclosure	55,551	55,424
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	36,016	35,502
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	87,639	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	36,016	35,502
Available-for-sale securities	0	0
Assets, Fair Value Disclosure	36,016	36,250
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	8,066	6,332
Available-for-sale securities	1,855	2,477
Assets, Fair Value Disclosure	3,300,728	3,053,308
Mortgage loans held-for-sale, at lower of cost or fair value	4,783	238
Significant Other Observable Inputs (Level 2) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	8,066	6,332
Available-for-sale securities	1,855	2,477
Assets, Fair Value Disclosure	19,287	19,309
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	620	91
Liabilities, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	124	33
Available-for-sale securities	835	952
Assets, Fair Value Disclosure	144,910	225,812
Mortgage loans held-for-sale, at lower of cost or fair value	8,672	7,856
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	124	33
Available-for-sale securities	835	952
Derivatives	198	194
Assets, Fair Value Disclosure	1,911	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	15	81
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	183	113
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Nonrecurring [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	4,334	3,771
Mortgage loans held-for-sale, at lower of cost or fair value	2,848	1,750
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Nonrecurring [Member] | Single Vendor Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	780	1,119
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Nonrecurring [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	1	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Nonrecurring [Member] | Consensus Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	2,067	631
Agency | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	174
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	124	32
Available-for-sale securities	56	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	118
Private-label and other mortgage securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	741	1,306
Available-for-sale securities	226	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	741	1,305
Available-for-sale securities	226	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	346	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	346	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	$ 232	$ 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 (%)	0.225%	(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 (%)	2.045%	3.328%
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 (%)	0.703%	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	323	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	315	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	41	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	$ 274	$ 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 (%)	0.775%	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 (%)	0.8	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 (%)	8.7	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 (%)	0.840	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 (%)	3.00%	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] | Maximum [Member] | Measurement Input, Default Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	0.8000	4.7000
Other [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Available-for-sale Securities [Member] | Maximum [Member] | Measurement Input, Constant Prepayment Rate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	8.700	8.200
Other [Member] | Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Available-for-sale Securities [Member] | Maximum [Member] | Measurement Input, Loss Severity [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Debt Securities, Available-for-sale, Measurement Input (%)	0.840	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] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	2.994%	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 (%)	0.8	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 (%)	8.7	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 (%)	0.840	0.700

Fair Value Level 3 Valuation -

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 8,183	$ 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	4,783	238
Mortgage loans held for investment, at fair value	3,241,129	2,990,104
Total assets at fair value	3,300,728	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	8,672	7,856
Mortgage loans held for investment, at fair value	134,732	216,404
Total assets at fair value	144,910	225,812
Fair Value, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	620	91
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	2,848	1,750
Total assets at fair value	4,334	3,771
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single Vendor Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	780	1,119
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consensus Without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	2,067	631
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held-for-sale, at lower of cost or fair value	$ 1	$ 0
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Number of Acquired Properties Valuated, Percentage	13.00%	15.00%
Fair Value, 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	83.00%	82.00%
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	$ 860	$ 1,011
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	32	41
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	543	818
Acquired property, net	152	219
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	100	151
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	386	419
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Walk Forwards [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	190	181
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	83	142
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Various Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	13	40
Acquired property, net	0	50
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Asset Manager Estimate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 70	$ 102

Fair Value Fair Value of Financ

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (1,663)	$ (2,266)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(2,299)	(2,315)
Mortgage loans held for investment, at fair value	8,183	8,922
Derivative assets, gross amount offset	(1,663)	(2,266)
Derivative liabilities, gross amount offset	(2,299)	(2,315)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	51,623	34,073
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	36,016	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	87,639	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	12,875	15,350
Federal funds sold and securities purchased under agreements to resell or similar arrangements	23,176	32,938
Trading securities	8,066	6,332
Available-for-sale securities	1,855	2,477
Mortgage loans held for sale	4,783	238
Mortgage loans held for investment, at fair value	3,241,129	2,990,104
Advances to lenders	6,935	3,354
Derivatives assets at fair value	1,909	2,515
Guaranty assets and buy-ups	0	0
Total financial assets	3,300,728	3,053,308
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	1,125
Derivative liabilities at fair value	2,866	3,077
Guaranty obligations	0	0
Total financial liabilities	3,500,144	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	124	33
Available-for-sale securities	835	952
Mortgage loans held for sale	8,672	7,856
Mortgage loans held for investment, at fair value	134,732	216,404
Advances to lenders	2	2
Derivatives assets at fair value	226	209
Guaranty assets and buy-ups	319	356
Total financial assets	144,910	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	28	15
Guaranty obligations	102	121
Total financial liabilities	34,644	39,950
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	6,041	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	35,818	24,901
Long-term debt	186,489	211,403
Fannie Mae [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	847	771
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	22,719	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	3,273,846	3,064,239
Consolidated Trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities [Abstract]
Long-term debt	33,667	39,043
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	64,498	49,423
Federal funds sold and securities purchased under agreements to resell or similar arrangements	23,176	32,938
Trading securities	44,206	41,867
Available-for-sale securities	2,690	3,429
Mortgage loans held for sale	12,289	7,701
Mortgage loans held for investment, at fair value	3,301,847	3,241,694
Advances to lenders	6,937	3,356
Derivatives assets at fair value	472	458
Guaranty assets and buy-ups	149	147
Total financial assets	3,456,264	3,381,013
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	1,125
Derivative liabilities at fair value	595	777
Guaranty obligations	161	160
Total financial liabilities	3,463,739	3,392,857
Carrying Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	35,812	24,896
Long-term debt	177,710	207,178
Carrying Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	3,248,336	3,159,846
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	64,498	49,423
Federal funds sold and securities purchased under agreements to resell or similar arrangements	23,176	32,938
Trading securities	44,206	41,867
Available-for-sale securities	2,690	3,429
Mortgage loans held for sale	13,455	8,094
Mortgage loans held for investment, at fair value	3,375,861	3,206,508
Advances to lenders	6,937	3,356
Derivatives assets at fair value	472	458
Guaranty assets and buy-ups	319	356
Total financial assets	3,531,614	3,346,429
Financial liabilities [Abstract]
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	1,125
Derivative liabilities at fair value	595	777
Guaranty obligations	102	121
Total financial liabilities	3,532,489	3,341,255
Estimated of Fair Value [Member] | Fannie Mae [Member]
Financial liabilities [Abstract]
Short-term debt	35,818	24,901
Long-term debt	187,336	212,174
Estimated of Fair Value [Member] | Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	$ 3,307,513	$ 3,103,282

Fair Value Fair Value Option (D

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fair Value, Option, Quantitative Disclosures [Line Items]
Document Period End Date			Sep. 30, 2019
Mortgage loans held for investment, at fair value	$ 8,183		$ 8,183		$ 8,922
Fair value of nonaccrual loans	127		127		161
Difference between unpaid principal balance and the fair value of nonaccrual loans	11		11		19
Fair value of loans that are 90 days or more past due	76		76		102
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	9		$ 9		$ 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	6,041		$ 6,041		$ 6,826
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	22,719		22,719		23,753
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	8,183		8,183		8,922
Loans, unpaid principal balance	7,866		7,866		8,832
Fair Value, Option, Changes in Fair Value, Gain (Loss)	95	$ (63)	334	$ (239)
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(245)	$ 128	(797)	$ 629
Long-term debt [Member] | Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	6,041		6,041		6,826
Long-term debt, unpaid principal balance	5,541		5,541		6,241
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	22,719		22,719		23,753
Long-term debt, unpaid principal balance	$ 20,380		$ 20,380		$ 22,080

Fair Value Changes in FV under

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ (95)	$ 63	$ (334)	$ 239
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value (gains) losses, net	$ 245	$ (128)	$ 797	$ (629)