CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net loss	$ (29,271)	$ (5,924)	$ (21,035)
Other comprehensive income (loss):
Adjustment to pension benefit plan	(159)	(206)	202
Translation gain (loss)	8,279	(1,437)	(4,433)
Loss reclassified into earnings	0	56	11
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Total	8,279	(1,381)	(4,422)
Other comprehensive income (loss) before tax	8,120	(1,587)	(4,220)
Provision for (benefit from) income taxes	(801)	262	378
Other comprehensive income (loss), net of tax	8,921	(1,849)	(4,598)
Total comprehensive loss	$ (20,350)	$ (7,773)	$ (25,633)