LHFI by Credit Quality Indicator (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 122,691	[1]	$ 122,495	[1]
Residential Nonguaranteed
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	23,653	[2]	23,243	[2]
Consumer Other Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,688	[3]	1,610	[3]
Federally Guaranteed Residential Loans | Residential Nonguaranteed
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	6,400		6,700
Guaranteed Student Loans | Consumer Other Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 464		$ 449

[1] Includes loans of consolidated VIEs1,378 3,322

[2] Excludes $6.4 billion and $6.7 billion at March 31, 2012 and December 31, 2011, respectively, of guaranteed residential loans. At both March 31, 2012 and December 31, 2011, the majority of these loans had FICO scores of 700 and above.

[3] Excludes $464 million and $449 million as of March 31, 2012 and December 31, 2011, respectively, of private-label student loans with third party insurance. At March 31, 2012 and December 31, 2011, the majority of these loans had FICO scores of 700 and above.