Derivative Financial Instruments (Details 8) (Foreign Operations Hedges [Member], USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ 185	$ (172)	$ 78	$ (145)
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)	185	(162)	72	(135)
Foreign currency forwards [Member] | Gain (Loss) on Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss) (Effective Portion)	0	0	0	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	(10)	6	(10)
Non-derivative hedging instruments [Member] | Gain (Loss) on Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss) (Effective Portion)	0	0	0	0
Gain (Loss) on Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss) (Effective Portion)	$ 0	$ 0	$ 0	$ 0