Financial Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
Total Derivatives, Assets	$ 224.2	$ 146.1
Total Derivatives, Liabilities	112.4	94.1
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	176.6	117.7
Total Derivatives, Liabilities	56.3	55.5
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	47.6	28.4
Total Derivatives, Liabilities	56.1	38.6
Forward Exchange Contracts | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	79.0	24.9
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	11.9	19.8
Forward Exchange Contracts | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	53.8	37.0
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.7	4.6
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	38.7	7.9
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	8.4	16.2
Forward Exchange Contracts | Not Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	36.3	14.9
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	19.8	23.7
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	24.8	24.3
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	60.9	48.7
Interest Rate Management Contracts | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	1.1	2.3
Interest Rate Management Contracts | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.7	11.6
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	0.0	4.0
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	0.5	0.3
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	0.0
Interest Rate Management Contracts | Not Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.0	$ 0.0