Supplemental Financial Information (Net Cash Provided by Operating Activities)(Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income	$ 2,080	$ 2,175	$ 4,304	$ 4,316
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,389	2,161	4,667	4,227
Share-based compensation			331	294
Noncash interest expense (income), net			113	95
Equity in net (income) losses of investees, net	19	236	30	203
Cash received from investees			42	52
Net (gain) loss on investment activity and other			(126)	(437)
Deferred income taxes			618	111
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net			172	(707)
Film and television costs, net			(171)	176
Accounts payable and accrued expenses related to trade creditors (cash flow)			(104)	109
Other operating assets and liabilities			(493)	395
Net cash provided by operating activities			9,383	8,834
NBCUniversal Media LLC [Member]
Net income	975	944	2,057	1,862
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	465	405	879	769
Equity in net (income) losses of investees, net	$ 19	$ 247	21	227
Cash received from investees			31	38
Net (gain) loss on investment activity and other			(92)	(38)
Deferred income taxes			64	(33)
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net			145	(726)
Film and television costs, net			(179)	172
Accounts payable and accrued expenses related to trade creditors (cash flow)			(185)	6
Other operating assets and liabilities			(263)	344
Net cash provided by operating activities			$ 2,478	$ 2,621