Basis of Presentation and Accounting Policies - Property (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Capital expenditures in accounts payable or other current liabilities at year end	$ 43.2	$ 29.6	$ 29.9
Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Minimum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Minimum | Software Development
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Maximum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	40 years
Maximum | Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	20 years
Maximum | Software Development
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years