Note 11 - Net Loss Per Share - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Number of potential common shares excluded (in shares)	36,423	33,531
Share-Based Payment Arrangement, Option [Member]
Number of potential common shares excluded (in shares)	14,743	11,089
Series B Convertible Preferred Stock [Member]
Number of potential common shares excluded (in shares)	165	165
Warrant [Member]
Number of potential common shares excluded (in shares)	21,515	22,277