Leases - Summary of Lease-Related Assets and Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2025	Sep. 30, 2024
Operating leases:
Right-of-use asset		$ 72.1	$ 81.3
Current portion of lease liabilities		24.7	24.9
Lease liabilities		53.5	62.6
Total operating lease liabilities		78.2	87.5
Finance leases:
Right-of-use asset	[1]	$ 79.3	$ 67.7
FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList		Property and equipment, net	Property and equipment, net
Current portion of lease liabilities	[2]	$ 44.8	$ 37.0
FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList		Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Lease liabilities	[3]	$ 37.1	$ 31.2
FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList		Other liabilities	Other liabilities
Total finance lease liabilities		$ 81.9	$ 68.2

[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.