Accumulated Other Comprehensive Income (Loss) - Components of and Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI, tax	$ (1)	$ 1,000
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	361,259	331,068
Other comprehensive (loss) before reclassifications	(714)	(627)
Amounts reclassified from accumulated other comprehensive income, net of tax	3	1
Net current period other comprehensive income (loss), net of tax	(711)	(626)
Balance at end of period	369,849	335,721
Unrecognized pension and postretirement benefits
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	55	263
Other comprehensive (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income, net of tax	3	1
Net current period other comprehensive income (loss), net of tax	3	1
Balance at end of period	58	264
Foreign currency
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	1,258	162
Other comprehensive (loss) before reclassifications	(714)	(627)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Net current period other comprehensive income (loss), net of tax	(714)	(627)
Balance at end of period	544	(465)
Accumulated other comprehensive income (loss)
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	1,313	425
Other comprehensive (loss) before reclassifications	(714)
Net current period other comprehensive income (loss), net of tax		(626)
Balance at end of period	$ 602	$ (201)