Mortgage Loans Individually Impaired Loans (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	$ 185,695		$ 190,677
Individually impaired loans with related allowance recorded: total recorded investment	175,619	[1]	180,519	[1]
Related allowance for loan losses	37,729	[2],[3]	45,034	[2],[3]
Individually impaired loans with no related allowance recorded: unpaid principal balance	20,452	[4]	23,594	[4]
Individually impaired loans with no related allowance recorded: total recorded investment	17,660	[1],[4]	19,872	[1],[4]
Total individually impaired loans: unpaid principal balance	206,147	[2]	214,271	[2]
Total individually impaired loans: total recorded investment	193,279	[1],[2]	200,391	[1],[2]
Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	688	[2]	998	[2]
Primary [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	130,080	[5]	132,754	[5]
Individually impaired loans with related allowance recorded: total recorded investment	123,631	[1],[5]	126,106	[1],[5]
Related allowance for loan losses	24,145	[5]	28,610	[5]
Individually impaired loans with no related allowance recorded: unpaid principal balance	14,076	[4],[5]	16,222	[4],[5]
Individually impaired loans with no related allowance recorded: total recorded investment	12,305	[1],[4],[5]	13,901	[1],[4],[5]
Primary [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	430	[5]	628	[5]
Government [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	213	[6]	214	[6]
Individually impaired loans with related allowance recorded: total recorded investment	210	[1],[6]	208	[1],[6]
Related allowance for loan losses	35	[6]	38	[6]
Individually impaired loans with no related allowance recorded: unpaid principal balance	120	[4],[6]	104	[4],[6]
Individually impaired loans with no related allowance recorded: total recorded investment	120	[1],[4],[6]	104	[1],[4],[6]
Government [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	5	[6]	4	[6]
Alt-A [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	37,356		38,387
Individually impaired loans with related allowance recorded: total recorded investment	34,479	[1]	35,620	[1]
Related allowance for loan losses	9,364		11,154
Individually impaired loans with no related allowance recorded: unpaid principal balance	3,290	[4]	3,994	[4]
Individually impaired loans with no related allowance recorded: total recorded investment	2,428	[1],[4]	2,822	[1],[4]
Alt-A [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	187		267
Other [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	15,789	[7]	16,873	[7]
Individually impaired loans with related allowance recorded: total recorded investment	15,023	[1],[7]	16,114	[1],[7]
Related allowance for loan losses	3,879	[7]	4,743	[7]
Individually impaired loans with no related allowance recorded: unpaid principal balance	1,039	[4],[7]	1,218	[4],[7]
Individually impaired loans with no related allowance recorded: total recorded investment	868	[1],[4],[7]	977	[1],[4],[7]
Other [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	56	[7]	86	[7]
Single-Family [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	183,438		188,228
Individually impaired loans with related allowance recorded: total recorded investment	173,343	[1]	178,048	[1]
Related allowance for loan losses	37,423	[3]	44,545	[3]
Individually impaired loans with no related allowance recorded: unpaid principal balance	18,525	[4]	21,538	[4]
Individually impaired loans with no related allowance recorded: total recorded investment	15,721	[1],[4]	17,804	[1],[4]
Table Footnote [Abstract]
Troubled debt restructuring recorded investment	187,600		193,400		161,900
Single-Family [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	678		985
Multifamily [Member]
Financing Receivable, Impaired [Line Items]
Individually impaired loans with related allowance recorded: unpaid principal balance	2,257		2,449
Individually impaired loans with related allowance recorded: total recorded investment	2,276	[1]	2,471	[1]
Related allowance for loan losses	306	[3]	489	[3]
Individually impaired loans with no related allowance recorded: unpaid principal balance	1,927	[4]	2,056	[4]
Individually impaired loans with no related allowance recorded: total recorded investment	1,939	[1],[4]	2,068	[1],[4]
Table Footnote [Abstract]
Troubled debt restructuring recorded investment	911		1,100		956
Multifamily [Member] | Interest Receivable [Member]
Financing Receivable, Impaired [Line Items]
Related allowance for loan losses	$ 10		$ 13

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

[2] Includes single-family loans restructured in a TDR with a recorded investment of $187.6 billion, $193.4 billion and $161.9 billion as of December 31, 2013, 2012 and 2011, respectively. Includes multifamily loans restructured in a TDR with a recorded investment of $911 million, $1.1 billion and $956 million as of December 31, 2013, 2012 and 2011, respectively.

[3] Includes acquired credit-impaired loans.

[4] The discounted cash flows or collateral value equals or exceeds the carrying value of the loan and, as such, no valuation allowance is required.

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

[6] 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.

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