Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Oct. 31, 2015	Jul. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 363,609	$ 348,868
Less accumulated depreciation	(120,094)	(114,823)
Property, plant and equipment, net	243,515	234,045
Land
Property, Plant and Equipment [Line Items]
Total cost	29,187	27,447
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Total cost	224,001	214,462
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 110,421	$ 106,959