Debt - Schedule of Debt (Details) - USD ($)	Aug. 31, 2015	May. 31, 2015
Total Notes Payable	$ 11,783,155	$ 12,579,011
Less: Current portion	(1,987,039)	(2,278,164)
Long-term Debt	9,796,116	10,300,847
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	$ 6,506,944	6,945,884
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		300,000
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	$ 3,151,685	3,207,553
Note Payable To Robert Rosene, 7.5% Interest, Due January 15, 2017 [Member]
Total Notes Payable	2,066,000	2,066,000
Other Notes Payable [Member]
Total Notes Payable	$ 58,526	$ 59,574