v2.4.1.9

Supplemental Financial Information (Receivables)(Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Receivables, gross | $ 6,634 us-gaap_AccountsReceivableGrossCurrent | $ 6,885 us-gaap_AccountsReceivableGrossCurrent
Less: Allowance for returns and customer incentives | 297 cmcsa_ReturnsAndIncentivesAllowance | 359 cmcsa_ReturnsAndIncentivesAllowance
Less: Allowance for doubtful accounts | 193 us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent | 205 us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Receivables, net | 6,144 us-gaap_AccountsReceivableNetCurrent | 6,321 us-gaap_AccountsReceivableNetCurrent
NBCUniversal Media, LLC [Member] |  |
Receivables, gross | 5,248 us-gaap_AccountsReceivableGrossCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 5,258 us-gaap_AccountsReceivableGrossCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Less: Allowance for returns and customer incentives | 294 cmcsa_ReturnsAndIncentivesAllowance / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 356 cmcsa_ReturnsAndIncentivesAllowance / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Less: Allowance for doubtful accounts | 63 us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | 60 us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember
Receivables, net | $ 4,891 us-gaap_AccountsReceivableNetCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember | $ 4,842 us-gaap_AccountsReceivableNetCurrent / dei_LegalEntityAxis = cmcsa_NBCUniversalMediaLLCMember

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- Definition A valuation allowance for sales returns and other incentives. + References No definition available. + Details
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Balance Type: | credit
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- Definition Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business. + 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 210.5-02.3) -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 03 -Paragraph 3 -Subparagraph a, b -Article 5 + Details
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- Definition Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. + 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 210.5-02.3-4) -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 3 -Subparagraph a(1) -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 + Details
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- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |