Derivatives and Hedging Activities (Details 1) (Fair Value Hedging [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other Expense [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative contract	$ (190)	$ 47	$ (293)	$ (36)
Hedged item	180	(42)	289	27
Net hedge ineffectiveness	(10)	5	(4)	(9)
Other Revenues [Member] | Total Return Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative contract	27	53	31	21
Hedged item	(27)	(53)	(31)	(21)
Net hedge ineffectiveness	$ 0	$ 0	$ 0	$ 0