Intangible Assets, net (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	$ 328.2	$ 328.2	$ 375.5
Finite-lived intangible assets, accumulated amortization	(182.1)	(182.1)	(198.7)
Finite-lived intangible assets, net	146.1	146.1	176.8
Accelerated amortization	0.0	17.4
Customer relationships
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	160.6	160.6	178.4
Finite-lived intangible assets, accumulated amortization	(92.4)	(92.4)	(97.2)
Finite-lived intangible assets, net	68.2	68.2	81.2
Trademarks and brands
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	164.5	164.5	194.0
Finite-lived intangible assets, accumulated amortization	(86.6)	(86.6)	(98.4)
Finite-lived intangible assets, net	77.9	77.9	95.6
Other intangible assets
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	3.1	3.1	3.1
Finite-lived intangible assets, accumulated amortization	(3.1)	(3.1)	(3.1)
Finite-lived intangible assets, net	$ 0.0	$ 0.0	$ 0.0