Condensed Consolidated Statement of Changes in Shareholders' Equity Statement - USD ($)	Total	Reclassification out of Accumulated Other Comprehensive Income	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	$ 1,540,500,000			$ 700,000	$ (906,100,000)	$ 1,593,800,000	$ 1,022,100,000	$ (170,000,000.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	4,800,000						4,800,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	27,000,000.0							27,000,000.0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(100,000)							(100,000)
Deferred gain (loss) on hedging activity, net of tax	(3,400,000)							(3,400,000)
Dividends declared to common shareholders	(7,600,000)						(7,600,000)
Treasury shares repurchased (in usd)	(15,500,000)				$ (15,500,000)
Treasury shares repurchased (in shares)					(400,000)
Activity under share plans (shares)					200,000
Activity under share plans (in usd)	100,000				$ 25,000,000.0
APIC activity under share plans						(24,900,000)
Ending shareholders' equity at Dec. 31, 2023	1,545,800,000			700,000	(896,600,000)	1,568,900,000	1,019,300,000	(146,500,000)
Beginning shareholders' equity at Sep. 30, 2023	1,540,500,000			700,000	(906,100,000)	1,593,800,000	1,022,100,000	(170,000,000.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	89,800,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(2,100,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(1,100,000)
Deferred gain (loss) on hedging activity, net of tax	(100,000)
Ending shareholders' equity at Jun. 30, 2024	1,576,600,000			$ 700,000	$ (920,600,000)	1,580,800,000	1,089,000,000	(173,300,000)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	4,400,000		$ 4,400,000
OCI Cash flow hedge, reclassification to earnings, tax		$ 1,400,000
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax		3,000,000.0
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax		(1,100,000)
Amortization of defined benefit pension and postretirement items, tax		(300,000)
Amortization of defined benefit pension and postretirement items, after tax		(800,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,200,000	2,200,000
Treasury Stock, Common, Shares					(15,200,000)
Common shares, issued (in shares)				65,200,000
Treasury Stock, Common, Shares					(15,200,000)
Beginning shareholders' equity at Dec. 31, 2023	1,545,800,000			$ 700,000	$ (896,600,000)	1,568,900,000	1,019,300,000	(146,500,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	36,000,000.0						36,000,000.0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(16,000,000.0)							(16,000,000.0)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(500,000)							(500,000)
Deferred gain (loss) on hedging activity, net of tax	2,700,000							2,700,000
Dividends declared to common shareholders	(7,600,000)						(7,600,000)
Treasury shares repurchased (in usd)	(15,400,000)				$ (15,400,000)
Treasury shares repurchased (in shares)					(400,000)
Activity under share plans (shares)					0
Activity under share plans (in usd)	6,300,000				$ 900,000
APIC activity under share plans						5,400,000
Ending shareholders' equity at Mar. 31, 2024	1,551,300,000			$ 700,000	$ (911,100,000)	1,574,300,000	1,047,700,000	(160,300,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(15,600,000)
Common shares, issued (in shares)				65,200,000
Treasury Stock, Common, Shares					(15,600,000)
Net earnings	49,000,000.0						49,000,000.0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(13,100,000)							(13,100,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(500,000)							(500,000)
Deferred gain (loss) on hedging activity, net of tax	600,000							600,000
Dividends declared to common shareholders	(7,700,000)						(7,700,000)
Treasury shares repurchased (in usd)	(9,900,000)				$ (9,900,000)
Treasury shares repurchased (in shares)					(300,000)
Activity under share plans (shares)					0
Activity under share plans (in usd)	6,900,000				$ 400,000
APIC activity under share plans						6,500,000
Ending shareholders' equity at Jun. 30, 2024	1,576,600,000			$ 700,000	$ (920,600,000)	1,580,800,000	1,089,000,000	(173,300,000)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	$ 2,000,000.0	2,000,000.0
OCI Cash flow hedge, reclassification to earnings, tax		600,000
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax		1,400,000
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax		(400,000)
Amortization of defined benefit pension and postretirement items, tax		(200,000)
Amortization of defined benefit pension and postretirement items, after tax		(200,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		1,200,000
Treasury Stock, Common, Shares					(15,900,000)
Common shares, issued (in shares)				65,200,000
Treasury Stock, Common, Shares					(15,900,000)
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	$ 1,584,100,000			$ 700,000	$ (937,900,000)	1,586,000,000	1,090,100,000	(154,800,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	(2,100,000)						2,100,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(48,300,000)							(48,300,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	400,000							400,000
Deferred gain (loss) on hedging activity, net of tax	5,000,000.0							5,000,000.0
Dividends declared to common shareholders	(7,100,000)						(7,100,000)
Treasury shares repurchased (in usd)	(30,100,000)				$ (30,100,000)
Treasury shares repurchased (in shares)					(800,000)
Stock Issued During Period, Shares, Period Increase (Decrease)	(900,000)
Activity under share plans (shares)					300,000
Activity under share plans (in usd)					$ 23,300,000
APIC activity under share plans						(24,200,000)
Ending shareholders' equity at Dec. 31, 2024	1,501,000,000			700,000	(944,700,000)	1,561,800,000	1,080,900,000	(197,700,000)
Beginning shareholders' equity at Sep. 30, 2024	1,584,100,000			700,000	(937,900,000)	1,586,000,000	1,090,100,000	(154,800,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	56,000,000.0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	28,200,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	1,200,000
Deferred gain (loss) on hedging activity, net of tax	$ (1,500,000)
Treasury shares repurchased (in shares)	(2,800,000)
Ending shareholders' equity at Jun. 30, 2025	$ 1,568,000,000			$ 700,000	$ (1,003,700,000)	1,573,500,000	1,124,400,000	(126,900,000)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	1,500,000		$ 1,500,000
OCI Cash flow hedge, reclassification to earnings, tax		400,000
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax		1,100,000
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax		(1,800,000)
Amortization of defined benefit pension and postretirement items, tax		(500,000)
Amortization of defined benefit pension and postretirement items, after tax		(1,300,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(200,000)	(200,000)
Treasury Stock, Common, Shares					(16,800,000)
Common shares, issued (in shares)				65,200,000
Treasury Stock, Common, Shares					(16,800,000)
Beginning shareholders' equity at Dec. 31, 2024	1,501,000,000			$ 700,000	$ (944,700,000)	1,561,800,000	1,080,900,000	(197,700,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	29,000,000.0						29,000,000.0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	23,000,000.0							23,000,000.0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	300,000							300,000
Deferred gain (loss) on hedging activity, net of tax	(2,800,000)							(2,800,000)
Dividends declared to common shareholders	(7,600,000)						(7,600,000)
Treasury shares repurchased (in usd)	(35,200,000)				$ (35,200,000)
Treasury shares repurchased (in shares)					(1,100,000)
Activity under share plans (shares)					0
Activity under share plans (in usd)	6,200,000				$ 700,000
APIC activity under share plans						5,500,000
Ending shareholders' equity at Mar. 31, 2025	1,513,900,000			$ 700,000	$ (979,200,000)	1,567,300,000	1,102,300,000	(177,200,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(17,900,000)
Common shares, issued (in shares)				65,200,000
Treasury Stock, Common, Shares					(17,900,000)
Net earnings	29,100,000						29,100,000
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	53,500,000							53,500,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	500,000							500,000
Deferred gain (loss) on hedging activity, net of tax	(3,700,000)							(3,700,000)
Dividends declared to common shareholders	(7,000,000.0)						(7,000,000.0)
Treasury shares repurchased (in usd)	(24,600,000)				$ (24,600,000)
Treasury shares repurchased (in shares)					(900,000)
Activity under share plans (shares)					0
Activity under share plans (in usd)	6,300,000				$ 100,000
APIC activity under share plans						6,200,000
Ending shareholders' equity at Jun. 30, 2025	1,568,000,000			$ 700,000	$ (1,003,700,000)	$ 1,573,500,000	$ 1,124,400,000	$ (126,900,000)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	$ (200,000)	(200,000)
OCI Cash flow hedge, reclassification to earnings, tax		(100,000)
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax		(100,000)
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax		(600,000)
Amortization of defined benefit pension and postretirement items, tax		(200,000)
Amortization of defined benefit pension and postretirement items, after tax		(400,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		$ (500,000)
Treasury Stock, Common, Shares	18,794,499				(18,800,000)
Common shares, issued (in shares)	65,251,989			65,200,000
Treasury Stock, Common, Shares	18,794,499				(18,800,000)