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 Income And Comprehensive Income [Abstract]
Net loss	$ (8,109)	$ (8,505)	$ (7,397)	$ (12,698)
Other comprehensive income (loss), net of tax:
Foreign currency translation (net of tax effect of $0 for all periods)	(4,350)	4,572	(5,685)	(446)
Retirement related benefit plans (net of tax effect of $0 for all periods)	117	(58)	344	110
Total other comprehensive income (loss)	(4,233)	4,514	(5,341)	(336)
Comprehensive loss	$ (12,342)	$ (3,991)	$ (12,738)	$ (13,034)