Stockholders' Equity (Summary of Components of Accumulated Other Comprehensive (Loss) Income, Net of Tax) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Equity [Abstract]
Benefit plan adjustments and other	$ (318)	$ (417)	$ (308)	[1]
Accumulated other comprehensive loss, net of tax	$ (318)	$ (417)	$ (308)

[1] Includes a reclassification of $13 million as a result of the adoption of ASU 2018-02, “Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” to eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act enacted in December 2017 and $157 million related to the Shared Plans (as defined in Note 15—Pension and Other Postretirement Benefits”) allocable to the Company’s employees that was transferred to the Company in fiscal 2019 (See Statements of Equity).