Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jul. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 369,895	$ 348,868
Less accumulated depreciation	(123,318)	(114,823)
Property, plant and equipment, net	246,577	234,045
Land
Property, Plant and Equipment [Line Items]
Total cost	29,208	27,447
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Total cost	228,622	214,462
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 112,065	$ 106,959