Derivative Financial Instruments - Derivative Instruments Gain (Loss) Recognized in Income (Detail) (Derivatives not designated as hedging instruments [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 Gain or (Loss) Recognized in Income on Derivative	$ 5	$ 2	$ 11	$ 1
Foreign forward exchange contracts [Member] | Interest expense, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	$ 5	$ 2	$ 11	$ 1