Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Sep. 30, 2025
Goodwill [Line Items]
Goodwill, gross	$ 1,265.8	$ 1,238.6
Goodwill, accumulated impairment losses	(294.3)	(274.7)
Goodwill, net	971.5	963.9
Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	(294.3)	(274.7)
Goodwill, net	$ 146.2	$ 143.5