Leases - Summary of Lease-Related Assets and Liabilities (Details) - USD ($) $ in Millions		Sep. 30, 2022	Sep. 30, 2021
Operating leases:
Right-of-use asset		$ 81.6	$ 69.5
Current portion of lease liabilities		26.8	22.0
Lease liabilities		61.3	54.2
Total operating lease liabilities		88.1	76.2
Finance leases:
Right-of-use asset	[1]	$ 41.9	$ 32.1
FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList		Property and equipment, net	Property and equipment, net
Current portion of lease liabilities	[2]	$ 19.3	$ 14.9
FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList		Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Lease liabilities	[3]	$ 22.4	$ 12.7
FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList		Other liabilities	Other liabilities
Total finance lease liabilities		$ 41.7	$ 27.6

[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.