Segment Information (Summary of Revenues by Segment by Component to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 3,778	$ 3,583	$ 6,445	$ 6,124
Operating Segments | Cable Network Programming Segment
Disaggregation Of Revenue [Line Items]
Revenues	1,469	1,434	2,754	2,699
Operating Segments | Cable Network Programming Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	957	938	1,896	1,877
Operating Segments | Cable Network Programming Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues	337	353	591	617
Operating Segments | Cable Network Programming Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues	175	143	267	205
Operating Segments | Television Segment
Disaggregation Of Revenue [Line Items]
Revenues	2,266	2,149	3,622	3,426
Operating Segments | Television Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	479	407	934	805
Operating Segments | Television Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues	1,673	1,634	2,460	2,433
Operating Segments | Television Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues	114	108	228	188
Operating Segments | Other, Corporate and Eliminations Segment
Disaggregation Of Revenue [Line Items]
Revenues	$ 43	$ 0	$ 69	$ (1)