Accumulated Other Comprehensive Loss - Components of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 290,311
Unrealized gain on derivative instruments, net of tax	$ 50	$ 271	76	$ 936
Unrealized loss on debt securities, net of tax	(1,942)		(2,469)
Foreign currency translation adjustment			651
Ending Balance	258,231		258,231
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(4,389)
Foreign currency translation adjustment			651
Ending Balance	(3,738)		(3,738)
Change in Fair Value of Derivatives [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			228
Unrealized gain on derivative instruments, net of tax			76
Ending Balance	304		304
Change in Fair Value of Debt Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(2,071)
Unrealized loss on debt securities, net of tax			(2,469)
Ending Balance	(4,540)		(4,540)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(6,232)
Ending Balance	$ (7,974)		$ (7,974)