Unrecognized cost of unvested share-based compensation awards.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

The tax effect of items occurring during the period that have been charged or credited directly to components of shareholders' equity and are not otherwise defined.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 20

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=18498875&loc=d3e39076-109324

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Share-Based Compensation (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income tax effects allocated directly to equity, other	$ 299	$ 244	$ 164
Share-based compensation arrangement by share-based payment award, award vesting period in years	5 years 0 months 0 days
NBCUniversal Media, LLC [Member]
Share-based compensation arrangement by share-based payment award, award vesting period in years	5 years 0 months 0 days
Stock Options [Member]
Unrecognized pretax compensation expense on nonvested awards	321
Unrecognized pretax compensation expense on nonvested awards, weighted average period of recognition (in years)	1 year 9 months 18 days
Period from grant date that an equity-based award expires	10 years 0 months 0 days
Stock Options [Member] \| NBCUniversal Media, LLC [Member]
Unrecognized pretax compensation expense on nonvested awards	25
Unrecognized pretax compensation expense on nonvested awards, weighted average period of recognition (in years)	2 years 1 month 6 days
Period from grant date that an equity-based award expires	10 years 0 months 0 days
Restricted Share Units [Member]
Unrecognized pretax compensation expense on nonvested awards	505
Unrecognized pretax compensation expense on nonvested awards, weighted average period of recognition (in years)	1 year 8 months 12 days
Restricted Share Units [Member] \| NBCUniversal Media, LLC [Member]
Unrecognized pretax compensation expense on nonvested awards	$ 124
Unrecognized pretax compensation expense on nonvested awards, weighted average period of recognition (in years)	1 year 7 months 6 days