Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Revenue	$ 31,198	$ 32,070	$ 91,397	$ 91,817
Costs and Expenses:
Programming and production	8,655	10,216	24,646	27,000
Marketing and promotion	2,196	1,989	6,435	5,929
Other operating and administrative	10,795	10,128	31,109	29,615
Depreciation	2,353	2,219	6,934	6,548
Amortization	1,666	1,659	5,089	4,421
Total costs and expenses	25,665	26,211	74,213	73,512
Operating income	5,534	5,859	17,184	18,304
Interest expense	(1,128)	(1,037)	(3,283)	(3,065)
Investment and other income (loss), net	61	(3)	9,705	(140)
Income before income taxes	4,468	4,819	23,607	15,099
Income tax expense	(1,218)	(1,243)	(6,017)	(3,906)
Net income	3,249	3,576	17,590	11,192
Less: Net income (loss) attributable to noncontrolling interests	(83)	(53)	(241)	(222)
Net income attributable to Comcast Corporation	$ 3,332	$ 3,629	$ 17,830	$ 11,415
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.91	$ 0.94	$ 4.79	$ 2.92
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.90	$ 0.94	$ 4.78	$ 2.90