LHFI by Credit Quality Indicator (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 124,560	[1]	$ 122,495	[1]
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,405	[2]	23,243	[2]
Consumer Other Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,225		2,059
Federally Guaranteed Residential Loans | Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 5,700		$ 6,700

[1] Includes loans of consolidated VIEs390 3,322

[2] Excludes $5.7 billion and $6.7 billion at June 30, 2012 and December 31, 2011, respectively, of guaranteed residential loans. At both June 30, 2012 and December 31, 2011, the majority of these loans had FICO scores of 700 and above.