Condensed Consolidated Statement of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities
Net cash provided by operating activities	$ 12,302,000,000	$ 11,679,000,000
Investing Activities
Capital expenditures	(5,196,000,000)	(4,593,000,000)
Cash paid for intangible assets	(735,000,000)	(694,000,000)
Acquisitions and construction of real estate properties	(28,000,000)	(1,705,000,000)
Acquisitions, net of cash acquired	(477,000,000)	(42,000,000)
Proceeds from sales of businesses and investments	622,000,000	655,000,000
Return of capital from investees	6,000,000	146,000,000
Purchases of investments	(145,000,000)	(1,177,000,000)
Other	(127,000,000)	83,000,000
Net cash provided by (used in) investing activities	(6,080,000,000)	(7,327,000,000)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(437,000,000)	395,000,000
Proceeds from borrowings	4,182,000,000	2,933,000,000
Repurchases and repayments of debt	(3,172,000,000)	(2,442,000,000)
Repurchases and retirements of common stock	(2,250,000,000)	(1,500,000,000)
Dividends paid	(1,676,000,000)	(1,454,000,000)
Issuances of common stock	33,000,000	35,000,000
Purchase of NBCUniversal noncontrolling common equity interest		(10,761,000,000)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(170,000,000)	(164,000,000)
Settlement of Station Venture liability		(602,000,000)
Other	97,000,000	(140,000,000)
Net cash provided by (used in) financing activities	(3,393,000,000)	(13,700,000,000)
Increase (decrease) in cash and cash equivalents	2,829,000,000	(9,348,000,000)
Cash and cash equivalents, beginning of period	1,718,000,000	10,951,000,000
Cash and cash equivalents, end of period	4,547,000,000	1,603,000,000
NBCUniversal Media, LLC [Member]
Operating Activities
Net cash provided by operating activities	3,156,000,000	3,734,000,000
Investing Activities
Capital expenditures	(884,000,000)	(807,000,000)
Cash paid for intangible assets	(86,000,000)	(86,000,000)
Acquisitions of real estate properties	0	(1,705,000,000)
Acquisitions, net of cash acquired	(118,000,000)	(42,000,000)
Note receivable from Comcast	0	(981,000,000)
Return of capital from investees	5,000,000	131,000,000
Purchases of investments	(29,000,000)	(235,000,000)
Other	(145,000,000)	(20,000,000)
Net cash provided by (used in) investing activities	(1,257,000,000)	(3,745,000,000)
Financing Activities
Proceeds from (repayments of) borrowings from Comcast, net	279,000,000	0
Repurchases and repayments of debt	(904,000,000)	(91,000,000)
Redemption Transaction distribution		(3,200,000,000)
Distributions to noncontrolling interests	(135,000,000)	(144,000,000)
Distributions to member	(1,237,000,000)	(938,000,000)
Settlement of Station Venture liability		(602,000,000)
Other	(4,000,000)	(65,000,000)
Net cash provided by (used in) financing activities	(2,001,000,000)	(5,040,000,000)
Increase (decrease) in cash and cash equivalents	(102,000,000)	(5,051,000,000)
Cash and cash equivalents, beginning of period	967,000,000	5,921,000,000
Cash and cash equivalents, end of period	$ 865,000,000	$ 870,000,000