Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 158,440	$ 146,509	$ 148,551
Other comprehensive (loss) income:
Net foreign currency translation adjustment	4,531	4,262	(3,936)
Actuarial loss on pension plans	(207)	0	0
Derivative instrument adjustment	1,642	(534)	(1,108)
Total comprehensive income	$ 164,406	$ 150,237	$ 143,507