Note 9 - Commitments and Contingencies (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating Lease, Payments	$ 2,000	$ 29,000	$ 11,000	$ 60,000
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	$ 26,000	$ 24,000	$ 53,000	$ 40,000