v3.4.0.3
Long-Term Debt (Narrative) (Details)
$ in Millions
3 Months Ended
Mar. 31, 2016
USD ($)
Total debt $ 55,600
Long-term Debt, Fair Value 63,400
Amounts available under revolving credit facilities 6,900
NBCUniversal Media LLC [Member]  
Total debt 12,800
Long-term Debt, Fair Value $ 14,100
Comcast ownership in cable holding company subsidiaries 100.00%
NBCUniversal Enterprise [Member]  
Commercial paper $ 450
NBCUniversal Enterprise [Member] | NBCUniversal Media LLC [Member]  
Related Party Aggregate Principal Amount Senior Notes Not Subject To Guarantee 4,000
Related Party Credit Facility Not Subject To Guarantee 1,350
Related Party Liquidation Preference Preferred Stock Not Subject To Guarantee 725
NBCUniversal Enterprise Credit Facility [Member]  
Amounts available under revolving credit facilities 900
Comcast And Comcast Cable Debt Securities [Member] | NBCUniversal Media LLC [Member]  
Guarantee Obligations Current Principal Balance $ 37,900
Comcast And Comcast Cable Communications, LLC Revolving Credit Facility [Member]  
Debt Instrument, Maturity Date, Description 2017
Guarantee Obligations Current Principal Balance $ 6,250
Comcast And Comcast Cable Communications, LLC Revolving Credit Facility [Member] | NBCUniversal Media LLC [Member]  
Debt Instrument, Maturity Date, Description June 2017
Revolver Line of credit amount outstanding $ 0
Guarantee Obligations Current Principal Balance $ 6,250