Leasing Activities (Net Investment In Leases By The Published Credit Ratings) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Leases [Line Items]
Rated Entities	$ 1,349	[1]	$ 1,258	[1]
Non Rated Entities			165	[1]
Total	1,349	[1]	1,423	[1]
AA/Aa And Above [Member]
Leases [Line Items]
Rated Entities	737	[1]	709	[1]
A [Member]
Leases [Line Items]
Rated Entities	$ 612	[1]	$ 549	[1]

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