Income Taxes - Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Reserve for receivables and inventories	$ 2,931	$ 2,979
Accrued compensation	1,131	1,180
Payables	1,107	1,237
Non-pension postretirement benefits	2,344	2,337
Net operating loss and credit carryforwards	968	1,193
Accrued pension benefits	413	1,398
Accrued employee benefits	4,103	3,969
Other	487	856
Total deferred tax assets	13,484	15,149
Depreciation	5,126	4,652
Amortization	8,992	9,850
Prepaids	567	0
Total deferred tax liabilities	14,685	14,502
Net deferred tax (liabilities)	$ (1,201)
Net deferred tax assets		$ 647