Derivatives and Hedging (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) Recognized in Income on Derivative	$ (18)		$ 2
Estimated pretax losses currently included within Accumulated Other Comprehensive Loss that will be reclassified to earnings in next twelve months	28
Derivatives accounted for as hedges: | Cash flow hedges
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) recognized in Accumulated Other Comprehensive Loss	(29)		2
Amount of Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into income (effective portion)	(11)		(8)
Interest rate contracts | Derivatives accounted for as hedges: | Cash flow hedges
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) recognized in Accumulated Other Comprehensive Loss	0		0
Amount of Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into income (effective portion)	0	[1]	0	[1]
Foreign exchange contracts | Derivatives accounted for as hedges:
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into income (effective portion)	0		0
Foreign exchange contracts | Derivatives accounted for as hedges: | Cash flow hedges
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) recognized in Accumulated Other Comprehensive Loss	(29)		2
Amount of Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into income (effective portion)	(11)	[2]	(8)	[2]
Foreign exchange contracts | Derivatives accounted for as hedges: | Net Investment Hedges
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) recognized in Accumulated Other Comprehensive Loss	0		(10)
Foreign exchange contracts | Derivatives accounted for as hedges: | Fair value hedges
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) Recognized in Income on Derivative	(1)	[3],[4]	2	[3],[4]
Amount of Gain (Loss) Recognized in Income on Related Hedged Item	1	[4]	(2)	[4]
Foreign exchange contracts | Derivatives not accounted for as hedges:
Derivative Instruments, Gain (Loss)
Amount of Gain (Loss) Recognized in Income on Derivative	$ 9		$ (5)

[1] Included within Other current assets or Other non-current assets

[2] Included within Other income and Interest expense

[3] Relates to fixed rate debt

[4] Included in Interest expense