v2.4.1.9

Related Party Transactions (Narrative) (Details) (USD $) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2015 | Dec. 31, 2014
Other noncurrent liabilities | $ 10,837,000,000 us-gaap_OtherLiabilitiesNoncurrent | $ 10,819,000,000 us-gaap_OtherLiabilitiesNoncurrent
NBCUniversal Media, LLC [Member] |  |
Borrowing margin for LIBOR based borrowings | 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
Other noncurrent liabilities | 3,692,000,000 us-gaap_OtherLiabilitiesNoncurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 3,722,000,000 us-gaap_OtherLiabilitiesNoncurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Nbcuniversal Holdings Preferred Stock [Member] | NBCUniversal Media, LLC [Member] |  |
Preferred stock liquidation preference value | 9,400,000,000 us-gaap_PreferredStockLiquidationPreferenceValue / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = cmcsa_NbcuniversalHoldingsPreferredStockMember |
Preferred stock dividend rate percentage | 8.25%us-gaap_PreferredStockDividendRatePercentage / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = cmcsa_NbcuniversalHoldingsPreferredStockMember |
Carrying Value Of Related Party Contractual Obligation [Member] | NBCUniversal Media, LLC [Member] |  |
Other noncurrent liabilities | 383,000,000 us-gaap_OtherLiabilitiesNoncurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = cmcsa_CarryingValueOfRelatedPartyContractualObligationMember |
Comcast Corporation And NBCUniversal Media LLC Revolving Credit Agreement [Member] | NBCUniversal Media, LLC [Member] |  |
Revolving Credit Agreement Capacity | $ 3,000,000,000 cmcsa_RevolvingCreditAgreementCapacity / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = cmcsa_ComcastCorporationAndNBCUniversalMediaLLCRevolvingCreditAgreementMember |

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- Definition The maximum amount of borrowing or lending capacity with respect to the cash management arrangement between Comcast and NBCUniversal under the revolving credit agreement. + References No definition available. + Details
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- Definition Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet. Noncurrent liabilities are expected to be paid 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 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 + Details
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- Details
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