Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net earnings	$ 22,731	$ 21,125	$ 46,142	$ 40,893
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	1,524	2,346	(4,619)	3,127
Unrealized gain (loss) on cash flow hedge	351	221	863	(2,886)
Change in postretirement benefit plans	8	8	15	(571)
Other comprehensive income (loss)	1,883	2,575	(3,741)	(330)
Comprehensive income	$ 24,614	$ 23,700	$ 42,401	$ 40,563