SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Allowance for doubtful accounts, early pay discounts, and sales returns
Valuation and qualifying accounts activity
Balance at Beginning of Period	$ 13.6	$ 10.1	$ 6.4
Charged to Revenue, Costs, and Expense	2.2	3.8	2.6
Charged to Other Accounts	0.2	0.4	1.7
Deductions Net of Recoveries	(4.2)	(0.7)	(0.6)
Divestiture	(0.5)	0.0	0.0
Balance at End of Period	11.3	13.6	10.1
Allowance for inventory valuation
Valuation and qualifying accounts activity
Balance at Beginning of Period	47.8	41.7	29.5
Charged to Revenue, Costs, and Expense	10.3	9.4	8.9
Charged to Other Accounts	2.1	1.4	5.8
Deductions Net of Recoveries	(7.7)	(4.7)	(2.5)
Divestiture	(13.1)	0.0	0.0
Balance at End of Period	$ 39.4	$ 47.8	$ 41.7