Accumulated Other Comprehensive Income (Loss) - Components of and Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI, tax	$ (2)	$ 1,000
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	361,259	331,068
Amounts reclassified from accumulated other comprehensive income, net of tax	5	2
Balance at end of period	381,847	341,143
Other comprehensive income before reclassifications	2,093	(182)
Net current period other comprehensive income, net of tax	2,098	(180)
Other comprehensive income before reclassifications	2,093	(182)
Net current period other comprehensive income, net of tax	2,098	(180)
Balance at end of period	381,847	341,143	$ 369,849	$ 335,721
Unrecognized pension and postretirement benefits
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	55	263
Amounts reclassified from accumulated other comprehensive income, net of tax	5	2
Balance at end of period	60	265
Other comprehensive income before reclassifications	0	0
Net current period other comprehensive income, net of tax	5	2
Other comprehensive income before reclassifications	0	0
Net current period other comprehensive income, net of tax	5	2
Balance at end of period	60	265
Foreign currency
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	1,258	162
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Balance at end of period	3,351	(20)
Other comprehensive income before reclassifications	2,093	(182)
Net current period other comprehensive income, net of tax	2,093	(182)
Other comprehensive income before reclassifications	2,093	(182)
Net current period other comprehensive income, net of tax	2,093	(182)
Balance at end of period	3,351	(20)
Accumulated other comprehensive income (loss)
Increase (Decrease) in Stockholders' Equity
Balance at beginning of period	1,313	425
Balance at end of period	3,411	245
Other comprehensive income before reclassifications	2,093
Net current period other comprehensive income, net of tax		(180)
Other comprehensive income before reclassifications	2,093
Net current period other comprehensive income, net of tax		(180)
Balance at end of period	$ 3,411	$ 245	$ 602	$ (201)