Accrued Expenses and Other Current Liabilities - Product Warranty Rollforward (Details) - USD ($)	9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
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	$ 8,638,000	$ 8,618,000
Provision for warranty obligations	3,183,000	3,255,000
Additions (in connection with the TCS acquisition)	154,000	0
Charges incurred	(3,336,000)	(3,580,000)
Accrued warranty obligations, as of the end of the period	$ 8,639,000	$ 8,293,000