UNAUDITED 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 Comprehensive Income [Abstract]
Net income	$ 36,369	$ 31,089	$ 73,589	$ 49,205
Other comprehensive (loss) income:
Unrealized gains (losses) on available-for-sale securities (net of tax of $2, $7, $60 and $95, respectively)	9	(932)	(84)	(1,138)
Reclassification adjustment for losses on available-for-sale securities included in net income	0	0	332	0
Unrealized loss on interest rate hedge	(3,865)	(310)	(17,896)	(310)
Reclassification adjustment for losses on interest rate hedge included in net income	614	0	1,369	0
Foreign currency translation adjustments (including a tax benefit of $5.6 million in the nine months ended September 30, 2018)	(6,177)	9,832	15,960	(11,650)
Other comprehensive (loss) income	(9,419)	8,590	(319)	(13,098)
Comprehensive income	$ 26,950	$ 39,679	$ 73,270	$ 36,107