Commitments and Contingencies - Additional Information (Detail) (USD $)	Jan. 31, 2014	Jul. 31, 2013
Legal Proceedings and Commitments and Contingencies [Abstract]
Purchase commitment of company	$ 1,500,000
Letters of credit outstanding	3,800,000
Letter of credit expires by January 31, 2015	1,000,000
Letter of credit expires in August 2015	2,800,000
Aggregate surety and performance bonds outstanding	10,000,000
Refundable customer deposits	$ 53,965,000	$ 28,663,000