Income Taxes - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Reserve for receivables and inventory	$ 2,532	$ 2,618
Accrued compensation	2,641	1,874
Reserves and payables	3,101	2,741
Accrued post-retirement medical benefits	1,381	1,535
Net operating loss and credit carryforwards	2,260	2,106
Deferred compensation	1,041	829
Accrued qualified plan benefits	1,034	511
Accrued stock-based compensation	1,212	1,216
Deferred revenue	2,530	2,596
Operating lease liabilities	959	1,708
Other	967	713
Total gross deferred tax assets	19,658	18,447
Less: valuation allowance	(2,169)	(2,140)
Total net deferred tax assets	17,489	16,307
Deferred tax liabilities:
Property, plant and equipment	5,056	5,204
Intangible assets	8,475	8,795
Prepaids	413	552
Operating lease assets	949	1,699
Other	452	663
Total deferred tax liabilities	15,345	16,913
Net deferred tax assets (liabilities)	$ 2,144
Net deferred tax assets (liabilities)		$ (606)