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	$ 56,630	$ 62,906	$ 73,486
Other comprehensive income (loss):
Foreign currency translation adjustment	8,862	3,363	(13,347)
Unrealized (loss) gains on derivative instruments	(9,326)	610	0
Net loss on pension and other post-retirement benefits	(1,096)	(683)	(1,667)
Other comprehensive (loss) income before income tax (expense) benefit	(1,560)	3,290	(15,014)
Income tax benefit related to items of other comprehensive income (loss)	2,072	703	349
Other comprehensive income (loss)	512	3,993	(14,665)
Comprehensive income	$ 57,142	$ 66,899	$ 58,821