CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - 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 (loss)	$ 7,511	$ 4,178	$ 21,096	$ (32,913)
Other comprehensive income (loss):
Foreign currency exchange translation adjustments	(1,225)	2,628	(1,809)	(257)
Minimum pension liability, net of tax	1,421	(957)	2,094	(1,850)
Derivative instrument, net of tax	(549)	893	(1,052)	(781)
Other comprehensive income (loss)	(353)	2,564	(767)	(2,888)
Comprehensive income (loss)	$ 7,158	$ 6,742	$ 20,329	$ (35,801)