Debt (Summary of Outstanding Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Short-term borrowings	$ 259.5	$ 10.7
Current portion of long-term debt	615.0	548.3
Total Debt	$ 10,305.8	$ 7,644.8
Short-term debt, weighted average interest rate	5.20%	4.20%
Nonrelated Party
Debt Instrument [Line Items]
Long-term debt	$ 9,280.6	$ 6,433.8
Related Party
Debt Instrument [Line Items]
Long-term debt	$ 150.7	$ 652.0