Note 3 - Net Income (Loss) Per Common Share - Basic and Diluted Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net loss	$ (2,698)	$ (1,885)
Preferred dividends and preferred stock discount accretion	(1,797)	(2,255)
Net loss available to common shareholders	$ (4,495)	$ (4,140)
Denominator for basic loss per share – weighted-average shares outstanding (in shares)	347,275,242	245,829,914
Basic and diluted loss per share available to common shareholders (in dollars per share)	$ (0.01)	$ (0.02)