Financial Instruments - Impact of Changes in Fair Value of Derivatives (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recognized into Income (Loss)	$ 1	$ (27)	$ (14)	$ (12)
Derivatives not designated as hedging instruments [Member] | Interest rate swaps [Member] | Interest expense, net [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recognized into Income (Loss)	(2)	(2)	(3)	(1)
Derivatives not designated as hedging instruments [Member] | Foreign currency contracts [Member] | Selling, general and administrative [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recognized into Income (Loss)	$ 3	$ (25)	$ (11)	$ (11)