CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Other Comprehensive Income [Abstract]
Net income	$ 15,902	$ 13,781	$ 58,035	$ 40,136
Other comprehensive income (loss), net of tax:
Foreign currency translation	(2)	(2)	(1)	(2)
Unrealized gains (losses) on marketable securities	18	(45)	246	(104)
Other comprehensive income (loss)	16	(47)	245	(106)
Comprehensive income	$ 15,918	$ 13,734	$ 58,280	$ 40,030

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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