Note 2 - Liquidity and Summary of Significant Accounting Principles - Anti-dilutive Securities Excluded From the Computation of Diluted Earnings (Loss) Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Anti-dilutive securities (in shares)	4,626,667	3,545,000
Share-Based Payment Arrangement, Option [Member]
Anti-dilutive securities (in shares)	3,376,667	3,311,667
Warrant [Member]
Anti-dilutive securities (in shares)	450,000	233,333
Contingent Warrants Upon Future Financing Events [Member]
Anti-dilutive securities (in shares)	500,000	0
Performance Shares [Member]
Anti-dilutive securities (in shares)	300,000	0