Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Sep. 30, 2024
Goodwill [Line Items]
Goodwill, gross	$ 1,131.5	$ 1,199.8
Goodwill, net	866.5	905.1
Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	(265.0)	(294.7)
Goodwill, net	$ 142.1	$ 146.3