Note 2 - Liquidity and Capital Resources (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Net Income (Loss) Attributable to Parent, Total	$ (26,960)	$ (20,606)
Net Cash Provided by (Used in) Operating Activities, Total	(20,760)	(16,472)
Cash and Cash Equivalents, at Carrying Value, Total	110,890	$ 136,377
Working Capital (Deficit)	$ 112,629