Other Income (Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Other Income and Expenses [Abstract]
Interest income	$ 3.1	$ 1.5	$ 11.6	$ 4.1
Royalty income	2.8	3.4	9.0	9.3
Legacy product liability and environmental charges	(3.4)	(4.8)	(11.1)	(10.7)
Non-operating pension and postretirement benefit credit (cost)	4.9	5.5	14.7	(87.5)
Other	(0.6)	0.9	6.3	1.5
Other income (expense)	$ 6.8	$ 6.5	$ 30.5	$ (83.3)