Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 14.4	$ 15.1	$ 5.8
Customer base
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	0.2
Finite-lived intangible assets write-off	$ 11.1
Finite-lived intangible assets write-off [Extensible Enumeration]	Provision for bad debts, net of recoveries and impairment