Changes in Accumulated Other Comprehensive Income by Component (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ 141		$ 119
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(55)		20
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	0		0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(55)	20	20
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	86	141	139
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(78)		88
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0		0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	(2)		(1)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax	2	1	1
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(76)	(78)	87
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	3		(1)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	3		2
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	1		0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax	2	2	2
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	5	3	1
Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	3
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	11
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	11
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	14	3
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax	69		30
Total Other Comprehensive Income Before Reclasification	(41)		22
Total Amount Reclassfied from Accumulated Other Comprehensive Income	(1)		(1)
Net Current-Period Other Comprehensive Income	(40)		23
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 29	$ 69	$ 53