Commitment and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended
	Apr. 30, 2019 Complaint	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)
Commitments And Contingencies [Line Items]
Reserve for unpaid and incurred but not reported claims, amount		$ 133.4	$ 124.5
Reserve for unpaid and incurred but not reported claims, classified in current liabilities		45.6	37.4
Reserve for unpaid and incurred but not reported claims, classified in non-current liabilities		87.8	87.1
Claims recoverable from third party insurance carriers		38.7	32.1
Number of purported class action complaints | Complaint	2
Other Current Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers		8.1	6.1
Other Assets
Commitments And Contingencies [Line Items]
Claims recoverable from third party insurance carriers		$ 30.6	$ 26.0