Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Goodwill [Line Items]
Goodwill, gross	$ 1,200.2	$ 1,158.4
Goodwill, net	899.4	861.7
Americas
Goodwill [Line Items]
Goodwill, accumulated impairment losses	(300.8)	(296.7)
Goodwill, net	$ 147.2	$ 146.6