Financial Instruments (Fair Value and Balance Sheet Location of Derivatives) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Total Derivatives, Assets	$ 59.9	$ 143.3
Total Derivatives, Liabilities	112.7	85.6
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	59.1	110.9
Total Derivatives, Liabilities	112.0	57.6
Designated as Hedging Instrument | Other Receivables and Current Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	25.0	51.1
Designated as Hedging Instrument | Other Receivables and Current Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	9.9	14.7
Designated as Hedging Instrument | Other Noncurrent Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	6.3	0.8
Designated as Hedging Instrument | Other Noncurrent Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	17.9	44.3
Designated as Hedging Instrument | Accrued Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	38.0	22.5
Designated as Hedging Instrument | Accrued Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	1.1	0.4
Designated as Hedging Instrument | Other Noncurrent Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	37.7	33.0
Designated as Hedging Instrument | Other Noncurrent Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	35.2	1.7
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	0.8	32.4
Total Derivatives, Liabilities	0.7	28.0
Not Designated as Hedging Instrument | Other Receivables and Current Assets | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Assets	0.8	31.7
Not Designated as Hedging Instrument | Other Noncurrent Assets | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Assets	0.0	0.7
Not Designated as Hedging Instrument | Accrued Liabilities | Forward exchange contracts
Derivative [Line Items]
Total Derivatives, Liabilities	0.5	28.0
Not Designated as Hedging Instrument | Other Noncurrent Liabilities | Interest Rate Management Contracts
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.2	$ 0.0