Components of Inventory (Detail) (USD $)	Oct. 31, 2013	Jul. 31, 2013
Inventory [Line Items]
Raw materials	$ 56,500,000	$ 78,700,000
Work in process	36,400,000	11,900,000
Finished goods	25,900,000	25,700,000
Total inventory	$ 118,830,000	$ 116,280,000