v2.4.1.9

Consolidated Statement of Income (NBCUniversal) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue	$ 17,732,000,000us-gaap_Revenues	$ 16,791,000,000us-gaap_Revenues	$ 16,844,000,000us-gaap_Revenues	$ 17,408,000,000us-gaap_Revenues	$ 16,926,000,000us-gaap_Revenues	$ 16,151,000,000us-gaap_Revenues	$ 16,270,000,000us-gaap_Revenues	$ 15,310,000,000us-gaap_Revenues	$ 68,775,000,000us-gaap_Revenues	$ 64,657,000,000us-gaap_Revenues	$ 62,570,000,000us-gaap_Revenues
Costs and Expenses:
Programming and production									20,912,000,000cmcsa_ProgrammingAndProductionCosts	19,670,000,000cmcsa_ProgrammingAndProductionCosts	19,929,000,000cmcsa_ProgrammingAndProductionCosts
Other operating and administrative									19,862,000,000cmcsa_OtherOperatingAndAdministrative	18,584,000,000cmcsa_OtherOperatingAndAdministrative	17,833,000,000cmcsa_OtherOperatingAndAdministrative
Advertising, marketing and promotion									5,078,000,000us-gaap_MarketingAndAdvertisingExpense	4,969,000,000us-gaap_MarketingAndAdvertisingExpense	4,831,000,000us-gaap_MarketingAndAdvertisingExpense
Depreciation									6,337,000,000us-gaap_Depreciation	6,254,000,000us-gaap_Depreciation	6,150,000,000us-gaap_Depreciation
Amortization									1,682,000,000us-gaap_AmortizationOfIntangibleAssets	1,617,000,000us-gaap_AmortizationOfIntangibleAssets	1,648,000,000us-gaap_AmortizationOfIntangibleAssets
Total costs and expenses									53,871,000,000us-gaap_CostsAndExpenses	51,094,000,000us-gaap_CostsAndExpenses	50,391,000,000us-gaap_CostsAndExpenses
Operating income	3,787,000,000us-gaap_OperatingIncomeLoss	3,745,000,000us-gaap_OperatingIncomeLoss	3,804,000,000us-gaap_OperatingIncomeLoss	3,568,000,000us-gaap_OperatingIncomeLoss	3,647,000,000us-gaap_OperatingIncomeLoss	3,414,000,000us-gaap_OperatingIncomeLoss	3,435,000,000us-gaap_OperatingIncomeLoss	3,067,000,000us-gaap_OperatingIncomeLoss	14,904,000,000us-gaap_OperatingIncomeLoss	13,563,000,000us-gaap_OperatingIncomeLoss	12,179,000,000us-gaap_OperatingIncomeLoss
Other Income (Expense):
Interest expense									(2,617,000,000)us-gaap_InterestExpense	(2,574,000,000)us-gaap_InterestExpense	(2,521,000,000)us-gaap_InterestExpense
Investment income (loss), net									296,000,000us-gaap_InvestmentIncomeNonoperating	576,000,000us-gaap_InvestmentIncomeNonoperating	219,000,000us-gaap_InvestmentIncomeNonoperating
Equity in net income (losses) of investees, net									97,000,000us-gaap_IncomeLossFromEquityMethodInvestments	(86,000,000)us-gaap_IncomeLossFromEquityMethodInvestments	959,000,000us-gaap_IncomeLossFromEquityMethodInvestments
Other income (expense), net									(215,000,000)us-gaap_OtherNonoperatingIncomeExpense	(364,000,000)us-gaap_OtherNonoperatingIncomeExpense	773,000,000us-gaap_OtherNonoperatingIncomeExpense
Nonoperating income (expense)									(2,439,000,000)us-gaap_NonoperatingIncomeExpense	(2,448,000,000)us-gaap_NonoperatingIncomeExpense	(570,000,000)us-gaap_NonoperatingIncomeExpense
Income before income taxes									12,465,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	11,115,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	11,609,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income tax expense									(3,873,000,000)us-gaap_IncomeTaxExpenseBenefit	(3,980,000,000)us-gaap_IncomeTaxExpenseBenefit	(3,744,000,000)us-gaap_IncomeTaxExpenseBenefit
Net income									8,592,000,000us-gaap_ProfitLoss	7,135,000,000us-gaap_ProfitLoss	7,865,000,000us-gaap_ProfitLoss
Net income attributable to Parent	1,925,000,000us-gaap_NetIncomeLoss	2,592,000,000us-gaap_NetIncomeLoss	1,992,000,000us-gaap_NetIncomeLoss	1,871,000,000us-gaap_NetIncomeLoss	1,913,000,000us-gaap_NetIncomeLoss	1,732,000,000us-gaap_NetIncomeLoss	1,734,000,000us-gaap_NetIncomeLoss	1,437,000,000us-gaap_NetIncomeLoss	8,380,000,000us-gaap_NetIncomeLoss	6,816,000,000us-gaap_NetIncomeLoss	6,203,000,000us-gaap_NetIncomeLoss
N B C Universal Media L L C [Member]
Revenue									25,428,000,000us-gaap_Revenues / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	23,650,000,000us-gaap_Revenues / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	23,812,000,000us-gaap_Revenues / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Costs and Expenses:
Programming and production									12,318,000,000cmcsa_ProgrammingAndProductionCosts / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	11,770,000,000cmcsa_ProgrammingAndProductionCosts / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	12,710,000,000cmcsa_ProgrammingAndProductionCosts / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Other operating and administrative									5,364,000,000cmcsa_OtherOperatingAndAdministrative / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	4,949,000,000cmcsa_OtherOperatingAndAdministrative / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	4,763,000,000cmcsa_OtherOperatingAndAdministrative / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Advertising, marketing and promotion									2,158,000,000us-gaap_MarketingAndAdvertisingExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	2,199,000,000us-gaap_MarketingAndAdvertisingExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	2,232,000,000us-gaap_MarketingAndAdvertisingExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Depreciation									654,000,000us-gaap_Depreciation / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	639,000,000us-gaap_Depreciation / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	562,000,000us-gaap_Depreciation / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Amortization									841,000,000us-gaap_AmortizationOfIntangibleAssets / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	772,000,000us-gaap_AmortizationOfIntangibleAssets / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	764,000,000us-gaap_AmortizationOfIntangibleAssets / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Total costs and expenses									21,335,000,000us-gaap_CostsAndExpenses / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	20,329,000,000us-gaap_CostsAndExpenses / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	21,031,000,000us-gaap_CostsAndExpenses / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Operating income									4,093,000,000us-gaap_OperatingIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	3,321,000,000us-gaap_OperatingIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	2,781,000,000us-gaap_OperatingIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Other Income (Expense):
Interest expense									(508,000,000)us-gaap_InterestExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(515,000,000)us-gaap_InterestExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(480,000,000)us-gaap_InterestExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Investment income (loss), net									27,000,000us-gaap_InvestmentIncomeNonoperating / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	17,000,000us-gaap_InvestmentIncomeNonoperating / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	27,000,000us-gaap_InvestmentIncomeNonoperating / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Equity in net income (losses) of investees, net									46,000,000us-gaap_IncomeLossFromEquityMethodInvestments / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(93,000,000)us-gaap_IncomeLossFromEquityMethodInvestments / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	183,000,000us-gaap_IncomeLossFromEquityMethodInvestments / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Other income (expense), net									(218,000,000)us-gaap_OtherNonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(402,000,000)us-gaap_OtherNonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	917,000,000us-gaap_OtherNonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Nonoperating income (expense)									(653,000,000)us-gaap_NonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(993,000,000)us-gaap_NonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	647,000,000us-gaap_NonoperatingIncomeExpense / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Income before income taxes									3,440,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	2,328,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	3,428,000,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Income tax expense									(143,000,000)us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(206,000,000)us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(197,000,000)us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Net income									3,297,000,000us-gaap_ProfitLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	2,122,000,000us-gaap_ProfitLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	3,231,000,000us-gaap_ProfitLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Net (income) loss attributable to noncontrolling interests									(182,000,000)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(154,000,000)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	(176,000,000)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Net income attributable to Parent									$ 3,115,000,000us-gaap_NetIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	$ 1,968,000,000us-gaap_NetIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember	$ 3,055,000,000us-gaap_NetIncomeLoss / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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The net result for the period of deducting operating expenses from operating revenues.

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No definition available.

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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