Financial Instruments - Effect on Derivative Instruments on Consolidated Financial Performance (Detail) (Foreign Currency Forward Contracts [Member], Foreign Currency (Loss) Gain [Member], Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Foreign Currency Forward Contracts [Member] | Foreign Currency (Loss) Gain [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Gain Recognized in Earnings	$ (4,964)	$ 15,186	$ (4,000)	$ 9,533