CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - UNAUDITED - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 16,130	$ 13,566	$ 55,082	$ 45,446
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(6,492)	7,667	(4,635)	(4,746)
Unrealized holding gains (losses) on short-term investments arising during period	3	(14)	(10)	14
Other comprehensive income (loss), net of tax	(6,489)	7,653	(4,645)	(4,732)
Total comprehensive income, net of tax	$ 9,641	$ 21,219	$ 50,437	$ 40,714