CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - UNAUDITED - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 21,559	$ 16,101	$ 60,189	$ 45,232
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(6,897)	(109)	(6,868)	(8,630)
Unrealized holding gains (losses) on short-term investments arising during period	(4)	107	24	81
Other comprehensive loss, net of tax	(6,901)	(2)	(6,844)	(8,549)
Total comprehensive income, net of tax	$ 14,658	$ 16,099	$ 53,345	$ 36,683

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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