CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Other Comprehensive Income [Abstract]
Net income	$ 77,916	$ 55,789	$ 27,721
Other comprehensive income (loss), net of tax:
Foreign currency translation	1	(2)	(71)
Change in fair value of marketable securities	197	(11)	65
Adjustment for net losses realized and included in net income			11
Total change in unrealized gains (losses) on investment securities	197	(11)	76
Other comprehensive income (loss)	198	(13)	5
Comprehensive income	$ 78,114	$ 55,776	$ 27,726