Note 2 - Summary of Significant Accounting Policies - Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Net loss applicable to common stockholders	$ (27,244)	$ (21,587)
Weighted average common stock outstanding, basic and diluted (in shares)	6,249	4,722
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (4.36)	$ (4.57)