Supplemental Balance Sheet Information (Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Apr. 30, 2018	Jul. 31, 2017
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ (796.9)	$ (744.2)
Property, plant and equipment, net	511.1	484.6
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	21.1	20.6
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	310.6	292.5
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	909.1	866.8
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 67.2	$ 48.9