Property, Plant, and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Property, Plant and Equipment [Line Items]
Land and improvements	$ 6,900	$ 7,500
Building and improvements	83,000	85,100
Leasehold improvements	10,000	9,800
Equipment and software	133,700	129,200
Furniture and fixtures	7,100	7,300
Property, Plant and Equipment, Gross, Total	240,700	238,900
Less accumulated depreciation and amortization	(134,400)	(124,700)
Total property, plant and equipment	$ 106,299	$ 114,165	$ 111,000
Land and Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	15 years
Building And Improvement | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	10 years
Building And Improvement | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	35 years
Leasehold and Capital Lease Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	lesser of useful life or the lease term
Manufacturing and Engineering Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	3 years
Manufacturing and Engineering Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	7 years
Furniture, Fixtures and Computer Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment estimated useful lives	5 years