Condensed Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 26,827	$ 22,135	$ 80,544	$ 66,661
Costs and Expenses:
Programming and production	8,316	6,711	25,140	20,440
Other operating and administrative	8,090	6,444	24,076	19,323
Advertising, marketing and promotion	1,901	1,667	5,674	4,924
Depreciation	2,124	2,038	6,561	6,070
Amortization	1,056	580	3,215	1,750
Other operating gains	0	(141)	0	(341)
Total costs and expenses	21,487	17,299	64,666	52,166
Operating income (loss)	5,340	4,836	15,878	14,495
Interest expense	(1,167)	(830)	(3,454)	(2,413)
Investment and other income (loss), net	(110)	(111)	511	92
Income (loss) before income taxes	4,063	3,895	12,935	12,174
Income tax expense	(775)	(999)	(2,812)	(2,894)
Net income (loss)	3,288	2,896	10,123	9,280
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	71	10	228	60
Net income (loss) attributable to Comcast Corporation	$ 3,217	$ 2,886	$ 9,895	$ 9,220
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.71	$ 0.63	$ 2.18	$ 2.00
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.70	$ 0.62	$ 2.15	$ 1.98
NBCUniversal Media LLC [Member]
Revenue	$ 8,294	$ 8,625	$ 24,866	$ 26,468
Costs and Expenses:
Programming and production	3,531	3,896	10,182	11,947
Other operating and administrative	2,013	1,959	5,943	5,886
Advertising, marketing and promotion	661	704	1,994	2,124
Depreciation	259	250	755	750
Amortization	278	264	824	827
Other operating gains	0	(141)	0	(141)
Total costs and expenses	6,742	6,932	19,698	21,393
Operating income (loss)	1,552	1,693	5,168	5,075
Interest expense	(348)	(134)	(601)	(394)
Investment and other income (loss), net	169	(205)	449	(377)
Income (loss) before income taxes	1,373	1,354	5,016	4,304
Income tax expense	(63)	(112)	(239)	(291)
Net income (loss)	1,310	1,242	4,777	4,013
Less: Net income (loss) attributable to noncontrolling interests	54	11	166	22
Net income (loss) attributable to Comcast Corporation	$ 1,256	$ 1,231	$ 4,611	$ 3,991