Reportable Segments (Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets	$ 51,188	$ 49,519
Assets of discontinued operations	11	15
Operating Segments [Member] | TV Entertainment [Member]
Segment Reporting Information [Line Items]
Assets	19,289	19,689
Operating Segments [Member] | Cable Networks [Member]
Segment Reporting Information [Line Items]
Assets	22,539	22,109
Operating Segments [Member] | Filmed Entertainment [Member]
Segment Reporting Information [Line Items]
Assets	6,454	5,477
Operating Segments [Member] | Publishing [Member]
Segment Reporting Information [Line Items]
Assets	1,246	1,262
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Assets	$ 1,649	$ 967