Note 6 - Operating Lease Right-of-use Asset, Net - Impact of New Lease Standard (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Straight-line rent expense recognized for operating lease	$ 601	$ 601
Variable rent expense recognized for operating lease	395	264
Total rent expense	$ 996	$ 865
Weighted average remaining lease term (in years) (Year)	1 year	2 years
Weighted average discount rate	12.05%	12.05%