Short-Term and Long-Term Debt - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2022
Debt Instrument [Line Items]
Short-term debt	$ 743.0	$ 771.0
Commercial Paper
Debt Instrument [Line Items]
Short-term debt	$ 629.0	$ 657.0
Debt, weighted average interest rate	4.67%	5.14%
Debt instrument, term	33 days	24 days
Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 75.0
Short-term bank loans and notes payable	$ 70.0	$ 70.0
Stated interest rate	5.34%	6.17%
Interest Bearing Loan
Debt Instrument [Line Items]
Short-term debt		$ 42.0
Long-term debt	$ 42.0