Note 9 - Income Taxes (Details Textual) - USD ($) Pure in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (121,000)
Deferred Tax Assets, Valuation Allowance	7,900,000
Operating Loss Carryforwards	37,200,000
Income Taxes Paid, Net, Total	0	$ 0
Deferred Tax Assets, Net of Valuation Allowance, Total	$ 0
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%