Investment in Lease Financing (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accumulated allowance for uncollectible minimum lease payments	$ 1,854	[1]	$ 2,255	[1]	$ 3,004	$ 3,749
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accumulated allowance for uncollectible minimum lease payments	$ 67		$ 79

[1] At December 31, 2012 and 2011, includes $0 and $30 of cash, $0 and $7 of other short-term investments, $50 and $50 of commercial mortgage loans, $0 and $223 of home equity loans, $0 and $259 of automobile loans, ($5) and ($10) of ALLL, $3 and $4 of other assets, $0 and $4 of other liabilities, $0 and $191 of long-term debt from consolidated VIEs that are included in their respective captions. See Note 10.