Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating Activities
Net cash provided by operating activities	$ 10,814	$ 9,794
Investing Activities
Capital expenditures	(4,405)	(4,156)
Cash paid for intangible assets	(836)	(737)
Acquisitions and construction of real estate properties	(250)	(211)
Acquisitions, net of cash acquired	(398)	(126)
Proceeds from sales of investments	57	138
Purchases of investments	(1,825)	(580)
Other	170	(156)
Net cash provided by (used in) investing activities	(7,487)	(5,828)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(1,695)	205
Proceeds from borrowings	8,963	4,753
Repurchases and repayments of debt	(4,967)	(2,551)
Repurchases of common stock under repurchase program and employee plans	(2,476)	(2,636)
Dividends paid	(1,404)	(1,281)
Purchase of Universal Studios Japan noncontrolling interests	(2,299)	0
Issuances of common stock	0	19
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(137)	(125)
Other	80	20
Net cash provided by (used in) financing activities	(3,935)	(1,596)
Increase (decrease) in cash and cash equivalents	(608)	2,370
Cash and cash equivalents, beginning of period	3,301	2,295
Cash and cash equivalents, end of period	2,693	4,665
NBCUniversal Media LLC [Member]
Operating Activities
Net cash provided by operating activities	3,526	2,478
Investing Activities
Capital expenditures	(623)	(655)
Cash paid for intangible assets	(128)	(114)
Acquisitions of real estate properties	0	(78)
Proceeds from sales of investments	10	102
Other	(241)	(107)
Net cash provided by (used in) investing activities	(982)	(852)
Financing Activities
Proceeds from borrowings	3,948	0
Repurchases and repayments of debt	(3,402)	(1,083)
Proceeds from (repayments of) borrowings from Comcast, net	278	134
Purchase of Universal Studios Japan noncontrolling interests	(2,299)	0
Distributions to member	(1,141)	(853)
Distributions to noncontrolling interests	(116)	(104)
Other	66	25
Net cash provided by (used in) financing activities	(2,666)	(1,881)
Increase (decrease) in cash and cash equivalents	(122)	(255)
Cash and cash equivalents, beginning of period	1,966	1,410
Cash and cash equivalents, end of period	$ 1,844	$ 1,155