Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Settlement Of Station Venture Liability			$ 602
Other noncurrent liabilities	$ 10,637	$ 10,819
NBCUniversal Media LLC [Member]
Revolving Credit Agreement Capacity			3,000
Collateral Liability For Unconsolidated Subsidiary Debt			482
Borrowing margin for LIBOR based borrowings	1.00%
Settlement Of Station Venture Liability	$ 0	0	602
Redemption Transaction Distribution	0	0	$ 3,200
Other noncurrent liabilities	3,790	3,721
NBCUniversal Holdings Preferred Stock [Member] | NBCUniversal Media LLC [Member]
Preferred stock liquidation preference value	$ 9,400
Preferred stock dividend rate percentage	8.25%
Carrying Value Of Related Party Contractual Obligation [Member] | NBCUniversal Media LLC [Member]
Other noncurrent liabilities	$ 383	$ 383