Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Goodwill [Line Items]
Goodwill, gross	$ 1,160.1	$ 1,158.4
Goodwill, net	879.0	861.7
Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	(281.1)	(296.7)
Goodwill, net	$ 144.4	$ 146.6