Intangible Assets, Goodwill and Acquisitions - Additional Information (Details) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2020 USD ($) Company	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 13.9		$ 13.5
Goodwill impairment		$ 15.5		$ 15.5
Acquisition of operations, Percentage	100.00%
Number of unrelated maintenance services companies acquired | Company	3
Consideration paid, net of cash acquired	$ 62.2		$ 18.4
Number of unrelated companies allocated between maintenance services and development services | Company	1
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Identifiable assets acquired related to intangible assets	$ 16.5