Consolidated Statements of Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019
Income Statement [Abstract]
Sales	$ 15,523,318	$ 19,503,462	$ 33,091,494	$ 38,167,971
Cost of Sales	12,423,073	17,353,239	27,032,690	33,656,973
Gross Profit	3,100,245	2,150,223	6,058,804	4,510,998
Selling, General and Administrative Expenses	1,331,219	1,112,630	2,471,457	2,190,228
Operating Income	1,769,026	1,037,593	3,587,347	2,320,770
Other Income (Expense):
Other income	2,434	2,880	8,944	4,913
Interest expense	(291,387)	(432,788)	(653,060)	(913,699)
Income before Income Taxes	1,480,073	607,685	2,943,231	1,411,984
Provision for Income Taxes	457,000	135,000	911,000	320,000
Net Income	1,023,073	472,685	2,032,231	1,091,984
Income Attributable to Non-controlling Interest	(67,975)	(65,620)	(135,014)	(130,306)
Preferred Dividends	(81,918)	(102,637)	(163,836)	(215,000)
Net Income Attributable to Common Stockholders	$ 873,180	$ 304,428	$ 1,733,381	$ 746,678
Income Per Share of Common Stock - Basic and Diluted	$ 0.03	$ 0.01	$ 0.06	$ 0.03
Weighted Average Shares of Common Stock Outstanding - Basic	28,361,201	28,361,201	28,361,201	28,361,201
Weighted Average Shares of Common Stock Outstanding - Diluted	32,363,683	29,001,160	32,363,351	29,005,432