Property and Equipment, Net (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 910,593	$ 892,717
Less accumulated depreciation and amortization	(323,430)	(292,329)
Property, plant and equipment, net, total	587,163	600,388
Transportation and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	52,066	65,009
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	53,363	53,411
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	54,399	46,761
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	350,463	343,170
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 400,302	$ 384,366

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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