Note 12 - Net Loss Per Share - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Number of potential common shares excluded (in shares)	42,273	35,431	39,423	34,832
Share-Based Payment Arrangement, Option [Member]
Number of potential common shares excluded (in shares)	20,593	13,751	17,743	12,736
Series B Convertible Preferred Stock [Member]
Number of potential common shares excluded (in shares)	165	165	165	165
Warrant [Member]
Number of potential common shares excluded (in shares)	21,515	21,515	21,515	21,931