Supplemental Balance Sheet Information (Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Oct. 31, 2017	Jul. 31, 2017
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ (758.4)	$ (744.2)
Property, plant and equipment, net	483.8	484.6
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	20.5	20.6
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	293.6	292.5
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	871.3	866.8
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 56.8	$ 48.9