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Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 12,069		$ 12,069		$ 10,972
Recognized share-based compensation expense	168	$ 181	307	$ 305
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	5,138		5,138		$ 4,153
Recognized share-based compensation expense	46	$ 40	78	$ 65
Carrying Value of Related Party Contractual Obligation [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 383		$ 383

X

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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- Definition

Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

+ References

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- Definition

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.

+ References

No definition available.

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