Fair Value Disclosure Rollforward (Details) $ in Millions	9 Months Ended
Sep. 30, 2015 USD ($)
NBCUniversal Enterprise [Member]
Fair value of redeemable preferred stock	$ 762
Contingent Consideration Settlement [Member]
Contingent Consideration, Amount of Settlement Payment	450
Gain related to contingent consideration settlement	$ 240
Minimum [Member]
Discount rate used to determine fair value	12.00%
Minimum [Member] \| NBCUniversal Media, LLC [Member]
Discount rate used to determine fair value	12.00%
Maximum [Member]
Discount rate used to determine fair value	13.00%
Maximum [Member] \| NBCUniversal Media, LLC [Member]
Discount rate used to determine fair value	13.00%
Contractual Obligations [Member]
Beginning balance	$ 883
Fair value adjustments	236
Payments	(63)
Ending balance	1,056
Contractual Obligations [Member] \| NBCUniversal Media, LLC [Member]
Beginning balance	883
Fair value adjustments	236
Payments	(63)
Ending balance	$ 1,056

Amount paid for the settlement of a contingent consideration obligation.

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- Definition

Fair value of our redeemable subsidiary preferred shares and/or stock

+ References

No definition available.

+ Details

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- Definition

Gain related to the settlement of a contingent consideration obligation recorded in other income (expense), net.

+ References

No definition available.

+ Details

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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- Definition

Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

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- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

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