Fair Value Measurements (Schedule of the Carrying Values and Fair Values of Financial Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion and related party, carrying value	$ 8,832.8	$ 7,634.1
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion and related party, fair value	8,084.2	6,721.2
Forward exchange contracts | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	95.9	138.6
Derivative liabilities	91.5	275.3
Forward exchange contracts | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	95.9	138.6
Derivative liabilities	91.5	275.3
Interest Rate Management Contracts | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	42.3	50.5
Derivative liabilities	82.8	91.2
Interest Rate Management Contracts | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	42.3	50.5
Derivative liabilities	$ 82.8	$ 91.2