Debt (Details) - USD ($)	3 Months Ended			6 Months Ended
	Mar. 31, 2024		Mar. 31, 2023	Mar. 31, 2023	Apr. 02, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Total	$ 1,361,000,000					$ 1,372,000,000
Long-term debt	1,350,800,000					1,360,700,000
Notes payable	23,600,000					19,500,000
Unamortized debt issuance costs	$ 10,200,000	[1]				$ 11,300,000
Short-Term Debt, Weighted Average Interest Rate, at Point in Time	3.80%					3.90%
Defined benefit settlement loss				$ (7,200,000)
Pension Plan
Debt Instrument [Line Items]
Defined benefit settlement loss	$ 7,200,000		$ 7,200,000	$ 7,200,000
2024 Revolving Credit Facility [Member] | Subsequent Event
Debt Instrument [Line Items]
Line of Credit, Current					$ 425,000,000.0
Senior notes | Senior Notes, Due 2028
Debt Instrument [Line Items]
Total	750,000,000.0					$ 750,000,000.0
Unamortized debt issuance costs	$ 6,200,000					6,900,000
Long term debt, stated interest rate	5.50%
Minimum Debt amount	$ 150.0
Senior notes | Senior Notes, Due 2029
Debt Instrument [Line Items]
Total	500,000,000.0					500,000,000.0
Unamortized debt issuance costs	$ 4,000,000.0					4,400,000
Long term debt, stated interest rate	4.125%
Minimum Debt amount	$ 150.0
Revolving credit facility
Debt Instrument [Line Items]
Total	$ 111,000,000.0					$ 122,000,000.0

[1] As of March 31, 2024, debt issuance costs were $6.2 and $4.0 related to the Senior Notes due 2028 and the Senior Notes due 2029, respectively. As of September 30, 2023, debt issuance costs were $6.9 and $4.4 related to the Senior Notes due 2028 and the Senior Notes due 2029, respectively.