Pension and Other Postretirement Benefits - Summary of Projected Benefit Obligations in Excess of Plan Assets and Accumulated Benefit Obligations in Excess of Plan Assets (Details) - USD ($) $ in Millions	Jun. 30, 2026	Jun. 30, 2025
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 636.3	$ 674.2
Fair value of plan assets	547.1	528.4
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	24.3	171.1
Fair value of plan assets	$ 0.0	$ 143.3

Pension and Other Postretirement Benefits - Summary of Projected Benefit Obligations in Excess of Plan Assets and Accumulated Benefit Obligations in Excess of Plan Assets (Details) - USD ($)
$ in Millions

Jun. 30, 2026

Jun. 30, 2025

Defined Benefit Plan Disclosure [Line Items]

Accumulated benefit obligation

$ 636.3

$ 674.2

Fair value of plan assets

547.1

528.4

Other Postretirement Plans

Defined Benefit Plan Disclosure [Line Items]

Accumulated benefit obligation

24.3

171.1

Fair value of plan assets

$ 0.0

$ 143.3

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details