Derivatives and Hedging (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value
Derivative Assets	$ 237	$ 157
Derivative Liabilities	258	189
Notional Amount	2,010	2,245
Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	234	156
Derivative Liabilities	257	188
Notional Amount	1,738	1,999
Interest rate contracts | Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	18	16
Notional Amount	361	702
Foreign exchange contracts | Derivatives accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	216	140
Derivative Liabilities	257	188
Notional Amount	1,377	1,297
Foreign exchange contracts | Derivatives not accounted for as hedges:
Derivatives, Fair Value
Derivative Assets	3	1
Derivative Liabilities	1	1
Notional Amount	$ 272	$ 246