Derivatives and Hedging Activities (Details 3) (Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses)	$ 26	$ (14)	$ 109	$ 31
Other Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses)	1	(1)	1	(2)
Other Expense [Member] | Foreign exchange contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses)	25	(13)	106	31
Other Income [Member] | Equity-linked contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses)	$ 0	$ 0	$ 2	$ 2