Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023
Commitments And Contingencies [Line Items]
Reserve for unpaid and incurred but not reported claims, amount	$ 160.9	$ 159.9
Reserve for unpaid and incurred but not reported claims, classified in current liabilities	52.6	54.8
Reserve for unpaid and incurred but not reported claims, classified in non-current liabilities	108.3	105.1
Claims recoverable from third party insurance carriers	15.9	18.1
Other Current Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	4.6	5.3
Other Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	$ 11.3	$ 12.8