Note 11 - Income Taxes (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 1.7	$ 2.1
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards, Total	7.8
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 11.1