Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			1 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012 LegalMatter	Oct. 31, 2014 Scenario, Forecast Covered by Insurance Proceeds	Jul. 31, 2014 Vendor Agreements
Commitments and Contingencies [Line Items]
Total rent and equipment lease expense charged to continuing operations	$ 21.3	$ 25.2	$ 26.5
Annual lease payments per year	1.6
Sponsorship period	15 years
Outstanding obligations					0
Number of purported class actions filed following the announcement			3
Class settlement amount				$ 4