Note 7 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Lease, Weighted Average Remaining Lease Term (Year)	2 years 1 month 6 days	3 years
Operating Lease, Weighted Average Discount Rate, Percent	6.25%	6.25%
Operating Lease, Expense	$ 1.2	$ 1.7