Long-Term Debt - Repayments (Details) $ in Millions	3 Months Ended		9 Months Ended
Long-Term Debt - Repayments (Details) $ in Millions	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)
Debt Disclosure [Abstract]
Debt Covenant, Leverage Ratio	4.25		4.25
Debt Covenant, Percentage of Revolving Credit Commitments	30.00%		30.00%
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt	$ 18.0	$ 50.0	$ 1,274.5	$ 201.7
Gross Exchanges of Long-term debt	$ 0.0	0.0	$ 0.0	99.9
Debt Covenant, Leverage Ratio	4.25		4.25
Debt Covenant, Percentage of Revolving Credit Commitments	30.00%		30.00%
Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums	$ (1.9)	(6.4)	$ (3.5)	(23.3)
Write off of Debt Issuance Costs and Deferred Financing Fees	0.1	0.3	3.5	2.4
Write-off of Unamortized Debt Discount/(Premium)	0.0	(0.3)	(4.6)	(0.3)
Municipal Bonds
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt			1.1	1.1
Gross Exchanges of Long-term debt			0.0	0.0
Municipal Bonds \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums			0.0	0.0
Write off of Debt Issuance Costs and Deferred Financing Fees			0.0	0.0
Write-off of Unamortized Debt Discount/(Premium)			0.0	0.0
Revolving Credit Facility
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt			345.0
Gross Exchanges of Long-term debt			0.0
Revolving Credit Facility \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums			0.0
Write off of Debt Issuance Costs and Deferred Financing Fees			0.0
Write-off of Unamortized Debt Discount/(Premium)			0.0
4.50% Senior Notes Maturing in September 2031 \| Senior Notes
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt	18.0	20.7	69.1	141.2
Gross Exchanges of Long-term debt	0.0	0.0	0.0	0.0
4.50% Senior Notes Maturing in September 2031 \| Senior Notes \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums	(1.9)	(3.0)	(7.9)	(19.9)
Write off of Debt Issuance Costs and Deferred Financing Fees	0.1	0.1	0.5	1.1
Write-off of Unamortized Debt Discount/(Premium)	$ 0.0	0.0	0.0	0.0
4.625% Senior Notes Maturing April 2030 \| Senior Notes
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt		29.3		29.3
Gross Exchanges of Long-term debt		0.0		0.0
4.625% Senior Notes Maturing April 2030 \| Senior Notes \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums		(3.4)		(3.4)
Write off of Debt Issuance Costs and Deferred Financing Fees		0.2		0.2
Write-off of Unamortized Debt Discount/(Premium)		$ (0.3)		(0.3)
5.75% Senior Notes Maturing March 2027 \| Senior Notes
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt			459.3
Gross Exchanges of Long-term debt			0.0
5.75% Senior Notes Maturing March 2027 \| Senior Notes \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums			4.4
Write off of Debt Issuance Costs and Deferred Financing Fees			1.6
Write-off of Unamortized Debt Discount/(Premium)			(4.6)
Fourth Incremental Term Loan \| Term Loan
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt			400.0
Gross Exchanges of Long-term debt			0.0
Fourth Incremental Term Loan \| Term Loan \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums			0.0
Write off of Debt Issuance Costs and Deferred Financing Fees			1.4
Write-off of Unamortized Debt Discount/(Premium)			$ 0.0
Third Incremental Term Loan \| Term Loan
Extinguishment of Debt [Line Items]
Gross Repayments of Long-term debt				30.1
Gross Exchanges of Long-term debt				99.9
Third Incremental Term Loan \| Term Loan \| Loss on extinguishment of debt and refinancing fees, net
Extinguishment of Debt [Line Items]
Payment (Proceeds) for debt discounts and premiums				0.0
Write off of Debt Issuance Costs and Deferred Financing Fees				1.1
Write-off of Unamortized Debt Discount/(Premium)				$ 0.0