Fair Value Measurements - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) (Interest Rate Swap, Derivatives Designated as Hedging Instruments, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Interest Rate Swap | Derivatives Designated as Hedging Instruments
Derivatives Fair Value [Line Items]
Other Non-Current Assets	$ 1
Accounts Payable and Other Current Liabilities	4	2
Other Non-Current Liabilities	$ 2	$ 8