Condensed Consolidated Statement of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	Other expense (income), net Reclassification out of Accumulated Other Comprehensive Income	Common shares	Treasury Stock, Common	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares				(15,000,000.0)
Common shares, issued (in shares)			65,200,000
Treasury Stock, Common, Shares				(15,000,000.0)
Beginning shareholders' equity at Sep. 30, 2023	$ 1,540.5		$ 0.7	$ (906.1)	$ 1,593.8	$ 1,022.1	$ (170.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) earnings	4.8					4.8
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	27.0						27.0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(0.1)						(0.1)
Deferred gain (loss) on hedging activity, net of tax	(3.4)						(3.4)
Dividends declared to common shareholders	(7.6)					(7.6)
Treasury shares repurchased (in usd)	(15.5)			$ (15.5)
Treasury shares repurchased (in shares)				(400,000)
Activity under share plans (shares)				200,000
Activity under share plans (in usd)	0.1			$ 25.0
APIC activity under share plans					(24.9)
Ending shareholders' equity at Dec. 31, 2023	$ 1,545.8		$ 0.7	$ (896.6)	1,568.9	1,019.3	(146.5)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax		$ 1.6
Treasury Stock, Common, Shares				(15,200,000)
Common shares, issued (in shares)			65,200,000
Treasury Stock, Common, Shares				(15,200,000)
Treasury Stock, Common, Shares	16,331,176			(16,300,000)
Common shares, issued (in shares)	65,251,989		65,200,000
Treasury Stock, Common, Shares	16,331,176			(16,300,000)
Beginning shareholders' equity at Sep. 30, 2024	$ 1,584.1		$ 0.7	$ (937.9)	1,586.0	1,090.1	(154.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) earnings	(2.1)					2.1
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(48.3)						(48.3)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0.4						0.4
Deferred gain (loss) on hedging activity, net of tax	5.0						5.0
Dividends declared to common shareholders	(7.1)					(7.1)
Treasury shares repurchased (in usd)	$ (30.1)			$ (30.1)
Treasury shares repurchased (in shares)	(800,000)			(800,000)
Activity under share plans (shares)				300,000
Activity under share plans (in usd)	$ (0.9)			$ 23.3
APIC activity under share plans					(24.2)
Ending shareholders' equity at Dec. 31, 2024	$ 1,501.0		$ 0.7	$ (944.7)	$ 1,561.8	$ 1,080.9	$ (197.7)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax		$ 0.5
Treasury Stock, Common, Shares	16,836,101			(16,800,000)
Common shares, issued (in shares)	65,251,989		65,200,000
Treasury Stock, Common, Shares	16,836,101			(16,800,000)