Note 5 - Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Right-of-use lease assets	$ 1,522	$ 1,598	$ 1,773
Current portion of operating lease liability	358	357	344
Operating lease liability, net of current portion	1,286	$ 1,363	1,552
Total operating lease liabilities	$ 1,644		$ 1,896
Weighted average remaining lease term (years) (Year)	4 years 10 months 24 days		5 years 10 months 24 days
Weighted average discount rate	8.50%		8.50%