Income Taxes - Components of Deferred Tax Asset and Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Accounts receivable	$ 172	$ 132
Inventories	520	164
Net operating loss carryforwards	6,095	5,339
Other accrued liabilities	3,426	1,053
Pension	5,181	1,482
Tax Credits	1,846	1,735
Total deferred tax assets	17,240	9,905
Deferred tax liabilities:
Intangible assets	25,133	2,073
Property, plant and equipment	23,353	15,691
Total deferred tax liabilities	48,486	17,764
Valuation allowance	5,964	5,709
Net deferred tax liabilities	$ (37,210)	$ (13,568)