Derivatives and Hedging Activities (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Pre-tax net gains (losses) on derivatives not designated as hedging instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	$ 16	$ 7
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	6	2
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	9	10
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	5	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	$ (4)	$ (7)