Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 5,000	$ 8,100
Operating Loss Carryforwards	2,400
Unrecognized Tax Benefits, Ending Balance	165	$ 164	$ 164
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 300