v2.4.0.8
Related Party Transactions (Narrative) (Details) (USD $)
9 Months Ended
Sep. 30, 2014
Dec. 31, 2013
Sep. 30, 2014
NBCUniversal Media, LLC [Member]
Dec. 31, 2013
NBCUniversal Media, LLC [Member]
Sep. 30, 2014
Nbcuniversal Holdings Preferred Stock [Member]
NBCUniversal Media, LLC [Member]
Sep. 30, 2014
Carrying Value Of Related Party Contractual Obligation [Member]
NBCUniversal Media, LLC [Member]
Sep. 30, 2014
Comcast Corporation And NBCUniversal Media LLC Revolving Credit Agreement [Member]
NBCUniversal Media, LLC [Member]
Preferred stock liquidition preference value         $ 9,400,000,000    
Revolving Credit Agreement Capacity             3,000,000,000
Preferred stock dividend rate percentage         8.25%    
Borrowing margin for LIBOR based borrowings     1.00%        
Other noncurrent liabilities $ 10,388,000,000 $ 11,384,000,000 $ 3,514,000,000 $ 3,412,000,000   $ 383,000,000