Leasing Activities (Net Investment In Leases By The Published Credit Ratings) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Leases [Line Items]
Rated Entities	$ 1,362	[1]	$ 1,349	[1]
AA/Aa And Above [Member]
Leases [Line Items]
Rated Entities	746	[1]	737	[1]
A [Member]
Leases [Line Items]
Rated Entities	$ 616	[1]	$ 612	[1]

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