Note 5 - Operating Lease Right-of-use Asset, Net - Impact of New Lease Standard (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Straight-line rent expense recognized for operating lease	$ 623	$ 601
Variable rent expense recognized for operating lease	322	395
Total rent expense	$ 945	$ 996
Weighted average remaining lease term (in years) (Year)	5 years 1 month 6 days	1 year
Weighted average discount rate	10.74%	12.05%