Intangible Assets, Goodwill and Acquisitions - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023 USD ($) Company	Mar. 31, 2022 USD ($) Company	Mar. 31, 2023 USD ($) Company	Mar. 31, 2022 USD ($) Company
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 11.0	$ 12.0	$ 22.9	$ 25.5
Number of unrelated maintenance services companies acquired | Company	3	6	3	6
Consideration paid, net of cash acquired			$ 13.8	$ 84.4
Net Service Revenues	$ 650.4	$ 711.9	$ 1,306.3	$ 1,303.8
Unrelated Maintenance Services Companies
Finite Lived Intangible Assets [Line Items]
Acquisition of operations, Percentage	100.00%	100.00%	100.00%	100.00%
Consideration paid, net of cash acquired			$ 13.8	$ 84.4
Business Acquisitions
Finite Lived Intangible Assets [Line Items]
Net Service Revenues			6.3
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Identifiable assets acquired related to intangible assets	$ 4.0	$ 21.2	$ 4.0	$ 21.2