Leases - Summary of Lease-Related Assets and Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2024	Sep. 30, 2023
Operating leases:
Right-of-use asset		$ 81.3	$ 86.1
Current portion of lease liabilities		24.9	27.3
Lease liabilities		62.6	65.1
Total operating lease liabilities		87.5	92.4
Finance leases:
Right-of-use asset	[1]	$ 67.7	$ 41.3
FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList		Property and equipment, net	Property and equipment, net
Current portion of lease liabilities	[2]	$ 37.0	$ 21.5
FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList		Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Lease liabilities	[3]	$ 31.2	$ 21.3
FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList		Other liabilities	Other liabilities
Total finance lease liabilities		$ 68.2	$ 42.8

[1] Included in “Property and equipment, net” in the Consolidated Balance Sheets.

[2] Included in “Accrued expenses and other liabilities” in the Consolidated Balance Sheets.

[3] Included in “Other liabilities” in the Consolidated Balance Sheets.