Note 9 - Commitments and Contingencies (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Lease, Payments	$ 9,000	$ 31,000
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	90.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 27,000	$ 16,000