Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Jan. 31, 2018	Jul. 31, 2017
Property, Plant and Equipment [Line Items]
Total cost	$ 649,398	$ 590,675
Less accumulated depreciation	(183,183)	(165,437)
Property, plant and equipment, net	466,215	425,238
Land
Property, Plant and Equipment [Line Items]
Total cost	53,045	48,812
Building and Building Improvements
Property, Plant and Equipment [Line Items]
Total cost	415,794	380,139
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 180,559	$ 161,724