Goodwill (Schedule of Goodwill by Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Goodwill [Roll Forward]
Goodwill, net, beginning balance	$ 905.1	$ 861.7
Acquisition	31.3
Currency translation and other	27.5	43.4
Goodwill, net, ending balance	963.9	905.1
Americas
Goodwill [Roll Forward]
Goodwill, net, beginning balance	146.3	146.6
Acquisition	0.0
Currency translation and other	(2.8)	(0.3)
Goodwill, net, ending balance	143.5	146.3
Asia
Goodwill [Roll Forward]
Goodwill, net, beginning balance	174.7	171.9
Acquisition	0.0
Currency translation and other	(2.2)	2.8
Goodwill, net, ending balance	172.5	174.7
Europe
Goodwill [Roll Forward]
Goodwill, net, beginning balance	534.3	493.5
Acquisition	31.3
Currency translation and other	32.3	40.8
Goodwill, net, ending balance	597.9	534.3
Middle East and India
Goodwill [Roll Forward]
Goodwill, net, beginning balance	15.8	15.8
Acquisition	0.0
Currency translation and other	0.0	0.0
Goodwill, net, ending balance	15.8	15.8
Corporate and other
Goodwill [Roll Forward]
Goodwill, net, beginning balance	34.0	33.9
Acquisition	0.0
Currency translation and other	0.2	0.1
Goodwill, net, ending balance	$ 34.2	$ 34.0