Comcast (CMCSA) 10-Q 25 Oct 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2018shares
Document And Entity Information [Line Items]
Entity Registrant Name	COMCAST CORP
Entity Central Index Key	1,166,691
Trading Symbol	cmcsa
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
NBCUniversal Media LLC [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	NBCUniversal Media, LLC
Entity Central Index Key	902,739
Entity Filer Category	Non-accelerated Filer
Class A Common Stock [Member]
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	4,540,060,394
Class B Common Stock [Member]
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	9,444,375

Condensed Consolidated Statemen

Condensed Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Costs and Expenses:
Programming and production	6,711	6,059	20,440	18,450
Other operating and administrative	6,444	6,535	19,323	18,642
Advertising, marketing and promotion	1,667	1,604	4,924	4,894
Depreciation	2,038	1,991	6,070	5,876
Amortization	580	555	1,750	1,645
Other operating gains	(141)	(442)	(341)	(442)
Total costs and expenses	17,299	16,302	52,166	49,065
Operating income	4,836	4,779	14,495	13,889
Interest expense	(830)	(766)	(2,413)	(2,279)
Investment and other income (loss), net	(111)	70	92	299
Income before income taxes	3,895	4,083	12,174	11,909
Income tax expense	(999)	(1,409)	(2,894)	(4,038)
Net income	2,896	2,674	9,280	7,871
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	10	32	60	135
Net income attributable to Comcast Corporation	$ 2,886	$ 2,642	$ 9,220	$ 7,736
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.63	$ 0.56	$ 2	$ 1.64
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	0.62	0.55	1.98	1.61
Dividends declared per common share (in dollars per share)	$ 0.19	$ 0.1575	$ 0.57	$ 0.4725
NBCUniversal Media LLC [Member]
Revenue	$ 8,625	$ 7,976	$ 26,468	$ 24,147
Costs and Expenses:
Programming and production	3,896	3,239	11,947	10,115
Other operating and administrative	1,959	1,856	5,886	5,574
Advertising, marketing and promotion	704	624	2,124	2,108
Depreciation	250	253	750	749
Amortization	264	254	827	786
Other operating gains	(141)	(337)	(141)	(337)
Total costs and expenses	6,932	5,889	21,393	18,995
Operating income	1,693	2,087	5,075	5,152
Interest expense	(134)	(139)	(394)	(431)
Investment and other income (loss), net	(205)	(26)	(377)	(42)
Income before income taxes	1,354	1,922	4,304	4,679
Income tax expense	(112)	(98)	(291)	(289)
Net income	1,242	1,824	4,013	4,390
Less: Net income (loss) attributable to noncontrolling interests	11	17	22	102
Net income attributable to Comcast Corporation	$ 1,231	$ 1,807	$ 3,991	$ 4,288

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 2,896	$ 2,674	$ 9,280	$ 7,871
Unrealized gains (losses) on marketable securities, net of deferred taxes	2	(59)	0	(42)
Deferred gains (losses) on cash flow hedges, net of deferred taxes	(15)	16	(26)	28
Amounts reclassified to net income:
Realized (gains) losses on marketable securities, net of deferred taxes	0	(1)	0	(1)
Realized (gains) losses on cash flow hedges, net of deferred taxes	17	(12)	43	(26)
Employee benefit obligations, net of deferred taxes	(8)	(6)	(24)	51
Currency translation adjustments, net of deferred taxes	(103)	20	(119)	166
Comprehensive income	2,789	2,632	9,154	8,047
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	10	32	60	135
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(20)	5	(45)	87
Comprehensive income (loss) attributable to Comcast Corporation	2,799	2,595	9,139	7,825
NBCUniversal Media LLC [Member]
Net income	1,242	1,824	4,013	4,390
Unrealized gains (losses) on marketable securities, net of deferred taxes	0	(94)	0	(233)
Deferred gains (losses) on cash flow hedges, net of deferred taxes	(2)	(5)	(4)	(27)
Amounts reclassified to net income:
Employee benefit obligations, net of deferred taxes	(4)	(3)	(11)	101
Currency translation adjustments, net of deferred taxes	(133)	22	(144)	211
Comprehensive income	1,103	1,744	3,854	4,442
Less: Net income (loss) attributable to noncontrolling interests	11	17	22	102
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(20)	5	(45)	87
Comprehensive income (loss) attributable to Comcast Corporation	$ 1,112	$ 1,722	$ 3,877	$ 4,253

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on marketable securities, deferred taxes	$ (1)	$ 35	$ (1)	$ 26
Deferred gains (losses) on cash flow hedges, deferred taxes	5	(9)	8	(16)
Realized (gains) losses on marketable securities, deferred taxes	0	0	0	0
Realized (gains) losses on cash flow hedges, deferred taxes	(5)	7	(13)	15
Employee benefit obligations, deferred taxes	2	3	7	(30)
Currency translation adjustments, deferred taxes	$ 25	$ (8)	$ 22	$ (47)

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities
Net income	$ 9,280	$ 7,871
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other operating gains	7,479	7,079
Share-based compensation	607	594
Noncash interest expense (income), net	289	187
Net (gain) loss on investment activity and other	118	(133)
Deferred income taxes	877	681
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net	(225)	123
Film and television costs, net	64	(71)
Accounts payable and accrued expenses related to trade creditors	(85)	(20)
Other operating assets and liabilities	103	(454)
Net cash provided by operating activities	18,507	15,857
Investing Activities
Capital expenditures	(6,607)	(6,839)
Cash paid for intangible assets	(1,375)	(1,136)
Acquisitions and construction of real estate properties	(129)	(325)
Construction of Universal Beijing Resort	(257)	(47)
Acquisitions, net of cash acquired	(88)	(429)
Proceeds from sales of investments	127	120
Purchases of investments	(840)	(2,064)
Other	579	797
Net cash provided by (used in) investing activities	(8,590)	(9,923)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	2,909	(2,807)
Proceeds from borrowings	9,850	11,460
Repurchases and repayments of debt	(4,405)	(5,021)
Repurchases of common stock under repurchase program and employee plans	(4,282)	(4,212)
Dividends paid	(2,487)	(2,147)
Purchase of Universal Studios Japan noncontrolling interests	0	(2,299)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(209)	(198)
Other	(242)	103
Net cash provided by (used in) financing activities	1,134	(5,121)
Increase (decrease) in cash, cash equivalents and restricted cash	11,051	813
Cash, cash equivalents and restricted cash, beginning of period	3,571	3,415
Cash, cash equivalents and restricted cash, end of period	14,622	4,228
NBCUniversal Media LLC [Member]
Operating Activities
Net income	4,013	4,390
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other operating gains	1,436	1,198
Net (gain) loss on investment activity and other	497	125
Deferred income taxes	21	(6)
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net	90	247
Film and television costs, net	69	(77)
Accounts payable and accrued expenses related to trade creditors	(123)	(270)
Other operating assets and liabilities	(165)	(35)
Net cash provided by operating activities	5,838	5,572
Investing Activities
Capital expenditures	(1,135)	(977)
Cash paid for intangible assets	(374)	(197)
Note receivable from Comcast	(1,522)	0
Construction of Universal Beijing Resort	(257)	(47)
Purchases of investments	(450)	(368)
Other	(45)	566
Net cash provided by (used in) investing activities	(3,783)	(1,023)
Financing Activities
Proceeds from borrowings	485	3,948
Repurchases and repayments of debt	(387)	(3,450)
Proceeds from (repayments of) borrowings from Comcast, net	(1,791)	(898)
Distributions to member	(1,228)	(1,720)
Distributions to noncontrolling interests	(163)	(165)
Purchase of Universal Studios Japan noncontrolling interests	0	(2,299)
Other	(147)	86
Net cash provided by (used in) financing activities	(3,231)	(4,498)
Increase (decrease) in cash, cash equivalents and restricted cash	(1,176)	51
Cash, cash equivalents and restricted cash, beginning of period	2,377	1,987
Cash, cash equivalents and restricted cash, end of period	$ 1,201	$ 2,038

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 10,616	$ 3,428
Receivables, net	8,983	8,834
Programming rights	1,223	1,613
Other current assets	2,384	2,468
Total current assets	23,206	16,343
Film and television costs	7,377	7,087
Investments	7,724	6,931
Property and equipment, net	39,855	38,470
Franchise rights	59,365	59,364
Goodwill	36,703	36,780
Other intangible assets, net	18,649	18,133
Other noncurrent assets, net	7,756	4,354
Total assets	200,635	187,462
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	7,036	6,908
Accrued participations and residuals	1,809	1,644
Deferred revenue	1,633	1,687
Accrued expenses and other current liabilities	5,976	6,620
Current portion of long-term debt	3,173	5,134
Total current liabilities	19,627	21,993
Long-term debt, less current portion	69,711	59,422
Deferred income taxes	25,167	24,259
Other noncurrent liabilities	12,468	10,972
Commitments and contingencies (Note 11)
Redeemable noncontrolling interests	1,317	1,357
Equity:
Preferred stock—authorized, 20,000,000 shares; issued, zero	0	0
Common stock	54	55
Additional paid-in capital	37,394	37,497
Retained earnings	41,218	38,202
Treasury stock, 872,791,028 Class A common shares	(7,517)	(7,517)
Accumulated other comprehensive income (loss)	374	379
Total Comcast Corporation shareholders’ equity	71,523	68,616
Noncontrolling interests	822	843
Total equity	72,345	69,459
Total liabilities and equity	200,635	187,462
NBCUniversal Media LLC [Member]
Current Assets:
Cash and cash equivalents	1,181	2,347
Receivables, net	6,851	6,967
Programming rights	1,213	1,606
Note receivable from Comcast	1,522	0
Other current assets	1,103	1,037
Total current assets	11,870	11,957
Film and television costs	7,369	7,082
Investments	1,722	1,816
Property and equipment, net	12,427	11,346
Goodwill	23,918	23,989
Intangible assets, net	13,829	13,306
Other noncurrent assets, net	1,799	1,804
Total assets	72,934	71,300
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	1,665	1,663
Accrued participations and residuals	1,809	1,644
Program obligations	615	745
Deferred revenue	1,336	1,457
Accrued expenses and other current liabilities	1,914	2,394
Note payable to Comcast	41	1,831
Current portion of long-term debt	162	198
Total current liabilities	7,542	9,932
Long-term debt, less current portion	12,401	12,275
Accrued participations, residuals and program obligations	1,703	1,490
Other noncurrent liabilities	5,189	4,153
Commitments and contingencies (Note 11)
Redeemable noncontrolling interests	387	409
Equity:
Member’s capital	44,771	42,148
Accumulated other comprehensive income (loss)	98	(20)
Total NBCUniversal member’s equity	44,869	42,128
Noncontrolling interests	843	913
Total equity	45,712	43,041
Total liabilities and equity	72,934	71,300
Class A Common Stock [Member]
Equity:
Common stock	54	55
Class B Common Stock [Member]
Equity:
Common stock	$ 0	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Property and equipment - accumulated depreciation	$ 50,934	$ 49,916
Other intangible assets - accumulated amortization	$ 13,391	$ 11,950
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
NBCUniversal Media LLC [Member]
Property and equipment - accumulated depreciation	$ 4,816	$ 4,166
Other intangible assets - accumulated amortization	$ 8,358	$ 7,585
Class A Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	7,500,000,000	7,500,000,000
Common stock, shares issued (in shares)	5,412,851,422	5,507,854,670
Common stock, shares outstanding (in shares)	4,540,060,394	4,635,063,642
Treasury stock (in shares)	872,791,028	872,791,028
Class B Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	9,444,375	9,444,375
Common stock, shares outstanding (in shares)	9,444,375	9,444,375

Condensed Consolidated Statem_5

Condensed Consolidated Statement of Changes in Equity - USD ($) $ in Millions	Total	Redeemable Noncontrolling Interests and Redeemable Subsidiary Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock at Cost [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	NBCUniversal Media LLC [Member]	NBCUniversal Media LLC [Member]Redeemable Noncontrolling Interest [Member]	NBCUniversal Media LLC [Member]Member's Capital [Member]	NBCUniversal Media LLC [Member]Accumulated Other Comprehensive Income (Loss) [Member]	NBCUniversal Media LLC [Member]Noncontrolling Interest [Member]	Class A Common Stock [Member]Common Stock [Member]	Class B Common Stock [Member]Common Stock [Member]
Beginning balance at Dec. 31, 2016	$ 56,163		$ 38,230	$ 23,065	$ (7,517)	$ 98	$ 2,231						$ 56	$ 0
Beginning balance at Dec. 31, 2016								$ 40,875		$ 38,894	$ (135)	$ 2,116
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation plans	440		440
Repurchases of common stock under repurchase program and employee plans	(4,221)		(633)	(3,587)									(1)
Employee stock purchase plans	140		140
Dividends declared	(2,239)			(2,239)				(1,720)		(1,720)
Other comprehensive income (loss)	176					89	87	52			(35)	87
Contributions from (distributions to) noncontrolling interests, net	(81)						(81)	(95)				(95)
Contribution from member								662		662
Purchase of Universal Studios Japan noncontrolling interests	(2,238)		(696)			194	(1,736)	(2,299)		(704)	141	(1,736)
Other	299		48	(1)			252	655		185		470
Net income (loss)	7,819			7,736			83	4,372		4,288		84
Ending balance at Sep. 30, 2017	56,258		37,529	24,974	(7,517)	381	836						55	0
Ending balance at Sep. 30, 2017								42,502		41,605	(29)	926
Beginning balance at Dec. 31, 2016		$ 1,446							$ 530
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions from (distributions to) noncontrolling interests, net		(31)							(56)
Other		(114)							(85)
Net income (loss)		52							18
Ending balance at Sep. 30, 2017		1,353							407
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of adoption of accounting standards	33			(43)		76		0		(232)	232
Beginning balance at Dec. 31, 2017	69,459		37,497	38,202	(7,517)	379	843						55	0
Beginning balance at Dec. 31, 2017								43,041		42,148	(20)	913
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation plans	434		434
Repurchases of common stock under repurchase program and employee plans	(4,288)		(757)	(3,530)									(1)
Employee stock purchase plans	161		161
Dividends declared	(2,631)			(2,631)				(1,228)		(1,228)
Other comprehensive income (loss)	(126)					(81)	(45)	(159)			(114)	(45)
Contributions from (distributions to) noncontrolling interests, net	277						277	272				272
Other	(217)		59				(276)	(201)		92		(293)
Net income (loss)	9,243			9,220			23	3,987		3,991		(4)
Ending balance at Sep. 30, 2018	72,345		$ 37,394	$ 41,218	$ (7,517)	$ 374	$ 822						$ 54	$ 0
Ending balance at Sep. 30, 2018								45,712		$ 44,771	$ 98	$ 843
Beginning balance at Dec. 31, 2017	1,357	1,357						409	409
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions from (distributions to) noncontrolling interests, net		(42)							(43)
Other		(35)							(5)
Net income (loss)		37							26
Ending balance at Sep. 30, 2018	$ 1,317	$ 1,317						$ 387	$ 387

Condensed Consolidated Financia

Condensed Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2018
Condensed Consolidated Financial Statements [Line Items]
Condensed Consolidated Financial Statements	Condensed Consolidated Financial Statements Business and Basis of Presentation We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2017 Annual Report on Form 10-K and the footnotes within this Form 10-Q. On October 9, 2018, we acquired a controlling interest in Sky plc. Beginning in the fourth quarter of 2018, Sky’s results will be included in our consolidated financial statements. See Note 6 for additional information on the transaction. Reclassifications Reclassifications have been made to our condensed consolidated financial statements for the prior year periods to conform to classifications used in 2018 . See Note 7 for a discussion of the effects of the adoption of new accounting pronouncements and tax reform on our condensed consolidated financial statements.
NBCUniversal Media LLC [Member]
Condensed Consolidated Financial Statements [Line Items]
Condensed Consolidated Financial Statements	Condensed Consolidated Financial Statements Basis of Presentation Unless indicated otherwise, throughout these notes to the condensed consolidated financial statements, we refer to NBCUniversal and its consolidated subsidiaries as “we,” “us” and “our.” We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2017 Annual Report on Form 10-K and the footnotes within this Form 10-Q. See Note 6 for a discussion of the effects of the adoption of new accounting pronouncements on our condensed consolidated financial statements.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting Information [Line Items]
Segment Information	Segment Information We present our operations in five reportable business segments: • Cable Communications: Consists of the operations of Comcast Cable, which is one of the nation’s largest providers of video, high-speed Internet, voice, and security and automation services (“cable services”) to residential customers under the XFINITY brand ; we also provide these and other services to business customers and sell advertising. • Cable Networks: Consists primarily of our national cable networks that provide a variety of entertainment, news and information, and sports content, our regional sports and news networks, our international cable networks, our cable television studio production operations, and various digital properties. • Broadcast Television: Consists primarily of the NBC and Telemundo broadcast networks, our NBC and Telemundo owned local broadcast television stations, the NBC Universo national cable network, our broadcast television studio production operations, and various digital properties. • Filmed Entertainment: Consists primarily of the operations of Universal Pictures, which produces, acquires, markets and distributes filmed entertainment worldwide; our films are also produced under the Illumination, DreamWorks Animation and Focus Features names. • Theme Parks: Consists primarily of our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. In addition, along with a consortium of Chinese state-owned companies, we are developing a Universal theme park and resort in Beijing, China. We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to Comcast Corporation excluded from Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Communications $ 13,787 $ 5,615 $ 2,071 $ 1,944 $ 353 NBCUniversal Cable Networks 2,884 968 180 11 6 Broadcast Television 2,452 321 32 37 — Filmed Entertainment 1,819 214 26 9 6 Theme Parks 1,528 725 170 269 23 Headquarters and Other (a) 15 (161 ) 106 79 43 Eliminations (b) (73 ) (1 ) — — — NBCUniversal 8,625 2,066 514 405 78 Corporate and Other (c) 276 (378 ) 33 35 14 Eliminations (b) (553 ) 10 — — — Comcast Consolidated $ 22,135 $ 7,313 $ 2,618 $ 2,384 $ 445 Three Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Communications $ 13,339 $ 5,216 $ 2,015 $ 2,061 $ 284 NBCUniversal Cable Networks 2,603 906 179 5 4 Broadcast Television 2,125 316 33 66 4 Filmed Entertainment 1,753 383 32 18 6 Theme Parks 1,550 775 166 199 18 Headquarters and Other (a) 15 (122 ) 97 66 37 Eliminations (b) (70 ) (1 ) — — — NBCUniversal 7,976 2,257 507 354 69 Corporate and Other (c) 266 (349 ) 24 19 12 Eliminations (b) (500 ) 9 — — — Comcast Consolidated $ 21,081 $ 7,133 $ 2,546 $ 2,434 $ 365 Nine Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 41,015 $ 16,668 $ 6,171 $ 5,398 $ 950 NBCUniversal Cable Networks (e) 8,994 3,422 548 22 15 Broadcast Television (e) 8,340 1,245 106 99 75 Filmed Entertainment 5,176 555 117 24 20 Theme Parks 4,170 1,789 492 811 158 Headquarters and Other (a) 44 (497 ) 314 179 106 Eliminations (b)(e) (256 ) (3 ) — — — NBCUniversal 26,468 6,511 1,577 1,135 374 Corporate and Other (c) 922 (1,167 ) 72 74 51 Eliminations (b)(e) (1,744 ) (38 ) — — — Comcast Consolidated $ 66,661 $ 21,974 $ 7,820 $ 6,607 $ 1,375 Nine Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 39,646 $ 15,683 $ 5,928 $ 5,798 $ 897 NBCUniversal Cable Networks 7,939 3,076 574 15 11 Broadcast Television 6,574 1,054 96 125 11 Filmed Entertainment 5,862 1,041 79 47 17 Theme Parks 3,982 1,723 494 671 57 Headquarters and Other (a) 32 (542 ) 292 119 101 Eliminations (b) (242 ) (2 ) — — — NBCUniversal 24,147 6,350 1,535 977 197 Corporate and Other (c) 679 (845 ) 58 64 42 Eliminations (b) (1,518 ) 30 — — — Comcast Consolidated $ 62,954 $ 21,218 $ 7,521 $ 6,839 $ 1,136 (a) NBCUniversal Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another. The most common types of transactions are the following: • our Cable Networks segment generates revenue by selling programming to our Cable Communications segment, which represents a substantial majority of the revenue elimination amount • our Broadcast Television segment generates revenue from the fees received under retransmission consent agreements with our Cable Communications segment • our Cable Communications segment generates revenue by selling advertising and by selling the use of satellite feeds to our Cable Networks segment • our Cable Networks and Broadcast Television segments generate revenue by selling advertising to our Cable Communications segment • our Filmed Entertainment and Broadcast Television segments generate revenue by licensing content to our Cable Networks segment; for segment reporting, this revenue is recognized as the programming rights asset for the licensed content is amortized based on third party revenue (c) Corporate and Other activities include costs associated with overhead and personnel, revenue and expenses associated with other business development initiatives, including our wireless phone service, and the operations of Comcast Spectacor, which owns the Philadelphia Flyers and the Wells Fargo Center arena in Philadelphia, Pennsylvania. (d) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to Comcast Corporation before net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock, income tax expense, investment and other income (loss), net, interest expense, depreciation and amortization expense, and other operating gains and losses (such as impairment charges related to fixed and intangible assets and gains or losses on the sale of long-lived assets), if any. From time to time we may exclude from Adjusted EBITDA the impact of certain events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 7,313 $ 7,133 $ 21,974 $ 21,218 Adjustment for legal settlement — (250 ) — (250 ) Depreciation (2,038 ) (1,991 ) (6,070 ) (5,876 ) Amortization (580 ) (555 ) (1,750 ) (1,645 ) Other operating gains 141 442 341 442 Interest expense (830 ) (766 ) (2,413 ) (2,279 ) Investment and other income (loss), net (111 ) 70 92 299 Income before income taxes $ 3,895 $ 4,083 $ 12,174 $ 11,909 (e) The revenue and operating costs and expenses associated with our broadcast of the 2018 PyeongChang Olympics were reported in our Cable Networks and Broadcast Television segments. The revenue and operating costs and expenses associated with our broadcast of the 2018 Super Bowl were reported in our Broadcast Television segment. Included in Eliminations are transactions relating to these events that our Broadcast Television and Cable Networks segments enter into with our other segments.
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Segment Information	Segment Information We present our operations in four reportable business segments: • Cable Networks: Consists primarily of our national cable networks that provide a variety of entertainment, news and information, and sports content, our regional sports and news networks, our international cable networks, our cable television studio production operations, and various digital properties. • Broadcast Television: Consists primarily of the NBC and Telemundo broadcast networks, our NBC and Telemundo owned local broadcast television stations, the NBC Universo national cable network, our broadcast television studio production operations, and various digital properties. • Filmed Entertainment: Consists primarily of the operations of Universal Pictures, which produces, acquires, markets and distributes filmed entertainment worldwide; our films are also produced under the Illumination, DreamWorks Animation and Focus Features names. • Theme Parks: Consists primarily of our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. In addition, along with a consortium of Chinese state-owned companies, we are developing a Universal theme park and resort in Beijing, China. We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to NBCUniversal excluded from Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Networks $ 2,884 $ 968 $ 180 $ 11 $ 6 Broadcast Television 2,452 321 32 37 — Filmed Entertainment 1,819 214 26 9 6 Theme Parks 1,528 725 170 269 23 Headquarters and Other (a) 15 (161 ) 106 79 43 Eliminations (b) (73 ) (1 ) — — — Total $ 8,625 $ 2,066 $ 514 $ 405 $ 78 Three Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Networks $ 2,603 $ 906 $ 179 $ 5 $ 4 Broadcast Television 2,125 316 33 66 4 Filmed Entertainment 1,753 383 32 18 6 Theme Parks 1,550 775 166 199 18 Headquarters and Other (a) 15 (122 ) 97 66 37 Eliminations (b) (70 ) (1 ) — — — Total $ 7,976 $ 2,257 $ 507 $ 354 $ 69 Nine Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks (d) $ 8,994 $ 3,422 $ 548 $ 22 $ 15 Broadcast Television (d) 8,340 1,245 106 99 75 Filmed Entertainment 5,176 555 117 24 20 Theme Parks 4,170 1,789 492 811 158 Headquarters and Other (a) 44 (497 ) 314 179 106 Eliminations (b)(d) (256 ) (3 ) — — — Total $ 26,468 $ 6,511 $ 1,577 $ 1,135 $ 374 Nine Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 7,939 $ 3,076 $ 574 $ 15 $ 11 Broadcast Television 6,574 1,054 96 125 11 Filmed Entertainment 5,862 1,041 79 47 17 Theme Parks 3,982 1,723 494 671 57 Headquarters and Other (a) 32 (542 ) 292 119 101 Eliminations (b) (242 ) (2 ) — — — Total $ 24,147 $ 6,350 $ 1,535 $ 977 $ 197 (a) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another, which consisted primarily of the licensing of film and television content from our Filmed Entertainment and Broadcast Television segments to our Cable Networks segment; for segment reporting, this revenue is recognized as the programming rights asset for the licensed content is amortized based on third party revenue. (c) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to NBCUniversal before net income (loss) attributable to noncontrolling interests, income tax expense, investment and other income (loss), net, interest expense, depreciation and amortization expense, and other operating gains and losses (such as impairment charges related to fixed and intangible assets and gains or losses on the sale of long-lived assets), if any. From time to time we may exclude from Adjusted EBITDA the impact of certain events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 2,066 $ 2,257 $ 6,511 $ 6,350 Depreciation (250 ) (253 ) (750 ) (749 ) Amortization (264 ) (254 ) (827 ) (786 ) Other operating gains 141 337 141 337 Interest expense (134 ) (139 ) (394 ) (431 ) Investment and other income (loss), net (205 ) (26 ) (377 ) (42 ) Income before income taxes $ 1,354 $ 1,922 $ 4,304 $ 4,679 (d) The revenue and operating costs and expenses associated with our broadcast of the 2018 PyeongChang Olympics were reported in our Cable Networks and Broadcast Television segments. The revenue and operating costs and expenses associated with our broadcast of the 2018 Super Bowl were reported in our Broadcast Television segment. Included in Eliminations are transactions relating to these events that our Broadcast Television and Cable Networks segments enter into with our other segments.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2018
Revenue [Line Items]
Revenue	Revenue Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Residential: Video $ 5,591 $ 5,760 $ 16,878 $ 17,206 High-Speed Internet 4,321 3,942 12,740 11,682 Voice 982 1,013 2,982 3,081 Business services 1,803 1,629 5,290 4,757 Advertising 684 594 1,932 1,774 Other 406 401 1,193 1,146 Total Cable Communications (a) 13,787 13,339 41,015 39,646 Distribution 1,680 1,533 5,251 4,645 Advertising 820 787 2,746 2,519 Content licensing and other 384 283 997 775 Total Cable Networks 2,884 2,603 8,994 7,939 Advertising 1,355 1,241 5,107 3,790 Content licensing 538 432 1,541 1,458 Distribution and other 559 452 1,692 1,326 Total Broadcast Television 2,452 2,125 8,340 6,574 Theatrical 601 515 1,564 2,003 Content licensing 719 662 2,100 2,080 Home entertainment 260 299 733 919 Other 239 277 779 860 Total Filmed Entertainment 1,819 1,753 5,176 5,862 Total Theme Parks 1,528 1,550 4,170 3,982 Headquarters and Other 15 15 44 32 Eliminations (b) (73 ) (70 ) (256 ) (242 ) Total NBCUniversal 8,625 7,976 26,468 24,147 Corporate and Other 276 266 922 679 Eliminations (b) (553 ) (500 ) (1,744 ) (1,518 ) Total revenue $ 22,135 $ 21,081 $ 66,661 $ 62,954 (a) For the three and nine months ended September 30, 2018 , 2.6% and 2.7% , respectively, of Cable Communications segment revenue was derived from franchise and other regulatory fees. For both the three and nine months ended September 30, 2017, 2.8% of Cable Communications segment revenue was derived from franchise and other regulatory fees. (b) Included in Eliminations are transactions that our segments enter into with one another. See Note 2 for a description of these transactions. We operate primarily in the United States, but also in select international markets, primarily in Europe and Asia. The table below summarizes revenue by geographic location. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 United States $ 20,244 $ 19,142 $ 61,060 $ 57,047 Foreign 1,891 1,939 5,601 5,907 Total revenue $ 22,135 $ 21,081 $ 66,661 $ 62,954 No single customer accounted for a significant amount of revenue in any period presented. Cable Communications Segment Residential Our Cable Communications segment generates revenue from residential customers subscribing to our video, high-speed Internet, voice, and security and automation services, which we market individually and as bundled services at a discounted rate in the United States. Revenue from residential customers that purchase bundled services at a discounted rate is allocated between the separate services based on the respective stand-alone selling prices. The stand-alone selling prices are determined based on the current prices at which we separately sell the cable services. Significant judgment is used to determine performance obligations that should be accounted for separately and the allocation of revenue when services are combined in a bundle. Revenue related to our security and automation services is reported in other revenue. We recognize revenue from residential cable services as the services are provided on a monthly basis. Subscription rates and related charges vary according to the services and features customers receive. Customers are typically billed in advance and pay on a monthly basis. Installation fees are deferred and recognized as revenue over the period of benefit to the customer, which is less than a year for residential customers. While a portion of our residential customers are subject to contracts for their cable services, which are typically 2 years in length, based on our evaluation of the terms of these contracts, we recognize revenue for these cable services on a basis that is consistent with our customers that are not subject to contracts. Our cable services generally involve customer premise equipment, such as set-top boxes, cable modems and wireless gateways. The timing and pattern of recognition for customer premise equipment revenue are consistent with those of our residential cable services. Sales commissions related to our residential customers are expensed as incurred, as the related period of benefit is less than a year. Under the terms of our cable franchise agreements, we are generally required to pay the cable franchising authority an amount based on our gross video revenue. We generally pass these and other similar fees through to our cable services customers and classify these fees in the respective cable service revenue, with the corresponding costs included in other operating and administrative expenses. Business Services Our Cable Communications segment generates revenue from business customers subscribing to a variety of products and services. Our small business services offerings primarily include high-speed Internet services, as well as voice and video services, similar to those that we provide to our residential customers, and also include cloud-based solutions that provide file sharing, online backup and web conferencing, among other features. We also offer Ethernet network services that connect multiple locations and provide higher downstream and upstream speed options to medium-sized customers and larger enterprises, as well as advanced voice services. In addition, we provide cellular backhaul services to mobile network operators to help these customers manage their network bandwidth. Recently, we have expanded our enterprise service offerings to include a software-defined networking product and our managed solutions business to offer enterprise customers support related to Wi-Fi networks, router management, network security, business continuity risks and other services. We primarily offer our enterprise service offerings to Fortune 1000 companies and other large enterprises with multiple locations both within and outside of our cable distribution footprint where we have agreements with other companies to use their networks to provide coverage. We recognize revenue from business services as the services are provided on a monthly basis. Substantially all of our business customers are initially under contracts, with terms typically ranging from 2 years for small and medium-sized businesses to up to 5 years for larger enterprises. At any given time, the amount of future revenue to be earned related to fixed pricing under existing agreements is equal to approximately half of our annual business services revenue, of which the substantial majority will be recognized within 2 years. Customers with contracts may only discontinue service in accordance with the terms of their contracts. We receive payments from business customers based on a billing schedule established in our contracts, which is typically on a monthly basis. Installation revenue related to our business services customers and sales commissions are generally deferred and recognized over the respective contract terms. Advertising Our Cable Communications segment generates revenue from the sale of advertising and from our advanced advertising business. As part of our distribution agreements with cable networks, we generally receive an allocation of scheduled advertising time on cable networks that we sell to local, regional and national advertisers. In most cases, the available advertising units are sold by our sales force. We also represent the advertising sales efforts of other multichannel video providers in some markets. Since we are acting as the principal in these arrangements, we record the advertising that is sold in advertising revenue and the fees paid to multichannel video providers in other operating and administrative expenses. In some cases, we work with representation firms as an extension of our sales force to sell a portion of the advertising units allocated to us and record the revenue net of agency commissions. In addition, we generate revenue from the sale of advertising online and on our On Demand service. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms and conditions are agreed upon. Advertising revenue is recognized in the period in which advertisements are aired or viewed. Payment terms vary by contract, although terms generally require payment within 30 to 60 days from when advertisements are aired or viewed. Our advanced advertising business provide technology, tools, marketplace solutions and data-driven insights to various customers in the media industry to more effectively engage with their targeted audiences. Revenue earned from our advanced advertising business is recognized when services are provided. NBCUniversal Segments Distribution Our Cable Networks segment generates distribution revenue from the distribution of our cable network programming to traditional and virtual multichannel video providers. Our Broadcast Television segment generates distribution revenue from the fees received under retransmission consent agreements and associated fees received from NBC-affiliated local broadcast television stations. Distribution revenue is recognized as programming is provided on a monthly basis, generally under multiyear agreements. Monthly fees received under distribution agreements with multichannel video providers are generally based on the number of subscribers. Payment terms and conditions vary by contract type, although terms generally include payment within 30 to 60 days. Advertising Our Cable Networks and Broadcast Television segments generate advertising revenue from the sale of advertising on our cable and broadcast networks, our owned local broadcast television stations, and various digital properties. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms are agreed upon. Advertising revenue is recognized, net of agency commissions, in the period in which advertisements are aired or viewed and payment occurs thereafter, generally within 30 days. In some instances, we guarantee audience ratings for the advertisements. To the extent there is a shortfall in contracts where the ratings were guaranteed, a portion of the revenue is deferred until the shortfall is settled, typically by providing additional advertising units generally within one year of the original airing. Theatrical Our Filmed Entertainment segment theatrical revenue is generated from the worldwide theatrical release of our produced and acquired films for exhibition in movie theaters and is affected by the timing, nature and number of films released in movie theaters and their acceptance by audiences. Theatrical revenue is also affected by the number of exhibition screens, ticket prices, the percentage of ticket sale retention by the exhibitors and the popularity of competing films at the time our films are released. We recognize theatrical revenue as the films are viewed and exhibited in theaters and payment generally occurs within 60 days after exhibition. Content Licensing Our Cable Networks, Broadcast Television and Filmed Entertainment segments generate revenue from the licensing of our owned film and television content in the United States and internationally to cable, broadcast and premium networks and subscription video on demand services. Our content licensing agreements generally include fixed pricing and span multiple years. For example, following a film’s theatrical release, our Filmed Entertainment segment may license the exhibition rights of a film to different customers over multiple successive distribution windows. We recognize revenue when the content is delivered and available for use by the licensee. When the term of an existing agreement is renewed or extended, we recognize revenue at the later of when the content is available or when the renewal or extension period begins. Payment terms and conditions vary by contract type, although payments are generally collected over the license term. The amount of future revenue to be earned related to fixed pricing under existing agreements primarily relates to our Filmed Entertainment segment, which at any given time equals approximately 1 to 2 years of our annual Filmed Entertainment content licensing revenue. The substantial majority of this revenue will be recognized within 2 years. This amount may fluctuate from period to period depending on the timing of the release and the availability of content under existing agreements and may not represent the total content licensing revenue expected to be recognized as it does not include revenue from future agreements or from variable pricing or optional purchases under existing agreements. For our content licensing agreements that include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service sold by our customers, we generally recognize revenue as our customers sell to their subscribers. Home Entertainment Our Filmed Entertainment segment generates revenue from the sale of our produced and acquired films on standard-definition digital video discs and Blu-ray discs (together, “DVDs”) and through digital distribution services. Our Cable Networks and Broadcast Television networks also generate revenue from the sale of owned programming on DVDs and through digital distribution services, which is reported in other revenue. We recognize revenue from DVD sales, net of estimated returns and customer incentives, on the date that DVDs are delivered to and made available for sale by retailers. Payment terms generally include payment within 60 to 90 days from delivery to the retailer. Theme Parks Our Theme Parks segment generates revenue primarily from ticket sales and guest spending at our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. Guest spending includes in-park spending on food, beverages and merchandise. We recognize revenue from theme park ticket sales when the tickets are used, generally within a year from the date of purchase. For annual passes, we generally recognize revenue on a straight-line basis over the period the pass is available to be used. We recognize revenue from guest spending at the point of sale. Condensed Consolidated Balance Sheet The following tables summarize our accounts receivable and other balances that are not separately presented in our condensed consolidated balance sheet that relate to the recognition of revenue and collection of the related cash , as well as deferred costs associated with our contracts with customers. (in millions) September 30, December 31, Receivables, gross $ 9,300 $ 9,122 Less: Allowance for doubtful accounts 317 288 Receivables, net $ 8,983 $ 8,834 (in millions) September 30, December 31, Noncurrent receivables, net (included in other noncurrent assets, net) $ 1,207 $ 1,184 Contract acquisition and fulfillment costs (included in other noncurrent assets, net) $ 928 $ 922 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 572 $ 497 In our Cable Communications segment, we manage credit risk by screening applicants through the use of internal customer information, identification verification tools and credit bureau data, as well as offering customers the opportunity to establish automatic monthly payments. If a customer’s account is delinquent, various measures are used to collect outstanding amounts, including termination of the customer’s cable services.
Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
Revenue [Line Items]
Revenue	Revenue Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Distribution $ 1,680 $ 1,533 $ 5,251 $ 4,645 Advertising 820 787 2,746 2,519 Content licensing and other 384 283 997 775 Total Cable Networks 2,884 2,603 8,994 7,939 Advertising 1,355 1,241 5,107 3,790 Content licensing 538 432 1,541 1,458 Distribution and other 559 452 1,692 1,326 Total Broadcast Television 2,452 2,125 8,340 6,574 Theatrical 601 515 1,564 2,003 Content licensing 719 662 2,100 2,080 Home entertainment 260 299 733 919 Other 239 277 779 860 Total Filmed Entertainment 1,819 1,753 5,176 5,862 Total Theme Parks 1,528 1,550 4,170 3,982 Headquarters and Other 15 15 44 32 Eliminations (a) (73 ) (70 ) (256 ) (242 ) Total revenue $ 8,625 $ 7,976 $ 26,468 $ 24,147 (a) Included in Eliminations are transactions that our segments enter into with one another. See Note 2 for a description of these transactions. We operate primarily in the United States, but also in select international markets primarily in Europe and Asia. The table below summarizes revenue by geographic location. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 United States $ 6,758 $ 6,088 $ 20,945 $ 18,344 Foreign 1,867 1,888 5,523 5,803 Total revenue $ 8,625 $ 7,976 $ 26,468 $ 24,147 No single customer accounted for a significant amount of revenue in any period presented. Distribution Our Cable Networks segment generates distribution revenue from the distribution of our cable network programming to traditional and virtual multichannel video providers. Our Broadcast Television segment generates distribution revenue from the fees received under retransmission consent agreements and associated fees received from NBC-affiliated local broadcast television stations. Distribution revenue is recognized as programming is provided on a monthly basis, generally under multiyear agreements. Monthly fees received under distribution agreements with multichannel video providers are generally based on the number of subscribers. Payment terms and conditions vary by contract type, although terms generally include payment within 30 to 60 days. Advertising Our Cable Networks and Broadcast Television segments generate advertising revenue from the sale of advertising on our cable and broadcast networks, our owned local broadcast television stations, and various digital properties. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms are agreed upon. Advertising revenue is recognized, net of agency commissions, in the period in which advertisements are aired or viewed and payment occurs thereafter, generally within 30 days. In some instances, we guarantee audience ratings for the advertisements. To the extent there is a shortfall in contracts where the ratings were guaranteed, a portion of the revenue is deferred until the shortfall is settled, typically by providing additional advertising units generally within one year of the original airing. Theatrical Our Filmed Entertainment segment theatrical revenue is generated from the worldwide theatrical release of our produced and acquired films for exhibition in movie theaters and is affected by the timing, nature and number of films released in movie theaters and their acceptance by audiences. Theatrical revenue is also affected by the number of exhibition screens, ticket prices, the percentage of ticket sale retention by the exhibitors and the popularity of competing films at the time our films are released. We recognize theatrical revenue as the films are viewed and exhibited in theaters and payment generally occurs within 60 days after exhibition. Content Licensing Our Cable Networks, Broadcast Television and Filmed Entertainment segments generate revenue from the licensing of our owned film and television content in the United States and internationally to cable, broadcast and premium networks and subscription video on demand services. Our content licensing agreements generally include fixed pricing and span multiple years. For example, following a film’s theatrical release, our Filmed Entertainment segment may license the exhibition rights of a film to different customers over multiple successive distribution windows. We recognize revenue when the content is delivered and available for use by the licensee. When the term of an existing agreement is renewed or extended, we recognize revenue at the later of when the content is available or when the renewal or extension period begins. Payment terms and conditions vary by contract type, although payments are generally collected over the license term. The amount of future revenue to be earned related to fixed pricing under existing agreements primarily relates to our Filmed Entertainment segment, which at any given time equals approximately 1 to 2 years of our annual Filmed Entertainment content licensing revenue. The substantial majority of this revenue will be recognized within 2 years. This amount may fluctuate from period to period depending on the timing of the release and the availability of content under existing agreements and may not represent the total content licensing revenue expected to be recognized as it does not include revenue from future agreements or from variable pricing or optional purchases under existing agreements. For our content licensing agreements that include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service sold by our customers, we generally recognize revenue as our customers sell to their subscribers. Home Entertainment Our Filmed Entertainment segment generates revenue from the sale of our produced and acquired films on standard-definition digital video discs and Blu-ray discs (together, “DVDs”) and through digital distribution services. Our Cable Networks and Broadcast Television networks also generate revenue from the sale of owned programming on DVDs and through digital distribution services, which is reported in other revenue. We recognize revenue from DVD sales, net of estimated returns and customer incentives, on the date that DVDs are delivered to and made available for sale by retailers. Payment terms generally include payment within 60 to 90 days from delivery to the retailer. Theme Parks Our Theme Parks segment generates revenue primarily from ticket sales and guest spending at our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. Guest spending includes in-park spending on food, beverages and merchandise. We recognize revenue from theme park ticket sales when the tickets are used, generally within a year from the date of purchase. For annual passes, we generally recognize revenue on a straight-line basis over the period the pass is available to be used. We recognize revenue from guest spending at the point of sale. Condensed Consolidated Balance Sheet The following tables summarize our accounts receivable and other balances that are not separately presented in our condensed consolidated balance sheet that relate to the recognition of revenue and collection of the related cash . (in millions) September 30, December 31, Receivables, gross $ 6,951 $ 7,055 Less: Allowance for doubtful accounts 100 88 Receivables, net $ 6,851 $ 6,967 (in millions) September 30, December 31, Noncurrent receivables, net (included in other noncurrent assets, net) $ 1,098 $ 1,093 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 451 $ 392

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Computation of Diluted EPS Three Months Ended September 30 2018 2017 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 2,886 4,564 $ 0.63 $ 2,642 4,698 $ 0.56 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 55 79 Diluted EPS attributable to Comcast Corporation shareholders $ 2,886 4,619 $ 0.62 $ 2,642 4,777 $ 0.55 Nine Months Ended September 30 2018 2017 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 9,220 4,599 $ 2.00 $ 7,736 4,725 $ 1.64 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 56 81 Diluted EPS attributable to Comcast Corporation shareholders $ 9,220 4,655 $ 1.98 $ 7,736 4,806 $ 1.61 Diluted earnings per common share attributable to Comcast Corporation shareholders (“diluted EPS”) considers the impact of potentially dilutive securities using the treasury stock method. Our potentially dilutive securities include potential common shares related to our stock options and our restricted share units (“RSUs”). The amount of potential common shares related to our share-based compensation plans that were excluded from diluted EPS because their effect would have been antidilutive was not material for the three and nine months ended September 30, 2018 and 2017 .

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of September 30, 2018 , our debt had a carrying value of $72.9 billion and an estimated fair value of $74.5 billion . The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities. See Note 6 for information regarding the financing of the Sky transaction. Debt Borrowings (in millions) Nine Months Ended Comcast sterling-denominated term loan due 2021 (see Note 6) $ 3,913 Comcast revolving credit facility (see Note 6) 1,500 Comcast 3.90% senior notes due 2038 1,200 Comcast 3.55% senior notes due 2028 1,000 Comcast 4.00% senior notes due 2048 1,000 Comcast 4.25% senior notes due 2053 800 Universal Beijing Resort term loans (see Note 6) 386 Other 51 Total $ 9,850 Debt Repayments (in millions) Nine Months Ended NBCUniversal Enterprise 1.662% senior notes due 2018 $ 1,100 Comcast 5.70% senior notes due 2018 1,000 Comcast 5.875% senior notes due 2018 900 NBCUniversal Enterprise senior floating rate notes due 2018 700 Universal Studios Japan term loans maturing 2022 362 Other 343 Total $ 4,405 Revolving Credit Facilities As of September 30, 2018 , $1.5 billion was outstanding under our consolidated revolving credit facilities. Amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper programs and outstanding letters of credit, totaled $3.8 billion , which included $823 million available under NBCUniversal Enterprise’s revolving credit facility. Commercial Paper Programs As of September 30, 2018 , Comcast had $3 billion face amount of commercial paper outstanding. As of September 30, 2018 , NBCUniversal Enterprise had $794 million face amount of commercial paper outstanding.
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of September 30, 2018 , our debt, excluding the note payable to Comcast, had a carrying value of $12.6 billion and an estimated fair value of $12.9 billion . The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities. For the nine months ended September 30, 2018 , Universal Beijing Resort borrowed $386 million under its debt financing agreement to fund the construction of a Universal theme park and resort in Beijing, China (see Note 5). For the nine months ended September 30, 2018 , we repaid $362 million of Universal Studios Japan term loans maturing 2022. Cross-Guarantee Structure We, Comcast and a 100% owned cable holding company subsidiary of Comcast (“CCCL Parent”) have fully and unconditionally guaranteed each other’s debt securities, including the $7.6 billion Comcast revolving credit facility due 2021 and the £3.0 billion of borrowings ( $3.9 billion using the exchange rate on the date of borrowing) under Comcast’s £7.0 billion unsecured sterling-denominated term loan credit agreement. As of September 30, 2018 , outstanding debt securities of $58.7 billion of Comcast and CCCL Parent were subject to the cross-guarantee structure. In October 2018, in connection with Comcast’s acquisition of Sky on October 9, 2018, Comcast issued $27.0 billion aggregate amount of senior unsecured fixed and floating rate notes that will mature between 2020 and 2058, and borrowed £3.6 billion ( $4.8 billion using the exchange rates on the dates of borrowings) under Comcast’s £7.0 billion unsecured sterling-denominated term loan credit agreement and $3.0 billion under Comcast’s $3.0 billion unsecured dollar-denominated term loan credit agreement. We also guarantee these senior notes and unsecured term loans under the cross-guarantee structure. We do not, however, guarantee the obligations of NBCUniversal Enterprise with respect to its $3.0 billion aggregate principal amount of senior notes, $1.6 billion revolving credit facility and commercial paper program, or $725 million liquidation preference of Series A cumulative preferred stock. Additionally, the Universal Studios Japan and Universal Beijing Resort term loans are not subject to the cross-guarantee structure and are not guaranteed by us; however, the Universal Studios Japan term loans have a separate guarantee from Comcast.

Significant Transactions

Significant Transactions	9 Months Ended
	Sep. 30, 2018
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions Sky Transaction On October 9, 2018, in connection with our offer to acquire the share capital of Sky, we acquired a controlling interest in Sky through a series of purchases of Sky shares and acceptances of the offer at our offer price of £17.28 per Sky share. Because shareholders owning over 90% of the fully diluted share capital of Sky have either accepted our offer or sold their Sky shares to us, we have exercised, in accordance with applicable U.K. law, our right to acquire the remaining shares of Sky, which we expect will be completed in the fourth quarter of 2018. The consideration under our offer implies a value of approximately £30.2 billion (approximately $39.4 billion using the exchange rate on October 9, 2018) for the fully diluted share capital of Sky. As of October 9, 2018, Sky had outstanding indebtedness that will be consolidated in our financial statements with an aggregate principal amount of approximately $11 billion using the exchange rates as of such date, which is not guaranteed by us, Comcast Cable Communications, LLC or NBCUniversal. Sky is one of Europe’s leading media and entertainment companies, connecting customers to a broad range of video content through its pay television services. It also provides communication services, including residential high-speed Internet, voice, and wireless phone services. Sky operates the Sky News broadcast network and sports and entertainment networks, produces original content, and has exclusive content rights. To finance our acquisition, in September 2018, we borrowed £3.0 billion ($3.9 billion using the exchange rate on the date of borrowing) under our £7.0 billion unsecured sterling-denominated term loan credit agreement and $1.5 billion under Comcast’s revolving credit facility, and issued $3.0 billion of commercial paper under Comcast’s commercial paper program, all of which were classified as long-term debt at September 30, 2018. The proceeds from the term loan borrowing were restricted as to use for purchase of Sky shares and were classified as restricted cash in other noncurrent assets, net. Additionally, in October 2018, we issued $27.0 billion aggregate amount of senior unsecured fixed and floating rate notes that will mature between 2020 and 2058, and borrowed £3.6 billion ( $4.8 billion using the exchange rates on the dates of borrowings) under our £7.0 billion unsecured sterling-denominated term loan credit agreement and $3.0 billion under our $3.0 billion unsecured dollar-denominated term loan credit agreement. The unsecured term loans and senior notes are guaranteed by Comcast Cable Communications, LLC and NBCUniversal. In October 2018, we used a portion of the net proceeds from the senior notes offering to repay the commercial paper outstanding and revolving credit facility borrowings, and to replenish a portion of our cash, in each case, that had been previously used for purchases of Sky shares. Acquisition-Related Expenses As a result of the Sky transaction, we have incurred incremental expenses related to legal, accounting, valuation and other professional services, which are reflected in other operating and administrative expenses. We also incurred certain financing costs associated with our borrowings, which are reflected in interest expense. The table below presents the amounts related to these expenses included in our consolidated statement of operations. Additional acquisition-related fees are expected in the fourth quarter of 2018. Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2018 2018 Other operating and administrative expenses $ 8 $ 29 Interest expense $ 34 $ 45 Preliminary Purchase Price Allocation and Unaudited Pro Forma Information We will apply acquisition accounting to Sky and its results of operations will be included in our consolidated results of operations from the date of acquisition. The assets and liabilities acquired as a result of the transaction will be recorded at their estimated fair values. Due to the limited time since the acquisition date and limitations on access to Sky information prior to the acquisition date, the initial accounting for the transaction is incomplete at this time. As a result, we are unable to provide amounts recognized as of the acquisition date for assets and liabilities acquired. Also, because the initial accounting for the transaction is incomplete, we are unable to provide supplemental pro forma revenue and earnings of the combined entity. We will include this information in future filings. Universal Beijing Resort We entered into an agreement with a consortium of Chinese state-owned companies to build and operate a Universal theme park and resort in Beijing, China (“Universal Beijing Resort”). We own a 30% interest in Universal Beijing Resort and the construction will be funded through a combination of debt financing and equity contributions from the investors in accordance with their equity interests. The debt financing, which is being provided by a syndicate of Chinese financial institutions, contains certain financial and operating covenants and a maximum borrowing limit of ¥ 26.6 billion RMB (approximately $4 billion as of quarter end). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. For the nine months ended September 30, 2018 , Universal Beijing Resort borrowed $386 million of term loans under the debt financing agreements. We have concluded that Universal Beijing Resort is a variable interest entity based on its governance structure, and we consolidate it because we have the power to direct activities that most significantly impact its economic performance. There are no liquidity arrangements, guarantees or other financial commitments between us and Universal Beijing Resort, and therefore our maximum risk of financial loss is our 30% interest. Universal Beijing Resort’s results of operations are reported in our Theme Parks segment. Our condensed consolidated statement of cash flows includes the costs of construction and related borrowings in the "construction of Universal Beijing Resort" and "proceeds from borrowings" captions, respectively, and equity contributions from our investing partner are included in other financing activities. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors. As of September 30, 2018, our condensed consolidated balance sheet included assets, primarily property and equipment, and liabilities, including the term loans, of Universal Beijing Resort totaling $1.2 billion and $728 million , respectively. FCC Spectrum Auction On April 13, 2017, the Federal Communications Commission announced the results of its spectrum auction. In the auction, NBCUniversal relinquished its spectrum rights in the New York, Philadelphia and Chicago designated market areas (“DMAs”) where NBC and Telemundo had overlapping spectrum. NBCUniversal received proceeds of $482 million in July 2017, which were recorded in other investing activities in our condensed consolidated statement of cash flows. NBCUniversal recognized a pretax gain of $337 million in other operating gains for the three and nine months ended September 30, 2017 in our condensed consolidated statement of income. NBC and Telemundo stations share broadcast signals in these DMAs. In connection with the auction, we also acquired the rights to $1.7 billion of spectrum, which were recorded to other intangible assets, net in our condensed consolidated balance sheet. We had previously made a deposit of $1.8 billion to participate in the auction in the third quarter of 2016 and received a refund for amounts in excess of the purchase price in the second quarter of 2017. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion . The acquisition was funded through cash on hand and borrowings under our commercial paper program. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related tax and accumulated other comprehensive income impacts, were recorded to additional paid-in capital.
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions Universal Beijing Resort We entered into an agreement with a consortium of Chinese state-owned companies to build and operate a Universal theme park and resort in Beijing, China (“Universal Beijing Resort”). We own a 30% interest in Universal Beijing Resort and the construction will be funded through a combination of debt financing and equity contributions from the investors in accordance with their equity interests. The debt financing, which is being provided by a syndicate of Chinese financial institutions, contains certain financial and operating covenants and a maximum borrowing limit of ¥ 26.6 billion RMB (approximately $4 billion as of quarter end). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. For the nine months ended September 30, 2018 , Universal Beijing Resort borrowed $386 million of term loans under the debt financing agreements. We have concluded that Universal Beijing Resort is a variable interest entity based on its governance structure, and we consolidate it because we have the power to direct activities that most significantly impact its economic performance. There are no liquidity arrangements, guarantees or other financial commitments between us and Universal Beijing Resort, and therefore our maximum risk of financial loss is our 30% interest. Universal Beijing Resort’s results of operations are reported in our Theme Parks segment. Our condensed consolidated statement of cash flows includes the costs of construction and related borrowings in the "construction of Universal Beijing Resort" and "proceeds from borrowings" captions, respectively, and equity contributions from our investing partner are included in other financing activities. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors. As of September 30, 2018, our condensed consolidated balance sheet included assets, primarily property and equipment, and liabilities, including the term loans, of Universal Beijing Resort totaling $1.2 billion and $728 million , respectively. FCC Spectrum Auction On April 13, 2017, the Federal Communications Commission announced the results of its spectrum auction. In the auction, we relinquished our spectrum rights in the New York, Philadelphia and Chicago designated market areas (“DMAs”) where NBC and Telemundo had overlapping spectrum. We received proceeds of $482 million in July 2017, which were recorded in other investing activities in our condensed consolidated statement of cash flows. We recognized a pretax gain of $337 million in other operating gains for the three and nine months ended September 30, 2017 in our condensed consolidated statement of income. NBC and Telemundo stations will share broadcast signals in these DMAs. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion . The acquisition was funded through borrowings under our revolving credit agreement with Comcast. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related accumulated other comprehensive income impact, were recorded to member’s capital.

Recent Accounting Pronouncement

Recent Accounting Pronouncements and Tax Reform	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Recent Accounting Pronouncements and Tax Reform	Recent Accounting Pronouncements and Tax Reform Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) updated the accounting guidance related to revenue recognition. The updated accounting guidance provides a single, contract-based revenue recognition model to help improve financial reporting by providing clearer guidance on when an entity should recognize revenue and by reducing the number of standards to which an entity has to refer. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. We adopted the updated guidance on January 1, 2018 on a full retrospective basis, which required us to reflect the impact of the updated guidance for all periods presented. Upon adoption, we also implemented changes in our presentation of certain revenues and expenses, primarily in our Cable Communications segment. The adoption of the new standard did not have a material impact on our consolidated results of operations or financial position for any period presented. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions (see Note 3). The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 20,983 $ 98 $ 21,081 $ 62,611 $ 343 $ 62,954 Total costs and expenses $ 16,191 $ 111 $ 16,302 $ 48,731 $ 334 $ 49,065 Operating income $ 4,792 $ (13 ) $ 4,779 $ 13,880 $ 9 $ 13,889 Net income attributable to Comcast Corporation $ 2,650 $ (8 ) $ 2,642 $ 7,729 $ 7 $ 7,736 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 16,060 $ 283 $ 16,343 Film and television costs $ 7,076 $ 11 $ 7,087 Other intangible assets, net $ 18,779 $ (646 ) $ 18,133 Other noncurrent assets, net $ 3,489 $ 865 $ 4,354 Total assets $ 186,949 $ 513 $ 187,462 Total current liabilities $ 21,561 $ 432 $ 21,993 Deferred income taxes $ 24,256 $ 3 $ 24,259 Other noncurrent liabilities $ 10,904 $ 68 $ 10,972 Total equity $ 69,449 $ 10 $ 69,459 Total liabilities and equity $ 186,949 $ 513 $ 187,462 Cable Communications A summary of the changes implemented for the Cable Communications segment is presented below. Changes to Presentation of Revenue and Related Costs • Revenue from our residential video services decreased with corresponding increases to high-speed Internet and voice revenue due to a change in the allocation of revenue among our cable services included in a bundle that our residential customers purchase at a discount. • Revenue from franchise and other regulatory fees, which was previously presented in other revenue, is now presented with the corresponding cable services. This resulted in increases to video, voice and business services revenue. • Residential customer late fees are now presented in other revenue. These fees were previously presented as a reduction to other operating costs and expenses. • Certain costs, including costs related to the fulfillment of contracts with customers, are now presented as other assets and the related costs are recognized over time in operating costs and expenses, which are comprised of total costs and expenses, excluding depreciation and amortization expense and other operating gains. These amounts were previously presented as intangible assets, and the expenses were previously presented in amortization expense. The payments related to these assets are now presented in net cash provided by operating activities rather than in cash paid for intangible assets in our consolidated statement of cash flows. Changes to the Timing of Recognition of Revenue and Related Costs • Installation revenue and commission expense are now recognized as revenue and operating costs and expenses, respectively, over a period of time rather than recognized immediately as they were previously. We recorded a deferred revenue liability related to upfront installation fees that are not distinct services, which required us to allocate the installation fees to the respective service. The installation fees are generally recognized as revenue over the period that the fee would influence a customer to renew their service. This period is less than a year for residential customers and the term of the related contract for business services customers. Incremental costs to obtain a contract with a customer, such as commissions for our business customers, are now deferred and recognized over the contract term. Sales commissions related to our residential customers are expensed as incurred as the related period of benefit is less than a year. The table below presents the effects these changes had on our Cable Communications segment revenue, operating costs and expenses, and depreciation and amortization expense as a result of the updated guidance for the prior year periods. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,825 $ (65 ) $ 5,760 $ 17,396 $ (190 ) $ 17,206 High-speed Internet 3,709 233 3,942 10,994 688 11,682 Voice 840 173 1,013 2,559 522 3,081 Business services 1,575 54 1,629 4,596 161 4,757 Advertising 542 52 594 1,628 146 1,774 Other 712 (311 ) 401 2,064 (918 ) 1,146 Total Cable Communications revenue $ 13,203 $ 136 $ 13,339 $ 39,237 $ 409 $ 39,646 Operating costs and expenses $ 7,957 $ 166 $ 8,123 $ 23,473 $ 490 $ 23,963 Depreciation and amortization expense $ 2,049 $ (34 ) $ 2,015 $ 6,030 $ (102 ) $ 5,928 NBCUniversal Segments The adoption of the updated guidance impacted the timing of recognition for some of our revenue contracts, primarily for content licensing agreements. As a result of the adoption of the updated guidance, when the term of existing content licensing agreements is renewed or extended, revenue is not recognized until the date when the renewal or extension period begins. Under the prior guidance, revenue for the content licensing renewal period was recognized on the date that the renewal was agreed to contractually. This change resulted in delayed revenue recognition for content licensing renewals or extensions in our Cable Networks, Broadcast Television and Filmed Entertainment segments. This change also impacted the timing of the related amortization of our film and television costs and participations and residuals expenses. The adoption of the updated guidance did not have a material impact on the results of operations or financial position for the NBCUniversal segments. Financial Assets and Financial Liabilities In January 2016, the FASB updated the accounting guidance related to the recognition and measurement of financial assets and financial liabilities. The updated accounting guidance, among other things, requires that all nonconsolidated equity investments, except those accounted for under the equity method, be measured at fair value and the changes in fair value be recognized in net income. On January 1, 2018, we adopted the updated guidance prospectively along with a related clarifying update and as a result, we recorded an immaterial cumulative effect adjustment to retained earnings, accumulated other comprehensive income (loss) and investments. See Note 9 for further information. Tax Reform On December 22, 2017, new federal tax reform legislation was enacted in the United States (“2017 Tax Act”), resulting in significant changes from previous tax law. The new legislation reduced the federal corporate income tax rate to 21% from 35% effective January 1, 2018. In the fourth quarter of 2017, we recorded a net income tax benefit of approximately $12.7 billion on the date of enactment of the new legislation, primarily relating to a reduction of our net deferred tax liabilities as a result of the rate change. This amount also includes the reversal of our net deferred tax liabilities related to cumulative undistributed foreign earnings and deferred tax assets for related foreign tax credits, partially offset by the one-time deemed repatriation tax on undistributed foreign earnings and profits. The adjustments to deferred tax assets and liabilities, and the liability related to the transition tax, are provisional amounts based on information available as of September 30, 2018. These amounts are subject to change as we obtain information necessary to complete the calculations. During the nine months ended September 30, 2018 , we recorded immaterial adjustments to the provisional amounts related to the cumulative temporary differences and the one-time deemed repatriation tax on undistributed foreign earnings and profits. We expect to complete our analysis of the provisional items in the fourth quarter of 2018. In February 2018, the FASB issued guidance that permits companies to reclassify disproportionate tax effects recorded in accumulated other comprehensive income as a result of the 2017 Tax Act to retained earnings. We adopted the guidance as of January 1, 2018 and, as a result, we recorded an immaterial cumulative effect adjustment to retained earnings and accumulated other comprehensive income (loss). In February 2018, the Bipartisan Budget Act of 2018 was enacted. As part of this legislation, various tax provisions that had expired on December 31, 2016 were retroactively extended to December 31, 2017, including the statute permitting the immediate deduction for certain film and television production costs. We recorded an income tax benefit of $128 million in the first quarter of 2018 as a result of the enactment of this legislation. Restricted Cash In November 2016, the FASB updated the accounting guidance related to restricted cash. The new standard requires that the statement of cash flows present the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents, and a reconciliation of such total to amounts on the balance sheet. We adopted the updated guidance on January 1, 2018 and as required applied the retrospective transition method. The adoption did not have a material impact for any period presented. Leases In February 2016, the FASB updated the accounting guidance related to leases. The updated accounting guidance requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet for all leases with the exception of short-term leases. The asset and liability are initially measured based on the present value of committed lease payments. For a lessee, the recognition, measurement and presentation of expenses and cash flows arising from a lease do not significantly change from previous guidance. For a lessor, the accounting applied is also largely unchanged from previous guidance. We will adopt the updated accounting guidance in the first quarter of 2019 and prior periods will not be adjusted. We are currently in the process of determining the impact that the updated accounting guidance will have on our consolidated financial statements.
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Recent Accounting Pronouncements and Tax Reform	Recent Accounting Pronouncements Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) updated the accounting guidance related to revenue recognition. The updated accounting guidance provides a single, contract-based revenue recognition model to help improve financial reporting by providing clearer guidance on when an entity should recognize revenue and by reducing the number of standards to which an entity has to refer. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. We adopted the updated guidance on January 1, 2018 on a full retrospective basis, which required us to reflect the impact of the updated guidance for all periods presented. The adoption of the new standard did not have a material impact on our consolidated results of operations or financial position for any period presented. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions (see Note 3). The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 8,014 $ (38 ) $ 7,976 $ 24,213 $ (66 ) $ 24,147 Total costs and expenses $ 5,909 $ (20 ) $ 5,889 $ 19,048 $ (53 ) $ 18,995 Operating income $ 2,105 $ (18 ) $ 2,087 $ 5,165 $ (13 ) $ 5,152 Net income attributable to NBCUniversal $ 1,825 $ (18 ) $ 1,807 $ 4,301 $ (13 ) $ 4,288 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 11,673 $ 284 $ 11,957 Film and television costs $ 7,071 $ 11 $ 7,082 Other noncurrent assets, net $ 1,872 $ (68 ) $ 1,804 Total assets $ 71,073 $ 227 $ 71,300 Total current liabilities $ 9,602 $ 330 $ 9,932 Other noncurrent liabilities $ 4,109 $ 44 $ 4,153 Total equity $ 43,188 $ (147 ) $ 43,041 Total liabilities and equity $ 71,073 $ 227 $ 71,300 The adoption of the updated guidance impacted the timing of recognition for some of our revenue contracts, primarily for content licensing agreements. As a result of the adoption of the updated guidance, when the term of existing content licensing agreements is renewed or extended, revenue is not recognized until the date when the renewal or extension period begins. Under the prior guidance, revenue for the content licensing renewal period was recognized on the date that the renewal was agreed to contractually. This change resulted in delayed revenue recognition for content licensing renewals or extensions in our Cable Networks, Broadcast Television and Filmed Entertainment segments. This change also impacted the timing of the related amortization of our film and television costs and participations and residuals expenses. The adoption of the updated guidance did not have a material impact on the results of operations or financial position for our reportable segments. Financial Assets and Financial Liabilities In January 2016, the FASB updated the accounting guidance related to the recognition and measurement of financial assets and financial liabilities. The updated accounting guidance, among other things, requires that all nonconsolidated equity investments, except those accounted for under the equity method, be measured at fair value and the changes in fair value be recognized in net income. On January 1, 2018, we adopted the updated guidance prospectively along with a related clarifying update and as a result, we recorded a $232 million cumulative effect adjustment to member’s capital and accumulated other comprehensive income (loss). See Note 8 for further information. Restricted Cash In November 2016, the FASB updated the accounting guidance related to restricted cash. The new standard requires that the statement of cash flows present the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents, and a reconciliation of such total to amounts on the balance sheet. We adopted the updated guidance on January 1, 2018 and as required applied the retrospective transition method. The adoption did not have a material impact for any period presented. Leases In February 2016, the FASB updated the accounting guidance related to leases. The updated accounting guidance requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet for all leases with the exception of short-term leases. The asset and liability are initially measured based on the present value of committed lease payments. For a lessee, the recognition, measurement and presentation of expenses and cash flows arising from a lease do not significantly change from previous guidance. For a lessor, the accounting applied is also largely unchanged from previous guidance. We will adopt the updated accounting guidance in the first quarter of 2019 and prior periods will not be adjusted. We are currently in the process of determining the impact that the updated accounting guidance will have on our consolidated financial statements.

Film and Television Costs

Film and Television Costs	9 Months Ended
	Sep. 30, 2018
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,573 $ 1,734 Completed, not released 242 50 In production and in development 1,010 1,149 2,825 2,933 Television Costs: Released, less amortization 2,286 2,260 In production and in development 905 818 3,191 3,078 Programming rights, less amortization 2,584 2,689 8,600 8,700 Less: Current portion of programming rights 1,223 1,613 Film and television costs $ 7,377 $ 7,087
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,573 $ 1,734 Completed, not released 242 50 In production and in development 1,010 1,149 2,825 2,933 Television Costs: Released, less amortization 2,286 2,260 In production and in development 905 818 3,191 3,078 Programming rights, less amortization 2,566 2,677 8,582 8,688 Less: Current portion of programming rights 1,213 1,606 Film and television costs $ 7,369 $ 7,082

Investments

Investments	9 Months Ended
	Sep. 30, 2018
Investments [Line Items]
Investments	Investments (in millions) September 30, December 31, Equity method $ 4,163 $ 3,546 Marketable equity securities 322 433 Nonmarketable equity securities 1,528 1,186 Other investments 1,798 1,785 Total investments 7,811 6,950 Less: Current investments 87 19 Noncurrent investments $ 7,724 $ 6,931 Investment and Other Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Equity in net income (losses) of investees, net $ (76 ) $ (39 ) $ (56 ) $ 12 Realized and unrealized gains (losses) on equity securities, net (38 ) 7 (50 ) — Other income (loss), net 3 102 198 287 Investment and other income (loss), net $ (111 ) $ 70 $ 92 $ 299 Beginning January 1, 2018, in connection with our adoption of the updated accounting guidance related to the recognition and measurement of financial assets and financial liabilities (see Note 7) , we updated the presentation and accounting policies for our investments previously classified as fair value and cost method investments. The investment categories presented in the table above are based on the new guidance and updated policies, where applicable, are presented below. Equity Method Atairos In February 2018, we amended our agreement with Atairos, which primarily increases our commitment to fund Atairos from up to $4 billion to up to $5 billion in the aggregate at any one time, subject to certain offsets. As of September 30, 2018 and December 31, 2017, we had an investment in Atairos of $2.9 billion and $2.4 billion , respectively. For the nine months ended September 30, 2018 and 2017, we made cash capital contributions to Atairos totaling $133 million and $994 million , respectively. Atairos follows investment company accounting and records its investments at their fair values each reporting period with the net gains or losses reflected in its statement of income. We recognize our share of Atairos’ income and losses in equity in net income (losses) of investees, net. For the three and nine months ended September 30, 2018 , our share of Atairos’ income was $38 million and $224 million , respectively. For the three and nine months ended September 30, 2017 , our share of Atairos’ income was $7 million and $106 million , respectively. In April 2018, we sold a controlling interest in our arena management-related businesses to Atairos and received as consideration additional equity interests in Atairos. We account for our retained ownership in the businesses as an equity method investment. In connection with the sale of the businesses, we recognized a pretax gain of $200 million in other operating gains in the second quarter of 2018. In July 2017, we sold a business to a company owned by Atairos and received as consideration an investment in that company, which we account for as an equity method investment. In connection with the sale of the business, we recognized a pretax gain of $105 million in other operating gains in the third quarter of 2017. Hulu As of September 30, 2018 and December 31, 2017, we had an investment in Hulu of $219 million and $249 million , respectively. For the nine months ended September 30, 2018 and 2017, we made cash capital contributions to Hulu totaling $341 million and $198 million , respectively. We recognize our proportionate share of Hulu’s income and losses in equity in net income (losses) of investees, net. For the three and nine months ended September 30, 2018 , we recognized our proportionate share of Hulu’s losses of $132 million and $370 million , respectively. For the three and nine months ended September 30, 2017 , we recognized our proportionate share of Hulu’s losses of $62 million and $168 million , respectively. The Weather Channel In March 2018, we sold our investment in The Weather Channel cable network and recognized a pretax gain of $64 million in other income (loss), net. Marketable Equity Securities We classify publicly traded investments with readily determinable fair values that are not accounted for under the equity method as marketable equity securities. Marketable equity securities are recorded at cost and adjusted to fair value at each reporting period. The changes in fair value between measurement dates are recorded in realized and unrealized gains (losses) on equity securities, net. The fair values of our marketable equity securities are based on Level 1 inputs that use quoted market prices. Snap In March 2017, we acquired an interest in Snap Inc. for $500 million as part of its initial public offering, which we have classified as a marketable equity security. Snap is a camera company whose primary product is Snapchat, a camera app that was created to help people communicate through short videos and images. As of September 30, 2018 and December 31, 2017, we had an investment in Snap of $249 million and $430 million , respectively. For the three and nine months ended September 30, 2018 , we recognized unrealized losses of $135 million and $180 million , respectively, in realized and unrealized gains (losses) on equity securities, net related to our investment in Snap. Nonmarketable Equity Securities We classify investments without readily determinable fair values that are not accounted for under the equity method as nonmarketable equity securities. The accounting guidance requires nonmarketable equity securities to be recorded at cost and adjusted to fair value at each reporting period. However, the guidance allows for a measurement alternative, which is to record the investments at cost, less impairment, if any, and subsequently adjust for observable price changes of identical or similar investments of the same issuer. We apply this measurement alternative to a majority of our nonmarketable equity securities. When an observable event occurs, we estimate the fair values of our nonmarketable equity securities based on Level 2 inputs that are derived from observable price changes of similar securities adjusted for insignificant differences in rights and obligations. The changes in value are recorded in realized and unrealized gains (losses) on equity securities, net. Other Investments AirTouch We hold two series of preferred stock of Verizon Americas, Inc., formerly known as AirTouch Communications, Inc. (“AirTouch”), a subsidiary of Verizon Communications Inc., which are redeemable in April 2020. As of both September 30, 2018 and December 31, 2017, we had an investment in AirTouch of $1.6 billion . We account for our investment in AirTouch as a held to maturity investment using the cost method. As of September 30, 2018 , the estimated fair value of the AirTouch preferred stock and the estimated fair value of the associated liability related to the redeemable subsidiary preferred shares issued by one of our consolidated subsidiaries were each $1.7 billion . The estimated fair values are based on Level 2 inputs that use pricing models whose inputs are derived primarily from or corroborated by observable market data through correlation or other means for substantially the full term of the financial instrument.
NBCUniversal Media LLC [Member]
Investments [Line Items]
Investments	Investments (in millions) September 30, December 31, Equity method $ 660 $ 690 Marketable equity securities 249 430 Nonmarketable equity securities 813 696 Total investments $ 1,722 $ 1,816 Investment and Other Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Equity in net income (losses) of investees, net $ (119 ) $ (52 ) $ (306 ) $ (107 ) Realized and unrealized gains (losses) on equity securities, net (91 ) — (128 ) 2 Other income (loss), net 5 26 57 63 Investment and other income (loss), net $ (205 ) $ (26 ) $ (377 ) $ (42 ) Beginning January 1, 2018, in connection with our adoption of the updated accounting guidance related to the recognition and measurement of financial assets and financial liabilities (see Note 6) , we updated the presentation and accounting policies for our investments previously classified as fair value and cost method investments. The investment categories presented in the table above are based on the new guidance and updated policies, where applicable, are presented below. Equity Method Hulu As of September 30, 2018 and December 31, 2017, we had an investment in Hulu of $219 million and $249 million , respectively. For the nine months ended September 30, 2018 and 2017, we made cash capital contributions to Hulu totaling $341 million and $198 million , respectively. We recognize our proportionate share of Hulu’s income and losses in equity in net income (losses) of investees, net. For the three and nine months ended September 30, 2018 , we recognized our proportionate share of Hulu’s losses of $132 million and $370 million , respectively. For the three and nine months ended September 30, 2017 , we recognized our proportionate share of Hulu’s losses of $62 million and $168 million , respectively. The Weather Channel In March 2018, we sold our investment in The Weather Channel cable network and recognized a pretax gain of $64 million in other income (loss), net. Marketable Equity Securities We classify publicly traded investments with readily determinable fair values that are not accounted for under the equity method as marketable equity securities. Marketable equity securities are recorded at cost and adjusted to fair value at each reporting period. The changes in fair value between measurement dates are recorded in realized and unrealized gains (losses) on equity securities, net. The fair values of our marketable equity securities are based on Level 1 inputs that use quoted market prices. Snap In March 2017, Comcast acquired an interest in Snap Inc. as part of its initial public offering. On March 31, 2017, Comcast contributed its investment in Snap to us as an equity contribution of $662 million , which was recorded in our condensed consolidated statement of equity based on the fair value of the investment as of March 31, 2017. We have classified our investment as a marketable equity security. Snap is a camera company whose primary product is Snapchat, a camera app that was created to help people communicate through short videos and images. As of September 30, 2018 and December 31, 2017, we had an investment in Snap of $249 million and $430 million , respectively. For the three and nine months ended September 30, 2018 , we recognized unrealized losses of $135 million and $180 million , respectively, in realized and unrealized gains (losses) on equity securities, net related to our investment in Snap. Nonmarketable Equity Securities We classify investments without readily determinable fair values that are not accounted for under the equity method as nonmarketable equity securities. The accounting guidance requires nonmarketable equity securities to be recorded at cost and adjusted to fair value at each reporting period. However, the guidance allows for a measurement alternative, which is to record the investments at cost, less impairment, if any, and subsequently adjust for observable price changes of identical or similar investments of the same issuer. We apply this measurement alternative to our nonmarketable equity securities. When an observable event occurs, we estimate the fair values of our nonmarketable equity securities based on Level 2 inputs that are derived from observable price changes of similar securities adjusted for insignificant differences in rights and obligations. The changes in value are recorded in realized and unrealized gains (losses) on equity securities, net.

Supplemental Financial Informat

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2018
Supplemental Financial Information [Line Items]
Supplemental Financial Information	Supplemental Financial Information Share-Based Compensation Our share-based compensation plans consist primarily of awards of RSUs and stock options to certain employees and directors as part of our approach to long-term incentive compensation. Additionally, through our employee stock purchase plans, employees are able to purchase shares of our common stock at a discount through payroll deductions. In March 2018, we granted 12.1 million RSUs and 41.0 million stock options related to our annual management awards. The weighted-average fair values associated with these grants were $35.94 per RSU and $7.15 per stock option. Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Restricted share units $ 94 $ 99 $ 279 $ 284 Stock options 50 52 155 155 Employee stock purchase plans 7 8 24 25 Total $ 151 $ 159 $ 458 $ 464 As of September 30, 2018 , we had unrecognized pretax compensation expense of $914 million and $489 million related to nonvested RSUs and nonvested stock options, respectively. Cash Payments for Interest and Income Taxes Nine Months Ended (in millions) 2018 2017 Interest $ 2,240 $ 2,277 Income taxes $ 1,533 $ 3,415 Noncash Investing and Financing Activities During the nine months ended September 30, 2018 : • we acquired $2.1 billion of property and equipment and intangible assets that were accrued but unpaid • we recorded a liability of $864 million for a quarterly cash dividend of $0.19 per common share to be paid in October 2018 • we received noncash contributions from noncontrolling interests totaling $391 million related to Universal Beijing Resort (see Note 6) Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the condensed consolidated balance sheet to the total of the amounts reported in our condensed consolidated statement of cash flows. (in millions) September 30, December 31, Cash and cash equivalents $ 10,616 $ 3,428 Restricted cash included in other current assets 47 60 Restricted cash included in other noncurrent assets, net 3,959 83 Cash, cash equivalents and restricted cash, end of period $ 14,622 $ 3,571 Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ 2 $ (43 ) Deferred gains (losses) on cash flow hedges 28 (12 ) Unrecognized gains (losses) on employee benefit obligations 294 270 Cumulative translation adjustments 50 166 Accumulated other comprehensive income (loss), net of deferred taxes $ 374 $ 381
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Supplemental Financial Information	Supplemental Financial Information Cash Payments for Interest and Income Taxes Nine Months Ended (in millions) 2018 2017 Interest $ 253 $ 340 Income taxes $ 373 $ 213 Noncash Investing and Financing Activities During the nine months ended September 30, 2018 : • we acquired $1.2 billion of property and equipment and intangible assets that were accrued but unpaid • we received noncash contributions from noncontrolling interests totaling $391 million related to Universal Beijing Resort (see Note 5) Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the condensed consolidated balance sheet to the total of the amounts reported in our condensed consolidated statement of cash flows. (in millions) September 30, December 31, Cash and cash equivalents $ 1,181 $ 2,347 Restricted cash included in other noncurrent assets, net 20 30 Cash, cash equivalents and restricted cash, end of period $ 1,201 $ 2,377 Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ — $ (233 ) Deferred gains (losses) on cash flow hedges 5 (4 ) Unrecognized gains (losses) on employee benefit obligations 115 115 Cumulative translation adjustments (22 ) 93 Accumulated other comprehensive income (loss) $ 98 $ (29 )

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Related Party Transactions	Related Party Transactions In the ordinary course of our business, we enter into transactions with Comcast. We generate revenue from Comcast primarily from the distribution of our cable network programming, the fees received under retransmission consent agreements in our Broadcast Television segment and, to a lesser extent, the sale of advertising and our owned programming, and we incur expenses primarily related to advertising and various support services provided by Comcast to us. Comcast is also the counterparty to one of our contractual obligations. As of September 30, 2018 , the carrying value of the liability associated with this contractual obligation was $383 million . The following tables present transactions with Comcast and its consolidated subsidiaries that are included in our condensed consolidated financial statements. Condensed Consolidated Statement of Income Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 506 $ 463 $ 1,580 $ 1,382 Total costs and expenses $ (59 ) $ (38 ) $ (162 ) $ (148 ) Interest expense and investment and other income (loss), net $ (9 ) $ (20 ) $ (52 ) $ (67 ) Condensed Consolidated Balance Sheet (in millions) September 30, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 350 $ 326 Note receivable from Comcast $ 1,522 $ — Accounts payable and accrued expenses related to trade creditors $ 48 $ 54 Accrued expenses and other current liabilities $ 20 $ 50 Note payable to Comcast $ 41 $ 1,831 Long-term debt $ 698 $ 610 Other noncurrent liabilities $ 394 $ 389 Share-Based Compensation Comcast maintains share-based compensation plans that consist primarily of awards of restricted share units and stock options to certain employees and directors as part of its approach to long-term incentive compensation. Additionally, through its employee stock purchase plans, employees are able to purchase shares of Comcast common stock at a discount through payroll deductions. Certain of our employees participate in these plans and the expense associated with their participation is settled in cash with Comcast. For the three months ended September 30, 2018 and 2017, we recognized share-based compensation expense of $37 million and $38 million , respectively. For the nine months ended September 30, 2018 and 2017, we recognized share-based compensation expense of $115 million and $103 million , respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Redeemable Subsidiary Preferred Stock As of September 30, 2018 , the fair value of the NBCUniversal Enterprise redeemable subsidiary preferred stock was $742 million . The estimated fair value is based on Level 2 inputs that use pricing models whose inputs are derived primarily from or corroborated by observable market data through correlation or other means for substantially the full term of the financial instrument. Contingencies We are a defendant in several unrelated lawsuits claiming infringement of various patents relating to various aspects of our businesses. In certain of these cases, other industry participants are also defendants, and also in certain of these cases, we expect that any potential liability would be in part or in whole the responsibility of our equipment and technology vendors under applicable contractual indemnification provisions. In addition, we are subject to other legal proceedings and claims that arise in the ordinary course of our business. While the amount of ultimate liability with respect to such actions is not expected to materially affect our results of operations, cash flows or financial position, any litigation resulting from any such legal proceedings or claims could be time-consuming and injure our reputation.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Financial Information	Condensed Consolidating Financial Information Comcast (“Comcast Parent”), Comcast Cable Communications, LLC (“CCCL Parent”), and NBCUniversal (“NBCUniversal Media Parent”) have fully and unconditionally guaranteed each other’s debt securities, including the Comcast revolving credit facility. Comcast Parent and CCCL Parent also fully and unconditionally guarantee NBCUniversal Enterprise’s $3 billion aggregate principal amount of senior notes and $1.6 billion revolving credit facility and commercial paper program. NBCUniversal Media Parent does not guarantee the NBCUniversal Enterprise senior notes, revolving credit facility or commercial paper program. Comcast Parent provides an unconditional guarantee of the Universal Studios Japan $3.5 billion term loans with a final maturity of March 2022. Comcast Parent also provides an unconditional subordinated guarantee of the $185 million principal amount currently outstanding of Comcast Holdings’ ZONES due October 2029. Neither CCCL Parent nor NBCUniversal Media Parent guarantee the Comcast Holdings’ ZONES due October 2029. None of Comcast Parent, CCCL Parent nor NBCUniversal Media Parent guarantee the $62 million principal amount currently outstanding of Comcast Holdings’ ZONES due November 2029 or the Universal Beijing Resort term loans. Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 22,135 $ — $ 22,135 Management fee revenue 299 — 294 — — (593 ) — Total revenue 299 — 294 — 22,135 (593 ) 22,135 Costs and Expenses: Programming and production — — — — 6,711 — 6,711 Other operating and administrative 208 — 294 230 6,305 (593 ) 6,444 Advertising, marketing and promotion — — — — 1,667 — 1,667 Depreciation 12 — — — 2,026 — 2,038 Amortization 1 — — — 579 — 580 Other operating gains — — — — (141 ) — (141 ) Total cost and expenses 221 — 294 230 17,147 (593 ) 17,299 Operating income (loss) 78 — — (230 ) 4,988 — 4,836 Interest expense (600 ) (3 ) (48 ) (113 ) (66 ) — (830 ) Investment and other income (loss), net 3,299 3,380 3,007 1,576 1,065 (12,438 ) (111 ) Income (loss) before income taxes 2,777 3,377 2,959 1,233 5,987 (12,438 ) 3,895 Income tax (expense) benefit 109 (1 ) 10 (2 ) (1,115 ) — (999 ) Net income (loss) 2,886 3,376 2,969 1,231 4,872 (12,438 ) 2,896 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 10 — 10 Net income (loss) attributable to Comcast Corporation $ 2,886 $ 3,376 $ 2,969 $ 1,231 $ 4,862 $ (12,438 ) $ 2,886 Comprehensive income (loss) attributable to Comcast Corporation $ 2,799 $ 3,349 $ 2,974 $ 1,112 $ 4,663 $ (12,098 ) $ 2,799 Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 21,081 $ — $ 21,081 Management fee revenue 285 — 280 — — (565 ) — Total revenue 285 — 280 — 21,081 (565 ) 21,081 Costs and Expenses: Programming and production — — — — 6,059 — 6,059 Other operating and administrative 183 — 280 277 6,360 (565 ) 6,535 Advertising, marketing and promotion — — — — 1,604 — 1,604 Depreciation 7 — — — 1,984 — 1,991 Amortization 1 — — — 554 — 555 Other operating gains — — — — (442 ) — (442 ) Total cost and expenses 191 — 280 277 16,119 (565 ) 16,302 Operating income (loss) 94 — — (277 ) 4,962 — 4,779 Interest expense (544 ) (3 ) (48 ) (116 ) (55 ) — (766 ) Investment and other income (loss), net 2,934 2,513 1,995 2,206 1,845 (11,423 ) 70 Income (loss) before income taxes 2,484 2,510 1,947 1,813 6,752 (11,423 ) 4,083 Income tax (expense) benefit 158 (10 ) 17 (6 ) (1,568 ) — (1,409 ) Net income (loss) 2,642 2,500 1,964 1,807 5,184 (11,423 ) 2,674 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 32 — 32 Net income (loss) attributable to Comcast Corporation $ 2,642 $ 2,500 $ 1,964 $ 1,807 $ 5,152 $ (11,423 ) $ 2,642 Comprehensive income (loss) attributable to Comcast Corporation $ 2,595 $ 2,484 $ 1,968 $ 1,722 $ 5,024 $ (11,198 ) $ 2,595 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 66,661 $ — $ 66,661 Management fee revenue 889 — 873 — — (1,762 ) — Total revenue 889 — 873 — 66,661 (1,762 ) 66,661 Costs and Expenses: Programming and production — — — — 20,440 — 20,440 Other operating and administrative 626 — 873 772 18,814 (1,762 ) 19,323 Advertising, marketing and promotion — — — — 4,924 — 4,924 Depreciation 34 — — — 6,036 — 6,070 Amortization 4 — — — 1,746 — 1,750 Other operating gains — — — — (341 ) — (341 ) Total cost and expenses 664 — 873 772 51,619 (1,762 ) 52,166 Operating income (loss) 225 — — (772 ) 15,042 — 14,495 Interest expense (1,739 ) (9 ) (143 ) (332 ) (190 ) — (2,413 ) Investment and other income (loss), net 10,416 10,279 8,832 5,107 3,977 (38,519 ) 92 Income (loss) before income taxes 8,902 10,270 8,689 4,003 18,829 (38,519 ) 12,174 Income tax (expense) benefit 318 — 29 (12 ) (3,229 ) — (2,894 ) Net income (loss) 9,220 10,270 8,718 3,991 15,600 (38,519 ) 9,280 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 60 — 60 Net income (loss) attributable to Comcast Corporation $ 9,220 $ 10,270 $ 8,718 $ 3,991 $ 15,540 $ (38,519 ) $ 9,220 Comprehensive income (loss) attributable to Comcast Corporation $ 9,139 $ 10,245 $ 8,723 $ 3,877 $ 15,357 $ (38,202 ) $ 9,139 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 62,954 $ — $ 62,954 Management fee revenue 841 — 827 — — (1,668 ) — Total revenue 841 — 827 — 62,954 (1,668 ) 62,954 Costs and Expenses: Programming and production — — — — 18,450 — 18,450 Other operating and administrative 553 — 827 844 18,086 (1,668 ) 18,642 Advertising, marketing and promotion — — — — 4,894 — 4,894 Depreciation 21 — — — 5,855 — 5,876 Amortization 4 — — — 1,641 — 1,645 Other operating gains — — — — (442 ) — (442 ) Total costs and expenses 578 — 827 844 48,484 (1,668 ) 49,065 Operating income (loss) 263 — — (844 ) 14,470 — 13,889 Interest expense (1,592 ) (9 ) (159 ) (344 ) (175 ) — (2,279 ) Investment and other income (loss), net 8,600 7,841 6,628 5,493 4,476 (32,739 ) 299 Income (loss) before income taxes 7,271 7,832 6,469 4,305 18,771 (32,739 ) 11,909 Income tax (expense) benefit 465 (26 ) 56 (17 ) (4,516 ) — (4,038 ) Net income (loss) 7,736 7,806 6,525 4,288 14,255 (32,739 ) 7,871 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 135 — 135 Net income (loss) attributable to Comcast Corporation $ 7,736 $ 7,806 $ 6,525 $ 4,288 $ 14,120 $ (32,739 ) $ 7,736 Comprehensive income (loss) attributable to Comcast Corporation $ 7,825 $ 7,804 $ 6,531 $ 4,253 $ 13,993 $ (32,581 ) $ 7,825 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (1,461 ) $ 137 $ (206 ) $ (1,047 ) $ 21,084 $ — $ 18,507 Investing Activities: Net transactions with affiliates (1,087 ) (586 ) 206 800 667 — — Capital expenditures (15 ) — — — (6,592 ) — (6,607 ) Cash paid for intangible assets (3 ) — — — (1,372 ) — (1,375 ) Acquisitions and construction of real estate properties (94 ) — — — (35 ) — (129 ) Construction of Universal Beijing Resort — — — — (257 ) — (257 ) Acquisitions, net of cash acquired — — — — (88 ) — (88 ) Proceeds from sales of investments — — — 67 60 — 127 Purchases of investments (118 ) — — (50 ) (672 ) — (840 ) Other — 449 — — 130 — 579 Net cash provided by (used in) investing activities (1,317 ) (137 ) 206 817 (8,159 ) — (8,590 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net 2,117 — — — 792 — 2,909 Proceeds from borrowings 9,386 — — — 464 — 9,850 Repurchases and repayments of debt (1,900 ) — — (3 ) (2,502 ) — (4,405 ) Repurchases of common stock under repurchase program and employee plans (4,282 ) — — — — — (4,282 ) Dividends paid (2,487 ) — — — — — (2,487 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (209 ) — (209 ) Other (56 ) — — — (186 ) — (242 ) Net cash provided by (used in) financing activities 2,778 — — (3 ) (1,641 ) — 1,134 Increase (decrease) in cash, cash equivalents and restricted cash — — — (233 ) 11,284 — 11,051 Cash, cash equivalents and restricted cash, beginning of period — — — 496 3,075 — 3,571 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 263 $ 14,359 $ — $ 14,622 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (931 ) $ 91 $ (233 ) $ (1,055 ) $ 17,985 $ — $ 15,857 Investing Activities: Net transactions with affiliates 4,216 (91 ) 818 833 (5,776 ) — — Capital expenditures (6 ) — — — (6,833 ) — (6,839 ) Cash paid for intangible assets (2 ) — — — (1,134 ) — (1,136 ) Acquisitions and construction of real estate properties (190 ) — — — (135 ) — (325 ) Construction of Universal Beijing Resort — — — — (47 ) — (47 ) Acquisitions, net of cash acquired — — — — (429 ) — (429 ) Proceeds from sales of investments — — — 10 110 — 120 Purchases of investments (56 ) — (35 ) (57 ) (1,916 ) — (2,064 ) Other 101 — — 49 647 — 797 Net cash provided by (used in) investing activities 4,063 (91 ) 783 835 (15,513 ) — (9,923 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (1,068 ) — (2,807 ) Proceeds from borrowings 5,997 — — — 5,463 — 11,460 Repurchases and repayments of debt (1,000 ) — (550 ) (3 ) (3,468 ) — (5,021 ) Repurchases of common stock under repurchase program and employee plans (4,212 ) — — — — — (4,212 ) Dividends paid (2,147 ) — — — — — (2,147 ) Purchase of Universal Studios Japan noncontrolling interests — — — — (2,299 ) — (2,299 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (198 ) — (198 ) Other (31 ) — — — 134 — 103 Net cash provided by (used in) financing activities (3,132 ) — (550 ) (3 ) (1,436 ) — (5,121 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — (223 ) 1,036 — 813 Cash, cash equivalents and restricted cash, beginning of period — — — 482 2,933 — 3,415 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 259 $ 3,969 $ — $ 4,228 Condensed Consolidating Balance Sheet September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 263 $ 10,353 $ — $ 10,616 Receivables, net — — — — 8,983 — 8,983 Programming rights — — — — 1,223 — 1,223 Other current assets 58 8 — 34 2,284 — 2,384 Total current assets 58 8 — 297 22,843 — 23,206 Film and television costs — — — — 7,377 — 7,377 Investments 267 11 122 790 6,534 — 7,724 Investments in and amounts due from subsidiaries eliminated upon consolidation 129,360 146,297 132,562 53,078 103,526 (564,823 ) — Property and equipment, net 649 — — — 39,206 — 39,855 Franchise rights — — — — 59,365 — 59,365 Goodwill — — — — 36,703 — 36,703 Other intangible assets, net 11 — — — 18,638 — 18,649 Other noncurrent assets, net 782 230 — 95 6,884 (235 ) 7,756 Total assets $ 131,127 $ 146,546 $ 132,684 $ 54,260 $ 301,076 $ (565,058 ) $ 200,635 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 13 $ — $ — $ — $ 7,023 $ — $ 7,036 Accrued participations and residuals — — — — 1,809 — 1,809 Deferred revenue — — — — 1,633 — 1,633 Accrued expenses and other current liabilities 1,852 150 231 346 3,397 — 5,976 Current portion of long-term debt 699 — — 4 2,470 — 3,173 Total current liabilities 2,564 150 231 350 16,332 — 19,627 Long-term debt, less current portion 54,120 144 2,100 7,748 5,599 — 69,711 Deferred income taxes — 330 — 68 25,070 (301 ) 25,167 Other noncurrent liabilities 2,920 — — 1,225 8,257 66 12,468 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,317 — 1,317 Equity: Common stock 54 — — — — — 54 Other shareholders’ equity 71,469 145,922 130,353 44,869 243,679 (564,823 ) 71,469 Total Comcast Corporation shareholders’ equity 71,523 145,922 130,353 44,869 243,679 (564,823 ) 71,523 Noncontrolling interests — — — — 822 — 822 Total equity 71,523 145,922 130,353 44,869 244,501 (564,823 ) 72,345 Total liabilities and equity $ 131,127 $ 146,546 $ 132,684 $ 54,260 $ 301,076 $ (565,058 ) $ 200,635 Condensed Consolidating Balance Sheet December 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 496 $ 2,932 $ — $ 3,428 Receivables, net — — — — 8,834 — 8,834 Programming rights — — — — 1,613 — 1,613 Other current assets 60 — 7 25 2,376 — 2,468 Total current assets 60 — 7 521 15,755 — 16,343 Film and television costs — — — — 7,087 — 7,087 Investments 146 21 108 693 5,963 — 6,931 Investments in and amounts due from subsidiaries eliminated upon consolidation 117,164 142,519 139,528 50,102 113,332 (562,645 ) — Property and equipment, net 551 — — — 37,919 — 38,470 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 36,780 — 36,780 Other intangible assets, net 12 — — — 18,121 — 18,133 Other noncurrent assets, net 435 708 — 88 3,437 (314 ) 4,354 Total assets $ 118,368 $ 143,248 $ 139,643 $ 51,404 $ 297,758 $ (562,959 ) $ 187,462 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 16 $ — $ — $ — $ 6,892 $ — $ 6,908 Accrued participations and residuals — — — — 1,644 — 1,644 Deferred revenue — — — — 1,687 — 1,687 Accrued expenses and other current liabilities 1,888 92 333 326 3,981 — 6,620 Current portion of long-term debt 2,810 — — 4 2,320 — 5,134 Total current liabilities 4,714 92 333 330 16,524 — 21,993 Long-term debt, less current portion 42,428 140 2,100 7,751 7,003 — 59,422 Deferred income taxes — 285 — 67 24,250 (343 ) 24,259 Other noncurrent liabilities 2,610 — — 1,128 7,205 29 10,972 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,357 — 1,357 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 68,561 142,731 137,210 42,128 240,576 (562,645 ) 68,561 Total Comcast Corporation shareholders’ equity 68,616 142,731 137,210 42,128 240,576 (562,645 ) 68,616 Noncontrolling interests — — — — 843 — 843 Total equity 68,616 142,731 137,210 42,128 241,419 (562,645 ) 69,459 Total liabilities and equity $ 118,368 $ 143,248 $ 139,643 $ 51,404 $ 297,758 $ (562,959 ) $ 187,462

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements and Tax Reform (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Line Items]
Basis of Presentation	We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2017 Annual Report on Form 10-K and the footnotes within this Form 10-Q.
Revenue Recognition	Cable Communications Segment Residential Our Cable Communications segment generates revenue from residential customers subscribing to our video, high-speed Internet, voice, and security and automation services, which we market individually and as bundled services at a discounted rate in the United States. Revenue from residential customers that purchase bundled services at a discounted rate is allocated between the separate services based on the respective stand-alone selling prices. The stand-alone selling prices are determined based on the current prices at which we separately sell the cable services. Significant judgment is used to determine performance obligations that should be accounted for separately and the allocation of revenue when services are combined in a bundle. Revenue related to our security and automation services is reported in other revenue. We recognize revenue from residential cable services as the services are provided on a monthly basis. Subscription rates and related charges vary according to the services and features customers receive. Customers are typically billed in advance and pay on a monthly basis. Installation fees are deferred and recognized as revenue over the period of benefit to the customer, which is less than a year for residential customers. While a portion of our residential customers are subject to contracts for their cable services, which are typically 2 years in length, based on our evaluation of the terms of these contracts, we recognize revenue for these cable services on a basis that is consistent with our customers that are not subject to contracts. Our cable services generally involve customer premise equipment, such as set-top boxes, cable modems and wireless gateways. The timing and pattern of recognition for customer premise equipment revenue are consistent with those of our residential cable services. Sales commissions related to our residential customers are expensed as incurred, as the related period of benefit is less than a year. Under the terms of our cable franchise agreements, we are generally required to pay the cable franchising authority an amount based on our gross video revenue. We generally pass these and other similar fees through to our cable services customers and classify these fees in the respective cable service revenue, with the corresponding costs included in other operating and administrative expenses. Business Services Our Cable Communications segment generates revenue from business customers subscribing to a variety of products and services. Our small business services offerings primarily include high-speed Internet services, as well as voice and video services, similar to those that we provide to our residential customers, and also include cloud-based solutions that provide file sharing, online backup and web conferencing, among other features. We also offer Ethernet network services that connect multiple locations and provide higher downstream and upstream speed options to medium-sized customers and larger enterprises, as well as advanced voice services. In addition, we provide cellular backhaul services to mobile network operators to help these customers manage their network bandwidth. Recently, we have expanded our enterprise service offerings to include a software-defined networking product and our managed solutions business to offer enterprise customers support related to Wi-Fi networks, router management, network security, business continuity risks and other services. We primarily offer our enterprise service offerings to Fortune 1000 companies and other large enterprises with multiple locations both within and outside of our cable distribution footprint where we have agreements with other companies to use their networks to provide coverage. We recognize revenue from business services as the services are provided on a monthly basis. Substantially all of our business customers are initially under contracts, with terms typically ranging from 2 years for small and medium-sized businesses to up to 5 years for larger enterprises. At any given time, the amount of future revenue to be earned related to fixed pricing under existing agreements is equal to approximately half of our annual business services revenue, of which the substantial majority will be recognized within 2 years. Customers with contracts may only discontinue service in accordance with the terms of their contracts. We receive payments from business customers based on a billing schedule established in our contracts, which is typically on a monthly basis. Installation revenue related to our business services customers and sales commissions are generally deferred and recognized over the respective contract terms. Advertising Our Cable Communications segment generates revenue from the sale of advertising and from our advanced advertising business. As part of our distribution agreements with cable networks, we generally receive an allocation of scheduled advertising time on cable networks that we sell to local, regional and national advertisers. In most cases, the available advertising units are sold by our sales force. We also represent the advertising sales efforts of other multichannel video providers in some markets. Since we are acting as the principal in these arrangements, we record the advertising that is sold in advertising revenue and the fees paid to multichannel video providers in other operating and administrative expenses. In some cases, we work with representation firms as an extension of our sales force to sell a portion of the advertising units allocated to us and record the revenue net of agency commissions. In addition, we generate revenue from the sale of advertising online and on our On Demand service. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms and conditions are agreed upon. Advertising revenue is recognized in the period in which advertisements are aired or viewed. Payment terms vary by contract, although terms generally require payment within 30 to 60 days from when advertisements are aired or viewed. Our advanced advertising business provide technology, tools, marketplace solutions and data-driven insights to various customers in the media industry to more effectively engage with their targeted audiences. Revenue earned from our advanced advertising business is recognized when services are provided. NBCUniversal Segments Distribution Our Cable Networks segment generates distribution revenue from the distribution of our cable network programming to traditional and virtual multichannel video providers. Our Broadcast Television segment generates distribution revenue from the fees received under retransmission consent agreements and associated fees received from NBC-affiliated local broadcast television stations. Distribution revenue is recognized as programming is provided on a monthly basis, generally under multiyear agreements. Monthly fees received under distribution agreements with multichannel video providers are generally based on the number of subscribers. Payment terms and conditions vary by contract type, although terms generally include payment within 30 to 60 days. Advertising Our Cable Networks and Broadcast Television segments generate advertising revenue from the sale of advertising on our cable and broadcast networks, our owned local broadcast television stations, and various digital properties. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms are agreed upon. Advertising revenue is recognized, net of agency commissions, in the period in which advertisements are aired or viewed and payment occurs thereafter, generally within 30 days. In some instances, we guarantee audience ratings for the advertisements. To the extent there is a shortfall in contracts where the ratings were guaranteed, a portion of the revenue is deferred until the shortfall is settled, typically by providing additional advertising units generally within one year of the original airing. Theatrical Our Filmed Entertainment segment theatrical revenue is generated from the worldwide theatrical release of our produced and acquired films for exhibition in movie theaters and is affected by the timing, nature and number of films released in movie theaters and their acceptance by audiences. Theatrical revenue is also affected by the number of exhibition screens, ticket prices, the percentage of ticket sale retention by the exhibitors and the popularity of competing films at the time our films are released. We recognize theatrical revenue as the films are viewed and exhibited in theaters and payment generally occurs within 60 days after exhibition. Content Licensing Our Cable Networks, Broadcast Television and Filmed Entertainment segments generate revenue from the licensing of our owned film and television content in the United States and internationally to cable, broadcast and premium networks and subscription video on demand services. Our content licensing agreements generally include fixed pricing and span multiple years. For example, following a film’s theatrical release, our Filmed Entertainment segment may license the exhibition rights of a film to different customers over multiple successive distribution windows. We recognize revenue when the content is delivered and available for use by the licensee. When the term of an existing agreement is renewed or extended, we recognize revenue at the later of when the content is available or when the renewal or extension period begins. Payment terms and conditions vary by contract type, although payments are generally collected over the license term. The amount of future revenue to be earned related to fixed pricing under existing agreements primarily relates to our Filmed Entertainment segment, which at any given time equals approximately 1 to 2 years of our annual Filmed Entertainment content licensing revenue. The substantial majority of this revenue will be recognized within 2 years. This amount may fluctuate from period to period depending on the timing of the release and the availability of content under existing agreements and may not represent the total content licensing revenue expected to be recognized as it does not include revenue from future agreements or from variable pricing or optional purchases under existing agreements. For our content licensing agreements that include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service sold by our customers, we generally recognize revenue as our customers sell to their subscribers. Home Entertainment Our Filmed Entertainment segment generates revenue from the sale of our produced and acquired films on standard-definition digital video discs and Blu-ray discs (together, “DVDs”) and through digital distribution services. Our Cable Networks and Broadcast Television networks also generate revenue from the sale of owned programming on DVDs and through digital distribution services, which is reported in other revenue. We recognize revenue from DVD sales, net of estimated returns and customer incentives, on the date that DVDs are delivered to and made available for sale by retailers. Payment terms generally include payment within 60 to 90 days from delivery to the retailer. Theme Parks Our Theme Parks segment generates revenue primarily from ticket sales and guest spending at our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. Guest spending includes in-park spending on food, beverages and merchandise. We recognize revenue from theme park ticket sales when the tickets are used, generally within a year from the date of purchase. For annual passes, we generally recognize revenue on a straight-line basis over the period the pass is available to be used. We recognize revenue from guest spending at the point of sale.
Recent Accounting Pronouncements	Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) updated the accounting guidance related to revenue recognition. The updated accounting guidance provides a single, contract-based revenue recognition model to help improve financial reporting by providing clearer guidance on when an entity should recognize revenue and by reducing the number of standards to which an entity has to refer. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. We adopted the updated guidance on January 1, 2018 on a full retrospective basis, which required us to reflect the impact of the updated guidance for all periods presented. Upon adoption, we also implemented changes in our presentation of certain revenues and expenses, primarily in our Cable Communications segment. The adoption of the new standard did not have a material impact on our consolidated results of operations or financial position for any period presented. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions (see Note 3). The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 20,983 $ 98 $ 21,081 $ 62,611 $ 343 $ 62,954 Total costs and expenses $ 16,191 $ 111 $ 16,302 $ 48,731 $ 334 $ 49,065 Operating income $ 4,792 $ (13 ) $ 4,779 $ 13,880 $ 9 $ 13,889 Net income attributable to Comcast Corporation $ 2,650 $ (8 ) $ 2,642 $ 7,729 $ 7 $ 7,736 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 16,060 $ 283 $ 16,343 Film and television costs $ 7,076 $ 11 $ 7,087 Other intangible assets, net $ 18,779 $ (646 ) $ 18,133 Other noncurrent assets, net $ 3,489 $ 865 $ 4,354 Total assets $ 186,949 $ 513 $ 187,462 Total current liabilities $ 21,561 $ 432 $ 21,993 Deferred income taxes $ 24,256 $ 3 $ 24,259 Other noncurrent liabilities $ 10,904 $ 68 $ 10,972 Total equity $ 69,449 $ 10 $ 69,459 Total liabilities and equity $ 186,949 $ 513 $ 187,462 Cable Communications A summary of the changes implemented for the Cable Communications segment is presented below. Changes to Presentation of Revenue and Related Costs • Revenue from our residential video services decreased with corresponding increases to high-speed Internet and voice revenue due to a change in the allocation of revenue among our cable services included in a bundle that our residential customers purchase at a discount. • Revenue from franchise and other regulatory fees, which was previously presented in other revenue, is now presented with the corresponding cable services. This resulted in increases to video, voice and business services revenue. • Residential customer late fees are now presented in other revenue. These fees were previously presented as a reduction to other operating costs and expenses. • Certain costs, including costs related to the fulfillment of contracts with customers, are now presented as other assets and the related costs are recognized over time in operating costs and expenses, which are comprised of total costs and expenses, excluding depreciation and amortization expense and other operating gains. These amounts were previously presented as intangible assets, and the expenses were previously presented in amortization expense. The payments related to these assets are now presented in net cash provided by operating activities rather than in cash paid for intangible assets in our consolidated statement of cash flows. Changes to the Timing of Recognition of Revenue and Related Costs • Installation revenue and commission expense are now recognized as revenue and operating costs and expenses, respectively, over a period of time rather than recognized immediately as they were previously. We recorded a deferred revenue liability related to upfront installation fees that are not distinct services, which required us to allocate the installation fees to the respective service. The installation fees are generally recognized as revenue over the period that the fee would influence a customer to renew their service. This period is less than a year for residential customers and the term of the related contract for business services customers. Incremental costs to obtain a contract with a customer, such as commissions for our business customers, are now deferred and recognized over the contract term. Sales commissions related to our residential customers are expensed as incurred as the related period of benefit is less than a year. The table below presents the effects these changes had on our Cable Communications segment revenue, operating costs and expenses, and depreciation and amortization expense as a result of the updated guidance for the prior year periods. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,825 $ (65 ) $ 5,760 $ 17,396 $ (190 ) $ 17,206 High-speed Internet 3,709 233 3,942 10,994 688 11,682 Voice 840 173 1,013 2,559 522 3,081 Business services 1,575 54 1,629 4,596 161 4,757 Advertising 542 52 594 1,628 146 1,774 Other 712 (311 ) 401 2,064 (918 ) 1,146 Total Cable Communications revenue $ 13,203 $ 136 $ 13,339 $ 39,237 $ 409 $ 39,646 Operating costs and expenses $ 7,957 $ 166 $ 8,123 $ 23,473 $ 490 $ 23,963 Depreciation and amortization expense $ 2,049 $ (34 ) $ 2,015 $ 6,030 $ (102 ) $ 5,928 NBCUniversal Segments The adoption of the updated guidance impacted the timing of recognition for some of our revenue contracts, primarily for content licensing agreements. As a result of the adoption of the updated guidance, when the term of existing content licensing agreements is renewed or extended, revenue is not recognized until the date when the renewal or extension period begins. Under the prior guidance, revenue for the content licensing renewal period was recognized on the date that the renewal was agreed to contractually. This change resulted in delayed revenue recognition for content licensing renewals or extensions in our Cable Networks, Broadcast Television and Filmed Entertainment segments. This change also impacted the timing of the related amortization of our film and television costs and participations and residuals expenses. The adoption of the updated guidance did not have a material impact on the results of operations or financial position for the NBCUniversal segments. Financial Assets and Financial Liabilities In January 2016, the FASB updated the accounting guidance related to the recognition and measurement of financial assets and financial liabilities. The updated accounting guidance, among other things, requires that all nonconsolidated equity investments, except those accounted for under the equity method, be measured at fair value and the changes in fair value be recognized in net income. On January 1, 2018, we adopted the updated guidance prospectively along with a related clarifying update and as a result, we recorded an immaterial cumulative effect adjustment to retained earnings, accumulated other comprehensive income (loss) and investments. See Note 9 for further information. Tax Reform On December 22, 2017, new federal tax reform legislation was enacted in the United States (“2017 Tax Act”), resulting in significant changes from previous tax law. The new legislation reduced the federal corporate income tax rate to 21% from 35% effective January 1, 2018. In the fourth quarter of 2017, we recorded a net income tax benefit of approximately $12.7 billion on the date of enactment of the new legislation, primarily relating to a reduction of our net deferred tax liabilities as a result of the rate change. This amount also includes the reversal of our net deferred tax liabilities related to cumulative undistributed foreign earnings and deferred tax assets for related foreign tax credits, partially offset by the one-time deemed repatriation tax on undistributed foreign earnings and profits. The adjustments to deferred tax assets and liabilities, and the liability related to the transition tax, are provisional amounts based on information available as of September 30, 2018. These amounts are subject to change as we obtain information necessary to complete the calculations. During the nine months ended September 30, 2018 , we recorded immaterial adjustments to the provisional amounts related to the cumulative temporary differences and the one-time deemed repatriation tax on undistributed foreign earnings and profits. We expect to complete our analysis of the provisional items in the fourth quarter of 2018. In February 2018, the FASB issued guidance that permits companies to reclassify disproportionate tax effects recorded in accumulated other comprehensive income as a result of the 2017 Tax Act to retained earnings. We adopted the guidance as of January 1, 2018 and, as a result, we recorded an immaterial cumulative effect adjustment to retained earnings and accumulated other comprehensive income (loss). In February 2018, the Bipartisan Budget Act of 2018 was enacted. As part of this legislation, various tax provisions that had expired on December 31, 2016 were retroactively extended to December 31, 2017, including the statute permitting the immediate deduction for certain film and television production costs. We recorded an income tax benefit of $128 million in the first quarter of 2018 as a result of the enactment of this legislation. Restricted Cash In November 2016, the FASB updated the accounting guidance related to restricted cash. The new standard requires that the statement of cash flows present the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents, and a reconciliation of such total to amounts on the balance sheet. We adopted the updated guidance on January 1, 2018 and as required applied the retrospective transition method. The adoption did not have a material impact for any period presented. Leases In February 2016, the FASB updated the accounting guidance related to leases. The updated accounting guidance requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet for all leases with the exception of short-term leases. The asset and liability are initially measured based on the present value of committed lease payments. For a lessee, the recognition, measurement and presentation of expenses and cash flows arising from a lease do not significantly change from previous guidance. For a lessor, the accounting applied is also largely unchanged from previous guidance. We will adopt the updated accounting guidance in the first quarter of 2019 and prior periods will not be adjusted. We are currently in the process of determining the impact that the updated accounting guidance will have on our consolidated financial statements.
Investments	Nonmarketable Equity Securities We classify investments without readily determinable fair values that are not accounted for under the equity method as nonmarketable equity securities. The accounting guidance requires nonmarketable equity securities to be recorded at cost and adjusted to fair value at each reporting period. However, the guidance allows for a measurement alternative, which is to record the investments at cost, less impairment, if any, and subsequently adjust for observable price changes of identical or similar investments of the same issuer. We apply this measurement alternative to a majority of our nonmarketable equity securities. When an observable event occurs, we estimate the fair values of our nonmarketable equity securities based on Level 2 inputs that are derived from observable price changes of similar securities adjusted for insignificant differences in rights and obligations. The changes in value are recorded in realized and unrealized gains (losses) on equity securities, net. Marketable Equity Securities We classify publicly traded investments with readily determinable fair values that are not accounted for under the equity method as marketable equity securities. Marketable equity securities are recorded at cost and adjusted to fair value at each reporting period. The changes in fair value between measurement dates are recorded in realized and unrealized gains (losses) on equity securities, net. The fair values of our marketable equity securities are based on Level 1 inputs that use quoted market prices.
NBCUniversal Media LLC [Member]
Accounting Policies [Line Items]
Basis of Presentation	Unless indicated otherwise, throughout these notes to the condensed consolidated financial statements, we refer to NBCUniversal and its consolidated subsidiaries as “we,” “us” and “our.” We have prepared these unaudited condensed consolidated financial statements based on SEC rules that permit reduced disclosure for interim periods. These financial statements include all adjustments that are necessary for a fair presentation of our consolidated results of operations, cash flows and financial condition for the periods shown, including normal, recurring accruals and other items. The consolidated results of operations for the interim periods presented are not necessarily indicative of results for the full year. The year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles in the United States (“GAAP”). For a more complete discussion of our accounting policies and certain other information, refer to our consolidated financial statements included in our 2017 Annual Report on Form 10-K and the footnotes within this Form 10-Q.
Revenue Recognition	Distribution Our Cable Networks segment generates distribution revenue from the distribution of our cable network programming to traditional and virtual multichannel video providers. Our Broadcast Television segment generates distribution revenue from the fees received under retransmission consent agreements and associated fees received from NBC-affiliated local broadcast television stations. Distribution revenue is recognized as programming is provided on a monthly basis, generally under multiyear agreements. Monthly fees received under distribution agreements with multichannel video providers are generally based on the number of subscribers. Payment terms and conditions vary by contract type, although terms generally include payment within 30 to 60 days. Advertising Our Cable Networks and Broadcast Television segments generate advertising revenue from the sale of advertising on our cable and broadcast networks, our owned local broadcast television stations, and various digital properties. We enter into advertising arrangements with customers and have determined that a contract exists once all terms and conditions are agreed upon, typically when the number of advertising units is specifically identified and the timing of airing is scheduled. Advertisements are generally aired or viewed within one year once all terms are agreed upon. Advertising revenue is recognized, net of agency commissions, in the period in which advertisements are aired or viewed and payment occurs thereafter, generally within 30 days. In some instances, we guarantee audience ratings for the advertisements. To the extent there is a shortfall in contracts where the ratings were guaranteed, a portion of the revenue is deferred until the shortfall is settled, typically by providing additional advertising units generally within one year of the original airing. Theatrical Our Filmed Entertainment segment theatrical revenue is generated from the worldwide theatrical release of our produced and acquired films for exhibition in movie theaters and is affected by the timing, nature and number of films released in movie theaters and their acceptance by audiences. Theatrical revenue is also affected by the number of exhibition screens, ticket prices, the percentage of ticket sale retention by the exhibitors and the popularity of competing films at the time our films are released. We recognize theatrical revenue as the films are viewed and exhibited in theaters and payment generally occurs within 60 days after exhibition. Content Licensing Our Cable Networks, Broadcast Television and Filmed Entertainment segments generate revenue from the licensing of our owned film and television content in the United States and internationally to cable, broadcast and premium networks and subscription video on demand services. Our content licensing agreements generally include fixed pricing and span multiple years. For example, following a film’s theatrical release, our Filmed Entertainment segment may license the exhibition rights of a film to different customers over multiple successive distribution windows. We recognize revenue when the content is delivered and available for use by the licensee. When the term of an existing agreement is renewed or extended, we recognize revenue at the later of when the content is available or when the renewal or extension period begins. Payment terms and conditions vary by contract type, although payments are generally collected over the license term. The amount of future revenue to be earned related to fixed pricing under existing agreements primarily relates to our Filmed Entertainment segment, which at any given time equals approximately 1 to 2 years of our annual Filmed Entertainment content licensing revenue. The substantial majority of this revenue will be recognized within 2 years. This amount may fluctuate from period to period depending on the timing of the release and the availability of content under existing agreements and may not represent the total content licensing revenue expected to be recognized as it does not include revenue from future agreements or from variable pricing or optional purchases under existing agreements. For our content licensing agreements that include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service sold by our customers, we generally recognize revenue as our customers sell to their subscribers. Home Entertainment Our Filmed Entertainment segment generates revenue from the sale of our produced and acquired films on standard-definition digital video discs and Blu-ray discs (together, “DVDs”) and through digital distribution services. Our Cable Networks and Broadcast Television networks also generate revenue from the sale of owned programming on DVDs and through digital distribution services, which is reported in other revenue. We recognize revenue from DVD sales, net of estimated returns and customer incentives, on the date that DVDs are delivered to and made available for sale by retailers. Payment terms generally include payment within 60 to 90 days from delivery to the retailer. Theme Parks Our Theme Parks segment generates revenue primarily from ticket sales and guest spending at our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. Guest spending includes in-park spending on food, beverages and merchandise. We recognize revenue from theme park ticket sales when the tickets are used, generally within a year from the date of purchase. For annual passes, we generally recognize revenue on a straight-line basis over the period the pass is available to be used. We recognize revenue from guest spending at the point of sale.
Recent Accounting Pronouncements	Revenue Recognition In May 2014, the Financial Accounting Standards Board (“FASB”) updated the accounting guidance related to revenue recognition. The updated accounting guidance provides a single, contract-based revenue recognition model to help improve financial reporting by providing clearer guidance on when an entity should recognize revenue and by reducing the number of standards to which an entity has to refer. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. We adopted the updated guidance on January 1, 2018 on a full retrospective basis, which required us to reflect the impact of the updated guidance for all periods presented. The adoption of the new standard did not have a material impact on our consolidated results of operations or financial position for any period presented. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions (see Note 3). The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 8,014 $ (38 ) $ 7,976 $ 24,213 $ (66 ) $ 24,147 Total costs and expenses $ 5,909 $ (20 ) $ 5,889 $ 19,048 $ (53 ) $ 18,995 Operating income $ 2,105 $ (18 ) $ 2,087 $ 5,165 $ (13 ) $ 5,152 Net income attributable to NBCUniversal $ 1,825 $ (18 ) $ 1,807 $ 4,301 $ (13 ) $ 4,288 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 11,673 $ 284 $ 11,957 Film and television costs $ 7,071 $ 11 $ 7,082 Other noncurrent assets, net $ 1,872 $ (68 ) $ 1,804 Total assets $ 71,073 $ 227 $ 71,300 Total current liabilities $ 9,602 $ 330 $ 9,932 Other noncurrent liabilities $ 4,109 $ 44 $ 4,153 Total equity $ 43,188 $ (147 ) $ 43,041 Total liabilities and equity $ 71,073 $ 227 $ 71,300 The adoption of the updated guidance impacted the timing of recognition for some of our revenue contracts, primarily for content licensing agreements. As a result of the adoption of the updated guidance, when the term of existing content licensing agreements is renewed or extended, revenue is not recognized until the date when the renewal or extension period begins. Under the prior guidance, revenue for the content licensing renewal period was recognized on the date that the renewal was agreed to contractually. This change resulted in delayed revenue recognition for content licensing renewals or extensions in our Cable Networks, Broadcast Television and Filmed Entertainment segments. This change also impacted the timing of the related amortization of our film and television costs and participations and residuals expenses. The adoption of the updated guidance did not have a material impact on the results of operations or financial position for our reportable segments. Financial Assets and Financial Liabilities In January 2016, the FASB updated the accounting guidance related to the recognition and measurement of financial assets and financial liabilities. The updated accounting guidance, among other things, requires that all nonconsolidated equity investments, except those accounted for under the equity method, be measured at fair value and the changes in fair value be recognized in net income. On January 1, 2018, we adopted the updated guidance prospectively along with a related clarifying update and as a result, we recorded a $232 million cumulative effect adjustment to member’s capital and accumulated other comprehensive income (loss). See Note 8 for further information. Restricted Cash In November 2016, the FASB updated the accounting guidance related to restricted cash. The new standard requires that the statement of cash flows present the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents, and a reconciliation of such total to amounts on the balance sheet. We adopted the updated guidance on January 1, 2018 and as required applied the retrospective transition method. The adoption did not have a material impact for any period presented. Leases In February 2016, the FASB updated the accounting guidance related to leases. The updated accounting guidance requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet for all leases with the exception of short-term leases. The asset and liability are initially measured based on the present value of committed lease payments. For a lessee, the recognition, measurement and presentation of expenses and cash flows arising from a lease do not significantly change from previous guidance. For a lessor, the accounting applied is also largely unchanged from previous guidance. We will adopt the updated accounting guidance in the first quarter of 2019 and prior periods will not be adjusted. We are currently in the process of determining the impact that the updated accounting guidance will have on our consolidated financial statements.
Investments	Marketable Equity Securities We classify publicly traded investments with readily determinable fair values that are not accounted for under the equity method as marketable equity securities. Marketable equity securities are recorded at cost and adjusted to fair value at each reporting period. The changes in fair value between measurement dates are recorded in realized and unrealized gains (losses) on equity securities, net. The fair values of our marketable equity securities are based on Level 1 inputs that use quoted market prices. Nonmarketable Equity Securities We classify investments without readily determinable fair values that are not accounted for under the equity method as nonmarketable equity securities. The accounting guidance requires nonmarketable equity securities to be recorded at cost and adjusted to fair value at each reporting period. However, the guidance allows for a measurement alternative, which is to record the investments at cost, less impairment, if any, and subsequently adjust for observable price changes of identical or similar investments of the same issuer. We apply this measurement alternative to our nonmarketable equity securities. When an observable event occurs, we estimate the fair values of our nonmarketable equity securities based on Level 2 inputs that are derived from observable price changes of similar securities adjusted for insignificant differences in rights and obligations. The changes in value are recorded in realized and unrealized gains (losses) on equity securities, net.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting Information [Line Items]
Financial Data by Business Segment	We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to Comcast Corporation excluded from Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Communications $ 13,787 $ 5,615 $ 2,071 $ 1,944 $ 353 NBCUniversal Cable Networks 2,884 968 180 11 6 Broadcast Television 2,452 321 32 37 — Filmed Entertainment 1,819 214 26 9 6 Theme Parks 1,528 725 170 269 23 Headquarters and Other (a) 15 (161 ) 106 79 43 Eliminations (b) (73 ) (1 ) — — — NBCUniversal 8,625 2,066 514 405 78 Corporate and Other (c) 276 (378 ) 33 35 14 Eliminations (b) (553 ) 10 — — — Comcast Consolidated $ 22,135 $ 7,313 $ 2,618 $ 2,384 $ 445 Three Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Communications $ 13,339 $ 5,216 $ 2,015 $ 2,061 $ 284 NBCUniversal Cable Networks 2,603 906 179 5 4 Broadcast Television 2,125 316 33 66 4 Filmed Entertainment 1,753 383 32 18 6 Theme Parks 1,550 775 166 199 18 Headquarters and Other (a) 15 (122 ) 97 66 37 Eliminations (b) (70 ) (1 ) — — — NBCUniversal 7,976 2,257 507 354 69 Corporate and Other (c) 266 (349 ) 24 19 12 Eliminations (b) (500 ) 9 — — — Comcast Consolidated $ 21,081 $ 7,133 $ 2,546 $ 2,434 $ 365 Nine Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 41,015 $ 16,668 $ 6,171 $ 5,398 $ 950 NBCUniversal Cable Networks (e) 8,994 3,422 548 22 15 Broadcast Television (e) 8,340 1,245 106 99 75 Filmed Entertainment 5,176 555 117 24 20 Theme Parks 4,170 1,789 492 811 158 Headquarters and Other (a) 44 (497 ) 314 179 106 Eliminations (b)(e) (256 ) (3 ) — — — NBCUniversal 26,468 6,511 1,577 1,135 374 Corporate and Other (c) 922 (1,167 ) 72 74 51 Eliminations (b)(e) (1,744 ) (38 ) — — — Comcast Consolidated $ 66,661 $ 21,974 $ 7,820 $ 6,607 $ 1,375 Nine Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 39,646 $ 15,683 $ 5,928 $ 5,798 $ 897 NBCUniversal Cable Networks 7,939 3,076 574 15 11 Broadcast Television 6,574 1,054 96 125 11 Filmed Entertainment 5,862 1,041 79 47 17 Theme Parks 3,982 1,723 494 671 57 Headquarters and Other (a) 32 (542 ) 292 119 101 Eliminations (b) (242 ) (2 ) — — — NBCUniversal 24,147 6,350 1,535 977 197 Corporate and Other (c) 679 (845 ) 58 64 42 Eliminations (b) (1,518 ) 30 — — — Comcast Consolidated $ 62,954 $ 21,218 $ 7,521 $ 6,839 $ 1,136 (a) NBCUniversal Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another. The most common types of transactions are the following: • our Cable Networks segment generates revenue by selling programming to our Cable Communications segment, which represents a substantial majority of the revenue elimination amount • our Broadcast Television segment generates revenue from the fees received under retransmission consent agreements with our Cable Communications segment • our Cable Communications segment generates revenue by selling advertising and by selling the use of satellite feeds to our Cable Networks segment • our Cable Networks and Broadcast Television segments generate revenue by selling advertising to our Cable Communications segment • our Filmed Entertainment and Broadcast Television segments generate revenue by licensing content to our Cable Networks segment; for segment reporting, this revenue is recognized as the programming rights asset for the licensed content is amortized based on third party revenue (c) Corporate and Other activities include costs associated with overhead and personnel, revenue and expenses associated with other business development initiatives, including our wireless phone service, and the operations of Comcast Spectacor, which owns the Philadelphia Flyers and the Wells Fargo Center arena in Philadelphia, Pennsylvania. (d) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to Comcast Corporation before net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock, income tax expense, investment and other income (loss), net, interest expense, depreciation and amortization expense, and other operating gains and losses (such as impairment charges related to fixed and intangible assets and gains or losses on the sale of long-lived assets), if any. From time to time we may exclude from Adjusted EBITDA the impact of certain events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 7,313 $ 7,133 $ 21,974 $ 21,218 Adjustment for legal settlement — (250 ) — (250 ) Depreciation (2,038 ) (1,991 ) (6,070 ) (5,876 ) Amortization (580 ) (555 ) (1,750 ) (1,645 ) Other operating gains 141 442 341 442 Interest expense (830 ) (766 ) (2,413 ) (2,279 ) Investment and other income (loss), net (111 ) 70 92 299 Income before income taxes $ 3,895 $ 4,083 $ 12,174 $ 11,909 (e) The revenue and operating costs and expenses associated with our broadcast of the 2018 PyeongChang Olympics were reported in our Cable Networks and Broadcast Television segments. The revenue and operating costs and expenses associated with our broadcast of the 2018 Super Bowl were reported in our Broadcast Television segment. Included in Eliminations are transactions relating to these events that our Broadcast Television and Cable Networks segments enter into with our other segments.
Reconciliation of Adjusted EBITDA from Segments to Consolidated	Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 7,313 $ 7,133 $ 21,974 $ 21,218 Adjustment for legal settlement — (250 ) — (250 ) Depreciation (2,038 ) (1,991 ) (6,070 ) (5,876 ) Amortization (580 ) (555 ) (1,750 ) (1,645 ) Other operating gains 141 442 341 442 Interest expense (830 ) (766 ) (2,413 ) (2,279 ) Investment and other income (loss), net (111 ) 70 92 299 Income before income taxes $ 3,895 $ 4,083 $ 12,174 $ 11,909
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Financial Data by Business Segment	We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to NBCUniversal excluded from Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Networks $ 2,884 $ 968 $ 180 $ 11 $ 6 Broadcast Television 2,452 321 32 37 — Filmed Entertainment 1,819 214 26 9 6 Theme Parks 1,528 725 170 269 23 Headquarters and Other (a) 15 (161 ) 106 79 43 Eliminations (b) (73 ) (1 ) — — — Total $ 8,625 $ 2,066 $ 514 $ 405 $ 78 Three Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Cash Paid for Intangible Assets Cable Networks $ 2,603 $ 906 $ 179 $ 5 $ 4 Broadcast Television 2,125 316 33 66 4 Filmed Entertainment 1,753 383 32 18 6 Theme Parks 1,550 775 166 199 18 Headquarters and Other (a) 15 (122 ) 97 66 37 Eliminations (b) (70 ) (1 ) — — — Total $ 7,976 $ 2,257 $ 507 $ 354 $ 69 Nine Months Ended September 30, 2018 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks (d) $ 8,994 $ 3,422 $ 548 $ 22 $ 15 Broadcast Television (d) 8,340 1,245 106 99 75 Filmed Entertainment 5,176 555 117 24 20 Theme Parks 4,170 1,789 492 811 158 Headquarters and Other (a) 44 (497 ) 314 179 106 Eliminations (b)(d) (256 ) (3 ) — — — Total $ 26,468 $ 6,511 $ 1,577 $ 1,135 $ 374 Nine Months Ended September 30, 2017 (in millions) Revenue Adjusted EBITDA (c) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 7,939 $ 3,076 $ 574 $ 15 $ 11 Broadcast Television 6,574 1,054 96 125 11 Filmed Entertainment 5,862 1,041 79 47 17 Theme Parks 3,982 1,723 494 671 57 Headquarters and Other (a) 32 (542 ) 292 119 101 Eliminations (b) (242 ) (2 ) — — — Total $ 24,147 $ 6,350 $ 1,535 $ 977 $ 197 (a) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another, which consisted primarily of the licensing of film and television content from our Filmed Entertainment and Broadcast Television segments to our Cable Networks segment; for segment reporting, this revenue is recognized as the programming rights asset for the licensed content is amortized based on third party revenue. (c) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to NBCUniversal before net income (loss) attributable to noncontrolling interests, income tax expense, investment and other income (loss), net, interest expense, depreciation and amortization expense, and other operating gains and losses (such as impairment charges related to fixed and intangible assets and gains or losses on the sale of long-lived assets), if any. From time to time we may exclude from Adjusted EBITDA the impact of certain events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 2,066 $ 2,257 $ 6,511 $ 6,350 Depreciation (250 ) (253 ) (750 ) (749 ) Amortization (264 ) (254 ) (827 ) (786 ) Other operating gains 141 337 141 337 Interest expense (134 ) (139 ) (394 ) (431 ) Investment and other income (loss), net (205 ) (26 ) (377 ) (42 ) Income before income taxes $ 1,354 $ 1,922 $ 4,304 $ 4,679 (d) The revenue and operating costs and expenses associated with our broadcast of the 2018 PyeongChang Olympics were reported in our Cable Networks and Broadcast Television segments. The revenue and operating costs and expenses associated with our broadcast of the 2018 Super Bowl were reported in our Broadcast Television segment. Included in Eliminations are transactions relating to these events that our Broadcast Television and Cable Networks segments enter into with our other segments.
Reconciliation of Adjusted EBITDA from Segments to Consolidated	Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Adjusted EBITDA $ 2,066 $ 2,257 $ 6,511 $ 6,350 Depreciation (250 ) (253 ) (750 ) (749 ) Amortization (264 ) (254 ) (827 ) (786 ) Other operating gains 141 337 141 337 Interest expense (134 ) (139 ) (394 ) (431 ) Investment and other income (loss), net (205 ) (26 ) (377 ) (42 ) Income before income taxes $ 1,354 $ 1,922 $ 4,304 $ 4,679

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue [Line Items]
Schedule of receivables, net	(in millions) September 30, December 31, Receivables, gross $ 9,300 $ 9,122 Less: Allowance for doubtful accounts 317 288 Receivables, net $ 8,983 $ 8,834
NBCUniversal Media LLC [Member]
Revenue [Line Items]
Schedule of receivables, net	(in millions) September 30, December 31, Receivables, gross $ 6,951 $ 7,055 Less: Allowance for doubtful accounts 100 88 Receivables, net $ 6,851 $ 6,967
Accounting Standards Update 2014-09 [Member]
Revenue [Line Items]
Disaggregation of revenue	Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Residential: Video $ 5,591 $ 5,760 $ 16,878 $ 17,206 High-Speed Internet 4,321 3,942 12,740 11,682 Voice 982 1,013 2,982 3,081 Business services 1,803 1,629 5,290 4,757 Advertising 684 594 1,932 1,774 Other 406 401 1,193 1,146 Total Cable Communications (a) 13,787 13,339 41,015 39,646 Distribution 1,680 1,533 5,251 4,645 Advertising 820 787 2,746 2,519 Content licensing and other 384 283 997 775 Total Cable Networks 2,884 2,603 8,994 7,939 Advertising 1,355 1,241 5,107 3,790 Content licensing 538 432 1,541 1,458 Distribution and other 559 452 1,692 1,326 Total Broadcast Television 2,452 2,125 8,340 6,574 Theatrical 601 515 1,564 2,003 Content licensing 719 662 2,100 2,080 Home entertainment 260 299 733 919 Other 239 277 779 860 Total Filmed Entertainment 1,819 1,753 5,176 5,862 Total Theme Parks 1,528 1,550 4,170 3,982 Headquarters and Other 15 15 44 32 Eliminations (b) (73 ) (70 ) (256 ) (242 ) Total NBCUniversal 8,625 7,976 26,468 24,147 Corporate and Other 276 266 922 679 Eliminations (b) (553 ) (500 ) (1,744 ) (1,518 ) Total revenue $ 22,135 $ 21,081 $ 66,661 $ 62,954 (a) For the three and nine months ended September 30, 2018 , 2.6% and 2.7% , respectively, of Cable Communications segment revenue was derived from franchise and other regulatory fees. For both the three and nine months ended September 30, 2017, 2.8% of Cable Communications segment revenue was derived from franchise and other regulatory fees. (b) Included in Eliminations are transactions that our segments enter into with one another. See Note 2 for a description of these transactions. We operate primarily in the United States, but also in select international markets, primarily in Europe and Asia. The table below summarizes revenue by geographic location. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 United States $ 20,244 $ 19,142 $ 61,060 $ 57,047 Foreign 1,891 1,939 5,601 5,907 Total revenue $ 22,135 $ 21,081 $ 66,661 $ 62,954
Other balance sheet accounts	(in millions) September 30, December 31, Noncurrent receivables, net (included in other noncurrent assets, net) $ 1,207 $ 1,184 Contract acquisition and fulfillment costs (included in other noncurrent assets, net) $ 928 $ 922 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 572 $ 497
Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
Revenue [Line Items]
Disaggregation of revenue	Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Distribution $ 1,680 $ 1,533 $ 5,251 $ 4,645 Advertising 820 787 2,746 2,519 Content licensing and other 384 283 997 775 Total Cable Networks 2,884 2,603 8,994 7,939 Advertising 1,355 1,241 5,107 3,790 Content licensing 538 432 1,541 1,458 Distribution and other 559 452 1,692 1,326 Total Broadcast Television 2,452 2,125 8,340 6,574 Theatrical 601 515 1,564 2,003 Content licensing 719 662 2,100 2,080 Home entertainment 260 299 733 919 Other 239 277 779 860 Total Filmed Entertainment 1,819 1,753 5,176 5,862 Total Theme Parks 1,528 1,550 4,170 3,982 Headquarters and Other 15 15 44 32 Eliminations (a) (73 ) (70 ) (256 ) (242 ) Total revenue $ 8,625 $ 7,976 $ 26,468 $ 24,147 (a) Included in Eliminations are transactions that our segments enter into with one another. See Note 2 for a description of these transactions. We operate primarily in the United States, but also in select international markets primarily in Europe and Asia. The table below summarizes revenue by geographic location. Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 United States $ 6,758 $ 6,088 $ 20,945 $ 18,344 Foreign 1,867 1,888 5,523 5,803 Total revenue $ 8,625 $ 7,976 $ 26,468 $ 24,147
Other balance sheet accounts	(in millions) September 30, December 31, Noncurrent receivables, net (included in other noncurrent assets, net) $ 1,098 $ 1,093 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 451 $ 392

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Computation of diluted EPS	Computation of Diluted EPS Three Months Ended September 30 2018 2017 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 2,886 4,564 $ 0.63 $ 2,642 4,698 $ 0.56 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 55 79 Diluted EPS attributable to Comcast Corporation shareholders $ 2,886 4,619 $ 0.62 $ 2,642 4,777 $ 0.55 Nine Months Ended September 30 2018 2017 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 9,220 4,599 $ 2.00 $ 7,736 4,725 $ 1.64 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 56 81 Diluted EPS attributable to Comcast Corporation shareholders $ 9,220 4,655 $ 1.98 $ 7,736 4,806 $ 1.61

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Borrowings	Debt Borrowings (in millions) Nine Months Ended Comcast sterling-denominated term loan due 2021 (see Note 6) $ 3,913 Comcast revolving credit facility (see Note 6) 1,500 Comcast 3.90% senior notes due 2038 1,200 Comcast 3.55% senior notes due 2028 1,000 Comcast 4.00% senior notes due 2048 1,000 Comcast 4.25% senior notes due 2053 800 Universal Beijing Resort term loans (see Note 6) 386 Other 51 Total $ 9,850
Debt Repayments and Repurchases	Debt Repayments (in millions) Nine Months Ended NBCUniversal Enterprise 1.662% senior notes due 2018 $ 1,100 Comcast 5.70% senior notes due 2018 1,000 Comcast 5.875% senior notes due 2018 900 NBCUniversal Enterprise senior floating rate notes due 2018 700 Universal Studios Japan term loans maturing 2022 362 Other 343 Total $ 4,405

Significant Transactions (Table

Significant Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Amounts Related to Expenses Included in Consolidated Statement of Operations	Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2018 2018 Other operating and administrative expenses $ 8 $ 29 Interest expense $ 34 $ 45

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements and Tax Reform (Tables)	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue From Contract With Customer Financial Statement Impact	The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 20,983 $ 98 $ 21,081 $ 62,611 $ 343 $ 62,954 Total costs and expenses $ 16,191 $ 111 $ 16,302 $ 48,731 $ 334 $ 49,065 Operating income $ 4,792 $ (13 ) $ 4,779 $ 13,880 $ 9 $ 13,889 Net income attributable to Comcast Corporation $ 2,650 $ (8 ) $ 2,642 $ 7,729 $ 7 $ 7,736 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 16,060 $ 283 $ 16,343 Film and television costs $ 7,076 $ 11 $ 7,087 Other intangible assets, net $ 18,779 $ (646 ) $ 18,133 Other noncurrent assets, net $ 3,489 $ 865 $ 4,354 Total assets $ 186,949 $ 513 $ 187,462 Total current liabilities $ 21,561 $ 432 $ 21,993 Deferred income taxes $ 24,256 $ 3 $ 24,259 Other noncurrent liabilities $ 10,904 $ 68 $ 10,972 Total equity $ 69,449 $ 10 $ 69,459 Total liabilities and equity $ 186,949 $ 513 $ 187,462 The table below presents the effects these changes had on our Cable Communications segment revenue, operating costs and expenses, and depreciation and amortization expense as a result of the updated guidance for the prior year periods. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,825 $ (65 ) $ 5,760 $ 17,396 $ (190 ) $ 17,206 High-speed Internet 3,709 233 3,942 10,994 688 11,682 Voice 840 173 1,013 2,559 522 3,081 Business services 1,575 54 1,629 4,596 161 4,757 Advertising 542 52 594 1,628 146 1,774 Other 712 (311 ) 401 2,064 (918 ) 1,146 Total Cable Communications revenue $ 13,203 $ 136 $ 13,339 $ 39,237 $ 409 $ 39,646 Operating costs and expenses $ 7,957 $ 166 $ 8,123 $ 23,473 $ 490 $ 23,963 Depreciation and amortization expense $ 2,049 $ (34 ) $ 2,015 $ 6,030 $ (102 ) $ 5,928
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue From Contract With Customer Financial Statement Impact	The tables below present the effects on our condensed consolidated statement of income and balance sheet for the prior year periods presented. Condensed Consolidated Statement of Income Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Previously Reported Effects of Adoption As Adjusted Revenue $ 8,014 $ (38 ) $ 7,976 $ 24,213 $ (66 ) $ 24,147 Total costs and expenses $ 5,909 $ (20 ) $ 5,889 $ 19,048 $ (53 ) $ 18,995 Operating income $ 2,105 $ (18 ) $ 2,087 $ 5,165 $ (13 ) $ 5,152 Net income attributable to NBCUniversal $ 1,825 $ (18 ) $ 1,807 $ 4,301 $ (13 ) $ 4,288 Condensed Consolidated Balance Sheet December 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Total current assets $ 11,673 $ 284 $ 11,957 Film and television costs $ 7,071 $ 11 $ 7,082 Other noncurrent assets, net $ 1,872 $ (68 ) $ 1,804 Total assets $ 71,073 $ 227 $ 71,300 Total current liabilities $ 9,602 $ 330 $ 9,932 Other noncurrent liabilities $ 4,109 $ 44 $ 4,153 Total equity $ 43,188 $ (147 ) $ 43,041 Total liabilities and equity $ 71,073 $ 227 $ 71,300

Film and Television Costs (Tabl

Film and Television Costs (Tables)	9 Months Ended
	Sep. 30, 2018
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,573 $ 1,734 Completed, not released 242 50 In production and in development 1,010 1,149 2,825 2,933 Television Costs: Released, less amortization 2,286 2,260 In production and in development 905 818 3,191 3,078 Programming rights, less amortization 2,584 2,689 8,600 8,700 Less: Current portion of programming rights 1,223 1,613 Film and television costs $ 7,377 $ 7,087
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,573 $ 1,734 Completed, not released 242 50 In production and in development 1,010 1,149 2,825 2,933 Television Costs: Released, less amortization 2,286 2,260 In production and in development 905 818 3,191 3,078 Programming rights, less amortization 2,566 2,677 8,582 8,688 Less: Current portion of programming rights 1,213 1,606 Film and television costs $ 7,369 $ 7,082

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Investments [Line Items]
Investment Summary	(in millions) September 30, December 31, Equity method $ 4,163 $ 3,546 Marketable equity securities 322 433 Nonmarketable equity securities 1,528 1,186 Other investments 1,798 1,785 Total investments 7,811 6,950 Less: Current investments 87 19 Noncurrent investments $ 7,724 $ 6,931
Investment and Other Income (Loss), Net	Investment and Other Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Equity in net income (losses) of investees, net $ (76 ) $ (39 ) $ (56 ) $ 12 Realized and unrealized gains (losses) on equity securities, net (38 ) 7 (50 ) — Other income (loss), net 3 102 198 287 Investment and other income (loss), net $ (111 ) $ 70 $ 92 $ 299
NBCUniversal Media LLC [Member]
Investments [Line Items]
Investment Summary	(in millions) September 30, December 31, Equity method $ 660 $ 690 Marketable equity securities 249 430 Nonmarketable equity securities 813 696 Total investments $ 1,722 $ 1,816
Investment and Other Income (Loss), Net	Investment and Other Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Equity in net income (losses) of investees, net $ (119 ) $ (52 ) $ (306 ) $ (107 ) Realized and unrealized gains (losses) on equity securities, net (91 ) — (128 ) 2 Other income (loss), net 5 26 57 63 Investment and other income (loss), net $ (205 ) $ (26 ) $ (377 ) $ (42 )

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
Supplemental Financial Information [Line Items]
Schedule of recognized share-based compensation expense	Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Restricted share units $ 94 $ 99 $ 279 $ 284 Stock options 50 52 155 155 Employee stock purchase plans 7 8 24 25 Total $ 151 $ 159 $ 458 $ 464
Schedule of cash payments for interest and income taxes	Cash Payments for Interest and Income Taxes Nine Months Ended (in millions) 2018 2017 Interest $ 2,240 $ 2,277 Income taxes $ 1,533 $ 3,415
Schedule of cash, cash equivalents and restricted cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the condensed consolidated balance sheet to the total of the amounts reported in our condensed consolidated statement of cash flows. (in millions) September 30, December 31, Cash and cash equivalents $ 10,616 $ 3,428 Restricted cash included in other current assets 47 60 Restricted cash included in other noncurrent assets, net 3,959 83 Cash, cash equivalents and restricted cash, end of period $ 14,622 $ 3,571
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ 2 $ (43 ) Deferred gains (losses) on cash flow hedges 28 (12 ) Unrecognized gains (losses) on employee benefit obligations 294 270 Cumulative translation adjustments 50 166 Accumulated other comprehensive income (loss), net of deferred taxes $ 374 $ 381
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Schedule of cash payments for interest and income taxes	Cash Payments for Interest and Income Taxes Nine Months Ended (in millions) 2018 2017 Interest $ 253 $ 340 Income taxes $ 373 $ 213
Schedule of cash, cash equivalents and restricted cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the condensed consolidated balance sheet to the total of the amounts reported in our condensed consolidated statement of cash flows. (in millions) September 30, December 31, Cash and cash equivalents $ 1,181 $ 2,347 Restricted cash included in other noncurrent assets, net 20 30 Cash, cash equivalents and restricted cash, end of period $ 1,201 $ 2,377
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ — $ (233 ) Deferred gains (losses) on cash flow hedges 5 (4 ) Unrecognized gains (losses) on employee benefit obligations 115 115 Cumulative translation adjustments (22 ) 93 Accumulated other comprehensive income (loss) $ 98 $ (29 )

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Related Party Transactions Condensed Financial Statements	The following tables present transactions with Comcast and its consolidated subsidiaries that are included in our condensed consolidated financial statements. Condensed Consolidated Statement of Income Three Months Ended Nine Months Ended (in millions) 2018 2017 2018 2017 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 506 $ 463 $ 1,580 $ 1,382 Total costs and expenses $ (59 ) $ (38 ) $ (162 ) $ (148 ) Interest expense and investment and other income (loss), net $ (9 ) $ (20 ) $ (52 ) $ (67 ) Condensed Consolidated Balance Sheet (in millions) September 30, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 350 $ 326 Note receivable from Comcast $ 1,522 $ — Accounts payable and accrued expenses related to trade creditors $ 48 $ 54 Accrued expenses and other current liabilities $ 20 $ 50 Note payable to Comcast $ 41 $ 1,831 Long-term debt $ 698 $ 610 Other noncurrent liabilities $ 394 $ 389

Condensed Consolidating Finan_2

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Statement of Income	Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 22,135 $ — $ 22,135 Management fee revenue 299 — 294 — — (593 ) — Total revenue 299 — 294 — 22,135 (593 ) 22,135 Costs and Expenses: Programming and production — — — — 6,711 — 6,711 Other operating and administrative 208 — 294 230 6,305 (593 ) 6,444 Advertising, marketing and promotion — — — — 1,667 — 1,667 Depreciation 12 — — — 2,026 — 2,038 Amortization 1 — — — 579 — 580 Other operating gains — — — — (141 ) — (141 ) Total cost and expenses 221 — 294 230 17,147 (593 ) 17,299 Operating income (loss) 78 — — (230 ) 4,988 — 4,836 Interest expense (600 ) (3 ) (48 ) (113 ) (66 ) — (830 ) Investment and other income (loss), net 3,299 3,380 3,007 1,576 1,065 (12,438 ) (111 ) Income (loss) before income taxes 2,777 3,377 2,959 1,233 5,987 (12,438 ) 3,895 Income tax (expense) benefit 109 (1 ) 10 (2 ) (1,115 ) — (999 ) Net income (loss) 2,886 3,376 2,969 1,231 4,872 (12,438 ) 2,896 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 10 — 10 Net income (loss) attributable to Comcast Corporation $ 2,886 $ 3,376 $ 2,969 $ 1,231 $ 4,862 $ (12,438 ) $ 2,886 Comprehensive income (loss) attributable to Comcast Corporation $ 2,799 $ 3,349 $ 2,974 $ 1,112 $ 4,663 $ (12,098 ) $ 2,799 Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 21,081 $ — $ 21,081 Management fee revenue 285 — 280 — — (565 ) — Total revenue 285 — 280 — 21,081 (565 ) 21,081 Costs and Expenses: Programming and production — — — — 6,059 — 6,059 Other operating and administrative 183 — 280 277 6,360 (565 ) 6,535 Advertising, marketing and promotion — — — — 1,604 — 1,604 Depreciation 7 — — — 1,984 — 1,991 Amortization 1 — — — 554 — 555 Other operating gains — — — — (442 ) — (442 ) Total cost and expenses 191 — 280 277 16,119 (565 ) 16,302 Operating income (loss) 94 — — (277 ) 4,962 — 4,779 Interest expense (544 ) (3 ) (48 ) (116 ) (55 ) — (766 ) Investment and other income (loss), net 2,934 2,513 1,995 2,206 1,845 (11,423 ) 70 Income (loss) before income taxes 2,484 2,510 1,947 1,813 6,752 (11,423 ) 4,083 Income tax (expense) benefit 158 (10 ) 17 (6 ) (1,568 ) — (1,409 ) Net income (loss) 2,642 2,500 1,964 1,807 5,184 (11,423 ) 2,674 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 32 — 32 Net income (loss) attributable to Comcast Corporation $ 2,642 $ 2,500 $ 1,964 $ 1,807 $ 5,152 $ (11,423 ) $ 2,642 Comprehensive income (loss) attributable to Comcast Corporation $ 2,595 $ 2,484 $ 1,968 $ 1,722 $ 5,024 $ (11,198 ) $ 2,595 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 66,661 $ — $ 66,661 Management fee revenue 889 — 873 — — (1,762 ) — Total revenue 889 — 873 — 66,661 (1,762 ) 66,661 Costs and Expenses: Programming and production — — — — 20,440 — 20,440 Other operating and administrative 626 — 873 772 18,814 (1,762 ) 19,323 Advertising, marketing and promotion — — — — 4,924 — 4,924 Depreciation 34 — — — 6,036 — 6,070 Amortization 4 — — — 1,746 — 1,750 Other operating gains — — — — (341 ) — (341 ) Total cost and expenses 664 — 873 772 51,619 (1,762 ) 52,166 Operating income (loss) 225 — — (772 ) 15,042 — 14,495 Interest expense (1,739 ) (9 ) (143 ) (332 ) (190 ) — (2,413 ) Investment and other income (loss), net 10,416 10,279 8,832 5,107 3,977 (38,519 ) 92 Income (loss) before income taxes 8,902 10,270 8,689 4,003 18,829 (38,519 ) 12,174 Income tax (expense) benefit 318 — 29 (12 ) (3,229 ) — (2,894 ) Net income (loss) 9,220 10,270 8,718 3,991 15,600 (38,519 ) 9,280 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 60 — 60 Net income (loss) attributable to Comcast Corporation $ 9,220 $ 10,270 $ 8,718 $ 3,991 $ 15,540 $ (38,519 ) $ 9,220 Comprehensive income (loss) attributable to Comcast Corporation $ 9,139 $ 10,245 $ 8,723 $ 3,877 $ 15,357 $ (38,202 ) $ 9,139 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 62,954 $ — $ 62,954 Management fee revenue 841 — 827 — — (1,668 ) — Total revenue 841 — 827 — 62,954 (1,668 ) 62,954 Costs and Expenses: Programming and production — — — — 18,450 — 18,450 Other operating and administrative 553 — 827 844 18,086 (1,668 ) 18,642 Advertising, marketing and promotion — — — — 4,894 — 4,894 Depreciation 21 — — — 5,855 — 5,876 Amortization 4 — — — 1,641 — 1,645 Other operating gains — — — — (442 ) — (442 ) Total costs and expenses 578 — 827 844 48,484 (1,668 ) 49,065 Operating income (loss) 263 — — (844 ) 14,470 — 13,889 Interest expense (1,592 ) (9 ) (159 ) (344 ) (175 ) — (2,279 ) Investment and other income (loss), net 8,600 7,841 6,628 5,493 4,476 (32,739 ) 299 Income (loss) before income taxes 7,271 7,832 6,469 4,305 18,771 (32,739 ) 11,909 Income tax (expense) benefit 465 (26 ) 56 (17 ) (4,516 ) — (4,038 ) Net income (loss) 7,736 7,806 6,525 4,288 14,255 (32,739 ) 7,871 Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 135 — 135 Net income (loss) attributable to Comcast Corporation $ 7,736 $ 7,806 $ 6,525 $ 4,288 $ 14,120 $ (32,739 ) $ 7,736 Comprehensive income (loss) attributable to Comcast Corporation $ 7,825 $ 7,804 $ 6,531 $ 4,253 $ 13,993 $ (32,581 ) $ 7,825
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (1,461 ) $ 137 $ (206 ) $ (1,047 ) $ 21,084 $ — $ 18,507 Investing Activities: Net transactions with affiliates (1,087 ) (586 ) 206 800 667 — — Capital expenditures (15 ) — — — (6,592 ) — (6,607 ) Cash paid for intangible assets (3 ) — — — (1,372 ) — (1,375 ) Acquisitions and construction of real estate properties (94 ) — — — (35 ) — (129 ) Construction of Universal Beijing Resort — — — — (257 ) — (257 ) Acquisitions, net of cash acquired — — — — (88 ) — (88 ) Proceeds from sales of investments — — — 67 60 — 127 Purchases of investments (118 ) — — (50 ) (672 ) — (840 ) Other — 449 — — 130 — 579 Net cash provided by (used in) investing activities (1,317 ) (137 ) 206 817 (8,159 ) — (8,590 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net 2,117 — — — 792 — 2,909 Proceeds from borrowings 9,386 — — — 464 — 9,850 Repurchases and repayments of debt (1,900 ) — — (3 ) (2,502 ) — (4,405 ) Repurchases of common stock under repurchase program and employee plans (4,282 ) — — — — — (4,282 ) Dividends paid (2,487 ) — — — — — (2,487 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (209 ) — (209 ) Other (56 ) — — — (186 ) — (242 ) Net cash provided by (used in) financing activities 2,778 — — (3 ) (1,641 ) — 1,134 Increase (decrease) in cash, cash equivalents and restricted cash — — — (233 ) 11,284 — 11,051 Cash, cash equivalents and restricted cash, beginning of period — — — 496 3,075 — 3,571 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 263 $ 14,359 $ — $ 14,622 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (931 ) $ 91 $ (233 ) $ (1,055 ) $ 17,985 $ — $ 15,857 Investing Activities: Net transactions with affiliates 4,216 (91 ) 818 833 (5,776 ) — — Capital expenditures (6 ) — — — (6,833 ) — (6,839 ) Cash paid for intangible assets (2 ) — — — (1,134 ) — (1,136 ) Acquisitions and construction of real estate properties (190 ) — — — (135 ) — (325 ) Construction of Universal Beijing Resort — — — — (47 ) — (47 ) Acquisitions, net of cash acquired — — — — (429 ) — (429 ) Proceeds from sales of investments — — — 10 110 — 120 Purchases of investments (56 ) — (35 ) (57 ) (1,916 ) — (2,064 ) Other 101 — — 49 647 — 797 Net cash provided by (used in) investing activities 4,063 (91 ) 783 835 (15,513 ) — (9,923 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (1,068 ) — (2,807 ) Proceeds from borrowings 5,997 — — — 5,463 — 11,460 Repurchases and repayments of debt (1,000 ) — (550 ) (3 ) (3,468 ) — (5,021 ) Repurchases of common stock under repurchase program and employee plans (4,212 ) — — — — — (4,212 ) Dividends paid (2,147 ) — — — — — (2,147 ) Purchase of Universal Studios Japan noncontrolling interests — — — — (2,299 ) — (2,299 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (198 ) — (198 ) Other (31 ) — — — 134 — 103 Net cash provided by (used in) financing activities (3,132 ) — (550 ) (3 ) (1,436 ) — (5,121 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — (223 ) 1,036 — 813 Cash, cash equivalents and restricted cash, beginning of period — — — 482 2,933 — 3,415 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 259 $ 3,969 $ — $ 4,228
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet September 30, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 263 $ 10,353 $ — $ 10,616 Receivables, net — — — — 8,983 — 8,983 Programming rights — — — — 1,223 — 1,223 Other current assets 58 8 — 34 2,284 — 2,384 Total current assets 58 8 — 297 22,843 — 23,206 Film and television costs — — — — 7,377 — 7,377 Investments 267 11 122 790 6,534 — 7,724 Investments in and amounts due from subsidiaries eliminated upon consolidation 129,360 146,297 132,562 53,078 103,526 (564,823 ) — Property and equipment, net 649 — — — 39,206 — 39,855 Franchise rights — — — — 59,365 — 59,365 Goodwill — — — — 36,703 — 36,703 Other intangible assets, net 11 — — — 18,638 — 18,649 Other noncurrent assets, net 782 230 — 95 6,884 (235 ) 7,756 Total assets $ 131,127 $ 146,546 $ 132,684 $ 54,260 $ 301,076 $ (565,058 ) $ 200,635 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 13 $ — $ — $ — $ 7,023 $ — $ 7,036 Accrued participations and residuals — — — — 1,809 — 1,809 Deferred revenue — — — — 1,633 — 1,633 Accrued expenses and other current liabilities 1,852 150 231 346 3,397 — 5,976 Current portion of long-term debt 699 — — 4 2,470 — 3,173 Total current liabilities 2,564 150 231 350 16,332 — 19,627 Long-term debt, less current portion 54,120 144 2,100 7,748 5,599 — 69,711 Deferred income taxes — 330 — 68 25,070 (301 ) 25,167 Other noncurrent liabilities 2,920 — — 1,225 8,257 66 12,468 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,317 — 1,317 Equity: Common stock 54 — — — — — 54 Other shareholders’ equity 71,469 145,922 130,353 44,869 243,679 (564,823 ) 71,469 Total Comcast Corporation shareholders’ equity 71,523 145,922 130,353 44,869 243,679 (564,823 ) 71,523 Noncontrolling interests — — — — 822 — 822 Total equity 71,523 145,922 130,353 44,869 244,501 (564,823 ) 72,345 Total liabilities and equity $ 131,127 $ 146,546 $ 132,684 $ 54,260 $ 301,076 $ (565,058 ) $ 200,635 Condensed Consolidating Balance Sheet December 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 496 $ 2,932 $ — $ 3,428 Receivables, net — — — — 8,834 — 8,834 Programming rights — — — — 1,613 — 1,613 Other current assets 60 — 7 25 2,376 — 2,468 Total current assets 60 — 7 521 15,755 — 16,343 Film and television costs — — — — 7,087 — 7,087 Investments 146 21 108 693 5,963 — 6,931 Investments in and amounts due from subsidiaries eliminated upon consolidation 117,164 142,519 139,528 50,102 113,332 (562,645 ) — Property and equipment, net 551 — — — 37,919 — 38,470 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 36,780 — 36,780 Other intangible assets, net 12 — — — 18,121 — 18,133 Other noncurrent assets, net 435 708 — 88 3,437 (314 ) 4,354 Total assets $ 118,368 $ 143,248 $ 139,643 $ 51,404 $ 297,758 $ (562,959 ) $ 187,462 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 16 $ — $ — $ — $ 6,892 $ — $ 6,908 Accrued participations and residuals — — — — 1,644 — 1,644 Deferred revenue — — — — 1,687 — 1,687 Accrued expenses and other current liabilities 1,888 92 333 326 3,981 — 6,620 Current portion of long-term debt 2,810 — — 4 2,320 — 5,134 Total current liabilities 4,714 92 333 330 16,524 — 21,993 Long-term debt, less current portion 42,428 140 2,100 7,751 7,003 — 59,422 Deferred income taxes — 285 — 67 24,250 (343 ) 24,259 Other noncurrent liabilities 2,610 — — 1,128 7,205 29 10,972 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,357 — 1,357 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 68,561 142,731 137,210 42,128 240,576 (562,645 ) 68,561 Total Comcast Corporation shareholders’ equity 68,616 142,731 137,210 42,128 240,576 (562,645 ) 68,616 Noncontrolling interests — — — — 843 — 843 Total equity 68,616 142,731 137,210 42,128 241,419 (562,645 ) 69,459 Total liabilities and equity $ 118,368 $ 143,248 $ 139,643 $ 51,404 $ 297,758 $ (562,959 ) $ 187,462

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			5
Financial Data by Business Segment
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Adjusted EBITDA	7,313	7,133	21,974	21,218
Depreciation and Amortization	2,618	2,546	7,820	7,521
Capital Expenditures	2,384	2,434	6,607	6,839
Cash Paid for Intangible Assets	445	365	$ 1,375	1,136
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Financial Data by Business Segment
Revenue	8,625	7,976	$ 26,468	24,147
Adjusted EBITDA	2,066	2,257	6,511	6,350
Depreciation and Amortization	514	507	1,577	1,535
Capital Expenditures	405	354	1,135	977
Cash Paid for Intangible Assets	78	69	374	197
Cable Communications [Member]
Financial Data by Business Segment
Revenue	13,787	13,339	41,015	39,646
Depreciation and Amortization		2,015		5,928
Cable Networks [Member]
Financial Data by Business Segment
Revenue	2,884	2,603	8,994	7,939
Cable Networks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,884	2,603	8,994	7,939
Broadcast Television [Member]
Financial Data by Business Segment
Revenue	2,452	2,125	8,340	6,574
Broadcast Television [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,452	2,125	8,340	6,574
Filmed Entertainment [Member]
Financial Data by Business Segment
Revenue	1,819	1,753	5,176	5,862
Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,819	1,753	5,176	5,862
Theme Parks [Member]
Financial Data by Business Segment
Revenue	1,528	1,550	4,170	3,982
Theme Parks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,528	1,550	4,170	3,982
NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	8,625	7,976	26,468	24,147
Adjusted EBITDA	2,066	2,257	6,511	6,350
Depreciation and Amortization	514	507	1,577	1,535
Capital Expenditures	405	354	1,135	977
Cash Paid for Intangible Assets	78	69	374	197
Operating Segments [Member] | Cable Communications [Member]
Financial Data by Business Segment
Revenue	13,787	13,339	41,015	39,646
Adjusted EBITDA	5,615	5,216	16,668	15,683
Depreciation and Amortization	2,071	2,015	6,171	5,928
Capital Expenditures	1,944	2,061	5,398	5,798
Cash Paid for Intangible Assets	353	284	950	897
Operating Segments [Member] | Cable Networks [Member]
Financial Data by Business Segment
Revenue	2,884	2,603	8,994	7,939
Adjusted EBITDA	968	906	3,422	3,076
Depreciation and Amortization	180	179	548	574
Capital Expenditures	11	5	22	15
Cash Paid for Intangible Assets	6	4	15	11
Operating Segments [Member] | Cable Networks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,884	2,603	8,994	7,939
Adjusted EBITDA	968	906	3,422	3,076
Depreciation and Amortization	180	179	548	574
Capital Expenditures	11	5	22	15
Cash Paid for Intangible Assets	6	4	15	11
Operating Segments [Member] | Broadcast Television [Member]
Financial Data by Business Segment
Revenue	2,452	2,125	8,340	6,574
Adjusted EBITDA	321	316	1,245	1,054
Depreciation and Amortization	32	33	106	96
Capital Expenditures	37	66	99	125
Cash Paid for Intangible Assets	0	4	75	11
Operating Segments [Member] | Broadcast Television [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,452	2,125	8,340	6,574
Adjusted EBITDA	321	316	1,245	1,054
Depreciation and Amortization	32	33	106	96
Capital Expenditures	37	66	99	125
Cash Paid for Intangible Assets	0	4	75	11
Operating Segments [Member] | Filmed Entertainment [Member]
Financial Data by Business Segment
Revenue	1,819	1,753	5,176	5,862
Adjusted EBITDA	214	383	555	1,041
Depreciation and Amortization	26	32	117	79
Capital Expenditures	9	18	24	47
Cash Paid for Intangible Assets	6	6	20	17
Operating Segments [Member] | Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,819	1,753	5,176	5,862
Adjusted EBITDA	214	383	555	1,041
Depreciation and Amortization	26	32	117	79
Capital Expenditures	9	18	24	47
Cash Paid for Intangible Assets	6	6	20	17
Operating Segments [Member] | Theme Parks [Member]
Financial Data by Business Segment
Revenue	1,528	1,550	4,170	3,982
Adjusted EBITDA	725	775	1,789	1,723
Depreciation and Amortization	170	166	492	494
Capital Expenditures	269	199	811	671
Cash Paid for Intangible Assets	23	18	158	57
Operating Segments [Member] | Theme Parks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,528	1,550	4,170	3,982
Adjusted EBITDA	725	775	1,789	1,723
Depreciation and Amortization	170	166	492	494
Capital Expenditures	269	199	811	671
Cash Paid for Intangible Assets	23	18	158	57
Corporate, Non-Segment [Member]
Financial Data by Business Segment
Revenue	276	266	922	679
Adjusted EBITDA	(378)	(349)	(1,167)	(845)
Depreciation and Amortization	33	24	72	58
Capital Expenditures	35	19	74	64
Cash Paid for Intangible Assets	14	12	51	42
Corporate, Non-Segment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	15	15	44	32
Adjusted EBITDA	(161)	(122)	(497)	(542)
Depreciation and Amortization	106	97	314	292
Capital Expenditures	79	66	179	119
Cash Paid for Intangible Assets	43	37	106	101
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	15	15	44	32
Adjusted EBITDA	(161)	(122)	(497)	(542)
Depreciation and Amortization	106	97	314	292
Capital Expenditures	79	66	179	119
Cash Paid for Intangible Assets	43	37	106	101
Eliminations [Member]
Financial Data by Business Segment
Revenue	(553)	(500)	(1,744)	(1,518)
Adjusted EBITDA	10	9	(38)	30
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	0	0
Eliminations [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	(73)	(70)	(256)	(242)
Adjusted EBITDA	(1)	(1)	(3)	(2)
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	0	0
Eliminations [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	(73)	(70)	(256)	(242)
Adjusted EBITDA	(1)	(1)	(3)	(2)
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	$ 0	$ 0	$ 0	$ 0

Segment Information (Reconcilia

Segment Information (Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	$ 7,313	$ 7,133	$ 21,974	$ 21,218
Adjustment for legal settlement	0	(250)	0	(250)
Depreciation	(2,038)	(1,991)	(6,070)	(5,876)
Amortization	(580)	(555)	(1,750)	(1,645)
Other operating gains	141	442	341	442
Interest expense	(830)	(766)	(2,413)	(2,279)
Investment and other income (loss), net	(111)	70	92	299
Income before income taxes	3,895	4,083	12,174	11,909
NBCUniversal Media LLC [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	2,066	2,257	6,511	6,350
Depreciation	(250)	(253)	(750)	(749)
Amortization	(264)	(254)	(827)	(786)
Other operating gains	141	337	141	337
Interest expense	(134)	(139)	(394)	(431)
Investment and other income (loss), net	(205)	(26)	(377)	(42)
Income before income taxes	$ 1,354	$ 1,922	$ 4,304	$ 4,679

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Cable Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,787	13,339	41,015	39,646
Cable Communications [Member] | Residential, Video [Member]
Disaggregation of Revenue [Line Items]
Revenue	5,591	5,760	16,878	17,206
Cable Communications [Member] | Residential, High-Speed Internet [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,321	3,942	12,740	11,682
Cable Communications [Member] | Residential, Voice [Member]
Disaggregation of Revenue [Line Items]
Revenue	982	1,013	2,982	3,081
Cable Communications [Member] | Business Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,803	1,629	5,290	4,757
Cable Communications [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	684	594	1,932	1,774
Cable Communications [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 406	$ 401	$ 1,193	$ 1,146
Cable Communications [Member] | Franchise And Other Regulatory Fees [Member]
Disaggregation of Revenue [Line Items]
Cable segment revenue types as percentage of total cable revenue	2.60%	2.80%	2.70%	2.80%
Cable Networks [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 2,884	$ 2,603	$ 8,994	$ 7,939
Cable Networks [Member] | Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,680	1,533	5,251	4,645
Cable Networks [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	820	787	2,746	2,519
Cable Networks [Member] | Content Licensing And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	384	283	997	775
Broadcast Television [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,452	2,125	8,340	6,574
Broadcast Television [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,355	1,241	5,107	3,790
Broadcast Television [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	538	432	1,541	1,458
Broadcast Television [Member] | Distribution And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	559	452	1,692	1,326
Filmed Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,819	1,753	5,176	5,862
Filmed Entertainment [Member] | Theatrical [Member]
Disaggregation of Revenue [Line Items]
Revenue	601	515	1,564	2,003
Filmed Entertainment [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	719	662	2,100	2,080
Filmed Entertainment [Member] | Home Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	260	299	733	919
Filmed Entertainment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	239	277	779	860
Theme Parks [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,528	1,550	4,170	3,982
NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,625	7,976	26,468	24,147
Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	276	266	922	679
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	15	15	44	32
Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(553)	(500)	(1,744)	(1,518)
Eliminations [Member] | NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	(73)	(70)	(256)	(242)
NBCUniversal Media LLC [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,625	7,976	26,468	24,147
NBCUniversal Media LLC [Member] | Cable Networks [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,884	2,603	8,994	7,939
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,680	1,533	5,251	4,645
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	820	787	2,746	2,519
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Content Licensing And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	384	283	997	775
NBCUniversal Media LLC [Member] | Broadcast Television [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,452	2,125	8,340	6,574
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,355	1,241	5,107	3,790
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	538	432	1,541	1,458
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Distribution And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	559	452	1,692	1,326
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,819	1,753	5,176	5,862
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Theatrical [Member]
Disaggregation of Revenue [Line Items]
Revenue	601	515	1,564	2,003
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	719	662	2,100	2,080
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Home Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	260	299	733	919
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	239	277	779	860
NBCUniversal Media LLC [Member] | Theme Parks [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,528	1,550	4,170	3,982
NBCUniversal Media LLC [Member] | Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	15	15	44	32
NBCUniversal Media LLC [Member] | Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ (73)	$ (70)	$ (256)	$ (242)

Revenue (Revenue by Geographic

Revenue (Revenue by Geographic Location) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
United States
Disaggregation of Revenue [Line Items]
Revenue	20,244	19,142	61,060	57,047
Foreign
Disaggregation of Revenue [Line Items]
Revenue	1,891	1,939	5,601	5,907
NBCUniversal Media LLC [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,625	7,976	26,468	24,147
NBCUniversal Media LLC [Member] | United States
Disaggregation of Revenue [Line Items]
Revenue	6,758	6,088	20,945	18,344
NBCUniversal Media LLC [Member] | Foreign
Disaggregation of Revenue [Line Items]
Revenue	$ 1,867	$ 1,888	$ 5,523	$ 5,803

Revenue (Narrative) (Details)

Revenue (Narrative) (Details)	9 Months Ended
	Sep. 30, 2018
Cable Communications [Member] | Residential [Member]
Revenue [Line Items]
Term of contract	2 years
Cable Communications [Member] | Business Services [Member]
Revenue [Line Items]
Timing period of recognition	2 years
Annual revenue that estimates remaining performance obligations	6 months
Cable Communications [Member] | Business Services [Member] | Minimum [Member]
Revenue [Line Items]
Term of contract	2 years
Cable Communications [Member] | Business Services [Member] | Maximum [Member]
Revenue [Line Items]
Term of contract	5 years
Cable Communications [Member] | Advertising [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
Cable Communications [Member] | Advertising [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
Cable Networks [Member] | Distribution [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
Cable Networks [Member] | Distribution [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
Cable Networks [Member] | Advertising [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
Broadcast Television [Member] | Distribution [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
Broadcast Television [Member] | Distribution [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
Broadcast Television [Member] | Advertising [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
Filmed Entertainment [Member] | Theatrical [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
Filmed Entertainment [Member] | Content Licensing [Member]
Revenue [Line Items]
Timing period of recognition	2 years
Filmed Entertainment [Member] | Content Licensing [Member] | Minimum [Member]
Revenue [Line Items]
Annual revenue that estimates remaining performance obligations	1 year
Filmed Entertainment [Member] | Content Licensing [Member] | Maximum [Member]
Revenue [Line Items]
Annual revenue that estimates remaining performance obligations	2 years
Filmed Entertainment [Member] | Home Entertainment [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
Filmed Entertainment [Member] | Home Entertainment [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	90 days
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Distribution [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Distribution [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Advertising [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Distribution [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Distribution [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Advertising [Member]
Revenue [Line Items]
Expected Payment Terms	30 days
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Theatrical [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Content Licensing [Member]
Revenue [Line Items]
Timing period of recognition	2 years
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Content Licensing [Member] | Minimum [Member]
Revenue [Line Items]
Annual revenue that estimates remaining performance obligations	1 year
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Content Licensing [Member] | Maximum [Member]
Revenue [Line Items]
Annual revenue that estimates remaining performance obligations	2 years
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Home Entertainment [Member] | Minimum [Member]
Revenue [Line Items]
Expected Payment Terms	60 days
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Home Entertainment [Member] | Maximum [Member]
Revenue [Line Items]
Expected Payment Terms	90 days

Revenue (Condensed Consolidated

Revenue (Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Condensed Consolidated Balance Sheet [Line Items]
Receivables, gross	$ 9,300	$ 9,122
Less: Allowance for doubtful accounts	317	288
Receivables, net	8,983	8,834
NBCUniversal Media LLC [Member]
Condensed Consolidated Balance Sheet [Line Items]
Receivables, gross	6,951	7,055
Less: Allowance for doubtful accounts	100	88
Receivables, net	6,851	6,967
Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Balance Sheet [Line Items]
Noncurrent receivables, net (included in other noncurrent assets, net)	1,207	1,184
Contract acquisition and fulfillment costs (included in other noncurrent assets, net)	928	922
Noncurrent deferred revenue (included in other noncurrent liabilities)	572	497
Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
Condensed Consolidated Balance Sheet [Line Items]
Noncurrent receivables, net (included in other noncurrent assets, net)	1,098	1,093
Noncurrent deferred revenue (included in other noncurrent liabilities)	$ 451	$ 392

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net Income Attributable to Comcast Corporation	$ 2,886	$ 2,642	$ 9,220	$ 7,736
Basic EPS attributable to Comcast Corporation shareholders (in shares)	4,564	4,698	4,599	4,725
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.63	$ 0.56	$ 2	$ 1.64
Effect of dilutive securities:
Net Income Attributable to Comcast Corporation	$ 2,886	$ 2,642	$ 9,220	$ 7,736
Assumed exercise or issuance of shares relating to stock plans (in shares)	55	79	56	81
Diluted EPS attributable to Comcast Corporation shareholders (in shares)	4,619	4,777	4,655	4,806
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.62	$ 0.55	$ 1.98	$ 1.61

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Total debt	$ 72,900
Fair value of debt	74,500
Proceeds from borrowings	9,850	$ 11,460
Repurchases and repayments of debt	4,405	5,021
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Total debt	12,600
Fair value of debt	12,900
Proceeds from borrowings	485	3,948
Repurchases and repayments of debt	387	$ 3,450
Universal Beijing Resort term loans [Member]
Debt Instrument [Line Items]
Proceeds from borrowings	386
Universal Beijing Resort term loans [Member] | NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Proceeds from borrowings	386
Universal Studios Japan Term Loans Maturing 2022 [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	362
Universal Studios Japan Term Loans Maturing 2022 [Member] | NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 362

Long-Term Debt (Debt Borrowings

Long-Term Debt (Debt Borrowings) (Details) $ in Millions, £ in Billions	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018GBP (£)
Debt Instrument [Line Items]
Proceeds from borrowings	$ 9,850	$ 11,460
Other [Member]
Debt Instrument [Line Items]
Other	51
Universal Beijing Resort term loans [Member]
Debt Instrument [Line Items]
Proceeds from borrowings	386
Unsecured Debt [Member] | Comcast Sterling-denominated term loan due 2021 [Member]
Debt Instrument [Line Items]
Debt face amount	3,913		£ 3
Senior Notes [Member] | Senior 3.90% notes due 2038 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,200
Interest rate	3.90%		3.90%
Senior Notes [Member] | Senior 3.55% notes due 2028 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,000
Interest rate	3.55%		3.55%
Senior Notes [Member] | Senior 4.00% notes due 2048 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,000
Interest rate	4.00%		4.00%
Senior Notes [Member] | Senior 4.25% notes due 2053 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 800
Interest rate	4.25%		4.25%
Comcast revolving credit facility [Member]
Debt Instrument [Line Items]
Revolving credit facility	$ 1,500

Long-Term Debt (Debt Repayments

Long-Term Debt (Debt Repayments) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 4,405	$ 5,021
NBCUniversal Enterprise 1.662% senior notes due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 1,100
Interest rate	1.662%
Senior 5.70% notes due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 1,000
Interest rate	5.70%
Senior 5.875% notes due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 900
Interest rate	5.875%
NBCUniveral Enterprise senior floating rate notes due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 700
Universal Studios Japan term loans maturing 2022
Debt Instrument [Line Items]
Repurchases and repayments of debt	362
Other [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 343

Long-Term Debt (Revolving Credi

Long-Term Debt (Revolving Credit Facilities) (Details) - Revolving Credit Facility [Member] $ in Millions	Sep. 30, 2018USD ($)
Line of Credit Facility [Line Items]
Amount outstanding	$ 1,500
Amounts available under revolving credit facilities	3,800
NBCUniversal Enterprise [Member]
Line of Credit Facility [Line Items]
Amounts available under revolving credit facilities	$ 823

Long-Term Debt (Commercial Pape

Long-Term Debt (Commercial Paper Programs) (Details) - Commercial Paper [Member] $ in Millions	Sep. 30, 2018USD ($)
Short-term Debt [Line Items]
Commercial paper outstanding	$ 3,000
Comcast [Member]
Short-term Debt [Line Items]
Commercial paper outstanding	3,000
NBCUniversal Enterprise [Member]
Short-term Debt [Line Items]
Commercial paper outstanding	$ 794

Long-Term Debt (Cross-Guarantee

Long-Term Debt (Cross-Guarantee Structure) (Details) - NBCUniversal Media LLC [Member]	Oct. 31, 2018USD ($)	Oct. 31, 2018GBP (£)	Sep. 30, 2018USD ($)	Sep. 30, 2018GBP (£)
Debt Instrument [Line Items]
Ownership in cable holding company subsidiaries			100.00%	100.00%
NBCUniversal Enterprise [Member]
Debt Instrument [Line Items]
Related party aggregate principal amount senior notes not subject to guarantee			$ 3,000,000,000
Related party credit facility not subject to guarantee			1,600,000,000
Related party liquidation preference preferred stock not subject to guarantee			725,000,000
Comcast Unsecured Sterling-Denominated Term Loan Credit Agreement [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Borrowings of debt securities subject to guarantee			3,900,000,000	£ 3,000,000,000
Maximum borrowing capacity under term loan subject to guarantee | £				£ 7,000,000,000
Comcast Unsecured Sterling-Denominated Term Loan Credit Agreement [Member] | Unsecured Debt [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Borrowings of debt securities subject to guarantee	$ 4,800,000,000	£ 3,600,000,000
Comcast and Comcast Cable Debt Securities [Member]
Debt Instrument [Line Items]
Principal amount of debt securities subject to guarantee			58,700,000,000
Comcast Senior Notes, Fixed and Floating Rates [Member] | Senior Notes [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Borrowings of debt securities subject to guarantee	27,000,000,000
Comcast Unsecured Dollar-Denominated Term Loan Credit Agreement [Member] | Unsecured Debt [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Borrowings of debt securities subject to guarantee	3,000,000,000
Maximum borrowing capacity under term loan subject to guarantee	$ 3,000,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Guarantee obligations, maximum capacity			$ 7,600,000,000

Significant Transactions (Sky O

Significant Transactions (Sky Offer) (Details)	Oct. 09, 2018USD ($)	Oct. 09, 2018GBP (£)	Oct. 31, 2018USD ($)	Oct. 31, 2018GBP (£)	Oct. 09, 2018£ / shares	Sep. 30, 2018USD ($)	Sep. 30, 2018GBP (£)
Commercial Paper [Member]
Business Acquisition [Line Items]
Commercial paper outstanding						$ 3,000,000,000
Revolving Credit Facility [Member]
Business Acquisition [Line Items]
Amount outstanding						1,500,000,000
Sky Outstanding Indebtedness [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Principal amount of debt securities not subject to guarantee	$ 11,000,000,000
Unsecured Debt [Member] | Comcast Unsecured Sterling-Denominated Term Loan Credit Agreement [Member]
Business Acquisition [Line Items]
Debt issued to finance cash consideration						$ 3,913,000,000	£ 3,000,000,000
Maximum borrowing capacity under term loans | £							£ 7,000,000,000
Unsecured Debt [Member] | Comcast Unsecured Sterling-Denominated Term Loan Credit Agreement [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Debt issued to finance cash consideration			$ 4,800,000,000	£ 3,600,000,000
Unsecured Debt [Member] | Comcast Unsecured Dollar-Denominated Term Loan Credit Agreement [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Debt issued to finance cash consideration			3,000,000,000
Maximum borrowing capacity under term loans			3,000,000,000
Senior Notes [Member] | Comcast Senior Notes, Fixed and Floating Rates [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Debt issued to finance cash consideration			$ 27,000,000,000
Sky PLC [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Shares acquired, share price (in gbp per share) | £ / shares					£ 17.28
Minimum percentage of issued share capital acquired	90.00%
Cash consideration	$ 39,400,000,000	£ 30,200,000,000

Significant Transactions (Acqui

Significant Transactions (Acquisition-Related Expenses) (Details) - Sky PLC [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Business Acquisition [Line Items]
Transaction expenses	$ 8	$ 29
Interest expense	$ 34	$ 45

Significant Transactions (Unive

Significant Transactions (Universal Beijing Resort) (Details) $ in Millions, ¥ in Billions	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018CNY (¥)
Variable Interest Entity [Line Items]
Proceeds from borrowings	$ 9,850	$ 11,460
Universal Beijing Resort [Member]
Variable Interest Entity [Line Items]
Ownership percentage in variable interest entity	30.00%		30.00%
Maximum borrowing capacity of variable interest entity	$ 4,000		¥ 26.6
Consolidated variable interest entity's assets included in condensed consolidated balance sheet	1,200
Consolidated variable interest entity's liabilities included in condensed consolidated balance sheet	728
Universal Beijing Resort term loans [Member]
Variable Interest Entity [Line Items]
Proceeds from borrowings	386
NBCUniversal Media LLC [Member]
Variable Interest Entity [Line Items]
Proceeds from borrowings	$ 485	$ 3,948
NBCUniversal Media LLC [Member] | Universal Beijing Resort [Member]
Variable Interest Entity [Line Items]
Ownership percentage in variable interest entity	30.00%		30.00%
Maximum borrowing capacity of variable interest entity	$ 4,000		¥ 26.6
Consolidated variable interest entity's assets included in condensed consolidated balance sheet	1,200
Consolidated variable interest entity's liabilities included in condensed consolidated balance sheet	728
NBCUniversal Media LLC [Member] | Universal Beijing Resort term loans [Member]
Variable Interest Entity [Line Items]
Proceeds from borrowings	$ 386

Significant Transactions (FCC S

Significant Transactions (FCC Spectrum Auction) (Details) - FCC Spectrum [Member] - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017
Indefinite-lived Intangible Assets [Line Items]
Proceeds from FCC spectrum auction	$ 482
Gain on sale of spectrum rights		$ 337		$ 337
Amount of spectrum acquired		1,700		1,700
Deposit to acquire intangible asset			$ 1,800
NBCUniversal Media LLC [Member]
Indefinite-lived Intangible Assets [Line Items]
Proceeds from FCC spectrum auction	$ 482
Gain on sale of spectrum rights		$ 337		$ 337

Significant Transaction (Univer

Significant Transaction (Universal Studios Japan) (Details) - USD ($) $ in Millions	Apr. 06, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests		$ 0	$ 2,299
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests		$ 0	$ 2,299
Universal Studios Japan [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests	$ 2,300
Universal Studios Japan [Member] | NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Purchase of Universal Studios Japan noncontrolling interests	$ 2,300

Recent Accounting Pronounceme_4

Recent Accounting Pronouncements and Tax Reform (Effect of Changes in Revenue Recognition - Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Total costs and expenses	17,299	16,302	52,166	49,065
Operating income	4,836	4,779	14,495	13,889
Net Income Attributable to Comcast Corporation	2,886	2,642	9,220	7,736
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	8,625	7,976	26,468	24,147
Total costs and expenses	6,932	5,889	21,393	18,995
Operating income	1,693	2,087	5,075	5,152
Net Income Attributable to Comcast Corporation	$ 1,231	1,807	$ 3,991	4,288
Previous Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		20,983		62,611
Total costs and expenses		16,191		48,731
Operating income		4,792		13,880
Net Income Attributable to Comcast Corporation		2,650		7,729
Previous Reported [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		8,014		24,213
Total costs and expenses		5,909		19,048
Operating income		2,105		5,165
Net Income Attributable to Comcast Corporation		1,825		4,301
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		98		343
Total costs and expenses		111		334
Operating income		(13)		9
Net Income Attributable to Comcast Corporation		(8)		7
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		(38)		(66)
Total costs and expenses		(20)		(53)
Operating income		(18)		(13)
Net Income Attributable to Comcast Corporation		$ (18)		$ (13)

Recent Accounting Pronounceme_5

Recent Accounting Pronouncements and Tax Reform (Effects of Changes in Revenue Recognition - Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets	$ 23,206	$ 16,343
Film and television costs	7,377	7,087
Other intangible assets, net	18,649	18,133
Other noncurrent assets, net	7,756	4,354
Assets	200,635	187,462
Total current liabilities	19,627	21,993
Deferred income taxes	25,167	24,259
Other noncurrent liabilities	12,468	10,972
Total equity	72,345	69,459	$ 56,258	$ 56,163
Total liabilities and equity	200,635	187,462
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets	11,870	11,957
Film and television costs	7,369	7,082
Other noncurrent assets, net	1,799	1,804
Assets	72,934	71,300
Total current liabilities	7,542	9,932
Other noncurrent liabilities	5,189	4,153
Total equity	45,712	43,041	$ 42,502	$ 40,875
Total liabilities and equity	$ 72,934	71,300
Previous Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets		16,060
Film and television costs		7,076
Other intangible assets, net		18,779
Other noncurrent assets, net		3,489
Assets		186,949
Total current liabilities		21,561
Deferred income taxes		24,256
Other noncurrent liabilities		10,904
Total equity		69,449
Total liabilities and equity		186,949
Previous Reported [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets		11,673
Film and television costs		7,071
Other noncurrent assets, net		1,872
Assets		71,073
Total current liabilities		9,602
Other noncurrent liabilities		4,109
Total equity		43,188
Total liabilities and equity		71,073
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets		283
Film and television costs		11
Other intangible assets, net		(646)
Other noncurrent assets, net		865
Assets		513
Total current liabilities		432
Deferred income taxes		3
Other noncurrent liabilities		68
Total equity		10
Total liabilities and equity		513
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets		284
Film and television costs		11
Other noncurrent assets, net		(68)
Assets		227
Total current liabilities		330
Other noncurrent liabilities		44
Total equity		(147)
Total liabilities and equity		$ 227

Recent Accounting Pronounceme_6

Recent Accounting Pronouncements and Tax Reform (Effect of Changes in Revenue Recognition - Cable Communications Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Depreciation and Amortization	2,618	2,546	7,820	7,521
Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	13,787	13,339	41,015	39,646
Operating costs and expenses		8,123		23,963
Depreciation and Amortization		2,015		5,928
Residential, Video [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	5,591	5,760	16,878	17,206
Residential, High-Speed Internet [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	4,321	3,942	12,740	11,682
Residential, Voice [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	982	1,013	2,982	3,081
Business Services [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	1,803	1,629	5,290	4,757
Advertising [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	684	594	1,932	1,774
Other [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 406	401	$ 1,193	1,146
Previous Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		20,983		62,611
Previous Reported [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		13,203		39,237
Operating costs and expenses		7,957		23,473
Depreciation and Amortization		2,049		6,030
Previous Reported [Member] | Residential, Video [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		5,825		17,396
Previous Reported [Member] | Residential, High-Speed Internet [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		3,709		10,994
Previous Reported [Member] | Residential, Voice [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		840		2,559
Previous Reported [Member] | Business Services [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		1,575		4,596
Previous Reported [Member] | Advertising [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		542		1,628
Previous Reported [Member] | Other [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		712		2,064
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		98		343
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		136		409
Operating costs and expenses		166		490
Depreciation and Amortization		(34)		(102)
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Residential, Video [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		(65)		(190)
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Residential, High-Speed Internet [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		233		688
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Residential, Voice [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		173		522
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Business Services [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		54		161
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Advertising [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		52		146
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Other [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		$ (311)		$ (918)

Recent Accounting Pronounceme_7

Recent Accounting Pronouncements and Tax Reform (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit, 2017 tax reform legislation		$ 12,700
Income tax benefit, 2018 tax reform legislation	$ 128
Cumulative Effect of New Accounting Principle in Period of Adoption		33
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		0
Member's Capital [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		(232)
AOCI Attributable to Parent [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		76
AOCI Attributable to Parent [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 232
Accounting Standards Update 2016-01 [Member] | Member's Capital [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ (232)
Accounting Standards Update 2016-01 [Member] | AOCI Attributable to Parent [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 232

Film and Television Costs (Film

Film and Television Costs (Film and Television Costs) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Film Costs:
Released, less amortization	$ 1,573	$ 1,734
Completed, not released	242	50
In production and in development	1,010	1,149
Total film costs	2,825	2,933
Television Costs:
Released, less amortization	2,286	2,260
In production and in development	905	818
Total television costs	3,191	3,078
Programming rights, less amortization	2,584	2,689
Total film costs, television costs and programming rights	8,600	8,700
Less: Current portion of programming rights	1,223	1,613
Film and television costs	7,377	7,087
NBCUniversal Media LLC [Member]
Film Costs:
Released, less amortization	1,573	1,734
Completed, not released	242	50
In production and in development	1,010	1,149
Total film costs	2,825	2,933
Television Costs:
Released, less amortization	2,286	2,260
In production and in development	905	818
Total television costs	3,191	3,078
Programming rights, less amortization	2,566	2,677
Total film costs, television costs and programming rights	8,582	8,688
Less: Current portion of programming rights	1,213	1,606
Film and television costs	$ 7,369	$ 7,082

Investments (Schedule of Invest

Investments (Schedule of Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Equity method	$ 4,163	$ 3,546
Marketable equity securities	322	433
Nonmarketable equity securities	1,528	1,186
Other investments	1,798	1,785
Total investments	7,811	6,950
Less: Current investments	87	19
Noncurrent investments	7,724	6,931
NBCUniversal Media LLC [Member]
Schedule of Investments [Line Items]
Equity method	660	690
Marketable equity securities	249	430
Nonmarketable equity securities	813	696
Total investments	1,722	1,816
Noncurrent investments	$ 1,722	$ 1,816

Investments (Investment and Oth

Investments (Investment and Other Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	$ (76)	$ (39)	$ (56)	$ 12
Realized and unrealized gains (losses) on equity securities, net	(38)	7	(50)	0
Other income (loss), net	3	102	198	287
Investment and other income (loss), net	(111)	70	92	299
NBCUniversal Media LLC [Member]
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	(119)	(52)	(306)	(107)
Realized and unrealized gains (losses) on equity securities, net	(91)	0	(128)	2
Other income (loss), net	5	26	57	63
Investment and other income (loss), net	$ (205)	$ (26)	$ (377)	$ (42)

Investments (Equity Method) (De

Investments (Equity Method) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Mar. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Feb. 28, 2018	Jan. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 4,163			$ 4,163				$ 3,546
Equity in net income (losses) of investees, net		(76)		$ (39)	(56)	$ 12
NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments		660			660				690
Equity in net income (losses) of investees, net		(119)		(52)	(306)	(107)
Atairos [Member]
Schedule of Equity Method Investments [Line Items]
Funding commitment							$ 5,000	$ 4,000
Equity method investments		2,900			2,900				2,400
Purchases of investments					133	994
Equity in net income (losses) of investees, net		38		7	224	106
Pretax gain, sale of business to Atairos			$ 200	105		105
Hulu [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments		219			219				249
Cash contributions to equity method investments					341	198
Equity in net income (losses) of investees, net		(132)		(62)	(370)	(168)
Hulu [Member] | NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments		219			219				$ 249
Cash contributions to equity method investments					341	198
Equity in net income (losses) of investees, net		$ (132)		$ (62)	$ (370)	$ (168)
The Weather Channel [Member]
Schedule of Equity Method Investments [Line Items]
Pretax gain on sale of investment	$ 64
The Weather Channel [Member] | NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Pretax gain on sale of investment	$ 64

Investments (Marketable Equity

Investments (Marketable Equity Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Schedule of Marketable Equity Securities [Line Items]
Marketable equity securities			$ 322	$ 322		$ 433
NBCUniversal Media LLC [Member]
Schedule of Marketable Equity Securities [Line Items]
Contribution from member					$ 662
Marketable equity securities			249	249		430
Snap [Member]
Schedule of Marketable Equity Securities [Line Items]
Payments to acquire marketable securities		$ 500
Marketable equity securities			249	249		430
Marketable securities, recognized unrealized gains (losses)			(135)	(180)
Snap [Member] | NBCUniversal Media LLC [Member]
Schedule of Marketable Equity Securities [Line Items]
Contribution from member	$ 662
Marketable equity securities			249	249		$ 430
Marketable securities, recognized unrealized gains (losses)			$ (135)	$ (180)

Investments (Other Investments)

Investments (Other Investments) (Details) $ in Billions	Sep. 30, 2018USD ($)preferred_stock_series	Dec. 31, 2017USD ($)
Level 2 [Member] | AirTouch [Member]
Schedule of Other Investments [Line Items]
Fair value of redeemable preferred shares	$ 1.7
AirTouch [Member]
Schedule of Other Investments [Line Items]
Number of series of preferred stock | preferred_stock_series	2
Held to maturity investment	$ 1.6	$ 1.6
AirTouch [Member] | Level 2 [Member]
Schedule of Other Investments [Line Items]
Fair value of held to maturity investment redeemable preferred shares	$ 1.7

Supplemental Financial Inform_3

Supplemental Financial Information (Share-Based Compensation) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		$ 151	$ 159	$ 458	$ 464
Restricted share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		94	99	279	284
Unrecognized pretax compensation expense on nonvested awards		914		914
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		50	52	155	155
Unrecognized pretax compensation expense on nonvested awards		489		489
Employee Stock purchase plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		$ 7	$ 8	$ 24	$ 25
Management Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options granted (in shares)	41
Weighted average fair value of stock options granted (in dollars per share)	$ 7.15
Management Grant [Member] | Restricted share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted share units granted (in shares)	12.1
Weighted average fair value of restricted share units granted (in dollars per share)	$ 35.94

Supplemental Financial Inform_4

Supplemental Financial Information (Cash Payments for Interest and Income Taxes) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash Payments for Interest and Income Taxes
Interest	$ 2,240	$ 2,277
Income taxes	1,533	3,415
NBCUniversal Media LLC [Member]
Cash Payments for Interest and Income Taxes
Interest	253	340
Income taxes	$ 373	$ 213

Supplemental Financial Inform_5

Supplemental Financial Information (Noncash Investing and Financing Activities) (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)$ / shares
Supplemental Financial Information [Line Items]
Property and equipment and intangible assets accrued but not yet paid	$ 2,100
Dividends payable	$ 864
Dividends payable (in dollars per share) | $ / shares	$ 0.19
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Property and equipment and intangible assets accrued but not yet paid	$ 1,200
Universal Beijing Resort [Member]
Supplemental Financial Information [Line Items]
Assets contributed to variable interest entity	391
Universal Beijing Resort [Member] | NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Assets contributed to variable interest entity	$ 391

Supplemental Financial Inform_6

Supplemental Financial Information (Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Supplemental Financial Information [Line Items]
Cash and cash equivalents	$ 10,616	$ 3,428
Restricted cash included in other current assets	47	60
Restricted cash included in other noncurrent assets, net	3,959	83
Cash, cash equivalents and restricted cash, end of period	14,622	3,571	$ 4,228	$ 3,415
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Cash and cash equivalents	1,181	2,347
Restricted cash included in other noncurrent assets, net	20	30
Cash, cash equivalents and restricted cash, end of period	$ 1,201	$ 2,377	$ 2,038	$ 1,987

Supplemental Financial Inform_7

Supplemental Financial Information (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	$ 2		$ (43)
Deferred gains (losses) on cash flow hedges	28		(12)
Unrecognized gains (losses) on employee benefit obligations	294		270
Cumulative translation adjustments	50		166
Accumulated other comprehensive income (loss), net of deferred taxes	374	$ 379	381
NBCUniversal Media LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	0		(233)
Deferred gains (losses) on cash flow hedges	5		(4)
Unrecognized gains (losses) on employee benefit obligations	115		115
Cumulative translation adjustments	(22)		93
Accumulated other comprehensive income (loss), net of deferred taxes	$ 98	$ (20)	$ (29)

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 12,468		$ 12,468		$ 10,972
Recognized share-based compensation expense	151	$ 159	458	$ 464
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	5,189		5,189		$ 4,153
Recognized share-based compensation expense	37	$ 38	115	$ 103
Carrying Value of Related Party Contractual Obligation [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 383		$ 383

Related Party Transactions (Con

Related Party Transactions (Condensed Consolidated Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Total costs and expenses	(17,299)	(16,302)	(52,166)	(49,065)
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	8,625	7,976	26,468	24,147
Total costs and expenses	(6,932)	(5,889)	(21,393)	(18,995)
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	506	463	1,580	1,382
Total costs and expenses	(59)	(38)	(162)	(148)
Interest expense and investment and other income (loss), net	$ (9)	$ (20)	$ (52)	$ (67)

Related Party Transactions (C_2

Related Party Transactions (Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Receivables, net	$ 8,983	$ 8,834
Accounts payable and accrued expenses related to trade creditors	7,036	6,908
Accrued expenses and other current liabilities	5,976	6,620
Long-term debt, less current portion	69,711	59,422
Other noncurrent liabilities	12,468	10,972
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	6,851	6,967
Note receivable from Comcast	1,522	0
Accounts payable and accrued expenses related to trade creditors	1,665	1,663
Accrued expenses and other current liabilities	1,914	2,394
Note payable to Comcast	41	1,831
Long-term debt, less current portion	12,401	12,275
Other noncurrent liabilities	5,189	4,153
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	350	326
Note receivable from Comcast	1,522	0
Accounts payable and accrued expenses related to trade creditors	48	54
Accrued expenses and other current liabilities	20	50
Note payable to Comcast	41	1,831
Long-term debt, less current portion	698	610
Other noncurrent liabilities	$ 394	$ 389

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) $ in Millions	Sep. 30, 2018USD ($)
Redeemable Preferred Stock [Member] | Level 2 [Member]
Temporary Equity [Line Items]
Fair Value of Redeemable subsidiary preferred stock	$ 742

Condensed Consolidating Finan_3

Condensed Consolidating Financial Information (Narrative) (Details) $ in Millions	Sep. 30, 2018USD ($)
NBCUniversal Enterprise Senior Debt Securities [Member]
Debt Instrument [Line Items]
Principal amount of debt securities subject to guarantee	$ 3,000
NBCUniversal Enterprise Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility subject to guarantee	1,600
Universal Studios Japan Term Loan Maturing March 2022 [Member]
Debt Instrument [Line Items]
Term loans subject to guarantee	3,500
Comcast Holdings' ZONES due October 2029 [Member]
Debt Instrument [Line Items]
Principal amount of debt securities subject to guarantee	185
Comcast Holdings' ZONES due November 2029 [Member]
Debt Instrument [Line Items]
Principal amount of debt securities not subject to guarantee	$ 62

Condensed Consolidating Finan_4

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Revenue	$ 22,135	$ 21,081	$ 66,661	$ 62,954
Costs and Expenses:
Programming and production	6,711	6,059	20,440	18,450
Other operating and administrative	6,444	6,535	19,323	18,642
Advertising, marketing and promotion	1,667	1,604	4,924	4,894
Depreciation	2,038	1,991	6,070	5,876
Amortization	580	555	1,750	1,645
Other operating gains	(141)	(442)	(341)	(442)
Total costs and expenses	17,299	16,302	52,166	49,065
Operating income	4,836	4,779	14,495	13,889
Interest expense	(830)	(766)	(2,413)	(2,279)
Investment and other income (loss), net	(111)	70	92	299
Income before income taxes	3,895	4,083	12,174	11,909
Income tax expense	(999)	(1,409)	(2,894)	(4,038)
Net income	2,896	2,674	9,280	7,871
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	10	32	60	135
Net income attributable to Comcast Corporation	2,886	2,642	9,220	7,736
Comprehensive income (loss) attributable to Comcast Corporation	2,799	2,595	9,139	7,825
Elimination and Consolidation Adjustments [Member]
Revenue:
Revenue	(593)	(565)	(1,762)	(1,668)
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	(593)	(565)	(1,762)	(1,668)
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	(593)	(565)	(1,762)	(1,668)
Operating income	0	0	0	0
Interest expense	0	0	0	0
Investment and other income (loss), net	(12,438)	(11,423)	(38,519)	(32,739)
Income before income taxes	(12,438)	(11,423)	(38,519)	(32,739)
Income tax expense	0	0	0	0
Net income	(12,438)	(11,423)	(38,519)	(32,739)
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	(12,438)	(11,423)	(38,519)	(32,739)
Comprehensive income (loss) attributable to Comcast Corporation	(12,098)	(11,198)	(38,202)	(32,581)
Comcast Parent [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	299	285	889	841
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	208	183	626	553
Advertising, marketing and promotion	0	0	0	0
Depreciation	12	7	34	21
Amortization	1	1	4	4
Other operating gains	0	0	0	0
Total costs and expenses	221	191	664	578
Operating income	78	94	225	263
Interest expense	(600)	(544)	(1,739)	(1,592)
Investment and other income (loss), net	3,299	2,934	10,416	8,600
Income before income taxes	2,777	2,484	8,902	7,271
Income tax expense	109	158	318	465
Net income	2,886	2,642	9,220	7,736
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	2,886	2,642	9,220	7,736
Comprehensive income (loss) attributable to Comcast Corporation	2,799	2,595	9,139	7,825
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	22,135	21,081	66,661	62,954
Costs and Expenses:
Programming and production	6,711	6,059	20,440	18,450
Other operating and administrative	6,305	6,360	18,814	18,086
Advertising, marketing and promotion	1,667	1,604	4,924	4,894
Depreciation	2,026	1,984	6,036	5,855
Amortization	579	554	1,746	1,641
Other operating gains	(141)	(442)	(341)	(442)
Total costs and expenses	17,147	16,119	51,619	48,484
Operating income	4,988	4,962	15,042	14,470
Interest expense	(66)	(55)	(190)	(175)
Investment and other income (loss), net	1,065	1,845	3,977	4,476
Income before income taxes	5,987	6,752	18,829	18,771
Income tax expense	(1,115)	(1,568)	(3,229)	(4,516)
Net income	4,872	5,184	15,600	14,255
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	10	32	60	135
Net income attributable to Comcast Corporation	4,862	5,152	15,540	14,120
Comprehensive income (loss) attributable to Comcast Corporation	4,663	5,024	15,357	13,993
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	0	0	0	0
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	0	0	0	0
Operating income	0	0	0	0
Interest expense	(3)	(3)	(9)	(9)
Investment and other income (loss), net	3,380	2,513	10,279	7,841
Income before income taxes	3,377	2,510	10,270	7,832
Income tax expense	(1)	(10)	0	(26)
Net income	3,376	2,500	10,270	7,806
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	3,376	2,500	10,270	7,806
Comprehensive income (loss) attributable to Comcast Corporation	3,349	2,484	10,245	7,804
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	294	280	873	827
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	294	280	873	827
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	294	280	873	827
Operating income	0	0	0	0
Interest expense	(48)	(48)	(143)	(159)
Investment and other income (loss), net	3,007	1,995	8,832	6,628
Income before income taxes	2,959	1,947	8,689	6,469
Income tax expense	10	17	29	56
Net income	2,969	1,964	8,718	6,525
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	2,969	1,964	8,718	6,525
Comprehensive income (loss) attributable to Comcast Corporation	2,974	1,968	8,723	6,531
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	230	277	772	844
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	230	277	772	844
Operating income	(230)	(277)	(772)	(844)
Interest expense	(113)	(116)	(332)	(344)
Investment and other income (loss), net	1,576	2,206	5,107	5,493
Income before income taxes	1,233	1,813	4,003	4,305
Income tax expense	(2)	(6)	(12)	(17)
Net income	1,231	1,807	3,991	4,288
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	1,231	1,807	3,991	4,288
Comprehensive income (loss) attributable to Comcast Corporation	1,112	1,722	3,877	4,253
Service [Member]
Revenue:
Revenue	22,135	21,081	66,661	62,954
Service [Member] | Elimination and Consolidation Adjustments [Member]
Revenue:
Revenue	0	0	0	0
Service [Member] | Comcast Parent [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Service [Member] | Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	22,135	21,081	66,661	62,954
Service [Member] | Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Service [Member] | CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Service [Member] | NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Management Fee [Member]
Revenue:
Revenue	0	0	0	0
Management Fee [Member] | Elimination and Consolidation Adjustments [Member]
Revenue:
Revenue	(593)	(565)	(1,762)	(1,668)
Management Fee [Member] | Comcast Parent [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	299	285	889	841
Management Fee [Member] | Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Management Fee [Member] | Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	0	0	0	0
Management Fee [Member] | CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	294	280	873	827
Management Fee [Member] | NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Revenue	$ 0	$ 0	$ 0	$ 0

Condensed Consolidating Finan_5

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			$ 18,507	$ 15,857
Investing Activities
Net transactions with affiliates			0	0
Capital expenditures	$ (2,384)	$ (2,434)	(6,607)	(6,839)
Cash paid for intangible assets	(445)	(365)	(1,375)	(1,136)
Acquisitions and construction of real estate properties			(129)	(325)
Construction of Universal Beijing Resort			(257)	(47)
Acquisitions, net of cash acquired			(88)	(429)
Proceeds from sales of investments			127	120
Purchases of investments			(840)	(2,064)
Other			579	797
Net cash provided by (used in) investing activities			(8,590)	(9,923)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			2,909	(2,807)
Proceeds from borrowings			9,850	11,460
Repurchases and repayments of debt			(4,405)	(5,021)
Repurchases of common stock under repurchase program and employee plans			(4,282)	(4,212)
Dividends paid			(2,487)	(2,147)
Purchase of Universal Studios Japan noncontrolling interests			0	(2,299)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			(209)	(198)
Other			(242)	103
Net cash provided by (used in) financing activities			1,134	(5,121)
Increase (decrease) in cash, cash equivalents and restricted cash			11,051	813
Cash, cash equivalents and restricted cash, beginning of period			3,571	3,415
Cash, cash equivalents and restricted cash, end of period	14,622	4,228	14,622	4,228
Elimination and Consolidation Adjustments [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			0	0
Investing Activities
Net transactions with affiliates			0	0
Capital expenditures			0	0
Cash paid for intangible assets			0	0
Acquisitions and construction of real estate properties			0	0
Construction of Universal Beijing Resort			0	0
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			0	0
Purchases of investments			0	0
Other			0	0
Net cash provided by (used in) investing activities			0	0
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			0	0
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests				0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			0	0
Net cash provided by (used in) financing activities			0	0
Increase (decrease) in cash, cash equivalents and restricted cash			0	0
Cash, cash equivalents and restricted cash, beginning of period			0	0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0
Comcast Parent [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(1,461)	(931)
Investing Activities
Net transactions with affiliates			(1,087)	4,216
Capital expenditures			(15)	(6)
Cash paid for intangible assets			(3)	(2)
Acquisitions and construction of real estate properties			(94)	(190)
Construction of Universal Beijing Resort			0	0
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			0	0
Purchases of investments			(118)	(56)
Other			0	101
Net cash provided by (used in) investing activities			(1,317)	4,063
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			2,117	(1,739)
Proceeds from borrowings			9,386	5,997
Repurchases and repayments of debt			(1,900)	(1,000)
Repurchases of common stock under repurchase program and employee plans			(4,282)	(4,212)
Dividends paid			(2,487)	(2,147)
Purchase of Universal Studios Japan noncontrolling interests				0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			(56)	(31)
Net cash provided by (used in) financing activities			2,778	(3,132)
Increase (decrease) in cash, cash equivalents and restricted cash			0	0
Cash, cash equivalents and restricted cash, beginning of period			0	0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			21,084	17,985
Investing Activities
Net transactions with affiliates			667	(5,776)
Capital expenditures			(6,592)	(6,833)
Cash paid for intangible assets			(1,372)	(1,134)
Acquisitions and construction of real estate properties			(35)	(135)
Construction of Universal Beijing Resort			(257)	(47)
Acquisitions, net of cash acquired			(88)	(429)
Proceeds from sales of investments			60	110
Purchases of investments			(672)	(1,916)
Other			130	647
Net cash provided by (used in) investing activities			(8,159)	(15,513)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			792	(1,068)
Proceeds from borrowings			464	5,463
Repurchases and repayments of debt			(2,502)	(3,468)
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests				(2,299)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			(209)	(198)
Other			(186)	134
Net cash provided by (used in) financing activities			(1,641)	(1,436)
Increase (decrease) in cash, cash equivalents and restricted cash			11,284	1,036
Cash, cash equivalents and restricted cash, beginning of period			3,075	2,933
Cash, cash equivalents and restricted cash, end of period	14,359	3,969	14,359	3,969
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			137	91
Investing Activities
Net transactions with affiliates			(586)	(91)
Capital expenditures			0	0
Cash paid for intangible assets			0	0
Acquisitions and construction of real estate properties			0	0
Construction of Universal Beijing Resort			0	0
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			0	0
Purchases of investments			0	0
Other			449	0
Net cash provided by (used in) investing activities			(137)	(91)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			0	0
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests				0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			0	0
Net cash provided by (used in) financing activities			0	0
Increase (decrease) in cash, cash equivalents and restricted cash			0	0
Cash, cash equivalents and restricted cash, beginning of period			0	0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(206)	(233)
Investing Activities
Net transactions with affiliates			206	818
Capital expenditures			0	0
Cash paid for intangible assets			0	0
Acquisitions and construction of real estate properties			0	0
Construction of Universal Beijing Resort			0	0
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			0	0
Purchases of investments			0	(35)
Other			0	0
Net cash provided by (used in) investing activities			206	783
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			0	(550)
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests				0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			0	0
Net cash provided by (used in) financing activities			0	(550)
Increase (decrease) in cash, cash equivalents and restricted cash			0	0
Cash, cash equivalents and restricted cash, beginning of period			0	0
Cash, cash equivalents and restricted cash, end of period	0	0	0	0
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(1,047)	(1,055)
Investing Activities
Net transactions with affiliates			800	833
Capital expenditures			0	0
Cash paid for intangible assets			0	0
Acquisitions and construction of real estate properties			0	0
Construction of Universal Beijing Resort			0	0
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			67	10
Purchases of investments			(50)	(57)
Other			0	49
Net cash provided by (used in) investing activities			817	835
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			(3)	(3)
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests				0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			0	0
Net cash provided by (used in) financing activities			(3)	(3)
Increase (decrease) in cash, cash equivalents and restricted cash			(233)	(223)
Cash, cash equivalents and restricted cash, beginning of period			496	482
Cash, cash equivalents and restricted cash, end of period	$ 263	$ 259	$ 263	$ 259

Condensed Consolidating Finan_6

Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 10,616	$ 3,428
Receivables, net	8,983	8,834
Programming rights	1,223	1,613
Other current assets	2,384	2,468
Total current assets	23,206	16,343
Film and television costs	7,377	7,087
Investments	7,724	6,931
Investments in and amounts due from subsidiaries eliminated upon consolidation	0	0
Property and equipment, net	39,855	38,470
Franchise rights	59,365	59,364
Goodwill	36,703	36,780
Other intangible assets, net	18,649	18,133
Other noncurrent assets, net	7,756	4,354
Total assets	200,635	187,462
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	7,036	6,908
Accrued participations and residuals	1,809	1,644
Deferred revenue	1,633	1,687
Accrued expenses and other current liabilities	5,976	6,620
Current portion of long-term debt	3,173	5,134
Total current liabilities	19,627	21,993
Long-term debt, less current portion	69,711	59,422
Deferred income taxes	25,167	24,259
Other noncurrent liabilities	12,468	10,972
Redeemable noncontrolling interests	1,317	1,357
Equity:
Common stock	54	55
Other shareholders’ equity	71,469	68,561
Total Comcast Corporation shareholders’ equity	71,523	68,616
Noncontrolling interests	822	843
Total equity	72,345	69,459	$ 56,258	$ 56,163
Total liabilities and equity	200,635	187,462
Elimination and Consolidation Adjustments [Member]
Assets
Cash and cash equivalents	0	0
Receivables, net	0	0
Programming rights	0	0
Other current assets	0	0
Total current assets	0	0
Film and television costs	0	0
Investments	0	0
Investments in and amounts due from subsidiaries eliminated upon consolidation	(564,823)	(562,645)
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	(235)	(314)
Total assets	(565,058)	(562,959)
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	0	0
Current portion of long-term debt	0	0
Total current liabilities	0	0
Long-term debt, less current portion	0	0
Deferred income taxes	(301)	(343)
Other noncurrent liabilities	66	29
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	(564,823)	(562,645)
Total Comcast Corporation shareholders’ equity	(564,823)	(562,645)
Noncontrolling interests	0	0
Total equity	(564,823)	(562,645)
Total liabilities and equity	(565,058)	(562,959)
Comcast Parent [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0
Receivables, net	0	0
Programming rights	0	0
Other current assets	58	60
Total current assets	58	60
Film and television costs	0	0
Investments	267	146
Investments in and amounts due from subsidiaries eliminated upon consolidation	129,360	117,164
Property and equipment, net	649	551
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	11	12
Other noncurrent assets, net	782	435
Total assets	131,127	118,368
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	13	16
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	1,852	1,888
Current portion of long-term debt	699	2,810
Total current liabilities	2,564	4,714
Long-term debt, less current portion	54,120	42,428
Deferred income taxes	0	0
Other noncurrent liabilities	2,920	2,610
Redeemable noncontrolling interests	0	0
Equity:
Common stock	54	55
Other shareholders’ equity	71,469	68,561
Total Comcast Corporation shareholders’ equity	71,523	68,616
Noncontrolling interests	0	0
Total equity	71,523	68,616
Total liabilities and equity	131,127	118,368
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	10,353	2,932
Receivables, net	8,983	8,834
Programming rights	1,223	1,613
Other current assets	2,284	2,376
Total current assets	22,843	15,755
Film and television costs	7,377	7,087
Investments	6,534	5,963
Investments in and amounts due from subsidiaries eliminated upon consolidation	103,526	113,332
Property and equipment, net	39,206	37,919
Franchise rights	59,365	59,364
Goodwill	36,703	36,780
Other intangible assets, net	18,638	18,121
Other noncurrent assets, net	6,884	3,437
Total assets	301,076	297,758
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	7,023	6,892
Accrued participations and residuals	1,809	1,644
Deferred revenue	1,633	1,687
Accrued expenses and other current liabilities	3,397	3,981
Current portion of long-term debt	2,470	2,320
Total current liabilities	16,332	16,524
Long-term debt, less current portion	5,599	7,003
Deferred income taxes	25,070	24,250
Other noncurrent liabilities	8,257	7,205
Redeemable noncontrolling interests	1,317	1,357
Equity:
Common stock	0	0
Other shareholders’ equity	243,679	240,576
Total Comcast Corporation shareholders’ equity	243,679	240,576
Noncontrolling interests	822	843
Total equity	244,501	241,419
Total liabilities and equity	301,076	297,758
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0
Receivables, net	0	0
Programming rights	0	0
Other current assets	8	0
Total current assets	8	0
Film and television costs	0	0
Investments	11	21
Investments in and amounts due from subsidiaries eliminated upon consolidation	146,297	142,519
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	230	708
Total assets	146,546	143,248
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	150	92
Current portion of long-term debt	0	0
Total current liabilities	150	92
Long-term debt, less current portion	144	140
Deferred income taxes	330	285
Other noncurrent liabilities	0	0
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	145,922	142,731
Total Comcast Corporation shareholders’ equity	145,922	142,731
Noncontrolling interests	0	0
Total equity	145,922	142,731
Total liabilities and equity	146,546	143,248
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0
Receivables, net	0	0
Programming rights	0	0
Other current assets	0	7
Total current assets	0	7
Film and television costs	0	0
Investments	122	108
Investments in and amounts due from subsidiaries eliminated upon consolidation	132,562	139,528
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	0	0
Total assets	132,684	139,643
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	231	333
Current portion of long-term debt	0	0
Total current liabilities	231	333
Long-term debt, less current portion	2,100	2,100
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	130,353	137,210
Total Comcast Corporation shareholders’ equity	130,353	137,210
Noncontrolling interests	0	0
Total equity	130,353	137,210
Total liabilities and equity	132,684	139,643
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	263	496
Receivables, net	0	0
Programming rights	0	0
Other current assets	34	25
Total current assets	297	521
Film and television costs	0	0
Investments	790	693
Investments in and amounts due from subsidiaries eliminated upon consolidation	53,078	50,102
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	95	88
Total assets	54,260	51,404
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	346	326
Current portion of long-term debt	4	4
Total current liabilities	350	330
Long-term debt, less current portion	7,748	7,751
Deferred income taxes	68	67
Other noncurrent liabilities	1,225	1,128
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	44,869	42,128
Total Comcast Corporation shareholders’ equity	44,869	42,128
Noncontrolling interests	0	0
Total equity	44,869	42,128
Total liabilities and equity	$ 54,260	$ 51,404