Long-Term Debt - Schedule of Long-Term Debt (Details) (Parenthetical) - USD ($)	12 Months Ended
	May 31, 2019	May 31, 2018
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Apr. 30, 2023	Apr. 30, 2023
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] | Maximum [Member]
Debt instrument interest rate	4.00%	4.00%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Aug. 04, 2020	Aug. 04, 2020
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] | Maximum [Member]
Debt instrument interest rate	4.00%	4.00%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Jan. 10, 2022	Jan. 10, 2022
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] | Maximum [Member]
Debt instrument interest rate	4.75%	4.75%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Jan. 10, 2022	Jan. 10, 2022
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] | Maximum [Member]
Debt instrument interest rate	4.75%	4.75%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Feb. 08, 2021	Feb. 08, 2021
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] | Maximum [Member]
Debt instrument interest rate	5.25%	5.25%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Apr. 30, 2024	Apr. 30, 2024
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] | Maximum [Member]
Debt instrument interest rate	5.25%	5.25%
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]
Debt instrument interest rate	0.50%	0.50%
Debt instrument maturity date	Jan. 31, 2021	Jan. 31, 2021
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] | Maximum [Member]
Debt instrument interest rate	5.50%	5.50%
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]
Debt instrument interest rate	5.50%	5.50%
Debt instrument maturity date	Apr. 30, 2023	Apr. 30, 2023
Debt instrument principal and interest amount	$ 27,688	$ 27,688
Note payable to Robert Rosene, 7.5% interest, due January 15, 2021 [Member]
Debt instrument interest rate	7.50%	7.50%
Debt instrument maturity date	Jan. 15, 2021	Jan. 15, 2021
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]
Debt instrument interest rate	1.45%	1.45%
Debt instrument maturity date	Aug. 21, 2021	Aug. 21, 2021
Debt instrument principal and interest amount	$ 30,628	$ 30,628
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] | Maximum [Member]
Debt instrument interest rate	4.95%	4.95%
Note payable to Yorktown Management & Financial Services, LLC, 5.0% interest, due February 28, 2019, monthly principal and interest payments of $20,629 [Member]
Debt instrument interest rate	5.00%	5.00%
Debt instrument maturity date	Feb. 28, 2019	Feb. 28, 2019
Debt instrument principal and interest amount	$ 20,629	$ 20,629