Income Taxes Components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforward	$ 12,120	$ 17,518
Compensation and benefits	7,828	12,126
Inventory reserve	1,689	2,750
Capital Loss Carryforward	1,326	2,210
Accounts receivable reserve	130	183
Other	1,155	1,770
Total deferred tax assets	24,248	36,557
Deferred Tax Liabilities, Intangible Assets	3,115	0
Deferred tax liabilities:
Property, plant and equipment	41	433
Other	403	688
Total deferred liabilities	3,559	1,121
Net deferred assets before valuation allowance	20,689	35,436
Valuation allowance	(2,556)	(35,416)
Net deferred assets	$ 18,133	$ 20