Retirement Benefits - Schedule of Information for Pension Plans with Projected Benefit Obligations in Excess of Plan Assets (Details) - Pension Plan - USD ($) $ in Millions	Jun. 30, 2025	Jun. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 3,865	$ 4,211
Fair value of plan assets	$ 3,665	$ 3,794