Consolidated Statement of Income - USD ($) $ in Millions	12 Months Ended
Consolidated Statement of Income - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Revenue	$ 123,707	$ 123,731	$ 121,572
Costs and Expenses:
Programming and production	34,951	37,026	36,762
Marketing and promotion	8,862	8,073	7,971
Other operating and administrative	43,013	40,533	39,190
Depreciation	9,327	8,729	8,854
Amortization	6,884	6,072	5,482
Total costs and expenses	103,035	100,434	98,258
Operating income	20,672	23,297	23,314
Interest expense	(4,409)	(4,134)	(4,087)
Investment and other income (loss), net	9,503	(490)	1,252
Income before income taxes	25,766	18,673	20,478
Income tax expense	(6,106)	(2,796)	(5,371)
Net income	19,660	15,877	15,107
Less: Net income (loss) attributable to noncontrolling interests	(338)	(315)	(282)
Net income attributable to Comcast Corporation	$ 19,998	$ 16,192	$ 15,388
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 5.41	$ 4.17	$ 3.73
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 5.39	$ 4.14	$ 3.71

Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Activities
Net income	$ 19,660	$ 15,877	$ 15,107
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,210	14,802	14,336
Share-based compensation	1,288	1,288	1,241
Noncash interest expense (income), net	488	464	316
Net (gain) loss on investment activity and other	(8,853)	1,088	(768)
Deferred income taxes	2,674	(902)	(2,739)
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net	(135)	136	(996)
Film and television costs, net	338	290	(260)
Accounts payable and accrued expenses related to trade creditors	(20)	(758)	(520)
Other operating assets and liabilities	1,994	(4,611)	2,784
Net cash provided by operating activities	33,643	27,673	28,501
Investing Activities
Capital expenditures	(11,750)	(12,181)	(12,242)
Cash paid for intangible assets	(2,658)	(2,949)	(3,298)
Construction of Universal Beijing Resort	(11)	(116)	(137)
Acquisitions, net of cash acquired	(1,306)	(119)	0
Proceeds from sales of businesses and investments	670	771	661
Advance on sale of investment	0	0	8,610
Purchases of investments	(1,302)	(1,082)	(1,313)
Other	199	6	558
Net cash provided by (used in) investing activities	(16,157)	(15,670)	(7,161)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	0	0	(660)
Proceeds from borrowings	3,494	6,268	6,052
Repurchases and repayments of debt	(5,740)	(3,573)	(4,015)
Repayment of collateralized obligation	0	0	(5,175)
Repurchases of common stock under repurchase program and employee plans	(7,155)	(9,103)	(11,291)
Dividends paid	(4,894)	(4,814)	(4,766)
Other	(50)	339	5
Net cash provided by (used in) financing activities	(14,346)	(10,883)	(19,850)
Impact of foreign currency on cash, cash equivalents and restricted cash	42	(26)	9
Increase (decrease) in cash, cash equivalents and restricted cash	3,182	1,095	1,500
Cash, cash equivalents and restricted cash, beginning of year	7,377	6,282	4,782
Cash, cash equivalents and restricted cash, end of year	$ 10,559	$ 7,377	$ 6,282

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Current Assets:
Cash and cash equivalents	$ 9,481	$ 7,322
Receivables, net	13,869	13,661
Other current assets	6,217	5,817
Total current assets	29,567	26,801
Film and television costs	12,214	12,541
Investments	7,952	8,647
Property and equipment, net	65,680	62,548
Goodwill	61,502	58,209
Franchise rights	59,365	59,365
Other intangible assets, net	22,474	25,599
Other noncurrent assets, net	13,877	12,501
Total assets	272,631	266,211
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	11,058	11,321
Deferred revenue	4,097	3,507
Accrued expenses and other current liabilities	12,410	10,679
Current portion of debt	5,958	4,907
Advance on sale of investment	0	9,167
Total current liabilities	33,524	39,581
Noncurrent portion of debt	92,979	94,186
Deferred income taxes	27,788	25,227
Other noncurrent liabilities	20,965	20,942
Commitments and contingencies
Redeemable noncontrolling interests	224	237
Equity:
Preferred stock—authorized, 20,000,000 shares; issued, zero	0	0
Additional paid-in capital	37,709	38,102
Retained earnings	66,675	56,972
Treasury stock, common, value	(7,517)	(7,517)
Accumulated other comprehensive income (loss)	(8)	(2,043)
Total Comcast Corporation shareholders’ equity	96,903	85,560
Noncontrolling interests	249	477
Total equity	97,151	86,038
Total liabilities and equity	$ 272,631	$ 266,211
Treasury stock (in shares)	919,026,355	919,026,355
Class A common stock, $0.01 par value—authorized, 7,500,000,000 shares; issued, 4,513,794,607 and 4,697,328,372; outstanding, 3,594,768,252 and 3,778,302,017
Equity:
Common stock	$ 45	$ 47
Common stock, shares outstanding (in shares)	3,594,768,252	3,778,302,017
Class B common stock, $0.01 par value—authorized, 75,000,000 shares; issued and outstanding, 9,444,375
Equity:
Common stock	$ 0	$ 0
Common stock, shares outstanding (in shares)	9,444,375	9,444,375