Segment Reporting (Details) (USD $)	3 Months Ended
	Oct. 31, 2013		Oct. 31, 2012		Jul. 31, 2013
United States [Member]
Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Line Items]
Revenue	$ 23,160,148		$ 24,810,663
Gross Long-Lived Assets	29,567,493				29,508,055
Foreign Countries [Member]
Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Line Items]
Revenue	11,589,143	[1]	12,011,105	[1]
Gross Long-Lived Assets	5,467,267				5,183,885
Peru [Member]
Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Line Items]
Revenue	4,300,000		3,500,000
Brazil [Member]
Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Line Items]
Revenue	4,000,000		4,100,000
Chile [Member]
Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Line Items]
Revenue	$ 2,400,000		$ 2,500,000

[1] Significant foreign revenues included revenues in Peru ($4.3 million and $3.5 million for the three months ended October 31, 2013 and 2012, respectively), Brazil ($4.0 million and $4.1 million for the three months ended October 31, 2013 and 2012, respectively) and Chile ($2.4 million and $2.5 million for the three months ended October 31, 2013 and 2012, respectively).