Debt (Summary of Outstanding Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Short-term borrowings	$ 83.5	$ 259.5
Current portion of long-term debt	611.4	615.0
Total Debt	$ 14,227.9	$ 10,305.8
Short-term debt, weighted average interest rate	4.00%	5.20%
Nonrelated Party
Debt Instrument [Line Items]
Less: Long-term debt – related party	$ 13,428.6	$ 9,280.6
Related Party
Debt Instrument [Line Items]
Less: Long-term debt – related party	$ 104.4	$ 150.7