Note 5 - Operating Lease Right-of-use Asset, Net - Impact of New Lease Standard (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Straight-line rent expense recognized for operating lease	$ 482	$ 623
Variable rent expense recognized for operating lease	62	322
Total rent expense	$ 544	$ 945
Weighted average remaining lease term (in years) (Year)	4 years 1 month 6 days	5 years 1 month 6 days
Weighted average discount rate	10.74%	10.74%