Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2026	Sep. 30, 2025
Commitments And Contingencies [Line Items]
Reserve for unpaid and incurred but not reported claims, amount	$ 184.4	$ 175.1
Reserve for unpaid and incurred but not reported claims, classified in current liabilities	53.2	52.3
Reserve for unpaid and incurred but not reported claims, classified in non-current liabilities	131.2	122.8
Claims recoverable from third party insurance carriers	33.2	24.2
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsCurrent
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	9.3	7.0
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	$ 23.9	$ 17.2