CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 82,770	$ 66,130	$ 61,364
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	3,418	(14,203)	16,479
Unrealized holding gains on short-term investments arising during period	14	90	71
Other comprehensive income (loss), net of tax	3,432	(14,113)	16,550
Total comprehensive income, net of tax	$ 86,202	$ 52,017	$ 77,914