Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2024	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		$ (170.0)	$ (216.1)
OCI before reclassifications	[1]	18.1	44.7
Reclassification to earnings		(2.9)	(1.4)
Ending Balance		(154.8)	(170.0)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(86.9)	(131.2)
OCI before reclassifications	[1]	18.6	44.3
Reclassification to earnings		0.0	0.0
Ending Balance		(68.3)	(86.9)
Pension and Post-retirement Activity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(86.0)	(92.6)
OCI before reclassifications	[1]	0.1	(0.3)
Reclassification to earnings		1.1	6.9
Ending Balance		(84.8)	(86.0)
Hedging Activity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		2.9	7.7
OCI before reclassifications	[1]	(0.6)	0.7
Reclassification to earnings		(4.0)	(5.5)
Ending Balance		$ (1.7)	$ 2.9

[1] OCI is defined as other comprehensive income.