v2.4.0.8
Supplemental Financial Information (Components of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2014
Dec. 31, 2013
Jun. 30, 2013
Unrealized gains (losses) on marketable securities $ 4   $ 277
Deferred gains (losses) on cash flow hedges (63)   (54)
Unrecognized gains (losses) on employee benefit obligations 70   (107)
Cumulative translation adjustments (25)   (39)
Accumulated other comprehensive income (loss), net of deferred taxes (14) 56 77
NBCUniversal Media, LLC [Member]
     
Unrealized gains (losses) on marketable securities 5    
Deferred gains (losses) on cash flow hedges (7)    
Unrecognized gains (losses) on employee benefit obligations 45   (51)
Cumulative translation adjustments (38)   (60)
Accumulated other comprehensive income (loss), net of deferred taxes $ 5 $ (16) $ (111)