Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Jul. 31, 2013
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life	32 years
Automobiles
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	Shorter of the remaining lease term or the estimated useful life of the asset
Minimum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years