Derivatives and Hedging (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value
Derivative Assets	$ 242	$ 157
Derivative Liabilities	284	189
Notional Amount	1,753	2,245
Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	240	156
Derivative Liabilities	283	188
Notional Amount	1,566	1,999
Interest rate contracts | Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	16	16
Notional Amount	342	702
Foreign exchange contracts | Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	224	140
Derivative Liabilities	283	188
Notional Amount	1,224	1,297
Foreign exchange contracts | Derivatives not accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	2	1
Derivative Liabilities	1	1
Notional Amount	$ 187	$ 246