v2.4.1.9

Consolidated Balance Sheet (Parenthetical) (USD $) | Dec. 31, 2014 | Dec. 31, 2013
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Preferred stock, authorized | 20,000,000 us-gaap_PreferredStockSharesAuthorized | 20,000,000 us-gaap_PreferredStockSharesAuthorized
Preferred stock, issued | 0 us-gaap_PreferredStockSharesIssued | 0 us-gaap_PreferredStockSharesIssued
Class A Common Stock [Member] |  |
Common stock, par value | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Common stock, authorized | 7,500,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember | 7,500,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Common stock, issued | 2,496,598,612 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember | 2,503,535,883 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Common stock, outstanding | 2,131,137,862 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember | 2,138,075,133 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Treasury stock common shares | 365,460,750 us-gaap_TreasuryStockShares / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember | 365,460,750 us-gaap_TreasuryStockShares / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Class A Special Common Stock [Member] |  |
Common stock, par value | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember
Common stock, authorized | 7,500,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember | 7,500,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember
Common stock, issued | 471,419,601 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember | 529,964,944 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember
Common stock, outstanding | 400,484,837 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember | 459,030,180 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember
Treasury stock common shares | 70,934,764 us-gaap_TreasuryStockShares / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember | 70,934,764 us-gaap_TreasuryStockShares / us-gaap_StatementClassOfStockAxis = cmcsa_ClassaSpecialCommonStockMember
Class B Common Stock [Member] |  |
Common stock, par value | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Common stock, authorized | 75,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember | 75,000,000 us-gaap_CommonStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Common stock, issued | 9,444,375 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember | 9,444,375 us-gaap_CommonStockSharesIssued / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Common stock, outstanding | 9,444,375 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember | 9,444,375 us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember

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- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
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