Comcast (CMCSA) 10-Q 30 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Trading Symbol	cmcsa
Entity Registrant Name	COMCAST CORP
Entity Central Index Key	1166691
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Class A Common Stock [Member]
Entity Common Stock, Shares Outstanding	2,136,124,018
ClassA Special Common Stock [Member]
Entity Common Stock, Shares Outstanding	469,858,896
Class B Common Stock [Member]
Entity Common Stock, Shares Outstanding	9,444,375

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheet (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets
Cash and cash equivalents	$1,603	$10,951
Investments [Current]	4,132	1,464
Receivables, net	5,501	5,521
Programming rights	959	909
Other current assets	1,212	1,146
Total current assets	13,407	19,991
Film and television costs	4,588	5,054
Investments	3,672	6,325
Property and equipment, net	28,806	27,232
Franchise rights	59,364	59,364
Goodwill	27,079	26,985
Other intangible assets, net	17,334	17,840
Other noncurrent assets, net	2,345	2,180
Total assets	156,595	164,971
Current Liabilities:
Accounts payable and accrued expenses related to trade creditors	6,032	6,206
Accrued participations and residuals	1,372	1,350
Deferred revenue	1,001	851
Accrued expenses and other current liabilities	7,924	5,931
Current portion of long-term debt	2,337	2,376
Total current liabilities	18,666	16,714
Long-term debt, less current portion	44,188	38,082
Deferred income taxes	31,261	30,110
Other noncurrent liabilities	11,493	13,271
Commitments and contingencies (Note 14)
Redeemable noncontrolling interests and redeemable subsidiary preferred stock	853	16,998
Equity:
Preferred stock - authorized, 20,000,000 shares; issued, zero	0	0
Common stock	30	31
Additional paid-in capital	38,991	40,547
Retained earnings	18,324	16,280
Treasury stock, 365,460,750 Class A common shares and 70,934,764 Class A Special common shares	-7,517	-7,517
Accumulated other comprehensive income (loss)	-110	15
Total Comcast Corporation shareholders' equity	49,718	49,356
Noncontrolling interests	416	440
Total equity	50,134	49,796
Total liabilities and equity	156,595	164,971
Class A Common Stock [Member]
Equity:
Common stock	25	25
Class B Common Stock [Member]
Equity:
Common stock	0	0
ClassA Special Common Stock [Member]
Equity:
Common stock	$5	$6

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheet (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Preferred stock, authorized	20,000,000	20,000,000
Preferred stock, issued	0	0
Accumulated depreciation	$41,816	$39,425
Accumulated amortization	$8,570	$7,662
Class A Common Stock [Member]
Common stock, par value	$0.01	$0.01
Common stock, authorized	7,500,000,000	7,500,000,000
Common stock, issued	2,501,584,768	2,487,739,385
Common stock, outstanding	2,136,124,018	2,122,278,635
Treasury stock common shares	365,460,750	365,460,750
ClassA Special Common Stock [Member]
Common stock, par value	$0.01	$0.01
Common stock, authorized	7,500,000,000	7,500,000,000
Common stock, issued	540,793,660	578,704,227
Common stock, outstanding	469,858,896	507,769,463
Treasury stock common shares	70,934,764	70,934,764
Class B Common Stock [Member]
Common stock, par value	$0.01	$0.01
Common stock, authorized	75,000,000	75,000,000
Common stock, issued	9,444,375	9,444,375
Common stock, outstanding	9,444,375	9,444,375

Condensed_Consolidated_Stateme

Condensed Consolidated Statement of Income (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$16,151	$16,544	$47,731	$46,633
Costs and Expenses:
Programming and production	4,787	5,726	14,418	15,013
Other operating and administrative	4,751	4,580	13,787	13,190
Advertising, marketing and promotion	1,283	1,230	3,737	3,730
Depreciation	1,520	1,549	4,669	4,594
Amortization	396	411	1,204	1,221
Total costs and expenses	12,737	13,496	37,815	37,748
Operating income	3,414	3,048	9,916	8,885
Other Income (Expense):
Interest expense	-639	-633	-1,928	-1,898
Investment income (loss), net	464	70	549	170
Equity in net income (losses) of investees, net	-130	911	-96	943
Other income (expense), net	-310	987	-280	924
Nonoperating income (expense)	-615	1,335	-1,755	139
Income before income taxes	2,799	4,383	8,161	9,024
Income tax expense	-1,021	-1,405	-2,994	-2,966
Net income	1,778	2,978	5,167	6,058
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	-46	-865	-264	-1,373
Net income attributable to Comcast Corporation	$1,732	$2,113	$4,903	$4,685
Basic earnings per common share attributable to Comcast Corporation shareholders	$0.66	$0.79	$1.86	$1.74
Diluted earnings per common share attributable to Comcast Corporation shareholders	$0.65	$0.78	$1.84	$1.72
Dividends declared per common share attributable to Comcast Corporation shareholders	$0.20	$0.16	$0.59	$0.49

Condensed_Consolidated_Stateme1

Condensed Consolidated Statement of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$1,778	$2,978	$5,167	$6,058
Unrealized gains (losses) on marketable securities, net of deferred taxes	19	75	136	75
Deferred gains (losses) on cash flow hedges, net of deferred taxes	45	50	10	35
Realized (gains) losses on marketable securities, net of deferred taxes	-278		-301
Realized (gains) losses on cash flow hedges, net of deferred taxes	-38	-15	10	-14
Employee benefit obligations, net of deferred taxes	57	11	60	6
Currency translation adjustments, net of deferred taxes	8	17	-23	10
Comprehensive income	1,591	3,116	5,059	6,170
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	-46	-865	-264	-1,373
Other comprehensive (income) loss attributable to noncontrolling interests		-16	9	-8
Comprehensive income attributable to Comcast Corporation	$1,545	$2,235	$4,804	$4,789

Condensed_Consolidated_Stateme2

Condensed Consolidated Statement of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Unrealized gains (losses) on marketable securities, deferred taxes	($11)	($44)	($82)	($44)
Deferred gains (losses) on cash flow hedges, deferred taxes	-26	-29	-6	-20
Realized (gains) losses on marketable securities, deferred taxes	165	0	177	0
Realized (gains) losses on cash flow hedges, deferred taxes	22	9	-6	8
Employee benefit obligations, deferred taxes	-34	-3	-36	-2
Currency translation adjustments, deferred taxes	($5)	($4)	$9	($2)

Condensed_Consolidated_Stateme3

Condensed Consolidated Statement of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities
Net cash provided by (used in) operating activities	$11,679	$11,239
Investing Activities
Capital expenditures	-4,593	-4,043
Cash paid for intangible assets	-694	-605
Acquisitions of real estate properties	-1,705
Acquisitions, net of cash acquired	-42	-95
Proceeds from sales of businesses and investments	655	3,095
Return of capital from investees	146	2,281
Purchases of investments	-1,177	-191
Other	83	68
Net cash provided by (used in) investing activities	-7,327	510
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	395	-555
Proceeds from borrowings	2,933	2,248
Repurchases and repayments of debt	-2,442	-2,505
Repurchases and retirements of common stock	-1,500	-2,250
Dividends paid	-1,454	-1,176
Issuances of common stock	35	215
Purchase of NBCUniversal noncontrolling common equity interest	-10,761
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	-164	-497
Settlement of Station Venture liability	-602
Other	-140	50
Net cash provided by (used in) financing activities	-13,700	-4,470
Increase (decrease) in cash and cash equivalents	-9,348	7,279
Cash and cash equivalents, beginning of period	10,951	1,620
Cash and cash equivalents, end of period	$1,603	$8,899

Condensed_Consolidated_Stateme4

Condensed Consolidated Statement of Changes in Equity (USD $)	Total	Redeemable Noncontrolling Interests And Redeemable Subisdiary Preferred Stock [Member]	Class A Common Stock [Member]	ClassA Special Common Stock [Member]	Class B Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock at Cost [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
In Millions
Beginning Balance at Dec. 31, 2011	$47,655	$16,014	$25	$7	$0	$40,940	$13,971	($7,517)	($152)	$381
Stock compensation plans	321					490	-169
Repurchase and retirements of common stock	-2,250			-1		-842	-1,407
Employee stock purchase plans	62					62
Dividends declared	-1,306						-1,306
Other comprehensive income (loss)	104	8							104
Contributions from (distributions to) noncontrolling interests, net	-119	-353								-119
Other	86	-43				2				84
Net income (loss)	4,788	1,270					4,685			103
Ending Balance at Sep. 30, 2012	49,341	16,896	25	6	0	40,652	15,774	-7,517	-48	449
Beginning Balance at Dec. 31, 2012	49,796	16,998	25	6	0	40,547	16,280	-7,517	15	440
Stock compensation plans	178					433	-255
Repurchase and retirements of common stock	-1,500			-1		-432	-1,067
Employee stock purchase plans	75					75
Dividends declared	-1,537						-1,537
Other comprehensive income (loss)	-99	-9							-99
Purchase of NBCUniversal noncontrolling common equity interest	-1,508	-17,006				-1,482			-26
Redeemable subsidiary preferred stock		725
Contributions from (distributions to) noncontrolling interests, net	-103	-14								-103
Other	-152	-24				-150				-2
Net income (loss)	4,984	183					4,903			81
Ending Balance at Sep. 30, 2013	$50,134	$853	$25	$5	$0	$38,991	$18,324	($7,517)	($110)	$416

Condensed_Consolidated_Financi

Condensed Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2013
Condensed Consolidated Financial Statements	Note 1: Condensed Consolidated Financial Statements
	Basis of Presentation
	We have prepared these unaudited condensed consolidated financial statements based on Securities and Exchange Commission (“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 filed with the SEC on Form 8-K on September 18, 2013.
	Reclassifications have been made to our condensed consolidated financial statements for the prior year periods to conform to classifications used in the current year periods.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share	Note 2: Earnings Per Share
	Computation of Diluted EPS
			Three Months Ended September 30
				2013					2012
	(in millions, except per share data)			Net Income Attributable to Comcast Corporation	Shares		Per Share Amount		Net Income Attributable to Comcast Corporation	Shares		Per Share Amount
	Basic EPS attributable to Comcast Corporation shareholders		$	1,732	2,622	$	0.66	$	2,113	2,668	$	0.79
	Effect of dilutive securities:
	Assumed exercise or issuance of shares relating to stock
		plans			36					35
	Diluted EPS attributable to Comcast Corporation
		shareholders	$	1,732	2,658	$	0.65	$	2,113	2,703	$	0.78
			Nine Months Ended September 30
				2013					2012
	(in millions, except per share data)			Net Income Attributable to Comcast Corporation	Shares		Per Share Amount		Net Income Attributable to Comcast Corporation	Shares		Per Share Amount
	Basic EPS attributable to Comcast Corporation shareholders		$	4,903	2,629	$	1.86	$	4,685	2,687	$	1.74
	Effect of dilutive securities:
	Assumed exercise or issuance of shares relating to stock
		plans			39					37
	Diluted EPS attributable to Comcast Corporation
		shareholders	$	4,903	2,668	$	1.84	$	4,685	2,724	$	1.72
	Our potentially dilutive securities include potential common shares related to our stock options and our restricted share units (“RSUs”). Diluted earnings per common share attributable to Comcast Corporation shareholders (“diluted EPS”) considers the impact of potentially dilutive securities using the treasury stock method. Diluted EPS excludes the impact of potential common shares related to our stock options in periods in which the option exercise price is greater than the average market price of our Class A common stock or our Class A Special common stock, as applicable.
	Diluted EPS for the three and nine months ended September 30, 2013 excludes 18 million and 13 million, respectively, of potential common shares related to our share-based compensation plans, because the inclusion of the potential common shares would have had an antidilutive effect. For the three and nine months ended September 30, 2012, diluted EPS excluded 21 million and 37 million, respectively, of potential common shares.

Significant_Transactions

Significant Transactions	9 Months Ended
	Sep. 30, 2013
Significant Transactions	Note 3: Significant Transactions
	Redemption Transaction
	On March 19, 2013, we acquired GE's remaining 49% common equity interest in NBCUniversal Holdings for approximately $16.7 billion (the “Redemption Transaction”). In addition to this transaction, NBCUniversal purchased from GE certain properties NBCUniversal occupies at 30 Rockefeller Plaza in New York City and CNBC's headquarters in Englewood Cliffs, New Jersey for approximately $1.4 billion.
	The total consideration for these transactions consisted of $11.4 billion of cash on hand; $4 billion of senior debt securities issued by NBCUniversal Enterprise, Inc. (“NBCUniversal Enterprise”), a holding company whose principal assets are its interests in NBCUniversal Holdings; $750 million of cash funded through our commercial paper program; $1.25 billion of borrowings under NBCUniversal Enterprise's credit facility, which replaced NBCUniversal's credit facility; and $725 million aggregate liquidation preference of Series A cumulative preferred stock of NBCUniversal Enterprise. See Note 7 for additional information on NBCUniversal Enterprise's senior debt securities and credit facility.
	Following the close of the Redemption Transaction, we control and consolidate NBCUniversal Enterprise and own all of its capital stock other than its preferred stock. NBCUniversal Enterprise's senior debt securities and credit facility are guaranteed by us and four of our wholly owned cable holding company subsidiaries, but are not guaranteed by NBCUniversal. In March 2013, NBCUniversal became a part of our existing cross-guarantee structure. See Note 16 for additional information on our cross-guarantee structure.
	After the close of the transaction, GE sold the interests in NBCUniversal Enterprise's senior debt securities and preferred stock it acquired in the Redemption Transaction to unaffiliated third parties. The preferred stock pays dividends at a fixed rate of 5.25% per annum and the holders have the right to cause NBCUniversal Enterprise to redeem their shares at a price equal to the liquidation preference plus accrued but unpaid dividends for a 30 day period beginning on March 19, 2020 and thereafter on every third anniversary of such date (each such date, a “put date”). Shares of preferred stock can be called for redemption by NBCUniversal Enterprise at a price equal to the liquidation preference plus accrued but unpaid dividends one year following each put date applicable to such shares. Because certain of these redemption provisions are outside of our control, the NBCUniversal Enterprise preferred stock is presented outside of equity under the caption “redeemable noncontrolling interests and redeemable subsidiary preferred stock” in our condensed consolidated balance sheet. Its initial value was based on the liquidation preference of the preferred stock and is adjusted for accrued but unpaid dividends.
	We recognized an increase to our deferred tax liabilities of $1.5 billion primarily due to an increase in our financial reporting basis in the consolidated net assets of NBCUniversal Holdings in excess of the tax basis following the Redemption Transaction. In addition, our condensed consolidated balance sheet now includes certain tax liabilities of NBCUniversal Enterprise related to periods prior to our acquisition of the common stock of NBCUniversal Enterprise for which we have been indemnified by GE and have recorded a related indemnification asset. We also expect to realize additional tax benefits in the future as a result of the Redemption Transaction, which are expected to increase the amounts we have agreed to share with GE. Our expected future payments to GE are accounted for as contingent consideration. See Note 8 for additional information on the fair value of this contingent consideration as of September 30, 2013.
	Because we maintained control of NBCUniversal Holdings, the difference between the consideration transferred and the recorded value of GE's 49% redeemable noncontrolling common equity interest, and the related tax impacts, were recorded to additional paid-in capital. The related tax impacts are preliminary and subject to change as we obtain the information necessary to complete our analysis.

Film_and_Television_Costs

Film and Television Costs	9 Months Ended
	Sep. 30, 2013
Film And Television Costs Disclosure [Text Block]	Note 4: Film and Television Costs
				September 30,		December 31,
	(in millions)			2013		2012
	Film Costs:
		Released, less amortization	$	1,439	$	1,472
		Completed, not released		189		99
		In production and in development		394		1,048
				2,022		2,619
	Television Costs:
		Released, less amortization		1,144		1,124
		In production and in development		321		334
				1,465		1,458
	Programming rights, less amortization			2,060		1,886
				5,547		5,963
	Less: Current portion of programming rights			959		909
	Film and television costs		$	4,588	$	5,054

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments	Note 5: Investments
				September 30,		December 31,
	(in millions)			2013		2012
	Fair Value Method		$	4,790	$	4,493
	Equity Method:
		The Weather Channel		331		471
		Other		709		693
				1,040		1,164
	Cost Method:
		AirTouch		1,549		1,538
		Other		425		594
				1,974		2,132
	Total investments			7,804		7,789
	Less: Current investments			4,132		1,464
	Noncurrent investments		$	3,672	$	6,325
	Investment Income (Loss), Net
			Three Months Ended				Nine Months Ended
			30-Sep				30-Sep
	(in millions)		2013		2012		2013		2012
	Gains on sales and exchanges of investments, net		$	445	$	1	$	483	$	28
	Investment impairment losses			-12		-1		-25		-22
	Unrealized gains (losses) on securities underlying prepaid
		forward sale agreements		345		500		1,197		988
	Mark to market adjustments on derivative component of prepaid
		forward sale agreements and indexed debt instruments		-348		-470		-1,189		-920
	Interest and dividend income			28		32		84		89
	Other, net			6		8		-1		7
	Investment income (loss), net		$	464	$	70	$	549	$	170
	Fair Value Method
	As of September 30, 2013, the majority of our fair value method investments were equity securities held as collateral that were related to our obligations under prepaid forward sale agreements.
	Prepaid Forward Sale Agreements
			September 30,		December 31,
	(in millions)		2013		2012
	Assets:
		Fair value equity securities held as collateral	$	3,555	$	4,143
	Liabilities:
		Obligations under prepaid forward sale agreements	$	799	$	1,248
		Derivative component of prepaid forward sale agreements		2,397		2,302
	Total liabilities		$	3,196	$	3,550
	During the nine months ended September 30, 2013, we purchased a total of $653 million of equity securities classified as trading securities and held as collateral under our prepaid forward sale agreements. We also settled obligations under certain of our prepaid forward sale agreements totaling $1.6 billion with a combination of cash on hand and $1.4 billion of equity securities. As of September 30, 2013, our remaining prepaid forward sale obligations had an estimated fair value of $3.2 billion. The estimated fair values are based on Level 2 inputs using 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.
	Liberty Media
	In October 2013, Liberty Media Corporation (“Liberty Media”) redeemed 6.3 million shares of Liberty Media Series A common stock (“Liberty stock”) that had been held by us as collateral as of December 31, 2012 under certain of our prepaid forward sale agreements in exchange for all of the equity of a subsidiary of Liberty Media. As of September 30, 2013, the fair value of the Liberty stock was $925 million. The assets of the subsidiary of Liberty Media included cash of $417 million, Liberty Media's interests in one of NBCUniversal's contractual obligations and a wholly owned operating subsidiary, Leisure Arts, Inc. As of September 30, 2013, a liability of $383 million associated with NBCUniversal's contractual obligation was included in our condensed consolidated balance sheet. Following the close of this transaction, we now consolidate the subsidiary transferred to us and the liability associated with NBCUniversal's contractual obligation is eliminated in consolidation.
	Clearwire
	In July 2013, in connection with Sprint's acquisition of Clearwire Corporation (“Clearwire”), Sprint acquired our investment of 89 million Class A shares of Clearwire for $443 million. As of the date of the acquisition by Sprint, we recognized a pretax gain of $443 million in our condensed consolidated statement of income, which represented the recognition of cumulative unrealized gains previously recorded in accumulated other comprehensive income.
	Equity Method
	In June 2013, NBCUniversal received a distribution from The Weather Channel Holding Corp. (“The Weather Channel”) of $152 million, of which $128 million was recorded as a return of its investment in The Weather Channel and is included under the caption “return of capital from investees” in our condensed consolidated statement of cash flows.
	Cost Method
	AirTouch
	We hold two series of preferred stock of AirTouch Communications, Inc. (“AirTouch”), a subsidiary of Vodafone, which are redeemable in April 2020. As of September 30, 2013, the estimated fair values of the AirTouch preferred stock and the associated liability related to the redeemable preferred shares issued by one of our consolidated subsidiaries were each $1.7 billion. The estimated fair values are based on Level 2 inputs using 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.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2013
Goodwill	Note 6: Goodwill
				NBCUniversal
	(in millions)		Cable Communications		Cable Networks		Broadcast Television		Filmed Entertainment		Theme Parks		Corporate and Other		Total
	Balance, December 31, 2012	$	12,206	$	13,026	$	761	$	1	$	982	$	9	$	26,985
	Acquisitions		-		17		1		-		-		-		18
	Adjustments		-		69		6		-		-		1		76
	Balance, September 30, 2013	$	12,206	$	13,112	$	768	$	1	$	982	$	10	$	27,079
	Adjustments to goodwill during the nine months ended September 30, 2013 were primarily related to an immaterial correction to the allocation of purchase price associated with the January 2011 NBCUniversal transaction, which was recorded in the second quarter of 2013.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Long-Term Debt	Note 7: Long-Term Debt
	Long-Term Debt Outstanding
		Weighted-Average Interest		September 30,		December 31,
	(in millions)	Rate as of September 30, 2013		2013		2012
	Commercial paper	0.29	%	$	400	$	-
	Revolving credit facilities	1.252	%		1,250		-
	Senior notes with maturities of 5 years or less	4.711	%		15,111		12,991
	Senior notes with maturities between 6 and 10 years	4.558	%		11,534		10,334
	Senior notes with maturities greater than 10 years	5.979	%		17,985		16,801
	Other, including capital lease obligations	–			245		332
	Total debt	4.86	%(a)		46,525		40,458
	Less: Current portion				2,337		2,376
	Long-term debt			$	44,188	$	38,082
	(a) Includes the effects of our derivative financial instruments.
	As of September 30, 2013, our debt had an estimated fair value of $51.1 billion. The estimated fair value of our publicly traded debt is based on quoted market values for the debt. To estimate the fair value of debt for which there are no quoted market prices, we use interest rates available to us for debt with similar terms and remaining maturities.
	Redemption Transaction
	The Redemption Transaction resulted in the consolidation of an additional $4 billion aggregate principal amount of senior notes issued by NBCUniversal Enterprise and $1.25 billion of borrowings under the NBCUniversal Enterprise credit facility. The total consideration for the Redemption Transaction also included $750 million of cash funded through our commercial paper program.
	The NBCUniversal Enterprise senior notes are comprised of $1.1 billion aggregate principal amount of 1.662% senior notes due 2018, $1.5 billion aggregate principal amount of 1.974% senior notes due 2019, $700 million aggregate principal amount of floating rate senior notes due 2016 and $700 million aggregate principal amount of floating rate senior notes due 2018. The floating rate senior notes due 2016 and 2018 accrue interest for each quarterly interest period at a rate equal to the three-month London Interbank Offered Rate (“LIBOR”) plus 0.537% and 0.685%, respectively.
	On March 19, 2013, NBCUniversal Enterprise amended and restated the existing credit agreement of NBCUniversal to, among other things, substitute NBCUniversal Enterprise for NBCUniversal as the sole borrower, reduce the borrowing capacity of the facility from $1.5 billion to $1.35 billion, extend the term of the facility to March 2018 and revise the interest rate on borrowings. The interest rate on the credit facility consists of a base rate plus a borrowing margin that is determined based on our credit rating. As of September 30, 2013, the interest rate was 1.252%.
	Debt Borrowings
	In January 2013, we issued $750 million aggregate principal amount of 2.850% senior notes due 2023, $1.7 billion aggregate principal amount of 4.250% senior notes due 2033 and $500 million aggregate principal amount of 4.500% senior notes due 2043.
	Commercial Paper Program
	During the nine months ended September 30, 2013, borrowings, net of repayments of commercial paper under our commercial paper program, were $400 million. Following the amendments to the NBCUniversal credit agreement, NBCUniversal's commercial paper program was terminated.
	Revolving Credit Facilities
	As of September 30, 2013, amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper program and undrawn letters of credit, totaled $5.7 billion, which included $100 million available under NBCUniversal Enterprise's credit facility.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	Note 8: Fair Value Measurements
	The accounting guidance related to financial assets and financial liabilities (“financial instruments”) establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques (market approach, income approach and cost approach). Level 1 consists of financial instruments whose values are based on quoted market prices for identical financial instruments in an active market. Level 2 consists of financial instruments that are valued using models or other valuation methodologies. These models use inputs that are observable either directly or indirectly. Level 3 consists of financial instruments whose values are determined using pricing models that use significant inputs that are primarily unobservable, discounted cash flow methodologies or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Our financial instruments that are accounted for at fair value on a recurring basis are presented in the table below.
	Recurring Fair Value Measures
			Fair Value as of
			30-Sep-13								31-Dec-12
	(in millions)			Level 1		Level 2		Level 3		Total		Total
	Assets
	Trading securities		$	4,477	$	-	$	-	$	4,477	$	4,027
	Available-for-sale securities			183		118		12		313		464
	Interest rate swap agreements			-		137		-		137		210
	Other			-		59		-		59		38
	Total		$	4,660	$	314	$	12	$	4,986	$	4,739
	Liabilities
	Derivative component of prepaid forward sale agreements
		and indexed debt instruments	$	-	$	2,402	$	-	$	2,402	$	2,305
	Contractual obligations			-		-		1,130		1,130		1,055
	Contingent consideration			-		-		682		682		587
	Other			-		116		-		116		14
	Total		$	-	$	2,518	$	1,812	$	4,330	$	3,961
	Contractual Obligations and Contingent Consideration
	The fair values of the contractual obligations and contingent consideration in the table above are primarily based on certain expected future discounted cash flows, the determination of which involves the use of significant unobservable inputs. The most significant unobservable inputs we use are our estimates of the future revenue we expect to generate from certain NBCUniversal entities, which are related to our contractual obligations, and future net tax benefits that will affect payments to GE, which are related to contingent consideration. The discount rates used in the measurements of fair value were between 5% and 14% and are based on the underlying risk associated with our estimate of future revenue, as well as the terms of the respective contracts, and the uncertainty in the timing of our payments to GE. The fair value adjustments to contractual obligations and contingent consideration are sensitive to the assumptions related to future revenue and tax benefits, respectively, as well as to current interest rates, and therefore, the adjustments are recorded to other income (expense), net in our condensed consolidated statement of income.
	Changes in Contractual Obligations and Contingent Consideration
	(in millions)		Contractual Obligations		Contingent Consideration
	Balance, December 31, 2012	$	1,055	$	587
	Fair value adjustments		141		25
	Payments		-66		-101
	Redemption Transaction		-		171
	Balance, September 30, 2013	$	1,130	$	682
	Nonrecurring Fair Value Measures
	We have assets and liabilities that we are required to record at fair value on a nonrecurring basis when certain circumstances occur. In the case of film or stage play production costs, upon the occurrence of an event or change in circumstance that may indicate that the fair value of a production is less than its unamortized costs, we determine the fair value of the production and record an adjustment for the amount by which the unamortized capitalized costs exceed the production's fair value. The estimate of the fair value of a production is determined using Level 3 inputs, primarily an analysis of future expected cash flows. Adjustments to capitalized film production costs of $150 million and $155 million were recorded during the nine months ended September 30, 2013 and 2012, respectively.

Noncontrolling_Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interests	Note 9: Noncontrolling Interests
	Certain of the subsidiaries that we consolidate are not wholly owned. Some of the agreements with the minority partners of these subsidiaries contain redemption features whereby interests held by the minority partners are redeemable either (i) at the option of the holder or (ii) upon the occurrence of an event that is not solely within our control. If interests were to be redeemed under these agreements, we would generally be required to purchase the interest at fair value on the date of redemption. These interests are presented on the balance sheet outside of equity as a component of the caption “redeemable noncontrolling interests and redeemable subsidiary preferred stock.” Noncontrolling interests and subsidiary preferred stock that do not contain such redemption features are presented in equity.
	We acquired GE's remaining 49% common equity interest in NBCUniversal Holdings, which had previously been presented as a redeemable noncontrolling interest in our condensed consolidated balance sheet. See Note 3 for additional information on the Redemption Transaction. The difference between the consideration transferred and the recorded value of GE's 49% redeemable noncontrolling common equity interest, as well as the related tax impacts, were recorded to additional paid-in capital. The table below includes the impact of the Redemption Transaction on our changes in equity.
	Changes in Equity
				Nine Months Ended
				30-Sep
	(in millions)			2013		2012
	Net income attributable to Comcast Corporation			$	4,903	$	4,685
	Transfers from (to) noncontrolling interests:
		Decrease in Comcast Corporation additional paid-in capital resulting from the
			purchase of GE’s redeemable noncontrolling common equity interest		-1,482		-
		Other			-26		2
	Changes in equity resulting from net income attributable to Comcast Corporation
		and transfers from (to) noncontrolling interests		$	3,395	$	4,687

Pension_Plans_and_Postretireme

Pension Plans and Postretirement Benefits	9 Months Ended
	Sep. 30, 2013
Pension Plans and Postretirement Benefits	Note 10: Pension Plans
	In August 2013, we settled all of our obligations related to the termination in February 2012 of the qualified pension plan that provided benefits to former AT&T Broadband employees. In connection with this final settlement, we fully funded the plan with additional contributions of $55 million and recorded an expense of $74 million in other operating and administrative expenses, which was previously recorded in accumulated other comprehensive income.

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2013
Share-Based Compensation	Note 11: Share-Based Compensation
	Our share-based compensation primarily consists of awards of stock options and RSUs to certain employees and directors and is awarded as part of our approach to long-term incentive compensation. Additionally, through our employee stock purchase plans, employees are able to purchase shares of Comcast Class A common stock at a discount through payroll deductions.
	In March 2013, we granted 18.4 million stock options and 5.2 million RSUs related to our annual management awards. The weighted-average fair values associated with these grants were $8.80 per stock option and $37.85 per RSU.
	Recognized Share-Based Compensation Expense
		Three Months Ended				Nine Months Ended
		30-Sep				30-Sep
	(in millions)	2013		2012		2013		2012
	Stock options	$	34	$	32	$	102	$	99
	Restricted share units		44		38		130		114
	Employee stock purchase plans		4		4		15		12
	Total	$	82	$	74	$	247	$	225
	As of September 30, 2013, we had unrecognized pretax compensation expense of $351 million and $414 million related to nonvested stock options and nonvested RSUs, respectively.

Supplemental_Financial_Informa

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2013
Supplemental Financial Information	Note 12: Supplemental Financial Information
	Receivables
		September 30,		December 31,
	(in millions)	2013		2012
	Receivables, gross	$	5,964	$	6,026
	Less: Allowance for returns and customer incentives		249		307
	Less: Allowance for doubtful accounts		214		198
	Receivables, net	$	5,501	$	5,521
	Accumulated Other Comprehensive Income (Loss)
			September 30,		September 30,
	(in millions)		2013		2012
	Unrealized gains (losses) on marketable securities		$	18	$	97
	Deferred gains (losses) on cash flow hedges			-47		-90
	Unrecognized gains (losses) on employee benefit obligations			-50		-54
	Cumulative translation adjustments			-31		-1
	Accumulated other comprehensive income (loss), net of deferred taxes		$	-110	$	-48
	Net Cash Provided by Operating Activities
					Nine Months Ended
					30-Sep
	(in millions)				2013		2012
	Net income				$	5,167	$	6,058
	Adjustments to reconcile net income to net cash provided by operating activities:
		Depreciation and amortization				5,873		5,815
		Amortization of film and television costs				5,998		7,295
		Share-based compensation				312		278
		Noncash interest expense (income), net				122		158
		Equity in net (income) losses of investees, net				96		-943
		Cash received from investees				89		178
		Net (gain) loss on investment activity and other				-239		-1,071
		Deferred income taxes				-52		321
	Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
		Change in current and noncurrent receivables, net				145		-865
		Change in film and television costs				-5,590		-7,290
		Change in accounts payable and accrued expenses related to trade creditors				-108		553
		Change in other operating assets and liabilities				-134		752
	Net cash provided by operating activities				$	11,679	$	11,239
	Cash Payments for Interest and Income Taxes
		Three Months Ended					Nine Months Ended
		30-Sep					30-Sep
	(in millions)		2013		2012			2013		2012
	Interest	$	636	$	567		$	1,768	$	1,725
	Income taxes	$	958	$	833		$	3,180	$	1,855
	Noncash Investing and Financing Activities
	During the nine months ended September 30, 2013:
	• we acquired GE's remaining 49% common equity interest in NBCUniversal Holdings for total consideration of $16.7 billion, which included noncash consideration of $6 billion from the consolidation of NBCUniversal Enterprise that was comprised of $4 billion aggregate principal amount of senior notes, $1.25 billion of borrowings under its credit facility and $725 million aggregate liquidation preference of its Series A cumulative preferred stock (see Note 3 for additional information on the Redemption Transaction)
	• we acquired $807 million of property and equipment and intangible assets that were accrued but unpaid
	• we recorded a liability of $510 million for a quarterly cash dividend of $0.195 per common share paid in October 2013
	•we used $1.4 billion of equity securities to settle a portion of our obligations under prepaid forward sale agreements

Receivables_Monetization

Receivables Monetization	9 Months Ended
	Sep. 30, 2013
Receivables Monetization	Note 13: Receivables Monetization
	NBCUniversal monetizes certain of its accounts receivable under programs with a syndicate of banks. We account for receivables monetized through these programs as sales in accordance with the appropriate accounting guidance. We receive deferred consideration from the assets sold in the form of a receivable, which is funded by residual cash flows after the senior interests have been fully paid. The deferred consideration is included in receivables, net at its initial fair value, which reflects the net cash flows we expect to receive related to these interests. The accounts receivable we sold that underlie the deferred consideration are generally short-term in nature and, therefore, the fair value of the deferred consideration approximated its carrying value as of September 30, 2013 and December 31, 2012.
	NBCUniversal is responsible for servicing the receivables and remitting collections to the purchasers under the monetization programs. NBCUniversal performs this service for a fee that is equal to the prevailing market rate for such services. As a result, no servicing asset or liability has been recorded on our condensed consolidated balance sheet as of September 30, 2013 and December 31, 2012. The servicing fees are recorded as a component of other income (expense), net.
	The net cash payments on transfers that are included within net cash provided by operating activities in our condensed consolidated statement of cash flows were $367 million for the nine months ended September 30, 2013. The net cash proceeds on transfers that are included within net cash provided by operating activities in our condensed consolidated statement of cash flows were $70 million for the nine months ended September 30, 2012. The receivables monetization program did not have a material effect on our condensed consolidated statement of income for the periods presented.
	Receivables Monetized and Deferred Consideration
		September 30,		December 31,
	(in millions)	2013		2012
	Monetized receivables sold	$	642	$	791
	Deferred consideration	$	217	$	274
	In addition to the amounts presented above, we had $616 million and $882 million payable to our monetization programs as of September 30, 2013 and December 31, 2012, respectively. These amounts represent cash receipts that were not yet remitted to the monetization programs as of the balance sheet date and are recorded to accounts payable and accrued expenses related to trade creditors

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies	Note 14: Commitments and Contingencies
	Commitments
	Station Venture
	NBCUniversal previously held an equity interest in Station Venture Holdings, LLC (“Station Venture”), a nonconsolidated variable interest entity, and the remaining equity interests in Station Venture were held by LIN TV, Corp. Station Venture was the obligor on an $816 million senior secured note (the “Station Venture note”) that was due in 2023 to General Electric Capital Corporation (“GECC”) as servicer. The Station Venture note, among other things, was collateralized by substantially all of the assets of Station Venture and Station Venture Operations, LP (“Station LP”). Station LP was a less than wholly owned consolidated subsidiary of NBCUniversal. In connection with the acquisition of our controlling interest in NBCUniversal Holdings on January 28, 2011, a liability of $482 million was recorded to noncurrent liabilities in our allocation of purchase price, which represented the fair value of the net assets of Station LP. In February 2013, we closed our agreement with GE, GECC and LIN TV under which, among other things, NBCUniversal purchased the Station Venture note from GECC for $602 million, which represented the agreed upon fair value of the assets of Station LP. As of the closing date of the transaction, the $482 million recorded liability was effectively settled, and Station Venture and Station LP became wholly owned subsidiaries of NBCUniversal. We now consolidate Station Venture, and the Station Venture note is eliminated in consolidation. Due to the related party nature of this transaction, the excess of the purchase price of the Station Venture note over the recorded amount of the liability was recorded to additional paid-in capital.
	Contingencies
	Antitrust Cases
	We are defendants in two purported class actions originally filed in December 2003 in the United States District Courts for the District of Massachusetts and the Eastern District of Pennsylvania. The potential class in the Massachusetts case, which has been transferred to the Eastern District of Pennsylvania, is our customer base in the “Boston Cluster” area, and the potential class in the Pennsylvania case is our customer base in the “Philadelphia and Chicago Clusters,” as those terms are defined in the complaints. In each case, the plaintiffs allege that certain customer exchange transactions with other cable providers resulted in unlawful horizontal market restraints in those areas and seek damages under antitrust statutes, including treble damages.
	Classes of Chicago Cluster and Philadelphia Cluster customers were certified in October 2007 and January 2010, respectively. We appealed the class certification in the Philadelphia Cluster case to the Third Circuit Court of Appeals, which affirmed the class certification in August 2011 and denied our petition for a rehearing en banc in September 2011. In March 2010, we moved for summary judgment dismissing all of the plaintiffs' claims in the Philadelphia Cluster. In April 2012, the District Court issued a decision dismissing some of the plaintiffs' claims, but allowing two claims to proceed to trial. The plaintiffs' claims concerning the other two clusters are stayed pending determination of the Philadelphia Cluster claims. In June 2012, the U.S. Supreme Court granted our petition to review the Third Circuit Court of Appeals' ruling and in September 2012, the trial court stayed all proceedings pending resolution of the Supreme Court appeal. In March 2013, the Supreme Court ruled that the class had been improperly certified and reversed the judgment of the Third Circuit. The matter has been returned to the District Court for action consistent with the Supreme Court's opinion. In August 2013, a plaintiff in the Philadelphia Cluster case moved to certify a new class, and in September 2013, we moved to strike that motion on procedural grounds.
	In addition, we are the defendant in 22 purported class actions filed in federal district courts throughout the country. All of these actions have been consolidated by the Judicial Panel on Multidistrict Litigation in the United States District Court for the Eastern District of Pennsylvania for pre-trial proceedings. In a consolidated complaint filed in November 2009 on behalf of all plaintiffs in the multidistrict litigation, the plaintiffs allege that we improperly “tie” the rental of set-top boxes to the provision of premium cable services in violation of Section 1 of the Sherman Antitrust Act, various state antitrust laws and unfair/deceptive trade practices acts in California, Illinois and Alabama. The plaintiffs also allege a claim for unjust enrichment and seek relief on behalf of a nationwide class of our premium cable customers and on behalf of subclasses consisting of premium cable customers from California, Alabama, Illinois, Pennsylvania and Washington. In January 2010, we moved to compel arbitration of the plaintiffs' claims for unjust enrichment and violations of the unfair/deceptive trade practices acts of Illinois and Alabama. In September 2010, the plaintiffs filed an amended complaint alleging violations of additional state antitrust laws and unfair/deceptive trade practices acts on behalf of new subclasses in Connecticut, Florida, Minnesota, Missouri, New Jersey, New Mexico and West Virginia. In the amended complaint, plaintiffs omitted their unjust enrichment claim, as well as their state law claims on behalf of the Alabama, Illinois and Pennsylvania subclasses. In June 2011, the plaintiffs filed another amended complaint alleging only violations of Section 1 of the Sherman Antitrust Act, antitrust law in Washington and unfair/deceptive trade practices acts in California and Washington. The plaintiffs seek relief on behalf of a nationwide class of our premium cable customers and on behalf of subclasses consisting of premium cable customers from California and Washington. In July 2011, we moved to compel arbitration of most of the plaintiffs' claims and to stay the remaining claims pending arbitration. The West Virginia Attorney General also filed a complaint in West Virginia state court in July 2009 alleging that we improperly “tie” the rental of set-top boxes to the provision of digital cable services in violation of the West Virginia Antitrust Act and the West Virginia Consumer Credit and Protection Act. The Attorney General also alleges a claim for unjust enrichment/restitution. We removed the case to the United States District Court for West Virginia, and it was subsequently transferred to the United States District Court for the Eastern District of Pennsylvania and consolidated with the multidistrict litigation described above. In June 2013, a comprehensive settlement agreement for all 23 cases was submitted to the District Court for preliminary approval. Regardless of whether this settlement agreement is approved, we do not expect these cases to have a material effect on our results of operations, cash flows or financial position.
	We believe the claims in each of the pending actions described above in this item are without merit and intend to defend the actions vigorously. We cannot predict the outcome of any of the actions described above, including a range of possible loss, or how the final resolution of any such actions would impact our results of operations or cash flows for any one period or our financial position. In addition, as any action nears a trial, there is an increased possibility that the action may be settled by the parties. Nevertheless, the final disposition of any of the above actions is not expected to have a material adverse effect on our consolidated financial position, but could possibly be material to our consolidated results of operations or cash flows for any one period.
	Other
	We are a defendant in several unrelated lawsuits claiming infringement of various patents relating to various aspects of our businesses. In certain of these cases other industry participants are also defendants, and also in certain of these cases we expect that any potential liability would be in part or in whole the responsibility of our equipment and technology vendors under applicable contractual indemnification provisions. We are also 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, costly and injure our reputation.

Financial_Data_by_Business_Seg

Financial Data by Business Segment	9 Months Ended
	Sep. 30, 2013
Financial Data by Business Segment	Note 15: 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 the nation's largest provider of video, high-speed Internet and voice services (“cable services”) to residential customers under the XFINITY brand, and we also provide these services to businesses and sell advertising.
	• Cable Networks: Consists primarily of our national cable networks, our regional sports and news networks, our international cable networks, our cable television production operations, and our related digital media properties.
	• Broadcast Television: Consists primarily of the NBC and Telemundo broadcast networks, our NBC and Telemundo owned local broadcast television stations, our broadcast television production operations, and our related digital media properties.
	• Filmed Entertainment: Consists primarily of the operations of Universal Pictures, which produces, acquires, markets and distributes filmed entertainment worldwide.
	• Theme Parks: Consists primarily of our Universal theme parks in Orlando and Hollywood.
	In evaluating the profitability of our operating segments, the components of net income (loss) below operating income (loss) before depreciation and amortization are not separately evaluated by our management. Our financial data by business segment is presented in the tables below.
			Three Months Ended September 30, 2013
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	10,491	$	4,246	$	1,549	$	2,697	$	1,432
	NBCUniversal
		Cable Networks		2,239		853		183		670		19
		Broadcast Television		1,644		34		23		11		21
		Filmed Entertainment		1,400		189		4		185		1
		Theme Parks		661		343		73		270		142
		Headquarters and Other(b)		7		-167		69		-236		101
		Eliminations(c)		-100		-2		-		-2		-
	NBCUniversal			5,851		1,250		352		898		284
	Corporate and Other			133		-178		16		-194		10
	Eliminations(c)			-324		12		-1		13		-
	Comcast Consolidated		$	16,151	$	5,330	$	1,916	$	3,414	$	1,726
			Three Months Ended September 30, 2012
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	9,976	$	3,998	$	1,607	$	2,391	$	1,364
	NBCUniversal
		Cable Networks		2,152		809		190		619		56
		Broadcast Television		2,790		88		25		63		17
		Filmed Entertainment		1,355		72		4		68		-
		Theme Parks		614		316		65		251		55
		Headquarters and Other(b)		8		-143		53		-196		81
		Eliminations(c)		-97		-2		-		-2		-
	NBCUniversal			6,822		1,140		337		803		209
	Corporate and Other			112		-101		14		-115		9
	Eliminations(c)			-366		-29		2		-31		-
	Comcast Consolidated		$	16,544	$	5,008	$	1,960	$	3,048	$	1,582
			Nine Months Ended September 30, 2013
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	31,175	$	12,800	$	4,780	$	8,020	$	3,766
	NBCUniversal
		Cable Networks		6,877		2,572		549		2,023		67
		Broadcast Television		4,893		205		74		131		38
		Filmed Entertainment		4,004		291		11		280		4
		Theme Parks		1,669		747		218		529		427
		Headquarters and Other(b)		25		-416		193		-609		271
		Eliminations(c)		-282		-5		-		-5		-
	NBCUniversal			17,186		3,394		1,045		2,349		807
	Corporate and Other			431		-380		48		-428		20
	Eliminations(c)			-1,061		-25		-		-25		-
	Comcast Consolidated		$	47,731	$	15,789	$	5,873	$	9,916	$	4,593
			Nine Months Ended September 30, 2012
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	29,472	$	12,054	$	4,802	$	7,252	$	3,544
	NBCUniversal
		Cable Networks		6,520		2,408		548		1,860		87
		Broadcast Television		6,203		268		70		198		36
		Filmed Entertainment		3,778		-5		12		-17		4
		Theme Parks		1,565		708		190		518		154
		Headquarters and Other(b)		31		-444		149		-593		195
		Eliminations(c)		-299		-		-		-		-
	NBCUniversal			17,798		2,935		969		1,966		476
	Corporate and Other			416		-255		44		-299		23
	Eliminations(c)			-1,053		-34		-		-34		-
	Comcast Consolidated		$	46,633	$	14,700	$	5,815	$	8,885	$	4,043
(a) For the three and nine months ended September 30, 2013 and 2012, Cable Communications segment revenue was derived from the following sources:
		Three Months Ended				Nine Months Ended
		30-Sep				30-Sep
		2013		2012		2013		2012
Residential:
	Video	48.9	%	49.9	%	49.4	%	50.7	%
	High-speed Internet	24.7	%	24.1	%	24.6	%	24.1	%
	Voice	8.8	%	9	%	8.8	%	9	%
Business services		8	%	6.6	%	7.6	%	6.3	%
Advertising		5.2	%	6.1	%	5.1	%	5.5	%
Other		4.4	%	4.3	%	4.5	%	4.4	%
Total		100	%	100	%	100	%	100	%
Subscription revenue received from customers who purchase bundled services at a discounted rate is allocated proportionally to each service based on the individual service's price on a stand-alone basis. Beginning in 2013, revenue from certain business customers, such as hotels, restaurants and bars, is presented in the business services revenue line item rather than in video revenue. Reclassifications have been made to the prior year periods to conform to this presentation.
For both the three and nine months ended September 30, 2013, 2.9% of Cable Communications revenue was derived from franchise and other regulatory fees. For both the three and nine months ended September 30, 2012, 2.8% of Cable Communications revenue was derived from franchise and other regulatory fees.
NBCUniversal Headquarters and Other activities included costs associated with overhead, personnel costs and headquarter initiatives.
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 and Broadcast Television segments generate revenue by selling programming to our Cable Communications segment, which represents the substantial majority of the transactions among our segments
• 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 by licensing content to our Cable Networks segment
• our Cable Communications segment receives incentives offered by our Cable Networks segment in connection with its distribution of the Cable Networks' content that are recorded as a reduction to programming expenses
No single customer accounted for a significant amount of revenue in any period.
We use operating income (loss) before depreciation and amortization, excluding impairment charges related to fixed and intangible assets and gains or losses from the sale of assets, if any, as the measure of profit or loss for our operating segments. 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 structure or 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) attributable to Comcast Corporation, net cash provided by operating activities, or other measures of performance or liquidity we have reported in accordance with GAAP.

Condensed_Consolidating_Financ

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2013
Condensed Consolidating Financial Information	Note 16: Condensed Consolidating Financial Information
	Comcast Corporation (“Comcast Parent”) and four of our wholly owned cable holding company subsidiaries, Comcast Cable Communications, LLC (“CCCL Parent”), Comcast MO Group, Inc. (“Comcast MO Group”), Comcast Cable Holdings, LLC (“CCH”) and Comcast MO of Delaware, LLC (“Comcast MO of Delaware”) (collectively, the “cable guarantors”), have fully and unconditionally guaranteed each other's debt securities. Comcast MO Group, CCH and Comcast MO of Delaware are collectively referred to as the “Combined CCHMO Parents.”
	On March 27, 2013, Comcast Parent, the cable guarantors and NBCUniversal Media, LLC (referred to as “NBCUniversal Media Parent” in the tables below) entered into a series of agreements and supplemental indentures to include NBCUniversal Media, LLC as part of our existing cross-guarantee structure. As members of the cross-guarantee structure, Comcast Parent and the cable guarantors fully and unconditionally guarantee NBCUniversal Media, LLC's public debt securities, and NBCUniversal Media, LLC fully and unconditionally guarantees all of Comcast Parent's and the cable guarantors' public debt securities, as well as the $6.25 billion revolving credit facility of Comcast Parent and Comcast Cable Communications, LLC.
	Comcast Parent and the cable guarantors also fully and unconditionally guarantee NBCUniversal Enterprise's $4 billion of senior notes and its $1.35 billion credit facility due March 2018. NBCUniversal Media, LLC does not guarantee the NBCUniversal Enterprise senior notes or credit facility.
	Comcast Parent provides an unconditional subordinated guarantee of the $185 million principal amount currently outstanding of Comcast Holdings' ZONES due October 2029. Neither the cable guarantors nor NBCUniversal Media, LLC guarantee the Comcast Holdings ZONES due October 2029. None of Comcast Parent, the cable guarantors nor NBCUniversal Media, LLC guarantee the $62 million principal amount currently outstanding of Comcast Holdings' ZONES due November 2029.
	Condensed Consolidating Balance Sheet
	30-Sep-13
	(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
	Assets
		Cash and cash equivalents	$	-	$	-	$	-	$	-	$	240	$	1,363	$	-	$	1,603
		Investments		-		-		-		-		-		4,132		-		4,132
		Receivables, net		-		-		-		-		-		5,501		-		5,501
		Programming rights		-		-		-		-		-		959		-		959
		Other current assets		203		-		-		-		45		964		-		1,212
	Total current assets			203		-		-		-		285		12,919		-		13,407
	Film and television costs			-		-		-		-		-		4,588		-		4,588
	Investments			8		-		-		-		374		3,290		-		3,672
	Investments in and amounts due from subsidiaries eliminated upon consolidation			78,024		95,366		100,411		53,230		40,496		82,558		-450,085		-
	Property and equipment, net			223		-		-		-		-		28,583		-		28,806
	Franchise rights			-		-		-		-		-		59,364		-		59,364
	Goodwill			-		-		-		-		-		27,079		-		27,079
	Other intangible assets, net			9		-		-		-		-		17,325		-		17,334
	Other noncurrent assets, net			1,095		145		-		-		118		1,881		-894		2,345
	Total assets		$	79,562	$	95,511	$	100,411	$	53,230	$	41,273	$	237,587	$	-450,979	$	156,595
	Liabilities and Equity
		Accounts payable and accrued expenses related to  trade creditors	$	7	$	-	$	-	$	-	$	-	$	6,025	$	-	$	6,032
		Accrued participations and residuals		-		-		-		-		-		1,372		-		1,372
		Accrued expenses and other current liabilities		1,232		266		301		21		385		6,720		-		8,925
		Current portion of long-term debt		1,411		-		-		-		904		22		-		2,337
	Total current liabilities			2,650		266		301		21		1,289		14,139		-		18,666
	Long-term debt, less current portion			25,163		119		1,827		1,507		10,239		5,333		-		44,188
	Deferred income taxes			-		774		-		-		74		31,166		-753		31,261
	Other noncurrent liabilities			2,031		-		-		-		989		8,614		-141		11,493
	Redeemable noncontrolling interests and redeemable subsidiary preferred stock			-		-		-		-		-		853		-		853
	Equity:
		Common stock		30		-		-		-		-		-		-		30
		Other shareholders’ equity		49,688		94,352		98,283		51,702		28,682		177,066		-450,085		49,688
	Total Comcast Corporation
		shareholders’ equity		49,718		94,352		98,283		51,702		28,682		177,066		-450,085		49,718
	Noncontrolling interests			-		-		-		-		-		416		-		416
	Total equity			49,718		94,352		98,283		51,702		28,682		177,482		-450,085		50,134
	Total liabilities and equity		$	79,562	$	95,511	$	100,411	$	53,230	$	41,273	$	237,587	$	-450,979	$	156,595
	Condensed Consolidating Balance Sheet
	31-Dec-12
	(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
	Assets
		Cash and cash equivalents	$	-	$	-	$	-	$	-	$	5,129	$	5,822	$	-	$	10,951
		Investments		-		-		-		-		-		1,464		-		1,464
		Receivables, net		-		-		-		-		3		5,518		-		5,521
		Programming rights		-		-		-		-		-		909		-		909
		Other current assets		233		-		14		4		51		844		-		1,146
	Total current assets			233		-		14		4		5,183		14,557		-		19,991
	Film and television costs			-		-		-		-		-		5,054		-		5,054
	Investments			-		-		-		-		529		5,796		-		6,325
	Investments in and amounts due from subsidiaries eliminated upon consolidation			74,227		87,630		96,853		50,242		38,464		73,298		-420,714		-
	Property and equipment, net			242		-		-		-		-		26,990		-		27,232
	Franchise rights			-		-		-		-		-		59,364		-		59,364
	Goodwill			-		-		-		-		-		26,985		-		26,985
	Other intangible assets, net			12		-		-		-		-		17,828		-		17,840
	Other noncurrent assets, net			1,130		147		1		-		152		1,650		-900		2,180
	Total assets		$	75,844	$	87,777	$	96,868	$	50,246	$	44,328	$	231,522	$	-421,614	$	164,971
	Liabilities and Equity
		Accounts payable and accrued expenses related to trade creditors	$	8	$	-	$	-	$	-	$	-	$	6,198	$	-	$	6,206
		Accrued participations and residuals		-		-		-		-		-		1,350		-		1,350
	Accrued expenses and other current liabilities		1,290		275		210		54		263		4,690		-		6,782
	Current portion of long-term debt		-		-		2,105		241		7		23		-		2,376
Total current liabilities			1,298		275		2,315		295		270		12,261		-		16,714
Long-term debt, less current portion			23,306		113		1,827		1,512		11,219		105		-		38,082
Deferred income taxes			-		754		-		-		78		30,035		-757		30,110
Other noncurrent liabilities			1,884		-		-		-		926		10,604		-143		13,271
Redeemable noncontrolling interests and redeemable subsidiary preferred stock			-		-		-		-		-		16,998		-		16,998
Equity:
	Common stock		31		-		-		-		-		-		-		31
	Other shareholders’ equity		49,325		86,635		92,726		48,439		31,835		161,079		-420,714		49,325
Total Comcast Corporation shareholders’ equity			49,356		86,635		92,726		48,439		31,835		161,079		-420,714		49,356
Noncontrolling interests			-		-		-		-		-		440		-		440
Total equity			49,356		86,635		92,726		48,439		31,835		161,519		-420,714		49,796
Total liabilities and equity		$	75,844	$	87,777	$	96,868	$	50,246	$	44,328	$	231,522	$	-421,614	$	164,971
Condensed Consolidating Statement of Income
For the Three Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	16,151	$	-	$	16,151
	Management fee revenue		225		-		219		137		-		-		-581		-
			225		-		219		137		-		16,151		-581		16,151
Costs and Expenses:
	Programming and production		-		-		-		-		-		4,787		-		4,787
	Other operating and administrative		92		-		219		137		211		4,673		-581		4,751
	Advertising, marketing and promotion		-		-		-		-		-		1,283		-		1,283
	Depreciation		7		-		-		-		-		1,513		-		1,520
	Amortization		1		-		-		-		-		395		-		396
			100		-		219		137		211		12,651		-581		12,737
Operating income (loss)			125		-		-		-		-211		3,500		-		3,414
Other Income (Expense):
	Interest expense		-382		-3		-45		-30		-123		-56		-		-639
	Investment income (loss), net		1		-5		-		-		-3		471		-		464
	Equity in net income
	(losses) of investees, net		1,898		1,787		1,850		1,371		576		106		-7,718		-130
	Other income (expense), net		-		-		-		-		-		-310		-		-310
			1,517		1,779		1,805		1,341		450		211		-7,718		-615
Income (loss) before income taxes			1,642		1,779		1,805		1,341		239		3,711		-7,718		2,799
Income tax (expense) benefit			90		3		15		11		-3		-1,137		-		-1,021
Net income (loss)			1,732		1,782		1,820		1,352		236		2,574		-7,718		1,778
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-46		-		-46
Net income (loss) attributable
	to Comcast Corporation	$	1,732	$	1,782	$	1,820	$	1,352	$	236	$	2,528	$	-7,718	$	1,732
Comprehensive income (loss)
	attributable to Comcast Corporation	$	1,545	$	1,828	$	1,864	$	1,415	$	244	$	2,327	$	-7,678	$	1,545
Condensed Consolidating Statement of Income
For the Three Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	16,544	$	-	$	16,544
	Management fee revenue		211		-		205		129		-		-		-545		-
			211		-		205		129		-		16,544		-545		16,544
Costs and Expenses:
	Programming and production		-		-		-		-		-		5,726		-		5,726
	Other operating and administrative		99		-		205		129		211		4,481		-545		4,580
	Advertising, marketing and promotion		-		-		-		-		-		1,230		-		1,230
	Depreciation		8		-		-		-		-		1,541		-		1,549
	Amortization		1		-		-		-		-		410		-		411
			108		-		205		129		211		13,388		-545		13,496
Operating income (loss)			103		-		-		-		-211		3,156		-		3,048
Other Income (Expense):
	Interest expense		-363		-4		-81		-33		-102		-50		-		-633
	Investment income (loss), net		1		-3		-		-		2		70		-		70
	Equity in net income (losses) of
	investees, net		2,281		2,047		1,641		1,216		1,988		2,583		-10,845		911
	Other income (expense), net		-		-		-		-		-1		988		-		987
			1,919		2,040		1,560		1,183		1,887		3,591		-10,845		1,335
Income (loss) before income taxes			2,022		2,040		1,560		1,183		1,676		6,747		-10,845		4,383
Income tax (expense) benefit			91		3		28		12		-4		-1,535		-		-1,405
Net income (loss)			2,113		2,043		1,588		1,195		1,672		5,212		-10,845		2,978
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-865		-		-865
Net (income) loss
	attributable to Comcast Corporation	$	2,113	$	2,043	$	1,588	$	1,195	$	1,672	$	4,347	$	-10,845	$	2,113
Comprehensive
	income (loss) attributable to Comcast Corporation	$	2,235	$	2,043	$	1,591	$	1,195	$	1,706	$	4,398	$	-10,933	$	2,235
Condensed Consolidating Statement of Income
For the Nine Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	47,731	$	-	$	47,731
	Management fee revenue		668		-		650		407		-		-		-1,725		-
			668		-		650		407		-		47,731		-1,725		47,731
Costs and Expenses:
	Programming and production		-		-		-		-		-		14,418		-		14,418
	Other operating and administrative		291		-		650		407		641		13,523		-1,725		13,787
	Advertising, marketing and promotion		-		-		-		-		-		3,737		-		3,737
	Depreciation		22		-		-		-		-		4,647		-		4,669
	Amortization		4		-		-		-		-		1,200		-		1,204
			317		-		650		407		641		37,525		-1,725		37,815
Operating income (loss)			351		-		-		-		-641		10,206		-		9,916
Other Income (Expense):
	Interest expense		-1,141		-8		-169		-96		-366		-148		-		-1,928
	Investment income (loss), net		3		-2		-		-		-2		550		-		549
	Equity in net income
	(losses) of investees, net		5,416		5,438		5,448		3,982		2,236		1,118		-23,734		-96
	Other income (expense), net		-2		-		2		-		-		-280		-		-280
			4,276		5,428		5,281		3,886		1,868		1,240		-23,734		-1,755
Income (loss) before income taxes			4,627		5,428		5,281		3,886		1,227		11,446		-23,734		8,161
Income tax (expense) benefit			276		4		58		34		-13		-3,353		-		-2,994
Net income (loss)			4,903		5,432		5,339		3,920		1,214		8,093		-23,734		5,167
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-264		-		-264
Net income (loss) attributable
	to Comcast Corporation	$	4,903	$	5,432	$	5,339	$	3,920	$	1,214	$	7,829	$	-23,734	$	4,903
Comprehensive income (loss)
	attributable to Comcast Corporation	$	4,804	$	5,471	$	5,386	$	3,983	$	1,176	$	7,741	$	-23,757	$	4,804
Condensed Consolidating Statement of Income
For the Nine Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	46,633	$	-	$	46,633
	Management fee revenue		625		-		610		381		-		-		-1,616		-
			625		-		610		381		-		46,633		-1,616		46,633
Costs and Expenses:
	Programming and production		-		-		-		-		-		15,013		-		15,013
	Other operating and administrative		290		-		610		381		686		12,839		-1,616		13,190
	Advertising, marketing and promotion		-		-		-		-		-		3,730		-		3,730
	Depreciation		23		-		-		-		-		4,571		-		4,594
	Amortization		3		-		-		-		-		1,218		-		1,221
			316		-		610		381		686		37,371		-1,616		37,748
Operating income (loss)			309		-		-		-		-686		9,262		-		8,885
Other Income (Expense):
	Interest expense		-1,084		-20		-246		-102		-309		-137		-		-1,898
	Investment income (loss), net		4		-2		-		-		2		166		-		170
	Equity in net income
	(losses) of investees, net		5,186		5,171		4,863		3,591		3,572		3,513		-24,953		943
	Other income (expense), net		-		-		-		-		-14		938		-		924
			4,106		5,149		4,617		3,489		3,251		4,480		-24,953		139
Income (loss) before income taxes			4,415		5,149		4,617		3,489		2,565		13,742		-24,953		9,024
Income tax (expense) benefit			270		8		86		36		5		-3,371		-		-2,966
Net income (loss)			4,685		5,157		4,703		3,525		2,570		10,371		-24,953		6,058
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-1,373		-		-1,373
Net income (loss) attributable
	to Comcast Corporation	$	4,685	$	5,157	$	4,703	$	3,525	$	2,570	$	8,998	$	-24,953	$	4,685
Comprehensive income (loss)
	attributable to Comcast Corporation	$	4,789	$	5,157	$	4,710	$	3,525	$	2,587	$	9,061	$	-25,040	$	4,789
Condensed Consolidating Statement of Cash Flows
For the Nine Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non-Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Net cash provided by (used in) operating activities		$	-451	$	-7	$	-3	$	-99	$	-767	$	13,006	$	-	$	11,679
Investing Activities:
	Net transactions with affiliates		-116		7		2,100		337		-900		-1,428		-		-
	Capital expenditures		-3		-		-		-		-		-4,590		-		-4,593
	Cash paid for intangible assets		-1		-		-		-		-		-693		-		-694
	Acquisitions of real estate properties		-		-		-		-		-		-1,705		-		-1,705
	Acquisitions, net of cash acquired		-		-		-		-		-		-42		-		-42
	Proceeds from sales of businesses and investments		-		-		-		-		-		655		-		655
	Return of capital from investees		-		-		-		-		128		18		-		146
	Purchases of investments		-8		-		-		-		-2		-1,167		-		-1,177
	Other		-		-		-		-		-20		103		-		83
Net cash provided by (used in) investing activities			-128		7		2,100		337		-794		-8,849		-		-7,327
Financing Activities:
	Proceeds from (repayments of) short-term borrowings, net		400		-		-		-		-		-5		-		395
	Proceeds from borrowings		2,933		-		-		-		-		-		-		2,933
	Repurchases and repayments of debt		-		-		-2,097		-238		-88		-19		-		-2,442
	Repurchases and retirements of common stock		-1,500		-		-		-		-		-		-		-1,500
	Dividends paid		-1,454		-		-		-		-		-		-		-1,454
	Issuances of common stock		35		-		-		-		-		-		-		35
	Purchase of NBCUniversal noncontrolling common equity interest		-		-		-		-		-3,200		-7,561		-		-10,761
	Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock		-		-		-		-		-		-164		-		-164
	Settlement of Station Venture liability		-		-		-		-		-		-602		-		-602
	Other		165		-		-		-		-40		-265		-		-140
Net cash provided by (used in) financing activities			579		-		-2,097		-238		-3,328		-8,616		-		-13,700
Increase (decrease) in cash and cash equivalents			-		-		-		-		-4,889		-4,459		-		-9,348
Cash and cash equivalents, beginning of period			-		-		-		-		5,129		5,822		-		10,951
Cash and cash equivalents, end of period		$	-	$	-	$	-	$	-	$	240	$	1,363	$	-	$	1,603
Condensed Consolidating Statement of Cash Flows
For the Nine Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non-Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Net cash provided by (used in) operating activities		$	-393	$	-4	$	-39	$	-122	$	-871	$	12,668	$	-	$	11,239
Investing Activities:
	Net transactions with affiliates		3,015		205		39		675		4,750		-8,684		-		-
	Capital expenditures		-8		-		-		-		-		-4,035		-		-4,043
	Cash paid for intangible assets		-4		-		-		-		-		-601		-		-605
	Acquisitions, net of cash acquired		-		-		-		-		-		-95		-		-95
	Proceeds from sales of businesses and investments		-		-		-		-		-		3,095		-		3,095
	Return of capital from investees		-		-		-		-		-		2,281		-		2,281
	Purchases of investments		-		-		-		-		-16		-175		-		-191
	Other		-		1		-		-		-22		89		-		68
Net cash provided by (used in) investing activities			3,003		206		39		675		4,712		-8,125		-		510
Financing Activities:
	Proceeds from (repayments of) short-term borrowings, net		-1		-		-		-		-550		-4		-		-555
	Proceeds from borrowings		2,248		-		-		-		-		-		-		2,248
	Repurchases and repayments of debt		-1,726		-202		-		-553		-1		-23		-		-2,505
	Repurchases and retirements of common stock		-2,250		-		-		-		-		-		-		-2,250
	Dividends paid		-1,176		-		-		-		-		-		-		-1,176
	Issuances of common stock		215		-		-		-		-		-		-		215
	Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock		-		-		-		-		-		-497		-		-497
	Other		80		-		-		-		-		-30		-		50
Net cash provided by (used in) financing activities			-2,610		-202		-		-553		-551		-554		-		-4,470
Increase (decrease) in cash and cash equivalents			-		-		-		-		3,290		3,989		-		7,279
Cash and cash equivalents, beginning of period			-		-		-		-		238		1,382		-		1,620
Cash and cash equivalents, end of period		$	-	$	-	$	-	$	-	$	3,528	$	5,371	$	-	$	8,899

Accounting_Policies_Policy

Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2013
Receivables Monetization	NBCUniversal monetizes certain of its accounts receivable under programs with a syndicate of banks. We account for receivables monetized through these programs as sales in accordance with the appropriate accounting guidance. We receive deferred consideration from the assets sold in the form of a receivable, which is funded by residual cash flows after the senior interests have been fully paid. The deferred consideration is included in receivables, net at its initial fair value, which reflects the net cash flows we expect to receive related to these interests. The accounts receivable we sold that underlie the deferred consideration are generally short-term in nature and, therefore, the fair value of the deferred consideration approximated its carrying value as of September 30, 2013 and December 31, 2012.
	NBCUniversal is responsible for servicing the receivables and remitting collections to the purchasers under the monetization programs. NBCUniversal performs this service for a fee that is equal to the prevailing market rate for such services. As a result, no servicing asset or liability has been recorded on our condensed consolidated balance sheet as of September 30, 2013 and December 31, 2012. The servicing fees are recorded as a component of other income (expense), net.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Computation of diluted EPS	Computation of Diluted EPS
			Three Months Ended September 30
				2013					2012
	(in millions, except per share data)			Net Income Attributable to Comcast Corporation	Shares		Per Share Amount		Net Income Attributable to Comcast Corporation	Shares		Per Share Amount
	Basic EPS attributable to Comcast Corporation shareholders		$	1,732	2,622	$	0.66	$	2,113	2,668	$	0.79
	Effect of dilutive securities:
	Assumed exercise or issuance of shares relating to stock
		plans			36					35
	Diluted EPS attributable to Comcast Corporation
		shareholders	$	1,732	2,658	$	0.65	$	2,113	2,703	$	0.78
			Nine Months Ended September 30
				2013					2012
	(in millions, except per share data)			Net Income Attributable to Comcast Corporation	Shares		Per Share Amount		Net Income Attributable to Comcast Corporation	Shares		Per Share Amount
	Basic EPS attributable to Comcast Corporation shareholders		$	4,903	2,629	$	1.86	$	4,685	2,687	$	1.74
	Effect of dilutive securities:
	Assumed exercise or issuance of shares relating to stock
		plans			39					37
	Diluted EPS attributable to Comcast Corporation
		shareholders	$	4,903	2,668	$	1.84	$	4,685	2,724	$	1.72

Film_and_Television_Costs_Tabl

Film and Television Costs (Tables)	9 Months Ended
	Sep. 30, 2013
Film and Television Costs				September 30,		December 31,
	(in millions)			2013		2012
	Film Costs:
		Released, less amortization	$	1,439	$	1,472
		Completed, not released		189		99
		In production and in development		394		1,048
				2,022		2,619
	Television Costs:
		Released, less amortization		1,144		1,124
		In production and in development		321		334
				1,465		1,458
	Programming rights, less amortization			2,060		1,886
				5,547		5,963
	Less: Current portion of programming rights			959		909
	Film and television costs		$	4,588	$	5,054

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investment Summary				September 30,		December 31,
	(in millions)			2013		2012
	Fair Value Method		$	4,790	$	4,493
	Equity Method:
		The Weather Channel		331		471
		Other		709		693
				1,040		1,164
	Cost Method:
		AirTouch		1,549		1,538
		Other		425		594
				1,974		2,132
	Total investments			7,804		7,789
	Less: Current investments			4,132		1,464
	Noncurrent investments		$	3,672	$	6,325
Investment Income (Loss), Net	Investment Income (Loss), Net
			Three Months Ended				Nine Months Ended
			30-Sep				30-Sep
	(in millions)		2013		2012		2013		2012
	Gains on sales and exchanges of investments, net		$	445	$	1	$	483	$	28
	Investment impairment losses			-12		-1		-25		-22
	Unrealized gains (losses) on securities underlying prepaid
		forward sale agreements		345		500		1,197		988
	Mark to market adjustments on derivative component of prepaid
		forward sale agreements and indexed debt instruments		-348		-470		-1,189		-920
	Interest and dividend income			28		32		84		89
	Other, net			6		8		-1		7
	Investment income (loss), net		$	464	$	70	$	549	$	170
Prepaid Forward Sale Agreements	Prepaid Forward Sale Agreements
			September 30,		December 31,
	(in millions)		2013		2012
	Assets:
		Fair value equity securities held as collateral	$	3,555	$	4,143
	Liabilities:
		Obligations under prepaid forward sale agreements	$	799	$	1,248
		Derivative component of prepaid forward sale agreements		2,397		2,302
	Total liabilities		$	3,196	$	3,550

Goodwill_Tables

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Goodwill				NBCUniversal
	(in millions)		Cable Communications		Cable Networks		Broadcast Television		Filmed Entertainment		Theme Parks		Corporate and Other		Total
	Balance, December 31, 2012	$	12,206	$	13,026	$	761	$	1	$	982	$	9	$	26,985
	Acquisitions		-		17		1		-		-		-		18
	Adjustments		-		69		6		-		-		1		76
	Balance, September 30, 2013	$	12,206	$	13,112	$	768	$	1	$	982	$	10	$	27,079

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Long-Term Debt	Long-Term Debt Outstanding
		Weighted-Average Interest		September 30,		December 31,
	(in millions)	Rate as of September 30, 2013		2013		2012
	Commercial paper	0.29	%	$	400	$	-
	Revolving credit facilities	1.252	%		1,250		-
	Senior notes with maturities of 5 years or less	4.711	%		15,111		12,991
	Senior notes with maturities between 6 and 10 years	4.558	%		11,534		10,334
	Senior notes with maturities greater than 10 years	5.979	%		17,985		16,801
	Other, including capital lease obligations	–			245		332
	Total debt	4.86	%(a)		46,525		40,458
	Less: Current portion				2,337		2,376
	Long-term debt			$	44,188	$	38,082
	(a) Includes the effects of our derivative financial instruments.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Assets and Liabilities Measured on Recurring Basis	Recurring Fair Value Measures
			Fair Value as of
			30-Sep-13								31-Dec-12
	(in millions)			Level 1		Level 2		Level 3		Total		Total
	Assets
	Trading securities		$	4,477	$	-	$	-	$	4,477	$	4,027
	Available-for-sale securities			183		118		12		313		464
	Interest rate swap agreements			-		137		-		137		210
	Other			-		59		-		59		38
	Total		$	4,660	$	314	$	12	$	4,986	$	4,739
	Liabilities
	Derivative component of prepaid forward sale agreements
		and indexed debt instruments	$	-	$	2,402	$	-	$	2,402	$	2,305
	Contractual obligations			-		-		1,130		1,130		1,055
	Contingent consideration			-		-		682		682		587
	Other			-		116		-		116		14
	Total		$	-	$	2,518	$	1,812	$	4,330	$	3,961
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
	Changes in Contractual Obligations and Contingent Consideration
	(in millions)		Contractual Obligations		Contingent Consideration
	Balance, December 31, 2012	$	1,055	$	587
	Fair value adjustments		141		25
	Payments		-66		-101
	Redemption Transaction		-		171
	Balance, September 30, 2013	$	1,130	$	682

Noncontrolling_Interests_Table

Noncontrolling Interests (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule Summarizing Changes in Equity Resulting from Net Income Attributable to Parent and Transfers to or from Noncontrolling Interests	Changes in Equity
				Nine Months Ended
				30-Sep
	(in millions)			2013		2012
	Net income attributable to Comcast Corporation			$	4,903	$	4,685
	Transfers from (to) noncontrolling interests:
		Decrease in Comcast Corporation additional paid-in capital resulting from the
			purchase of GE’s redeemable noncontrolling common equity interest		-1,482		-
		Other			-26		2
	Changes in equity resulting from net income attributable to Comcast Corporation
		and transfers from (to) noncontrolling interests		$	3,395	$	4,687

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Recognized Share-Based Compensation Expense	Recognized Share-Based Compensation Expense
		Three Months Ended				Nine Months Ended
		30-Sep				30-Sep
	(in millions)	2013		2012		2013		2012
	Stock options	$	34	$	32	$	102	$	99
	Restricted share units		44		38		130		114
	Employee stock purchase plans		4		4		15		12
	Total	$	82	$	74	$	247	$	225

Supplemental_Financial_Informa1

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
Receivable	Receivables
		September 30,		December 31,
	(in millions)	2013		2012
	Receivables, gross	$	5,964	$	6,026
	Less: Allowance for returns and customer incentives		249		307
	Less: Allowance for doubtful accounts		214		198
	Receivables, net	$	5,501	$	5,521
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)
			September 30,		September 30,
	(in millions)		2013		2012
	Unrealized gains (losses) on marketable securities		$	18	$	97
	Deferred gains (losses) on cash flow hedges			-47		-90
	Unrecognized gains (losses) on employee benefit obligations			-50		-54
	Cumulative translation adjustments			-31		-1
	Accumulated other comprehensive income (loss), net of deferred taxes		$	-110	$	-48
Schedule Of Adjustments To Reconcile Net Income To Net Cash Provided By Operating Activities	Net Cash Provided by Operating Activities
					Nine Months Ended
					30-Sep
	(in millions)				2013		2012
	Net income				$	5,167	$	6,058
	Adjustments to reconcile net income to net cash provided by operating activities:
		Depreciation and amortization				5,873		5,815
		Amortization of film and television costs				5,998		7,295
		Share-based compensation				312		278
		Noncash interest expense (income), net				122		158
		Equity in net (income) losses of investees, net				96		-943
		Cash received from investees				89		178
		Net (gain) loss on investment activity and other				-239		-1,071
		Deferred income taxes				-52		321
	Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
		Change in current and noncurrent receivables, net				145		-865
		Change in film and television costs				-5,590		-7,290
		Change in accounts payable and accrued expenses related to trade creditors				-108		553
		Change in other operating assets and liabilities				-134		752
	Net cash provided by operating activities				$	11,679	$	11,239
Cash Payments For Interest and Income Taxes	Cash Payments for Interest and Income Taxes
		Three Months Ended					Nine Months Ended
		30-Sep					30-Sep
	(in millions)		2013		2012			2013		2012
	Interest	$	636	$	567		$	1,768	$	1,725
	Income taxes	$	958	$	833		$	3,180	$	1,855

Receivables_Monetization_Table

Receivables Monetization (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables Monetized and Deferred Consideration	Receivables Monetized and Deferred Consideration
		September 30,		December 31,
	(in millions)	2013		2012
	Monetized receivables sold	$	642	$	791
	Deferred consideration	$	217	$	274

Financial_Data_by_Business_Seg1

Financial Data by Business Segment (Tables)	9 Months Ended
	Sep. 30, 2013
Financial Data by Business Segment			Three Months Ended September 30, 2013
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	10,491	$	4,246	$	1,549	$	2,697	$	1,432
	NBCUniversal
		Cable Networks		2,239		853		183		670		19
		Broadcast Television		1,644		34		23		11		21
		Filmed Entertainment		1,400		189		4		185		1
		Theme Parks		661		343		73		270		142
		Headquarters and Other(b)		7		-167		69		-236		101
		Eliminations(c)		-100		-2		-		-2		-
	NBCUniversal			5,851		1,250		352		898		284
	Corporate and Other			133		-178		16		-194		10
	Eliminations(c)			-324		12		-1		13		-
	Comcast Consolidated		$	16,151	$	5,330	$	1,916	$	3,414	$	1,726
			Three Months Ended September 30, 2012
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	9,976	$	3,998	$	1,607	$	2,391	$	1,364
	NBCUniversal
		Cable Networks		2,152		809		190		619		56
		Broadcast Television		2,790		88		25		63		17
		Filmed Entertainment		1,355		72		4		68		-
		Theme Parks		614		316		65		251		55
		Headquarters and Other(b)		8		-143		53		-196		81
		Eliminations(c)		-97		-2		-		-2		-
	NBCUniversal			6,822		1,140		337		803		209
	Corporate and Other			112		-101		14		-115		9
	Eliminations(c)			-366		-29		2		-31		-
	Comcast Consolidated		$	16,544	$	5,008	$	1,960	$	3,048	$	1,582
			Nine Months Ended September 30, 2013
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	31,175	$	12,800	$	4,780	$	8,020	$	3,766
	NBCUniversal
		Cable Networks		6,877		2,572		549		2,023		67
		Broadcast Television		4,893		205		74		131		38
		Filmed Entertainment		4,004		291		11		280		4
		Theme Parks		1,669		747		218		529		427
		Headquarters and Other(b)		25		-416		193		-609		271
		Eliminations(c)		-282		-5		-		-5		-
	NBCUniversal			17,186		3,394		1,045		2,349		807
	Corporate and Other			431		-380		48		-428		20
	Eliminations(c)			-1,061		-25		-		-25		-
	Comcast Consolidated		$	47,731	$	15,789	$	5,873	$	9,916	$	4,593
			Nine Months Ended September 30, 2012
	(in millions)			Revenue(d)		Operating Income (Loss) Before Depreciation and Amortization(e)		Depreciation and Amortization		Operating Income (Loss)		Capital Expenditures
	Cable Communications(a)		$	29,472	$	12,054	$	4,802	$	7,252	$	3,544
	NBCUniversal
		Cable Networks		6,520		2,408		548		1,860		87
		Broadcast Television		6,203		268		70		198		36
		Filmed Entertainment		3,778		-5		12		-17		4
		Theme Parks		1,565		708		190		518		154
		Headquarters and Other(b)		31		-444		149		-593		195
		Eliminations(c)		-299		-		-		-		-
	NBCUniversal			17,798		2,935		969		1,966		476
	Corporate and Other			416		-255		44		-299		23
	Eliminations(c)			-1,053		-34		-		-34		-
	Comcast Consolidated		$	46,633	$	14,700	$	5,815	$	8,885	$	4,043
Cable Segment Revenue Sources			Three Months Ended				Nine Months Ended
			30-Sep				30-Sep
			2013		2012		2013		2012
	Residential:
		Video	48.9	%	49.9	%	49.4	%	50.7	%
		High-speed Internet	24.7	%	24.1	%	24.6	%	24.1	%
		Voice	8.8	%	9	%	8.8	%	9	%
	Business services		8	%	6.6	%	7.6	%	6.3	%
	Advertising		5.2	%	6.1	%	5.1	%	5.5	%
	Other		4.4	%	4.3	%	4.5	%	4.4	%
	Total		100	%	100	%	100	%	100	%

Condensed_Consolidating_Financ1

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
Condensed Consolidating Financial Information [Abstract]
Condensed Consolidating Financial Statements	Condensed Consolidating Balance Sheet
	30-Sep-13
	(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
	Assets
		Cash and cash equivalents	$	-	$	-	$	-	$	-	$	240	$	1,363	$	-	$	1,603
		Investments		-		-		-		-		-		4,132		-		4,132
		Receivables, net		-		-		-		-		-		5,501		-		5,501
		Programming rights		-		-		-		-		-		959		-		959
		Other current assets		203		-		-		-		45		964		-		1,212
	Total current assets			203		-		-		-		285		12,919		-		13,407
	Film and television costs			-		-		-		-		-		4,588		-		4,588
	Investments			8		-		-		-		374		3,290		-		3,672
	Investments in and amounts due from subsidiaries eliminated upon consolidation			78,024		95,366		100,411		53,230		40,496		82,558		-450,085		-
	Property and equipment, net			223		-		-		-		-		28,583		-		28,806
	Franchise rights			-		-		-		-		-		59,364		-		59,364
	Goodwill			-		-		-		-		-		27,079		-		27,079
	Other intangible assets, net			9		-		-		-		-		17,325		-		17,334
	Other noncurrent assets, net			1,095		145		-		-		118		1,881		-894		2,345
	Total assets		$	79,562	$	95,511	$	100,411	$	53,230	$	41,273	$	237,587	$	-450,979	$	156,595
	Liabilities and Equity
		Accounts payable and accrued expenses related to  trade creditors	$	7	$	-	$	-	$	-	$	-	$	6,025	$	-	$	6,032
		Accrued participations and residuals		-		-		-		-		-		1,372		-		1,372
		Accrued expenses and other current liabilities		1,232		266		301		21		385		6,720		-		8,925
		Current portion of long-term debt		1,411		-		-		-		904		22		-		2,337
	Total current liabilities			2,650		266		301		21		1,289		14,139		-		18,666
	Long-term debt, less current portion			25,163		119		1,827		1,507		10,239		5,333		-		44,188
	Deferred income taxes			-		774		-		-		74		31,166		-753		31,261
	Other noncurrent liabilities			2,031		-		-		-		989		8,614		-141		11,493
	Redeemable noncontrolling interests and redeemable subsidiary preferred stock			-		-		-		-		-		853		-		853
	Equity:
		Common stock		30		-		-		-		-		-		-		30
		Other shareholders’ equity		49,688		94,352		98,283		51,702		28,682		177,066		-450,085		49,688
	Total Comcast Corporation
		shareholders’ equity		49,718		94,352		98,283		51,702		28,682		177,066		-450,085		49,718
	Noncontrolling interests			-		-		-		-		-		416		-		416
	Total equity			49,718		94,352		98,283		51,702		28,682		177,482		-450,085		50,134
	Total liabilities and equity		$	79,562	$	95,511	$	100,411	$	53,230	$	41,273	$	237,587	$	-450,979	$	156,595
	Condensed Consolidating Balance Sheet
	31-Dec-12
	(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
	Assets
		Cash and cash equivalents	$	-	$	-	$	-	$	-	$	5,129	$	5,822	$	-	$	10,951
		Investments		-		-		-		-		-		1,464		-		1,464
		Receivables, net		-		-		-		-		3		5,518		-		5,521
		Programming rights		-		-		-		-		-		909		-		909
		Other current assets		233		-		14		4		51		844		-		1,146
	Total current assets			233		-		14		4		5,183		14,557		-		19,991
	Film and television costs			-		-		-		-		-		5,054		-		5,054
	Investments			-		-		-		-		529		5,796		-		6,325
	Investments in and amounts due from subsidiaries eliminated upon consolidation			74,227		87,630		96,853		50,242		38,464		73,298		-420,714		-
	Property and equipment, net			242		-		-		-		-		26,990		-		27,232
	Franchise rights			-		-		-		-		-		59,364		-		59,364
	Goodwill			-		-		-		-		-		26,985		-		26,985
	Other intangible assets, net			12		-		-		-		-		17,828		-		17,840
	Other noncurrent assets, net			1,130		147		1		-		152		1,650		-900		2,180
	Total assets		$	75,844	$	87,777	$	96,868	$	50,246	$	44,328	$	231,522	$	-421,614	$	164,971
	Liabilities and Equity
		Accounts payable and accrued expenses related to trade creditors	$	8	$	-	$	-	$	-	$	-	$	6,198	$	-	$	6,206
		Accrued participations and residuals		-		-		-		-		-		1,350		-		1,350
		Accrued expenses and other current liabilities		1,290		275		210		54		263		4,690		-		6,782
		Current portion of long-term debt		-		-		2,105		241		7		23		-		2,376
	Total current liabilities			1,298		275		2,315		295		270		12,261		-		16,714
	Long-term debt, less current portion			23,306		113		1,827		1,512		11,219		105		-		38,082
	Deferred income taxes			-		754		-		-		78		30,035		-757		30,110
Other noncurrent liabilities			1,884		-		-		-		926		10,604		-143		13,271
Redeemable noncontrolling interests and redeemable subsidiary preferred stock			-		-		-		-		-		16,998		-		16,998
Equity:
	Common stock		31		-		-		-		-		-		-		31
	Other shareholders’ equity		49,325		86,635		92,726		48,439		31,835		161,079		-420,714		49,325
Total Comcast Corporation shareholders’ equity			49,356		86,635		92,726		48,439		31,835		161,079		-420,714		49,356
Noncontrolling interests			-		-		-		-		-		440		-		440
Total equity			49,356		86,635		92,726		48,439		31,835		161,519		-420,714		49,796
Total liabilities and equity		$	75,844	$	87,777	$	96,868	$	50,246	$	44,328	$	231,522	$	-421,614	$	164,971
Condensed Consolidating Statement of Income
For the Three Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	16,151	$	-	$	16,151
	Management fee revenue		225		-		219		137		-		-		-581		-
			225		-		219		137		-		16,151		-581		16,151
Costs and Expenses:
	Programming and production		-		-		-		-		-		4,787		-		4,787
	Other operating and administrative		92		-		219		137		211		4,673		-581		4,751
	Advertising, marketing and promotion		-		-		-		-		-		1,283		-		1,283
	Depreciation		7		-		-		-		-		1,513		-		1,520
	Amortization		1		-		-		-		-		395		-		396
			100		-		219		137		211		12,651		-581		12,737
Operating income (loss)			125		-		-		-		-211		3,500		-		3,414
Other Income (Expense):
	Interest expense		-382		-3		-45		-30		-123		-56		-		-639
	Investment income (loss), net		1		-5		-		-		-3		471		-		464
	Equity in net income
	(losses) of investees, net		1,898		1,787		1,850		1,371		576		106		-7,718		-130
	Other income (expense), net		-		-		-		-		-		-310		-		-310
			1,517		1,779		1,805		1,341		450		211		-7,718		-615
Income (loss) before income taxes			1,642		1,779		1,805		1,341		239		3,711		-7,718		2,799
Income tax (expense) benefit			90		3		15		11		-3		-1,137		-		-1,021
Net income (loss)			1,732		1,782		1,820		1,352		236		2,574		-7,718		1,778
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-46		-		-46
Net income (loss) attributable
	to Comcast Corporation	$	1,732	$	1,782	$	1,820	$	1,352	$	236	$	2,528	$	-7,718	$	1,732
Comprehensive income (loss)
	attributable to Comcast Corporation	$	1,545	$	1,828	$	1,864	$	1,415	$	244	$	2,327	$	-7,678	$	1,545
Condensed Consolidating Statement of Income
For the Three Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	16,544	$	-	$	16,544
	Management fee revenue		211		-		205		129		-		-		-545		-
			211		-		205		129		-		16,544		-545		16,544
Costs and Expenses:
	Programming and production		-		-		-		-		-		5,726		-		5,726
	Other operating and administrative		99		-		205		129		211		4,481		-545		4,580
	Advertising, marketing and promotion		-		-		-		-		-		1,230		-		1,230
	Depreciation		8		-		-		-		-		1,541		-		1,549
	Amortization		1		-		-		-		-		410		-		411
			108		-		205		129		211		13,388		-545		13,496
Operating income (loss)			103		-		-		-		-211		3,156		-		3,048
Other Income (Expense):
	Interest expense		-363		-4		-81		-33		-102		-50		-		-633
	Investment income (loss), net		1		-3		-		-		2		70		-		70
	Equity in net income (losses) of
	investees, net		2,281		2,047		1,641		1,216		1,988		2,583		-10,845		911
	Other income (expense), net		-		-		-		-		-1		988		-		987
			1,919		2,040		1,560		1,183		1,887		3,591		-10,845		1,335
Income (loss) before income taxes			2,022		2,040		1,560		1,183		1,676		6,747		-10,845		4,383
Income tax (expense) benefit			91		3		28		12		-4		-1,535		-		-1,405
Net income (loss)			2,113		2,043		1,588		1,195		1,672		5,212		-10,845		2,978
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-865		-		-865
Net (income) loss
	attributable to Comcast Corporation	$	2,113	$	2,043	$	1,588	$	1,195	$	1,672	$	4,347	$	-10,845	$	2,113
Comprehensive
	income (loss) attributable to Comcast Corporation	$	2,235	$	2,043	$	1,591	$	1,195	$	1,706	$	4,398	$	-10,933	$	2,235
Condensed Consolidating Statement of Income
For the Nine Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	47,731	$	-	$	47,731
	Management fee revenue		668		-		650		407		-		-		-1,725		-
			668		-		650		407		-		47,731		-1,725		47,731
Costs and Expenses:
	Programming and production		-		-		-		-		-		14,418		-		14,418
	Other operating and administrative		291		-		650		407		641		13,523		-1,725		13,787
	Advertising, marketing and promotion		-		-		-		-		-		3,737		-		3,737
	Depreciation		22		-		-		-		-		4,647		-		4,669
	Amortization		4		-		-		-		-		1,200		-		1,204
			317		-		650		407		641		37,525		-1,725		37,815
Operating income (loss)			351		-		-		-		-641		10,206		-		9,916
Other Income (Expense):
	Interest expense		-1,141		-8		-169		-96		-366		-148		-		-1,928
	Investment income (loss), net		3		-2		-		-		-2		550		-		549
	Equity in net income
	(losses) of investees, net		5,416		5,438		5,448		3,982		2,236		1,118		-23,734		-96
	Other income (expense), net		-2		-		2		-		-		-280		-		-280
			4,276		5,428		5,281		3,886		1,868		1,240		-23,734		-1,755
Income (loss) before income taxes			4,627		5,428		5,281		3,886		1,227		11,446		-23,734		8,161
Income tax (expense) benefit			276		4		58		34		-13		-3,353		-		-2,994
Net income (loss)			4,903		5,432		5,339		3,920		1,214		8,093		-23,734		5,167
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-264		-		-264
Net income (loss) attributable
	to Comcast Corporation	$	4,903	$	5,432	$	5,339	$	3,920	$	1,214	$	7,829	$	-23,734	$	4,903
Comprehensive income (loss)
	attributable to Comcast Corporation	$	4,804	$	5,471	$	5,386	$	3,983	$	1,176	$	7,741	$	-23,757	$	4,804
Condensed Consolidating Statement of Income
For the Nine Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non- Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Revenue:
	Service revenue	$	-	$	-	$	-	$	-	$	-	$	46,633	$	-	$	46,633
	Management fee revenue		625		-		610		381		-		-		-1,616		-
			625		-		610		381		-		46,633		-1,616		46,633
Costs and Expenses:
	Programming and production		-		-		-		-		-		15,013		-		15,013
	Other operating and administrative		290		-		610		381		686		12,839		-1,616		13,190
	Advertising, marketing and promotion		-		-		-		-		-		3,730		-		3,730
	Depreciation		23		-		-		-		-		4,571		-		4,594
	Amortization		3		-		-		-		-		1,218		-		1,221
			316		-		610		381		686		37,371		-1,616		37,748
Operating income (loss)			309		-		-		-		-686		9,262		-		8,885
Other Income (Expense):
	Interest expense		-1,084		-20		-246		-102		-309		-137		-		-1,898
	Investment income (loss), net		4		-2		-		-		2		166		-		170
	Equity in net income
	(losses) of investees, net		5,186		5,171		4,863		3,591		3,572		3,513		-24,953		943
	Other income (expense), net		-		-		-		-		-14		938		-		924
			4,106		5,149		4,617		3,489		3,251		4,480		-24,953		139
Income (loss) before income taxes			4,415		5,149		4,617		3,489		2,565		13,742		-24,953		9,024
Income tax (expense) benefit			270		8		86		36		5		-3,371		-		-2,966
Net income (loss)			4,685		5,157		4,703		3,525		2,570		10,371		-24,953		6,058
Net (income) loss attributable
	to noncontrolling interests and redeemable subsidiary preferred stock		-		-		-		-		-		-1,373		-		-1,373
Net income (loss) attributable
	to Comcast Corporation	$	4,685	$	5,157	$	4,703	$	3,525	$	2,570	$	8,998	$	-24,953	$	4,685
Comprehensive income (loss)
	attributable to Comcast Corporation	$	4,789	$	5,157	$	4,710	$	3,525	$	2,587	$	9,061	$	-25,040	$	4,789
Condensed Consolidating Statement of Cash Flows
For the Nine Months Ended September 30, 2013
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non-Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Net cash provided by (used in) operating activities		$	-451	$	-7	$	-3	$	-99	$	-767	$	13,006	$	-	$	11,679
Investing Activities:
	Net transactions with affiliates		-116		7		2,100		337		-900		-1,428		-		-
	Capital expenditures		-3		-		-		-		-		-4,590		-		-4,593
	Cash paid for intangible assets		-1		-		-		-		-		-693		-		-694
	Acquisitions of real estate properties		-		-		-		-		-		-1,705		-		-1,705
	Acquisitions, net of cash acquired		-		-		-		-		-		-42		-		-42
	Proceeds from sales of businesses and investments		-		-		-		-		-		655		-		655
	Return of capital from investees		-		-		-		-		128		18		-		146
	Purchases of investments		-8		-		-		-		-2		-1,167		-		-1,177
	Other		-		-		-		-		-20		103		-		83
Net cash provided by (used in) investing activities			-128		7		2,100		337		-794		-8,849		-		-7,327
Financing Activities:
	Proceeds from (repayments of) short-term borrowings, net		400		-		-		-		-		-5		-		395
	Proceeds from borrowings		2,933		-		-		-		-		-		-		2,933
	Repurchases and repayments of debt		-		-		-2,097		-238		-88		-19		-		-2,442
	Repurchases and retirements of common stock		-1,500		-		-		-		-		-		-		-1,500
	Dividends paid		-1,454		-		-		-		-		-		-		-1,454
	Issuances of common stock		35		-		-		-		-		-		-		35
	Purchase of NBCUniversal noncontrolling common equity interest		-		-		-		-		-3,200		-7,561		-		-10,761
	Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock		-		-		-		-		-		-164		-		-164
	Settlement of Station Venture liability		-		-		-		-		-		-602		-		-602
	Other		165		-		-		-		-40		-265		-		-140
Net cash provided by (used in) financing activities			579		-		-2,097		-238		-3,328		-8,616		-		-13,700
Increase (decrease) in cash and cash equivalents			-		-		-		-		-4,889		-4,459		-		-9,348
Cash and cash equivalents, beginning of period			-		-		-		-		5,129		5,822		-		10,951
Cash and cash equivalents, end of period		$	-	$	-	$	-	$	-	$	240	$	1,363	$	-	$	1,603
Condensed Consolidating Statement of Cash Flows
For the Nine Months Ended September 30, 2012
(in millions)			Comcast Parent		Comcast Holdings		CCCL Parent		Combined CCHMO Parents		NBCUniversal Media Parent		Non-Guarantor Subsidiaries		Elimination and Consolidation Adjustments		Consolidated Comcast Corporation
Net cash provided by (used in) operating activities		$	-393	$	-4	$	-39	$	-122	$	-871	$	12,668	$	-	$	11,239
Investing Activities:
	Net transactions with affiliates		3,015		205		39		675		4,750		-8,684		-		-
	Capital expenditures		-8		-		-		-		-		-4,035		-		-4,043
	Cash paid for intangible assets		-4		-		-		-		-		-601		-		-605
	Acquisitions, net of cash acquired		-		-		-		-		-		-95		-		-95
	Proceeds from sales of businesses and investments		-		-		-		-		-		3,095		-		3,095
	Return of capital from investees		-		-		-		-		-		2,281		-		2,281
	Purchases of investments		-		-		-		-		-16		-175		-		-191
	Other		-		1		-		-		-22		89		-		68
Net cash provided by (used in) investing activities			3,003		206		39		675		4,712		-8,125		-		510
Financing Activities:
	Proceeds from (repayments of) short-term borrowings, net		-1		-		-		-		-550		-4		-		-555
	Proceeds from borrowings		2,248		-		-		-		-		-		-		2,248
	Repurchases and repayments of debt		-1,726		-202		-		-553		-1		-23		-		-2,505
	Repurchases and retirements of common stock		-2,250		-		-		-		-		-		-		-2,250
	Dividends paid		-1,176		-		-		-		-		-		-		-1,176
	Issuances of common stock		215		-		-		-		-		-		-		215
	Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock		-		-		-		-		-		-497		-		-497
	Other		80		-		-		-		-		-30		-		50
Net cash provided by (used in) financing activities			-2,610		-202		-		-553		-551		-554		-		-4,470
Increase (decrease) in cash and cash equivalents			-		-		-		-		3,290		3,989		-		7,279
Cash and cash equivalents, beginning of period			-		-		-		-		238		1,382		-		1,620
Cash and cash equivalents, end of period		$	-	$	-	$	-	$	-	$	3,528	$	5,371	$	-	$	8,899

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share
Excluded shares from diluted EPS because their inclusion would have an antidilutive effect	18	21	13	37
Net income attributable to Comcast Corporation	$1,732	$2,113	$4,903	$4,685
Basic shares attributable to Comcast Corporation shareholders	2,622	2,668	2,629	2,687
Assumed exercise or issuance of shares relating to stock plans	36	35	39	37
Diluted shares attributable to Comcast Corporation shareholders	2,658	2,703	2,668	2,724
Basic earnings per common share attributable to Comcast Corporation shareholders	$0.66	$0.79	$1.86	$1.74
Diluted earnings per common share attributable to Comcast Corporation shareholders	$0.65	$0.78	$1.84	$1.72

Significant_Transactions_Narra

Significant Transactions (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Mar. 19, 2013
Significant Transactions [Line Items]
GE ownership percentage		49.00%
Purchase of NBCUniversal noncontrolling interest	$16,700,000,000
Payments related to acquisition of buildings	1,400,000,000
Preferred stock dividend rate percentage	5.25%
Deferred tax liabilities recognized associated with the redemption transaction	1,500,000,000
Cash On Hand
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	11,400,000,000
NBCUniversal Enterprise Senior Unsecured Debt Securities
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	4,000,000,000
Commercial Paper Program
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	750,000,000
NBCUniversal Enterprise Credit Facility
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	1,250,000,000
NBCUniversal Enterprise Preferred Stock
Significant Transactions [Line Items]
Consideration transferred related to the Redemption Transaction and purchase of certain properties	$725,000,000

Film_and_Television_Costs_Film

Film and Television Costs (Film and Television Costs)(Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Film And Television Costs [Line Items]
Total film costs	$2,022	$2,619
Total television costs	1,465	1,458
Programming rights, less amortization	2,060	1,886
Total film costs, television costs and programming rights	5,547	5,963
Less: Current portion of programming rights	959	909
Film and television costs	4,588	5,054
Film Costs [Member]
Film And Television Costs [Line Items]
Released, less amortization	1,439	1,472
Completed, not released	189	99
In production and in development	394	1,048
Television Costs [Member]
Film And Television Costs [Line Items]
Released, less amortization	1,144	1,124
In production and in development	$321	$334

Investments_Details

Investments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair value method	$4,790	$4,493
Equity method	1,040	1,164
Cost method	1,974	2,132
Total Investments	7,804	7,789
Less: Current investments	4,132	1,464
Noncurrent investments	3,672	6,325
Other Equity Method Investments [Member]
Equity method	709	693
Air Touch [Member]
Cost method	1,549	1,538
Other Cost Method Investment [Member]
Cost method	425	594
The Weather Channel [Member]
Equity method	$331	$471

Investments_Investment_Income_

Investments (Investment Income (Loss), Net) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Gains on sales and exchanges of investments, net	$445	$1	$483	$28
Investment impairment losses	-12	-1	-25	-22
Unrealized gains (losses) on securities underlying prepaid forward sale agreements	345	500	1,197	988
Mark to market adjustments on derivative component of prepaid forward sale agreements and indexed debt instruments	-348	-470	-1,189	-920
Interest and dividend income	28	32	84	89
Other, net	6	8	-1	7
Investment income (loss), net	$464	$70	$549	$170

Investments_Fair_Value_Method_

Investments (Fair Value Method Investments) (Details) (USD $)	9 Months Ended			9 Months Ended		0 Months Ended
Share data in Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Oct. 03, 2013	Sep. 30, 2013
				Clearwire LLC [Member]	Fair Value Of Specific Contract Obligation [Member]	Liberty Media Redemption Transaction [Member]	Liberty Media Redemption Transaction [Member]
Fair value equity securities held	$3,555,000,000		$4,143,000,000
Obligations under prepaid forward sale agreements	799,000,000		1,248,000,000
Derivative component of prepaid forward sale agreements	2,397,000,000		2,302,000,000
Total liabilities associated with prepaid forward sale agreements	3,196,000,000		3,550,000,000
Prepaid forward sale obligations fair value	3,200,000,000
Proceeds from sale of available-for-sale securities				443,000,000
Fair value method	4,790,000,000		4,493,000,000				925,000,000
Pre-tax gain realized on Clearwire				443,000,000
Prepaid Forward Obligations Settlement	1,600,000,000
Total equity securities used to settle prepaid forward obligations	1,400,000,000
Equity securities held as collateral under our prepaid forward sale agreements acquired during the period	653,000,000
Shares Redeemed						6.3
Shares Held In Acquired Entity				89
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value					383,000,000
Proceeds From Sales Of Businesses And Investments	$655,000,000	$3,095,000,000				$417,000,000

Investments_Equity_Method_Inve

Investments (Equity Method Investments) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Return of capital from investees	$146	$2,281
The Weather Channel [Member]
Total distribution from investee	152
Return of capital from investees	$128

Investments_Cost_Method_Invest

Investments (Cost Method Investments) (Details) (Air Touch [Member], USD $)	Sep. 30, 2013
In Billions, unless otherwise specified
Air Touch [Member]
Fair value of AirTouch preferred stock and the associated liability related to redeemable preferred shares	$1.70

Goodwill_Rollforward_Details

Goodwill Rollforward (Details) (USD $)	9 Months Ended			9 Months Ended						9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
		Cable Communications [Member]	Cable Communications [Member]	Cable Networks [Member]	Broadcast Television [Member]	Filmed Entertainment [Member]	Filmed Entertainment [Member]	Theme Parks [Member]	Theme Parks [Member]	Corporate and Other [Member]
Goodwill beginning balance	$26,985	$12,206	$12,206	$13,026	$761	$1	$1	$982	$982	$9
Acquisitions	18			17	1
Adjustments	76			69	6					1
Goodwill ending balance	$27,079	$12,206	$12,206	$13,112	$768	$1	$1	$982	$982	$10

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commercial paper	$400
Revolving credit facilities	1,250
Total debt	46,525	40,458
Less: current portion	2,337	2,376
Long-term debt	44,188	38,082
Weighted average interest rate	4.86%
Credit facility interest rate	1.25%
Commercial Paper Program
Weighted average interest rate	0.29%
NBCUniversal Enterprise Credit Facility [Member]
Credit facility interest rate	1.25%
Senior notes with maturities of 5 years or less [Member]
Senior notes	15,111	12,991
Weighted average interest rate	4.71%
Senior notes with maturities between 6 and 10 years [Member]
Senior notes	11,534	10,334
Weighted average interest rate	4.56%
Senior notes with maturities greater than 10 years [Member]
Senior notes	17,985	16,801
Weighted average interest rate	5.98%
Other Including Capital Lease Obligations [Member]
Other, including capital lease obligations	$245	$332

LongTerm_Debt_Narrative_Detail

Long-Term Debt (Narrative) (Details) (USD $)	9 Months Ended												9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Mar. 19, 2013	Sep. 30, 2013
		NBCUniversal Enterprise Senior Unsecured Debt Securities	Commercial Paper Program	NBCUniversal Enterprise Credit Facility	Senior 1.662% Notes Due 2018 [Member]	Senior 1.974% Notes Due 2019 [Member]	Floating Rate Senior Notes Due 2018 [Member]	Floating Rate Senior Notes Due 2016 [Member]	Senior 2.850% Notes Due 2023 [Member]	Senior 4.250% Notes Due 2033 [Member]	Senior 4.500% Notes Due 2043 [Member]	Prior NBCUniversal Credit Facility [Member]	NBCUniversal Enterprise Credit Facility [Member]
Long-term Debt, Fair Value	$51,100,000,000
Principal amount					1,100,000,000	1,500,000,000	700,000,000	700,000,000	750,000,000	1,700,000,000	500,000,000
Interest rate					1.66%	1.97%			2.85%	4.25%	4.50%
Debt Instrument, Maturity Date, Description					2018	2019	2018	2016	2023	2033	2043		Mar-18
Spread above LIBOR offered rate							0.69%	0.54%
Consideration transferred related to the Redemption Transaction and purchase of certain properties		4,000,000,000	750,000,000	1,250,000,000
Revolving credit facilities	1,250,000,000
Credit facility borrowing capacity												1,500,000,000	1,350,000,000
Amounts available under revolving credit facilities	5,700,000,000												100,000,000
Credit facility interest rate	1.25%												1.25%
Proceeds from commercial paper issued, net of repayments	$400,000,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Trading securities	$4,477	$4,027
Available-for-sale Securities	313	464
Interest rate swap agreements	137	210
Other [assets]	59	38
Fair value, assets measured on recurring basis, total	4,986	4,739
Derivative component of prepaid forward sale agreements and indexed debt instruments	2,402	2,305
Contractual obligations	1,130	1,055
Contingent consideration	682	587
Other [liabilities]	116	14
Fair value liabilities measured on recurring basis	4,330	3,961
Fair Value, Inputs, Level 1 [Member]
Trading securities	4,477
Available-for-sale Securities	183
Fair value, assets measured on recurring basis, total	4,660
Fair Value, Inputs, Level 2 [Member]
Available-for-sale Securities	118
Interest rate swap agreements	137
Other [assets]	59
Fair value, assets measured on recurring basis, total	314
Derivative component of prepaid forward sale agreements and indexed debt instruments	2,402
Other [liabilities]	116
Fair value liabilities measured on recurring basis	2,518
Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	12
Fair value, assets measured on recurring basis, total	12
Contractual obligations	1,130
Contingent consideration	682
Fair value liabilities measured on recurring basis	$1,812

Fair_Value_Disclosure_Rollforw

Fair Value Disclosure Rollforward (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Discount rate used to determine fair value, minimum	5.00%
Discount rate used to determine fair value, maximum	14.00%
Nonrecurring fair value adjustments	$150	$155
Contractual Obligations [Member]
Beginning balance	1,055
Fair value adjustments	141
Payments	-66
Ending balance	1,130
Contingent Consideration [Member]
Beginning balance	587
Fair value adjustments	25
Payments	-101
Redemption transaction	171
Ending balance	$682

Noncontrolling_Interests_Detai

Noncontrolling Interests (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 19, 2013
GE ownership percentage					49.00%
Net income attributable to Comcast Corporation	$1,732	$2,113	$4,903	$4,685
Changes in equity resulting from net income attributable to Comcast Corporation and transfers from (to) noncontrolling interests			3,395	4,687
Redemption Transaction [Member]
Increase (decrease) in Comcast Corporation additional paid-in capital resulting from the purchase of noncontrolling interest			-1,482	0
Other Purchase [Member]
Increase (decrease) in Comcast Corporation additional paid-in capital resulting from the purchase of noncontrolling interest			($26)	$2

Pension_Plans_and_Postretireme1

Pension Plans and Postretirement Benefits (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Contribution to fully fund and settle plan	$55
Reclassification adjustment from accumulated other comprehensive income before tax	$74

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Number of stock options granted	18.4
Number of restricted share units granted	5.2
Weighted average fair value of stock options granted	$8.80
Fair value of restricted share units granted	$37.85
Stock Options [Member]
Unrecognized pretax compensation expense on nonvested awards	$351
Restricted Share Units [Member]
Unrecognized pretax compensation expense on nonvested awards	$414

ShareBased_Compensation_Recogn

Share-Based Compensation (Recognized Share-Based Compensation Expense) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Allocated share-based compensation expense	$82	$74	$247	$225
Stock Options [Member]
Allocated share-based compensation expense	34	32	102	99
Restricted Share Units [Member]
Allocated share-based compensation expense	44	38	130	114
Employee Stock Purchase Plan [Member]
Allocated share-based compensation expense	$4	$4	$15	$12

Supplemental_Financial_Informa2

Supplemental Financial Information (Receivables)(Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Supplemental Financial Information [Abstract]
Receivables, gross	$5,964	$6,026
Less: Allowance for returns and customer incentives	249	307
Less: Allowance for doubtful accounts	214	198
Receivables, net	$5,501	$5,521

Supplemental_Financial_Informa3

Supplemental Financial Information (Components of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Millions, unless otherwise specified
Equity
Unrealized gains (losses) on marketable securities	$18		$97
Deferred gains (losses) on cash flow hedges	-47		-90
Unrecognized gains (losses) on employee benefit obligations	-50		-54
Cumulative translation adjustments	-31		-1
Accumulated other comprehensive income (loss), net of deferred taxes	($110)	$15	($48)

Supplemental_Financial_Informa4

Supplemental Financial Information (Net Cash Provided by Operating Activities)(Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating Activities
Net income	$1,778	$2,978	$5,167	$6,058
Depreciation and amortization	1,916	1,960	5,873	5,815
Amortization of film and television costs			5,998	7,295
Share-based compensation			312	278
Noncash interest expense (income), net			122	158
Equity in net (income) losses of investees, net	130	-911	96	-943
Cash received from investees			89	178
Net (gain) loss on investment activity and other			-239	-1,071
Deferred income taxes			-52	321
Change in current and noncurrent receivables, net			145	-865
Change in film and television costs			-5,590	-7,290
Change in accounts payable and accrued expenses related to trade creditors			-108	553
Change in other operating assets and liabilities			-134	752
Net cash provided by (used in) operating activities			$11,679	$11,239

Supplemental_Financial_Informa5

Supplemental Financial Information (Cash Payments for Interest and Income Taxes)(Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Supplemental Financial Information [Abstract]
Interest	$636	$567	$1,768	$1,725
Income taxes	$958	$833	$3,180	$1,855

Supplemental_Financial_Informa6

Supplemental Financial Information (Noncash Investing and Financing Activities)(Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Mar. 19, 2013
GE ownership percentage		49.00%
Purchase of NBCUniversal noncontrolling interest	$16,700,000,000
Total noncash consideration transferred related to the Redemption Transaction	6,000,000,000
Dividends payable, amount	510,000,000
Dividends payable, amount per share	$0.20
Capital expenditures incurred but not yet paid	807,000,000
Fair Value Equity Securities Settlement	1,400,000,000
NBCUniversal Enterprise Credit Facility
Consideration transferred related to the Redemption Transaction and purchase of certain properties	1,250,000,000
NBCUniversal Enterprise Senior Unsecured Debt Securities
Consideration transferred related to the Redemption Transaction and purchase of certain properties	4,000,000,000
NBCUniversal Enterprise Preferred Stock
Consideration transferred related to the Redemption Transaction and purchase of certain properties	$725,000,000

Receivables_Monetization_Narra

Receivables Monetization (Narrative)(Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Receivables Monetization [Abstract]
Monetization programs payable	$616	$882

Receivables_Monetization_Effec

Receivables Monetization (Effect on Income From Receivables Monetization and Cash Flows on Transfers)(Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Receivables Monetization [Abstract]
Net cash proceeds (payments) on transfers	($367)	$70

Receivables_Monetization_Recei

Receivables Monetization (Receivables Monetized and Deferred Consideration)(Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Receivables Monetization [Abstract]
Monetized receivables sold	$642	$791
Deferred consideration	$217	$274

Commitments_and_Contingencies_

Commitments and Contingencies (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Feb. 12, 2013
Collateral liability for unconsolidated subsidiary debt		$482
Settlement Of Station Venture Liability	602
Station Venture Senior Secured Note Due In 2023 [Member]
Debt of unconsolidated variable interest entity	$816
Maturity year	2023

Financial_Data_by_Business_Seg2

Financial Data by Business Segment (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$16,151	$16,544	$47,731	$46,633
Operating income (loss) before depreciation and amortization	5,330	5,008	15,789	14,700
Depreciation and amortization	1,916	1,960	5,873	5,815
Operating income (loss)	3,414	3,048	9,916	8,885
Capital expenditures	1,726	1,582	4,593	4,043
Cable segment revenue types as percentage of total cable revenue	100.00%	100.00%	100.00%	100.00%
Cable Communications [Member]
Revenue	10,491	9,976	31,175	29,472
Operating income (loss) before depreciation and amortization	4,246	3,998	12,800	12,054
Depreciation and amortization	1,549	1,607	4,780	4,802
Operating income (loss)	2,697	2,391	8,020	7,252
Capital expenditures	1,432	1,364	3,766	3,544
Cable Networks [Member]
Revenue	2,239	2,152	6,877	6,520
Operating income (loss) before depreciation and amortization	853	809	2,572	2,408
Depreciation and amortization	183	190	549	548
Operating income (loss)	670	619	2,023	1,860
Capital expenditures	19	56	67	87
Broadcast Television [Member]
Revenue	1,644	2,790	4,893	6,203
Operating income (loss) before depreciation and amortization	34	88	205	268
Depreciation and amortization	23	25	74	70
Operating income (loss)	11	63	131	198
Capital expenditures	21	17	38	36
Filmed Entertainment [Member]
Revenue	1,400	1,355	4,004	3,778
Operating income (loss) before depreciation and amortization	189	72	291	-5
Depreciation and amortization	4	4	11	12
Operating income (loss)	185	68	280	-17
Capital expenditures	1	0	4	4
Theme Parks [Member]
Revenue	661	614	1,669	1,565
Operating income (loss) before depreciation and amortization	343	316	747	708
Depreciation and amortization	73	65	218	190
Operating income (loss)	270	251	529	518
Capital expenditures	142	55	427	154
Headquarters And Other [Member]
Revenue	7	8	25	31
Operating income (loss) before depreciation and amortization	-167	-143	-416	-444
Depreciation and amortization	69	53	193	149
Operating income (loss)	-236	-196	-609	-593
Capital expenditures	101	81	271	195
NBCUniversal Eliminations [Member]
Revenue	-100	-97	-282	-299
Operating income (loss) before depreciation and amortization	-2	-2	-5	0
Depreciation and amortization	0	0	0	0
Operating income (loss)	-2	-2	-5	0
Capital expenditures	0	0	0	0
NBCUniversal [Member]
Revenue	5,851	6,822	17,186	17,798
Operating income (loss) before depreciation and amortization	1,250	1,140	3,394	2,935
Depreciation and amortization	352	337	1,045	969
Operating income (loss)	898	803	2,349	1,966
Capital expenditures	284	209	807	476
Corporate and Other [Member]
Revenue	133	112	431	416
Operating income (loss) before depreciation and amortization	-178	-101	-380	-255
Depreciation and amortization	16	14	48	44
Operating income (loss)	-194	-115	-428	-299
Capital expenditures	10	9	20	23
Eliminations [Member]
Revenue	-324	-366	-1,061	-1,053
Operating income (loss) before depreciation and amortization	12	-29	-25	-34
Depreciation and amortization	-1	2	0	0
Operating income (loss)	13	-31	-25	-34
Capital expenditures	$0	$0	$0	$0
Cable Communications Segment Revenue Percentage-Video [Member]
Cable segment revenue types as percentage of total cable revenue	48.90%	49.90%	49.40%	50.70%
Cable Communications Segment Revenue Percentage - High-speed Internet [Member]
Cable segment revenue types as percentage of total cable revenue	24.70%	24.10%	24.60%	24.10%
Cable Communications Segment Revenue Percentage- Phone [Member]
Cable segment revenue types as percentage of total cable revenue	8.80%	9.00%	8.80%	9.00%
Cable Communications Segment Revenue Percentage- Advertising [Member]
Cable segment revenue types as percentage of total cable revenue	5.20%	6.10%	5.10%	5.50%
Cable Communications Segment Revenue Percentage- Business Services [Member]
Cable segment revenue types as percentage of total cable revenue	8.00%	6.60%	7.60%	6.30%
Cable Communications Segment Revenue Percentage- Other [Member]
Cable segment revenue types as percentage of total cable revenue	4.40%	4.30%	4.50%	4.40%
Cable Communications Segment Revenue Percentage- Franchise and other regulatory fees [Member]
Cable segment revenue types as percentage of total cable revenue	2.90%	2.80%	2.90%	2.80%

Condensed_Consolidating_Financ2

Condensed Consolidating Financial Information (Narrative) (Details) (USD $)	Sep. 30, 2013
Comcast Holdings' ZONES due October 2029 [Member]
Principal amount of debt securities subject to guarantee	$185,000,000
Comcast Holdings' ZONES due November 2029 [Member]
Principal amount of debt securities not subject to guarantee	62,000,000
Comcast And Comcast Cable Communications LLC [Member]
Credit facility borrowing capacity	6,250,000,000
NBCUniversal Enterprise [Member]
Credit facility borrowing capacity	1,350,000,000
Principal amount of debt securities subject to guarantee	$4,000,000,000

Condensed_Consolidating_Financ3

Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheet) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Cash and cash equivalents	$1,603	$10,951	$8,899	$1,620
Investments [Current]	4,132	1,464
Receivables, net	5,501	5,521
Programming rights	959	909
Other current assets	1,212	1,146
Total current assets	13,407	19,991
Film and television costs	4,588	5,054
Investments	3,672	6,325
Property and equipment, net	28,806	27,232
Franchise rights	59,364	59,364
Goodwill	27,079	26,985
Other intangible assets, net	17,334	17,840
Other noncurrent assets, net	2,345	2,180
Total assets	156,595	164,971
Accounts payable and accrued expenses related to trade creditors	6,032	6,206
Accrued participations and residuals	1,372	1,350
Accrued expenses and other current liabilities [condensed]	8,925	6,782
Current portion of long-term debt	2,337	2,376
Total current liabilities	18,666	16,714
Long-term debt, less current portion	44,188	38,082
Deferred income taxes	31,261	30,110
Other noncurrent liabilities	11,493	13,271
Redeemable noncontrolling interests and redeemable subsidiary preferred stock	853	16,998
Common stock	30	31
Other shareholders' equity	49,688	49,325
Total Comcast Corporation shareholders' equity	49,718	49,356
Noncontrolling interests	416	440
Total equity	50,134	49,796	49,341	47,655
Total liabilities and equity	156,595	164,971
Comcast [Member]
Other current assets	203	233
Total current assets	203	233
Investments	8
Investments in and amounts due from subsidiaries eliminated upon consolidation	78,024	74,227
Property and equipment, net	223	242
Other intangible assets, net	9	12
Other noncurrent assets, net	1,095	1,130
Total assets	79,562	75,844
Accounts payable and accrued expenses related to trade creditors	7	8
Accrued expenses and other current liabilities [condensed]	1,232	1,290
Current portion of long-term debt	1,411
Total current liabilities	2,650	1,298
Long-term debt, less current portion	25,163	23,306
Other noncurrent liabilities	2,031	1,884
Common stock	30	31
Other shareholders' equity	49,688	49,325
Total Comcast Corporation shareholders' equity	49,718	49,356
Total equity	49,718	49,356
Total liabilities and equity	79,562	75,844
Comcast Holdings [Member]
Investments in and amounts due from subsidiaries eliminated upon consolidation	95,366	87,630
Other noncurrent assets, net	145	147
Total assets	95,511	87,777
Accrued expenses and other current liabilities [condensed]	266	275
Total current liabilities	266	275
Long-term debt, less current portion	119	113
Deferred income taxes	774	754
Other shareholders' equity	94,352	86,635
Total Comcast Corporation shareholders' equity	94,352	86,635
Total equity	94,352	86,635
Total liabilities and equity	95,511	87,777
CCCL Parent [Member]
Other current assets	0	14
Total current assets	0	14
Investments in and amounts due from subsidiaries eliminated upon consolidation	100,411	96,853
Other noncurrent assets, net		1
Total assets	100,411	96,868
Accrued expenses and other current liabilities [condensed]	301	210
Current portion of long-term debt		2,105
Total current liabilities	301	2,315
Long-term debt, less current portion	1,827	1,827
Other shareholders' equity	98,283	92,726
Total Comcast Corporation shareholders' equity	98,283	92,726
Total equity	98,283	92,726
Total liabilities and equity	100,411	96,868
Combined CCHMO Parents [Member]
Other current assets	0	4
Total current assets	0	4
Investments in and amounts due from subsidiaries eliminated upon consolidation	53,230	50,242
Total assets	53,230	50,246
Accrued expenses and other current liabilities [condensed]	21	54
Current portion of long-term debt		241
Total current liabilities	21	295
Long-term debt, less current portion	1,507	1,512
Other shareholders' equity	51,702	48,439
Total Comcast Corporation shareholders' equity	51,702	48,439
Total equity	51,702	48,439
Total liabilities and equity	53,230	50,246
NBCUniversal Media Parent [Member]
Cash and cash equivalents	240	5,129	3,528	238
Receivables, net		3
Other current assets	45	51
Total current assets	285	5,183
Investments	374	529
Investments in and amounts due from subsidiaries eliminated upon consolidation	40,496	38,464
Other noncurrent assets, net	118	152
Total assets	41,273	44,328
Accrued expenses and other current liabilities [condensed]	385	263
Current portion of long-term debt	904	7
Total current liabilities	1,289	270
Long-term debt, less current portion	10,239	11,219
Deferred income taxes	74	78
Other noncurrent liabilities	989	926
Other shareholders' equity	28,682	31,835
Total Comcast Corporation shareholders' equity	28,682	31,835
Total equity	28,682	31,835
Total liabilities and equity	41,273	44,328
Comcast Non-Guarantor Subsidiaries [Member]
Cash and cash equivalents	1,363	5,822	5,371	1,382
Investments [Current]	4,132	1,464
Receivables, net	5,501	5,518
Programming rights	959	909
Other current assets	964	844
Total current assets	12,919	14,557
Film and television costs	4,588	5,054
Investments	3,290	5,796
Investments in and amounts due from subsidiaries eliminated upon consolidation	82,558	73,298
Property and equipment, net	28,583	26,990
Franchise rights	59,364	59,364
Goodwill	27,079	26,985
Other intangible assets, net	17,325	17,828
Other noncurrent assets, net	1,881	1,650
Total assets	237,587	231,522
Accounts payable and accrued expenses related to trade creditors	6,025	6,198
Accrued participations and residuals	1,372	1,350
Accrued expenses and other current liabilities [condensed]	6,720	4,690
Current portion of long-term debt	22	23
Total current liabilities	14,139	12,261
Long-term debt, less current portion	5,333	105
Deferred income taxes	31,166	30,035
Other noncurrent liabilities	8,614	10,604
Redeemable noncontrolling interests and redeemable subsidiary preferred stock	853	16,998
Other shareholders' equity	177,066	161,079
Total Comcast Corporation shareholders' equity	177,066	161,079
Noncontrolling interests	416	440
Total equity	177,482	161,519
Total liabilities and equity	237,587	231,522
Elimination and Consolidation Adjustments [Member]
Investments in and amounts due from subsidiaries eliminated upon consolidation	-450,085	-420,714
Other noncurrent assets, net	-894	-900
Total assets	-450,979	-421,614
Deferred income taxes	-753	-757
Other noncurrent liabilities	-141	-143
Other shareholders' equity	-450,085	-420,714
Total Comcast Corporation shareholders' equity	-450,085	-420,714
Total equity	-450,085	-420,714
Total liabilities and equity	($450,979)	($421,614)

Condensed_Consolidating_Financ4

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Service revenue	$16,151	$16,544	$47,731	$46,633
Revenue	16,151	16,544	47,731	46,633
Programming and production	4,787	5,726	14,418	15,013
Other operating and administrative	4,751	4,580	13,787	13,190
Advertising, marketing and promotion	1,283	1,230	3,737	3,730
Depreciation	1,520	1,549	4,669	4,594
Amortization	396	411	1,204	1,221
Costs and expenses, total	12,737	13,496	37,815	37,748
Operating income (loss)	3,414	3,048	9,916	8,885
Interest expense	-639	-633	-1,928	-1,898
Investment income (loss), net	464	70	549	170
Equity in net income (losses) of investees, net	-130	911	-96	943
Other income (expense), net	-310	987	-280	924
Nonoperating income (Expense), Total	-615	1,335	-1,755	139
Income (loss) before income taxes	2,799	4,383	8,161	9,024
Income tax (expense) benefit	-1,021	-1,405	-2,994	-2,966
Net income (loss)	1,778	2,978	5,167	6,058
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	-46	-865	-264	-1,373
Net income (loss) attributable to Comcast Corporation	1,732	2,113	4,903	4,685
Comprehensive income attributable to Comcast Corporation	1,545	2,235	4,804	4,789
Comcast [Member]
Management fee revenue	225	211	668	625
Revenue	225	211	668	625
Other operating and administrative	92	99	291	290
Depreciation	7	8	22	23
Amortization	1	1	4	3
Costs and expenses, total	100	108	317	316
Operating income (loss)	125	103	351	309
Interest expense	-382	-363	-1,141	-1,084
Investment income (loss), net	1	1	3	4
Equity in net income (losses) of investees, net	1,898	2,281	5,416	5,186
Other income (expense), net	0		-2
Nonoperating income (Expense), Total	1,517	1,919	4,276	4,106
Income (loss) before income taxes	1,642	2,022	4,627	4,415
Income tax (expense) benefit	90	91	276	270
Net income (loss)	1,732	2,113	4,903	4,685
Net income (loss) attributable to Comcast Corporation	1,732	2,113	4,903	4,685
Comprehensive income attributable to Comcast Corporation	1,545	2,235	4,804	4,789
Comcast Holdings [Member]
Interest expense	-3	-4	-8	-20
Investment income (loss), net	-5	-3	-2	-2
Equity in net income (losses) of investees, net	1,787	2,047	5,438	5,171
Nonoperating income (Expense), Total	1,779	2,040	5,428	5,149
Income (loss) before income taxes	1,779	2,040	5,428	5,149
Income tax (expense) benefit	3	3	4	8
Net income (loss)	1,782	2,043	5,432	5,157
Net income (loss) attributable to Comcast Corporation	1,782	2,043	5,432	5,157
Comprehensive income attributable to Comcast Corporation	1,828	2,043	5,471	5,157
CCCL Parent [Member]
Management fee revenue	219	205	650	610
Revenue	219	205	650	610
Other operating and administrative	219	205	650	610
Costs and expenses, total	219	205	650	610
Interest expense	-45	-81	-169	-246
Equity in net income (losses) of investees, net	1,850	1,641	5,448	4,863
Other income (expense), net	0		2
Nonoperating income (Expense), Total	1,805	1,560	5,281	4,617
Income (loss) before income taxes	1,805	1,560	5,281	4,617
Income tax (expense) benefit	15	28	58	86
Net income (loss)	1,820	1,588	5,339	4,703
Net income (loss) attributable to Comcast Corporation	1,820	1,588	5,339	4,703
Comprehensive income attributable to Comcast Corporation	1,864	1,591	5,386	4,710
Combined CCHMO Parents [Member]
Management fee revenue	137	129	407	381
Revenue	137	129	407	381
Other operating and administrative	137	129	407	381
Costs and expenses, total	137	129	407	381
Interest expense	-30	-33	-96	-102
Equity in net income (losses) of investees, net	1,371	1,216	3,982	3,591
Nonoperating income (Expense), Total	1,341	1,183	3,886	3,489
Income (loss) before income taxes	1,341	1,183	3,886	3,489
Income tax (expense) benefit	11	12	34	36
Net income (loss)	1,352	1,195	3,920	3,525
Net income (loss) attributable to Comcast Corporation	1,352	1,195	3,920	3,525
Comprehensive income attributable to Comcast Corporation	1,415	1,195	3,983	3,525
NBCUniversal Media Parent [Member]
Other operating and administrative	211	211	641	686
Costs and expenses, total	211	211	641	686
Operating income (loss)	-211	-211	-641	-686
Interest expense	-123	-102	-366	-309
Investment income (loss), net	-3	2	-2	2
Equity in net income (losses) of investees, net	576	1,988	2,236	3,572
Other income (expense), net		-1		-14
Nonoperating income (Expense), Total	450	1,887	1,868	3,251
Income (loss) before income taxes	239	1,676	1,227	2,565
Income tax (expense) benefit	-3	-4	-13	5
Net income (loss)	236	1,672	1,214	2,570
Net income (loss) attributable to Comcast Corporation	236	1,672	1,214	2,570
Comprehensive income attributable to Comcast Corporation	244	1,706	1,176	2,587
Comcast Non-Guarantor Subsidiaries [Member]
Service revenue	16,151	16,544	47,731	46,633
Revenue	16,151	16,544	47,731	46,633
Programming and production	4,787	5,726	14,418	15,013
Other operating and administrative	4,673	4,481	13,523	12,839
Advertising, marketing and promotion	1,283	1,230	3,737	3,730
Depreciation	1,513	1,541	4,647	4,571
Amortization	395	410	1,200	1,218
Costs and expenses, total	12,651	13,388	37,525	37,371
Operating income (loss)	3,500	3,156	10,206	9,262
Interest expense	-56	-50	-148	-137
Investment income (loss), net	471	70	550	166
Equity in net income (losses) of investees, net	106	2,583	1,118	3,513
Other income (expense), net	-310	988	-280	938
Nonoperating income (Expense), Total	211	3,591	1,240	4,480
Income (loss) before income taxes	3,711	6,747	11,446	13,742
Income tax (expense) benefit	-1,137	-1,535	-3,353	-3,371
Net income (loss)	2,574	5,212	8,093	10,371
Net (income) loss attributable to noncontrolling interests and redeemable subsidiary preferred stock	-46	-865	-264	-1,373
Net income (loss) attributable to Comcast Corporation	2,528	4,347	7,829	8,998
Comprehensive income attributable to Comcast Corporation	2,327	4,398	7,741	9,061
Elimination and Consolidation Adjustments [Member]
Management fee revenue	-581	-545	-1,725	-1,616
Revenue	-581	-545	-1,725	-1,616
Other operating and administrative	-581	-545	-1,725	-1,616
Costs and expenses, total	-581	-545	-1,725	-1,616
Equity in net income (losses) of investees, net	-7,718	-10,845	-23,734	-24,953
Nonoperating income (Expense), Total	-7,718	-10,845	-23,734	-24,953
Income (loss) before income taxes	-7,718	-10,845	-23,734	-24,953
Net income (loss)	-7,718	-10,845	-23,734	-24,953
Net income (loss) attributable to Comcast Corporation	-7,718	-10,845	-23,734	-24,953
Comprehensive income attributable to Comcast Corporation	($7,678)	($10,933)	($23,757)	($25,040)

Condensed_Consolidating_Financ5

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities
Net cash provided by (used in) operating activities	$11,679	$11,239
Investing Activities
Capital expenditures	-4,593	-4,043
Cash paid for intangible assets	-694	-605
Acquisitions of real estate properties	-1,705
Acquisitions, net of cash acquired	-42	-95
Proceeds from sales of businesses and investments	655	3,095
Return of capital from investees	146	2,281
Purchases of investments	-1,177	-191
Other	83	68
Net cash provided by (used in) investing activities	-7,327	510
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	395	-555
Proceeds from borrowings	2,933	2,248
Repurchases and repayments of debt	-2,442	-2,505
Repurchases and retirements of common stock	-1,500	-2,250
Dividends paid	-1,454	-1,176
Issuances of common stock	35	215
Purchase of NBCUniversal noncontrolling common equity interest	-10,761
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	-164	-497
Settlement of Station Venture liability	-602
Other	-140	50
Net cash provided by (used in) financing activities	-13,700	-4,470
Increase (decrease) in cash and cash equivalents	-9,348	7,279
Cash and cash equivalents, beginning of period	10,951	1,620
Cash and cash equivalents, end of period	1,603	8,899
Comcast [Member]
Operating Activities
Net cash provided by (used in) operating activities	-451	-393
Investing Activities
Net transactions with affiliates	-116	3,015
Capital expenditures	-3	-8
Cash paid for intangible assets	-1	-4
Purchases of investments	-8
Net cash provided by (used in) investing activities	-128	3,003
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	400	-1
Proceeds from borrowings	2,933	2,248
Repurchases and repayments of debt		-1,726
Repurchases and retirements of common stock	-1,500	-2,250
Dividends paid	-1,454	-1,176
Issuances of common stock	35	215
Other	165	80
Net cash provided by (used in) financing activities	579	-2,610
Comcast Holdings [Member]
Operating Activities
Net cash provided by (used in) operating activities	-7	-4
Investing Activities
Net transactions with affiliates	7	205
Other		1
Net cash provided by (used in) investing activities	7	206
Financing Activities
Repurchases and repayments of debt		-202
Net cash provided by (used in) financing activities		-202
CCCL Parent [Member]
Operating Activities
Net cash provided by (used in) operating activities	-3	-39
Investing Activities
Net transactions with affiliates	2,100	39
Net cash provided by (used in) investing activities	2,100	39
Financing Activities
Repurchases and repayments of debt	-2,097
Net cash provided by (used in) financing activities	-2,097
Combined CCHMO Parents [Member]
Operating Activities
Net cash provided by (used in) operating activities	-99	-122
Investing Activities
Net transactions with affiliates	337	675
Net cash provided by (used in) investing activities	337	675
Financing Activities
Repurchases and repayments of debt	-238	-553
Net cash provided by (used in) financing activities	-238	-553
NBCUniversal Media Parent [Member]
Operating Activities
Net cash provided by (used in) operating activities	-767	-871
Investing Activities
Net transactions with affiliates	-900	4,750
Return of capital from investees	128
Purchases of investments	-2	-16
Other	-20	-22
Net cash provided by (used in) investing activities	-794	4,712
Financing Activities
Proceeds from (repayments of) short-term borrowings, net		-550
Repurchases and repayments of debt	-88	-1
Purchase of NBCUniversal noncontrolling common equity interest	-3,200
Other	-40
Net cash provided by (used in) financing activities	-3,328	-551
Increase (decrease) in cash and cash equivalents	-4,889	3,290
Cash and cash equivalents, beginning of period	5,129	238
Cash and cash equivalents, end of period	240	3,528
Comcast Non-Guarantor Subsidiaries [Member]
Operating Activities
Net cash provided by (used in) operating activities	13,006	12,668
Investing Activities
Net transactions with affiliates	-1,428	-8,684
Capital expenditures	-4,590	-4,035
Cash paid for intangible assets	-693	-601
Acquisitions of real estate properties	-1,705
Acquisitions, net of cash acquired	-42	-95
Proceeds from sales of businesses and investments	655	3,095
Return of capital from investees	18	2,281
Purchases of investments	-1,167	-175
Other	103	89
Net cash provided by (used in) investing activities	-8,849	-8,125
Financing Activities
Proceeds from (repayments of) short-term borrowings, net	-5	-4
Repurchases and repayments of debt	-19	-23
Purchase of NBCUniversal noncontrolling common equity interest	-7,561
Distributions to noncontrolling interests and dividends for redeemable subsidiary preferred stock	-164	-497
Settlement of Station Venture liability	-602
Other	-265	-30
Net cash provided by (used in) financing activities	-8,616	-554
Increase (decrease) in cash and cash equivalents	-4,459	3,989
Cash and cash equivalents, beginning of period	5,822	1,382
Cash and cash equivalents, end of period	$1,363	$5,371