CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - 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 income	$ 25,129	$ 7,006	$ 85,002	$ 34,785
Foreign currency translation adjustment	(8,126)	11,269	(18,627)	10,004
Pension and other postretirement benefits:
Pension settlement benefits, net of tax	0	0	0	(48)
Actuarial net gain incurred, net of tax	0	3	0	629
Amortization of loss, net of tax	52	66	173	199
Derivative instrument designated as cash flow hedge:
Change in unrealized gain (loss) before reclassifications, net of tax	0	(638)	0	(1,504)
Unrealized gain reclassified into earnings, net of tax	0	2,810	0	2,476
Other comprehensive income (loss)	(8,074)	13,510	(18,454)	11,756
Comprehensive income	$ 17,055	$ 20,516	$ 66,548	$ 46,541