v2.4.1.9

Quarterly Financial Information (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified | 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
Quarterly Financial Information Disclosure Abstract |  |  |  |  |  |  |  |  |  |  |
Revenue | $ 17,732 us-gaap_Revenues | $ 16,791 us-gaap_Revenues | $ 16,844 us-gaap_Revenues | $ 17,408 us-gaap_Revenues | $ 16,926 us-gaap_Revenues | $ 16,151 us-gaap_Revenues | $ 16,270 us-gaap_Revenues | $ 15,310 us-gaap_Revenues | $ 68,775 us-gaap_Revenues | $ 64,657 us-gaap_Revenues | $ 62,570 us-gaap_Revenues
Operating income | 3,787 us-gaap_OperatingIncomeLoss | 3,745 us-gaap_OperatingIncomeLoss | 3,804 us-gaap_OperatingIncomeLoss | 3,568 us-gaap_OperatingIncomeLoss | 3,647 us-gaap_OperatingIncomeLoss | 3,414 us-gaap_OperatingIncomeLoss | 3,435 us-gaap_OperatingIncomeLoss | 3,067 us-gaap_OperatingIncomeLoss | 14,904 us-gaap_OperatingIncomeLoss | 13,563 us-gaap_OperatingIncomeLoss | 12,179 us-gaap_OperatingIncomeLoss
Net income attributable to Parent | 1,925 us-gaap_NetIncomeLoss | 2,592 us-gaap_NetIncomeLoss | 1,992 us-gaap_NetIncomeLoss | 1,871 us-gaap_NetIncomeLoss | 1,913 us-gaap_NetIncomeLoss | 1,732 us-gaap_NetIncomeLoss | 1,734 us-gaap_NetIncomeLoss | 1,437 us-gaap_NetIncomeLoss | 8,380 us-gaap_NetIncomeLoss | 6,816 us-gaap_NetIncomeLoss | 6,203 us-gaap_NetIncomeLoss
Basic earnings per common share attributable to Comcast Corporation shareholders | $ 0.75 us-gaap_EarningsPerShareBasic | $ 1 us-gaap_EarningsPerShareBasic | $ 0.77 us-gaap_EarningsPerShareBasic | $ 0.72 us-gaap_EarningsPerShareBasic | $ 0.73 us-gaap_EarningsPerShareBasic | $ 0.66 us-gaap_EarningsPerShareBasic | $ 0.66 us-gaap_EarningsPerShareBasic | $ 0.55 us-gaap_EarningsPerShareBasic | $ 3.24 us-gaap_EarningsPerShareBasic | $ 2.6 us-gaap_EarningsPerShareBasic | $ 2.32 us-gaap_EarningsPerShareBasic
Diluted earnings per common share attributable to Comcast Corporation shareholders | $ 0.74 us-gaap_EarningsPerShareDiluted | $ 0.99 us-gaap_EarningsPerShareDiluted | $ 0.76 us-gaap_EarningsPerShareDiluted | $ 0.71 us-gaap_EarningsPerShareDiluted | $ 0.72 us-gaap_EarningsPerShareDiluted | $ 0.65 us-gaap_EarningsPerShareDiluted | $ 0.65 us-gaap_EarningsPerShareDiluted | $ 0.54 us-gaap_EarningsPerShareDiluted | $ 3.2 us-gaap_EarningsPerShareDiluted | $ 2.56 us-gaap_EarningsPerShareDiluted | $ 2.28 us-gaap_EarningsPerShareDiluted
Dividends declared per common share | $ 0.225 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.225 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.225 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.225 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.195 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.195 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.195 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.195 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.9 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.78 us-gaap_CommonStockDividendsPerShareDeclared | $ 0.65 us-gaap_CommonStockDividendsPerShareDeclared
Change In Income Tax Expense Related To Effectively Settled Uncertain Tax Positions |  | $ 724 cmcsa_ChangeInIncomeTaxExpenseRelatedToEffectivelySettledUncertainTaxPositions |  |  |  |  |  |  |  |  |

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