v2.4.0.6

Noncontrolling Interests (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2012
Noncontrolling Interests [Abstract] |
Schedule Summarizing Changes in Equity Resulting from Net Income Attributable to Parent and Transfers to or from Noncontrolling Interests |
|  |  | Six Months Ended
|  |  | June 30
(in millions) |  | 2012 |  | 2011
Net income attributable to Comcast Corporation | $ | 2,572 | $ | 1,965
Transfers from (to) noncontrolling interests: |  |  |  |
| Increase in Comcast Corporation additional paid-in capital resulting from the |  |  |  |
|  | issuance of noncontrolling equity interest |  | - |  | 1,692
| Increase in Comcast Corporation additional paid-in capital resulting from the |  |  |  |
|  | purchase of noncontrolling interest |  | 2 |  | -
Changes in equity resulting from net income attributable to Comcast Corporation |  |  |  |
| and transfers from (to) noncontrolling interests | $ | 2,574 | $ | 3,657

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- Definition Schedule Summarizing Changes In Equity Resulting From Net Income Attributable To Parent And Transfers To Or From Noncontrolling Interests [Text Block] + References No definition available. + Details
Name: | cmcsa_ChangesInEquityResultingFromNetIncomeAttributableToParentAndTransfersToOrFromNoncontrollingInterestsTextBlock
Namespace Prefix: | cmcsa_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | cmcsa_NoncontrollingInterestsAbstract
Namespace Prefix: | cmcsa_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration