Financial Instruments - Impact of Changes in Fair Values of Derivatives (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recorded Net Income (Loss)	$ (8)	$ 1	$ (6)	$ (14)
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recognized in Other Comprehensive Income (Loss)	5		4
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Caps [Member] | Interest Expense, Net [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Amount of Gain (Loss) Recorded Net Income (Loss)
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) Recorded Net Income (Loss)	(8)	(2)	(8)	(3)
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) Recorded Net Income (Loss)		$ 3	$ 2	$ (11)