Intangible Assets, net (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	$ 376.8	$ 376.8	$ 425.9
Finite-lived intangible assets, accumulated amortization	(148.8)	(148.8)	(151.6)
Finite-lived intangible assets, net	228.0	228.0	274.3
Accelerated amortization	11.8	29.9
Customer relationships
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	178.6	178.6	209.4
Finite-lived intangible assets, accumulated amortization	(72.9)	(72.9)	(76.9)
Finite-lived intangible assets, net	105.7	105.7	132.5
Trademarks and brands
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	195.1	195.1	213.4
Finite-lived intangible assets, accumulated amortization	(72.8)	(72.8)	(71.6)
Finite-lived intangible assets, net	122.3	122.3	141.8
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