Segment Information (Summary of Revenues by Segment by Component to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 2,752	$ 2,463	$ 8,876	$ 7,759
Operating Segments | Cable Network Programming Segment
Disaggregation Of Revenue [Line Items]
Revenues	1,383	1,325	4,082	3,778
Operating Segments | Cable Network Programming Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	968	931	2,845	2,609
Operating Segments | Cable Network Programming Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues	276	266	893	825
Operating Segments | Cable Network Programming Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues	139	128	344	344
Operating Segments | Television Segment
Disaggregation Of Revenue [Line Items]
Revenues	1,370	1,138	4,796	3,982
Operating Segments | Television Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	452	350	1,257	1,001
Operating Segments | Television Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues	812	735	3,245	2,796
Operating Segments | Television Segment | Other
Disaggregation Of Revenue [Line Items]
Revenues	106	53	294	185
Other, Corporate and Eliminations Segment
Disaggregation Of Revenue [Line Items]
Revenues	$ (1)	$ 0	$ (2)	$ (1)