v2.4.0.8

Related Party Transactions (Narrative) (Details) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013
Settlement Of Station Venture Liability | $ 602,000,000
NBCUniversal Media, LLC [Member] |
Redemption Transaction Distribution | 3,200,000,000
Revolving Credit Agreement Capacity | 3,000,000,000
Settlement Of Station Venture Liability | 602,000,000
Collateral Liability For Unconsolidated Subsidiary Debt | 482,000,000
Borrowing margin for LIBOR based borrowings | 1.00%
Nbcuniversal Holdings Preferred Stock [Member] | NBCUniversal Media, LLC [Member] |
Preferred stock liquidition preference value | $ 9,400,000,000
Preferred stock dividend rate percentage | 8.25%

X
- Definition Represents the borrowing margin for LIBOR-based borrowings + References No definition available. + Details
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Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Collateral Liability For Unconsolidated Subsidiary Debt + References No definition available. + Details
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Namespace Prefix: | cmcsa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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X
- Definition The cash distribution to NBCUniversal Holdings associated with the redemption transaction. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The maximum amount of borrowing or lending capacity with respect to the cash management arrangement between Comcast and NBCUniversal under the revolving credit agreement. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
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- Definition The cash outflow associated with the settlement of the Station Venture liability. + References No definition available. + Details
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X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
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- Definition Value of the difference between preference in liquidation and the par or stated values of the preferred shares. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
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