Pension and Other Postretirement Benefits - Schedule of Projected Benefit Obligations in Excess of Plan Assets and Accumulated Benefit Obligations in Excess of Plan Assets (Details) - USD ($) $ in Millions	Jun. 30, 2025	Jun. 30, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 674.2	$ 678.5
Fair value of plan assets	528.4	471.8
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	171.1	172.8
Fair value of plan assets	$ 143.3	$ 136.3