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	$ 1,910	$ 45,096	$ 32,909
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on investments	(44)	136	(89)
Change in currency translation adjustments	709	(194)	1,663
Total comprehensive income	$ 2,575	$ 45,038	$ 34,483