Pension and Other Postretirement Benefits (Schedule of Amounts Recognized in Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Millions		Jun. 30, 2019	Jun. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses	[1]	$ 385	$ 80
Prior service cost		3	5
Net amounts recognized		388	85
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses	[1]	22	0
Prior service cost		0	0
Net amounts recognized		$ 22	$ 0

[1] The increase in actuarial losses was primarily related to the accumulated actuarial losses transferred to the Company from 21CF of $188 million and $18 million for pension and postretirement benefits, respectively, and the change in the discount rate assumption utilized in measuring plan obligations.