Intangible Assets, Goodwill and Acquisitions - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Sep. 30, 2022
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 730.6	$ 729.6
Accumulated Amortization	(567.2)	(555.3)
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	724.1	723.1
Accumulated Amortization	$ 562.2	(550.5)
Customer Relationships | Minimum
Finite Lived Intangible Assets [Line Items]
Useful Life	6 years
Customer Relationships | Maximum
Finite Lived Intangible Assets [Line Items]
Useful Life	21 years
Trademarks
Finite Lived Intangible Assets [Line Items]
Useful Life	12 years
Gross Carrying Amount	$ 3.8	3.8
Accumulated Amortization	$ 2.7	(2.6)
Noncompete Agreements
Finite Lived Intangible Assets [Line Items]
Useful Life	5 years
Gross Carrying Amount	$ 2.7	2.7
Accumulated Amortization	$ 2.3	$ (2.2)