Financial Instruments (Fair Value and Balance Sheet Location of Derivatives) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Sep. 30, 2024
Derivative [Line Items]
Total Derivatives, Assets	$ 317.4	$ 142.6
Total Derivatives, Liabilities	140.1	100.6
Designated as hedging instrument
Derivative [Line Items]
Total Derivatives, Assets	270.3	119.6
Total Derivatives, Liabilities	79.1	78.6
Designated as hedging instrument | Other Receivables and Current Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	98.4	74.5
Designated as hedging instrument | Other Receivables and Current Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	6.8	1.2
Designated as hedging instrument | Other Noncurrent Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	10.3	9.6
Designated as hedging instrument | Other Noncurrent Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	154.8	34.3
Designated as hedging instrument | Payables and Accrued Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	44.1	21.6
Designated as hedging instrument | Payables and Accrued Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	2.0	1.2
Designated as hedging instrument | Other Noncurrent Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	5.6	15.6
Designated as hedging instrument | Other Noncurrent Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	27.4	40.2
Not designated as hedging instrument
Derivative [Line Items]
Total Derivatives, Assets	47.1	23.0
Total Derivatives, Liabilities	61.0	22.0
Not designated as hedging instrument | Other Receivables and Current Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	22.6	16.5
Not designated as hedging instrument | Other Receivables and Current Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	0.0	1.7
Not designated as hedging instrument | Other Noncurrent Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	8.8	0.2
Not designated as hedging instrument | Other Noncurrent Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	15.7	4.6
Not designated as hedging instrument | Payables and Accrued Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	25.1	21.8
Not designated as hedging instrument | Payables and Accrued Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	0.0
Not designated as hedging instrument | Other Noncurrent Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	35.9	0.2
Not designated as hedging instrument | Other Noncurrent Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.0	$ 0.0