Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($)	May 31, 2019	May 31, 2018
Face value of long-term debt	$ 22,697,464	$ 19,251,596
Less: Debt issuance costs, net of amortization	(37,686)	(91,370)
Long-term debt total	22,659,778	19,160,226
Less: Current portion of long-term debt	(3,030,630)	(2,324,046)
Long-term debt	19,629,148	16,836,180
Term Loan A Payable to International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.0%, Maturing April 30, 2023 [Member]
Face value of long-term debt	3,234,947	3,945,443
Term loan C payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 4.0%, maturing August 4, 2020 [Member]
Face value of long-term debt	1,399,490	1,613,445
Term loan D payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 4.75%, maturing January 10, 2022 [Member]
Face value of long-term debt	1,744,235	2,314,935
Term loan E payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 4.75%, maturing January 10, 2022 [Member]
Face value of long-term debt	927,199	843,200
Term loan F payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 5.25%, maturing February 8, 2021 [Member]
Face value of long-term debt	3,398,247
Term loan G payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 5.25%, maturing April 30, 2024 [Member]
Face value of long-term debt	876,934
Revolving loan payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 5.50%, due January 31, 2021 [Member]
Face value of long-term debt	3,205,000	1,879,000
Term loan payable by GRE to International Bank of Commerce, interest rate of 5.5%, monthly principal and interest payments of $27,688, due April 30, 2023 [Member]
Face value of long-term debt	2,461,116	2,652,428
Note payable to Robert Rosene, 7.5% interest, due January 15, 2021 [Member]
Face value of long-term debt	4,426,631	4,469,355
Note payable to First Bank, prime rate of interest plus 1.45% but not less than 4.95%, monthly principal and interest payment of $30,628, due August 21, 2021 [Member]
Face value of long-term debt	800,488	1,099,447
Note payable to Yorktown Management & Financial Services, LLC, 5.0% interest, due February 28, 2019, monthly principal and interest payments of $20,629 [Member]
Face value of long-term debt		181,850
Other Note Payable [Member]
Face value of long-term debt	$ 223,177	$ 252,493