Schedule of Long-Term Debt (Details) - USD ($)	Feb. 28, 2022	May 31, 2021
Short-term Debt [Line Items]
Total long-term debt	$ 14,245,772	$ 16,238,368
Debt issuance costs, net of amortization	(31,211)	(30,726)
Total debt, net of debt issuance costs	14,214,561	16,207,642
Less: Current portion of long-term debt	(2,818,321)	(3,236,113)
Long-term debt, net of current portion and debt issue costs	11,396,240	12,971,529
Other Note Payable [Member]
Short-term Debt [Line Items]
Total long-term debt	120,648	147,914
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
Short-term Debt [Line Items]
Total long-term debt	973,767	1,623,572
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
Short-term Debt [Line Items]
Total long-term debt	703,855	905,822
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
Short-term Debt [Line Items]
Total long-term debt		487,390
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
Short-term Debt [Line Items]
Total long-term debt	253,181	447,551
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
Short-term Debt [Line Items]
Total long-term debt	1,476,551	2,035,670
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
Short-term Debt [Line Items]
Total long-term debt		789,926
Revolving loan payable to International Bank of Commerce, prime rate of interest plus 0.5% but not less than 5.5%, due January 31, 2023
Short-term Debt [Line Items]
Total long-term debt	3,700,000
Paycheck Protection Program note, interest rate of 1.0%, debt forgiven June 2021
Short-term Debt [Line Items]
Total long-term debt		3,034,000
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
Short-term Debt [Line Items]
Total long-term debt	1,883,218	2,049,941
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
Short-term Debt [Line Items]
Total long-term debt	962,651	1,180,470
Term loan payable to Great Western Bank, interest rate of 3.5%, monthly principal and interest payments of $5,997, due August 10, 2028, secured by certain real estate
Short-term Debt [Line Items]
Total long-term debt	814,758
Note payable to Robert Rosene, 7.5% interest, due January 15, 2023
Short-term Debt [Line Items]
Total long-term debt	$ 3,357,143	$ 3,536,112