Stockholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018
Shareholders Equity [Line Items]
Beginning Balance	$ 991,457	$ 1,002,593	$ 936,890	$ 792,954	$ 723,359	$ 689,524
Ending Balance	1,046,863	991,457	1,002,593	851,530	792,954	723,359
Foreign Currency Items
Shareholders Equity [Line Items]
Beginning Balance	(18,410)	(12,694)	(15,028)	(11,049)	(10,449)	(3,597)
Other comprehensive income (loss)	1,945	(5,716)	2,334	(1,015)	(600)	(6,852)
Ending Balance	(16,465)	(18,410)	(12,694)	(12,064)	(11,049)	(10,449)
Unrealized Gains and Losses on investments
Shareholders Equity [Line Items]
Beginning Balance	854	939	339	(486)	(464)	(607)
Other comprehensive income (loss)	8	(85)	600	234	(22)	143
Ending Balance	862	854	939	(252)	(486)	(464)
Gains and Losses on Cash Flow Hedges
Shareholders Equity [Line Items]
Other comprehensive income (loss)	(1,392)
Ending Balance	(1,392)
Accumulated Other Comprehensive Loss
Shareholders Equity [Line Items]
Beginning Balance	(17,556)	(11,755)	(14,689)	(11,535)	(10,913)	(4,204)
Other comprehensive income (loss)	561	(5,801)	2,934	(781)	(622)	(6,709)
Ending Balance	$ (16,995)	$ (17,556)	$ (11,755)	$ (12,316)	$ (11,535)	$ (10,913)