Basis of Presentation and Accounting Policies - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 22.2		$ 22.2		$ 16.8
Antidilutive share-based compensation awards (in shares)	0.5	0.4	0.5	0.5
Capital expenditures in accounts payable or other current liabilities at period end			$ 29.5	$ 42.5
Outstanding purchase of common stock recorded in accounts payable			0.6	$ 0.8
Supplier finance program, obligation	$ 77.2		$ 77.2		$ 126.7