Note 5 - Operating Lease Right-of-use Asset, Net (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating Lease, Expense	$ 120,000	$ 150,000	$ 241,000	$ 301,000
Operating Lease, Payments	$ 76,000	$ 162,000	$ 173,000	$ 324,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	4 years 7 months 2 days		4 years 7 months 2 days
Operating Lease, Weighted Average Discount Rate, Percent	10.74%		10.74%