Derivative Financial Instruments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Gain or loss on non-qualifying hedges	$ (424)	$ (167)	$ (216)	$ (124)
Interest rate contracts [Member] | Derivative related income (expense) [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	(424)	(168)	(212)	(125)
Currency contracts [Member] | Derivative related income (expense) [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments		$ 1	$ (4)	$ 1