Segment Information (Summary of Revenues by Segment by Component to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 2,418	$ 3,440	$ 3,778	$ 2,667	$ 2,513	$ 2,752	$ 3,583	$ 2,541	$ 12,303	$ 11,389	$ 10,153
Operating Segments | Cable Network Programming Segment
Disaggregation Of Revenue [Line Items]
Revenues									5,492	5,381	5,049
Operating Segments | Cable Network Programming Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues									3,870	3,804	3,541
Operating Segments | Cable Network Programming Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues									1,164	1,184	1,120
Operating Segments | Cable Network Programming Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues									458	393	388
Operating Segments | Television Segment
Disaggregation Of Revenue [Line Items]
Revenues									6,661	5,979	5,106
Operating Segments | Television Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues									2,038	1,708	1,382
Operating Segments | Television Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues									4,169	3,872	3,478
Operating Segments | Television Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues									454	399	246
Operating Segments | Other, Corporate and Eliminations Segment
Disaggregation Of Revenue [Line Items]
Revenues									$ 150	$ 29	$ (2)