Debt - Schedule of Debt (Details) (USD $)	Feb. 28, 2015	May 31, 2014
Total Notes Payable	$ 13,325,752	$ 14,504,121
Less: Current portion	(2,550,923)	(3,979,376)
Long-term Debt	10,774,829	10,524,745
Term Note Payable To International Bank Of Commerce, Interest Rate Of 4.5%, Due January 31, 2019, Monthly Principal And Interest Payments Of $171,760 [Member]
Total Notes Payable	7,378,162	8,647,777
Revolving Note Payable To International Bank Of Commerce,Prime Rate Of Interest Plus 0.5% But Not Less Than 4.0%, Due January 31, 2016 [Member]
Total Notes Payable	600,000	385,000
Term Note Payable By GRE To International Bank Of Commerce, Interest Rate Of 4.5%, Due January 31, 2019, Monthly Principal And Interest Payments Of $26,215 [Member]
Total Notes Payable	3,250,190	3,371,660
Note Payable To Robert Rosene, 7.5% Interest, Due January 15, 2015 [Member]
Total Notes Payable	2,066,000	2,066,000
Other Notes Payable [Member]
Total Notes Payable	$ 31,400	$ 33,684