Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 22,900	$ 9,045	$ 8,413
Unrealized gains (losses) on marketable securities, net of deferred taxes	(42)	0	1
Deferred gains (losses) on cash flow hedges, net of deferred taxes	60	(60)	(106)
Amounts reclassified to net income:
Realized (gains) losses on marketable securities, net of deferred taxes	(1)	(1)	(1)
Realized (gains) losses on cash flow hedges, net of deferred taxes	(37)	92	64
Employee benefit obligations, net of deferred taxes	41	213	74
Currency translation adjustments, net of deferred taxes	147	102	(89)
Comprehensive income	23,068	9,391	8,356
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	(186)	(350)	(250)
Other comprehensive (income) loss attributable to noncontrolling interests	(81)	(74)	29
Comprehensive income attributable to Parent	22,801	8,967	8,135
NBCUniversal Media LLC [Member]
Net income	5,218	4,546	3,624
Unrealized gains (losses) on marketable securities, net of deferred taxes	(233)	0	0
Deferred gains (losses) on cash flow hedges, net of deferred taxes	(13)	24	(21)
Amounts reclassified to net income:
Employee benefit obligations, net of deferred taxes	112	15	60
Currency translation adjustments, net of deferred taxes	189	112	(121)
Comprehensive income	5,273	4,697	3,542
Net (income) loss attributable to noncontrolling interests	(134)	(311)	(210)
Other comprehensive (income) loss attributable to noncontrolling interests	(81)	(74)	29
Comprehensive income attributable to Parent	$ 5,058	$ 4,312	$ 3,361