CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 134,837	$ 97,740	$ 65,636
Other comprehensive (loss) income, net of tax:
Unrealized (losses) gains on available-for-sale securities	(8)	(120)	77
Reclassification adjustment for losses on available-for-sale securities included in net income	0	332	0
Unrealized loss on interest rate hedge	(20,970)	(14,401)	(9,579)
Reclassification adjustment for losses on interest rate hedge included in net income	8,180	2,335	806
Foreign currency translation adjustments	11,561	25,130	(42,350)
Unrealized (loss) gain on net pension liability	(189)	44	82
Other comprehensive (loss) income, net of tax	(1,426)	13,320	(50,964)
Comprehensive income	$ 133,411	$ 111,060	$ 14,672