Consolidated Statements of Income - USD ($)	12 Months Ended
	May 31, 2020	May 31, 2019
Income Statement [Abstract]
Sales	$ 76,204,608	$ 71,077,116
Cost of Sales	64,721,749	62,837,214
Gross Profit	11,482,859	8,239,902
Selling, General and Administrative Expenses	4,623,618	3,922,284
Operating Income	6,859,241	4,317,618
Other Income (Expense):
Other income	17,680	11,560
Interest expense	(1,705,351)	(1,836,294)
Income before Income Taxes	5,171,570	2,492,884
Provision for Income Taxes	209,000	435,677
Net Income	4,962,570	2,057,207
Income Attributable to Non-controlling Interest	(262,149)	(252,116)
Preferred Dividends	(398,836)	(428,455)
Net Income Attributable to Common Stockholders	$ 4,301,585	$ 1,376,636
Income Per Share of Common Stock - Basic and Diluted	$ 0.15	$ 0.05
Weighted Average Shares of Common Stock Outstanding - Basic	28,361,201	28,361,201
Weighted Average Shares of Common Stock Outstanding - Diluted	32,343,657	29,009,415