Consolidated Statements of Income (USD $)	12 Months Ended
	May 31, 2014	May 31, 2013
Income Statement [Abstract]
Sales	$ 23,449,936	$ 24,085,184
Cost of Sales	18,107,627	18,828,452
Gross Profit	5,342,309	5,256,732
General, Selling and Administrative Expenses	2,409,115	2,189,125
Operating Income	2,933,194	3,067,607
Other Income (Expense):
Other income	5,000	6,500
Interest expense	(846,568)	(828,897)
Total Other Expense, net	(841,568)	(822,397)
Income before Income Taxes	2,091,626	2,245,210
Benefit from Income Taxes	1,040,000	548,000
Net Income	3,131,626	2,793,210
Income Attributable to Variable Interest Entities, net	(200,563)	(201,552)
Preferred Dividends	(325,000)	(326,781)
Net Income Available to Common Stockholders	$ 2,606,063	$ 2,264,877
Income Per Share of Common Stock -
Basic	$ 0.1	$ 0.09
Diluted	$ 0.09	$ 0.08
Weighted Average Shares of Common Stock Outstanding -
Basic	26,198,701	26,111,201
Diluted	27,674,939	27,480,039