Pension and Other Postretirement Benefits - Defined Benefit - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plans, employer contribution	$ 70	$ 68	$ 58
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	1,010	1,040
Fair value of plan asset	891	853	801
Projected benefit obligation	$ 1,119	$ 1,172	$ 1,203
Actual asset allocation (as percent)	100.00%	100.00%
Pension Benefits | Return Seeking Assets
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation (as percent)	37.00%
Actual asset allocation (as percent)	44.00%
Pension Benefits | Liability Hedging Assets
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation (as percent)	63.00%
Actual asset allocation (as percent)	56.00%
Pension Benefits | Overfunded Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation		$ 112
Fair value of plan asset		123
Projected benefit obligation		$ 115