Derivative Financial Instruments (Details 8) (Foreign Operations Hedges [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ (78)	$ 185	$ (112)	$ 78
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)	(54)	185	(64)	72
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)	(24)	0	(48)	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