Note 6 - Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Lease, Right-of-Use Asset	$ 1,660	$ 1,853
Current portion of operating lease liability	354	344
Operating lease liability, net of current portion	1,430	$ 1,630
Total operating lease liabilities	$ 1,784
Weighted average remaining lease term (years) (Year)	5 years 4 months 24 days
Weighted average discount rate	8.50%