v2.4.1.9

Goodwill and Intangible Assets (Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013
Franchise rights | $ 59,364 us-gaap_IndefiniteLivedFranchiseRights | $ 59,364 us-gaap_IndefiniteLivedFranchiseRights
Accumulated amortization | (10,170)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization | (8,874)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Total | 86,514 us-gaap_IntangibleAssetsGrossExcludingGoodwill | 85,567 us-gaap_IntangibleAssetsGrossExcludingGoodwill
NBCUniversal Media, LLC [Member] |  |
Accumulated amortization | (4,829)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | (4,003)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Total | 19,016 us-gaap_IntangibleAssetsGrossExcludingGoodwill / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 18,860 us-gaap_IntangibleAssetsGrossExcludingGoodwill / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Trade names |  |
Indefinite Lived Intangible Assets Excluding Goodwill | 3,083 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember | 3,089 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember
Trade names | NBCUniversal Media, LLC [Member] |  |
Indefinite Lived Intangible Assets Excluding Goodwill | 3,059 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 3,089 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
FCC Licenses |  |
Indefinite Lived Intangible Assets Excluding Goodwill | 651 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_LicensingAgreementsMember | 652 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_LicensingAgreementsMember
FCC Licenses | NBCUniversal Media, LLC [Member] |  |
Indefinite Lived Intangible Assets Excluding Goodwill | 651 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_LicensingAgreementsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 652 us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_LicensingAgreementsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Customer relationships |  |
Finite-lived intangible assets, gross carrying amount | 15,129 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember | 15,037 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember
Accumulated amortization | (5,495)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember | (4,772)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember
Weighted average original useful life | 19 years 0 months 0 days |
Customer relationships | NBCUniversal Media, LLC [Member] |  |
Finite-lived intangible assets, gross carrying amount | 13,093 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 13,086 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Accumulated amortization | (3,636)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | (2,982)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Weighted average original useful life | 19 years 0 months 0 days |
Cable franchise renewal costs and contractual operating rights |  |
Finite-lived intangible assets, gross carrying amount | 1,418 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_CableFranchiseRenewalCostsAndContractualOperatingRightsMember | 1,360 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_CableFranchiseRenewalCostsAndContractualOperatingRightsMember
Accumulated amortization | (792)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_CableFranchiseRenewalCostsAndContractualOperatingRightsMember | (745)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_CableFranchiseRenewalCostsAndContractualOperatingRightsMember
Weighted average original useful life | 10 years 0 months 0 days |
Software |  |
Finite-lived intangible assets, gross carrying amount | 5,040 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember | 4,271 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember
Accumulated amortization | (2,832)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember | (2,405)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember
Weighted average original useful life | 5 years 0 months 0 days |
Software | NBCUniversal Media, LLC [Member] |  |
Finite-lived intangible assets, gross carrying amount | 657 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 522 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Accumulated amortization | (329)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | (240)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_ComputerSoftwareIntangibleAssetMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Weighted average original useful life | 5 years 0 months 0 days |
Patents and other technology rights |  |
Finite-lived intangible assets, gross carrying amount | 373 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_PatentsAndOtherTechnologyRightsMember | 361 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_PatentsAndOtherTechnologyRightsMember
Accumulated amortization | (330)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_PatentsAndOtherTechnologyRightsMember | (307)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = cmcsa_PatentsAndOtherTechnologyRightsMember
Weighted average original useful life | 8 years 0 months 0 days |
Other agreements and rights |  |
Finite-lived intangible assets, gross carrying amount | 1,456 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember | 1,433 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember
Accumulated amortization | (721)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember | (645)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember
Weighted average original useful life | 20 years 0 months 0 days |
Other agreements and rights | NBCUniversal Media, LLC [Member] |  |
Finite-lived intangible assets, gross carrying amount | 1,556 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 1,511 us-gaap_FiniteLivedIntangibleAssetsGross / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Accumulated amortization | $ (864)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | $ (781)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / cmcsa_IntangibleAssetsByMajorClassAxis = us-gaap_OtherIntangibleAssetsMember / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Weighted average original useful life | 21 years 0 months 0 days |

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