Derivatives (Hedges of Net Investments in Foreign Operations) (Details) (Foreign Operations Hedges [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	$ 216	$ 17	$ 386	$ (34)
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)	85	42	165	(10)
Currency options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)	131	(25)	221	(24)
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	$ 0