v3.20.4

Equity Method Investments (Reconciliation Of Investments In Equity Affiliates) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity Method Investments [Roll Forward]
Beginning of year	$ 3,695	$ 6,245
Additional investments	178	448
Equity in net income (loss) of affiliates	95	6	$ (48)
Dividends and distributions received	(133)	(301)
Currency translation adjustments	(10)	(10)
Impairments	(146)	0
Other adjustments	(9)	(35)
End of year	1,780	3,695	$ 6,245
HBO LAG
Equity Method Investments [Roll Forward]
Acquisition of remaining interest in HBO LAG	(1,141)	0
CME
Equity Method Investments [Roll Forward]
Disposition of investments	(749)	0
Hudson Yards
Equity Method Investments [Roll Forward]
Disposition of investments	0	(1,681)
Hulu
Equity Method Investments [Roll Forward]
Disposition of investments	0	(689)
Game Show Network
Equity Method Investments [Roll Forward]
Disposition of investments	$ 0	$ (288)

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Represents the purchase by the parent of an additional equity interest in a subsidiary during the period, thereby effecting a change in total (consolidated) equity attributable to the parent. The purchase of the additional equity interest represented by this element increases the parent's controlling interest in the subsidiary.

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Represents a sale by the parent of a portion of its equity interest in a subsidiary during the period, thereby effecting a change in total (consolidated) equity attributable to the parent. The sale of the equity interest represented by this element does not result in a loss of control by the parent.

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Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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