Investments (Investment and Other Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	$ (202)	$ 69	$ 60	$ 20
Realized and unrealized gains (losses) on equity securities, net	194	(40)	408	(12)
Other income (loss), net	(47)	48	153	195
Investment and other income (loss), net	(55)	77	621	203
NBCUniversal Media LLC [Member]
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	(91)	(87)	(211)	(187)
Realized and unrealized gains (losses) on equity securities, net	97	(74)	258	(37)
Other income (loss), net	34	(7)	233	52
Investment and other income (loss), net	$ 40	$ (168)	$ 280	$ (172)

Nonoperating income (losses), net recorded in the income statement that are not separately stated.

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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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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