Financial Instruments - Summary of Derivative Instruments Fair Value (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current assets	$ 27	$ 6
Other current liabilities	(58)	(70)
Derivative Assets (Liabilities), at Fair Value, Net	(31)	(64)
Derivatives Designated as Hedging Instruments [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(25)
Foreign exchange contracts - forwards [Member] | Derivatives Designated as Hedging Instruments [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(30)	(50)
Foreign exchange contracts - forwards [Member] | Derivatives Designated as Hedging Instruments [Member] | Other current assets [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current assets	7	1
Foreign exchange contracts - forwards [Member] | Derivatives Designated as Hedging Instruments [Member] | Other current liabilities [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current liabilities	(39)	(51)
Foreign exchange contracts - forwards [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(6)	(14)
Foreign exchange contracts - forwards [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Other current assets [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current assets	13	5
Foreign exchange contracts - forwards [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Other current liabilities [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current liabilities	(19)	(19)
Currency Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Other current assets [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current assets	2	0
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Other Noncurrent Assets [Member]
Summary Of Derivative Instruments By Hedge Designation [Abstract]
Other current assets	$ 5	$ 0