$CMCSA
COMCAST CORP Stock $cmcsa

$cmcsa Overview Financials Valuation SEC Filings Company Website

2012 Form 8-K Financial Statement

#000119312513370469 Filed on September 18, 2013

Income Statement

Concept	2012	2011 Q4	2011 Q3
Revenue	$62.57B	$15.04B	$14.34B
YoY Change	12.05%	54.74%	51.11%
Cost Of Revenue	$19.93B
YoY Change	20.08%
Gross Profit	$42.64B
YoY Change	8.65%
Gross Profit Margin	68.15%
Selling, General & Admin	$22.66B
YoY Change	8.5%
% of Gross Profit	53.15%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$6.150B	$1.998B	$1.540B
YoY Change	1.82%	17.32%	-27.46%
% of Gross Profit	14.42%
Operating Expenses	$30.46B	$12.12B	$11.70B
YoY Change	6.79%	218.3%	212.45%
Operating Profit	$12.18B	$2.918B	$2.641B
YoY Change	13.6%	44.96%	35.16%
Interest Expense	$2.521B	-$481.0M	$637.0M
YoY Change	0.64%	-5.5%	-236.7%
% of Operating Profit	20.7%	-16.48%	24.12%
Other Income/Expense, Net	-$570.0M	-$51.00M	-$836.0M
YoY Change	-77.33%	-125.25%	3383.33%
Pretax Income	$11.61B	$2.386B	$1.805B
YoY Change	41.45%	39.86%	24.14%
Income Tax	$3.744B	$801.0M	$639.0M
% Of Pretax Income	32.25%	33.57%	35.4%
Net Earnings	$6.203B	$1.287B	$908.0M
YoY Change	49.11%	26.42%	4.73%
Net Earnings / Revenue	9.91%	8.56%	6.33%
Basic Earnings Per Share	$2.32	$0.47	$0.33
Diluted Earnings Per Share	$2.28	$0.47	$0.33
COMMON SHARES
Basic Shares Outstanding	2.678B shares		2.739B shares
Diluted Shares Outstanding	2.717B shares		2.761B shares

Balance Sheet

Concept	2012	2011 Q4	2011 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$12.42B	$4.648B	$1.806B
YoY Change	641.64%	-47.18%	-60.86%
Cash & Equivalents	$10.95B	$1.620B	$1.806B
Short-Term Investments	$1.464B	$3.028B
Other Short-Term Assets	$2.055B	$1.260B	$2.680B
YoY Change	-8.54%	36.22%	288.41%
Inventory
Prepaid Expenses
Receivables	$5.521B	$4.652B	$4.096B
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$19.99B	$8.573B	$8.582B
YoY Change	133.19%	-3.52%	19.66%
LONG-TERM ASSETS
Property, Plant & Equipment	$27.23B	$27.56B	$27.44B
YoY Change	-1.19%	17.2%	17.63%
Goodwill		$26.87B
YoY Change		79.66%
Intangibles
YoY Change
Long-Term Investments	$6.325B	$4.880B	$9.575B
YoY Change	-35.81%	-26.84%	50.05%
Other Assets	$2.180B	$2.190B	$2.201B
YoY Change	-0.46%	86.86%	55.77%
Total Long-Term Assets	$145.0B	$149.2B	$148.2B
YoY Change	-2.86%	36.11%	35.57%
TOTAL ASSETS
Total Short-Term Assets	$19.99B	$8.573B	$8.582B
Total Long-Term Assets	$145.0B	$149.2B	$148.2B
Total Assets	$165.0B	$157.8B	$156.8B
YoY Change	4.53%	33.14%	34.59%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$6.206B	$5.705B	$5.455B
YoY Change	8.78%	73.35%	65.45%
Accrued Expenses	$7.281B	$4.124B	$6.243B
YoY Change	35.36%	34.77%	91.5%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$2.376B	$1.367B	$2.448B
YoY Change	73.81%	-24.06%	6.43%
Total Short-Term Liabilities	$16.71B	$13.24B	$14.15B
YoY Change	26.23%	60.81%	59.72%
LONG-TERM LIABILITIES
Long-Term Debt	$38.08B	$37.94B	$38.52B
YoY Change	0.37%	28.12%	34.05%
Other Long-Term Liabilities	$13.27B	$13.03B	$11.66B
YoY Change	1.82%	65.78%	53.97%
Total Long-Term Liabilities	$51.35B	$13.03B	$50.18B
YoY Change	0.74%	65.78%	38.2%
TOTAL LIABILITIES
Total Short-Term Liabilities	$16.71B	$13.24B	$14.15B
Total Long-Term Liabilities	$51.35B	$13.03B	$50.18B
Total Liabilities	$115.6B	$26.28B	$110.1B
YoY Change	4.59%	63.24%	51.42%
SHAREHOLDERS EQUITY
Retained Earnings		$13.97B
YoY Change		14.91%
Common Stock		$32.00M
YoY Change		0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)		$7.517B
YoY Change		0.0%
Treasury Stock Shares
Shareholders Equity	$49.36B	$47.27B	$46.68B
YoY Change
Total Liabilities & Shareholders Equity	$165.0B	$157.8B	$156.8B
YoY Change	4.53%	33.14%	34.59%

Cashflow Statement

Concept	2012	2011 Q4	2011 Q3
OPERATING ACTIVITIES
Net Income	$6.203B	$1.287B	$908.0M
YoY Change	49.11%	26.42%	4.73%
Depreciation, Depletion And Amortization	$6.150B	$1.998B	$1.540B
YoY Change	1.82%	17.32%	-27.46%
Cash From Operating Activities	$14.85B	$4.139B	$3.250B
YoY Change	3.55%	20.08%	35.42%
INVESTING ACTIVITIES
Capital Expenditures	$5.714B	-$1.971B	$1.408B
YoY Change	7.67%	16.21%	-193.8%
Acquisitions	$90.00M
YoY Change	-98.6%
Other Investing Activities	-$74.00M	$124.0M	-$758.0M
YoY Change	-489.47%	-184.35%	-503.19%
Cash From Investing Activities	-$1.486B	-$1.847B	-$2.375B
YoY Change	-88.12%	0.22%	80.88%
FINANCING ACTIVITIES
Cash Dividend Paid	$1.608B
YoY Change	35.47%
Common Stock Issuance & Retirement, Net	$2.767B
YoY Change	48.92%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-$4.037B	-2.478B	-1.066B
YoY Change	-34.9%	1429.63%	86.04%
NET CHANGE
Cash From Operating Activities	$14.85B	4.139B	3.250B
Cash From Investing Activities	-$1.486B	-1.847B	-2.375B
Cash From Financing Activities	-$4.037B	-2.478B	-1.066B
Net Change In Cash	$9.331B	-186.0M	-191.0M
YoY Change	-313.82%	-112.9%	-137.16%
FREE CASH FLOW
Cash From Operating Activities	$14.85B	$4.139B	$3.250B
Capital Expenditures	$5.714B	-$1.971B	$1.408B
Free Cash Flow	$9.140B	$6.110B	$1.842B
YoY Change	1.13%	18.8%	-52.78%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2012	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2012	dei	Trading Symbol TradingSymbol	cmcsa
CY2012	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2012	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2012	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2012	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2012	dei	Document Type DocumentType	8-K
CY2012	dei	Amendment Flag AmendmentFlag	false
CY2012	dei	Document Period End Date DocumentPeriodEndDate	2012-12-31
CY2012	dei	Entity Central Index Key EntityCentralIndexKey	0001166691
CY2012Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	10951000000	USD
CY2011Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1620000000	USD
CY2012Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	5521000000	USD
CY2011Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	4652000000	USD
CY2012Q4	us-gaap	Other Assets Current OtherAssetsCurrent	1146000000	USD
CY2011Q4	us-gaap	Other Assets Current OtherAssetsCurrent	1260000000	USD
CY2012Q4	us-gaap	Assets Current AssetsCurrent	19991000000	USD
CY2011Q4	us-gaap	Assets Current AssetsCurrent	8573000000	USD
CY2012Q4	us-gaap	Long Term Investments LongTermInvestments	6325000000	USD
CY2011Q4	us-gaap	Long Term Investments LongTermInvestments	9854000000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	27232000000	USD
CY2011Q4	us-gaap	Indefinite Lived Franchise Rights IndefiniteLivedFranchiseRights	59376000000	USD
CY2012Q4	us-gaap	Goodwill Goodwill	26985000000	USD
CY2011Q4	us-gaap	Goodwill Goodwill	26874000000	USD
CY2012Q4	us-gaap	Other Intangible Assets Net OtherIntangibleAssetsNet	17840000000	USD
CY2012Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	2180000000	USD
CY2011Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	2190000000	USD
CY2012	dei	Entity Registrant Name EntityRegistrantName	COMCAST CORP
CY2012	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2011Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	27559000000	USD
CY2012Q4	us-gaap	Indefinite Lived Franchise Rights IndefiniteLivedFranchiseRights	59364000000	USD
CY2011Q4	us-gaap	Other Intangible Assets Net OtherIntangibleAssetsNet	18165000000	USD
CY2012Q4	us-gaap	Assets Assets	164971000000	USD
CY2012Q4	us-gaap	Debt Current DebtCurrent	2376000000	USD
CY2011Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	13971000000	USD
CY2012Q4	us-gaap	Treasury Stock Value TreasuryStockValue	7517000000	USD
CY2011Q4	us-gaap	Treasury Stock Value TreasuryStockValue	7517000000	USD
CY2012Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	15000000	USD
CY2011Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-152000000	USD
CY2011	us-gaap	Revenues Revenues	55842000000	USD
CY2010	us-gaap	Costs And Expenses CostsAndExpenses	29957000000	USD
CY2010	us-gaap	Operating Income Loss OperatingIncomeLoss	7980000000	USD
CY2010	us-gaap	Interest Expense InterestExpense	2156000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	13000000	USD
CY2012	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	923000000	USD
CY2011	us-gaap	Share Based Compensation ShareBasedCompensation	344000000	USD
CY2011	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	954000000	USD
CY2010	cmcsa	Amortization Of Film And Television Costs AmortizationOfFilmAndTelevisionCosts	187000000	USD
CY2012	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	1736000000	USD
CY2012	cmcsa	Contributions From And Distributions To Noncontrolling Interests ContributionsFromAndDistributionsToNoncontrollingInterests	-169000000	USD
CY2012	cmcsa	Equity Profit Loss EquityProfitLoss	6351000000	USD
CY2011	cmcsa	Noncontrolling Interest Increase Decrease Related To Acquisition NoncontrollingInterestIncreaseDecreaseRelatedToAcquisition	1869000000	USD
CY2012	us-gaap	Stockholders Equity Other StockholdersEquityOther	76000000	USD
CY2011	cmcsa	Noncontrolling Interest Increase From Equity Issuance Or Sale Of Parent Equity Interest NoncontrollingInterestIncreaseFromEquityIssuanceOrSaleOfParentEquityInterest	88000000	USD
CY2012	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.65
CY2011	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.50
CY2011	us-gaap	Net Income Loss NetIncomeLoss	4160000000	USD
CY2012	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	959000000	USD
CY2012	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	773000000	USD
CY2012	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-570000000	USD
CY2012	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3744000000	USD
CY2012	us-gaap	Profit Loss ProfitLoss	7865000000	USD
CY2012	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	1662000000	USD
CY2012	us-gaap	Net Income Loss NetIncomeLoss	6203000000	USD
CY2012	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.32
CY2012	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.28
CY2010	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	2409000000	USD
CY2010	us-gaap	Investment Income Nonoperating InvestmentIncomeNonoperating	288000000	USD
CY2011	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.51
CY2012	us-gaap	Costs And Expenses CostsAndExpenses	50391000000	USD
CY2012	us-gaap	Operating Income Loss OperatingIncomeLoss	12179000000	USD
CY2012	us-gaap	Interest Expense InterestExpense	2521000000	USD
CY2012	us-gaap	Investment Income Nonoperating InvestmentIncomeNonoperating	219000000	USD
CY2011	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	997000000	USD
CY2011	us-gaap	Profit Loss ProfitLoss	5157000000	USD
CY2010	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-141000000	USD
CY2010	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	133000000	USD
CY2010	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-1876000000	USD
CY2010	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2436000000	USD
CY2010	us-gaap	Profit Loss ProfitLoss	3668000000	USD
CY2010	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	33000000	USD
CY2010	us-gaap	Net Income Loss NetIncomeLoss	3635000000	USD
CY2011	cmcsa	Other Operating And Administrative OtherOperatingAndAdministrative	16656000000	USD
CY2010	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.29
CY2010	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.29
CY2010	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.378
CY2012	us-gaap	Depreciation Depreciation	6150000000	USD
CY2011	us-gaap	Depreciation Depreciation	6040000000	USD
CY2010	us-gaap	Depreciation Depreciation	5539000000	USD
CY2012	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	11609000000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	6104000000	USD
CY2010	cmcsa	Other Operating And Administrative OtherOperatingAndAdministrative	12395000000	USD
CY2010	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1077000000	USD
CY2010	cmcsa	Programming And Production Costs ProgrammingAndProductionCosts	8537000000	USD
CY2010	cmcsa	Transaction Costs In Other Income Expense TransactionCostsInOtherIncomeExpense	129000000	USD
CY2010	cmcsa	Total Transaction Costs And Transaction Related Costs TotalTransactionCostsAndTransactionRelatedCosts	216000000	USD
CY2010	cmcsa	Transaction Costs And Transaction Related Costs In Operating Costs And Expenses TransactionCostsAndTransactionRelatedCostsInOperatingCostsAndExpenses	80000000	USD
CY2011	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	4231000000	USD
CY2011	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1596000000	USD
CY2011	cmcsa	Programming And Production Costs ProgrammingAndProductionCosts	16598000000	USD
CY2012	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1648000000	USD
CY2012	cmcsa	Other Operating And Administrative OtherOperatingAndAdministrative	17857000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	70000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	31000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax		USD
CY2011	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-12000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-1000000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	3615000000	USD
CY2011	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	5066000000	USD
CY2012	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	8038000000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	3582000000	USD
CY2011	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	4107000000	USD
CY2012	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	6370000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	22000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	22000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	9000000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-2000000	USD
CY2012	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-95000000	USD
CY2012	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-34000000	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	15000000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	47000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeTax	2000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeTax	5000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeTax	0	USD
CY2012	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeTax	8000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeTax	-11000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeTax	-21000000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	9000000	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	4000000	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-25000000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-80000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeNetOfTax	-2000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeNetOfTax	-8000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeNetOfTax		USD
CY2012	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	-15000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	20000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	34000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	0	USD
CY2011	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	-38000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	6000000	USD
CY2012	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	0	USD
CY2011	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	3000000	USD
CY2010	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	0	USD
CY2012	us-gaap	Depreciation And Amortization DepreciationAndAmortization	7798000000	USD
CY2012	cmcsa	Amortization Of Film And Television Costs AmortizationOfFilmAndTelevisionCosts	9454000000	USD
CY2012	us-gaap	Share Based Compensation ShareBasedCompensation	371000000	USD
CY2012	cmcsa	Other Non Cash Income Expense1 OtherNonCashIncomeExpense1	193000000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	167000000	USD
CY2012	cmcsa	Gain Loss On Investments And Noncash Other Income Expense Net GainLossOnInvestmentsAndNoncashOtherIncomeExpenseNet	1062000000	USD
CY2012	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	139000000	USD
CY2012	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	823000000	USD
CY2012	cmcsa	Change In Film And Television Costs ChangeInFilmAndTelevisionCosts	-9432000000	USD
CY2012	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	366000000	USD
CY2012	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-749000000	USD
CY2012	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	5714000000	USD
CY2012	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	90000000	USD
CY2012	us-gaap	Proceeds From Sale Maturity And Collections Of Investments ProceedsFromSaleMaturityAndCollectionsOfInvestments	3102000000	USD
CY2012	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	297000000	USD
CY2012	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-74000000	USD
CY2012	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1486000000	USD
CY2012	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-544000000	USD
CY2012	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	4544000000	USD
CY2012	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	2881000000	USD
CY2012	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	3000000000	USD
CY2012	us-gaap	Payments Of Dividends PaymentsOfDividends	1608000000	USD
CY2012	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	233000000	USD
CY2012	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-90000000	USD
CY2012	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-4037000000	USD
CY2012	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	9331000000	USD
CY2011	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-440000000	USD
CY2011	cmcsa	Gain Loss On Investments And Noncash Other Income Expense Net GainLossOnInvestmentsAndNoncashOtherIncomeExpenseNet	-23000000	USD
CY2011	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-85000000	USD
CY2011	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	427000000	USD
CY2011	cmcsa	Amortization Of Film And Television Costs AmortizationOfFilmAndTelevisionCosts	6787000000	USD
CY2011	cmcsa	Change In Film And Television Costs ChangeInFilmAndTelevisionCosts	-7080000000	USD
CY2011	cmcsa	Other Non Cash Income Expense1 OtherNonCashIncomeExpense1	146000000	USD
CY2011	us-gaap	Depreciation And Amortization DepreciationAndAmortization	7636000000	USD
CY2011	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1058000000	USD
CY2011	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-12508000000	USD
CY2011	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	5307000000	USD
CY2011	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	6407000000	USD
CY2011	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	2141000000	USD
CY2011	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	3216000000	USD
CY2010Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	5984000000	USD
CY2011	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	544000000	USD
CY2011	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-4364000000	USD
CY2011	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-6201000000	USD
CY2011	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	0	USD
CY2011	us-gaap	Proceeds From Sale Maturity And Collections Of Investments ProceedsFromSaleMaturityAndCollectionsOfInvestments	277000000	USD
CY2011	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-159000000	USD
CY2011	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	19000000	USD
CY2011	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	283000000	USD
CY2011	us-gaap	Payments Of Dividends PaymentsOfDividends	1187000000	USD
CY2010	us-gaap	Share Based Compensation ShareBasedCompensation	300000000	USD
CY2010	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	536000000	USD
CY2010	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	3420000000	USD
CY2010	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	5313000000	USD
CY2010	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	549000000	USD
CY2010	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	60000000	USD
CY2011	cmcsa	Transaction Costs In Other Income Expense TransactionCostsInOtherIncomeExpense	16000000	USD
CY2011	cmcsa	Transaction Costs And Transaction Related Costs In Operating Costs And Expenses TransactionCostsAndTransactionRelatedCostsInOperatingCostsAndExpenses	155000000	USD
CY2010	cmcsa	Transaction Costs In Interest Expense TransactionCostsInInterestExpense	7000000	USD
CY2012	us-gaap	Advertising Cost Policy Expensed Advertising Cost AdvertisingCostPolicyExpensedAdvertisingCost	<p style='margin-top:0pt; margin-bottom:5.4pt'><font style="font-family:Helvetica;font-size:10pt;font-weight:bold;margin-left:0px;">Advertising Expenses</font></p><p style='margin-top:0pt; margin-bottom:5.4pt'><font style="font-family:Times New Roman;font-size:10pt;margin-left:0px;">Advertising costs are expensed as incurred. </font></p>
CY2010	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-5711000000	USD
CY2009Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	671000000	USD
CY2010	us-gaap	Proceeds From Sale Maturity And Collections Of Investments ProceedsFromSaleMaturityAndCollectionsOfInvestments	99000000	USD
CY2010	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	183000000	USD
CY2010	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	4961000000	USD
CY2010	cmcsa	Gain Loss On Investments And Noncash Other Income Expense Net GainLossOnInvestmentsAndNoncashOtherIncomeExpenseNet	267000000	USD
CY2010	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	260000000	USD
CY2010	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	34000000	USD
CY2010	cmcsa	Other Non Cash Income Expense1 OtherNonCashIncomeExpense1	141000000	USD
CY2010	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-155000000	USD
CY2010	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-129000000	USD
CY2010	us-gaap	Payments Of Dividends PaymentsOfDividends	1064000000	USD
CY2010	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	0	USD
CY2010	us-gaap	Depreciation And Amortization DepreciationAndAmortization	6616000000	USD
CY2010	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	131000000	USD
CY2012	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	195000000	USD
CY2011	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	311000000	USD
CY2010	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	0	USD
CY2012	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	14854000000	USD
CY2011	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	14345000000	USD
CY2010	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	11179000000	USD
CY2011	cmcsa	Distributions To Other Noncontrolling Interests DistributionsToOtherNoncontrollingInterests	-206000000	USD
CY2012	cmcsa	Distributions To Other Noncontrolling Interests DistributionsToOtherNoncontrollingInterests	-218000000	USD
CY2010	cmcsa	Distributions To Other Noncontrolling Interests DistributionsToOtherNoncontrollingInterests	-67000000	USD
CY2012	cmcsa	Distributions To Nbc Universal Noncontrolling Interest Holders DistributionsToNBCUniversalNoncontrollingInterestHolders	-473000000	USD
CY2011	cmcsa	Distributions To Nbc Universal Noncontrolling Interest Holders DistributionsToNBCUniversalNoncontrollingInterestHolders	-119000000	USD
CY2011	cmcsa	Equity Method Investment Dividends Or Distributions Including Return Of Investment EquityMethodInvestmentDividendsOrDistributionsIncludingReturnOfInvestment	37000000	USD
CY2012	cmcsa	Equity Method Investment Dividends Or Distributions Including Return Of Investment EquityMethodInvestmentDividendsOrDistributionsIncludingReturnOfInvestment	2362000000	USD
CY2010	cmcsa	Equity Method Investment Dividends Or Distributions Including Return Of Investment EquityMethodInvestmentDividendsOrDistributionsIncludingReturnOfInvestment	190000000	USD
CY2009Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	42811000000	USD
CY2010	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	238000000	USD
CY2010	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	1200000000	USD
CY2010	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	61000000	USD
CY2010	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	1059000000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-53000000	USD
CY2010	cmcsa	Noncontrolling Interest Decrease From Redemptions Or Purchase Of Interests NoncontrollingInterestDecreaseFromRedemptionsOrPurchaseOfInterests	11000000	USD
CY2010	cmcsa	Contributions From And Distributions To Noncontrolling Interests ContributionsFromAndDistributionsToNoncontrollingInterests	-44000000	USD
CY2010	cmcsa	Equity Profit Loss EquityProfitLoss	3669000000	USD
CY2010Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	44434000000	USD
CY2011	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	469000000	USD
CY2011	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2141000000	USD
CY2011	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	68000000	USD
CY2011	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	1233000000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-53000000	USD
CY2011	cmcsa	Contributions From And Distributions To Noncontrolling Interests ContributionsFromAndDistributionsToNoncontrollingInterests	-161000000	USD
CY2011	cmcsa	Equity Profit Loss EquityProfitLoss	4315000000	USD
CY2012	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	372000000	USD
CY2012	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	3000000000	USD
CY2012	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	2678000000	shares
CY2011	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	2746000000	shares
CY2010	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	2808000000	shares
CY2010	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	12000000	shares
CY2011	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	32000000	shares
CY2012	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	39000000	shares
CY2012	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	2717000000	shares
CY2011	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	2778000000	shares
CY2010	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	2820000000	shares
CY2012	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1000000	shares
CY2011	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	45000000	shares
CY2010	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	168000000	shares
CY2011Q4	cmcsa	Ownership Percentage In New Company OwnershipPercentageInNewCompany	0.51	pure
CY2011Q1	cmcsa	Percentage Adjustment Factor To Determine Redemption And Purchase Price For Noncontrolling Investors Interest PercentageAdjustmentFactorToDetermineRedemptionAndPurchasePriceForNoncontrollingInvestorsInterest	1.2	pure
CY2011Q4	us-gaap	Assets Assets	157818000000	USD
CY2012Q4	cmcsa	Programming Rights Current ProgrammingRightsCurrent	909000000	USD
CY2011Q4	cmcsa	Programming Rights Current ProgrammingRightsCurrent	987000000	USD
CY2012Q4	cmcsa	Film And Television Costs FilmAndTelevisionCosts	5054000000	USD
CY2011Q4	cmcsa	Film And Television Costs FilmAndTelevisionCosts	5227000000	USD
CY2012Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	6206000000	USD
CY2011Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	5705000000	USD
CY2012Q4	cmcsa	Accrued Participations And Residuals Current AccruedParticipationsAndResidualsCurrent	1350000000	USD
CY2011Q4	cmcsa	Accrued Participations And Residuals Current AccruedParticipationsAndResidualsCurrent	1255000000	USD
CY2011Q4	us-gaap	Debt Current DebtCurrent	1367000000	USD
CY2012Q4	us-gaap	Liabilities Current LiabilitiesCurrent	16714000000	USD
CY2011Q4	us-gaap	Liabilities Current LiabilitiesCurrent	13241000000	USD
CY2012Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	38082000000	USD
CY2011Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	37942000000	USD
CY2012Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	30110000000	USD
CY2011Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	29932000000	USD
CY2012Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	13271000000	USD
CY2011Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	13034000000	USD
CY2012Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2011Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2012Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	40547000000	USD
CY2011Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	40940000000	USD
CY2012Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	16280000000	USD
CY2012Q4	us-gaap	Stockholders Equity StockholdersEquity	49356000000	USD
CY2011Q4	us-gaap	Stockholders Equity StockholdersEquity	47274000000	USD
CY2012Q4	us-gaap	Minority Interest MinorityInterest	440000000	USD
CY2011Q4	us-gaap	Minority Interest MinorityInterest	381000000	USD
CY2012Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	49796000000	USD
CY2011Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	47655000000	USD
CY2012Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	164971000000	USD
CY2011Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	157818000000	USD
CY2011Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2011Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2011Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	790000000	USD
CY2012Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	851000000	USD
CY2012Q4	us-gaap	Redeemable Noncontrolling Interest Equity Carrying Amount RedeemableNoncontrollingInterestEquityCarryingAmount	16998000000	USD
CY2011Q4	us-gaap	Redeemable Noncontrolling Interest Equity Carrying Amount RedeemableNoncontrollingInterestEquityCarryingAmount	16014000000	USD
CY2011Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2012Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2012Q4	us-gaap	Short Term Investments ShortTermInvestments	1464000000	USD
CY2011Q4	us-gaap	Short Term Investments ShortTermInvestments	54000000	USD
CY2010	cmcsa	Business Acquisition Pro Forma Profit Loss BusinessAcquisitionProFormaProfitLoss	4584000000	USD
CY2010	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	3844000000	USD
CY2010	us-gaap	Business Acquisition Pro Forma Earnings Per Share Basic BusinessAcquisitionProFormaEarningsPerShareBasic	1.37
CY2011	cmcsa	Business Acquisition Pro Forma Profit Loss BusinessAcquisitionProFormaProfitLoss	5169000000	USD
CY2011	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	4149000000	USD
CY2011	us-gaap	Business Acquisition Pro Forma Earnings Per Share Basic BusinessAcquisitionProFormaEarningsPerShareBasic	1.51
CY2010	us-gaap	Business Acquisition Pro Forma Earnings Per Share Diluted BusinessAcquisitionProFormaEarningsPerShareDiluted	1.36
CY2011	us-gaap	Business Acquisition Pro Forma Earnings Per Share Diluted BusinessAcquisitionProFormaEarningsPerShareDiluted	1.49
CY2011	us-gaap	Business Acquisitions Pro Forma Revenue BusinessAcquisitionsProFormaRevenue	57661000000	USD
CY2010	us-gaap	Business Acquisitions Pro Forma Revenue BusinessAcquisitionsProFormaRevenue	55054000000	USD
CY2011Q1	cmcsa	Cash Paid To Acquire Entity Including Transaction Related Costs CashPaidToAcquireEntityIncludingTransactionRelatedCosts	6200000000	USD
CY2011Q1	cmcsa	Amount Used For Determining Redemption And Purchase Price AmountUsedForDeterminingRedemptionAndPurchasePrice	28400000000	USD
CY2011Q1	cmcsa	Parents Cash Or Common Stock Funding Commitment For Each Of Noncontrolling Investors Two Redemption Rights ParentsCashOrCommonStockFundingCommitmentForEachOfNoncontrollingInvestorsTwoRedemptionRights	2875000000	USD
CY2011Q1	cmcsa	Aggregate Cash Or Common Stock Funding Commitment For Noncontrolling Investor Redemption Rights AggregateCashOrCommonStockFundingCommitmentForNoncontrollingInvestorRedemptionRights	5750000000	USD
CY2011Q1	cmcsa	Deferred Tax On Exchange Transaction DeferredTaxOnExchangeTransaction	576000000	USD
CY2012Q4	cmcsa	Programming Rights Less Amortization ProgrammingRightsLessAmortization	1886000000	USD
CY2012Q4	cmcsa	Total Film And Television Costs And Programming Rights After Amortization TotalFilmAndTelevisionCostsAndProgrammingRightsAfterAmortization	5963000000	USD
CY2011Q4	cmcsa	Total Film And Television Costs And Programming Rights After Amortization TotalFilmAndTelevisionCostsAndProgrammingRightsAfterAmortization	6214000000	USD
CY2011Q4	cmcsa	Programming Rights Less Amortization ProgrammingRightsLessAmortization	2061000000	USD
CY2012Q4	cmcsa	Film And Television Library Costs Unamortized FilmAndTelevisionLibraryCostsUnamortized	867000000	USD
CY2012Q4	cmcsa	Percentage Of Acquired Film And Television Libraries To Be Amortized In Next Three Years PercentageOfAcquiredFilmAndTelevisionLibrariesToBeAmortizedInNextThreeYears	0.47	pure
CY2012Q4	cmcsa	Amortization Of Original Film And Television Production Expected To Be Amortized During Next Fiscal Year AmortizationOfOriginalFilmAndTelevisionProductionExpectedToBeAmortizedDuringNextFiscalYear	1100000000	USD
CY2012Q4	cmcsa	Percentage Of Unamortized Film And Television Costs For Released Productions To Be Amortized In Next Three Years PercentageOfUnamortizedFilmAndTelevisionCostsForReleasedProductionsToBeAmortizedInNextThreeYears	0.87	pure
CY2012Q4	us-gaap	Cost Method Investments CostMethodInvestments	2132000000	USD
CY2011Q4	us-gaap	Cost Method Investments CostMethodInvestments	2000000000	USD
CY2011Q4	us-gaap	Marketable Securities MarketableSecurities	3028000000	USD
CY2012Q4	cmcsa	Prepaid Forward Sale Obligations Fair Value PrepaidForwardSaleObligationsFairValue	3600000000	USD
CY2012Q4	cmcsa	Obligations Under Prepaid Forward Sale Agreements ObligationsUnderPrepaidForwardSaleAgreements	1248000000	USD
CY2012Q4	us-gaap	Investments Investments	7789000000	USD
CY2011Q4	us-gaap	Investments Investments	9908000000	USD
CY2011Q4	us-gaap	Equity Method Investments EquityMethodInvestments	4880000000	USD
CY2012Q4	us-gaap	Equity Method Investments EquityMethodInvestments	1164000000	USD
CY2011	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	41000000	USD
CY2011	us-gaap	Impairment Of Investments ImpairmentOfInvestments	5000000	USD
CY2011	us-gaap	Unrealized Gain Loss On Securities UnrealizedGainLossOnSecurities	192000000	USD
CY2011	cmcsa	Mark To Market Adjustment On Derivative Component Of Prepaid Forward Sale Agreements MarkToMarketAdjustmentOnDerivativeComponentOfPrepaidForwardSaleAgreements	119000000	USD
CY2011	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	110000000	USD
CY2011	cmcsa	Other Investment Income Loss Net OtherInvestmentIncomeLossNet	60000000	USD
CY2012	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	119000000	USD
CY2012	us-gaap	Unrealized Gain Loss On Securities UnrealizedGainLossOnSecurities	1159000000	USD
CY2012	cmcsa	Other Investment Income Loss Net OtherInvestmentIncomeLossNet	-6000000	USD
CY2012	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	30000000	USD
CY2012	us-gaap	Impairment Of Investments ImpairmentOfInvestments	24000000	USD
CY2010	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	13000000	USD
CY2010	us-gaap	Unrealized Gain Loss On Securities UnrealizedGainLossOnSecurities	874000000	USD
CY2010	cmcsa	Mark To Market Adjustment On Derivative Component Of Prepaid Forward Sale Agreements MarkToMarketAdjustmentOnDerivativeComponentOfPrepaidForwardSaleAgreements	665000000	USD
CY2010	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	94000000	USD
CY2010	us-gaap	Impairment Of Investments ImpairmentOfInvestments	24000000	USD
CY2010	cmcsa	Other Investment Income Loss Net OtherInvestmentIncomeLossNet	4000000	USD
CY2012	cmcsa	Mark To Market Adjustment On Derivative Component Of Prepaid Forward Sale Agreements MarkToMarketAdjustmentOnDerivativeComponentOfPrepaidForwardSaleAgreements	1071000000	USD
CY2012Q4	cmcsa	Equity Securities Held As Collateral EquitySecuritiesHeldAsCollateral	4143000000	USD
CY2011Q4	cmcsa	Equity Securities Held As Collateral EquitySecuritiesHeldAsCollateral	2984000000	USD
CY2012Q4	cmcsa	Liabilities Related To Prepaid Forward Sale Agreements LiabilitiesRelatedToPrepaidForwardSaleAgreements	3550000000	USD
CY2011Q4	cmcsa	Derivative Fair Value Of Embedded Derivative Liability Component Of Prepaid Forward Sale Agreements DerivativeFairValueOfEmbeddedDerivativeLiabilityComponentOfPrepaidForwardSaleAgreements	1228000000	USD
CY2012Q4	cmcsa	Derivative Fair Value Of Embedded Derivative Liability Component Of Prepaid Forward Sale Agreements DerivativeFairValueOfEmbeddedDerivativeLiabilityComponentOfPrepaidForwardSaleAgreements	2302000000	USD
CY2011Q4	cmcsa	Liabilities Related To Prepaid Forward Sale Agreements LiabilitiesRelatedToPrepaidForwardSaleAgreements	2405000000	USD
CY2011Q4	cmcsa	Prepaid Forward Sale Obligations Fair Value PrepaidForwardSaleObligationsFairValue	2500000000	USD
CY2011Q4	cmcsa	Obligations Under Prepaid Forward Sale Agreements ObligationsUnderPrepaidForwardSaleAgreements	1177000000	USD
CY2011Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	5685000000	USD
CY2012Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	5468000000	USD
CY2011Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	5094000000	USD
CY2012Q4	us-gaap	Land Land	989000000	USD
CY2011Q4	us-gaap	Land Land	975000000	USD
CY2011Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	64087000000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	66657000000	USD
CY2012Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	39425000000	USD
CY2011Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	36528000000	USD
CY2012Q4	cmcsa	Cable Distribution Systems CableDistributionSystems	29528000000	USD
CY2012Q4	cmcsa	Customer Premises Equipment CustomerPremisesEquipment	24763000000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	5909000000	USD
CY2011Q4	cmcsa	Cable Distribution Systems CableDistributionSystems	28781000000	USD
CY2011Q4	cmcsa	Customer Premises Equipment CustomerPremisesEquipment	23552000000	USD
CY2010Q4	us-gaap	Goodwill Goodwill	14958000000	USD
CY2012	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	1000000	USD
CY2012Q4	cmcsa	Intangible Assets Gross IntangibleAssetsGross	84866000000	USD
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CY2012Q4	us-gaap	Debt Weighted Average Interest Rate DebtWeightedAverageInterestRate	0.0560	pure
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CY2012Q4	cmcsa	Commercial Paper To Be Issued At Any One Time Maximum CommercialPaperToBeIssuedAtAnyOneTimeMaximum	2250000000	USD
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CY2011Q4	cmcsa	Fair Value Liabilities Measured On Recurring Basis FairValueLiabilitiesMeasuredOnRecurringBasis	2898000000	USD
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CY2011Q4	us-gaap	Trading Securities Fair Value Disclosure TradingSecuritiesFairValueDisclosure	2895000000	USD
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CY2011Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Obligations FairValueLiabilitiesMeasuredOnRecurringBasisObligations	1004000000	USD
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CY2011Q4	us-gaap	Foreign Currency Derivative Liabilities At Fair Value ForeignCurrencyDerivativeLiabilitiesAtFairValue	8000000	USD
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CY2011	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	1626000000	USD
CY2010	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	1864000000	USD
CY2012	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	757000000	USD
CY2011	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1000000000	USD
CY2010	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	611000000	USD
CY2012Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	430000000	USD
CY2011Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	305000000	USD
CY2010Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	263000000	USD
CY2012	us-gaap	Noncash Or Part Noncash Acquisition Fixed Assets Acquired1 NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1	85000000	USD
CY2012Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.1625
CY2011Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.1125
CY2010Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.0945
CY2011Q4	cmcsa	Percentage Ownership Of Assets Contributed By Acquiring Entity PercentageOwnershipOfAssetsContributedByAcquiringEntity	0.49	pure
CY2012	us-gaap	Gain Loss On Securitization Of Financial Assets GainLossOnSecuritizationOfFinancialAssets	-1000000	USD
CY2012	us-gaap	Cash Flows Between Transferee And Transferor Proceeds From New Transfers CashFlowsBetweenTransfereeAndTransferorProceedsFromNewTransfers	-86000000	USD
CY2012	cmcsa	Interest Expense On Securitization Of Financial Assets InterestExpenseOnSecuritizationOfFinancialAssets	-12000000	USD
CY2011	us-gaap	Cash Flows Between Transferee And Transferor Proceeds From New Transfers CashFlowsBetweenTransfereeAndTransferorProceedsFromNewTransfers	-237000000	USD
CY2011	us-gaap	Gain Loss On Securitization Of Financial Assets GainLossOnSecuritizationOfFinancialAssets	-36000000	USD
CY2012Q4	us-gaap	Qualitative And Quantitative Information Assets Or Liabilities For Transferors Continuing Involvement In Securitization Or Assetbacked Financing Arrangement Principal Amounts Outstanding QualitativeAndQuantitativeInformationAssetsOrLiabilitiesForTransferorsContinuingInvolvementInSecuritizationOrAssetbackedFinancingArrangementPrincipalAmountsOutstanding	791000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	497000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	439000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	380000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	354000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	329000000	USD
CY2011Q4	us-gaap	Qualitative And Quantitative Information Assets Or Liabilities For Transferors Continuing Involvement In Securitization Or Assetbacked Financing Arrangement Principal Amounts Outstanding QualitativeAndQuantitativeInformationAssetsOrLiabilitiesForTransferorsContinuingInvolvementInSecuritizationOrAssetbackedFinancingArrangementPrincipalAmountsOutstanding	961000000	USD
CY2011Q4	us-gaap	Interests Continued To Be Held By Transferor Fair Value InterestsContinuedToBeHeldByTransferorFairValue	268000000	USD
CY2012Q4	cmcsa	Monetization Collections Owed Under Program MonetizationCollectionsOwedUnderProgram	882000000	USD
CY2011Q4	cmcsa	Monetization Collections Owed Under Program MonetizationCollectionsOwedUnderProgram	781000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments Current ProgrammingAndTalentCommitmentsFutureMinimumPaymentsCurrent	3789000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments In Two Years ProgrammingAndTalentCommitmentsFutureMinimumPaymentsInTwoYears	3495000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments In Three Years ProgrammingAndTalentCommitmentsFutureMinimumPaymentsInThreeYears	2301000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments In Four Years ProgrammingAndTalentCommitmentsFutureMinimumPaymentsInFourYears	3291000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments In Five Years ProgrammingAndTalentCommitmentsFutureMinimumPaymentsInFiveYears	2078000000	USD
CY2012	cmcsa	Programming And Talent Commitments Future Minimum Payments Due Thereafter ProgrammingAndTalentCommitmentsFutureMinimumPaymentsDueThereafter	15478000000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	1218000000	USD
CY2012	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	688000000	USD
CY2011	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	570000000	USD
CY2010	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	424000000	USD
CY2012Q4	cmcsa	Collateral Liability For Unconsolidated Subsidiary Debt CollateralLiabilityForUnconsolidatedSubsidiaryDebt	482000000	USD
CY2012Q4	cmcsa	Percentage Of Employees Covered Under Collective Bargaining Agreements Expired Or Scheduled To Expire During Next Year PercentageOfEmployeesCoveredUnderCollectiveBargainingAgreementsExpiredOrScheduledToExpireDuringNextYear	0.18	pure
CY2012Q4	cmcsa	Number Of Employees Covered Under Collective Bargaining Agreements NumberOfEmployeesCoveredUnderCollectiveBargainingAgreements	6700	numberofemployees
CY2013Q1	cmcsa	Cash Paid For Settlement Of Collateral Liability CashPaidForSettlementOfCollateralLiability	602000000	USD
CY2012	cmcsa	Operating Income Excluding Depreciation And Amortization OperatingIncomeExcludingDepreciationAndAmortization	19977000000	USD
CY2011	cmcsa	Operating Income Excluding Depreciation And Amortization OperatingIncomeExcludingDepreciationAndAmortization	18357000000	USD
CY2010	cmcsa	Operating Income Excluding Depreciation And Amortization OperatingIncomeExcludingDepreciationAndAmortization	14596000000	USD
CY2012	cmcsa	Cable Segment Revenue Types As Percentage Of Total Cable Revenue CableSegmentRevenueTypesAsPercentageOfTotalCableRevenue	1.00	pure
CY2012Q2	us-gaap	Net Income Loss NetIncomeLoss	1348000000	USD
CY2012Q3	us-gaap	Net Income Loss NetIncomeLoss	2113000000	USD
CY2012Q4	us-gaap	Net Income Loss NetIncomeLoss	1518000000	USD
CY2012Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.57
CY2012	us-gaap	Entity Wide Disclosure On Geographic Areas Revenue From External Customers Attributed To Foreign Countries EntityWideDisclosureOnGeographicAreasRevenueFromExternalCustomersAttributedToForeignCountries	4500000000	USD
CY2012Q2	us-gaap	Revenues Revenues	15211000000	USD
CY2012Q3	us-gaap	Revenues Revenues	16544000000	USD
CY2012Q4	us-gaap	Revenues Revenues	15937000000	USD
CY2012Q1	us-gaap	Revenues Revenues	14878000000	USD
CY2012Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	2758000000	USD
CY2012Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	3079000000	USD
CY2012Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	3048000000	USD
CY2012Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	3294000000	USD
CY2012Q1	us-gaap	Net Income Loss NetIncomeLoss	1224000000	USD
CY2012Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.45
CY2012Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.50
CY2012Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.78
CY2012Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.56
CY2012Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1625
CY2012Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1625
CY2012Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1625
CY2012Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1625
CY2011Q1	us-gaap	Revenues Revenues	12128000000	USD
CY2011Q2	us-gaap	Revenues Revenues	14333000000	USD
CY2011Q3	us-gaap	Revenues Revenues	14339000000	USD
CY2011Q4	us-gaap	Revenues Revenues	15042000000	USD
CY2011Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	2224000000	USD
CY2011Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	2938000000	USD
CY2011Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	2641000000	USD
CY2011Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	2918000000	USD
CY2011Q1	us-gaap	Net Income Loss NetIncomeLoss	943000000	USD
CY2011Q2	us-gaap	Net Income Loss NetIncomeLoss	1022000000	USD
CY2011Q3	us-gaap	Net Income Loss NetIncomeLoss	908000000	USD
CY2011Q4	us-gaap	Net Income Loss NetIncomeLoss	1287000000	USD
CY2011Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
CY2011Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.37
CY2011Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.33
CY2011Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.47
CY2011Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.47
CY2011Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1125
CY2012Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.45
CY2012Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2012Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.79
CY2011Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.37
CY2011Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.33
CY2011Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1125
CY2011Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1125
CY2011Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.1125
CY2012	us-gaap	Subsequent Event Description SubsequentEventDescription	On February 12, 2013, we entered into an agreement to acquire GE’s 49% noncontrolling common equity interest in NBCUniversal Holdings for approximately $16.7 billion. In addition, NBCUniversal agreed to acquire from GE the portion of 30 Rockefeller Plaza in New York City that NBCUniversal occupies and CNBC’s headquarters in Englewood Cliffs, New Jersey for approximately $1.4 billion. The transactions, which are subject to customary closing conditions, are expected to close by the end of March 2013. The consideration will consist of $11.4 billion of cash on hand; $4 billion of senior unsecured debt securities issued by a holding company (“HoldCo”), whose sole asset is its interests in NBCUniversal Holdings; $2 billion of cash funded through a combination of Comcast’s existing credit facility and NBCUniversal’s credit facility, which is expected to be amended, among other things, to substitute HoldCo as the sole borrower; and $725 million of Holdco preferred stock. After closing, we will control and consolidate HoldCo and own all of its capital stock other than the preferred stock. HoldCo’s debt securities and credit facility will be guaranteed by us and the cable holding company subsidiaries that guarantee our senior indebtedness. The preferred stock will pay dividends at a fixed rate and can be put to HoldCo for redemption at par on the later of seven years following the issuance of the preferred stock and three years following the sale by GE of shares to unaffiliated third parties, and thereafter, every third anniversary of such date (a “Put Date”). Shares of preferred stock can be called for redemption by HoldCo at par one year following each Put Date applicable to such shares.
CY2012Q4	us-gaap	Minority Interest Ownership Percentage By Noncontrolling Owners MinorityInterestOwnershipPercentageByNoncontrollingOwners	0.49	pure
CY2012Q4	us-gaap	Common Stock Value CommonStockValue	31000000	USD
CY2012Q4	cmcsa	Other Stockholders Equity OtherStockholdersEquity	49325000000	USD
CY2012Q4	cmcsa	Accrued Expenses And Other Current Liabilities Including Deferred Revenue AccruedExpensesAndOtherCurrentLiabilitiesIncludingDeferredRevenue	6782000000	USD
CY2012Q4	cmcsa	Investments In And Amounts Due From Subsidiaries Eliminated Upon Consolidation InvestmentsInAndAmountsDueFromSubsidiariesEliminatedUponConsolidation	0	USD
CY2012	cmcsa	Scheduleofacquisitionrelatedexpensesincludedinconsolidatedstatementofincometabletextblock Scheduleofacquisitionrelatedexpensesincludedinconsolidatedstatementofincometabletextblock	<div><table style="border-collapse:collapse;margin-top:20px;"><tr style="height: 17px"><td style="width: 431px; border-bottom-style:solid;border-bottom-width:1px;text-align:left;border-color:#000000;min-width:431px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 8pt;COLOR: #000000;">Year ended December 31 (in millions)</font></td><td style="width: 134px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:134px;"> </td><td style="width: 40px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 8pt;COLOR: #000000;TEXT-ALIGN: center;">2011</font></td><td style="width: 50px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:50px;"> </td><td style="width: 40px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 8pt;COLOR: #000000;TEXT-ALIGN: center;">2010</font></td></tr><tr style="height: 17px"><td style="width: 431px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:431px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;">Other operating and administrative expenses</font></td><td style="width: 134px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:134px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;">$</font></td><td style="width: 40px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;"> 155</font></td><td style="width: 50px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:50px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;">$</font></td><td style="width: 40px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;"> 80</font></td></tr><tr style="height: 17px"><td style="width: 431px; text-align:left;border-color:#000000;min-width:431px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;">Other expense</font></td><td style="width: 134px; text-align:right;border-color:#000000;min-width:134px;"> </td><td style="width: 40px; text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;"> 16</font></td><td style="width: 50px; text-align:right;border-color:#000000;min-width:50px;"> </td><td style="width: 40px; text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;"> 129</font></td></tr><tr style="height: 17px"><td style="width: 431px; border-bottom-style:solid;border-bottom-width:1px;text-align:left;border-color:#000000;min-width:431px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;">Interest expense</font></td><td style="width: 134px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:134px;"> </td><td style="width: 40px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;background-color:#FFFFFF;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;"> -</font></td><td style="width: 50px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:50px;"> </td><td style="width: 40px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;"> 7</font></td></tr><tr style="height: 17px"><td style="width: 431px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:2px;text-align:left;border-color:#000000;min-width:431px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;">Total</font></td><td style="width: 134px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:2px;text-align:right;border-color:#000000;min-width:134px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;">$</font></td><td style="width: 40px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:2px;text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;"> 171</font></td><td style="width: 50px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:2px;text-align:right;border-color:#000000;min-width:50px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;TEXT-ALIGN: right;">$</font></td><td style="width: 40px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:2px;text-align:right;border-color:#000000;min-width:40px;"><font style="FONT-FAMILY: Times New Roman;FONT-SIZE: 10pt;COLOR: #000000;"> 216</font></td></tr></table></div>
CY2011	cmcsa	Total Transaction Costs And Transaction Related Costs TotalTransactionCostsAndTransactionRelatedCosts	171000000	USD
CY2012Q4	us-gaap	Marketable Securities MarketableSecurities	4493000000	USD
CY2011	us-gaap	Goodwill Other Changes GoodwillOtherChanges	3000000	USD
CY2012	us-gaap	Goodwill Other Changes GoodwillOtherChanges	194000000	USD
CY2011	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	174000000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	3363000000	USD
CY2012	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	30.00
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	113000000	shares
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	29000000	shares
CY2012Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	2016000000	USD
CY2011Q4	cmcsa	Returns And Incentives Allowance ReturnsAndIncentivesAllowance	425000000	USD
CY2012Q4	us-gaap	Interests Continued To Be Held By Transferor Fair Value InterestsContinuedToBeHeldByTransferorFairValue	274000000	USD
CY2011	cmcsa	Cable Segment Revenue Types As Percentage Of Total Cable Revenue CableSegmentRevenueTypesAsPercentageOfTotalCableRevenue	1	pure
CY2010	cmcsa	Cable Segment Revenue Types As Percentage Of Total Cable Revenue CableSegmentRevenueTypesAsPercentageOfTotalCableRevenue	1	pure
CY2011	us-gaap	Entity Wide Disclosure On Geographic Areas Revenue From External Customers Attributed To Foreign Countries EntityWideDisclosureOnGeographicAreasRevenueFromExternalCustomersAttributedToForeignCountries	4100000000	USD
CY2011Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.34
CY2011Q4	us-gaap	Common Stock Value CommonStockValue	32000000	USD
CY2011Q4	cmcsa	Other Stockholders Equity OtherStockholdersEquity	47242000000	USD
CY2011Q4	cmcsa	Investments In And Amounts Due From Subsidiaries Eliminated Upon Consolidation InvestmentsInAndAmountsDueFromSubsidiariesEliminatedUponConsolidation	0	USD
CY2012	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	62570000000	USD
CY2012	us-gaap	Management Fees Revenue ManagementFeesRevenue	0	USD
CY2011Q4	cmcsa	Accrued Expenses And Other Current Liabilities Including Deferred Revenue AccruedExpensesAndOtherCurrentLiabilitiesIncludingDeferredRevenue	4914000000	USD
CY2011	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	55842000000	USD
CY2010	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	37937000000	USD
CY2012	cmcsa	Net Transactions With Affiliates NetTransactionsWithAffiliates	0	USD
CY2012	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	-691000000	USD
CY2011	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	-325000000	USD
CY2010	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	-67000000	USD
CY2012	cmcsa	Holding Company Ownership In Subsidiaries HoldingCompanyOwnershipInSubsidiaries	1	pure

Files In Submission

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$CMCSA
COMCAST CORP Stock $cmcsa

2012 Form 8-K Financial Statement

#000119312513370469 Filed on September 18, 2013

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CMCSA COMCAST CORP Stock $cmcsa

2012 Form 8-K Financial Statement

#000119312513370469 Filed on September 18, 2013

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CMCSA
COMCAST CORP Stock $cmcsa