Derivatives and Hedging Activities (Details 1) (Fair Value Hedging [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Other Expense [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative contract	$ 47	$ 142	$ (36)	$ (16)
Hedged item	(42)	(138)	27	1
Net hedge ineffectiveness	5	4	(9)	(15)
Other revenues [Member] | Total Return Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative contract	53	0	21	0
Hedged item	(53)	0	(21)	0
Net hedge ineffectiveness	$ 0	$ 0	$ 0	$ 0