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Restructuring, Impairment, and Other Corporate Matters (Rollforward) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			$ 400
Charges	$ 35	$ 28	371	$ 156
Payments			(318)
Other			(32)
Restructuring reserve, ending balance	360		360
Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			310
Stock-Based Compensation Expense [Member]
Restructuring Reserve [Roll Forward]
Charges			51
Lease Asset Impairment [Member]
Restructuring Reserve [Roll Forward]
Charges			10
Operating Segments [Member] \| TV Entertainment [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			99
Payments			(82)
Other			(11)
Restructuring reserve, ending balance	89		89
Operating Segments [Member] \| TV Entertainment [Member] \| Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			83
Operating Segments [Member] \| Cable Networks [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			137
Payments			(122)
Other			(11)
Restructuring reserve, ending balance	145		145
Operating Segments [Member] \| Cable Networks [Member] \| Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			141
Operating Segments [Member] \| Filmed Entertainment [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			17
Payments			(8)
Other			0
Restructuring reserve, ending balance	28		28
Operating Segments [Member] \| Filmed Entertainment [Member] \| Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			19
Operating Segments [Member] \| Publishing [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			4
Payments			(2)
Other			(2)
Restructuring reserve, ending balance	2		2
Operating Segments [Member] \| Publishing [Member] \| Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			2
Corporate [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			143
Payments			(104)
Other			(8)
Restructuring reserve, ending balance	$ 96		96
Corporate [Member] \| Restructuring Charges Excluding Stock-Based Compensation [Member]
Restructuring Reserve [Roll Forward]
Charges			$ 65