Intangible Assets, Goodwill, Acquisitions and Divestitures - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 715.9	$ 732.0
Accumulated Amortization	(620.1)	(599.7)
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	715.9	725.5
Accumulated Amortization	$ (620.1)	(594.1)
Customer Relationships | Minimum
Finite Lived Intangible Assets [Line Items]
Estimated Useful Life	6 years
Customer Relationships | Maximum
Finite Lived Intangible Assets [Line Items]
Estimated Useful Life	21 years
Trademarks
Finite Lived Intangible Assets [Line Items]
Estimated Useful Life	12 years
Gross Carrying Amount	$ 0.0	3.8
Accumulated Amortization	$ 0.0	(2.9)
Noncompete Agreements
Finite Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years
Gross Carrying Amount	$ 0.0	2.7
Accumulated Amortization	$ 0.0	$ (2.7)