Note 6 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets, Valuation Allowance, Total	$ 937	$ 2,879
Unrecognized Tax Benefits, Ending Balance	$ 3,633	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 937