Reportable Segments (Schedule of Adjusted OIBDA by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total Adjusted OIBDA	$ 954	$ 1,126	$ 3,194	$ 3,566
Operating Segments | U.S. Networks
Segment Reporting Information [Line Items]
Total Adjusted OIBDA	951	1,005	3,029	3,192
Operating Segments | International Networks
Segment Reporting Information [Line Items]
Total Adjusted OIBDA	127	237	527	742
Operating Segments | Corporate, inter-segment eliminations and other
Segment Reporting Information [Line Items]
Total Adjusted OIBDA	$ (124)	$ (116)	$ (362)	$ (368)