CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 58,711	$ 82,770	$ 66,130
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	8,368	3,418	(14,203)
Unrealized holding gains (losses) on short-term investments arising during period	(3)	14	90
Other comprehensive income (loss), net of tax	8,365	3,432	(14,113)
Total comprehensive income, net of tax	$ 67,076	$ 86,202	$ 52,017