Accumulated Other Comprehensive Loss - Components of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 263,477
Other comprehensive income (loss)			(338)
Income taxes			1,223
Other expense, net	$ 585	$ 147	(3,763)	$ 1,980
Income taxes	3,924	$ 3,685	7,848	$ 7,979
Ending Balance	276,947		276,947
Reclassification Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other expense, net			5,585
Income taxes			(2,123)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(5,115)
Other comprehensive income (loss)			2,882
Ending Balance	(2,233)		(2,233)
Debt Security [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(1,465)
Other comprehensive income (loss)			(3,220)
Income taxes			1,223
Debt Security [Member] | Reclassification Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other expense, net			5,585
Income taxes			(2,123)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(6,580)
Ending Balance	$ (2,233)		$ (2,233)