Retirement Plans (Schedule of Net Periodic Pension and Postretirement Benefit (Credit) Cost) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement loss recognized	[1]	$ 1.8	$ 0.0
Pension plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		3.8	4.4	$ 4.3
Interest cost		$ 10.2	$ 9.6	$ 13.5
Interest cost - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Expected return on plan assets		$ (21.1)	$ (22.4)	$ (23.1)
Expected return on plan assets - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Recognized net actuarial loss (gain)		$ 6.4	$ 9.5	$ 9.3
Recognized net actuarial loss (gain) - financial statement location		Nonoperating Income (Expense)	Nonoperating Income (Expense)	Nonoperating Income (Expense)
Settlement loss recognized		$ (1.8)	$ 0.0	$ (0.8)
Net periodic benefit cost (credit)		1.1	1.1	4.8
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	$ 0.3
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)	$ (0.1)
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)	$ 0.2

[1] Includes pre-tax other (income) expense of $1.8for fiscal 2022 for a pension settlement expenses.