Mortgage Loans Aging (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	$ 39,184	[1]	$ 47,925	[1]
60 - 89 days delinquent	12,138	[1]	17,023	[1]
Seriously delinquent	69,706	[1],[2]	99,213	[1],[2]
Total delinquent	121,028	[1]	164,161	[1]
Current	2,943,641	[1]	2,843,310	[1]
Total recorded investment in loans	3,064,669	[1]	3,007,471	[1]
Recorded investment in loans 90 days or more delinquent and accruing interest	460	[1]	3,301	[1],[3]
Recorded investment in nonaccrual loans	83,283	[1]	114,293	[1]
Government [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total recorded investment in loans	48,600		50,900
Repurchase Request Resolution Agreement [Member] | Bank of America [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment in loans 90 days or more delinquent and accruing interest	2,800
Single-Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	39,125	[1]	47,747	[1]
60 - 89 days delinquent	12,138	[1]	17,023	[1]
Seriously delinquent	69,520	[1],[2]	98,785	[1],[2]
Total delinquent	120,783	[1]	163,555	[1]
Current	2,757,908	[1]	2,652,865	[1]
Total recorded investment in loans	2,878,691	[1]	2,816,420	[1]
Recorded investment in loans 90 days or more delinquent and accruing interest	460	[1]	3,301	[1],[3]
Recorded investment in nonaccrual loans	81,074	[1]	112,079	[1]
Single-Family [Member] | Primary [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	32,371	[1],[4]	39,043	[1],[4]
60 - 89 days delinquent	9,755	[1],[4]	13,513	[1],[4]
Seriously delinquent	48,345	[1],[2],[4]	67,737	[1],[2],[4]
Total delinquent	90,471	[1],[4]	120,293	[1],[4]
Current	2,558,826	[1],[4]	2,424,022	[1],[4]
Total recorded investment in loans	2,649,297	[1],[4],[5],[6]	2,544,315	[1],[4],[5],[6]
Recorded investment in loans 90 days or more delinquent and accruing interest	81	[1],[4]	2,162	[1],[3],[4]
Recorded investment in nonaccrual loans	57,973	[1],[4]	78,822	[1],[4]
Single-Family [Member] | Government [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	66	[1],[7]	82	[1],[7]
60 - 89 days delinquent	32	[1],[7]	40	[1],[7]
Seriously delinquent	346	[1],[2],[7]	340	[1],[2],[7]
Total delinquent	444	[1],[7]	462	[1],[7]
Current	48,150	[1],[7]	50,408	[1],[7]
Total recorded investment in loans	48,594	[1],[7]	50,870	[1],[7]
Recorded investment in loans 90 days or more delinquent and accruing interest	346	[1],[7]	340	[1],[3],[7]
Recorded investment in nonaccrual loans	0	[1],[7]	0	[1],[7]
Single-Family [Member] | Alt-A [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	4,748	[1]	6,009	[1]
60 - 89 days delinquent	1,692	[1]	2,417	[1]
Seriously delinquent	15,425	[1],[2]	22,181	[1],[2]
Total delinquent	21,865	[1]	30,607	[1]
Current	105,644	[1]	121,099	[1]
Total recorded investment in loans	127,509	[1],[5],[6]	151,706	[1],[5],[6]
Recorded investment in loans 90 days or more delinquent and accruing interest	11	[1]	502	[1],[3]
Recorded investment in nonaccrual loans	17,102	[1]	24,048	[1]
Single-Family [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	1,940	[1],[8]	2,613	[1],[8]
60 - 89 days delinquent	659	[1],[8]	1,053	[1],[8]
Seriously delinquent	5,404	[1],[2],[8]	8,527	[1],[2],[8]
Total delinquent	8,003	[1],[8]	12,193	[1],[8]
Current	45,288	[1],[8]	57,336	[1],[8]
Total recorded investment in loans	53,291	[1],[5],[6],[8]	69,529	[1],[5],[6],[8]
Recorded investment in loans 90 days or more delinquent and accruing interest	22	[1],[8]	297	[1],[3],[8]
Recorded investment in nonaccrual loans	5,999	[1],[8]	9,209	[1],[8]
Single-Family [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	90 days		90 days
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days delinquent	59	[1],[9]	178	[1],[9]
Seriously delinquent	186	[1],[2],[9]	428	[1],[2],[9]
Total delinquent	245	[1],[9]	606	[1],[9]
Current	185,733	[1],[9]	190,445	[1],[9]
Total recorded investment in loans	185,978	[1],[10],[9]	191,051	[1],[11],[9]
Recorded investment in loans 90 days or more delinquent and accruing interest	0	[1],[9]	0	[1],[3],[9]
Recorded investment in nonaccrual loans	$ 2,209	[1],[9]	$ 2,214	[1],[9]
Multifamily [Member] | Minimum [Member]
Table Footnote [Abstract]
Serious delinquency, days past due	60 days		60 days

[1] Recorded investment consists of unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, and accrued interest receivable.

[2] 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.

[3] Includes loans with a recorded investment of $2.8 billion, which were repurchased in January 2013 pursuant to our resolution agreement with Bank of America. These loans were returned to accrual status to reflect the change in our assessment of collectibility resulting from this agreement.

[4] Consists of mortgage loans that are not included in other loan classes.

[5] 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.

[6] Excludes $48.6 billion and $50.9 billion as of December 31, 2013 and 2012, 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.

[7] Consists 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. Primarily consists of reverse mortgages which due to their nature are not aged and are included in the current column.

[8] Includes loans with higher-risk characteristics, such as interest-only loans and negative-amortizing loans, that are neither government nor Alt-A.

[9] Multifamily loans 60-89 days delinquent are included in the seriously delinquent column.

[10] 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).

[11] Green (loan with acceptable risk); yellow (loan with signs of potential weakness); orange (loan with a well defined weakness that may jeopardize the timely full repayment); and red (loan with a weakness that makes timely collection or liquidation in full more questionable based on existing conditions and values).