Short-Term and Long-Term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Current portion of long-term debt	$ 608.3	$ 609.1
Reported Value Measurement
Debt Instrument [Line Items]
Current portion of long-term debt	608.3	609.1
Long-term debt	2,866.9	2,867.8
Estimate of Fair Value Measurement
Debt Instrument [Line Items]
Current portion of long-term debt	605.0	589.1
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Long-term debt	$ 2,585.8	$ 2,485.4