v2.4.1.9
Earnings Per Share (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
Earnings Per Share                      
Net income attributable to Parent $ 1,925us-gaap_NetIncomeLoss $ 2,592us-gaap_NetIncomeLoss $ 1,992us-gaap_NetIncomeLoss $ 1,871us-gaap_NetIncomeLoss $ 1,913us-gaap_NetIncomeLoss $ 1,732us-gaap_NetIncomeLoss $ 1,734us-gaap_NetIncomeLoss $ 1,437us-gaap_NetIncomeLoss $ 8,380us-gaap_NetIncomeLoss $ 6,816us-gaap_NetIncomeLoss $ 6,203us-gaap_NetIncomeLoss
Basic shares attributable to Comcast Corporation shareholders                 2,583us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 2,625us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 2,678us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Assumed exercise or issuance of shares relating to stock plans                 37us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements 40us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements 39us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Diluted shares attributable to Comcast Corporation shareholders                 2,620us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 2,665us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 2,717us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Basic earnings per common share attributable to Comcast Corporation shareholders $ 0.75us-gaap_EarningsPerShareBasic $ 1us-gaap_EarningsPerShareBasic $ 0.77us-gaap_EarningsPerShareBasic $ 0.72us-gaap_EarningsPerShareBasic $ 0.73us-gaap_EarningsPerShareBasic $ 0.66us-gaap_EarningsPerShareBasic $ 0.66us-gaap_EarningsPerShareBasic $ 0.55us-gaap_EarningsPerShareBasic $ 3.24us-gaap_EarningsPerShareBasic $ 2.6us-gaap_EarningsPerShareBasic $ 2.32us-gaap_EarningsPerShareBasic
Diluted earnings per common share attributable to Comcast Corporation shareholders $ 0.74us-gaap_EarningsPerShareDiluted $ 0.99us-gaap_EarningsPerShareDiluted $ 0.76us-gaap_EarningsPerShareDiluted $ 0.71us-gaap_EarningsPerShareDiluted $ 0.72us-gaap_EarningsPerShareDiluted $ 0.65us-gaap_EarningsPerShareDiluted $ 0.65us-gaap_EarningsPerShareDiluted $ 0.54us-gaap_EarningsPerShareDiluted $ 3.2us-gaap_EarningsPerShareDiluted $ 2.56us-gaap_EarningsPerShareDiluted $ 2.28us-gaap_EarningsPerShareDiluted