Retirement Plans (Schedule of Net Periodic Pension and Postretirement Benefit (Credit) Cost) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement loss recognized	[1]			$ 0.0
Pension plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		$ 1.9	$ 3.8	4.4
Interest cost		$ 20.6	$ 10.2	$ 9.6
Interest cost - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Expected return on plan assets		$ (21.5)	$ (21.1)	$ (22.4)
Expected return on plan assets - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Recognized net actuarial loss (gain)		$ 1.7	$ 6.4	$ 9.5
Recognized net actuarial loss (gain) - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Settlement loss recognized		$ (7.9)	$ (1.8)	$ 0.0
Net periodic benefit cost (credit)		10.6	1.1	1.1
Postretirement plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.0	0.0	0.0
Interest cost		$ 0.2	$ 0.2	$ 0.2
Interest cost - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Expected return on plan assets		$ 0.0	$ 0.0	$ 0.0
Expected return on plan assets - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Recognized net actuarial loss (gain)		$ (0.3)	$ (0.3)	$ (0.3)
Recognized net actuarial loss (gain) - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Settlement loss recognized		$ 0.0	$ 0.0	$ 0.0
Net periodic benefit cost (credit)		$ (0.1)	$ (0.1)	$ (0.1)

[1] Includes pre-tax Other expense (income), net of $7.9 and $1.8 for fiscal 2023 and 2022, respectively, related to pension settlement expenses. (8)Includes pre-tax SG&A of $0.4 for fiscal 2023 related to the write off of assets associated with a prior year divestiture.