Income Taxes (Details) - The income tax effects of temporary differences that comprise deferred tax assets and liabilities - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Noncurrent deferred tax assets (liabilities):
Accounts receivable	$ 99	$ 150
Other accrued expenses	587	248
Property, plant and equipment	(1,190)	(1,255)
Employee benefits	3,979	4,252
Contribution carryforward	181	278
AMT credit	1,205	676
Net operating loss	7,727	14,845
Gross non-current deferred tax assets	12,588	19,194
Less valuation allowance	(12,588)	(19,194)
Net noncurrent deferred tax assets