Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Sep. 30, 2024
Goodwill [Line Items]
Goodwill, gross	$ 1,165.3	$ 1,199.8
Goodwill, net	887.1	905.1
Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	(278.2)	(294.7)
Goodwill, net	$ 144.0	$ 146.3