Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($)	May 31, 2021	May 31, 2020
Debt Instrument [Line Items]
Total long-term debt	$ 16,238,368	$ 22,781,896
Debt issuance costs, net of amortization	(30,726)	(35,886)
Total debt, net of debt issuance costs	16,207,642	22,746,010
Less: Current portion of long-term debt	(3,236,113)	(4,416,377)
Long-term debt, net of current portion and debt issue costs	12,971,529	18,329,633
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 [Line Items]
Total long-term debt	1,623,572	2,459,854
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, 2024 [Member]
Debt Instrument [Line Items]
Total long-term debt	905,822	1,165,774
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 [Line Items]
Total long-term debt	487,390	1,136,455
Term Loan E Payable to International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.75%, Maturing February 28, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt	447,551	696,174
Term Loan F Payable to International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 5.25%, Maturing February 29, 2024 [Member]
Debt Instrument [Line Items]
Total long-term debt	2,035,670	2,752,293
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 [Line Items]
Total long-term debt	789,926	837,811
Revolving Loan Payable to International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.50%, Due January 31, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt		2,540,000
Term Loan Payable by GRE to International Bank of Commerce, Interest Rate of 5.5%, Monthly Principal and Interest Payment of $27,688, Due April 30, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt	2,049,941	2,261,425
Term Note Payable to Great Western Bank, Interest Rate of 3.7%, Monthly Principal and Interest Payments of $27,593, due March 19, 2025, Secured by Certain Equipment [Member]
Debt Instrument [Line Items]
Total long-term debt	1,180,470	1,461,726
Paycheck Protection Program Note, Principal and Interest Forgiven as of June 11, 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt	3,034,000	3,034,000
Note Payable to Robert Rosene, 7.5% Interest, Due January 15, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt	3,536,112	4,253,228
Other [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 147,914	$ 183,156