Leases (Details Narrative) - USD ($)	3 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	May 31, 2019
Lessee, Lease, Description [Line Items]
Production equipment gross carrying amount	$ 7,861,233		$ 7,861,233
Amortization	$ 208,157	$ 208,245
Equipment One [Member]
Lessee, Lease, Description [Line Items]
Operating Lease term	52 months
Operating lease discount rate	5.40%
Equipment Two [Member]
Lessee, Lease, Description [Line Items]
Operating Lease term	48 months
Operating lease discount rate	5.40%
Office Space [Member]
Lessee, Lease, Description [Line Items]
Operating Lease term	60 months
Operating lease discount rate	5.00%
Production Equipment [Member]
Lessee, Lease, Description [Line Items]
Production equipment gross carrying amount	$ 7,861,233
Sale and Leaseback Agreement [Member] | Yorktown Production Equipment [Member]
Lessee, Lease, Description [Line Items]
Payments of monthly rental amount	7,695
Value of production equipment purchased	$ 968,168
Lease maturity date	Dec. 27, 2022
Bargain purchase option amount	$ 10,000
Sale and Leaseback Agreement [Member] | Yorktown Production Equipment [Member] | Initial Thirty Six Months [Member]
Lessee, Lease, Description [Line Items]
Payments of monthly rental amount	27,915
Three Five-Year Lease Agreements [Member]
Lessee, Lease, Description [Line Items]
Leased equipment	$ 6,900,000
Finance Lease term	5 years
Lease interest rate	7.40%
Lease payment per invoice rate	$ 3.32
Payments of monthly rental amount	$ 168,000