Financing Receivables and Allowance for Losses on Financing Receivables (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Loans and Leases Receivable Disclosure [Abstract]
Loans net of deferred income	$ 241,465	$ 256,895
Investment In Financing Leases, Net Of Deferred Income	32,471	38,142
Loans and leases receivable, Gross	273,936	295,037
Less allowance for losses	(4,985)	(6,190)	(7,919)
Financing receivables, net	268,951	288,847
Deferred income	2,182	2,329
Loans that have been acquired in a transfer but have been subject to credit deterioration since origination per ASC 310, Receivables	$ 750	$ 1,062