Pension and Other Postretirement Benefits - Schedule of Amounts Recognized in Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Net amounts recognized	$ 374
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Pension assets	8	$ 6
Accrued pension liabilities	(327)	(408)
Net amounts recognized	(319)	(402)
Postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Pension assets	0	0
Accrued pension liabilities	(47)	(53)
Net amounts recognized	$ (47)	$ (53)