Segment and Revenue Information (Revenues) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 6,874	$ 5,837	$ 6,075	$ 6,499	$ 6,656	$ 6,481	$ 6,925	$ 6,936	$ 25,285	$ 26,998	$ 26,425
Advertising [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									9,751	11,074	10,841
Affiliate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									9,166	8,602	8,376
Content Licensing [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									5,963	6,483	6,163
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									225	292	301
Theatrical [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									180	547	744
Operating Segments [Member] | TV Entertainment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									10,700	11,924	11,061
Operating Segments [Member] | TV Entertainment [Member] | Advertising [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									5,035	6,008	5,751
Operating Segments [Member] | TV Entertainment [Member] | Affiliate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									3,129	2,550	2,082
Operating Segments [Member] | TV Entertainment [Member] | Content Licensing [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,369	3,157	3,006
Operating Segments [Member] | TV Entertainment [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									167	209	222
Operating Segments [Member] | Cable Networks [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									12,589	12,449	12,683
Operating Segments [Member] | Cable Networks [Member] | Advertising [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									4,743	5,129	5,130
Operating Segments [Member] | Cable Networks [Member] | Affiliate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									6,037	6,052	6,294
Operating Segments [Member] | Cable Networks [Member] | Content Licensing [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,809	1,268	1,259
Operating Segments [Member] | Filmed Entertainment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,562	2,990	2,956
Operating Segments [Member] | Filmed Entertainment [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									75	111	102
Operating Segments [Member] | Filmed Entertainment [Member] | Theatrical [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									180	547	744
Operating Segments [Member] | Filmed Entertainment [Member] | Home Entertainment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									709	623	617
Operating Segments [Member] | Filmed Entertainment [Member] | Licensing [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,598	1,709	1,493
Corporate/Eliminations [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									(566)	(365)	(275)
Intersegment Eliminations [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									(566)	(396)	(306)
Intersegment Eliminations [Member] | TV Entertainment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									(285)	(226)	(164)
Intersegment Eliminations [Member] | Cable Networks [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									(79)	(53)	(47)
Intersegment Eliminations [Member] | Filmed Entertainment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ (202)	$ (117)	$ (95)