Basis of Presentation and Accounting Policies - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 16.2		$ 16.2		$ 13.1
Allowance for certain customer returns, rebates and incentives	$ 28.2		$ 28.2		$ 13.9
Antidilutive share-based compensation awards (in shares)	0.4	0.3	0.5	0.3
Capital expenditures in accounts payable or other current liabilities at period end			$ 34.0	$ 8.1
Outstanding purchase of common stock recorded in accounts payable			$ 0.8	$ 0.0