Schedule of Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Components Of Other Comprehensive Income Loss [Line Items]
Foreign currency translation adjustment	$ 9,385	$ (3,453)	$ 17,310	$ 11,433
Unrealized (loss) gain on cash flow hedging instruments	(1,280)	536	(1,399)	(2,033)
Income tax benefit (expense)	346	(145)	378	549
Unrealized (loss) gain on cash flow hedging instruments, net of tax	(934)	391	(1,021)	(1,484)
Reclassification of loss (gain) on cash flow hedging instruments into earnings	88	129	(1,092)	674
Income tax (benefit) expense	(24)	(35)	295	(182)
Reclassification of loss (gain) on cash flow hedging instruments into earnings, net of tax	64	94	(797)	492
Unrealized gain on available-for-sale securities	20	19	25	4
Income tax expense	(7)	(7)	(9)	(1)
Unrealized gain on available-for-sale securities, net of tax	13	12	16	3
Other comprehensive income (loss)	$ 8,528	$ (2,956)	$ 15,508	$ 10,444

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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