Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income	$ 75,629	$ 64,566	$ 65,091
Other comprehensive income (loss):
Foreign currency translation adjustment	2,512	3,301	1,766
Adjustment to post-retirement benefit liability, net of tax	136	(371)	77
Other comprehensive income	2,648	2,930	1,843
Total comprehensive income	$ 78,277	$ 67,496	$ 66,934