Accrued Expenses and Other Current Liabilities (Product Warranty Rollforward) (Details) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Accrued Liabilities, Current [Abstract]
Minimum coverage period of product warranty from the date of shipment	1 year
Changes in Product Warranty Liability
Accrued warranty obligations, as of the beginning of the period	$ 8,618,000	$ 7,797,000
Provision for warranty obligations	4,707,000	6,307,000
Charges incurred	(4,687,000)	(5,486,000)
Accrued warranty obligations, as of the end of the period	$ 8,638,000	$ 8,618,000