Divestitures - Schedule of Discontinued Operations, Income Statement (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations (net of income tax expense)	$ 19.5	$ 99.5	$ 127.2
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation		9.3
Gain on divestiture of discontinued operations (net of income tax expense)	443.1	0.0	0.0
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	213.7	625.6	623.4
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	142.2	434.8	398.4
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)	71.5	190.8	225.0
Disposal Group, Including Discontinued Operation, Operating Expense	42.3	76.4	77.9
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	29.2	114.4	147.1
Discontinued Operation, Tax Effect of Discontinued Operation	9.7	14.9	19.9
Income from discontinued operations (net of income tax expense)	19.5	99.5	127.2
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation	142.9
Total income from discontinued operations (net of income tax expense)	$ 462.6	$ 99.5	$ 127.2