Note 2 - Liquidity and Summary of Significant Accounting Principles - Anti-dilutive Securities Excluded From the Computation of Diluted Earnings (Loss) Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Anti-dilutive securities (in shares)	4,626,667	2,770,000
Share-Based Payment Arrangement, Option [Member]
Anti-dilutive securities (in shares)	3,376,667	2,536,667
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