CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Common Stock in Treasury, at Cost
Balance at Sep. 30, 2020	$ 2,924.4	$ 0.7	$ 800.9	$ 2,821.4	$ (198.4)	$ (500.2)
Net income	508.9			508.9
Employee pension and postretirement benefits, net of tax	61.7				61.7
Currency translation adjustments	3.8				3.8
Derivative instruments, net of tax	1.9				1.9
Cash dividends	(90.4)			(90.4)
Repurchases of Common Stock	(107.8)					(107.8)
Exercise of stock options	42.8		0.2			42.6
Stock-based compensation expense	27.2		27.2
Payment of stock-based restricted and performance shares			(23.3)			23.3
Shares tendered for taxes on stock-based compensation	(14.3)					(14.3)
Other	(0.5)		(0.4)	(0.7)		0.6
Balance at Sep. 30, 2021	3,357.7	0.7	804.6	3,239.2	(131.0)	(555.8)
Net income	24.2			24.2
Employee pension and postretirement benefits, net of tax	8.6				8.6
Currency translation adjustments	(6.9)				(6.9)
Derivative instruments, net of tax	0.7				0.7
Cash dividends	(24.9)			(24.9)
Repurchases of Common Stock	(150.0)					(150.0)
Exercise of stock options	2.7		0.1			2.6
Stock-based compensation expense	4.2		4.2
Payment of stock-based restricted and performance shares			(16.5)			16.5
Shares tendered for taxes on stock-based compensation	(12.0)					(12.0)
Balance at Dec. 31, 2021	3,204.3	0.7	792.4	3,238.5	(128.6)	(698.7)
Net income	173.9			173.9
Employee pension and postretirement benefits, net of tax	56.7				56.7
Currency translation adjustments	(26.4)				(26.4)
Derivative instruments, net of tax	6.0				6.0
Cash dividends	(97.3)			(97.3)
Repurchases of Common Stock	(155.0)					(155.0)
Exercise of stock options	3.1		(0.3)			3.4
Stock-based compensation expense	28.6		28.6
Payment of stock-based restricted and performance shares			(14.0)			14.0
Shares tendered for taxes on stock-based compensation	(8.3)					(8.3)
Other	0.1		(0.7)	(0.1)		0.9
Balance at Dec. 31, 2022	3,185.7	0.7	806.0	3,315.0	(92.3)	(843.7)
Net income	598.0			598.0
Employee pension and postretirement benefits, net of tax	1.9				1.9
Currency translation adjustments	27.1				27.1
Derivative instruments, net of tax	(8.7)				(8.7)
Cash dividends	(107.2)			(107.2)
Repurchases of Common Stock	(22.5)					(22.5)
Exercise of stock options	9.2		1.5			7.7
Stock-based compensation expense	31.9		31.9
Payment of stock-based restricted and performance shares			(16.8)			16.8
Shares tendered for taxes on stock-based compensation	(11.0)					(11.0)
Other	0.9		0.4			0.5
Balance at Dec. 31, 2023	$ 3,705.3	$ 0.7	$ 823.0	$ 3,805.8	$ (72.0)	$ (852.2)