Note 11 - Net Loss Per Share - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of potential common shares excluded (in shares)	34,981	33,351
Share-Based Payment Arrangement, Option [Member]
Number of potential common shares excluded (in shares)	12,990	9,036
Series B Convertible Preferred Stock [Member]
Number of potential common shares excluded (in shares)	165	171
Warrant [Member]
Number of potential common shares excluded (in shares)	21,826	24,144