Derivatives and Hedging Activities (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	$ 20	$ 43
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	19	16
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	42	44
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	4	5
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	$ (45)	$ (22)