Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net earnings	$ 25,013	$ 21,568	$ 71,155	$ 62,461
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	(3,362)	4,313	(7,981)	7,440
Unrealized gain (loss) on cash flow hedge	341	227	1,204	(2,659)
Change in postretirement benefit plans	11	137	26	(434)
Other comprehensive (loss) income	(3,010)	4,677	(6,751)	4,347
Comprehensive income	$ 22,003	$ 26,245	$ 64,404	$ 66,808