Debt (Details) - USD ($)		Sep. 30, 2025	Sep. 30, 2024	Apr. 02, 2024
Debt Instrument [Line Items]
Total long-term debt, including current maturities		$ 1,390,000,000	$ 1,284,000,000
Long-term debt		1,383,300,000	1,275,000,000
Unamortized debt issuance costs		6,700,000	9,000,000.0
Notes payable		$ 29,500,000	$ 24,500,000
Notes payable, weighted-average interest rate		3.70%	3.80%
Line of Credit, Current				$ 425,000,000.0
Senior notes | Senior notes due 2028
Debt Instrument [Line Items]
Total long-term debt, including current maturities		$ 750,000,000.0	$ 750,000,000.0
Unamortized debt issuance costs		$ 3,900,000	5,400,000
Debt, stated interest rate		5.50%
Minimum Debt amount		$ 150,000,000.0
Minimum Debt amount		150,000,000.0
Senior notes | Senior Notes, Due 2029
Debt Instrument [Line Items]
Total long-term debt, including current maturities	[1]	500,000,000.0	500,000,000.0
Unamortized debt issuance costs		$ 2,800,000	3,600,000
Debt, stated interest rate		4.125%
Minimum Debt amount		$ 150,000,000.0
Minimum Debt amount		150,000,000.0
Domestic Line of Credit and Senior Notes | Senior Notes and Revolving Line of Credit, Due 2029
Debt Instrument [Line Items]
Total long-term debt, including current maturities		500,000,000.0
Revolving Credit Facility
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	[1]	$ 140,000,000.0	$ 34,000,000.0

[1] At September 30, 2025, the balance for the Senior Notes due 2028 and the Senior Notes due 2029 are reflected net of debt issuance costs of $3.9 and $2.8, respectively. At September 30, 2024, the balance for the Senior Notes due 2028 and the Senior Notes due 2029 are reflected net of debt issuance costs of $5.4 and $3.6, respectively.