Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Retirement Benefits [Abstract]
Service cost	$ 0.5	$ 0.5	$ 1.4	$ 1.4
Interest cost	5.3	5.3	16.0	15.9
Expected return on plan assets	(4.9)	(5.4)	(14.6)	(16.3)
Recognized net actuarial loss	0.4	0.4	1.1	1.2
Net periodic cost	1.3	0.8	3.9	9.4
Defined benefit settlement loss		0.0		(7.2)
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.5	0.5	1.4	1.4
Interest cost	5.3	5.3	16.0	15.9
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	4.9	5.4	14.6	16.3
Defined Benefit Plan, Amortization of Gain (Loss)	(0.4)	(0.4)	(1.1)	(1.2)
Defined benefit settlement loss		0.0		7.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	1.3	$ 0.8	$ 3.9	9.4
Pension Plan
Retirement Benefits [Abstract]
Defined benefit settlement loss	7.2			7.2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit settlement loss	$ (7.2)			$ (7.2)