Derivative Financial Instruments - Notional Amounts of Company's Outstanding Foreign Currency Forward Contracts by Currency (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Derivative [Line Items]
Notional amount of foreign currency forward contracts	$ 221
U.S. dollar [Member]
Derivative [Line Items]
Notional amount of foreign currency forward contracts	116
Euro [Member]
Derivative [Line Items]
Notional amount of foreign currency forward contracts	59
Canadian dollar [Member]
Derivative [Line Items]
Notional amount of foreign currency forward contracts	24
British pound [Member]
Derivative [Line Items]
Notional amount of foreign currency forward contracts	$ 22