Retirement Plans (Schedule of Fair Value of Plan Assets Measured at NAV) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 412.3	$ 363.9
Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	251.7	228.9
US Equity securities | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	53.0	48.9
Non-US equity securities | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22.5	21.4
US Government Agencies Debt Securities | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	64.9	$ 158.6
Corporate | Fair value measured at net asset value per share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 111.3