Financial Instruments (Fair Value and Balance Sheet Location of Derivatives) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Total Derivatives, Assets	$ 83.4	$ 143.3
Total Derivatives, Liabilities	121.5	85.6
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	74.7	110.9
Total Derivatives, Liabilities	115.1	57.6
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	8.7	32.4
Total Derivatives, Liabilities	6.4	28.0
Forward exchange contracts | Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	35.1	51.1
Forward exchange contracts | Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	5.5	0.8
Forward exchange contracts | Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	57.2	22.5
Forward exchange contracts | Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	25.2	33.0
Forward exchange contracts | Not Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	8.7	31.7
Forward exchange contracts | Not Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	6.4	28.0
Interest rate management contracts | Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	16.0	14.7
Interest rate management contracts | Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	18.1	44.3
Interest rate management contracts | Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	5.2	0.4
Interest rate management contracts | Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	27.5	1.7
Interest rate management contracts | Not Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	0.0	0.7
Interest rate management contracts | Not Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.0	$ 0.0