Change in Fair Value of Forward Contracts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss from the change in the fair value of forward contracts included in other expense, net	$ (5,643)	$ (1,047)	$ (532)
Foreign currency transaction gains (losses) from the remeasurement of foreign currency assets and liabilities	$ 2,247	$ (4,168)	$ (3,769)