Note 9 - Revenue and Revenue Recognition (Details Textual) - USD ($)	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 17,413,671	$ 18,953,599
Non-US [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 137,000	$ 125,000