Financial Instruments (Fair Value and Balance Sheet Location of Derivatives) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Total Derivatives, Assets	$ 143.3	$ 224.2
Total Derivatives, Liabilities	85.6	112.4
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	110.9	176.6
Total Derivatives, Liabilities	57.6	56.3
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	32.4	47.6
Total Derivatives, Liabilities	28.0	56.1
Forward Exchange Contracts | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	51.1	79.0
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	0.8	11.9
Forward Exchange Contracts | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	22.5	53.8
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	33.0	0.7
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	31.7	38.7
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	0.0	8.4
Forward Exchange Contracts | Not Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	28.0	36.3
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	19.8
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	14.7	24.8
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	44.3	60.9
Interest Rate Management Contracts | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.4	1.1
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	1.7	0.7
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	0.7	0.5
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.0	$ 0.0