Financial Instruments (Fair Value and Balance Sheet Location of Derivatives) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Derivative [Line Items]
Total Derivatives, Assets	$ 244.4	$ 142.6
Total Derivatives, Liabilities	93.6	100.6
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	212.1	119.6
Total Derivatives, Liabilities	48.9	78.6
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	32.3	23.0
Total Derivatives, Liabilities	44.7	22.0
Forward exchange contracts | Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	50.7	74.5
Forward exchange contracts | Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	10.1	9.6
Forward exchange contracts | Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	21.4	21.6
Forward exchange contracts | Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	3.4	15.6
Forward exchange contracts | Not Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	17.8	16.5
Forward exchange contracts | Not Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	2.7	0.2
Forward exchange contracts | Not Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	14.2	21.8
Forward exchange contracts | Not Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	30.5	0.2
Interest rate management contracts | Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	13.1	1.2
Interest rate management contracts | Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	138.2	34.3
Interest rate management contracts | Designated as Hedging Instrument | Payables and accrued liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	0.3	1.2
Interest rate management contracts | Designated as Hedging Instrument | Other noncurrent liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	23.8	40.2
Interest rate management contracts | Not Designated as Hedging Instrument | Other receivables and current assets
Derivative [Line Items]
Total Derivatives, Assets	0.0	1.7
Interest rate management contracts | Not Designated as Hedging Instrument | Other noncurrent assets
Derivative [Line Items]
Total Derivatives, Assets	11.8	4.6
Interest rate management contracts | Not Designated as Hedging Instrument | Payables and 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