Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2026	Sep. 30, 2025
Commitments And Contingencies [Line Items]
Reserve for unpaid and incurred but not reported claims, amount	$ 177.9	$ 175.1
Reserve for unpaid and incurred but not reported claims, classified in current liabilities	54.0	52.3
Reserve for unpaid and incurred but not reported claims, classified in non-current liabilities	123.9	122.8
Claims recoverable from third party insurance carriers	29.8	24.2
Other Current Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	8.4	7.0
Other Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers	$ 21.4	$ 17.2

Amount, after valuation allowance, recoverable under reinsurance contracts for losses reported to the ceding insurer but not yet paid and amounts expected for incurred losses and settlement expenses, which have not yet been reported to the ceding insurer.