Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Commitments and contingencies (Textual)
Purchase commitment of company	$ 2,300,000
Rental expenses under operating leases	6,400,000	5,900,000	4,100,000
Connectivity charges under operating leases	10,400,000	11,800,000	16,300,000
Letters of credit outstanding	3,700,000		3,800,000
Letter of credit expires by July 31, 2015	900,000
Letter of credit expires in August 2015	2,800,000
Performance bonds outstanding	10,000,000
Refundable customer deposits	62,685,000	28,663,000
Substantially restricted cash and cash equivalents	$ 12,900,000	$ 7,800,000