Note 9 - Revenue and Revenue Recognition (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2023	Nov. 30, 2022	Nov. 30, 2023	Nov. 30, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 15,597,036	$ 12,101,674	$ 33,010,707	$ 31,055,273
Non-US [Member]
Revenue from Contract with Customer, Excluding Assessed Tax			$ 228,051	$ 292,025