Supplemental Financial Information (Noncash Investing and Financing Activities)(Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Mar. 19, 2013
GE ownership percentage		49.00%
Purchase of NBCUniversal noncontrolling interest	$ 16,700,000,000
Total noncash consideration transferred related to the Redemption Transaction	6,000,000,000
Dividends payable, amount	512,000,000
Dividends payable, amount per share	$ 0.195
Capital expenditures incurred but not yet paid	573,000,000
NBCUniversal Enterprise Credit Facility
Total consideration transferred related to the Redemption Transaction and purchase of certain properties	1,250,000,000
NBCUniversal Enterprise Senior Unsecured Debt Securities
Total consideration transferred related to the Redemption Transaction and purchase of certain properties	4,000,000,000
NBCUniversal Enterprise Preferred Stock
Total consideration transferred related to the Redemption Transaction and purchase of certain properties	$ 725,000,000