Discontinued Operations - Assets and Liabilities of Discontinued Operations Were Considered Held for Sale (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other branch related assets held for sale	$ 0		$ 440
Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	0	[1]	21,185	[1]
Other branch related assets held for sale	0		269
Assets of discontinued operations	0		21,454
Deposits in domestic offices - noninterest bearing	0		35
Other liabilities	0		876
Liabilities of discontinued operations	$ 0		$ 911

[1] At December 31, 2011, the receivables are carried at the lower of amortized cost or fair value.