Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Current Income Tax Expense (Benefit), Total	$ 0	$ 0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	6,300
Operating Loss Carryforwards, Total	$ 51,300	$ 32,100