Derivatives and Hedging Activities (Details 3) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	$ 26	$ 18
Interest rate [Member]
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	10	6
Foreign exchange [Member]
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	19	20
Energy and commodity [Member]
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	6	2
Credit [Member]
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	$ (9)	$ (10)