Note 8 - Deferred Revenue (Details Textual) - USD ($)	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	May 31, 2023
Revenue from Contract with Customer, Excluding Assessed Tax	$ 17,413,671	$ 18,953,599
Revenue, Remaining Performance Obligation, Amount	23,007		$ 23,007
Pallets [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 5,015,520