v2.4.0.8

Significant Transactions (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 19, 2013	Jan. 28, 2011
Significant Transactions [Line Items]
Purchase of NBCUniversal noncontrolling interest	$ 16,700,000,000
Ownership Percentage In New Company			51.00%		51.00%
Cash paid to acquire entity including transaction related costs					6,200,000,000
Remaining equity interest acquired				49.00%
Acquisitions, net of cash acquired	99,000,000	90,000,000	6,407,000,000
Deferred income taxes	31,935,000,000	30,110,000,000
NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Purchase of NBCUniversal noncontrolling interest	16,700,000,000
Cash paid to acquire entity including transaction related costs					6,200,000,000
Remaining equity interest acquired				49.00%
Redemption percentage	15.00%
Comcast Corporation [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Ownership percentage in NBCUniversal Holdings	96.00%
NBCUniversal [Member]
Significant Transactions [Line Items]
Deferred income tax liabilities					35,000,000
Goodwill					10,900,000,000
Universal Orlando [Member]
Significant Transactions [Line Items]
Remaining equity interest acquired			50.00%
Cash paid to acquire entity, net			1,000,000,000
Universal Orlando [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Remaining equity interest acquired			50.00%
Cash paid to acquire entity, net			1,000,000,000
Comcast Cash On Hand
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	11,400,000,000
Comcast Cash On Hand | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	11,400,000,000
NBCUniversal Cash On Hand [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Portion Of Consideration Transferred Funded By NBCUniversal	4,600,000,000
NBCUniversal Enterprise Senior Unsecured Debt Securities
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	4,000,000,000
NBCUniversal Enterprise Senior Unsecured Debt Securities | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	4,000,000,000
Comcast Commercial Paper Program
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	750,000,000
Comcast Commercial Paper Program | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	750,000,000
NBCUniversal Enterprise Credit Facility
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	1,250,000,000
NBCUniversal Enterprise Credit Facility | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	1,250,000,000
NBCUniversal Enterprise Preferred Stock
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	725,000,000
Fair Value Amount Of Redeemable Preferred Stock	741,000,000
NBCUniversal Enterprise Preferred Stock | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	725,000,000
Nbcuniversal Holdings Preferred Stock [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Preferred stock dividend rate percentage	8.25%
Preferred stock liquidition preference value	9,400,000,000
Preferred stock dividend reset rate percentage description	On March 1, 2018, and thereafter on every fifth anniversary of such date, this rate will reset to 7.44% plus the yield on actively traded United States Treasury securities having a 5 year maturity.
30 Rockefeller Plaza And Englewood Cliffs [Member]
Significant Transactions [Line Items]
Payments related to acquisition of real estate properties	1,400,000,000
30 Rockefeller Plaza And Englewood Cliffs [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Payments related to acquisition of real estate properties	1,400,000,000
NBCUniversal Enterprise [Member]
Significant Transactions [Line Items]
Preferred stock dividend rate percentage	5.25%
NBCUniversal Enterprise [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Ownership percentage in NBCUniversal Holdings	4.00%
NBCUniversal Transaction [Member]
Significant Transactions [Line Items]
Deferred income taxes					576,000,000
Theme Parks Segment [Member]
Significant Transactions [Line Items]
Goodwill			982,000,000
Theme Parks Segment [Member] | NBCUniversal Media, LLC [Member]
Significant Transactions [Line Items]
Goodwill			982,000,000
Redemption Transaction [Member]
Significant Transactions [Line Items]
Deferred income taxes	$ 1,600,000,000

X

- Definition

Amount of cash paid to acquire the remaining interest in an unconsolidated subsidiary net of the portion of cash and cash equivalents not previously attributable to the acquiror.

+ References

No definition available.

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- Definition

Amount of acquisition cost of a business combination allocated to noncurrent deferred tax assets net of valuation allowance and noncurrent deferred tax liabilities.

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No definition available.

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- Definition

Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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No definition available.

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- Definition

Cash Paid To Acquire Entity Including Transaction-Related Costs

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- Definition

The consideration associated with the purchase of GE's 49% noncontrolling common equity interest in NBCUniversal related to the Redemption Transaction and the acquisition of certain properties at 30 Rockefeller Plaza and Engelwood Cliffs.

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No definition available.

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- Definition

The total consideration associated with the purchase of GE's 49% noncontrolling common equity interest in NBCUniversal.

+ References

No definition available.

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- Definition

Fair value of our redeemable subsidiary preferred stock.

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No definition available.

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- Definition

Represents the percentage of voting interest acquired at the acquisition date from a noncontrolling interest.

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No definition available.

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- Definition

Represents the ownership percentage in NBCUniversal Holdings.

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- Definition

The Company's ownership percentage in new company.

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- Definition

The total purchase price for acquisitions of real estate properties.

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- Definition

Portion of consideration transferred related to the Redemption Transaction and purchase of certain properties funded by NBCUniversal.

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No definition available.

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- Definition

The description of the percentage rate used to calculate dividend payments on preferred stock at the future reset date.

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No definition available.

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- Definition

The percentage of preferred units that NBCUniversal Enterprise owns for which NBCUniversal Enterprise has the right to cause NBCUniversal Holdings to redeem at a future date.

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No definition available.

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e31917-109318



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- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133



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- Definition

The percentage rate used to calculate dividend payments on preferred stock.

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- Definition

Value of the difference between preference in liquidation and the par or stated values of the preferred shares.

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