Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Net Income (Loss) Attributable to Parent [Abstract]
Net revenues	$ 1,443.5	$ 1,236.1	$ 1,037.2
Cost of sales	899.0	759.7	604.9
Gross profit	544.5	476.4	432.3
Selling, general and administrative expenses	264.5	244.7	223.9
Net legacy and separation-related expenses (income)	32.8	20.5	(23.6)
Other income, net	0.0	(9.1)	(8.1)
Operating income	247.2	220.3	240.1
Net pension and other postretirement plan (income) expense	(27.6)	6.9	(128.2)
Net interest and other financing expenses	38.3	69.3	108.3
Total income before income taxes	236.5	144.1	260.0
Income tax expense	37.1	34.7	59.9
Income from continuing operations	199.4	109.4	200.1
(Loss) income from discontinued operations, net of tax	1,220.3	314.9	220.2
Net income	$ 1,419.7	$ 424.3	$ 420.3
NET EARNINGS PER SHARE
Continuing operations, basic earnings per share (usd per share)	$ 1.24	$ 0.61	$ 1.10
Discontinued operations, basic earnings per share (usd per share)	7.55	1.76	1.20
Basic earnings per share (usd per share)	8.79	2.37	2.30
Continuing operations, diluted earnings per share (usd per share)	1.23	0.61	1.09
Discontinued operations, diluted earnings per share (usd per share)	7.50	1.74	1.20
Diluted earnings per share (usd per share)	$ 8.73	$ 2.35	$ 2.29
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
Weighted average common shares outstanding, basic (in shares)	161.6	179.1	182.5
Weighted average common shares outstanding, diluted (in shares)	162.6	180.4	183.5
COMPREHENSIVE INCOME
Net income	$ 1,419.7	$ 424.3	$ 420.3
Other comprehensive income (loss), net of tax
Currency translation adjustments	43.7	(39.6)	6.6
Amortization of pension and other postretirement plan prior service credits	(1.7)	(1.7)	(9.0)
Unrealized (loss) gain on cash flow hedges	(7.5)	12.5	1.7
Other comprehensive income (loss)	34.5	(28.8)	(0.7)
Comprehensive income	$ 1,454.2	$ 395.5	$ 419.6