Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Commitments And Contingencies [Line Items]
Reserve for unpaid and incurred but not reported claims, amount	$ 161.5	$ 159.9
Reserve for unpaid and incurred but not reported claims, classified in current liabilities	53.4	54.8
Reserve for unpaid and incurred but not reported claims, classified in non-current liabilities	108.1	105.1
Claims recoverable from third party insurance carriers	19.7	18.1
Other Current Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	5.7	5.3
Other Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	$ 14.0	$ 12.8