Leasing Activities (Net Investment In Leases By Published Credit Ratings) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Leases [Line Items]
Rated Entities	$ 1,226	[1]	$ 1,349	[1]
AA/Aa And Above [Member]
Leases [Line Items]
Rated Entities	759	[1]	737	[1]
A [Member]
Leases [Line Items]
Rated Entities	$ 467	[1]	$ 612	[1]

[1] Excludes the credit ratings associated with collateral posted by the lessees in these transactions.