Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Goodwill [Line Items]
Goodwill, gross	$ 1,238.6	$ 1,199.8	$ 1,158.4
Goodwill, net	963.9	905.1	861.7
Americas
Goodwill [Line Items]
Accumulated impairment losses	(274.7)	(294.7)	(296.7)
Goodwill, net	$ 143.5	$ 146.3	$ 146.6