Federal National Mortgage Association (FNMA) 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 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	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding	1,158,082,750

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Assets:
Cash and cash equivalents	$ 26,559	$ 14,674
Restricted cash (includes $37,856 and $25,865, respectively, related to consolidated trusts)	42,926	30,879
Federal funds sold and securities purchased under agreements to resell or similar arrangements	18,350	27,350
Investments in securities:
Trading, at fair value (includes $1,191 and $135, respectively, pledged as collateral)	40,547	39,908
Available-for-sale, at fair value (includes $110 and $285, respectively, related to consolidated trusts)	9,865	20,230
Total investments in securities	50,412	60,138
Mortgage loans:
Loans held for sale, at lower of cost or fair value	3,405	5,361
Loans held for investment, at amortized cost	3,068,262	3,042,234
Allowance for loan losses	(22,706)	(27,951)
Total loans held for investment, net of allowance	3,045,556	3,014,283
Total mortgage loans	3,048,961	3,019,644
Deferred tax assets, net	35,101	37,187
Accrued interest receivable (includes $7,032 and $6,974, respectively, related to consolidated trusts)	7,728	7,726
Acquired property, net	5,041	6,766
Other assets	20,864	17,553
Total assets	3,255,942	3,221,917
Liabilities:
Accrued interest payable (includes $8,199 and $8,194, respectively, related to consolidated trusts)	9,512	9,794
Other liabilities (includes $392 and $448, respectively, related to consolidated trusts)	9,141	10,393
Total liabilities	3,251,766	3,217,858
Commitments and contingencies (Note 16)	0	0
Fannie Mae stockholders’ equity:
Senior preferred stock, 1,000,000 shares issued and outstanding	117,149	117,149
Preferred stock, 700,000,000 shares are authorized—555,374,922 shares issued and outstanding	19,130	19,130
Common stock, no par value, no maximum authorization—1,308,762,703 shares issued and 1,158,082,750 shares outstanding	687	687
Accumulated deficit	(126,312)	(126,942)
Accumulated other comprehensive income	923	1,407
Treasury stock, at cost, 150,679,953 shares	(7,401)	(7,401)
Total Fannie Mae stockholders’ equity	4,176	4,030
Noncontrolling interest	0	29
Total equity (See Note 1: Impact of U.S. Government Support for information on our dividend obligation to Treasury)	4,176	4,059
Total liabilities and equity	3,255,942	3,221,917
Fannie Mae [Member]
Mortgage loans:
Loans held for investment, at amortized cost	216,958	233,054
Allowance for loan losses	(21,858)	(26,510)
Total mortgage loans	198,497	211,887
Liabilities:
Debt (includes $10,460 and $11,133, respectively, of debt of Fannie Mae at fair value and $35,453 and $23,609, respectively, of debt of consolidated trusts, at fair value)	351,568	386,135
Consolidated Trusts [Member]
Assets:
Restricted cash (includes $37,856 and $25,865, respectively, related to consolidated trusts)	37,856	25,865
Investments in securities:
Available-for-sale, at fair value (includes $110 and $285, respectively, related to consolidated trusts)	110	285
Mortgage loans:
Loans held for investment, at amortized cost	2,851,304	2,809,180
Allowance for loan losses	(848)	(1,441)
Total mortgage loans	2,850,464	2,807,757
Accrued interest receivable (includes $7,032 and $6,974, respectively, related to consolidated trusts)	7,032	6,974
Liabilities:
Accrued interest payable (includes $8,199 and $8,194, respectively, related to consolidated trusts)	8,199	8,194
Debt (includes $10,460 and $11,133, respectively, of debt of Fannie Mae at fair value and $35,453 and $23,609, respectively, of debt of consolidated trusts, at fair value)	2,881,545	2,811,536
Other liabilities (includes $392 and $448, respectively, related to consolidated trusts)	$ 392	$ 448

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Assets:
Restricted cash (includes $37,856 and $25,865, respectively, related to consolidated trusts)	$ 42,926	$ 30,879
Investments in securities:
Trading, at fair value (includes $1,191 and $135, respectively, pledged as collateral)	1,191	135
Available-for-sale, at fair value (includes $110 and $285, respectively, related to consolidated trusts)	9,865	20,230
Accrued interest receivable (includes $7,032 and $6,974, respectively, related to consolidated trusts)	7,728	7,726
Mortgage loans:
Total loans held for investment (includes $12,914 and $14,075, respectively, at fair value)	12,914	14,075
Liabilities:
Accrued interest payable (includes $8,199 and $8,194, respectively, related to consolidated trusts)	9,512	9,794
Other liabilities (includes $392 and $448, respectively, related to consolidated trusts)	$ 9,141	$ 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 $37,856 and $25,865, respectively, related to consolidated trusts)	$ 37,856	$ 25,865
Investments in securities:
Available-for-sale, at fair value (includes $110 and $285, respectively, related to consolidated trusts)	110	285
Accrued interest receivable (includes $7,032 and $6,974, respectively, related to consolidated trusts)	7,032	6,974
Liabilities:
Accrued interest payable (includes $8,199 and $8,194, respectively, related to consolidated trusts)	8,199	8,194
Debt at fair value	35,453	23,609
Other liabilities (includes $392 and $448, respectively, related to consolidated trusts)	392	448
Fannie Mae [Member]
Liabilities:
Debt at fair value	$ 10,460	$ 11,133

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest income:
Trading securities	$ 140	$ 99	$ 388	$ 330
Available-for-sale securities	134	261	507	931
Mortgage loans (includes $23,254 and $24,537, respectively, for the three months ended and $71,746 and $73,426, respectively, for the nine months ended related to consolidated trusts)	25,611	26,980	78,828	80,706
Other	66	37	160	104
Total interest income	25,951	27,377	79,883	82,071
Interest expense:
Short-term debt	56	37	164	99
Long-term debt (includes $18,814 and $19,891, respectively, for the three months ended and $58,993 and $59,934, respectively, for the nine months ended related to consolidated trusts)	20,460	21,752	64,229	65,640
Total interest expense	20,516	21,789	64,393	65,739
Net interest income	5,435	5,588	15,490	16,332
Benefit for credit losses	673	1,550	3,458	1,050
Net interest income after benefit for credit losses	6,108	7,138	18,948	17,382
Non-interest income (loss):
Investment gains, net	467	299	934	1,155
Fair value losses, net	(491)	(2,589)	(4,971)	(1,902)
Fee and other income	175	259	552	1,123
Non-interest income (loss)	151	(2,031)	(3,485)	376
Administrative expenses:
Salaries and employee benefits	322	317	1,017	999
Professional services	237	219	684	741
Occupancy expenses	45	43	136	129
Other administrative expenses	57	373	190	495
Total administrative expenses	661	952	2,027	2,364
Foreclosed property expense	110	497	507	1,152
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees	465	413	1,358	1,192
Other expenses, net	300	215	818	412
Total expenses	1,536	2,077	4,710	5,120
Income before federal income taxes	4,723	3,030	10,753	12,638
Provision for federal income taxes	(1,527)	(1,070)	(3,475)	(4,150)
Net income	3,196	1,960	7,278	8,488
Other comprehensive income (loss):
Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes	(205)	(177)	(478)	(548)
Other	(2)	430	(6)	428
Total other comprehensive income (loss)	(207)	253	(484)	(120)
Total comprehensive income attributable to Fannie Mae	2,989	2,213	6,794	8,368
Net income attributable to Fannie Mae	3,196	1,960	7,278	8,488
Dividends distributed or available for distribution to senior preferred stockholder (Note 10)	(2,977)	(2,202)	(6,765)	(8,357)
Net income (loss) attributable to common stockholders (Note 10)	$ 219	$ (242)	$ 513	$ 131
Earnings (loss) per share, basic (in dollars per share)	$ 0.04	$ (0.04)	$ 0.09	$ 0.02
Earnings (loss) per share, diluted (in dollars per share)	$ 0.04	$ (0.04)	$ 0.09	$ 0.02
Weighted-average common shares outstanding, basic	5,762	5,762	5,762	5,762
Weighted-average common shares outstanding, diluted	5,893	5,762	5,893	5,893

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Mortgage loans (includes $23,254 and $24,537, respectively, for the three months ended and $71,746 and $73,426, respectively, for the nine months ended related to consolidated trusts)	$ 25,611	$ 26,980	$ 78,828	$ 80,706
Long-term debt (includes $18,814 and $19,891, respectively, for the three months ended and $58,993 and $59,934, respectively, for the nine months ended related to consolidated trusts)	20,460	21,752	64,229	65,640
Consolidated Trusts [Member]
Mortgage loans (includes $23,254 and $24,537, respectively, for the three months ended and $71,746 and $73,426, respectively, for the nine months ended related to consolidated trusts)	23,254	24,537	71,746	73,426
Long-term debt (includes $18,814 and $19,891, respectively, for the three months ended and $58,993 and $59,934, respectively, for the nine months ended related to consolidated trusts)	$ 18,814	$ 19,891	$ 58,993	$ 59,934

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Net cash used in operating activities
Net cash used in operating activities	$ (4,749)	$ (6,375)
Cash flows provided by investing activities:
Proceeds from maturities and paydowns of trading securities held for investment	1,282	633
Proceeds from sales of trading securities held for investment	1,405	1,028
Proceeds from maturities and paydowns of available-for-sale securities	2,355	3,477
Proceeds from sales of available-for-sale securities	10,481	6,919
Purchases of loans held for investment	(168,729)	(146,577)
Net change in restricted cash	(12,047)	2,261
Advances to lenders	(96,797)	(92,345)
Proceeds from disposition of acquired property and preforeclosure sales	12,478	16,306
Net change in federal funds sold and securities purchased under agreements to resell or similar arrangements	9,000	4,350
Other, net	(305)	103
Net cash provided by investing activities	176,306	193,784
Cash flows used in financing activities:
Payments of cash dividends on senior preferred stock to Treasury	(6,647)	(8,075)
Other, net	(62)	68
Net cash used in financing activities	(159,672)	(189,517)
Net increase (decrease) in cash and cash equivalents	11,885	(2,108)
Cash and cash equivalents at beginning of period	14,674	22,023
Cash and cash equivalents at end of period	26,559	19,915
Cash paid during the period for:
Interest	78,281	78,584
Income taxes	1,141	470
Fannie Mae [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	18,413	19,145
Proceeds from sales of loans acquired as held for investment of Fannie Mae	3,209	2,315
Cash flows used in financing activities:
Proceeds from issuance of debt	736,239	337,748
Payments to redeem debt	(772,380)	(381,487)
Consolidated Trusts [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans acquired as held for investment	395,561	376,169
Cash flows used in financing activities:
Proceeds from issuance of debt	290,146	259,254
Payments to redeem debt	$ (406,968)	$ (397,025)

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 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 September 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 September 30, 2016 . As of September 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 $2.9 billion on 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 . We expect to pay Treasury an additional dividend of $3.0 billion by December 31, 2016 based on our net worth of $4.2 billion as of September 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 nine months ended September 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 nine months ended September 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 $138.9 billion as of September 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 September 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 $14 million and $18 million for the three months ended September 30, 2016 and 2015 , respectively, and $45 million and $50 million for the nine months ended September 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 nine months ended September 30, 2016 , we made tax payments of $531 million and $1.1 billion , respectively, to the Internal Revenue Service (“IRS”), a bureau of Treasury. We made tax payments of $100 million and $470 million during the three and nine months ended September 30, 2015 . We received no refund from the IRS during the nine months ended September 30, 2016 . We received a refund of $277 million from the IRS during the nine months ended September 30, 2015 for income tax adjustments related to tax years 2004 through 2010. 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 September 30, 2016 , under the NIB program, Fannie Mae and Freddie Mac had $6.5 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 $465 million and $413 million in TCCA fees during the three months ended September 30, 2016 and 2015 , respectively, and $1.4 billion and $1.2 billion for the nine months ended September 30, 2016 and 2015 , respectively, of which $465 million had not been remitted to Treasury as of September 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 $40 million and $56 million in other expenses in connection with Treasury’s Capital Magnet and HOPE Funds for the three months ended September 30, 2016 and 2015 , respectively, and $96 million and $168 million for the nine months ended September 30, 2016 and 2015 , respectively, of which $96 million resulting from 2016 purchases had not been remitted as of September 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 September 30, 2016 and December 31, 2015 , we held Treasury securities with a fair value of $31.3 billion and $29.5 billion , respectively, and accrued interest receivable of $28 million and $15 million , respectively. We recognized interest income on these securities held by us of $40 million and $8 million for the three months ended September 30, 2016 and 2015 , respectively, and $105 million and $17 million for the nine months ended September 30, 2016 and 2015 , respectively. Transactions with Freddie Mac As of September 30, 2016 and December 31, 2015 , we held Freddie Mac mortgage-related securities with a fair value of $1.4 billion and $5.6 billion , respectively, and accrued interest receivable of $5 million and $22 million , respectively. We recognized interest income on these securities held by us of $19 million and $55 million for the three months ended September 30, 2016 and 2015 , respectively, and $100 million and $174 million for the nine months ended September 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 September 30, 2016 and 2015 , and $84 million for the nine months ended September 30, 2016 and 2015 . Transactions with CSS In connection with our jointly owned company with Freddie Mac, we contributed $23 million and $17 million for the three months ended September 30, 2016 and 2015 , respectively, and $88 million and $47 million for the nine months ended September 30, 2016 and 2015 , respectively, of capital into CSS. No other transactions outside of normal business activities have occurred between us and CSS during the nine months ended September 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 debt issued in 2016 at amortized cost. As credit events occur and the principal balance of the CAS debt is legally reduced, we recognize an extinguishment gain. We elected the fair value option on CAS debt that was 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 condensed consolidated financial statements and the timing of our adoption. In August 2016, FASB issued guidance regarding classification of certain items within the statement of cash flows in order to reduce diversity in practice with respect to cash flow classifications. The guidance is effective for us on January 1, 2018 and will be applied retrospectively for each period presented. We are currently evaluating the impact of this guidance on our condensed consolidated financial statements.

Consolidations and Transfers of

Consolidations and Transfers of Financial Assets	9 Months Ended
	Sep. 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 September 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 $154 million in unpaid principal balance as of September 30, 2016, we derecognized our investment in these entities and recognized the assets and liabilities of the consolidated entities at fair value. As of September 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 $5.3 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 September 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 $ 4,793 $ 4,704 Non-Fannie Mae 4,336 5,596 Total trading securities 9,129 10,300 Available-for-sale securities: Fannie Mae 2,601 3,936 Non-Fannie Mae 6,106 14,644 Total available-for-sale securities 8,707 18,580 Other assets 67 100 Other liabilities (450 ) (827 ) Net carrying amount $ 17,453 $ 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 $24 billion and $34 billion as of September 30, 2016 and December 31, 2015, respectively. The total assets of our unconsolidated mortgage-backed trusts were approximately $170 billion and $220 billion as of September 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 $123 million and the related carrying value was $92 million as of September 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 $4.0 billion and $4.9 billion as of September 30, 2016 and December 31, 2015 , respectively. The unpaid principal balance of our multifamily loan portfolio was $221.9 billion as of September 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 September 30, 2016 and 2015, the unpaid principal balance of portfolio securitizations was $76.1 billion and $55.4 billion , respectively. For the nine months ended September 30, 2016 and 2015 , the unpaid principal balance of portfolio securitizations was $188.7 billion and $166.3 billion , respectively. We retain interests from the transfer and sale of mortgage-related securities to unconsolidated single-class and multi-class portfolio securitization trusts. As of September 30, 2016 , the unpaid principal balance of retained interests was $4.5 billion and its related fair value was $6.0 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 September 30, 2016 and 2015, the principal and interest received on retained interests was $284 million and $273 million , respectively. For the nine months ended September 30, 2016 and 2015 , the principal and interest received on retained interests was $907 million and $919 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 $1.4 billion and $1.6 billion as of September 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	9 Months Ended
	Sep. 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 “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. We define the recorded investment of HFI loans as unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable. For purposes of the single-family mortgage loan disclosures below, we define “primary” class as mortgage loans that are not included in other loan classes; “government” class as mortgage loans 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 September 30, 2016 December 31, 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family $ 221,384 $ 2,586,398 $ 2,807,782 $ 238,237 $ 2,574,174 $ 2,812,411 Multifamily 10,678 211,182 221,860 13,099 185,243 198,342 Total unpaid principal balance of mortgage loans 232,062 2,797,580 3,029,642 251,336 2,759,417 3,010,753 Cost basis and fair value adjustments, net (11,707 ) 53,732 42,025 (12,939 ) 49,781 36,842 Allowance for loan losses for loans held for investment (21,858 ) (848 ) (22,706 ) (26,510 ) (1,441 ) (27,951 ) Total mortgage loans $ 198,497 $ 2,850,464 $ 3,048,961 $ 211,887 $ 2,807,757 $ 3,019,644 During the three and nine months ended September 30, 2016 , we redesignated loans with a carrying value of $652 million and $2.3 billion , respectively, from HFI to HFS. During the three and nine months ended September 30, 2015 , we redesignated loans with a carrying value of $1.3 billion and $5.9 billion , respectively, from HFI to HFS. We sold loans with an unpaid principal balance of $1.6 billion and $4.2 billion during the three and nine months ended September 30, 2016 , respectively. We sold loans with an unpaid principal balance of $1.9 billion and $2.5 billion during the three and nine months ended September 30, 2015 , respectively. The recorded investment of single-family mortgage loans for which formal foreclosure proceedings are in process was $19.5 billion and $25.6 billion as of September 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 loan to accrual status at the point that the borrower successfully makes all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes three months or more past due according to its contractual terms or is deemed to be individually impaired, unless the loan is well secured such that collectibility of principal and accrued interest is reasonably assured. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan or we otherwise determine that the loan is well secured such that collectibility is reasonably assured. Aging Analysis The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of September 30, 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 $ 29,741 $ 7,505 $ 21,501 $ 58,747 $ 2,625,085 $ 2,683,832 $ 24 $ 32,806 Government (2) 54 23 264 341 37,698 38,039 264 — Alt-A 3,706 1,131 4,607 9,444 76,207 85,651 2 6,386 Other 1,401 450 1,654 3,505 27,778 31,283 6 2,337 Total single-family 34,902 9,109 28,026 72,037 2,766,768 2,838,805 296 41,529 Multifamily (3) 25 N/A 163 188 223,917 224,105 — 498 Total $ 34,927 $ 9,109 $ 28,189 $ 72,225 $ 2,990,685 $ 3,062,910 $ 296 $ 42,027 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 September 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% $ 2,313,365 $ 58,287 $ 20,442 $ 2,228,533 $ 59,000 $ 21,274 Greater than 80% and less than or equal to 90% 233,787 10,291 3,966 250,373 12,588 4,936 Greater than 90% and less than or equal to 100% 98,865 7,156 2,818 122,939 9,345 3,861 Greater than 100% and less than or equal to 110% 18,071 4,405 1,805 27,875 6,231 2,596 Greater than 110% and less than or equal to 120% 9,071 2,436 1,012 14,625 3,730 1,592 Greater than 120% and less than or equal to 125% 2,721 791 307 4,520 1,260 545 Greater than 125% 7,952 2,285 933 13,328 3,947 1,606 Total $ 2,683,832 $ 85,651 $ 31,283 $ 2,662,193 $ 96,101 $ 36,410 __________ (1) Excludes $38.0 billion and $40.8 billion as of September 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 September 30, December 31, 2016 2015 (Dollars in millions) Credit risk profile by internally assigned grade: (1) Pass $ 219,613 $ 194,132 Special mention 1,851 3,202 Substandard 2,637 2,833 Doubtful 4 7 Total $ 224,105 $ 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 September 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 $ 107,455 $ 102,148 $ 14,034 $ 116,477 $ 110,502 $ 16,745 Government 302 306 58 322 327 59 Alt-A 29,294 26,763 5,204 31,888 29,103 6,217 Other 11,627 11,010 1,989 12,893 12,179 2,416 Total single-family 148,678 140,227 21,285 161,580 152,111 25,437 Multifamily 447 450 41 650 654 80 Total individually impaired loans with related allowance recorded 149,125 140,677 21,326 162,230 152,765 25,517 With no related allowance recorded: (1) Single-family: Primary 16,798 15,574 — 15,891 14,725 — Government 66 62 — 58 54 — Alt-A 3,892 3,325 — 3,721 3,169 — Other 1,256 1,119 — 1,222 1,102 — Total single-family 22,012 20,080 — 20,892 19,050 — Multifamily 315 316 — 353 354 — Total individually impaired loans with no related allowance recorded 22,327 20,396 — 21,245 19,404 — Total individually impaired loans (2) $ 171,452 $ 161,073 $ 21,326 $ 183,475 $ 172,169 $ 25,517 For the Three Months Ended September 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 $ 103,523 $ 992 $ 68 $ 113,634 $ 1,090 $ 71 Government 310 3 — 299 3 — Alt-A 27,115 250 10 30,041 272 14 Other 11,220 91 4 12,652 95 6 Total single-family 142,168 1,336 82 156,626 1,460 91 Multifamily 492 3 — 878 9 — Total individually impaired loans with related allowance recorded 142,660 1,339 82 157,504 1,469 91 With no related allowance recorded: (1) Single-family: Primary 15,534 320 19 15,627 279 16 Government 61 1 — 53 1 — Alt-A 3,312 81 — 3,674 64 1 Other 1,115 27 — 1,259 21 — Total single-family 20,022 429 19 20,613 365 17 Multifamily 311 3 — 386 5 — Total individually impaired loans with no related allowance recorded 20,333 432 19 20,999 370 17 Total individually impaired loans $ 162,993 $ 1,771 $ 101 $ 178,503 $ 1,839 $ 108 For the Nine Months Ended September 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 $ 106,498 $ 3,028 $ 243 $ 115,762 $ 3,152 $ 248 Government 317 9 — 290 9 — Alt-A 27,899 759 40 30,760 774 41 Other 11,622 276 15 13,030 282 15 Total single-family 146,336 4,072 298 159,842 4,217 304 Multifamily 555 21 — 1,053 15 — Total individually impaired loans with related allowance recorded 146,891 4,093 298 160,895 4,232 304 With no related allowance recorded: (1) Single-family: Primary 15,398 915 69 15,967 779 76 Government 59 3 — 55 3 — Alt-A 3,350 224 8 3,720 158 8 Other 1,128 79 3 1,287 56 2 Total single-family 19,935 1,221 80 21,029 996 86 Multifamily 330 9 — 463 8 — Total individually impaired loans with no related allowance recorded 20,265 1,230 80 21,492 1,004 86 Total individually impaired loans $ 167,156 $ 5,323 $ 378 $ 182,387 $ 5,236 $ 390 __________ (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 $159.6 billion and $170.3 billion as of September 30, 2016 and December 31, 2015 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $324 million and $451 million as of September 30, 2016 and December 31, 2015 , respectively. (3) Total single-family interest income recognized of $1.8 billion for the three months ended September 30, 2016 consists of $1.4 billion of contractual interest and $320 million of effective yield adjustments. Total single-family interest income recognized of $1.8 billion for the three months ended September 30, 2015 consists of $1.5 billion of contractual interest and $327 million of effective yield adjustments. Total single-family interest income recognized of $5.3 billion for the nine months ended September 30, 2016 consists of $4.3 billion of contractual interest and $961 million of effective yield adjustments. Total single-family interest income recognized of $5.2 billion for the nine months ended September 30, 2015 consists of $4.3 billion of contractual interest and $907 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 September 30, 2016 and 2015 , the average term extension of a single-family modified loan was 153 months and 159 months , respectively, and the average interest rate reduction was 0.82 and 0.69 percentage points, respectively. During the nine months ended September 30, 2016 and 2015 , the average term extension of a single-family modified loan was 157 months and 161 months , respectively, and the average interest rate reduction was 0.76 and 0.75 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 September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 13,983 $ 1,922 14,926 $ 2,021 Government 54 5 54 6 Alt-A 1,578 227 1,805 268 Other 317 57 324 57 Total single-family 15,932 2,211 17,109 2,352 Multifamily 2 5 3 10 Total TDRs 15,934 $ 2,216 17,112 $ 2,362 For the Nine Months Ended September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 45,987 $ 6,282 54,284 $ 7,443 Government 136 14 192 22 Alt-A 5,112 735 7,127 1,101 Other 1,078 190 1,453 265 Total single-family 52,313 7,221 63,056 8,831 Multifamily 6 50 7 16 Total TDRs 52,319 $ 7,271 63,063 $ 8,847 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 September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 5,268 $ 734 6,847 $ 1,003 Government 31 4 31 3 Alt-A 734 116 1,052 183 Other 235 41 328 65 Total single-family 6,268 895 8,258 1,254 Multifamily — — — — Total TDRs that subsequently defaulted 6,268 $ 895 8,258 $ 1,254 For the Nine Months Ended September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 15,377 $ 2,174 19,726 $ 2,870 Government 73 9 88 12 Alt-A 2,342 376 3,168 537 Other 767 130 922 186 Total single-family 18,559 2,689 23,904 3,605 Multifamily — — 3 6 Total TDRs that subsequently defaulted 18,559 $ 2,689 23,907 $ 3,611

Allowance for Loan Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses We maintain an allowance for loan losses for HFI loans held by Fannie Mae and 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 September 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 $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Provision (benefit) for loan losses (1) (561 ) (48 ) (609 ) (1,722 ) 330 (1,392 ) Charge-offs (2)(3) (587 ) (17 ) (604 ) (748 ) (22 ) (770 ) Recoveries 108 27 135 161 3 164 Transfers (4) 113 (113 ) — 262 (262 ) — Other (5) 10 — 10 (13 ) — (13 ) Ending balance $ 21,819 $ 697 $ 22,516 $ 27,564 $ 1,301 $ 28,865 Multifamily allowance for loan losses: Beginning balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Provision (benefit) for loan losses (1) (22 ) (5 ) (27 ) (10 ) 8 (2 ) Charge-offs (2)(3) (2 ) (2 ) (4 ) (5 ) (2 ) (7 ) Recoveries 6 — 6 4 — 4 Transfers (4) — — — 1 (1 ) — Other (5) — — — 1 — 1 Ending balance $ 39 $ 151 $ 190 $ 91 $ 179 $ 270 Total allowance for loan losses: Beginning balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 Provision (benefit) for loan losses (1) (583 ) (53 ) (636 ) (1,732 ) 338 (1,394 ) Charge-offs (2)(3) (589 ) (19 ) (608 ) (753 ) (24 ) (777 ) Recoveries 114 27 141 165 3 168 Transfers (4) 113 (113 ) — 263 (263 ) — Other (5) 10 — 10 (12 ) — (12 ) Ending balance $ 21,858 $ 848 $ 22,706 $ 27,655 $ 1,480 $ 29,135 For the Nine Months Ended September 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) (2,979 ) 22 (2,957 ) (249 ) (44 ) (293 ) Charge-offs (2)(3) (2,629 ) (72 ) (2,701 ) (8,108 ) (64 ) (8,172 ) Recoveries 339 30 369 1,032 15 1,047 Transfers (4) 553 (553 ) — 877 (877 ) — Other (5) 96 — 96 1,056 50 1,106 Ending balance $ 21,819 $ 697 $ 22,516 $ 27,564 $ 1,301 $ 28,865 Multifamily allowance for loan losses: Beginning balance $ 71 $ 171 $ 242 $ 161 $ 203 $ 364 Benefit for loan losses (1) (33 ) (14 ) (47 ) (41 ) (23 ) (64 ) Charge-offs (2)(3) (10 ) (2 ) (12 ) (39 ) (2 ) (41 ) Recoveries 7 — 7 4 — 4 Transfers (4) 4 (4 ) — 1 (1 ) — Other (5) — — — 5 2 7 Ending balance $ 39 $ 151 $ 190 $ 91 $ 179 $ 270 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) (3,012 ) 8 (3,004 ) (290 ) (67 ) (357 ) Charge-offs (2)(3) (2,639 ) (74 ) (2,713 ) (8,147 ) (66 ) (8,213 ) Recoveries 346 30 376 1,036 15 1,051 Transfers (4) 557 (557 ) — 878 (878 ) — Other (5) 96 — 96 1,061 52 1,113 Ending balance $ 21,858 $ 848 $ 22,706 $ 27,655 $ 1,480 $ 29,135 __________ (1) Provision (benefit) for loan losses is included in “Benefit 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 include the 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 September 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) $ 21,285 $ 41 $ 21,326 $ 25,437 $ 80 $ 25,517 Collectively reserved loans 1,231 149 1,380 2,272 162 2,434 Total allowance for loan losses $ 22,516 $ 190 $ 22,706 $ 27,709 $ 242 $ 27,951 Recorded investment in loans by segment: Individually impaired loans (1) $ 160,307 $ 766 $ 161,073 $ 171,161 $ 1,008 $ 172,169 Collectively reserved loans 2,678,498 223,339 2,901,837 2,664,377 199,166 2,863,543 Total recorded investment in loans $ 2,838,805 $ 224,105 $ 3,062,910 $ 2,835,538 $ 200,174 $ 3,035,712 __________ (1) Includes acquired credit-impaired loans.

Investments in Securities

Investments in Securities	9 Months Ended
	Sep. 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 losses, net” in our condensed consolidated statements of operations and comprehensive income. The following table displays our investments in trading securities. As of September 30, 2016 December 31, 2015 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 4,931 $ 4,813 Freddie Mac 808 1,314 Ginnie Mae 1,393 426 Alt-A private-label securities 313 436 Subprime private-label securities 353 644 Commercial mortgage-backed securities (“CMBS”) 1,281 2,341 Mortgage revenue bonds 191 449 Total mortgage-related securities 9,270 10,423 U.S. Treasury securities 31,277 29,485 Total trading securities $ 40,547 $ 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 income (loss)” and we recognize realized gains and losses from the sale of AFS securities in “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income. The following table displays the gross realized gains, losses and proceeds on sales of AFS securities. For the Three For the Nine Months Ended Months Ended September 30 , September 30 , 2016 2015 2016 2015 (Dollars in millions) Gross realized gains $ 400 $ 94 $ 845 $ 907 Gross realized losses — 9 12 66 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 2,819 1,556 10,086 6,764 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 September 30, 2016 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 2,545 $ 187 $ (20 ) $ 2,712 Freddie Mac 534 48 — 582 Ginnie Mae 54 7 — 61 Alt-A private-label securities 883 535 (1 ) 1,417 Subprime private-label securities 1,437 486 (4 ) 1,919 CMBS 971 8 (1 ) 978 Mortgage revenue bonds 1,639 90 (4 ) 1,725 Other mortgage-related securities 449 22 — 471 Total $ 8,512 $ 1,383 $ (30 ) $ 9,865 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 September 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 ) $ 85 $ (19 ) $ 502 Alt-A private-label securities (1 ) 38 — — Subprime private-label securities — — (4 ) 76 CMBS (1 ) 136 — — Mortgage revenue bonds (3 ) 16 (1 ) 5 Total $ (6 ) $ 275 $ (24 ) $ 583 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 $3 million and $5 million of OTTI for the three months ended September 30, 2016 and 2015 , respectively, and $ 34 million and $ 187 million of OTTI for the nine months ended September 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 September 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 September 30, 2016 Alt-A Subprime Option ARM Fixed Rate Variable Rate Hybrid Rate (Dollars in millions) Unpaid principal balance $ 2,688 $ 360 $ 270 $ 548 $ 571 Weighted average collateral default (1) 37.4 % 24.3 % 17.0 % 18.8 % 7.4 % Weighted average collateral severities (2) 49.8 29.3 52.4 38.2 35.0 Weighted average voluntary prepayment rates (3) 2.9 9.3 7.9 8.6 13.9 Average credit enhancement (4) 12.8 3.7 0.4 2.0 1.6 __________ (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 September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance $ 2,219 $ 2,557 $ 2,421 $ 5,260 Additions for the credit component on debt securities for which OTTI was not previously recognized 1 — 1 — Additions for the credit component on debt securities for which OTTI was previously recognized — 1 6 5 Reductions for securities no longer in portfolio at period end (3 ) (2 ) (106 ) (1,167 ) 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 (223 ) — (254 ) (1,439 ) Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities (30 ) (43 ) (104 ) (146 ) Ending balance $ 1,964 $ 2,513 $ 1,964 $ 2,513 Maturity Information The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time. As of September 30, 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 $ 2,545 $ 2,712 $ — $ — $ 29 $ 29 $ 60 $ 66 $ 2,456 $ 2,617 Freddie Mac 534 582 1 1 65 68 95 102 373 411 Ginnie Mae 54 61 — — 1 1 3 4 50 56 Alt-A private-label securities 883 1,417 — — — — — — 883 1,417 Subprime private-label securities 1,437 1,919 — — — — — — 1,437 1,919 CMBS 971 978 776 782 154 156 — — 41 40 Mortgage revenue bonds 1,639 1,725 10 10 88 88 170 172 1,371 1,455 Other mortgage-related securities 449 471 — — — 1 3 3 446 467 Total $ 8,512 $ 9,865 $ 787 $ 793 $ 337 $ 343 $ 331 $ 347 $ 7,057 $ 8,382

Financial Guarantees

Financial Guarantees	9 Months Ended
	Sep. 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 September 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 $ 13,333 $ 147 $ 8,269 $ 15,069 $ 194 $ 8,857 Other guaranty arrangements (3) 15,469 135 2,707 16,504 135 2,869 Total $ 28,802 $ 282 $ 10,976 $ 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 $433 million and $488 million as of September 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	9 Months Ended
	Sep. 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 September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance — Acquired property $ 5,928 $ 9,199 $ 7,481 $ 11,442 Additions 1,391 2,236 4,876 7,602 Disposals (1,906 ) (3,125 ) (6,944 ) (10,734 ) Ending balance — Acquired property 5,413 8,310 5,413 8,310 Valuation allowance (372 ) (619 ) (372 ) (619 ) Ending balance — Acquired property, net $ 5,041 $ 7,691 $ 5,041 $ 7,691

Short-Term Borrowings and Long-

Short-Term Borrowings and Long-Term Debt	9 Months Ended
	Sep. 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 September 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) $ 35 — % $ 62 — % Short-term debt of Fannie Mae $ 51,442 0.44 % $ 71,007 0.26 % Debt of consolidated trusts 612 0.46 943 0.19 Total short-term debt $ 52,054 0.44 % $ 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 September 30, 2016 and December 31, 2015 . We had no borrowings outstanding under this line of credit as of September 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 September 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 $ 153,481 2.23 % 2016 - 2030 $ 154,057 2.49 % Medium-term notes (2) 2016 - 2026 83,661 1.39 2016 - 2025 96,997 1.53 Other (3) 2017 - 2038 13,557 6.58 2016 - 2038 27,772 4.88 Total senior fixed 250,699 2.19 278,826 2.39 Senior floating: Medium-term notes (2) 2016 - 2019 28,715 0.59 2016 - 2019 20,791 0.27 Connecticut Avenue Securities (4) 2023 - 2029 15,636 4.59 2023 - 2028 10,764 3.84 Other (5) 2020 - 2037 419 6.65 2020 - 2037 368 10.46 Total senior floating 44,770 2.01 31,923 1.58 Subordinated debentures 2019 4,537 9.93 2019 4,227 9.93 Secured borrowings (6) 2021 - 2022 120 1.42 2021 - 2022 152 1.47 Total long-term debt of Fannie Mae (7) 300,126 2.28 315,128 2.41 Debt of consolidated trusts 2016 - 2054 2,880,933 2.53 2016 - 2054 2,810,593 2.94 Total long-term debt $ 3,181,059 2.51 % $ 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 $2.0 billion and $3.2 billion as of September 30, 2016 and December 31, 2015 , respectively.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 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 September 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 $ 6,324 $ 19 $ 127,859 $ (11,071 ) $ 33,154 $ 267 $ 123,106 $ (6,920 ) Receive-fixed 99,254 5,218 70,551 (146 ) 59,796 3,436 143,209 (753 ) Basis 1,764 198 15,700 (21 ) 1,864 141 17,100 (15 ) Foreign currency 225 75 227 (82 ) 295 95 258 (52 ) Swaptions: Pay-fixed 6,175 36 6,850 (13 ) 7,050 45 14,950 (26 ) Receive-fixed 1,625 7 6,600 (157 ) 2,000 8 13,950 (171 ) Other (1) 9,371 22 — (1 ) 9,196 28 — (2 ) Total gross risk management derivatives 124,738 5,575 227,787 (11,491 ) 113,355 4,020 312,573 (7,939 ) Accrued interest receivable (payable) — 720 — (1,097 ) — 758 — (977 ) Netting adjustment (2) — (6,154 ) — 12,423 — (4,024 ) — 8,650 Total net risk management derivatives $ 124,738 $ 141 $ 227,787 $ (165 ) $ 113,355 $ 754 $ 312,573 $ (266 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 10,820 $ 31 $ 4,568 $ (6 ) $ 4,815 $ 9 $ 2,960 $ (9 ) Forward contracts to purchase mortgage-related securities 66,637 280 18,467 (29 ) 31,273 66 19,418 (57 ) Forward contracts to sell mortgage-related securities 18,666 38 117,252 (502 ) 26,224 65 40,753 (92 ) Total mortgage commitment derivatives $ 96,123 $ 349 $ 140,287 $ (537 ) $ 62,312 $ 140 $ 63,131 $ (158 ) Derivatives at fair value $ 220,861 $ 490 $ 368,074 $ (702 ) $ 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 $6.7 billion and $4.9 billion as of September 30, 2016 and December 31, 2015 , respectively. Cash collateral received was $419 million and $314 million as of September 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 $3.3 billion and $2.4 billion as of September 30, 2016 and December 31, 2015 , respectively, for which we posted collateral of $3.3 billion and $2.2 billion in the normal course of business as of September 30, 2016 and December 31, 2015 , respectively. Had all of the credit-risk-related contingency features underlying these agreements been triggered, an additional $85 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 September 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 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 Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ 1,386 $ (4,402 ) $ (6,044 ) $ (3,120 ) Receive-fixed (1,020 ) 2,295 3,338 2,236 Basis 2 37 51 25 Foreign currency (6 ) (20 ) (37 ) (33 ) Swaptions: Pay-fixed (3 ) 32 26 137 Receive-fixed 10 (102 ) (126 ) (181 ) Other (7 ) 22 153 20 Net accrual of periodic settlements (295 ) (266 ) (855 ) (694 ) Total risk management derivatives fair value gains (losses), net $ 67 $ (2,404 ) $ (3,494 ) $ (1,610 ) Mortgage commitment derivatives fair value losses, net (216 ) (361 ) (945 ) (427 ) Total derivatives fair value losses, net $ (149 ) $ (2,765 ) $ (4,439 ) $ (2,037 ) 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 (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) 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 (loss) per share of common stock. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars and shares in millions, except per share amounts) Net income attributable to Fannie Mae $ 3,196 $ 1,960 $ 7,278 $ 8,488 Dividends distributed or available for distribution to senior preferred stockholder (1) (2,977 ) (2,202 ) (6,765 ) (8,357 ) Net income (loss) attributable to common stockholders $ 219 $ (242 ) $ 513 $ 131 Weighted-average common shares outstanding—Basic (2) 5,762 5,762 5,762 5,762 Convertible preferred stock 131 — 131 131 Weighted-average common shares outstanding—Diluted (2) 5,893 5,762 5,893 5,893 Earnings (loss) per share: Basic $ 0.04 $ (0.04 ) $ 0.09 $ 0.02 Diluted 0.04 (0.04 ) 0.09 0.02 __________ (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 September 30, 2016 and 2015.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 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 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 September 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 166 $ (22 ) $ 1,049 $ 4,242 (2) $ 5,435 Benefit for credit losses 645 28 — — 673 Net interest income after benefit for credit losses 811 6 1,049 4,242 6,108 Guaranty fee income (expense) (3) 3,305 431 (189 ) (3,524 ) (4) 23 (4) Investment gains (losses), net — 23 2,232 (1,788 ) (5) 467 Fair value gains (losses), net — — (530 ) 39 (6) (491 ) Gains (losses) from partnership investments (7) (17 ) 5 — — (12 ) Fee and other income (expense) 89 49 69 (55 ) 152 Administrative expenses (479 ) (84 ) (98 ) — (661 ) Foreclosed property (expense) income (114 ) 4 — — (110 ) TCCA fees (3) (465 ) — — — (465 ) Other income (expenses), net (382 ) (10 ) (44 ) 148 (288 ) Income (loss) before federal income taxes 2,748 424 2,489 (938 ) 4,723 Provision for federal income taxes (808 ) (49 ) (670 ) — (1,527 ) Net income (loss) attributable to Fannie Mae $ 1,940 $ 375 $ 1,819 $ (938 ) $ 3,196 For the Nine Months Ended September 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 485 $ (62 ) $ 3,221 $ 11,846 (2) $ 15,490 Benefit for credit losses 3,404 54 — — 3,458 Net interest income (loss) after benefit for credit losses 3,889 (8 ) 3,221 11,846 18,948 Guaranty fee income (expense) (3) 9,787 1,216 (576 ) (10,349 ) (4) 78 (4) Investment gains (losses), net (1 ) 37 5,735 (4,837 ) (5) 934 Fair value gains (losses), net — — (5,063 ) 92 (6) (4,971 ) Gains (losses) from partnership investments (7) (54 ) 45 — — (9 ) Fee and other income (expense) 290 156 121 (93 ) 474 Administrative expenses (1,483 ) (254 ) (290 ) — (2,027 ) Foreclosed property (expense) income (510 ) 3 — — (507 ) TCCA fees (3) (1,358 ) — — — (1,358 ) Other income (expenses), net (1,046 ) (21 ) (103 ) 361 (809 ) Income (loss) before federal income taxes 9,514 1,174 3,045 (2,980 ) 10,753 Provision for federal income taxes (2,544 ) (127 ) (804 ) — (3,475 ) Net income (loss) attributable to Fannie Mae $ 6,970 $ 1,047 $ 2,241 $ (2,980 ) $ 7,278 For the Three Months Ended September 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 66 $ (16 ) $ 1,401 $ 4,137 (2) $ 5,588 Benefit for credit losses 1,545 5 — — 1,550 Net interest income (loss) after benefit for credit losses 1,611 (11 ) 1,401 4,137 7,138 Guaranty fee income (expense) (3) 3,145 367 (210 ) (3,271 ) (4) 31 (4) Investment gains (losses), net (1 ) 5 1,608 (1,313 ) (5) 299 Fair value gains (losses), net (4 ) — (2,697 ) 112 (6) (2,589 ) Gains (losses) from partnership investments (7) (12 ) 7 — — (5 ) Fee and other income (expense) 98 58 83 (11 ) 228 Administrative expenses (649 ) (109 ) (194 ) — (952 ) Foreclosed property (expense) income (516 ) 19 — — (497 ) TCCA fees (3) (413 ) — — — (413 ) Other income (expenses), net (180 ) 5 (1 ) (34 ) (210 ) Income (loss) before federal income taxes 3,079 341 (10 ) (380 ) 3,030 Provision for federal income taxes (1,040 ) (17 ) (13 ) — (1,070 ) Net income (loss) attributable to Fannie Mae $ 2,039 $ 324 $ (23 ) $ (380 ) $ 1,960 For the Nine Months Ended September 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 93 $ (73 ) $ 4,516 $ 11,796 (2) $ 16,332 Benefit for credit losses 967 83 — — 1,050 Net interest income after benefit for credit losses 1,060 10 4,516 11,796 17,382 Guaranty fee income (expense) (3) 9,277 1,064 (658 ) (9,584 ) (4) 99 (4) Investment gains (losses), net (2 ) 29 4,679 (3,551 ) (5) 1,155 Fair value gains (losses), net (8 ) — (2,112 ) 218 (6) (1,902 ) Gains (losses) from partnership investments (7) (27 ) 262 — — 235 Fee and other income (expense) 571 193 288 (28 ) 1,024 Administrative expenses (1,591 ) (280 ) (493 ) — (2,364 ) Foreclosed property (expense) income (1,183 ) 31 — — (1,152 ) TCCA fees (3) (1,192 ) — — — (1,192 ) Other income (expenses), net (669 ) (8 ) (12 ) 42 (647 ) Income (loss) before federal income taxes 6,236 1,301 6,208 (1,107 ) 12,638 Provision for federal income taxes (2,040 ) (128 ) (1,982 ) — (4,150 ) Net income (loss) attributable to Fannie Mae $ 4,196 $ 1,173 $ 4,226 $ (1,107 ) $ 8,488 __________ (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	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Equity	Equity The following table displays the activity in other comprehensive income (loss), net of tax, by major categories. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Net income $ 3,196 $ 1,960 $ 7,278 $ 8,488 Other comprehensive income (loss), net of tax effect: Changes in net unrealized gains (losses) on AFS securities (net of tax of $18 and $58, respectively, for the three months ended and net of tax of $3 and $89, respectively, for the nine months ended) 33 (107 ) (6 ) (164 ) Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $2, respectively, for the three months ended and net of tax of $12 and $66, respectively, for the nine months ended) 2 3 22 121 Reclassification adjustment for gains on AFS securities included in net income (net of tax of $129 and $32, respectively, for the three months ended and net of tax of $266 and $265, respectively, for the nine months ended) (240 ) (73 ) (494 ) (505 ) Other (1) (2 ) 430 (6 ) 428 Total other comprehensive income (loss) (207 ) 253 (484 ) (120 ) Total comprehensive income $ 2,989 $ 2,213 $ 6,794 $ 8,368 __________ (1) For the three and nine months ended September 30, 2015, includes reclassification adjustment related to the termination of the defined benefit pension plan recognized in “Administrative expenses” and “Provision for federal income taxes” in our condensed consolidated statements of operations and comprehensive income. The following table displays our accumulated other comprehensive income by major categories. As of September 30, December 31, 2016 2015 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax $ 198 $ 455 Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax 682 903 Other, net of tax 43 49 Accumulated other comprehensive income $ 923 $ 1,407 The table below displays changes in accumulated other comprehensive income, net of tax. For the Three Months Ended September 30, For the Nine Months Ended September 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 $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 $ 1,358 $ 49 $ 1,407 $ 2,121 $ (388 ) $ 1,733 Other comprehensive income (loss) before reclassifications 33 — 33 (107 ) 6 (101 ) (6 ) — (6 ) (164 ) 6 (158 ) Amounts reclassified from other comprehensive income (loss) (238 ) (2 ) (240 ) (70 ) 424 354 (472 ) (6 ) (478 ) (384 ) 422 38 Net other comprehensive income (loss) (205 ) (2 ) (207 ) (177 ) 430 253 (478 ) (6 ) (484 ) (548 ) 428 (120 ) Ending balance $ 880 $ 43 $ 923 $ 1,573 $ 40 $ 1,613 $ 880 $ 43 $ 923 $ 1,573 $ 40 $ 1,613 __________ (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” and “Provision for federal income taxes” 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	9 Months Ended
	Sep. 30, 2016
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	Concentrations of Credit Risk Risk Characteristics of our Guaranty 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 September 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) 1.27 % 0.34 % 1.23 % 1.27 % 0.37 % 1.59 % Percentage of single-family conventional loans (4) 1.45 0.39 1.24 1.46 0.41 1.55 As of September 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% 2 % 10.56 % 3 % 10.76 % Geographical distribution: California 20 0.49 20 0.58 Florida 6 2.05 6 2.86 New Jersey 4 3.47 4 4.87 New York 5 2.77 5 3.55 All other states 65 1.11 65 1.34 Product distribution: Alt-A 3 5.27 4 6.53 Vintages: 2004 and prior 4 2.75 5 3.06 2005-2008 9 6.49 10 7.60 2009-2016 87 0.33 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 September 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 September 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 September 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 0.02 % 0.07 % 0.03 % 0.07 % As of September 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 % 0.11 % 3 % 0.40 % Less than or equal to 80% 98 0.07 97 0.06 Current DSCR less than 1.0 (5) 2 1.95 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 September 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 40% of our single-family guaranty book of business as of September 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 September 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 $124.2 billion and $117.9 billion on the single-family mortgage loans in our guaranty book of business as of September 30, 2016 and December 31, 2015 , respectively, which represented 4% of our single-family guaranty book of business as of September 30, 2016 and December 31, 2015 . Our primary mortgage insurance coverage risk in force was $123.6 billion and $117.2 billion as of September 30, 2016 and December 31, 2015 , respectively. Our pool mortgage insurance coverage risk in force was $646 million and $736 million as of September 30, 2016 and December 31, 2015 , respectively. Our top four mortgage insurance companies provided 77% and 79% of our mortgage insurance coverage risk in force as of September 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 $8.5 billion , or 7% , of our risk in force mortgage insurance coverage of our single-family guaranty book of business as of September 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 September 30, 2016 and December 31, 2015 , the amount by which our estimated benefit from mortgage insurance reduced our total loss reserves was $1.5 billion and $2.3 billion , respectively. We had outstanding receivables of $1.0 billion recorded in “Other assets” in our condensed consolidated balance sheets as of September 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, $135 million as of September 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 $658 million as of September 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 September 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	9 Months Ended
	Sep. 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 September 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 $ 4,760 $ (4,737 ) $ 23 $ — $ — $ 23 Cleared risk management derivatives 1,512 (1,417 ) 95 — — 95 Mortgage commitment derivatives 349 — 349 (214 ) — 135 Total derivative assets 6,621 (6,154 ) 467 (4) (214 ) — 253 Securities purchased under agreements to resell or similar arrangements (5) 40,600 — 40,600 — (40,600 ) — Total assets $ 47,221 $ (6,154 ) $ 41,067 $ (214 ) $ (40,600 ) $ 253 Liabilities: OTC risk management derivatives $ (7,739 ) $ 7,580 $ (159 ) $ — $ — $ (159 ) Cleared risk management derivatives (4,848 ) 4,843 (5 ) — 5 — Mortgage commitment derivatives (537 ) — (537 ) 214 1 (322 ) Total derivative liabilities (13,124 ) 12,423 (701 ) (4) 214 6 (481 ) Securities sold under agreements to repurchase or similar arrangements (35 ) — (35 ) — 35 — Total liabilities $ (13,159 ) $ 12,423 $ (736 ) $ 214 $ 41 $ (481 ) 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 September 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 $40.7 billion and $38.0 billion , of which $37.4 billion and $36.2 billion could be sold or repledged as of September 30, 2016 and December 31, 2015, respectively. None of the underlying collateral was sold or repledged as of September 30, 2016 and December 31, 2015 . (4) Excludes derivative assets of $23 million and $28 million as of September 30, 2016 and December 31, 2015 , and derivative liabilities of $1 million and $2 million recognized in our condensed consolidated balance sheets as of September 30, 2016 and December 31, 2015 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $22.3 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 September 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	9 Months Ended
	Sep. 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 September 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 $ — $ 4,931 $ — $ — $ 4,931 Freddie Mac — 808 — — 808 Ginnie Mae — 1,393 — — 1,393 Alt-A private-label securities — 48 265 — 313 Subprime private-label securities — 319 34 — 353 CMBS — 1,281 — — 1,281 Mortgage revenue bonds — — 191 — 191 Non-mortgage-related securities: U.S. Treasury securities 31,277 — — — 31,277 Total trading securities 31,277 8,780 490 — 40,547 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 2,712 — — 2,712 Freddie Mac — 580 2 — 582 Ginnie Mae — 61 — — 61 Alt-A private-label securities — 1,243 174 — 1,417 Subprime private-label securities — 1,871 48 — 1,919 CMBS — 978 — — 978 Mortgage revenue bonds — — 1,725 — 1,725 Other — 35 436 — 471 Total available-for-sale securities — 7,480 2,385 — 9,865 Mortgage loans — 11,741 1,173 — 12,914 Other assets: Risk management derivatives: Swaps — 6,018 212 — 6,230 Swaptions — 43 — — 43 Other — — 22 — 22 Netting adjustment — — — (6,154 ) (6,154 ) Mortgage commitment derivatives — 346 3 — 349 Total other assets — 6,407 237 (6,154 ) 490 Total assets at fair value $ 31,277 $ 34,408 $ 4,285 $ (6,154 ) $ 63,816 Fair Value Measurements as of September 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 $ — $ 10,041 $ 419 $ — $ 10,460 Total of Fannie Mae — 10,041 419 — 10,460 Of consolidated trusts — 35,151 302 — 35,453 Total long-term debt — 45,192 721 — 45,913 Other liabilities: Risk management derivatives: Swaps — 12,407 10 — 12,417 Swaptions — 170 — — 170 Other — — 1 — 1 Netting adjustment — — — (12,423 ) (12,423 ) Mortgage commitment derivatives — 527 10 — 537 Total other liabilities — 13,104 21 (12,423 ) 702 Total liabilities at fair value $ — $ 58,296 $ 742 $ (12,423 ) $ 46,615 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 September 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2016 (5)(6) Balance, June 30, 2016 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Alt-A private-label securities $ 259 $ 17 $ — $ — $ — $ — $ (11 ) $ — $ — $ 265 $ 17 Subprime private-label securities 44 (9 ) — — — — (1 ) — — 34 (9 ) Mortgage revenue bonds 193 5 — — — — (7 ) — — 191 4 Total trading securities $ 496 $ 13 (6)(7) $ — $ — $ — $ — $ (19 ) $ — $ — $ 490 $ 12 Available-for-sale securities: Mortgage-related: Freddie Mac $ 1 $ — $ — $ — $ — $ — $ — $ — $ 1 $ 2 $ — Alt-A private-label securities 175 1 1 — — — (3 ) — — 174 — Subprime private-label securities 173 79 (77 ) — (123 ) — (4 ) — — 48 — Mortgage revenue bonds 2,029 35 (23 ) — (201 ) — (115 ) — — 1,725 — Other 450 — 6 — — — (20 ) — — 436 — Total available-for-sale securities $ 2,828 $ 115 (7)(8) $ (93 ) $ — $ (324 ) $ — $ (142 ) $ — $ 1 $ 2,385 $ — Mortgage loans $ 1,280 $ 23 (6)(7) $ — $ 4 $ (72 ) $ — $ (60 ) $ (17 ) $ 15 $ 1,173 $ 6 Net derivatives 248 11 (6) — — — (1 ) (43 ) — 1 216 (18 ) Long-term debt: Of Fannie Mae: Senior floating $ (410 ) $ (9 ) $ — $ — $ — $ — $ — $ — $ — $ (419 ) $ (9 ) Of consolidated trusts (326 ) (2 ) — — — (16 ) 11 95 (64 ) (302 ) — Total long-term debt $ (736 ) $ (11 ) (6) $ — $ — $ — $ (16 ) $ 11 $ 95 $ (64 ) $ (721 ) $ (9 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2016 (5)(6) Balance, December 31, 2015 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ 25 $ — $ — Freddie Mac — — — — — — — (1 ) 1 — — Alt-A private-label securities 305 (13 ) — — — — (27 ) — — 265 (13 ) Subprime private-label securities 644 (43 ) — — (187 ) — (17 ) (363 ) — 34 (19 ) Mortgage revenue bonds 449 34 — — (279 ) — (13 ) — — 191 14 Total trading securities $ 1,398 $ (22 ) (6)(7) $ — $ — $ (466 ) $ — $ (58 ) $ (388 ) $ 26 $ 490 $ (18 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ — $ (1 ) $ 1 $ — $ — Freddie Mac 4 — — — — — — (3 ) 1 2 — Alt-A private-label securities 1,041 13 (26 ) — (291 ) — (47 ) (516 ) — 174 — Subprime private-label securities 3,281 171 (209 ) — (707 ) — (165 ) (2,323 ) — 48 — Mortgage revenue bonds 2,701 115 25 — (812 ) — (304 ) — — 1,725 — Other 1,404 — (20 ) — (605 ) — (59 ) (284 ) — 436 — Total available-for-sale securities $ 8,431 $ 299 (7)(8) $ (230 ) $ — $ (2,415 ) $ — $ (575 ) $ (3,127 ) $ 2 $ 2,385 $ — Mortgage loans $ 1,477 $ 139 (6)(7) $ — $ 29 $ (392 ) $ — $ (199 ) $ (101 ) $ 220 $ 1,173 $ 24 Net derivatives 157 243 (6) — — — (8 ) (176 ) (2 ) 2 216 41 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) $ (50 ) $ — $ — $ — $ — $ — $ — $ — $ (419 ) $ (50 ) Of consolidated trusts (496 ) (77 ) — — — (70 ) 329 140 (128 ) (302 ) (9 ) Total long-term debt $ (865 ) $ (127 ) (6) $ — $ — $ — $ (70 ) $ 329 $ 140 $ (128 ) $ (721 ) $ (59 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2015 (5)(6) Balance, June 30, 2015 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Alt-A private-label securities $ 325 $ (3 ) $ — $ — $ — $ — $ (7 ) $ — $ — $ 315 $ (3 ) Subprime private-label securities 718 (5 ) — — — — (17 ) — — 696 (5 ) Mortgage revenue bonds 602 (19 ) — — — — (4 ) — — 579 (19 ) Total trading securities $ 1,645 $ (27 ) (6)(7) $ — $ — $ — $ — $ (28 ) $ — $ — $ 1,590 $ (27 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ 129 $ — $ — $ — $ (122 ) $ — $ (8 ) $ — $ 1 $ — $ — Freddie Mac 4 — — — — — — (1 ) 1 4 — Alt-A private-label securities 1,654 2 (8 ) — — — (178 ) — 24 1,494 — Subprime private-label securities 3,837 33 (45 ) — — — (148 ) — — 3,677 — Mortgage revenue bonds 3,171 4 (29 ) — (8 ) — (205 ) — — 2,933 — Other 2,158 73 (95 ) — (644 ) — (48 ) — — 1,444 — Total available-for-sale securities $ 10,953 $ 112 (7)(8) $ (177 ) $ — $ (774 ) $ — $ (587 ) $ (1 ) $ 26 $ 9,552 $ — Mortgage loans $ 1,595 $ 9 (6)(7) $ — $ — $ — $ — $ (97 ) $ (77 ) $ 70 $ 1,500 $ (24 ) Net derivatives 4 79 (6) — — — — (32 ) — 9 60 28 Long-term debt: Of Fannie Mae: Senior floating $ (346 ) $ (23 ) $ — $ — $ — $ — $ — $ — $ — $ (369 ) $ (23 ) Of consolidated trusts (493 ) — — — — (64 ) 18 33 (65 ) (571 ) — Total long-term debt $ (839 ) $ (23 ) (6) $ — $ — $ — $ (64 ) $ 18 $ 33 $ (65 ) $ (940 ) $ (23 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2015 (5)(6) Balance, December 31, 2014 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 305 $ (27 ) $ — $ — $ (2 ) $ — $ — $ (278 ) $ 2 $ — $ — Alt-A private-label securities 597 41 — — (267 ) — (40 ) (44 ) 28 315 (3 ) Subprime private-label securities 1,307 38 — — (580 ) — (69 ) — — 696 (2 ) Mortgage revenue bonds 722 (17 ) — — (118 ) — (8 ) — — 579 (17 ) Other 99 4 — — (100 ) — (3 ) — — — — Total trading securities $ 3,030 $ 39 (6)(7) $ — $ — $ (1,067 ) $ — $ (120 ) $ (322 ) $ 30 $ 1,590 $ (22 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ 421 $ (425 ) $ — $ (8 ) $ — $ 12 $ — $ — Freddie Mac 6 — — — — — (1 ) (2 ) 1 4 — Alt-A private-label securities 3,140 174 (124 ) — (1,108 ) — (387 ) (538 ) 337 1,494 — Subprime private-label securities 5,240 478 (277 ) — (1,325 ) — (439 ) — — 3,677 — Mortgage revenue bonds 4,023 44 (56 ) — (324 ) — (754 ) — — 2,933 — Other 2,671 (20 ) (10 ) — (1,012 ) — (185 ) — — 1,444 — Total available-for-sale securities $ 15,080 $ 676 (7)(8) $ (467 ) $ 421 $ (4,194 ) $ — $ (1,774 ) $ (540 ) $ 350 $ 9,552 $ — Mortgage loans $ 1,833 $ 47 (6)(7) $ — $ 5 $ — $ — $ (273 ) $ (331 ) $ 219 $ 1,500 $ (17 ) Net derivatives 45 (20 ) (6) — — — — 26 — 9 60 23 Long-term debt: Of Fannie Mae: Senior floating $ (363 ) $ (6 ) $ — $ — $ — $ — $ — $ — $ — $ (369 ) $ (6 ) Of consolidated trusts (527 ) (8 ) — — — (64 ) 43 142 (157 ) (571 ) 11 Total long-term debt $ (890 ) $ (14 ) (6) $ — $ — $ — $ (64 ) $ 43 $ 142 $ (157 ) $ (940 ) $ 5 __________ (1) Gains (losses) included in other comprehensive income (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 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 September 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) $ 38 Single Vendor Default Rate (%) 1.8 1.8 Prepayment Speed (%) 6.0 6.0 Severity (%) 37.0 37.0 Spreads (bps) 296.3 296.3 227 Consensus Default Rate (%) 2.0 - 4.0 3.5 Prepayment Speed (%) 4.0 - 9.0 7.7 Severity (%) 37.0 - 95.0 80.0 Spreads (bps) 247.5 - 427.4 380.8 Total Alt-A private-label securities 265 Subprime private-label securities (2) 34 Consensus Default Rate (%) 5.0 5.0 Prepayment Speed (%) 5.0 5.0 Severity (%) 75.0 75.0 Spreads (bps) 608.7 608.7 Total subprime private-label securities 34 Mortgage revenue bonds 189 Discounted Cash Flow Spreads (bps) 10.0 - 292.8 290.0 2 Other Total mortgage revenue bonds 191 Total trading securities $ 490 Fair Value Measurements as of September 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) $ 2 Other Alt-A private-label securities (2) 32 Single Vendor Default Rate (%) 5.2 - 8.0 7.2 Prepayment Speed (%) 7.9 - 8.0 8.0 Severity (%) 53.0 - 55.0 54.4 Spreads (bps) 275.3 - 298.5 282.3 82 Consensus Default Rate (%) 2.5 - 6.0 2.9 Prepayment Speed (%) 3.0 - 8.0 3.6 Severity (%) 60.0 - 65.0 60.6 Spreads (bps) 232.7 - 307.8 299.1 45 Discounted Cash Flow Spreads (bps) 430.0 - 434.0 432.0 15 Other Total Alt-A private-label securities 174 Subprime private-label securities (2) 48 Other Mortgage revenue bonds 828 Single Vendor Spreads (bps) (17.9 ) - 371.9 38.2 785 Discounted Cash Flow Spreads (bps) (17.9 ) - 406.4 276.4 112 Other Total mortgage revenue bonds 1,725 Other 49 Consensus Default Rate (%) 3.5 3.5 Prepayment Speed (%) 2.5 2.5 Severity (%) 88.0 88.0 Spreads (bps) 247.0 - 346.9 285.0 354 Discounted Cash Flow Default Rate (%) 2.3 2.3 Prepayment Speed (%) 0.5 0.5 Severity (%) 35.0 35.0 Spreads (bps) 190.0 - 450.0 449.1 33 Other Total other 436 Total available-for-sale securities $ 2,385 Fair Value Measurements as of September 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 545 Build-Up 267 Consensus 201 Other Total single-family 1,013 Multifamily 160 Build-Up Spreads (bps) 66.0 - 376.2 179.8 Total mortgage loans $ 1,173 Net derivatives $ 202 Dealer Mark 14 Other Total net derivatives $ 216 Long-term debt: Of Fannie Mae: Senior floating $ (419 ) Discounted Cash Flow Of consolidated trusts (4) (302 ) Other Total long-term debt $ (721 ) 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 September 30, 2016 or December 31, 2015 that were measured at fair value on a nonrecurring basis. We held $475 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 September 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 September 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 $ 909 $ 3,651 Single Vendor 32 336 Other 5 4 Total mortgage loans held for sale, at lower of cost or fair value 946 3,991 Single-family mortgage loans held for investment, at amortized cost Internal Model 3,296 6,379 Multifamily mortgage loans held for investment, at amortized cost Broker Price Opinions 22 82 Asset Manager Estimate 222 236 Other 3 5 Total multifamily mortgage loans held for investment, at amortized cost 247 323 Acquired property, net: Single-family Accepted Offers 402 541 Appraisals 684 1,117 Walk Forwards 323 433 Internal Model 458 986 Other 64 134 Total single-family 1,931 3,211 Multifamily Other 2 — Other assets Other 10 30 Total nonrecurring assets at fair value $ 6,432 $ 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 primarily 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 and certain reperforming loans represents an estimate of the prices we would receive if we were to sell these loans in the whole-loan market. Key factors that influence the price of these loans include collateral value, estimated loan cash flows and mortgage insurance. Collateral value is derived from the current estimated mark-to-market LTV ratio of the individual loan and, where appropriate, a state-level distressed property sales discount. Cash flow characteristics include attributes such as the weighted average coupon rate and loan payment history. The fair value of mortgage insurance is estimated by taking the loan level coverage and adjusting it by the expected claims paying ability of the associated mortgage insurer. The expected claims paying abilities used for estimating the fair value of mortgage insurance are consistent with our credit loss forecast. Fair value is estimated from the extrapolation of indicative sample bids obtained from multiple active m

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 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. The defendants filed motions to dismiss on September 20, 2016. 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)	9 Months Ended
	Sep. 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 nine months ended September 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 nine months ended September 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 condensed consolidated financial statements and the timing of our adoption. In August 2016, FASB issued guidance regarding classification of certain items within the statement of cash flows in order to reduce diversity in practice with respect to cash flow classifications. The guidance is effective for us on January 1, 2018 and will be applied retrospectively for each period presented. We are currently evaluating the impact of this guidance on our condensed consolidated financial statements.

Consolidations and Transfers 24

Consolidations and Transfers of Financial Assets (Policies)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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 “Investment gains, net” 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 loan to accrual status at the point that the borrower successfully makes all required payments during the trial period (generally three to four months) and the modification is made permanent. We place a multifamily loan on nonaccrual status when the loan becomes three months or more past due according to its contractual terms or is deemed to be individually impaired, unless the loan is well secured such that collectibility of principal and accrued interest is reasonably assured. We return a multifamily loan to accrual status when the borrower cures the delinquency of the loan or we otherwise determine that the loan is well secured such that collectibility is reasonably assured.
Troubled Debt Restructurings [Policy Text Block]	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)	9 Months Ended
	Sep. 30, 2016
Receivables [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)	9 Months Ended
	Sep. 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 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 income (loss)” and we recognize realized gains and losses from the sale of AFS securities in “Investment gains, net” in our condensed consolidated statements of operations and comprehensive income.

Acquired Property, Net (Policie

Acquired Property, Net (Policies)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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 losses, net ” in our condensed consolidated statements of operations and comprehensive income.

Segment Reporting (Policies)

Segment Reporting (Policies)	9 Months Ended
	Sep. 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 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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)	9 Months Ended
	Sep. 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 September 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 $ 4,793 $ 4,704 Non-Fannie Mae 4,336 5,596 Total trading securities 9,129 10,300 Available-for-sale securities: Fannie Mae 2,601 3,936 Non-Fannie Mae 6,106 14,644 Total available-for-sale securities 8,707 18,580 Other assets 67 100 Other liabilities (450 ) (827 ) Net carrying amount $ 17,453 $ 28,153

Mortgage Loans (Tables)

Mortgage Loans (Tables)	9 Months Ended
	Sep. 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 September 30, 2016 December 31, 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family $ 221,384 $ 2,586,398 $ 2,807,782 $ 238,237 $ 2,574,174 $ 2,812,411 Multifamily 10,678 211,182 221,860 13,099 185,243 198,342 Total unpaid principal balance of mortgage loans 232,062 2,797,580 3,029,642 251,336 2,759,417 3,010,753 Cost basis and fair value adjustments, net (11,707 ) 53,732 42,025 (12,939 ) 49,781 36,842 Allowance for loan losses for loans held for investment (21,858 ) (848 ) (22,706 ) (26,510 ) (1,441 ) (27,951 ) Total mortgage loans $ 198,497 $ 2,850,464 $ 3,048,961 $ 211,887 $ 2,807,757 $ 3,019,644 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 September 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) $ 21,285 $ 41 $ 21,326 $ 25,437 $ 80 $ 25,517 Collectively reserved loans 1,231 149 1,380 2,272 162 2,434 Total allowance for loan losses $ 22,516 $ 190 $ 22,706 $ 27,709 $ 242 $ 27,951 Recorded investment in loans by segment: Individually impaired loans (1) $ 160,307 $ 766 $ 161,073 $ 171,161 $ 1,008 $ 172,169 Collectively reserved loans 2,678,498 223,339 2,901,837 2,664,377 199,166 2,863,543 Total recorded investment in loans $ 2,838,805 $ 224,105 $ 3,062,910 $ 2,835,538 $ 200,174 $ 3,035,712 __________ (1) Includes acquired credit-impaired loans.
Aging Analysis [Table Text Block]	The following tables display an aging analysis of the total recorded investment in our HFI mortgage loans by portfolio segment and class, excluding loans for which we have elected the fair value option. As of September 30, 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 $ 29,741 $ 7,505 $ 21,501 $ 58,747 $ 2,625,085 $ 2,683,832 $ 24 $ 32,806 Government (2) 54 23 264 341 37,698 38,039 264 — Alt-A 3,706 1,131 4,607 9,444 76,207 85,651 2 6,386 Other 1,401 450 1,654 3,505 27,778 31,283 6 2,337 Total single-family 34,902 9,109 28,026 72,037 2,766,768 2,838,805 296 41,529 Multifamily (3) 25 N/A 163 188 223,917 224,105 — 498 Total $ 34,927 $ 9,109 $ 28,189 $ 72,225 $ 2,990,685 $ 3,062,910 $ 296 $ 42,027 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 September 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 $ 107,455 $ 102,148 $ 14,034 $ 116,477 $ 110,502 $ 16,745 Government 302 306 58 322 327 59 Alt-A 29,294 26,763 5,204 31,888 29,103 6,217 Other 11,627 11,010 1,989 12,893 12,179 2,416 Total single-family 148,678 140,227 21,285 161,580 152,111 25,437 Multifamily 447 450 41 650 654 80 Total individually impaired loans with related allowance recorded 149,125 140,677 21,326 162,230 152,765 25,517 With no related allowance recorded: (1) Single-family: Primary 16,798 15,574 — 15,891 14,725 — Government 66 62 — 58 54 — Alt-A 3,892 3,325 — 3,721 3,169 — Other 1,256 1,119 — 1,222 1,102 — Total single-family 22,012 20,080 — 20,892 19,050 — Multifamily 315 316 — 353 354 — Total individually impaired loans with no related allowance recorded 22,327 20,396 — 21,245 19,404 — Total individually impaired loans (2) $ 171,452 $ 161,073 $ 21,326 $ 183,475 $ 172,169 $ 25,517 For the Three Months Ended September 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 $ 103,523 $ 992 $ 68 $ 113,634 $ 1,090 $ 71 Government 310 3 — 299 3 — Alt-A 27,115 250 10 30,041 272 14 Other 11,220 91 4 12,652 95 6 Total single-family 142,168 1,336 82 156,626 1,460 91 Multifamily 492 3 — 878 9 — Total individually impaired loans with related allowance recorded 142,660 1,339 82 157,504 1,469 91 With no related allowance recorded: (1) Single-family: Primary 15,534 320 19 15,627 279 16 Government 61 1 — 53 1 — Alt-A 3,312 81 — 3,674 64 1 Other 1,115 27 — 1,259 21 — Total single-family 20,022 429 19 20,613 365 17 Multifamily 311 3 — 386 5 — Total individually impaired loans with no related allowance recorded 20,333 432 19 20,999 370 17 Total individually impaired loans $ 162,993 $ 1,771 $ 101 $ 178,503 $ 1,839 $ 108 For the Nine Months Ended September 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 $ 106,498 $ 3,028 $ 243 $ 115,762 $ 3,152 $ 248 Government 317 9 — 290 9 — Alt-A 27,899 759 40 30,760 774 41 Other 11,622 276 15 13,030 282 15 Total single-family 146,336 4,072 298 159,842 4,217 304 Multifamily 555 21 — 1,053 15 — Total individually impaired loans with related allowance recorded 146,891 4,093 298 160,895 4,232 304 With no related allowance recorded: (1) Single-family: Primary 15,398 915 69 15,967 779 76 Government 59 3 — 55 3 — Alt-A 3,350 224 8 3,720 158 8 Other 1,128 79 3 1,287 56 2 Total single-family 19,935 1,221 80 21,029 996 86 Multifamily 330 9 — 463 8 — Total individually impaired loans with no related allowance recorded 20,265 1,230 80 21,492 1,004 86 Total individually impaired loans $ 167,156 $ 5,323 $ 378 $ 182,387 $ 5,236 $ 390 __________ (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 $159.6 billion and $170.3 billion as of September 30, 2016 and December 31, 2015 , respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $324 million and $451 million as of September 30, 2016 and December 31, 2015 , respectively. (3) Total single-family interest income recognized of $1.8 billion for the three months ended September 30, 2016 consists of $1.4 billion of contractual interest and $320 million of effective yield adjustments. Total single-family interest income recognized of $1.8 billion for the three months ended September 30, 2015 consists of $1.5 billion of contractual interest and $327 million of effective yield adjustments. Total single-family interest income recognized of $5.3 billion for the nine months ended September 30, 2016 consists of $4.3 billion of contractual interest and $961 million of effective yield adjustments. Total single-family interest income recognized of $5.2 billion for the nine months ended September 30, 2015 consists of $4.3 billion of contractual interest and $907 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 September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 13,983 $ 1,922 14,926 $ 2,021 Government 54 5 54 6 Alt-A 1,578 227 1,805 268 Other 317 57 324 57 Total single-family 15,932 2,211 17,109 2,352 Multifamily 2 5 3 10 Total TDRs 15,934 $ 2,216 17,112 $ 2,362 For the Nine Months Ended September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 45,987 $ 6,282 54,284 $ 7,443 Government 136 14 192 22 Alt-A 5,112 735 7,127 1,101 Other 1,078 190 1,453 265 Total single-family 52,313 7,221 63,056 8,831 Multifamily 6 50 7 16 Total TDRs 52,319 $ 7,271 63,063 $ 8,847 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 September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 5,268 $ 734 6,847 $ 1,003 Government 31 4 31 3 Alt-A 734 116 1,052 183 Other 235 41 328 65 Total single-family 6,268 895 8,258 1,254 Multifamily — — — — Total TDRs that subsequently defaulted 6,268 $ 895 8,258 $ 1,254 For the Nine Months Ended September 30, 2016 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment (Dollars in millions) Single-family: Primary 15,377 $ 2,174 19,726 $ 2,870 Government 73 9 88 12 Alt-A 2,342 376 3,168 537 Other 767 130 922 186 Total single-family 18,559 2,689 23,904 3,605 Multifamily — — 3 6 Total TDRs that subsequently defaulted 18,559 $ 2,689 23,907 $ 3,611
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 September 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% $ 2,313,365 $ 58,287 $ 20,442 $ 2,228,533 $ 59,000 $ 21,274 Greater than 80% and less than or equal to 90% 233,787 10,291 3,966 250,373 12,588 4,936 Greater than 90% and less than or equal to 100% 98,865 7,156 2,818 122,939 9,345 3,861 Greater than 100% and less than or equal to 110% 18,071 4,405 1,805 27,875 6,231 2,596 Greater than 110% and less than or equal to 120% 9,071 2,436 1,012 14,625 3,730 1,592 Greater than 120% and less than or equal to 125% 2,721 791 307 4,520 1,260 545 Greater than 125% 7,952 2,285 933 13,328 3,947 1,606 Total $ 2,683,832 $ 85,651 $ 31,283 $ 2,662,193 $ 96,101 $ 36,410 __________ (1) Excludes $38.0 billion and $40.8 billion as of September 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 September 30, December 31, 2016 2015 (Dollars in millions) Credit risk profile by internally assigned grade: (1) Pass $ 219,613 $ 194,132 Special mention 1,851 3,202 Substandard 2,637 2,833 Doubtful 4 7 Total $ 224,105 $ 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)	9 Months Ended
	Sep. 30, 2016
Receivables [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 September 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 $ 22,736 $ 848 $ 23,584 $ 29,624 $ 1,252 $ 30,876 Provision (benefit) for loan losses (1) (561 ) (48 ) (609 ) (1,722 ) 330 (1,392 ) Charge-offs (2)(3) (587 ) (17 ) (604 ) (748 ) (22 ) (770 ) Recoveries 108 27 135 161 3 164 Transfers (4) 113 (113 ) — 262 (262 ) — Other (5) 10 — 10 (13 ) — (13 ) Ending balance $ 21,819 $ 697 $ 22,516 $ 27,564 $ 1,301 $ 28,865 Multifamily allowance for loan losses: Beginning balance $ 57 $ 158 $ 215 $ 100 $ 174 $ 274 Provision (benefit) for loan losses (1) (22 ) (5 ) (27 ) (10 ) 8 (2 ) Charge-offs (2)(3) (2 ) (2 ) (4 ) (5 ) (2 ) (7 ) Recoveries 6 — 6 4 — 4 Transfers (4) — — — 1 (1 ) — Other (5) — — — 1 — 1 Ending balance $ 39 $ 151 $ 190 $ 91 $ 179 $ 270 Total allowance for loan losses: Beginning balance $ 22,793 $ 1,006 $ 23,799 $ 29,724 $ 1,426 $ 31,150 Provision (benefit) for loan losses (1) (583 ) (53 ) (636 ) (1,732 ) 338 (1,394 ) Charge-offs (2)(3) (589 ) (19 ) (608 ) (753 ) (24 ) (777 ) Recoveries 114 27 141 165 3 168 Transfers (4) 113 (113 ) — 263 (263 ) — Other (5) 10 — 10 (12 ) — (12 ) Ending balance $ 21,858 $ 848 $ 22,706 $ 27,655 $ 1,480 $ 29,135 For the Nine Months Ended September 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) (2,979 ) 22 (2,957 ) (249 ) (44 ) (293 ) Charge-offs (2)(3) (2,629 ) (72 ) (2,701 ) (8,108 ) (64 ) (8,172 ) Recoveries 339 30 369 1,032 15 1,047 Transfers (4) 553 (553 ) — 877 (877 ) — Other (5) 96 — 96 1,056 50 1,106 Ending balance $ 21,819 $ 697 $ 22,516 $ 27,564 $ 1,301 $ 28,865 Multifamily allowance for loan losses: Beginning balance $ 71 $ 171 $ 242 $ 161 $ 203 $ 364 Benefit for loan losses (1) (33 ) (14 ) (47 ) (41 ) (23 ) (64 ) Charge-offs (2)(3) (10 ) (2 ) (12 ) (39 ) (2 ) (41 ) Recoveries 7 — 7 4 — 4 Transfers (4) 4 (4 ) — 1 (1 ) — Other (5) — — — 5 2 7 Ending balance $ 39 $ 151 $ 190 $ 91 $ 179 $ 270 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) (3,012 ) 8 (3,004 ) (290 ) (67 ) (357 ) Charge-offs (2)(3) (2,639 ) (74 ) (2,713 ) (8,147 ) (66 ) (8,213 ) Recoveries 346 30 376 1,036 15 1,051 Transfers (4) 557 (557 ) — 878 (878 ) — Other (5) 96 — 96 1,061 52 1,113 Ending balance $ 21,858 $ 848 $ 22,706 $ 27,655 $ 1,480 $ 29,135 __________ (1) Provision (benefit) for loan losses is included in “Benefit 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 include the 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 carrying value of our mortgage loans. As of September 30, 2016 December 31, 2015 Of Fannie Mae Of Consolidated Trusts Total Of Fannie Mae Of Consolidated Trusts Total (Dollars in millions) Single-family $ 221,384 $ 2,586,398 $ 2,807,782 $ 238,237 $ 2,574,174 $ 2,812,411 Multifamily 10,678 211,182 221,860 13,099 185,243 198,342 Total unpaid principal balance of mortgage loans 232,062 2,797,580 3,029,642 251,336 2,759,417 3,010,753 Cost basis and fair value adjustments, net (11,707 ) 53,732 42,025 (12,939 ) 49,781 36,842 Allowance for loan losses for loans held for investment (21,858 ) (848 ) (22,706 ) (26,510 ) (1,441 ) (27,951 ) Total mortgage loans $ 198,497 $ 2,850,464 $ 3,048,961 $ 211,887 $ 2,807,757 $ 3,019,644 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 September 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) $ 21,285 $ 41 $ 21,326 $ 25,437 $ 80 $ 25,517 Collectively reserved loans 1,231 149 1,380 2,272 162 2,434 Total allowance for loan losses $ 22,516 $ 190 $ 22,706 $ 27,709 $ 242 $ 27,951 Recorded investment in loans by segment: Individually impaired loans (1) $ 160,307 $ 766 $ 161,073 $ 171,161 $ 1,008 $ 172,169 Collectively reserved loans 2,678,498 223,339 2,901,837 2,664,377 199,166 2,863,543 Total recorded investment in loans $ 2,838,805 $ 224,105 $ 3,062,910 $ 2,835,538 $ 200,174 $ 3,035,712 __________ (1) Includes acquired credit-impaired loans.

Investments in Securities (Tabl

Investments in Securities (Tables)	9 Months Ended
	Sep. 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 September 30, 2016 December 31, 2015 (Dollars in millions) Mortgage-related securities: Fannie Mae $ 4,931 $ 4,813 Freddie Mac 808 1,314 Ginnie Mae 1,393 426 Alt-A private-label securities 313 436 Subprime private-label securities 353 644 Commercial mortgage-backed securities (“CMBS”) 1,281 2,341 Mortgage revenue bonds 191 449 Total mortgage-related securities 9,270 10,423 U.S. Treasury securities 31,277 29,485 Total trading securities $ 40,547 $ 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 Nine Months Ended Months Ended September 30 , September 30 , 2016 2015 2016 2015 (Dollars in millions) Gross realized gains $ 400 $ 94 $ 845 $ 907 Gross realized losses — 9 12 66 Total proceeds (excludes initial sale of securities from new portfolio securitizations) 2,819 1,556 10,086 6,764
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 September 30, 2016 Total Amortized Cost (1) Gross Unrealized Gains Gross Unrealized Losses (2) Total Fair Value (Dollars in millions) Fannie Mae $ 2,545 $ 187 $ (20 ) $ 2,712 Freddie Mac 534 48 — 582 Ginnie Mae 54 7 — 61 Alt-A private-label securities 883 535 (1 ) 1,417 Subprime private-label securities 1,437 486 (4 ) 1,919 CMBS 971 8 (1 ) 978 Mortgage revenue bonds 1,639 90 (4 ) 1,725 Other mortgage-related securities 449 22 — 471 Total $ 8,512 $ 1,383 $ (30 ) $ 9,865 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 September 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 ) $ 85 $ (19 ) $ 502 Alt-A private-label securities (1 ) 38 — — Subprime private-label securities — — (4 ) 76 CMBS (1 ) 136 — — Mortgage revenue bonds (3 ) 16 (1 ) 5 Total $ (6 ) $ 275 $ (24 ) $ 583 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 September 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 September 30, 2016 Alt-A Subprime Option ARM Fixed Rate Variable Rate Hybrid Rate (Dollars in millions) Unpaid principal balance $ 2,688 $ 360 $ 270 $ 548 $ 571 Weighted average collateral default (1) 37.4 % 24.3 % 17.0 % 18.8 % 7.4 % Weighted average collateral severities (2) 49.8 29.3 52.4 38.2 35.0 Weighted average voluntary prepayment rates (3) 2.9 9.3 7.9 8.6 13.9 Average credit enhancement (4) 12.8 3.7 0.4 2.0 1.6 __________ (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 September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance $ 2,219 $ 2,557 $ 2,421 $ 5,260 Additions for the credit component on debt securities for which OTTI was not previously recognized 1 — 1 — Additions for the credit component on debt securities for which OTTI was previously recognized — 1 6 5 Reductions for securities no longer in portfolio at period end (3 ) (2 ) (106 ) (1,167 ) 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 (223 ) — (254 ) (1,439 ) Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities (30 ) (43 ) (104 ) (146 ) Ending balance $ 1,964 $ 2,513 $ 1,964 $ 2,513
Investments Classified by Contractual Maturity Date [Table Text Block]	The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time. As of September 30, 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 $ 2,545 $ 2,712 $ — $ — $ 29 $ 29 $ 60 $ 66 $ 2,456 $ 2,617 Freddie Mac 534 582 1 1 65 68 95 102 373 411 Ginnie Mae 54 61 — — 1 1 3 4 50 56 Alt-A private-label securities 883 1,417 — — — — — — 883 1,417 Subprime private-label securities 1,437 1,919 — — — — — — 1,437 1,919 CMBS 971 978 776 782 154 156 — — 41 40 Mortgage revenue bonds 1,639 1,725 10 10 88 88 170 172 1,371 1,455 Other mortgage-related securities 449 471 — — — 1 3 3 446 467 Total $ 8,512 $ 9,865 $ 787 $ 793 $ 337 $ 343 $ 331 $ 347 $ 7,057 $ 8,382

Financial Guarantees (Tables)

Financial Guarantees (Tables)	9 Months Ended
	Sep. 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 September 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 $ 13,333 $ 147 $ 8,269 $ 15,069 $ 194 $ 8,857 Other guaranty arrangements (3) 15,469 135 2,707 16,504 135 2,869 Total $ 28,802 $ 282 $ 10,976 $ 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)	9 Months Ended
	Sep. 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 September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Beginning balance — Acquired property $ 5,928 $ 9,199 $ 7,481 $ 11,442 Additions 1,391 2,236 4,876 7,602 Disposals (1,906 ) (3,125 ) (6,944 ) (10,734 ) Ending balance — Acquired property 5,413 8,310 5,413 8,310 Valuation allowance (372 ) (619 ) (372 ) (619 ) Ending balance — Acquired property, net $ 5,041 $ 7,691 $ 5,041 $ 7,691

Short-Term Borrowings and Lon40

Short-Term Borrowings and Long-Term Debt (Tables)	9 Months Ended
	Sep. 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 September 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) $ 35 — % $ 62 — % Short-term debt of Fannie Mae $ 51,442 0.44 % $ 71,007 0.26 % Debt of consolidated trusts 612 0.46 943 0.19 Total short-term debt $ 52,054 0.44 % $ 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 September 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 $ 153,481 2.23 % 2016 - 2030 $ 154,057 2.49 % Medium-term notes (2) 2016 - 2026 83,661 1.39 2016 - 2025 96,997 1.53 Other (3) 2017 - 2038 13,557 6.58 2016 - 2038 27,772 4.88 Total senior fixed 250,699 2.19 278,826 2.39 Senior floating: Medium-term notes (2) 2016 - 2019 28,715 0.59 2016 - 2019 20,791 0.27 Connecticut Avenue Securities (4) 2023 - 2029 15,636 4.59 2023 - 2028 10,764 3.84 Other (5) 2020 - 2037 419 6.65 2020 - 2037 368 10.46 Total senior floating 44,770 2.01 31,923 1.58 Subordinated debentures 2019 4,537 9.93 2019 4,227 9.93 Secured borrowings (6) 2021 - 2022 120 1.42 2021 - 2022 152 1.47 Total long-term debt of Fannie Mae (7) 300,126 2.28 315,128 2.41 Debt of consolidated trusts 2016 - 2054 2,880,933 2.53 2016 - 2054 2,810,593 2.94 Total long-term debt $ 3,181,059 2.51 % $ 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 $2.0 billion and $3.2 billion as of September 30, 2016 and December 31, 2015 , respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 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 September 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 $ 6,324 $ 19 $ 127,859 $ (11,071 ) $ 33,154 $ 267 $ 123,106 $ (6,920 ) Receive-fixed 99,254 5,218 70,551 (146 ) 59,796 3,436 143,209 (753 ) Basis 1,764 198 15,700 (21 ) 1,864 141 17,100 (15 ) Foreign currency 225 75 227 (82 ) 295 95 258 (52 ) Swaptions: Pay-fixed 6,175 36 6,850 (13 ) 7,050 45 14,950 (26 ) Receive-fixed 1,625 7 6,600 (157 ) 2,000 8 13,950 (171 ) Other (1) 9,371 22 — (1 ) 9,196 28 — (2 ) Total gross risk management derivatives 124,738 5,575 227,787 (11,491 ) 113,355 4,020 312,573 (7,939 ) Accrued interest receivable (payable) — 720 — (1,097 ) — 758 — (977 ) Netting adjustment (2) — (6,154 ) — 12,423 — (4,024 ) — 8,650 Total net risk management derivatives $ 124,738 $ 141 $ 227,787 $ (165 ) $ 113,355 $ 754 $ 312,573 $ (266 ) Mortgage commitment derivatives: Mortgage commitments to purchase whole loans $ 10,820 $ 31 $ 4,568 $ (6 ) $ 4,815 $ 9 $ 2,960 $ (9 ) Forward contracts to purchase mortgage-related securities 66,637 280 18,467 (29 ) 31,273 66 19,418 (57 ) Forward contracts to sell mortgage-related securities 18,666 38 117,252 (502 ) 26,224 65 40,753 (92 ) Total mortgage commitment derivatives $ 96,123 $ 349 $ 140,287 $ (537 ) $ 62,312 $ 140 $ 63,131 $ (158 ) Derivatives at fair value $ 220,861 $ 490 $ 368,074 $ (702 ) $ 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 $6.7 billion and $4.9 billion as of September 30, 2016 and December 31, 2015 , respectively. Cash collateral received was $419 million and $314 million as of September 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 Nine Months Ended September 30, Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Risk management derivatives: Swaps: Pay-fixed $ 1,386 $ (4,402 ) $ (6,044 ) $ (3,120 ) Receive-fixed (1,020 ) 2,295 3,338 2,236 Basis 2 37 51 25 Foreign currency (6 ) (20 ) (37 ) (33 ) Swaptions: Pay-fixed (3 ) 32 26 137 Receive-fixed 10 (102 ) (126 ) (181 ) Other (7 ) 22 153 20 Net accrual of periodic settlements (295 ) (266 ) (855 ) (694 ) Total risk management derivatives fair value gains (losses), net $ 67 $ (2,404 ) $ (3,494 ) $ (1,610 ) Mortgage commitment derivatives fair value losses, net (216 ) (361 ) (945 ) (427 ) Total derivatives fair value losses, net $ (149 ) $ (2,765 ) $ (4,439 ) $ (2,037 )

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	9 Months Ended
	Sep. 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 (loss) per share of common stock. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars and shares in millions, except per share amounts) Net income attributable to Fannie Mae $ 3,196 $ 1,960 $ 7,278 $ 8,488 Dividends distributed or available for distribution to senior preferred stockholder (1) (2,977 ) (2,202 ) (6,765 ) (8,357 ) Net income (loss) attributable to common stockholders $ 219 $ (242 ) $ 513 $ 131 Weighted-average common shares outstanding—Basic (2) 5,762 5,762 5,762 5,762 Convertible preferred stock 131 — 131 131 Weighted-average common shares outstanding—Diluted (2) 5,893 5,762 5,893 5,893 Earnings (loss) per share: Basic $ 0.04 $ (0.04 ) $ 0.09 $ 0.02 Diluted 0.04 (0.04 ) 0.09 0.02 __________ (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 September 30, 2016 and 2015.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment results [Table Text Block]	For the Three Months Ended September 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 166 $ (22 ) $ 1,049 $ 4,242 (2) $ 5,435 Benefit for credit losses 645 28 — — 673 Net interest income after benefit for credit losses 811 6 1,049 4,242 6,108 Guaranty fee income (expense) (3) 3,305 431 (189 ) (3,524 ) (4) 23 (4) Investment gains (losses), net — 23 2,232 (1,788 ) (5) 467 Fair value gains (losses), net — — (530 ) 39 (6) (491 ) Gains (losses) from partnership investments (7) (17 ) 5 — — (12 ) Fee and other income (expense) 89 49 69 (55 ) 152 Administrative expenses (479 ) (84 ) (98 ) — (661 ) Foreclosed property (expense) income (114 ) 4 — — (110 ) TCCA fees (3) (465 ) — — — (465 ) Other income (expenses), net (382 ) (10 ) (44 ) 148 (288 ) Income (loss) before federal income taxes 2,748 424 2,489 (938 ) 4,723 Provision for federal income taxes (808 ) (49 ) (670 ) — (1,527 ) Net income (loss) attributable to Fannie Mae $ 1,940 $ 375 $ 1,819 $ (938 ) $ 3,196 For the Nine Months Ended September 30, 2016 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 485 $ (62 ) $ 3,221 $ 11,846 (2) $ 15,490 Benefit for credit losses 3,404 54 — — 3,458 Net interest income (loss) after benefit for credit losses 3,889 (8 ) 3,221 11,846 18,948 Guaranty fee income (expense) (3) 9,787 1,216 (576 ) (10,349 ) (4) 78 (4) Investment gains (losses), net (1 ) 37 5,735 (4,837 ) (5) 934 Fair value gains (losses), net — — (5,063 ) 92 (6) (4,971 ) Gains (losses) from partnership investments (7) (54 ) 45 — — (9 ) Fee and other income (expense) 290 156 121 (93 ) 474 Administrative expenses (1,483 ) (254 ) (290 ) — (2,027 ) Foreclosed property (expense) income (510 ) 3 — — (507 ) TCCA fees (3) (1,358 ) — — — (1,358 ) Other income (expenses), net (1,046 ) (21 ) (103 ) 361 (809 ) Income (loss) before federal income taxes 9,514 1,174 3,045 (2,980 ) 10,753 Provision for federal income taxes (2,544 ) (127 ) (804 ) — (3,475 ) Net income (loss) attributable to Fannie Mae $ 6,970 $ 1,047 $ 2,241 $ (2,980 ) $ 7,278 For the Three Months Ended September 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 66 $ (16 ) $ 1,401 $ 4,137 (2) $ 5,588 Benefit for credit losses 1,545 5 — — 1,550 Net interest income (loss) after benefit for credit losses 1,611 (11 ) 1,401 4,137 7,138 Guaranty fee income (expense) (3) 3,145 367 (210 ) (3,271 ) (4) 31 (4) Investment gains (losses), net (1 ) 5 1,608 (1,313 ) (5) 299 Fair value gains (losses), net (4 ) — (2,697 ) 112 (6) (2,589 ) Gains (losses) from partnership investments (7) (12 ) 7 — — (5 ) Fee and other income (expense) 98 58 83 (11 ) 228 Administrative expenses (649 ) (109 ) (194 ) — (952 ) Foreclosed property (expense) income (516 ) 19 — — (497 ) TCCA fees (3) (413 ) — — — (413 ) Other income (expenses), net (180 ) 5 (1 ) (34 ) (210 ) Income (loss) before federal income taxes 3,079 341 (10 ) (380 ) 3,030 Provision for federal income taxes (1,040 ) (17 ) (13 ) — (1,070 ) Net income (loss) attributable to Fannie Mae $ 2,039 $ 324 $ (23 ) $ (380 ) $ 1,960 For the Nine Months Ended September 30, 2015 Business Segments Single-Family Multifamily Capital Markets Reconciling Items (1) Total Results (Dollars in millions) Net interest income (loss) $ 93 $ (73 ) $ 4,516 $ 11,796 (2) $ 16,332 Benefit for credit losses 967 83 — — 1,050 Net interest income after benefit for credit losses 1,060 10 4,516 11,796 17,382 Guaranty fee income (expense) (3) 9,277 1,064 (658 ) (9,584 ) (4) 99 (4) Investment gains (losses), net (2 ) 29 4,679 (3,551 ) (5) 1,155 Fair value gains (losses), net (8 ) — (2,112 ) 218 (6) (1,902 ) Gains (losses) from partnership investments (7) (27 ) 262 — — 235 Fee and other income (expense) 571 193 288 (28 ) 1,024 Administrative expenses (1,591 ) (280 ) (493 ) — (2,364 ) Foreclosed property (expense) income (1,183 ) 31 — — (1,152 ) TCCA fees (3) (1,192 ) — — — (1,192 ) Other income (expenses), net (669 ) (8 ) (12 ) 42 (647 ) Income (loss) before federal income taxes 6,236 1,301 6,208 (1,107 ) 12,638 Provision for federal income taxes (2,040 ) (128 ) (1,982 ) — (4,150 ) Net income (loss) attributable to Fannie Mae $ 4,196 $ 1,173 $ 4,226 $ (1,107 ) $ 8,488 __________ (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)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Schedule of Other Comprehensive Income (Loss) [Table Text Block]	The following table displays the activity in other comprehensive income (loss), net of tax, by major categories. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2016 2015 2016 2015 (Dollars in millions) Net income $ 3,196 $ 1,960 $ 7,278 $ 8,488 Other comprehensive income (loss), net of tax effect: Changes in net unrealized gains (losses) on AFS securities (net of tax of $18 and $58, respectively, for the three months ended and net of tax of $3 and $89, respectively, for the nine months ended) 33 (107 ) (6 ) (164 ) Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $2, respectively, for the three months ended and net of tax of $12 and $66, respectively, for the nine months ended) 2 3 22 121 Reclassification adjustment for gains on AFS securities included in net income (net of tax of $129 and $32, respectively, for the three months ended and net of tax of $266 and $265, respectively, for the nine months ended) (240 ) (73 ) (494 ) (505 ) Other (1) (2 ) 430 (6 ) 428 Total other comprehensive income (loss) (207 ) 253 (484 ) (120 ) Total comprehensive income $ 2,989 $ 2,213 $ 6,794 $ 8,368 __________ (1) For the three and nine months ended September 30, 2015, includes reclassification adjustment related to the termination of the defined benefit pension plan recognized in “Administrative expenses” and “Provision for federal income taxes” in our condensed consolidated statements of operations and comprehensive income.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table displays our accumulated other comprehensive income by major categories. As of September 30, December 31, 2016 2015 (Dollars in millions) Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax $ 198 $ 455 Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax 682 903 Other, net of tax 43 49 Accumulated other comprehensive income $ 923 $ 1,407 The table below displays changes in accumulated other comprehensive income, net of tax. For the Three Months Ended September 30, For the Nine Months Ended September 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 $ 1,085 $ 45 $ 1,130 $ 1,750 $ (390 ) $ 1,360 $ 1,358 $ 49 $ 1,407 $ 2,121 $ (388 ) $ 1,733 Other comprehensive income (loss) before reclassifications 33 — 33 (107 ) 6 (101 ) (6 ) — (6 ) (164 ) 6 (158 ) Amounts reclassified from other comprehensive income (loss) (238 ) (2 ) (240 ) (70 ) 424 354 (472 ) (6 ) (478 ) (384 ) 422 38 Net other comprehensive income (loss) (205 ) (2 ) (207 ) (177 ) 430 253 (478 ) (6 ) (484 ) (548 ) 428 (120 ) Ending balance $ 880 $ 43 $ 923 $ 1,573 $ 40 $ 1,613 $ 880 $ 43 $ 923 $ 1,573 $ 40 $ 1,613 __________ (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” and “Provision for federal income taxes” 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)	9 Months Ended
	Sep. 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 September 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) 1.27 % 0.34 % 1.23 % 1.27 % 0.37 % 1.59 % Percentage of single-family conventional loans (4) 1.45 0.39 1.24 1.46 0.41 1.55
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of September 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% 2 % 10.56 % 3 % 10.76 % Geographical distribution: California 20 0.49 20 0.58 Florida 6 2.05 6 2.86 New Jersey 4 3.47 4 4.87 New York 5 2.77 5 3.55 All other states 65 1.11 65 1.34 Product distribution: Alt-A 3 5.27 4 6.53 Vintages: 2004 and prior 4 2.75 5 3.06 2005-2008 9 6.49 10 7.60 2009-2016 87 0.33 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 September 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 September 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 September 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 0.02 % 0.07 % 0.03 % 0.07 %
Schedule of Risk Characteristics Guaranty Book of Business [Table Text Block]	As of September 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 % 0.11 % 3 % 0.40 % Less than or equal to 80% 98 0.07 97 0.06 Current DSCR less than 1.0 (5) 2 1.95 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 September 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)	9 Months Ended
	Sep. 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 September 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 $ 4,760 $ (4,737 ) $ 23 $ — $ — $ 23 Cleared risk management derivatives 1,512 (1,417 ) 95 — — 95 Mortgage commitment derivatives 349 — 349 (214 ) — 135 Total derivative assets 6,621 (6,154 ) 467 (4) (214 ) — 253 Securities purchased under agreements to resell or similar arrangements (5) 40,600 — 40,600 — (40,600 ) — Total assets $ 47,221 $ (6,154 ) $ 41,067 $ (214 ) $ (40,600 ) $ 253 Liabilities: OTC risk management derivatives $ (7,739 ) $ 7,580 $ (159 ) $ — $ — $ (159 ) Cleared risk management derivatives (4,848 ) 4,843 (5 ) — 5 — Mortgage commitment derivatives (537 ) — (537 ) 214 1 (322 ) Total derivative liabilities (13,124 ) 12,423 (701 ) (4) 214 6 (481 ) Securities sold under agreements to repurchase or similar arrangements (35 ) — (35 ) — 35 — Total liabilities $ (13,159 ) $ 12,423 $ (736 ) $ 214 $ 41 $ (481 ) 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 September 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 $40.7 billion and $38.0 billion , of which $37.4 billion and $36.2 billion could be sold or repledged as of September 30, 2016 and December 31, 2015, respectively. None of the underlying collateral was sold or repledged as of September 30, 2016 and December 31, 2015 . (4) Excludes derivative assets of $23 million and $28 million as of September 30, 2016 and December 31, 2015 , and derivative liabilities of $1 million and $2 million recognized in our condensed consolidated balance sheets as of September 30, 2016 and December 31, 2015 , respectively, that are not subject to enforceable master netting arrangements. (5) Includes $22.3 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 September 30, 2016 and December 31, 2015 , respectively.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 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 September 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 $ — $ 4,931 $ — $ — $ 4,931 Freddie Mac — 808 — — 808 Ginnie Mae — 1,393 — — 1,393 Alt-A private-label securities — 48 265 — 313 Subprime private-label securities — 319 34 — 353 CMBS — 1,281 — — 1,281 Mortgage revenue bonds — — 191 — 191 Non-mortgage-related securities: U.S. Treasury securities 31,277 — — — 31,277 Total trading securities 31,277 8,780 490 — 40,547 Available-for-sale securities: Mortgage-related securities: Fannie Mae — 2,712 — — 2,712 Freddie Mac — 580 2 — 582 Ginnie Mae — 61 — — 61 Alt-A private-label securities — 1,243 174 — 1,417 Subprime private-label securities — 1,871 48 — 1,919 CMBS — 978 — — 978 Mortgage revenue bonds — — 1,725 — 1,725 Other — 35 436 — 471 Total available-for-sale securities — 7,480 2,385 — 9,865 Mortgage loans — 11,741 1,173 — 12,914 Other assets: Risk management derivatives: Swaps — 6,018 212 — 6,230 Swaptions — 43 — — 43 Other — — 22 — 22 Netting adjustment — — — (6,154 ) (6,154 ) Mortgage commitment derivatives — 346 3 — 349 Total other assets — 6,407 237 (6,154 ) 490 Total assets at fair value $ 31,277 $ 34,408 $ 4,285 $ (6,154 ) $ 63,816 Fair Value Measurements as of September 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 $ — $ 10,041 $ 419 $ — $ 10,460 Total of Fannie Mae — 10,041 419 — 10,460 Of consolidated trusts — 35,151 302 — 35,453 Total long-term debt — 45,192 721 — 45,913 Other liabilities: Risk management derivatives: Swaps — 12,407 10 — 12,417 Swaptions — 170 — — 170 Other — — 1 — 1 Netting adjustment — — — (12,423 ) (12,423 ) Mortgage commitment derivatives — 527 10 — 537 Total other liabilities — 13,104 21 (12,423 ) 702 Total liabilities at fair value $ — $ 58,296 $ 742 $ (12,423 ) $ 46,615 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 September 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2016 (5)(6) Balance, June 30, 2016 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Alt-A private-label securities $ 259 $ 17 $ — $ — $ — $ — $ (11 ) $ — $ — $ 265 $ 17 Subprime private-label securities 44 (9 ) — — — — (1 ) — — 34 (9 ) Mortgage revenue bonds 193 5 — — — — (7 ) — — 191 4 Total trading securities $ 496 $ 13 (6)(7) $ — $ — $ — $ — $ (19 ) $ — $ — $ 490 $ 12 Available-for-sale securities: Mortgage-related: Freddie Mac $ 1 $ — $ — $ — $ — $ — $ — $ — $ 1 $ 2 $ — Alt-A private-label securities 175 1 1 — — — (3 ) — — 174 — Subprime private-label securities 173 79 (77 ) — (123 ) — (4 ) — — 48 — Mortgage revenue bonds 2,029 35 (23 ) — (201 ) — (115 ) — — 1,725 — Other 450 — 6 — — — (20 ) — — 436 — Total available-for-sale securities $ 2,828 $ 115 (7)(8) $ (93 ) $ — $ (324 ) $ — $ (142 ) $ — $ 1 $ 2,385 $ — Mortgage loans $ 1,280 $ 23 (6)(7) $ — $ 4 $ (72 ) $ — $ (60 ) $ (17 ) $ 15 $ 1,173 $ 6 Net derivatives 248 11 (6) — — — (1 ) (43 ) — 1 216 (18 ) Long-term debt: Of Fannie Mae: Senior floating $ (410 ) $ (9 ) $ — $ — $ — $ — $ — $ — $ — $ (419 ) $ (9 ) Of consolidated trusts (326 ) (2 ) — — — (16 ) 11 95 (64 ) (302 ) — Total long-term debt $ (736 ) $ (11 ) (6) $ — $ — $ — $ (16 ) $ 11 $ 95 $ (64 ) $ (721 ) $ (9 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2016 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2016 (5)(6) Balance, December 31, 2015 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2016 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ (1 ) $ (24 ) $ 25 $ — $ — Freddie Mac — — — — — — — (1 ) 1 — — Alt-A private-label securities 305 (13 ) — — — — (27 ) — — 265 (13 ) Subprime private-label securities 644 (43 ) — — (187 ) — (17 ) (363 ) — 34 (19 ) Mortgage revenue bonds 449 34 — — (279 ) — (13 ) — — 191 14 Total trading securities $ 1,398 $ (22 ) (6)(7) $ — $ — $ (466 ) $ — $ (58 ) $ (388 ) $ 26 $ 490 $ (18 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ — $ — $ — $ — $ (1 ) $ 1 $ — $ — Freddie Mac 4 — — — — — — (3 ) 1 2 — Alt-A private-label securities 1,041 13 (26 ) — (291 ) — (47 ) (516 ) — 174 — Subprime private-label securities 3,281 171 (209 ) — (707 ) — (165 ) (2,323 ) — 48 — Mortgage revenue bonds 2,701 115 25 — (812 ) — (304 ) — — 1,725 — Other 1,404 — (20 ) — (605 ) — (59 ) (284 ) — 436 — Total available-for-sale securities $ 8,431 $ 299 (7)(8) $ (230 ) $ — $ (2,415 ) $ — $ (575 ) $ (3,127 ) $ 2 $ 2,385 $ — Mortgage loans $ 1,477 $ 139 (6)(7) $ — $ 29 $ (392 ) $ — $ (199 ) $ (101 ) $ 220 $ 1,173 $ 24 Net derivatives 157 243 (6) — — — (8 ) (176 ) (2 ) 2 216 41 Long-term debt: Of Fannie Mae: Senior floating $ (369 ) $ (50 ) $ — $ — $ — $ — $ — $ — $ — $ (419 ) $ (50 ) Of consolidated trusts (496 ) (77 ) — — — (70 ) 329 140 (128 ) (302 ) (9 ) Total long-term debt $ (865 ) $ (127 ) (6) $ — $ — $ — $ (70 ) $ 329 $ 140 $ (128 ) $ (721 ) $ (59 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Three Months Ended September 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2015 (5)(6) Balance, June 30, 2015 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Alt-A private-label securities $ 325 $ (3 ) $ — $ — $ — $ — $ (7 ) $ — $ — $ 315 $ (3 ) Subprime private-label securities 718 (5 ) — — — — (17 ) — — 696 (5 ) Mortgage revenue bonds 602 (19 ) — — — — (4 ) — — 579 (19 ) Total trading securities $ 1,645 $ (27 ) (6)(7) $ — $ — $ — $ — $ (28 ) $ — $ — $ 1,590 $ (27 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ 129 $ — $ — $ — $ (122 ) $ — $ (8 ) $ — $ 1 $ — $ — Freddie Mac 4 — — — — — — (1 ) 1 4 — Alt-A private-label securities 1,654 2 (8 ) — — — (178 ) — 24 1,494 — Subprime private-label securities 3,837 33 (45 ) — — — (148 ) — — 3,677 — Mortgage revenue bonds 3,171 4 (29 ) — (8 ) — (205 ) — — 2,933 — Other 2,158 73 (95 ) — (644 ) — (48 ) — — 1,444 — Total available-for-sale securities $ 10,953 $ 112 (7)(8) $ (177 ) $ — $ (774 ) $ — $ (587 ) $ (1 ) $ 26 $ 9,552 $ — Mortgage loans $ 1,595 $ 9 (6)(7) $ — $ — $ — $ — $ (97 ) $ (77 ) $ 70 $ 1,500 $ (24 ) Net derivatives 4 79 (6) — — — — (32 ) — 9 60 28 Long-term debt: Of Fannie Mae: Senior floating $ (346 ) $ (23 ) $ — $ — $ — $ — $ — $ — $ — $ (369 ) $ (23 ) Of consolidated trusts (493 ) — — — — (64 ) 18 33 (65 ) (571 ) — Total long-term debt $ (839 ) $ (23 ) (6) $ — $ — $ — $ (64 ) $ 18 $ 33 $ (65 ) $ (940 ) $ (23 ) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) For the Nine Months Ended September 30, 2015 Total Gains (Losses) (Realized/Unrealized) Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held as of September 30, 2015 (5)(6) Balance, December 31, 2014 Included in Net Income Included in Total Other Comprehensive Income (Loss) (1) Purchases (2) Sales (2) Issues (3) Settlements (3) Transfers out of Level 3 (4) Transfers into Level 3 (4) Balance, September 30, 2015 (Dollars in millions) Trading securities: Mortgage-related: Fannie Mae $ 305 $ (27 ) $ — $ — $ (2 ) $ — $ — $ (278 ) $ 2 $ — $ — Alt-A private-label securities 597 41 — — (267 ) — (40 ) (44 ) 28 315 (3 ) Subprime private-label securities 1,307 38 — — (580 ) — (69 ) — — 696 (2 ) Mortgage revenue bonds 722 (17 ) — — (118 ) — (8 ) — — 579 (17 ) Other 99 4 — — (100 ) — (3 ) — — — — Total trading securities $ 3,030 $ 39 (6)(7) $ — $ — $ (1,067 ) $ — $ (120 ) $ (322 ) $ 30 $ 1,590 $ (22 ) Available-for-sale securities: Mortgage-related: Fannie Mae $ — $ — $ — $ 421 $ (425 ) $ — $ (8 ) $ — $ 12 $ — $ — Freddie Mac 6 — — — — — (1 ) (2 ) 1 4 — Alt-A private-label securities 3,140 174 (124 ) — (1,108 ) — (387 ) (538 ) 337 1,494 — Subprime private-label securities 5,240 478 (277 ) — (1,325 ) — (439 ) — — 3,677 — Mortgage revenue bonds 4,023 44 (56 ) — (324 ) — (754 ) — — 2,933 — Other 2,671 (20 ) (10 ) — (1,012 ) — (185 ) — — 1,444 — Total available-for-sale securities $ 15,080 $ 676 (7)(8) $ (467 ) $ 421 $ (4,194 ) $ — $ (1,774 ) $ (540 ) $ 350 $ 9,552 $ — Mortgage loans $ 1,833 $ 47 (6)(7) $ — $ 5 $ — $ — $ (273 ) $ (331 ) $ 219 $ 1,500 $ (17 ) Net derivatives 45 (20 ) (6) — — — — 26 — 9 60 23 Long-term debt: Of Fannie Mae: Senior floating $ (363 ) $ (6 ) $ — $ — $ — $ — $ — $ — $ — $ (369 ) $ (6 ) Of consolidated trusts (527 ) (8 ) — — — (64 ) 43 142 (157 ) (571 ) 11 Total long-term debt $ (890 ) $ (14 ) (6) $ — $ — $ — $ (64 ) $ 43 $ 142 $ (157 ) $ (940 ) $ 5 __________ (1) Gains (losses) included in other comprehensive income (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 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 September 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) $ 38 Single Vendor Default Rate (%) 1.8 1.8 Prepayment Speed (%) 6.0 6.0 Severity (%) 37.0 37.0 Spreads (bps) 296.3 296.3 227 Consensus Default Rate (%) 2.0 - 4.0 3.5 Prepayment Speed (%) 4.0 - 9.0 7.7 Severity (%) 37.0 - 95.0 80.0 Spreads (bps) 247.5 - 427.4 380.8 Total Alt-A private-label securities 265 Subprime private-label securities (2) 34 Consensus Default Rate (%) 5.0 5.0 Prepayment Speed (%) 5.0 5.0 Severity (%) 75.0 75.0 Spreads (bps) 608.7 608.7 Total subprime private-label securities 34 Mortgage revenue bonds 189 Discounted Cash Flow Spreads (bps) 10.0 - 292.8 290.0 2 Other Total mortgage revenue bonds 191 Total trading securities $ 490 Fair Value Measurements as of September 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) $ 2 Other Alt-A private-label securities (2) 32 Single Vendor Default Rate (%) 5.2 - 8.0 7.2 Prepayment Speed (%) 7.9 - 8.0 8.0 Severity (%) 53.0 - 55.0 54.4 Spreads (bps) 275.3 - 298.5 282.3 82 Consensus Default Rate (%) 2.5 - 6.0 2.9 Prepayment Speed (%) 3.0 - 8.0 3.6 Severity (%) 60.0 - 65.0 60.6 Spreads (bps) 232.7 - 307.8 299.1 45 Discounted Cash Flow Spreads (bps) 430.0 - 434.0 432.0 15 Other Total Alt-A private-label securities 174 Subprime private-label securities (2) 48 Other Mortgage revenue bonds 828 Single Vendor Spreads (bps) (17.9 ) - 371.9 38.2 785 Discounted Cash Flow Spreads (bps) (17.9 ) - 406.4 276.4 112 Other Total mortgage revenue bonds 1,725 Other 49 Consensus Default Rate (%) 3.5 3.5 Prepayment Speed (%) 2.5 2.5 Severity (%) 88.0 88.0 Spreads (bps) 247.0 - 346.9 285.0 354 Discounted Cash Flow Default Rate (%) 2.3 2.3 Prepayment Speed (%) 0.5 0.5 Severity (%) 35.0 35.0 Spreads (bps) 190.0 - 450.0 449.1 33 Other Total other 436 Total available-for-sale securities $ 2,385 Fair Value Measurements as of September 30, 2016 Fair Value Significant Valuation Techniques Significant Unobservable Inputs (1) Range (1) Weighted - Average (1) (Dollars in millions) Mortgage loans: Single-family $ 545 Build-Up 267 Consensus 201 Other Total single-family 1,013 Multifamily 160 Build-Up Spreads (bps) 66.0 - 376.2 179.8 Total mortgage loans $ 1,173 Net derivatives $ 202 Dealer Mark 14 Other Total net derivatives $ 216 Long-term debt: Of Fannie Mae: Senior floating $ (419 ) Discounted Cash Flow Of consolidated trusts (4) (302 ) Other Total long-term debt $ (721 ) 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 September 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 $ 909 $ 3,651 Single Vendor 32 336 Other 5 4 Total mortgage loans held for sale, at lower of cost or fair value 946 3,991 Single-family mortgage loans held for investment, at amortized cost Internal Model 3,296 6,379 Multifamily mortgage loans held for investment, at amortized cost Broker Price Opinions 22 82 Asset Manager Estimate 222 236 Other 3 5 Total multifamily mortgage loans held for investment, at amortized cost 247 323 Acquired property, net: Single-family Accepted Offers 402 541 Appraisals 684 1,117 Walk Forwards 323 433 Internal Model 458 986 Other 64 134 Total single-family 1,931 3,211 Multifamily Other 2 — Other assets Other 10 30 Total nonrecurring assets at fair value $ 6,432 $ 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 September 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 $ 69,485 $ 47,235 $ 22,250 $ — $ — $ 69,485 Federal funds sold and securities purchased under agreements to resell or similar arrangements 18,350 — 18,350 — — 18,350 Trading securities 40,547 31,277 8,780 490 — 40,547 Available-for-sale securities 9,865 — 7,480 2,385 — 9,865 Mortgage loans held for sale 3,405 — 1,020 2,789 — 3,809 Mortgage loans held for investment, net of allowance for loan losses: Of Fannie Mae 195,100 — 24,145 184,970 — 209,115 Of consolidated trusts 2,850,456 — 2,703,713 231,972 — 2,935,685 Mortgage loans held for investment 3,045,556 — 2,727,858 416,942 — 3,144,800 Advances to lenders 6,627 — 6,271 382 — 6,653 Derivative assets at fair value 490 — 6,407 237 (6,154 ) 490 Guaranty assets and buy-ups 152 — — 450 — 450 Total financial assets $ 3,194,477 $ 78,512 $ 2,798,416 $ 423,675 $ (6,154 ) $ 3,294,449 Financial liabilities: Federal funds purchased and securities sold under agreements to repurchase $ 35 $ — $ 35 $ — $ — $ 35 Short-term debt: Of Fannie Mae 51,442 — 51,457 — — 51,457 Of consolidated trusts 612 — — 612 — 612 Long-term debt: Of Fannie Mae 300,126 — 312,323 886 — 313,209 Of consolidated trusts 2,880,933 — 2,934,252 37,376 — 2,971,628 Derivative liabilities at fair value 702 — 13,104 21 (12,423 ) 702 Guaranty obligations 282 — — 714 — 714 Total financial liabilities $ 3,234,132 $ — $ 3,311,171 $ 39,609 $ (12,423 ) $ 3,338,357 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 September 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 $ 12,914 $ 10,460 $ 35,453 $ 14,075 $ 11,133 $ 23,609 Unpaid principal balance 12,173 9,924 31,633 13,661 11,263 21,604 __________ (1) Includes nonaccrual loans with a fair value of $159 million and $238 million as of September 30, 2016 and December 31, 2015 , respectively. The difference between unpaid principal balance and the fair value of these nonaccrual loans as of September 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 $156 million and $256 million as of September 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 September 30, 2016 and December 31, 2015 was $26 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 losses, net” in our condensed consolidated statements of operations and comprehensive income. For the Three Months Ended September 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 $ 14 $ (389 ) $ (375 ) $ 73 $ 150 $ 223 Other changes in fair value 48 (65 ) (17 ) (15 ) (81 ) (96 ) Fair value gains (losses), net $ 62 $ (454 ) $ (392 ) $ 58 $ 69 $ 127 For the Nine Months Ended September 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 $ 46 $ (610 ) $ (564 ) $ 110 $ 45 $ 155 Other changes in fair value 392 (511 ) (119 ) (65 ) (42 ) (107 ) Fair value gains (losses), net $ 438 $ (1,121 ) $ (683 ) $ 45 $ 3 $ 48

Summary of Significant Accoun48

Summary of Significant Accounting Policies Regulatory Capital (Details) - USD ($) $ in Billions	Sep. 30, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Deficit of core capital over statutory minimum capital requirement	$ 138.9	$ 139.7

Summary of Significant Accoun49

Summary of Significant Accounting Policies Related Parties (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 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	$ 2,900,000,000				$ 6,647,000,000	$ 8,075,000,000
Net worth	4,176,000,000		$ 4,176,000,000		4,176,000,000		$ 4,100,000,000	$ 4,059,000,000
Income Taxes Paid					1,141,000,000	470,000,000
Unpaid principal balance guaranteed by a related party	$ 6,500,000,000		6,500,000,000		6,500,000,000
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			$ 465,000,000	$ 413,000,000	$ 1,358,000,000	1,192,000,000
Basis Points of Each Dollar of Unpaid Principal Balance	0.042%		0.042%		0.042%
Trading, at fair value (includes $1,191 and $135, respectively, pledged as collateral)	$ 40,547,000,000		$ 40,547,000,000		$ 40,547,000,000			39,908,000,000
Interest Receivable	7,728,000,000		7,728,000,000		7,728,000,000			7,726,000,000
Interest income recognized on Treasury securities			140,000,000	99,000,000	388,000,000	330,000,000
Scenario, Forecast [Member]
Related Parties [Line Items]
Expected undeclared dividends payable on senior preferred stock for the next quarter		$ 3,000,000,000
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			$ 14,000,000	18,000,000	$ 45,000,000	50,000,000
Income Taxes Paid			$ 531,000,000	100,000,000	1,141,000,000	470,000,000
Proceeds from Income Tax Refunds					$ 0	277,000,000
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			$ 465,000,000	413,000,000	$ 1,358,000,000	1,192,000,000
US Treasury [Member] | Single-family [Member]
Related Parties [Line Items]
Temporary Payroll Tax Cut Continuation Act of 2011 (“TCCA”) fees			465,000,000	413,000,000	1,400,000,000	1,200,000,000
Recognized TCCA fees that had not been remitted to Treasury as of period end	$ 465,000,000		465,000,000		465,000,000
Freddie Mac [Member] | Freddie Mac [Member]
Related Parties [Line Items]
Interest Receivable	5,000,000		5,000,000		5,000,000			22,000,000
Fair value of mortgage-related securities	1,400,000,000		1,400,000,000		1,400,000,000			5,600,000,000
Interest income recognized on mortgage-related securities			19,000,000	55,000,000	100,000,000	174,000,000
Federal Housing Finance Agency [Member]
Related Parties [Line Items]
FHFA assessment fees			28,000,000	28,000,000	84,000,000	84,000,000
Common Securitization Solutions [Member]
Related Parties [Line Items]
Payments to Acquire or Advance to Equity Method Investments			23,000,000	17,000,000	88,000,000	47,000,000
U.S. Treasury securities [Member]
Related Parties [Line Items]
Trading, at fair value (includes $1,191 and $135, respectively, pledged as collateral)	31,277,000,000		31,277,000,000		31,277,000,000			29,485,000,000
U.S. Treasury securities [Member] | US Treasury [Member]
Related Parties [Line Items]
Trading, at fair value (includes $1,191 and $135, respectively, pledged as collateral)	31,300,000,000		31,300,000,000		31,300,000,000			29,500,000,000
Interest Receivable	28,000,000		28,000,000		28,000,000			$ 15,000,000
Interest income recognized on Treasury securities			40,000,000	8,000,000	105,000,000	17,000,000
Other Expense [Member] | US Treasury [Member]
Related Parties [Line Items]
Affordable Housing Program Assessments			40,000,000	$ 56,000,000	96,000,000	$ 168,000,000
Recognized affordable housing program expenses that had not been remitted to Treasury as of period end	$ 96,000,000		$ 96,000,000		$ 96,000,000

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	Sep. 30, 2016	Dec. 31, 2015
Variable Interest Entities [Line Items]
Trading, at fair value	$ 40,547	$ 39,908
Available-for-sale, at fair value	9,865	20,230
Other assets	20,864	17,553
Other liabilities	(9,141)	(10,393)
Unpaid principal balance of mortgage loans	3,029,642	3,010,753
Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	221,860	198,342
Consolidated VIEs [Member]
Variable Interest Entities [Line Items]
Change in assets due to change in consolidation status	154
Unconsolidated VIEs [Member]
Variable Interest Entities [Line Items]
Change in assets due to change in consolidation status		5,300
Unconsolidated VIEs [Member] | Multifamily [Member]
Variable Interest Entities [Line Items]
Unpaid principal balance of mortgage loans	221,900
Unconsolidated VIEs [Member] | Mortgage-related securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	9,129	10,300
Available-for-sale, at fair value	8,707	18,580
Other assets	67	100
Other liabilities	(450)	(827)
Net carrying amount	17,453	28,153
Maximum exposure to loss	24,000	34,000
Total unconsolidated assets	170,000	220,000
Unconsolidated VIEs [Member] | Partnership interest [Member]
Variable Interest Entities [Line Items]
Net carrying amount	92	(24)
Maximum exposure to loss	123	12
Total unconsolidated assets	4,000	4,900
Unconsolidated VIEs [Member] | Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	4,793	4,704
Available-for-sale, at fair value	2,601	3,936
Unconsolidated VIEs [Member] | Non-Fannie Mae Securities [Member]
Variable Interest Entities [Line Items]
Trading, at fair value	4,336	5,596
Available-for-sale, at fair value	$ 6,106	$ 14,644

Consolidations and Transfers 52

Consolidations and Transfers of Financial Assets Transfers of Financial Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Transfers of Financial Assets [Line Items]
Portfolio securitizations: unpaid principal balance	$ 76,100	$ 55,400	$ 188,700	$ 166,300
Unconsolidated VIEs [Member]
Transfers of Financial Assets [Line Items]
Retained interests: principal and interest received	284	$ 273	907	$ 919
Unconsolidated VIEs [Member] | Single Class MBS, REMIC & Megas [Member]
Transfers of Financial Assets [Line Items]
Retained interests: unpaid principal balance	4,500		4,500		$ 5,500
Retained interests: fair value	$ 6,000		$ 6,000		$ 6,800

Consolidations and Transfers 53

Consolidations and Transfers of Financial Assets Managed Loans (Details) - USD ($) $ in Billions	Sep. 30, 2016	Dec. 31, 2015
Consolidations and Transfers of Financial Assets [Abstract]
Securitized loans in unconsolidated portfolio securitization trusts: unpaid principal balance	$ 1.4	$ 1.6

Mortgage Loans Loans in Mortgag

Mortgage Loans Loans in Mortgage Portfolio (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 3,029,642		$ 3,029,642			$ 3,010,753
Cost basis and fair value adjustments, net	42,025		42,025			36,842
Allowance for loan losses for loans held for investment	(22,706)	$ (29,135)	(22,706)	$ (29,135)	$ (23,799)	(27,951)	$ (31,150)	$ (35,541)
Total mortgage loans	3,048,961		3,048,961			3,019,644
Carrying value of loans redesignated from HFI to HFS	652	1,300	2,300	5,900
Sale of loans, unpaid principal balance	1,600	1,900	4,200	2,500
Fannie Mae [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	232,062		232,062			251,336
Cost basis and fair value adjustments, net	(11,707)		(11,707)			(12,939)
Allowance for loan losses for loans held for investment	(21,858)	(27,655)	(21,858)	(27,655)	(22,793)	(26,510)	(29,724)	(33,117)
Total mortgage loans	198,497		198,497			211,887
Consolidated Trusts [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,797,580		2,797,580			2,759,417
Cost basis and fair value adjustments, net	53,732		53,732			49,781
Allowance for loan losses for loans held for investment	(848)	$ (1,480)	(848)	$ (1,480)	$ (1,006)	(1,441)	$ (1,426)	$ (2,424)
Total mortgage loans	2,850,464		2,850,464			2,807,757
Single-family [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,807,782		2,807,782			2,812,411
Recorded investment of single-family mortgage loans referred to foreclosure	19,500		19,500			25,600
Single-family [Member] | Fannie Mae [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	221,384		221,384			238,237
Single-family [Member] | Consolidated Trusts [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	2,586,398		2,586,398			2,574,174
Multifamily [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	221,860		221,860			198,342
Multifamily [Member] | Fannie Mae [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	10,678		10,678			13,099
Multifamily [Member] | Consolidated Trusts [Member]
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 211,182		$ 211,182			$ 185,243

Mortgage Loans Aging (Details)

Mortgage Loans Aging (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 72,225	$ 79,592
Current	2,990,685	2,956,120
Total recorded investment in loans	3,062,910	3,035,712
Recorded investment in loans 90 days or more delinquent and accruing interest	296	349
Recorded investment in nonaccrual loans	42,027	44,846
30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	34,927	34,814
60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	9,109	9,717
Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	28,189	35,061
Single-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	72,037	79,446
Current	2,766,768	2,756,092
Total recorded investment in loans	2,838,805	2,835,538
Recorded investment in loans 90 days or more delinquent and accruing interest	296	349
Recorded investment in nonaccrual loans	$ 41,529	$ 44,255
Single-family [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days	90 days
Single-family [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 34,902	$ 34,791
Single-family [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	9,109	9,717
Single-family [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	28,026	34,938
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	58,747	63,437
Current	2,625,085	2,598,756
Total recorded investment in loans	2,683,832	2,662,193
Recorded investment in loans 90 days or more delinquent and accruing interest	24	46
Recorded investment in nonaccrual loans	32,806	34,216
Single-family [Member] | Primary [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	29,741	29,154
Single-family [Member] | Primary [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	7,505	7,937
Single-family [Member] | Primary [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	21,501	26,346
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	341	373
Current	37,698	40,461
Total recorded investment in loans	38,039	40,834
Recorded investment in loans 90 days or more delinquent and accruing interest	264	291
Recorded investment in nonaccrual loans	0	0
Single-family [Member] | Government [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	54	58
Single-family [Member] | Government [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	23	24
Single-family [Member] | Government [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	264	291
Single-family [Member] | Alt-A [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	9,444	11,498
Current	76,207	84,603
Total recorded investment in loans	85,651	96,101
Recorded investment in loans 90 days or more delinquent and accruing interest	2	6
Recorded investment in nonaccrual loans	6,386	7,407
Single-family [Member] | Alt-A [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	3,706	4,085
Single-family [Member] | Alt-A [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	1,131	1,272
Single-family [Member] | Alt-A [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	4,607	6,141
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	3,505	4,138
Current	27,778	32,272
Total recorded investment in loans	31,283	36,410
Recorded investment in loans 90 days or more delinquent and accruing interest	6	6
Recorded investment in nonaccrual loans	2,337	2,632
Single-family [Member] | Other [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	1,401	1,494
Single-family [Member] | Other [Member] | 60 to 89 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	450	484
Single-family [Member] | Other [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	1,654	2,160
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	188	146
Current	223,917	200,028
Total recorded investment in loans	224,105	200,174
Recorded investment in loans 90 days or more delinquent and accruing interest	0	0
Recorded investment in nonaccrual loans	$ 498	$ 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
Multifamily [Member] | 30 to 59 Days Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 25	$ 23
Multifamily [Member] | Seriously Delinquent [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Days delinquent	$ 163	$ 123

Mortgage Loans Credit Quality I

Mortgage Loans Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,062,910	$ 3,035,712
Single-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,838,805	2,835,538
Single-family [Member] | Primary [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,683,832	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	2,313,365	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	233,787	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	98,865	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	18,071	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	9,071	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	2,721	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	7,952	13,328
Single-family [Member] | Alt-A [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	85,651	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	58,287	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	10,291	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	7,156	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	4,405	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	2,436	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	791	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	2,285	3,947
Single-family [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	31,283	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	20,442	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	3,966	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	2,818	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	1,805	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	1,012	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	307	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	933	1,606
Single-family [Member] | Government [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 38,039	$ 40,834

Mortgage Loans Credit Quality57

Mortgage Loans Credit Quality Indicators - MF (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 3,062,910	$ 3,035,712
Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	224,105	200,174
Multifamily [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	219,613	194,132
Multifamily [Member] | Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,851	3,202
Multifamily [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,637	2,833
Multifamily [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 4	$ 7

Mortgage Loans Individually Imp

Mortgage Loans Individually Impaired Loans (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	$ 149,125	$ 162,230
Individually impaired loans with related allowance recorded: total recorded investment	140,677	152,765
Related allowance for loan losses	21,326	25,517
Individually impaired loans with no related allowance recorded: unpaid principal balance	22,327	21,245
Individually impaired loans with no related allowance recorded: total recorded investment	20,396	19,404
Total individually impaired loans: unpaid principal balance	171,452	183,475
Total individually impaired loans: total recorded investment	161,073	172,169
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	148,678	161,580
Individually impaired loans with related allowance recorded: total recorded investment	140,227	152,111
Related allowance for loan losses	21,285	25,437
Individually impaired loans with no related allowance recorded: unpaid principal balance	22,012	20,892
Individually impaired loans with no related allowance recorded: total recorded investment	20,080	19,050
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	107,455	116,477
Individually impaired loans with related allowance recorded: total recorded investment	102,148	110,502
Related allowance for loan losses	14,034	16,745
Individually impaired loans with no related allowance recorded: unpaid principal balance	16,798	15,891
Individually impaired loans with no related allowance recorded: total recorded investment	15,574	14,725
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	302	322
Individually impaired loans with related allowance recorded: total recorded investment	306	327
Related allowance for loan losses	58	59
Individually impaired loans with no related allowance recorded: unpaid principal balance	66	58
Individually impaired loans with no related allowance recorded: total recorded investment	62	54
Single-family [Member] | Alt-A [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	29,294	31,888
Individually impaired loans with related allowance recorded: total recorded investment	26,763	29,103
Related allowance for loan losses	5,204	6,217
Individually impaired loans with no related allowance recorded: unpaid principal balance	3,892	3,721
Individually impaired loans with no related allowance recorded: total recorded investment	3,325	3,169
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	11,627	12,893
Individually impaired loans with related allowance recorded: total recorded investment	11,010	12,179
Related allowance for loan losses	1,989	2,416
Individually impaired loans with no related allowance recorded: unpaid principal balance	1,256	1,222
Individually impaired loans with no related allowance recorded: total recorded investment	1,119	1,102
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	447	650
Individually impaired loans with related allowance recorded: total recorded investment	450	654
Related allowance for loan losses	41	80
Individually impaired loans with no related allowance recorded: unpaid principal balance	315	353
Individually impaired loans with no related allowance recorded: total recorded investment	$ 316	$ 354

Mortgage Loans Individually I59

Mortgage Loans Individually Impaired Loans - 2 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	$ 142,660	$ 157,504	$ 146,891	$ 160,895
Individually impaired loans with related allowance recorded: total interest income recognized	1,339	1,469	4,093	4,232
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	82	91	298	304
Individually impaired loans with no related allowance recorded: average recorded investment	20,333	20,999	20,265	21,492
Individually impaired loans with no related allowance recorded: total interest income recognized	432	370	1,230	1,004
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	19	17	80	86
Individually impaired loans: average recorded investment	162,993	178,503	167,156	182,387
Individually impaired loans: total interest income recognized	1,771	1,839	5,323	5,236
Individually impaired loans: interest income recognized on a cash basis	101	108	378	390
Table Footnote [Abstract]
Individually impaired loans: total interest income recognized	1,771	1,839	5,323	5,236
Single-family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	142,168	156,626	146,336	159,842
Individually impaired loans with related allowance recorded: total interest income recognized	1,336	1,460	4,072	4,217
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	82	91	298	304
Individually impaired loans with no related allowance recorded: average recorded investment	20,022	20,613	19,935	21,029
Individually impaired loans with no related allowance recorded: total interest income recognized	429	365	1,221	996
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	19	17	80	86
Individually impaired loans: total interest income recognized	1,800	1,800	5,300	5,200
Table Footnote [Abstract]
Troubled debt restructuring recorded investment	159,600		159,600		$ 170,300
Individually impaired loans: total interest income recognized	1,800	1,800	5,300	5,200
Individually impaired loans: contractual interest income	1,400	1,500	4,300	4,300
Individually impaired loans: effective yield adjustments	320	327	961	907
Single-family [Member] | Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	103,523	113,634	106,498	115,762
Individually impaired loans with related allowance recorded: total interest income recognized	992	1,090	3,028	3,152
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	68	71	243	248
Individually impaired loans with no related allowance recorded: average recorded investment	15,534	15,627	15,398	15,967
Individually impaired loans with no related allowance recorded: total interest income recognized	320	279	915	779
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	19	16	69	76
Single-family [Member] | Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	310	299	317	290
Individually impaired loans with related allowance recorded: total interest income recognized	3	3	9	9
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	61	53	59	55
Individually impaired loans with no related allowance recorded: total interest income recognized	1	1	3	3
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Single-family [Member] | Alt-A [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	27,115	30,041	27,899	30,760
Individually impaired loans with related allowance recorded: total interest income recognized	250	272	759	774
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	10	14	40	41
Individually impaired loans with no related allowance recorded: average recorded investment	3,312	3,674	3,350	3,720
Individually impaired loans with no related allowance recorded: total interest income recognized	81	64	224	158
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	1	8	8
Single-family [Member] | Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	11,220	12,652	11,622	13,030
Individually impaired loans with related allowance recorded: total interest income recognized	91	95	276	282
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	4	6	15	15
Individually impaired loans with no related allowance recorded: average recorded investment	1,115	1,259	1,128	1,287
Individually impaired loans with no related allowance recorded: total interest income recognized	27	21	79	56
Individually impaired loans with no related allowance recorded: interest income recognized on a cash basis	0	0	3	2
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: average recorded investment	492	878	555	1,053
Individually impaired loans with related allowance recorded: total interest income recognized	3	9	21	15
Individually impaired loans with related allowance recorded: interest income recognized on a cash basis	0	0	0	0
Individually impaired loans with no related allowance recorded: average recorded investment	311	386	330	463
Individually impaired loans with no related allowance recorded: total interest income recognized	3	5	9	8
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	$ 324		$ 324		$ 451

Mortgage Loans TDRs (Details)

Mortgage Loans TDRs (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)contracts	Sep. 30, 2015USD ($)contracts	Sep. 30, 2016USD ($)contracts	Sep. 30, 2015USD ($)contracts
Financing Receivable, Modifications [Line Items]
Average term extension of a single-family modified loan	153 months	159 months	157 months	161 months
Average interest rate reduction of a single-family modified loan	0.82%	0.69%	0.76%	0.75%
Number of loans troubled debt restructurings activity | contracts	15,934	17,112	52,319	63,063
Recorded investment troubled debt restructurings activity | $	$ 2,216	$ 2,362	$ 7,271	$ 8,847
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	15,932	17,109	52,313	63,056
Recorded investment troubled debt restructurings activity | $	$ 2,211	$ 2,352	$ 7,221	$ 8,831
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	13,983	14,926	45,987	54,284
Recorded investment troubled debt restructurings activity | $	$ 1,922	$ 2,021	$ 6,282	$ 7,443
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	54	54	136	192
Recorded investment troubled debt restructurings activity | $	$ 5	$ 6	$ 14	$ 22
Single-family [Member] | Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	1,578	1,805	5,112	7,127
Recorded investment troubled debt restructurings activity | $	$ 227	$ 268	$ 735	$ 1,101
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	317	324	1,078	1,453
Recorded investment troubled debt restructurings activity | $	$ 57	$ 57	$ 190	$ 265
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings activity | contracts	2	3	6	7
Recorded investment troubled debt restructurings activity | $	$ 5	$ 10	$ 50	$ 16

Mortgage Loans TDRs with Sub De

Mortgage Loans TDRs with Sub Defaults (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)contracts	Sep. 30, 2015USD ($)contracts	Sep. 30, 2016USD ($)contracts	Sep. 30, 2015USD ($)contracts
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	6,268	8,258	18,559	23,907
Recorded investment troubled debt restructurings subsequent default | $	$ 895	$ 1,254	$ 2,689	$ 3,611
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	6,268	8,258	18,559	23,904
Recorded investment troubled debt restructurings subsequent default | $	$ 895	$ 1,254	$ 2,689	$ 3,605
Single-family [Member] | Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	5,268	6,847	15,377	19,726
Recorded investment troubled debt restructurings subsequent default | $	$ 734	$ 1,003	$ 2,174	$ 2,870
Single-family [Member] | Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	31	31	73	88
Recorded investment troubled debt restructurings subsequent default | $	$ 4	$ 3	$ 9	$ 12
Single-family [Member] | Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	734	1,052	2,342	3,168
Recorded investment troubled debt restructurings subsequent default | $	$ 116	$ 183	$ 376	$ 537
Single-family [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	235	328	767	922
Recorded investment troubled debt restructurings subsequent default | $	$ 41	$ 65	$ 130	$ 186
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default | contracts	0	0	0	3
Recorded investment troubled debt restructurings subsequent default | $	$ 0	$ 0	$ 0	$ 6

Allowance for Loan Losses Rollf

Allowance for Loan Losses Rollforward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Allowance for Loan Losses [Roll Forward]
Beginning balance	$ 23,799	$ 31,150	$ 27,951	$ 35,541
Provision (benefit) for loan losses	(636)	(1,394)	(3,004)	(357)
Charge-offs	(608)	(777)	(2,713)	(8,213)
Recoveries	141	168	376	1,051
Transfers	0	0	0	0
Other	10	(12)	96	1,113
Ending balance	22,706	29,135	22,706	29,135
Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	22,793	29,724	26,510	33,117
Provision (benefit) for loan losses	(583)	(1,732)	(3,012)	(290)
Charge-offs	(589)	(753)	(2,639)	(8,147)
Recoveries	114	165	346	1,036
Transfers	113	263	557	878
Other	10	(12)	96	1,061
Ending balance	21,858	27,655	21,858	27,655
Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	1,006	1,426	1,441	2,424
Provision (benefit) for loan losses	(53)	338	8	(67)
Charge-offs	(19)	(24)	(74)	(66)
Recoveries	27	3	30	15
Transfers	(113)	(263)	(557)	(878)
Other	0	0	0	52
Ending balance	848	1,480	848	1,480
Single-family [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	23,584	30,876	27,709	35,177
Provision (benefit) for loan losses	(609)	(1,392)	(2,957)	(293)
Charge-offs	(604)	(770)	(2,701)	(8,172)
Recoveries	135	164	369	1,047
Transfers	0	0	0	0
Other	10	(13)	96	1,106
Ending balance	22,516	28,865	22,516	28,865
Single-family [Member] | Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	22,736	29,624	26,439	32,956
Provision (benefit) for loan losses	(561)	(1,722)	(2,979)	(249)
Charge-offs	(587)	(748)	(2,629)	(8,108)
Recoveries	108	161	339	1,032
Transfers	113	262	553	877
Other	10	(13)	96	1,056
Ending balance	21,819	27,564	21,819	27,564
Single-family [Member] | Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	848	1,252	1,270	2,221
Provision (benefit) for loan losses	(48)	330	22	(44)
Charge-offs	(17)	(22)	(72)	(64)
Recoveries	27	3	30	15
Transfers	(113)	(262)	(553)	(877)
Other	0	0	0	50
Ending balance	697	1,301	697	1,301
Multifamily [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	215	274	242	364
Provision (benefit) for loan losses	(27)	(2)	(47)	(64)
Charge-offs	(4)	(7)	(12)	(41)
Recoveries	6	4	7	4
Transfers	0	0	0	0
Other	0	1	0	7
Ending balance	190	270	190	270
Multifamily [Member] | Fannie Mae [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	57	100	71	161
Provision (benefit) for loan losses	(22)	(10)	(33)	(41)
Charge-offs	(2)	(5)	(10)	(39)
Recoveries	6	4	7	4
Transfers	0	1	4	1
Other	0	1	0	5
Ending balance	39	91	39	91
Multifamily [Member] | Consolidated Trusts [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	158	174	171	203
Provision (benefit) for loan losses	(5)	8	(14)	(23)
Charge-offs	(2)	(2)	(2)	(2)
Recoveries	0	0	0	0
Transfers	0	(1)	(4)	(1)
Other	0	0	0	2
Ending balance	$ 151	$ 179	$ 151	$ 179

Allowance for Loan Losses and T

Allowance for Loan Losses and Total Recorded Investment in HFI Loans (Details) - USD ($) $ in Millions	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	$ 21,326		$ 25,517
Allowance for loan losses for collectively reserved loans	1,380		2,434
Total allowance for loan losses	22,706	$ 23,799	27,951	$ 29,135	$ 31,150	$ 35,541
Recorded investment in individually impaired loans	161,073		172,169
Recorded investment in collectively reserved loans	2,901,837		2,863,543
Total recorded investment in loans	3,062,910		3,035,712
Single-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	21,285		25,437
Allowance for loan losses for collectively reserved loans	1,231		2,272
Total allowance for loan losses	22,516	23,584	27,709	28,865	30,876	35,177
Recorded investment in individually impaired loans	160,307		171,161
Recorded investment in collectively reserved loans	2,678,498		2,664,377
Total recorded investment in loans	2,838,805		2,835,538
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	41		80
Allowance for loan losses for collectively reserved loans	149		162
Total allowance for loan losses	190	$ 215	242	$ 270	$ 274	$ 364
Recorded investment in individually impaired loans	766		1,008
Recorded investment in collectively reserved loans	223,339		199,166
Total recorded investment in loans	$ 224,105		$ 200,174

Investments in Securities Tradi

Investments in Securities Trading 1 (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 40,547	$ 39,908
Mortgage-related securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	9,270	10,423
Fannie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	4,931	4,813
Freddie Mac [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	808	1,314
Ginnie Mae [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,393	426
Alt-A private-label securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	313	436
Subprime private-label securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	353	644
CMBS [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,281	2,341
Mortgage revenue bonds [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	191	449
U.S. Treasury securities [Member]
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 31,277	$ 29,485

Investments in Securities Avail

Investments in Securities Available-for-sale Securities 1 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 400	$ 94	$ 845	$ 907
Gross realized losses	0	9	12	66
Total proceeds (excludes initial sale of securities from new portfolio securitizations)	$ 2,819	$ 1,556	$ 10,086	$ 6,764

Investments in Securities Ava66

Investments in Securities Available-for-sale Securities 2 (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	$ 8,512	$ 18,141
Gross unrealized gains	1,383	2,170
Gross unrealized losses	(30)	(81)
Available-for-sale, at fair value	9,865	20,230
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	2,545	4,008
Gross unrealized gains	187	243
Gross unrealized losses	(20)	(30)
Available-for-sale, at fair value	2,712	4,221
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	534	4,000
Gross unrealized gains	48	299
Gross unrealized losses	0	0
Available-for-sale, at fair value	582	4,299
Ginnie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	54	343
Gross unrealized gains	7	48
Gross unrealized losses	0	0
Available-for-sale, at fair value	61	391
Alt-A private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	883	2,029
Gross unrealized gains	535	653
Gross unrealized losses	(1)	(4)
Available-for-sale, at fair value	1,417	2,678
Subprime private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,437	2,526
Gross unrealized gains	486	759
Gross unrealized losses	(4)	(4)
Available-for-sale, at fair value	1,919	3,281
CMBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	971	1,235
Gross unrealized gains	8	20
Gross unrealized losses	(1)	0
Available-for-sale, at fair value	978	1,255
Mortgage revenue bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	1,639	2,639
Gross unrealized gains	90	99
Gross unrealized losses	(4)	(37)
Available-for-sale, at fair value	1,725	2,701
Other mortgage-related securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total amortized cost	449	1,361
Gross unrealized gains	22	49
Gross unrealized losses	0	(6)
Available-for-sale, at fair value	$ 471	$ 1,404

Investments in Securities Ava67

Investments in Securities Available-for-sale Securities 3 (Details) - USD ($) $ in Millions	Sep. 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	275	1,552
12 Consecutive Months or Longer, Gross Unrealized Losses	(24)	(31)
12 Consecutive Months or Longer, Fair Value	583	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	85	659
12 Consecutive Months or Longer, Gross Unrealized Losses	(19)	(22)
12 Consecutive Months or Longer, Fair Value	502	491
Alt-A private-label securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Consecutive Months, Gross Unrealized Losses	(1)	(1)
Less than 12 Consecutive Months, Fair Value	38	26
12 Consecutive Months or Longer, Gross Unrealized Losses	0	(3)
12 Consecutive Months or Longer, Fair Value	0	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	(4)	(4)
12 Consecutive Months or Longer, Fair Value	76	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	136
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	(3)	(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	$ 5	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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Other-than-temporary-impairments	$ 3	$ 5	$ 34	$ 187
Subprime private-label securities [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 2,688		$ 2,688
Weighted average collateral default	37.40%		37.40%
Weighted average collateral severities	49.80%		49.80%
Weighted average voluntary prepayment rates	2.90%		2.90%
Average credit enhancement	12.80%		12.80%
Alt-A Option ARM [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 360		$ 360
Weighted average collateral default	24.30%		24.30%
Weighted average collateral severities	29.30%		29.30%
Weighted average voluntary prepayment rates	9.30%		9.30%
Average credit enhancement	3.70%		3.70%
Alt-A Fixed Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 270		$ 270
Weighted average collateral default	17.00%		17.00%
Weighted average collateral severities	52.40%		52.40%
Weighted average voluntary prepayment rates	7.90%		7.90%
Average credit enhancement	0.40%		0.40%
Alt-A Variable Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 548		$ 548
Weighted average collateral default	18.80%		18.80%
Weighted average collateral severities	38.20%		38.20%
Weighted average voluntary prepayment rates	8.60%		8.60%
Average credit enhancement	2.00%		2.00%
Alt-A Hybrid Rate [Member]
UPB and Modeled Attributes [Line Items]
Unpaid principal balance	$ 571		$ 571
Weighted average collateral default	7.40%		7.40%
Weighted average collateral severities	35.00%		35.00%
Weighted average voluntary prepayment rates	13.90%		13.90%
Average credit enhancement	1.60%		1.60%

Investments in Securities Oth69

Investments in Securities Other-than-temporary Impairments 2 (Details) - Available-for-sale securities [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 2,219	$ 2,557	$ 2,421	$ 5,260
Additions for the credit component on debt securities for which OTTI was not previously recognized	1	0	1	0
Additions for the credit component on debt securities for which OTTI was previously recognized	0	1	6	5
Reductions for securities no longer in portfolio at period end	(3)	(2)	(106)	(1,167)
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	(223)	0	(254)	(1,439)
Reductions for amortization resulting from changes in cash flows expected to be collected over the remaining life of the securities	(30)	(43)	(104)	(146)
Balance, end of period	$ 1,964	$ 2,513	$ 1,964	$ 2,513

Investments in Securities Matur

Investments in Securities Maturity Information (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	$ 8,512	$ 18,141
Total fair value	9,865	20,230
One Year or Less, Amortized Cost	787
One Year or Less, Fair Value	793
After One Year through Five Years, Amortized Cost	337
After One Year through Five Years, Fair Value	343
After Five Years through Ten Years, Amortized Cost	331
After Five Years through Ten Years, Fair Value	347
After Ten Years, Amortized Cost	7,057
After Ten Years, Fair Value	8,382
Fannie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	2,545	4,008
Total fair value	2,712	4,221
One Year or Less, Amortized Cost	0
One Year or Less, Fair Value	0
After One Year through Five Years, Amortized Cost	29
After One Year through Five Years, Fair Value	29
After Five Years through Ten Years, Amortized Cost	60
After Five Years through Ten Years, Fair Value	66
After Ten Years, Amortized Cost	2,456
After Ten Years, Fair Value	2,617
Freddie Mac [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	534	4,000
Total fair value	582	4,299
One Year or Less, Amortized Cost	1
One Year or Less, Fair Value	1
After One Year through Five Years, Amortized Cost	65
After One Year through Five Years, Fair Value	68
After Five Years through Ten Years, Amortized Cost	95
After Five Years through Ten Years, Fair Value	102
After Ten Years, Amortized Cost	373
After Ten Years, Fair Value	411
Ginnie Mae [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	54	343
Total fair value	61	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	3
After Five Years through Ten Years, Fair Value	4
After Ten Years, Amortized Cost	50
After Ten Years, Fair Value	56
Alt-A private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	883	2,029
Total fair value	1,417	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	883
After Ten Years, Fair Value	1,417
Subprime private-label securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,437	2,526
Total fair value	1,919	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	1,437
After Ten Years, Fair Value	1,919
CMBS [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	971	1,235
Total fair value	978	1,255
One Year or Less, Amortized Cost	776
One Year or Less, Fair Value	782
After One Year through Five Years, Amortized Cost	154
After One Year through Five Years, Fair Value	156
After Five Years through Ten Years, Amortized Cost	0
After Five Years through Ten Years, Fair Value	0
After Ten Years, Amortized Cost	41
After Ten Years, Fair Value	40
Mortgage revenue bonds [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	1,639	2,639
Total fair value	1,725	2,701
One Year or Less, Amortized Cost	10
One Year or Less, Fair Value	10
After One Year through Five Years, Amortized Cost	88
After One Year through Five Years, Fair Value	88
After Five Years through Ten Years, Amortized Cost	170
After Five Years through Ten Years, Fair Value	172
After Ten Years, Amortized Cost	1,371
After Ten Years, Fair Value	1,455
Other mortgage-related securities [Member]
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity
Total amortized cost	449	1,361
Total fair value	471	$ 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	446
After Ten Years, Fair Value	$ 467

Financial Guarantees Financial

Financial Guarantees Financial Guarantees and Maximum Recovery (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	$ 28,802	$ 31,573
Guaranty Obligation	282	329
Maximum Recovery	10,976	11,726
Fair Value of guaranty obligations in Investments in securities	433	488
Unconsolidated VIEs [Member] | Unconsolidated Fannie Mae MBS [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	13,333	15,069
Guaranty Obligation	147	194
Maximum Recovery	8,269	8,857
Unconsolidated VIEs [Member] | Other guaranty arrangements [Member]
Financial Guarantees and Maximum Recovery [Line Items]
Maximum Exposure	15,469	16,504
Guaranty Obligation	135	135
Maximum Recovery	$ 2,707	$ 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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Acquired Property [Roll Forward]
Beginning balance - Acquired property	$ 5,928	$ 9,199	$ 7,481	$ 11,442
Additions	1,391	2,236	4,876	7,602
Disposals	(1,906)	(3,125)	(6,944)	(10,734)
Ending balance - Acquired property	5,413	8,310	5,413	8,310
Valuation allowance	(372)	(619)	(372)	(619)
Ending balance - Acquired property, net	$ 5,041	$ 7,691	$ 5,041	$ 7,691	$ 6,766

Short-Term Borrowings and Lon73

Short-Term Borrowings and Long-Term Debt Short-Term Borrowings (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Short-Term Borrowings [Line Items]
Federal funds purchased and securities sold under agreements to repurchase, outstanding	$ 35,000,000	$ 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	$ 52,054,000,000	$ 71,950,000,000
Short-term debt, weighted-average interest rate	0.44%	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	$ 51,442,000,000	$ 71,007,000,000
Short-term debt, weighted-average interest rate	0.44%	0.26%
Consolidated Trusts [Member]
Short-Term Borrowings [Line Items]
Short-term debt, outstanding	$ 612,000,000	$ 943,000,000
Short-term debt, weighted-average interest rate	0.46%	0.19%

Short-Term Borrowings and Lon74

Short-Term Borrowings and Long-Term Debt Long-Term Debt (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 3,181,059	$ 3,125,721
Long-term debt, weighted-average interest rate	2.51%	2.88%
Fannie Mae [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 300,126	$ 315,128
Long-term debt, weighted-average interest rate	2.28%	2.41%
Unamortized discounts and premiums, other cost basis adjustments and fair value adjustments	$ 2,000	$ 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	$ 250,699	$ 278,826
Long-term debt, weighted-average interest rate	2.19%	2.39%
Fannie Mae [Member] | Senior fixed benchmark notes and bonds [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 153,481	$ 154,057
Long-term debt, weighted-average interest rate	2.23%	2.49%
Fannie Mae [Member] | Senior fixed medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 83,661	$ 96,997
Long-term debt, weighted-average interest rate	1.39%	1.53%
Fannie Mae [Member] | Senior fixed other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 13,557	$ 27,772
Long-term debt, weighted-average interest rate	6.58%	4.88%
Fannie Mae [Member] | Senior floating [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 44,770	$ 31,923
Long-term debt, weighted-average interest rate	2.01%	1.58%
Fannie Mae [Member] | Senior floating medium-term notes [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 28,715	$ 20,791
Long-term debt, weighted-average interest rate	0.59%	0.27%
Fannie Mae [Member] | Senior floating Connecticut Avenue Security [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 15,636	$ 10,764
Long-term debt, weighted-average interest rate	4.59%	3.84%
Fannie Mae [Member] | Senior floating other debt [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 419	$ 368
Long-term debt, weighted-average interest rate	6.65%	10.46%
Fannie Mae [Member] | Subordinated debentures [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 4,537	$ 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	$ 120	$ 152
Long-term debt, weighted-average interest rate	1.42%	1.47%
Consolidated Trusts [Member]
Long-Term Debt [Line Items]
Long-term debt, outstanding	$ 2,880,933	$ 2,810,593
Long-term debt, weighted-average interest rate	2.53%	2.94%

Derivative Instruments Derivati

Derivative Instruments Derivatives 1 - Notional and FV Position (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Asset Derivatives [Abstract]
Notional amount	$ 220,861	$ 175,667
Derivative asset, estimated fair value	490	894
Netting adjustment	(6,154)	(4,024)
Liability Derivatives [Abstract]
Notional amount	368,074	375,704
Derivative liability, estimated fair value	(702)	(424)
Netting adjustment	12,423	8,650
Table Footnote [Abstract]
Cash collateral posted for derivative instruments	6,700	4,900
Cash collateral received for derivative instruments	419	314
Risk Management Derivatives [Member]
Asset Derivatives [Abstract]
Notional amount	124,738	113,355
Derivative asset, estimated fair value	5,575	4,020
Accrued interest receivable	720	758
Netting adjustment	(6,154)	(4,024)
Total net risk management derivatives - Asset	141	754
Liability Derivatives [Abstract]
Notional amount	227,787	312,573
Derivative liability, estimated fair value	(11,491)	(7,939)
Accrued interest payable	(1,097)	(977)
Netting adjustment	12,423	8,650
Total net risk management derivatives - Liability	(165)	(266)
Mortgage commitment derivatives [Member]
Asset Derivatives [Abstract]
Notional amount	96,123	62,312
Derivative asset, estimated fair value	349	140
Netting adjustment	0	0
Liability Derivatives [Abstract]
Notional amount	140,287	63,131
Derivative liability, estimated fair value	(537)	(158)
Netting adjustment	0	0
Pay-fixed Swap
Asset Derivatives [Abstract]
Notional amount	6,324	33,154
Derivative asset, estimated fair value	19	267
Liability Derivatives [Abstract]
Notional amount	127,859	123,106
Derivative liability, estimated fair value	(11,071)	(6,920)
Receive-fixed Swap
Asset Derivatives [Abstract]
Notional amount	99,254	59,796
Derivative asset, estimated fair value	5,218	3,436
Liability Derivatives [Abstract]
Notional amount	70,551	143,209
Derivative liability, estimated fair value	(146)	(753)
Basis Swap
Asset Derivatives [Abstract]
Notional amount	1,764	1,864
Derivative asset, estimated fair value	198	141
Liability Derivatives [Abstract]
Notional amount	15,700	17,100
Derivative liability, estimated fair value	(21)	(15)
Foreign Currency Swap
Asset Derivatives [Abstract]
Notional amount	225	295
Derivative asset, estimated fair value	75	95
Liability Derivatives [Abstract]
Notional amount	227	258
Derivative liability, estimated fair value	(82)	(52)
Pay-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	6,175	7,050
Derivative asset, estimated fair value	36	45
Liability Derivatives [Abstract]
Notional amount	6,850	14,950
Derivative liability, estimated fair value	(13)	(26)
Received-fixed Swaption
Asset Derivatives [Abstract]
Notional amount	1,625	2,000
Derivative asset, estimated fair value	7	8
Liability Derivatives [Abstract]
Notional amount	6,600	13,950
Derivative liability, estimated fair value	(157)	(171)
Other [Member]
Asset Derivatives [Abstract]
Notional amount	9,371	9,196
Derivative asset, estimated fair value	22	28
Liability Derivatives [Abstract]
Notional amount	0	0
Derivative liability, estimated fair value	(1)	(2)
Mortgage commitment to purchase whole loans
Asset Derivatives [Abstract]
Notional amount	10,820	4,815
Derivative asset, estimated fair value	31	9
Liability Derivatives [Abstract]
Notional amount	4,568	2,960
Derivative liability, estimated fair value	(6)	(9)
Forward contracts to purchase mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	66,637	31,273
Derivative asset, estimated fair value	280	66
Liability Derivatives [Abstract]
Notional amount	18,467	19,418
Derivative liability, estimated fair value	(29)	(57)
Forward contracts to sell mortgage-related securities
Asset Derivatives [Abstract]
Notional amount	18,666	26,224
Derivative asset, estimated fair value	38	65
Liability Derivatives [Abstract]
Notional amount	117,252	40,753
Derivative liability, estimated fair value	$ (502)	$ (92)

Derivative Instruments Narrativ

Derivative Instruments Narratives (Details) - USD ($) $ in Millions	Sep. 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	$ 3,300	$ 2,400
Aggregate fair value of collateral posted	3,300	2,200
Additional collateral required or amount required to immediately settle our positions if all of the credit-risk-related contingency features were triggered	$ 85	$ 257

Derivative Instruments Deriva77

Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	$ (149)	$ (2,765)	$ (4,439)	$ (2,037)
Net accrual of periodic settlements	5,435	5,588	15,490	16,332
Pay-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	1,386	(4,402)	(6,044)	(3,120)
Receive-fixed Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(1,020)	2,295	3,338	2,236
Basis Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	2	37	51	25
Foreign Currency Swap
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(6)	(20)	(37)	(33)
Pay-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(3)	32	26	137
Received-fixed Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	10	(102)	(126)	(181)
Risk Management Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	67	(2,404)	(3,494)	(1,610)
Net accrual of periodic settlements	(295)	(266)	(855)	(694)
Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	(7)	22	153	20
Mortgage commitment derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net	$ (216)	$ (361)	$ (945)	$ (427)

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to Fannie Mae	$ 3,196	$ 1,960	$ 7,278	$ 8,488
Dividends distributed or available for distribution to senior preferred stockholder	(2,977)	(2,202)	(6,765)	(8,357)
Net income attributable to common stockholders	$ 219	$ (242)	$ 513	$ 131
Weighted-average common shares outstanding, Basic	5,762	5,762	5,762	5,762
Convertible preferred stock	131	0	131	131
Weighted-average common shares outstanding, Diluted	5,893	5,762	5,893	5,893
Earnings (loss) per share, Basic (in dollars per share)	$ 0.04	$ (0.04)	$ 0.09	$ 0.02
Earnings (loss) per share, Diluted (in dollars per share)	$ 0.04	$ (0.04)	$ 0.09	$ 0.02
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)	9 Months Ended
	Sep. 30, 2016segments
Segment Reporting [Abstract]
Number of Reportable Segments	3

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Net interest income (loss)	$ 5,435	$ 5,588	$ 15,490	$ 16,332
Benefit for credit losses	673	1,550	3,458	1,050
Net interest income (loss) after benefit for credit losses	6,108	7,138	18,948	17,382
Guaranty fee income	23	31	78	99
Investment gains (losses), net	467	299	934	1,155
Fair value gains (losses), net	(491)	(2,589)	(4,971)	(1,902)
Gains (losses) from partnership investments	(12)	(5)	(9)	235
Fee and other income (expense)	152	228	474	1,024
Administrative expenses	(661)	(952)	(2,027)	(2,364)
Foreclosed property income (expense)	(110)	(497)	(507)	(1,152)
TCCA fees	(465)	(413)	(1,358)	(1,192)
Other income (expenses), net	(288)	(210)	(809)	(647)
Income (loss) before federal income taxes	4,723	3,030	10,753	12,638
Provision for federal income taxes	(1,527)	(1,070)	(3,475)	(4,150)
Net income (loss) attributable to Fannie Mae	3,196	1,960	7,278	8,488
US Treasury [Member]
Segment Reporting Information [Line Items]
TCCA fees	(465)	(413)	(1,358)	(1,192)
Business Segments [Member] | Single-Family [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	166	66	485	93
Benefit for credit losses	645	1,545	3,404	967
Net interest income (loss) after benefit for credit losses	811	1,611	3,889	1,060
Guaranty fee income	3,305	3,145	9,787	9,277
Investment gains (losses), net	0	(1)	(1)	(2)
Fair value gains (losses), net	0	(4)	0	(8)
Gains (losses) from partnership investments	(17)	(12)	(54)	(27)
Fee and other income (expense)	89	98	290	571
Administrative expenses	(479)	(649)	(1,483)	(1,591)
Foreclosed property income (expense)	(114)	(516)	(510)	(1,183)
Other income (expenses), net	(382)	(180)	(1,046)	(669)
Income (loss) before federal income taxes	2,748	3,079	9,514	6,236
Provision for federal income taxes	(808)	(1,040)	(2,544)	(2,040)
Net income (loss) attributable to Fannie Mae	1,940	2,039	6,970	4,196
Business Segments [Member] | Single-Family [Member] | US Treasury [Member]
Segment Reporting Information [Line Items]
TCCA fees	(465)	(413)	(1,358)	(1,192)
Business Segments [Member] | Multifamily [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	(22)	(16)	(62)	(73)
Benefit for credit losses	28	5	54	83
Net interest income (loss) after benefit for credit losses	6	(11)	(8)	10
Guaranty fee income	431	367	1,216	1,064
Investment gains (losses), net	23	5	37	29
Fair value gains (losses), net	0	0	0	0
Gains (losses) from partnership investments	5	7	45	262
Fee and other income (expense)	49	58	156	193
Administrative expenses	(84)	(109)	(254)	(280)
Foreclosed property income (expense)	4	19	3	31
Other income (expenses), net	(10)	5	(21)	(8)
Income (loss) before federal income taxes	424	341	1,174	1,301
Provision for federal income taxes	(49)	(17)	(127)	(128)
Net income (loss) attributable to Fannie Mae	375	324	1,047	1,173
Business Segments [Member] | Capital Markets [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	1,049	1,401	3,221	4,516
Benefit for credit losses	0	0	0	0
Net interest income (loss) after benefit for credit losses	1,049	1,401	3,221	4,516
Guaranty fee expense	(189)	(210)	(576)	(658)
Investment gains (losses), net	2,232	1,608	5,735	4,679
Fair value gains (losses), net	(530)	(2,697)	(5,063)	(2,112)
Gains (losses) from partnership investments	0	0	0	0
Fee and other income (expense)	69	83	121	288
Administrative expenses	(98)	(194)	(290)	(493)
Foreclosed property income (expense)	0	0	0	0
Other income (expenses), net	(44)	(1)	(103)	(12)
Income (loss) before federal income taxes	2,489	(10)	3,045	6,208
Provision for federal income taxes	(670)	(13)	(804)	(1,982)
Net income (loss) attributable to Fannie Mae	1,819	(23)	2,241	4,226
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	4,242	4,137	11,846	11,796
Benefit for credit losses	0	0	0	0
Net interest income (loss) after benefit for credit losses	4,242	4,137	11,846	11,796
Guaranty fee expense	(3,524)	(3,271)	(10,349)	(9,584)
Investment gains (losses), net	(1,788)	(1,313)	(4,837)	(3,551)
Fair value gains (losses), net	39	112	92	218
Gains (losses) from partnership investments	0	0	0	0
Fee and other income (expense)	(55)	(11)	(93)	(28)
Administrative expenses	0	0	0	0
Foreclosed property income (expense)	0	0	0	0
Other income (expenses), net	148	(34)	361	42
Income (loss) before federal income taxes	(938)	(380)	(2,980)	(1,107)
Provision for federal income taxes	0	0	0	0
Net income (loss) attributable to Fannie Mae	$ (938)	$ (380)	$ (2,980)	$ (1,107)

Equity Activity in OCI (Details

Equity Activity in OCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Net income	$ 3,196	$ 1,960	$ 7,278	$ 8,488
Other comprehensive (loss) income, net of tax effect:
Changes in net unrealized gains (losses) on AFS securities (net of tax of $18 and $58, respectively, for the three months ended and net of tax of $3 and $89, respectively, for the nine months ended)	33	(107)	(6)	(164)
Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $2, respectively, for the three months ended and net of tax of $12 and $66, respectively, for the nine months ended)	2	3	22	121
Reclassification adjustment for gains on AFS securities included in net income (net of tax of $129 and $32, respectively, for the three months ended and net of tax of $266 and $265, respectively, for the nine months ended)	(240)	(73)	(494)	(505)
Other	(2)	430	(6)	428
Total other comprehensive income (loss)	(207)	253	(484)	(120)
Total comprehensive income	2,989	2,213	6,794	8,368
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]
Changes in net unrealized gains (losses) on AFS securities (net of tax of $18 and $58, respectively, for the three months ended and net of tax of $3 and $89, respectively, for the nine months ended)	18	(58)	(3)	(89)
Reclassification adjustment for OTTI recognized in net income (net of tax of $1 and $2, respectively, for the three months ended and net of tax of $12 and $66, respectively, for the nine months ended)	1	2	12	66
Reclassification adjustment for gains on AFS securities included in net income (net of tax of $129 and $32, respectively, for the three months ended and net of tax of $266 and $265, respectively, for the nine months ended)	$ 129	$ 32	$ 266	$ 265

Equity AOCI (Details)

Equity AOCI (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Equity [Abstract]
Net unrealized gains on AFS securities for which we have not recorded OTTI, net of tax	$ 198	$ 455
Net unrealized gains on AFS securities for which we have recorded OTTI, net of tax	682	903
Other, net of tax	43	49
Accumulated other comprehensive income	$ 923	$ 1,407

Equity Changes in AOCI (Details

Equity Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 4,030
Total other comprehensive income (loss)	$ (207)	$ 253	(484)	$ (120)
Ending Balance	4,176		4,176
Accumulated net unrealized investment gain (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,085	1,750	1,358	2,121
Other comprehensive income (loss) before reclassifications	33	(107)	(6)	(164)
Amounts reclassified from other comprehensive income (loss)	(238)	(70)	(472)	(384)
Total other comprehensive income (loss)	(205)	(177)	(478)	(548)
Ending Balance	880	1,573	880	1,573
Accumulated other comprehensive income (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	45	(390)	49	(388)
Other comprehensive income (loss) before reclassifications	0	6	0	6
Amounts reclassified from other comprehensive income (loss)	(2)	424	(6)	422
Total other comprehensive income (loss)	(2)	430	(6)	428
Ending Balance	43	40	43	40
Accumulated other comprehensive income [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,130	1,360	1,407	1,733
Other comprehensive income (loss) before reclassifications	33	(101)	(6)	(158)
Amounts reclassified from other comprehensive income (loss)	(240)	354	(478)	38
Total other comprehensive income (loss)	(207)	253	(484)	(120)
Ending Balance	$ 923	$ 1,613	$ 923	$ 1,613

Concentrations of Credit Risk S

Concentrations of Credit Risk SF Risk Characteristics (Details) - Single-family [Member]	9 Months Ended	12 Months Ended
	Sep. 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)	1.27%	1.27%
60 days delinquent (percentage of book of business)	0.34%	0.37%
Seriously delinquent (percentage of book of business)	1.23%	1.59%
30 days delinquent (percentage of conventional loans)	1.45%	1.46%
60 days delinquent (percentage of conventional loans)	0.39%	0.41%
Seriously delinquent (percentage of conventional loans)	1.24%	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)	0.49%	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)	2.05%	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)	3.47%	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)	2.77%	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)	1.11%	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)	10.56%	10.76%
Percentage of book of business	2.00%	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)	5.27%	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)	2.75%	3.06%
Percentage of book of business	4.00%	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)	6.49%	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)	0.33%	0.36%
Percentage of book of business	87.00%	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]	9 Months Ended	12 Months Ended
	Sep. 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)	0.02%	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	0.11%	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	0.07%	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	1.95%	1.51%

Concentrations of Credit Risk O

Concentrations of Credit Risk Other Concentrations (Details) $ in Millions	Sep. 30, 2016USD ($)servicersinsurers	Dec. 31, 2015USD ($)servicersinsurers
Concentration Risk [Line Items]
Estimated benefit included in total loss reserves	$ 1,500	$ 2,300
Receivable from claims on insured, defaulted loans excluding government insured loans	1,000	1,200
Allowance for mortgage insurance receivable	658	770
Mortgage Sellers and Servicers [Member]
Concentration Risk [Line Items]
Receivable from claims on insured, defaulted loans excluding government insured loans	$ 135	$ 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	$ 124,200	$ 117,900
Mortgage insurance coverage risk in force as percentage	4.00%	4.00%
Primary mortgage insurance coverage risk in force	$ 123,600	$ 117,200
Pool mortgage insurance coverage risk in force	$ 646	$ 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	40.00%	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	$ 8,500
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	77.00%	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	Sep. 30, 2016	Dec. 31, 2015
Assets
Derivative assets, gross amount	$ 6,621	$ 4,890
Derivative assets, gross amount offset	(6,154)	(4,024)
Derivative assets, net amount presented in the condensed consolidated balance sheets	467	866
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	(214)	(119)
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	0	(21)
Derivative assets, net amount	253	726
Securities purchased under agreements to resell or similar arrangements, gross amount	40,600	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	40,600	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	(40,600)	(37,950)
Securities purchased under agreements to resell or similar arrangements, net amount	0	0
Total assets, gross amount	47,221	42,840
Total assets, gross amount offset	(6,154)	(4,024)
Total assets, net amount presented in the condensed consolidated balance sheets	41,067	38,816
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, financial instruments	(214)	(119)
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, collateral	(40,600)	(37,971)
Total assets, net amount	253	726
Liabilities:
Derivative liabilities, gross amount	(13,124)	(9,072)
Derivative liabilities, gross amount offset	12,423	8,650
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(701)	(422)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	214	119
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	6	(1)
Derivative liabilities, net amount	(481)	(304)
Securities sold under agreements to repurchase or similar arrangements, gross amount	(35)	(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	(35)	(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	35	62
Securities sold under agreements to repurchase or similar arrangements, net amount	0	0
Total liabilities, gross amount	(13,159)	(9,134)
Total liabilities, gross amount offset	12,423	8,650
Total liabilities, net amount presented in the condensed consolidated balance sheets	(736)	(484)
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	214	119
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	41	61
Total liabilities, net amount	(481)	(304)
Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount offset	(6,154)	(4,024)
Liabilities:
Derivative liabilities, gross amount offset	12,423	8,650
Mortgage commitment derivatives [Member]
Assets
Derivative assets, gross amount	349	140
Derivative assets, gross amount offset	0	0
Derivative assets, net amount presented in the condensed consolidated balance sheets	349	140
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	(214)	(119)
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	0	(3)
Derivative assets, net amount	135	18
Liabilities:
Derivative liabilities, gross amount	(537)	(158)
Derivative liabilities, gross amount offset	0	0
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(537)	(158)
Derivative Liability, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments	214	119
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral	1	(1)
Derivative liabilities, net amount	(322)	(40)
Over the Counter [Member] | Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount	4,760	4,042
Derivative assets, gross amount offset	(4,737)	(4,021)
Derivative assets, net amount presented in the condensed consolidated balance sheets	23	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	23	3
Liabilities:
Derivative liabilities, gross amount	(7,739)	(6,118)
Derivative liabilities, gross amount offset	7,580	5,861
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(159)	(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	(159)	(257)
Exchange Cleared [Member] | Risk Management Derivatives [Member]
Assets
Derivative assets, gross amount	1,512	708
Derivative assets, gross amount offset	(1,417)	(3)
Derivative assets, net amount presented in the condensed consolidated balance sheets	95	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	95	705
Liabilities:
Derivative liabilities, gross amount	(4,848)	(2,796)
Derivative liabilities, gross amount offset	4,843	2,789
Derivative liabilities, net amount presented in the condensed consolidated balance sheets	(5)	(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	5	0
Derivative liabilities, net amount	$ 0	$ (7)

Netting Arrangements Narratives

Netting Arrangements Narratives (Details) - USD ($)	Sep. 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	40,700,000,000	38,000,000,000
Fair value of non-cash collateral received that can be resold or repledged	37,400,000,000	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	23,000,000	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	$ 22,300,000,000	$ 10,600,000,000

Fair Value Levels Hierarchy (De

Fair Value Levels Hierarchy (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Mortgage loans held for investment, at fair value	$ 12,914	$ 14,075
Other assets [Abstract]
Derivative assets, gross amount offset	(6,154)	(4,024)
Other liabilities [Abstract]
Derivative liabilities, gross amount offset	(12,423)	(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	10,460	11,133
Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	35,453	23,609
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	31,277	29,485
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Other assets [Abstract]
Derivatives assets at fair value	0	0
Total assets at fair value	78,512	64,438
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Total liabilities at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fannie Mae [Member]
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	8,780	9,025
Available-for-sale securities	7,480	11,799
Mortgage loans held for investment, at fair value	2,727,858	2,702,526
Other assets [Abstract]
Derivatives assets at fair value	6,407	4,729
Total assets at fair value	2,798,416	2,770,088
Other liabilities [Abstract]
Derivative liabilities at fair value	13,104	9,042
Total liabilities at fair value	3,311,171	3,224,091
Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	24,145	26,544
Liabilities [Abstract]
Long-term debt, fair value	312,323	324,248
Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	2,703,713	2,675,982
Liabilities [Abstract]
Long-term debt, fair value	2,934,252	2,819,733
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Trading securities	490	1,398
Available-for-sale securities	2,385	8,431
Mortgage loans held for investment, at fair value	416,942	351,355
Other assets [Abstract]
Derivatives assets at fair value	237	189
Total assets at fair value	423,675	367,852
Other liabilities [Abstract]
Derivative liabilities at fair value	21	32
Total liabilities at fair value	39,609	30,061
Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	184,970	193,670
Liabilities [Abstract]
Long-term debt, fair value	886	898
Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Assets [Abstract]
Mortgage loans held for investment, at fair value	231,972	157,685
Liabilities [Abstract]
Long-term debt, fair value	37,376	27,175
Recurring Fair Value Measurements [Member]
Assets [Abstract]
Trading securities	40,547	39,908
Available-for-sale securities	9,865	20,230
Mortgage loans held for investment, at fair value	12,914	14,075
Other assets [Abstract]
Derivatives assets at fair value	490	894
Derivative assets, gross amount offset	(6,154)	(4,024)
Total assets at fair value	63,816	75,107
Liabilities [Abstract]
Long-term debt, fair value	45,913	34,742
Other liabilities [Abstract]
Derivative liabilities at fair value	702	424
Derivative liabilities, gross amount offset	(12,423)	(8,650)
Total liabilities at fair value	46,615	35,166
Recurring Fair Value Measurements [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	6,230	4,697
Other liabilities [Abstract]
Derivative liabilities at fair value	12,417	8,717
Recurring Fair Value Measurements [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	43	53
Other liabilities [Abstract]
Derivative liabilities at fair value	170	197
Recurring Fair Value Measurements [Member] | Other [Member]
Other assets [Abstract]
Derivatives assets at fair value	22	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	349	140
Other liabilities [Abstract]
Derivative liabilities at fair value	537	158
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,460	11,133
Recurring Fair Value Measurements [Member] | Fannie Mae [Member] | Senior floating [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,460	11,133
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	35,453	23,609
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	4,931	4,813
Available-for-sale securities	2,712	4,221
Recurring Fair Value Measurements [Member] | Freddie Mac [Member]
Assets [Abstract]
Trading securities	808	1,314
Available-for-sale securities	582	4,299
Recurring Fair Value Measurements [Member] | Ginnie Mae [Member]
Assets [Abstract]
Trading securities	1,393	426
Available-for-sale securities	61	391
Recurring Fair Value Measurements [Member] | Alt-A private-label securities [Member]
Assets [Abstract]
Trading securities	313	436
Available-for-sale securities	1,417	2,678
Recurring Fair Value Measurements [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	353	644
Available-for-sale securities	1,919	3,281
Recurring Fair Value Measurements [Member] | CMBS [Member]
Assets [Abstract]
Trading securities	1,281	2,341
Available-for-sale securities	978	1,255
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Assets [Abstract]
Trading securities	191	449
Available-for-sale securities	1,725	2,701
Recurring Fair Value Measurements [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	471	1,404
Recurring Fair Value Measurements [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Trading securities	31,277	29,485
Recurring Fair Value Measurements [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Trading securities	31,277	29,485
Available-for-sale securities	0	0
Mortgage loans held for investment, at fair value	0	0
Other assets [Abstract]
Derivatives assets at fair value	0	0
Total assets at fair value	31,277	29,485
Liabilities [Abstract]
Long-term debt, fair value	0	0
Other liabilities [Abstract]
Derivative liabilities at fair value	0	0
Total liabilities at fair value	0	0
Recurring Fair Value Measurements [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | 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	31,277	29,485
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Trading securities	8,780	9,025
Available-for-sale securities	7,480	11,799
Mortgage loans held for investment, at fair value	11,741	12,598
Other assets [Abstract]
Derivatives assets at fair value	6,407	4,729
Total assets at fair value	34,408	38,151
Liabilities [Abstract]
Long-term debt, fair value	45,192	33,877
Other liabilities [Abstract]
Derivative liabilities at fair value	13,104	9,042
Total liabilities at fair value	58,296	42,919
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	6,018	4,541
Other liabilities [Abstract]
Derivative liabilities at fair value	12,407	8,697
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Swaptions [Member]
Other assets [Abstract]
Derivatives assets at fair value	43	53
Other liabilities [Abstract]
Derivative liabilities at fair value	170	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	346	135
Other liabilities [Abstract]
Derivative liabilities at fair value	527	148
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	10,041	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	10,041	10,764
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	35,151	23,113
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fannie Mae [Member]
Assets [Abstract]
Trading securities	4,931	4,813
Available-for-sale securities	2,712	4,221
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Freddie Mac [Member]
Assets [Abstract]
Trading securities	808	1,314
Available-for-sale securities	580	4,295
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Ginnie Mae [Member]
Assets [Abstract]
Trading securities	1,393	426
Available-for-sale securities	61	391
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Alt-A private-label securities [Member]
Assets [Abstract]
Trading securities	48	131
Available-for-sale securities	1,243	1,637
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	319	0
Available-for-sale securities	1,871	0
Recurring Fair Value Measurements [Member] | Significant Other Observable Inputs (Level 2) [Member] | CMBS [Member]
Assets [Abstract]
Trading securities	1,281	2,341
Available-for-sale securities	978	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	35	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	490	1,398
Available-for-sale securities	2,385	8,431
Mortgage loans held for investment, at fair value	1,173	1,477
Other assets [Abstract]
Derivatives assets at fair value	237	189
Total assets at fair value	4,285	11,495
Liabilities [Abstract]
Long-term debt, fair value	721	865
Other liabilities [Abstract]
Derivative liabilities at fair value	21	32
Total liabilities at fair value	742	897
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swaps
Other assets [Abstract]
Derivatives assets at fair value	212	156
Other liabilities [Abstract]
Derivative liabilities at fair value	10	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	22	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	3	5
Other liabilities [Abstract]
Derivative liabilities at fair value	10	10
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fannie Mae [Member]
Liabilities [Abstract]
Long-term debt, fair value	419	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	419	369
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consolidated Trusts [Member]
Liabilities [Abstract]
Long-term debt, fair value	302	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	2	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	265	305
Available-for-sale securities	174	1,041
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Subprime private-label securities [Member]
Assets [Abstract]
Trading securities	34	644
Available-for-sale securities	48	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	191	449
Available-for-sale securities	1,725	2,701
Recurring Fair Value Measurements [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-sale securities	436	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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 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)	$ 12	$ (27)	$ (18)	$ (22)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	496	1,645	1,398	3,030
Total gains (losses) (realized/unrealized) Included in Net Income	13	(27)	(22)	39
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	(466)	(1,067)
Issues	0	0	0	0
Settlements	(19)	(28)	(58)	(120)
Transfers out of Level 3	0	0	(388)	(322)
Transfers into Level 3	0	0	26	30
Ending Balance	490	1,590	490	1,590
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
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance			0	305
Total gains (losses) (realized/unrealized) Included in Net Income			0	(27)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)			0	0
Purchases			0	0
Sales			0	(2)
Issues			0	0
Settlements			(1)	0
Transfers out of Level 3			(24)	(278)
Transfers into Level 3			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
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance			0
Total gains (losses) (realized/unrealized) Included in Net Income			0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)			0
Purchases			0
Sales			0
Issues			0
Settlements			0
Transfers out of Level 3			(1)
Transfers into Level 3			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)	17	(3)	(13)	(3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	259	325	305	597
Total gains (losses) (realized/unrealized) Included in Net Income	17	(3)	(13)	41
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	(267)
Issues	0	0	0	0
Settlements	(11)	(7)	(27)	(40)
Transfers out of Level 3	0	0	0	(44)
Transfers into Level 3	0	0	0	28
Ending Balance	265	315	265	315
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)	(9)	(5)	(19)	(2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	44	718	644	1,307
Total gains (losses) (realized/unrealized) Included in Net Income	(9)	(5)	(43)	38
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	(187)	(580)
Issues	0	0	0	0
Settlements	(1)	(17)	(17)	(69)
Transfers out of Level 3	0	0	(363)	0
Transfers into Level 3	0	0	0	0
Ending Balance	34	696	34	696
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)	4	(19)	14	(17)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	193	602	449	722
Total gains (losses) (realized/unrealized) Included in Net Income	5	(19)	34	(17)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	(279)	(118)
Issues	0	0	0	0
Settlements	(7)	(4)	(13)	(8)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	191	579	191	579
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)				0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance				99
Total gains (losses) (realized/unrealized) Included in Net Income				4
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)				0
Purchases				0
Sales				(100)
Issues				0
Settlements				(3)
Transfers out of Level 3				0
Transfers into Level 3				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	2,828	10,953	8,431	15,080
Total gains (losses) (realized/unrealized) Included in Net Income	115	112	299	676
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(93)	(177)	(230)	(467)
Purchases	0	0	0	421
Sales	(324)	(774)	(2,415)	(4,194)
Issues	0	0	0	0
Settlements	(142)	(587)	(575)	(1,774)
Transfers out of Level 3	0	(1)	(3,127)	(540)
Transfers into Level 3	1	26	2	350
Ending Balance	2,385	9,552	2,385	9,552
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
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		129	0	0
Total gains (losses) (realized/unrealized) Included in Net Income		0	0	0
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)		0	0	0
Purchases		0	0	421
Sales		(122)	0	(425)
Issues		0	0	0
Settlements		(8)	0	(8)
Transfers out of Level 3		0	(1)	0
Transfers into Level 3		1	1	12
Ending Balance	0	0	0	0
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	1	4	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 (Loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issues	0	0	0	0
Settlements	0	0	0	(1)
Transfers out of Level 3	0	(1)	(3)	(2)
Transfers into Level 3	1	1	1	1
Ending Balance	2	4	2	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	175	1,654	1,041	3,140
Total gains (losses) (realized/unrealized) Included in Net Income	1	2	13	174
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	1	(8)	(26)	(124)
Purchases	0	0	0	0
Sales	0	0	(291)	(1,108)
Issues	0	0	0	0
Settlements	(3)	(178)	(47)	(387)
Transfers out of Level 3	0	0	(516)	(538)
Transfers into Level 3	0	24	0	337
Ending Balance	174	1,494	174	1,494
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	173	3,837	3,281	5,240
Total gains (losses) (realized/unrealized) Included in Net Income	79	33	171	478
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(77)	(45)	(209)	(277)
Purchases	0	0	0	0
Sales	(123)	0	(707)	(1,325)
Issues	0	0	0	0
Settlements	(4)	(148)	(165)	(439)
Transfers out of Level 3	0	0	(2,323)	0
Transfers into Level 3	0	0	0	0
Ending Balance	48	3,677	48	3,677
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	2,029	3,171	2,701	4,023
Total gains (losses) (realized/unrealized) Included in Net Income	35	4	115	44
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	(23)	(29)	25	(56)
Purchases	0	0	0	0
Sales	(201)	(8)	(812)	(324)
Issues	0	0	0	0
Settlements	(115)	(205)	(304)	(754)
Transfers out of Level 3	0	0	0	0
Transfers into Level 3	0	0	0	0
Ending Balance	1,725	2,933	1,725	2,933
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	450	2,158	1,404	2,671
Total gains (losses) (realized/unrealized) Included in Net Income	0	73	0	(20)
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	6	(95)	(20)	(10)
Purchases	0	0	0	0
Sales	0	(644)	(605)	(1,012)
Issues	0	0	0	0
Settlements	(20)	(48)	(59)	(185)
Transfers out of Level 3	0	0	(284)	0
Transfers into Level 3	0	0	0	0
Ending Balance	436	1,444	436	1,444
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)	6	(24)	24	(17)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,280	1,595	1,477	1,833
Total gains (losses) (realized/unrealized) Included in Net Income	23	9	139	47
Total gains (losses) (realized/unrealized) Included in Other Comprehensive Income (Loss)	0	0	0	0
Purchases	4	0	29	5
Sales	(72)	0	(392)	0
Issues	0	0	0	0
Settlements	(60)	(97)	(199)	(273)
Transfers out of Level 3	(17)	(77)	(101)	(331)
Transfers into Level 3	15	70	220	219
Ending Balance	1,173	1,500	1,173	1,500
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)	(18)	28	41	23
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	248	4	157	45
Total gains (losses) (realized/unrealized) Included in Net Income	11	79	243	(20)
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	(1)	0	(8)	0
Settlements	(43)	(32)	(176)	26
Transfers out of Level 3	0	0	(2)	0
Transfers into Level 3	1	9	2	9
Ending Balance	216	60	216	60
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)	(9)	(23)	(59)	5
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(736)	(839)	(865)	(890)
Total gains (losses) (realized/unrealized) Included in Net Income	(11)	(23)	(127)	(14)
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	(16)	(64)	(70)	(64)
Settlements	11	18	329	43
Transfers out of Level 3	95	33	140	142
Transfers into Level 3	(64)	(65)	(128)	(157)
Ending Balance	(721)	(940)	(721)	(940)
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)	0	0	(9)	11
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(326)	(493)	(496)	(527)
Total gains (losses) (realized/unrealized) Included in Net Income	(2)	0	(77)	(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	(16)	(64)	(70)	(64)
Settlements	11	18	329	43
Transfers out of Level 3	95	33	140	142
Transfers into Level 3	(64)	(65)	(128)	(157)
Ending Balance	(302)	(571)	(302)	(571)
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)	(9)	(23)	(50)	(6)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(410)	(346)	(369)	(363)
Total gains (losses) (realized/unrealized) Included in Net Income	(9)	(23)	(50)	(6)
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	$ (419)	$ (369)	$ (419)	$ (369)

Fair Value Level 3 Valuation In

Fair Value Level 3 Valuation Inputs (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 12,914	$ 14,075
Derivatives	467	866
Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(10,460)	(11,133)
Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(35,453)	(23,609)
Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	40,547	39,908
Available-for-sale securities	9,865	20,230
Mortgage loans held for investment, at fair value	12,914	14,075
Long-term Debt, Fair Value	(45,913)	(34,742)
Recurring Fair Value Measurements [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	313	436
Available-for-sale securities	1,417	2,678
Recurring Fair Value Measurements [Member] | Subprime private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	353	644
Available-for-sale securities	1,919	3,281
Recurring Fair Value Measurements [Member] | Mortgage revenue bonds [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	191	449
Available-for-sale securities	1,725	2,701
Recurring Fair Value Measurements [Member] | Other [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	471	1,404
Recurring Fair Value Measurements [Member] | Fannie Mae [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(10,460)	(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	(10,460)	(11,133)
Recurring Fair Value Measurements [Member] | Consolidated Trusts [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	(35,453)	(23,609)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	490	1,398
Available-for-sale securities	2,385	8,431
Mortgage loans held for investment, at fair value	416,942	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	184,970	193,670
Long-term Debt, Fair Value	(886)	(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	231,972	157,685
Long-term Debt, Fair Value	(37,376)	(27,175)
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Trading securities	490	1,398
Available-for-sale securities	2,385	8,431
Mortgage loans held for investment, at fair value	1,173	1,477
Derivatives	216	157
Long-term Debt, Fair Value	(721)	(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	265	305
Available-for-sale securities	174	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	34	644
Available-for-sale securities	48	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	191	449
Available-for-sale securities	1,725	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	436	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	38
Available-for-sale securities	$ 32
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 (%)	6.00%
Severity (%)	37.00%
Spreads (%)	2.963%
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 (%)	6.00%
Severity (%)	37.00%
Spreads (%)	2.963%
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 (%)	6.00%
Severity (%)	37.00%
Spreads (%)	2.963%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor 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 (%)	5.20%
Prepayment Speed (%)	7.90%
Severity (%)	53.00%
Spreads (%)	2.753%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor 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 (%)	8.00%
Prepayment Speed (%)	8.00%
Severity (%)	55.00%
Spreads (%)	2.985%
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Single Vendor 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 (%)	7.20%
Prepayment Speed (%)	8.00%
Severity (%)	54.40%
Spreads (%)	2.823%
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]
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] | 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	$ 828	$ 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 (%)	(0.179%)	(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 (%)	3.719%	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 (%)	0.382%	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	$ 227	$ 305
Available-for-sale securities	$ 82	$ 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 (%)	4.00%	2.20%
Severity (%)	37.00%	20.50%
Spreads (%)	2.475%	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 (%)	4.00%	4.90%
Prepayment Speed (%)	9.00%	4.50%
Severity (%)	95.00%	95.00%
Spreads (%)	4.274%	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 (%)	3.50%	3.60%
Prepayment Speed (%)	7.70%	3.70%
Severity (%)	80.00%	69.30%
Spreads (%)	3.808%	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 (%)	2.50%	0.50%
Prepayment Speed (%)	3.00%	1.70%
Severity (%)	60.00%	1.40%
Spreads (%)	2.327%	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 (%)	65.00%	95.00%
Spreads (%)	3.078%	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 (%)	2.90%	3.40%
Prepayment Speed (%)	3.60%	13.50%
Severity (%)	60.60%	58.50%
Spreads (%)	2.991%	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	$ 34	$ 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 (%)	5.00%	4.20%
Prepayment Speed (%)	5.00%	0.40%
Severity (%)	75.00%	55.90%
Spreads (%)	6.087%	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 (%)	5.00%	8.40%
Prepayment Speed (%)	5.00%	5.30%
Severity (%)	75.00%	95.00%
Spreads (%)	6.087%	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 (%)	5.00%	5.90%
Prepayment Speed (%)	5.00%	3.30%
Severity (%)	75.00%	73.70%
Spreads (%)	6.087%	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	$ 49	$ 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 (%)	3.50%	0.50%
Prepayment Speed (%)	2.50%	2.50%
Severity (%)	88.00%	6.60%
Spreads (%)	2.47%	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 (%)	2.50%	15.50%
Severity (%)	88.00%	95.00%
Spreads (%)	3.469%	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 (%)	88.00%	65.70%
Spreads (%)	2.85%	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	$ 45	$ 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 (%)		4.00%
Prepayment Speed (%)		4.00%
Severity (%)		50.00%
Spreads (%)	4.30%	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 (%)		5.00%
Prepayment Speed (%)		7.50%
Severity (%)		64.00%
Spreads (%)	4.34%	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 (%)		4.80%
Prepayment Speed (%)		6.40%
Severity (%)		59.20%
Spreads (%)	4.32%	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	$ 189	$ 437
Available-for-sale securities	$ 785	$ 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 (%)	0.10%	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 (%)	2.928%	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 (%)	2.90%	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 (%)	(0.179%)	(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 (%)	4.064%	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 (%)	2.764%	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	$ 354	$ 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 (%)	2.30%	0.00%
Prepayment Speed (%)	0.50%	0.00%
Severity (%)	35.00%	95.00%
Spreads (%)	1.90%	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 (%)	2.30%	1.80%
Prepayment Speed (%)	0.50%	0.50%
Severity (%)	35.00%	95.00%
Spreads (%)	4.50%	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 (%)	2.30%	0.00%
Prepayment Speed (%)	0.50%	0.00%
Severity (%)	35.00%	95.00%
Spreads (%)	4.491%	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	$ 14	$ 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	2	4
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Other Valuation Technique without Inputs [Member] | Alt-A private-label securities [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Available-for-sale securities	15
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	48	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	2	12
Available-for-sale securities	112	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	33	201
Significant Unobservable Inputs (Level 3) [Member] | Recurring Fair Value Measurements [Member] | Dealer Mark without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Derivatives	202	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	1,013	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		$ 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 (%)		0.50%
Prepayment Speed (%)		2.50%
Severity (%)		20.00%
Spreads (%)		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 (%)		5.00%
Prepayment Speed (%)		26.00%
Severity (%)		89.10%
Spreads (%)		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 (%)		3.70%
Prepayment Speed (%)		6.40%
Severity (%)		69.00%
Spreads (%)		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	267	$ 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	545	$ 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	201	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	$ 160	$ 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 (%)	0.66%	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 (%)	3.762%	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 (%)	1.798%	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	$ (419)	$ (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	(419)	(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	(419)	(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	(302)	(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] | Other Valuation Technique without Inputs [Member]
Fair Value Inputs, Quantitative Information [Line Items]
Long-term Debt, Fair Value	$ (302)	$ (166)

Fair Value Level 3 Valuation -

Fair Value Level 3 Valuation - Nonrecurring (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Quantitative Information [Line Items]
Mortgage loans held for investment, at fair value	$ 12,914	$ 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	1,020	157
Mortgage loans held for investment, at fair value	2,727,858	2,702,526
Total assets at fair value	2,798,416	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	2,789	5,541
Mortgage loans held for investment, at fair value	416,942	351,355
Total assets at fair value	423,675	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	475	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	946	3,991
Total assets at fair value	6,432	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	909	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	5	4
Other assets	$ 10	$ 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	20.00%	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	$ 1,931	$ 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	64	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	3,296	6,379
Acquired property, net	458	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	402	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	684	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	323	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	247	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	3	5
Acquired property, net	2	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	22	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	$ 222	$ 236

Fair Value Fair Value of Financ

Fair Value Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value Measurement [Domain]
Financial assets [Abstract]
Derivative assets, gross amount offset	$ (6,154)	$ (4,024)
Financial liabilities [Abstract]
Derivative liabilities, gross amount offset	(12,423)	(8,650)
Mortgage loans held for investment, at fair value	12,914	14,075
Derivative assets, gross amount offset	(6,154)	(4,024)
Derivative liabilities, gross amount offset	(12,423)	(8,650)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	47,235	34,953
Federal funds sold and securities purchased under agreements to resell or similar arrangements	0	0
Trading securities	31,277	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	78,512	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	22,250	10,600
Federal funds sold and securities purchased under agreements to resell or similar arrangements	18,350	27,350
Trading securities	8,780	9,025
Available-for-sale securities	7,480	11,799
Mortgage loans held for sale	1,020	157
Mortgage loans held for investment, at fair value	2,727,858	2,702,526
Advances to lenders	6,271	3,902
Derivatives assets at fair value	6,407	4,729
Guaranty assets and buy-ups	0	0
Total financial assets	2,798,416	2,770,088
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	35	62
Derivative liabilities at fair value	13,104	9,042
Guaranty obligations	0	0
Total financial liabilities	3,311,171	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	490	1,398
Available-for-sale securities	2,385	8,431
Mortgage loans held for sale	2,789	5,541
Mortgage loans held for investment, at fair value	416,942	351,355
Advances to lenders	382	394
Derivatives assets at fair value	237	189
Guaranty assets and buy-ups	450	544
Total financial assets	423,675	367,852
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	0	0
Derivative liabilities at fair value	21	32
Guaranty obligations	714	1,012
Total financial liabilities	39,609	30,061
Fannie Mae [Member]
Financial liabilities [Abstract]
Long-term debt	10,460	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	24,145	26,544
Financial liabilities [Abstract]
Short-term debt	51,457	71,006
Long-term debt	312,323	324,248
Fannie Mae [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	184,970	193,670
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	886	898
Consolidated Trusts [Member]
Financial liabilities [Abstract]
Long-term debt	35,453	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	2,703,713	2,675,982
Financial liabilities [Abstract]
Short-term debt	0	0
Long-term debt	2,934,252	2,819,733
Consolidated Trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	231,972	157,685
Financial liabilities [Abstract]
Short-term debt	612	944
Long-term debt	37,376	27,175
Carrying Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	69,485	45,553
Federal funds sold and securities purchased under agreements to resell or similar arrangements	18,350	27,350
Trading securities	40,547	39,908
Available-for-sale securities	9,865	20,230
Mortgage loans held for sale	3,405	5,361
Mortgage loans held for investment, at fair value	3,045,556	3,014,283
Advances to lenders	6,627	4,308
Derivatives assets at fair value	490	894
Guaranty assets and buy-ups	152	184
Total financial assets	3,194,477	3,158,071
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	35	62
Derivative liabilities at fair value	702	424
Guaranty obligations	282	329
Total financial liabilities	3,234,132	3,198,486
Carrying Value [Member] | Fannie Mae [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	195,100	206,544
Financial liabilities [Abstract]
Short-term debt	51,442	71,007
Long-term debt	300,126	315,128
Carrying Value [Member] | Consolidated Trusts [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	2,850,456	2,807,739
Financial liabilities [Abstract]
Short-term debt	612	943
Long-term debt	2,880,933	2,810,593
Estimated of Fair Value [Member]
Financial assets [Abstract]
Cash and cash equivalents and restricted cash	69,485	45,553
Federal funds sold and securities purchased under agreements to resell or similar arrangements	18,350	27,350
Trading securities	40,547	39,908
Available-for-sale securities	9,865	20,230
Mortgage loans held for sale	3,809	5,698
Mortgage loans held for investment, at fair value	3,144,800	3,053,881
Advances to lenders	6,653	4,296
Derivatives assets at fair value	490	894
Guaranty assets and buy-ups	450	544
Total financial assets	3,294,449	3,198,354
Financial liabilities [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	35	62
Derivative liabilities at fair value	702	424
Guaranty obligations	714	1,012
Total financial liabilities	3,338,357	3,245,502
Estimated of Fair Value [Member] | Fannie Mae [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	209,115	220,214
Financial liabilities [Abstract]
Short-term debt	51,457	71,006
Long-term debt	313,209	325,146
Estimated of Fair Value [Member] | Consolidated Trusts [Member]
Financial assets [Abstract]
Mortgage loans held for investment, at fair value	2,935,685	2,833,667
Financial liabilities [Abstract]
Short-term debt	612	944
Long-term debt	$ 2,971,628	$ 2,846,908

Fair Value Fair Value Option (D

Fair Value Fair Value Option (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage loans held for investment, at fair value	$ 12,914	$ 14,075
Fair value of nonaccrual loans	159	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	156	256
Difference between unpaid principal balance and the fair value of these 90 days or more past due loans	$ 26	$ 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	$ 10,460	$ 11,133
Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, fair value	35,453	23,609
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, unpaid principal balance	12,173	13,661
Long-term debt [Member] | Fannie Mae [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, unpaid principal balance	9,924	11,263
Long-term debt [Member] | Consolidated Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Long-term debt, unpaid principal balance	$ 31,633	$ 21,604

Fair Value Changes in FV under

Fair Value Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Total Gains (Losses)	$ (375)	$ 223	$ (564)	$ 155
Other changes in fair value	(17)	(96)	(119)	(107)
Fair value gains (losses), net	(392)	127	(683)	48
Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Loans	14	73	46	110
Other changes in fair value	48	(15)	392	(65)
Fair value gains (losses), net	62	58	438	45
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in instrument-specific credit risk - Long-Term Debt	(389)	150	(610)	45
Other changes in fair value	(65)	(81)	(511)	(42)
Fair value gains (losses), net	$ (454)	$ 69	$ (1,121)	$ 3