Note 1 - Organization and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Potentially dilutive securities excluded from calculation (in shares)	13,169,240	12,650,658	13,280,608
Unvested Restricted Stock [Member]
Potentially dilutive securities excluded from calculation (in shares)	8,139,037	7,232,254	10,532,029
Share-Based Payment Arrangement, Option [Member]
Potentially dilutive securities excluded from calculation (in shares)	4,697,029	5,135,685	2,467,537
Warrant [Member]
Potentially dilutive securities excluded from calculation (in shares)	312,272	262,100	262,100
Convertible Debt Securities [Member]
Potentially dilutive securities excluded from calculation (in shares)	20,902	20,619	18,942