Deferred Revenue (Details Narrative) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019	May 31, 2020
Revenue	$ 15,523,318	$ 19,503,462	$ 33,091,494	$ 38,167,971
Customer advances			1,380,000	0
Deferred revenue	$ 1,403,007		1,403,007		$ 3,793,167
Pallets [Member]
Revenue			$ 3,770,160	$ 686,572