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Income Taxes (Federal Statutory) (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 tax at statutory rate | $ 4,363us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | $ 3,890us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | $ 4,063us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate |
| State income taxes, net of federal benefit | 329us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | 319us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | 178us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes |
| Foreign income taxes, net of federal credit | 0us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential | 15us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential | 92us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential |
| Nontaxable income attributable to noncontrolling interests | (62)us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense | (103)us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense | (620)us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense |
| Other adjustments | (114)us-gaap_IncomeTaxReconciliationOtherAdjustments | (313)us-gaap_IncomeTaxReconciliationOtherAdjustments | (106)us-gaap_IncomeTaxReconciliationOtherAdjustments |
| Income tax expense | 3,873us-gaap_IncomeTaxExpenseBenefit | 3,980us-gaap_IncomeTaxExpenseBenefit | 3,744us-gaap_IncomeTaxExpenseBenefit |
| Uncertain And Effectively Settled Tax Positions, Net [Member] | |||
| Other adjustments | (408)us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_UncertainAndEffectivelySettledTaxPositionsNetMember |
58us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_UncertainAndEffectivelySettledTaxPositionsNetMember |
114us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_UncertainAndEffectivelySettledTaxPositionsNetMember |
| Accrued Interest On Uncertain And Effectively Settled Tax Positions Net [Member] | |||
| Other adjustments | $ (235)us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_AccruedInterestOnUncertainAndEffectivelySettledTaxPositionsNetMember |
$ 114us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_AccruedInterestOnUncertainAndEffectivelySettledTaxPositionsNetMember |
$ 23us-gaap_IncomeTaxReconciliationOtherAdjustments / cmcsa_TaxAdjustmentsAxis = cmcsa_AccruedInterestOnUncertainAndEffectivelySettledTaxPositionsNetMember |
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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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- Definition
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to noncontrolling interest income (loss) exempt from income taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Details
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