Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Deferred Tax Assets, State Taxes	$ 633	$ 1,229
Deferred Tax Assets, Reserves and Accruals	1,893	2,407
Deferred Tax Assets, Intangible Assets	207	359
Deferred Tax Assets, Tax Deferred Expense, Share-based Compensation	1,585	2,118
Deferred Tax Assets, Inventory	627	1,150
Deferred Tax Assets, Investments in JVs	1,411	1,290
Deferred Tax Liabilities, Depreciation	(39)	(119)
Deferred tax asset	$ 6,317	$ 8,434