Note 11 - Net Loss Per Share - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Number of potential common shares excluded (in shares)	35,431	32,566	34,832	33,630
Share-Based Payment Arrangement, Option [Member]
Number of potential common shares excluded (in shares)	13,751	10,044	12,736	8,683
Series B Convertible Preferred Stock [Member]
Number of potential common shares excluded (in shares)	165	166	165	173
Warrant [Member]
Number of potential common shares excluded (in shares)	21,515	22,356	21,931	24,774