Federal National Mortgage Association (FNMA) 10-Q 4 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2016shares
Entity [Abstract]
Entity Registrant Name	FEDERAL NATIONAL MORTGAGE ASSOCIATION FANNIE MAE
Entity Central Index Key	310,522
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding	1,158,082,750

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Assets:
Cash and cash equivalents	$ 23,619,000,000	$ 14,674,000,000
Restricted cash (includes $33,121 and $25,865, respectively, related to consolidated trusts)	37,697,000,000	30,879,000,000
Federal funds sold and securities purchased under agreements to resell or similar arrangements	22,325,000,000	27,350,000,000
Investments in securities:
Trading, at fair value (includes $1,111 and $135, respectively, pledged as collateral)	39,167,000,000	39,908,000,000
Available-for-sale, at fair value (includes $179 and $285, respectively, related to consolidated trusts)	13,180,000,000	20,230,000,000
Total investments in securities	52,347,000,000	60,138,000,000
Mortgage loans:
Loans held for sale, at lower of cost or fair value	4,277,000,000	5,361,000,000
Loans held for investment, at amortized cost	3,049,391,000,000	3,042,234,000,000
Allowance for loan losses	(23,799,000,000)	(27,951,000,000)
Total loans held for investment, net of allowance	3,025,592,000,000	3,014,283,000,000
Total mortgage loans	3,029,869,000,000	3,019,644,000,000
Deferred tax assets, net	35,953,000,000	37,187,000,000
Accrued interest receivable (includes $7,281 and $6,974, respectively, related to consolidated trusts)	8,018,000,000	7,726,000,000
Acquired property, net	5,500,000,000	6,766,000,000
Other assets	19,565,000,000	17,553,000,000
Total assets	3,234,893,000,000	3,221,917,000,000
Liabilities:
Accrued interest payable (includes $8,200 and $8,194, respectively, related to consolidated trusts)	9,548,000,000	9,794,000,000
Other liabilities (includes $368 and $448, respectively, related to consolidated trusts)	9,372,000,000	10,393,000,000
Total liabilities	3,230,824,000,000	3,217,858,000,000
Commitments and contingencies (Note 16)	0	0
Fannie Mae stockholders’ equity:
Senior preferred stock, 1,000,000 shares issued and outstanding	117,149,000,000	117,149,000,000
Preferred stock, 700,000,000 shares are authorized—555,374,922 shares issued and outstanding	19,130,000,000	19,130,000,000
Common stock, no par value, no maximum authorization—1,308,762,703 shares issued and 1,158,082,750 shares outstanding	687,000,000	687,000,000
Accumulated deficit	(126,638,000,000)	(126,942,000,000)
Accumulated other comprehensive income	1,130,000,000	1,407,000,000
Treasury stock, at cost, 150,679,953 shares	(7,401,000,000)	(7,401,000,000)
Total Fannie Mae stockholders’ equity	4,057,000,000	4,030,000,000
Noncontrolling interest	12,000,000	29,000,000
Total equity (See Note 1: Impact of U.S. Government Support for information on our dividend obligation to Treasury)	4,069,000,000	4,059,000,000
Total liabilities and equity	3,234,893,000,000	3,221,917,000,000
Fannie Mae [Member]
Mortgage loans:
Loans held for investment, at amortized cost	224,036,000,000	233,054,000,000
Allowance for loan losses	(22,793,000,000)	(26,510,000,000)
Total mortgage loans	205,512,000,000	211,887,000,000
Liabilities:
Debt (includes $10,650 and $11,133, respectively, of debt of Fannie Mae at fair value and $32,798 and $23,609, respectively, of debt of consolidated trusts, at fair value)	362,418,000,000	386,135,000,000
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $33,121 and $25,865, respectively, related to consolidated trusts)	33,121,000,000	25,865,000,000
Investments in securities:
Available-for-sale, at fair value (includes $179 and $285, respectively, related to consolidated trusts)	179,000,000	285,000,000
Mortgage loans:
Loans held for investment, at amortized cost	2,825,355,000,000	2,809,180,000,000
Allowance for loan losses	(1,006,000,000)	(1,441,000,000)
Total mortgage loans	2,824,357,000,000	2,807,757,000,000
Accrued interest receivable (includes $7,281 and $6,974, respectively, related to consolidated trusts)	7,281,000,000	6,974,000,000
Liabilities:
Accrued interest payable (includes $8,200 and $8,194, respectively, related to consolidated trusts)	8,200,000,000	8,194,000,000
Debt (includes $10,650 and $11,133, respectively, of debt of Fannie Mae at fair value and $32,798 and $23,609, respectively, of debt of consolidated trusts, at fair value)	2,849,486,000,000	2,811,536,000,000
Other liabilities (includes $368 and $448, respectively, related to consolidated trusts)	$ 368,000,000	$ 448,000,000

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets:
Restricted cash (includes $33,121 and $25,865, respectively, related to consolidated trusts)	$ 37,697	$ 30,879
Investments in securities:
Trading, at fair value (includes $1,111 and $135, respectively, pledged as collateral)	1,111	135
Available-for-sale, at fair value (includes $179 and $285, respectively, related to consolidated trusts)	13,180	20,230
Accrued interest receivable (includes $7,281 and $6,974, respectively, related to consolidated trusts)	8,018	7,726
Mortgage loans:
Total loans held for investment (includes $13,413 and $14,075, respectively, at fair value)	13,413	14,075
Liabilities:
Accrued interest payable (includes $8,200 and $8,194, respectively, related to consolidated trusts)	9,548	9,794
Other liabilities (includes $368 and $448, respectively, related to consolidated trusts)	$ 9,372	$ 10,393
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, 1,158,082,750 shares outstanding	1,158,082,750	1,158,082,750
Treasury stock, at cost, 150,679,953 shares	150,679,953	150,679,953
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $33,121 and $25,865, respectively, related to consolidated trusts)	$ 33,121	$ 25,865
Investments in securities:
Available-for-sale, at fair value (includes $179 and $285, respectively, related to consolidated trusts)	179	285
Accrued interest receivable (includes $7,281 and $6,974, respectively, related to consolidated trusts)	7,281	6,974
Liabilities:
Accrued interest payable (includes $8,200 and $8,194, respectively, related to consolidated trusts)	8,200	8,194
Debt at fair value	32,798	23,609
Other liabilities (includes $368 and $448, respectively, related to consolidated trusts)	368	448
Fannie Mae [Member]
Liabilities:
Debt at fair value	$ 10,650	$ 11,133

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest income:
Trading securities	$ 128	$ 116	$ 248	$ 231
Available-for-sale securities	170	294	373	670
Mortgage loans (includes $23,866 and $24,267, respectively, for the three months ended and $48,492 and $48,889, respectively, for the six months ended related to consolidated trusts)	26,256	26,682	53,217	53,726
Other	46	34	94	67
Total interest income	26,600	27,126	53,932	54,694
Interest expense:
Short-term debt	57	33	108	62
Long-term debt (includes $19,521 and $19,528, respectively, for the three months ended and $40,179 and $40,043, respectively, for the six months ended related to consolidated trusts)	21,257	21,416	43,769	43,888
Total interest expense	21,314	21,449	43,877	43,950
Net interest income	5,286	5,677	10,055	10,744
Benefit (provision) for credit losses	1,601	(1,033)	2,785	(500)
Net interest income after benefit (provision) for credit losses	6,887	4,644	12,840	10,244
Non-interest income (loss):
Investment gains, net	398	514	467	856
Fair value gains (losses), net	(1,667)	2,606	(4,480)	687
Fee and other income	174	556	377	864
Non-interest income (loss)	(1,095)	3,676	(3,636)	2,407
Administrative expenses:
Salaries and employee benefits	331	331	695	682
Professional services	232	251	447	522
Occupancy expenses	46	43	91	86
Other administrative expenses	69	64	133	122
Total administrative expenses	678	689	1,366	1,412
Foreclosed property expense	63	182	397	655
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	453	397	893	779
Other expenses, net	254	202	518	197
Total expenses	1,448	1,470	3,174	3,043
Income before federal income taxes	4,344	6,850	6,030	9,608
Provision for federal income taxes	(1,398)	(2,210)	(1,948)	(3,080)
Net income	2,946	4,640	4,082	6,528
Other comprehensive loss:
Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes	(75)	(280)	(273)	(371)
Other	(2)	(1)	(4)	(2)
Total other comprehensive loss	(77)	(281)	(277)	(373)
Total comprehensive income attributable to Fannie Mae	2,869	4,359	3,805	6,155
Net income attributable to Fannie Mae	2,946	4,640	4,082	6,528
Dividends distributed or available for distribution to senior preferred stockholder (Note 10)	(2,869)	(4,359)	(3,788)	(6,155)
Net income attributable to common stockholders (Note 10)	$ 77	$ 281	$ 294	$ 373
Earnings per share, basic (in dollars per share)	$ 0.01	$ 0.05	$ 0.05	$ 0.06
Earnings per share, diluted (in dollars per share)	$ 0.01	$ 0.05	$ 0.05	$ 0.06
Weighted-average common shares outstanding, basic	5,762	5,762	5,762	5,762
Weighted-average common shares outstanding, diluted	5,893	5,893	5,893	5,893

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Mortgage loans (includes $23,866 and $24,267, respectively, for the three months ended and $48,492 and $48,889, respectively, for the six months ended related to consolidated trusts)	$ 26,256	$ 26,682	$ 53,217	$ 53,726
Long-term debt (includes $19,521 and $19,528, respectively, for the three months ended and $40,179 and $40,043, respectively, for the six months ended related to consolidated trusts)	21,257	21,416	43,769	43,888
Consolidated Trusts [Member]
Mortgage loans (includes $23,866 and $24,267, respectively, for the three months ended and $48,492 and $48,889, respectively, for the six months ended related to consolidated trusts)	23,866	24,267	48,492	48,889
Long-term debt (includes $19,521 and $19,528, respectively, for the three months ended and $40,179 and $40,043, respectively, for the six months ended related to consolidated trusts)	$ 19,521	$ 19,528	$ 40,179	$ 40,043

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Net cash used in operating activities
Net cash used in operating activities	$ (3,982)	$ (1,506)
Cash flows provided by investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	1,109	484
Proceeds from sales of trading securities held for investment	1,313	992
Proceeds from maturities and paydowns of available-for-sale securities	1,778	2,279
Proceeds from sales of available-for-sale securities	7,584	5,311
Purchases of loans held for investment	(97,024)	(98,042)
Net change in restricted cash	(6,818)	(4,846)
Advances to lenders	(57,956)	(62,110)
Proceeds from disposition of acquired property and preforeclosure sales	8,557	11,384
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	5,025	8,940
Other, net	(661)	(65)
Net cash provided by investing activities	114,863	136,609
Cash flows used in financing activities:
Payments of cash dividends on senior preferred stock to Treasury	(3,778)	(3,716)
Other, net	30	(46)
Net cash used in financing activities	(101,936)	(137,813)
Net increase (decrease) in cash and cash equivalents	8,945	(2,710)
Cash and cash equivalents at beginning of period	14,674	22,023
Cash and cash equivalents at end of period	23,619	19,313
Cash paid during the period for:
Interest	52,354	52,679
Income taxes	610	370
Fannie Mae [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	11,804	12,487
Proceeds from sales of loans acquired as held for investment of Fannie Mae	1,964	366
Cash flows used in financing activities:
Proceeds from issuance of debt	432,025	213,648
Payments to redeem debt	(456,586)	(249,610)
Consolidated Trusts [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	238,188	259,429
Cash flows used in financing activities:
Proceeds from issuance of debt	171,004	167,880
Payments to redeem debt	$ (244,631)	$ (265,969)

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Organization 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. Conservatorship On September 7, 2008, the Secretary of the Treasury and the Director of FHFA announced several actions taken by Treasury and FHFA regarding Fannie Mae, which included: (1) placing us in conservatorship, and (2) the execution of a senior preferred stock purchase agreement by our conservator, on our behalf, and Treasury, pursuant to which we issued to Treasury both senior preferred stock and a warrant to purchase common stock. Under the Federal Housing Enterprises Financial Safety and Soundness Act of 1992, as amended by the Federal Housing Finance Regulatory Reform Act of 2008 (together, the “GSE Act”), the conservator immediately succeeded to (1) all rights, titles, powers and privileges of Fannie Mae, and of any stockholder, officer or director of Fannie Mae with respect to Fannie Mae and its assets, and (2) title to the books, records and assets of any other legal custodian of Fannie Mae. The conservator has since delegated specified authorities to our Board of Directors and has delegated to management the authority to conduct our day-to-day operations. The conservator retains the authority to withdraw its delegations at any time. The conservatorship has no specified termination date and there continues to be significant uncertainty regarding our future, including how long we will continue to exist in our current form, the extent of our role in the market, how long we will be in conservatorship, what form we will have and what ownership interest, if any, our current common and preferred stockholders will hold in us after the conservatorship is terminated and whether we will continue to exist following conservatorship. Under the GSE Act, FHFA must place us into receivership if the Director of FHFA makes a written determination that our assets are less than our obligations or if we have not been paying our debts, in either case, for a period of 60 days. In addition, the Director of FHFA may place us into receivership at his discretion at any time for other reasons set forth in the GSE Act, including if we are critically undercapitalized or if we are undercapitalized and have no reasonable prospect of becoming adequately capitalized. Should we be placed into receivership, different assumptions would be required to determine the carrying value of our assets, which could lead to substantially different financial results. We are not aware of any plans of FHFA to fundamentally change our business model or capital structure in the near term. Impact of U.S. Government Support We continue to rely on support from Treasury to eliminate any net worth deficits we may experience in the future, which would otherwise trigger our being placed into receivership. Based on consideration of all the relevant conditions and events affecting our operations, including our reliance on the U.S. government, we continue to operate as a going concern and in accordance with our delegation of authority from FHFA. We believe that continued federal government support of our business, as well as our status as a GSE, are essential to maintaining our access to debt funding. Changes or perceived changes in federal government support of our business or our status as a GSE could materially and adversely affect our liquidity, financial condition and results of operations. Pursuant to the senior preferred stock purchase agreement, Treasury has committed to provide us with funding to help us maintain a positive net worth thereby avoiding the mandatory receivership trigger described above. We have received a total of $116.1 billion from Treasury pursuant to the senior preferred stock purchase agreement as of June 30, 2016 . The aggregate liquidation preference of the senior preferred stock, including the initial aggregate liquidation preference of $1.0 billion , was $117.1 billion as of June 30, 2016 . As of June 30, 2016 , the amount of remaining funding available to us under the senior preferred stock purchase agreement was $117.6 billion . Based on the terms of the senior preferred stock, we paid Treasury a dividend of $919 million on June 30, 2016 based on our net worth of $2.1 billion as of March 31, 2016 less the applicable capital reserve amount of $1.2 billion . We expect to pay Treasury an additional dividend of $2.9 billion by September 30, 2016 based on our net worth of $4.1 billion as of June 30, 2016 less the applicable capital reserve amount of $ 1.2 billion . The capital reserve amount was $1.8 billion for dividend periods in 2015 . The capital reserve amount will continue to be reduced by $600 million each year until it reaches zero on January 1, 2018. Basis of Presentation The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted 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 periods’ condensed consolidated financial statements. Results for the six months ended June 30, 2016 may not necessarily be indicative of the results for the year ending December 31, 2016 . The unaudited interim condensed consolidated financial statements as of and for the six months ended June 30, 2016 should be read in conjunction with our audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2015 (“ 2015 Form 10-K”), filed with the SEC on February 19, 2016 . Regulatory Capital FHFA stated that, during conservatorship, our existing statutory and FHFA-directed regulatory capital requirements will not be binding and FHFA will not issue quarterly capital classifications. We submit capital reports to FHFA and FHFA monitors our capital levels. The deficit of core capital over statutory minimum capital was $139.1 billion as of June 30, 2016 and $139.7 billion as of December 31, 2015 . Under the terms of the senior preferred stock, we are required to pay Treasury a dividend each quarter, when, as and if declared, equal to the excess of our net worth as of the end of the preceding quarter over an applicable capital reserve amount. The Director of FHFA has directed us to make dividend payments on the senior preferred stock on a quarterly basis. Therefore, we do not expect to eliminate our deficit of core capital over statutory minimum capital. Related Parties As a result of our issuance to Treasury of the warrant to purchase shares of Fannie Mae common stock equal to 79.9% of the total number of shares of Fannie Mae common stock, we and Treasury are deemed related parties. As of June 30, 2016 , Treasury held an investment in our senior preferred stock with an aggregate liquidation preference of $117.1 billion . FHFA’s control of both us and Freddie Mac has caused us, FHFA and Freddie Mac to be deemed related parties. In 2013, Fannie Mae and Freddie Mac established Common Securitization Solutions, LLC (“CSS”), a jointly owned limited liability company to operate a common securitization platform; therefore, CSS is deemed a related party. Transactions with Treasury Our administrative expenses were reduced by $15 million and $16 million for the three months ended June 30, 2016 and 2015 , respectively, and $31 million and $32 million for the six months ended June 30, 2016 and 2015 , respectively, due to reimbursements from Treasury and Freddie Mac for expenses incurred as program administrator for Treasury’s Home Affordable Modification Program (“HAMP”) and other initiatives under Treasury’s Making Home Affordable Program. During the three and six months ended June 30, 2016 , we made tax payments of $250 million and $610 million , respectively, to the Internal Revenue Service (“IRS”), a bureau of Treasury. We made tax payments of $370 million during the three and six months ended June 30, 2015 . We received no refund from the IRS during the six months ended June 30, 2016 . We received a refund of $135 million from the IRS during the six months ended June 30, 2015 for income tax adjustments related to tax years 2004 through 2006. In 2009, we entered into a memorandum of understanding with Treasury, FHFA and Freddie Mac pursuant to which we agreed to provide assistance to state and local housing finance agencies (“HFAs”) through different programs, including a new issue bond (“NIB”) program. As of June 30, 2016 , under the NIB program, Fannie Mae and Freddie Mac had $7.1 billion outstanding of pass-through securities backed by single-family and multifamily housing bonds issued by HFAs, which is less than 35% of the total original principal under the program, the amount of losses that Treasury would bear. Accordingly, we do not have a potential risk of loss under the NIB program. The fee revenue and expense related to the Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) are recorded in “Mortgage loans interest income” and “TCCA fees,” respectively, in our condensed consolidated statements of operations and comprehensive income. We recognized $453 million and $397 million in TCCA fees during the three months ended June 30, 2016 and 2015 , respectively, and $893 million and $779 million for the six months ended June 30, 2016 and 2015 , respectively, of which $453 million had not been remitted to Treasury as of June 30, 2016 . We incurred expenses in connection with certain funding obligations under the GSE Act, a portion of which is attributable to Treasury’s Capital Magnet and HOPE Funds. These expenses, recognized in “Other expenses, net” in our condensed consolidated statements of operations and comprehensive income, were measured as the product of 4.2 basis points and the unpaid principal balance of our total new business purchases for the respective period. We recognized $31 million and $60 million in other expenses in connection with Treasury’s Capital Magnet and HOPE Funds for the three months ended June 30, 2016 and 2015 , respectively, and $56 million and $112 million for the six months ended June 30, 2016 and 2015 , respectively, of which $56 million resulting from 2016 purchases had not been remitted as of June 30, 2016 . In addition to the transactions with Treasury mentioned above, we also purchase and sell Treasury securities in the normal course of business. As of June 30, 2016 and December 31, 2015 , we held Treasury securities with a fair value of $29.7 billion and $29.5 billion , respectively, and accrued interest receivable of $24 million and $15 million , respectively. We recognized interest income on these securities held by us of $33 million and $5 million for the three months ended June 30, 2016 and 2015 , respectively, and $65 million and $9 million for the six months ended June 30, 2016 and 2015 , respectively. Transactions with Freddie Mac As of June 30, 2016 and December 31, 2015 , we held Freddie Mac mortgage-related securities with a fair value of $3.4 billion and $5.6 billion , respectively, and accrued interest receivable of $14 million and $22 million , respectively. We recognized interest income on these securities held by us of $36 million and $58 million for the three months ended June 30, 2016 and 2015 , respectively, and $81 million and $119 million for the six months ended June 30, 2016 and 2015 , respectively. In addition, Freddie Mac may be an investor in variable interest entities (“VIEs”) that we have consolidated, and we may be an investor in VIEs that Freddie Mac has consolidated. 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 $28 million for the three months ended June 30, 2016 and 2015 , and $56 million for the six months ended June 30, 2016 and 2015 . Transactions with CSS In connection with our jointly owned company with Freddie Mac, we contributed $35 million and $17 million for the three months ended June 30, 2016 and 2015 , respectively, and $65 million and $30 million for the six months ended June 30, 2016 and 2015 , respectively, of capital into CSS. No other transactions outside of normal business activities have occurred between us and Freddie Mac during the six months ended June 30, 2016 and 2015 . Use of Estimates Preparing condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect our reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities as of the dates of our condensed consolidated financial statements, as well as our reported amounts of revenues and expenses during the reporting periods. Management has made significant estimates in a variety of areas including, but not limited to, valuation of certain financial instruments and other assets and liabilities and allowance for loan losses. Actual results could be different from these estimates. On January 1, 2015, we adopted regulatory guidance issued by FHFA which prescribes, among other things, guidance on when a loan should be charged off. This change in estimate resulted in the recognition on January 1, 2015 of (1) $1.8 billion in charge-offs of held for investment loans, (2) $ 724 million in charge-offs of preforeclosure property taxes and insurance receivable and (3) a reduction to our allowance for loan losses and our allowance for preforeclosure property taxes and insurance receivable in amounts equal to charge-offs recognized in connection with held for investment loans and preforeclosure property taxes and insurance receivable. For the majority of our delinquent single-family loans, we charge off the loan at the date of foreclosure or other liquidation event (such as a deed-in-lieu of foreclosure or a short sale). For a subset of delinquent single-family loans, we charge off the portion of the loans that is deemed uncollectible prior to foreclosure when the loans have been delinquent for a specified length of time and meet specified mark-to-market loan-to-value (“LTV”) ratios. We continue to enhance our data collection and analysis efforts to further refine our loss estimates as we obtain incremental information on the performance of our loans. Debt We issue debt in the form of credit risk transfer notes under the Connecticut Avenue Securities (“CAS”) program where repayment of the debt is linked to a reference portfolio of mortgage loans. We account for CAS notes issued in 2016 at amortized cost. As credit events occur and the principal balance of these CAS notes is legally reduced, we recognize an extinguishment gain. We elected the fair value option on CAS notes that were issued prior to 2016. New Accounting Guidance Effective January 1, 2016, we adopted guidance regarding consolidation of legal entities such as limited partnerships, limited liability corporations and securitization structures. The impact of the adoption was not material to our condensed consolidated financial statements. In February 2016, the Financial Accounting Standards Board (“FASB”) issued guidance on leases. The guidance clarified the definition of a lease and requires lessees to recognize on the balance sheet a right-of-use asset, representing its right to use the underlying asset for the lease term, and a corresponding lease liability for all leases with terms greater than 12 months. This guidance supersedes the existing lease guidance; however, we must continue to classify leases to determine how to recognize lease-related expense in our condensed consolidated statements of operations and comprehensive income. The new guidance is effective for us on January 1, 2019. We have evaluated this guidance and determined it will not have a material impact on our condensed consolidated financial statements. In June 2016, FASB issued guidance that changes the impairment model for most financial assets and certain other instruments. For loans, held-to-maturity debt securities and other financial assets recorded at amortized cost, entities will be required to use a new forward-looking “expected loss” model that will replace today’s “incurred loss” model and generally will result in the earlier recognition of allowances for losses. The guidance is effective on January 1, 2020 with early adoption permitted on January 1, 2019. We will recognize the impact of the new guidance through a cumulative-effect adjustment to retained earnings as of the beginning of the year of adoption. We are currently evaluating the impact of this guidance on our financial statements and the timing of our adoption.

Consolidations and Transfers of

Consolidations and Transfers of Financial Assets	6 Months Ended
	Jun. 30, 2016
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 VIEs. The primary types of entities are securitization trusts guaranteed by us via lender swap and portfolio securitization transactions and mortgage-backed trusts that were not created by us, as well as housing partnerships that are established to finance the acquisition, construction, development or rehabilitation of affordable multifamily and single-family housing. 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. We continually assess whether we are the primary beneficiary of the VIEs with which we are involved and therefore may consolidate or deconsolidate a VIE through the duration of our involvement. Examples of certain events that may change whether or not we consolidate the VIE include a change in the design of the entity or a change in our ownership in the entity such that we no longer hold substantially all of the certificates issued by a multi-class securitization trust. As of June 30, 2016, we consolidated certain VIEs that were not consolidated as of December 31, 2015. As a result of consolidating these entities, which had combined total assets of $166 million in unpaid principal balance as of June 30, 2016, we derecognized our investment in these entities and recognized the assets and liabilities of the consolidated entities at fair value. As of June 30, 2016, we also deconsolidated certain VIEs that were consolidated as of December 31, 2015. As a result of deconsolidating these entities, which had combined total assets of $5.1 billion in unpaid principal balance as of December 31, 2015, we derecognized the assets and liabilities of the entities and recognized at fair value our retained interests as securities in our condensed consolidated balance sheets. Unconsolidated VIEs We do not consolidate VIEs when we are not deemed to be the primary beneficiary. Our unconsolidated VIEs include securitization trusts and limited partnerships. The following table displays the carrying amount and classification of our assets and liabilities that relate to our involvement with unconsolidated mortgage-backed trusts. As of June 30, 2016 December 31, 2015 (Dollars in millions) Assets and liabilities recorded in our condensed consolidated balance sheets related to mortgage-backed trusts: Assets: Trading securities: Fannie Mae $ 5,203 $ 4,704 Non-Fannie Mae 4,153 5,596 Total trading securities 9,356 10,300 Available-for-sale securities: Fannie Mae 3,160 3,936 Non-Fannie Mae 8,678 14,644 Total available-for-sale securities 11,838 18,580 Other assets 53 100 Other liabilities (430 ) (827 ) Net carrying amount $ 20,817 $ 28,153 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. However, our securities issued by Fannie Mae 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. The maximum exposure to loss related to unconsolidated mortgage-backed trusts was approximately $26 billion and $34 billion as of June 30, 2016 and December 31, 2015, respectively. The total assets of our unconsolidated mortgage-backed trusts were approximately $180 billion and $220 billion as of June 30, 2016 and December 31, 2015, respectively. The maximum exposure to loss for our unconsolidated limited partnerships and similar legal entities, which consist of low-income housing tax credit investments, community investments and other entities, was $125 million and the related carrying value was $93 million as of June 30, 2016. As of December 31, 2015, the maximum exposure to loss was $12 million and the related carrying value was a deficit of $24 million . The total assets of these limited partnership investments were $4.2 billion and $4.9 billion as of June 30, 2016 and December 31, 2015 , respectively. The unpaid principal balance of our multifamily loan portfolio was $210.7 billion as of June 30, 2016 . As our lending relationship does not provide us with a controlling financial interest in the borrower entity, we do not consolidate these borrowers regardless of their status as either a VIE or a voting interest entity. We have excluded these entities from our VIE disclosures. However, the disclosures we have provided in “ Note 3, Mortgage Loans ,” “ Note 4, Allowance for Loan Losses ” and “ Note 6, Financial Guarantees ” with respect to this population are consistent with the FASB’s stated objectives for the disclosures related to unconsolidated VIEs. Transfers of Financial Assets We issue Fannie Mae MBS through portfolio securitization transactions by transferring pools of mortgage loans or mortgage-related securities to one or more trusts or special purpose entities. We are considered to be the transferor when we transfer assets from our own retained mortgage portfolio in a portfolio securitization transaction. For the three months ended June 30, 2016 and 2015, the unpaid principal balance of portfolio securitizations was $64.3 billion and $62.0 billion , respectively. For the six months ended June 30, 2016 and 2015 , the unpaid principal balance of portfolio securitizations was $112.6 billion and $110.9 billion , respectively. We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts. As of June 30, 2016 , the unpaid principal balance of retained interests was $5.1 billion and its related fair value was $6.9 billion . The unpaid principal balance of retained interests was $5.5 billion and its related fair value was $6.8 billion as of December 31, 2015. For the three months ended June 30, 2016 and 2015, the principal and interest received on retained interests was $315 million and $296 million , respectively. For the six months ended June 30, 2016 and 2015 , the principal and interest received on retained interests was $623 million and $646 million , respectively. Managed Loans Managed loans are on-balance sheet mortgage loans, as well as mortgage loans that we have securitized in unconsolidated portfolio securitization trusts. The unpaid principal balance of securitized loans in unconsolidated portfolio securitization trusts, which are primarily loans that are guaranteed or insured, in whole or in part, by the U.S. government, was $1.5 billion and $1.6 billion as of June 30, 2016 and December 31, 2015 , respectively. For information on our on-balance sheet mortgage loans, see “ Note 3, Mortgage Loans .”

Mortgage Loans

Mortgage Loans	6 Months Ended
	Jun. 30, 2016
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 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 guaranteed or insured, in whole or in part, by the U.S. government or one of its agencies, that are not Alt-A; and “other” class as loans with higher-risk characteristics, such as interest-only loans and negative-amortizing loans, that are neither government nor Alt-A. The following table displays the carrying value of our mortgage loans. As of June 30, 2016 December 31, 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family $ 228,866 $ 2,574,334 $ 2,803,200 $ 238,237 $ 2,574,174 $ 2,812,411 Multifamily 11,641 199,037 210,678 13,099 185,243 198,342 Total unpaid principal balance of mortgage loans 240,507 2,773,371 3,013,878 251,336 2,759,417 3,010,753 Cost basis and fair value adjustments, net (12,202 ) 51,992 39,790 (12,939 ) 49,781 36,842 Allowance for loan losses for loans held for investment (22,793 ) (1,006 ) (23,799 ) (26,510 ) (1,441 ) (27,951 ) Total mortgage loans $ 205,512 $ 2,824,357 $ 3,029,869 $ 211,887 $ 2,807,757 $ 3,019,644 During the three and six months ended June 30, 2016, we redesignated loans with a carrying value of $1.0 billion and $1.6 billion , respectively, from HFI to HFS. During the three and six months ended June 30, 2015 , we redesignated loans with a carrying value of $4.3 billion and $4.6 billion , respectively, from HFI to HFS. We sold loans with an unpaid principal balance of $1.5 billion and $2.6 billion during the three and six months ended June 30, 2016 , respectively. We sold loans with an unpaid principal balance of $633 million during the three and six months ended June 30, 2015 . The recorded investment of single-family mortgage loans for which formal foreclosure proceedings are in process was $21.5 billion and $25.6 billion as of June 30, 2016 and December 31, 2015, 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 loans to accrual status at the point that the borrower successfully makes all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes three months or more past due according to its contractual terms or is deemed to be individually impaired, unless the loan is well secured such that collectibility of principal and accrued interest is reasonably assured. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan or we otherwise determine that the loan is well secured such that collectibility is reasonably assured. Aging Analysis The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of June 30, 2016 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 $ 28,547 $ 7,002 $ 22,221 $ 57,770 $ 2,611,816 $ 2,669,586 $ 41 $ 32,854 Government (2) 56 22 268 346 38,831 39,177 268 — Alt-A 3,725 1,111 4,925 9,761 79,383 89,144 6 6,684 Other 1,453 425 1,757 3,635 29,460 33,095 6 2,411 Total single-family 33,781 8,560 29,171 71,512 2,759,490 2,831,002 321 41,949 Multifamily (3) 80 N/A 101 181 212,578 212,759 — 475 Total $ 33,861 $ 8,560 $ 29,272 $ 71,693 $ 2,972,068 $ 3,043,761 $ 321 $ 42,424 As of December 31, 2015 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 $ 29,154 $ 7,937 $ 26,346 $ 63,437 $ 2,598,756 $ 2,662,193 $ 46 $ 34,216 Government (2) 58 24 291 373 40,461 40,834 291 — Alt-A 4,085 1,272 6,141 11,498 84,603 96,101 6 7,407 Other 1,494 484 2,160 4,138 32,272 36,410 6 2,632 Total single-family 34,791 9,717 34,938 79,446 2,756,092 2,835,538 349 44,255 Multifamily (3) 23 N/A 123 146 200,028 200,174 — 591 Total $ 34,814 $ 9,717 $ 35,061 $ 79,592 $ 2,956,120 $ 3,035,712 $ 349 $ 44,846 __________ (1) Single-family seriously delinquent loans are loans that are 90 days or more past due or in the foreclosure process. Multifamily seriously delinquent loans are loans that are 60 days or more past due. (2) Primarily consists of reverse mortgages, which due to their nature, are not aged and are included in the current column. (3) Multifamily loans 60 - 89 days delinquent are included in the seriously delinquent column. Credit Quality Indicators The following table displays the total recorded investment in our single-family HFI loans by class and credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, 2016 (1) December 31, 2015 (1) Primary Alt-A Other Primary Alt-A Other (Dollars in millions) Estimated mark-to-market LTV ratio: (2) Less than or equal to 80% $ 2,279,064 $ 58,301 $ 20,834 $ 2,228,533 $ 59,000 $ 21,274 Greater than 80% and less than or equal to 90% 238,897 11,003 4,225 250,373 12,588 4,936 Greater than 90% and less than or equal to 100% 104,938 7,907 3,162 122,939 9,345 3,861 Greater than 100% and less than or equal to 110% 21,829 5,066 2,076 27,875 6,231 2,596 Greater than 110% and less than or equal to 120% 11,218 2,951 1,216 14,625 3,730 1,592 Greater than 120% and less than or equal to 125% 3,459 946 391 4,520 1,260 545 Greater than 125% 10,181 2,970 1,191 13,328 3,947 1,606 Total $ 2,669,586 $ 89,144 $ 33,095 $ 2,662,193 $ 96,101 $ 36,410 __________ (1) Excludes $39.2 billion and $40.8 billion as of June 30, 2016 and December 31, 2015 , 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 segment 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 as of the end of each reported period divided by the estimated current value of the property, which we calculate using an internal valuation model that estimates periodic changes in home value. The following table displays the total recorded investment in our multifamily HFI loans by credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, December 31, 2016 2015 (Dollars in millions) Credit risk profile by internally assigned grade: (1) Pass $ 207,481 $ 194,132 Special mention 2,476 3,202 Substandard 2,792 2,833 Doubtful 10 7 Total $ 212,759 $ 200,174 _________ (1) Pass (loan is current and adequately protected by the current financial strength and debt service capacity of the borrower); special mention (loan with signs of potential weakness); substandard (loan with a well defined weakness that jeopardizes the timely full repayment); and doubtful (loan with a weakness that makes collection or liquidation in full highly questionable and improbable based on existing conditions and values). 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. The following tables display the total unpaid principal balance, recorded investment, related allowance, average recorded investment and interest income recognized for individually impaired loans. As of June 30, 2016 December 31, 2015 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 $ 110,529 $ 104,999 $ 14,536 $ 116,477 $ 110,502 $ 16,745 Government 310 314 58 322 327 59 Alt-A 30,100 27,477 5,401 31,888 29,103 6,217 Other 12,092 11,441 2,080 12,893 12,179 2,416 Total single-family 153,031 144,231 22,075 161,580 152,111 25,437 Multifamily 532 535 59 650 654 80 Total individually impaired loans with related allowance recorded 153,563 144,766 22,134 162,230 152,765 25,517 With no related allowance recorded: (1) Single-family: Primary 16,603 15,414 — 15,891 14,725 — Government 65 60 — 58 54 — Alt-A 3,827 3,285 — 3,721 3,169 — Other 1,226 1,100 — 1,222 1,102 — Total single-family 21,721 19,859 — 20,892 19,050 — Multifamily 305 306 — 353 354 — Total individually impaired loans with no related allowance recorded 22,026 20,165 — 21,245 19,404 — Total individually impaired loans (2) $ 175,589 $ 164,931 $ 22,134 $ 183,475 $ 172,169 $ 25,517 For the Three Months Ended June 30, 2016 2015 Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 106,674 $ 1,015 $ 71 $ 115,856 $ 1,028 $ 73 Government 317 3 — 288 3 — Alt-A 27,901 256 11 30,642 251 10 Other 11,639 93 3 12,994 93 2 Total single-family 146,531 1,367 85 159,780 1,375 85 Multifamily 556 13 — 1,090 3 — Total individually impaired loans with related allowance recorded 147,087 1,380 85 160,870 1,378 85 With no related allowance recorded: (1) Single-family: Primary 15,377 327 30 16,453 253 19 Government 59 1 — 54 1 — Alt-A 3,361 81 5 4,010 50 — Other 1,126 30 2 1,378 17 — Total single-family 19,923 439 37 21,895 321 19 Multifamily 326 3 — 460 2 — Total individually impaired loans with no related allowance recorded 20,249 442 37 22,355 323 19 Total individually impaired loans $ 167,336 $ 1,822 $ 122 $ 183,225 $ 1,701 $ 104 For the Six Months Ended June 30, 2016 2015 Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 107,984 $ 2,036 $ 175 $ 116,811 $ 2,062 $ 177 Government 320 6 — 285 6 — Alt-A 28,287 509 30 31,094 502 27 Other 11,827 185 11 13,216 187 9 Total single-family 148,418 2,736 216 161,406 2,757 213 Multifamily 589 18 — 1,140 6 — Total individually impaired loans with related allowance recorded 149,007 2,754 216 162,546 2,763 213 With no related allowance recorded: (1) Single-family: Primary 15,323 595 50 16,178 500 60 Government 58 2 — 56 2 — Alt-A 3,362 143 8 3,775 94 7 Other 1,131 52 3 1,311 35 2 Total single-family 19,874 792 61 21,320 631 69 Multifamily 335 6 — 496 3 — Total individually impaired loans with no related allowance recorded 20,209 798 61 21,816 634 69 Total individually impaired loans $ 169,216 $ 3,552 $ 277 $ 184,362 $ 3,397 $ 282 __________ (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 $163.4 billion and $170.3 billion as of June 30, 2016 and December 31, 2015 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $415 million and $451 million as of June 30, 2016 and December 31, 2015 , respectively. (3) Total single-family interest income recognized of $1.8 billion for the three months ended June 30, 2016 consists of $1.5 billion of contractual interest and $331 million of effective yield adjustments. Total single-family interest income recognized of $1.7 billion for the three months ended June 30, 2015 consists of $1.4 billion of contractual interest and $304 million of effective yield adjustments. Total single-family interest income recognized of $3.5 billion for the six months ended June 30, 2016 consists of $2.9 billion of contractual interest and $641 million of effective yield adjustments. Total single-family interest income recognized of $3.4 billion for the six months ended June 30, 2015 consists of $2.8 billion of contractual interest and $580 million of effective yield adjustments. Troubled Debt Restructurings A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a TDR. In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for these informal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs. The substantial majority of the loan modifications we complete result in term extensions, interest rate reductions or a combination of both. During the three months ended June 30, 2016 and 2015 , the average term extension of a single-family modified loan was 159 months and 162 months , respectively, and the average interest rate reduction was 0.72 and 0.77 percentage points, respectively. During the six months ended June 30, 2016 and 2015 , the average term extension of a single-family modified loan was 159 months and 162 months , respectively, and the average interest rate reduction was 0.73 and 0.77 percentage points, respectively. The following tables display the number of loans and recorded investment in loans restructured in a TDR. For the Three Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 14,814 $ 2,028 17,951 $ 2,477 Government 28 3 64 8 Alt-A 1,623 238 2,533 395 Other 362 61 539 100 Total single-family 16,827 2,330 21,087 2,980 Multifamily 4 45 1 1 Total TDRs 16,831 $ 2,375 21,088 $ 2,981 For the Six Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 32,004 $ 4,360 39,358 $ 5,422 Government 82 9 138 16 Alt-A 3,534 508 5,322 833 Other 761 133 1,129 208 Total single-family 36,381 5,010 45,947 6,479 Multifamily 4 45 4 6 Total TDRs 36,385 $ 5,055 45,951 $ 6,485 The following tables display the number of loans and our recorded investment in these loans at the time of payment default for loans that were restructured in a TDR in the twelve months prior to the payment default. For purposes of this disclosure, we define loans that had a payment default as: single-family and multifamily loans with completed TDRs that liquidated during the period, either through foreclosure, deed-in-lieu of foreclosure or a short sale; single-family loans with completed modifications that are two or more months delinquent during the period; or multifamily loans with completed modifications that are one or more months delinquent during the period. For the Three Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 4,648 $ 638 6,156 $ 864 Government 27 3 37 6 Alt-A 756 116 963 151 Other 289 40 290 55 Total single-family 5,720 797 7,446 1,076 Multifamily — — 1 2 Total TDRs that subsequently defaulted 5,720 $ 797 7,447 $ 1,078 For the Six Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 10,109 $ 1,440 12,879 $ 1,867 Government 42 5 57 9 Alt-A 1,608 260 2,116 354 Other 532 89 594 121 Total single-family 12,291 1,794 15,646 2,351 Multifamily — — 3 6 Total TDRs that subsequently defaulted 12,291 $ 1,794 15,649 $ 2,357

Allowance for Loan Losses

Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2016
Loans and Leases Receivable, Allowance [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses We maintain an allowance for loan losses for HFI loans held by Fannie Mae and loans backing Fannie Mae MBS issued from consolidated trusts. When calculating our allowance for loan losses, we consider our net recorded investment in the loan at the balance sheet date, which includes unpaid principal balance, net of amortized premiums and discounts, and other cost basis adjustments. We record charge-offs as a reduction to the allowance for loan losses when losses are confirmed through the receipt of assets in full satisfaction of a loan, such as the underlying collateral upon foreclosure or cash upon completion of a short sale. Additionally, we record charge-offs as a reduction to our allowance for loan losses when a loan is determined to be uncollectible or upon the redesignation of nonperforming loans from HFI to HFS. 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. 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 restructured in a TDR and acquired credit-impaired loans. When a loan has been restructured, we measure impairment using a cash flow analysis discounted at the loan’s original effective interest rate. However, 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 fair value of the collateral, reduced by estimated disposal costs and adjusted for estimated proceeds from mortgage, flood, or hazard insurance and other credit enhancements. 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. We establish a collective loss reserve for all loans in our multifamily guaranty book of business that are not individually impaired 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. The following tables display changes in single-family, multifamily and total allowance for loan losses. For the Three Months Ended June 30, 2016 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ 24,490 $ 1,107 $ 25,597 $ 29,759 $ 1,755 $ 31,514 Provision (benefit) for loan losses (1) (1,292 ) (40 ) (1,332 ) 1,268 (227 ) 1,041 Charge-offs (2)(3) (789 ) (29 ) (818 ) (2,032 ) (23 ) (2,055 ) Recoveries 114 1 115 257 4 261 Transfers (4) 191 (191 ) — 256 (256 ) — Other (5) 22 — 22 116 (1 ) 115 Ending balance $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Multifamily allowance for loan losses: Beginning balance $ 67 $ 155 $ 222 $ 114 $ 192 $ 306 Provision (benefit) for loan losses (1) (8 ) 4 (4 ) 6 (18 ) (12 ) Charge-offs (2)(3) (3 ) — (3 ) (19 ) — (19 ) Transfers (4) 1 (1 ) — — — — Other (5) — — — (1 ) — (1 ) Ending balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Total allowance for loan losses: Beginning balance $ 24,557 $ 1,262 $ 25,819 $ 29,873 $ 1,947 $ 31,820 Provision (benefit) for loan losses (1) (1,300 ) (36 ) (1,336 ) 1,274 (245 ) 1,029 Charge-offs (2)(3) (792 ) (29 ) (821 ) (2,051 ) (23 ) (2,074 ) Recoveries 114 1 115 257 4 261 Transfers (4) 192 (192 ) — 256 (256 ) — Other (5) 22 — 22 115 (1 ) 114 Ending balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 For the Six Months Ended June 30, 2016 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ 26,439 $ 1,270 $ 27,709 $ 32,956 $ 2,221 $ 35,177 Provision (benefit) for loan losses (1) (2,418 ) 70 (2,348 ) 1,473 (374 ) 1,099 Charge-offs (2)(3) (2,042 ) (55 ) (2,097 ) (7,360 ) (42 ) (7,402 ) Recoveries 231 3 234 871 12 883 Transfers (4) 440 (440 ) — 615 (615 ) — Other (5) 86 — 86 1,069 50 1,119 Ending balance $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Multifamily allowance for loan losses: Beginning balance $ 71 $ 171 $ 242 $ 161 $ 203 $ 364 Benefit for loan losses (1) (11 ) (9 ) (20 ) (31 ) (31 ) (62 ) Charge-offs (2)(3) (8 ) — (8 ) (34 ) — (34 ) Recoveries 1 — 1 — — — Transfers (4) 4 (4 ) — — — — Other (5) — — — 4 2 6 Ending balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Total allowance for loan losses: Beginning balance $ 26,510 $ 1,441 $ 27,951 $ 33,117 $ 2,424 $ 35,541 Provision (benefit) for loan losses (1) (2,429 ) 61 (2,368 ) 1,442 (405 ) 1,037 Charge-offs (2)(3) (2,050 ) (55 ) (2,105 ) (7,394 ) (42 ) (7,436 ) Recoveries 232 3 235 871 12 883 Transfers (4) 444 (444 ) — 615 (615 ) — Other (5) 86 — 86 1,073 52 1,125 Ending balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 __________ (1) Provision (benefit) for loan losses is included in “Benefit (provision) for credit losses” in our condensed consolidated statements of operations and comprehensive income. (2) While we purchase the substantial majority of loans that are four or more months delinquent from our MBS trusts, we do not exercise this option to purchase loans during a forbearance period. Charge-offs of consolidated trusts generally represent loans that remained in our consolidated trusts at the time of default. (3) Our charge-offs for 2015 reflect initial charge-offs associated with our approach to adopting the charge-off provisions of Advisory Bulletin AB 2012-02, “Framework for Adversely Classifying Loans, Other Real Estate Owned, and Other Assets and Listing Assets for Special Mention,” as well as charge-offs relating to a change in accounting policy for nonaccrual loans. (4) Includes transfers from trusts for delinquent loan purchases. (5) Amounts represent changes in other loss reserves which are reflected in provision (benefit) for loan losses, charge-offs, and recoveries. The following table displays the allowance for loan losses and recorded investment in our HFI loans, excluding loans for which we have elected the fair value option, by impairment or reserve methodology and portfolio segment. As of June 30, 2016 December 31, 2015 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans (1) $ 22,075 $ 59 $ 22,134 $ 25,437 $ 80 $ 25,517 Collectively reserved loans 1,509 156 1,665 2,272 162 2,434 Total allowance for loan losses $ 23,584 $ 215 $ 23,799 $ 27,709 $ 242 $ 27,951 Recorded investment in loans by segment: Individually impaired loans (1) $ 164,090 $ 841 $ 164,931 $ 171,161 $ 1,008 $ 172,169 Collectively reserved loans 2,666,912 211,918 2,878,830 2,664,377 199,166 2,863,543 Total recorded investment in loans $ 2,831,002 $ 212,759 $ 3,043,761 $ 2,835,538 $ 200,174 $ 3,035,712 __________ (1) Includes acquired credit-impaired loans.

Investments in Securities

Investments in Securities	6 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investments in Securities	Investments in Securities Trading Securities Trading securities are recorded at fair value with subsequent changes in fair value recorded as “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. The following table displays our investments in trading securities. As of June 30, 2016 December 31, 2015 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 5,352 $ 4,813 Freddie Mac 1,328 1,314 Ginnie Mae 542 426 Alt-A private-label securities 316 436 Subprime private-label securities 395 644 Commercial mortgage-backed securities (“CMBS”) 1,389 2,341 Mortgage revenue bonds 193 449 Total mortgage-related securities 9,515 10,423 U.S. Treasury securities 29,652 29,485 Total trading securities $ 39,167 $ 39,908 Available-for-Sale Securities We record available-for-sale (“AFS”) securities at fair value with unrealized gains and losses, recorded net of tax, as a component of “Other comprehensive 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, losses and proceeds on sales of AFS securities. For the Three For the Six Months Ended Months Ended June 30 , June 30 , 2016 2015 2016 2015 (Dollars in millions) Gross realized gains $ 234 $ 413 $ 445 $ 813 Gross realized losses 8 50 12 57 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 3,645 3,096 7,267 5,208 The following tables display the amortized cost, gross unrealized gains and losses, and fair value by major security type for AFS securities in our retained mortgage portfolio. As of June 30, 2016 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 3,163 $ 194 $ (21 ) $ 3,336 Freddie Mac 1,899 139 — 2,038 Ginnie Mae 58 8 — 66 Alt-A private-label securities 1,269 564 (6 ) 1,827 Subprime private-label securities 1,722 656 (5 ) 2,373 CMBS 1,010 14 (1 ) 1,023 Mortgage revenue bonds 1,919 113 (3 ) 2,029 Other mortgage-related securities 471 17 — 488 Total $ 11,511 $ 1,705 $ (36 ) $ 13,180 As of December 31, 2015 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 4,008 $ 243 $ (30 ) $ 4,221 Freddie Mac 4,000 299 — 4,299 Ginnie Mae 343 48 — 391 Alt-A private-label securities 2,029 653 (4 ) 2,678 Subprime private-label securities 2,526 759 (4 ) 3,281 CMBS 1,235 20 — 1,255 Mortgage revenue bonds 2,639 99 (37 ) 2,701 Other mortgage-related securities 1,361 49 (6 ) 1,404 Total $ 18,141 $ 2,170 $ (81 ) $ 20,230 __________ (1) Amortized cost consists of unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments as well as net other-than-temporary impairments (“OTTI”) recognized in “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. (2) Represents the gross unrealized losses on securities for which we have not recognized OTTI, as well as the noncredit component of OTTI and cumulative changes in fair value of securities for which we previously recognized the credit component of OTTI in “Accumulated other comprehensive income” in our condensed consolidated balance sheets. The following tables display additional information regarding gross unrealized losses and fair value by major security type for AFS securities in an unrealized loss position. As of June 30, 2016 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 $ (1 ) $ 86 $ (20 ) $ 514 Alt-A private-label securities (2 ) 106 (4 ) 49 Subprime private-label securities — — (5 ) 82 CMBS (1 ) 70 — — Mortgage revenue bonds (2 ) 16 (1 ) 7 Total $ (6 ) $ 278 $ (30 ) $ 652 As of December 31, 2015 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 ) $ 659 $ (22 ) $ 491 Alt-A private-label securities (1 ) 26 (3 ) 54 Subprime private-label securities — 12 (4 ) 91 Mortgage revenue bonds (35 ) 631 (2 ) 22 Other mortgage-related securities (6 ) 224 — — Total $ (50 ) $ 1,552 $ (31 ) $ 658 Other-Than-Temporary Impairments We recognized $2 million and $12 million of OTTI for the three months ended June 30, 2016 and 2015 , respectively, and $ 31 million and $ 182 million of OTTI for the six months ended June 30, 2016 and 2015 , respectively, which are included in “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. The following table displays the modeled attributes, including default rates and severities, which were used to determine as of June 30, 2016 whether our senior interests in certain non-agency mortgage-related securities (including those we intend to sell) will experience a cash shortfall. An estimate of voluntary prepayment rates is also an input to the present value of expected losses. As of June 30, 2016 Alt-A Subprime Option ARM Fixed Rate Variable Rate Hybrid Rate (Dollars in millions) Unpaid principal balance $ 3,299 $ 373 $ 514 $ 625 $ 674 Weighted average collateral default (1) 39.2 % 25.7 % 13.2 % 18.5 % 7.4 % Weighted average collateral severities (2) 54.4 36.6 45.3 30.1 30.5 Weighted average voluntary prepayment rates (3) 2.6 8.8 10.9 8.7 13.5 Average credit enhancement (4) 16.7 3.9 6.8 4.7 1.8 __________ (1) The expected remaining cumulative default rate of the collateral pool backing the securities, as a percentage of the current collateral unpaid principal balance, weighted by security unpaid principal balance. (2) The expected remaining loss given default of the collateral pool backing the securities, calculated as the ratio of remaining cumulative loss divided by cumulative defaults, weighted by security unpaid principal balance. (3) The average monthly voluntary prepayment rate, weighted by security unpaid principal balance. (4) The average percent current credit enhancement provided by subordination of other securities. Excludes excess interest projections and monoline bond insurance. The following table displays activity related to the unrealized credit loss component on debt securities held by us and recognized in our condensed consolidated statements of operations and comprehensive income. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance $ 2,293 $ 2,744 $ 2,421 $ 5,260 Additions for the credit component on debt securities for which OTTI was previously recognized 2 — 6 4 Reductions for securities no longer in portfolio at period end (10 ) (72 ) (103 ) (1,165 ) Reductions for securities which we intend to sell or it is more likely than not that we will be required to sell before recovery of amortized cost basis (31 ) (70 ) (31 ) (1,439 ) Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities (35 ) (45 ) (74 ) (103 ) Ending balance $ 2,219 $ 2,557 $ 2,219 $ 2,557 Maturity Information The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time. As of June 30, 2016 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 $ 3,163 $ 3,336 $ — $ — $ 77 $ 78 $ 84 $ 90 $ 3,002 $ 3,168 Freddie Mac 1,899 2,038 1 1 101 104 203 221 1,594 1,712 Ginnie Mae 58 66 — — 1 1 4 4 53 61 Alt-A private-label securities 1,269 1,827 — — — — — — 1,269 1,827 Subprime private-label securities 1,722 2,373 — — — — — — 1,722 2,373 CMBS 1,010 1,023 521 528 444 451 — — 45 44 Mortgage revenue bonds 1,919 2,029 11 11 95 96 171 174 1,642 1,748 Other mortgage-related securities 471 488 — — — 1 3 3 468 484 Total $ 11,511 $ 13,180 $ 533 $ 540 $ 718 $ 731 $ 465 $ 492 $ 9,795 $ 11,417

Financial Guarantees

Financial Guarantees	6 Months Ended
	Jun. 30, 2016
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 guarantees expose us to credit losses on the mortgage loans or, in the case of mortgage-related securities, the underlying mortgage loans of the related securities. The remaining contractual terms of our guarantees range from 1 day to 36 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. The following table displays our maximum exposure, guaranty obligation recognized in our condensed consolidated balance sheets and the maximum potential recovery from third parties through available credit enhancements and recourse related to our financial guarantees. As of June 30, 2016 December 31, 2015 Maximum Exposure (1) Guaranty Obligation Maximum Recovery (2) Maximum Exposure (1) Guaranty Obligation Maximum Recovery (2) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 13,947 $ 151 $ 8,448 $ 15,069 $ 194 $ 8,857 Other guaranty arrangements (3) 15,744 125 2,708 16,504 135 2,869 Total $ 29,691 $ 276 $ 11,156 $ 31,573 $ 329 $ 11,726 __________ (1) Primarily consists of the unpaid principal balance of the underlying mortgage loans. (2) Recoverability of such credit enhancements and recourse is subject to, among other factors, our mortgage insurers’ and financial guarantors’ ability to meet their obligations to us. For information on our mortgage insurers, see “ Note 13, Concentrations of Credit Risk .” (3) Primarily consists of credit enhancements and long-term standby commitments. The fair value of our guaranty obligations associated with the Fannie Mae MBS included in “Investments in securities” in our condensed consolidated balance sheets was $517 million and $488 million as of June 30, 2016 and December 31, 2015 , respectively. These Fannie Mae MBS consist primarily of private-label wraps where our guaranty arrangement is with an unconsolidated MBS trust.

Acquired Property, Net

Acquired Property, Net	6 Months Ended
	Jun. 30, 2016
Real Estate [Abstract]
Acquired Property, Net	Acquired Property, Net Acquired property, net consists of held-for-sale foreclosed property received in satisfaction of a loan, net of a valuation allowance for declines in the fair value of the properties after initial acquisition. We classify properties as held for sale when we intend to sell the property, are actively marketing it and it is ready for immediate sale in its current condition. The following table displays the activity in acquired property, and the related valuation allowance. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance — Acquired property $ 6,737 $ 10,348 $ 7,481 $ 11,442 Additions 1,648 2,431 3,485 5,366 Disposals (2,457 ) (3,580 ) (5,038 ) (7,609 ) Ending balance — Acquired property 5,928 9,199 5,928 9,199 Valuation allowance (428 ) (693 ) (428 ) (693 ) Ending balance — Acquired property, net $ 5,500 $ 8,506 $ 5,500 $ 8,506

Short-Term Borrowings and Long-

Short-Term Borrowings and Long-Term Debt	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Short-Term Borrowings and Long-Term Debt	Short-Term Borrowings and Long-Term Debt Short-Term Borrowings The following table displays our outstanding short-term borrowings (borrowings with an original contractual maturity of one year or less) and weighted-average interest rates of these borrowings. As of June 30, 2016 December 31, 2015 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) $ 115 — % $ 62 — % Short-term debt of Fannie Mae $ 60,495 0.43 % $ 71,007 0.26 % Debt of consolidated trusts 742 0.41 943 0.19 Total short-term debt $ 61,237 0.43 % $ 71,950 0.26 % __________ (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Represents agreements to repurchase securities for a specified price, with repayment generally occurring on the following day. Intraday Line of Credit We use a secured intraday funding line of credit provided by a large financial institution. We post collateral which, in some circumstances, the secured party has the right to repledge to third parties. As this line of credit is an uncommitted intraday loan facility, we may be unable to draw on it if and when needed. The line of credit under this facility was $15.0 billion as of June 30, 2016 and December 31, 2015 . We had no borrowings outstanding under this line of credit as of June 30, 2016 . Long-Term Debt Long-term debt represents borrowings with an original contractual maturity of greater than one year. The following table displays our outstanding long-term debt. As of June 30, 2016 December 31, 2015 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2016 - 2030 $ 157,023 2.36 % 2016 - 2030 $ 154,057 2.49 % Medium-term notes (2) 2016 - 2026 79,663 1.48 2016 - 2025 96,997 1.53 Other (3) 2016 - 2038 20,451 5.39 2016 - 2038 27,772 4.88 Total senior fixed 257,137 2.33 278,826 2.39 Senior floating: Medium-term notes (2) 2016 - 2019 26,465 0.51 2016 - 2019 20,791 0.27 Connecticut Avenue Securities (4) 2023 - 2028 13,350 4.43 2023 - 2028 10,764 3.84 Other (5) 2020 - 2037 410 8.66 2020 - 2037 368 10.46 Total senior floating 40,225 1.87 31,923 1.58 Subordinated debentures 2019 4,431 9.93 2019 4,227 9.93 Secured borrowings (6) 2021 - 2022 130 1.44 2021 - 2022 152 1.47 Total long-term debt of Fannie Mae (7) 301,923 2.38 315,128 2.41 Debt of consolidated trusts 2016 - 2054 2,848,744 2.73 2016 - 2054 2,810,593 2.94 Total long-term debt $ 3,150,667 2.70 % $ 3,125,721 2.88 % __________ (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 and foreign exchange bonds. (4) Credit risk-sharing securities that transfer a portion of the credit risk on specified pools of mortgage loans to the investors in these securities, a portion of which is reported at fair value. (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 $2.7 billion and $3.2 billion as of June 30, 2016 and December 31, 2015 , respectively.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2016
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 derivatives we use for interest rate risk management purposes consist primarily of interest rate swaps and interest rate options. We enter into various forms of credit risk sharing agreements, including credit risk transfer transactions, swap credit enhancements and mortgage insurance contracts, that we account for as derivatives. 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. 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 15, Fair Value ” for additional information on derivatives recorded at fair value. We present cash flows from derivatives as operating activities in our condensed consolidated statements of cash flows. Notional and Fair Value Position of our Derivatives The following table displays the notional amount and estimated fair value of our asset and liability derivative instruments. As of June 30, 2016 As of December 31, 2015 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 $ 325 $ 1 $ 156,864 $ (13,141 ) $ 33,154 $ 267 $ 123,106 $ (6,920 ) Receive-fixed 170,271 6,516 11,113 (5 ) 59,796 3,436 143,209 (753 ) Basis 1,864 189 17,100 (15 ) 1,864 141 17,100 (15 ) Foreign currency 222 80 233 (81 ) 295 95 258 (52 ) Swaptions: Pay-fixed 6,880 36 2,350 (4 ) 7,050 45 14,950 (26 ) Receive-fixed — — 3,430 (154 ) 2,000 8 13,950 (171 ) Other (1) 9,749 27 136 (1 ) 9,196 28 — (2 ) Total gross risk management derivatives 189,311 6,849 191,226 (13,401 ) 113,355 4,020 312,573 (7,939 ) Accrued interest receivable (payable) — 819 — (1,045 ) — 758 — (977 ) Netting adjustment (2) — (7,530 ) — 14,269 — (4,024 ) — 8,650 Total net risk management derivatives $ 189,311 $ 138 $ 191,226 $ (177 ) $ 113,355 $ 754 $ 312,573 $ (266 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 13,157 $ 99 $ 29 $ — $ 4,815 $ 9 $ 2,960 $ (9 ) Forward contracts to purchase mortgage-related securities 75,635 533 4,024 (9 ) 31,273 66 19,418 (57 ) Forward contracts to sell mortgage-related securities 1,935 5 117,407 (949 ) 26,224 65 40,753 (92 ) Total mortgage commitment derivatives $ 90,727 $ 637 $ 121,460 $ (958 ) $ 62,312 $ 140 $ 63,131 $ (158 ) Derivatives at fair value $ 280,038 $ 775 $ 312,686 $ (1,135 ) $ 175,667 $ 894 $ 375,704 $ (424 ) __________ (1) Includes credit risk transfer transactions, futures, swap credit enhancements and mortgage insurance contracts that we account for as derivatives. (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 $7.1 billion and $4.9 billion as of June 30, 2016 and December 31, 2015 , respectively. Cash collateral received was $345 million and $314 million as of June 30, 2016 and December 31, 2015 , respectively. A majority of our OTC derivative contracts contain provisions that require our senior unsecured debt to maintain a minimum credit rating from S&P and Moody’s. If our senior unsecured debt credit ratings were downgraded to established thresholds in these derivative contracts, which range from A+ to BBB+, we could be required to provide additional collateral to or terminate transactions with certain counterparties. The aggregate fair value of all OTC derivatives with credit-risk-related contingent features that were in a net liability position was $3.6 billion and $2.4 billion as of June 30, 2016 and December 31, 2015 , respectively, for which we posted collateral of $3.6 billion and $2.2 billion in the normal course of business as of June 30, 2016 and December 31, 2015 , respectively. Had all of the credit-risk-related contingency features underlying these agreements been triggered, an additional $81 million and $257 million would have been required to be posted as collateral or to immediately settle our positions based on the individual agreements and our fair value position as of June 30, 2016 and December 31, 2015 , respectively. A reduction in our credit ratings may also cause derivatives clearing organizations or their members to demand that we post additional collateral for our cleared derivatives contracts. 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 For the Six Months Ended June 30, Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (2,257 ) $ 4,351 $ (7,430 ) $ 1,282 Receive-fixed 1,371 (1,906 ) 4,358 (59 ) Basis 14 (44 ) 49 (12 ) Foreign currency (34 ) 16 (31 ) (13 ) Swaptions: Pay-fixed 4 14 29 105 Receive-fixed (19 ) 80 (136 ) (79 ) Other 22 (4 ) 160 (2 ) Net accrual of periodic settlements (291 ) (199 ) (560 ) (428 ) Total risk management derivatives fair value gains (losses), net $ (1,190 ) $ 2,308 $ (3,561 ) $ 794 Mortgage commitment derivatives fair value gains (losses), net (367 ) 173 (729 ) (66 ) Total derivatives fair value gains (losses), net $ (1,557 ) $ 2,481 $ (4,290 ) $ 728 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 14 , Netting Arrangements ” for information on our rights to offset assets and liabilities.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The calculation of income available to common stockholders and earnings per share is based on the underlying premise that all income after payment of dividends on preferred shares is available to and will be distributed to common stockholders. However, as a result of our conservatorship status and the terms of the senior preferred stock, no amounts are available to distribute as dividends to common or preferred stockholders (other than to Treasury as holder of the senior preferred stock). The following table displays the computation of basic and diluted earnings per share of common stock. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars and shares in millions, except per share amounts) Net income attributable to Fannie Mae $ 2,946 $ 4,640 $ 4,082 $ 6,528 Dividends distributed or available for distribution to senior preferred stockholder (1) (2,869 ) (4,359 ) (3,788 ) (6,155 ) Net income attributable to common stockholders $ 77 $ 281 $ 294 $ 373 Weighted-average common shares outstanding—Basic (2) 5,762 5,762 5,762 5,762 Convertible preferred stock 131 131 131 131 Weighted-average common shares outstanding—Diluted (2) 5,893 5,893 5,893 5,893 Earnings per share: Basic $ 0.01 $ 0.05 $ 0.05 $ 0.06 Diluted 0.01 0.05 0.05 0.06 __________ (1) Dividends distributed or available for distribution were calculated based on our net worth as of the end of the fiscal quarters, less the applicable capital reserve amount. See “Note 1, Summary of Significant Accounting Policies” in our 2015 Form 10-K for additional information on our senior preferred stock agreement and our payment of dividends to Treasury. (2) Includes 4.6 billion of weighted average shares of common stock that would be issued upon the full exercise of the warrant issued to Treasury from the date the warrant was issued through June 30, 2016 and 2015.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting Our three reportable segments are: Single-Family, Multifamily and Capital Markets. We use these three segments to generate revenue and manage business risk, and each segment is based on the type of business activities it performs. Under our segment reporting, the sum of the results for our three business segments does not equal our condensed consolidated statements of operations and comprehensive income as we separate the activity related to our consolidated trusts from the results generated by our three segments. Our business segment financial results include directly attributable revenues and expenses. We apply accounting methods for segment reporting purposes that differ from our condensed consolidated results. Additionally, we allocate to each of our segments: (1) capital using FHFA minimum capital requirements adjusted for over- or under-capitalization; (2) indirect administrative costs; and (3) a provision or benefit for federal income taxes. In addition, we allocate intracompany guaranty fee income as a charge from the Single-Family and Multifamily segments to Capital Markets for managing the credit risk on mortgage loans held by the Capital Markets group. Therefore, we reconcile the sum of the results for our three business segments to our condensed consolidated results of operations. For the Three Months Ended June 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 176 $ (15 ) $ 1,080 $ 4,045 (2) $ 5,286 Benefit for credit losses 1,596 5 — — 1,601 Net interest income (loss) after benefit for credit losses 1,772 (10 ) 1,080 4,045 6,887 Guaranty fee income (expense) (3) 3,260 400 (192 ) (3,438 ) (4) 30 (4) Investment gains (losses), net — 11 2,088 (1,701 ) (5) 398 Fair value gains (losses), net — — (1,730 ) 63 (6) (1,667 ) Gains (losses) from partnership investments (7) (18 ) 20 — — 2 Fee and other income (expense) 100 48 31 (35 ) 144 Administrative expenses (496 ) (86 ) (96 ) — (678 ) Foreclosed property expense (61 ) (2 ) — — (63 ) TCCA fees (3) (453 ) — — — (453 ) Other income (expenses), net (361 ) (2 ) (30 ) 137 (256 ) Income (loss) before federal income taxes 3,743 379 1,151 (929 ) 4,344 Provision for federal income taxes (1,093 ) (40 ) (265 ) — (1,398 ) Net income (loss) attributable to Fannie Mae $ 2,650 $ 339 $ 886 $ (929 ) $ 2,946 For the Six Months Ended June 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 319 $ (40 ) $ 2,172 $ 7,604 (2) $ 10,055 Benefit for credit losses 2,759 26 — — 2,785 Net interest income (loss) after benefit for credit losses 3,078 (14 ) 2,172 7,604 12,840 Guaranty fee income (expense) (3) 6,482 785 (387 ) (6,825 ) (4) 55 (4) Investment gains (losses), net (1 ) 14 3,503 (3,049 ) (5) 467 Fair value gains (losses), net — — (4,533 ) 53 (6) (4,480 ) Gains (losses) from partnership investments (7) (37 ) 40 — — 3 Fee and other income (expense) 201 107 52 (38 ) 322 Administrative expenses (1,004 ) (170 ) (192 ) — (1,366 ) Foreclosed property expense (396 ) (1 ) — — (397 ) TCCA fees (3) (893 ) — — — (893 ) Other income (expenses), net (664 ) (11 ) (59 ) 213 (521 ) Income (loss) before federal income taxes 6,766 750 556 (2,042 ) 6,030 Provision for federal income taxes (1,736 ) (78 ) (134 ) — (1,948 ) Net income (loss) attributable to Fannie Mae $ 5,030 $ 672 $ 422 $ (2,042 ) $ 4,082 For the Three Months Ended June 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 18 $ (26 ) $ 1,513 $ 4,172 (2) $ 5,677 (Provision) benefit for credit losses (1,056 ) 23 — — (1,033 ) Net interest income (loss) after (provision) benefit for credit losses (1,038 ) (3 ) 1,513 4,172 4,644 Guaranty fee income (expense) (3) 3,092 357 (221 ) (3,191 ) (4) 37 (4) Investment gains (losses), net (1 ) 15 1,562 (1,062 ) (5) 514 Fair value gains, net — — 2,555 51 (6) 2,606 Gains (losses) from partnership investments (7) (10 ) 43 — — 33 Fee and other income (expense) 301 84 150 (16 ) 519 Administrative expenses (458 ) (83 ) (148 ) — (689 ) Foreclosed property expense (182 ) — — — (182 ) TCCA fees (3) (397 ) — — — (397 ) Other income (expenses), net (262 ) (6 ) (11 ) 44 (235 ) Income (loss) before federal income taxes 1,045 407 5,400 (2 ) 6,850 Provision for federal income taxes (419 ) (41 ) (1,750 ) — (2,210 ) Net income (loss) attributable to Fannie Mae $ 626 $ 366 $ 3,650 $ (2 ) $ 4,640 For the Six Months Ended June 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 27 $ (57 ) $ 3,115 $ 7,659 (2) $ 10,744 (Provision) benefit for credit losses (578 ) 78 — — (500 ) Net interest income (loss) after (provision) benefit for credit losses (551 ) 21 3,115 7,659 10,244 Guaranty fee income (expense) (3) 6,132 697 (448 ) (6,313 ) (4) 68 (4) Investment gains (losses), net (1 ) 24 3,071 (2,238 ) (5) 856 Fair value gains (losses), net (4 ) — 585 106 (6) 687 Gains (losses) from partnership investments (7) (15 ) 255 — — 240 Fee and other income (expense) 473 135 205 (17 ) 796 Administrative expenses (942 ) (171 ) (299 ) — (1,412 ) Foreclosed property income (expense) (667 ) 12 — — (655 ) TCCA fees (3) (779 ) — — — (779 ) Other income (expenses), net (489 ) (13 ) (11 ) 76 (437 ) Income (loss) before federal income taxes 3,157 960 6,218 (727 ) 9,608 Provision for federal income taxes (1,000 ) (111 ) (1,969 ) — (3,080 ) Net income (loss) attributable to Fannie Mae $ 2,157 $ 849 $ 4,249 $ (727 ) $ 6,528 __________ (1) Represents activity related to the assets and liabilities of consolidated trusts in our condensed consolidated balance sheets, and the elimination of intercompany transactions occurring between the three business segments and our consolidated trusts, as well as other adjustments to reconcile to our condensed consolidated results. (2) Represents net interest income of consolidated trusts and amortization expense of cost basis adjustments on securities in the Capital Markets group’s mortgage portfolio that on a GAAP basis are eliminated. (3) Reflects the impact of a 10 basis point guaranty fee increase implemented in 2012 pursuant to the TCCA, the incremental revenue from which is remitted to Treasury. The resulting revenue is included in guaranty fee income and the expense is recognized as “TCCA fees.” (4) Represents the guaranty fees paid from consolidated trusts to the Single-Family and Multifamily segments and the elimination of the amortization of deferred cash fees related to consolidated trusts that were re-established for segment reporting. Total guaranty fee income related to unconsolidated Fannie Mae MBS trusts and other credit enhancement arrangements is included in fee and other income in our condensed consolidated statements of operations and comprehensive income. (5) Primarily represents the removal of realized gains and losses on sales of Fannie Mae MBS classified as available-for-sale securities that are issued by consolidated trusts and in the Capital Markets group’s mortgage portfolio. The adjustment also includes the removal of securitization gains (losses) recognized in the Capital Markets segment relating to portfolio securitization transactions that do not qualify for sale accounting under GAAP. (6) Represents the removal of fair value adjustments on consolidated Fannie Mae MBS classified as trading that are in the Capital Markets group’s mortgage portfolio. (7) Gains (losses) from partnership investments are included in “Other expenses, net” in our condensed consolidated statements of operations and comprehensive income.

Equity

Equity	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Equity	Equity The following table displays the activity in other comprehensive loss, net of tax, by major categories. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Net income $ 2,946 $ 4,640 $ 4,082 $ 6,528 Other comprehensive loss, net of tax effect: Changes in net unrealized gains (losses) on AFS securities (net of tax of $27 and $44, respectively, for the three months ended and net of tax of $21 and $31, respectively, for the six months ended) 50 (81 ) (39 ) (57 ) Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $4, respectively, for the three months ended and net of tax of $11 and $64, respectively, for the six months ended) 1 8 20 118 Reclassification adjustment for gains on AFS securities included in net income (net of tax of $68 and $112, respectively, for the three months ended and net of tax of $137 and $233, respectively, for the six months ended) (126 ) (207 ) (254 ) (432 ) Other (2 ) (1 ) (4 ) (2 ) Total other comprehensive loss (77 ) (281 ) (277 ) (373 ) Total comprehensive income $ 2,869 $ 4,359 $ 3,805 $ 6,155 The following table displays our accumulated other comprehensive income by major categories. As of June 30, December 31, 2016 2015 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax $ 292 $ 455 Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax 793 903 Other, net of tax 45 49 Accumulated other comprehensive income $ 1,130 $ 1,407 The table below displays changes in accumulated other comprehensive income, net of tax. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 AFS (1) Other Total AFS (1) Other (2) Total AFS (1) Other Total AFS (1) Other (2) Total (Dollars in millions) Beginning balance $ 1,160 $ 47 $ 1,207 $ 2,030 $ (389 ) $ 1,641 $ 1,358 $ 49 $ 1,407 $ 2,121 $ (388 ) $ 1,733 Other comprehensive income (loss) before reclassifications 50 — 50 (81 ) — (81 ) (39 ) — (39 ) (57 ) — (57 ) Amounts reclassified from other comprehensive loss (125 ) (2 ) (127 ) (199 ) (1 ) (200 ) (234 ) (4 ) (238 ) (314 ) (2 ) (316 ) Net other comprehensive loss (75 ) (2 ) (77 ) (280 ) (1 ) (281 ) (273 ) (4 ) (277 ) (371 ) (2 ) (373 ) Ending balance $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 __________ (1) The amounts reclassified from accumulated other comprehensive income represent the gain or loss recognized in earnings due to a sale of an AFS security or the recognition of a net impairment recognized in earnings, which are recorded in “Investments gains, net” in our condensed consolidated statements of operations and comprehensive income. (2) The amounts reclassified from accumulated other comprehensive income represent activity from our defined benefit pension plans, which is recorded in “Administrative expenses” in our condensed consolidated statements of operations and comprehensive income. The defined benefit pension plans were terminated and all remaining benefits were distributed during the third quarter of 2015.

Concentrations of Credit Risk

Concentrations of Credit Risk	6 Months Ended
	Jun. 30, 2016
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	Concentrations of Credit Risk Risk Characteristics of our Book of Business We gauge our performance risk under our guaranty based on the delinquency status of the mortgage loans we hold in our retained mortgage portfolio, or in the case of mortgage-backed securities, the mortgage loans underlying the related securities. For single-family loans, management monitors the serious delinquency rate, which is the percentage of single-family loans 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. For multifamily loans, management monitors the serious delinquency rate, which is the percentage of loans, based on unpaid principal balance, that are 60 days or more past due, and other loans that have higher risk characteristics, to determine our overall credit quality indicator. Higher risk characteristics include, but are not limited to, current debt service coverage ratio (“DSCR”) below 1.0 and high original LTV ratios. We stratify multifamily loans into different internal risk categories based on the credit risk inherent in each individual loan. 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. The following tables display the delinquency status and serious delinquency rates for specified loan categories of our single-family conventional and total multifamily guaranty book of business. As of June 30, 2016 (1) December 31, 2015 (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) 1.23 % 0.32 % 1.33 % 1.27 % 0.37 % 1.59 % Percentage of single-family conventional loans (4) 1.42 0.36 1.32 1.46 0.41 1.55 As of June 30, 2016 (1) December 31, 2015 (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 loan-to-value ratio: Greater than 100% 3 % 10.54 % 3 % 10.76 % Geographical distribution: California 20 0.52 20 0.58 Florida 6 2.27 6 2.86 New Jersey 4 3.88 4 4.87 New York 5 3.03 5 3.55 All other states 65 1.16 65 1.34 Product distribution: Alt-A 3 5.68 4 6.53 Vintages: 2004 and prior 5 2.82 5 3.06 2005-2008 9 6.73 10 7.60 2009-2016 86 0.34 85 0.36 __________ (1) Consists of the portion of our single-family conventional guaranty book of business for which we have detailed loan level information, which constituted approximately 99% our total single-family conventional guaranty book of business as of June 30, 2016 and December 31, 2015 . (2) Consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of June 30, 2016 and December 31, 2015 . (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. As of June 30, 2016 (1)(2) December 31, 2015 (1)(2) 30 Days Delinquent Seriously Delinquent (3) 30 Days Delinquent Seriously Delinquent (3) Percentage of multifamily guaranty book of business 0.03 % 0.07 % 0.03 % 0.07 % As of June 30, 2016 (1) December 31, 2015 (1) Percentage of Multifamily Guaranty Book of Business (2) Percentage Seriously Delinquent (3)(4) Percentage of Multifamily Guaranty Book of Business (2) Percentage Seriously Delinquent (3)(4) Original LTV ratio: Greater than 80% 2 % 0.03 % 3 % 0.40 % Less than or equal to 80% 98 0.08 97 0.06 Current DSCR less than 1.0 (5) 2 1.02 2 1.51 __________ (1) Consists of the portion of our multifamily guaranty book of business for which we have detailed loan level information, which constituted approximately 99% of our total multifamily guaranty book of business as of June 30, 2016 and December 31, 2015 , excluding loans that have been defeased. (2) 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. (3) Consists of multifamily loans that were 60 days or more past due as of the dates indicated. (4) 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 guaranty book of business. (5) 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 Sellers and Servicers. 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 sellers and servicers 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. However, under our revised representation and warranty framework, we no longer 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. Our five largest single-family mortgage servicers, including their affiliates, serviced approximately 41% of our single-family guaranty book of business as of June 30, 2016 , compared with approximately 44% as of December 31, 2015 . Our five largest multifamily mortgage servicers, including their affiliates, serviced approximately 46% of our multifamily guaranty book of business as of June 30, 2016 , compared with approximately 45% as of December 31, 2015 . If a significant mortgage seller or servicer counterparty, or a number of mortgage sellers or servicers, fails to meet their obligations to us, it could result in an increase in our credit losses and credit-related expense, and have a material adverse effect on our results of operations, liquidity, financial condition and net worth. Mortgage Insurers. Mortgage insurance “risk in force” generally represents our maximum potential loss recovery under the applicable mortgage insurance policies. We had total mortgage insurance coverage risk in force of $121.5 billion and $117.9 billion on the single-family mortgage loans in our guaranty book of business as of June 30, 2016 and December 31, 2015 , respectively, which represented 4% of our single-family guaranty book of business as of June 30, 2016 and December 31, 2015 . Our primary mortgage insurance coverage risk in force was $120.8 billion and $117.2 billion as of June 30, 2016 and December 31, 2015 , respectively. Our pool mortgage insurance coverage risk in force was $676 million and $736 million as of June 30, 2016 and December 31, 2015 , respectively. Our top four mortgage insurance companies provided 78% and 79% of our mortgage insurance coverage risk in force as of June 30, 2016 and December 31, 2015 , respectively. Of our largest primary mortgage insurers, PMI Mortgage Insurance Co., Triad Guaranty Insurance Corporation and Republic Mortgage Insurance Company are under various forms of supervised control by their state regulators and are in run-off. 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 $9.1 billion , or 7% , of our risk in force mortgage insurance coverage of our single-family guaranty book of business as of June 30, 2016 . Although the financial condition of our mortgage insurer counterparties currently approved to write new business has improved in recent years, there is still risk that these counterparties may fail to fulfill their obligations to pay our claims under insurance policies. If we determine that it is probable that we will not collect all of our claims from one or more of our mortgage insurer counterparties, it could result in an increase in 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 result in an increase in our loss reserves. As of June 30, 2016 and December 31, 2015 , the amount by which our estimated benefit from mortgage insurance reduced our total loss reserves was $1.7 billion and $2.3 billion , respectively. We had outstanding receivables of $1.1 billion recorded in “Other assets” in our condensed consolidated balance sheets as of June 30, 2016 and $1.2 billion as of December 31, 2015 related to amounts claimed on insured, defaulted loans excluding government insured loans. Of this amount, $154 million as of June 30, 2016 and $241 million as of December 31, 2015 was due from our mortgage sellers or servicers. We assessed the total outstanding receivables for collectibility, and they are recorded net of a valuation allowance of $678 million as of June 30, 2016 and $770 million as of December 31, 2015 . The valuation allowance reduces our claim receivable to the amount which is considered probable of collection as of June 30, 2016 and December 31, 2015 . For information on credit risk associated with our derivative transactions and repurchase agreements refer to “ Note 9, Derivative Instruments ” and “ Note 14, Netting Arrangements .”

Netting Arrangements

Netting Arrangements	6 Months Ended
	Jun. 30, 2016
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 June 30, 2016 Net Amount Presented in our Condensed Consolidated Balance Sheets Amounts Not Offset in our Condensed Consolidated Balance Sheets Gross Amount Gross Amount Offset (1) Financial Instruments (2) Collateral (3) Net Amount (Dollars in millions) Assets: OTC risk management derivatives $ 4,949 $ (4,925 ) $ 24 $ — $ — $ 24 Cleared risk management derivatives 2,692 (2,605 ) 87 — — 87 Mortgage commitment derivatives 637 — 637 (291 ) (8 ) 338 Total derivative assets 8,278 (7,530 ) 748 (4) (291 ) (8 ) 449 Securities purchased under agreements to resell or similar arrangements (5) 41,445 — 41,445 — (41,445 ) — Total assets $ 49,723 $ (7,530 ) $ 42,193 $ (291 ) $ (41,453 ) $ 449 Liabilities: OTC risk management derivatives $ (8,303 ) $ 8,156 $ (147 ) $ — $ — $ (147 ) Cleared risk management derivatives (6,142 ) 6,113 (29 ) — 29 — Mortgage commitment derivatives (958 ) — (958 ) 291 2 (665 ) Total derivative liabilities (15,403 ) 14,269 (1,134 ) (4) 291 31 (812 ) Securities sold under agreements to repurchase or similar arrangements (115 ) — (115 ) — 115 — Total liabilities $ (15,518 ) $ 14,269 $ (1,249 ) $ 291 $ 146 $ (812 ) As of December 31, 2015 Net Amount Presented in our Condensed Consolidated Balance Sheets Amounts Not Offset in our Condensed Consolidated Balance Sheets Gross Amount Gross Amount Offset (1) Financial Instruments (2) Collateral (3) Net Amount (Dollars in millions) Assets: OTC risk management derivatives $ 4,042 $ (4,021 ) $ 21 $ — $ (18 ) $ 3 Cleared risk management derivatives 708 (3 ) 705 — — 705 Mortgage commitment derivatives 140 — 140 (119 ) (3 ) 18 Total derivative assets 4,890 (4,024 ) 866 (4) (119 ) (21 ) 726 Securities purchased under agreements to resell or similar arrangements (5) 37,950 — 37,950 — (37,950 ) — Total assets $ 42,840 $ (4,024 ) $ 38,816 $ (119 ) $ (37,971 ) $ 726 Liabilities: OTC risk management derivatives $ (6,118 ) $ 5,861 $ (257 ) $ — $ — $ (257 ) Cleared risk management derivatives (2,796 ) 2,789 (7 ) — — (7 ) Mortgage commitment derivatives (158 ) — (158 ) 119 (1 ) (40 ) Total derivative liabilities (9,072 ) 8,650 (422 ) (4) 119 (1 ) (304 ) Securities sold under agreements to repurchase or similar arrangements (62 ) — (62 ) — 62 — Total liabilities $ (9,134 ) $ 8,650 $ (484 ) $ 119 $ 61 $ (304 ) __________ (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 non-cash collateral received that has not been recognized and not offset in our condensed consolidated balance sheets as well as non-cash collateral posted which has been recognized but not offset in our condensed consolidated balance sheets. Does not include collateral held or posted in excess of our exposure. The fair value of non-cash collateral we pledged was $1.2 billion and $197 million as of June 30, 2016 and December 31, 2015 , respectively, which the counterparty was permitted to sell or repledge. The fair value of non-cash collateral received was $41.5 billion and $38.0 billion , of which $38.9 billion and $36.2 billion could be sold or repledged as of June 30, 2016 and December 31, 2015, respectively. None of the underlying collateral was sold or repledged as of June 30, 2016 and December 31, 2015 . (4) Excludes derivative assets of $27 million and $28 million as of June 30, 2016 and December 31, 2015 , and derivative liabilities of $1 million and $2 million recognized in our condensed consolidated balance sheets as of June 30, 2016 and December 31, 2015 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $19.1 billion and $10.6 billion of securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of June 30, 2016 and December 31, 2015 , 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. We determine our rights to offset the assets and liabilities presented above with the same counterparty, including collateral posted or received, based on the contractual arrangements entered into with our individual counterparties and various rules and regulations that would govern the insolvency of a derivative counterparty. The following is a description, under various agreements, of the nature of those rights and their effect or potential effect on our financial position. The terms of the majority of our contracts for OTC risk management derivatives are governed under master agreements of the International Swaps and Derivatives Association Inc. (“ISDA”). These agreements provide that all transactions entered into under the agreement with the counterparty constitute a single contractual relationship. An event of default by the counterparty allows the early termination of all outstanding transactions under the same ISDA agreement and we may offset all outstanding amounts related to the terminated transactions including collateral posted or received. The terms of our contracts for cleared derivatives are governed under the rules of the clearing organization and the agreement between us and the clearing member of that clearing organization. In the event of a clearing organization default, all open positions at the clearing organization are closed and a net position (on a clearing member by clearing member basis) is calculated. Unless otherwise transferred, in the event of a clearing member default, all open positions cleared through that clearing member are closed and a net position is calculated. The terms of our contracts for mortgage commitment derivatives are primarily governed by the Fannie Mae Single-Family Selling Guide (“Guide”), for Fannie Mae-approved lenders, or Master Securities Forward Transaction Agreements (“MSFTA”), for counterparties that are not Fannie Mae-approved lenders. In the event of default by the counterparty, both the Guide and the MSFTA allow us to terminate all outstanding transactions under the applicable agreement and offset all outstanding amounts related to the terminated transactions including collateral posted or received. Under the Guide, upon a lender event of default, we generally may offset any amounts owed to a lender against any amounts a lender may owe us under any other existing agreement, regardless of whether or not such other agreements are in default or payments are immediately due. The terms of our contracts for securities purchased under agreements to resell and securities sold under agreements to repurchase are governed by Master Repurchase Agreements, which are based on the guidelines prescribed by the Securities Industry and Financial Markets Association. Master Repurchase Agreements provide that all transactions under the agreement constitute a single contractual relationship. An event of default by the counterparty allows the early termination of all outstanding transactions under the same agreement and we may offset all outstanding amounts related to the terminated transactions including collateral posted or received. We also have securities purchased under agreements to resell which we transact through the Fixed Income Clearing Corporation (“FICC”). Under the rules of the FICC, all agreements for securities purchased under agreements to resell that are submitted to the FICC for clearing become transactions with the FICC that are subject to FICC clearing rules. In the event of a FICC default, all open positions at the FICC are closed and a net position is calculated.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value	Fair Value We use fair value measurements for the initial recording of certain assets and liabilities and periodic remeasurement of certain assets and liabilities on a recurring or nonrecurring basis. Fair Value Measurement Fair value measurement guidance defines fair value, establishes a framework for measuring fair value and sets forth disclosures around fair value measurements. This guidance applies whenever other accounting guidance requires or permits assets or liabilities to be measured at fair value. The guidance establishes a three-level fair value hierarchy that prioritizes the inputs into the valuation techniques used to measure fair value. The fair value hierarchy gives the highest priority, Level 1, to measurements based on unadjusted quoted prices in active markets for identical assets or liabilities. The next highest priority, Level 2, is given to measurements of assets and liabilities based on limited observable inputs or observable inputs for similar assets and liabilities. The lowest priority, Level 3, is given to measurements based on unobservable inputs. Recurring Changes in Fair Value The following tables display our assets and liabilities measured in our condensed consolidated balance sheets at fair value on a recurring basis subsequent to initial recognition, including instruments for which we have elected the fair value option. Fair Value Measurements as of June 30, 2016 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 $ — $ 5,352 $ — $ — $ 5,352 Freddie Mac — 1,328 — — 1,328 Ginnie Mae — 542 — — 542 Alt-A private-label securities — 57 259 — 316 Subprime private-label securities — 351 44 — 395 CMBS — 1,389 — — 1,389 Mortgage revenue bonds — — 193 — 193 Non-mortgage-related securities: U.S. Treasury securities 29,652 — — — 29,652 Total trading securities 29,652 9,019 496 — 39,167 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 3,336 — — 3,336 Freddie Mac — 2,037 1 — 2,038 Ginnie Mae — 66 — — 66 Alt-A private-label securities — 1,652 175 — 1,827 Subprime private-label securities — 2,200 173 — 2,373 CMBS — 1,023 — — 1,023 Mortgage revenue bonds — — 2,029 — 2,029 Other — 38 450 — 488 Total available-for-sale securities — 10,352 2,828 — 13,180 Mortgage loans — 12,133 1,280 — 13,413 Other assets: Risk management derivatives: Swaps — 7,389 216 — 7,605 Swaptions — 36 — — 36 Other — — 27 — 27 Netting adjustment — — — (7,530 ) (7,530 ) Mortgage commitment derivatives — 623 14 — 637 Total other assets — 8,048 257 (7,530 ) 775 Total assets at fair value $ 29,652 $ 39,552 $ 4,861 $ (7,530 ) $ 66,535 Fair Value Measurements as of June 30, 2016 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 $ — $ 10,240 $ 410 $ — $ 10,650 Total of Fannie Mae — 10,240 410 — 10,650 Of consolidated trusts — 32,472 326 — 32,798 Total long-term debt — 42,712 736 — 43,448 Other liabilities: Risk management derivatives: Swaps — 14,283 4 — 14,287 Swaptions — 158 — — 158 Other — — 1 — 1 Netting adjustment — — — (14,269 ) (14,269 ) Mortgage commitment derivatives — 954 4 — 958 Total other liabilities — 15,395 9 (14,269 ) 1,135 Total liabilities at fair value $ — $ 58,107 $ 745 $ (14,269 ) $ 44,583 Fair Value Measurements as of December 31, 2015 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) Assets: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 4,813 $ — $ — $ 4,813 Freddie Mac — 1,314 — — 1,314 Ginnie Mae — 426 — — 426 Alt-A private-label securities — 131 305 — 436 Subprime private-label securities — — 644 — 644 CMBS — 2,341 — — 2,341 Mortgage revenue bonds — — 449 — 449 Non-mortgage-related securities: U.S. Treasury securities 29,485 — — — 29,485 Total trading securities 29,485 9,025 1,398 — 39,908 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 4,221 — — 4,221 Freddie Mac — 4,295 4 — 4,299 Ginnie Mae — 391 — — 391 Alt-A private-label securities — 1,637 1,041 — 2,678 Subprime private-label securities — — 3,281 — 3,281 CMBS — 1,255 — — 1,255 Mortgage revenue bonds — — 2,701 — 2,701 Other — — 1,404 — 1,404 Total available-for-sale securities — 11,799 8,431 — 20,230 Mortgage loans — 12,598 1,477 — 14,075 Other assets: Risk management derivatives: Swaps — 4,541 156 — 4,697 Swaptions — 53 — — 53 Other — — 28 — 28 Netting adjustment — — — (4,024 ) (4,024 ) Mortgage commitment derivatives — 135 5 — 140 Total other assets — 4,729 189 (4,024 ) 894 Total assets at fair value $ 29,485 $ 38,151 $ 11,495 $ (4,024 ) $ 75,107 Fair Value Measurements as of December 31, 2015 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 $ — $ 10,764 $ 369 $ — $ 11,133 Total of Fannie Mae — 10,764 369 — 11,133 Of consolidated trusts — 23,113 496 — 23,609 Total long-term debt — 33,877 865 — 34,742 Other liabilities: Risk management derivatives: Swaps — 8,697 20 — 8,717 Swaptions — 197 — — 197 Other — — 2 — 2 Netting adjustment — — — (8,650 ) (8,650 ) Mortgage commitment derivatives — 148 10 — 158 Total other liabilities — 9,042 32 (8,650 ) 424 Total liabilities at fair value $ — $ 42,919 $ 897 $ (8,650 ) $ 35,166 __________ (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. 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 both realized and unrealized gains and losses, recognized in our condensed consolidated statements of operations and comprehensive income for Level 3 assets and liabilities. When assets and liabilities are transferred between levels, we recognize the transfer as of the end of the period. Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2016 (5)(6) Balance, March 31, 2016 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 25 $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ — $ — $ — Freddie Mac 1 — — — — — — (1 ) — — — Alt-A private-label securities 245 24 — — — — (10 ) — — 259 25 Subprime private-label securities 43 3 — — — — (2 ) — — 44 2 Mortgage revenue bonds 363 17 — — (184 ) — (3 ) — — 193 6 Total trading securities $ 677 $ 44 (6)(7) $ — $ — $ (184 ) $ — $ (16 ) $ (25 ) $ — $ 496 $ 33 Available-for-sale securities: Mortgage-related: Fannie Mae $ 1 $ — $ — $ — $ — $ — $ — $ (1 ) $ — $ — $ — Freddie Mac 2 — — — — — — (1 ) — 1 — Alt-A private-label securities 177 — 2 — — — (4 ) — — 175 — Subprime private-label securities 222 1 7 — — — (57 ) — — 173 — Mortgage revenue bonds 2,564 76 18 — (568 ) — (61 ) — — 2,029 — Other 655 3 (1 ) — (201 ) — (6 ) — — 450 — Total available-for-sale securities $ 3,621 $ 80 (7)(8) $ 26 $ — $ (769 ) $ — $ (128 ) $ (2 ) $ — $ 2,828 $ — Mortgage loans $ 1,311 $ 15 (6)(7) $ — $ 25 $ — $ — $ (67 ) $ (19 ) $ 15 $ 1,280 $ 10 Net derivatives 231 52 (6) — — — (3 ) (33 ) — 1 248 41 Long-term debt: Of Fannie Mae: Senior floating $ (395 ) $ (15 ) $ — $ — $ — $ — $ — $ — $ — $ (410 ) $ (15 ) Of consolidated trusts (246 ) (7 ) — — — (47 ) 9 8 (43 ) (326 ) (7 ) Total long-term debt $ (641 ) $ (22 ) (6) $ — $ — $ — $ (47 ) $ 9 $ 8 $ (43 ) $ (736 ) $ (22 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2016 (5)(6) Balance, December 31, 2015 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ 25 $ — $ — Freddie Mac — — — — — — — (1 ) 1 — — Alt-A private-label securities 305 (30 ) — — — — (16 ) — — 259 (30 ) Subprime private-label securities 644 (34 ) — — (187 ) — (16 ) (363 ) — 44 (10 ) Mortgage revenue bonds 449 29 — — (279 ) — (6 ) — — 193 10 Total trading securities $ 1,398 $ (35 ) (6)(7) $ — $ — $ (466 ) $ — $ (39 ) $ (388 ) $ 26 $ 496 $ (30 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ — $ (1 ) $ 1 $ — $ — Freddie Mac 4 — — — — — — (3 ) — 1 — Alt-A private-label securities 1,041 12 (27 ) — (291 ) — (44 ) (516 ) — 175 — Subprime private-label securities 3,281 92 (132 ) — (584 ) — (161 ) (2,323 ) — 173 — Mortgage revenue bonds 2,701 80 48 — (611 ) — (189 ) — — 2,029 — Other 1,404 — (26 ) — (605 ) — (39 ) (284 ) — 450 — Total available-for-sale securities $ 8,431 $ 184 (7)(8) $ (137 ) $ — $ (2,091 ) $ — $ (433 ) $ (3,127 ) $ 1 $ 2,828 $ — Mortgage loans $ 1,477 $ 116 (6)(7) $ — $ 25 $ (320 ) $ — $ (139 ) $ (84 ) $ 205 $ 1,280 $ 20 Net derivatives 157 232 (6) — — — (7 ) (133 ) (2 ) 1 248 76 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) $ (41 ) $ — $ — $ — $ — $ — $ — $ — $ (410 ) $ (41 ) Of consolidated trusts (496 ) (75 ) — — — (54 ) 318 45 (64 ) (326 ) (8 ) Total long-term debt $ (865 ) $ (116 ) (6) $ — $ — $ — $ (54 ) $ 318 $ 45 $ (64 ) $ (736 ) $ (49 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2015 (5)(6) Balance, March 31, 2015 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 2 $ — $ — $ — $ (2 ) $ — $ — $ — $ — $ — $ — Alt-A private-label securities 572 36 — — (267 ) — (16 ) — — 325 45 Subprime private-label securities 876 42 — — (182 ) — (18 ) — — 718 97 Mortgage revenue bonds 742 (33 ) — — (106 ) — (1 ) — — 602 (36 ) Other 94 6 — — (100 ) — — — — — 20 Total trading securities $ 2,286 $ 51 (6)(7) $ — $ — $ (657 ) $ — $ (35 ) $ — $ — $ 1,645 $ 126 Available-for-sale securities: Mortgage-related: Fannie Mae $ 205 $ — $ — $ 182 $ (269 ) $ — $ — $ — $ 11 $ 129 $ — Freddie Mac 5 — — — — — (1 ) — — 4 — Alt-A private-label securities 2,486 71 (38 ) — (552 ) — (85 ) (228 ) — 1,654 — Subprime private-label securities 4,608 265 (131 ) — (760 ) — (145 ) — — 3,837 — Mortgage revenue bonds 3,560 17 (79 ) — (154 ) — (173 ) — — 3,171 — Other 2,607 45 (55 ) — (368 ) — (71 ) — — 2,158 — Total available-for-sale securities $ 13,471 $ 398 (7)(8) $ (303 ) $ 182 $ (2,103 ) $ — $ (475 ) $ (228 ) $ 11 $ 10,953 $ — Mortgage loans $ 1,810 $ 4 (6)(7) $ — $ 2 $ — $ — $ (99 ) $ (197 ) $ 75 $ 1,595 $ (6 ) Net derivatives 66 (126 ) (6) — — — — 64 — — 4 (40 ) Long-term debt: Of Fannie Mae: Senior floating $ (391 ) $ 45 $ — $ — $ — $ — $ — $ — $ — $ (346 ) $ 44 Of consolidated trusts (547 ) 5 — — — — 16 59 (26 ) (493 ) 8 Total long-term debt $ (938 ) $ 50 (6) $ — $ — $ — $ — $ 16 $ 59 $ (26 ) $ (839 ) $ 52 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2015 (5)(6) Balance, December 31, 2014 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 305 $ (27 ) $ — $ — $ (2 ) $ — $ — $ (278 ) $ 2 $ — $ — Alt-A private-label securities 597 44 — — (267 ) — (33 ) (44 ) 28 325 51 Subprime private-label securities 1,307 43 — — (580 ) — (52 ) — — 718 99 Mortgage revenue bonds 722 2 — — (118 ) — (4 ) — — 602 (1 ) Other 99 4 — — (100 ) — (3 ) — — — 19 Total trading securities $ 3,030 $ 66 (6)(7) $ — $ — $ (1,067 ) $ — $ (92 ) $ (322 ) $ 30 $ 1,645 $ 168 Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ 421 $ (303 ) $ — $ — $ — $ 11 $ 129 $ — Freddie Mac 6 — — — — — (1 ) (1 ) — 4 — Alt-A private-label securities 3,140 172 (116 ) — (1,108 ) — (209 ) (538 ) 313 1,654 — Subprime private-label securities 5,240 445 (232 ) — (1,325 ) — (291 ) — — 3,837 — Mortgage revenue bonds 4,023 40 (27 ) — (316 ) — (549 ) — — 3,171 — Other 2,671 (93 ) 85 — (368 ) — (137 ) — — 2,158 — Total available-for-sale securities $ 15,080 $ 564 (7)(8) $ (290 ) $ 421 $ (3,420 ) $ — $ (1,187 ) $ (539 ) $ 324 $ 10,953 $ — Mortgage loans $ 1,833 $ 38 (6)(7) $ — $ 5 $ — $ — $ (176 ) $ (254 ) $ 149 $ 1,595 $ 5 Net derivatives 45 (99 ) (6) — — — — 58 — — 4 (23 ) Long-term debt: Of Fannie Mae: Senior floating $ (363 ) $ 17 $ — $ — $ — $ — $ — $ — $ — $ (346 ) $ 16 Of consolidated trusts (527 ) (8 ) — — — — 25 109 (92 ) (493 ) (4 ) Total long-term debt $ (890 ) $ 9 (6) $ — $ — $ — $ — $ 25 $ 109 $ (92 ) $ (839 ) $ 12 __________ (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on AFS securities, net of reclassification adjustments and taxes” in our condensed consolidated statements of operations and comprehensive income. (2) Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts. (3) Issues and settlements include activity related to the consolidation and deconsolidation of liabilities of securitization trusts. (4) Transfers out of Level 3 consisted primarily of private-label mortgage-related securities backed by Alt-A loans and subprime loans. Prices for these securities were available from multiple third-party vendors and have demonstrated an increased and sustained level of observability over time. Transfers into Level 3 consisted primarily of private-label mortgage-related securities backed by Alt-A loans. Prices for these securities were based on inputs from a single source or inputs that were not readily observable during that time. (5) Amount represents temporary changes in fair value. Amortization, accretion and OTTI are not considered unrealized and are not included in this amount. (6) Gains (losses) are included in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. (7) Gains (losses) are included in “Net interest income” in our condensed consolidated statements of operations and comprehensive income. (8) 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. Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Alt-A private-label securities (2) $ 37 Single Vendor Default Rate (%) 1.8 1.8 Prepayment Speed (%) 3.1 3.1 Severity (%) 72.0 72.0 Spreads (bps) 335.5 335.5 222 Consensus Default Rate (%) 2.0 - 5.0 4.2 Prepayment Speed (%) 3.0 - 8.0 6.7 Severity (%) 50.0 - 95.0 83.3 Spreads (bps) 280.0 - 493.4 437.8 Total Alt-A private-label securities 259 Subprime private-label securities (2) 44 Single Vendor Default Rate (%) 5.0 5.0 Prepayment Speed (%) 5.0 5.0 Severity (%) 75.0 75.0 Spreads (bps) 667.8 667.8 Total subprime private-label securities 44 Mortgage revenue bonds 185 Discounted Cash Flow Spreads (bps) 27.5 - 321.4 317.3 8 Other Total mortgage revenue bonds 193 Total trading securities $ 496 Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Available-for-sale securities: Mortgage-related securities: Agency (3) $ 1 Other Alt-A private-label securities (2) 121 Consensus Default Rate (%) 3.0 - 6.0 3.4 Prepayment Speed (%) 5.0 - 8.0 5.2 Severity (%) 60.0 - 80.0 61.6 Spreads (bps) 302.5 - 342.0 330.2 54 Discounted Cash Flow Default Rate (%) 6.0 6.0 Prepayment Speed (%) 8.0 8.0 Severity (%) 65.0 65.0 Spreads (bps) 301.6 - 367.0 355.2 Total Alt-A private-label securities 175 Subprime private-label securities (2) 123 Dealer Mark Default Rate (%) 6.5 - 10.0 8.3 Prepayment Speed (%) 5.0 - 6.0 5.5 Severity (%) 85.0 - 95.0 90.0 Spreads (bps) 330.0 330.0 50 Other Total subprime private-label securities 173 Mortgage revenue bonds 951 Single Vendor Spreads (bps) 7.5 - 414.3 60.3 970 Discounted Cash Flow Spreads (bps) 7.5 - 442.8 286.8 108 Other Total mortgage revenue bonds 2,029 Other 87 Consensus Default Rate (%) 0.5 - 3.5 3.5 Prepayment Speed (%) 2.5 - 5.0 2.5 Severity (%) 20.0 - 88.0 87.7 Spreads (bps) 303.5 - 453.0 376.1 357 Discounted Cash Flow Default Rate (%) 0.8 0.8 Prepayment Speed (%) 1.0 1.0 Severity (%) 95.0 95.0 Spreads (bps) 220.0 - 487.0 485.1 6 Other Total other 450 Total available-for-sale securities $ 2,828 Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 572 Build-Up 149 Consensus Default Rate (%) 1.0 - 7.0 3.1 Prepayment Speed (%) 3.0 - 23.3 7.3 Severity (%) 44.0 - 95.0 70.5 Spreads (bps) 245.0 - 310.0 259.7 239 Consensus 164 Other Total single-family 1,124 Multifamily 156 Build-Up Spreads (bps) 80.0 - 387.2 194.0 Total mortgage loans $ 1,280 Net derivatives $ 212 Dealer Mark 36 Other Total net derivatives $ 248 Long-term debt: Of Fannie Mae: Senior floating $ (410 ) Discounted Cash Flow Of consolidated trusts (4) (125 ) Discounted Cash Flow Default Rate (%) 2.0 - 7.0 4.9 Prepayment Speed (%) 3.0 - 100.0 92.4 Severity (%) 58.0 - 95.0 83.0 Spreads (bps) 88.0 - 366.3 224.7 (201 ) Other Total of consolidated trusts (326 ) Total long-term debt $ (736 ) Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Alt-A private-label securities (2) $ 305 Consensus Default Rate (%) 1.3 - 4.9 3.6 Prepayment Speed (%) 2.2 - 4.5 3.7 Severity (%) 20.5 - 95.0 69.3 Spreads (bps) 219.0 - 263.3 253.1 Total Alt-A private-label securities 305 Subprime private-label securities (2) 526 Consensus Default Rate (%) 4.2 - 8.4 5.9 Prepayment Speed (%) 0.4 - 5.3 3.3 Severity (%) 55.9 - 95.0 73.7 Spreads (bps) 285.0 285.0 73 Consensus 45 Other Total subprime private-label securities 644 Mortgage revenue bonds 437 Discounted Cash Flow Spreads (bps) 1.5 - 376.2 298.9 12 Other Total mortgage revenue bonds 449 Total trading securities $ 1,398 Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Available-for-sale securities: Mortgage-related securities: Agency (3) $ 4 Other Alt-A private-label securities (2) 671 Consensus Default Rate (%) 0.5 - 40.7 3.4 Prepayment Speed (%) 1.7 - 72.6 13.5 Severity (%) 1.4 - 95.0 58.5 Spreads (bps) 225.6 - 280.4 260.0 201 Consensus 169 Discounted Cash Flow Default Rate (%) 4.0 - 5.0 4.8 Prepayment Speed (%) 4.0 - 7.5 6.4 Severity (%) 50.0 - 64.0 59.2 Spreads (bps) 260.0 - 369.4 296.5 Total Alt-A private-label securities 1,041 Subprime private-label securities (2) 343 Single Vendor Default Rate (%) 2.5 - 7.5 4.8 Prepayment Speed (%) 1.9 - 5.7 3.3 Severity (%) 67.6 - 85.7 72.7 Spreads (bps) 285.0 - 340.0 299.6 1,848 Consensus Default Rate (%) 0.5 - 11.3 5.9 Prepayment Speed (%) 0.5 - 11.2 3.8 Severity (%) 20.0 - 95.0 79.0 Spreads (bps) 255.0 - 285.0 283.3 945 Consensus 145 Other Total subprime private-label securities 3,281 Mortgage revenue bonds 991 Single Vendor Spreads (bps) (33.1 ) - 386.8 37.9 1,462 Discounted Cash Flow Spreads (bps) (15.8 ) - 379.1 283.8 248 Other Total mortgage revenue bonds 2,701 Other 683 Consensus Default Rate (%) 0.5 - 4.6 3.4 Prepayment Speed (%) 2.5 - 15.5 4.7 Severity (%) 6.6 - 95.0 65.7 Spreads (bps) 200.0 - 454.4 315.6 520 Discounted Cash Flow Default Rate (%) 0.0 - 1.8 0.0 Prepayment Speed (%) 0.0 - 0.5 0.0 Severity (%) 95.0 95.0 Spreads (bps) 260.0 - 350.0 323.6 201 Other Total other 1,404 Total available-for-sale securities $ 8,431 Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 127 Build-Up Default Rate (%) 0.0 - 99.2 34.8 Prepayment Speed (%) 3.0 - 100.0 10.4 Severity (%) 0.0 - 100.0 39.9 632 Build-Up 234 Consensus Default Rate (%) 0.5 - 5.0 3.7 Prepayment Speed (%) 2.5 - 26.0 6.4 Severity (%) 20.0 - 89.1 69.0 Spreads (bps) 255.0 - 277.6 264.6 274 Consensus 54 Other Total single-family 1,321 Multifamily 156 Build-Up Spreads (bps) 70.0 - 327.2 158.8 Total mortgage loans $ 1,477 Net derivatives $ 17 Internal Model 136 Dealer Mark 4 Other Total net derivatives $ 157 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) Discounted Cash Flow Of consolidated trusts (4) (181 ) Consensus Default Rate (%) 0.5 - 3.8 3.4 Prepayment Speed (%) 2.5 - 26.0 5.6 Severity (%) 20.0 - 80.6 67.8 Spreads (bps) 255.0 - 270.0 265.8 (149 ) Consensus (166 ) Other Total of consolidated trusts (496 ) Total long-term debt $ (865 ) _________ (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) Default rate as disclosed represents the estimated beginning annualized rate of default and is used as a basis to forecast the future default rates that serve as an input for valuation. (3) Includes Fannie Mae and Freddie Mac securities. (4) Includes instruments for which the prepayment speed as disclosed represents the estimated annualized rate of prepayment after all prepayment penalty provisions have expired and also instruments for which prepayment speed as disclosed represents the estimated rate of prepayment over the remaining life of the instrument. 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 did not have any Level 1 assets or liabilities held as of June 30, 2016 or December 31, 2015 that were measured at fair value on a nonrecurring basis. We held $119 million and $17 million in Level 2 assets, comprised of mortgage loans held for sale, and no Level 2 liabilities that were measured at fair value on a nonrecurring basis as of June 30, 2016 and December 31, 2015 , respectively. The following table displays valuation techniques for our Level 3 assets measured at fair value on a nonrecurring basis. The significant unobservable inputs related to these techniques primarily relate to collateral dependent valuations. The related ranges and weighted averages are not meaningful when aggregated as they vary significantly from property to property. Fair Value Measurements (Level 3) of Assets Held as of Valuation Techniques June 30, 2016 December 31, 2015 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,919 $ 3,651 Single Vendor 32 336 Other 3 4 Total mortgage loans held for sale, at lower of cost or fair value 1,954 3,991 Single-family mortgage loans held for investment, at amortized cost Internal Model 3,640 6,379 Multifamily mortgage loans held for investment, at amortized cost Broker Price Opinions 27 82 Asset Manager Estimate 211 236 Other 5 5 Total multifamily mortgage loans held for investment, at amortized cost 243 323 Acquired property, net: Single-family Accepted Offers 443 541 Appraisals 728 1,117 Walk Forwards 307 433 Internal Model 476 986 Other 60 134 Total single-family 2,014 3,211 Multifamily Other 9 — Other assets Other 12 30 Total nonrecurring assets at fair value $ 7,872 $ 13,934 We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The following is a description of 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. Trading Securities and Available-for-Sale Securities These securities are recorded in our condensed consolidated balance sheets at fair value on a recurring basis. Fair value is measured using quoted market prices in active markets for identical assets, when available. We classify securities whose values are based on quoted market prices in active markets for identical assets as Level 1 of the valuation hierarchy. We classify securities in active markets as Level 2 of the valuation hierarchy if quoted market prices in active markets for identical assets are not available. For all valuation techniques used for securities where there is limited activity or less transparency around these inputs to the valuation, these securities are classified as Level 3 of the valuation hierarchy. A description of our securities valuation techniques is as follows: Single Vendor: This valuation technique utilizes one vendor price to estimate fair value. We generally validate these observations of fair value through the use of a discounted cash flow technique whose unobservable inputs (for example, default rates) are disclosed in the table above. Dealer Mark: This valuation technique utilizes one dealer price to estimate fair value. We generally validate these observations of fair value through the use of a discounted cash flow technique whose unobservable inputs (for example, default rates) are disclosed in the table above. Consensus: This technique utilizes an average of two or more vendor prices for similar securities. We generally validate these observations of fair value through the use of a discounted cash flow technique whose unobservable inputs (for example, default rates) are disclosed in the table above. Discounted Cash Flow: In the absence of prices provided by third-party pricing services supported by observable market data, we estimate the fair value of a portion of our securities using a discounted cash flow technique that uses inputs such as default rates, prepayment speeds, loss severity and spreads based on market assumptions where available. For private-label securities, an increase in unobservable prepayment speeds in isolation would generally result in an increase in fair value, and an increase in unobservable spreads, severity rates or default rates in isolation would generally result in a decrease in fair value. For mortgage revenue bonds classified as Level 3 of the valuation hierarchy, an increase in unobservable spreads would result in a decrease in fair value. Although the sensitivities of the fair value of our recurring Level 3 securities of the valuation hierarchy to various unobservable inputs are discussed above in isolation, interrelationships exist among these inputs such that a change in one unobservable input typically results in a change to one or more of the other inputs. Mortgage Loans Held for Investment The majority of HFI loans are reported in our condensed consolidated balance sheets at the principal amount outstanding, net of cost basis adjustments and an allowance for loan losses. We estimate the fair value of HFI loans using the build-up and consensus valuation techniques, as discussed below, for periodic disclosure of financial instruments as required by GAAP. For our remaining loans, which include those containing embedded derivatives that would otherwise require bifurcation and consolidated loans of senior-subordinated trust structures, we elected the fair value option and therefore, we record these loans at fair value in our condensed consolidated balance sheets. We measure these loans on a recurring basis using the build-up, consensus, discounted cash flow and single vendor price techniques. Certain impaired loans are measured at fair value on a nonrecurring basis by using the fair value of their underlying collateral. Specific techniques used include internal models, broker price opinions and appraisals. A description of our loan valuation techniques is as follows: Build-up: We derive the fair value of mortgage loans using a build-up valuation technique. In the build-up valuation technique we start with the base value for our Fannie Mae MBS and then add or subtract the fair value of the associated guaranty asset, guaranty obligation (“GO”) and master servicing arrangement. We use observable market values of Fannie Mae MBS with similar characteristics, either on a pool or loan level, determined primarily from third party pricing services, quoted market prices in active markets for similar securities, and other observable market data as a base value. We set the GO equal to the estimated fair value we would receive if we were to issue our guaranty to an unrelated party in a stand-alone arm’s length transaction at the measurement date. We estimate the fair value of the GO using our internal valuation models, which calculate the present value of expected cash flows based on management’s best estimate of certain key assumptions such as current mark-to-market LTV ratios, future house prices, default rates, severity rates and required rate of return. We also estimate the fair value of the GO using our current guaranty pricing and adjust that pricing, as appropriate, for the seasoning of the collateral when such transactions reflect credit characteristics of loans held in our portfolio. As a result, the fair value of our mortgage loans will change when the pricing for our credit guaranty changes in the GSE securitization market. Our performing loans are generally classified as Level 2 of the valuation hierarchy to the extent that significant inputs are observable. To the extent that unobservable inputs are significant, the loans are classified as Level 3 of the valuation hierarchy. Consensus: The fair value of single-family nonperforming loans and TDRs on accrual status represents an estimate of the prices we would receive if we were to sell these loans in the whole-loan market. These nonperforming loans and TDRs on accrual status are either two or more months delinquent, in an open modification period, or in a closed modification state (both performing and nonperforming in accordance with the loan’s modified terms). Key factors that influence the price of these loans include collateral value, estimated loan c

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2016
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. 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 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. We establish an accrual for matters when a loss is probable and we can reasonably estimate the amount of such loss. For legal actions or proceedings where there is only a reasonable possibility that a loss may be incurred, or where we are not currently able to estimate the reasonably possible loss or range of loss, we do not establish an accrual. 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 number of putative class action lawsuits were filed in the U.S. District Court for the District of Columbia against us, FHFA as our conservator, Treasury and Freddie Mac from July through September 2013 by shareholders of Fannie Mae and/or Freddie Mac challenging the August 2012 amendment to each company’s senior preferred stock purchase agreement with Treasury. These lawsuits were consolidated and, on December 3, 2013, plaintiffs (preferred and common shareholders of Fannie Mae and/or Freddie Mac) filed a consolidated class action complaint in the U.S. District Court for the District of Columbia against us, FHFA as our conservator, Treasury and Freddie Mac (“ In re Fannie Mae/Freddie Mac Senior Preferred Stock Purchase Agreement Class Action Litigations ”). The preferred shareholder plaintiffs allege that the net worth sweep dividend provisions of the senior preferred stock that were implemented pursuant to the August 2012 amendments to the senior preferred stock purchase agreements nullified certain of the shareholders’ rights, particularly the right to receive dividends. The common shareholder plaintiffs allege that the August 2012 amendments constituted a taking of their property by requiring that all future profits of Fannie Mae and Freddie Mac be paid to Treasury. Plaintiffs allege claims for breach of contract and breach of the implied covenant of good faith and fair dealing against us, FHFA and Freddie Mac, a takings claim against FHFA and Treasury, and a breach of fiduciary duty claim derivatively on our and Freddie Mac’s behalf against FHFA and Treasury. Plaintiffs 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. Plaintiffs seek unspecified damages, equitable and injunctive relief, and costs and expenses, including attorneys’ fees. A non-class action suit, Arrowood Indemnity Company v. Fannie Mae , was filed in the U.S. District Court for the District of Columbia on September 20, 2013 by preferred shareholders against us, FHFA as our conservator, the Director of FHFA (in his official capacity), Treasury, the Secretary of the Treasury (in his official capacity) and Freddie Mac. Plaintiffs bring claims for breach of contract and breach of the implied covenant of good faith and fair dealing against us, FHFA and Freddie Mac, and claims for violation of the Administrative Procedure Act against the FHFA and Treasury defendants, alleging that the net worth sweep dividend provisions nullified certain rights of the preferred shareholders, particularly the right to receive dividends. Plaintiffs seek damages, equitable and injunctive relief, and costs and expenses, including attorneys’ fees. On September 30, 2014, the court dismissed both lawsuits and plaintiffs in both suits filed timely notices of appeal. On October 27, 2014, the U.S. Court of Appeals for the D.C. Circuit consolidated these appeals with appeals in two other cases involving the same subject matter, but to which we are not a party. The D.C. Circuit heard oral argument on these appeals on April 15, 2016. On June 26, 2016, shareholder David J. Voacolo filed a lawsuit, Voacolo v. Fannie Mae , in the U.S. District Court for the District of Columbia against Fannie Mae, FHFA and Treasury alleging a violation of the Administrative Procedure Act. Plaintiff seeks damages and a holding that the August 2012 amendment to the senior preferred stock purchase agreement was arbitrary, capricious or not otherwise in accordance with the law. 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 Accoun23

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2016
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 accounting principles generally accepted 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 periods’ condensed consolidated financial statements. Results for the six months ended June 30, 2016 may not necessarily be indicative of the results for the year ending December 31, 2016 . The unaudited interim condensed consolidated financial statements as of and for the six months ended June 30, 2016 should be read in conjunction with our audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2015 (“ 2015 Form 10-K”), filed with the SEC on February 19, 2016 .
Use of Estimates, Policy [Policy Text Block]	Use of Estimates Preparing condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect our reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities as of the dates of our condensed consolidated financial statements, as well as our reported amounts of revenues and expenses during the reporting periods. Management has made significant estimates in a variety of areas including, but not limited to, valuation of certain financial instruments and other assets and liabilities and allowance for loan losses. Actual results could be different from these estimates. On January 1, 2015, we adopted regulatory guidance issued by FHFA which prescribes, among other things, guidance on when a loan should be charged off. This change in estimate resulted in the recognition on January 1, 2015 of (1) $1.8 billion in charge-offs of held for investment loans, (2) $ 724 million in charge-offs of preforeclosure property taxes and insurance receivable and (3) a reduction to our allowance for loan losses and our allowance for preforeclosure property taxes and insurance receivable in amounts equal to charge-offs recognized in connection with held for investment loans and preforeclosure property taxes and insurance receivable. For the majority of our delinquent single-family loans, we charge off the loan at the date of foreclosure or other liquidation event (such as a deed-in-lieu of foreclosure or a short sale). For a subset of delinquent single-family loans, we charge off the portion of the loans that is deemed uncollectible prior to foreclosure when the loans have been delinquent for a specified length of time and meet specified mark-to-market loan-to-value (“LTV”) ratios. We continue to enhance our data collection and analysis efforts to further refine our loss estimates as we obtain incremental information on the performance of our loans.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Guidance Effective January 1, 2016, we adopted guidance regarding consolidation of legal entities such as limited partnerships, limited liability corporations and securitization structures. The impact of the adoption was not material to our condensed consolidated financial statements. In February 2016, the Financial Accounting Standards Board (“FASB”) issued guidance on leases. The guidance clarified the definition of a lease and requires lessees to recognize on the balance sheet a right-of-use asset, representing its right to use the underlying asset for the lease term, and a corresponding lease liability for all leases with terms greater than 12 months. This guidance supersedes the existing lease guidance; however, we must continue to classify leases to determine how to recognize lease-related expense in our condensed consolidated statements of operations and comprehensive income. The new guidance is effective for us on January 1, 2019. We have evaluated this guidance and determined it will not have a material impact on our condensed consolidated financial statements. In June 2016, FASB issued guidance that changes the impairment model for most financial assets and certain other instruments. For loans, held-to-maturity debt securities and other financial assets recorded at amortized cost, entities will be required to use a new forward-looking “expected loss” model that will replace today’s “incurred loss” model and generally will result in the earlier recognition of allowances for losses. The guidance is effective on January 1, 2020 with early adoption permitted on January 1, 2019. We will recognize the impact of the new guidance through a cumulative-effect adjustment to retained earnings as of the beginning of the year of adoption. We are currently evaluating the impact of this guidance on our financial statements and the timing of our adoption.

Consolidations and Transfers 24

Consolidations and Transfers of Financial Assets (Policies)	6 Months Ended
	Jun. 30, 2016
Consolidations and Transfers of Financial Assets [Abstract]
Consolidations, Policy [Policy Text Block]	We have interests in various entities that are considered to be VIEs. The primary types of entities are securitization trusts guaranteed by us via lender swap and portfolio securitization transactions and mortgage-backed trusts that were not created by us, as well as housing partnerships that are established to finance the acquisition, construction, development or rehabilitation of affordable multifamily and single-family housing. 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. Unconsolidated VIEs We do not consolidate VIEs when we are not deemed to be the primary beneficiary. Our unconsolidated VIEs include securitization trusts and limited partnerships.
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]	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.

Mortgage Loans (Policies)

Mortgage Loans (Policies)	6 Months Ended
	Jun. 30, 2016
Mortgage Loans on Real Estate [Abstract]
Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block]	We define the recorded investment of HFI loans as unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable. We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and an allowance for loan losses.
Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block]	We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in our condensed consolidated statements of operations and comprehensive income.
Nonaccrual Loans [Policy Text Block]	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 loans 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]	Troubled Debt Restructurings A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a TDR. In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for these informal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs.

Allowance for Loan Losses (Poli

Allowance for Loan Losses (Policies)	6 Months Ended
	Jun. 30, 2016
Loans and Leases Receivable, Allowance [Abstract]
Allowance for Loan Losses [Policy Text Block]	We maintain an allowance for loan losses for HFI loans held by Fannie Mae and loans backing Fannie Mae MBS issued from consolidated trusts. When calculating our allowance for loan losses, we consider our net recorded investment in the loan at the balance sheet date, which includes unpaid principal balance, net of amortized premiums and discounts, and other cost basis adjustments. We record charge-offs as a reduction to the allowance for loan losses when losses are confirmed through the receipt of assets in full satisfaction of a loan, such as the underlying collateral upon foreclosure or cash upon completion of a short sale. Additionally, we record charge-offs as a reduction to our allowance for loan losses when a loan is determined to be uncollectible or upon the redesignation of nonperforming loans from HFI to HFS. 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. 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 restructured in a TDR and acquired credit-impaired loans. When a loan has been restructured, we measure impairment using a cash flow analysis discounted at the loan’s original effective interest rate. However, 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 fair value of the collateral, reduced by estimated disposal costs and adjusted for estimated proceeds from mortgage, flood, or hazard insurance and other credit enhancements. 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. We establish a collective loss reserve for all loans in our multifamily guaranty book of business that are not individually impaired 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.

Investment in Securities (Polic

Investment in Securities (Policies)	6 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Trading 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” in our condensed consolidated statements of operations and comprehensive income.
Available-for-sale Securities, Policy [Policy Text Block]	Available-for-Sale Securities We record available-for-sale (“AFS”) securities at fair value with unrealized gains and losses, recorded net of tax, as a component of “Other comprehensive 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.

Acquired Property, Net (Policie

Acquired Property, Net (Policies)	6 Months Ended
	Jun. 30, 2016
Real Estate [Abstract]
Acquired Property Held-For-Sale Foreclosed Assets Policy [Policy Text Block]	Acquired property, net consists of held-for-sale foreclosed property received in satisfaction of a loan, net of a valuation allowance for declines in the fair value of the properties after initial acquisition. We classify properties as held for sale when we intend to sell the property, are actively marketing it and it is ready for immediate sale in its current condition.

Derivative Instruments (Policie

Derivative Instruments (Policies)	6 Months Ended
	Jun. 30, 2016
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 15, 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. 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.

Segment Reporting (Policies)

Segment Reporting (Policies)	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Segment Reporting, Policy [Policy Text Block]	Our three reportable segments are: Single-Family, Multifamily and Capital Markets. We use these three segments to generate revenue and manage business risk, and each segment is based on the type of business activities it performs. Under our segment reporting, the sum of the results for our three business segments does not equal our condensed consolidated statements of operations and comprehensive income as we separate the activity related to our consolidated trusts from the results generated by our three segments. Our business segment financial results include directly attributable revenues and expenses. We apply accounting methods for segment reporting purposes that differ from our condensed consolidated results. Additionally, we allocate to each of our segments: (1) capital using FHFA minimum capital requirements adjusted for over- or under-capitalization; (2) indirect administrative costs; and (3) a provision or benefit for federal income taxes. In addition, we allocate intracompany guaranty fee income as a charge from the Single-Family and Multifamily segments to Capital Markets for managing the credit risk on mortgage loans held by the Capital Markets group.

Netting Arrangements (Policies)

Netting Arrangements (Policies)	6 Months Ended
	Jun. 30, 2016
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. We determine our rights to offset the assets and liabilities presented above with the same counterparty, including collateral posted or received, based on the contractual arrangements entered into with our individual counterparties and various rules and regulations that would govern the insolvency of a derivative counterparty.

Fair Value (Policies)

Fair Value (Policies)	6 Months Ended
	Jun. 30, 2016
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 our credit risk sharing debt securities issued under our CAS series issued prior to January 1, 2016 and certain loans that contain embedded derivatives that would otherwise require bifurcation. Under the fair value option, we elected to carry these instruments at fair value instead of bifurcating the embedded derivative from such instruments. We elected the fair value option for all long-term structured debt instruments that are issued in response to specific investor demand and have interest rates that are based on a calculated index or formula and are economically hedged with derivatives at the time of issuance. By electing the fair value option for these instruments, we are able to eliminate the volatility in our results of operations that would otherwise result from the accounting asymmetry created by recording these structured debt instruments at cost while recording the related derivatives at fair value. We elected the fair value option for the financial assets and liabilities of the consolidated senior-subordinate trust structures. By electing the fair value option for these instruments, we are able to eliminate the volatility in our results of operations that would otherwise result from different accounting treatment between loans at cost and debt at cost. Interest income for the mortgage loans is recorded in “Interest income—Mortgage loans” and interest expense for the debt instruments is recorded in “Interest expense—Long-term debt” in our condensed consolidated statements of operations and comprehensive income.

Commitments and Contingencies (

Commitments and Contingencies (Policies)	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies, Policy [Policy Text Block]	We establish an accrual for matters when a loss is probable and we can reasonably estimate the amount of such loss. For legal actions or proceedings where there is only a reasonable possibility that a loss may be incurred, or where we are not currently able to estimate the reasonably possible loss or range of loss, we do not establish an accrual. 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.

Consolidations and Transfers 34

Consolidations and Transfers of Financial Assets (Tables)	6 Months Ended
	Jun. 30, 2016
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 mortgage-backed trusts. As of June 30, 2016 December 31, 2015 (Dollars in millions) Assets and liabilities recorded in our condensed consolidated balance sheets related to mortgage-backed trusts: Assets: Trading securities: Fannie Mae $ 5,203 $ 4,704 Non-Fannie Mae 4,153 5,596 Total trading securities 9,356 10,300 Available-for-sale securities: Fannie Mae 3,160 3,936 Non-Fannie Mae 8,678 14,644 Total available-for-sale securities 11,838 18,580 Other assets 53 100 Other liabilities (430 ) (827 ) Net carrying amount $ 20,817 $ 28,153

Mortgage Loans (Tables)

Mortgage Loans (Tables)	6 Months Ended
	Jun. 30, 2016
Mortgage Loans on Real Estate [Line Items]
Loans in Mortgage Portfolio [Table Text Block]	The following table displays the carrying value of our mortgage loans. As of June 30, 2016 December 31, 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family $ 228,866 $ 2,574,334 $ 2,803,200 $ 238,237 $ 2,574,174 $ 2,812,411 Multifamily 11,641 199,037 210,678 13,099 185,243 198,342 Total unpaid principal balance of mortgage loans 240,507 2,773,371 3,013,878 251,336 2,759,417 3,010,753 Cost basis and fair value adjustments, net (12,202 ) 51,992 39,790 (12,939 ) 49,781 36,842 Allowance for loan losses for loans held for investment (22,793 ) (1,006 ) (23,799 ) (26,510 ) (1,441 ) (27,951 ) Total mortgage loans $ 205,512 $ 2,824,357 $ 3,029,869 $ 211,887 $ 2,807,757 $ 3,019,644
Aging Analysis [Table Text Block]	The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of June 30, 2016 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 $ 28,547 $ 7,002 $ 22,221 $ 57,770 $ 2,611,816 $ 2,669,586 $ 41 $ 32,854 Government (2) 56 22 268 346 38,831 39,177 268 — Alt-A 3,725 1,111 4,925 9,761 79,383 89,144 6 6,684 Other 1,453 425 1,757 3,635 29,460 33,095 6 2,411 Total single-family 33,781 8,560 29,171 71,512 2,759,490 2,831,002 321 41,949 Multifamily (3) 80 N/A 101 181 212,578 212,759 — 475 Total $ 33,861 $ 8,560 $ 29,272 $ 71,693 $ 2,972,068 $ 3,043,761 $ 321 $ 42,424 As of December 31, 2015 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 $ 29,154 $ 7,937 $ 26,346 $ 63,437 $ 2,598,756 $ 2,662,193 $ 46 $ 34,216 Government (2) 58 24 291 373 40,461 40,834 291 — Alt-A 4,085 1,272 6,141 11,498 84,603 96,101 6 7,407 Other 1,494 484 2,160 4,138 32,272 36,410 6 2,632 Total single-family 34,791 9,717 34,938 79,446 2,756,092 2,835,538 349 44,255 Multifamily (3) 23 N/A 123 146 200,028 200,174 — 591 Total $ 34,814 $ 9,717 $ 35,061 $ 79,592 $ 2,956,120 $ 3,035,712 $ 349 $ 44,846 __________ (1) Single-family seriously delinquent loans are loans that are 90 days or more past due or in the foreclosure process. Multifamily seriously delinquent loans are loans that are 60 days or more past due. (2) Primarily consists of reverse mortgages, which due to their nature, are not aged and are included in the current column. (3) Multifamily loans 60 - 89 days delinquent are included in the seriously delinquent column.
Individually Impaired Loans [Table Text Block]	The following tables display the total unpaid principal balance, recorded investment, related allowance, average recorded investment and interest income recognized for individually impaired loans. As of June 30, 2016 December 31, 2015 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 $ 110,529 $ 104,999 $ 14,536 $ 116,477 $ 110,502 $ 16,745 Government 310 314 58 322 327 59 Alt-A 30,100 27,477 5,401 31,888 29,103 6,217 Other 12,092 11,441 2,080 12,893 12,179 2,416 Total single-family 153,031 144,231 22,075 161,580 152,111 25,437 Multifamily 532 535 59 650 654 80 Total individually impaired loans with related allowance recorded 153,563 144,766 22,134 162,230 152,765 25,517 With no related allowance recorded: (1) Single-family: Primary 16,603 15,414 — 15,891 14,725 — Government 65 60 — 58 54 — Alt-A 3,827 3,285 — 3,721 3,169 — Other 1,226 1,100 — 1,222 1,102 — Total single-family 21,721 19,859 — 20,892 19,050 — Multifamily 305 306 — 353 354 — Total individually impaired loans with no related allowance recorded 22,026 20,165 — 21,245 19,404 — Total individually impaired loans (2) $ 175,589 $ 164,931 $ 22,134 $ 183,475 $ 172,169 $ 25,517 For the Three Months Ended June 30, 2016 2015 Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 106,674 $ 1,015 $ 71 $ 115,856 $ 1,028 $ 73 Government 317 3 — 288 3 — Alt-A 27,901 256 11 30,642 251 10 Other 11,639 93 3 12,994 93 2 Total single-family 146,531 1,367 85 159,780 1,375 85 Multifamily 556 13 — 1,090 3 — Total individually impaired loans with related allowance recorded 147,087 1,380 85 160,870 1,378 85 With no related allowance recorded: (1) Single-family: Primary 15,377 327 30 16,453 253 19 Government 59 1 — 54 1 — Alt-A 3,361 81 5 4,010 50 — Other 1,126 30 2 1,378 17 — Total single-family 19,923 439 37 21,895 321 19 Multifamily 326 3 — 460 2 — Total individually impaired loans with no related allowance recorded 20,249 442 37 22,355 323 19 Total individually impaired loans $ 167,336 $ 1,822 $ 122 $ 183,225 $ 1,701 $ 104 For the Six Months Ended June 30, 2016 2015 Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis Average Recorded Investment Total Interest Income Recognized (3) Interest Income Recognized on a Cash Basis (Dollars in millions) Individually impaired loans: With related allowance recorded: Single-family: Primary $ 107,984 $ 2,036 $ 175 $ 116,811 $ 2,062 $ 177 Government 320 6 — 285 6 — Alt-A 28,287 509 30 31,094 502 27 Other 11,827 185 11 13,216 187 9 Total single-family 148,418 2,736 216 161,406 2,757 213 Multifamily 589 18 — 1,140 6 — Total individually impaired loans with related allowance recorded 149,007 2,754 216 162,546 2,763 213 With no related allowance recorded: (1) Single-family: Primary 15,323 595 50 16,178 500 60 Government 58 2 — 56 2 — Alt-A 3,362 143 8 3,775 94 7 Other 1,131 52 3 1,311 35 2 Total single-family 19,874 792 61 21,320 631 69 Multifamily 335 6 — 496 3 — Total individually impaired loans with no related allowance recorded 20,209 798 61 21,816 634 69 Total individually impaired loans $ 169,216 $ 3,552 $ 277 $ 184,362 $ 3,397 $ 282 __________ (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 $163.4 billion and $170.3 billion as of June 30, 2016 and December 31, 2015 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $415 million and $451 million as of June 30, 2016 and December 31, 2015 , respectively. (3) Total single-family interest income recognized of $1.8 billion for the three months ended June 30, 2016 consists of $1.5 billion of contractual interest and $331 million of effective yield adjustments. Total single-family interest income recognized of $1.7 billion for the three months ended June 30, 2015 consists of $1.4 billion of contractual interest and $304 million of effective yield adjustments. Total single-family interest income recognized of $3.5 billion for the six months ended June 30, 2016 consists of $2.9 billion of contractual interest and $641 million of effective yield adjustments. Total single-family interest income recognized of $3.4 billion for the six months ended June 30, 2015 consists of $2.8 billion of contractual interest and $580 million of effective yield adjustments.
Troubled Debt Restructurings Activity [Table Text Block]	The following tables display the number of loans and recorded investment in loans restructured in a TDR. For the Three Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 14,814 $ 2,028 17,951 $ 2,477 Government 28 3 64 8 Alt-A 1,623 238 2,533 395 Other 362 61 539 100 Total single-family 16,827 2,330 21,087 2,980 Multifamily 4 45 1 1 Total TDRs 16,831 $ 2,375 21,088 $ 2,981 For the Six Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 32,004 $ 4,360 39,358 $ 5,422 Government 82 9 138 16 Alt-A 3,534 508 5,322 833 Other 761 133 1,129 208 Total single-family 36,381 5,010 45,947 6,479 Multifamily 4 45 4 6 Total TDRs 36,385 $ 5,055 45,951 $ 6,485 The following tables display the number of loans and our recorded investment in these loans at the time of payment default for loans that were restructured in a TDR in the twelve months prior to the payment default. For purposes of this disclosure, we define loans that had a payment default as: single-family and multifamily loans with completed TDRs that liquidated during the period, either through foreclosure, deed-in-lieu of foreclosure or a short sale; single-family loans with completed modifications that are two or more months delinquent during the period; or multifamily loans with completed modifications that are one or more months delinquent during the period. For the Three Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 4,648 $ 638 6,156 $ 864 Government 27 3 37 6 Alt-A 756 116 963 151 Other 289 40 290 55 Total single-family 5,720 797 7,446 1,076 Multifamily — — 1 2 Total TDRs that subsequently defaulted 5,720 $ 797 7,447 $ 1,078 For the Six Months Ended June 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 10,109 $ 1,440 12,879 $ 1,867 Government 42 5 57 9 Alt-A 1,608 260 2,116 354 Other 532 89 594 121 Total single-family 12,291 1,794 15,646 2,351 Multifamily — — 3 6 Total TDRs that subsequently defaulted 12,291 $ 1,794 15,649 $ 2,357
Single-family [Member]
Mortgage Loans on Real Estate [Line Items]
Credit Quality Indicators [Table Text Block]	The following table displays the total recorded investment in our single-family HFI loans by class and credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, 2016 (1) December 31, 2015 (1) Primary Alt-A Other Primary Alt-A Other (Dollars in millions) Estimated mark-to-market LTV ratio: (2) Less than or equal to 80% $ 2,279,064 $ 58,301 $ 20,834 $ 2,228,533 $ 59,000 $ 21,274 Greater than 80% and less than or equal to 90% 238,897 11,003 4,225 250,373 12,588 4,936 Greater than 90% and less than or equal to 100% 104,938 7,907 3,162 122,939 9,345 3,861 Greater than 100% and less than or equal to 110% 21,829 5,066 2,076 27,875 6,231 2,596 Greater than 110% and less than or equal to 120% 11,218 2,951 1,216 14,625 3,730 1,592 Greater than 120% and less than or equal to 125% 3,459 946 391 4,520 1,260 545 Greater than 125% 10,181 2,970 1,191 13,328 3,947 1,606 Total $ 2,669,586 $ 89,144 $ 33,095 $ 2,662,193 $ 96,101 $ 36,410 __________ (1) Excludes $39.2 billion and $40.8 billion as of June 30, 2016 and December 31, 2015 , 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 segment 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 as of the end of each reported period divided by the estimated current value of the property, which we calculate using an internal valuation model that estimates periodic changes in home value.
Multifamily [Member]
Mortgage Loans on Real Estate [Line Items]
Credit Quality Indicators [Table Text Block]	The following table displays the total recorded investment in our multifamily HFI loans by credit quality indicator, excluding loans for which we have elected the fair value option. As of June 30, December 31, 2016 2015 (Dollars in millions) Credit risk profile by internally assigned grade: (1) Pass $ 207,481 $ 194,132 Special mention 2,476 3,202 Substandard 2,792 2,833 Doubtful 10 7 Total $ 212,759 $ 200,174 _________ (1) Pass (loan is current and adequately protected by the current financial strength and debt service capacity of the borrower); special mention (loan with signs of potential weakness); substandard (loan with a well defined weakness that jeopardizes the timely full repayment); and doubtful (loan with a weakness that makes collection or liquidation in full highly questionable and improbable based on existing conditions and values).

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2016
Loans and Leases Receivable, Allowance [Abstract]
Allowance for Loan Losses Rollforward by Segment [Table Text Block]	The following tables display changes in single-family, multifamily and total allowance for loan losses. For the Three Months Ended June 30, 2016 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ 24,490 $ 1,107 $ 25,597 $ 29,759 $ 1,755 $ 31,514 Provision (benefit) for loan losses (1) (1,292 ) (40 ) (1,332 ) 1,268 (227 ) 1,041 Charge-offs (2)(3) (789 ) (29 ) (818 ) (2,032 ) (23 ) (2,055 ) Recoveries 114 1 115 257 4 261 Transfers (4) 191 (191 ) — 256 (256 ) — Other (5) 22 — 22 116 (1 ) 115 Ending balance $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Multifamily allowance for loan losses: Beginning balance $ 67 $ 155 $ 222 $ 114 $ 192 $ 306 Provision (benefit) for loan losses (1) (8 ) 4 (4 ) 6 (18 ) (12 ) Charge-offs (2)(3) (3 ) — (3 ) (19 ) — (19 ) Transfers (4) 1 (1 ) — — — — Other (5) — — — (1 ) — (1 ) Ending balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Total allowance for loan losses: Beginning balance $ 24,557 $ 1,262 $ 25,819 $ 29,873 $ 1,947 $ 31,820 Provision (benefit) for loan losses (1) (1,300 ) (36 ) (1,336 ) 1,274 (245 ) 1,029 Charge-offs (2)(3) (792 ) (29 ) (821 ) (2,051 ) (23 ) (2,074 ) Recoveries 114 1 115 257 4 261 Transfers (4) 192 (192 ) — 256 (256 ) — Other (5) 22 — 22 115 (1 ) 114 Ending balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 For the Six Months Ended June 30, 2016 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family allowance for loan losses: Beginning balance $ 26,439 $ 1,270 $ 27,709 $ 32,956 $ 2,221 $ 35,177 Provision (benefit) for loan losses (1) (2,418 ) 70 (2,348 ) 1,473 (374 ) 1,099 Charge-offs (2)(3) (2,042 ) (55 ) (2,097 ) (7,360 ) (42 ) (7,402 ) Recoveries 231 3 234 871 12 883 Transfers (4) 440 (440 ) — 615 (615 ) — Other (5) 86 — 86 1,069 50 1,119 Ending balance $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Multifamily allowance for loan losses: Beginning balance $ 71 $ 171 $ 242 $ 161 $ 203 $ 364 Benefit for loan losses (1) (11 ) (9 ) (20 ) (31 ) (31 ) (62 ) Charge-offs (2)(3) (8 ) — (8 ) (34 ) — (34 ) Recoveries 1 — 1 — — — Transfers (4) 4 (4 ) — — — — Other (5) — — — 4 2 6 Ending balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Total allowance for loan losses: Beginning balance $ 26,510 $ 1,441 $ 27,951 $ 33,117 $ 2,424 $ 35,541 Provision (benefit) for loan losses (1) (2,429 ) 61 (2,368 ) 1,442 (405 ) 1,037 Charge-offs (2)(3) (2,050 ) (55 ) (2,105 ) (7,394 ) (42 ) (7,436 ) Recoveries 232 3 235 871 12 883 Transfers (4) 444 (444 ) — 615 (615 ) — Other (5) 86 — 86 1,073 52 1,125 Ending balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 __________ (1) Provision (benefit) for loan losses is included in “Benefit (provision) for credit losses” in our condensed consolidated statements of operations and comprehensive income. (2) While we purchase the substantial majority of loans that are four or more months delinquent from our MBS trusts, we do not exercise this option to purchase loans during a forbearance period. Charge-offs of consolidated trusts generally represent loans that remained in our consolidated trusts at the time of default. (3) Our charge-offs for 2015 reflect initial charge-offs associated with our approach to adopting the charge-off provisions of Advisory Bulletin AB 2012-02, “Framework for Adversely Classifying Loans, Other Real Estate Owned, and Other Assets and Listing Assets for Special Mention,” as well as charge-offs relating to a change in accounting policy for nonaccrual loans. (4) Includes transfers from trusts for delinquent loan purchases. (5) Amounts represent changes in other loss reserves which are reflected in provision (benefit) for loan losses, charge-offs, and recoveries.
Allowance for Loan Losses and Total Recorded Investment in HFI Loans [Table Text Block]	The following table displays the allowance for loan losses and recorded investment in our HFI loans, excluding loans for which we have elected the fair value option, by impairment or reserve methodology and portfolio segment. As of June 30, 2016 December 31, 2015 Single-Family Multifamily Total Single-Family Multifamily Total (Dollars in millions) Allowance for loan losses by segment: Individually impaired loans (1) $ 22,075 $ 59 $ 22,134 $ 25,437 $ 80 $ 25,517 Collectively reserved loans 1,509 156 1,665 2,272 162 2,434 Total allowance for loan losses $ 23,584 $ 215 $ 23,799 $ 27,709 $ 242 $ 27,951 Recorded investment in loans by segment: Individually impaired loans (1) $ 164,090 $ 841 $ 164,931 $ 171,161 $ 1,008 $ 172,169 Collectively reserved loans 2,666,912 211,918 2,878,830 2,664,377 199,166 2,863,543 Total recorded investment in loans $ 2,831,002 $ 212,759 $ 3,043,761 $ 2,835,538 $ 200,174 $ 3,035,712 __________ (1) Includes acquired credit-impaired loans.

Investments in Securities (Tabl

Investments in Securities (Tables)	6 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investments In Trading Securities [Table Text Block]	The following table displays our investments in trading securities. As of June 30, 2016 December 31, 2015 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 5,352 $ 4,813 Freddie Mac 1,328 1,314 Ginnie Mae 542 426 Alt-A private-label securities 316 436 Subprime private-label securities 395 644 Commercial mortgage-backed securities (“CMBS”) 1,389 2,341 Mortgage revenue bonds 193 449 Total mortgage-related securities 9,515 10,423 U.S. Treasury securities 29,652 29,485 Total trading securities $ 39,167 $ 39,908
Schedule of Realized Gain (Loss) [Table Text Block]	The following table displays the gross realized gains, losses and proceeds on sales of AFS securities. For the Three For the Six Months Ended Months Ended June 30 , June 30 , 2016 2015 2016 2015 (Dollars in millions) Gross realized gains $ 234 $ 413 $ 445 $ 813 Gross realized losses 8 50 12 57 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 3,645 3,096 7,267 5,208
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 in our retained mortgage portfolio. As of June 30, 2016 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 3,163 $ 194 $ (21 ) $ 3,336 Freddie Mac 1,899 139 — 2,038 Ginnie Mae 58 8 — 66 Alt-A private-label securities 1,269 564 (6 ) 1,827 Subprime private-label securities 1,722 656 (5 ) 2,373 CMBS 1,010 14 (1 ) 1,023 Mortgage revenue bonds 1,919 113 (3 ) 2,029 Other mortgage-related securities 471 17 — 488 Total $ 11,511 $ 1,705 $ (36 ) $ 13,180 As of December 31, 2015 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 4,008 $ 243 $ (30 ) $ 4,221 Freddie Mac 4,000 299 — 4,299 Ginnie Mae 343 48 — 391 Alt-A private-label securities 2,029 653 (4 ) 2,678 Subprime private-label securities 2,526 759 (4 ) 3,281 CMBS 1,235 20 — 1,255 Mortgage revenue bonds 2,639 99 (37 ) 2,701 Other mortgage-related securities 1,361 49 (6 ) 1,404 Total $ 18,141 $ 2,170 $ (81 ) $ 20,230 __________ (1) Amortized cost consists of unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments as well as net other-than-temporary impairments (“OTTI”) recognized in “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. (2) Represents the gross unrealized losses on securities for which we have not recognized OTTI, as well as the noncredit component of OTTI and cumulative changes in fair value of securities for which we previously recognized the credit component of OTTI in “Accumulated other comprehensive income” in our condensed consolidated balance sheets.
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	The following tables display additional information regarding gross unrealized losses and fair value by major security type for AFS securities in an unrealized loss position. As of June 30, 2016 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 $ (1 ) $ 86 $ (20 ) $ 514 Alt-A private-label securities (2 ) 106 (4 ) 49 Subprime private-label securities — — (5 ) 82 CMBS (1 ) 70 — — Mortgage revenue bonds (2 ) 16 (1 ) 7 Total $ (6 ) $ 278 $ (30 ) $ 652 As of December 31, 2015 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 ) $ 659 $ (22 ) $ 491 Alt-A private-label securities (1 ) 26 (3 ) 54 Subprime private-label securities — 12 (4 ) 91 Mortgage revenue bonds (35 ) 631 (2 ) 22 Other mortgage-related securities (6 ) 224 — — Total $ (50 ) $ 1,552 $ (31 ) $ 658
Schedule of Modeled Attributes Used to Determine Potential Cash Shortfalls [Table Text Block]	The following table displays the modeled attributes, including default rates and severities, which were used to determine as of June 30, 2016 whether our senior interests in certain non-agency mortgage-related securities (including those we intend to sell) will experience a cash shortfall. An estimate of voluntary prepayment rates is also an input to the present value of expected losses. As of June 30, 2016 Alt-A Subprime Option ARM Fixed Rate Variable Rate Hybrid Rate (Dollars in millions) Unpaid principal balance $ 3,299 $ 373 $ 514 $ 625 $ 674 Weighted average collateral default (1) 39.2 % 25.7 % 13.2 % 18.5 % 7.4 % Weighted average collateral severities (2) 54.4 36.6 45.3 30.1 30.5 Weighted average voluntary prepayment rates (3) 2.6 8.8 10.9 8.7 13.5 Average credit enhancement (4) 16.7 3.9 6.8 4.7 1.8 __________ (1) The expected remaining cumulative default rate of the collateral pool backing the securities, as a percentage of the current collateral unpaid principal balance, weighted by security unpaid principal balance. (2) The expected remaining loss given default of the collateral pool backing the securities, calculated as the ratio of remaining cumulative loss divided by cumulative defaults, weighted by security unpaid principal balance. (3) The average monthly voluntary prepayment rate, weighted by security unpaid principal balance. (4) The average percent current credit enhancement provided by subordination of other securities. Excludes excess interest projections and monoline bond insurance.
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block]	The following table displays activity related to the unrealized credit loss component on debt securities held by us and recognized in our condensed consolidated statements of operations and comprehensive income. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance $ 2,293 $ 2,744 $ 2,421 $ 5,260 Additions for the credit component on debt securities for which OTTI was previously recognized 2 — 6 4 Reductions for securities no longer in portfolio at period end (10 ) (72 ) (103 ) (1,165 ) Reductions for securities which we intend to sell or it is more likely than not that we will be required to sell before recovery of amortized cost basis (31 ) (70 ) (31 ) (1,439 ) Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities (35 ) (45 ) (74 ) (103 ) Ending balance $ 2,219 $ 2,557 $ 2,219 $ 2,557
Investments Classified by Contractual Maturity Date [Table Text Block]	The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time. As of June 30, 2016 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 $ 3,163 $ 3,336 $ — $ — $ 77 $ 78 $ 84 $ 90 $ 3,002 $ 3,168 Freddie Mac 1,899 2,038 1 1 101 104 203 221 1,594 1,712 Ginnie Mae 58 66 — — 1 1 4 4 53 61 Alt-A private-label securities 1,269 1,827 — — — — — — 1,269 1,827 Subprime private-label securities 1,722 2,373 — — — — — — 1,722 2,373 CMBS 1,010 1,023 521 528 444 451 — — 45 44 Mortgage revenue bonds 1,919 2,029 11 11 95 96 171 174 1,642 1,748 Other mortgage-related securities 471 488 — — — 1 3 3 468 484 Total $ 11,511 $ 13,180 $ 533 $ 540 $ 718 $ 731 $ 465 $ 492 $ 9,795 $ 11,417

Financial Guarantees (Tables)

Financial Guarantees (Tables)	6 Months Ended
	Jun. 30, 2016
Guarantees [Abstract]
Financial Guarantees and Maximum Recovery [Table Text Block]	The following table displays our maximum exposure, guaranty obligation recognized in our condensed consolidated balance sheets and the maximum potential recovery from third parties through available credit enhancements and recourse related to our financial guarantees. As of June 30, 2016 December 31, 2015 Maximum Exposure (1) Guaranty Obligation Maximum Recovery (2) Maximum Exposure (1) Guaranty Obligation Maximum Recovery (2) (Dollars in millions) Unconsolidated Fannie Mae MBS $ 13,947 $ 151 $ 8,448 $ 15,069 $ 194 $ 8,857 Other guaranty arrangements (3) 15,744 125 2,708 16,504 135 2,869 Total $ 29,691 $ 276 $ 11,156 $ 31,573 $ 329 $ 11,726 __________ (1) Primarily consists of the unpaid principal balance of the underlying mortgage loans. (2) Recoverability of such credit enhancements and recourse is subject to, among other factors, our mortgage insurers’ and financial guarantors’ ability to meet their obligations to us. For information on our mortgage insurers, see “ Note 13, Concentrations of Credit Risk .” (3) Primarily consists of credit enhancements and long-term standby commitments.

Acquired Property, Net (Tables)

Acquired Property, Net (Tables)	6 Months Ended
	Jun. 30, 2016
Real Estate [Abstract]
Activity in acquired property and the related valuation allowance [Table Text Block]	The following table displays the activity in acquired property, and the related valuation allowance. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance — Acquired property $ 6,737 $ 10,348 $ 7,481 $ 11,442 Additions 1,648 2,431 3,485 5,366 Disposals (2,457 ) (3,580 ) (5,038 ) (7,609 ) Ending balance — Acquired property 5,928 9,199 5,928 9,199 Valuation allowance (428 ) (693 ) (428 ) (693 ) Ending balance — Acquired property, net $ 5,500 $ 8,506 $ 5,500 $ 8,506

Short-Term Borrowings and Lon40

Short-Term Borrowings and Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Short-Term Borrowings [Table Text Block]	The following table displays our outstanding short-term borrowings (borrowings with an original contractual maturity of one year or less) and weighted-average interest rates of these borrowings. As of June 30, 2016 December 31, 2015 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) $ 115 — % $ 62 — % Short-term debt of Fannie Mae $ 60,495 0.43 % $ 71,007 0.26 % Debt of consolidated trusts 742 0.41 943 0.19 Total short-term debt $ 61,237 0.43 % $ 71,950 0.26 % __________ (1) Includes the effects of discounts, premiums and other cost basis adjustments. (2) Represents agreements to repurchase securities for a specified price, with repayment generally occurring on the following day.
Long-Term Debt [Table Text Block]	The following table displays our outstanding long-term debt. As of June 30, 2016 December 31, 2015 Maturities Outstanding Weighted- Average Interest Rate (1) Maturities Outstanding Weighted- Average Interest Rate (1) (Dollars in millions) Senior fixed: Benchmark notes and bonds 2016 - 2030 $ 157,023 2.36 % 2016 - 2030 $ 154,057 2.49 % Medium-term notes (2) 2016 - 2026 79,663 1.48 2016 - 2025 96,997 1.53 Other (3) 2016 - 2038 20,451 5.39 2016 - 2038 27,772 4.88 Total senior fixed 257,137 2.33 278,826 2.39 Senior floating: Medium-term notes (2) 2016 - 2019 26,465 0.51 2016 - 2019 20,791 0.27 Connecticut Avenue Securities (4) 2023 - 2028 13,350 4.43 2023 - 2028 10,764 3.84 Other (5) 2020 - 2037 410 8.66 2020 - 2037 368 10.46 Total senior floating 40,225 1.87 31,923 1.58 Subordinated debentures 2019 4,431 9.93 2019 4,227 9.93 Secured borrowings (6) 2021 - 2022 130 1.44 2021 - 2022 152 1.47 Total long-term debt of Fannie Mae (7) 301,923 2.38 315,128 2.41 Debt of consolidated trusts 2016 - 2054 2,848,744 2.73 2016 - 2054 2,810,593 2.94 Total long-term debt $ 3,150,667 2.70 % $ 3,125,721 2.88 % __________ (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 and foreign exchange bonds. (4) Credit risk-sharing securities that transfer a portion of the credit risk on specified pools of mortgage loans to the investors in these securities, a portion of which is reported at fair value. (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 $2.7 billion and $3.2 billion as of June 30, 2016 and December 31, 2015 , respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional and Fair Value Position [Table Text Block]	The following table displays the notional amount and estimated fair value of our asset and liability derivative instruments. As of June 30, 2016 As of December 31, 2015 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 $ 325 $ 1 $ 156,864 $ (13,141 ) $ 33,154 $ 267 $ 123,106 $ (6,920 ) Receive-fixed 170,271 6,516 11,113 (5 ) 59,796 3,436 143,209 (753 ) Basis 1,864 189 17,100 (15 ) 1,864 141 17,100 (15 ) Foreign currency 222 80 233 (81 ) 295 95 258 (52 ) Swaptions: Pay-fixed 6,880 36 2,350 (4 ) 7,050 45 14,950 (26 ) Receive-fixed — — 3,430 (154 ) 2,000 8 13,950 (171 ) Other (1) 9,749 27 136 (1 ) 9,196 28 — (2 ) Total gross risk management derivatives 189,311 6,849 191,226 (13,401 ) 113,355 4,020 312,573 (7,939 ) Accrued interest receivable (payable) — 819 — (1,045 ) — 758 — (977 ) Netting adjustment (2) — (7,530 ) — 14,269 — (4,024 ) — 8,650 Total net risk management derivatives $ 189,311 $ 138 $ 191,226 $ (177 ) $ 113,355 $ 754 $ 312,573 $ (266 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 13,157 $ 99 $ 29 $ — $ 4,815 $ 9 $ 2,960 $ (9 ) Forward contracts to purchase mortgage-related securities 75,635 533 4,024 (9 ) 31,273 66 19,418 (57 ) Forward contracts to sell mortgage-related securities 1,935 5 117,407 (949 ) 26,224 65 40,753 (92 ) Total mortgage commitment derivatives $ 90,727 $ 637 $ 121,460 $ (958 ) $ 62,312 $ 140 $ 63,131 $ (158 ) Derivatives at fair value $ 280,038 $ 775 $ 312,686 $ (1,135 ) $ 175,667 $ 894 $ 375,704 $ (424 ) __________ (1) Includes credit risk transfer transactions, futures, swap credit enhancements and mortgage insurance contracts that we account for as derivatives. (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 $7.1 billion and $4.9 billion as of June 30, 2016 and December 31, 2015 , respectively. Cash collateral received was $345 million and $314 million as of June 30, 2016 and December 31, 2015 , 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 For the Six Months Ended June 30, Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ (2,257 ) $ 4,351 $ (7,430 ) $ 1,282 Receive-fixed 1,371 (1,906 ) 4,358 (59 ) Basis 14 (44 ) 49 (12 ) Foreign currency (34 ) 16 (31 ) (13 ) Swaptions: Pay-fixed 4 14 29 105 Receive-fixed (19 ) 80 (136 ) (79 ) Other 22 (4 ) 160 (2 ) Net accrual of periodic settlements (291 ) (199 ) (560 ) (428 ) Total risk management derivatives fair value gains (losses), net $ (1,190 ) $ 2,308 $ (3,561 ) $ 794 Mortgage commitment derivatives fair value gains (losses), net (367 ) 173 (729 ) (66 ) Total derivatives fair value gains (losses), net $ (1,557 ) $ 2,481 $ (4,290 ) $ 728

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share, Basic and Diluted [Table Text Block]	The following table displays the computation of basic and diluted earnings per share of common stock. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars and shares in millions, except per share amounts) Net income attributable to Fannie Mae $ 2,946 $ 4,640 $ 4,082 $ 6,528 Dividends distributed or available for distribution to senior preferred stockholder (1) (2,869 ) (4,359 ) (3,788 ) (6,155 ) Net income attributable to common stockholders $ 77 $ 281 $ 294 $ 373 Weighted-average common shares outstanding—Basic (2) 5,762 5,762 5,762 5,762 Convertible preferred stock 131 131 131 131 Weighted-average common shares outstanding—Diluted (2) 5,893 5,893 5,893 5,893 Earnings per share: Basic $ 0.01 $ 0.05 $ 0.05 $ 0.06 Diluted 0.01 0.05 0.05 0.06 __________ (1) Dividends distributed or available for distribution were calculated based on our net worth as of the end of the fiscal quarters, less the applicable capital reserve amount. See “Note 1, Summary of Significant Accounting Policies” in our 2015 Form 10-K for additional information on our senior preferred stock agreement and our payment of dividends to Treasury. (2) Includes 4.6 billion of weighted average shares of common stock that would be issued upon the full exercise of the warrant issued to Treasury from the date the warrant was issued through June 30, 2016 and 2015.

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Segment results [Table Text Block]	For the Three Months Ended June 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 176 $ (15 ) $ 1,080 $ 4,045 (2) $ 5,286 Benefit for credit losses 1,596 5 — — 1,601 Net interest income (loss) after benefit for credit losses 1,772 (10 ) 1,080 4,045 6,887 Guaranty fee income (expense) (3) 3,260 400 (192 ) (3,438 ) (4) 30 (4) Investment gains (losses), net — 11 2,088 (1,701 ) (5) 398 Fair value gains (losses), net — — (1,730 ) 63 (6) (1,667 ) Gains (losses) from partnership investments (7) (18 ) 20 — — 2 Fee and other income (expense) 100 48 31 (35 ) 144 Administrative expenses (496 ) (86 ) (96 ) — (678 ) Foreclosed property expense (61 ) (2 ) — — (63 ) TCCA fees (3) (453 ) — — — (453 ) Other income (expenses), net (361 ) (2 ) (30 ) 137 (256 ) Income (loss) before federal income taxes 3,743 379 1,151 (929 ) 4,344 Provision for federal income taxes (1,093 ) (40 ) (265 ) — (1,398 ) Net income (loss) attributable to Fannie Mae $ 2,650 $ 339 $ 886 $ (929 ) $ 2,946 For the Six Months Ended June 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 319 $ (40 ) $ 2,172 $ 7,604 (2) $ 10,055 Benefit for credit losses 2,759 26 — — 2,785 Net interest income (loss) after benefit for credit losses 3,078 (14 ) 2,172 7,604 12,840 Guaranty fee income (expense) (3) 6,482 785 (387 ) (6,825 ) (4) 55 (4) Investment gains (losses), net (1 ) 14 3,503 (3,049 ) (5) 467 Fair value gains (losses), net — — (4,533 ) 53 (6) (4,480 ) Gains (losses) from partnership investments (7) (37 ) 40 — — 3 Fee and other income (expense) 201 107 52 (38 ) 322 Administrative expenses (1,004 ) (170 ) (192 ) — (1,366 ) Foreclosed property expense (396 ) (1 ) — — (397 ) TCCA fees (3) (893 ) — — — (893 ) Other income (expenses), net (664 ) (11 ) (59 ) 213 (521 ) Income (loss) before federal income taxes 6,766 750 556 (2,042 ) 6,030 Provision for federal income taxes (1,736 ) (78 ) (134 ) — (1,948 ) Net income (loss) attributable to Fannie Mae $ 5,030 $ 672 $ 422 $ (2,042 ) $ 4,082 For the Three Months Ended June 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 18 $ (26 ) $ 1,513 $ 4,172 (2) $ 5,677 (Provision) benefit for credit losses (1,056 ) 23 — — (1,033 ) Net interest income (loss) after (provision) benefit for credit losses (1,038 ) (3 ) 1,513 4,172 4,644 Guaranty fee income (expense) (3) 3,092 357 (221 ) (3,191 ) (4) 37 (4) Investment gains (losses), net (1 ) 15 1,562 (1,062 ) (5) 514 Fair value gains, net — — 2,555 51 (6) 2,606 Gains (losses) from partnership investments (7) (10 ) 43 — — 33 Fee and other income (expense) 301 84 150 (16 ) 519 Administrative expenses (458 ) (83 ) (148 ) — (689 ) Foreclosed property expense (182 ) — — — (182 ) TCCA fees (3) (397 ) — — — (397 ) Other income (expenses), net (262 ) (6 ) (11 ) 44 (235 ) Income (loss) before federal income taxes 1,045 407 5,400 (2 ) 6,850 Provision for federal income taxes (419 ) (41 ) (1,750 ) — (2,210 ) Net income (loss) attributable to Fannie Mae $ 626 $ 366 $ 3,650 $ (2 ) $ 4,640 For the Six Months Ended June 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 27 $ (57 ) $ 3,115 $ 7,659 (2) $ 10,744 (Provision) benefit for credit losses (578 ) 78 — — (500 ) Net interest income (loss) after (provision) benefit for credit losses (551 ) 21 3,115 7,659 10,244 Guaranty fee income (expense) (3) 6,132 697 (448 ) (6,313 ) (4) 68 (4) Investment gains (losses), net (1 ) 24 3,071 (2,238 ) (5) 856 Fair value gains (losses), net (4 ) — 585 106 (6) 687 Gains (losses) from partnership investments (7) (15 ) 255 — — 240 Fee and other income (expense) 473 135 205 (17 ) 796 Administrative expenses (942 ) (171 ) (299 ) — (1,412 ) Foreclosed property income (expense) (667 ) 12 — — (655 ) TCCA fees (3) (779 ) — — — (779 ) Other income (expenses), net (489 ) (13 ) (11 ) 76 (437 ) Income (loss) before federal income taxes 3,157 960 6,218 (727 ) 9,608 Provision for federal income taxes (1,000 ) (111 ) (1,969 ) — (3,080 ) Net income (loss) attributable to Fannie Mae $ 2,157 $ 849 $ 4,249 $ (727 ) $ 6,528 __________ (1) Represents activity related to the assets and liabilities of consolidated trusts in our condensed consolidated balance sheets, and the elimination of intercompany transactions occurring between the three business segments and our consolidated trusts, as well as other adjustments to reconcile to our condensed consolidated results. (2) Represents net interest income of consolidated trusts and amortization expense of cost basis adjustments on securities in the Capital Markets group’s mortgage portfolio that on a GAAP basis are eliminated. (3) Reflects the impact of a 10 basis point guaranty fee increase implemented in 2012 pursuant to the TCCA, the incremental revenue from which is remitted to Treasury. The resulting revenue is included in guaranty fee income and the expense is recognized as “TCCA fees.” (4) Represents the guaranty fees paid from consolidated trusts to the Single-Family and Multifamily segments and the elimination of the amortization of deferred cash fees related to consolidated trusts that were re-established for segment reporting. Total guaranty fee income related to unconsolidated Fannie Mae MBS trusts and other credit enhancement arrangements is included in fee and other income in our condensed consolidated statements of operations and comprehensive income. (5) Primarily represents the removal of realized gains and losses on sales of Fannie Mae MBS classified as available-for-sale securities that are issued by consolidated trusts and in the Capital Markets group’s mortgage portfolio. The adjustment also includes the removal of securitization gains (losses) recognized in the Capital Markets segment relating to portfolio securitization transactions that do not qualify for sale accounting under GAAP. (6) Represents the removal of fair value adjustments on consolidated Fannie Mae MBS classified as trading that are in the Capital Markets group’s mortgage portfolio. (7) Gains (losses) from partnership investments are included in “Other expenses, net” in our condensed consolidated statements of operations and comprehensive income.

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Schedule of Other Comprehensive Income (Loss) [Table Text Block]	The following table displays the activity in other comprehensive loss, net of tax, by major categories. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 (Dollars in millions) Net income $ 2,946 $ 4,640 $ 4,082 $ 6,528 Other comprehensive loss, net of tax effect: Changes in net unrealized gains (losses) on AFS securities (net of tax of $27 and $44, respectively, for the three months ended and net of tax of $21 and $31, respectively, for the six months ended) 50 (81 ) (39 ) (57 ) Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $4, respectively, for the three months ended and net of tax of $11 and $64, respectively, for the six months ended) 1 8 20 118 Reclassification adjustment for gains on AFS securities included in net income (net of tax of $68 and $112, respectively, for the three months ended and net of tax of $137 and $233, respectively, for the six months ended) (126 ) (207 ) (254 ) (432 ) Other (2 ) (1 ) (4 ) (2 ) Total other comprehensive loss (77 ) (281 ) (277 ) (373 ) Total comprehensive income $ 2,869 $ 4,359 $ 3,805 $ 6,155
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table displays our accumulated other comprehensive income by major categories. As of June 30, December 31, 2016 2015 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax $ 292 $ 455 Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax 793 903 Other, net of tax 45 49 Accumulated other comprehensive income $ 1,130 $ 1,407 The table below displays changes in accumulated other comprehensive income, net of tax. For the Three Months Ended June 30, For the Six Months Ended June 30, 2016 2015 2016 2015 AFS (1) Other Total AFS (1) Other (2) Total AFS (1) Other Total AFS (1) Other (2) Total (Dollars in millions) Beginning balance $ 1,160 $ 47 $ 1,207 $ 2,030 $ (389 ) $ 1,641 $ 1,358 $ 49 $ 1,407 $ 2,121 $ (388 ) $ 1,733 Other comprehensive income (loss) before reclassifications 50 — 50 (81 ) — (81 ) (39 ) — (39 ) (57 ) — (57 ) Amounts reclassified from other comprehensive loss (125 ) (2 ) (127 ) (199 ) (1 ) (200 ) (234 ) (4 ) (238 ) (314 ) (2 ) (316 ) Net other comprehensive loss (75 ) (2 ) (77 ) (280 ) (1 ) (281 ) (273 ) (4 ) (277 ) (371 ) (2 ) (373 ) Ending balance $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 __________ (1) The amounts reclassified from accumulated other comprehensive income represent the gain or loss recognized in earnings due to a sale of an AFS security or the recognition of a net impairment recognized in earnings, which are recorded in “Investments gains, net” in our condensed consolidated statements of operations and comprehensive income. (2) The amounts reclassified from accumulated other comprehensive income represent activity from our defined benefit pension plans, which is recorded in “Administrative expenses” in our condensed consolidated statements of operations and comprehensive income. The defined benefit pension plans were terminated and all remaining benefits were distributed during the third quarter of 2015.

Concentrations of Credit Risk (

Concentrations of Credit Risk (Tables)	6 Months Ended
	Jun. 30, 2016
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 and total multifamily guaranty book of business. As of June 30, 2016 (1) December 31, 2015 (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) 1.23 % 0.32 % 1.33 % 1.27 % 0.37 % 1.59 % Percentage of single-family conventional loans (4) 1.42 0.36 1.32 1.46 0.41 1.55
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of June 30, 2016 (1) December 31, 2015 (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 loan-to-value ratio: Greater than 100% 3 % 10.54 % 3 % 10.76 % Geographical distribution: California 20 0.52 20 0.58 Florida 6 2.27 6 2.86 New Jersey 4 3.88 4 4.87 New York 5 3.03 5 3.55 All other states 65 1.16 65 1.34 Product distribution: Alt-A 3 5.68 4 6.53 Vintages: 2004 and prior 5 2.82 5 3.06 2005-2008 9 6.73 10 7.60 2009-2016 86 0.34 85 0.36 __________ (1) Consists of the portion of our single-family conventional guaranty book of business for which we have detailed loan level information, which constituted approximately 99% our total single-family conventional guaranty book of business as of June 30, 2016 and December 31, 2015 . (2) Consists of single-family conventional loans that were 90 days or more past due or in the foreclosure process as of June 30, 2016 and December 31, 2015 . (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 [Member]
Concentration Risk [Line Items]
Schedule of Delinquency Status Guaranty Book of Business [Table Text Block]	As of June 30, 2016 (1)(2) December 31, 2015 (1)(2) 30 Days Delinquent Seriously Delinquent (3) 30 Days Delinquent Seriously Delinquent (3) Percentage of multifamily guaranty book of business 0.03 % 0.07 % 0.03 % 0.07 %
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of June 30, 2016 (1) December 31, 2015 (1) Percentage of Multifamily Guaranty Book of Business (2) Percentage Seriously Delinquent (3)(4) Percentage of Multifamily Guaranty Book of Business (2) Percentage Seriously Delinquent (3)(4) Original LTV ratio: Greater than 80% 2 % 0.03 % 3 % 0.40 % Less than or equal to 80% 98 0.08 97 0.06 Current DSCR less than 1.0 (5) 2 1.02 2 1.51 __________ (1) Consists of the portion of our multifamily guaranty book of business for which we have detailed loan level information, which constituted approximately 99% of our total multifamily guaranty book of business as of June 30, 2016 and December 31, 2015 , excluding loans that have been defeased. (2) 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. (3) Consists of multifamily loans that were 60 days or more past due as of the dates indicated. (4) 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 guaranty book of business. (5) 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.

Netting Arrangements (Tables)

Netting Arrangements (Tables)	6 Months Ended
	Jun. 30, 2016
Offsetting [Abstract]
Offsetting [Table Text Block]	The tables below display information related to derivatives, securities purchased under agreements to resell or similar arrangements, and securities sold under agreements to repurchase or similar arrangements, which are subject to an enforceable master netting arrangement or similar agreement that are either offset or not offset in our condensed consolidated balance sheets. As of June 30, 2016 Net Amount Presented in our Condensed Consolidated Balance Sheets Amounts Not Offset in our Condensed Consolidated Balance Sheets Gross Amount Gross Amount Offset (1) Financial Instruments (2) Collateral (3) Net Amount (Dollars in millions) Assets: OTC risk management derivatives $ 4,949 $ (4,925 ) $ 24 $ — $ — $ 24 Cleared risk management derivatives 2,692 (2,605 ) 87 — — 87 Mortgage commitment derivatives 637 — 637 (291 ) (8 ) 338 Total derivative assets 8,278 (7,530 ) 748 (4) (291 ) (8 ) 449 Securities purchased under agreements to resell or similar arrangements (5) 41,445 — 41,445 — (41,445 ) — Total assets $ 49,723 $ (7,530 ) $ 42,193 $ (291 ) $ (41,453 ) $ 449 Liabilities: OTC risk management derivatives $ (8,303 ) $ 8,156 $ (147 ) $ — $ — $ (147 ) Cleared risk management derivatives (6,142 ) 6,113 (29 ) — 29 — Mortgage commitment derivatives (958 ) — (958 ) 291 2 (665 ) Total derivative liabilities (15,403 ) 14,269 (1,134 ) (4) 291 31 (812 ) Securities sold under agreements to repurchase or similar arrangements (115 ) — (115 ) — 115 — Total liabilities $ (15,518 ) $ 14,269 $ (1,249 ) $ 291 $ 146 $ (812 ) As of December 31, 2015 Net Amount Presented in our Condensed Consolidated Balance Sheets Amounts Not Offset in our Condensed Consolidated Balance Sheets Gross Amount Gross Amount Offset (1) Financial Instruments (2) Collateral (3) Net Amount (Dollars in millions) Assets: OTC risk management derivatives $ 4,042 $ (4,021 ) $ 21 $ — $ (18 ) $ 3 Cleared risk management derivatives 708 (3 ) 705 — — 705 Mortgage commitment derivatives 140 — 140 (119 ) (3 ) 18 Total derivative assets 4,890 (4,024 ) 866 (4) (119 ) (21 ) 726 Securities purchased under agreements to resell or similar arrangements (5) 37,950 — 37,950 — (37,950 ) — Total assets $ 42,840 $ (4,024 ) $ 38,816 $ (119 ) $ (37,971 ) $ 726 Liabilities: OTC risk management derivatives $ (6,118 ) $ 5,861 $ (257 ) $ — $ — $ (257 ) Cleared risk management derivatives (2,796 ) 2,789 (7 ) — — (7 ) Mortgage commitment derivatives (158 ) — (158 ) 119 (1 ) (40 ) Total derivative liabilities (9,072 ) 8,650 (422 ) (4) 119 (1 ) (304 ) Securities sold under agreements to repurchase or similar arrangements (62 ) — (62 ) — 62 — Total liabilities $ (9,134 ) $ 8,650 $ (484 ) $ 119 $ 61 $ (304 ) __________ (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 non-cash collateral received that has not been recognized and not offset in our condensed consolidated balance sheets as well as non-cash collateral posted which has been recognized but not offset in our condensed consolidated balance sheets. Does not include collateral held or posted in excess of our exposure. The fair value of non-cash collateral we pledged was $1.2 billion and $197 million as of June 30, 2016 and December 31, 2015 , respectively, which the counterparty was permitted to sell or repledge. The fair value of non-cash collateral received was $41.5 billion and $38.0 billion , of which $38.9 billion and $36.2 billion could be sold or repledged as of June 30, 2016 and December 31, 2015, respectively. None of the underlying collateral was sold or repledged as of June 30, 2016 and December 31, 2015 . (4) Excludes derivative assets of $27 million and $28 million as of June 30, 2016 and December 31, 2015 , and derivative liabilities of $1 million and $2 million recognized in our condensed consolidated balance sheets as of June 30, 2016 and December 31, 2015 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $19.1 billion and $10.6 billion of securities purchased under agreements to resell classified as “Cash and cash equivalents” in our condensed consolidated balance sheets as of June 30, 2016 and December 31, 2015 , respectively.

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Recurring Changes in Fair Value [Table Text Block]	The following tables display our assets and liabilities measured in our condensed consolidated balance sheets at fair value on a recurring basis subsequent to initial recognition, including instruments for which we have elected the fair value option. Fair Value Measurements as of June 30, 2016 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 $ — $ 5,352 $ — $ — $ 5,352 Freddie Mac — 1,328 — — 1,328 Ginnie Mae — 542 — — 542 Alt-A private-label securities — 57 259 — 316 Subprime private-label securities — 351 44 — 395 CMBS — 1,389 — — 1,389 Mortgage revenue bonds — — 193 — 193 Non-mortgage-related securities: U.S. Treasury securities 29,652 — — — 29,652 Total trading securities 29,652 9,019 496 — 39,167 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 3,336 — — 3,336 Freddie Mac — 2,037 1 — 2,038 Ginnie Mae — 66 — — 66 Alt-A private-label securities — 1,652 175 — 1,827 Subprime private-label securities — 2,200 173 — 2,373 CMBS — 1,023 — — 1,023 Mortgage revenue bonds — — 2,029 — 2,029 Other — 38 450 — 488 Total available-for-sale securities — 10,352 2,828 — 13,180 Mortgage loans — 12,133 1,280 — 13,413 Other assets: Risk management derivatives: Swaps — 7,389 216 — 7,605 Swaptions — 36 — — 36 Other — — 27 — 27 Netting adjustment — — — (7,530 ) (7,530 ) Mortgage commitment derivatives — 623 14 — 637 Total other assets — 8,048 257 (7,530 ) 775 Total assets at fair value $ 29,652 $ 39,552 $ 4,861 $ (7,530 ) $ 66,535 Fair Value Measurements as of June 30, 2016 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 $ — $ 10,240 $ 410 $ — $ 10,650 Total of Fannie Mae — 10,240 410 — 10,650 Of consolidated trusts — 32,472 326 — 32,798 Total long-term debt — 42,712 736 — 43,448 Other liabilities: Risk management derivatives: Swaps — 14,283 4 — 14,287 Swaptions — 158 — — 158 Other — — 1 — 1 Netting adjustment — — — (14,269 ) (14,269 ) Mortgage commitment derivatives — 954 4 — 958 Total other liabilities — 15,395 9 (14,269 ) 1,135 Total liabilities at fair value $ — $ 58,107 $ 745 $ (14,269 ) $ 44,583 Fair Value Measurements as of December 31, 2015 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) Assets: Trading securities: Mortgage-related securities: Fannie Mae $ — $ 4,813 $ — $ — $ 4,813 Freddie Mac — 1,314 — — 1,314 Ginnie Mae — 426 — — 426 Alt-A private-label securities — 131 305 — 436 Subprime private-label securities — — 644 — 644 CMBS — 2,341 — — 2,341 Mortgage revenue bonds — — 449 — 449 Non-mortgage-related securities: U.S. Treasury securities 29,485 — — — 29,485 Total trading securities 29,485 9,025 1,398 — 39,908 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 4,221 — — 4,221 Freddie Mac — 4,295 4 — 4,299 Ginnie Mae — 391 — — 391 Alt-A private-label securities — 1,637 1,041 — 2,678 Subprime private-label securities — — 3,281 — 3,281 CMBS — 1,255 — — 1,255 Mortgage revenue bonds — — 2,701 — 2,701 Other — — 1,404 — 1,404 Total available-for-sale securities — 11,799 8,431 — 20,230 Mortgage loans — 12,598 1,477 — 14,075 Other assets: Risk management derivatives: Swaps — 4,541 156 — 4,697 Swaptions — 53 — — 53 Other — — 28 — 28 Netting adjustment — — — (4,024 ) (4,024 ) Mortgage commitment derivatives — 135 5 — 140 Total other assets — 4,729 189 (4,024 ) 894 Total assets at fair value $ 29,485 $ 38,151 $ 11,495 $ (4,024 ) $ 75,107 Fair Value Measurements as of December 31, 2015 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 $ — $ 10,764 $ 369 $ — $ 11,133 Total of Fannie Mae — 10,764 369 — 11,133 Of consolidated trusts — 23,113 496 — 23,609 Total long-term debt — 33,877 865 — 34,742 Other liabilities: Risk management derivatives: Swaps — 8,697 20 — 8,717 Swaptions — 197 — — 197 Other — — 2 — 2 Netting adjustment — — — (8,650 ) (8,650 ) Mortgage commitment derivatives — 148 10 — 158 Total other liabilities — 9,042 32 (8,650 ) 424 Total liabilities at fair value $ — $ 42,919 $ 897 $ (8,650 ) $ 35,166 __________ (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.
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 both realized and unrealized gains and losses, recognized in our condensed consolidated statements of operations and comprehensive income for Level 3 assets and liabilities. When assets and liabilities are transferred between levels, we recognize the transfer as of the end of the period. Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2016 (5)(6) Balance, March 31, 2016 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 25 $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ — $ — $ — Freddie Mac 1 — — — — — — (1 ) — — — Alt-A private-label securities 245 24 — — — — (10 ) — — 259 25 Subprime private-label securities 43 3 — — — — (2 ) — — 44 2 Mortgage revenue bonds 363 17 — — (184 ) — (3 ) — — 193 6 Total trading securities $ 677 $ 44 (6)(7) $ — $ — $ (184 ) $ — $ (16 ) $ (25 ) $ — $ 496 $ 33 Available-for-sale securities: Mortgage-related: Fannie Mae $ 1 $ — $ — $ — $ — $ — $ — $ (1 ) $ — $ — $ — Freddie Mac 2 — — — — — — (1 ) — 1 — Alt-A private-label securities 177 — 2 — — — (4 ) — — 175 — Subprime private-label securities 222 1 7 — — — (57 ) — — 173 — Mortgage revenue bonds 2,564 76 18 — (568 ) — (61 ) — — 2,029 — Other 655 3 (1 ) — (201 ) — (6 ) — — 450 — Total available-for-sale securities $ 3,621 $ 80 (7)(8) $ 26 $ — $ (769 ) $ — $ (128 ) $ (2 ) $ — $ 2,828 $ — Mortgage loans $ 1,311 $ 15 (6)(7) $ — $ 25 $ — $ — $ (67 ) $ (19 ) $ 15 $ 1,280 $ 10 Net derivatives 231 52 (6) — — — (3 ) (33 ) — 1 248 41 Long-term debt: Of Fannie Mae: Senior floating $ (395 ) $ (15 ) $ — $ — $ — $ — $ — $ — $ — $ (410 ) $ (15 ) Of consolidated trusts (246 ) (7 ) — — — (47 ) 9 8 (43 ) (326 ) (7 ) Total long-term debt $ (641 ) $ (22 ) (6) $ — $ — $ — $ (47 ) $ 9 $ 8 $ (43 ) $ (736 ) $ (22 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2016 (5)(6) Balance, December 31, 2015 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ 25 $ — $ — Freddie Mac — — — — — — — (1 ) 1 — — Alt-A private-label securities 305 (30 ) — — — — (16 ) — — 259 (30 ) Subprime private-label securities 644 (34 ) — — (187 ) — (16 ) (363 ) — 44 (10 ) Mortgage revenue bonds 449 29 — — (279 ) — (6 ) — — 193 10 Total trading securities $ 1,398 $ (35 ) (6)(7) $ — $ — $ (466 ) $ — $ (39 ) $ (388 ) $ 26 $ 496 $ (30 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ — $ (1 ) $ 1 $ — $ — Freddie Mac 4 — — — — — — (3 ) — 1 — Alt-A private-label securities 1,041 12 (27 ) — (291 ) — (44 ) (516 ) — 175 — Subprime private-label securities 3,281 92 (132 ) — (584 ) — (161 ) (2,323 ) — 173 — Mortgage revenue bonds 2,701 80 48 — (611 ) — (189 ) — — 2,029 — Other 1,404 — (26 ) — (605 ) — (39 ) (284 ) — 450 — Total available-for-sale securities $ 8,431 $ 184 (7)(8) $ (137 ) $ — $ (2,091 ) $ — $ (433 ) $ (3,127 ) $ 1 $ 2,828 $ — Mortgage loans $ 1,477 $ 116 (6)(7) $ — $ 25 $ (320 ) $ — $ (139 ) $ (84 ) $ 205 $ 1,280 $ 20 Net derivatives 157 232 (6) — — — (7 ) (133 ) (2 ) 1 248 76 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) $ (41 ) $ — $ — $ — $ — $ — $ — $ — $ (410 ) $ (41 ) Of consolidated trusts (496 ) (75 ) — — — (54 ) 318 45 (64 ) (326 ) (8 ) Total long-term debt $ (865 ) $ (116 ) (6) $ — $ — $ — $ (54 ) $ 318 $ 45 $ (64 ) $ (736 ) $ (49 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended June 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2015 (5)(6) Balance, March 31, 2015 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 2 $ — $ — $ — $ (2 ) $ — $ — $ — $ — $ — $ — Alt-A private-label securities 572 36 — — (267 ) — (16 ) — — 325 45 Subprime private-label securities 876 42 — — (182 ) — (18 ) — — 718 97 Mortgage revenue bonds 742 (33 ) — — (106 ) — (1 ) — — 602 (36 ) Other 94 6 — — (100 ) — — — — — 20 Total trading securities $ 2,286 $ 51 (6)(7) $ — $ — $ (657 ) $ — $ (35 ) $ — $ — $ 1,645 $ 126 Available-for-sale securities: Mortgage-related: Fannie Mae $ 205 $ — $ — $ 182 $ (269 ) $ — $ — $ — $ 11 $ 129 $ — Freddie Mac 5 — — — — — (1 ) — — 4 — Alt-A private-label securities 2,486 71 (38 ) — (552 ) — (85 ) (228 ) — 1,654 — Subprime private-label securities 4,608 265 (131 ) — (760 ) — (145 ) — — 3,837 — Mortgage revenue bonds 3,560 17 (79 ) — (154 ) — (173 ) — — 3,171 — Other 2,607 45 (55 ) — (368 ) — (71 ) — — 2,158 — Total available-for-sale securities $ 13,471 $ 398 (7)(8) $ (303 ) $ 182 $ (2,103 ) $ — $ (475 ) $ (228 ) $ 11 $ 10,953 $ — Mortgage loans $ 1,810 $ 4 (6)(7) $ — $ 2 $ — $ — $ (99 ) $ (197 ) $ 75 $ 1,595 $ (6 ) Net derivatives 66 (126 ) (6) — — — — 64 — — 4 (40 ) Long-term debt: Of Fannie Mae: Senior floating $ (391 ) $ 45 $ — $ — $ — $ — $ — $ — $ — $ (346 ) $ 44 Of consolidated trusts (547 ) 5 — — — — 16 59 (26 ) (493 ) 8 Total long-term debt $ (938 ) $ 50 (6) $ — $ — $ — $ — $ 16 $ 59 $ (26 ) $ (839 ) $ 52 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Six Months Ended June 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of June 30, 2015 (5)(6) Balance, December 31, 2014 Included in Net Income Included in Total Other Comprehensive Loss (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, June 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 305 $ (27 ) $ — $ — $ (2 ) $ — $ — $ (278 ) $ 2 $ — $ — Alt-A private-label securities 597 44 — — (267 ) — (33 ) (44 ) 28 325 51 Subprime private-label securities 1,307 43 — — (580 ) — (52 ) — — 718 99 Mortgage revenue bonds 722 2 — — (118 ) — (4 ) — — 602 (1 ) Other 99 4 — — (100 ) — (3 ) — — — 19 Total trading securities $ 3,030 $ 66 (6)(7) $ — $ — $ (1,067 ) $ — $ (92 ) $ (322 ) $ 30 $ 1,645 $ 168 Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ 421 $ (303 ) $ — $ — $ — $ 11 $ 129 $ — Freddie Mac 6 — — — — — (1 ) (1 ) — 4 — Alt-A private-label securities 3,140 172 (116 ) — (1,108 ) — (209 ) (538 ) 313 1,654 — Subprime private-label securities 5,240 445 (232 ) — (1,325 ) — (291 ) — — 3,837 — Mortgage revenue bonds 4,023 40 (27 ) — (316 ) — (549 ) — — 3,171 — Other 2,671 (93 ) 85 — (368 ) — (137 ) — — 2,158 — Total available-for-sale securities $ 15,080 $ 564 (7)(8) $ (290 ) $ 421 $ (3,420 ) $ — $ (1,187 ) $ (539 ) $ 324 $ 10,953 $ — Mortgage loans $ 1,833 $ 38 (6)(7) $ — $ 5 $ — $ — $ (176 ) $ (254 ) $ 149 $ 1,595 $ 5 Net derivatives 45 (99 ) (6) — — — — 58 — — 4 (23 ) Long-term debt: Of Fannie Mae: Senior floating $ (363 ) $ 17 $ — $ — $ — $ — $ — $ — $ — $ (346 ) $ 16 Of consolidated trusts (527 ) (8 ) — — — — 25 109 (92 ) (493 ) (4 ) Total long-term debt $ (890 ) $ 9 (6) $ — $ — $ — $ — $ 25 $ 109 $ (92 ) $ (839 ) $ 12 __________ (1) Gains (losses) included in other comprehensive loss are included in “Changes in unrealized gains on AFS securities, net of reclassification adjustments and taxes” in our condensed consolidated statements of operations and comprehensive income. (2) Purchases and sales include activity related to the consolidation and deconsolidation of assets of securitization trusts. (3) Issues and settlements include activity related to the consolidation and deconsolidation of liabilities of securitization trusts. (4) Transfers out of Level 3 consisted primarily of private-label mortgage-related securities backed by Alt-A loans and subprime loans. Prices for these securities were available from multiple third-party vendors and have demonstrated an increased and sustained level of observability over time. Transfers into Level 3 consisted primarily of private-label mortgage-related securities backed by Alt-A loans. Prices for these securities were based on inputs from a single source or inputs that were not readily observable during that time. (5) Amount represents temporary changes in fair value. Amortization, accretion and OTTI are not considered unrealized and are not included in this amount. (6) Gains (losses) are included in “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. (7) Gains (losses) are included in “Net interest income” in our condensed consolidated statements of operations and comprehensive income. (8) 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. Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Alt-A private-label securities (2) $ 37 Single Vendor Default Rate (%) 1.8 1.8 Prepayment Speed (%) 3.1 3.1 Severity (%) 72.0 72.0 Spreads (bps) 335.5 335.5 222 Consensus Default Rate (%) 2.0 - 5.0 4.2 Prepayment Speed (%) 3.0 - 8.0 6.7 Severity (%) 50.0 - 95.0 83.3 Spreads (bps) 280.0 - 493.4 437.8 Total Alt-A private-label securities 259 Subprime private-label securities (2) 44 Single Vendor Default Rate (%) 5.0 5.0 Prepayment Speed (%) 5.0 5.0 Severity (%) 75.0 75.0 Spreads (bps) 667.8 667.8 Total subprime private-label securities 44 Mortgage revenue bonds 185 Discounted Cash Flow Spreads (bps) 27.5 - 321.4 317.3 8 Other Total mortgage revenue bonds 193 Total trading securities $ 496 Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Available-for-sale securities: Mortgage-related securities: Agency (3) $ 1 Other Alt-A private-label securities (2) 121 Consensus Default Rate (%) 3.0 - 6.0 3.4 Prepayment Speed (%) 5.0 - 8.0 5.2 Severity (%) 60.0 - 80.0 61.6 Spreads (bps) 302.5 - 342.0 330.2 54 Discounted Cash Flow Default Rate (%) 6.0 6.0 Prepayment Speed (%) 8.0 8.0 Severity (%) 65.0 65.0 Spreads (bps) 301.6 - 367.0 355.2 Total Alt-A private-label securities 175 Subprime private-label securities (2) 123 Dealer Mark Default Rate (%) 6.5 - 10.0 8.3 Prepayment Speed (%) 5.0 - 6.0 5.5 Severity (%) 85.0 - 95.0 90.0 Spreads (bps) 330.0 330.0 50 Other Total subprime private-label securities 173 Mortgage revenue bonds 951 Single Vendor Spreads (bps) 7.5 - 414.3 60.3 970 Discounted Cash Flow Spreads (bps) 7.5 - 442.8 286.8 108 Other Total mortgage revenue bonds 2,029 Other 87 Consensus Default Rate (%) 0.5 - 3.5 3.5 Prepayment Speed (%) 2.5 - 5.0 2.5 Severity (%) 20.0 - 88.0 87.7 Spreads (bps) 303.5 - 453.0 376.1 357 Discounted Cash Flow Default Rate (%) 0.8 0.8 Prepayment Speed (%) 1.0 1.0 Severity (%) 95.0 95.0 Spreads (bps) 220.0 - 487.0 485.1 6 Other Total other 450 Total available-for-sale securities $ 2,828 Fair Value Measurements as of June 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 572 Build-Up 149 Consensus Default Rate (%) 1.0 - 7.0 3.1 Prepayment Speed (%) 3.0 - 23.3 7.3 Severity (%) 44.0 - 95.0 70.5 Spreads (bps) 245.0 - 310.0 259.7 239 Consensus 164 Other Total single-family 1,124 Multifamily 156 Build-Up Spreads (bps) 80.0 - 387.2 194.0 Total mortgage loans $ 1,280 Net derivatives $ 212 Dealer Mark 36 Other Total net derivatives $ 248 Long-term debt: Of Fannie Mae: Senior floating $ (410 ) Discounted Cash Flow Of consolidated trusts (4) (125 ) Discounted Cash Flow Default Rate (%) 2.0 - 7.0 4.9 Prepayment Speed (%) 3.0 - 100.0 92.4 Severity (%) 58.0 - 95.0 83.0 Spreads (bps) 88.0 - 366.3 224.7 (201 ) Other Total of consolidated trusts (326 ) Total long-term debt $ (736 ) Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Recurring fair value measurements: Trading securities: Mortgage-related securities: Alt-A private-label securities (2) $ 305 Consensus Default Rate (%) 1.3 - 4.9 3.6 Prepayment Speed (%) 2.2 - 4.5 3.7 Severity (%) 20.5 - 95.0 69.3 Spreads (bps) 219.0 - 263.3 253.1 Total Alt-A private-label securities 305 Subprime private-label securities (2) 526 Consensus Default Rate (%) 4.2 - 8.4 5.9 Prepayment Speed (%) 0.4 - 5.3 3.3 Severity (%) 55.9 - 95.0 73.7 Spreads (bps) 285.0 285.0 73 Consensus 45 Other Total subprime private-label securities 644 Mortgage revenue bonds 437 Discounted Cash Flow Spreads (bps) 1.5 - 376.2 298.9 12 Other Total mortgage revenue bonds 449 Total trading securities $ 1,398 Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Available-for-sale securities: Mortgage-related securities: Agency (3) $ 4 Other Alt-A private-label securities (2) 671 Consensus Default Rate (%) 0.5 - 40.7 3.4 Prepayment Speed (%) 1.7 - 72.6 13.5 Severity (%) 1.4 - 95.0 58.5 Spreads (bps) 225.6 - 280.4 260.0 201 Consensus 169 Discounted Cash Flow Default Rate (%) 4.0 - 5.0 4.8 Prepayment Speed (%) 4.0 - 7.5 6.4 Severity (%) 50.0 - 64.0 59.2 Spreads (bps) 260.0 - 369.4 296.5 Total Alt-A private-label securities 1,041 Subprime private-label securities (2) 343 Single Vendor Default Rate (%) 2.5 - 7.5 4.8 Prepayment Speed (%) 1.9 - 5.7 3.3 Severity (%) 67.6 - 85.7 72.7 Spreads (bps) 285.0 - 340.0 299.6 1,848 Consensus Default Rate (%) 0.5 - 11.3 5.9 Prepayment Speed (%) 0.5 - 11.2 3.8 Severity (%) 20.0 - 95.0 79.0 Spreads (bps) 255.0 - 285.0 283.3 945 Consensus 145 Other Total subprime private-label securities 3,281 Mortgage revenue bonds 991 Single Vendor Spreads (bps) (33.1 ) - 386.8 37.9 1,462 Discounted Cash Flow Spreads (bps) (15.8 ) - 379.1 283.8 248 Other Total mortgage revenue bonds 2,701 Other 683 Consensus Default Rate (%) 0.5 - 4.6 3.4 Prepayment Speed (%) 2.5 - 15.5 4.7 Severity (%) 6.6 - 95.0 65.7 Spreads (bps) 200.0 - 454.4 315.6 520 Discounted Cash Flow Default Rate (%) 0.0 - 1.8 0.0 Prepayment Speed (%) 0.0 - 0.5 0.0 Severity (%) 95.0 95.0 Spreads (bps) 260.0 - 350.0 323.6 201 Other Total other 1,404 Total available-for-sale securities $ 8,431 Fair Value Measurements as of December 31, 2015 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 127 Build-Up Default Rate (%) 0.0 - 99.2 34.8 Prepayment Speed (%) 3.0 - 100.0 10.4 Severity (%) 0.0 - 100.0 39.9 632 Build-Up 234 Consensus Default Rate (%) 0.5 - 5.0 3.7 Prepayment Speed (%) 2.5 - 26.0 6.4 Severity (%) 20.0 - 89.1 69.0 Spreads (bps) 255.0 - 277.6 264.6 274 Consensus 54 Other Total single-family 1,321 Multifamily 156 Build-Up Spreads (bps) 70.0 - 327.2 158.8 Total mortgage loans $ 1,477 Net derivatives $ 17 Internal Model 136 Dealer Mark 4 Other Total net derivatives $ 157 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) Discounted Cash Flow Of consolidated trusts (4) (181 ) Consensus Default Rate (%) 0.5 - 3.8 3.4 Prepayment Speed (%) 2.5 - 26.0 5.6 Severity (%) 20.0 - 80.6 67.8 Spreads (bps) 255.0 - 270.0 265.8 (149 ) Consensus (166 ) Other Total of consolidated trusts (496 ) Total long-term debt $ (865 ) _________ (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) Default rate as disclosed represents the estimated beginning annualized rate of default and is used as a basis to forecast the future default rates that serve as an input for valuation. (3) Includes Fannie Mae and Freddie Mac securities. (4) Includes instruments for which the prepayment speed as disclosed represents the estimated annualized rate of prepayment after all prepayment penalty provisions have expired and also instruments for which prepayment speed as disclosed represents the estimated rate of prepayment over the remaining life of the instrument.
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 (Level 3) of Assets Held as of Valuation Techniques June 30, 2016 December 31, 2015 (Dollars in millions) Nonrecurring fair value measurements: Mortgage loans held for sale, at lower of cost or fair value Consensus $ 1,919 $ 3,651 Single Vendor 32 336 Other 3 4 Total mortgage loans held for sale, at lower of cost or fair value 1,954 3,991 Single-family mortgage loans held for investment, at amortized cost Internal Model 3,640 6,379 Multifamily mortgage loans held for investment, at amortized cost Broker Price Opinions 27 82 Asset Manager Estimate 211 236 Other 5 5 Total multifamily mortgage loans held for investment, at amortized cost 243 323 Acquired property, net: Single-family Accepted Offers 443 541 Appraisals 728 1,117 Walk Forwards 307 433 Internal Model 476 986 Other 60 134 Total single-family 2,014 3,211 Multifamily Other 9 — Other assets Other 12 30 Total nonrecurring assets at fair value $ 7,872 $ 13,934
Fair Value of Financial Instruments [Table Text Block]	The following table displays the carrying value and estimated fair value of our financial instruments. The fair value of financial instruments we disclose includes commitments to purchase multifamily and single-family mortgage loans that we do not record in our condensed consolidated balance sheets. The fair values of these commitments are included as “Mortgage loans held for investment, net of allowance for loan losses.” The disclosure excludes all non-financial instruments; therefore, the fair value of our financial assets and liabilities does not represent the underlying fair value of our total consolidated assets and liabilities. As of June 30, 2016 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 $ 61,316 $ 42,196 $ 19,120 $ — $ — $ 61,316 Federal funds sold and securities purchased under agreements to resell or similar arrangements 22,325 — 22,325 — — 22,325 Trading securities 39,167 29,652 9,019 496 — 39,167 Available-for-sale securities 13,180 — 10,352 2,828 — 13,180 Mortgage loans held for sale 4,277 — 401 4,268 4,669 Mortgage loans held for investment, net of allowance for loan losses: Of Fannie Mae 201,243 — 29,508 183,942 — 213,450 Of consolidated trusts 2,824,349 — 2,676,296 231,183 — 2,907,479 Mortgage loans held for investment 3,025,592 — 2,705,804 415,125 — 3,120,929 Advances to lenders 5,288 — 4,915 365 — 5,280 Derivative assets at fair value 775 — 8,048 257 (7,530 ) 775 Guaranty assets and buy-ups 141 — — 454 — 454 Total financial assets $ 3,172,061 $ 71,848 $ 2,779,984 $ 423,793 $ (7,530 ) $ 3,268,095 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 115 $ — $ 115 $ — $ — $ 115 Short-term debt: Of Fannie Mae 60,495 — 60,520 — — 60,520 Of consolidated trusts 742 — — 742 — 742 Long-term debt: Of Fannie Mae 301,923 — 315,023 881 — 315,904 Of consolidated trusts 2,848,744 — 2,901,213 40,138 — 2,941,351 Derivative liabilities at fair value 1,135 — 15,395 9 (14,269 ) 1,135 Guaranty obligations 276 — — 890 — 890 Total financial liabilities $ 3,213,430 $ — $ 3,292,266 $ 42,660 $ (14,269 ) $ 3,320,657 As of December 31, 2015 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 $ 45,553 $ 34,953 $ 10,600 $ — $ — $ 45,553 Federal funds sold and securities purchased under agreements to resell or similar arrangements 27,350 — 27,350 — — 27,350 Trading securities 39,908 29,485 9,025 1,398 — 39,908 Available-for-sale securities 20,230 — 11,799 8,431 — 20,230 Mortgage loans held for sale 5,361 — 157 5,541 — 5,698 Mortgage loans held for investment, net of allowance for loan losses: Of Fannie Mae 206,544 — 26,544 193,670 — 220,214 Of consolidated trusts 2,807,739 — 2,675,982 157,685 — 2,833,667 Mortgage loans held for investment 3,014,283 — 2,702,526 351,355 — 3,053,881 Advances to lenders 4,308 — 3,902 394 — 4,296 Derivative assets at fair value 894 — 4,729 189 (4,024 ) 894 Guaranty assets and buy-ups 184 — — 544 — 544 Total financial assets $ 3,158,071 $ 64,438 $ 2,770,088 $ 367,852 $ (4,024 ) $ 3,198,354 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 62 $ — $ 62 $ — $ — $ 62 Short-term debt: Of Fannie Mae 71,007 — 71,006 — — 71,006 Of consolidated trusts 943 — — 944 — 944 Long-term debt: Of Fannie Mae 315,128 — 324,248 898 — 325,146 Of consolidated trusts 2,810,593 — 2,819,733 27,175 — 2,846,908 Derivative liabilities at fair value 424 — 9,042 32 (8,650 ) 424 Guaranty obligations 329 — — 1,012 — 1,012 Total financial liabilities $ 3,198,486 $ — $ 3,224,091 $ 30,061 $ (8,650 ) $ 3,245,502
Fair Value Option [Table Text Block]	The following table displays the fair value and unpaid principal balance of the financial instruments for which we have made fair value elections. As of June 30, 2016 December 31, 2015 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 $ 13,413 $ 10,650 $ 32,798 $ 14,075 $ 11,133 $ 23,609 Unpaid principal balance 12,690 10,511 29,365 13,661 11,263 21,604 __________ (1) Includes nonaccrual loans with a fair value of $152 million and $238 million as of June 30, 2016 and December 31, 2015 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of June 30, 2016 and December 31, 2015 was $32 million and $59 million , respectively. Includes loans that are 90 days or more past due with a fair value of $162 million and $256 million as of June 30, 2016 and December 31, 2015 , respectively. The difference between unpaid principal balance and the fair value of these 90 or more days past due loans as of June 30, 2016 and December 31, 2015 was $25 million and $52 million , respectively. The following table displays fair value gains and losses, net, including changes attributable to instrument-specific credit risk, for loans and debt for which the fair value election was made. Amounts are recorded as a component of “Fair value gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. For the Three Months Ended June 30, 2016 2015 Loans Long-Term Debt Total Gains (Losses) Loans Long-Term Debt Total Gains (Losses) (Dollars in millions) Changes in instrument-specific credit risk $ 19 $ (169 ) $ (150 ) $ 49 $ 88 $ 137 Other changes in fair value 126 (144 ) (18 ) (217 ) 227 10 Fair value gains (losses), net $ 145 $ (313 ) $ (168 ) $ (168 ) $ 315 $ 147 For the Six Months Ended June 30, 2016 2015 Loans Long-Term Debt Total Gains (Losses) Loans Long-Term Debt Total Gains (Losses) (Dollars in millions) Changes in instrument-specific credit risk $ 32 $ (221 ) $ (189 ) $ 37 $ (105 ) $ (68 ) Other changes in fair value 344 (446 ) (102 ) (50 ) 39 (11 ) Fair value gains (losses), net $ 376 $ (667 ) $ (291 ) $ (13 ) $ (66 ) $ (79 )

Summary of Significant Accoun48

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) $ in Billions	Jun. 30, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Deficit of core capital over statutory minimum capital requirement	$ 139.1	$ 139.7

Summary of Significant Accoun49

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	Jun. 30, 2016	Sep. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016	Dec. 31, 2015
Related Parties [Line Items]
Number of days after which we have not been paying debts or liabilities exceed assets FHFA must place us into receivership					60 days
Payments of cash dividends on senior preferred stock to Treasury	$ 919,000,000				$ 3,778,000,000	$ 3,716,000,000
Net worth	4,069,000,000		$ 4,069,000,000		4,069,000,000		$ 2,100,000,000	$ 4,059,000,000
Income Taxes Paid					610,000,000	370,000,000
Unpaid principal balance guaranteed by a related party	$ 7,100,000,000		7,100,000,000		7,100,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			$ 453,000,000	$ 397,000,000	$ 893,000,000	779,000,000
Basis Points of Each Dollar of Unpaid Principal Balance	0.042%		0.042%		0.042%
Trading, at fair value (includes $1,111 and $135, respectively, pledged as collateral)	$ 39,167,000,000		$ 39,167,000,000		$ 39,167,000,000			39,908,000,000
Interest Receivable	8,018,000,000		8,018,000,000		8,018,000,000			7,726,000,000
Interest income recognized on Treasury securities			128,000,000	116,000,000	248,000,000	231,000,000
Scenario, Forecast [Member]
Related Parties [Line Items]
Expected undeclared dividends payable on senior preferred stock for the next quarter		$ 2,900,000,000
US Treasury [Member]
Related Parties [Line Items]
Aggregate funding received from US Treasury pursuant to the senior preferred stock purchase agreement	116,100,000,000		116,100,000,000		116,100,000,000
Initial aggregate liquidation preference of senior preferred stock held by US Treasury	1,000,000,000		1,000,000,000		1,000,000,000
Aggregate liquidation preference of senior preferred stock	117,100,000,000		117,100,000,000		117,100,000,000
Total available funding from US Treasury pursuant to the senior preferred stock agreement	117,600,000,000		117,600,000,000		117,600,000,000
Capital Reserve Amount, current year, Senior Preferred Stock Purchase Agreement, Amendment	1,200,000,000		1,200,000,000		1,200,000,000		$ 1,200,000,000
Capital Reserve Amount, prior year, Senior Preferred Stock Purchase Agreement, Amendment								1,800,000,000
Annual Reduction of Capital Reserve Amount from 2013 to 2018, Senior Preferred Stock Purchase Agreement, Amendment	$ 600,000,000		$ 600,000,000		$ 600,000,000
Percentage of common shares attributable to warrants issued to US Treasury as percentage to total diluted common shares	79.90%		79.90%		79.90%
Home Affordable Modification Program administrative expense reimbursements from Treasury and Freddie Mac			$ 15,000,000	16,000,000	$ 31,000,000	32,000,000
Income Taxes Paid			$ 250,000,000	370,000,000	610,000,000	370,000,000
Proceeds from Income Tax Refunds					$ 0	135,000,000
Percentage of initial principal loss US Treasury will bear for New Issue Bond Program	35.00%		35.00%		35.00%
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			$ 453,000,000	397,000,000	$ 893,000,000	779,000,000
US Treasury [Member] | Single-family [Member]
Related Parties [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			453,000,000	397,000,000	893,000,000	779,000,000
Recognized TCCA fees that had not been remitted to Treasury as of period end	$ 453,000,000		453,000,000		453,000,000
Freddie Mac [Member] | Freddie Mac [Member]
Related Parties [Line Items]
Interest Receivable	14,000,000		14,000,000		14,000,000			22,000,000
Fair value of mortgage-related securities	3,400,000,000		3,400,000,000		3,400,000,000			5,600,000,000
Interest income recognized on mortgage-related securities			36,000,000	58,000,000	81,000,000	119,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees			28,000,000	28,000,000	56,000,000	56,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments			35,000,000	17,000,000	65,000,000	30,000,000
U.S. Treasury securities [Member]
Related Parties [Line Items]
Trading, at fair value (includes $1,111 and $135, respectively, pledged as collateral)	29,652,000,000		29,652,000,000		29,652,000,000			29,485,000,000
U.S. Treasury securities [Member] | US Treasury [Member]
Related Parties [Line Items]
Trading, at fair value (includes $1,111 and $135, respectively, pledged as collateral)	29,700,000,000		29,700,000,000		29,700,000,000			29,500,000,000
Interest Receivable	$ 24,000,000		24,000,000		24,000,000			$ 15,000,000
Interest income recognized on Treasury securities			33,000,000	5,000,000	65,000,000	9,000,000
Other Expense [Member] | US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments			$ 31,000,000	$ 60,000,000	$ 56,000,000	$ 112,000,000

Summary of Significant Accoun50

Summary of Significant Accounting Policies Use of Estimates (Details) - Change in Accounting Method Accounted for as Change in Estimate [Member] $ in Millions	Jan. 01, 2015USD ($)
Change in Accounting Estimate [Line Items]
Advisory Bulletin impact for HFI loans	$ 1,800
Advisory Bulletin impact for preforeclosure property taxes and insurance receivable	$ 724

Consolidations and Transfers 51

Consolidations and Transfers of Financial Assets Unconsolidated VIEs (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Variable Interest Entities [Line Items]
Trading, at fair value	$ 39,167	$ 39,908
Available-for-sale, at fair value	13,180	20,230
Other assets	19,565	17,553
Other liabilities	(9,372)	(10,393)
Unpaid principal balance of mortgage loans	3,013,878	3,010,753
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	210,678	198,342
Consolidated VIEs [Member]
Variable Interest Entities [Line Items]
Change in assets due to change in consolidation status	166
Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Change in assets due to change in consolidation status		5,100
Unconsolidated VIEs [Member] | Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	210,700
Unconsolidated VIEs [Member] | Mortgage-related securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	9,356	10,300
Available-for-sale, at fair value	11,838	18,580
Other assets	53	100
Other liabilities	(430)	(827)
Net carrying amount	20,817	28,153
Maximum exposure to loss	26,000	34,000
Total unconsolidated assets	180,000	220,000
Unconsolidated VIEs [Member] | Partnership interest [Member]
Variable Interest Entities [Line Items]
Net carrying amount	93	(24)
Maximum exposure to loss	125	12
Total unconsolidated assets	4,200	4,900
Unconsolidated VIEs [Member] | Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	5,203	4,704
Available-for-sale, at fair value	3,160	3,936
Unconsolidated VIEs [Member] | Non-Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	4,153	5,596
Available-for-sale, at fair value	$ 8,678	$ 14,644

Consolidations and Transfers 52

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Transfers of Financial Assets [Line Items]
Portfolio securitizations: unpaid principal balance	$ 64,300	$ 62,000	$ 112,600	$ 110,900
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Principal and interest received on retained interests	315	$ 296	623	$ 646
Unconsolidated VIEs [Member] | Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	5,100		5,100		$ 5,500
Retained interest: fair value	$ 6,900		$ 6,900		$ 6,800

Consolidations and Transfers 53

Consolidations and Transfers of Financial Assets Managed Loans (Details) - USD ($) $ in Billions	Jun. 30, 2016	Dec. 31, 2015
Consolidations and Transfers of Financial Assets [Abstract]
Securitized loans in unconsolidated portfolio securitization trusts, unpaid principal balance	$ 1.5	$ 1.6

Mortgage Loans Loans in Mortgag

Mortgage Loans Loans in Mortgage Portfolio (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,013,878,000,000		$ 3,013,878,000,000			$ 3,010,753,000,000
Cost basis and fair value adjustments, net	39,790,000,000		39,790,000,000			36,842,000,000
Allowance for loan losses for loans held for investment	(23,799,000,000)	$ (31,150,000,000)	(23,799,000,000)	$ (31,150,000,000)	$ (25,819,000,000)	(27,951,000,000)	$ (31,820,000,000)	$ (35,541,000,000)
Total mortgage loans	3,029,869,000,000		3,029,869,000,000			3,019,644,000,000
Carrying value of loans redesignated from HFI to HFS	1,000,000,000	4,300,000,000	1,600,000,000	4,600,000,000
Sale of loans, unpaid principal balance	1,500,000,000	633,000,000	2,600,000,000	633,000,000
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,803,200,000,000		2,803,200,000,000			2,812,411,000,000
Recorded investment of single-family mortgage loans referred to foreclosure	21,500,000,000		21,500,000,000			25,600,000,000
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	210,678,000,000		210,678,000,000			198,342,000,000
Fannie Mae [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	240,507,000,000		240,507,000,000			251,336,000,000
Cost basis and fair value adjustments, net	(12,202,000,000)		(12,202,000,000)			(12,939,000,000)
Allowance for loan losses for loans held for investment	(22,793,000,000)	(29,724,000,000)	(22,793,000,000)	(29,724,000,000)	(24,557,000,000)	(26,510,000,000)	(29,873,000,000)	(33,117,000,000)
Total mortgage loans	205,512,000,000		205,512,000,000			211,887,000,000
Fannie Mae [Member] | Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	228,866,000,000		228,866,000,000			238,237,000,000
Fannie Mae [Member] | Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	11,641,000,000		11,641,000,000			13,099,000,000
Consolidated Trusts [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,773,371,000,000		2,773,371,000,000			2,759,417,000,000
Cost basis and fair value adjustments, net	51,992,000,000		51,992,000,000			49,781,000,000
Allowance for loan losses for loans held for investment	(1,006,000,000)	$ (1,426,000,000)	(1,006,000,000)	$ (1,426,000,000)	$ (1,262,000,000)	(1,441,000,000)	$ (1,947,000,000)	$ (2,424,000,000)
Total mortgage loans	2,824,357,000,000		2,824,357,000,000			2,807,757,000,000
Consolidated Trusts [Member] | Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,574,334,000,000		2,574,334,000,000			2,574,174,000,000
Consolidated Trusts [Member] | Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 199,037,000,000		$ 199,037,000,000			$ 185,243,000,000

Mortgage Loans Aging (Details)

Mortgage Loans Aging (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	$ 33,861	$ 34,814
60 - 89 days delinquent	8,560	9,717
Seriously delinquent	29,272	35,061
Total delinquent	71,693	79,592
Current	2,972,068	2,956,120
Total recorded investment in loans	3,043,761	3,035,712
Recorded investment in loans 90 days or more delinquent and accruing interest	321	349
Recorded investment in nonaccrual loans	42,424	44,846
Single-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	33,781	34,791
60 - 89 days delinquent	8,560	9,717
Seriously delinquent	29,171	34,938
Total delinquent	71,512	79,446
Current	2,759,490	2,756,092
Total recorded investment in loans	2,831,002	2,835,538
Recorded investment in loans 90 days or more delinquent and accruing interest	321	349
Recorded investment in nonaccrual loans	$ 41,949	$ 44,255
Single-family [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days	90 days
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	$ 28,547	$ 29,154
60 - 89 days delinquent	7,002	7,937
Seriously delinquent	22,221	26,346
Total delinquent	57,770	63,437
Current	2,611,816	2,598,756
Total recorded investment in loans	2,669,586	2,662,193
Recorded investment in loans 90 days or more delinquent and accruing interest	41	46
Recorded investment in nonaccrual loans	32,854	34,216
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	56	58
60 - 89 days delinquent	22	24
Seriously delinquent	268	291
Total delinquent	346	373
Current	38,831	40,461
Total recorded investment in loans	39,177	40,834
Recorded investment in loans 90 days or more delinquent and accruing interest	268	291
Recorded investment in nonaccrual loans	0	0
Single-family [Member] | Alt-A [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	3,725	4,085
60 - 89 days delinquent	1,111	1,272
Seriously delinquent	4,925	6,141
Total delinquent	9,761	11,498
Current	79,383	84,603
Total recorded investment in loans	89,144	96,101
Recorded investment in loans 90 days or more delinquent and accruing interest	6	6
Recorded investment in nonaccrual loans	6,684	7,407
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	1,453	1,494
60 - 89 days delinquent	425	484
Seriously delinquent	1,757	2,160
Total delinquent	3,635	4,138
Current	29,460	32,272
Total recorded investment in loans	33,095	36,410
Recorded investment in loans 90 days or more delinquent and accruing interest	6	6
Recorded investment in nonaccrual loans	2,411	2,632
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	80	23
Seriously delinquent	101	123
Total delinquent	181	146
Current	212,578	200,028
Total recorded investment in loans	212,759	200,174
Recorded investment in loans 90 days or more delinquent and accruing interest	0	0
Recorded investment in nonaccrual loans	$ 475	$ 591
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

Mortgage Loans Credit Quality I

Mortgage Loans Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,043,761	$ 3,035,712
Single-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,831,002	2,835,538
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,669,586	2,662,193
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,279,064	2,228,533
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	238,897	250,373
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	104,938	122,939
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% and less than or equal to 110% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	21,829	27,875
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 110% and less than or equal to 120% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	11,218	14,625
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 120% and less than or equal to 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	3,459	4,520
Single-family [Member] | Primary [Member] | Estimated mark-to-market loan-to-value ratio greater than 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	10,181	13,328
Single-family [Member] | Alt-A [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	89,144	96,101
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	58,301	59,000
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	11,003	12,588
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	7,907	9,345
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% and less than or equal to 110% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	5,066	6,231
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 110% and less than or equal to 120% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,951	3,730
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 120% and less than or equal to 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	946	1,260
Single-family [Member] | Alt-A [Member] | Estimated mark-to-market loan-to-value ratio greater than 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,970	3,947
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	33,095	36,410
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio less than or equal to 80% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	20,834	21,274
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	4,225	4,936
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	3,162	3,861
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 100% and less than or equal to 110% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,076	2,596
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 110% and less than or equal to 120% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,216	1,592
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 120% and less than or equal to 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	391	545
Single-family [Member] | Other [Member] | Estimated mark-to-market loan-to-value ratio greater than 125% [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,191	1,606
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 39,177	$ 40,834

Mortgage Loans Credit Quality57

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,043,761	$ 3,035,712
Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	212,759	200,174
Multifamily [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	207,481	194,132
Multifamily [Member] | Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,476	3,202
Multifamily [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,792	2,833
Multifamily [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 10	$ 7

Mortgage Loans Individually Imp

Mortgage Loans Individually Impaired Loans (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	$ 153,563	$ 162,230
Individually impaired loans with related allowance recorded: total recorded investment	144,766	152,765
Related allowance for loan losses	22,134	25,517
Individually impaired loans with no related allowance recorded: unpaid principal balance	22,026	21,245
Individually impaired loans with no related allowance recorded: total recorded investment	20,165	19,404
Total individually impaired loans: unpaid principal balance	175,589	183,475
Total individually impaired loans: total recorded investment	164,931	172,169
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	153,031	161,580
Individually impaired loans with related allowance recorded: total recorded investment	144,231	152,111
Related allowance for loan losses	22,075	25,437
Individually impaired loans with no related allowance recorded: unpaid principal balance	21,721	20,892
Individually impaired loans with no related allowance recorded: total recorded investment	19,859	19,050
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	110,529	116,477
Individually impaired loans with related allowance recorded: total recorded investment	104,999	110,502
Related allowance for loan losses	14,536	16,745
Individually impaired loans with no related allowance recorded: unpaid principal balance	16,603	15,891
Individually impaired loans with no related allowance recorded: total recorded investment	15,414	14,725
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	310	322
Individually impaired loans with related allowance recorded: total recorded investment	314	327
Related allowance for loan losses	58	59
Individually impaired loans with no related allowance recorded: unpaid principal balance	65	58
Individually impaired loans with no related allowance recorded: total recorded investment	60	54
Single-family [Member] | Alt-A [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	30,100	31,888
Individually impaired loans with related allowance recorded: total recorded investment	27,477	29,103
Related allowance for loan losses	5,401	6,217
Individually impaired loans with no related allowance recorded: unpaid principal balance	3,827	3,721
Individually impaired loans with no related allowance recorded: total recorded investment	3,285	3,169
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	12,092	12,893
Individually impaired loans with related allowance recorded: total recorded investment	11,441	12,179
Related allowance for loan losses	2,080	2,416
Individually impaired loans with no related allowance recorded: unpaid principal balance	1,226	1,222
Individually impaired loans with no related allowance recorded: total recorded investment	1,100	1,102
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	532	650
Individually impaired loans with related allowance recorded: total recorded investment	535	654
Related allowance for loan losses	59	80
Individually impaired loans with no related allowance recorded: unpaid principal balance	305	353
Individually impaired loans with no related allowance recorded: total recorded investment	$ 306	$ 354

Mortgage Loans Individually I59

Mortgage Loans Individually Impaired Loans - 2 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	$ 147,087	$ 160,870	$ 149,007	$ 162,546
Individually impaired loans with related allowance recorded: total interest income recognized	1,380	1,378	2,754	2,763
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	85	85	216	213
Individually impaired loans with no related allowance recorded: average recorded investment	20,249	22,355	20,209	21,816
Individually impaired loans with no related allowance recorded: total interest income recognized	442	323	798	634
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	37	19	61	69
Individually impaired loans: average recorded investment	167,336	183,225	169,216	184,362
Individually impaired loans: total interest income recognized	1,822	1,701	3,552	3,397
Individually impaired loans: interest income recognized on a cash basis	122	104	277	282
Table Footnote [Abstract]
Individually impaired loans: total interest income recognized	1,822	1,701	3,552	3,397
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	146,531	159,780	148,418	161,406
Individually impaired loans with related allowance recorded: total interest income recognized	1,367	1,375	2,736	2,757
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	85	85	216	213
Individually impaired loans with no related allowance recorded: average recorded investment	19,923	21,895	19,874	21,320
Individually impaired loans with no related allowance recorded: total interest income recognized	439	321	792	631
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	37	19	61	69
Individually impaired loans: total interest income recognized	1,800	1,700	3,500	3,400
Table Footnote [Abstract]
Troubled debt restructuring recorded investment	163,400		163,400		$ 170,300
Individually impaired loans: total interest income recognized	1,800	1,700	3,500	3,400
Individually impaired loans: contractual interest income	1,500	1,400	2,900	2,800
Individually impaired loans: effective yield adjustments	331	304	641	580
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	106,674	115,856	107,984	116,811
Individually impaired loans with related allowance recorded: total interest income recognized	1,015	1,028	2,036	2,062
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	71	73	175	177
Individually impaired loans with no related allowance recorded: average recorded investment	15,377	16,453	15,323	16,178
Individually impaired loans with no related allowance recorded: total interest income recognized	327	253	595	500
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	30	19	50	60
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	317	288	320	285
Individually impaired loans with related allowance recorded: total interest income recognized	3	3	6	6
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	59	54	58	56
Individually impaired loans with no related allowance recorded: total interest income recognized	1	1	2	2
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Single-family [Member] | Alt-A [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	27,901	30,642	28,287	31,094
Individually impaired loans with related allowance recorded: total interest income recognized	256	251	509	502
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	11	10	30	27
Individually impaired loans with no related allowance recorded: average recorded investment	3,361	4,010	3,362	3,775
Individually impaired loans with no related allowance recorded: total interest income recognized	81	50	143	94
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	5	0	8	7
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	11,639	12,994	11,827	13,216
Individually impaired loans with related allowance recorded: total interest income recognized	93	93	185	187
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	3	2	11	9
Individually impaired loans with no related allowance recorded: average recorded investment	1,126	1,378	1,131	1,311
Individually impaired loans with no related allowance recorded: total interest income recognized	30	17	52	35
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	2	0	3	2
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	556	1,090	589	1,140
Individually impaired loans with related allowance recorded: total interest income recognized	13	3	18	6
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	326	460	335	496
Individually impaired loans with no related allowance recorded: total interest income recognized	3	2	6	3
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	$ 0	0	$ 0
Table Footnote [Abstract]
Troubled debt restructuring recorded investment	$ 415		$ 415		$ 451

Mortgage Loans TDRs (Details)

Mortgage Loans TDRs (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)contracts	Jun. 30, 2015USD ($)contracts	Jun. 30, 2016USD ($)contracts	Jun. 30, 2015USD ($)contracts
Financing Receivable, Modifications [Line Items]
Average term extension of a single-family modified loan	159 months	162 months	159 months	162 months
Average interest rate reduction of a single-family modified loan	0.72%	0.77%	0.73%	0.77%
Number of loans troubled debt restructurings activity | contracts	16,831	21,088	36,385	45,951
Recorded investment troubled debt restructurings activity | $	$ 2,375	$ 2,981	$ 5,055	$ 6,485
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	16,827	21,087	36,381	45,947
Recorded investment troubled debt restructurings activity | $	$ 2,330	$ 2,980	$ 5,010	$ 6,479
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	14,814	17,951	32,004	39,358
Recorded investment troubled debt restructurings activity | $	$ 2,028	$ 2,477	$ 4,360	$ 5,422
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	28	64	82	138
Recorded investment troubled debt restructurings activity | $	$ 3	$ 8	$ 9	$ 16
Single-family [Member] | Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	1,623	2,533	3,534	5,322
Recorded investment troubled debt restructurings activity | $	$ 238	$ 395	$ 508	$ 833
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	362	539	761	1,129
Recorded investment troubled debt restructurings activity | $	$ 61	$ 100	$ 133	$ 208
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	4	1	4	4
Recorded investment troubled debt restructurings activity | $	$ 45	$ 1	$ 45	$ 6

Mortgage Loans TDRs with Sub De

Mortgage Loans TDRs with Sub Defaults (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)contracts	Jun. 30, 2015USD ($)contracts	Jun. 30, 2016USD ($)contracts	Jun. 30, 2015USD ($)contracts
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	5,720	7,447	12,291	15,649
Recorded investment troubled debt restructurings subsequent default | $	$ 797	$ 1,078	$ 1,794	$ 2,357
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	5,720	7,446	12,291	15,646
Recorded investment troubled debt restructurings subsequent default | $	$ 797	$ 1,076	$ 1,794	$ 2,351
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	4,648	6,156	10,109	12,879
Recorded investment troubled debt restructurings subsequent default | $	$ 638	$ 864	$ 1,440	$ 1,867
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	27	37	42	57
Recorded investment troubled debt restructurings subsequent default | $	$ 3	$ 6	$ 5	$ 9
Single-family [Member] | Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	756	963	1,608	2,116
Recorded investment troubled debt restructurings subsequent default | $	$ 116	$ 151	$ 260	$ 354
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	289	290	532	594
Recorded investment troubled debt restructurings subsequent default | $	$ 40	$ 55	$ 89	$ 121
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	0	1	0	3
Recorded investment troubled debt restructurings subsequent default | $	$ 0	$ 2	$ 0	$ 6

Allowance for Loan Losses Rollf

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for Loan Losses [Roll Forward]
Beginning balance	$ 25,819	$ 31,820	$ 27,951	$ 35,541
Provision (benefit) for loan losses	(1,336)	1,029	(2,368)	1,037
Charge-offs	(821)	(2,074)	(2,105)	(7,436)
Recoveries	115	261	235	883
Transfers	0	0	0	0
Other	22	114	86	1,125
Ending balance	23,799	31,150	23,799	31,150
Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	24,557	29,873	26,510	33,117
Provision (benefit) for loan losses	(1,300)	1,274	(2,429)	1,442
Charge-offs	(792)	(2,051)	(2,050)	(7,394)
Recoveries	114	257	232	871
Transfers	192	256	444	615
Other	22	115	86	1,073
Ending balance	22,793	29,724	22,793	29,724
Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	1,262	1,947	1,441	2,424
Provision (benefit) for loan losses	(36)	(245)	61	(405)
Charge-offs	(29)	(23)	(55)	(42)
Recoveries	1	4	3	12
Transfers	(192)	(256)	(444)	(615)
Other	0	(1)	0	52
Ending balance	1,006	1,426	1,006	1,426
Single-family [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	25,597	31,514	27,709	35,177
Provision (benefit) for loan losses	(1,332)	1,041	(2,348)	1,099
Charge-offs	(818)	(2,055)	(2,097)	(7,402)
Recoveries	115	261	234	883
Transfers	0	0	0	0
Other	22	115	86	1,119
Ending balance	23,584	30,876	23,584	30,876
Single-family [Member] | Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	24,490	29,759	26,439	32,956
Provision (benefit) for loan losses	(1,292)	1,268	(2,418)	1,473
Charge-offs	(789)	(2,032)	(2,042)	(7,360)
Recoveries	114	257	231	871
Transfers	191	256	440	615
Other	22	116	86	1,069
Ending balance	22,736	29,624	22,736	29,624
Single-family [Member] | Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	1,107	1,755	1,270	2,221
Provision (benefit) for loan losses	(40)	(227)	70	(374)
Charge-offs	(29)	(23)	(55)	(42)
Recoveries	1	4	3	12
Transfers	(191)	(256)	(440)	(615)
Other	0	(1)	0	50
Ending balance	848	1,252	848	1,252
Multifamily [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	222	306	242	364
Provision (benefit) for loan losses	(4)	(12)	(20)	(62)
Charge-offs	(3)	(19)	(8)	(34)
Recoveries			1	0
Transfers	0	0	0	0
Other	0	(1)	0	6
Ending balance	215	274	215	274
Multifamily [Member] | Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	67	114	71	161
Provision (benefit) for loan losses	(8)	6	(11)	(31)
Charge-offs	(3)	(19)	(8)	(34)
Recoveries			1	0
Transfers	1	0	4	0
Other	0	(1)	0	4
Ending balance	57	100	57	100
Multifamily [Member] | Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	155	192	171	203
Provision (benefit) for loan losses	4	(18)	(9)	(31)
Charge-offs	0	0	0	0
Recoveries			0	0
Transfers	(1)	0	(4)	0
Other	0	0	0	2
Ending balance	$ 158	$ 174	$ 158	$ 174

Allowance for Loan Losses and T

Allowance for Loan Losses and Total Recorded Investment in HFI Loans (Details) - USD ($) $ in Millions	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	$ 22,134		$ 25,517
Allowance for loan losses for collectively reserved loans	1,665		2,434
Total allowance for loan losses	23,799	$ 25,819	27,951	$ 31,150	$ 31,820	$ 35,541
Recorded investment in individually impaired loans	164,931		172,169
Recorded investment in collectively reserved loans	2,878,830		2,863,543
Total recorded investment in loans	3,043,761		3,035,712
Single-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	22,075		25,437
Allowance for loan losses for collectively reserved loans	1,509		2,272
Total allowance for loan losses	23,584	25,597	27,709	30,876	31,514	35,177
Recorded investment in individually impaired loans	164,090		171,161
Recorded investment in collectively reserved loans	2,666,912		2,664,377
Total recorded investment in loans	2,831,002		2,835,538
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	59		80
Allowance for loan losses for collectively reserved loans	156		162
Total allowance for loan losses	215	$ 222	242	$ 274	$ 306	$ 364
Recorded investment in individually impaired loans	841		1,008
Recorded investment in collectively reserved loans	211,918		199,166
Total recorded investment in loans	$ 212,759		$ 200,174

Investments in Securities Tradi

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 39,167	$ 39,908
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	9,515	10,423
Fannie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	5,352	4,813
Freddie Mac [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,328	1,314
Ginnie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	542	426
Alt-A private-label securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	316	436
Subprime private-label securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	395	644
CMBS [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,389	2,341
Mortgage revenue bonds [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	193	449
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 29,652	$ 29,485

Investments in Securities Avail

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 234	$ 413	$ 445	$ 813
Gross realized losses	8	50	12	57
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 3,645	$ 3,096	$ 7,267	$ 5,208

Investments in Securities Ava66

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	$ 11,511	$ 18,141
Gross unrealized gains	1,705	2,170
Gross unrealized losses	(36)	(81)
Available-for-sale, at fair value	13,180	20,230
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	3,163	4,008
Gross unrealized gains	194	243
Gross unrealized losses	(21)	(30)
Available-for-sale, at fair value	3,336	4,221
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,899	4,000
Gross unrealized gains	139	299
Gross unrealized losses	0	0
Available-for-sale, at fair value	2,038	4,299
Ginnie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	58	343
Gross unrealized gains	8	48
Gross unrealized losses	0	0
Available-for-sale, at fair value	66	391
Alt-A private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,269	2,029
Gross unrealized gains	564	653
Gross unrealized losses	(6)	(4)
Available-for-sale, at fair value	1,827	2,678
Subprime private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,722	2,526
Gross unrealized gains	656	759
Gross unrealized losses	(5)	(4)
Available-for-sale, at fair value	2,373	3,281
CMBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,010	1,235
Gross unrealized gains	14	20
Gross unrealized losses	(1)	0
Available-for-sale, at fair value	1,023	1,255
Mortgage revenue bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,919	2,639
Gross unrealized gains	113	99
Gross unrealized losses	(3)	(37)
Available-for-sale, at fair value	2,029	2,701
Other mortgage-related securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	471	1,361
Gross unrealized gains	17	49
Gross unrealized losses	0	(6)
Available-for-sale, at fair value	$ 488	$ 1,404

Investments in Securities Ava67

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	$ (6)	$ (50)
Less than 12 Consecutive Months, Fair Value	278	1,552
12 Consecutive Months or Longer, Gross Unrealized Losses	(30)	(31)
12 Consecutive Months or Longer, Fair Value	652	658
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	(1)	(8)
Less than 12 Consecutive Months, Fair Value	86	659
12 Consecutive Months or Longer, Gross Unrealized Losses	(20)	(22)
12 Consecutive Months or Longer, Fair Value	514	491
Alt-A private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	(2)	(1)
Less than 12 Consecutive Months, Fair Value	106	26
12 Consecutive Months or Longer, Gross Unrealized Losses	(4)	(3)
12 Consecutive Months or Longer, Fair Value	49	54
Subprime private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	0	0
Less than 12 Consecutive Months, Fair Value	0	12
12 Consecutive Months or Longer, Gross Unrealized Losses	(5)	(4)
12 Consecutive Months or Longer, Fair Value	82	91
CMBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	(1)
Less than 12 Consecutive Months, Fair Value	70
12 Consecutive Months or Longer, Gross Unrealized Losses	0
12 Consecutive Months or Longer, Fair Value	0
Mortgage revenue bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	(2)	(35)
Less than 12 Consecutive Months, Fair Value	16	631
12 Consecutive Months or Longer, Gross Unrealized Losses	(1)	(2)
12 Consecutive Months or Longer, Fair Value	$ 7	22
Other mortgage-related securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses		(6)
Less than 12 Consecutive Months, Fair Value		224
12 Consecutive Months or Longer, Gross Unrealized Losses		0
12 Consecutive Months or Longer, Fair Value		$ 0

Investments in Securities Other

Investments in Securities Other-than-temporary Impairments 1 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Other-than-temporary-impairments	$ 2	$ 12	$ 31	$ 182
Subprime private-label securities [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 3,299		$ 3,299
Weighted average collateral default	39.20%		39.20%
Weighted average collateral severities	54.40%		54.40%
Weighted average voluntary prepayment rates	2.60%		2.60%
Average credit enhancement	16.70%		16.70%
Alt-A Option ARM [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 373		$ 373
Weighted average collateral default	25.70%		25.70%
Weighted average collateral severities	36.60%		36.60%
Weighted average voluntary prepayment rates	8.80%		8.80%
Average credit enhancement	3.90%		3.90%
Alt-A Fixed Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 514		$ 514
Weighted average collateral default	13.20%		13.20%
Weighted average collateral severities	45.30%		45.30%
Weighted average voluntary prepayment rates	10.90%		10.90%
Average credit enhancement	6.80%		6.80%
Alt-A Variable Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 625		$ 625
Weighted average collateral default	18.50%		18.50%
Weighted average collateral severities	30.10%		30.10%
Weighted average voluntary prepayment rates	8.70%		8.70%
Average credit enhancement	4.70%		4.70%
Alt-A Hybrid Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 674		$ 674
Weighted average collateral default	7.40%		7.40%
Weighted average collateral severities	30.50%		30.50%
Weighted average voluntary prepayment rates	13.50%		13.50%
Average credit enhancement	1.80%		1.80%

Investments in Securities Oth69

Investments in Securities Other-than-temporary Impairments 2 (Details) - Available-for-sale securities [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 2,293	$ 2,744	$ 2,421	$ 5,260
Additions for the credit component on debt securities for which OTTI was previously recognized	2	0	6	4
Reductions for securities no longer in portfolio at period end	(10)	(72)	(103)	(1,165)
Reductions for securities which we intend to sell or it is more likely than not that we will be required to sell before recovery of amortized cost basis	(31)	(70)	(31)	(1,439)
Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities	(35)	(45)	(74)	(103)
Balance, end of period	$ 2,219	$ 2,557	$ 2,219	$ 2,557

Investments in Securities Matur

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 11,511	$ 18,141
Total fair value	13,180	20,230
One Year or Less, Amortized Cost	533
One Year or Less, Fair Value	540
After One Year through Five Years, Amortized Cost	718
After One Year through Five Years, Fair Value	731
After Five Years through Ten Years, Amortized Cost	465
After Five Years through Ten Years, Fair Value	492
After Ten Years, Amortized Cost	9,795
After Ten Years, Fair Value	11,417
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	3,163	4,008
Total fair value	3,336	4,221
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	77
After One Year through Five Years, Fair Value	78
After Five Years through Ten Years, Amortized Cost	84
After Five Years through Ten Years, Fair Value	90
After Ten Years, Amortized Cost	3,002
After Ten Years, Fair Value	3,168
Freddie Mac [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,899	4,000
Total fair value	2,038	4,299
One Year or Less, Amortized Cost	1
One Year or Less, Fair Value	1
After One Year through Five Years, Amortized Cost	101
After One Year through Five Years, Fair Value	104
After Five Years through Ten Years, Amortized Cost	203
After Five Years through Ten Years, Fair Value	221
After Ten Years, Amortized Cost	1,594
After Ten Years, Fair Value	1,712
Ginnie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	58	343
Total fair value	66	391
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	1
After One Year through Five Years, Fair Value	1
After Five Years through Ten Years, Amortized Cost	4
After Five Years through Ten Years, Fair Value	4
After Ten Years, Amortized Cost	53
After Ten Years, Fair Value	61
Alt-A private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,269	2,029
Total fair value	1,827	2,678
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	0
After Five Years through Ten Years, Fair Value	0
After Ten Years, Amortized Cost	1,269
After Ten Years, Fair Value	1,827
Subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,722	2,526
Total fair value	2,373	3,281
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	0
After Five Years through Ten Years, Fair Value	0
After Ten Years, Amortized Cost	1,722
After Ten Years, Fair Value	2,373
CMBS [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,010	1,235
Total fair value	1,023	1,255
One Year or Less, Amortized Cost	521
One Year or Less, Fair Value	528
After One Year through Five Years, Amortized Cost	444
After One Year through Five Years, Fair Value	451
After Five Years through Ten Years, Amortized Cost	0
After Five Years through Ten Years, Fair Value	0
After Ten Years, Amortized Cost	45
After Ten Years, Fair Value	44
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,919	2,639
Total fair value	2,029	2,701
One Year or Less, Amortized Cost	11
One Year or Less, Fair Value	11
After One Year through Five Years, Amortized Cost	95
After One Year through Five Years, Fair Value	96
After Five Years through Ten Years, Amortized Cost	171
After Five Years through Ten Years, Fair Value	174
After Ten Years, Amortized Cost	1,642
After Ten Years, Fair Value	1,748
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	471	1,361
Total fair value	488	$ 1,404
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	1
After Five Years through Ten Years, Amortized Cost	3
After Five Years through Ten Years, Fair Value	3
After Ten Years, Amortized Cost	468
After Ten Years, Fair Value	$ 484

Financial Guarantees Financial

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	$ 29,691	$ 31,573
Guaranty Obligation	276	329
Maximum Recovery	11,156	11,726
Fair Value of guaranty obligations in Investments in securities	517	488
Unconsolidated VIEs [Member] | Unconsolidated Fannie Mae MBS [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	13,947	15,069
Guaranty Obligation	151	194
Maximum Recovery	8,448	8,857
Unconsolidated VIEs [Member] | Other guaranty arrangements [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	15,744	16,504
Guaranty Obligation	125	135
Maximum Recovery	$ 2,708	$ 2,869
Minimum [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Remaining contractual terms of our guarantees	1 day
Maximum [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Remaining contractual terms of our guarantees	36 years

Acquired Property, Net (Details

Acquired Property, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Acquired Property [Roll Forward]
Beginning balance - Acquired property	$ 6,737	$ 10,348	$ 7,481	$ 11,442
Additions	1,648	2,431	3,485	5,366
Disposals	(2,457)	(3,580)	(5,038)	(7,609)
Ending balance - Acquired property	5,928	9,199	5,928	9,199
Valuation allowance	(428)	(693)	(428)	(693)
Ending balance - Acquired property, net	$ 5,500	$ 8,506	$ 5,500	$ 8,506	$ 6,766

Short-Term Borrowings and Lon73

Short-Term Borrowings and Long-Term Debt Short-Term Borrowings (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Short-Term Borrowings [Line Items]
Federal funds purchased and securities sold under agreements to repurchase, outstanding	$ 115,000,000	$ 62,000,000
Federal funds purchased and securities sold under agreements to repurchase, weighted-average interest rate	0.00%	0.00%
Short-term debt, outstanding	$ 61,237,000,000	$ 71,950,000,000
Short-term debt, weighted-average interest rate	0.43%	0.26%
Secured uncommitted line of credit [Member]
Short-Term Borrowings [Line Items]
Line of credit maximum borrowing capacity	$ 15,000,000,000	$ 15,000,000,000
Line of credit amount outstanding	0
Fannie Mae [Member]
Short-Term Borrowings [Line Items]
Short-term debt, outstanding	$ 60,495,000,000	$ 71,007,000,000
Short-term debt, weighted-average interest rate	0.43%	0.26%
Consolidated Trusts [Member]
Short-Term Borrowings [Line Items]
Short-term debt, outstanding	$ 742,000,000	$ 943,000,000
Short-term debt, weighted-average interest rate	0.41%	0.19%

Short-Term Borrowings and Lon74

Short-Term Borrowings and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,150,667	$ 3,125,721
Long-term debt, weighted-average interest rate	2.70%	2.88%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 301,923	$ 315,128
Long-term debt, weighted-average interest rate	2.38%	2.41%
Unamortized discounts and premiums, other cost basis adjustments and fair value adjustments	$ 2,700	$ 3,200
Fannie Mae [Member] | Minimum [Member]
Long-Term Debt [Line Items]
Medium-term notes original contractual maturity	1 year	1 year
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	$ 257,137	$ 278,826
Long-term debt, weighted-average interest rate	2.33%	2.39%
Fannie Mae [Member] | Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 157,023	$ 154,057
Long-term debt, weighted-average interest rate	2.36%	2.49%
Fannie Mae [Member] | Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 79,663	$ 96,997
Long-term debt, weighted-average interest rate	1.48%	1.53%
Fannie Mae [Member] | Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 20,451	$ 27,772
Long-term debt, weighted-average interest rate	5.39%	4.88%
Fannie Mae [Member] | Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 40,225	$ 31,923
Long-term debt, weighted-average interest rate	1.87%	1.58%
Fannie Mae [Member] | Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 26,465	$ 20,791
Long-term debt, weighted-average interest rate	0.51%	0.27%
Fannie Mae [Member] | Senior floating Connecticut Avenue Security [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 13,350	$ 10,764
Long-term debt, weighted-average interest rate	4.43%	3.84%
Fannie Mae [Member] | Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 410	$ 368
Long-term debt, weighted-average interest rate	8.66%	10.46%
Fannie Mae [Member] | Subordinated debentures [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 4,431	$ 4,227
Long-term debt, weighted-average interest rate	9.93%	9.93%
Fannie Mae [Member] | Secured borrowings [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 130	$ 152
Long-term debt, weighted-average interest rate	1.44%	1.47%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 2,848,744	$ 2,810,593
Long-term debt, weighted-average interest rate	2.73%	2.94%

Derivative Instruments Derivati

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Asset Derivatives [Abstract]
Notional amount	$ 280,038	$ 175,667
Derivative asset, estimated fair value	775	894
Netting adjustment	(7,530)	(4,024)
Liability Derivatives [Abstract]
Notional amount	312,686	375,704
Derivative liability, estimated fair value	(1,135)	(424)
Netting adjustment	14,269	8,650
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	7,100	4,900
Cash collateral received for derivative instruments	345	314
Risk Management Derivatives [Member]
Asset Derivatives [Abstract]
Notional amount	189,311	113,355
Derivative asset, estimated fair value	6,849	4,020
Accrued interest receivable	819	758
Netting adjustment	(7,530)	(4,024)
Total net risk management derivatives - Asset	138	754
Liability Derivatives [Abstract]
Notional amount	191,226	312,573
Derivative liability, estimated fair value	(13,401)	(7,939)
Accrued interest payable	(1,045)	(977)
Netting adjustment	14,269	8,650
Total net risk management derivatives - Liability	(177)	(266)
Risk Management Derivatives [Member] | Pay-fixed Swap [Member]
Asset Derivatives [Abstract]
Notional amount	325	33,154
Derivative asset, estimated fair value	1	267
Liability Derivatives [Abstract]
Notional amount	156,864	123,106
Derivative liability, estimated fair value	(13,141)	(6,920)
Risk Management Derivatives [Member] | Receive-fixed Swap [Member]
Asset Derivatives [Abstract]
Notional amount	170,271	59,796
Derivative asset, estimated fair value	6,516	3,436
Liability Derivatives [Abstract]
Notional amount	11,113	143,209
Derivative liability, estimated fair value	(5)	(753)
Risk Management Derivatives [Member] | Basis Swap [Member]
Asset Derivatives [Abstract]
Notional amount	1,864	1,864
Derivative asset, estimated fair value	189	141
Liability Derivatives [Abstract]
Notional amount	17,100	17,100
Derivative liability, estimated fair value	(15)	(15)
Risk Management Derivatives [Member] | Foreign Currency Swap [Member]
Asset Derivatives [Abstract]
Notional amount	222	295
Derivative asset, estimated fair value	80	95
Liability Derivatives [Abstract]
Notional amount	233	258
Derivative liability, estimated fair value	(81)	(52)
Risk Management Derivatives [Member] | Pay-fixed Swaption [Member]
Asset Derivatives [Abstract]
Notional amount	6,880	7,050
Derivative asset, estimated fair value	36	45
Liability Derivatives [Abstract]
Notional amount	2,350	14,950
Derivative liability, estimated fair value	(4)	(26)
Risk Management Derivatives [Member] | Receive-fixed Swaption [Member]
Asset Derivatives [Abstract]
Notional amount	0	2,000
Derivative asset, estimated fair value	0	8
Liability Derivatives [Abstract]
Notional amount	3,430	13,950
Derivative liability, estimated fair value	(154)	(171)
Risk Management Derivatives [Member] | Other [Member]
Asset Derivatives [Abstract]
Notional amount	9,749	9,196
Derivative asset, estimated fair value	27	28
Liability Derivatives [Abstract]
Notional amount	136	0
Derivative liability, estimated fair value	(1)	(2)
Mortgage commitment derivatives [Member]
Asset Derivatives [Abstract]
Notional amount	90,727	62,312
Derivative asset, estimated fair value	637	140
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	121,460	63,131
Derivative liability, estimated fair value	(958)	(158)
Netting adjustment	0	0
Mortgage commitment derivatives [Member] | Mortgage Commitments to Purchase Whole Loans [Member]
Asset Derivatives [Abstract]
Notional amount	13,157	4,815
Derivative asset, estimated fair value	99	9
Liability Derivatives [Abstract]
Notional amount	29	2,960
Derivative liability, estimated fair value	0	(9)
Mortgage commitment derivatives [Member] | Forward Contracts to Purchase Mortgage-related Securities [Member]
Asset Derivatives [Abstract]
Notional amount	75,635	31,273
Derivative asset, estimated fair value	533	66
Liability Derivatives [Abstract]
Notional amount	4,024	19,418
Derivative liability, estimated fair value	(9)	(57)
Mortgage commitment derivatives [Member] | Forward Contracts to Sell Mortgage-related Securities [Member]
Asset Derivatives [Abstract]
Notional amount	1,935	26,224
Derivative asset, estimated fair value	5	65
Liability Derivatives [Abstract]
Notional amount	117,407	40,753
Derivative liability, estimated fair value	$ (949)	$ (92)

Derivative Instruments Narrativ

Derivative Instruments Narratives (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Aggregate fair value of all OTC derivatives with credit-risk-related contingent features that were in a net liability position	$ 3,600	$ 2,400
Aggregate fair value of collateral posted	3,600	2,200
Additional collateral required or amount required to immediately settle our positions if all of the credit-risk-related contingency features were triggered	$ 81	$ 257

Derivative Instruments Deriva77

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net accrual of periodic settlements	$ 5,286	$ 5,677	$ 10,055	$ 10,744
Derivative fair value gains (losses), net	(1,557)	2,481	(4,290)	728
Risk Management Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(1,190)	2,308	(3,561)	794
Risk Management Derivatives [Member] | Pay-fixed Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(2,257)	4,351	(7,430)	1,282
Risk Management Derivatives [Member] | Receive-fixed Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	1,371	(1,906)	4,358	(59)
Risk Management Derivatives [Member] | Basis Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	14	(44)	49	(12)
Risk Management Derivatives [Member] | Foreign Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(34)	16	(31)	(13)
Risk Management Derivatives [Member] | Pay-fixed Swaption [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	4	14	29	105
Risk Management Derivatives [Member] | Receive-fixed Swaption [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(19)	80	(136)	(79)
Risk Management Derivatives [Member] | Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	22	(4)	160	(2)
Risk Management Derivatives [Member] | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net accrual of periodic settlements	(291)	(199)	(560)	(428)
Mortgage commitment derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	$ (367)	$ 173	$ (729)	$ (66)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to Fannie Mae	$ 2,946	$ 4,640	$ 4,082	$ 6,528
Dividends distributed or available for distribution to senior preferred stockholder	(2,869)	(4,359)	(3,788)	(6,155)
Net income attributable to common stockholders	$ 77	$ 281	$ 294	$ 373
Weighted-average common shares outstanding, Basic	5,762	5,762	5,762	5,762
Convertible preferred stock	131	131	131	131
Weighted-average common shares outstanding, Diluted	5,893	5,893	5,893	5,893
Earnings (loss) per share, Basic (in dollars per share)	$ 0.01	$ 0.05	$ 0.05	$ 0.06
Earnings (loss) per share, Diluted (in dollars per share)	$ 0.01	$ 0.05	$ 0.05	$ 0.06
Weighted average shares of common stock that would be issued upon the full exercise of the warrant issued to Treasury	4,600	4,600	4,600	4,600

Segment Reporting Narrative (De

Segment Reporting Narrative (Details)	6 Months Ended
	Jun. 30, 2016segments
Segment Reporting [Abstract]
Number of Reportable Segments	3

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net interest income (loss)	$ 5,286	$ 5,677	$ 10,055	$ 10,744
Benefit (provision) for credit losses	1,601	(1,033)	2,785	(500)
Net interest income (loss) after benefit (provision) for credit losses	6,887	4,644	12,840	10,244
Guaranty fee income	30	37	55	68
Investment gains (losses), net	398	514	467	856
Fair value gains (losses), net	(1,667)	2,606	(4,480)	687
Gains (losses) from partnership investments	2	33	3	240
Fee and other income (expense)	144	519	322	796
Administrative expenses	(678)	(689)	(1,366)	(1,412)
Foreclosed property income (expense)	(63)	(182)	(397)	(655)
TCCA fees	(453)	(397)	(893)	(779)
Other income (expenses), net	(256)	(235)	(521)	(437)
Income (loss) before federal income taxes	4,344	6,850	6,030	9,608
Provision for federal income taxes	(1,398)	(2,210)	(1,948)	(3,080)
Net income (loss) attributable to Fannie Mae	2,946	4,640	4,082	6,528
US Treasury [Member]
Segment Reporting Information [Line Items]
TCCA fees	(453)	(397)	(893)	(779)
Business Segments [Member] | Single-Family [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	176	18	319	27
Benefit (provision) for credit losses	1,596	(1,056)	2,759	(578)
Net interest income (loss) after benefit (provision) for credit losses	1,772	(1,038)	3,078	(551)
Guaranty fee income	3,260	3,092	6,482	6,132
Investment gains (losses), net	0	(1)	(1)	(1)
Fair value gains (losses), net	0	0	0	(4)
Gains (losses) from partnership investments	(18)	(10)	(37)	(15)
Fee and other income (expense)	100	301	201	473
Administrative expenses	(496)	(458)	(1,004)	(942)
Foreclosed property income (expense)	(61)	(182)	(396)	(667)
Other income (expenses), net	(361)	(262)	(664)	(489)
Income (loss) before federal income taxes	3,743	1,045	6,766	3,157
Provision for federal income taxes	(1,093)	(419)	(1,736)	(1,000)
Net income (loss) attributable to Fannie Mae	2,650	626	5,030	2,157
Business Segments [Member] | Single-Family [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
TCCA fees	(453)	(397)	(893)	(779)
Business Segments [Member] | Multifamily [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	(15)	(26)	(40)	(57)
Benefit (provision) for credit losses	5	23	26	78
Net interest income (loss) after benefit (provision) for credit losses	(10)	(3)	(14)	21
Guaranty fee income	400	357	785	697
Investment gains (losses), net	11	15	14	24
Fair value gains (losses), net	0	0	0	0
Gains (losses) from partnership investments	20	43	40	255
Fee and other income (expense)	48	84	107	135
Administrative expenses	(86)	(83)	(170)	(171)
Foreclosed property income (expense)	(2)	0	(1)	12
Other income (expenses), net	(2)	(6)	(11)	(13)
Income (loss) before federal income taxes	379	407	750	960
Provision for federal income taxes	(40)	(41)	(78)	(111)
Net income (loss) attributable to Fannie Mae	339	366	672	849
Business Segments [Member] | Capital Markets [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	1,080	1,513	2,172	3,115
Benefit (provision) for credit losses	0	0	0	0
Net interest income (loss) after benefit (provision) for credit losses	1,080	1,513	2,172	3,115
Guaranty fee expense	(192)	(221)	(387)	(448)
Investment gains (losses), net	2,088	1,562	3,503	3,071
Fair value gains (losses), net	(1,730)	2,555	(4,533)	585
Gains (losses) from partnership investments	0	0	0	0
Fee and other income (expense)	31	150	52	205
Administrative expenses	(96)	(148)	(192)	(299)
Foreclosed property income (expense)	0	0	0	0
Other income (expenses), net	(30)	(11)	(59)	(11)
Income (loss) before federal income taxes	1,151	5,400	556	6,218
Provision for federal income taxes	(265)	(1,750)	(134)	(1,969)
Net income (loss) attributable to Fannie Mae	886	3,650	422	4,249
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	4,045	4,172	7,604	7,659
Benefit (provision) for credit losses	0	0	0	0
Net interest income (loss) after benefit (provision) for credit losses	4,045	4,172	7,604	7,659
Guaranty fee expense	(3,438)	(3,191)	(6,825)	(6,313)
Investment gains (losses), net	(1,701)	(1,062)	(3,049)	(2,238)
Fair value gains (losses), net	63	51	53	106
Gains (losses) from partnership investments	0	0	0	0
Fee and other income (expense)	(35)	(16)	(38)	(17)
Administrative expenses	0	0	0	0
Foreclosed property income (expense)	0	0	0	0
Other income (expenses), net	137	44	213	76
Income (loss) before federal income taxes	(929)	(2)	(2,042)	(727)
Provision for federal income taxes	0	0	0	0
Net income (loss) attributable to Fannie Mae	$ (929)	$ (2)	$ (2,042)	$ (727)

Equity Activity in OCI (Details

Equity Activity in OCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Equity [Abstract]
Net income	$ 2,946	$ 4,640	$ 4,082	$ 6,528
Other comprehensive (loss) income, net of tax effect:
Changes in net unrealized gains (losses) on AFS securities (net of tax of $27 and $44, respectively, for the three months ended and net of tax of $21 and $31, respectively, for the six months ended)	50	(81)	(39)	(57)
Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $4, respectively, for the three months ended and net of tax of $11 and $64, respectively, for the six months ended)	1	8	20	118
Reclassification adjustment for gains on AFS securities included in net income (net of tax of $68 and $112, respectively, for the three months ended and net of tax of $137 and $233, respectively, for the six months ended)	(126)	(207)	(254)	(432)
Other	(2)	(1)	(4)	(2)
Total other comprehensive loss	(77)	(281)	(277)	(373)
Total comprehensive income	2,869	4,359	3,805	6,155
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]
Changes in net unrealized gains (losses) on AFS securities (net of tax of $27 and $44, respectively, for the three months ended and net of tax of $21 and $31, respectively, for the six months ended)	27	(44)	(21)	(31)
Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $4, respectively, for the three months ended and net of tax of $11 and $64, respectively, for the six months ended)	1	4	11	64
Reclassification adjustment for gains on AFS securities included in net income (net of tax of $68 and $112, respectively, for the three months ended and net of tax of $137 and $233, respectively, for the six months ended)	$ 68	$ 112	$ 137	$ 233

Equity AOCI (Details)

Equity AOCI (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Equity [Abstract]
Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax	$ 292	$ 455
Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax	793	903
Other, net of tax	45	49
Accumulated other comprehensive income	$ 1,130	$ 1,407

Equity Changes in AOCI (Details

Equity Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 4,030
Total other comprehensive loss	$ (77)	$ (281)	(277)	$ (373)
Ending Balance	4,057		4,057
Accumulated net unrealized investment gain (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,160	2,030	1,358	2,121
Other comprehensive income (loss) before reclassifications	50	(81)	(39)	(57)
Amounts reclassified from other comprehensive loss	(125)	(199)	(234)	(314)
Total other comprehensive loss	(75)	(280)	(273)	(371)
Ending Balance	1,085	1,750	1,085	1,750
Accumulated other comprehensive income (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	47	(389)	49	(388)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from other comprehensive loss	(2)	(1)	(4)	(2)
Total other comprehensive loss	(2)	(1)	(4)	(2)
Ending Balance	45	(390)	45	(390)
Accumulated other comprehensive income [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,207	1,641	1,407	1,733
Other comprehensive income (loss) before reclassifications	50	(81)	(39)	(57)
Amounts reclassified from other comprehensive loss	(127)	(200)	(238)	(316)
Total other comprehensive loss	(77)	(281)	(277)	(373)
Ending Balance	$ 1,130	$ 1,360	$ 1,130	$ 1,360

Concentrations of Credit Risk S

Concentrations of Credit Risk SF Risk Characteristics (Details) - Single-family [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Guaranty Book of Business [Member] | Conventional Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	1.23%	1.27%
60 days delinquent (percentage of book of business)	0.32%	0.37%
Seriously delinquent (percentage of book of business)	1.33%	1.59%
30 days delinquent (percentage of conventional loans)	1.42%	1.46%
60 days delinquent (percentage of conventional loans)	0.36%	0.41%
Seriously delinquent (percentage of conventional loans)	1.32%	1.55%
Percentage of loans with detailed loan level information	99.00%	99.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.52%	0.58%
Percentage of book of business	20.00%	20.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	2.27%	2.86%
Percentage of book of business	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)	3.88%	4.87%
Percentage of book of business	4.00%	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)	3.03%	3.55%
Percentage of book of business	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)	1.16%	1.34%
Percentage of book of business	65.00%	65.00%
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)	10.54%	10.76%
Percentage of book of business	3.00%	3.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | Alt-A [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	5.68%	6.53%
Percentage of book of business	3.00%	4.00%
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)	2.82%	3.06%
Percentage of book of business	5.00%	5.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2005-2008
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	6.73%	7.60%
Percentage of book of business	9.00%	10.00%
Guaranty Book of Business [Member] | Conventional Loan [Member] | 2009-2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Seriously delinquent (percentage of conventional loans)	0.34%	0.36%
Percentage of book of business	86.00%	85.00%
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]	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Serious delinquency, days past due	60 days	60 days
Current debt service coverage ratio reporting lag	3 months	3 months
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current debt service coverage ratio (higher risk loans)	1	1
Serious delinquency, days past due	89 days	89 days
Current debt service coverage ratio reporting lag	6 months	6 months
Guaranty Book of Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 days delinquent (percentage of book of business)	0.03%	0.03%
Seriously delinquent (percentage of book of business)	0.07%	0.07%
Percentage of loans with detailed loan level information	99.00%	99.00%
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	2.00%	3.00%
Loans seriously delinquent, percentage by unpaid principal balance	0.03%	0.40%
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	98.00%	97.00%
Loans seriously delinquent, percentage by unpaid principal balance	0.08%	0.06%
Guaranty Book of Business [Member] | Current DSCR less than 100% [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of book of business	2.00%	2.00%
Loans seriously delinquent, percentage by unpaid principal balance	1.02%	1.51%

Concentrations of Credit Risk O

Concentrations of Credit Risk Other Concentrations (Details) $ in Millions	Jun. 30, 2016USD ($)servicersinsurers	Dec. 31, 2015USD ($)servicersinsurers
Concentration Risk [Line Items]
Estimated benefit included in total loss reserves	$ 1,700	$ 2,300
Receivable from claims on insured, defaulted loans excluding government insured loans	1,100	1,200
Allowance for mortgage insurance receivable	678	770
Mortgage Sellers and Servicers [Member]
Concentration Risk [Line Items]
Receivable from claims on insured, defaulted loans excluding government insured loans	$ 154	$ 241
Single-family [Member]
Concentration Risk [Line Items]
Number of mortgage servicers, including their affiliates, which serviced the majority of our guaranty book of business | servicers	5	5
Number of mortgage insurance companies provided majority of our mortgage insurance | insurers	4	4
Number of mortgage Insurers publicly disclosed credit quality deterioration | insurers	3
Single-family [Member] | Guaranty Book of Business [Member]
Concentration Risk [Line Items]
Mortgage insurance coverage risk in force	$ 121,500	$ 117,900
Mortgage insurance coverage risk in force as percentage	4.00%	4.00%
Primary mortgage insurance coverage risk in force	$ 120,800	$ 117,200
Pool mortgage insurance coverage risk in force	$ 676	$ 736
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 concentration risk	41.00%	44.00%
Single-family [Member] | Guaranty Book of Business [Member] | Insurance Service Provider Concentration Risk [Member]
Concentration Risk [Line Items]
Percentage of concentration risk	7.00%
Mortgage insurance coverage risk in force for insurers with credit quality deterioration	$ 9,100
Single-family [Member] | Guaranty Book of Business [Member] | Insurance Service Provider Concentration Risk [Member] | Group of Top Mortgage Insurance Companies [Member]
Concentration Risk [Line Items]
Percentage of concentration risk	78.00%	79.00%
Multifamily [Member]
Concentration Risk [Line Items]
Number of mortgage servicers, including their affiliates, which serviced the majority of our guaranty book of business | servicers	5	5
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 concentration risk	46.00%	45.00%

Netting Arrangements (Details)

Netting Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets
Derivative assets, gross amount	$ 8,278	$ 4,890
Derivative assets, gross amount offset	(7,530)	(4,024)
Derivative assets, net amount presented in the condensed consolidated balance sheets	748	866
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	(291)	(119)
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	(8)	(21)
Derivative assets, net amount	449	726
Securities purchased under agreements to resell or similar arrangements, gross amount	41,445	37,950
Securities purchased under agreements to resell or similar arrangements, gross amount offset	0	0
Securities purchased under agreements to resell or similar arrangements, net amount presented in the condensed consolidated balance sheets	41,445	37,950
Securities purchased under agreements to resell, under master netting arrangement, amounts not offset in the 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 the condensed consolidated balance sheets, collateral	(41,445)	(37,950)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	49,723	42,840
Total assets, gross amount offset	(7,530)	(4,024)
Total assets, net amount presented in the condensed consolidated balance sheets	42,193	38,816
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, financial instruments	(291)	(119)
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, collateral	(41,453)	(37,971)
Total assets, net amount	449	726
Liabilities:
Derivative liabilities, gross amount	(15,403)	(9,072)
Derivative liabilities, gross amount offset	14,269	8,650
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(1,134)	(422)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	291	119
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	31	(1)
Derivative liabilities, net amount	(812)	(304)
Securities sold under agreements to repurchase or similar arrangements, gross amount	(115)	(62)
Securities sold under agreements to repurchase or similar arrangements, gross amount offset	0	0
Securities sold under agreements to repurchase or similar arrangements, net amount presented in the condensed consolidated balance sheets	(115)	(62)
Securities sold under agreements to repurchase or similar arrangements, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	0	0
Securities sold under agreements to repurchase or similar arrangements, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	115	62
Securities sold under agreements to repurchase or similar arrangements, net amount	0	0
Total liabilities, gross amount	(15,518)	(9,134)
Total liabilities, gross amount offset	14,269	8,650
Total liabilities, net amount presented in the condensed consolidated balance sheets	(1,249)	(484)
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	291	119
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	146	61
Total liabilities, net amount	(812)	(304)
Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount offset	(7,530)	(4,024)
Liabilities:
Derivative liabilities, gross amount offset	14,269	8,650
Risk Management Derivatives [Member] | OTC Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount	4,949	4,042
Derivative assets, gross amount offset	(4,925)	(4,021)
Derivative assets, net amount presented in the condensed consolidated balance sheets	24	21
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	0	(18)
Derivative assets, net amount	24	3
Liabilities:
Derivative liabilities, gross amount	(8,303)	(6,118)
Derivative liabilities, gross amount offset	8,156	5,861
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(147)	(257)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	0	0
Derivative liabilities, net amount	(147)	(257)
Risk Management Derivatives [Member] | Cleared Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount	2,692	708
Derivative assets, gross amount offset	(2,605)	(3)
Derivative assets, net amount presented in the condensed consolidated balance sheets	87	705
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	0	0
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	0	0
Derivative assets, net amount	87	705
Liabilities:
Derivative liabilities, gross amount	(6,142)	(2,796)
Derivative liabilities, gross amount offset	6,113	2,789
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(29)	(7)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	0	0
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	29	0
Derivative liabilities, net amount	0	(7)
Mortgage commitment derivatives [Member]
Assets
Derivative assets, gross amount	637	140
Derivative assets, gross amount offset	0	0
Derivative assets, net amount presented in the condensed consolidated balance sheets	637	140
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	(291)	(119)
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	(8)	(3)
Derivative assets, net amount	338	18
Liabilities:
Derivative liabilities, gross amount	(958)	(158)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(958)	(158)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	291	119
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	2	(1)
Derivative liabilities, net amount	$ (665)	$ (40)

Netting Arrangements Narratives

Netting Arrangements Narratives (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair value of non-cash collateral we pledged	$ 1,200,000,000	$ 197,000,000
Fair value of non-cash collateral received	41,500,000,000	38,000,000,000
Fair value of non-cash collateral received that can be resold or repledged	38,900,000,000	36,200,000,000
Fair value of securities received as collateral that have been resold or repledge	0	0
Derivative assets not subject to enforceable master netting arrangement	27,000,000	28,000,000
Derivative liabilities not subject to enforceable master netting arrangement	1,000,000	2,000,000
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Securities purchased under agreements to resell or similar arrangements	$ 19,100,000,000	$ 10,600,000,000

Fair Value Levels Hierarchy (De

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 13,413	$ 14,075
Other assets [Abstract]
Derivative assets, gross amount offset	(7,530)	(4,024)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(14,269)	(8,650)
Mortgage commitment derivatives [Member]
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	10,650	11,133
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	32,798	23,609
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	29,652	29,485
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Total assets at fair value	71,848	64,438
Other assets [Abstract]
Derivatives assets at fair value	0	0
Liabilities [Abstract]
Total liabilities at fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fannie Mae [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	0	0
Liabilities [Abstract]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Consolidated Trusts [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	0	0
Liabilities [Abstract]
Long-term debt, fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Trading securities	9,019	9,025
Available-for-sale securities	10,352	11,799
Mortgage loans held for investment, at fair value	2,705,804	2,702,526
Total assets at fair value	2,779,984	2,770,088
Other assets [Abstract]
Derivatives assets at fair value	8,048	4,729
Liabilities [Abstract]
Total liabilities at fair value	3,292,266	3,224,091
Other liabilities [Abstract]
Derivative liabilities at fair value	15,395	9,042
Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	29,508	26,544
Liabilities [Abstract]
Long-term debt, fair value	315,023	324,248
Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	2,676,296	2,675,982
Liabilities [Abstract]
Long-term debt, fair value	2,901,213	2,819,733
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	496	1,398
Available-for-sale securities	2,828	8,431
Mortgage loans held for investment, at fair value	415,125	351,355
Total assets at fair value	423,793	367,852
Other assets [Abstract]
Derivatives assets at fair value	257	189
Liabilities [Abstract]
Total liabilities at fair value	42,660	30,061
Other liabilities [Abstract]
Derivative liabilities at fair value	9	32
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	183,942	193,670
Liabilities [Abstract]
Long-term debt, fair value	881	898
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	231,183	157,685
Liabilities [Abstract]
Long-term debt, fair value	40,138	27,175
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Trading securities	39,167	39,908
Available-for-sale securities	13,180	20,230
Mortgage loans held for investment, at fair value	13,413	14,075
Total assets at fair value	66,535	75,107
Other assets [Abstract]
Derivatives assets at fair value	775	894
Derivative assets, gross amount offset	(7,530)	(4,024)
Liabilities [Abstract]
Long-term debt, fair value	43,448	34,742
Total liabilities at fair value	44,583	35,166
Other liabilities [Abstract]
Derivative liabilities at fair value	1,135	424
Derivative liabilities, gross amount offset	(14,269)	(8,650)
Recurring Fair Value Measurements [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	7,605	4,697
Other liabilities [Abstract]
Derivative liabilities at fair value	14,287	8,717
Recurring Fair Value Measurements [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	36	53
Other liabilities [Abstract]
Derivative liabilities at fair value	158	197
Recurring Fair Value Measurements [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	27	28
Other liabilities [Abstract]
Derivative liabilities at fair value	1	2
Recurring Fair Value Measurements [Member] | Mortgage commitment derivatives [Member]
Other assets [Abstract]
Derivatives assets at fair value	637	140
Other liabilities [Abstract]
Derivative liabilities at fair value	958	158
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,650	11,133
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,650	11,133
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	32,798	23,609
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	5,352	4,813
Available-for-sale securities	3,336	4,221
Recurring Fair Value Measurements [Member] | Freddie Mac [Member]
Assets [Abstract]
Trading securities	1,328	1,314
Available-for-sale securities	2,038	4,299
Recurring Fair Value Measurements [Member] | Ginnie Mae [Member]
Assets [Abstract]
Trading securities	542	426
Available-for-sale securities	66	391
Recurring Fair Value Measurements [Member] | Alt-A private-label securities [Member]
Assets [Abstract]
Trading securities	316	436
Available-for-sale securities	1,827	2,678
Recurring Fair Value Measurements [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	395	644
Available-for-sale securities	2,373	3,281
Recurring Fair Value Measurements [Member] | CMBS [Member]
Assets [Abstract]
Trading securities	1,389	2,341
Available-for-sale securities	1,023	1,255
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Trading securities	193	449
Available-for-sale securities	2,029	2,701
Recurring Fair Value Measurements [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	488	1,404
Recurring Fair Value Measurements [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	29,652	29,485
Recurring Fair Value Measurements [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	29,652	29,485
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Total assets at fair value	29,652	29,485
Other assets [Abstract]
Derivatives assets at fair value	0	0
Liabilities [Abstract]
Long-term debt, fair value	0	0
Total liabilities 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] | Interest Rate Swaps
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] | 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] | Mortgage commitment derivatives [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] | Freddie Mac [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] | Ginnie 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] | Alt-A private-label 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] | Subprime private-label 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] | CMBS [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]
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 [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	29,652	29,485
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Trading securities	9,019	9,025
Available-for-sale securities	10,352	11,799
Mortgage loans held for investment, at fair value	12,133	12,598
Total assets at fair value	39,552	38,151
Other assets [Abstract]
Derivatives assets at fair value	8,048	4,729
Liabilities [Abstract]
Long-term debt, fair value	42,712	33,877
Total liabilities at fair value	58,107	42,919
Other liabilities [Abstract]
Derivative liabilities at fair value	15,395	9,042
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	7,389	4,541
Other liabilities [Abstract]
Derivative liabilities at fair value	14,283	8,697
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	36	53
Other liabilities [Abstract]
Derivative liabilities at fair value	158	197
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] | Mortgage commitment derivatives [Member]
Other assets [Abstract]
Derivatives assets at fair value	623	135
Other liabilities [Abstract]
Derivative liabilities at fair value	954	148
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,240	10,764
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	10,240	10,764
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	32,472	23,113
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	5,352	4,813
Available-for-sale securities	3,336	4,221
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Freddie Mac [Member]
Assets [Abstract]
Trading securities	1,328	1,314
Available-for-sale securities	2,037	4,295
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Ginnie Mae [Member]
Assets [Abstract]
Trading securities	542	426
Available-for-sale securities	66	391
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Alt-A private-label securities [Member]
Assets [Abstract]
Trading securities	57	131
Available-for-sale securities	1,652	1,637
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	351	0
Available-for-sale securities	2,200	0
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | CMBS [Member]
Assets [Abstract]
Trading securities	1,389	2,341
Available-for-sale securities	1,023	1,255
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Trading securities	0	0
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	38	0
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 Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	496	1,398
Available-for-sale securities	2,828	8,431
Mortgage loans held for investment, at fair value	1,280	1,477
Total assets at fair value	4,861	11,495
Other assets [Abstract]
Derivatives assets at fair value	257	189
Liabilities [Abstract]
Long-term debt, fair value	736	865
Total liabilities at fair value	745	897
Other liabilities [Abstract]
Derivative liabilities at fair value	9	32
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	216	156
Other liabilities [Abstract]
Derivative liabilities at fair value	4	20
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] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	27	28
Other liabilities [Abstract]
Derivative liabilities at fair value	1	2
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage commitment derivatives [Member]
Other assets [Abstract]
Derivatives assets at fair value	14	5
Other liabilities [Abstract]
Derivative liabilities at fair value	4	10
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	410	369
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	410	369
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	326	496
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Freddie Mac [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	1	4
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Ginnie Mae [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Alt-A private-label securities [Member]
Assets [Abstract]
Trading securities	259	305
Available-for-sale securities	175	1,041
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	44	644
Available-for-sale securities	173	3,281
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | CMBS [Member]
Assets [Abstract]
Trading securities	0	0
Available-for-sale securities	0	0
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Trading securities	193	449
Available-for-sale securities	2,029	2,701
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	450	1,404
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	$ 0	$ 0

Fair Value Level 3 Rollforward

Fair Value Level 3 Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Trading securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 33	$ 126	$ (30)	$ 168
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	677	2,286	1,398	3,030
Total gains (losses) (realized/unrealized) Included in Net Income	44	51	(35)	66
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	(184)	(657)	(466)	(1,067)
Issues	0	0	0	0
Settlements	(16)	(35)	(39)	(92)
Transfers out of Level 3	(25)	0	(388)	(322)
Transfers into Level 3	0	0	26	30
Ending Balance	496	1,645	496	1,645
Trading securities [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	25	2	0	305
Total gains (losses) (realized/unrealized) Included in Net Income	0	0	0	(27)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	0	(2)	0	(2)
Issues	0	0	0	0
Settlements	(1)	0	(1)	0
Transfers out of Level 3	(24)	0	(24)	(278)
Transfers into Level 3	0	0	25	2
Ending Balance	0	0	0	0
Trading securities [Member] | Freddie Mac [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1		0
Total gains (losses) (realized/unrealized) Included in Net Income	0		0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0		0
Purchases	0		0
Sales	0		0
Issues	0		0
Settlements	0		0
Transfers out of Level 3	(1)		(1)
Transfers into Level 3	0		1
Ending Balance	0		0
Trading securities [Member] | Alt-A private-label securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	25	45	(30)	51
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	245	572	305	597
Total gains (losses) (realized/unrealized) Included in Net Income	24	36	(30)	44
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	0	(267)	0	(267)
Issues	0	0	0	0
Settlements	(10)	(16)	(16)	(33)
Transfers out of Level 3	0	0	0	(44)
Transfers into Level 3	0	0	0	28
Ending Balance	259	325	259	325
Trading securities [Member] | Subprime private-label securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	2	97	(10)	99
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	43	876	644	1,307
Total gains (losses) (realized/unrealized) Included in Net Income	3	42	(34)	43
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	0	(182)	(187)	(580)
Issues	0	0	0	0
Settlements	(2)	(18)	(16)	(52)
Transfers out of Level 3	0	0	(363)	0
Transfers into Level 3	0	0	0	0
Ending Balance	44	718	44	718
Trading securities [Member] | Mortgage revenue bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	6	(36)	10	(1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	363	742	449	722
Total gains (losses) (realized/unrealized) Included in Net Income	17	(33)	29	2
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	(184)	(106)	(279)	(118)
Issues	0	0	0	0
Settlements	(3)	(1)	(6)	(4)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	193	602	193	602
Trading securities [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		20		19
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		94		99
Total gains (losses) (realized/unrealized) Included in Net Income		6		4
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income		0		0
Purchases		0		0
Sales		(100)		(100)
Issues		0		0
Settlements		0		(3)
Transfers out of Level 3		0		0
Transfers into Level 3		0		0
Ending Balance		0		0
Available-for-sale securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	3,621	13,471	8,431	15,080
Total gains (losses) (realized/unrealized) Included in Net Income	80	398	184	564
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	26	(303)	(137)	(290)
Purchases	0	182	0	421
Sales	(769)	(2,103)	(2,091)	(3,420)
Issues	0	0	0	0
Settlements	(128)	(475)	(433)	(1,187)
Transfers out of Level 3	(2)	(228)	(3,127)	(539)
Transfers into Level 3	0	11	1	324
Ending Balance	2,828	10,953	2,828	10,953
Available-for-sale securities [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1	205	0	0
Total gains (losses) (realized/unrealized) Included in Net Income	0	0	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	182	0	421
Sales	0	(269)	0	(303)
Issues	0	0	0	0
Settlements	0	0	0	0
Transfers out of Level 3	(1)	0	(1)	0
Transfers into Level 3	0	11	1	11
Ending Balance	0	129	0	129
Available-for-sale securities [Member] | Freddie Mac [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2	5	4	6
Total gains (losses) (realized/unrealized) Included in Net Income	0	0	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	0	(1)	0	(1)
Transfers out of Level 3	(1)	0	(3)	(1)
Transfers into Level 3	0	0	0	0
Ending Balance	1	4	1	4
Available-for-sale securities [Member] | Alt-A private-label securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	177	2,486	1,041	3,140
Total gains (losses) (realized/unrealized) Included in Net Income	0	71	12	172
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	2	(38)	(27)	(116)
Purchases	0	0	0	0
Sales	0	(552)	(291)	(1,108)
Issues	0	0	0	0
Settlements	(4)	(85)	(44)	(209)
Transfers out of Level 3	0	(228)	(516)	(538)
Transfers into Level 3	0	0	0	313
Ending Balance	175	1,654	175	1,654
Available-for-sale securities [Member] | Subprime private-label securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	222	4,608	3,281	5,240
Total gains (losses) (realized/unrealized) Included in Net Income	1	265	92	445
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	7	(131)	(132)	(232)
Purchases	0	0	0	0
Sales	0	(760)	(584)	(1,325)
Issues	0	0	0	0
Settlements	(57)	(145)	(161)	(291)
Transfers out of Level 3	0	0	(2,323)	0
Transfers into Level 3	0	0	0	0
Ending Balance	173	3,837	173	3,837
Available-for-sale securities [Member] | Mortgage revenue bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2,564	3,560	2,701	4,023
Total gains (losses) (realized/unrealized) Included in Net Income	76	17	80	40
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	18	(79)	48	(27)
Purchases	0	0	0	0
Sales	(568)	(154)	(611)	(316)
Issues	0	0	0	0
Settlements	(61)	(173)	(189)	(549)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	2,029	3,171	2,029	3,171
Available-for-sale securities [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	655	2,607	1,404	2,671
Total gains (losses) (realized/unrealized) Included in Net Income	3	45	0	(93)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	(1)	(55)	(26)	85
Purchases	0	0	0	0
Sales	(201)	(368)	(605)	(368)
Issues	0	0	0	0
Settlements	(6)	(71)	(39)	(137)
Transfers out of Level 3	0	0	(284)	0
Transfers into Level 3	0	0	0	0
Ending Balance	450	2,158	450	2,158
Mortgage loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	10	(6)	20	5
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,311	1,810	1,477	1,833
Total gains (losses) (realized/unrealized) Included in Net Income	15	4	116	38
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	25	2	25	5
Sales	0	0	(320)	0
Issues	0	0	0	0
Settlements	(67)	(99)	(139)	(176)
Transfers out of Level 3	(19)	(197)	(84)	(254)
Transfers into Level 3	15	75	205	149
Ending Balance	1,280	1,595	1,280	1,595
Net derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	41	(40)	76	(23)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	231	66	157	45
Total gains (losses) (realized/unrealized) Included in Net Income	52	(126)	232	(99)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	(3)	0	(7)	0
Settlements	(33)	64	(133)	58
Transfers out of Level 3	0	0	(2)	0
Transfers into Level 3	1	0	1	0
Ending Balance	248	4	248	4
Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(22)	52	(49)	12
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(641)	(938)	(865)	(890)
Total gains (losses) (realized/unrealized) Included in Net Loss	(22)	50	(116)	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
Issues	(47)	0	(54)	0
Settlements	9	16	318	25
Transfers out of Level 3	8	59	45	109
Transfers into Level 3	(43)	(26)	(64)	(92)
Ending Balance	(736)	(839)	(736)	(839)
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(7)	8	(8)	(4)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(246)	(547)	(496)	(527)
Total gains (losses) (realized/unrealized) Included in Net Loss	(7)	5	(75)	(8)
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	(47)	0	(54)	0
Settlements	9	16	318	25
Transfers out of Level 3	8	59	45	109
Transfers into Level 3	(43)	(26)	(64)	(92)
Ending Balance	(326)	(493)	(326)	(493)
Long-term debt [Member] | Senior floating [Member] | Fannie Mae [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(15)	44	(41)	16
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(395)	(391)	(369)	(363)
Total gains (losses) (realized/unrealized) Included in Net Loss	(15)	45	(41)	17
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	0	0	0	0
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	$ (410)	$ (346)	$ (410)	$ (346)

Fair Value Level 3 Valuation In

Fair Value Level 3 Valuation Inputs (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 13,413	$ 14,075
Derivatives	748	866
Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(10,650)	(11,133)
Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(32,798)	(23,609)
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	39,167	39,908
Available-for-sale securities	13,180	20,230
Mortgage loans held for investment, at fair value	13,413	14,075
Long-term Debt, Fair Value	(43,448)	(34,742)
Recurring Fair Value Measurements [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	316	436
Available-for-sale securities	1,827	2,678
Recurring Fair Value Measurements [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	395	644
Available-for-sale securities	2,373	3,281
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	193	449
Available-for-sale securities	2,029	2,701
Recurring Fair Value Measurements [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	488	1,404
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(10,650)	(11,133)
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(10,650)	(11,133)
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(32,798)	(23,609)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	496	1,398
Available-for-sale securities	2,828	8,431
Mortgage loans held for investment, at fair value	415,125	351,355
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	183,942	193,670
Long-term Debt, Fair Value	(881)	(898)
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	231,183	157,685
Long-term Debt, Fair Value	(40,138)	(27,175)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	496	1,398
Available-for-sale securities	2,828	8,431
Mortgage loans held for investment, at fair value	1,280	1,477
Derivatives	248	157
Long-term Debt, Fair Value	(736)	(865)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	259	305
Available-for-sale securities	175	1,041
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	44	644
Available-for-sale securities	173	3,281
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	193	449
Available-for-sale securities	2,029	2,701
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	450	1,404
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	$ 37
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	1.80%
Prepayment Speed (%)	3.10%
Severity (%)	72.00%
Spreads (%)	3.355%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	1.80%
Prepayment Speed (%)	3.10%
Severity (%)	72.00%
Spreads (%)	3.355%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	1.80%
Prepayment Speed (%)	3.10%
Severity (%)	72.00%
Spreads (%)	3.355%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	$ 44
Available-for-sale securities		$ 343
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	5.00%
Prepayment Speed (%)	5.00%
Severity (%)	75.00%
Spreads (%)	6.678%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	5.00%
Prepayment Speed (%)	5.00%
Severity (%)	75.00%
Spreads (%)	6.678%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	5.00%
Prepayment Speed (%)	5.00%
Severity (%)	75.00%
Spreads (%)	6.678%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		2.50%
Prepayment Speed (%)		1.90%
Severity (%)		67.60%
Spreads (%)		2.85%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		7.50%
Prepayment Speed (%)		5.70%
Severity (%)		85.70%
Spreads (%)		3.40%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		4.80%
Prepayment Speed (%)		3.30%
Severity (%)		72.70%
Spreads (%)		2.996%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 951	$ 991
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.075%	(0.331%)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	4.143%	3.868%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor With Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.603%	0.379%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	$ 222	$ 305
Available-for-sale securities	$ 121	$ 671
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	2.00%	1.30%
Prepayment Speed (%)	3.00%	2.20%
Severity (%)	50.00%	20.50%
Spreads (%)	2.80%	2.19%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	5.00%	4.90%
Prepayment Speed (%)	8.00%	4.50%
Severity (%)	95.00%	95.00%
Spreads (%)	4.934%	2.633%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Trading securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	4.20%	3.60%
Prepayment Speed (%)	6.70%	3.70%
Severity (%)	83.30%	69.30%
Spreads (%)	4.378%	2.531%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	3.00%	0.50%
Prepayment Speed (%)	5.00%	1.70%
Severity (%)	60.00%	1.40%
Spreads (%)	3.025%	2.256%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	6.00%	40.70%
Prepayment Speed (%)	8.00%	72.60%
Severity (%)	80.00%	95.00%
Spreads (%)	3.42%	2.804%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	3.40%	3.40%
Prepayment Speed (%)	5.20%	13.50%
Severity (%)	61.60%	58.50%
Spreads (%)	3.302%	2.60%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities		$ 526
Available-for-sale securities		$ 1,848
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		4.20%
Prepayment Speed (%)		0.40%
Severity (%)		55.90%
Spreads (%)		2.85%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		8.40%
Prepayment Speed (%)		5.30%
Severity (%)		95.00%
Spreads (%)		2.85%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Trading securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		5.90%
Prepayment Speed (%)		3.30%
Severity (%)		73.70%
Spreads (%)		2.85%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		0.50%
Prepayment Speed (%)		0.50%
Severity (%)		20.00%
Spreads (%)		2.55%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		11.30%
Prepayment Speed (%)		11.20%
Severity (%)		95.00%
Spreads (%)		2.85%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		5.90%
Prepayment Speed (%)		3.80%
Severity (%)		79.00%
Spreads (%)		2.833%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 87	$ 683
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	0.50%	0.50%
Prepayment Speed (%)	2.50%	2.50%
Severity (%)	20.00%	6.60%
Spreads (%)	3.035%	2.00%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	3.50%	4.60%
Prepayment Speed (%)	5.00%	15.50%
Severity (%)	88.00%	95.00%
Spreads (%)	4.53%	4.544%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	3.50%	3.40%
Prepayment Speed (%)	2.50%	4.70%
Severity (%)	87.70%	65.70%
Spreads (%)	3.761%	3.156%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus without Inputs [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities		$ 201
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consensus without Inputs [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities		73
Available-for-sale securities		945
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 54	$ 169
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	6.00%	4.00%
Prepayment Speed (%)	8.00%	4.00%
Severity (%)	65.00%	50.00%
Spreads (%)	3.016%	2.60%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	6.00%	5.00%
Prepayment Speed (%)	8.00%	7.50%
Severity (%)	65.00%	64.00%
Spreads (%)	3.67%	3.694%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Alt-A private-label securities [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	6.00%	4.80%
Prepayment Speed (%)	8.00%	6.40%
Severity (%)	65.00%	59.20%
Spreads (%)	3.552%	2.965%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	$ 185	$ 437
Available-for-sale securities	$ 970	$ 1,462
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Trading securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.275%	0.015%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Trading securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	3.214%	3.762%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Trading securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	3.173%	2.989%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.075%	(0.158%)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	4.428%	3.791%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Mortgage revenue bonds [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	2.868%	2.838%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 357	$ 520
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	0.80%	0.00%
Prepayment Speed (%)	1.00%	0.00%
Severity (%)	95.00%	95.00%
Spreads (%)	2.20%	2.60%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	0.80%	1.80%
Prepayment Speed (%)	1.00%	0.50%
Severity (%)	95.00%	95.00%
Spreads (%)	4.87%	3.50%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Discounted Cash Flow with Inputs [Member] | Other [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	0.80%	0.00%
Prepayment Speed (%)	1.00%	0.00%
Severity (%)	95.00%	95.00%
Spreads (%)	4.851%	3.236%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 36	$ 4
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member] | Agency [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	1	4
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities		45
Available-for-sale securities	50	145
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	8	12
Available-for-sale securities	108	248
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	6	201
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark with Inputs [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	$ 123
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	6.50%
Prepayment Speed (%)	5.00%
Severity (%)	85.00%
Spreads (%)	3.30%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	10.00%
Prepayment Speed (%)	6.00%
Severity (%)	95.00%
Spreads (%)	330.00%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark with Inputs [Member] | Subprime private-label securities [Member] | Available-for-sale securities [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	8.30%
Prepayment Speed (%)	5.50%
Severity (%)	90.00%
Spreads (%)	3.30%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	$ 212	136
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives		17
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	1,124	1,321
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Consensus with Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 149	$ 234
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Consensus with Inputs [Member] | Mortgage loans [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	1.00%	0.50%
Prepayment Speed (%)	3.00%	2.50%
Severity (%)	44.00%	20.00%
Spreads (%)	2.45%	2.55%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Consensus with Inputs [Member] | Mortgage loans [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	7.00%	5.00%
Prepayment Speed (%)	23.30%	26.00%
Severity (%)	95.00%	89.10%
Spreads (%)	3.10%	2.776%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Consensus with Inputs [Member] | Mortgage loans [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	3.10%	3.70%
Prepayment Speed (%)	7.30%	6.40%
Severity (%)	70.50%	69.00%
Spreads (%)	2.597%	2.646%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Consensus without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 239	$ 274
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Build-Up with inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value		$ 127
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		0.00%
Prepayment Speed (%)		3.00%
Severity (%)		0.00%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		99.20%
Prepayment Speed (%)		100.00%
Severity (%)		100.00%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		34.80%
Prepayment Speed (%)		10.40%
Severity (%)		39.90%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Build-Up without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	572	$ 632
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single-family [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	164	54
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Multifamily [Member] | Build-Up with inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 156	$ 156
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Multifamily [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	0.80%	0.70%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Multifamily [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	3.872%	3.272%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Multifamily [Member] | Build-Up with inputs [Member] | Mortgage loans [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Spreads (%)	1.94%	1.588%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	$ (410)	$ (369)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(410)	(369)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Discounted Cash Flow without Inputs [Member] | Senior floating [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(410)	(369)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(326)	(496)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Consensus with Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value		$ (181)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Consensus with Inputs [Member] | Long-term debt [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		0.50%
Prepayment Speed (%)		2.50%
Severity (%)		20.00%
Spreads (%)		2.55%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Consensus with Inputs [Member] | Long-term debt [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		3.80%
Prepayment Speed (%)		26.00%
Severity (%)		80.60%
Spreads (%)		2.70%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Consensus with Inputs [Member] | Long-term debt [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)		3.40%
Prepayment Speed (%)		5.60%
Severity (%)		67.80%
Spreads (%)		2.658%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Consensus without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value		$ (149)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Discounted Cash Flow with Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	$ (125)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Discounted Cash Flow with Inputs [Member] | Long-term debt [Member] | Minimum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	2.00%
Prepayment Speed (%)	3.00%
Severity (%)	58.00%
Spreads (%)	0.88%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Discounted Cash Flow with Inputs [Member] | Long-term debt [Member] | Maximum [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	7.00%
Prepayment Speed (%)	100.00%
Severity (%)	95.00%
Spreads (%)	3.663%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Discounted Cash Flow with Inputs [Member] | Long-term debt [Member] | Weighted Average [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Default Rate (%)	4.90%
Prepayment Speed (%)	92.40%
Severity (%)	83.00%
Spreads (%)	2.247%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	$ (201)	$ (166)

Fair Value Level 3 Valuation -

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 13,413	$ 14,075
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	401	157
Mortgage loans held for investment, at fair value	2,705,804	2,702,526
Total assets at fair value	2,779,984	2,770,088
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	4,268	5,541
Mortgage loans held for investment, at fair value	415,125	351,355
Total assets at fair value	423,793	367,852
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for sale, at lower of cost or fair value	119	17
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for sale, at lower of cost or fair value	1,954	3,991
Total assets at fair value	7,872	13,934
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consensus without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for sale, at lower of cost or fair value	1,919	3,651
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single Vendor without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for sale, at lower of cost or fair value	32	336
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for sale, at lower of cost or fair value	3	4
Other assets	$ 12	$ 30
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Number of Acquired Properties Valuated, Percentage	22.00%	18.00%
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Proprietary Home Price Model and Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Number of Acquired Properties Valuated, Percentage	74.00%	77.00%
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	$ 2,014	$ 3,211
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	60	134
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Internal Model [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	3,640	6,379
Acquired property, net	476	986
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Accepted Offers [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	443	541
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Appraisals [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	728	1,117
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Single-family [Member] | Walk Forwards [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Acquired property, net	307	433
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	243	323
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	5	5
Acquired property, net	9	0
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Broker Price Opinions [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	27	82
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Multifamily [Member] | Asset Manager Estimate [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 211	$ 236

Fair Value Fair Value of Financ

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (7,530)	$ (4,024)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(14,269)	(8,650)
Mortgage loans held for investment, at fair value	13,413	14,075
Derivative assets, gross amount offset	(7,530)	(4,024)
Derivative liabilities, gross amount offset	(14,269)	(8,650)
Fair Value Estimation Process [Member] | Home Affordable Refinance Program (HARP) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	270,900	282,000
Financial liabilities [Abstract]
Change In Estimated Fair Value Resulting From Change In Principal Market	256	1,100
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	42,196	34,953
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	29,652	29,485
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	71,848	64,438
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	0	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	19,120	10,600
Federal funds sold and securities purchased under agreements to resell or similar arrangements	22,325	27,350
Trading securities	9,019	9,025
Available-for-sale securities	10,352	11,799
Mortgage loans held for sale	401	157
Mortgage loans held for investment, at fair value	2,705,804	2,702,526
Advances to lenders	4,915	3,902
Derivatives assets at fair value	8,048	4,729
Guaranty assets and buy-ups	0	0
Total financial assets	2,779,984	2,770,088
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	115	62
Derivative liabilities at fair value	15,395	9,042
Guaranty obligations	0	0
Total financial liabilities	3,292,266	3,224,091
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	496	1,398
Available-for-sale securities	2,828	8,431
Mortgage loans held for sale	4,268	5,541
Mortgage loans held for investment, at fair value	415,125	351,355
Advances to lenders	365	394
Derivatives assets at fair value	257	189
Guaranty assets and buy-ups	454	544
Total financial assets	423,793	367,852
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	0	0
Derivative liabilities at fair value	9	32
Guaranty obligations	890	1,012
Total financial liabilities	42,660	30,061
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	10,650	11,133
Fannie Mae [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	0	0
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	0	0
Fannie Mae [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	29,508	26,544
Financial liabilities [Abstract]
Short-term debt	60,520	71,006
Long-term debt	315,023	324,248
Fannie Mae [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	183,942	193,670
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	881	898
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	32,798	23,609
Consolidated Trusts [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	0	0
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	0	0
Consolidated Trusts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	2,676,296	2,675,982
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	2,901,213	2,819,733
Consolidated Trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	231,183	157,685
Financial liabilities [Abstract]
Short-term debt	742	944
Long-term debt	40,138	27,175
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	61,316	45,553
Federal funds sold and securities purchased under agreements to resell or similar arrangements	22,325	27,350
Trading securities	39,167	39,908
Available-for-sale securities	13,180	20,230
Mortgage loans held for sale	4,277	5,361
Mortgage loans held for investment, at fair value	3,025,592	3,014,283
Advances to lenders	5,288	4,308
Derivatives assets at fair value	775	894
Guaranty assets and buy-ups	141	184
Total financial assets	3,172,061	3,158,071
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	115	62
Derivative liabilities at fair value	1,135	424
Guaranty obligations	276	329
Total financial liabilities	3,213,430	3,198,486
Carrying Value [Member] | Fannie Mae [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	201,243	206,544
Financial liabilities [Abstract]
Short-term debt	60,495	71,007
Long-term debt	301,923	315,128
Carrying Value [Member] | Consolidated Trusts [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	2,824,349	2,807,739
Financial liabilities [Abstract]
Short-term debt	742	943
Long-term debt	2,848,744	2,810,593
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	61,316	45,553
Federal funds sold and securities purchased under agreements to resell or similar arrangements	22,325	27,350
Trading securities	39,167	39,908
Available-for-sale securities	13,180	20,230
Mortgage loans held for sale	4,669	5,698
Mortgage loans held for investment, at fair value	3,120,929	3,053,881
Advances to lenders	5,280	4,296
Derivatives assets at fair value	775	894
Guaranty assets and buy-ups	454	544
Total financial assets	3,268,095	3,198,354
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	115	62
Derivative liabilities at fair value	1,135	424
Guaranty obligations	890	1,012
Total financial liabilities	3,320,657	3,245,502
Estimated of Fair Value [Member] | Fannie Mae [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	213,450	220,214
Financial liabilities [Abstract]
Short-term debt	60,520	71,006
Long-term debt	315,904	325,146
Estimated of Fair Value [Member] | Consolidated Trusts [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	2,907,479	2,833,667
Financial liabilities [Abstract]
Short-term debt	742	944
Long-term debt	$ 2,941,351	$ 2,846,908

Fair Value Fair Value Option (D

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	$ 13,413	$ 14,075
Fair value of nonaccrual loans	152	238
Difference between unpaid principal balance and the fair value of nonaccrual loans	32	59
Fair value of loans that are 90 days or more past due	162	256
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	$ 25	$ 52
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	$ 10,650	$ 11,133
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	32,798	23,609
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	13,413	14,075
Loans, unpaid principal balance	12,690	13,661
Long-term debt [Member] | Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	10,650	11,133
Long-term debt, unpaid principal balance	10,511	11,263
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	32,798	23,609
Long-term debt, unpaid principal balance	$ 29,365	$ 21,604

Fair Value Changes in FV under

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Total Gains (Losses)	$ (150)	$ 137	$ (189)	$ (68)
Other changes in fair value	(18)	10	(102)	(11)
Fair value gains (losses), net	(168)	147	(291)	(79)
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Loans	19	49	32	37
Other changes in fair value	126	(217)	344	(50)
Fair value gains (losses), net	145	(168)	376	(13)
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Long-Term Debt	(169)	88	(221)	(105)
Other changes in fair value	(144)	227	(446)	39
Fair value gains (losses), net	$ (313)	$ 315	$ (667)	$ (66)