Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Jul. 31, 2015	Jul. 31, 2014
Property, Plant and Equipment [Line Items]
Total cost	$ 348,868	$ 273,501
Less accumulated depreciation	(114,823)	(103,639)
Net property, plant and equipment	234,045	169,862
Land
Property, Plant and Equipment [Line Items]
Total cost	27,447	21,592
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Total cost	214,462	175,611
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 106,959	$ 76,298