Derivative Financial Instruments (Details 8) (Foreign Operations Hedges [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
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ 17	$ (57)	$ (34)	$ (107)
Foreign currency forwards [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	42	(57)	(10)	(113)
Foreign currency swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	(25)	0	(24)	0
Non-derivative hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ 0	$ 0	$ 0	$ 6