Basis of Presentation and Accounting Policies - Property (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Line Items]
Capital expenditures in accounts payable or other current liabilities at year end	$ 56.0	$ 42.0	$ 43.0
Supplier finance program, obligation, current	$ 68.0	$ 77.0
Supplier finance program, obligation, current, statement of financial position [Extensible Enumeration]	Accounts Payable, Current
Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 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