Stockholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019
Shareholders Equity [Line Items]
Beginning Balance	$ 1,182,409	$ 1,101,848	$ 1,065,466	$ 991,457	$ 1,002,593	$ 936,890
Ending Balance	1,261,441	1,182,409	1,101,848	1,046,863	991,457	1,002,593
Foreign Currency Translation Gains (Losses)
Shareholders Equity [Line Items]
Beginning Balance	(13,084)	(15,500)	(16,860)	(18,410)	(12,694)	(15,028)
Other comprehensive income (loss)	4,823	2,416	1,360	1,945	(5,716)	2,334
Ending Balance	(8,261)	(13,084)	(15,500)	(16,465)	(18,410)	(12,694)
Unrealized Gains on Investments
Shareholders Equity [Line Items]
Beginning Balance	2,613	3,427	1,672	854	939	339
Other comprehensive income (loss)	(525)	(814)	1,755	8	(85)	600
Ending Balance	2,088	2,613	3,427	862	854	939
Gains (Losses) on Derivative Instruments
Shareholders Equity [Line Items]
Beginning Balance	3,272	3,538	3,999
Other comprehensive income (loss)	(1,268)	(266)	(461)	(1,392)
Ending Balance	2,004	3,272	3,538	(1,392)
Accumulated Other Comprehensive Loss
Shareholders Equity [Line Items]
Beginning Balance	(7,199)	(8,535)	(11,189)	(17,556)	(11,755)	(14,689)
Other comprehensive income (loss)	3,030	1,336	2,654	561	(5,801)	2,934
Ending Balance	$ (4,169)	$ (7,199)	$ (8,535)	$ (16,995)	$ (17,556)	$ (11,755)