Short-Term and Long-Term Debt - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Short-term debt	$ 278.5	$ 359.3
Commercial Paper
Debt Instrument [Line Items]
Short-term debt	$ 183.0	$ 317.0
Debt, weighted average interest rate	5.10%	3.03%
Debt instrument, term	9 days	22 days
Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 75.0
Unsecured line of credit, amount borrowed	$ 65.0
Stated interest rate	6.14%
Interest Bearing Loan
Debt Instrument [Line Items]
Short-term debt	$ 23.5	$ 42.3