Financial Instruments (Currency Price Risk Management Instruments) (Details) - Forward exchange contracts - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Derivative [Line Items]
US$ Notional	$ 6,331.3	$ 5,601.5
Years Average Maturity	10 months 24 days	9 months 18 days
Designated as hedging instrument | Cash flow hedges
Derivative [Line Items]
US$ Notional	$ 4,628.7	$ 4,525.0
Years Average Maturity	7 months 6 days	8 months 12 days
Designated as hedging instrument | Net investment hedges
Derivative [Line Items]
US$ Notional	$ 860.4	$ 542.2
Years Average Maturity	2 years 10 months 24 days	2 years 2 months 12 days
Not designated as hedging instrument
Derivative [Line Items]
US$ Notional	$ 842.2	$ 534.3
Years Average Maturity	3 months 18 days	3 months 18 days