Retirement Plans (Schedule of Fair Value of Plan Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 417.8	$ 412.3
Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	173.8	160.6
Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0.0	0.0
Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	244.0	251.7
Non-US equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	49.5	45.5
Non-US equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	49.5	45.5
Non-US equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0.0	0.0
Non-US equity securities | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	20.4	22.5
US Government Agencies Debt Securities | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	67.7	64.9
Defined Benefit Plan, Equity Securities, US, Large Cap
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	28.5	26.9
Defined Benefit Plan, Equity Securities, US, Large Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	28.5	26.9
Defined Benefit Plan, Equity Securities, US, Large Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0.0	0.0
Defined Benefit Plan, Equity Securities, US, Large Cap | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	36.7	53.0
Defined Benefit Plan, Cash
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	5.7	4.8
Defined Benefit Plan, Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	5.7	4.8
Defined Benefit Plan, Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0.0	0.0
Debt Security, Corporate, US
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	90.1	83.4
Debt Security, Corporate, US | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	90.1	83.4
Debt Security, Corporate, US | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0.0	0.0
Debt Security, Corporate, US | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	119.2	111.3
Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 244.0	$ 251.7