NBCUniversal Media 10-Q 25 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 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
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
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	4,607,671,892
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
	Mar. 31, 2018	Mar. 31, 2017
Revenue	$ 22,791	$ 20,587
Costs and Expenses:
Programming and production	7,429	6,061
Other operating and administrative	6,514	5,939
Advertising, marketing and promotion	1,604	1,577
Depreciation	2,011	1,915
Amortization	588	553
Total costs and expenses	18,146	16,045
Operating income	4,645	4,542
Interest expense	(777)	(755)
Investment and other income (loss), net	126	130
Income before income taxes	3,994	3,917
Income tax expense	(818)	(1,262)
Net income	3,176	2,655
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	58	82
Net income attributable to Comcast Corporation	$ 3,118	$ 2,573
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.67	$ 0.54
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	0.66	0.53
Dividends declared per common share (in dollars per share)	$ 0.19	$ 0.1575
NBCUniversal Media LLC [Member]
Revenue	$ 9,530	$ 7,853
Costs and Expenses:
Programming and production	4,573	3,300
Other operating and administrative	1,972	1,828
Advertising, marketing and promotion	700	706
Depreciation	242	231
Amortization	268	277
Total costs and expenses	7,755	6,342
Operating income	1,775	1,511
Interest expense	(127)	(143)
Investment and other income (loss), net	(4)	(1)
Income before income taxes	1,644	1,367
Income tax expense	(91)	(92)
Net income	1,553	1,275
Less: Net income attributable to noncontrolling interests	40	73
Net income attributable to Comcast Corporation	$ 1,513	$ 1,202

Condensed Consolidated Stateme3

Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income	$ 3,176	$ 2,655
Unrealized gains (losses) on marketable securities, net of deferred taxes	(1)	104
Deferred gains (losses) on cash flow hedges, net of deferred taxes	29	7
Amounts reclassified to net income:
Realized (gains) losses on cash flow hedges, net of deferred taxes	(20)	0
Employee benefit obligations, net of deferred taxes	(8)	63
Currency translation adjustments, net of deferred taxes	157	157
Comprehensive income	3,333	2,986
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	58	82
Less: Other comprehensive income (loss) attributable to noncontrolling interests	4	87
Comprehensive income (loss) attributable to Comcast Corporation	3,271	2,817
NBCUniversal Media LLC [Member]
Net income	1,553	1,275
Unrealized gains (losses) on marketable securities, net of deferred taxes	0	1
Deferred gains (losses) on cash flow hedges, net of deferred taxes	(13)	(14)
Amounts reclassified to net income:
Employee benefit obligations, net of deferred taxes	(4)	106
Currency translation adjustments, net of deferred taxes	204	200
Comprehensive income	1,740	1,568
Less: Net income attributable to noncontrolling interests	40	73
Less: Other comprehensive income (loss) attributable to noncontrolling interests	4	87
Comprehensive income (loss) attributable to Comcast Corporation	$ 1,696	$ 1,408

Condensed Consolidated Stateme4

Condensed Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on marketable securities, deferred taxes	$ 0	$ (61)
Deferred gains (losses) on cash flow hedges, deferred taxes	(9)	(4)
Realized (gains) losses on cash flow hedges, deferred taxes	6	0
Employee benefit obligations, deferred taxes	2	(37)
Currency translation adjustments, deferred taxes	$ (47)	$ (41)

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 3,176	$ 2,655
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and Amortization	2,599	2,468
Share-based compensation	199	173
Noncash interest expense (income), net	75	58
Net (gain) loss on investment activity and other	(74)	(73)
Deferred income taxes	389	269
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net	85	522
Film and television costs, net	(45)	46
Accounts payable and accrued expenses related to trade creditors	200	(194)
Other operating assets and liabilities	(1,130)	(299)
Net cash provided by operating activities	5,474	5,625
Investing Activities
Capital expenditures	(1,973)	(2,078)
Cash paid for intangible assets	(419)	(385)
Acquisitions and construction of real estate properties	(59)	(130)
Acquisitions, net of cash acquired	(89)	(216)
Proceeds from sales of investments	81	51
Purchases of investments	(220)	(1,062)
Other	387	67
Net cash provided by (used in) investing activities	(2,292)	(3,753)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(902)	(1,893)
Proceeds from borrowings	4,043	3,500
Repurchases and repayments of debt	(1,265)	(1,059)
Repurchases of common stock under repurchase program and employee plans	(1,729)	(996)
Dividends paid	(738)	(657)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(79)	(72)
Other	94	36
Net cash provided by (used in) financing activities	(576)	(1,141)
Increase (decrease) in cash, cash equivalents and restricted cash	2,606	731
Cash, cash equivalents and restricted cash, beginning of period	3,571	3,415
Cash, cash equivalents and restricted cash, end of period	6,177	4,146
NBCUniversal Media LLC [Member]
Operating Activities
Net income	1,553	1,275
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and Amortization	510	508
Net (gain) loss on investment activity and other	25	31
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net	(200)	162
Film and television costs, net	(47)	46
Accounts payable and accrued expenses related to trade creditors	(24)	(190)
Other operating assets and liabilities	(551)	(355)
Net cash provided by operating activities	1,266	1,477
Investing Activities
Capital expenditures	(269)	(285)
Cash paid for intangible assets	(130)	(55)
Purchases of investments	(133)	(63)
Other	(113)	(32)
Net cash provided by (used in) investing activities	(645)	(435)
Financing Activities
Repurchases and repayments of debt	(55)	(49)
Proceeds from (repayments of) borrowings from Comcast, net	(547)	(849)
Distributions to member	(195)	(195)
Distributions to noncontrolling interests	(62)	(61)
Other	117	28
Net cash provided by (used in) financing activities	(742)	(1,126)
Increase (decrease) in cash, cash equivalents and restricted cash	(121)	(84)
Cash, cash equivalents and restricted cash, beginning of period	2,377	1,987
Cash, cash equivalents and restricted cash, end of period	$ 2,256	$ 1,903

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 6,030	$ 3,428
Receivables, net	8,759	8,834
Programming rights	1,354	1,613
Other current assets	2,610	2,468
Total current assets	18,753	16,343
Film and television costs	7,402	7,087
Investments	7,095	6,931
Property and equipment, net	39,068	38,470
Franchise rights	59,365	59,364
Goodwill	37,147	36,780
Other intangible assets, net	18,339	18,133
Other noncurrent assets, net	3,707	4,354
Total assets	190,876	187,462
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	7,349	6,908
Accrued participations and residuals	1,659	1,644
Deferred revenue	1,578	1,687
Accrued expenses and other current liabilities	5,554	6,620
Current portion of long-term debt	3,039	5,134
Total current liabilities	19,179	21,993
Long-term debt, less current portion	63,678	59,422
Deferred income taxes	24,702	24,259
Other noncurrent liabilities	11,253	10,972
Commitments and contingencies (Note 11)
Redeemable noncontrolling interests	1,354	1,357
Equity:
Preferred stock—authorized, 20,000,000 shares; issued, zero	0	0
Common stock	55	55
Additional paid-in capital	37,375	37,497
Retained earnings	38,961	38,202
Treasury stock, 872,791,028 Class A common shares	(7,517)	(7,517)
Accumulated other comprehensive income (loss)	608	379
Total Comcast Corporation shareholders’ equity	69,482	68,616
Noncontrolling interests	1,228	843
Total equity	70,710	69,459
Total liabilities and equity	190,876	187,462
NBCUniversal Media LLC [Member]
Current Assets:
Cash and cash equivalents	2,225	2,347
Receivables, net	7,176	6,967
Programming rights	1,347	1,606
Other current assets	1,065	1,037
Total current assets	11,813	11,957
Film and television costs	7,398	7,082
Investments	1,863	1,816
Property and equipment, net	11,960	11,346
Goodwill	24,356	23,989
Intangible assets, net	13,562	13,306
Other noncurrent assets, net	1,775	1,804
Total assets	72,727	71,300
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	1,862	1,663
Accrued participations and residuals	1,659	1,644
Program obligations	898	745
Deferred revenue	1,313	1,457
Accrued expenses and other current liabilities	1,760	2,394
Note payable to Comcast	1,284	1,831
Current portion of long-term debt	218	198
Total current liabilities	8,994	9,932
Long-term debt, less current portion	12,478	12,275
Accrued participations, residuals and program obligations	1,453	1,490
Other noncurrent liabilities	4,487	4,153
Commitments and contingencies (Note 11)
Redeemable noncontrolling interests	405	409
Equity:
Member’s capital	43,228	42,148
Accumulated other comprehensive income (loss)	396	(20)
Total NBCUniversal member’s equity	43,624	42,128
Noncontrolling interests	1,286	913
Total equity	44,910	43,041
Total liabilities and equity	72,727	71,300
Class A Common Stock [Member]
Equity:
Common stock	55	55
Class B Common Stock [Member]
Equity:
Common stock	$ 0	$ 0

Condensed Consolidated Balance7

Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Property and equipment - accumulated depreciation	$ 50,393	$ 49,916
Other intangible assets - accumulated amortization	$ 12,465	$ 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	$ 4,394	$ 4,166
Other intangible assets - accumulated amortization	$ 7,874	$ 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)	5,480,462,920	5,507,854,670
Common stock, shares outstanding (in shares)	4,607,671,892	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 Stateme8

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	114		114
Repurchases of common stock under repurchase program and employee plans	(1,006)		(178)	(828)
Employee stock purchase plans	39		39
Dividends declared	(751)			(751)				(195)		(195)
Other comprehensive income (loss)	331					244	87	293			206	87
Contributions from (distributions to) noncontrolling interests, net	(34)						(34)	(41)				(41)
Contribution from member								662		662
Other	162		(90)				252	342		89		253
Net income (loss)	2,626			2,573			53	1,257		1,202		55
Ending balance at Mar. 31, 2017	57,644		38,115	24,059	(7,517)	342	2,589						56	0
Ending balance at Mar. 31, 2017								43,193		40,652	71	2,470
Beginning balance at Dec. 31, 2016		$ 1,446							$ 530
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions from (distributions to) noncontrolling interests, net		(8)							(20)
Other		(11)							(1)
Net income (loss)		29							18
Ending balance at Mar. 31, 2017		1,456							527
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	127		127
Repurchases of common stock under repurchase program and employee plans	(1,726)		(294)	(1,432)
Employee stock purchase plans	48		48
Dividends declared	(884)			(884)				(195)		(195)
Other comprehensive income (loss)	157					153	4	188			184	4
Contributions from (distributions to) noncontrolling interests, net	350						350	346				346
Other	(6)		(3)				(3)	(10)		(6)		(4)
Net income (loss)	3,152			3,118			34	1,540		1,513		27
Ending balance at Mar. 31, 2018	70,710		$ 37,375	$ 38,961	$ (7,517)	$ 608	$ 1,228						$ 55	$ 0
Ending balance at Mar. 31, 2018								44,910		$ 43,228	$ 396	$ 1,286
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		(17)							(17)
Other		(10)
Net income (loss)		24							13
Ending balance at Mar. 31, 2018	$ 1,354	$ 1,354						$ 405	$ 405

Condensed Consolidated Financia

Condensed Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2018
Condensed Consolidated Financial Statements [Line Items]
Condensed Consolidated Financial Statements	Condensed Consolidated Financial Statements 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. Reclassifications Reclassifications have been made to our condensed consolidated financial statements for the prior year period 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	3 Months Ended
	Mar. 31, 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 March 31, 2018 (in millions) Revenue Adjusted EBITDA (e) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 13,518 $ 5,415 $ 2,053 $ 1,688 $ 269 NBCUniversal Cable Networks (a) 3,194 1,268 189 3 4 Broadcast Television (a) 3,497 507 34 30 72 Filmed Entertainment 1,647 203 28 7 6 Theme Parks 1,281 495 155 182 16 Headquarters and Other (b) 14 (188 ) 104 47 32 Eliminations (a)(c) (103 ) — — — — NBCUniversal 9,530 2,285 510 269 130 Corporate and Other (d) 391 (397 ) 36 16 20 Eliminations (a)(c) (648 ) (59 ) — — — Comcast Consolidated $ 22,791 $ 7,244 $ 2,599 $ 1,973 $ 419 Three Months Ended March 31, 2017 (in millions) Revenue Adjusted EBITDA (e) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 13,050 $ 5,174 $ 1,946 $ 1,781 $ 322 NBCUniversal Cable Networks 2,640 1,115 214 2 3 Broadcast Television 2,208 322 32 29 3 Filmed Entertainment 1,967 371 22 10 5 Theme Parks 1,118 397 142 229 13 Headquarters and Other (b) 8 (185 ) 98 15 31 Eliminations (c) (88 ) (1 ) — — — NBCUniversal 7,853 2,019 508 285 55 Corporate and Other (d) 208 (194 ) 14 12 8 Eliminations (c) (524 ) 11 — — — Comcast Consolidated $ 20,587 $ 7,010 $ 2,468 $ 2,078 $ 385 (a) 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. (b) NBCUniversal Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (c) 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 (d) 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 and operates arena management-related businesses. (e) 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 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 (in millions) 2018 2017 Adjusted EBITDA $ 7,244 $ 7,010 Depreciation (2,011 ) (1,915 ) Amortization (588 ) (553 ) Interest expense (777 ) (755 ) Investment and other income (loss), net 126 130 Income before income taxes $ 3,994 $ 3,917
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 March 31, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks (a) $ 3,194 $ 1,268 $ 189 $ 3 $ 4 Broadcast Television (a) 3,497 507 34 30 72 Filmed Entertainment 1,647 203 28 7 6 Theme Parks 1,281 495 155 182 16 Headquarters and Other (b) 14 (188 ) 104 47 32 Eliminations (a)(c) (103 ) — — — — Total $ 9,530 $ 2,285 $ 510 $ 269 $ 130 Three Months Ended March 31, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 2,640 $ 1,115 $ 214 $ 2 $ 3 Broadcast Television 2,208 322 32 29 3 Filmed Entertainment 1,967 371 22 10 5 Theme Parks 1,118 397 142 229 13 Headquarters and Other (b) 8 (185 ) 98 15 31 Eliminations (c) (88 ) (1 ) — — — Total $ 7,853 $ 2,019 $ 508 $ 285 $ 55 (a) 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. (b) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (c) 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. (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 NBCUniversal before net income 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 (in millions) 2018 2017 Adjusted EBITDA $ 2,285 $ 2,019 Depreciation (242 ) (231 ) Amortization (268 ) (277 ) Interest expense (127 ) (143 ) Investment and other income (loss), net (4 ) (1 ) Income before income taxes $ 1,644 $ 1,367

Revenue

Revenue	3 Months Ended
	Mar. 31, 2018
Revenue [Line Items]
Revenue	Revenue Three Months Ended (in millions) 2018 2017 Residential: Video $ 5,659 $ 5,706 High-Speed Internet 4,157 3,842 Voice 1,006 1,034 Business services 1,726 1,543 Advertising 582 554 Other 388 371 Total Cable Communications (a) 13,518 13,050 Distribution 1,887 1,562 Advertising 988 826 Content licensing and other 319 252 Total Cable Networks 3,194 2,640 Advertising 2,365 1,279 Content licensing 522 503 Distribution and other 610 426 Total Broadcast Television 3,497 2,208 Theatrical 423 651 Content licensing 733 734 Home entertainment 248 286 Other 243 296 Total Filmed Entertainment 1,647 1,967 Total Theme Parks 1,281 1,118 Headquarters and Other 14 8 Eliminations (b) (103 ) (88 ) Total NBCUniversal 9,530 7,853 Corporate and Other 391 208 Eliminations (b) (648 ) (524 ) Total revenue $ 22,791 $ 20,587 (a) For the three months ended March 31, 2018 and 2017, 2.8% and 2.9% , respectively, 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 (in millions) 2018 2017 United States $ 20,885 $ 18,832 Foreign 1,906 1,755 Total revenue $ 22,791 $ 20,587 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 businesses. 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 businesses 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 businesses 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 also include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service, we generally recognize revenue for variable pricing as the content is delivered and available and as the variable amounts become known. 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) March 31, December 31, Receivables, gross $ 9,052 $ 9,122 Less: Allowance for doubtful accounts 293 288 Receivables, net $ 8,759 $ 8,834 (in millions) March 31, December 31, Noncurrent receivables (included in other noncurrent assets, net) $ 1,180 $ 1,184 Contract acquisition and fulfillment costs (included in other noncurrent assets, net) $ 929 $ 922 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 536 $ 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 (in millions) 2018 2017 Distribution $ 1,887 $ 1,562 Advertising 988 826 Content licensing and other 319 252 Total Cable Networks 3,194 2,640 Advertising 2,365 1,279 Content licensing 522 503 Distribution and other 610 426 Total Broadcast Television 3,497 2,208 Theatrical 423 651 Content licensing 733 734 Home entertainment 248 286 Other 243 296 Total Filmed Entertainment 1,647 1,967 Total Theme Parks 1,281 1,118 Headquarters and Other 14 8 Eliminations (a) (103 ) (88 ) Total revenue $ 9,530 $ 7,853 (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 (in millions) 2018 2017 United States $ 7,654 $ 6,117 Foreign 1,876 1,736 Total revenue $ 9,530 $ 7,853 No single customer accounted for a significant amount of revenue in any period. 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 also include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service, we generally recognize revenue for variable pricing as the content is delivered and available and as the variable amounts become known. 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) March 31, December 31, Receivables, gross $ 7,269 $ 7,055 Less: Allowance for doubtful accounts 93 88 Receivables, net $ 7,176 $ 6,967 (in millions) March 31, December 31, Noncurrent receivables (included in other noncurrent assets, net) $ 1,090 $ 1,093 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 405 $ 392

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Computation of Diluted EPS Three Months Ended March 31 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 $ 3,118 4,633 $ 0.67 $ 2,573 4,747 $ 0.54 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 72 85 Diluted EPS attributable to Comcast Corporation shareholders $ 3,118 4,705 $ 0.66 $ 2,573 4,832 $ 0.53 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 months ended March 31, 2018 and 2017 .

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2018
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of March 31, 2018 , our debt had a carrying value of $66.7 billion and an estimated fair value of $70.7 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. Debt Borrowings (in millions) Three months ended 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 Other 43 Total $ 4,043 Debt Repayments (in millions) Three months ended Comcast 5.875% senior notes due 2018 $ 900 Other 365 Total $ 1,265 In April 2018, NBCUniversal Enterprise repaid at maturity $700 million aggregate principal amount of senior floating rate notes due 2018 and $1.1 billion aggregate principal amount of 1.662% senior notes due 2018. Revolving Credit Facilities As of March 31, 2018 , amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper programs and outstanding letters of credit, totaled $8.3 billion , which included $1.5 billion available under NBCUniversal Enterprise’s revolving credit facility. Commercial Paper Programs As of March 31, 2018 , Comcast and NBCUniversal Enterprise had no commercial paper outstanding.
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of March 31, 2018 , our debt, excluding the note payable to Comcast, had a carrying value of $12.7 billion and an estimated fair value of $13.3 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. 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 billion Comcast revolving credit facility due 2021. As of March 31, 2018 , outstanding debt securities of $51.4 billion of Comcast and CCCL Parent were subject to the cross-guarantee structure. We do not, however, guarantee the obligations of NBCUniversal Enterprise with respect to its $4.8 billion aggregate principal amount of senior notes, $1.5 billion revolving credit facility, commercial paper program, or $725 million liquidation preference of Series A cumulative preferred stock. The Universal Studios Japan term loans are not subject to the cross-guarantee structure, however they have a separate guarantee from Comcast.

Significant Transactions

Significant Transactions	3 Months Ended
	Mar. 31, 2018
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 ). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. 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. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors . As of March 31, 2018, our condensed consolidated balance sheet included assets, primarily including property and equipment, and liabilities of Universal Beijing Resort totaling $1.2 billion and $523 million , respectively. Sky Offer On April 25, 2018, we announced a pre-conditional all-cash firm offer for the entire issued and to be issued share capital of Sky plc. Pursuant to the offer, Sky shareholders will be entitled to receive £12.50 in cash for each Sky share (implying a value of approximately £22 billion , or $31 billion using the exchange rate at the time of the offer), plus any final dividend in respect of Sky’s fiscal year ending June 30, 2018 up to an amount of £0.218 per Sky share which is declared and paid prior to the offer going wholly unconditional. The acquisition is subject to the satisfaction (or waiver, where applicable) of certain conditions, including receipt of antitrust and regulatory approvals and securing acceptances carrying more than 50% of the voting rights then normally exercisable at a general meeting of Sky. In connection with the offer, we have entered into an unsecured bridge credit agreement in an aggregate principal amount of up to £16 billion and an unsecured term loan credit agreement in an aggregate principal amount of up to £7 billion ( $22 billion and $10 billion , respectively, using the exchange rate at the time of the offer), which will be guaranteed by Comcast Cable Communications, LLC and NBCUniversal.
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 ). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. 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. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors . As of March 31, 2018, our condensed consolidated balance sheet included assets, primarily including property and equipment, and liabilities of Universal Beijing Resort totaling $1.2 billion and $523 million , respectively.

Recent Accounting Pronouncement

Recent Accounting Pronouncements and Tax Reform	3 Months Ended
	Mar. 31, 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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 20,463 $ 124 $ 20,587 Total costs and expenses $ 15,933 $ 112 $ 16,045 Operating income $ 4,530 $ 12 $ 4,542 Net income attributable to Comcast Corporation $ 2,566 $ 7 $ 2,573 Condensed Consolidated Balance Sheet As of 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 period. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three months ended March 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,774 $ (68 ) $ 5,706 High-speed Internet 3,606 236 3,842 Voice 863 171 1,034 Business services 1,490 53 1,543 Advertising 512 42 554 Other 667 (296 ) 371 Total Cable Communications revenue $ 12,912 $ 138 $ 13,050 Operating costs and expenses $ 7,714 $ 162 $ 7,876 Depreciation and amortization expense $ 1,980 $ (34 ) $ 1,946 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 March 31, 2018. These amounts are subject to change as we obtain information necessary to complete the calculations. We did not recognize any changes to the provisional amounts for the three months ended March 31, 2018. We will update the provisional amounts as we refine our estimates of cumulative temporary differences, including those related to the immediate deduction for qualified property, and our interpretations of the application of the new legislation. We expect to complete our analysis of the provisional items during the second half 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. The legislation resulted in an income tax benefit of $128 million for the three months ended March 31, 2018. 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. The updated guidance is effective for us as of January 1, 2019 and early adoption is permitted. The updated accounting guidance must be adopted using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. 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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 7,868 $ (15 ) $ 7,853 Total costs and expenses $ 6,359 $ (17 ) $ 6,342 Operating income $ 1,509 $ 2 $ 1,511 Net income attributable to NBCUniversal $ 1,200 $ 2 $ 1,202 Condensed Consolidated Balance Sheet As of 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 the 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. The updated guidance is effective for us as of January 1, 2019 and early adoption is permitted. The updated accounting guidance must be adopted using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. 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	3 Months Ended
	Mar. 31, 2018
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) March 31, December 31, Film Costs: Released, less amortization $ 1,590 $ 1,734 Completed, not released 54 50 In production and in development 1,287 1,149 2,931 2,933 Television Costs: Released, less amortization 2,361 2,260 In production and in development 845 818 3,206 3,078 Programming rights, less amortization 2,619 2,689 8,756 8,700 Less: Current portion of programming rights 1,354 1,613 Film and television costs $ 7,402 $ 7,087
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) March 31, December 31, Film Costs: Released, less amortization $ 1,590 $ 1,734 Completed, not released 54 50 In production and in development 1,287 1,149 2,931 2,933 Television Costs: Released, less amortization 2,361 2,260 In production and in development 845 818 3,206 3,078 Programming rights, less amortization 2,608 2,677 8,745 8,688 Less: Current portion of programming rights 1,347 1,606 Film and television costs $ 7,398 $ 7,082

Investments

Investments	3 Months Ended
	Mar. 31, 2018
Investments [Line Items]
Investments	Investments (in millions) March 31, December 31, Equity method $ 3,615 $ 3,546 Marketable equity securities 471 433 Nonmarketable equity securities 1,235 1,186 Other investments 1,789 1,785 Total investments 7,110 6,950 Less: Current investments 15 19 Noncurrent investments $ 7,095 $ 6,931 Investment and Other Income (Loss), Net Three Months Ended (in millions) 2018 2017 Equity in net income (losses) of investees, net $ (49 ) $ 36 Realized and unrealized gains (losses) on equity securities, net 28 (5 ) Other income (loss), net 147 99 Investment and other income (loss), net $ 126 $ 130 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 both March 31, 2018 and December 31, 2017, we had an investment in Atairos of $2.4 billion . For the three months ended March 31, 2018 and 2017, we made cash capital contributions to Atairos totaling $31 million and $457 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 these gains and losses in equity in net income (losses) of investees, net. For the three months ended March 31, 2018 and 2017, our share of Atairos income was $35 million and $57 million , respectively. Hulu As of March 31, 2018 and December 31, 2017, we had an investment in Hulu of $231 million and $249 million , respectively. For the three months ended March 31, 2018 , we made cash capital contributions totaling $114 million to Hulu. For the three months ended March 31, 2018 and 2017, we recognized our proportionate share of Hulu’s losses of $131 million and $54 million , respectively, in equity in net income (losses) of investees, net. 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 March 31, 2018 and December 31, 2017, we had an investment in Snap of $467 million and $430 million , respectively. For the three months ended March 31, 2018 , we recognized unrealized gains of $37 million 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 March 31, 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 March 31, 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) March 31, December 31, Equity method $ 697 $ 690 Marketable equity securities 467 430 Nonmarketable equity securities 699 696 Total investments $ 1,863 $ 1,816 Investment and Other Income (Loss), Net Three Months Ended (in millions) 2018 2017 Equity in net income (losses) of investees, net $ (100 ) $ (26 ) Realized and unrealized gains (losses) on equity securities, net 37 2 Other income (loss), net 59 23 Investment and other income (loss), net $ (4 ) $ (1 ) 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 March 31, 2018 and December 31, 2017, we had an investment in Hulu of $231 million and $249 million , respectively. For the three months ended March 31, 2018 , we made cash capital contributions totaling $114 million to Hulu. For the three months ended March 31, 2018 and 2017, we recognized our proportionate share of Hulu’s losses of $131 million and $54 million , respectively, in equity in net income (losses) of investees, net. 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 March 31, 2018 and December 31, 2017, we had an investment in Snap of $467 million and $430 million , respectively. For the three months ended March 31, 2018 , we recognized unrealized gains of $37 million 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	3 Months Ended
	Mar. 31, 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 (in millions) 2018 2017 Restricted share units $ 83 $ 74 Stock options 44 40 Employee stock purchase plans 12 10 Total $ 139 $ 124 As of March 31, 2018 , we had unrecognized pretax compensation expense of $1.1 billion and $607 million related to nonvested RSUs and nonvested stock options, respectively. Cash Payments for Interest and Income Taxes Three Months Ended (in millions) 2018 2017 Interest $ 854 $ 895 Income taxes $ 162 $ 132 Noncash Investing and Financing Activities During the three months ended March 31, 2018 : • we acquired $1.5 billion of property and equipment and intangible assets that were accrued but unpaid • we recorded a liability of $877 million for a quarterly cash dividend of $0.19 per common share to be paid in April 2018 • we received noncash contributions from noncontrolling interests totaling $316 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) March 31, December 31, Cash and cash equivalents $ 6,030 $ 3,428 Restricted cash included in other current assets 64 60 Restricted cash included in other noncurrent assets, net 83 83 Cash, cash equivalents and restricted cash, end of period $ 6,177 $ 3,571 Accumulated Other Comprehensive Income (Loss) (in millions) March 31, March 31, Unrealized gains (losses) on marketable securities $ 1 $ 104 Deferred gains (losses) on cash flow hedges 20 (7 ) Unrecognized gains (losses) on employee benefit obligations 310 282 Cumulative translation adjustments 277 (37 ) Accumulated other comprehensive income (loss), net of deferred taxes $ 608 $ 342
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Supplemental Financial Information	Supplemental Financial Information Cash Payments for Interest and Income Taxes Three Months Ended (in millions) 2018 2017 Interest $ 51 $ 77 Income taxes $ 173 $ 52 Noncash Investing and Financing Activities During the three months ended March 31, 2018 : • we acquired $721 million of property and equipment and intangible assets that were accrued but unpaid • we received noncash contributions from noncontrolling interests totaling $316 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) March 31, December 31, Cash and cash equivalents $ 2,225 $ 2,347 Restricted cash included in other noncurrent assets, net 31 30 Cash, cash equivalents and restricted cash, end of period $ 2,256 $ 2,377 Accumulated Other Comprehensive Income (Loss) (in millions) March 31, March 31, Unrealized gains (losses) on marketable securities $ — $ 1 Deferred gains (losses) on cash flow hedges (3 ) 9 Unrecognized gains (losses) on employee benefit obligations 122 120 Cumulative translation adjustments 277 (59 ) Accumulated other comprehensive income (loss) $ 396 $ 71

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 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 March 31, 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 (in millions) 2018 2017 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 594 $ 459 Operating costs and expenses $ (61 ) $ (61 ) Interest expense and investment and other income (loss), net $ (23 ) $ (19 ) Condensed Consolidated Balance Sheet (in millions) March 31, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 376 $ 326 Accounts payable and accrued expenses related to trade creditors $ 51 $ 54 Accrued expenses and other current liabilities $ 13 $ 50 Note payable to Comcast $ 1,284 $ 1,831 Long-term debt $ 610 $ 610 Other noncurrent liabilities $ 389 $ 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. As of March 31, 2018 and 2017, we recognized share-based compensation expense of $32 million and $25 million , respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Redeemable Subsidiary Preferred Stock As of March 31, 2018 , the fair value of the NBCUniversal Enterprise redeemable subsidiary preferred stock was $753 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	3 Months Ended
	Mar. 31, 2018
Condensed Financial Information of Parent Company Only 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 $4.8 billion aggregate principal amount of senior notes, $1.5 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 ¥430 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. Condensed Consolidating Statement of Income For the Three Months Ended March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 22,791 $ — $ 22,791 Management fee revenue 292 — 286 — — (578 ) — Total revenue 292 — 286 — 22,791 (578 ) 22,791 Costs and Expenses: Programming and production — — — — 7,429 — 7,429 Other operating and administrative 228 — 286 318 6,260 (578 ) 6,514 Advertising, marketing and promotion — — — — 1,604 — 1,604 Depreciation 11 — — — 2,000 — 2,011 Amortization 1 — — — 587 — 588 Total cost and expenses 240 — 286 318 17,880 (578 ) 18,146 Operating income (loss) 52 — — (318 ) 4,911 — 4,645 Interest expense (561 ) (3 ) (47 ) (106 ) (60 ) — (777 ) Investment and other income (loss), net 3,520 3,319 2,826 1,942 1,588 (13,069 ) 126 Income (loss) before income taxes 3,011 3,316 2,779 1,518 6,439 (13,069 ) 3,994 Income tax (expense) benefit 107 — 9 (5 ) (929 ) — (818 ) Net income (loss) 3,118 3,316 2,788 1,513 5,510 (13,069 ) 3,176 Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 58 — 58 Net income (loss) attributable to Comcast Corporation $ 3,118 $ 3,316 $ 2,788 $ 1,513 $ 5,452 $ (13,069 ) $ 3,118 Comprehensive income (loss) attributable to Comcast Corporation $ 3,271 $ 3,369 $ 2,789 $ 1,696 $ 5,791 $ (13,645 ) $ 3,271 Condensed Consolidating Statement of Income For the Three Months Ended March 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 20,587 $ — $ 20,587 Management fee revenue 275 — 270 — — (545 ) — Total revenue 275 — 270 — 20,587 (545 ) 20,587 Costs and Expenses: Programming and production — — — — 6,061 — 6,061 Other operating and administrative 170 — 270 306 5,738 (545 ) 5,939 Advertising, marketing and promotion — — — — 1,577 — 1,577 Depreciation 7 — — — 1,908 — 1,915 Amortization 2 — — — 551 — 553 Total costs and expenses 179 — 270 306 15,835 (545 ) 16,045 Operating income (loss) 96 — — (306 ) 4,752 — 4,542 Interest expense (517 ) (3 ) (60 ) (112 ) (63 ) — (755 ) Investment and other income (loss), net 2,847 2,686 2,327 1,623 1,279 (10,632 ) 130 Income (loss) before income taxes 2,426 2,683 2,267 1,205 5,968 (10,632 ) 3,917 Income tax (expense) benefit 147 (9 ) 21 (3 ) (1,418 ) — (1,262 ) Net income (loss) 2,573 2,674 2,288 1,202 4,550 (10,632 ) 2,655 Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 82 — 82 Net income (loss) attributable to Comcast Corporation $ 2,573 $ 2,674 $ 2,288 $ 1,202 $ 4,468 $ (10,632 ) $ 2,573 Comprehensive income (loss) attributable to Comcast Corporation $ 2,817 $ 2,724 $ 2,289 $ 1,408 $ 4,712 $ (11,133 ) $ 2,817 Condensed Consolidating Statement of Cash Flows For the Three Months Ended March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (270 ) $ 453 $ (149 ) $ (382 ) $ 5,822 $ — $ 5,474 Investing Activities: Net transactions with affiliates 640 (897 ) 149 347 (239 ) — — Capital expenditures — — — — (1,973 ) — (1,973 ) Cash paid for intangible assets (2 ) — — — (417 ) — (419 ) Acquisitions and construction of real estate properties (39 ) — — — (20 ) — (59 ) Acquisitions, net of cash acquired — — — — (89 ) — (89 ) Proceeds from sales of investments — — — 57 24 — 81 Purchases of investments (11 ) — — (5 ) (204 ) — (220 ) Other — 444 — — (57 ) — 387 Net cash provided by (used in) investing activities 588 (453 ) 149 399 (2,975 ) — (2,292 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (902 ) — — — — — (902 ) Proceeds from borrowings 3,973 — — — 70 — 4,043 Repurchases and repayments of debt (900 ) — — (3 ) (362 ) — (1,265 ) Repurchases of common stock under repurchase program and employee plans (1,729 ) — — — — — (1,729 ) Dividends paid (738 ) — — — — — (738 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (79 ) — (79 ) Other (22 ) — — — 116 — 94 Net cash provided by (used in) financing activities (318 ) — — (3 ) (255 ) — (576 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — 14 2,592 — 2,606 Cash, cash equivalents and restricted cash, beginning of period — — — 496 3,075 — 3,571 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 510 $ 5,667 $ — $ 6,177 Condensed Consolidating Statement of Cash Flows For the Three Months Ended March 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (453 ) $ (10 ) $ (168 ) $ (330 ) $ 6,586 $ — $ 5,625 Investing Activities: Net transactions with affiliates 1,385 10 168 115 (1,678 ) — — Capital expenditures (1 ) — — — (2,077 ) — (2,078 ) Cash paid for intangible assets — — — — (385 ) — (385 ) Acquisitions and construction of real estate properties (69 ) — — — (61 ) — (130 ) Acquisitions, net of cash acquired — — — — (216 ) — (216 ) Proceeds from sales of investments — — — 10 41 — 51 Purchases of investments (9 ) — — (4 ) (1,049 ) — (1,062 ) Other 55 — — — 12 — 67 Net cash provided by (used in) investing activities 1,361 10 168 121 (5,413 ) — (3,753 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (154 ) — (1,893 ) Proceeds from borrowings 3,500 — — — — — 3,500 Repurchases and repayments of debt (1,000 ) — — (3 ) (56 ) — (1,059 ) Repurchases of common stock under repurchase program and employee plans (996 ) — — — — — (996 ) Dividends paid (657 ) — — — — — (657 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (72 ) — (72 ) Other (16 ) — — — 52 — 36 Net cash provided by (used in) financing activities (908 ) — — (3 ) (230 ) — (1,141 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — (212 ) 943 — 731 Cash, cash equivalents and restricted cash, beginning of period — — — 482 2,933 — 3,415 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 270 $ 3,876 $ — $ 4,146 Condensed Consolidating Balance Sheet March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 510 $ 5,520 $ — $ 6,030 Receivables, net — — — — 8,759 — 8,759 Programming rights — — — — 1,354 — 1,354 Other current assets 56 — — 19 2,535 — 2,610 Total current assets 56 — — 529 18,168 — 18,753 Film and television costs — — — — 7,402 — 7,402 Investments 157 21 110 701 6,106 — 7,095 Investments in and amounts due from subsidiaries eliminated upon consolidation 120,165 146,308 142,199 51,648 114,646 (574,966 ) — Property and equipment, net 622 — — — 38,446 — 39,068 Franchise rights — — — — 59,365 — 59,365 Goodwill — — — — 37,147 — 37,147 Other intangible assets, net 12 — — — 18,327 — 18,339 Other noncurrent assets, net 370 265 — 87 3,234 (249 ) 3,707 Total assets $ 121,382 $ 146,594 $ 142,309 $ 52,965 $ 302,841 $ (575,215 ) $ 190,876 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 39 $ — $ — $ — $ 7,310 $ — $ 7,349 Accrued participations and residuals — — — — 1,659 — 1,659 Deferred revenue — — — — 1,578 — 1,578 Accrued expenses and other current liabilities 1,846 92 215 336 3,065 — 5,554 Current portion of long-term debt 1,002 — — 4 2,033 — 3,039 Total current liabilities 2,887 92 215 340 15,645 — 19,179 Long-term debt, less current portion 46,424 141 2,100 7,748 7,265 — 63,678 Deferred income taxes — 304 — 71 24,605 (278 ) 24,702 Other noncurrent liabilities 2,589 — — 1,182 7,453 29 11,253 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,354 — 1,354 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 69,427 146,057 139,994 43,624 245,291 (574,966 ) 69,427 Total Comcast Corporation shareholders’ equity 69,482 146,057 139,994 43,624 245,291 (574,966 ) 69,482 Noncontrolling interests — — — — 1,228 — 1,228 Total equity 69,482 146,057 139,994 43,624 246,519 (574,966 ) 70,710 Total liabilities and equity $ 121,382 $ 146,594 $ 142,309 $ 52,965 $ 302,841 $ (575,215 ) $ 190,876 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

Accounting Policies (Policies)

Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 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 businesses. 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 businesses 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 businesses 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 also include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service, we generally recognize revenue for variable pricing as the content is delivered and available and as the variable amounts become known. 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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 20,463 $ 124 $ 20,587 Total costs and expenses $ 15,933 $ 112 $ 16,045 Operating income $ 4,530 $ 12 $ 4,542 Net income attributable to Comcast Corporation $ 2,566 $ 7 $ 2,573 Condensed Consolidated Balance Sheet As of 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 period. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three months ended March 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,774 $ (68 ) $ 5,706 High-speed Internet 3,606 236 3,842 Voice 863 171 1,034 Business services 1,490 53 1,543 Advertising 512 42 554 Other 667 (296 ) 371 Total Cable Communications revenue $ 12,912 $ 138 $ 13,050 Operating costs and expenses $ 7,714 $ 162 $ 7,876 Depreciation and amortization expense $ 1,980 $ (34 ) $ 1,946 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 March 31, 2018. These amounts are subject to change as we obtain information necessary to complete the calculations. We did not recognize any changes to the provisional amounts for the three months ended March 31, 2018. We will update the provisional amounts as we refine our estimates of cumulative temporary differences, including those related to the immediate deduction for qualified property, and our interpretations of the application of the new legislation. We expect to complete our analysis of the provisional items during the second half 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. The legislation resulted in an income tax benefit of $128 million for the three months ended March 31, 2018. 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. The updated guidance is effective for us as of January 1, 2019 and early adoption is permitted. The updated accounting guidance must be adopted using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. 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 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.
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 also include variable pricing, such as pricing based on the number of subscribers to a subscription video on demand service, we generally recognize revenue for variable pricing as the content is delivered and available and as the variable amounts become known. 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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 7,868 $ (15 ) $ 7,853 Total costs and expenses $ 6,359 $ (17 ) $ 6,342 Operating income $ 1,509 $ 2 $ 1,511 Net income attributable to NBCUniversal $ 1,200 $ 2 $ 1,202 Condensed Consolidated Balance Sheet As of 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 the 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. The updated guidance is effective for us as of January 1, 2019 and early adoption is permitted. The updated accounting guidance must be adopted using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. 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)	3 Months Ended
	Mar. 31, 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 March 31, 2018 (in millions) Revenue Adjusted EBITDA (e) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 13,518 $ 5,415 $ 2,053 $ 1,688 $ 269 NBCUniversal Cable Networks (a) 3,194 1,268 189 3 4 Broadcast Television (a) 3,497 507 34 30 72 Filmed Entertainment 1,647 203 28 7 6 Theme Parks 1,281 495 155 182 16 Headquarters and Other (b) 14 (188 ) 104 47 32 Eliminations (a)(c) (103 ) — — — — NBCUniversal 9,530 2,285 510 269 130 Corporate and Other (d) 391 (397 ) 36 16 20 Eliminations (a)(c) (648 ) (59 ) — — — Comcast Consolidated $ 22,791 $ 7,244 $ 2,599 $ 1,973 $ 419 Three Months Ended March 31, 2017 (in millions) Revenue Adjusted EBITDA (e) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Communications $ 13,050 $ 5,174 $ 1,946 $ 1,781 $ 322 NBCUniversal Cable Networks 2,640 1,115 214 2 3 Broadcast Television 2,208 322 32 29 3 Filmed Entertainment 1,967 371 22 10 5 Theme Parks 1,118 397 142 229 13 Headquarters and Other (b) 8 (185 ) 98 15 31 Eliminations (c) (88 ) (1 ) — — — NBCUniversal 7,853 2,019 508 285 55 Corporate and Other (d) 208 (194 ) 14 12 8 Eliminations (c) (524 ) 11 — — — Comcast Consolidated $ 20,587 $ 7,010 $ 2,468 $ 2,078 $ 385 (a) 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. (b) NBCUniversal Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (c) 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 (d) 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 and operates arena management-related businesses. (e) 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 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 (in millions) 2018 2017 Adjusted EBITDA $ 7,244 $ 7,010 Depreciation (2,011 ) (1,915 ) Amortization (588 ) (553 ) Interest expense (777 ) (755 ) Investment and other income (loss), net 126 130 Income before income taxes $ 3,994 $ 3,917
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 (in millions) 2018 2017 Adjusted EBITDA $ 7,244 $ 7,010 Depreciation (2,011 ) (1,915 ) Amortization (588 ) (553 ) Interest expense (777 ) (755 ) Investment and other income (loss), net 126 130 Income before income taxes $ 3,994 $ 3,917
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 March 31, 2018 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks (a) $ 3,194 $ 1,268 $ 189 $ 3 $ 4 Broadcast Television (a) 3,497 507 34 30 72 Filmed Entertainment 1,647 203 28 7 6 Theme Parks 1,281 495 155 182 16 Headquarters and Other (b) 14 (188 ) 104 47 32 Eliminations (a)(c) (103 ) — — — — Total $ 9,530 $ 2,285 $ 510 $ 269 $ 130 Three Months Ended March 31, 2017 (in millions) Revenue Adjusted EBITDA (d) Depreciation and Amortization Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 2,640 $ 1,115 $ 214 $ 2 $ 3 Broadcast Television 2,208 322 32 29 3 Filmed Entertainment 1,967 371 22 10 5 Theme Parks 1,118 397 142 229 13 Headquarters and Other (b) 8 (185 ) 98 15 31 Eliminations (c) (88 ) (1 ) — — — Total $ 7,853 $ 2,019 $ 508 $ 285 $ 55 (a) 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. (b) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (c) 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. (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 NBCUniversal before net income 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 (in millions) 2018 2017 Adjusted EBITDA $ 2,285 $ 2,019 Depreciation (242 ) (231 ) Amortization (268 ) (277 ) Interest expense (127 ) (143 ) Investment and other income (loss), net (4 ) (1 ) Income before income taxes $ 1,644 $ 1,367
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 (in millions) 2018 2017 Adjusted EBITDA $ 2,285 $ 2,019 Depreciation (242 ) (231 ) Amortization (268 ) (277 ) Interest expense (127 ) (143 ) Investment and other income (loss), net (4 ) (1 ) Income before income taxes $ 1,644 $ 1,367

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue [Line Items]
Schedule of receivables, net	(in millions) March 31, December 31, Receivables, gross $ 9,052 $ 9,122 Less: Allowance for doubtful accounts 293 288 Receivables, net $ 8,759 $ 8,834
NBCUniversal Media LLC [Member]
Revenue [Line Items]
Schedule of receivables, net	(in millions) March 31, December 31, Receivables, gross $ 7,269 $ 7,055 Less: Allowance for doubtful accounts 93 88 Receivables, net $ 7,176 $ 6,967
Accounting Standards Update 2014-09 [Member]
Revenue [Line Items]
Disaggregation of revenue	Three Months Ended (in millions) 2018 2017 Residential: Video $ 5,659 $ 5,706 High-Speed Internet 4,157 3,842 Voice 1,006 1,034 Business services 1,726 1,543 Advertising 582 554 Other 388 371 Total Cable Communications (a) 13,518 13,050 Distribution 1,887 1,562 Advertising 988 826 Content licensing and other 319 252 Total Cable Networks 3,194 2,640 Advertising 2,365 1,279 Content licensing 522 503 Distribution and other 610 426 Total Broadcast Television 3,497 2,208 Theatrical 423 651 Content licensing 733 734 Home entertainment 248 286 Other 243 296 Total Filmed Entertainment 1,647 1,967 Total Theme Parks 1,281 1,118 Headquarters and Other 14 8 Eliminations (b) (103 ) (88 ) Total NBCUniversal 9,530 7,853 Corporate and Other 391 208 Eliminations (b) (648 ) (524 ) Total revenue $ 22,791 $ 20,587 (a) For the three months ended March 31, 2018 and 2017, 2.8% and 2.9% , respectively, 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 (in millions) 2018 2017 United States $ 20,885 $ 18,832 Foreign 1,906 1,755 Total revenue $ 22,791 $ 20,587
Other balance sheet accounts	(in millions) March 31, December 31, Noncurrent receivables (included in other noncurrent assets, net) $ 1,180 $ 1,184 Contract acquisition and fulfillment costs (included in other noncurrent assets, net) $ 929 $ 922 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 536 $ 497
Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
Revenue [Line Items]
Disaggregation of revenue	Three Months Ended (in millions) 2018 2017 Distribution $ 1,887 $ 1,562 Advertising 988 826 Content licensing and other 319 252 Total Cable Networks 3,194 2,640 Advertising 2,365 1,279 Content licensing 522 503 Distribution and other 610 426 Total Broadcast Television 3,497 2,208 Theatrical 423 651 Content licensing 733 734 Home entertainment 248 286 Other 243 296 Total Filmed Entertainment 1,647 1,967 Total Theme Parks 1,281 1,118 Headquarters and Other 14 8 Eliminations (a) (103 ) (88 ) Total revenue $ 9,530 $ 7,853 (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 (in millions) 2018 2017 United States $ 7,654 $ 6,117 Foreign 1,876 1,736 Total revenue $ 9,530 $ 7,853
Other balance sheet accounts	(in millions) March 31, December 31, Noncurrent receivables (included in other noncurrent assets, net) $ 1,090 $ 1,093 Noncurrent deferred revenue (included in other noncurrent liabilities) $ 405 $ 392

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computation of diluted EPS	Computation of Diluted EPS Three Months Ended March 31 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 $ 3,118 4,633 $ 0.67 $ 2,573 4,747 $ 0.54 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 72 85 Diluted EPS attributable to Comcast Corporation shareholders $ 3,118 4,705 $ 0.66 $ 2,573 4,832 $ 0.53

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Borrowings	Debt Borrowings (in millions) Three months ended 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 Other 43 Total $ 4,043
Debt Repayments and Repurchases	Debt Repayments (in millions) Three months ended Comcast 5.875% senior notes due 2018 $ 900 Other 365 Total $ 1,265

Recent Accounting Pronounceme27

Recent Accounting Pronouncements and Tax Reform (Tables)	3 Months Ended
	Mar. 31, 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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 20,463 $ 124 $ 20,587 Total costs and expenses $ 15,933 $ 112 $ 16,045 Operating income $ 4,530 $ 12 $ 4,542 Net income attributable to Comcast Corporation $ 2,566 $ 7 $ 2,573 Condensed Consolidated Balance Sheet As of 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 period. Previously reported amounts are based on amounts previously presented in the segment information footnote. Three months ended March 31, 2017 (in millions) Previously Reported Effects of Adoption As Adjusted Residential: Video $ 5,774 $ (68 ) $ 5,706 High-speed Internet 3,606 236 3,842 Voice 863 171 1,034 Business services 1,490 53 1,543 Advertising 512 42 554 Other 667 (296 ) 371 Total Cable Communications revenue $ 12,912 $ 138 $ 13,050 Operating costs and expenses $ 7,714 $ 162 $ 7,876 Depreciation and amortization expense $ 1,980 $ (34 ) $ 1,946
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 (in millions) Previously Reported Effects of Adoption As Adjusted Revenue $ 7,868 $ (15 ) $ 7,853 Total costs and expenses $ 6,359 $ (17 ) $ 6,342 Operating income $ 1,509 $ 2 $ 1,511 Net income attributable to NBCUniversal $ 1,200 $ 2 $ 1,202 Condensed Consolidated Balance Sheet As of 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)	3 Months Ended
	Mar. 31, 2018
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) March 31, December 31, Film Costs: Released, less amortization $ 1,590 $ 1,734 Completed, not released 54 50 In production and in development 1,287 1,149 2,931 2,933 Television Costs: Released, less amortization 2,361 2,260 In production and in development 845 818 3,206 3,078 Programming rights, less amortization 2,619 2,689 8,756 8,700 Less: Current portion of programming rights 1,354 1,613 Film and television costs $ 7,402 $ 7,087
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) March 31, December 31, Film Costs: Released, less amortization $ 1,590 $ 1,734 Completed, not released 54 50 In production and in development 1,287 1,149 2,931 2,933 Television Costs: Released, less amortization 2,361 2,260 In production and in development 845 818 3,206 3,078 Programming rights, less amortization 2,608 2,677 8,745 8,688 Less: Current portion of programming rights 1,347 1,606 Film and television costs $ 7,398 $ 7,082

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Investments [Line Items]
Investment Summary	(in millions) March 31, December 31, Equity method $ 3,615 $ 3,546 Marketable equity securities 471 433 Nonmarketable equity securities 1,235 1,186 Other investments 1,789 1,785 Total investments 7,110 6,950 Less: Current investments 15 19 Noncurrent investments $ 7,095 $ 6,931
Investment and Other Income (Loss), Net	Investment and Other Income (Loss), Net Three Months Ended (in millions) 2018 2017 Equity in net income (losses) of investees, net $ (49 ) $ 36 Realized and unrealized gains (losses) on equity securities, net 28 (5 ) Other income (loss), net 147 99 Investment and other income (loss), net $ 126 $ 130
NBCUniversal Media LLC [Member]
Investments [Line Items]
Investment Summary	(in millions) March 31, December 31, Equity method $ 697 $ 690 Marketable equity securities 467 430 Nonmarketable equity securities 699 696 Total investments $ 1,863 $ 1,816
Investment and Other Income (Loss), Net	Investment and Other Income (Loss), Net Three Months Ended (in millions) 2018 2017 Equity in net income (losses) of investees, net $ (100 ) $ (26 ) Realized and unrealized gains (losses) on equity securities, net 37 2 Other income (loss), net 59 23 Investment and other income (loss), net $ (4 ) $ (1 )

Supplemental Financial Inform30

Supplemental Financial Information (Tables)	3 Months Ended
	Mar. 31, 2018
Supplemental Financial Information [Line Items]
Schedule of recognized share-based compensation expense	Recognized Share-Based Compensation Expense Three Months Ended (in millions) 2018 2017 Restricted share units $ 83 $ 74 Stock options 44 40 Employee stock purchase plans 12 10 Total $ 139 $ 124
Schedule of cash payments for interest and income taxes	Cash Payments for Interest and Income Taxes Three Months Ended (in millions) 2018 2017 Interest $ 854 $ 895 Income taxes $ 162 $ 132
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) March 31, December 31, Cash and cash equivalents $ 6,030 $ 3,428 Restricted cash included in other current assets 64 60 Restricted cash included in other noncurrent assets, net 83 83 Cash, cash equivalents and restricted cash, end of period $ 6,177 $ 3,571
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) March 31, March 31, Unrealized gains (losses) on marketable securities $ 1 $ 104 Deferred gains (losses) on cash flow hedges 20 (7 ) Unrecognized gains (losses) on employee benefit obligations 310 282 Cumulative translation adjustments 277 (37 ) Accumulated other comprehensive income (loss), net of deferred taxes $ 608 $ 342
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 Three Months Ended (in millions) 2018 2017 Interest $ 51 $ 77 Income taxes $ 173 $ 52
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) March 31, December 31, Cash and cash equivalents $ 2,225 $ 2,347 Restricted cash included in other noncurrent assets, net 31 30 Cash, cash equivalents and restricted cash, end of period $ 2,256 $ 2,377
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) March 31, March 31, Unrealized gains (losses) on marketable securities $ — $ 1 Deferred gains (losses) on cash flow hedges (3 ) 9 Unrecognized gains (losses) on employee benefit obligations 122 120 Cumulative translation adjustments 277 (59 ) Accumulated other comprehensive income (loss) $ 396 $ 71

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 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 (in millions) 2018 2017 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 594 $ 459 Operating costs and expenses $ (61 ) $ (61 ) Interest expense and investment and other income (loss), net $ (23 ) $ (19 ) Condensed Consolidated Balance Sheet (in millions) March 31, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 376 $ 326 Accounts payable and accrued expenses related to trade creditors $ 51 $ 54 Accrued expenses and other current liabilities $ 13 $ 50 Note payable to Comcast $ 1,284 $ 1,831 Long-term debt $ 610 $ 610 Other noncurrent liabilities $ 389 $ 389

Condensed Consolidating Finan32

Condensed Consolidating Financial Information (Tables)	3 Months Ended
	Mar. 31, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Assets Cash and cash equivalents $ — $ — $ — $ 510 $ 5,520 $ — $ 6,030 Receivables, net — — — — 8,759 — 8,759 Programming rights — — — — 1,354 — 1,354 Other current assets 56 — — 19 2,535 — 2,610 Total current assets 56 — — 529 18,168 — 18,753 Film and television costs — — — — 7,402 — 7,402 Investments 157 21 110 701 6,106 — 7,095 Investments in and amounts due from subsidiaries eliminated upon consolidation 120,165 146,308 142,199 51,648 114,646 (574,966 ) — Property and equipment, net 622 — — — 38,446 — 39,068 Franchise rights — — — — 59,365 — 59,365 Goodwill — — — — 37,147 — 37,147 Other intangible assets, net 12 — — — 18,327 — 18,339 Other noncurrent assets, net 370 265 — 87 3,234 (249 ) 3,707 Total assets $ 121,382 $ 146,594 $ 142,309 $ 52,965 $ 302,841 $ (575,215 ) $ 190,876 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 39 $ — $ — $ — $ 7,310 $ — $ 7,349 Accrued participations and residuals — — — — 1,659 — 1,659 Deferred revenue — — — — 1,578 — 1,578 Accrued expenses and other current liabilities 1,846 92 215 336 3,065 — 5,554 Current portion of long-term debt 1,002 — — 4 2,033 — 3,039 Total current liabilities 2,887 92 215 340 15,645 — 19,179 Long-term debt, less current portion 46,424 141 2,100 7,748 7,265 — 63,678 Deferred income taxes — 304 — 71 24,605 (278 ) 24,702 Other noncurrent liabilities 2,589 — — 1,182 7,453 29 11,253 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,354 — 1,354 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 69,427 146,057 139,994 43,624 245,291 (574,966 ) 69,427 Total Comcast Corporation shareholders’ equity 69,482 146,057 139,994 43,624 245,291 (574,966 ) 69,482 Noncontrolling interests — — — — 1,228 — 1,228 Total equity 69,482 146,057 139,994 43,624 246,519 (574,966 ) 70,710 Total liabilities and equity $ 121,382 $ 146,594 $ 142,309 $ 52,965 $ 302,841 $ (575,215 ) $ 190,876 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
Condensed Consolidating Statement of Income	Condensed Consolidating Statement of Income For the Three Months Ended March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 22,791 $ — $ 22,791 Management fee revenue 292 — 286 — — (578 ) — Total revenue 292 — 286 — 22,791 (578 ) 22,791 Costs and Expenses: Programming and production — — — — 7,429 — 7,429 Other operating and administrative 228 — 286 318 6,260 (578 ) 6,514 Advertising, marketing and promotion — — — — 1,604 — 1,604 Depreciation 11 — — — 2,000 — 2,011 Amortization 1 — — — 587 — 588 Total cost and expenses 240 — 286 318 17,880 (578 ) 18,146 Operating income (loss) 52 — — (318 ) 4,911 — 4,645 Interest expense (561 ) (3 ) (47 ) (106 ) (60 ) — (777 ) Investment and other income (loss), net 3,520 3,319 2,826 1,942 1,588 (13,069 ) 126 Income (loss) before income taxes 3,011 3,316 2,779 1,518 6,439 (13,069 ) 3,994 Income tax (expense) benefit 107 — 9 (5 ) (929 ) — (818 ) Net income (loss) 3,118 3,316 2,788 1,513 5,510 (13,069 ) 3,176 Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 58 — 58 Net income (loss) attributable to Comcast Corporation $ 3,118 $ 3,316 $ 2,788 $ 1,513 $ 5,452 $ (13,069 ) $ 3,118 Comprehensive income (loss) attributable to Comcast Corporation $ 3,271 $ 3,369 $ 2,789 $ 1,696 $ 5,791 $ (13,645 ) $ 3,271 Condensed Consolidating Statement of Income For the Three Months Ended March 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 20,587 $ — $ 20,587 Management fee revenue 275 — 270 — — (545 ) — Total revenue 275 — 270 — 20,587 (545 ) 20,587 Costs and Expenses: Programming and production — — — — 6,061 — 6,061 Other operating and administrative 170 — 270 306 5,738 (545 ) 5,939 Advertising, marketing and promotion — — — — 1,577 — 1,577 Depreciation 7 — — — 1,908 — 1,915 Amortization 2 — — — 551 — 553 Total costs and expenses 179 — 270 306 15,835 (545 ) 16,045 Operating income (loss) 96 — — (306 ) 4,752 — 4,542 Interest expense (517 ) (3 ) (60 ) (112 ) (63 ) — (755 ) Investment and other income (loss), net 2,847 2,686 2,327 1,623 1,279 (10,632 ) 130 Income (loss) before income taxes 2,426 2,683 2,267 1,205 5,968 (10,632 ) 3,917 Income tax (expense) benefit 147 (9 ) 21 (3 ) (1,418 ) — (1,262 ) Net income (loss) 2,573 2,674 2,288 1,202 4,550 (10,632 ) 2,655 Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — 82 — 82 Net income (loss) attributable to Comcast Corporation $ 2,573 $ 2,674 $ 2,288 $ 1,202 $ 4,468 $ (10,632 ) $ 2,573 Comprehensive income (loss) attributable to Comcast Corporation $ 2,817 $ 2,724 $ 2,289 $ 1,408 $ 4,712 $ (11,133 ) $ 2,817
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows For the Three Months Ended March 31, 2018 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (270 ) $ 453 $ (149 ) $ (382 ) $ 5,822 $ — $ 5,474 Investing Activities: Net transactions with affiliates 640 (897 ) 149 347 (239 ) — — Capital expenditures — — — — (1,973 ) — (1,973 ) Cash paid for intangible assets (2 ) — — — (417 ) — (419 ) Acquisitions and construction of real estate properties (39 ) — — — (20 ) — (59 ) Acquisitions, net of cash acquired — — — — (89 ) — (89 ) Proceeds from sales of investments — — — 57 24 — 81 Purchases of investments (11 ) — — (5 ) (204 ) — (220 ) Other — 444 — — (57 ) — 387 Net cash provided by (used in) investing activities 588 (453 ) 149 399 (2,975 ) — (2,292 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (902 ) — — — — — (902 ) Proceeds from borrowings 3,973 — — — 70 — 4,043 Repurchases and repayments of debt (900 ) — — (3 ) (362 ) — (1,265 ) Repurchases of common stock under repurchase program and employee plans (1,729 ) — — — — — (1,729 ) Dividends paid (738 ) — — — — — (738 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (79 ) — (79 ) Other (22 ) — — — 116 — 94 Net cash provided by (used in) financing activities (318 ) — — (3 ) (255 ) — (576 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — 14 2,592 — 2,606 Cash, cash equivalents and restricted cash, beginning of period — — — 496 3,075 — 3,571 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 510 $ 5,667 $ — $ 6,177 Condensed Consolidating Statement of Cash Flows For the Three Months Ended March 31, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (453 ) $ (10 ) $ (168 ) $ (330 ) $ 6,586 $ — $ 5,625 Investing Activities: Net transactions with affiliates 1,385 10 168 115 (1,678 ) — — Capital expenditures (1 ) — — — (2,077 ) — (2,078 ) Cash paid for intangible assets — — — — (385 ) — (385 ) Acquisitions and construction of real estate properties (69 ) — — — (61 ) — (130 ) Acquisitions, net of cash acquired — — — — (216 ) — (216 ) Proceeds from sales of investments — — — 10 41 — 51 Purchases of investments (9 ) — — (4 ) (1,049 ) — (1,062 ) Other 55 — — — 12 — 67 Net cash provided by (used in) investing activities 1,361 10 168 121 (5,413 ) — (3,753 ) Financing Activities: Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (154 ) — (1,893 ) Proceeds from borrowings 3,500 — — — — — 3,500 Repurchases and repayments of debt (1,000 ) — — (3 ) (56 ) — (1,059 ) Repurchases of common stock under repurchase program and employee plans (996 ) — — — — — (996 ) Dividends paid (657 ) — — — — — (657 ) Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (72 ) — (72 ) Other (16 ) — — — 52 — 36 Net cash provided by (used in) financing activities (908 ) — — (3 ) (230 ) — (1,141 ) Increase (decrease) in cash, cash equivalents and restricted cash — — — (212 ) 943 — 731 Cash, cash equivalents and restricted cash, beginning of period — — — 482 2,933 — 3,415 Cash, cash equivalents and restricted cash, end of period $ — $ — $ — $ 270 $ 3,876 $ — $ 4,146

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)segment	Mar. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	5
Financial Data by Business Segment
Revenue	$ 22,791	$ 20,587
Adjusted EBITDA	7,244	7,010
Depreciation and Amortization	2,599	2,468
Capital Expenditures	1,973	2,078
Cash Paid for Intangible Assets	$ 419	385
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4
Financial Data by Business Segment
Revenue	$ 9,530	7,853
Adjusted EBITDA	2,285	2,019
Depreciation and Amortization	510	508
Capital Expenditures	269	285
Cash Paid for Intangible Assets	130	55
Cable Communications [Member]
Financial Data by Business Segment
Revenue	13,518	13,050
Depreciation and Amortization		1,946
Cable Networks [Member]
Financial Data by Business Segment
Revenue	3,194	2,640
Cable Networks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	3,194	2,640
Broadcast Television [Member]
Financial Data by Business Segment
Revenue	3,497	2,208
Broadcast Television [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	3,497	2,208
Filmed Entertainment [Member]
Financial Data by Business Segment
Revenue	1,647	1,967
Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,647	1,967
Theme Parks [Member]
Financial Data by Business Segment
Revenue	1,281	1,118
Theme Parks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,281	1,118
NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	9,530	7,853
Adjusted EBITDA	2,285	2,019
Depreciation and Amortization	510	508
Capital Expenditures	269	285
Cash Paid for Intangible Assets	130	55
Operating Segments [Member] | Cable Communications [Member]
Financial Data by Business Segment
Revenue	13,518	13,050
Adjusted EBITDA	5,415	5,174
Depreciation and Amortization	2,053	1,946
Capital Expenditures	1,688	1,781
Cash Paid for Intangible Assets	269	322
Operating Segments [Member] | Cable Networks [Member]
Financial Data by Business Segment
Revenue	3,194	2,640
Adjusted EBITDA	1,268	1,115
Depreciation and Amortization	189	214
Capital Expenditures	3	2
Cash Paid for Intangible Assets	4	3
Operating Segments [Member] | Cable Networks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	3,194	2,640
Adjusted EBITDA	1,268	1,115
Depreciation and Amortization	189	214
Capital Expenditures	3	2
Cash Paid for Intangible Assets	4	3
Operating Segments [Member] | Broadcast Television [Member]
Financial Data by Business Segment
Revenue	3,497	2,208
Adjusted EBITDA	507	322
Depreciation and Amortization	34	32
Capital Expenditures	30	29
Cash Paid for Intangible Assets	72	3
Operating Segments [Member] | Broadcast Television [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	3,497	2,208
Adjusted EBITDA	507	322
Depreciation and Amortization	34	32
Capital Expenditures	30	29
Cash Paid for Intangible Assets	72	3
Operating Segments [Member] | Filmed Entertainment [Member]
Financial Data by Business Segment
Revenue	1,647	1,967
Adjusted EBITDA	203	371
Depreciation and Amortization	28	22
Capital Expenditures	7	10
Cash Paid for Intangible Assets	6	5
Operating Segments [Member] | Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,647	1,967
Adjusted EBITDA	203	371
Depreciation and Amortization	28	22
Capital Expenditures	7	10
Cash Paid for Intangible Assets	6	5
Operating Segments [Member] | Theme Parks [Member]
Financial Data by Business Segment
Revenue	1,281	1,118
Adjusted EBITDA	495	397
Depreciation and Amortization	155	142
Capital Expenditures	182	229
Cash Paid for Intangible Assets	16	13
Operating Segments [Member] | Theme Parks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,281	1,118
Adjusted EBITDA	495	397
Depreciation and Amortization	155	142
Capital Expenditures	182	229
Cash Paid for Intangible Assets	16	13
Corporate, Non-Segment [Member]
Financial Data by Business Segment
Revenue	391	208
Adjusted EBITDA	(397)	(194)
Depreciation and Amortization	36	14
Capital Expenditures	16	12
Cash Paid for Intangible Assets	20	8
Corporate, Non-Segment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	14	8
Adjusted EBITDA	(188)	(185)
Depreciation and Amortization	104	98
Capital Expenditures	47	15
Cash Paid for Intangible Assets	32	31
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	14	8
Adjusted EBITDA	(188)	(185)
Depreciation and Amortization	104	98
Capital Expenditures	47	15
Cash Paid for Intangible Assets	32	31
Eliminations [Member]
Financial Data by Business Segment
Revenue	(648)	(524)
Adjusted EBITDA	(59)	11
Depreciation and Amortization	0	0
Capital Expenditures	0	0
Cash Paid for Intangible Assets	0	0
Eliminations [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	(103)	(88)
Adjusted EBITDA	0	(1)
Depreciation and Amortization	0	0
Capital Expenditures	0	0
Cash Paid for Intangible Assets	0	0
Eliminations [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	(103)	(88)
Adjusted EBITDA	0	(1)
Depreciation and Amortization	0	0
Capital Expenditures	0	0
Cash Paid for Intangible Assets	$ 0	$ 0

Segment Information (Reconcilia

Segment Information (Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	$ 7,244	$ 7,010
Depreciation	(2,011)	(1,915)
Amortization	(588)	(553)
Interest expense	(777)	(755)
Investment and other income (loss), net	126	130
Income before income taxes	3,994	3,917
NBCUniversal Media LLC [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	2,285	2,019
Depreciation	(242)	(231)
Amortization	(268)	(277)
Interest expense	(127)	(143)
Investment and other income (loss), net	(4)	(1)
Income before income taxes	$ 1,644	$ 1,367

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 22,791	$ 20,587
Cable Communications [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,518	13,050
Cable Communications [Member] | Residential, Video [Member]
Disaggregation of Revenue [Line Items]
Revenue	5,659	5,706
Cable Communications [Member] | Residential, High-Speed Internet [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,157	3,842
Cable Communications [Member] | Residential, Voice [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,006	1,034
Cable Communications [Member] | Business Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,726	1,543
Cable Communications [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	582	554
Cable Communications [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 388	$ 371
Cable Communications [Member] | Franchise And Other Regulatory Fees [Member]
Disaggregation of Revenue [Line Items]
Cable segment revenue types as percentage of total cable revenue	2.80%	2.90%
Cable Networks [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 3,194	$ 2,640
Cable Networks [Member] | Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,887	1,562
Cable Networks [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	988	826
Cable Networks [Member] | Content Licensing And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	319	252
Broadcast Television [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,497	2,208
Broadcast Television [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,365	1,279
Broadcast Television [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	522	503
Broadcast Television [Member] | Distribution And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	610	426
Filmed Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,647	1,967
Filmed Entertainment [Member] | Theatrical [Member]
Disaggregation of Revenue [Line Items]
Revenue	423	651
Filmed Entertainment [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	733	734
Filmed Entertainment [Member] | Home Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	248	286
Filmed Entertainment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	243	296
Theme Parks [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,281	1,118
NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,530	7,853
Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	391	208
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	14	8
Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(648)	(524)
Eliminations [Member] | NBCUniversal Segments [Member]
Disaggregation of Revenue [Line Items]
Revenue	(103)	(88)
NBCUniversal Media LLC [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,530	7,853
NBCUniversal Media LLC [Member] | Cable Networks [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,194	2,640
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,887	1,562
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	988	826
NBCUniversal Media LLC [Member] | Cable Networks [Member] | Content Licensing And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	319	252
NBCUniversal Media LLC [Member] | Broadcast Television [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,497	2,208
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Advertising [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,365	1,279
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	522	503
NBCUniversal Media LLC [Member] | Broadcast Television [Member] | Distribution And Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	610	426
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,647	1,967
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Theatrical [Member]
Disaggregation of Revenue [Line Items]
Revenue	423	651
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Content Licensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	733	734
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Home Entertainment [Member]
Disaggregation of Revenue [Line Items]
Revenue	248	286
NBCUniversal Media LLC [Member] | Filmed Entertainment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	243	296
NBCUniversal Media LLC [Member] | Theme Parks [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,281	1,118
NBCUniversal Media LLC [Member] | Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	14	8
NBCUniversal Media LLC [Member] | Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ (103)	$ (88)

Revenue (Revenue by Geographic

Revenue (Revenue by Geographic Location) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 22,791	$ 20,587
United States
Disaggregation of Revenue [Line Items]
Revenue	20,885	18,832
Foreign
Disaggregation of Revenue [Line Items]
Revenue	1,906	1,755
NBCUniversal Media LLC [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,530	7,853
NBCUniversal Media LLC [Member] | United States
Disaggregation of Revenue [Line Items]
Revenue	7,654	6,117
NBCUniversal Media LLC [Member] | Foreign
Disaggregation of Revenue [Line Items]
Revenue	$ 1,876	$ 1,736

Revenue (Narrative) (Details)

Revenue (Narrative) (Details)	3 Months Ended
	Mar. 31, 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	Mar. 31, 2018	Dec. 31, 2017
Condensed Consolidated Balance Sheet [Line Items]
Receivables, gross	$ 9,052	$ 9,122
Less: Allowance for doubtful accounts	293	288
Receivables, net	8,759	8,834
NBCUniversal Media LLC [Member]
Condensed Consolidated Balance Sheet [Line Items]
Receivables, gross	7,269	7,055
Less: Allowance for doubtful accounts	93	88
Receivables, net	7,176	6,967
Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Balance Sheet [Line Items]
Noncurrent receivables (included in other noncurrent assets, net)	1,180	1,184
Contract acquisition and fulfillment costs (included in other noncurrent assets, net)	929	922
Noncurrent deferred revenue (included in other noncurrent liabilities)	536	497
Accounting Standards Update 2014-09 [Member] | NBCUniversal Media LLC [Member]
Condensed Consolidated Balance Sheet [Line Items]
Noncurrent receivables (included in other noncurrent assets, net)	1,090	1,093
Noncurrent deferred revenue (included in other noncurrent liabilities)	$ 405	$ 392

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net Income Attributable to Comcast Corporation	$ 3,118	$ 2,573
Basic EPS attributable to Comcast Corporation shareholders (in shares)	4,633	4,747
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.67	$ 0.54
Effect of dilutive securities:
Net Income Attributable to Comcast Corporation	$ 3,118	$ 2,573
Assumed exercise or issuance of shares relating to stock plans (in shares)	72	85
Diluted EPS attributable to Comcast Corporation shareholders (in shares)	4,705	4,832
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.66	$ 0.53

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) $ in Billions	Mar. 31, 2018USD ($)
Debt Instrument [Line Items]
Total debt	$ 66.7
Fair value of debt	70.7
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Total debt	12.7
Fair value of debt	$ 13.3

Long-Term Debt (Debt Borrowings

Long-Term Debt (Debt Borrowings)(Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Proceeds from borrowings	$ 4,043	$ 3,500
Other Borrowings [Member]
Debt Instrument [Line Items]
Other	43
Senior Notes [Member] | Senior 3.90% Notes Due 2038 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,200
Interest rate	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%
Senior Notes [Member] | Senior 4.00% Notes Due 2048 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,000
Interest rate	4.00%
Senior Notes [Member] | Senior 4.25% Notes Due 2053 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 800
Interest rate	4.25%

Long-Term Debt (Debt Repayments

Long-Term Debt (Debt Repayments) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 25, 2018	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Repurchases and repayments of debt		$ 1,265	$ 1,059
Senior 5.875% Notes Due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt		$ 900
Interest rate		5.875%
Other Long-Term Debt [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt		$ 365
Subsequent Event [Member] | NBCUniveral Enterprise Senior Floating Rate Notes Due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 700
Subsequent Event [Member] | NBCUniversal Enterprise Senior 1.662% Notes Due 2018 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 1,100
Interest rate	1.662%

Long-Term Debt (Revolving Credi

Long-Term Debt (Revolving Credit Facilities) (Details) - Revolving Credit Facility [Member] $ in Billions	Mar. 31, 2018USD ($)
Line of Credit Facility [Line Items]
Amounts available under revolving credit facilities	$ 8.3
NBCUniversal Enterprise [Member]
Line of Credit Facility [Line Items]
Amounts available under revolving credit facilities	$ 1.5

Long-Term Debt (Commercial Pape

Long-Term Debt (Commercial Paper Programs) (Details) - Commercial Paper [Member]	Mar. 31, 2018USD ($)
Short-term Debt [Line Items]
Commercial paper outstanding	$ 0
NBCUniversal Enterprise [Member]
Short-term Debt [Line Items]
Commercial paper outstanding	$ 0

Long-Term Debt (Cross-Guarantee

Long-Term Debt (Cross-Guarantee Structure) (Details) - NBCUniversal Media LLC [Member] $ in Millions	Mar. 31, 2018USD ($)
Debt Instrument [Line Items]
Ownership in cable holding company subsidiaries	100.00%
NBCUniversal Enterprise [Member]
Debt Instrument [Line Items]
Related party aggregate principal amount senior notes not subject to guarantee	$ 4,800
Related party credit facility not subject to guarantee	1,500
Related party liquidation preference preferred stock not subject to guarantee	725
Comcast and Comcast Cable Debt Securities [Member]
Debt Instrument [Line Items]
Principal amount of debt securities subject to guarantee	51,400
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Guarantee obligations, maximum capacity	$ 7,000

Significant Transactions (Unive

Significant Transactions (Universal Beijing Resort) (Details) - Universal Beijing Resort [Member] $ in Millions, ¥ in Billions	Mar. 31, 2018CNY (¥)	Mar. 31, 2018USD ($)
Variable Interest Entity [Line Items]
Ownership percentage in variable interest entity	30.00%	30.00%
Maximum borrowing capacity of variable interest entity	¥ 26.6	$ 4,000
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		$ 523
NBCUniversal Media LLC [Member]
Variable Interest Entity [Line Items]
Ownership percentage in variable interest entity	30.00%	30.00%
Maximum borrowing capacity of variable interest entity	¥ 26.6	$ 4,000
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		$ 523

Significant Transactions (Sky O

Significant Transactions (Sky Offer) (Details) - Apr. 25, 2018 - Subsequent Event [Member] - Sky PLC [Member] £ / shares in Units, £ in Billions, $ in Billions	USD ($)	GBP (£)	GBP (£)£ / shares
Business Acquisition [Line Items]
Cash offer price per share (in gbp per share)			£ 12.50
Offer consideration	$ 31	£ 22
Final dividend based on fiscal year end			£ 0.218
Acquisition conditions, percentage of secured acceptance of voting rights	50.00%		50.00%
Unsecured bridge credit agreement maximum borrowing capacity	$ 22		£ 16
Unsecured term loan credit agreement maximum borrowing capacity	$ 10		£ 7

Recent Accounting Pronounceme48

Recent Accounting Pronouncements and Tax Reform (Effect of Changes in Revenue Recognition - Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 22,791	$ 20,587
Total costs and expenses	18,146	16,045
Operating income	4,645	4,542
Net Income Attributable to Comcast Corporation	3,118	2,573
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	9,530	7,853
Total costs and expenses	7,755	6,342
Operating income	1,775	1,511
Net Income Attributable to Comcast Corporation	$ 1,513	1,202
Previous Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		20,463
Total costs and expenses		15,933
Operating income		4,530
Net Income Attributable to Comcast Corporation		2,566
Previous Reported [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		7,868
Total costs and expenses		6,359
Operating income		1,509
Net Income Attributable to Comcast Corporation		1,200
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		124
Total costs and expenses		112
Operating income		12
Net Income Attributable to Comcast Corporation		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		(15)
Total costs and expenses		(17)
Operating income		2
Net Income Attributable to Comcast Corporation		$ 2

Recent Accounting Pronounceme49

Recent Accounting Pronouncements and Tax Reform (Effects of Changes in Revenue Recognition - Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets	$ 18,753	$ 16,343
Film and television costs	7,402	7,087
Other intangible assets, net	18,339	18,133
Other noncurrent assets, net	3,707	4,354
Assets	190,876	187,462
Total current liabilities	19,179	21,993
Deferred income taxes	24,702	24,259
Other noncurrent liabilities	11,253	10,972
Total equity	70,710	69,459	$ 57,644	$ 56,163
Total liabilities and equity	190,876	187,462
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total current assets	11,813	11,957
Film and television costs	7,398	7,082
Other noncurrent assets, net	1,775	1,804
Assets	72,727	71,300
Total current liabilities	8,994	9,932
Other noncurrent liabilities	4,487	4,153
Total equity	44,910	43,041	$ 43,193	$ 40,875
Total liabilities and equity	$ 72,727	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 Pronounceme50

Recent Accounting Pronouncements and Tax Reform (Effect of Changes in Revenue Recognition - Cable Communications Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 22,791	$ 20,587
Total costs and expenses	18,146	16,045
Depreciation and Amortization	2,599	2,468
Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	13,518	13,050
Total costs and expenses		7,876
Depreciation and Amortization		1,946
Residential, Video [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	5,659	5,706
Residential, High-Speed Internet [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	4,157	3,842
Residential, Voice [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	1,006	1,034
Business Services [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	1,726	1,543
Advertising [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	582	554
Other [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 388	371
Previous Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		20,463
Total costs and expenses		15,933
Previous Reported [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		12,912
Total costs and expenses		7,714
Depreciation and Amortization		1,980
Previous Reported [Member] | Residential, Video [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		5,774
Previous Reported [Member] | Residential, High-Speed Internet [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		3,606
Previous Reported [Member] | Residential, Voice [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		863
Previous Reported [Member] | Business Services [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		1,490
Previous Reported [Member] | Advertising [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		512
Previous Reported [Member] | Other [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		667
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		124
Total costs and expenses		112
Effects of Adoption [Member] | Accounting Standards Update 2014-09 [Member] | Cable Communications [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		138
Total costs and expenses		162
Depreciation and Amortization		(34)
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		(68)
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		236
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		171
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		53
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		42
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		$ (296)

Recent Accounting Pronounceme51

Recent Accounting Pronouncements and Tax Reform (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 33
Income tax benefit, 2017 tax reform legislation		12,700
Income tax benefit, 2018 tax reform legislation	$ 128
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)
Member's Capital [Member] | Accounting Standards Update 2016-01 [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
AOCI Attributable to Parent [Member] | Accounting Standards Update 2016-01 [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	Mar. 31, 2018	Dec. 31, 2017
Film Costs:
Released, less amortization	$ 1,590	$ 1,734
Completed, not released	54	50
In production and in development	1,287	1,149
Total film costs	2,931	2,933
Television Costs:
Released, less amortization	2,361	2,260
In production and in development	845	818
Total television costs	3,206	3,078
Programming rights, less amortization	2,619	2,689
Total film costs, television costs and programming rights	8,756	8,700
Less: Current portion of programming rights	1,354	1,613
Film and television costs	7,402	7,087
NBCUniversal Media LLC [Member]
Film Costs:
Released, less amortization	1,590	1,734
Completed, not released	54	50
In production and in development	1,287	1,149
Total film costs	2,931	2,933
Television Costs:
Released, less amortization	2,361	2,260
In production and in development	845	818
Total television costs	3,206	3,078
Programming rights, less amortization	2,608	2,677
Total film costs, television costs and programming rights	8,745	8,688
Less: Current portion of programming rights	1,347	1,606
Film and television costs	$ 7,398	$ 7,082

Investments (Schedule of Invest

Investments (Schedule of Investments) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Equity method	$ 3,615	$ 3,546
Marketable equity securities	471	433
Nonmarketable equity securities	1,235	1,186
Other investments	1,789	1,785
Total investments	7,110	6,950
Less: Current investments	15	19
Noncurrent investments	7,095	6,931
NBCUniversal Media LLC [Member]
Schedule of Investments [Line Items]
Equity method	697	690
Marketable equity securities	467	430
Nonmarketable equity securities	699	696
Total investments	1,863	1,816
Noncurrent investments	$ 1,863	$ 1,816

Investments (Investment and Oth

Investments (Investment and Other Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	$ (49)	$ 36
Realized and unrealized gains (losses) on equity securities, net	28	(5)
Other income (loss), net	147	99
Investment and other income (loss), net	126	130
NBCUniversal Media LLC [Member]
Investment and Other Income (Loss), Net [Line Items]
Equity in net income (losses) of investees, net	(100)	(26)
Realized and unrealized gains (losses) on equity securities, net	37	2
Other income (loss), net	59	23
Investment and other income (loss), net	$ (4)	$ (1)

Investments (Equity Method) (De

Investments (Equity Method) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017	Feb. 28, 2018	Jan. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 3,615	$ 3,615				$ 3,546
Equity in net income (losses) of investees, net		(49)	$ 36
NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	697	697				690
Equity in net income (losses) of investees, net		(100)	(26)
Atairos [Member]
Schedule of Equity Method Investments [Line Items]
Funding commitment				$ 5,000	$ 4,000
Equity method investments	2,400	2,400				2,400
Purchases of investments		31	457
Equity in net income (losses) of investees, net		35	57
Hulu [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	231	231				249
Equity in net income (losses) of investees, net		(131)	(54)
Cash capital contribution, equity method investment	114	114
Hulu [Member] | NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	231	231				$ 249
Equity in net income (losses) of investees, net		(131)	$ (54)
Cash capital contribution, equity method investment	114	$ 114
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	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Marketable Equity Securities [Line Items]
Marketable equity securities			$ 471		$ 433
NBCUniversal Media LLC [Member]
Schedule of Marketable Equity Securities [Line Items]
Contribution from member				$ 662
Marketable equity securities			467		430
Snap [Member]
Schedule of Marketable Equity Securities [Line Items]
Payments to acquire marketable securities		$ 500
Marketable equity securities			467		430
Marketable securities, recognized unrealized gains			37
Snap [Member] | NBCUniversal Media LLC [Member]
Schedule of Marketable Equity Securities [Line Items]
Contribution from member	$ 662
Marketable equity securities			467		$ 430
Marketable securities, recognized unrealized gains			$ 37

Investments (Other Investments)

Investments (Other Investments) (Details) $ in Billions	3 Months Ended
	Mar. 31, 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 Inform58

Supplemental Financial Information (Share-Based Compensation) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		$ 139	$ 124
Restricted share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		83	74
Unrecognized pretax compensation expense on nonvested awards	$ 1,100	1,100
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		44	40
Unrecognized pretax compensation expense on nonvested awards	$ 607	607
Employee Stock purchase plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense		$ 12	$ 10
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 Inform59

Supplemental Financial Information (Cash Payments for Interest and Income Taxes)(Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Payments for Interest and Income Taxes
Interest	$ 854	$ 895
Income taxes	162	132
NBCUniversal Media LLC [Member]
Cash Payments for Interest and Income Taxes
Interest	51	77
Income taxes	$ 173	$ 52

Supplemental Financial Inform60

Supplemental Financial Information (Noncash Investing and Financing Activities)(Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / shares
Supplemental Financial Information [Line Items]
Capital expenditures incurred but not yet paid	$ 1,500
Dividends payable	$ 877
Dividends payable (in dollars per share) | $ / shares	$ 0.19
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Capital expenditures incurred but not yet paid	$ 721
Universal Beijing Resort [Member]
Supplemental Financial Information [Line Items]
Assets contributed to variable interest entity	316
Universal Beijing Resort [Member] | NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Assets contributed to variable interest entity	$ 316

Supplemental Financial Inform61

Supplemental Financial Information (Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Supplemental Financial Information [Line Items]
Cash and cash equivalents	$ 6,030	$ 3,428
Restricted cash included in other current assets	64	60
Restricted cash included in other noncurrent assets, net	83	83
Cash, cash equivalents and restricted cash, end of period	6,177	3,571	$ 4,146	$ 3,415
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Cash and cash equivalents	2,225	2,347
Restricted cash included in other noncurrent assets, net	31	30
Cash, cash equivalents and restricted cash, end of period	$ 2,256	$ 2,377	$ 1,903	$ 1,987

Supplemental Financial Inform62

Supplemental Financial Information (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	$ 1		$ 104
Deferred gains (losses) on cash flow hedges	20		(7)
Unrecognized gains (losses) on employee benefit obligations	310		282
Cumulative translation adjustments	277		(37)
Accumulated other comprehensive income (loss), net of deferred taxes	608	$ 379	342
NBCUniversal Media LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	0		1
Deferred gains (losses) on cash flow hedges	(3)		9
Unrecognized gains (losses) on employee benefit obligations	122		120
Cumulative translation adjustments	277		(59)
Accumulated other comprehensive income (loss), net of deferred taxes	$ 396	$ (20)	$ 71

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 11,253		$ 10,972
Recognized share-based compensation expense	139	$ 124
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	4,487		$ 4,153
Recognized share-based compensation expense	32	$ 25
Carrying Value of Related Party Contractual Obligation [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 383

Related Party Transactions (Con

Related Party Transactions (Condensed Consolidated Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Related Party Transaction [Line Items]
Revenue	$ 22,791	$ 20,587
Operating costs and expenses	(18,146)	(16,045)
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	9,530	7,853
Operating costs and expenses	(7,755)	(6,342)
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	594	459
Operating costs and expenses	(61)	(61)
Interest expense and investment and other income (loss), net	$ (23)	$ (19)

Related Party Transactions (C65

Related Party Transactions (Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Receivables, net	$ 8,759	$ 8,834
Accounts payable and accrued expenses related to trade creditors	7,349	6,908
Accrued expenses and other current liabilities	5,554	6,620
Long-term debt, less current portion	63,678	59,422
Other noncurrent liabilities	11,253	10,972
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	7,176	6,967
Accounts payable and accrued expenses related to trade creditors	1,862	1,663
Accrued expenses and other current liabilities	1,760	2,394
Note payable to Comcast	1,284	1,831
Long-term debt, less current portion	12,478	12,275
Other noncurrent liabilities	4,487	4,153
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	376	326
Accounts payable and accrued expenses related to trade creditors	51	54
Accrued expenses and other current liabilities	13	50
Note payable to Comcast	1,284	1,831
Long-term debt, less current portion	610	610
Other noncurrent liabilities	$ 389	$ 389

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) $ in Millions	Mar. 31, 2018USD ($)
Redeemable Preferred Stock [Member] | Level 2 [Member]
Temporary Equity [Line Items]
Fair Value of Redeemable subsidiary preferred stock	$ 753

Condensed Consolidating Finan67

Condensed Consolidating Financial Information (Narrative) (Details) - Mar. 31, 2018 $ in Millions, ¥ in Billions	USD ($)	JPY (¥)
NBCUniversal Enterprise Senior Debt Securities [Member]
Debt Instrument [Line Items]
Principal amount of debt securities subject to guarantee	$ 4,800
NBCUniversal Enterprise Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility subject to guarantee	1,500
Universal Studios Japan Term Loan Maturing March 2022 [Member]
Debt Instrument [Line Items]
Term loans subject to guarantee | ¥		¥ 430
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 Finan68

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Service revenue	$ 22,791	$ 20,587
Management fee revenue	0	0
Revenue	22,791	20,587
Costs and Expenses:
Programming and production	7,429	6,061
Other operating and administrative	6,514	5,939
Advertising, marketing and promotion	1,604	1,577
Depreciation	2,011	1,915
Amortization	588	553
Total costs and expenses	18,146	16,045
Operating income	4,645	4,542
Interest expense	(777)	(755)
Investment and other income (loss), net	126	130
Income before income taxes	3,994	3,917
Income tax expense	(818)	(1,262)
Net income	3,176	2,655
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	58	82
Net income attributable to Comcast Corporation	3,118	2,573
Comprehensive income (loss) attributable to Comcast Corporation	3,271	2,817
Elimination and Consolidation Adjustments [Member]
Revenue:
Service revenue	0	0
Management fee revenue	(578)	(545)
Revenue	(578)	(545)
Costs and Expenses:
Programming and production	0	0
Other operating and administrative	(578)	(545)
Advertising, marketing and promotion	0	0
Depreciation	0	0
Amortization	0	0
Total costs and expenses	(578)	(545)
Operating income	0	0
Interest expense	0	0
Investment and other income (loss), net	(13,069)	(10,632)
Income before income taxes	(13,069)	(10,632)
Income tax expense	0	0
Net income	(13,069)	(10,632)
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0
Net income attributable to Comcast Corporation	(13,069)	(10,632)
Comprehensive income (loss) attributable to Comcast Corporation	(13,645)	(11,133)
Comcast Parent [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0
Management fee revenue	292	275
Revenue	292	275
Costs and Expenses:
Programming and production	0	0
Other operating and administrative	228	170
Advertising, marketing and promotion	0	0
Depreciation	11	7
Amortization	1	2
Total costs and expenses	240	179
Operating income	52	96
Interest expense	(561)	(517)
Investment and other income (loss), net	3,520	2,847
Income before income taxes	3,011	2,426
Income tax expense	107	147
Net income	3,118	2,573
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0
Net income attributable to Comcast Corporation	3,118	2,573
Comprehensive income (loss) attributable to Comcast Corporation	3,271	2,817
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	22,791	20,587
Management fee revenue	0	0
Revenue	22,791	20,587
Costs and Expenses:
Programming and production	7,429	6,061
Other operating and administrative	6,260	5,738
Advertising, marketing and promotion	1,604	1,577
Depreciation	2,000	1,908
Amortization	587	551
Total costs and expenses	17,880	15,835
Operating income	4,911	4,752
Interest expense	(60)	(63)
Investment and other income (loss), net	1,588	1,279
Income before income taxes	6,439	5,968
Income tax expense	(929)	(1,418)
Net income	5,510	4,550
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	58	82
Net income attributable to Comcast Corporation	5,452	4,468
Comprehensive income (loss) attributable to Comcast Corporation	5,791	4,712
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0
Management fee revenue	0	0
Revenue	0	0
Costs and Expenses:
Programming and production	0	0
Other operating and administrative	0	0
Advertising, marketing and promotion	0	0
Depreciation	0	0
Amortization	0	0
Total costs and expenses	0	0
Operating income	0	0
Interest expense	(3)	(3)
Investment and other income (loss), net	3,319	2,686
Income before income taxes	3,316	2,683
Income tax expense	0	(9)
Net income	3,316	2,674
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0
Net income attributable to Comcast Corporation	3,316	2,674
Comprehensive income (loss) attributable to Comcast Corporation	3,369	2,724
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0
Management fee revenue	286	270
Revenue	286	270
Costs and Expenses:
Programming and production	0	0
Other operating and administrative	286	270
Advertising, marketing and promotion	0	0
Depreciation	0	0
Amortization	0	0
Total costs and expenses	286	270
Operating income	0	0
Interest expense	(47)	(60)
Investment and other income (loss), net	2,826	2,327
Income before income taxes	2,779	2,267
Income tax expense	9	21
Net income	2,788	2,288
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0
Net income attributable to Comcast Corporation	2,788	2,288
Comprehensive income (loss) attributable to Comcast Corporation	2,789	2,289
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0
Management fee revenue	0	0
Revenue	0	0
Costs and Expenses:
Programming and production	0	0
Other operating and administrative	318	306
Advertising, marketing and promotion	0	0
Depreciation	0	0
Amortization	0	0
Total costs and expenses	318	306
Operating income	(318)	(306)
Interest expense	(106)	(112)
Investment and other income (loss), net	1,942	1,623
Income before income taxes	1,518	1,205
Income tax expense	(5)	(3)
Net income	1,513	1,202
Less: Net income attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0
Net income attributable to Comcast Corporation	1,513	1,202
Comprehensive income (loss) attributable to Comcast Corporation	$ 1,696	$ 1,408

Condensed Consolidating Finan69

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities	$ 5,474	$ 5,625
Investing Activities
Net transactions with affiliates	0	0
Capital expenditures	(1,973)	(2,078)
Cash paid for intangible assets	(419)	(385)
Acquisitions and construction of real estate properties	(59)	(130)
Acquisitions, net of cash acquired	(89)	(216)
Proceeds from sales of investments	81	51
Purchases of investments	(220)	(1,062)
Other	387	67
Net cash provided by (used in) investing activities	(2,292)	(3,753)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(902)	(1,893)
Proceeds from borrowings	4,043	3,500
Repurchases and repayments of debt	(1,265)	(1,059)
Repurchases of common stock under repurchase program and employee plans	(1,729)	(996)
Dividends paid	(738)	(657)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(79)	(72)
Other	94	36
Net cash provided by (used in) financing activities	(576)	(1,141)
Increase (decrease) in cash, cash equivalents and restricted cash	2,606	731
Cash, cash equivalents and restricted cash, beginning of period	3,571	3,415
Cash, cash equivalents and restricted cash, end of period	6,177	4,146
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
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
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
Comcast Parent [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities	(270)	(453)
Investing Activities
Net transactions with affiliates	640	1,385
Capital expenditures	0	(1)
Cash paid for intangible assets	(2)	0
Acquisitions and construction of real estate properties	(39)	(69)
Acquisitions, net of cash acquired	0	0
Proceeds from sales of investments	0	0
Purchases of investments	(11)	(9)
Other	0	55
Net cash provided by (used in) investing activities	588	1,361
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(902)	(1,739)
Proceeds from borrowings	3,973	3,500
Repurchases and repayments of debt	(900)	(1,000)
Repurchases of common stock under repurchase program and employee plans	(1,729)	(996)
Dividends paid	(738)	(657)
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	0	0
Other	(22)	(16)
Net cash provided by (used in) financing activities	(318)	(908)
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
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities	5,822	6,586
Investing Activities
Net transactions with affiliates	(239)	(1,678)
Capital expenditures	(1,973)	(2,077)
Cash paid for intangible assets	(417)	(385)
Acquisitions and construction of real estate properties	(20)	(61)
Acquisitions, net of cash acquired	(89)	(216)
Proceeds from sales of investments	24	41
Purchases of investments	(204)	(1,049)
Other	(57)	12
Net cash provided by (used in) investing activities	(2,975)	(5,413)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	0	(154)
Proceeds from borrowings	70	0
Repurchases and repayments of debt	(362)	(56)
Repurchases of common stock under repurchase program and employee plans	0	0
Dividends paid	0	0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(79)	(72)
Other	116	52
Net cash provided by (used in) financing activities	(255)	(230)
Increase (decrease) in cash, cash equivalents and restricted cash	2,592	943
Cash, cash equivalents and restricted cash, beginning of period	3,075	2,933
Cash, cash equivalents and restricted cash, end of period	5,667	3,876
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	453	(10)
Investing Activities
Net transactions with affiliates	(897)	10
Capital expenditures	0	0
Cash paid for intangible assets	0	0
Acquisitions and construction of real estate properties	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from sales of investments	0	0
Purchases of investments	0	0
Other	444	0
Net cash provided by (used in) investing activities	(453)	10
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
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
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	(149)	(168)
Investing Activities
Net transactions with affiliates	149	168
Capital expenditures	0	0
Cash paid for intangible assets	0	0
Acquisitions and construction of real estate properties	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	149	168
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
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
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	(382)	(330)
Investing Activities
Net transactions with affiliates	347	115
Capital expenditures	0	0
Cash paid for intangible assets	0	0
Acquisitions and construction of real estate properties	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from sales of investments	57	10
Purchases of investments	(5)	(4)
Other	0	0
Net cash provided by (used in) investing activities	399	121
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
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	14	(212)
Cash, cash equivalents and restricted cash, beginning of period	496	482
Cash, cash equivalents and restricted cash, end of period	$ 510	$ 270

Condensed Consolidating Finan70

Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 6,030	$ 3,428
Receivables, net	8,759	8,834
Programming rights	1,354	1,613
Other current assets	2,610	2,468
Total current assets	18,753	16,343
Film and television costs	7,402	7,087
Investments	7,095	6,931
Investments in and amounts due from subsidiaries eliminated upon consolidation	0	0
Property and equipment, net	39,068	38,470
Franchise rights	59,365	59,364
Goodwill	37,147	36,780
Other intangible assets, net	18,339	18,133
Other noncurrent assets, net	3,707	4,354
Total assets	190,876	187,462
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	7,349	6,908
Accrued participations and residuals	1,659	1,644
Deferred revenue	1,578	1,687
Accrued expenses and other current liabilities	5,554	6,620
Current portion of long-term debt	3,039	5,134
Total current liabilities	19,179	21,993
Long-term debt, less current portion	63,678	59,422
Deferred income taxes	24,702	24,259
Other noncurrent liabilities	11,253	10,972
Redeemable noncontrolling interests	1,354	1,357
Equity:
Common stock	55	55
Other shareholders’ equity	69,427	68,561
Total Comcast Corporation shareholders’ equity	69,482	68,616
Noncontrolling interests	1,228	843
Total equity	70,710	69,459	$ 57,644	$ 56,163
Total liabilities and equity	190,876	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	(574,966)	(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	(249)	(314)
Total assets	(575,215)	(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	(278)	(343)
Other noncurrent liabilities	29	29
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	(574,966)	(562,645)
Total Comcast Corporation shareholders’ equity	(574,966)	(562,645)
Noncontrolling interests	0	0
Total equity	(574,966)	(562,645)
Total liabilities and equity	(575,215)	(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	56	60
Total current assets	56	60
Film and television costs	0	0
Investments	157	146
Investments in and amounts due from subsidiaries eliminated upon consolidation	120,165	117,164
Property and equipment, net	622	551
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	12	12
Other noncurrent assets, net	370	435
Total assets	121,382	118,368
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	39	16
Accrued participations and residuals	0	0
Deferred revenue	0	0
Accrued expenses and other current liabilities	1,846	1,888
Current portion of long-term debt	1,002	2,810
Total current liabilities	2,887	4,714
Long-term debt, less current portion	46,424	42,428
Deferred income taxes	0	0
Other noncurrent liabilities	2,589	2,610
Redeemable noncontrolling interests	0	0
Equity:
Common stock	55	55
Other shareholders’ equity	69,427	68,561
Total Comcast Corporation shareholders’ equity	69,482	68,616
Noncontrolling interests	0	0
Total equity	69,482	68,616
Total liabilities and equity	121,382	118,368
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	5,520	2,932
Receivables, net	8,759	8,834
Programming rights	1,354	1,613
Other current assets	2,535	2,376
Total current assets	18,168	15,755
Film and television costs	7,402	7,087
Investments	6,106	5,963
Investments in and amounts due from subsidiaries eliminated upon consolidation	114,646	113,332
Property and equipment, net	38,446	37,919
Franchise rights	59,365	59,364
Goodwill	37,147	36,780
Other intangible assets, net	18,327	18,121
Other noncurrent assets, net	3,234	3,437
Total assets	302,841	297,758
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	7,310	6,892
Accrued participations and residuals	1,659	1,644
Deferred revenue	1,578	1,687
Accrued expenses and other current liabilities	3,065	3,981
Current portion of long-term debt	2,033	2,320
Total current liabilities	15,645	16,524
Long-term debt, less current portion	7,265	7,003
Deferred income taxes	24,605	24,250
Other noncurrent liabilities	7,453	7,205
Redeemable noncontrolling interests	1,354	1,357
Equity:
Common stock	0	0
Other shareholders’ equity	245,291	240,576
Total Comcast Corporation shareholders’ equity	245,291	240,576
Noncontrolling interests	1,228	843
Total equity	246,519	241,419
Total liabilities and equity	302,841	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	0	0
Total current assets	0	0
Film and television costs	0	0
Investments	21	21
Investments in and amounts due from subsidiaries eliminated upon consolidation	146,308	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	265	708
Total assets	146,594	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	92	92
Current portion of long-term debt	0	0
Total current liabilities	92	92
Long-term debt, less current portion	141	140
Deferred income taxes	304	285
Other noncurrent liabilities	0	0
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	146,057	142,731
Total Comcast Corporation shareholders’ equity	146,057	142,731
Noncontrolling interests	0	0
Total equity	146,057	142,731
Total liabilities and equity	146,594	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	110	108
Investments in and amounts due from subsidiaries eliminated upon consolidation	142,199	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	142,309	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	215	333
Current portion of long-term debt	0	0
Total current liabilities	215	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	139,994	137,210
Total Comcast Corporation shareholders’ equity	139,994	137,210
Noncontrolling interests	0	0
Total equity	139,994	137,210
Total liabilities and equity	142,309	139,643
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	510	496
Receivables, net	0	0
Programming rights	0	0
Other current assets	19	25
Total current assets	529	521
Film and television costs	0	0
Investments	701	693
Investments in and amounts due from subsidiaries eliminated upon consolidation	51,648	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	87	88
Total assets	52,965	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	336	326
Current portion of long-term debt	4	4
Total current liabilities	340	330
Long-term debt, less current portion	7,748	7,751
Deferred income taxes	71	67
Other noncurrent liabilities	1,182	1,128
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	43,624	42,128
Total Comcast Corporation shareholders’ equity	43,624	42,128
Noncontrolling interests	0	0
Total equity	43,624	42,128
Total liabilities and equity	$ 52,965	$ 51,404