Segment Information (Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	$ 8,553	$ 7,313	$ 25,822	$ 21,974
Adjustment for Sky transaction-related costs	(33)	0	(168)	0
Depreciation	(2,124)	(2,038)	(6,561)	(6,070)
Amortization	(1,056)	(580)	(3,215)	(1,750)
Other operating gains	0	141	0	341
Interest expense	(1,167)	(830)	(3,454)	(2,413)
Investment and other income (loss), net	(110)	(111)	511	92
Income (loss) before income taxes	4,063	3,895	12,935	12,174
NBCUniversal Media LLC [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	2,089	2,066	6,747	6,511
Depreciation	(259)	(250)	(755)	(750)
Amortization	(278)	(264)	(824)	(827)
Other operating gains	0	141	0	141
Interest expense	(348)	(134)	(601)	(394)
Investment and other income (loss), net	169	(205)	449	(377)
Income (loss) before income taxes	$ 1,373	$ 1,354	$ 5,016	$ 4,304

The measure used to evaluate the profitability of operating segments.

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Acquisition related and integration costs which have been expensed during the period. Such costs could include costs directly related to the transaction, including the U.K. share acquisition tax and success-based investment banker fees, and legal, accounting and valuation services, and costs incurred to effect a business combination, such as business integration costs, systems integration and conversion costs, and severance and other employee-related costs.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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