Income Taxes - Deferred tax assets (liabilities) (Details 2) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Inventories	$ 665	$ 493
Accrued employees compensation and benefits costs	612	508
Accrued arbitration award and related liability	160	1,903
Net operating loss and credit carryforwards	388	287
Other	52	45
Minimum pension liability	2	7
Total deferred tax assets	1,879	3,243
Valuation allowance	(397)	(295)
Net deferred tax asset	1,482	2,948
Deferred tax liabilities:
Property, plant and equipment	(972)	(691)
Total deferred tax liabilities	(972)	(691)
Net deferred tax asset	$ 510	$ 2,257