Commitments and Contingencies - Additional Information (Detail) (USD $)	Oct. 31, 2013	Jul. 31, 2013
Legal Proceedings and Commitments and Contingencies [Abstract]
Purchase commitment of company	$ 1,400,000
Letters of credit outstanding	4,000,000
Letter of credit expires by October 31, 2014	1,200,000
Letter of credit expires in October 31, 2015	2,800,000
Aggregate surety and performance bonds outstanding	9,500,000
Refundable customer deposits	$ 36,945,000	$ 28,663,000