NBCUniversal Media 10-Q 26 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2017shares
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	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
NBCUniversal Media LLC [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	NBCUniversal Media, LLC
Entity Central Index Key	902,739
Entity Filer Category	Non-accelerated Filer
Class A Common Stock [Member]
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	4,664,327,455
Class B Common Stock [Member]
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	9,444,375

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 4,114	$ 3,301
Receivables, net	7,915	7,955
Programming rights	1,779	1,250
Other current assets	2,152	3,855
Total current assets	15,960	16,361
Film and television costs	6,796	7,252
Investments	6,695	5,247
Property and equipment, net	37,856	36,253
Franchise rights	59,364	59,364
Goodwill	36,752	35,980
Other intangible assets, net	18,733	17,274
Other noncurrent assets, net	3,145	2,769
Total assets	185,301	180,500
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	6,976	6,915
Accrued participations and residuals	1,811	1,726
Deferred revenue	1,572	1,132
Accrued expenses and other current liabilities	5,849	6,282
Current portion of long-term debt	5,241	5,480
Total current liabilities	21,449	21,535
Long-term debt, less current portion	59,720	55,566
Deferred income taxes	35,602	34,854
Other noncurrent liabilities	10,914	10,925
Commitments and contingencies (Note 10)
Redeemable noncontrolling interests	1,353	1,446
Equity:
Preferred stock—authorized, 20,000,000 shares; issued, zero	0	0
Common stock	55	56
Additional paid-in capital	37,529	38,230
Retained earnings	24,979	23,076
Treasury stock, 872,791,028 Class A common shares	(7,517)	(7,517)
Accumulated other comprehensive income (loss)	381	98
Total Comcast Corporation shareholders’ equity	55,427	53,943
Noncontrolling interests	836	2,231
Total equity	56,263	56,174
Total liabilities and equity	185,301	180,500
NBCUniversal Media LLC [Member]
Current Assets:
Cash and cash equivalents	2,014	1,966
Receivables, net	6,177	6,302
Programming rights	1,772	1,241
Other current assets	1,114	938
Total current assets	11,077	10,447
Film and television costs	6,791	7,245
Investments	1,817	1,263
Property and equipment, net	11,040	10,511
Goodwill	23,963	23,323
Intangible assets, net	13,375	13,777
Other noncurrent assets, net	1,582	1,688
Total assets	69,645	68,254
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	1,449	1,647
Accrued participations and residuals	1,811	1,726
Program obligations	576	807
Deferred revenue	1,479	1,016
Accrued expenses and other current liabilities	1,807	1,888
Note payable to Comcast	1,805	2,703
Current portion of long-term debt	196	127
Total current liabilities	9,123	9,914
Long-term debt, less current portion	12,157	11,461
Accrued participations, residuals and program obligations	1,202	1,202
Other noncurrent liabilities	4,099	4,130
Commitments and contingencies (Note 10)
Redeemable noncontrolling interests	407	530
Equity:
Member’s capital	41,760	39,036
Accumulated other comprehensive income (loss)	(29)	(135)
Total NBCUniversal member’s equity	41,731	38,901
Noncontrolling interests	926	2,116
Total equity	42,657	41,017
Total liabilities and equity	69,645	68,254
Class A Common Stock [Member]
Equity:
Common stock	55	56
Class B Common Stock [Member]
Equity:
Common stock	$ 0	$ 0

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Property and equipment - accumulated depreciation	$ 49,943	$ 49,694
Other intangible assets - accumulated amortization	$ 12,371	$ 11,013
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	$ 3,999	$ 3,350
Other intangible assets - accumulated amortization	$ 7,372	$ 6,568
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)	5,537,118,483	5,614,950,039
Common stock, shares outstanding (in shares)	4,664,327,455	4,742,159,011
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 Statemen

Condensed Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue	$ 20,983	$ 21,319	$ 62,611	$ 59,378
Costs and Expenses:
Programming and production	6,077	7,003	18,492	17,926
Other operating and administrative	6,423	5,996	18,310	17,285
Advertising, marketing and promotion	1,553	1,485	4,748	4,510
Depreciation	1,991	1,865	5,876	5,518
Amortization	589	530	1,747	1,544
Other operating gains	(442)	0	(442)	0
Total costs and expenses	16,191	16,879	48,731	46,783
Operating income	4,792	4,440	13,880	12,595
Other Income (Expense):
Interest expense	(766)	(751)	(2,279)	(2,186)
Investment income (loss), net	82	80	205	168
Equity in net income (losses) of investees, net	(39)	(34)	12	(64)
Other income (expense), net	27	(11)	82	104
Total other income (expense)	(696)	(716)	(1,980)	(1,978)
Income before income taxes	4,096	3,724	11,900	10,617
Income tax expense	(1,413)	(1,400)	(4,035)	(3,989)
Net income	2,683	2,324	7,865	6,628
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	(33)	(87)	(136)	(229)
Net income attributable to Comcast Corporation	$ 2,650	$ 2,237	$ 7,729	$ 6,399
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.56	$ 0.47	$ 1.64	$ 1.32
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	0.55	0.46	1.61	1.31
Dividends declared per common share (in dollars per share)	$ 0.1575	$ 0.1375	$ 0.4725	$ 0.4125
NBCUniversal Media LLC [Member]
Revenue	$ 8,014	$ 9,178	$ 24,213	$ 23,142
Costs and Expenses:
Programming and production	3,257	4,501	10,157	10,503
Other operating and administrative	1,859	1,912	5,586	5,159
Advertising, marketing and promotion	624	619	2,108	2,023
Depreciation	253	209	749	624
Amortization	253	236	785	700
Other operating gains	(337)	0	(337)	0
Total costs and expenses	5,909	7,477	19,048	19,009
Operating income	2,105	1,701	5,165	4,133
Other Income (Expense):
Interest expense	(139)	(151)	(431)	(444)
Investment income (loss), net	10	6	34	20
Equity in net income (losses) of investees, net	(52)	(34)	(107)	(55)
Other income (expense), net	16	(16)	31	81
Total other income (expense)	(165)	(195)	(473)	(398)
Income before income taxes	1,940	1,506	4,692	3,735
Income tax expense	(98)	(139)	(289)	(311)
Net income	1,842	1,367	4,403	3,424
Net (income) loss attributable to noncontrolling interests	(17)	(78)	(102)	(200)
Net income attributable to Comcast Corporation	$ 1,825	$ 1,289	$ 4,301	$ 3,224

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income	$ 2,683	$ 2,324	$ 7,865	$ 6,628
Unrealized gains (losses) on marketable securities, net of deferred taxes	(59)	(1)	(42)	2
Deferred gains (losses) on cash flow hedges, net of deferred taxes	16	12	28	(79)
Amounts reclassified to net income:
Realized (gains) losses on marketable securities, net of deferred taxes	(1)	0	(1)	(1)
Realized (gains) losses on cash flow hedges, net of deferred taxes	(12)	11	(26)	73
Employee benefit obligations, net of deferred taxes	(6)	0	51	2
Currency translation adjustments, net of deferred taxes	20	45	166	532
Comprehensive income	2,641	2,391	8,041	7,157
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	(33)	(87)	(136)	(229)
Other comprehensive (income) loss attributable to noncontrolling interests	(5)	(34)	(87)	(321)
Comprehensive income (loss) attributable to Comcast Corporation	2,603	2,270	7,818	6,607
NBCUniversal Media LLC [Member]
Net income	1,842	1,367	4,403	3,424
Unrealized gains (losses) on marketable securities, net of deferred taxes	(94)	0	(233)	0
Deferred gains (losses) on cash flow hedges, net of deferred taxes	(5)	5	(27)	(7)
Amounts reclassified to net income:
Employee benefit obligations, net of deferred taxes	(3)	0	101	4
Currency translation adjustments, net of deferred taxes	22	50	211	652
Comprehensive income	1,762	1,422	4,455	4,073
Net (income) loss attributable to noncontrolling interests	(17)	(78)	(102)	(200)
Other comprehensive (income) loss attributable to noncontrolling interests	(5)	(34)	(87)	(321)
Comprehensive income (loss) attributable to Comcast Corporation	$ 1,740	$ 1,310	$ 4,266	$ 3,552

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on marketable securities, deferred taxes	$ 35	$ 0	$ 26	$ (1)
Deferred gains (losses) on cash flow hedges, deferred taxes	(9)	(7)	(16)	46
Realized (gains) losses on marketable securities, deferred taxes	0	0	0	1
Realized (gains) losses on cash flow hedges, deferred taxes	7	(6)	15	(42)
Employee benefit obligations, deferred taxes	3	0	(30)	(2)
Currency translation adjustments, deferred taxes	$ (8)	$ (6)	$ (47)	$ (122)

Condensed Consolidated Stateme7

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities
Net cash provided by operating activities	$ 15,961	$ 13,989
Investing Activities
Capital expenditures	(6,839)	(6,562)
Cash paid for intangible assets	(1,240)	(1,163)
Acquisitions and construction of real estate properties	(325)	(303)
Acquisitions, net of cash acquired	(429)	(3,904)
Proceeds from sales of investments	120	188
Purchases of investments	(2,064)	(618)
Deposits	0	(1,748)
Other	750	(42)
Net cash provided by (used in) investing activities	(10,027)	(14,152)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	(2,807)	610
Proceeds from borrowings	11,460	9,231
Repurchases and repayments of debt	(5,021)	(2,994)
Repurchases of common stock under repurchase program and employee plans	(4,212)	(4,061)
Dividends paid	(2,147)	(1,944)
Purchase of Universal Studios Japan noncontrolling interests	(2,299)	0
Issuances of common stock	0	23
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	(198)	(194)
Other	103	4
Net cash provided by (used in) financing activities	(5,121)	675
Increase (decrease) in cash and cash equivalents	813	512
Cash and cash equivalents, beginning of period	3,301	2,295
Cash and cash equivalents, end of period	4,114	2,807
NBCUniversal Media LLC [Member]
Operating Activities
Net cash provided by operating activities	5,572	3,339
Investing Activities
Capital expenditures	(977)	(991)
Cash paid for intangible assets	(197)	(181)
Acquisitions of real estate properties	0	(78)
Proceeds from sales of investments	42	104
Purchases of investments	(368)	(74)
Other	474	(236)
Net cash provided by (used in) investing activities	(1,026)	(1,456)
Financing Activities
Proceeds from borrowings	3,948	0
Repurchases and repayments of debt	(3,450)	(1,515)
Proceeds from (repayments of) borrowings from Comcast, net	(898)	1,132
Purchase of Universal Studios Japan noncontrolling interests	(2,299)	0
Distributions to member	(1,720)	(1,213)
Distributions to noncontrolling interests	(165)	(161)
Other	86	354
Net cash provided by (used in) financing activities	(4,498)	(1,403)
Increase (decrease) in cash and cash equivalents	48	480
Cash and cash equivalents, beginning of period	1,966	1,410
Cash and cash equivalents, end of period	$ 2,014	$ 1,890

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, 2015	$ 53,978		$ 38,490	$ 21,413	$ (7,517)	$ (174)	$ 1,709						$ 57	$ 0
Beginning balance at Dec. 31, 2015								$ 34,303		$ 32,834	$ (212)	$ 1,681
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation plans	582		582
Repurchases of common stock under repurchase program and employee plans	(4,062)		(758)	(3,303)									(1)
Employee stock purchase plans	117		117
Dividends declared	(1,999)			(1,999)				(1,213)		(1,213)
Other comprehensive income (loss)	529					208	321	649			328	321
Contributions from (distributions to) noncontrolling interests, net	(99)						(99)	(114)				(114)
Contribution from member								3,647		3,558		89
Other	212		(33)				245	163		3		160
Net income (loss)	6,565			6,399			166	3,394		3,224		170
Ending balance at Sep. 30, 2016	55,823		38,398	22,510	(7,517)	34	2,342						56	0
Ending balance at Sep. 30, 2016								40,829		38,406	116	2,307
Beginning balance at Dec. 31, 2015		$ 1,221							$ 372
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions from (distributions to) noncontrolling interests, net		(20)							(47)
Other		62							72
Net income (loss)		63							30
Ending balance at Sep. 30, 2016		1,326							427
Beginning balance at Dec. 31, 2016	56,174		38,230	23,076	(7,517)	98	2,231						56	0
Beginning balance at Dec. 31, 2016								41,017		39,036	(135)	2,116
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation plans	440		440
Repurchases of common stock under repurchase program and employee plans	(4,221)		(633)	(3,587)									(1)
Employee stock purchase plans	140		140
Dividends declared	(2,239)			(2,239)				(1,720)		(1,720)
Other comprehensive income (loss)	176					89	87	52			(35)	87
Contributions from (distributions to) noncontrolling interests, net	(81)						(81)	(95)				(95)
Contribution from member								662		662
Purchase of Universal Studios Japan noncontrolling interests	(2,238)		(696)			194	(1,736)	(2,299)		(704)	141	(1,736)
Other	299		48				251	655		185		470
Net income (loss)	7,813			7,729			84	4,385		4,301		84
Ending balance at Sep. 30, 2017	56,263		$ 37,529	$ 24,979	$ (7,517)	$ 381	$ 836						$ 55	$ 0
Ending balance at Sep. 30, 2017								42,657		$ 41,760	$ (29)	$ 926
Beginning balance at Dec. 31, 2016	1,446	1,446						530	530
Increase (Decrease) in Temporary Equity [Roll Forward]
Contributions from (distributions to) noncontrolling interests, net		(31)							(56)
Other		(114)							(85)
Net income (loss)		52							18
Ending balance at Sep. 30, 2017	$ 1,353	$ 1,353						$ 407	$ 407

Condensed Consolidated Financia

Condensed Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2017
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, financial condition and cash flows 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 2016 Annual Report on Form 10-K. Stock Split On January 24, 2017, our Board of Directors approved a two -for-one stock split in the form of a 100% stock dividend that was distributed on February 17, 2017 to shareholders of record as of February 8, 2017. The stock split was in the form of one additional share for every share held and was payable in shares of Class A common stock on the existing Class A common stock and Class B common stock. All share-based data, including the number of shares outstanding and per share amounts, have been adjusted to reflect the stock split for all periods presented. Reclassifications Reclassifications have been made to our condensed consolidated financial statements for the prior year periods to conform to classifications used in 2017 .
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, financial condition and cash flows 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 2016 Annual Report on Form 10-K.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Recent Accounting Pronouncements	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 updated accounting guidance is effective for us as of January 1, 2018. We have substantially completed the review of our revenue arrangements and do not currently expect that the adoption of the new standard will have a material impact on our financial position or results of operations. Upon adoption, we anticipate implementing certain changes in the presentation of revenue and expenses, including changes related to the allocation of revenue among the cable services included in a bundle that our residential customers purchase at a discount. We also expect that the new standard will impact the timing of recognition for (1) our Cable Communications segment’s installation revenue and commission expenses, which will be recognized as revenue and costs over a period of time instead of immediately, and (2) our Cable Networks, Broadcast Television and Filmed Entertainment segments’ content licensing revenue associated with renewals or extensions of existing program licensing agreements, which will be recognized as revenue when the licensed content becomes available under the renewal or extension instead of when the agreement is renewed or extended. In addition, the updated guidance requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions. We intend to adopt the provisions of the guidance using the full retrospective method, under which we will adjust any prior periods presented to reflect the updated guidance. 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 that the changes in fair value be recognized in net income. The updated guidance is effective for us as of January 1, 2018. The updated accounting guidance requires a cumulative effect adjustment to beginning retained earnings in the year the guidance is adopted with certain exceptions. If we had adopted the provisions of the updated guidance as of January 1, 2017 for our equity investments classified as available-for-sale securities, primarily our investment in Snap Inc. (see Note 6), net income attributable to Comcast Corporation would have decreased for the three and nine months ended September 30, 2017 by $63 million and $47 million , respectively. We are currently in the process of determining the impact that the updated accounting guidance will have on our cost method investments. 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. Share-Based Compensation In March 2016, the FASB updated the accounting guidance that affects several aspects of the accounting for share-based compensation. The most significant change for us relates to the presentation of the income and withholding tax consequences of share-based compensation in our consolidated financial statements. Among the changes, the updated guidance requires that the excess income tax benefits or deficiencies that arise when the tax consequences of share-based compensation differ from amounts previously recognized in the statement of income be recognized as income tax benefit or expense in the statement of income rather than as additional paid-in capital in the balance sheet. The guidance also states that excess income tax benefits should not be presented separately from other income taxes in the statement of cash flows and, thus, should be classified as an operating activity rather than a financing activity as they were under the prior guidance. In addition, the updated guidance requires that, when an employer withholds shares upon exercise of options or the vesting of restricted stock for the purpose of meeting withholding tax requirements, the cash paid for withholding taxes be classified as a financing activity and we include these amounts in the caption “repurchases of common stock under repurchase program and employee plans” in our consolidated statement of cash flows. We previously recorded these amounts as operating activities. We adopted the updated guidance as of January 1, 2017 and, as required, we prospectively adopted the provisions that relate to the recognition of the excess income tax benefits or deficiencies in our condensed consolidated statement of income. The excess tax benefits resulted in a decrease to income tax expense of $49 million and $247 million for the three and nine months ended September 30, 2017, respectively. In addition, the excess tax benefits resulted in an increase to diluted earnings per common share attributable to Comcast Corporation shareholders of $0.01 and $0.04 for the three and nine months ended September 30, 2017 , respectively. As required by the updated guidance, the prior year periods in our condensed consolidated statement of income were not adjusted as a result of these provisions. In addition, we retrospectively adopted the provisions of this guidance related to changes to the statement of cash flows for all periods presented. This resulted in increases to net cash provided by operating activities and decreases to net cash provided by (used in) financing activities of $644 million and $492 million for the nine months ended September 30, 2017 and 2016, respectively.
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Recent Accounting Pronouncements	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 updated accounting guidance is effective for us as of January 1, 2018. We have substantially completed the review of our revenue arrangements and do not currently expect that the adoption of the new standard will have a material impact on our financial position or results of operations. However, we do expect that the new standard will impact the timing of recognition for our Cable Networks, Broadcast Television and Filmed Entertainment segments’ content licensing revenue associated with renewals or extensions of existing program licensing agreements, which will be recognized as revenue when the licensed content becomes available under the renewal or extension instead of when the agreement is renewed or extended. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions. We intend to adopt the provisions of the guidance using the full retrospective method, under which we will adjust any prior periods presented to reflect the updated guidance. 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 that the changes in fair value be recognized in net income. The updated guidance is effective for us as of January 1, 2018. The updated accounting guidance requires a cumulative effect adjustment to beginning retained earnings in the year the guidance is adopted with certain exceptions. If we had adopted the provisions of the updated guidance as of January 1, 2017 for our equity investments classified as available-for-sale securities, primarily our investment in Snap Inc. (see Note 6), net income attributable to NBCUniversal would have decreased for the three and nine months ended September 30, 2017 by $95 million and $234 million , respectively. We are currently in the process of determining the impact that the updated accounting guidance will have on our cost method investments. 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.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Computation of Diluted EPS Three Months Ended September 30 2017 2016 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 2,650 4,698 $ 0.56 $ 2,237 4,805 $ 0.47 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 79 56 Diluted EPS attributable to Comcast Corporation shareholders $ 2,650 4,777 $ 0.55 $ 2,237 4,861 $ 0.46 Nine Months Ended September 30 2017 2016 (in millions, except per share amounts) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 7,729 4,725 $ 1.64 $ 6,399 4,837 $ 1.32 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 81 56 Diluted EPS attributable to Comcast Corporation shareholders $ 7,729 4,806 $ 1.61 $ 6,399 4,893 $ 1.31 Diluted earnings per common share attributable to Comcast Corporation shareholders (“diluted EPS”) considers the impact of potentially dilutive securities using the treasury stock method. Our potentially dilutive securities include potential common shares related to our stock options and our restricted share units (“RSUs”). The amount of potential common shares related to our share-based compensation plans that were excluded from diluted EPS because their effect would have been antidilutive was not material for the three and nine months ended September 30, 2017 and 2016 .

Significant Transactions

Significant Transactions	9 Months Ended
	Sep. 30, 2017
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions FCC Spectrum Auction On April 13, 2017, the Federal Communications Commission announced the results of its spectrum auction. In the auction, NBCUniversal relinquished its spectrum rights in the New York, Philadelphia and Chicago designated market areas (“DMAs”) where NBC and Telemundo had overlapping spectrum. NBCUniversal received proceeds of $482 million in July 2017, which were recorded in other investing activities in our condensed consolidated statement of cash flows. NBCUniversal recognized a pretax gain of $337 million in other operating gains for the three months ended September 30, 2017 in our condensed consolidated statement of income. NBC and Telemundo stations will share broadcast signals in these DMAs. In connection with the auction, we also acquired the rights to $1.7 billion of spectrum, which were recorded to other intangible assets, net in our condensed consolidated balance sheet. We had previously made a deposit of $1.8 billion to participate in the auction in the third quarter of 2016 and received a refund for amounts in excess of the purchase price in the second quarter of 2017. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion . The acquisition was funded through cash on hand and borrowings under our commercial paper program. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related tax and accumulated other comprehensive income impacts, were recorded to additional paid-in capital. DreamWorks Animation On August 22, 2016, we acquired all of the outstanding stock of DreamWorks Animation for $3.8 billion . DreamWorks Animation ’ s stockholders received $41 in cash for each share of DreamWorks Animation common stock. DreamWorks Animation creates animated feature films, television series and specials, live entertainment, and related consumer products. The results of operations for DreamWorks Animation are reported in our Filmed Entertainment segment following the acquisition date. Allocation of Purchase Price The transaction was accounted for under the acquisition method of accounting and, accordingly, the assets and liabilities are to be recorded at their fair market values as of the acquisition date. We recorded the acquired assets and liabilities of DreamWorks Animation at their estimated fair values based on valuation analyses. In valuing acquired assets and liabilities, fair value estimates were primarily based on Level 3 inputs, including future expected cash flows, market rate assumptions and discount rates. The fair value of the assumed debt was primarily based on quoted market values. The fair value of the liability related to a tax receivable agreement that DreamWorks Animation had previously entered into with one of its former stockholders (the “tax receivable agreement”) was based on the contractual settlement provisions in the agreement. Further, we recorded deferred income taxes based on the tax basis of the acquired net assets and the valuation allowances based on the expected use of net operating loss carryforwards. The goodwill is not deductible for tax purposes. During the nine months ended September 30, 2017 , we updated the allocation of purchase price for DreamWorks Animation based on final valuation analyses, which primarily resulted in increases to noncontrolling interests, intangible assets and goodwill and decreases to working capital and deferred income tax assets. The changes did not have a material impact on our condensed consolidated financial statements. The table below presents the allocation of the purchase price to the assets and liabilities of DreamWorks Animation. Allocation of Purchase Price (in millions) Film and television costs $ 838 Intangible assets 396 Working capital 156 Debt (381 ) Tax receivable agreement (146 ) Deferred income taxes 291 Other noncurrent assets and liabilities 170 Identifiable net assets (liabilities) acquired 1,324 Noncontrolling interests (337 ) Goodwill 2,786 Cash consideration transferred $ 3,773 The tax receivable agreement was settled immediately following the acquisition and the payment was recorded as an operating activity in our condensed consolidated statement of cash flows in the third quarter of 2016. We also repaid all of the assumed debt of DreamWorks Animation in the third quarter of 2016. Revenue and net income attributable to the acquisition of DreamWorks Animation were not material for the three and nine months ended September 30, 2017 and 2016 .
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions FCC Spectrum Auction On April 13, 2017, the Federal Communications Commission announced the results of its spectrum auction. In the auction, we relinquished our spectrum rights in the New York, Philadelphia and Chicago designated market areas (“DMAs”) where NBC and Telemundo had overlapping spectrum. We received proceeds of $482 million in July 2017, which were recorded in other investing activities in our condensed consolidated statement of cash flows. We recognized a pretax gain of $337 million in other operating gains for the three months ended September 30, 2017 in our condensed consolidated statement of income. NBC and Telemundo stations will share broadcast signals in these DMAs. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion . The acquisition was funded through borrowings under our revolving credit agreement with Comcast. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related accumulated other comprehensive income impact, were recorded to additional paid-in capital. DreamWorks Animation On August 22, 2016, Comcast acquired all of the outstanding stock of DreamWorks Animation for $3.8 billion . DreamWorks Animation’s stockholders received $41 in cash for each share of DreamWorks Animation common stock. DreamWorks Animation creates animated feature films, television series and specials, live entertainment, and related consumer products. Following the acquisition, Comcast converted DreamWorks Animation to a limited liability company and contributed its equity to us as a capital contribution. The net assets contributed to us excluded deferred income taxes and other tax-related items recorded by Comcast. The results of operations for DreamWorks Animation are reported in our Filmed Entertainment segment following the acquisition date and are presented as if the initial equity contribution occurred on the date of Comcast’s acquisition. Allocation of Purchase Price The transaction was accounted for under the acquisition method of accounting and, accordingly, the assets and liabilities are to be recorded at their fair market values as of the acquisition date. We recorded the acquired assets and liabilities of DreamWorks Animation at their estimated fair values based on valuation analyses. In valuing acquired assets and liabilities, fair value estimates were primarily based on Level 3 inputs, including future expected cash flows, market rate assumptions and discount rates. The fair value of the assumed debt was primarily based on quoted market values. The fair value of the liability related to a tax receivable agreement that DreamWorks Animation had previously entered into with one of its former stockholders (the “tax receivable agreement”) was based on the contractual settlement provisions in the agreement. During the nine months ended September 30, 2017 , we updated the allocation of purchase price for DreamWorks Animation based on final valuation analyses, which primarily resulted in increases to noncontrolling interests, intangible assets and goodwill and a decrease to working capital. The changes did not have a material impact on our condensed consolidated financial statements. The table below presents the allocation of the purchase price to the assets and liabilities of DreamWorks Animation. Allocation of Purchase Price (in millions) Film and television costs $ 838 Intangible assets 396 Working capital 156 Debt (381 ) Tax receivable agreement (a) (146 ) Other noncurrent assets and liabilities and other (b) 461 Identifiable net assets (liabilities) acquired 1,324 Noncontrolling interests (337 ) Goodwill 2,786 Cash consideration transferred $ 3,773 (a) The tax receivable agreement was settled immediately following the acquisition and the payment was recorded as an operating activity in our condensed consolidated statement of cash flows in the third quarter of 2016. Comcast made a separate cash capital contribution of $146 million to fund the settlement which was recorded as a financing activity in our condensed consolidated statement of cash flows in the third quarter of 2016. (b) Other included $279 million recorded to member’s capital that represented deferred income tax assets and other tax-related items recorded by Comcast but excluded from the net assets contributed to us. Revenue and net income attributable to the acquisition of DreamWorks Animation were not material for the three and nine months ended September 30, 2017 and 2016 .

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2017
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Related Party Transactions	Related Party Transactions In the ordinary course of our business, we enter into transactions with Comcast. We generate revenue from Comcast primarily from the distribution of our cable network programming, the fees received under retransmission consent agreements in our Broadcast Television segment and, to a lesser extent, the sale of advertising and our owned programming, and we incur expenses primarily related to advertising and various support services provided by Comcast to us. Comcast is also the counterparty to one of our contractual obligations. As of September 30, 2017 , 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 Balance Sheet (in millions) September 30, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 327 $ 285 Accounts payable and accrued expenses related to trade creditors $ 33 $ 55 Accrued expenses and other current liabilities $ 39 $ 4 Note payable to Comcast $ 1,805 $ 2,703 Other noncurrent liabilities $ 389 $ 389 Condensed Consolidated Statement of Income Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 463 $ 522 $ 1,382 $ 1,335 Operating costs and expenses $ (38 ) $ (53 ) $ (148 ) $ (157 ) Other income (expense) $ (20 ) $ (18 ) $ (67 ) $ (48 )

Film and Television Costs

Film and Television Costs	9 Months Ended
	Sep. 30, 2017
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,747 $ 1,750 Completed, not released 198 50 In production and in development 829 1,310 2,774 3,110 Television Costs: Released, less amortization 2,047 1,953 In production and in development 853 853 2,900 2,806 Programming rights, less amortization 2,901 2,586 8,575 8,502 Less: Current portion of programming rights 1,779 1,250 Film and television costs $ 6,796 $ 7,252
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film And Television Costs	Film and Television Costs (in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,747 $ 1,750 Completed, not released 198 50 In production and in development 829 1,310 2,774 3,110 Television Costs: Released, less amortization 2,047 1,953 In production and in development 853 853 2,900 2,806 Programming rights, less amortization 2,889 2,570 8,563 8,486 Less: Current portion of programming rights 1,772 1,241 Film and television costs $ 6,791 $ 7,245

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Fair Value, Equity And Cost Method Investments [Line Items]
Investments	Investments (in millions) September 30, December 31, Fair Value Method: Snap $ 427 $ — Other 164 198 591 198 Equity Method: Atairos 2,225 1,601 Hulu 255 225 Other 871 550 3,351 2,376 Cost Method: AirTouch 1,610 1,599 BuzzFeed 400 400 Other 756 771 2,766 2,770 Total investments 6,708 5,344 Less: Current investments 13 97 Noncurrent investments $ 6,695 $ 5,247 Investment Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Gains (losses) on sales and exchanges of investments, net $ 10 $ 24 $ 9 $ 39 Investment impairment losses (3 ) (7 ) (9 ) (28 ) Interest and dividend income 36 31 101 91 Other, net 39 32 104 66 Investment income (loss), net $ 82 $ 80 $ 205 $ 168 Fair Value Method 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 an available-for-sale 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. Equity Method Atairos For the nine months ended September 30, 2017 , we made cash capital contributions totaling $994 million to Atairos Group, Inc., which included amounts accrued as of December 31, 2016. 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 and nine months ended September 30, 2017 , our share of Atairos income was $7 million and $106 million , respectively. For the three and nine months ended September 30, 2016 , our share of Atairos losses was $9 million and $36 million , respectively. In July 2017, we sold a business to a company owned by Atairos and received as consideration an investment in that company, which we account for as an equity method investment. In connection with the sale of the business, we recognized a pretax gain of $105 million in other operating gains for the three months ended September 30, 2017. The Weather Channel In January 2016, following a legal restructuring at The Weather Channel, we and the other investors sold the entity holding The Weather Channel’s product and technology businesses to IBM. Following the close of the transaction, we continue to hold an investment in The Weather Channel cable network through a new holding company. As a result of the sale of our investment, we recognized a pretax gain of $108 million in other income (expense), net for the nine months ended September 30, 2016 . Cost Method 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 September 30, 2017 , the estimated fair value of the AirTouch preferred stock was $1.7 billion . The estimated fair value of the associated liability related to the redeemable subsidiary preferred shares issued by one of our consolidated subsidiaries was $1.8 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]
Fair Value, Equity And Cost Method Investments [Line Items]
Investments	Investments (in millions) September 30, December 31, Fair Value Method: Snap $ 427 $ — Other 4 6 431 6 Equity Method: Hulu 255 225 Other 432 336 687 561 Cost Method: BuzzFeed 400 400 Other 299 296 699 696 Total investments $ 1,817 $ 1,263 Fair Value Method 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 an available-for-sale 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. Equity Method The Weather Channel In January 2016, following a legal restructuring at The Weather Channel, we and the other investors sold the entity holding The Weather Channel’s product and technology businesses to IBM. Following the close of the transaction, we continue to hold an investment in The Weather Channel cable network through a new holding company. As a result of the sale of our investment, we recognized a pretax gain of $108 million in other income (expense), net for the nine months ended September 30, 2016 .

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2017
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of September 30, 2017 , our debt had a carrying value of $65.0 billion and an estimated fair value of $71.7 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 and Repayments In August 2017, we issued $ 1.65 billion aggregate principal amount of 3.15% senior notes due 2028 and $850 million aggregate principal amount of 4.00% senior notes due 2047. In June 2017, NBCUniversal Enterprise issued $ 1.5 billion aggregate principal amount of senior floating rate notes due 2021. In March 2017, we issued $1.005 billion aggregate principal amount of 4.45% senior notes due 2047. In January 2017, we issued $1.25 billion aggregate principal amount of 3.00% senior notes due 2024 and $1.25 billion aggregate principal amount of 3.30% senior notes due 2027. In May 2017, we repaid at maturity $550 million aggregate principal amount of 8.875% senior notes due 2017. In January 2017, we repaid at maturity $1.0 billion aggregate principal amount of 6.50% senior notes due 2017. In May 2017, Universal Studios Japan entered into ¥450 billion ( $3.9 billion at issuance) of new term loans with a final maturity of March 2022. We used the proceeds from these borrowings to repay in full $3.3 billion of Universal Studios Japan’s existing yen-denominated term loans and a portion of amounts outstanding under our commercial paper program. Revolving Credit Facilities As of September 30, 2017 , 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 In June 2017, we increased the Comcast and NBCUniversal Enterprise commercial paper programs to $7.0 billion and $1.5 billion , respectively, to coincide with the borrowing capacities under the Comcast and NBCUniversal Enterprise revolving credit facilities. As of September 30, 2017 , Comcast and NBCUniversal Enterprise had no commercial paper outstanding. Senior Notes Exchange In October 2017, we and NBCUniversal announced and settled a private debt exchange transaction. We issued $ 2.0 billion aggregate principal amount of new 3.969% senior notes due 2047, $ 2.0 billion aggregate principal amount of new 3.999% senior notes due 2049, and $ 1.5 billion aggregate principal amount of new 4.049% senior notes due 2052 in exchange for $3.9 billion aggregate principal amount of certain series of outstanding senior notes issued by Comcast and NBCUniversal. The new notes are fully and unconditionally guaranteed by NBCUniversal and Comcast Cable Communications, LLC.
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of September 30, 2017 , our debt, excluding the note payable to Comcast, had a carrying value of $12.4 billion and an estimated fair value of $13.5 billion . The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities. In May 2017, Universal Studios Japan entered into ¥450 billion ( $3.9 billion at issuance) of new term loans with a final maturity of March 2022. We used the proceeds from these borrowings to repay in full $3.3 billion of Universal Studios Japan’s existing yen-denominated term loans and a portion of amounts outstanding under our revolving credit agreement with Comcast. 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 September 30, 2017 , outstanding debt securities of $47.5 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. Senior Notes Exchange In October 2017, we and Comcast announced and settled a private debt exchange transaction. Comcast issued $ 2.0 billion aggregate principal amount of new 3.969% senior notes due 2047, $ 2.0 billion aggregate principal amount of new 3.999% senior notes due 2049, and $ 1.5 billion aggregate principal amount of new 4.049% senior notes due 2052 in exchange for $3.9 billion aggregate principal amount of certain series of outstanding senior notes issued by Comcast and us, including $442 million of our 6.400% senior notes due 2040. The new notes are fully and unconditionally guaranteed by us and Comcast Cable Communications, LLC. In connection with the exchange transaction, we issued $610 million of 3.999% notes due 2049 to Comcast.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation	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 2017, we granted 10.6 million RSUs and 39.1 million stock options related to our annual management awards. The weighted-average fair values associated with these grants were $37.42 per RSU and $7.01 per stock option. Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Restricted share units $ 99 $ 77 $ 284 $ 236 Stock options 52 48 155 133 Employee stock purchase plans 8 6 25 22 Total $ 159 $ 131 $ 464 $ 391 As of September 30, 2017 , we had unrecognized pretax compensation expense of $886 million and $451 million related to nonvested RSUs and nonvested stock options, respectively.
NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation	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. Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Restricted share units $ 32 $ 19 $ 86 $ 64 Stock options 3 3 10 7 Employee stock purchase plans 3 1 7 6 Total $ 38 $ 23 $ 103 $ 77

Supplemental Financial Informat

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2017
Supplemental Financial Information [Line Items]
Supplemental Financial Information	Supplemental Financial Information Receivables (in millions) September 30, December 31, Receivables, gross $ 8,549 $ 8,622 Less: Allowance for returns and customer incentives 357 417 Less: Allowance for doubtful accounts 277 250 Receivables, net $ 7,915 $ 7,955 Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ (43 ) $ 2 Deferred gains (losses) on cash flow hedges (12 ) (52 ) Unrecognized gains (losses) on employee benefit obligations 270 8 Cumulative translation adjustments 166 76 Accumulated other comprehensive income (loss), net of deferred taxes $ 381 $ 34 Net Cash Provided by Operating Activities Nine Months Ended (in millions) 2017 2016 Net income $ 7,865 $ 6,628 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, amortization and other operating gains 7,181 7,062 Share-based compensation 594 495 Noncash interest expense (income), net 187 172 Equity in net (income) losses of investees, net (12 ) 64 Cash received from investees 72 58 Net (gain) loss on investment activity and other (193 ) (159 ) Deferred income taxes 678 985 Changes in operating assets and liabilities, net of effects of acquisitions and divestitures: Current and noncurrent receivables, net 28 (315 ) Film and television costs, net (71 ) (593 ) Accounts payable and accrued expenses related to trade creditors (17 ) 46 Other operating assets and liabilities (351 ) (454 ) Net cash provided by operating activities $ 15,961 $ 13,989 Cash Payments for Interest and Income Taxes Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Interest $ 905 $ 808 $ 2,277 $ 2,043 Income taxes $ 1,206 $ 1,031 $ 3,415 $ 2,716 Noncash Investing and Financing Activities During the nine months ended September 30, 2017 : • we acquired $1.4 billion of property and equipment and intangible assets that were accrued but unpaid • we recorded a liability of $736 million for a quarterly cash dividend of $0.1575 per common share to be paid in October 2017
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Supplemental Financial Information	Supplemental Financial Information Receivables (in millions) September 30, December 31, Receivables, gross $ 6,610 $ 6,799 Less: Allowance for returns and customer incentives 352 413 Less: Allowance for doubtful accounts 81 84 Receivables, net $ 6,177 $ 6,302 Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ (233 ) $ — Deferred gains (losses) on cash flow hedges (4 ) (8 ) Unrecognized gains (losses) on employee benefit obligations 115 3 Cumulative translation adjustments 93 121 Accumulated other comprehensive income (loss) $ (29 ) $ 116 Net Cash Provided by Operating Activities Nine Months Ended (in millions) 2017 2016 Net income $ 4,403 $ 3,424 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, amortization and other operating gains 1,197 1,324 Equity in net (income) losses of investees, net 107 55 Cash received from investees 63 45 Net (gain) loss on investment activity and other (45 ) (72 ) Deferred income taxes (6 ) 139 Changes in operating assets and liabilities, net of effects of acquisitions and divestitures: Current and noncurrent receivables, net 152 (338 ) Film and television costs, net (75 ) (600 ) Accounts payable and accrued expenses related to trade creditors (270 ) (114 ) Other operating assets and liabilities 46 (524 ) Net cash provided by operating activities $ 5,572 $ 3,339 Cash Payments for Interest and Income Taxes Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Interest $ 53 $ 69 $ 340 $ 354 Income taxes $ 64 $ 33 $ 213 $ 155 Noncash Investing and Financing Activities During the nine months ended September 30, 2017 : • we acquired $296 million of property and equipment and intangible assets that were accrued but unpaid • Comcast contributed its investment in Snap to us at its fair value as of March 31, 2017, which was a noncash transaction (see Note 6 for additional information)

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Redeemable Subsidiary Preferred Stock As of September 30, 2017 , the fair value of the NBCUniversal Enterprise redeemable subsidiary preferred stock was $756 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 were a defendant in a lawsuit filed in December 2011 by Sprint Communications Company L.P. (“Sprint”) in the United States District Court for the District of Kansas. Sprint’s initial complaint alleged that Comcast Digital Voice and XFINITY Voice infringe twelve Sprint patents covering various aspects of a telecommunications system. In March 2015, Sprint withdrew its allegations of infringement for two of the patents. In December 2016, the Court granted summary judgment for us with respect to non-infringement on one of the patents and granted summary judgment for Sprint on one of the patents as to infringement with respect to some but not all of our accused telecommunications systems but not as to the patent’s validity. In January 2017, the Court entered judgment in favor of us on Sprint’s claims for infringement of two of the patents. In March 2017, Sprint indicated that it would not proceed to trial on three of the patents. Trial with respect to the four remaining patents, including the patent for which the Court granted partial summary judgment to Sprint, was set to begin on October 23, 2017. On October 16, 2017, the parties entered into a settlement agreement which dismisses all claims and resolves the parties’ disputes asserted in the matters described above, as well as in all other outstanding patent litigation matters between the parties, for a payment to Sprint and certain contractual rights. In connection therewith, we recorded a charge of $250 million in the third quarter of 2017. We also 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.

Financial Data by Business Segm

Financial Data by Business Segment	9 Months Ended
	Sep. 30, 2017
Segment Reporting Information [Line Items]
Financial Data by Business Segment	Financial Data by Business Segment 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 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, our regional sports and news networks, our international cable networks, and our cable television studio production operations. • 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, and our broadcast television studio production operations. • 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, Focus Features and DreamWorks Animation names. • Theme Parks: Consists primarily of our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to Comcast Corporation below Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2017 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other (h) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 13,203 $ 5,246 $ 2,049 $ 3,197 $ 2,061 $ 322 NBCUniversal Cable Networks 2,603 905 179 726 5 4 Broadcast Television 2,133 321 (305 ) 626 66 4 Filmed Entertainment 1,784 394 32 362 18 6 Theme Parks 1,550 775 166 609 199 18 Headquarters and Other (b) 15 (122 ) 97 (219 ) 66 37 Eliminations (c) (71 ) 1 — 1 — — NBCUniversal 8,014 2,274 169 2,105 354 69 Corporate and Other (d) 266 (349 ) 170 (519 ) 19 13 Eliminations (c) (500 ) 9 — 9 — — Comcast Consolidated $ 20,983 $ 7,180 $ 2,388 $ 4,792 $ 2,434 $ 404 Three Months Ended September 30, 2016 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 12,557 $ 4,986 $ 1,929 $ 3,057 $ 2,044 $ 352 NBCUniversal Cable Networks (e) 2,942 893 184 709 7 4 Broadcast Television (e) 3,087 378 27 351 28 6 Filmed Entertainment 1,792 353 13 340 6 4 Theme Parks 1,440 706 130 576 228 19 Headquarters and Other (b) 1 (183 ) 91 (274 ) 67 34 Eliminations (c) (84 ) (1 ) — (1 ) — — NBCUniversal 9,178 2,146 445 1,701 336 67 Corporate and Other (d) 168 (223 ) 21 (244 ) 26 7 Eliminations (c) (584 ) (74 ) — (74 ) — — Comcast Consolidated $ 21,319 $ 6,835 $ 2,395 $ 4,440 $ 2,406 $ 426 Nine Months Ended September 30, 2017 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other (h) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 39,237 $ 15,764 $ 6,030 $ 9,734 $ 5,798 $ 1,001 NBCUniversal Cable Networks 7,940 3,076 574 2,502 15 11 Broadcast Television 6,582 1,059 (242 ) 1,301 125 11 Filmed Entertainment 5,920 1,047 79 968 47 17 Theme Parks 3,982 1,723 494 1,229 671 57 Headquarters and Other (b) 32 (542 ) 292 (834 ) 119 101 Eliminations (c) (243 ) (1 ) — (1 ) — — NBCUniversal 24,213 6,362 1,197 5,165 977 197 Corporate and Other (d) 679 (845 ) 204 (1,049 ) 64 42 Eliminations (c) (1,518 ) 30 — 30 — — Comcast Consolidated $ 62,611 $ 21,311 $ 7,431 $ 13,880 $ 6,839 $ 1,240 Nine Months Ended September 30, 2016 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 37,205 $ 14,923 $ 5,676 $ 9,247 $ 5,501 $ 965 NBCUniversal Cable Networks (e) 7,961 2,793 561 2,232 15 8 Broadcast Television (e) 7,299 1,056 89 967 77 12 Filmed Entertainment 4,526 576 33 543 14 10 Theme Parks 3,602 1,550 373 1,177 668 48 Headquarters and Other (b) 10 (518 ) 268 (786 ) 217 103 Eliminations (c) (256 ) — — — — — NBCUniversal 23,142 5,457 1,324 4,133 991 181 Corporate and Other (d) 547 (668 ) 62 (730 ) 70 17 Eliminations (c) (1,516 ) (55 ) — (55 ) — — Comcast Consolidated $ 59,378 $ 19,657 $ 7,062 $ 12,595 $ 6,562 $ 1,163 (a) For the three and nine months ended September 30, 2017 and 2016 , Cable Communications segment revenue was derived from the following sources: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Residential: Video 44.1 % 44.5 % 44.3 % 44.9 % High-speed Internet 28.1 % 27.1 % 28.0 % 27.0 % Voice 6.4 % 7.0 % 6.5 % 7.2 % Business services 11.9 % 11.1 % 11.7 % 10.9 % Advertising 4.1 % 5.0 % 4.1 % 4.7 % Other 5.4 % 5.3 % 5.4 % 5.3 % Total 100.0 % 100.0 % 100.0 % 100.0 % Subscription revenue received from residential customers who purchase bundled services at a discounted rate is allocated proportionally to each cable service based on the individual service’s price on a stand-alone basis. For the three and nine months ended September 30, 2017 , 2.7% and 2.8% , respectively, of Cable Communications segment revenue was derived from franchise and other regulatory fees. For both the three and nine months ended September 30, 2016 , 2.8% of Cable Communications segment revenue was derived from franchise and other regulatory fees. (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 Filmed Entertainment and Broadcast Television segments generate revenue from the licensing of film and television content to our Cable Networks segment (d) Corporate and Other activities include costs associated with overhead and personnel, the costs of other business development initiatives, including our new 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) The revenue and operating costs and expenses associated with our broadcast of the 2016 Rio Olympics were reported in our Cable Networks and Broadcast Television segments. (f) No single customer accounted for a significant amount of revenue in any period. (g) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to Comcast Corporation before net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock, income tax expense, other income (expense) items, net, depreciation and amortization expense, and other operating gains, and excluding 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 events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Other income (expense) items, net include interest expense, investment income (loss), equity in net income (losses) of investees, and other income (expense), net (as stated in our condensed consolidated statement of income). This measure eliminates the significant level of noncash depreciation and amortization expense that results from the capital-intensive nature of certain of our businesses and from intangible assets recognized in business combinations. Additionally, it is unaffected by our capital and tax structures and by our investment activities. We use this measure to evaluate our consolidated operating performance and the operating performance of our operating segments and to allocate resources and capital to our operating segments. It is also a significant performance measure in our annual incentive compensation programs. We believe that this measure is useful to investors because it is one of the bases for comparing our operating performance with that of other companies in our industries, although our measure may not be directly comparable to similar measures used by other companies. This measure should not be considered a substitute for operating income (loss), net income (loss), net income (loss) attributable to Comcast Corporation, net cash provided by operating activities, or other measures of performance or liquidity we have reported in accordance with GAAP. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 7,180 $ 6,835 $ 21,311 $ 19,657 Adjustment for legal settlement (250 ) — (250 ) — Depreciation (1,991 ) (1,865 ) (5,876 ) (5,518 ) Amortization (589 ) (530 ) (1,747 ) (1,544 ) Other operating gains 442 — 442 — Other income (expense) items, net (696 ) (716 ) (1,980 ) (1,978 ) Income before income taxes $ 4,096 $ 3,724 $ 11,900 $ 10,617 (h) Other represents other operating gains in our condensed consolidated statement of income and a charge related to a legal settlement. For both the three and nine months ended September 30, 2017 , other operating gains included a pretax gain of $337 million related to NBCUniversal’s relinquishment of spectrum rights in our Broadcast Television segment and a pretax gain of $105 million related to the sale of a business in Corporate and Other. A charge related to a legal settlement of $250 million was recorded in other operating and administrative expenses in Corporate and Other and was excluded from Adjusted EBITDA for both the three and nine months ended September 30, 2017 .
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Financial Data by Business Segment	Financial Data by Business Segment We present our operations in four reportable business segments: • Cable Networks: Consists primarily of our national cable networks, our regional sports and news networks, our international cable networks, and our cable television studio production operations. • 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, and our broadcast television studio production operations. • 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, Focus Features and DreamWorks Animation names. • Theme Parks: Consists primarily of our Universal theme parks in Orlando, Florida; Hollywood, California; and Osaka, Japan. We use Adjusted EBITDA to evaluate the profitability of our operating segments and the components of net income attributable to NBCUniversal below Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2017 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other (f) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 2,603 $ 905 $ 179 $ 726 $ 5 $ 4 Broadcast Television 2,133 321 (305 ) 626 66 4 Filmed Entertainment 1,784 394 32 362 18 6 Theme Parks 1,550 775 166 609 199 18 Headquarters and Other (a) 15 (122 ) 97 (219 ) 66 37 Eliminations (b) (71 ) 1 — 1 — — Total $ 8,014 $ 2,274 $ 169 $ 2,105 $ 354 $ 69 Three Months Ended September 30, 2016 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks (c) $ 2,942 $ 893 $ 184 $ 709 $ 7 $ 4 Broadcast Television (c) 3,087 378 27 351 28 6 Filmed Entertainment 1,792 353 13 340 6 4 Theme Parks 1,440 706 130 576 228 19 Headquarters and Other (a) 1 (183 ) 91 (274 ) 67 34 Eliminations (b) (84 ) (1 ) — (1 ) — — Total $ 9,178 $ 2,146 $ 445 $ 1,701 $ 336 $ 67 Nine Months Ended September 30, 2017 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other (f) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 7,940 $ 3,076 $ 574 $ 2,502 $ 15 $ 11 Broadcast Television 6,582 1,059 (242 ) 1,301 125 11 Filmed Entertainment 5,920 1,047 79 968 47 17 Theme Parks 3,982 1,723 494 1,229 671 57 Headquarters and Other (a) 32 (542 ) 292 (834 ) 119 101 Eliminations (b) (243 ) (1 ) — (1 ) — — Total $ 24,213 $ 6,362 $ 1,197 $ 5,165 $ 977 $ 197 Nine Months Ended September 30, 2016 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks (c) $ 7,961 $ 2,793 $ 561 $ 2,232 $ 15 $ 8 Broadcast Television (c) 7,299 1,056 89 967 77 12 Filmed Entertainment 4,526 576 33 543 14 10 Theme Parks 3,602 1,550 373 1,177 668 48 Headquarters and Other (a) 10 (518 ) 268 (786 ) 217 103 Eliminations (b) (256 ) — — — — — Total $ 23,142 $ 5,457 $ 1,324 $ 4,133 $ 991 $ 181 (a) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another, which consist primarily of the licensing of film and television content from our Filmed Entertainment and Broadcast Television segments to our Cable Networks segment. (c) The revenue and operating costs and expenses associated with our broadcast of the 2016 Rio Olympics were reported in our Cable Networks and Broadcast Television segments. (d) No single customer accounted for a significant amount of revenue in any period. (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 NBCUniversal before net (income) loss attributable to noncontrolling interests, income tax expense, other income (expense) items, net, depreciation and amortization expense, and other operating gains, and excluding 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 events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Other income (expense) items, net include interest expense, investment income (loss), equity in net income (losses) of investees, and other income (expense), net (as stated in our condensed consolidated statement of income). This measure eliminates the significant level of noncash amortization expense that results from intangible assets recognized in business combinations. Additionally, it is unaffected by our capital and tax structures and by our investment activities. We use this measure to evaluate our consolidated operating performance and the operating performance of our operating segments and to allocate resources and capital to our operating segments. It is also a significant performance measure in our annual incentive compensation programs. We believe that this measure is useful to investors because it is one of the bases for comparing our operating performance with that of other companies in our industries, although our measure may not be directly comparable to similar measures used by other companies. This measure should not be considered a substitute for operating income (loss), net income (loss), net income (loss) attributable to NBCUniversal, net cash provided by operating activities, or other measures of performance or liquidity we have reported in accordance with GAAP. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 2,274 $ 2,146 $ 6,362 $ 5,457 Depreciation (253 ) (209 ) (749 ) (624 ) Amortization (253 ) (236 ) (785 ) (700 ) Other operating gains 337 — 337 — Other income (expense) items, net (165 ) (195 ) (473 ) (398 ) Income before income taxes $ 1,940 $ 1,506 $ 4,692 $ 3,735 (f) Other represents other operating gains in our condensed consolidated statement of income. For both the three and nine months ended September 30, 2017 , other operating gains included a pretax gain of $337 million related to our relinquishment of spectrum rights in our Broadcast Television segment.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2017
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 ¥450 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 Balance Sheet September 30, 2017 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Assets Cash and cash equivalents $ — $ — $ — $ 260 $ 3,854 $ — $ 4,114 Receivables, net — — — — 7,915 — 7,915 Programming rights — — — — 1,779 — 1,779 Other current assets 65 — — 30 2,057 — 2,152 Total current assets 65 — — 290 15,605 — 15,960 Film and television costs — — — — 6,796 — 6,796 Investments 132 11 79 691 5,782 — 6,695 Investments in and amounts due from subsidiaries eliminated upon consolidation 102,930 128,663 126,361 50,474 111,087 (519,515 ) — Property and equipment, net 482 — — — 37,374 — 37,856 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 36,752 — 36,752 Other intangible assets, net 11 — — — 18,722 — 18,733 Other noncurrent assets, net 1,178 687 — 86 2,249 (1,055 ) 3,145 Total assets $ 104,798 $ 129,361 $ 126,440 $ 51,541 $ 293,731 $ (520,570 ) $ 185,301 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 17 $ — $ — $ — $ 6,959 $ — $ 6,976 Accrued participations and residuals — — — — 1,811 — 1,811 Accrued expenses and other current liabilities 1,640 92 208 394 5,087 — 7,421 Current portion of long-term debt 2,913 — — 4 2,324 — 5,241 Total current liabilities 4,570 92 208 398 16,181 — 21,449 Long-term debt, less current portion 42,237 139 2,100 8,204 7,040 — 59,720 Deferred income taxes — 492 — 70 36,124 (1,084 ) 35,602 Other noncurrent liabilities 2,564 — — 1,138 7,183 29 10,914 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,353 — 1,353 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 55,372 128,638 124,132 41,731 225,014 (519,515 ) 55,372 Total Comcast Corporation shareholders’ equity 55,427 128,638 124,132 41,731 225,014 (519,515 ) 55,427 Noncontrolling interests — — — — 836 — 836 Total equity 55,427 128,638 124,132 41,731 225,850 (519,515 ) 56,263 Total liabilities and equity $ 104,798 $ 129,361 $ 126,440 $ 51,541 $ 293,731 $ (520,570 ) $ 185,301 Condensed Consolidating Balance Sheet December 31, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Assets Cash and cash equivalents $ — $ — $ — $ 482 $ 2,819 $ — $ 3,301 Receivables, net — — — — 7,955 — 7,955 Programming rights — — — — 1,250 — 1,250 Other current assets 151 — — 36 3,668 — 3,855 Total current assets 151 — — 518 15,692 — 16,361 Film and television costs — — — — 7,252 — 7,252 Investments 75 — — 651 4,521 — 5,247 Investments in and amounts due from subsidiaries eliminated upon consolidation 98,350 120,071 117,696 47,393 97,704 (481,214 ) — Property and equipment, net 298 — — — 35,955 — 36,253 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 35,980 — 35,980 Other intangible assets, net 13 — — — 17,261 — 17,274 Other noncurrent assets, net 1,138 638 — 89 1,921 (1,017 ) 2,769 Total assets $ 100,025 $ 120,709 $ 117,696 $ 48,651 $ 275,650 $ (482,231 ) $ 180,500 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 23 $ — $ — $ — $ 6,892 $ — $ 6,915 Accrued participations and residuals — — — — 1,726 — 1,726 Accrued expenses and other current liabilities 1,726 — 341 302 5,045 — 7,414 Current portion of long-term debt 3,739 — 550 4 1,187 — 5,480 Total current liabilities 5,488 — 891 306 14,850 — 21,535 Long-term debt, less current portion 38,123 141 2,100 8,208 6,994 — 55,566 Deferred income taxes — 542 — 70 35,259 (1,017 ) 34,854 Other noncurrent liabilities 2,471 — — 1,166 7,288 — 10,925 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,446 — 1,446 Equity: Common stock 56 — — — — — 56 Other shareholders’ equity 53,887 120,026 114,705 38,901 207,582 (481,214 ) 53,887 Total Comcast Corporation shareholders’ equity 53,943 120,026 114,705 38,901 207,582 (481,214 ) 53,943 Noncontrolling interests — — — — 2,231 — 2,231 Total equity 53,943 120,026 114,705 38,901 209,813 (481,214 ) 56,174 Total liabilities and equity $ 100,025 $ 120,709 $ 117,696 $ 48,651 $ 275,650 $ (482,231 ) $ 180,500 Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 20,983 $ — $ 20,983 Management fee revenue 285 — 280 — — (565 ) — 285 — 280 — 20,983 (565 ) 20,983 Costs and Expenses: Programming and production — — — — 6,077 — 6,077 Other operating and administrative 183 — 280 277 6,248 (565 ) 6,423 Advertising, marketing and promotion — — — — 1,553 — 1,553 Depreciation 7 — — — 1,984 — 1,991 Amortization 1 — — — 588 — 589 Other operating gains — — — — (442 ) — (442 ) 191 — 280 277 16,008 (565 ) 16,191 Operating income (loss) 94 — — (277 ) 4,975 — 4,792 Other Income (Expense): Interest expense (544 ) (3 ) (48 ) (116 ) (55 ) — (766 ) Investment income (loss), net (2 ) 32 — (9 ) 61 — 82 Equity in net income (losses) of investees, net 2,944 2,483 1,992 2,221 1,786 (11,465 ) (39 ) Other income (expense), net — — — 12 15 — 27 2,398 2,512 1,944 2,108 1,807 (11,465 ) (696 ) Income (loss) before income taxes 2,492 2,512 1,944 1,831 6,782 (11,465 ) 4,096 Income tax (expense) benefit 158 (10 ) 17 (6 ) (1,572 ) — (1,413 ) Net income (loss) 2,650 2,502 1,961 1,825 5,210 (11,465 ) 2,683 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (33 ) — (33 ) Net income (loss) attributable to Comcast Corporation $ 2,650 $ 2,502 $ 1,961 $ 1,825 $ 5,177 $ (11,465 ) $ 2,650 Comprehensive income (loss) attributable to Comcast Corporation $ 2,603 $ 2,486 $ 1,965 $ 1,740 $ 5,049 $ (11,240 ) $ 2,603 Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2016 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 21,319 $ — $ 21,319 Management fee revenue 268 — 263 — — (531 ) — 268 — 263 — 21,319 (531 ) 21,319 Costs and Expenses: Programming and production — — — — 7,003 — 7,003 Other operating and administrative 194 — 263 222 5,848 (531 ) 5,996 Advertising, marketing and promotion — — — — 1,485 — 1,485 Depreciation 7 — — — 1,858 — 1,865 Amortization 1 — — — 529 — 530 Other operating gains — — — — — — — 202 — 263 222 16,723 (531 ) 16,879 Operating income (loss) 66 — — (222 ) 4,596 — 4,440 Other Income (Expense): Interest expense (502 ) (3 ) (59 ) (113 ) (74 ) — (751 ) Investment income (loss), net 3 (4 ) — (12 ) 93 — 80 Equity in net income (losses) of investees, net 2,519 2,385 2,134 1,644 1,255 (9,971 ) (34 ) Other income (expense), net — — — (2 ) (9 ) — (11 ) 2,020 2,378 2,075 1,517 1,265 (9,971 ) (716 ) Income (loss) before income taxes 2,086 2,378 2,075 1,295 5,861 (9,971 ) 3,724 Income tax (expense) benefit 151 2 21 (6 ) (1,568 ) — (1,400 ) Net income (loss) 2,237 2,380 2,096 1,289 4,293 (9,971 ) 2,324 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (87 ) — (87 ) Net income (loss) attributable to Comcast Corporation $ 2,237 $ 2,380 $ 2,096 $ 1,289 $ 4,206 $ (9,971 ) $ 2,237 Comprehensive income (loss) attributable to Comcast Corporation $ 2,270 $ 2,388 $ 2,096 $ 1,310 $ 4,235 $ (10,029 ) $ 2,270 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2017 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Revenue: Service revenue $ — $ — $ — $ — $ 62,611 $ — $ 62,611 Management fee revenue 841 — 827 — — (1,668 ) — 841 — 827 — 62,611 (1,668 ) 62,611 Costs and Expenses: Programming and production — — — — 18,492 — 18,492 Other operating and administrative 553 — 827 844 17,754 (1,668 ) 18,310 Advertising, marketing and promotion — — — — 4,748 — 4,748 Depreciation 21 — — — 5,855 — 5,876 Amortization 4 — — — 1,743 — 1,747 Other operating gains — — — — (442 ) — (442 ) 578 — 827 844 48,150 (1,668 ) 48,731 Operating income (loss) 263 — — (844 ) 14,461 — 13,880 Other Income (Expense): Interest expense (1,592 ) (9 ) (159 ) (344 ) (175 ) — (2,279 ) Investment income (loss), net (1 ) 84 — (29 ) 151 — 205 Equity in net income (losses) of investees, net 8,594 7,746 6,613 5,477 4,313 (32,731 ) 12 Other income (expense), net — — — 58 24 — 82 7,001 7,821 6,454 5,162 4,313 (32,731 ) (1,980 ) Income (loss) before income taxes 7,264 7,821 6,454 4,318 18,774 (32,731 ) 11,900 Income tax (expense) benefit 465 (26 ) 56 (17 ) (4,513 ) — (4,035 ) Net income (loss) 7,729 7,795 6,510 4,301 14,261 (32,731 ) 7,865 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (136 ) — (136 ) Net income (loss) attributable to Comcast Corporation $ 7,729 $ 7,795 $ 6,510 $ 4,301 $ 14,125 $ (32,731 ) $ 7,729 Comprehensive income (loss) attributable to Comcast Corporation $ 7,818 $ 7,793 $ 6,516 $ 4,266 $ 13,998 $ (32,573 ) $ 7,818 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Revenue: Service revenue $ — $ — $ — $ — $ 59,378 $ — $ 59,378 Management fee revenue 793 — 778 — — (1,571 ) — 793 — 778 — 59,378 (1,571 ) 59,378 Costs and Expenses: Programming and production — — — — 17,926 — 17,926 Other operating and administrative 635 — 778 739 16,704 (1,571 ) 17,285 Advertising, marketing and promotion — — — — 4,510 — 4,510 Depreciation 21 — — — 5,497 — 5,518 Amortization 4 — — — 1,540 — 1,544 Other operating gains — — — — — — — 660 — 778 739 46,177 (1,571 ) 46,783 Operating income (loss) 133 — — (739 ) 13,201 — 12,595 Other Income (Expense): Interest expense (1,431 ) (9 ) (179 ) (342 ) (225 ) — (2,186 ) Investment income (loss), net 6 (3 ) — (20 ) 185 — 168 Equity in net income (losses) of investees, net 7,239 6,924 6,375 4,229 3,160 (27,991 ) (64 ) Other income (expense), net — — — 115 (11 ) — 104 5,814 6,912 6,196 3,982 3,109 (27,991 ) (1,978 ) Income (loss) before income taxes 5,947 6,912 6,196 3,243 16,310 (27,991 ) 10,617 Income tax (expense) benefit 452 4 63 (19 ) (4,489 ) — (3,989 ) Net income (loss) 6,399 6,916 6,259 3,224 11,821 (27,991 ) 6,628 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (229 ) — (229 ) Net income (loss) attributable to Comcast Corporation $ 6,399 $ 6,916 $ 6,259 $ 3,224 $ 11,592 $ (27,991 ) $ 6,399 Comprehensive income (loss) attributable to Comcast Corporation $ 6,607 $ 7,015 $ 6,261 $ 3,552 $ 12,134 $ (28,962 ) $ 6,607 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (931 ) $ 91 $ (233 ) $ (1,054 ) $ 18,088 $ — $ 15,961 Investing Activities Net transactions with affiliates 4,216 (91 ) 818 833 (5,776 ) — — Capital expenditures (6 ) — — — (6,833 ) — (6,839 ) Cash paid for intangible assets (2 ) — — — (1,238 ) — (1,240 ) Acquisitions and construction of real estate properties (190 ) — — — (135 ) — (325 ) Acquisitions, net of cash acquired — — — — (429 ) — (429 ) Proceeds from sales of investments — — — 10 110 — 120 Purchases of investments (56 ) — (35 ) (57 ) (1,916 ) — (2,064 ) Deposits — — — — — — — Other 101 — — 49 600 — 750 Net cash provided by (used in) investing activities 4,063 (91 ) 783 835 (15,617 ) — (10,027 ) Financing Activities Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (1,068 ) — (2,807 ) Proceeds from borrowings 5,997 — — — 5,463 — 11,460 Repurchases and repayments of debt (1,000 ) — (550 ) (3 ) (3,468 ) — (5,021 ) Repurchases of common stock under repurchase program and employee plans (4,212 ) — — — — — (4,212 ) Dividends paid (2,147 ) — — — — — (2,147 ) Purchase of Universal Studios Japan noncontrolling interests — — — — (2,299 ) — (2,299 ) Issuances of common stock — — — — — — — Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (198 ) — (198 ) Other (31 ) — — — 134 — 103 Net cash provided by (used in) financing activities (3,132 ) — (550 ) (3 ) (1,436 ) — (5,121 ) Increase (decrease) in cash and cash equivalents — — — (222 ) 1,035 — 813 Cash and cash equivalents, beginning of period — — — 482 2,819 — 3,301 Cash and cash equivalents, end of period $ — $ — $ — $ 260 $ 3,854 $ — $ 4,114 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Net cash provided by (used in) operating activities $ (637 ) $ — $ (179 ) $ (1,068 ) $ 15,873 $ — $ 13,989 Investing Activities Net transactions with affiliates (1,746 ) — 179 2,150 (583 ) — — Capital expenditures (9 ) — — — (6,553 ) — (6,562 ) Cash paid for intangible assets (4 ) — — — (1,159 ) — (1,163 ) Acquisitions and construction of real estate properties (2 ) — — — (301 ) — (303 ) Acquisitions, net of cash acquired — — — — (3,904 ) — (3,904 ) Proceeds from sales of investments — — — 104 84 — 188 Purchases of investments (23 ) — — (9 ) (586 ) — (618 ) Deposits — — — — (1,748 ) — (1,748 ) Other (108 ) — — (35 ) 101 — (42 ) Net cash provided by (used in) investing activities (1,892 ) — 179 2,210 (14,649 ) — (14,152 ) Financing Activities Proceeds from (repayments of) short-term borrowings, net 105 — — — 505 — 610 Proceeds from borrowings 9,231 — — — — — 9,231 Repurchases and repayments of debt (750 ) — — (1,005 ) (1,239 ) — (2,994 ) Repurchases of common stock under repurchase program and employee plans (4,061 ) — — — — — (4,061 ) Dividends paid (1,944 ) — — — — — (1,944 ) Issuances of common stock 23 — — — — — 23 Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (194 ) — (194 ) Other (75 ) — — 25 54 — 4 Net cash provided by (used in) financing activities 2,529 — — (980 ) (874 ) — 675 Increase (decrease) in cash and cash equivalents — — — 162 350 — 512 Cash and cash equivalents, beginning of period — — — 414 1,881 — 2,295 Cash and cash equivalents, end of period $ — $ — $ — $ 576 $ 2,231 $ — $ 2,807

Recent Accounting Pronounceme22

Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [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, financial condition and cash flows 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 2016 Annual Report on Form 10-K.
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 updated accounting guidance is effective for us as of January 1, 2018. We have substantially completed the review of our revenue arrangements and do not currently expect that the adoption of the new standard will have a material impact on our financial position or results of operations. Upon adoption, we anticipate implementing certain changes in the presentation of revenue and expenses, including changes related to the allocation of revenue among the cable services included in a bundle that our residential customers purchase at a discount. We also expect that the new standard will impact the timing of recognition for (1) our Cable Communications segment’s installation revenue and commission expenses, which will be recognized as revenue and costs over a period of time instead of immediately, and (2) our Cable Networks, Broadcast Television and Filmed Entertainment segments’ content licensing revenue associated with renewals or extensions of existing program licensing agreements, which will be recognized as revenue when the licensed content becomes available under the renewal or extension instead of when the agreement is renewed or extended. In addition, the updated guidance requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions. We intend to adopt the provisions of the guidance using the full retrospective method, under which we will adjust any prior periods presented to reflect the updated guidance. 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 that the changes in fair value be recognized in net income. The updated guidance is effective for us as of January 1, 2018. The updated accounting guidance requires a cumulative effect adjustment to beginning retained earnings in the year the guidance is adopted with certain exceptions. If we had adopted the provisions of the updated guidance as of January 1, 2017 for our equity investments classified as available-for-sale securities, primarily our investment in Snap Inc. (see Note 6), net income attributable to Comcast Corporation would have decreased for the three and nine months ended September 30, 2017 by $63 million and $47 million , respectively. We are currently in the process of determining the impact that the updated accounting guidance will have on our cost method investments. 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. Share-Based Compensation In March 2016, the FASB updated the accounting guidance that affects several aspects of the accounting for share-based compensation. The most significant change for us relates to the presentation of the income and withholding tax consequences of share-based compensation in our consolidated financial statements. Among the changes, the updated guidance requires that the excess income tax benefits or deficiencies that arise when the tax consequences of share-based compensation differ from amounts previously recognized in the statement of income be recognized as income tax benefit or expense in the statement of income rather than as additional paid-in capital in the balance sheet. The guidance also states that excess income tax benefits should not be presented separately from other income taxes in the statement of cash flows and, thus, should be classified as an operating activity rather than a financing activity as they were under the prior guidance. In addition, the updated guidance requires that, when an employer withholds shares upon exercise of options or the vesting of restricted stock for the purpose of meeting withholding tax requirements, the cash paid for withholding taxes be classified as a financing activity and we include these amounts in the caption “repurchases of common stock under repurchase program and employee plans” in our consolidated statement of cash flows. We previously recorded these amounts as operating activities. We adopted the updated guidance as of January 1, 2017 and, as required, we prospectively adopted the provisions that relate to the recognition of the excess income tax benefits or deficiencies in our condensed consolidated statement of income. The excess tax benefits resulted in a decrease to income tax expense of $49 million and $247 million for the three and nine months ended September 30, 2017, respectively. In addition, the excess tax benefits resulted in an increase to diluted earnings per common share attributable to Comcast Corporation shareholders of $0.01 and $0.04 for the three and nine months ended September 30, 2017 , respectively. As required by the updated guidance, the prior year periods in our condensed consolidated statement of income were not adjusted as a result of these provisions. In addition, we retrospectively adopted the provisions of this guidance related to changes to the statement of cash flows for all periods presented. This resulted in increases to net cash provided by operating activities and decreases to net cash provided by (used in) financing activities of $644 million and $492 million for the nine months ended September 30, 2017 and 2016, respectively.
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [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, financial condition and cash flows 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 2016 Annual Report on Form 10-K.
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 updated accounting guidance is effective for us as of January 1, 2018. We have substantially completed the review of our revenue arrangements and do not currently expect that the adoption of the new standard will have a material impact on our financial position or results of operations. However, we do expect that the new standard will impact the timing of recognition for our Cable Networks, Broadcast Television and Filmed Entertainment segments’ content licensing revenue associated with renewals or extensions of existing program licensing agreements, which will be recognized as revenue when the licensed content becomes available under the renewal or extension instead of when the agreement is renewed or extended. The updated guidance also requires additional disclosures regarding the nature, timing and uncertainty of our revenue transactions. We intend to adopt the provisions of the guidance using the full retrospective method, under which we will adjust any prior periods presented to reflect the updated guidance. 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 that the changes in fair value be recognized in net income. The updated guidance is effective for us as of January 1, 2018. The updated accounting guidance requires a cumulative effect adjustment to beginning retained earnings in the year the guidance is adopted with certain exceptions. If we had adopted the provisions of the updated guidance as of January 1, 2017 for our equity investments classified as available-for-sale securities, primarily our investment in Snap Inc. (see Note 6), net income attributable to NBCUniversal would have decreased for the three and nine months ended September 30, 2017 by $95 million and $234 million , respectively. We are currently in the process of determining the impact that the updated accounting guidance will have on our cost method investments. 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.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Computation of diluted EPS	Computation of Diluted EPS Three Months Ended September 30 2017 2016 (in millions, except per share data) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 2,650 4,698 $ 0.56 $ 2,237 4,805 $ 0.47 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 79 56 Diluted EPS attributable to Comcast Corporation shareholders $ 2,650 4,777 $ 0.55 $ 2,237 4,861 $ 0.46 Nine Months Ended September 30 2017 2016 (in millions, except per share amounts) Net Income Shares Per Share Net Income Shares Per Share Basic EPS attributable to Comcast Corporation shareholders $ 7,729 4,725 $ 1.64 $ 6,399 4,837 $ 1.32 Effect of dilutive securities: Assumed exercise or issuance of shares relating to stock plans 81 56 Diluted EPS attributable to Comcast Corporation shareholders $ 7,729 4,806 $ 1.61 $ 6,399 4,893 $ 1.31

Significant Transactions (Table

Significant Transactions (Tables) - DreamWorks Animation [Member]	9 Months Ended
	Sep. 30, 2017
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition	The table below presents the allocation of the purchase price to the assets and liabilities of DreamWorks Animation. Allocation of Purchase Price (in millions) Film and television costs $ 838 Intangible assets 396 Working capital 156 Debt (381 ) Tax receivable agreement (146 ) Deferred income taxes 291 Other noncurrent assets and liabilities 170 Identifiable net assets (liabilities) acquired 1,324 Noncontrolling interests (337 ) Goodwill 2,786 Cash consideration transferred $ 3,773
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition	The table below presents the allocation of the purchase price to the assets and liabilities of DreamWorks Animation. Allocation of Purchase Price (in millions) Film and television costs $ 838 Intangible assets 396 Working capital 156 Debt (381 ) Tax receivable agreement (a) (146 ) Other noncurrent assets and liabilities and other (b) 461 Identifiable net assets (liabilities) acquired 1,324 Noncontrolling interests (337 ) Goodwill 2,786 Cash consideration transferred $ 3,773 (a) The tax receivable agreement was settled immediately following the acquisition and the payment was recorded as an operating activity in our condensed consolidated statement of cash flows in the third quarter of 2016. Comcast made a separate cash capital contribution of $146 million to fund the settlement which was recorded as a financing activity in our condensed consolidated statement of cash flows in the third quarter of 2016. (b) Other included $279 million recorded to member’s capital that represented deferred income tax assets and other tax-related items recorded by Comcast but excluded from the net assets contributed to us.

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2017
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 Balance Sheet (in millions) September 30, December 31, Transactions with Comcast and Consolidated Subsidiaries Receivables, net $ 327 $ 285 Accounts payable and accrued expenses related to trade creditors $ 33 $ 55 Accrued expenses and other current liabilities $ 39 $ 4 Note payable to Comcast $ 1,805 $ 2,703 Other noncurrent liabilities $ 389 $ 389 Condensed Consolidated Statement of Income Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Transactions with Comcast and Consolidated Subsidiaries Revenue $ 463 $ 522 $ 1,382 $ 1,335 Operating costs and expenses $ (38 ) $ (53 ) $ (148 ) $ (157 ) Other income (expense) $ (20 ) $ (18 ) $ (67 ) $ (48 )

Film and Television Costs (Tabl

Film and Television Costs (Tables)	9 Months Ended
	Sep. 30, 2017
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,747 $ 1,750 Completed, not released 198 50 In production and in development 829 1,310 2,774 3,110 Television Costs: Released, less amortization 2,047 1,953 In production and in development 853 853 2,900 2,806 Programming rights, less amortization 2,901 2,586 8,575 8,502 Less: Current portion of programming rights 1,779 1,250 Film and television costs $ 6,796 $ 7,252
NBCUniversal Media LLC [Member]
Film And Television Cost [Line Items]
Film and Television Costs	(in millions) September 30, December 31, Film Costs: Released, less amortization $ 1,747 $ 1,750 Completed, not released 198 50 In production and in development 829 1,310 2,774 3,110 Television Costs: Released, less amortization 2,047 1,953 In production and in development 853 853 2,900 2,806 Programming rights, less amortization 2,889 2,570 8,563 8,486 Less: Current portion of programming rights 1,772 1,241 Film and television costs $ 6,791 $ 7,245

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value, Equity And Cost Method Investments [Line Items]
Investment Summary	(in millions) September 30, December 31, Fair Value Method: Snap $ 427 $ — Other 164 198 591 198 Equity Method: Atairos 2,225 1,601 Hulu 255 225 Other 871 550 3,351 2,376 Cost Method: AirTouch 1,610 1,599 BuzzFeed 400 400 Other 756 771 2,766 2,770 Total investments 6,708 5,344 Less: Current investments 13 97 Noncurrent investments $ 6,695 $ 5,247
Investment Income (Loss), Net	Investment Income (Loss), Net Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Gains (losses) on sales and exchanges of investments, net $ 10 $ 24 $ 9 $ 39 Investment impairment losses (3 ) (7 ) (9 ) (28 ) Interest and dividend income 36 31 101 91 Other, net 39 32 104 66 Investment income (loss), net $ 82 $ 80 $ 205 $ 168
NBCUniversal Media LLC [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Investment Summary	(in millions) September 30, December 31, Fair Value Method: Snap $ 427 $ — Other 4 6 431 6 Equity Method: Hulu 255 225 Other 432 336 687 561 Cost Method: BuzzFeed 400 400 Other 299 296 699 696 Total investments $ 1,817 $ 1,263

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of recognized share-based compensation expense	Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Restricted share units $ 99 $ 77 $ 284 $ 236 Stock options 52 48 155 133 Employee stock purchase plans 8 6 25 22 Total $ 159 $ 131 $ 464 $ 391
NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of recognized share-based compensation expense	Recognized Share-Based Compensation Expense Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Restricted share units $ 32 $ 19 $ 86 $ 64 Stock options 3 3 10 7 Employee stock purchase plans 3 1 7 6 Total $ 38 $ 23 $ 103 $ 77

Supplemental Financial Inform29

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2017
Supplemental Financial Information [Line Items]
Schedule of receivables, net	Receivables (in millions) September 30, December 31, Receivables, gross $ 8,549 $ 8,622 Less: Allowance for returns and customer incentives 357 417 Less: Allowance for doubtful accounts 277 250 Receivables, net $ 7,915 $ 7,955
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ (43 ) $ 2 Deferred gains (losses) on cash flow hedges (12 ) (52 ) Unrecognized gains (losses) on employee benefit obligations 270 8 Cumulative translation adjustments 166 76 Accumulated other comprehensive income (loss), net of deferred taxes $ 381 $ 34
Schedule of adjustments to reconcile net income to net cash provided by operating activities	Net Cash Provided by Operating Activities Nine Months Ended (in millions) 2017 2016 Net income $ 7,865 $ 6,628 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, amortization and other operating gains 7,181 7,062 Share-based compensation 594 495 Noncash interest expense (income), net 187 172 Equity in net (income) losses of investees, net (12 ) 64 Cash received from investees 72 58 Net (gain) loss on investment activity and other (193 ) (159 ) Deferred income taxes 678 985 Changes in operating assets and liabilities, net of effects of acquisitions and divestitures: Current and noncurrent receivables, net 28 (315 ) Film and television costs, net (71 ) (593 ) Accounts payable and accrued expenses related to trade creditors (17 ) 46 Other operating assets and liabilities (351 ) (454 ) Net cash provided by operating activities $ 15,961 $ 13,989
Schedule of cash payments for interest and income taxes	Cash Payments for Interest and Income Taxes Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Interest $ 905 $ 808 $ 2,277 $ 2,043 Income taxes $ 1,206 $ 1,031 $ 3,415 $ 2,716
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Schedule of receivables, net	Receivables (in millions) September 30, December 31, Receivables, gross $ 6,610 $ 6,799 Less: Allowance for returns and customer incentives 352 413 Less: Allowance for doubtful accounts 81 84 Receivables, net $ 6,177 $ 6,302
Schedule of accumulated other comprehensive income (loss)	Accumulated Other Comprehensive Income (Loss) (in millions) September 30, September 30, Unrealized gains (losses) on marketable securities $ (233 ) $ — Deferred gains (losses) on cash flow hedges (4 ) (8 ) Unrecognized gains (losses) on employee benefit obligations 115 3 Cumulative translation adjustments 93 121 Accumulated other comprehensive income (loss) $ (29 ) $ 116
Schedule of adjustments to reconcile net income to net cash provided by operating activities	Net Cash Provided by Operating Activities Nine Months Ended (in millions) 2017 2016 Net income $ 4,403 $ 3,424 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, amortization and other operating gains 1,197 1,324 Equity in net (income) losses of investees, net 107 55 Cash received from investees 63 45 Net (gain) loss on investment activity and other (45 ) (72 ) Deferred income taxes (6 ) 139 Changes in operating assets and liabilities, net of effects of acquisitions and divestitures: Current and noncurrent receivables, net 152 (338 ) Film and television costs, net (75 ) (600 ) Accounts payable and accrued expenses related to trade creditors (270 ) (114 ) Other operating assets and liabilities 46 (524 ) Net cash provided by operating activities $ 5,572 $ 3,339
Schedule of cash payments for interest and income taxes	Cash Payments for Interest and Income Taxes Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Interest $ 53 $ 69 $ 340 $ 354 Income taxes $ 64 $ 33 $ 213 $ 155

Financial Data by Business Se30

Financial Data by Business Segment (Tables)	9 Months Ended
	Sep. 30, 2017
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 below Adjusted EBITDA are not separately evaluated. Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2017 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other (h) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 13,203 $ 5,246 $ 2,049 $ 3,197 $ 2,061 $ 322 NBCUniversal Cable Networks 2,603 905 179 726 5 4 Broadcast Television 2,133 321 (305 ) 626 66 4 Filmed Entertainment 1,784 394 32 362 18 6 Theme Parks 1,550 775 166 609 199 18 Headquarters and Other (b) 15 (122 ) 97 (219 ) 66 37 Eliminations (c) (71 ) 1 — 1 — — NBCUniversal 8,014 2,274 169 2,105 354 69 Corporate and Other (d) 266 (349 ) 170 (519 ) 19 13 Eliminations (c) (500 ) 9 — 9 — — Comcast Consolidated $ 20,983 $ 7,180 $ 2,388 $ 4,792 $ 2,434 $ 404 Three Months Ended September 30, 2016 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 12,557 $ 4,986 $ 1,929 $ 3,057 $ 2,044 $ 352 NBCUniversal Cable Networks (e) 2,942 893 184 709 7 4 Broadcast Television (e) 3,087 378 27 351 28 6 Filmed Entertainment 1,792 353 13 340 6 4 Theme Parks 1,440 706 130 576 228 19 Headquarters and Other (b) 1 (183 ) 91 (274 ) 67 34 Eliminations (c) (84 ) (1 ) — (1 ) — — NBCUniversal 9,178 2,146 445 1,701 336 67 Corporate and Other (d) 168 (223 ) 21 (244 ) 26 7 Eliminations (c) (584 ) (74 ) — (74 ) — — Comcast Consolidated $ 21,319 $ 6,835 $ 2,395 $ 4,440 $ 2,406 $ 426 Nine Months Ended September 30, 2017 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other (h) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 39,237 $ 15,764 $ 6,030 $ 9,734 $ 5,798 $ 1,001 NBCUniversal Cable Networks 7,940 3,076 574 2,502 15 11 Broadcast Television 6,582 1,059 (242 ) 1,301 125 11 Filmed Entertainment 5,920 1,047 79 968 47 17 Theme Parks 3,982 1,723 494 1,229 671 57 Headquarters and Other (b) 32 (542 ) 292 (834 ) 119 101 Eliminations (c) (243 ) (1 ) — (1 ) — — NBCUniversal 24,213 6,362 1,197 5,165 977 197 Corporate and Other (d) 679 (845 ) 204 (1,049 ) 64 42 Eliminations (c) (1,518 ) 30 — 30 — — Comcast Consolidated $ 62,611 $ 21,311 $ 7,431 $ 13,880 $ 6,839 $ 1,240 Nine Months Ended September 30, 2016 (in millions) Revenue (f) Adjusted EBITDA (g) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Communications (a) $ 37,205 $ 14,923 $ 5,676 $ 9,247 $ 5,501 $ 965 NBCUniversal Cable Networks (e) 7,961 2,793 561 2,232 15 8 Broadcast Television (e) 7,299 1,056 89 967 77 12 Filmed Entertainment 4,526 576 33 543 14 10 Theme Parks 3,602 1,550 373 1,177 668 48 Headquarters and Other (b) 10 (518 ) 268 (786 ) 217 103 Eliminations (c) (256 ) — — — — — NBCUniversal 23,142 5,457 1,324 4,133 991 181 Corporate and Other (d) 547 (668 ) 62 (730 ) 70 17 Eliminations (c) (1,516 ) (55 ) — (55 ) — — Comcast Consolidated $ 59,378 $ 19,657 $ 7,062 $ 12,595 $ 6,562 $ 1,163 (a) For the three and nine months ended September 30, 2017 and 2016 , Cable Communications segment revenue was derived from the following sources: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Residential: Video 44.1 % 44.5 % 44.3 % 44.9 % High-speed Internet 28.1 % 27.1 % 28.0 % 27.0 % Voice 6.4 % 7.0 % 6.5 % 7.2 % Business services 11.9 % 11.1 % 11.7 % 10.9 % Advertising 4.1 % 5.0 % 4.1 % 4.7 % Other 5.4 % 5.3 % 5.4 % 5.3 % Total 100.0 % 100.0 % 100.0 % 100.0 % Subscription revenue received from residential customers who purchase bundled services at a discounted rate is allocated proportionally to each cable service based on the individual service’s price on a stand-alone basis. For the three and nine months ended September 30, 2017 , 2.7% and 2.8% , respectively, of Cable Communications segment revenue was derived from franchise and other regulatory fees. For both the three and nine months ended September 30, 2016 , 2.8% of Cable Communications segment revenue was derived from franchise and other regulatory fees. (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 Filmed Entertainment and Broadcast Television segments generate revenue from the licensing of film and television content to our Cable Networks segment (d) Corporate and Other activities include costs associated with overhead and personnel, the costs of other business development initiatives, including our new 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) The revenue and operating costs and expenses associated with our broadcast of the 2016 Rio Olympics were reported in our Cable Networks and Broadcast Television segments. (f) No single customer accounted for a significant amount of revenue in any period. (g) We use Adjusted EBITDA as the measure of profit or loss for our operating segments. Adjusted EBITDA is defined as net income attributable to Comcast Corporation before net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock, income tax expense, other income (expense) items, net, depreciation and amortization expense, and other operating gains, and excluding 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 events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Other income (expense) items, net include interest expense, investment income (loss), equity in net income (losses) of investees, and other income (expense), net (as stated in our condensed consolidated statement of income). This measure eliminates the significant level of noncash depreciation and amortization expense that results from the capital-intensive nature of certain of our businesses and from intangible assets recognized in business combinations. Additionally, it is unaffected by our capital and tax structures and by our investment activities. We use this measure to evaluate our consolidated operating performance and the operating performance of our operating segments and to allocate resources and capital to our operating segments. It is also a significant performance measure in our annual incentive compensation programs. We believe that this measure is useful to investors because it is one of the bases for comparing our operating performance with that of other companies in our industries, although our measure may not be directly comparable to similar measures used by other companies. This measure should not be considered a substitute for operating income (loss), net income (loss), net income (loss) attributable to Comcast Corporation, net cash provided by operating activities, or other measures of performance or liquidity we have reported in accordance with GAAP. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 7,180 $ 6,835 $ 21,311 $ 19,657 Adjustment for legal settlement (250 ) — (250 ) — Depreciation (1,991 ) (1,865 ) (5,876 ) (5,518 ) Amortization (589 ) (530 ) (1,747 ) (1,544 ) Other operating gains 442 — 442 — Other income (expense) items, net (696 ) (716 ) (1,980 ) (1,978 ) Income before income taxes $ 4,096 $ 3,724 $ 11,900 $ 10,617 (h) Other represents other operating gains in our condensed consolidated statement of income and a charge related to a legal settlement. For both the three and nine months ended September 30, 2017 , other operating gains included a pretax gain of $337 million related to NBCUniversal’s relinquishment of spectrum rights in our Broadcast Television segment and a pretax gain of $105 million related to the sale of a business in Corporate and Other.
Cable Communications Segment Revenue Sources	For the three and nine months ended September 30, 2017 and 2016 , Cable Communications segment revenue was derived from the following sources: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Residential: Video 44.1 % 44.5 % 44.3 % 44.9 % High-speed Internet 28.1 % 27.1 % 28.0 % 27.0 % Voice 6.4 % 7.0 % 6.5 % 7.2 % Business services 11.9 % 11.1 % 11.7 % 10.9 % Advertising 4.1 % 5.0 % 4.1 % 4.7 % Other 5.4 % 5.3 % 5.4 % 5.3 % Total 100.0 % 100.0 % 100.0 % 100.0 %
Reconciliation of Adjusted EBITDA from Segments to Consolidated	Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 7,180 $ 6,835 $ 21,311 $ 19,657 Adjustment for legal settlement (250 ) — (250 ) — Depreciation (1,991 ) (1,865 ) (5,876 ) (5,518 ) Amortization (589 ) (530 ) (1,747 ) (1,544 ) Other operating gains 442 — 442 — Other income (expense) items, net (696 ) (716 ) (1,980 ) (1,978 ) Income before income taxes $ 4,096 $ 3,724 $ 11,900 $ 10,617
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Financial Data by Business Segment	Our financial data by business segment is presented in the tables below. Three Months Ended September 30, 2017 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other (f) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 2,603 $ 905 $ 179 $ 726 $ 5 $ 4 Broadcast Television 2,133 321 (305 ) 626 66 4 Filmed Entertainment 1,784 394 32 362 18 6 Theme Parks 1,550 775 166 609 199 18 Headquarters and Other (a) 15 (122 ) 97 (219 ) 66 37 Eliminations (b) (71 ) 1 — 1 — — Total $ 8,014 $ 2,274 $ 169 $ 2,105 $ 354 $ 69 Three Months Ended September 30, 2016 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks (c) $ 2,942 $ 893 $ 184 $ 709 $ 7 $ 4 Broadcast Television (c) 3,087 378 27 351 28 6 Filmed Entertainment 1,792 353 13 340 6 4 Theme Parks 1,440 706 130 576 228 19 Headquarters and Other (a) 1 (183 ) 91 (274 ) 67 34 Eliminations (b) (84 ) (1 ) — (1 ) — — Total $ 9,178 $ 2,146 $ 445 $ 1,701 $ 336 $ 67 Nine Months Ended September 30, 2017 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other (f) Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks $ 7,940 $ 3,076 $ 574 $ 2,502 $ 15 $ 11 Broadcast Television 6,582 1,059 (242 ) 1,301 125 11 Filmed Entertainment 5,920 1,047 79 968 47 17 Theme Parks 3,982 1,723 494 1,229 671 57 Headquarters and Other (a) 32 (542 ) 292 (834 ) 119 101 Eliminations (b) (243 ) (1 ) — (1 ) — — Total $ 24,213 $ 6,362 $ 1,197 $ 5,165 $ 977 $ 197 Nine Months Ended September 30, 2016 (in millions) Revenue (d) Adjusted EBITDA (e) Depreciation, Amortization and Other Operating Income (Loss) Capital Expenditures Cash Paid for Intangible Assets Cable Networks (c) $ 7,961 $ 2,793 $ 561 $ 2,232 $ 15 $ 8 Broadcast Television (c) 7,299 1,056 89 967 77 12 Filmed Entertainment 4,526 576 33 543 14 10 Theme Parks 3,602 1,550 373 1,177 668 48 Headquarters and Other (a) 10 (518 ) 268 (786 ) 217 103 Eliminations (b) (256 ) — — — — — Total $ 23,142 $ 5,457 $ 1,324 $ 4,133 $ 991 $ 181 (a) Headquarters and Other activities include costs associated with overhead, allocations, personnel costs and headquarter initiatives. (b) Included in Eliminations are transactions that our segments enter into with one another, which consist primarily of the licensing of film and television content from our Filmed Entertainment and Broadcast Television segments to our Cable Networks segment. (c) The revenue and operating costs and expenses associated with our broadcast of the 2016 Rio Olympics were reported in our Cable Networks and Broadcast Television segments. (d) No single customer accounted for a significant amount of revenue in any period. (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 NBCUniversal before net (income) loss attributable to noncontrolling interests, income tax expense, other income (expense) items, net, depreciation and amortization expense, and other operating gains, and excluding 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 events, gains, losses or other charges (such as significant legal settlements) that affect the period-to-period comparability of our operating performance. Other income (expense) items, net include interest expense, investment income (loss), equity in net income (losses) of investees, and other income (expense), net (as stated in our condensed consolidated statement of income). This measure eliminates the significant level of noncash amortization expense that results from intangible assets recognized in business combinations. Additionally, it is unaffected by our capital and tax structures and by our investment activities. We use this measure to evaluate our consolidated operating performance and the operating performance of our operating segments and to allocate resources and capital to our operating segments. It is also a significant performance measure in our annual incentive compensation programs. We believe that this measure is useful to investors because it is one of the bases for comparing our operating performance with that of other companies in our industries, although our measure may not be directly comparable to similar measures used by other companies. This measure should not be considered a substitute for operating income (loss), net income (loss), net income (loss) attributable to NBCUniversal, net cash provided by operating activities, or other measures of performance or liquidity we have reported in accordance with GAAP. Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 2,274 $ 2,146 $ 6,362 $ 5,457 Depreciation (253 ) (209 ) (749 ) (624 ) Amortization (253 ) (236 ) (785 ) (700 ) Other operating gains 337 — 337 — Other income (expense) items, net (165 ) (195 ) (473 ) (398 ) Income before income taxes $ 1,940 $ 1,506 $ 4,692 $ 3,735 (f) Other represents other operating gains in our condensed consolidated statement of income. For both the three and nine months ended September 30, 2017 , other operating gains included a pretax gain of $337 million related to our relinquishment of spectrum rights in our Broadcast Television segment.
Reconciliation of Adjusted EBITDA from Segments to Consolidated	Our reconciliation of the aggregate amount of Adjusted EBITDA for our reportable segments to consolidated income before income taxes is presented in the table below. Three Months Ended Nine Months Ended (in millions) 2017 2016 2017 2016 Adjusted EBITDA $ 2,274 $ 2,146 $ 6,362 $ 5,457 Depreciation (253 ) (209 ) (749 ) (624 ) Amortization (253 ) (236 ) (785 ) (700 ) Other operating gains 337 — 337 — Other income (expense) items, net (165 ) (195 ) (473 ) (398 ) Income before income taxes $ 1,940 $ 1,506 $ 4,692 $ 3,735

Condensed Consolidating Finan31

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet September 30, 2017 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Assets Cash and cash equivalents $ — $ — $ — $ 260 $ 3,854 $ — $ 4,114 Receivables, net — — — — 7,915 — 7,915 Programming rights — — — — 1,779 — 1,779 Other current assets 65 — — 30 2,057 — 2,152 Total current assets 65 — — 290 15,605 — 15,960 Film and television costs — — — — 6,796 — 6,796 Investments 132 11 79 691 5,782 — 6,695 Investments in and amounts due from subsidiaries eliminated upon consolidation 102,930 128,663 126,361 50,474 111,087 (519,515 ) — Property and equipment, net 482 — — — 37,374 — 37,856 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 36,752 — 36,752 Other intangible assets, net 11 — — — 18,722 — 18,733 Other noncurrent assets, net 1,178 687 — 86 2,249 (1,055 ) 3,145 Total assets $ 104,798 $ 129,361 $ 126,440 $ 51,541 $ 293,731 $ (520,570 ) $ 185,301 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 17 $ — $ — $ — $ 6,959 $ — $ 6,976 Accrued participations and residuals — — — — 1,811 — 1,811 Accrued expenses and other current liabilities 1,640 92 208 394 5,087 — 7,421 Current portion of long-term debt 2,913 — — 4 2,324 — 5,241 Total current liabilities 4,570 92 208 398 16,181 — 21,449 Long-term debt, less current portion 42,237 139 2,100 8,204 7,040 — 59,720 Deferred income taxes — 492 — 70 36,124 (1,084 ) 35,602 Other noncurrent liabilities 2,564 — — 1,138 7,183 29 10,914 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,353 — 1,353 Equity: Common stock 55 — — — — — 55 Other shareholders’ equity 55,372 128,638 124,132 41,731 225,014 (519,515 ) 55,372 Total Comcast Corporation shareholders’ equity 55,427 128,638 124,132 41,731 225,014 (519,515 ) 55,427 Noncontrolling interests — — — — 836 — 836 Total equity 55,427 128,638 124,132 41,731 225,850 (519,515 ) 56,263 Total liabilities and equity $ 104,798 $ 129,361 $ 126,440 $ 51,541 $ 293,731 $ (520,570 ) $ 185,301 Condensed Consolidating Balance Sheet December 31, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Assets Cash and cash equivalents $ — $ — $ — $ 482 $ 2,819 $ — $ 3,301 Receivables, net — — — — 7,955 — 7,955 Programming rights — — — — 1,250 — 1,250 Other current assets 151 — — 36 3,668 — 3,855 Total current assets 151 — — 518 15,692 — 16,361 Film and television costs — — — — 7,252 — 7,252 Investments 75 — — 651 4,521 — 5,247 Investments in and amounts due from subsidiaries eliminated upon consolidation 98,350 120,071 117,696 47,393 97,704 (481,214 ) — Property and equipment, net 298 — — — 35,955 — 36,253 Franchise rights — — — — 59,364 — 59,364 Goodwill — — — — 35,980 — 35,980 Other intangible assets, net 13 — — — 17,261 — 17,274 Other noncurrent assets, net 1,138 638 — 89 1,921 (1,017 ) 2,769 Total assets $ 100,025 $ 120,709 $ 117,696 $ 48,651 $ 275,650 $ (482,231 ) $ 180,500 Liabilities and Equity Accounts payable and accrued expenses related to trade creditors $ 23 $ — $ — $ — $ 6,892 $ — $ 6,915 Accrued participations and residuals — — — — 1,726 — 1,726 Accrued expenses and other current liabilities 1,726 — 341 302 5,045 — 7,414 Current portion of long-term debt 3,739 — 550 4 1,187 — 5,480 Total current liabilities 5,488 — 891 306 14,850 — 21,535 Long-term debt, less current portion 38,123 141 2,100 8,208 6,994 — 55,566 Deferred income taxes — 542 — 70 35,259 (1,017 ) 34,854 Other noncurrent liabilities 2,471 — — 1,166 7,288 — 10,925 Redeemable noncontrolling interests and redeemable subsidiary preferred stock — — — — 1,446 — 1,446 Equity: Common stock 56 — — — — — 56 Other shareholders’ equity 53,887 120,026 114,705 38,901 207,582 (481,214 ) 53,887 Total Comcast Corporation shareholders’ equity 53,943 120,026 114,705 38,901 207,582 (481,214 ) 53,943 Noncontrolling interests — — — — 2,231 — 2,231 Total equity 53,943 120,026 114,705 38,901 209,813 (481,214 ) 56,174 Total liabilities and equity $ 100,025 $ 120,709 $ 117,696 $ 48,651 $ 275,650 $ (482,231 ) $ 180,500
Condensed Consolidating Statement of Income	Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 20,983 $ — $ 20,983 Management fee revenue 285 — 280 — — (565 ) — 285 — 280 — 20,983 (565 ) 20,983 Costs and Expenses: Programming and production — — — — 6,077 — 6,077 Other operating and administrative 183 — 280 277 6,248 (565 ) 6,423 Advertising, marketing and promotion — — — — 1,553 — 1,553 Depreciation 7 — — — 1,984 — 1,991 Amortization 1 — — — 588 — 589 Other operating gains — — — — (442 ) — (442 ) 191 — 280 277 16,008 (565 ) 16,191 Operating income (loss) 94 — — (277 ) 4,975 — 4,792 Other Income (Expense): Interest expense (544 ) (3 ) (48 ) (116 ) (55 ) — (766 ) Investment income (loss), net (2 ) 32 — (9 ) 61 — 82 Equity in net income (losses) of investees, net 2,944 2,483 1,992 2,221 1,786 (11,465 ) (39 ) Other income (expense), net — — — 12 15 — 27 2,398 2,512 1,944 2,108 1,807 (11,465 ) (696 ) Income (loss) before income taxes 2,492 2,512 1,944 1,831 6,782 (11,465 ) 4,096 Income tax (expense) benefit 158 (10 ) 17 (6 ) (1,572 ) — (1,413 ) Net income (loss) 2,650 2,502 1,961 1,825 5,210 (11,465 ) 2,683 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (33 ) — (33 ) Net income (loss) attributable to Comcast Corporation $ 2,650 $ 2,502 $ 1,961 $ 1,825 $ 5,177 $ (11,465 ) $ 2,650 Comprehensive income (loss) attributable to Comcast Corporation $ 2,603 $ 2,486 $ 1,965 $ 1,740 $ 5,049 $ (11,240 ) $ 2,603 Condensed Consolidating Statement of Income For the Three Months Ended September 30, 2016 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Revenue: Service revenue $ — $ — $ — $ — $ 21,319 $ — $ 21,319 Management fee revenue 268 — 263 — — (531 ) — 268 — 263 — 21,319 (531 ) 21,319 Costs and Expenses: Programming and production — — — — 7,003 — 7,003 Other operating and administrative 194 — 263 222 5,848 (531 ) 5,996 Advertising, marketing and promotion — — — — 1,485 — 1,485 Depreciation 7 — — — 1,858 — 1,865 Amortization 1 — — — 529 — 530 Other operating gains — — — — — — — 202 — 263 222 16,723 (531 ) 16,879 Operating income (loss) 66 — — (222 ) 4,596 — 4,440 Other Income (Expense): Interest expense (502 ) (3 ) (59 ) (113 ) (74 ) — (751 ) Investment income (loss), net 3 (4 ) — (12 ) 93 — 80 Equity in net income (losses) of investees, net 2,519 2,385 2,134 1,644 1,255 (9,971 ) (34 ) Other income (expense), net — — — (2 ) (9 ) — (11 ) 2,020 2,378 2,075 1,517 1,265 (9,971 ) (716 ) Income (loss) before income taxes 2,086 2,378 2,075 1,295 5,861 (9,971 ) 3,724 Income tax (expense) benefit 151 2 21 (6 ) (1,568 ) — (1,400 ) Net income (loss) 2,237 2,380 2,096 1,289 4,293 (9,971 ) 2,324 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (87 ) — (87 ) Net income (loss) attributable to Comcast Corporation $ 2,237 $ 2,380 $ 2,096 $ 1,289 $ 4,206 $ (9,971 ) $ 2,237 Comprehensive income (loss) attributable to Comcast Corporation $ 2,270 $ 2,388 $ 2,096 $ 1,310 $ 4,235 $ (10,029 ) $ 2,270 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2017 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Revenue: Service revenue $ — $ — $ — $ — $ 62,611 $ — $ 62,611 Management fee revenue 841 — 827 — — (1,668 ) — 841 — 827 — 62,611 (1,668 ) 62,611 Costs and Expenses: Programming and production — — — — 18,492 — 18,492 Other operating and administrative 553 — 827 844 17,754 (1,668 ) 18,310 Advertising, marketing and promotion — — — — 4,748 — 4,748 Depreciation 21 — — — 5,855 — 5,876 Amortization 4 — — — 1,743 — 1,747 Other operating gains — — — — (442 ) — (442 ) 578 — 827 844 48,150 (1,668 ) 48,731 Operating income (loss) 263 — — (844 ) 14,461 — 13,880 Other Income (Expense): Interest expense (1,592 ) (9 ) (159 ) (344 ) (175 ) — (2,279 ) Investment income (loss), net (1 ) 84 — (29 ) 151 — 205 Equity in net income (losses) of investees, net 8,594 7,746 6,613 5,477 4,313 (32,731 ) 12 Other income (expense), net — — — 58 24 — 82 7,001 7,821 6,454 5,162 4,313 (32,731 ) (1,980 ) Income (loss) before income taxes 7,264 7,821 6,454 4,318 18,774 (32,731 ) 11,900 Income tax (expense) benefit 465 (26 ) 56 (17 ) (4,513 ) — (4,035 ) Net income (loss) 7,729 7,795 6,510 4,301 14,261 (32,731 ) 7,865 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (136 ) — (136 ) Net income (loss) attributable to Comcast Corporation $ 7,729 $ 7,795 $ 6,510 $ 4,301 $ 14,125 $ (32,731 ) $ 7,729 Comprehensive income (loss) attributable to Comcast Corporation $ 7,818 $ 7,793 $ 6,516 $ 4,266 $ 13,998 $ (32,573 ) $ 7,818 Condensed Consolidating Statement of Income For the Nine Months Ended September 30, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Revenue: Service revenue $ — $ — $ — $ — $ 59,378 $ — $ 59,378 Management fee revenue 793 — 778 — — (1,571 ) — 793 — 778 — 59,378 (1,571 ) 59,378 Costs and Expenses: Programming and production — — — — 17,926 — 17,926 Other operating and administrative 635 — 778 739 16,704 (1,571 ) 17,285 Advertising, marketing and promotion — — — — 4,510 — 4,510 Depreciation 21 — — — 5,497 — 5,518 Amortization 4 — — — 1,540 — 1,544 Other operating gains — — — — — — — 660 — 778 739 46,177 (1,571 ) 46,783 Operating income (loss) 133 — — (739 ) 13,201 — 12,595 Other Income (Expense): Interest expense (1,431 ) (9 ) (179 ) (342 ) (225 ) — (2,186 ) Investment income (loss), net 6 (3 ) — (20 ) 185 — 168 Equity in net income (losses) of investees, net 7,239 6,924 6,375 4,229 3,160 (27,991 ) (64 ) Other income (expense), net — — — 115 (11 ) — 104 5,814 6,912 6,196 3,982 3,109 (27,991 ) (1,978 ) Income (loss) before income taxes 5,947 6,912 6,196 3,243 16,310 (27,991 ) 10,617 Income tax (expense) benefit 452 4 63 (19 ) (4,489 ) — (3,989 ) Net income (loss) 6,399 6,916 6,259 3,224 11,821 (27,991 ) 6,628 Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock — — — — (229 ) — (229 ) Net income (loss) attributable to Comcast Corporation $ 6,399 $ 6,916 $ 6,259 $ 3,224 $ 11,592 $ (27,991 ) $ 6,399 Comprehensive income (loss) attributable to Comcast Corporation $ 6,607 $ 7,015 $ 6,261 $ 3,552 $ 12,134 $ (28,962 ) $ 6,607
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2017 (in millions) Comcast Comcast CCCL NBCUniversal Non- Elimination Consolidated Net cash provided by (used in) operating activities $ (931 ) $ 91 $ (233 ) $ (1,054 ) $ 18,088 $ — $ 15,961 Investing Activities Net transactions with affiliates 4,216 (91 ) 818 833 (5,776 ) — — Capital expenditures (6 ) — — — (6,833 ) — (6,839 ) Cash paid for intangible assets (2 ) — — — (1,238 ) — (1,240 ) Acquisitions and construction of real estate properties (190 ) — — — (135 ) — (325 ) Acquisitions, net of cash acquired — — — — (429 ) — (429 ) Proceeds from sales of investments — — — 10 110 — 120 Purchases of investments (56 ) — (35 ) (57 ) (1,916 ) — (2,064 ) Deposits — — — — — — — Other 101 — — 49 600 — 750 Net cash provided by (used in) investing activities 4,063 (91 ) 783 835 (15,617 ) — (10,027 ) Financing Activities Proceeds from (repayments of) short-term borrowings, net (1,739 ) — — — (1,068 ) — (2,807 ) Proceeds from borrowings 5,997 — — — 5,463 — 11,460 Repurchases and repayments of debt (1,000 ) — (550 ) (3 ) (3,468 ) — (5,021 ) Repurchases of common stock under repurchase program and employee plans (4,212 ) — — — — — (4,212 ) Dividends paid (2,147 ) — — — — — (2,147 ) Purchase of Universal Studios Japan noncontrolling interests — — — — (2,299 ) — (2,299 ) Issuances of common stock — — — — — — — Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (198 ) — (198 ) Other (31 ) — — — 134 — 103 Net cash provided by (used in) financing activities (3,132 ) — (550 ) (3 ) (1,436 ) — (5,121 ) Increase (decrease) in cash and cash equivalents — — — (222 ) 1,035 — 813 Cash and cash equivalents, beginning of period — — — 482 2,819 — 3,301 Cash and cash equivalents, end of period $ — $ — $ — $ 260 $ 3,854 $ — $ 4,114 Condensed Consolidating Statement of Cash Flows For the Nine Months Ended September 30, 2016 (in millions) Comcast Parent Comcast Holdings CCCL Parent NBCUniversal Media Parent Non- Guarantor Subsidiaries Elimination and Consolidation Adjustments Consolidated Comcast Corporation Net cash provided by (used in) operating activities $ (637 ) $ — $ (179 ) $ (1,068 ) $ 15,873 $ — $ 13,989 Investing Activities Net transactions with affiliates (1,746 ) — 179 2,150 (583 ) — — Capital expenditures (9 ) — — — (6,553 ) — (6,562 ) Cash paid for intangible assets (4 ) — — — (1,159 ) — (1,163 ) Acquisitions and construction of real estate properties (2 ) — — — (301 ) — (303 ) Acquisitions, net of cash acquired — — — — (3,904 ) — (3,904 ) Proceeds from sales of investments — — — 104 84 — 188 Purchases of investments (23 ) — — (9 ) (586 ) — (618 ) Deposits — — — — (1,748 ) — (1,748 ) Other (108 ) — — (35 ) 101 — (42 ) Net cash provided by (used in) investing activities (1,892 ) — 179 2,210 (14,649 ) — (14,152 ) Financing Activities Proceeds from (repayments of) short-term borrowings, net 105 — — — 505 — 610 Proceeds from borrowings 9,231 — — — — — 9,231 Repurchases and repayments of debt (750 ) — — (1,005 ) (1,239 ) — (2,994 ) Repurchases of common stock under repurchase program and employee plans (4,061 ) — — — — — (4,061 ) Dividends paid (1,944 ) — — — — — (1,944 ) Issuances of common stock 23 — — — — — 23 Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock — — — — (194 ) — (194 ) Other (75 ) — — 25 54 — 4 Net cash provided by (used in) financing activities 2,529 — — (980 ) (874 ) — 675 Increase (decrease) in cash and cash equivalents — — — 162 350 — 512 Cash and cash equivalents, beginning of period — — — 414 1,881 — 2,295 Cash and cash equivalents, end of period $ — $ — $ — $ 576 $ 2,231 $ — $ 2,807

Condensed Consolidated Financ32

Condensed Consolidated Financial Statements (Details)	Jan. 24, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Stock split, conversion ratio	2

Recent Accounting Pronounceme33

Recent Accounting Pronouncements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		$ 15,961	$ 13,989
Net cash provided by (used in) financing activities		(5,121)	675
NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		5,572	3,339
Net cash provided by (used in) financing activities		(4,498)	(1,403)
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement impact on net income if adopted	$ (63)	(47)
Accounting Standards Update 2016-01 [Member] | NBCUniversal Media LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement impact on net income if adopted	(95)	(234)
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in income tax expense	$ 49	$ 247
Increase in diluted earnings per share (in dollars per share)	$ 0.01	$ 0.04
Net cash provided by operating activities		$ 644	492
Net cash provided by (used in) financing activities		$ (644)	$ (492)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Income Attributable to Comcast Corporation	$ 2,650	$ 2,237	$ 7,729	$ 6,399
Basic EPS attributable to Comcast Corporation shareholders (in shares)	4,698	4,805	4,725	4,837
Basic earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.56	$ 0.47	$ 1.64	$ 1.32
Effect of dilutive securities:
Net Income Attributable to Comcast Corporation	$ 2,650	$ 2,237	$ 7,729	$ 6,399
Assumed exercise or issuance of shares relating to stock plans (in shares)	79	56	81	56
Diluted EPS attributable to Comcast Corporation shareholders (in shares)	4,777	4,861	4,806	4,893
Diluted earnings per common share attributable to Comcast Corporation shareholders (in dollars per share)	$ 0.55	$ 0.46	$ 1.61	$ 1.31

Significant Transactions (FCC S

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

Significant Transaction (Univer

Significant Transaction (Universal Studios Japan) (Details) - USD ($) $ in Millions	Apr. 06, 2017	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Payments to acquire additional interest in noncontrolling interest		$ 2,299	$ 0
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Payments to acquire additional interest in noncontrolling interest		$ 2,299	$ 0
Universal Studios Japan [Member]
Business Acquisition [Line Items]
Payments to acquire additional interest in noncontrolling interest	$ 2,300
Universal Studios Japan [Member] | NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Payments to acquire additional interest in noncontrolling interest	$ 2,300

Significant Transactions (Dream

Significant Transactions (DreamWorks Animation) (Details) - DreamWorks Animation [Member] $ / shares in Units, $ in Millions	Aug. 22, 2016USD ($)$ / shares
Business Acquisition [Line Items]
Cash consideration transferred	$ 3,773
Business acquisition, price paid per share (in dollars per share) | $ / shares	$ 41
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Cash consideration transferred	$ 3,773
Consideration Transferred By Comcast [Member] | NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Cash consideration transferred	$ 3,800
Business acquisition, price paid per share (in dollars per share) | $ / shares	$ 41

Significant Transactions (Alloc

Significant Transactions (Allocation of Purchase Price) (Details) - USD ($) $ in Millions	Aug. 22, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Allocation of Purchase Price
Goodwill		$ 36,752		$ 35,980
NBCUniversal Media LLC [Member]
Allocation of Purchase Price
Goodwill		23,963		$ 23,323
Contribution from member		$ 662	$ 3,647
DreamWorks Animation [Member]
Allocation of Purchase Price
Film and television costs	$ 838
Intangible assets	396
Working capital	156
Debt	(381)
Tax receivable agreement	(146)
Deferred income taxes	291
Other noncurrent assets and liabilities	170
Identifiable net assets (liabilities) acquired	1,324
Noncontrolling interests	(337)
Goodwill	2,786
Cash consideration transferred	3,773
DreamWorks Animation [Member] | NBCUniversal Media LLC [Member]
Allocation of Purchase Price
Film and television costs	838
Intangible assets	396
Working capital	156
Debt	(381)
Tax receivable agreement	(146)
Other noncurrent assets and liabilities	461
Identifiable net assets (liabilities) acquired	1,324
Noncontrolling interests	(337)
Goodwill	2,786
Cash consideration transferred	3,773
DreamWorks Animation [Member] | Member's contribution that represented Deferred Income Tax Assets and Other Tax-related Items recorded by Parent but excluded from net assets contributed [Member] | NBCUniversal Media LLC [Member]
Allocation of Purchase Price
Contribution from member	279
Tax Receivable Agreement [Member] | DreamWorks Animation [Member] | NBCUniversal Media LLC [Member]
Allocation of Purchase Price
Contribution from member	$ 146

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Other noncurrent liabilities	$ 10,914	$ 10,925
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Other noncurrent liabilities	4,099	$ 4,130
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 Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Receivables, net	$ 7,915	$ 7,955
Accounts payable and accrued expenses related to trade creditors	6,976	6,915
Accrued expenses and other current liabilities	5,849	6,282
Other noncurrent liabilities	10,914	10,925
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	6,177	6,302
Accounts payable and accrued expenses related to trade creditors	1,449	1,647
Accrued expenses and other current liabilities	1,807	1,888
Note payable to Comcast	1,805	2,703
Other noncurrent liabilities	4,099	4,130
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Receivables, net	327	285
Accounts payable and accrued expenses related to trade creditors	33	55
Accrued expenses and other current liabilities	39	4
Note payable to Comcast	1,805	2,703
Other noncurrent liabilities	$ 389	$ 389

Related Party Transactions (C41

Related Party Transactions (Condensed Consolidated Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transaction [Line Items]
Revenue	$ 20,983	$ 21,319	$ 62,611	$ 59,378
Operating costs and expenses	(16,191)	(16,879)	(48,731)	(46,783)
NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	8,014	9,178	24,213	23,142
Operating costs and expenses	(5,909)	(7,477)	(19,048)	(19,009)
Comcast and Consolidated Subsidiaries [Member] | NBCUniversal Media LLC [Member]
Related Party Transaction [Line Items]
Revenue	463	522	1,382	1,335
Operating costs and expenses	(38)	(53)	(148)	(157)
Other income (expense)	$ (20)	$ (18)	$ (67)	$ (48)

Film and Television Costs (Film

Film and Television Costs (Film and Television Costs)(Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Film Costs:
Released, less amortization	$ 1,747	$ 1,750
Completed, not released	198	50
In production and in development	829	1,310
Total film costs	2,774	3,110
Television Costs:
Released, less amortization	2,047	1,953
In production and in development	853	853
Total television costs	2,900	2,806
Programming rights, less amortization	2,901	2,586
Total film costs, television costs and programming rights	8,575	8,502
Less: Current portion of programming rights	1,779	1,250
Film and television costs	6,796	7,252
NBCUniversal Media LLC [Member]
Film Costs:
Released, less amortization	1,747	1,750
Completed, not released	198	50
In production and in development	829	1,310
Total film costs	2,774	3,110
Television Costs:
Released, less amortization	2,047	1,953
In production and in development	853	853
Total television costs	2,900	2,806
Programming rights, less amortization	2,889	2,570
Total film costs, television costs and programming rights	8,563	8,486
Less: Current portion of programming rights	1,772	1,241
Film and television costs	$ 6,791	$ 7,245

Investments (Schedule of Invest

Investments (Schedule of Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	$ 591	$ 198
Equity method	3,351	2,376
Cost method	2,766	2,770
Total Investments	6,708	5,344
Less: Current investments	13	97
Noncurrent Investments	6,695	5,247
Snap [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	427	0
Other Fair Value Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	164	198
Atairos [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Equity method	2,225	1,601
Hulu [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Equity method	255	225
Other Equity Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Equity method	871	550
AirTouch [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Cost method	1,610	1,599
BuzzFeed [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Cost method	400	400
Other Cost Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Cost method	756	771
NBCUniversal Media LLC [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	431	6
Equity method	687	561
Cost method	699	696
Total Investments	1,817	1,263
Noncurrent Investments	1,817	1,263
NBCUniversal Media LLC [Member] | Snap [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	427	0
NBCUniversal Media LLC [Member] | Other Fair Value Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Fair value method	4	6
NBCUniversal Media LLC [Member] | Hulu [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Equity method	255	225
NBCUniversal Media LLC [Member] | Other Equity Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Equity method	432	336
NBCUniversal Media LLC [Member] | BuzzFeed [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Cost method	400	400
NBCUniversal Media LLC [Member] | Other Cost Method Investments [Member]
Fair Value, Equity And Cost Method Investments [Line Items]
Cost method	$ 299	$ 296

Investments (Investment Income

Investments (Investment Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investments [Abstract]
Gains (losses) on sales and exchanges of investments, net	$ 10	$ 24	$ 9	$ 39
Investment impairment losses	(3)	(7)	(9)	(28)
Interest and dividend income	36	31	101	91
Other, net	39	32	104	66
Investment income (loss), net	$ 82	$ 80	$ 205	$ 168

Investments (Fair Value Method

Investments (Fair Value Method Investments) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016
NBCUniversal Media LLC [Member]
Schedule of Fair Value Method Investments [Line Items]
Contributed investment from Comcast			$ 662	$ 3,647
Snap [Member]
Schedule of Fair Value Method Investments [Line Items]
Payments to acquire available-for-sale securities		$ 500
Snap [Member] | NBCUniversal Media LLC [Member]
Schedule of Fair Value Method Investments [Line Items]
Contributed investment from Comcast	$ 662

Investments (Equity Method Inve

Investments (Equity Method Investments) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Equity in net income (losses) of investees	$ (39)	$ (34)	$ 12	$ (64)
Pretax gain, sale of business	105		105
Atairos [Member]
Schedule of Equity Method Investments [Line Items]
Purchases of investments			994
Equity in net income (losses) of investees	7	(9)	106	(36)
Pretax gain, sale of business	105
The Weather Channel [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of The Weather Channel product and technology businesses				108
NBCUniversal Media LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net income (losses) of investees	$ (52)	$ (34)	$ (107)	(55)
NBCUniversal Media LLC [Member] | The Weather Channel [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of The Weather Channel product and technology businesses				$ 108

Investments (Cost Method Invest

Investments (Cost Method Investments) (Details) $ in Billions	9 Months Ended
	Sep. 30, 2017USD ($)preferred_stock_series
AirTouch [Member] | Level 2 [Member]
Schedule of Cost-method Investments [Line Items]
Fair value of redeemable preferred shares	$ 1.8
AirTouch [Member]
Schedule of Cost-method Investments [Line Items]
Number of series of preferred stock | preferred_stock_series	2
AirTouch [Member] | Level 2 [Member]
Schedule of Cost-method Investments [Line Items]
Fair value of cost method investment redeemable preferred shares	$ 1.7

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) ¥ in Billions, $ in Billions	9 Months Ended
	Sep. 30, 2017USD ($)	May 31, 2017JPY (¥)	May 31, 2017USD ($)
Debt Instrument [Line Items]
Total debt	$ 65
Fair value of debt	71.7
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Total debt	12.4
Fair value of debt	13.5
Universal Studios Japan Term Loan Maturing March 2022 [Member]
Debt Instrument [Line Items]
Debt face amount		¥ 450	$ 3.9
Universal Studios Japan Term Loan Maturing March 2022 [Member] | NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Debt face amount		¥ 450	$ 3.9
Former Universal Studios Japan Term Loans [Member]
Debt Instrument [Line Items]
Repayments of debt	3.3
Former Universal Studios Japan Term Loans [Member] | NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Repayments of debt	$ 3.3

Long-Term Debt (Debt Borrowings

Long-Term Debt (Debt Borrowings)(Details) - Senior Notes [Member] - USD ($) $ in Millions	Aug. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Jan. 31, 2017
Senior 3.15% Notes Due 2028 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,650
Interest rate	3.15%
Senior 4.00% Notes Due 2047 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 850
Interest rate	4.00%
Floating Rate Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt face amount		$ 1,500
Senior 4.45% Notes Due 2047 [Member]
Debt Instrument [Line Items]
Debt face amount			$ 1,005
Interest rate			4.45%
Senior 3.0% Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt face amount				$ 1,250
Interest rate				3.00%
Senior 3.3% Notes Due 2027 [Member]
Debt Instrument [Line Items]
Debt face amount				$ 1,250
Interest rate				3.30%

Long-term Debt (Debt Repayments

Long-term Debt (Debt Repayments) (Details) - USD ($) $ in Millions	1 Months Ended		9 Months Ended
	May 31, 2017	Jan. 31, 2017	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Repurchases and repayments of debt			$ 5,021	$ 2,994
Senior Notes [Member] | Senior 8.875% Notes Due 2017 [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt	$ 550
Interest rate	8.875%
Senior Notes [Member] | Senior 6.50% Notes Due 2017 [Member]
Debt Instrument [Line Items]
Repurchases and repayments of debt		$ 1,000
Interest rate		6.50%

Long-Term Debt (Revolving Credi

Long-Term Debt (Revolving Credit Facilities) (Details) - Revolving Credit Facility [Member] $ in Billions	Sep. 30, 2017USD ($)
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] - USD ($)	Sep. 30, 2017	Jun. 30, 2017
Short-term Debt [Line Items]
Maximum borrowing under commercial paper programs		$ 7,000,000,000
Commercial paper outstanding	$ 0
NBCUniversal Enterprise [Member]
Short-term Debt [Line Items]
Maximum borrowing under commercial paper programs		$ 1,500,000,000
Commercial paper outstanding	$ 0

Long-Term Debt Long-term Debt (

Long-Term Debt Long-term Debt (Cross-Guarantee Structure) (Details) - NBCUniversal Media LLC [Member] $ in Millions	Sep. 30, 2017USD ($)
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	47,500
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Guarantee obligations, maximum capacity	$ 7,000

Long-Term Debt (Senior Notes Ex

Long-Term Debt (Senior Notes Exchange) (Details) - Subsequent Event [Member] - Senior Notes Exchange [Member] $ in Millions	1 Months Ended
	Oct. 31, 2017USD ($)
Comcast New Senior 3.969% Notes Due 2047 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 2,000
Interest rate	3.969%
Comcast New Senior 3.999% Notes Due 2049 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 2,000
Interest rate	3.999%
Comcast New Senior 4.049% Notes Due 2052 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 1,500
Interest rate	4.049%
Comcast and NBCUniversal Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of certain series of outstanding notes	$ 3,900
NBCUniversal Media LLC [Member] | Comcast New Senior 3.969% Notes Due 2047 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 2,000
Interest rate	3.969%
NBCUniversal Media LLC [Member] | Comcast New Senior 3.999% Notes Due 2049 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 2,000
Interest rate	3.999%
NBCUniversal Media LLC [Member] | Comcast New Senior 4.049% Notes Due 2052 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 1,500
Interest rate	4.049%
NBCUniversal Media LLC [Member] | Comcast and NBCUniversal Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount of certain series of outstanding notes	$ 3,900
NBCUniversal Media LLC [Member] | NBCUniversal Senior 6.400% Notes Due 2040 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Interest rate	6.40%
Aggregate principal amount of certain series of outstanding notes	$ 442
NBCUniversal Media LLC [Member] | NBCUniversal 3.999% Notes Due 2049 to Comcast [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 610
Interest rate	3.999%

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended
	Mar. 31, 2017	Sep. 30, 2017
Restricted share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized pretax compensation expense on nonvested awards		$ 886
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized pretax compensation expense on nonvested awards		$ 451
Management Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options granted (in shares)	39.1
Weighted average fair value of stock options granted (in dollars per share)	$ 7.01
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)	10.6
Weighted average fair value of restricted share units granted (in dollars per share)	$ 37.42

Share-Based Compensation (Recog

Share-Based Compensation (Recognized Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	$ 159	$ 131	$ 464	$ 391
NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	38	23	103	77
Restricted share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	99	77	284	236
Restricted share units [Member] | NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	32	19	86	64
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	52	48	155	133
Stock options [Member] | NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	3	3	10	7
Employee stock purchase plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	8	6	25	22
Employee stock purchase plans [Member] | NBCUniversal Media LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	$ 3	$ 1	$ 7	$ 6

Supplemental Financial Inform57

Supplemental Financial Information (Receivables)(Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Supplemental Financial Information [Line Items]
Receivables, gross	$ 8,549	$ 8,622
Less: Allowance for returns and customer incentives	357	417
Less: Allowance for doubtful accounts	277	250
Receivables, net	7,915	7,955
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Receivables, gross	6,610	6,799
Less: Allowance for returns and customer incentives	352	413
Less: Allowance for doubtful accounts	81	84
Receivables, net	$ 6,177	$ 6,302

Supplemental Financial Inform58

Supplemental Financial Information (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	$ (43)		$ 2
Deferred gains (losses) on cash flow hedges	(12)		(52)
Unrecognized gains (losses) on employee benefit obligations	270		8
Cumulative translation adjustments	166		76
Accumulated other comprehensive income (loss), net of deferred taxes	381	$ 98	34
NBCUniversal Media LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) on marketable securities	(233)		0
Deferred gains (losses) on cash flow hedges	(4)		(8)
Unrecognized gains (losses) on employee benefit obligations	115		3
Cumulative translation adjustments	93		121
Accumulated other comprehensive income (loss), net of deferred taxes	$ (29)	$ (135)	$ 116

Supplemental Financial Inform59

Supplemental Financial Information (Net Cash Provided by Operating Activities)(Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Supplemental Financial Information [Line Items]
Net income	$ 2,683	$ 2,324	$ 7,865	$ 6,628
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other operating gains			7,181	7,062
Share-based compensation			594	495
Noncash interest expense (income), net			187	172
Equity in net (income) losses of investees, net	39	34	(12)	64
Cash received from investees			72	58
Net (gain) loss on investment activity and other			(193)	(159)
Deferred income taxes			678	985
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net			28	(315)
Film and television costs, net			(71)	(593)
Accounts payable and accrued expenses related to trade creditors			(17)	46
Other operating assets and liabilities			(351)	(454)
Net cash provided by operating activities			15,961	13,989
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Net income	1,842	1,367	4,403	3,424
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other operating gains			1,197	1,324
Equity in net (income) losses of investees, net	$ 52	$ 34	107	55
Cash received from investees			63	45
Net (gain) loss on investment activity and other			(45)	(72)
Deferred income taxes			(6)	139
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Current and noncurrent receivables, net			152	(338)
Film and television costs, net			(75)	(600)
Accounts payable and accrued expenses related to trade creditors			(270)	(114)
Other operating assets and liabilities			46	(524)
Net cash provided by operating activities			$ 5,572	$ 3,339

Supplemental Financial Inform60

Supplemental Financial Information (Cash Payments for Interest and Income Taxes)(Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Cash Payments for Interest and Income Taxes
Interest	$ 905	$ 808	$ 2,277	$ 2,043
Income taxes	1,206	1,031	3,415	2,716
NBCUniversal Media LLC [Member]
Cash Payments for Interest and Income Taxes
Interest	53	69	340	354
Income taxes	$ 64	$ 33	$ 213	$ 155

Supplemental Financial Inform61

Supplemental Financial Information (Noncash Investing and Financing Activities)(Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)$ / shares
Supplemental Financial Information [Line Items]
Capital expenditures incurred but not yet paid	$ 1,400
Dividends payable	$ 736
Dividends payable (in dollars per share) | $ / shares	$ 0.1575
NBCUniversal Media LLC [Member]
Supplemental Financial Information [Line Items]
Capital expenditures incurred but not yet paid	$ 296

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Loss Contingencies [Line Items]
Charge related to a legal settlement	$ 250	$ 0	$ 250	$ 0
Settled Litigation [Member] | Sprint Communications Company L.P. Lawsuit [Member]
Loss Contingencies [Line Items]
Charge related to a legal settlement	250
Redeemable Preferred Stock [Member] | Level 2 [Member]
Temporary Equity [Line Items]
Fair Value of Redeemable subsidiary preferred stock	$ 756		$ 756

Financial Data by Business Se63

Financial Data by Business Segment (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)segment	Sep. 30, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			5
Financial Data by Business Segment
Revenue	$ 20,983	$ 21,319	$ 62,611	$ 59,378
Adjusted EBITDA	7,180	6,835	21,311	19,657
Depreciation, Amortization and Other	2,388	2,395	7,431	7,062
Operating income	4,792	4,440	13,880	12,595
Capital Expenditures	2,434	2,406	6,839	6,562
Cash Paid for Intangible Assets	404	426	1,240	1,163
Pretax gain, sale of business	105		105
Charge related to a legal settlement	250	0	$ 250	0
NBCUniversal Media LLC [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Financial Data by Business Segment
Revenue	8,014	9,178	$ 24,213	23,142
Adjusted EBITDA	2,274	2,146	6,362	5,457
Depreciation, Amortization and Other	169	445	1,197	1,324
Operating income	2,105	1,701	5,165	4,133
Capital Expenditures	354	336	977	991
Cash Paid for Intangible Assets	69	$ 67	197	$ 181
FCC Spectrum [Member]
Financial Data by Business Segment
Gain on sale of spectrum rights	337		337
FCC Spectrum [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Gain on sale of spectrum rights	$ 337		$ 337
Cable Communications [Member] | Residential Video Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	44.10%	44.50%	44.30%	44.90%
Cable Communications [Member] | Residential High-speed Internet Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	28.10%	27.10%	28.00%	27.00%
Cable Communications [Member] | Residential Voice Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	6.40%	7.00%	6.50%	7.20%
Cable Communications [Member] | Business Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	11.90%	11.10%	11.70%	10.90%
Cable Communications [Member] | Advertising Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	4.10%	5.00%	4.10%	4.70%
Cable Communications [Member] | Other Products And Services [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	5.40%	5.30%	5.40%	5.30%
NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	$ 8,014	$ 9,178	$ 24,213	$ 23,142
Adjusted EBITDA	2,274	2,146	6,362	5,457
Depreciation, Amortization and Other	169	445	1,197	1,324
Operating income	2,105	1,701	5,165	4,133
Capital Expenditures	354	336	977	991
Cash Paid for Intangible Assets	69	67	197	181
Operating Segments [Member] | Cable Communications [Member]
Financial Data by Business Segment
Revenue	13,203	12,557	39,237	37,205
Adjusted EBITDA	5,246	4,986	15,764	14,923
Depreciation, Amortization and Other	2,049	1,929	6,030	5,676
Operating income	3,197	3,057	9,734	9,247
Capital Expenditures	2,061	2,044	5,798	5,501
Cash Paid for Intangible Assets	$ 322	$ 352	$ 1,001	$ 965
Cable segment revenue types as percentage of total cable revenue	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Cable Communications [Member] | Franchise And Other Regulatory Fees [Member]
Financial Data by Business Segment
Cable segment revenue types as percentage of total cable revenue	2.70%	2.80%	2.80%	2.80%
Operating Segments [Member] | Cable Networks [Member]
Financial Data by Business Segment
Revenue	$ 2,603	$ 2,942	$ 7,940	$ 7,961
Adjusted EBITDA	905	893	3,076	2,793
Depreciation, Amortization and Other	179	184	574	561
Operating income	726	709	2,502	2,232
Capital Expenditures	5	7	15	15
Cash Paid for Intangible Assets	4	4	11	8
Operating Segments [Member] | Cable Networks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,603	2,942	7,940	7,961
Adjusted EBITDA	905	893	3,076	2,793
Depreciation, Amortization and Other	179	184	574	561
Operating income	726	709	2,502	2,232
Capital Expenditures	5	7	15	15
Cash Paid for Intangible Assets	4	4	11	8
Operating Segments [Member] | Broadcast Television [Member]
Financial Data by Business Segment
Revenue	2,133	3,087	6,582	7,299
Adjusted EBITDA	321	378	1,059	1,056
Depreciation, Amortization and Other	(305)	27	(242)	89
Operating income	626	351	1,301	967
Capital Expenditures	66	28	125	77
Cash Paid for Intangible Assets	4	6	11	12
Operating Segments [Member] | Broadcast Television [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	2,133	3,087	6,582	7,299
Adjusted EBITDA	321	378	1,059	1,056
Depreciation, Amortization and Other	(305)	27	(242)	89
Operating income	626	351	1,301	967
Capital Expenditures	66	28	125	77
Cash Paid for Intangible Assets	4	6	11	12
Operating Segments [Member] | Filmed Entertainment [Member]
Financial Data by Business Segment
Revenue	1,784	1,792	5,920	4,526
Adjusted EBITDA	394	353	1,047	576
Depreciation, Amortization and Other	32	13	79	33
Operating income	362	340	968	543
Capital Expenditures	18	6	47	14
Cash Paid for Intangible Assets	6	4	17	10
Operating Segments [Member] | Filmed Entertainment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,784	1,792	5,920	4,526
Adjusted EBITDA	394	353	1,047	576
Depreciation, Amortization and Other	32	13	79	33
Operating income	362	340	968	543
Capital Expenditures	18	6	47	14
Cash Paid for Intangible Assets	6	4	17	10
Operating Segments [Member] | Theme Parks [Member]
Financial Data by Business Segment
Revenue	1,550	1,440	3,982	3,602
Adjusted EBITDA	775	706	1,723	1,550
Depreciation, Amortization and Other	166	130	494	373
Operating income	609	576	1,229	1,177
Capital Expenditures	199	228	671	668
Cash Paid for Intangible Assets	18	19	57	48
Operating Segments [Member] | Theme Parks [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	1,550	1,440	3,982	3,602
Adjusted EBITDA	775	706	1,723	1,550
Depreciation, Amortization and Other	166	130	494	373
Operating income	609	576	1,229	1,177
Capital Expenditures	199	228	671	668
Cash Paid for Intangible Assets	18	19	57	48
Corporate, Non-Segment [Member]
Financial Data by Business Segment
Revenue	266	168	679	547
Adjusted EBITDA	(349)	(223)	(845)	(668)
Depreciation, Amortization and Other	170	21	204	62
Operating income	(519)	(244)	(1,049)	(730)
Capital Expenditures	19	26	64	70
Cash Paid for Intangible Assets	13	7	42	17
Corporate, Non-Segment [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	15	1	32	10
Adjusted EBITDA	(122)	(183)	(542)	(518)
Depreciation, Amortization and Other	97	91	292	268
Operating income	(219)	(274)	(834)	(786)
Capital Expenditures	66	67	119	217
Cash Paid for Intangible Assets	37	34	101	103
Corporate, Non-Segment [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	15	1	32	10
Adjusted EBITDA	(122)	(183)	(542)	(518)
Depreciation, Amortization and Other	97	91	292	268
Operating income	(219)	(274)	(834)	(786)
Capital Expenditures	66	67	119	217
Cash Paid for Intangible Assets	37	34	101	103
Eliminations [Member]
Financial Data by Business Segment
Revenue	(500)	(584)	(1,518)	(1,516)
Adjusted EBITDA	9	(74)	30	(55)
Depreciation, Amortization and Other	0	0	0	0
Operating income	9	(74)	30	(55)
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	0	0
Eliminations [Member] | NBCUniversal Media LLC [Member]
Financial Data by Business Segment
Revenue	(71)	(84)	(243)	(256)
Adjusted EBITDA	1	(1)	(1)	0
Depreciation, Amortization and Other	0	0	0	0
Operating income	1	(1)	(1)	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	0	0	0	0
Eliminations [Member] | NBCUniversal Segments [Member]
Financial Data by Business Segment
Revenue	(71)	(84)	(243)	(256)
Adjusted EBITDA	1	(1)	(1)	0
Depreciation, Amortization and Other	0	0	0	0
Operating income	1	(1)	(1)	0
Capital Expenditures	0	0	0	0
Cash Paid for Intangible Assets	$ 0	$ 0	$ 0	$ 0

Financial Data by Business Se64

Financial Data by Business Segment (Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	$ 7,180	$ 6,835	$ 21,311	$ 19,657
Adjustment for legal settlement	(250)	0	(250)	0
Depreciation	(1,991)	(1,865)	(5,876)	(5,518)
Amortization	(589)	(530)	(1,747)	(1,544)
Other operating gains	442	0	442	0
Operating costs and expenses	(696)	(716)	(1,980)	(1,978)
Income before income taxes	4,096	3,724	11,900	10,617
NBCUniversal Media LLC [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBITDA	2,274	2,146	6,362	5,457
Depreciation	(253)	(209)	(749)	(624)
Amortization	(253)	(236)	(785)	(700)
Other operating gains	337	0	337	0
Operating costs and expenses	(165)	(195)	(473)	(398)
Income before income taxes	$ 1,940	$ 1,506	$ 4,692	$ 3,735

Condensed Consolidating Finan65

Condensed Consolidating Financial Information (Narrative) (Details) - Sep. 30, 2017 $ in Millions	JPY (¥)	USD ($)
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 | ¥	¥ 450,000,000,000
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 Finan66

Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 4,114	$ 3,301	$ 2,807	$ 2,295
Receivables, net	7,915	7,955
Programming rights	1,779	1,250
Other current assets	2,152	3,855
Total current assets	15,960	16,361
Film and television costs	6,796	7,252
Investments	6,695	5,247
Investments in and amounts due from subsidiaries eliminated upon consolidation	0	0
Property and equipment, net	37,856	36,253
Franchise rights	59,364	59,364
Goodwill	36,752	35,980
Other intangible assets, net	18,733	17,274
Other noncurrent assets, net	3,145	2,769
Total assets	185,301	180,500
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	6,976	6,915
Accrued participations and residuals	1,811	1,726
Accrued expenses and other current liabilities	7,421	7,414
Current portion of long-term debt	5,241	5,480
Total current liabilities	21,449	21,535
Long-term debt, less current portion	59,720	55,566
Deferred income taxes	35,602	34,854
Other noncurrent liabilities	10,914	10,925
Redeemable noncontrolling interests	1,353	1,446
Equity:
Common stock	55	56
Other shareholders’ equity	55,372	53,887
Total Comcast Corporation shareholders’ equity	55,427	53,943
Noncontrolling interests	836	2,231
Total equity	56,263	56,174	55,823	53,978
Total liabilities and equity	185,301	180,500
Elimination and Consolidation Adjustments [Member]
Assets
Cash and cash equivalents	0	0	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	(519,515)	(481,214)
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	(1,055)	(1,017)
Total assets	(520,570)	(482,231)
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	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	(1,084)	(1,017)
Other noncurrent liabilities	29	0
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	(519,515)	(481,214)
Total Comcast Corporation shareholders’ equity	(519,515)	(481,214)
Noncontrolling interests	0	0
Total equity	(519,515)	(481,214)
Total liabilities and equity	(520,570)	(482,231)
Comcast Parent [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0	0	0
Receivables, net	0	0
Programming rights	0	0
Other current assets	65	151
Total current assets	65	151
Film and television costs	0	0
Investments	132	75
Investments in and amounts due from subsidiaries eliminated upon consolidation	102,930	98,350
Property and equipment, net	482	298
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	11	13
Other noncurrent assets, net	1,178	1,138
Total assets	104,798	100,025
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	17	23
Accrued participations and residuals	0	0
Accrued expenses and other current liabilities	1,640	1,726
Current portion of long-term debt	2,913	3,739
Total current liabilities	4,570	5,488
Long-term debt, less current portion	42,237	38,123
Deferred income taxes	0	0
Other noncurrent liabilities	2,564	2,471
Redeemable noncontrolling interests	0	0
Equity:
Common stock	55	56
Other shareholders’ equity	55,372	53,887
Total Comcast Corporation shareholders’ equity	55,427	53,943
Noncontrolling interests	0	0
Total equity	55,427	53,943
Total liabilities and equity	104,798	100,025
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	3,854	2,819	2,231	1,881
Receivables, net	7,915	7,955
Programming rights	1,779	1,250
Other current assets	2,057	3,668
Total current assets	15,605	15,692
Film and television costs	6,796	7,252
Investments	5,782	4,521
Investments in and amounts due from subsidiaries eliminated upon consolidation	111,087	97,704
Property and equipment, net	37,374	35,955
Franchise rights	59,364	59,364
Goodwill	36,752	35,980
Other intangible assets, net	18,722	17,261
Other noncurrent assets, net	2,249	1,921
Total assets	293,731	275,650
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	6,959	6,892
Accrued participations and residuals	1,811	1,726
Accrued expenses and other current liabilities	5,087	5,045
Current portion of long-term debt	2,324	1,187
Total current liabilities	16,181	14,850
Long-term debt, less current portion	7,040	6,994
Deferred income taxes	36,124	35,259
Other noncurrent liabilities	7,183	7,288
Redeemable noncontrolling interests	1,353	1,446
Equity:
Common stock	0	0
Other shareholders’ equity	225,014	207,582
Total Comcast Corporation shareholders’ equity	225,014	207,582
Noncontrolling interests	836	2,231
Total equity	225,850	209,813
Total liabilities and equity	293,731	275,650
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0	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	11	0
Investments in and amounts due from subsidiaries eliminated upon consolidation	128,663	120,071
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	687	638
Total assets	129,361	120,709
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Accrued expenses and other current liabilities	92	0
Current portion of long-term debt	0	0
Total current liabilities	92	0
Long-term debt, less current portion	139	141
Deferred income taxes	492	542
Other noncurrent liabilities	0	0
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	128,638	120,026
Total Comcast Corporation shareholders’ equity	128,638	120,026
Noncontrolling interests	0	0
Total equity	128,638	120,026
Total liabilities and equity	129,361	120,709
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	0	0	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	79	0
Investments in and amounts due from subsidiaries eliminated upon consolidation	126,361	117,696
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	126,440	117,696
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Accrued expenses and other current liabilities	208	341
Current portion of long-term debt	0	550
Total current liabilities	208	891
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	124,132	114,705
Total Comcast Corporation shareholders’ equity	124,132	114,705
Noncontrolling interests	0	0
Total equity	124,132	114,705
Total liabilities and equity	126,440	117,696
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	260	482	$ 576	$ 414
Receivables, net	0	0
Programming rights	0	0
Other current assets	30	36
Total current assets	290	518
Film and television costs	0	0
Investments	691	651
Investments in and amounts due from subsidiaries eliminated upon consolidation	50,474	47,393
Property and equipment, net	0	0
Franchise rights	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	86	89
Total assets	51,541	48,651
Liabilities and Equity
Accounts payable and accrued expenses related to trade creditors	0	0
Accrued participations and residuals	0	0
Accrued expenses and other current liabilities	394	302
Current portion of long-term debt	4	4
Total current liabilities	398	306
Long-term debt, less current portion	8,204	8,208
Deferred income taxes	70	70
Other noncurrent liabilities	1,138	1,166
Redeemable noncontrolling interests	0	0
Equity:
Common stock	0	0
Other shareholders’ equity	41,731	38,901
Total Comcast Corporation shareholders’ equity	41,731	38,901
Noncontrolling interests	0	0
Total equity	41,731	38,901
Total liabilities and equity	$ 51,541	$ 48,651

Condensed Consolidating Finan67

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue:
Service revenue	$ 20,983	$ 21,319	$ 62,611	$ 59,378
Management fee revenue	0	0	0	0
Revenue	20,983	21,319	62,611	59,378
Costs and Expenses:
Programming and production	6,077	7,003	18,492	17,926
Other operating and administrative	6,423	5,996	18,310	17,285
Advertising, marketing and promotion	1,553	1,485	4,748	4,510
Depreciation	1,991	1,865	5,876	5,518
Amortization	589	530	1,747	1,544
Other operating gains	(442)	0	(442)	0
Total costs and expenses	16,191	16,879	48,731	46,783
Operating income	4,792	4,440	13,880	12,595
Other Income (Expense):
Interest expense	(766)	(751)	(2,279)	(2,186)
Investment income (loss), net	82	80	205	168
Equity in net income (losses) of investees, net	(39)	(34)	12	(64)
Other income (expense), net	27	(11)	82	104
Total other income (expense)	(696)	(716)	(1,980)	(1,978)
Income before income taxes	4,096	3,724	11,900	10,617
Income tax expense	(1,413)	(1,400)	(4,035)	(3,989)
Net income	2,683	2,324	7,865	6,628
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	(33)	(87)	(136)	(229)
Net income attributable to Comcast Corporation	2,650	2,237	7,729	6,399
Comprehensive income (loss) attributable to Comcast Corporation	2,603	2,270	7,818	6,607
Elimination and Consolidation Adjustments [Member]
Revenue:
Service revenue	0	0	0	0
Management fee revenue	(565)	(531)	(1,668)	(1,571)
Revenue	(565)	(531)	(1,668)	(1,571)
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	(565)	(531)	(1,668)	(1,571)
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	(565)	(531)	(1,668)	(1,571)
Operating income	0	0	0	0
Other Income (Expense):
Interest expense	0	0	0	0
Investment income (loss), net	0	0	0	0
Equity in net income (losses) of investees, net	(11,465)	(9,971)	(32,731)	(27,991)
Other income (expense), net	0	0	0	0
Total other income (expense)	(11,465)	(9,971)	(32,731)	(27,991)
Income before income taxes	(11,465)	(9,971)	(32,731)	(27,991)
Income tax expense	0	0	0	0
Net income	(11,465)	(9,971)	(32,731)	(27,991)
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	(11,465)	(9,971)	(32,731)	(27,991)
Comprehensive income (loss) attributable to Comcast Corporation	(11,240)	(10,029)	(32,573)	(28,962)
Comcast Parent [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0	0	0
Management fee revenue	285	268	841	793
Revenue	285	268	841	793
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	183	194	553	635
Advertising, marketing and promotion	0	0	0	0
Depreciation	7	7	21	21
Amortization	1	1	4	4
Other operating gains	0	0	0	0
Total costs and expenses	191	202	578	660
Operating income	94	66	263	133
Other Income (Expense):
Interest expense	(544)	(502)	(1,592)	(1,431)
Investment income (loss), net	(2)	3	(1)	6
Equity in net income (losses) of investees, net	2,944	2,519	8,594	7,239
Other income (expense), net	0	0	0	0
Total other income (expense)	2,398	2,020	7,001	5,814
Income before income taxes	2,492	2,086	7,264	5,947
Income tax expense	158	151	465	452
Net income	2,650	2,237	7,729	6,399
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	2,650	2,237	7,729	6,399
Comprehensive income (loss) attributable to Comcast Corporation	2,603	2,270	7,818	6,607
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	20,983	21,319	62,611	59,378
Management fee revenue	0	0	0	0
Revenue	20,983	21,319	62,611	59,378
Costs and Expenses:
Programming and production	6,077	7,003	18,492	17,926
Other operating and administrative	6,248	5,848	17,754	16,704
Advertising, marketing and promotion	1,553	1,485	4,748	4,510
Depreciation	1,984	1,858	5,855	5,497
Amortization	588	529	1,743	1,540
Other operating gains	(442)	0	(442)	0
Total costs and expenses	16,008	16,723	48,150	46,177
Operating income	4,975	4,596	14,461	13,201
Other Income (Expense):
Interest expense	(55)	(74)	(175)	(225)
Investment income (loss), net	61	93	151	185
Equity in net income (losses) of investees, net	1,786	1,255	4,313	3,160
Other income (expense), net	15	(9)	24	(11)
Total other income (expense)	1,807	1,265	4,313	3,109
Income before income taxes	6,782	5,861	18,774	16,310
Income tax expense	(1,572)	(1,568)	(4,513)	(4,489)
Net income	5,210	4,293	14,261	11,821
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	(33)	(87)	(136)	(229)
Net income attributable to Comcast Corporation	5,177	4,206	14,125	11,592
Comprehensive income (loss) attributable to Comcast Corporation	5,049	4,235	13,998	12,134
Comcast Holdings [Member] | Subsidiary Issuer [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0	0	0
Management fee revenue	0	0	0	0
Revenue	0	0	0	0
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	0	0	0	0
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	0	0	0	0
Operating income	0	0	0	0
Other Income (Expense):
Interest expense	(3)	(3)	(9)	(9)
Investment income (loss), net	32	(4)	84	(3)
Equity in net income (losses) of investees, net	2,483	2,385	7,746	6,924
Other income (expense), net	0	0	0	0
Total other income (expense)	2,512	2,378	7,821	6,912
Income before income taxes	2,512	2,378	7,821	6,912
Income tax expense	(10)	2	(26)	4
Net income	2,502	2,380	7,795	6,916
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	2,502	2,380	7,795	6,916
Comprehensive income (loss) attributable to Comcast Corporation	2,486	2,388	7,793	7,015
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0	0	0
Management fee revenue	280	263	827	778
Revenue	280	263	827	778
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	280	263	827	778
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	280	263	827	778
Operating income	0	0	0	0
Other Income (Expense):
Interest expense	(48)	(59)	(159)	(179)
Investment income (loss), net	0	0	0	0
Equity in net income (losses) of investees, net	1,992	2,134	6,613	6,375
Other income (expense), net	0	0	0	0
Total other income (expense)	1,944	2,075	6,454	6,196
Income before income taxes	1,944	2,075	6,454	6,196
Income tax expense	17	21	56	63
Net income	1,961	2,096	6,510	6,259
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	1,961	2,096	6,510	6,259
Comprehensive income (loss) attributable to Comcast Corporation	1,965	2,096	6,516	6,261
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenue:
Service revenue	0	0	0	0
Management fee revenue	0	0	0	0
Revenue	0	0	0	0
Costs and Expenses:
Programming and production	0	0	0	0
Other operating and administrative	277	222	844	739
Advertising, marketing and promotion	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Other operating gains	0	0	0	0
Total costs and expenses	277	222	844	739
Operating income	(277)	(222)	(844)	(739)
Other Income (Expense):
Interest expense	(116)	(113)	(344)	(342)
Investment income (loss), net	(9)	(12)	(29)	(20)
Equity in net income (losses) of investees, net	2,221	1,644	5,477	4,229
Other income (expense), net	12	(2)	58	115
Total other income (expense)	2,108	1,517	5,162	3,982
Income before income taxes	1,831	1,295	4,318	3,243
Income tax expense	(6)	(6)	(17)	(19)
Net income	1,825	1,289	4,301	3,224
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	0	0	0	0
Net income attributable to Comcast Corporation	1,825	1,289	4,301	3,224
Comprehensive income (loss) attributable to Comcast Corporation	$ 1,740	$ 1,310	$ 4,266	$ 3,552

Condensed Consolidating Finan68

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			$ 15,961	$ 13,989
Investing Activities
Net transactions with affiliates			0	0
Capital expenditures	$ (2,434)	$ (2,406)	(6,839)	(6,562)
Cash paid for intangible assets	(404)	(426)	(1,240)	(1,163)
Acquisitions and construction of real estate properties			(325)	(303)
Acquisitions, net of cash acquired			(429)	(3,904)
Proceeds from sales of investments			120	188
Purchases of investments			(2,064)	(618)
Deposits			0	(1,748)
Other			750	(42)
Net cash provided by (used in) investing activities			(10,027)	(14,152)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			(2,807)	610
Proceeds from borrowings			11,460	9,231
Repurchases and repayments of debt			(5,021)	(2,994)
Repurchases of common stock under repurchase program and employee plans			(4,212)	(4,061)
Dividends paid			(2,147)	(1,944)
Purchase of Universal Studios Japan noncontrolling interests			(2,299)	0
Issuances of common stock			0	23
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			(198)	(194)
Other			103	4
Net cash provided by (used in) financing activities			(5,121)	675
Increase (decrease) in cash and cash equivalents			813	512
Cash and cash equivalents, beginning of period			3,301	2,295
Cash and cash equivalents, end of period	4,114	2,807	4,114	2,807
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
Deposits			0	0
Other			0	0
Net cash provided by (used in) investing activities			0	0
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			0	0
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests			0
Issuances of common stock			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 and cash equivalents			0	0
Cash and cash equivalents, beginning of period			0	0
Cash and cash equivalents, end of period	0	0	0	0
Comcast Parent [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(931)	(637)
Investing Activities
Net transactions with affiliates			4,216	(1,746)
Capital expenditures			(6)	(9)
Cash paid for intangible assets			(2)	(4)
Acquisitions and construction of real estate properties			(190)	(2)
Acquisitions, net of cash acquired			0	0
Proceeds from sales of investments			0	0
Purchases of investments			(56)	(23)
Deposits			0	0
Other			101	(108)
Net cash provided by (used in) investing activities			4,063	(1,892)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			(1,739)	105
Proceeds from borrowings			5,997	9,231
Repurchases and repayments of debt			(1,000)	(750)
Repurchases of common stock under repurchase program and employee plans			(4,212)	(4,061)
Dividends paid			(2,147)	(1,944)
Purchase of Universal Studios Japan noncontrolling interests			0
Issuances of common stock			0	23
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			(31)	(75)
Net cash provided by (used in) financing activities			(3,132)	2,529
Increase (decrease) in cash and cash equivalents			0	0
Cash and cash equivalents, beginning of period			0	0
Cash and cash equivalents, end of period	0	0	0	0
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			18,088	15,873
Investing Activities
Net transactions with affiliates			(5,776)	(583)
Capital expenditures			(6,833)	(6,553)
Cash paid for intangible assets			(1,238)	(1,159)
Acquisitions and construction of real estate properties			(135)	(301)
Acquisitions, net of cash acquired			(429)	(3,904)
Proceeds from sales of investments			110	84
Purchases of investments			(1,916)	(586)
Deposits			0	(1,748)
Other			600	101
Net cash provided by (used in) investing activities			(15,617)	(14,649)
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			(1,068)	505
Proceeds from borrowings			5,463	0
Repurchases and repayments of debt			(3,468)	(1,239)
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests			(2,299)
Issuances of common stock			0	0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			(198)	(194)
Other			134	54
Net cash provided by (used in) financing activities			(1,436)	(874)
Increase (decrease) in cash and cash equivalents			1,035	350
Cash and cash equivalents, beginning of period			2,819	1,881
Cash and cash equivalents, end of period	3,854	2,231	3,854	2,231
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			91	0
Investing Activities
Net transactions with affiliates			(91)	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
Deposits			0	0
Other			0	0
Net cash provided by (used in) investing activities			(91)	0
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			0	0
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests			0
Issuances of common stock			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 and cash equivalents			0	0
Cash and cash equivalents, beginning of period			0	0
Cash and cash equivalents, end of period	0	0	0	0
CCCL Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(233)	(179)
Investing Activities
Net transactions with affiliates			818	179
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			(35)	0
Deposits			0	0
Other			0	0
Net cash provided by (used in) investing activities			783	179
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			(550)	0
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests			0
Issuances of common stock			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			(550)	0
Increase (decrease) in cash and cash equivalents			0	0
Cash and cash equivalents, beginning of period			0	0
Cash and cash equivalents, end of period	0	0	0	0
NBCUniversal Media Parent [Member] | Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by operating activities			(1,054)	(1,068)
Investing Activities
Net transactions with affiliates			833	2,150
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			10	104
Purchases of investments			(57)	(9)
Deposits			0	0
Other			49	(35)
Net cash provided by (used in) investing activities			835	2,210
Financing Activities
Proceeds from (repayments of) short-term borrowings, net			0	0
Proceeds from borrowings			0	0
Repurchases and repayments of debt			(3)	(1,005)
Repurchases of common stock under repurchase program and employee plans			0	0
Dividends paid			0	0
Purchase of Universal Studios Japan noncontrolling interests			0
Issuances of common stock			0	0
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock			0	0
Other			0	25
Net cash provided by (used in) financing activities			(3)	(980)
Increase (decrease) in cash and cash equivalents			(222)	162
Cash and cash equivalents, beginning of period			482	414
Cash and cash equivalents, end of period	$ 260	$ 576	$ 260	$ 576