Financial Instruments - Summary of Fair Value of Company's Derivative Contracts (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Fair Value Asset	$ 16	$ 15
Derivative liabilities, Fair Value	(1)	(4)
Derivatives designated as hedging instruments [Member] | Interest rate caps [Member] | Other non-current liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Fair Value
Derivatives designated as hedging instruments [Member] | Interest rate caps [Member] | Other non-current assets [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset	10
Derivatives not designated as hedging instruments [Member] | Interest rate swaps [Member] | Accrued expenses and other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Fair Value		(3)
Derivatives not designated as hedging instruments [Member] | Interest rate swaps [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset
Derivatives not designated as hedging instruments [Member] | Foreign currency contracts [Member] | Other non-current liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Fair Value
Derivatives not designated as hedging instruments [Member] | Foreign currency contracts [Member] | Accrued expenses and other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities, Fair Value	(1)	(1)
Derivatives not designated as hedging instruments [Member] | Foreign currency contracts [Member] | Other non-current assets [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset		5
Derivatives not designated as hedging instruments [Member] | Foreign currency contracts [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Fair Value Asset	$ 6	$ 10