Segment Information (Summary of Revenues by Segment by Component to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Revenues	$ 3,583	$ 3,108	$ 6,124	$ 5,296
Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	1,345	1,174	2,682	2,329
Advertising
Disaggregation Of Revenue [Line Items]
Revenues	1,987	1,732	3,050	2,620
Operating Segments | Cable Network Programming Segment
Disaggregation Of Revenue [Line Items]
Revenues	1,434	1,315	2,699	2,453
Operating Segments | Cable Network Programming Segment | Affiliate Fee
Disaggregation Of Revenue [Line Items]
Revenues	938	848	1,877	1,678
Operating Segments | Cable Network Programming Segment | Advertising and other
Disaggregation Of Revenue [Line Items]
Revenues	496	467	822	775
Operating Segments | Television Segment
Disaggregation Of Revenue [Line Items]
Revenues	2,149	1,793	3,426	2,844
Operating Segments | Television Segment | Advertising
Disaggregation Of Revenue [Line Items]
Revenues	1,634	1,411	2,433	2,061
Operating Segments | Television Segment | Affiliate fee and other
Disaggregation Of Revenue [Line Items]
Revenues	515	382	993	783
Other, Corporate and Eliminations Segment
Disaggregation Of Revenue [Line Items]
Revenues	$ 0	$ 0	$ (1)	$ (1)