Intangible Assets, Goodwill and Acquisitions - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020 USD ($) Company	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Company	Jun. 30, 2019 USD ($)
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 13.6	$ 13.9	$ 40.6	$ 42.9
Acquisition of operations, Percentage	100.00%		100.00%
Number of unrelated maintenance services companies acquired | Company	5		5
Consideration paid, net of cash acquired			$ 86.5	$ 59.5
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Identifiable assets acquired related to intangible assets	$ 17.3		$ 17.3