Note 13 - Income Taxes - Components of the Net Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued compensation	$ 148	$ 84
Inventory adjustments	297	276
Depreciation and amortization	98	113
Stock-based compensation	744	648
Net operating loss and tax credit carryforwards	23,809	20,698
Other	11	12
Gross Deferred Tax Asset	25,107	21,831
Valuation Allowance	(25,107)	(21,831)
Net deferred tax asset