Change in Fair Value of Forward Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss from the change in the fair value of forward contracts included in other expense, net	$ (279)	$ (2,297)
Foreign currency transaction gain from the remeasurement of foreign currency assets and liabilities	676	1,376
Net gain (loss)	$ 397	$ (921)