Allowance for Loan Losses Allowance at Recorded Investment (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2011		Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	$ 42,622			$ 46,482
Allowance for loan losses for collectively reserved loans	20,460			25,299
Allowance for loan losses for acquired credit-impaired loans	293			375		414
Allowance for loan losses	63,375	[1]	70,109	72,156		69,506	[1]	67,557	61,556
Recorded investment in individually impaired loans	170,159	[2]		166,521	[2]
Recorded investment in collectively reserved loans	2,819,226	[2]		2,809,051	[2]
Recorded investment in acquired credit-impaired loans	2,862	[2]		3,319	[2]
Recorded investment in loans	2,992,247	[2]		2,978,891	[2]
Single-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	42,115			45,765
Allowance for loan losses for collectively reserved loans	19,727			24,494
Allowance for loan losses for acquired credit-impaired loans	292			374
Allowance for loan losses	62,134		68,738	70,633		68,027		66,084	59,980
Recorded investment in individually impaired loans	165,938	[2]		161,942	[2]
Recorded investment in collectively reserved loans	2,640,139	[2]		2,634,456	[2]
Recorded investment in acquired credit-impaired loans	2,821	[2]		3,272	[2]
Recorded investment in loans	2,808,898	[2]		2,799,670	[2]
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses for individually impaired loans	507			717
Allowance for loan losses for collectively reserved loans	733			805
Allowance for loan losses for acquired credit-impaired loans	1			1
Allowance for loan losses	1,241		1,371	1,523		1,479		1,473	1,576
Recorded investment in individually impaired loans	4,221	[2]		4,579	[2]
Recorded investment in collectively reserved loans	179,087	[2]		174,595	[2]
Recorded investment in acquired credit-impaired loans	41	[2]		47	[2]
Recorded investment in loans	$ 183,349	[2],[3],[4]		$ 179,221	[2],[3],[4]

[1] Total allowance for loan losses includes $293 million and $414 million as of June 30, 2012 and 2011, respectively, for acquired credit-impaired loans.

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

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

[4] 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).