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Income Taxes (Components of Income Tax Expense) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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| Federal | $ 2,392us-gaap_CurrentFederalTaxExpenseBenefit | $ 3,183us-gaap_CurrentFederalTaxExpenseBenefit | $ 3,004us-gaap_CurrentFederalTaxExpenseBenefit |
| State | 174us-gaap_CurrentStateAndLocalTaxExpenseBenefit | 581us-gaap_CurrentStateAndLocalTaxExpenseBenefit | 432us-gaap_CurrentStateAndLocalTaxExpenseBenefit |
| Foreign | 142us-gaap_CurrentForeignTaxExpenseBenefit | 200us-gaap_CurrentForeignTaxExpenseBenefit | 169us-gaap_CurrentForeignTaxExpenseBenefit |
| Current income tax expense (benefit) | 2,708us-gaap_CurrentIncomeTaxExpenseBenefit | 3,964us-gaap_CurrentIncomeTaxExpenseBenefit | 3,605us-gaap_CurrentIncomeTaxExpenseBenefit |
| Federal | 1,000us-gaap_DeferredFederalIncomeTaxExpenseBenefit | (76)us-gaap_DeferredFederalIncomeTaxExpenseBenefit | 160us-gaap_DeferredFederalIncomeTaxExpenseBenefit |
| State | 173us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit | 108us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit | (40)us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit |
| Foreign deferred income tax expense | (8)us-gaap_DeferredForeignIncomeTaxExpenseBenefit | (16)us-gaap_DeferredForeignIncomeTaxExpenseBenefit | 19us-gaap_DeferredForeignIncomeTaxExpenseBenefit |
| Deferred income tax expense (benefit) | 1,165us-gaap_DeferredIncomeTaxExpenseBenefit | 16us-gaap_DeferredIncomeTaxExpenseBenefit | 139us-gaap_DeferredIncomeTaxExpenseBenefit |
| Income tax expense | 3,873us-gaap_IncomeTaxExpenseBenefit | 3,980us-gaap_IncomeTaxExpenseBenefit | 3,744us-gaap_IncomeTaxExpenseBenefit |
| NBCUniversal Media, LLC [Member] | |||
| Foreign | 33us-gaap_CurrentForeignTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
77us-gaap_CurrentForeignTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
69us-gaap_CurrentForeignTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| Foreign deferred income tax expense | (8)us-gaap_DeferredForeignIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
(16)us-gaap_DeferredForeignIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
16us-gaap_DeferredForeignIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| Deferred income tax expense (benefit) | (12)us-gaap_DeferredIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
(10)us-gaap_DeferredIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
15us-gaap_DeferredIncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| Withholding tax expense | 108cmcsa_WithholdingTaxExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
123cmcsa_WithholdingTaxExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
103cmcsa_WithholdingTaxExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| U.S. domestic tax expense | 10cmcsa_StateAndLocalTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
22cmcsa_StateAndLocalTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
9cmcsa_StateAndLocalTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| Income tax expense | $ 143us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
$ 206us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
$ 197us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember |
| X | ||||||||||
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- Definition
Amount of current and deferred income tax expense (benefit) attributable to income (loss) from continuing domestic operations within the country of domicile of the entity. No definition available.
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| X | ||||||||||
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- Definition
The amount of tax liability incurred by the Company in licensing its content to non-US territories. No definition available.
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- Definition
Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of current foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of deferred foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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