Note 1 - Basis of Presentation and Summary of Significant Accounting Policies (Details Textual) - shares	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants (in shares)	77,819,141	36,687,326
Restricted Stock Units (RSUs) [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements (in shares)	21,202,933	16,989,328
Share-Based Payment Arrangement, Option [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements (in shares)	6,325,348	4,741,653
Warrants [Member]
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants (in shares)	7,847,219	6,209,000