Commitments and Contingencies - Additional Information (Detail)		1 Months Ended	12 Months Ended
	Jun. 08, 2015 USD ($)	Oct. 31, 2014 USD ($)	Jul. 31, 2015 USD ($)	Jul. 31, 2014 USD ($)	Jul. 31, 2013 USD ($)	Jul. 31, 2012 LegalMatter
Commitments and Contingencies [Line Items]
Total rent and equipment lease expense charged to continuing operations			$ 19,700,000	$ 21,300,000	$ 25,200,000
Loss contingency			1,600,000
Number of purported class actions filed following the announcement | LegalMatter						3
Pending Litigation
Commitments and Contingencies [Line Items]
Damages sought	$ 1,000,000
Vendor Agreements
Commitments and Contingencies [Line Items]
Outstanding obligations			$ 0
Covered by Insurance Proceeds
Commitments and Contingencies [Line Items]
Class settlement amount		$ 4,000,000