Intangible Assets, Goodwill and Acquisitions - Additional Information (Details) $ in Millions	3 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) Company
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 10.1	$ 11.9
Net service revenues	626.7	$ 655.9
Number of unrelated maintenance services companies acquired | Company		2
Consideration paid, net of cash acquired	$ 0.0	$ 10.0
Weighted average amortization periods of intangible assets acquired		7 years
Unrelated Maintenance Services Companies
Finite Lived Intangible Assets [Line Items]
Acquisition of operations, Percentage		100.00%
Consideration paid, net of cash acquired		$ 10.0
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Identifiable assets acquired related to intangible assets		$ 2.6