Additional Financial Information (Components of Other Non-current Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Investments	[1]	$ 1,006	$ 618
Operating lease ROU assets		474	539
Grantor Trust		279	247
Inventories, net		232	202
Other		176	195
Total other non-current assets		$ 2,167	$ 1,801

[1] Included investments accounted for at fair value on a recurring basis of $894 million and $531 million as of December 31, 2020 and June 30, 2020, respectively (See Note 4—Fair Value).