Southwestern Energy (SWN) 10-Q 20 Oct 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 18, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Registrant Name	SOUTHWESTERN ENERGY CO
Entity Central Index Key	7,332
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		495,453,279
Trading Symbol	SWN

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Revenues:
Gas sales	$ 340	$ 458	$ 906	$ 1,540
Oil sales	19	19	50	60
NGL sales	22	14	59	47
Marketing	237	216	631	663
Gas gathering	33	42	106	136
Total Operating Revenues	651	749	1,752	2,446
Operating Costs and Expenses:
Marketing purchases	234	213	627	654
Operating expenses	139	176	455	507
General and administrative expenses	61	60	171	188
Restructuring charges	2		77
Depreciation, depletion and amortization	99	275	349	876
Impairment of natural gas and oil properties	817	2,839	2,321	4,374
(Gain) loss on sale of assets, net		1		(276)
Taxes, other than income taxes	24	27	69	84
Total Operating Costs and Expenses	1,376	3,591	4,069	6,407
Operating Loss	(725)	(2,842)	(2,317)	(3,961)
Interest Expense:
Interest on debt	59	51	168	153
Other interest charges	8	2	12	54
Interest capitalized	(41)	(53)	(123)	(155)
Total Interest Expense	26		57	52
Gain (Loss) on Derivatives	71	15	(28)	30
Loss on early extinguishment of debt	(51)		(51)
Other Income, Net	3			2
Loss Before Income Taxes	(728)	(2,827)	(2,453)	(3,981)
Provision (Benefit) for Income Taxes:
Current				7
Deferred	(20)	(1,088)	(20)	(1,539)
Provision (Benefit) for Income Taxes	(20)	(1,088)	(20)	(1,532)
Net Loss	(708)	(1,739)	(2,433)	(2,449)
Mandatory convertible preferred stock dividend	27	27	81	79
Net Loss Attributable to Common Stock	$ (735)	$ (1,766)	$ (2,514)	$ (2,528)
Loss Per Common Share:
Basic	$ (1.52)	$ (4.62)	$ (6.02)	$ (6.65)
Diluted	$ (1.52)	$ (4.62)	$ (6.02)	$ (6.65)
Weighted Average Common Shares Outstanding:
Basic	482,485,150	382,098,080	417,222,661	379,909,748
Diluted	482,485,150	382,098,080	417,222,661	379,909,748

CONDENSED CONSOLIDATED STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME LOSS [Abstract]
Net loss		$ (708)	$ (1,739)	$ (2,433)	$ (2,449)
Change in derivatives:
Settlements	[1]		(31)		(89)
Ineffectiveness			1		1
Change in fair value of derivative instruments	[2]		8		21
Total change in derivatives			(22)		(67)
Change in value of pension and other postretirement liabilities:
Amortization of prior service cost and net loss included in net periodic pension cost	[3]	1	1	1	1
Net gain incurred in period	[4]	1		5
Change in currency translation adjustment			(5)	3	(9)
Comprehensive loss		$ (706)	$ (1,765)	$ (2,424)	$ (2,524)
[1]	Net of ($19) million and ($56) million in taxes for the three and nine months ended September 30, 2015, respectively.
[2]	Net of $5 million and $13 million in taxes for the three and nine months ended September 30, 2015, respectively.
[3]	Net of $1 million in taxes for the nine months ended September 30, 2016 and 2015.
[4]	Net of $1 million and $2 million in taxes for the three and nine months ended September 30, 2016, respectively.

CONDENSED CONSOLIDATED STATEME4

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME LOSS [Abstract]
Settlements tax		$ (19)		$ (56)
Change in fair value of derivative instruments tax		$ 5		13
Amortization of prior service cost and net loss included in net periodic pension cost tax			$ 1	$ 1
Net gain incurred in period tax	$ 1		$ 2

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 1,474	$ 15
Accounts receivable, net	274	327
Derivative assets	93	3
Other current assets	48	48
Total current assets	1,889	393
Natural gas and oil properties, using the full cost method, including $2,189 million as of September 30, 2016 and $3,727 million as of December 31, 2015 excluded from amortization	22,421	22,478
Gathering systems	1,281	1,280
Other	588	606
Less: Accumulated depreciation, depletion and amortization	(19,501)	(16,821)
Total property and equipment, net	4,789	7,543
Other long-term assets	212	150
TOTAL ASSETS	6,890	8,086
Current liabilities:
Short-term debt	1	1
Accounts payable	423	513
Taxes payable	47	64
Interest payable	31	75
Dividends payable	27	27
Derivative liabilities	100	3
Other current liabilities	20	24
Total current liabilities	649	707
Long-term debt	4,651	4,704
Pension and other postretirement liabilities	51	50
Other long-term liabilities	416	343
Total long-term liabilities	5,118	5,097
Commitments and contingencies (Note 11)
Equity:
Common stock, $0.01 par value; 1,250,000,000 shares authorized; issued 493,446,371 shares as of September 30, 2016 (does not include 2,043,780 shares issued on October 17, 2016, on account of a dividend declared on September 21, 2016) and 390,138,549 as of December 31, 2015	5	4
Preferred stock, $0.01 par value, 10,000,000 shares authorized, 6.25% Series B Mandatory Convertible, $1,000 per share liquidation preference, 1,725,000 shares issued and outstanding as of September 30, 2016 and December 31, 2015, conversion in January 2018
Additional paid-in capital	4,673	3,409
Accumulated deficit	(3,515)	(1,082)
Accumulated other comprehensive loss	(39)	(48)
Common stock in treasury, 31,269 shares as of September 30, 2016 and 47,149 shares as of December 31, 2015	(1)	(1)
Total equity	1,123	2,282
TOTAL LIABILITIES AND EQUITY	$ 6,890	$ 8,086

CONDENSED CONSOLIDATED BALANCE6

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Natural gas and oil properties, using the full cost method, costs excluded from amortization	$ 2,189	$ 3,727
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,250,000,000	1,250,000,000
Common stock, shares issued	493,446,371	390,138,549
Treasury stock, shares	31,269	47,149
Series B Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, dividend rate	6.25%	6.25%
Liquidation preference per share	$ 1,000	$ 1,000
Preferred stock, shares issued	1,725,000	1,725,000
Preferred stock, shares outstanding	1,725,000	1,725,000

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash Flows From Operating Activities
Net loss	$ (2,433)	$ (2,449)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	349	877
Impairment of natural gas and oil properties	2,321	4,374
Amortization of debt issuance costs	12	50
Deferred income taxes	(20)	(1,539)
Loss on derivatives, net of settlement	48	105
Stock-based compensation	24	18
(Gain) loss on sale of assets, net		(276)
Restructuring charges	30
Loss on early extinguishment of debt	51
Other	5	2
Change in assets and liabilities:
Accounts receivable	53	175
Accounts payable	(72)	(55)
Taxes payable	(17)	(43)
Interest payable	(14)	(1)
Other assets and liabilities		(11)
Net cash provided by operating activities	337	1,227
Cash Flows From Investing Activities
Capital investments	(391)	(1,392)
Acquisitions		(582)
Proceeds from sale of property and equipment	434	704
Other		7
Net cash provided by (used in) investing activities	43	(1,263)
Cash Flows From Financing Activities
Payments on current portion of long-term debt	(1)	(1)
Payments on long-term debt	(1,175)	(500)
Payments on short-term debt		(4,500)
Payments on revolving credit facility	(3,268)	(2,168)
Borrowings under revolving credit facility	3,152	2,148
Payments on commercial paper	(242)	(5,179)
Borrowings under commercial paper	242	5,699
Change in bank drafts outstanding	(19)	26
Proceeds from issuance of long-term debt	1,191	2,200
Debt issuance costs	(17)	(17)
Proceeds from issuance of common stock	1,247	669
Proceeds from issuance of mandatory convertible preferred stock		1,673
Preferred stock dividend	(27)	(52)
Other	(4)
Net cash provided by (used in) financing activities	1,079	(2)
Increase (decrease) in cash and cash equivalents	1,459	(38)
Cash and cash equivalents at beginning of year	15	53
Cash and cash equivalents at end of period	$ 1,474	$ 15

CONDENSED CONSOLIDATED STATEME8

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - 9 months ended Sep. 30, 2016 - USD ($) $ in Millions		Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Common Stock in Treasury [Member]	Total
Balance, shares at Dec. 31, 2015		390,138,549	1,725,000
Balance at Dec. 31, 2015		$ 4		$ 3,409	$ (1,082)	$ (48)	$ (1)	$ 2,282
Comprehensive loss:
Net loss					(2,433)			(2,433)
Other comprehensive income						9		9
Comprehensive loss								(2,424)
Stock-based compensation				50				50
Preferred stock dividend, shares	[1]	5,124,856
Preferred stock dividend	[1]			(27)				(27)
Issuance of common stock, shares		98,900,000
Issuance of common stock		$ 1		1,246				1,247
Issuance of restricted stock, shares		85,305
Cancellation of restricted stock, shares		(137,629)
Tax withholding - stock compensation, shares		(664,710)
Tax withholding - stock compensation				(5)				(5)
Balance, shares at Sep. 30, 2016		493,446,371	1,725,000
Balance at Sep. 30, 2016		$ 5		$ 4,673	$ (3,515)	$ (39)	$ (1)	$ 1,123
[1]	Does not include 2,043,780 shares issued on October 17, 2016, on account of a dividend declared on September 21, 2016, distributed to holders of the Company's mandatory convertible preferred stock.

CONDENSED CONSOLIDATED STATEME9

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical)	Oct. 17, 2016shares
Subsequent Event [Member]
Common stock, shares issued as stock dividend	2,043,780

Basis Of Presentation

Basis Of Presentation	9 Months Ended
	Sep. 30, 2016
Basis Of Presentation [Abstract]
Basis Of Presentation	(1) BASIS OF PRESEN TATION  Southwestern Energy Company (including its subsidiaries, collectively “Southwestern” or the “Company”) is an independent energy company engaged in natural gas and oil exploration, development and production (“E&P”). The Company is also focused on creating and capturing additional value through its natural gas gathering and marketing businesses (“Midstream”). Southwestern conducts most of its businesses through subsidiaries and operates principally in two segments: E&P and Midstream.  Exploration and Production. Southwestern’s primary business is the exploration for and production of natural gas and oil, with current operations principally focused on the development of unconventional natural gas reservoirs located in Pennsylvania, West Virginia and Arkansas. The Company’s operations in northeast Pennsylvania, herein referred to as “Northeast Appalachia,” are primarily focused on the unconventional natural gas reservoir known as the Marcellus Shale. Operations in West Virginia and southwest Pennsylvania, herein referred to as “Southwest Appalachia,” are focused on the Marcellus Shale, the Utica and the Upper Devonian unconventional natural gas and oil reservoirs. Collectively, Southwestern refers to its properties located in Pennsylvania and West Virginia as the “Appalachian Basin.” The Company’s operations in Arkansas are primarily focused on an unconventional natural gas reservoir known as the Fayetteville Shale. Southwestern has exploration and production activities ongoing in Colorado and Louisiana, along with other areas in which it is currently exploring for new development opportunities. The Company also has drilling rigs located in Pennsylvania, West Virginia and Arkansas and provides oilfield products and services, principally serving its E&P operations.  Midstream. Through the Company’s affiliated midstream subsidiaries, Southwestern engage s in natural gas gathering activities in Arkansas and Louisiana. These activities primarily support the Company’s E&P operations and generate revenue from fees associated with the gathering of natural gas. Southwestern’s marketing activities capture opportunities that arise through the marketing and transportation of the natural gas, oil and NGLs produced in its E&P operations.  The accompanying unaudited condensed consolidated financial statements were prepared using accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and in accordance with the rules and regulations of the Securities and Exchange Commission. Certain information relating to the Company’s organization and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been appropriately condensed or omitted in this Quarterly Report. The Company believes the disclosures made are adequate to make the information presented not misleading.  The unaudited condensed consolidated financial statements contained in this report include all normal and recurring material adjustments that, in the opinion of management, are necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented herein. It is recommended that these unaudited condensed consolidated financial statements be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report for the year ended December 31, 201 5 (“2015 Annual Report”).  The Company’s significant accounting policies, which have been reviewed and approved by the Audit Committee of the Company’s Board of Directors, are summarized in Note 1 in the Notes to the Consolidated Financial Statement s included in the Company’s 2015 Annual Report.  Certain reclassifications have been made to the prior year financial statements to conform to the 2016 presentation. The effects of the reclassifications were not material to the Company’s unaudited condensed consolidated financial statements. 

Cash And Cash Equivalents

Cash And Cash Equivalents	9 Months Ended
	Sep. 30, 2016
Cash And Cash Equivalents [Abstract]
Cash And Cash Equivalents	 (2) CASH AND CASH EQUIVALENTS  The following table presents a summary of c ash and cash equivalents as of September 30, 2016 and December 31, 2015:     September 30, December 31,  2016 2015  (in millions)   Cash $ 31 $ 15  Marketable securities (1) 1,443 –  Total cash and cash equivalents $ 1,474 $ 15 (1) Consists of government stable value money market funds . 

Reduction In Workforce

Reduction In Workforce	9 Months Ended
	Sep. 30, 2016
Reduction In Workforce [Abstract]
Reduction In Workforce	(3) REDUC TION IN WORKFORCE  In January 2016, the Company announced a 40% workforce reduction of approximately 1,100 employees as a result of lower anticipated drilling activity. This reduction was substantially complete d in the first quarter of 2016 . In April 2016, the Company also partially restructured executive management, which was substantially completed in the second quarter of 2016.  The following table presents a summary of the restructuring charges for the three and nine months ended September 3 0 , 2016:    For the three months ended For the nine months ended  September 30, 2016 September 30, 2016  (in millions)  Severance (including payroll taxes) (1) $ – $ 44  Stock-based compensation (2) – 24 Pension and other postretirement benefits (3) 2 5  Other benefits – 3  Outplacement services, other – 1  Total restructuring charges (4) $ 2 $ 77 (1) Includes $1 million related to executive management res tructuring for the nine months ended September 30, 2016. (2) Includes $3 million related to executive management restructuring for the nine months ended September 30, 2016. (3) Includes non-cash charges related to the curtailment and settlement of the pension and other postretirement benefit plans. See Note 12 for additional details regarding the Company’s retirement and employee benefit plans. (4) Total restructuring charges were $2 million for the Company’s E&P segment for the three months ended September 30, 2016. For the nine months ended September 30, 2016, restructuring charges were $74 million and $3 million for the Company’s E&P and Midstream segments, respectively.  The following table presents a summary of liabilities associated with the Company’s restructuring activities for the three months ended September 30, 2016, which are reflected in accounts payable on the unaudited condensed consolidated balance sheet (in millions):    Liability at June 3 0 , 2016 $ 2  Additions −  Distributions (1)  Liability at September 30, 2016 $ 1  Severance payments and other separation costs related to restructuring will be completed by the end of the fourth quarter and are not expected to be material.    

Acquisitions And Divestitures

Acquisitions And Divestitures	9 Months Ended
	Sep. 30, 2016
Acquisitions And Divestitures [Abstract]
Acquisitions And Divestitures	(4) ACQUIS ITIONS AND DIVESTITURES  In September 2016, the Company sold approximately 55,000 net acres in West Virginia to Antero Resources Corporation for approximately $426 m illion , which reflects customary adjustments at closing and is subject to customary post-closing adjustments. Under full cost accounting rules, the Company accounted for the sale of these oil and natural gas properties as adjustments to capitalized costs, with no recognition of gain or loss as the sales did not involve a significant change in proved reserves or significantly alter the relationship between costs and proved reserves. In September 2016, $48 million of the net proceeds was used to repay borrowings under the Company’s term loan entered into in November 2015. The Company intends to use the remaining net proceeds from the sale for general corporate purposes, including to fund capital projects.  In May 2015, the Company sold conventional oil and gas assets located in East Texas and the Arkoma Basin for approximately $ 211 million. The Company also accounted for the sale of these oil and natural gas properties as adjustments to capitalized costs, with no recognition of gain or loss as the sales did not involve a significant change in proved reserves or significantly alter the relationship between costs and proved reserves. The proceeds from the transaction were used to reduce the Company’s debt. Approximately $ 205 million of the proceeds received were recorded as a reduction of the capitalized costs of the Company’s natural gas and oil properties in the United States pursuant to the full cost method of accounting.  In April 2015, the Company sold its gathering assets located in Bradford and Lycoming counties in northeast Pennsylvania to Howard Midstream Energy Partners, LLC for an adjusted sales price of approximately $ 489 million. The net book value of these assets was $206 million and was held in the Midstream segment as of the closing date. A gain on sale of $ 283 million was recognized and wa s included in gain on sale of assets, net on the unaudited condensed consolidated statement of operations. The assets include d approximately 100 miles of natural gas gathering pipelines, with nearly 600 million cubic feet per day of capacity. The proceeds from the transaction were used to substantially repay borrowings under the Company’s $500 million term loan facility that would have matured in December 2016 .  In January 2015, the Company completed an acquisition of certain natural gas and oil assets including approximately 46,700 net acres in northeast Pennsylvania from WPX Energy, Inc. for an adjusted purchase price of $270 million (the “WPX Property Acquisition”). This acreage was producing approximately 50 million net cubic feet of gas per day from 63 operated horizontal wells as of December 2014. As part of this transaction, the Company assumed firm transportation capacity of 260 million cubic feet of gas per day predominantly on the Millennium pipeline. The firm transport is being amortized over 19 years. As of September 3 0 , 2016 and December 31, 2015 the Company has amortized $15 million and $8 million, respectively. This transaction was funded with the revolving credit facility and was accounted for as a business combination.  In January 2015, the Company completed an acquisition of certain natural gas and oil assets from Statoil ASA including approximately 30,000 net acres in West Virginia and southwest Pennsylvania for $ 357 million, which was comprised of approximately 20% of Statoil’s interests in the properties (the “Statoil Property Acquisition”). All of these assets were also assets in which the Company had acquired interests under the Chesapeake Property Acquisition, as defined below. This transaction was funded with the revolving credit facility and was accounted for as a business combination. The Company allocated the purchase price to natural gas and oil properties, based on the respective fair values of the assets acquired.  In December 2014, the Company completed an acquisition of certain oil and gas assets from Chesapeake Energy Corporation covering approximately 413,000 net acres in West Virginia and southwest Pennsylvania targeting natural gas, NG Ls and crude oil contained in the Upper Devonian, Marcellus and Utica Shales for approximately $5.0 billion (the “Chesapeake Property Acquisition”). The transaction was temporarily financed using a $ 4.5 billion 364 -day senior unsecured bridge term loan credit facility and a $ 500 million two -year unsecured term loan. The Company repaid all principal and interest outstanding on the $ 4.5 billion bridge facility in January 2015 after permanent financing was finalized and, as a result, expensed $47 million of short-term unamortized debt issuance costs related to the bridge facility in January 2015 , recognized in other interest charges on the unaudited condensed consolidated statement of operations. The term loan facility was repaid in full in April 2015 with proceeds from the divestiture of the Company’s northeastern Pennsylvania gathering assets and borrowings under the revolving credit facility. 

Natural Gas And Oil Properties

Natural Gas And Oil Properties	9 Months Ended
	Sep. 30, 2016
Natural Gas And Oil Properties [Abstract]
Natural Gas And Oil Properties	( 5 ) NATURAL GA S AND OIL PROPERTIES  The Company utilizes the full cost method of accounting for costs related to the exploration, development an d acquisition of natural gas and oil properties. Under this method, all such costs (productive and nonproductive), including salaries, benefits and other internal costs directly attributable to these activities a re capitalized on a country-by- country basis and amortized over the estimated lives of the properties using the units-of-production method. These capitalized costs are subject to a ceiling test that limits such pooled costs , net of applicable deferred taxes, to the aggregate of the present value of future net revenues attributable to proved natural gas , oil and NGL reserves discounted at 10 % (standardized measure) plus the lower of cost or market value of unproved properties. Any costs in excess of the ceiling are written off as a non-cash expense. The expense may not be reversed in future periods, even though higher natural gas, oil and NGL prices may subsequently increase the ceiling. Companies using the full cost method are required to use the average quoted price from the first day of each month from the previous 12 months, incl uding the impact of derivatives designated for hedge accounting , to calculate the ceiling value of their reserves.  Using the average quoted price from the first day of each month from the previous 12 months for Henry Hub natural gas of $ 2.28 per MMBtu, West Texas Intermediate oil of $ 38.17 per barrel and NGLs of $ 6.46 per barrel, adjusted for market differentials, the Company’s net book value of its United States natural gas and oil properties exceeded the ceiling by $506 million (net of tax) at September 30 , 2016 and resulted in a non-cash ceiling test impairment. The Company had no hedge positions that were designated for hedge account ing as of September 3 0 , 2016. Decreases in market prices as well as changes in production rates, levels of reserves, evaluation of costs excluded from amortization, future development costs and production costs could result in future ceiling test impairments.  Using the average quoted price from the first day of each month from the previous 12 months for Henry Hub natural gas of $ 3.06 per MMBtu, West Texas Intermediate oil of $ 55.73 per barrel and NGLs of $8.62 per barrel , adjusted for market differentials, the net book value of the Company’s United States natura l gas and oil properties exceeded the ceiling by $1,746 million (net of tax) at September 30, 2015 and result ed in a non-cash ceiling test impairment . Cash flow hedges of natural gas production in place increased the ceiling amount by approximately $40 million as of September 30, 2015 . In the first and second quarters of 2016, the Company’s net book value of its United States and Canada natural gas and oil properties exceeded the ceiling by approximately $641 million (net of tax) at March 31, 2016 and $297 million (net of tax) at June 30, 2016, resulting in non-cash ceiling test impairments in each quarter. 

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share	( 6 ) EARN INGS PER SHARE  Basic earnings per common share is computed by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding during the reportable period. The diluted earnings per share calculation adds to the weighted average number of common shares outstanding: the incremental shares that would have been outstanding assuming the exercise of dilutive stock options, the vesting of unvested restricted shares of common stock , performance units, the assumed conversion of mandatory convertible preferred stock and the shares of common stock declared as a preferred stock dividend. An antidilutive impact is an increase in earnings per share or a reduction in net loss per share resulting from the conversion, exercise, or contingent issuance of certain securities.  In July 2016, the Company completed an underwritten public offering of 98,900,000 shares of its common stock, with an offering price to the public of $13.00 per share. Net proceeds, after underwriting discount and offering expenses, from the common stock offering were approximately $1,247 million. The proceeds from the offering were used to repay $375 million of the $750 million term loan entered into in November 2015 and to settle certain tender offers by purchasing an aggregate principal amount of approximately $700 million of the Company’s outstanding senior notes due in the first quarter of 2018. The remaining proceeds of the offering will be used for general corporate purposes.  In January 2015, the Company completed concurrent underwritten public offerings of 30,000,000 shares of its common stock and 34,500,000 depositary shares (both share counts include shares issued as a result of the underwriters exercising their options to purchase additional shares). The common stock offering was priced at $23.00 per share. Net proceeds, after underwriting discount and expenses, from the common stock offering were approximately $669 million. Net proceeds, after underwriting discount and expenses, from the depositary share offering were approximately $1.7 billion. Each depositary share represents a 1/20th interest in a share of the Company’s mandatory convertible preferred stock, with a liquidation preference of $1,000 per share (equivalent to a $50 liquidation preference per depositary share). The proceeds from the offerings were used to partially repay borrowings under the Company’s $4.5 billion 364 -day bridge facility with the remaining balance of the bridge facility fully repaid with proceeds from the Company’s January 2015 public offering of $2.2 billion in long-term senior notes.  The mandatory convertible pref erred stock entitles the holder to a proportional fractional interest in the rights and preferences of the convertible preferred stock, including conversion, dividend, liquidation and voting rights. Unless converted earlier at the option of the holders, on or around January 15, 2018 each share of convertible preferred stock will automatically convert into between 37.0028 and 43.4782 shares of the Company’s common stock (and, correspondingly, each depositary share will convert into between 1.85014 and 2.17391 shares of the Company’s common stock), subject to customary anti-dilution adjustments, depending on the volume-weighted average price of the Company’s common stock over a 20 trading day averaging period immediately prior to that date. The total potential shares of common stock resulting from the conversion will range from 63,829,830 to 74,999,895 shares.  The mandatory convertible preferred stock has the non-forfeitable right to participate on an as - converted basis at the conversion rate then in effect in any common stock dividends declared and as such, is considered a participating security. A ccordingly , it is included in the computation of basic and diluted earnings per share, pursuant to the two-class method. In the calculation of basic earnings per share attributable to common shareholders, participating securities are allocated earnings based on actual dividend distributions received plus a proportionate share of undistributed net income attributable to common shareholders, if any, after recognizing distributed earnings. The Company’s participating securities do not participate in undistributed net losses because they are not contractually obligated to do so.  On September 21 , 2016 , the Company declared its quarterly dividend, payable to holders of the mandatory convertible preferred stock , and announced that it would pay the quarterly dividend in common stock, in lieu of cash, to the extent permitted by the certificate of designations for the Series B preferred stock. The Company issued 2,043,780 shares of common stock on October 17, 2016 in payment for the dividend. Dividends declared in the first and second quarters of 2016 were settled in common stock, while the dividend declared in December 2015 was paid in cash in January 2016.  The following table presents the computation of earnings per share for the three and nine months ended September 30 , 201 6 and 201 5 :      For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions, except share/per share amounts)  Net loss $ (708) $ (1,739) $ (2,433) $ (2,449)  Mandatory convertible preferred stock dividend 27 27 81 79  Net loss attributable to common stock $ (735) $ (1,766) $ (2,514) $ (2,528)   Number of common shares:  Weighted average outstanding 482,485,150 382,098,080 417,222,661 379,909,748  Issued upon assumed exercise of outstanding stock options (1) – – – –  Effect of issuance of non-vested restricted common stock (2) – – – –  Effect of issuance of non-vested performance units (3) – – – –  Effect of issuance of mandatory convertible preferred stock (4) – – – –  Effect of declaration of preferred stock dividends (5) – – – –  Weighted average and potential dilutive outstanding 482,485,150 382,098,080 417,222,661 379,909,748   Loss per common share:  Basic $ (1.52) $ (4.62) $ (6.02) $ (6.65)  Diluted $ (1.52) $ (4.62) $ (6.02) $ (6.65) (1) Due to the net loss for the three and nine months ended September 30 , 2016 and 2015 , the unvested stock options were not recognized in diluted earnings per share calculations as they would have had an antidilutive effect . Options for 3,409,596 shares and 3,714,095 shares were excluded from the calculation of diluted shares for the three and nine months ended September 30, 2016, respectively, because they would have had an antidilutive effect. Options for 3,796,778 shares and 3,778,140 shares were excluded from the calculation of diluted shares for the three and nine months ended September 30, 2015, respectively, because they would have had an antidilutive effect. (2) Due to the net loss for the three and nine months ended September 30, 2016 and 2015 , the unvested share-based payments were not recognized in diluted earnings per share calculations as they would have had an antidilutive effect. The calculation excluded 599,372 shares and 993,576 sh ares of restricted stock for the three and nine months ended September 30, 2016, respectively, because they would have had an antidilutive effect. The calculation excluded 1,469,380 shares and 1,472,379 shares of restricted stock for the three and nine months ended September 30, 2015, respectively, because they would have had an antidilutive effect . (3) Due to the net loss f or the three and nine months ended September 30 , 2016, 935,330 shares and 762,171 shares , respectively, of performance units were excluded from the calculation of diluted earnings per share as they would have had an antidilutive effect. Due to the net loss for the three and nine months ended September 30, 2015, the calculation excluded 89,802 shares and 135,836 shares , respectively, of performance units as they would have had an antidilutive effect. (4) Due to the net loss f or the three and nine months ended September 30 , 2016 , 74,999,895 of weighted average common shares issuable upon the assumed conversion of the mandatory convertible preferred stock were excluded from the diluted earnings per sh are calculation as they would have had an antidilutive effect. Due to the net loss for the three and nine months ended September 30, 2015, 74,999,895 and 69,505,397 of weighted average common shares issuable upon the assumed conversion of the mandatory convertible preferred stock were excluded from the diluted earnings per sh are calculation , respectively, as they would have had an antidilutive effect. (5) Due to the net loss for the three months ended September 30, 2016, the 2,043,780 shares of common stock declared as preferred stock dividends were excluded from the diluted earnings per share calculations as they would have had an antidilutive effect. 

Derivatives And Risk Management

Derivatives And Risk Management	9 Months Ended
	Sep. 30, 2016
Derivatives And Risk Management [Abstract]
Derivatives And Risk Management	(7 ) DERIVATIVES A ND RISK MANAGEMENT  The Company is exposed to volatility in market prices and basis di fferentials for natural gas, oil and NGLs which impacts the predictability of its cash flows related to the sale of those commodities. These risks are managed by the Company’s use of certain derivative financial instruments. As of September 3 0, 2016 , the Company’s derivative financial instruments consisted of fixed price swaps, purchased put options, two-way costless collars, three-way costless collars, basis swaps, sold call options and interest rate swaps. The Company had basis swaps and sold call options as of December 31, 2015. A description of the Company’s derivative financial instruments is provided below:  Fixed price swaps The Company receives a fixed price for the contract and pays a floating market price to the counterparty.  Purchased put options The Company purchases put options from the counterparty by payment of a cash premium. If the market price is lower than the put’s strike price at the time of settlement, the Company receives from the counterparty such difference on purchased put options. If the market price settles above the put’s strike price, no payment is due from either party.  Two-way costless collars Arrangements that contain a fixed floor price (purchased put option) and a fixed ceiling price (sold call option) which, in aggregate, have no net cost. At the contract settlement date, (1) if the index price is higher than the ceiling price, the Company pays the counterparty the difference between the index price and ceiling price, (2) if the index price is between the floor price and the ceiling price, no payments are due from either party, and (3) if the index price is below the floor price, the Company will receive the difference between the floor price and the index price.  Three-way costless collars Arrangements that contain a purchased put option, a sold call option and a sold put option which, in aggregate, have no net cost. At the contract settlement date, (1) if the index price is higher than the ceiling price, the Company pays the counterparty the difference between the index price and ceiling price, (2) if the index price is between the middle strike price and the ceiling price, no payments are due from either party, (3) if the index is between the lowest strike price and the middle strike price, the Company will receive the difference between the middle strike price and the index price, and (4) if the index price is below the floor price, the Company will receive the difference between the purchased put strike price and the sold put strike price.  Basis swaps Arrangements that guarantee a price differential for natural gas from a specified delivery point. The Company receives a payment from the counterparty if the price differential is greater than the stated terms of the contract and pays the counterparty if the price differential is less than the stated terms of the contract.  Sold call options The Company sells call options in exchange for a premium. I f the market price exceeds the strike price of the call option a t the time of settlement, the Company pays the counterparty such excess on sold call options. If the market price settles below the call’s strike price , no payment is due from either party.  Interest rate swaps Interest rate swaps are used to fix or float interest rates on existing or anticipated indebtedness. The purpose of these instruments is to manage the Company’s existing or anticipated exposure to un favorable interest rate changes.  The Company utilizes counterparties for its derivative instruments that it believes are creditworthy at the time the transactions are entered into and the Company closely monitors the credit ratings of these counterparties. Additionally, the Company performs both quantitative and qualitative assessments of these counterparties based on their credit ratings and credit default swap rates where applicable. However, the events in the financial markets in recent years demonstrate there can be no assurance that a counterparty will be able to meet its obligations to the Company.  The following table provides information about the Company’s financial instruments that are sensitive to changes in commodity prices and that are used to protect the Company’s exposure. None of the financial instruments below are designated for hedge accounting treatment. The table presents the notional amount in Bcf, the weighted average contract prices and the fair value by expected maturity dates as of September 30, 2016.     Weighted Average Price per MMBtu  Volume (Bcf) Swaps Sold Puts Purchased Puts Sold Calls Basis Differential Fair value at September 30, 2016 ($ in millions)  Financial protection on production  2016  Fixed price swaps 51 $ 2.81 $ – $ – $ – $ – $ (8)  Purchased put options 4 $ – $ – $ 2.34 $ – $ – $ –  Two-way costless-collars 40 $ – $ – $ 2.93 $ 3.33 $ – $ 2  Three-way costless-collars 5 $ – $ 2.30 $ 3.00 $ 3.25 $ – $ –  Basis swaps 16 $ – $ – $ – $ – $ 0.02 $ 18  Total 116 $ 12  2017  Fixed price swaps 296 $ 3.04 $ – $ – $ – $ – $ (9)  Two-way costless-collars 103 $ – $ – $ 2.94 $ 3.38 $ – $ (1)  Three-way costless-collars 135 $ – $ 2.29 $ 2.97 $ 3.30 $ – $ (5)  Basis swaps 76 $ – $ – $ – $ – $ (0.59) $ 13  Total 610 $ (2) 2018  Two-way costless-collars 14 $ – $ – $ 3.00 $ 3.46 $ – $ (1)  Three-way costless-collars 73 $ – $ 2.28 $ 2.93 $ 3.37 $ – $ 4  Basis swaps 2 $ – $ – $ – $ – $ 0.83 $ (1)  Total 89 $ 2   Sold call options  2016 30 $ – $ – $ – $ 5.00 $ – $ –  2017 86 $ – $ – $ – $ 3.25 $ – $ (23)  2018 63 $ – $ – $ – $ 3.50 $ – $ (13)  2019 52 $ – $ – $ – $ 3.50 $ – $ (11)  2020 32 $ – $ – $ – $ 3.75 $ – $ (7)  Total 263 $ (54)  The balance sheet classification of the assets and liabilities related to derivative financial instruments (none of which are designated for hedge accounting) are summarized below as of September 3 0, 2016 a nd December 31, 2015 :     Derivative Assets  Balance Sheet Classification Fair Value  September 30, 2016 December 31, 2015  (in millions)  Derivatives not designated as hedging instruments: Fixed price swaps Derivative assets $ 9 $ –  Two-way costless collars Derivative assets 20 –  Three-way costless collars Derivative assets 27 –  Basis swaps Derivative assets 37 3  Fixed price swaps Other long-term assets 1 –  Two-way costless collars Other long-term assets 14 –  Three-way costless collars Other long-term assets 42 – Basis swaps Other long-term assets 4 –  Total derivative assets $ 154 $ 3   Derivative Liabilities  Balance Sheet Classification Fair Value  September 30, 2016 December 31, 2015  (in millions)  Derivatives not designated as hedging instruments:  Fixed price swaps Derivative liabilities $ 23 $ –  Two-way costless collars Derivative liabilities 20 –  Three-way costless collars Derivative liabilities 29 –  Basis swaps Derivative liabilities 10 –  Sold call options Derivative liabilities 15 –  Interest rate swaps Derivative liabilities 3 3  Fixed price swaps Other long-term liabilities 4 –  Two-way costless collars Other long-term liabilities 14 –  Three-way costless collars Other long-term liabilities 41 – Basis swaps Other long-term liabilities 1 –  Sold call options Other long-term liabilities 39 –  Interest rate swaps Other long-term liabilities 5 2  Total derivative liabilities $ 204 $ 5  At September 30, 2016, the net fair value of the Company’s financial instruments related to natural gas was a $42 million liability. The net fair value of the Company’s interest rate swaps was a n $8 million liability at Septem ber 30, 2016.  Derivative Contracts not Designated for Hedge Accounting  As of September 30 , 2016, the Company had no positions designated for hedge accounting treatment . G ains and losses on derivatives that are not designated for hedge accounting treatment , or that do not meet hedge accounting requirements , are recorded as a component of gain (loss) on derivatives on the unaudited condensed consolidated statements of operations. Accordingly, the gain (loss) on derivatives component of the statement s of operations reflects the gains and losses on both settled and unsettled derivatives. The Company calculates gains and losses on settled derivatives as the summation of gains and losses on positions which have settled within the reporting period. Only the settled gains and losses are included in the Company’s realized commodity price calculations.  The Company is a party to interest rate swaps that were entered into to mitigate the Company’s exposure to volatility in interest rates. The interest rate swaps have a notional amount of $170 million and expire in June 2020 . The Company did not designate the interest rate swaps for hedge accounting treatment . Changes in the fair value of the interest rate swaps are included in gain (loss) on derivatives o n the unaudited condensed consolidated statements of operations.  The following tables summarize the before tax effect of fixed price swaps, purchased put options, two-way costless collars, three-way costless collars, basis swaps, sold call options and interest rate swaps not designated for hedge accounting on the unaudited condensed consolidated statements of operations for the three and nine months ended September 30 , 201 6 and 201 5 :    Gain (Loss) on Derivatives, Unsettled  Recognized in Earnings  Consolidated Statement of Operations For the three months ended For the nine months ended  Classification of Gain (Loss) September 30, September 30,  Derivative Instrument on Derivatives, Unsettled 2016 2015 2016 2015  (in millions)  Fixed price swaps Gain (Loss) on Derivatives $ 23 $ (37) $ (17) $ (110)  Purchased put options Gain (Loss) on Derivatives – – – –  Two-way costless collars Gain (Loss) on Derivatives 5 – – –  Three-way costless collars Gain (Loss) on Derivatives 1 – (1) –  Basis swaps Gain (Loss) on Derivatives 31 1 27 (4)  Sold call options Gain (Loss) on Derivatives 21 3 (54) 11  Interest rate swaps Gain (Loss) on Derivatives – (1) (3) (2)  Total gain (loss) on unsettled derivatives $ 81 $ (34) $ (48) $ (105)   Gain (Loss) on Derivatives, Settled (1)  Recognized in Earnings  Consolidated Statement of Operations For the three months ended For the nine months ended  Classification of Gain (Loss) September 30, September 30,  Derivative Instrument on Derivatives, Settled 2016 2015 2016 2015  (in millions)  Fixed price swaps Gain (Loss) on Derivatives $ (9) $ 49 $ 7 $ 143  Purchased put options Gain (Loss) on Derivatives – – 11 –  Basis swaps Gain (Loss) on Derivatives – – 4 (6)  Interest rate swaps Gain (Loss) on Derivatives (1) – (2) (2)  Total gain (loss) on settled derivatives (2) $ (10) $ 49 $ 20 $ 135   Total gain (loss) on derivatives $ 71 $ 15 $ (28) $ 30  (1) T he Company calculates gain (loss) on derivatives, settled, as the summation of gains and losses on positions that have settled within the period . (2) Excluding interest rate swaps, t hese amounts are included, along with gas sales revenues, in the calculation of the Company’s realized natural gas price .  Derivative Contracts Designated for Hedge Accounting  A ll derivatives are recognized in the balance sheet as either an asset or liability and are measured at fair value other than transactions for which normal purchase/normal sale is applied. Certain criteria must be satisfied in order for derivative financial instruments to be designated for hedge accounting . Accounting guidance for qualifying hedges allows an unsettled derivative’s unrealized gains and losses to be recorded either in earnings or as a component of other comprehensive income until settled. In the period of settlement, the Company recognizes the gains and losses from these qualifying hedges in gas sales revenues. As of September 30 , 2016, the Company had no positions designated for hedge accounting treatment . In 2015, the Company had certain fixed price swaps that were designated for hedge accounting. For the three and nine months ended September 3 0 , 2 015, the Company reported pre-tax gain s in other comprehensive income of $14 million and $35 million , respectively, related to the effective portion of our unsettled fixed price swaps. The ineffective portion of those fixed price swaps was recognized in earnings and had an inconsequential impact to the unaudited condensed consolidated statement of operations for the three and nine months ended September 30 , 2015. For the three and nine months ended September 30, 2015 , pre-tax gain s of $50 million and $145 million , respectively, on settled fixed p rice swaps w ere transferred from other comprehensive income into gas sales revenues in the consolidated statements of operations.

Reclassifications From Accumula

Reclassifications From Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2016
Reclassifications From Accumulated Other Comprehensive Income (Loss) [Abstract]
Reclassifications From Accumulated Other Comprehensive Income (Loss)	(8 ) RECL ASSIFICATIONS FROM ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)  The following tables detail the components of accumulated other comprehensive income (loss) and the related tax effects for the nine months ended September 3 0 , 201 6 :     September 30, 2016  Pension and Other Postretirement Foreign Currency Total  (in millions) (1)  Beginning balance at December 31, 2015 $ (25) $ (23) $ (48)  Other comprehensive income before reclassifications 5 3 8  Amounts reclassified from/to other comprehensive income (loss) (2) 1 – 1  Net current-period other comprehensive income (loss) 6 3 9  Ending balance at September 30, 2016 $ (19) $ (20) $ (39) (1) All amounts are net of tax. (2) See separate table below for details about these reclassifications . 1       Details about Accumulated Other Comprehensive Income Affected Line Item in the Consolidated Statement of Operations Amount Reclassified from Accumulated Other Comprehensive Income  For the nine months ended September 30, 2016  (in millions)  Pension and other postretirement  Amortization of prior service cost and net loss (1) General and administrative expenses $ 2  Provision (benefit) for income taxes 1  Total reclassifications for the period Net loss $ 1  (1) See Note 12 for additional details regarding the Company’s retirement and employee benefit plans. 

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Measurements [Abstract]
Fair Value Measurements	( 9 ) FAIR VALU E MEASUREMENTS  The carrying amounts and estimated fair values of the Company’s financial instruments as of September 3 0 , 201 6 and December 31, 201 5 were as follows:    September 30, 2016 December 31, 2015  Carrying Fair Carrying Fair  Amount Value Amount Value  (in millions)  Cash and cash equivalents $ 1,474 $ 1,474 $ 15 $ 15  Credit facility – – 116 116  Term loan facility due Dec ember 2020 (1) 325 325 747 747  Term loan facility due December 2020 (1) 1,180 1,180 – –  Senior notes 3,147 3,093 3,842 2,651  Derivative instruments, net (50) (50) (2) (2)  (1) The maturity date will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes.  The carrying values of cash and cash equivalents, accounts receivable, other current assets , accounts payable and other current liabilities on the unaudited condensed consolidated balance sheets approxim ate fair value because of their short-term nature. For debt and derivative instruments, the following methods and assumptions were used to estimate fair value:  Debt: The fair values of the Company’s senior notes were based on the market value of the Company’s publicly traded debt as determined based on the yield of the Company’s senior notes.   The carrying values of the borrowings under the Company’s term loan facilities approximate fair value because the interest rate is variable and reflective of market rates. The Company considers the fair value of its debt to be a Level 2 measurement on the fair value hierarchy.  Derivative Instruments: The fair value of all derivative instruments is the amount at which the instrument could be exchanged currently between willing parties. The amounts are based on quoted market prices, best estimates obtained from counterparties and an option pricing model, when necessary, for price option contracts.  The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value. As presented in the tables below, this hierarchy consists of three broad levels:  Level 1 valuations - Consist of unadjusted quoted prices in active markets for identical assets and liabilities and have the highest priority .  Level 2 valuations - Consist of quoted market information for the ca lculation of fair market value.  Level 3 valuations - Consist of internal estimates and have the lowest priority.  The Company has classified its derivatives into these levels depending upon the data utilized to determine their fair values. The Company’s fixed price swaps (Level 2) are estimated using third-party discounted cash flow calculations using the NYMEX futures index. The Company utilized discounted cash flow models for valuing its interest rate derivatives (Level 2). The net derivative values attributable to the Company's interest rate derivative contracts as of September 30, 2016 are based on (i) the contracted notional amounts, (ii) active market-quoted London Interbank Offered Rate (“LIBOR”) yield curves and (iii) the applicable credit-adjusted risk-free rate yield curve. The Company’s sold call options, purchased put options, two-way costless collars and three-way costless collars (Level 3) are valued using the Black-Scholes model, an industry standard option valuation model that takes into account inputs such as contract terms, including maturity, and market parameters, including assumptions of the NYMEX futures index, interest rates, volatility and credit worthiness. The Company’s basis swaps (Level 3) are estimated using third-party calculations based upon forward commodity price curves.  Inputs to the Black-Scholes model, including the volatility input, which is the significant unobservable input for Level 3 fair value measurements, are obtained from a third-party pricing source, with independent verification of the most significant inputs on a monthly basis. An increase (decrease) in volatility would result in an increase (decrease) in fair value measurement, respectively.  Assets and liabilities measured at fair value on a recurring basis are summarized below (in millions):    September 30, 2016  Fair Value Measurements Using:  Quoted Prices Significant  in Active Significant Other Unobservable  Markets Observable Inputs Inputs Assets (Liabilities)  (Level 1) (Level 2) (Level 3) at Fair Value Fixed price swap assets $ – $ 10 $ – $ 10  Two-way costless collars assets – – 34 34  Three-way costless collars assets – – 69 69  Basis swap assets – – 41 41  Fixed price swap liabilities – (27) – (27) Two-way costless collars liabilities – – (34) (34)  Three-way costless collars liabilities – – (70) (70)  Basis swap liabilities – – (11) (11)  Sold call option liabilities – – (54) (54)  Interest rate swap liabilities – (8) – (8)  Total $ – $ (25) $ (25) $ (50)   December 31, 2015  Fair Value Measurements Using:  Quoted Prices Significant Other Significant  in Active Markets Observable Inputs Unobservable Inputs Assets (Liabilities)  (Level 1) (Level 2) (Level 3) at Fair Value  Basis swap assets $ – $ – $ 3 $ 3  Interest rate swap liabilities – (5) – (5)  Total $ – $ (5) $ 3 $ (2)  The table below presents reconciliations for the change in net fair value of derivative assets and liabilities measured at fair value on a recurring basis using significant unobse rvable inputs (Level 3) for the three and nine months ended September 3 0 , 201 6 and 2015. The fair values of Level 3 derivative instruments are estimated using proprietary valuation models that utilize both market observable and unobservable parameters. Level 3 instruments presented in the table consist of net derivatives valued using pricing models incorporating assumptions that, in the Company’s judgment, reflect reasonable assumptions a marketplace partic ipant would have used as of September 30, 2016 and 2015.            For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Balance at beginning of period $ (83) $ (5) $ 3 $ (8)  Total gains (losses):  Included in earnings 58 4 (13) 1  Purchases, issuances, and settlements:  Settlements – – (15) 6  Transfers into/out of Level 3 – – – –  Balance at end of period $ (25) $ (1) $ (25) $ (1)  Change in gains (losses) included in earnings relating to derivativ es still held as of September 30 $ 58 $ 4 $ (28) $ 7  

Debt

Debt	9 Months Ended
	Sep. 30, 2016
Debt [Abstract]
Debt	( 10 ) D EBT  The c omponents of debt as of September 30 , 201 6 and December 31, 201 5 consisted of the following:      September 30, 2016  Debt Instrument Unamortized Issuance Cost Unamortized Debt Discount Total  (in millions) Short-term debt:  7.15% Senior Notes due June 2018 $ 1 $ – $ – $ 1  Total short-term debt $ 1 $ – $ – $ 1   Long-term debt:  Variable rate ( 2.960% at September 30, 2016) term loan facility, due December 2020 (1) $ 327 $ (2) $ – $ 325  Variable rate ( 2.960% at September 30, 2016) term loan facility, due December 2020 (2) 1,191 (11) – 1,180  7.35% Senior Notes due October 2017 15 – – 15  7.125% Senior Notes due October 2017 25 – – 25  3.30% Senior Notes due January 2018 (3) ( 4 ) 38 – – 38  7.50% Senior Notes due February 2018 ( 3 ) 212 – – 212  7.15% Senior Notes due June 2018 26 – – 26  4.05% Senior Notes due January 2020 ( 4 ) 850 (5) – 845  4.10% Senior Notes due March 2022 1,000 (5) (1) 994  4.95% Senior Notes due January 2025 ( 4 ) 1,000 (7) (2) 991  Total long-term debt $ 4,684 $ (30) $ (3) $ 4,651   Total debt $ 4,685 $ (30) $ (3) $ 4,652  (1) In July 2016, $375 million was repaid on the term loan facility, extending the maturity from November 2018 to December 2020 , which will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes. In September 2016, an additional $48 million was repaid.  (2) The maturity date will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes.  (3) In July 2016, the Company purchased approximately $312 million of the 3.3 0 % Senior Notes due January 2018 and $388 million of the 7.5 0 % Senior Notes due February 2018.  (4) In February and June 2016, Moody’s and S&P downgraded certain senior n otes, increasing the interest rates by 175 basis points effective July 2016. As a result of the downgrades, interest rates increased to 5.05% for the 2018 Notes, 5.80% for the 2020 Notes and 6.70% for the 2025 Notes .   December 31, 2015  Debt Instrument Unamortized Issuance Cost Unamortized Debt Discount Total  (in millions) Short-term debt:  7.15% Senior Notes due June 2018 $ 1 $ – $ – $ 1  Total short-term debt $ 1 $ – $ – $ 1   Long-term debt:  Variable rate ( 1.886% at December 31, 2015) credit facility, expires December 2018 $ 116 $ – $ – $ 116  Variable rate ( 1.775% at December 31, 2015) term loan facility, due November 2018 750 (3) – 747  7.35% Senior Notes due October 2017 15 – – 15  7.125% Senior Notes due October 2017 25 – – 25  3.30% Senior Notes due January 2018 350 (2) – 348  7.50% Senior Notes due February 2018 600 (2) – 598  7.15% Senior Notes due June 2018 26 – – 26  4.05% Senior Notes due January 2020 850 (5) (1) 844  4.10% Senior Notes due March 2022 1,000 (5) (1) 994  4.95% Senior Notes due January 2025 1,000 (7) (2) 991  Total long-term debt $ 4,732 $ (24) $ (4) $ 4,704   Total debt $ 4,733 $ (24) $ (4) $ 4,705  2016 Credit Facility  In June 2016, the Company reduced its existing $2.0 billion unsecured revolving credit facility to $66 million and entered into a new credit agreement for $1,934 million, consisting of a $1,191 million secured term loan and a new $743 million unsecured revolving credit facility, which matures in December 2020 . The maturity date will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes. The $1,191 million secured term loan is fully drawn, with approximately $285 million of this balance used to pay down the previous revolving credit facility bala nce in its entirety. As of September 30, 2016, there were no borrowings under either revolving credit facilit y , however, there was $174 million in letters of credit outstanding against the 2016 revolving credit facility.  Loans under the 2016 credit agreement are subject to varying rates of interest based on whether the loan is a Eurodollar loan or an alternate base rate loan. Eurodollar loans bear interest at the Eurodollar rate, which is adjusted LIBOR plus applicable margins ranging from 1.750% to 2.500% . Alternate base rate loans bear interest at the alternate base rate plus the applicable margin ranging from 0.750% to 1.500% . The interest rate on the term loan facility is determined based upon the Company’s public debt ratings and was 250 basis points over the LIBOR as of September 30, 2016.  The new term loan and revolving credit facility contain financial covenants that impose certain restrictions on the Company. Under the new credit agreement, the Company must maintain a minimum interest coverage of 0.75x in 2016, increasing by 0.25x increments per year to 1.50x in 2019 and 2020 . The Company is also subject to a minimum liquidity requirement of $300 million, which could be increased up to $500 million upon certain conditions, as well as an anti-hoarding provision, requiring unrestricted cash in excess of $100 million to pay down any amounts borrowed under the new revolving credit facility. The financial covenant with respect to minimum interest coverage consists of EBITDAX divided by consolidated interest expense. EBITDAX excludes the effects of interest expense, income taxes, depreciation, depletion and amortization, any non-cash impacts from impairments, certain non-cash hedging activities, stock-based compensation expense, non-cash gains or losses on asset sales, unamortized issuance cost, unamortized debt discount and certain restructuring costs. Colla teral for the new secured term loan is principally the Company’s E&P properties in the Fayetteville Shale area, and the new credit agreement requires a minimum collateral coverage ratio of 1.50x the new secured term loan. This collateral also may support all or a part of revolving credit extensions depending on restrictions in the Company’s senior notes indentures.  A s of September 30, 2016 , the Company was in compliance with all of the covenants of this credit agreement. Although the Company does not anticipate any violations of the financial covenants, its ability to comply with these covenants is dependent upon the success of its exploration and development program and upon factors beyond the Company’s control, such as the market prices for natural gas and oil.  2013 Credit Facility  In December 2013, the Company entered into a credit agreement that exchanged its previous revolving credit facility. Under the revolving credit facility, the Company had a borrowing capacity of $2.0 billion. The revolving credit facility was unsecured and was not guaranteed by any subsidiaries. In June 2016, this credit facility was substantially exchanged for a new credit facility comprised of a $1,191 m illion secured term loan and a new $743 m illion revolving credit facility. The borrowing capacity of the original 2013 credit agreement was reduced from $2.0 billion to $66 million , remains unsecured and the maturity remain s December 2018 . As of September 30, 2016, there were no borrowings under this facility.  The existing unsecured 2013 revolving credit facility includes a financial covenant under which the Company may not have total debt in excess of 60% of its total adjusted book capital. This financial covenant with respect to capitalization percentages excludes the effects of any full cost ceiling impairments, certain hedging activities and the Company’s pension and other postretirement liabilities.  2015 Term Facility  In November 2015, the Company entered into a $750 million unsecured three -year term loan credit agreement with various lenders that was utilized to repay borrowings under the revolving credit facility. The interest rate on the term loan facility is determined based upon the Company’s public debt ratings from Moody’s and S&P and was 250 basis points over LIBOR as of September 30, 2016. The term loan facility requires prepayment unde r certain circumstances from the net cash proceeds of sales of equity or certain assets and borrowings outside the ordinary course of business. In June 2016, the 2015 term loan agreement was amended to extend the maturity date upon a repayment threshold. As a result of the July 2016 equity offering, the Company repaid $375 million of the $750 million term loan, which had the effect of extending the term loan maturity from November 2018 to December 2020 , which will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes. As a result of the repayment, the Company expensed $3 million of unamortized debt issuance costs, recognized in other interest charges on the unaudited condensed consolidated statement of operations for the three and nine months ended September 30, 2016. In September 2016, the Company repaid a n additional $48 million from the proceeds received from the closing of the sale of approximately 55,000 net acres in West Virginia to Antero Resources Corporation, resulting in an additional $0.4 million of interest expense related to unamortized debt issuance costs.  Senior Notes  In January 2015, the Company completed a public offering of $350 million aggregate principal amount of its 3.30% senior notes due 2018 (the “2018 Notes”), $850 million aggregate principal amount of its 4.05% senior notes due 2020 (the “2020 Notes”) and $1.0 billion aggregate principal amount of its 4.95% senior notes due 2025 (the “2025 Notes” together with the 2018 and 2020 Notes, the “Notes”), with net proceeds from the offering totaling approximately $2.2 billion after underwriting discounts and offering expenses. The proceeds from this offering were used to repay the remaining principal and interest outstanding under the Company’s $4.5 billion 364 -day bridge term loan facility, which was first reduced with proceeds from the Company’s concurrent underwritten public offerings of common and preferred stock, and were also used to repay a portion of amounts outstanding under the Company’s revolving credit facility. As a result of this repayment, the Company expensed $47 million of short-term unamortized debt issuance costs related to the bridge facility in January 2015 , recognized in other interest charges on the unaudited condensed consolidated statement of operations for the three months ended March 31, 2015 . The Notes were sold to the public at a price of 99.949% of their face value for the 2018 Notes, 99.897% of their face value for the 2020 Notes and 99.782% of their face value for the 2025 Notes. The interest rates on the Notes are determined based upon the public bond ratings from Moody’s and S&P. Downgrades on the Notes from either rating agency increase interest costs by 25 basis points per downgrade level and upgrades decrease interest costs by 25 basis points per upgrade level on the following semi-annual bond interest payment. In February and June 2016, Moody’s and S&P downgraded the Notes, increasing the interest rates by 175 basis points effective July 2016. As a result of the downgrades, interest rates increased to 5.05% for the 2018 Notes, 5.80% for the 2020 Notes and 6.70% for the 2025 Notes. In the event of future downgrades, the coupons for this series of notes are capped at 5.30% , 6.05% and 6.95% , respectively. T he first coupon payment to bondholders at the higher interest rate s will be paid in J anuary 201 7.  In July 2016, the Company used a portion of the proceeds from the July 2016 equity offering to settle certain tender offers by purchasing an aggregate principal amount of approximately $700 million of the Company’s outstanding senior notes due in the first quarter of 2018, resulting in a loss of $51 million for the early retirement and redemption of these senior notes includ ing $50 million of premi ums paid. Additionally, the Company expensed $2 million of unamortized debt issuance costs and debt discounts, recognized in other interest charges. 

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies [Abstract]
Commitments And Contingencies	(1 1 ) COMMIT MENTS AND CONTINGENCIES  Operating Commitments and Contingencies  As of September 30, 2016, the Company’s contractual obligations for demand and similar charges under firm transportation and gathering agreements to guarantee access capacity on natural gas and liquids pipelines and gathering systems totaled approximately $ 8.6 billion , $3.4 billion of which related to access capacity on future pipeline and gathering infrastructure projects that still require the granting of regulatory approvals and additional construction efforts. The Company also had guarantee obligations of up to $ 862 million of that amount. As of September 30, 2016, future payments under non-cancelable firm transportation and gathering agreements are as follows:      Payments Due by Period  Total Less than 1 Year 1 to 3 Years 3 to 5 Years 5 to 8 Years More than 8 Years  (in millions)  Infrastructure currently in service $ 5,157 $ 545 $ 1,140 $ 865 $ 851 $ 1,756  Pending regulatory approval and/or construction (1) 3,429 14 294 465 694 1,962  Total transportation charges $ 8,586 $ 559 $ 1,434 $ 1,330 $ 1,545 $ 3,718  (1) Based on the estim ated in-service dates as of September 30, 2016.  Environmental Risk  The Company is subject to laws and regulations relating to the protection of the environment. Environmental and cleanup related costs of a non-capital nature are accrued when it is both probable that a liability has been incurred and when the amount can be reasonably estimated. Management believes any future remediation or other compliance related costs will not have a material effect on the financial position or results of operations of the Company.  Litigation  The Company is subject to various litigation, claims and proceedings that have arisen in the ordinary course of business, such as for alleged breaches of contract, miscalculation of royalties, and pollution, contamination or nuisance. Management believes that such litigation, claims and proceedings, individually or in aggregate and after taking into account insurance, are not likely to have a material adverse impact on the Company’s financial position, results of operations or cash flows. Many of these matters are in early stages, so the allegations and the damage theories have not been fully developed, and are all subject to inhe rent uncertainties; therefore, m anagement’s view may change in the future. If an unfavorable final outcome were to occur, there exists the possibility of a material impact on the Company’s financial position, results of operations or cash flows for the period in which the effect becomes reasonably estimable. The Company accrues for such items when a liability is both probable and the amount can be reasonably estimated.  Berry-Helfand (Tovah Energy)  In February 2009, one of the Company’s subsidiaries was added as a defendant in a case then styled Tovah Energy, LLC and Toby Berry-Helfand v. David Michael Grimes, et al., then pending in the 273rd District Court in Shelby County, Texas. The plaintiff alleged that the subsidiary used information provided by the plaintiff under a confidentiality agreement, which she claimed, among other things, breached the agreement and constituted a misappropriation of a trade secret. Following a trial in December 2010, the court awarded approximately $11 million in actual damages and approximately $24 million in disgorgement of profits. Both sides appealed, and in July 2013 the Texas Court of Appeals for the Twelfth District reversed on all claims except misappropriation of trade secrets, reduced the judgment to the actual damages award and ordered the case remanded for an award of attorneys’ fees to the Company’s subsidiary on one of the claims on which judgment was reversed. Both parties petitioned the Supreme Court of Texas for review. On June 10, 2016, the Supreme Court ruled that insufficient evidence supported the damage award and remanded the case for a new trial. The date for the new trial has not yet been set. The Company’s subsidiary continues to deny that it breached any obligation or misappropriated any trade secret, the only two remaining claims. Based on the Company’s understanding and judgment of the facts and merits of this case, and after considering the advice of counsel, the Company has determined that, although reasonably possible, a materially adverse final outcome to this action is not probable. As such, the Company has not accrued any amounts with respect to this action. The Company’s assessment may change in the future depending on further court proceedings, and such a re-assessment could lead to the determination that the potential liability is probable and could be material to the Company’s results of operations, fi nancial position or cash flows.  Arkansas Royalty Litigation  Certain of the Company’s subsidiaries are defendants in three cases, two filed in Arkansas state court in 2010 and 2013 and one in federal court in 2014, on behalf of putative classes of royalty owners on some of the Company’s leases located in Arkansas. The chief complaint in all three cases is that one of the Company’s subsidiaries underpaid the royalty owners by, among other things, deducting from royalty payments costs for gathering, transportation, and compression of natural gas in excess of what is permitted by the relevant leases. In September and October 2014, the judges in the two Arkansas state actions entered orders certifying classes of royalty owners who are citizens of Arkansas. The Company’s subsidiaries have appealed those orders. Oral argument on both cases has been set for November 2016.  On November 17, 2015, the court in the federal case denied the plaintiff’s motion to certify a class of royalty owners not included in either of the two state cases. On April 11, 2016, the court certified a broader class that includes Arkansas residents and citizens . The plaintiff in the federal case presented two alternative damages theories. Under one theory, plaintiffs have asserted that obligations to affiliates are not “incurred” and therefore the exploration and production subsidiary was not entitled to deduct any post-production costs; the federal court has granted partial summary judgment for the Company’s subsidiaries on this theory. Under another theory, plaintiffs assert that the gathering and treating rates the Company deducted from royalty payments exceeded the affiliates’ actual costs or otherwise were not reasonable. The plaintiffs have not disclosed a specific damage calculation for any putative class, but based on the class representative’s disclosure regarding the calculation of claimed damages, class-wide damages could exceed $100 million. The Company has moved for summary judgement. A trial date has not been set.  In addition, in September 2015 three cases were filed in Arkansas state court on behalf of a total of 248 individually named plaintiffs. Each case asserts complaints that are in substance virtually identical to the above-described case. The Company and its subsidiaries have removed two of the cases to federal court, and those cases have been assigned to the court in which the above-described federal case is pending. All three cases have been stayed.  Management believes that, in all of the above cases, the deductions from royalty payments as calculated are permitted and intends to defend the cases vigorously. The Company’s assessment may change in the future due to the occurrence of certain events, such as adverse judgments, and such a re-assessment could lead to the determination that the potential liability is probable and could be material to the Company’s results of operations, financial position or cash flows.  Indemnifications  The Company provides certain indemnifications in relation to dispositions of assets. These indemnifications typically relate to disputes, litigation or tax matters existing at the date of disposition. No liability has been recognized in connection with these indemnifications. 

Pension Plan And Other Postreti

Pension Plan And Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2016
Pension Plan And Other Postretirement Benefits [Abstract]
Pension Plan And Other Postretirement Benefits	 (1 2 ) PENSION PLAN AND OTHER POSTRETIREMENT BENEFITS  The Company has defined pension and postretirement benefit plans which cover substantially all of the Company’s employees. Net periodic pension costs include the following components for the three and nine months ended September 30, 2016 and 2015 :    Pension Benefits  For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Service cost $ 3 $ 4 $ 9 $ 12  Interest cost 1 1 4 4  Expected return on plan assets (2) (2) (5) (6)  Amortization of prior service cost – – – –  Amortization of net loss – 1 1 2 Curtailment loss – – 1 –  Settlement loss 2 – 10 –  Net periodic benefit cost $ 4 $ 4 $ 20 $ 12  In January 2016, the Company initiated a reduction in workforce that was effectively completed by the end of the first quarter . As a result of the workforce reduction, the Company recognized a $1 million non-cash curtailment loss related to its pension plan for both the curtailment-related decrease to the benefit obligation and the recognition of the proportionate share of unrecognized prior service cost and net loss from other comprehensive income (loss) in the second quarter of 2016. Additionally, the Company recognized a non-cash settlement loss of $2 million and $10 million for the three and nine months ended September 30, 2016, respectively, related to a total of $35 million of lump sum payments from the pension plan during the second and third quarters of 2016.  The Company’s other postretirement benefit plan had a net periodic benefit cost ( gain) of $1 , $1 , ($4) and $3 million for the three months ended September 3 0 , 2016 and 2015 and nine months ended September 30, 2016 and 2015, respectively. Included in the net peri odic benefit cost for the nine months ended September 30, 2016 is a curtailment gain of $6 million, which more than offset the other components of net periodic benefit cost.  As of September 30 , 2016, the Company has contributed $8 million to the pension and other postretirement benefit plan s in 2016. The Company expects to contribute an additional $3 million during the remainder of 2016. The Company recognized a liability of $40 million and $12 million related to its pension and other postretirement be nefits, respectively, as of September 30, 2016 , compared to a liability of $31 million and $20 million as of December 31, 2015. The Company updated the discount rate used in the measurement of the benefit obligation of the pension plan and other postretirement benefits plan to 4.20% in the second quarter of 2016. The Company used an assumption of 4.60% from January 1, 2016 to March 31, 2016 for both the pension and other postretirement benefit plans.  The Company maintains a non-qualified deferred compensation supplemental retirement savings plan (“Non-Qualified Plan”) for certain key employees who may elect to defer and contribute a portion of their compensation, as permitted by the plan. Shares of the Company’s common stock purchased under the terms of the Non-Qualified Plan are presented as treasury stock and totaled 31,269 shares at September 3 0 , 2016 , compared to 47,149 s hares at December 31, 2015 .

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
Stock-Based Compensation [Abstract]
Stock-Based Compensation	 (1 3 ) STOCK-BASE D COMPENSATION  The Company recognized the following amounts in employee stock-based compensation costs for the three and nine months ended September 30, 2016 and 201 5 :    For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Stock-based compensation cost – expensed (1) $ 6 $ 6 $ 43 $ 18  Stock-based compensation cost – capitalized $ 2 $ 6 $ 7 $ 17 (1) Includes $16 million and $3 million related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016.  In January 2016, the Company announced a 40% workforce reduction that was substantially concluded by the end of March 2016. In April 2016, the Company also partially restructured executive management, which was substantially completed in the second quarter of 2016. Affected employees were offered a severance package that included, if applicable, amendments to outstanding equity awards that modified forfeiture provisions on separation from the Company. As a result, unvested stock-based equity awards became fully vested at the time of separation. These shares were revalued and recognized immediately as a component of restructuring charges on the Company’s unaudited condensed consolidated statements of operations.  As of September 30, 2016, there was $ 55 million of total unrecognized compensation cost related to the Company’s unvested stock option grants, restricted stock grants and performance units. This cost is expected to be recognized over a weighted-average period of 2 y ears .  Stock Options  The following table summarizes s tock option activity for the nine months ended September 30, 2016 and provides information for options outstanding an d options exercisable as of September 30, 2016 :    Number Weighted Average  of Options Exercise Price  (in thousands) (per share)  Outstanding at December 31, 2015 5,623 $ 24.57  Granted 156 8.60  Exercised – –  Forfeited or expired (63) 27.81  Outstanding at September 30, 2016 5,716 24.10  Exercisable at September 30, 2016 2,627 $ 35.80  Restricted Stock  The following table summarizes restr icted stock activity for the nine months ended September 30, 2016 and provides information for unvested shares as of September 30, 2016 :    Number Weighted Average  of Shares Fair Value  (in thousands) (per share)  Unvested shares at December 31, 2015 7,222 $ 13.24  Granted 79 8.41  Vested (1) (2,525) 9.24  Forfeited (138) 12.20  Unvested shares at September 30, 2016 4,638 $ 12.86 (1) I ncludes 2,041,877 shares related to the reduction in workforce and 151,575 shares related to the executive management restructuring for the nine months ended September 30, 2016.  Equity-Classified Performance Units  The following table summarizes performance unit activity for the nine months ended September 30, 2016 to be paid out in Company stock and provides information for unvested units as o f September 30, 2016. The performance units awarded in 2013 and 2014 inclu ded a market condition based on r elative Total Shareholder Return (“TSR”) and a performance condition based on the Company's Present Value Index (“PVI”), collectively the “Performance Measures .” The fair value of the TSR market condition of the performance units is based on a Monte Carlo model and is amortized to compensation expense on a straight-line basis over the vesting period of the award. The fair value of the PVI performance condition of the p erformance units is based on economic analysis for each investment opportunity based upon the expected present value added for each dollar to be invested and amortized to com pensation expense on a straight- line basis over the vesting period of the award. The performance units awarded in 2016 and 2015 are based exclusively on TSR. The grant date fair value is calculated using the applicable Performance Measures and the closing price of the Company’s common stock at the grant date.     Number Weighted Average  of Units (1) Fair Value  (in thousands) (per share)  Unvested units at December 31, 2015 407 $ 36.65  Granted 1,502 8.60  Vested (2 ) (414) 7.62  Forfeited (3) (290) 11.32  Unvested units at September 30, 2016 1,205 $ 13.70 (1) These amounts reflect the number of performance units granted in thousands. The actual payout of shares may range from a minimum of zero shares to a maximum of two shares contingent upon the actual performance against the applicable Performance Measures. (2) Includes 15,632 units and 37,590 units related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016. (3) Includes 76,281 units and 195,834 units related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016.  Liability-Classified Performance Units  Prior to 2013, c ertain employees were provided performance units vesting equally over three yea rs, payable in cash. The payout of these units wa s based on certain metrics, such as total shareholder return and reserve replacement efficiency, compared to a predetermined group of peer companies and Company goal s . At the end of each performance period, the value of the vest ed performance units, if any, would be paid in cash. In the first quarter of 2016, the Company completed the final payout under these performance unit agreements .

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2016
Segment Information [Abstract]
Segment Information	 (1 4 ) SEGM ENT INFORMATION  The Company’s reportable business segments have been identified based on the differences in products or services provided. Revenues for the E&P segment are derived from the production and sale of natural gas and liquids. The Midstream segment generates revenue through the marketing of both Company and third-party produced natural gas and liquids volumes and through gathering fees associated with the transportation of natural gas to market.  Summarized financial information for the Company’s reportable segments is shown in the following table. The accounting policies of the segments are the same as those described in Note 1 of the Notes to Consolidated Financial Statements included in Item 8 of the 201 5 Annual Report. Management evaluates the performance of its segments based on operating income, defined as operating revenues less operating costs. Income before income taxes, for the purpose of reconciling the operating income amount shown below to consolidated income before income taxes, is the sum of oper ating income, interest expense, gain (loss) on derivatives, loss on early extinguishment of debt and other income (loss ). The “Other” column includes items not related to the Company’s reportable segments including real estate and corporate items.      Exploration and  Production Midstream Other Total  (in millions)  Three months ended September 30, 2016:  Revenues from external customers $ 381 $ 270 $ – $ 651  Intersegment revenues (3) 412 – 409  Depreciation, depletion and amortization expense 83 16 – 99  Impairment of natural gas and oil properties 817 – – 817  Operating income (loss) (777) (1) 52 – (725)  Interest expense (3) 26 – – 26  Gain on derivatives 71 – – 71  Loss on early extinguishment of debt – – (51) (51)  Other income, net 2 1 – 3 Benefit for income taxes (3) (20) – – (20)  Assets 4,015 1,253 1,622 (4) 6,890  Capital investments (5) 179 1 – 180   Three months ended September 30, 2015:  Revenues from external customers $ 491 $ 258 $ – $ 749  Intersegment revenues (3) 489 – 486  Depreciation, depletion and amortization expense 255 20 – 275  Impairment of natural gas and oil properties 2,839 – – 2,839  Operating income (loss) (2,910) 68 – (2,842)  Gain on derivatives 15 – – 15  Provision (benefit) for income taxes (3) (1,112) 24 – (1,088)  Assets 9,159 1,329 215 10,703  Capital investments (5) 461 7 – 468     Exploration and  Production Midstream Other Total  (in millions)  Nine months ended September 30, 2016:  Revenues from external customers $ 1,015 $ 737 $ – $ 1,752  Intersegment revenues (17) 1,125 – 1,108  Depreciation, depletion and amortization expense 300 49 – 349  Impairment of natural gas and oil properties 2,321 – – 2,321  Operating income (loss) (2,486) (1) 169 (2) – (2,317)  Interest expense (3) 56 1 – 57  Loss on derivatives (27) (1) – (28)  Loss on early extinguishment of debt – – (51) (51)  Other income (loss), net 3 (2) (1) – Benefit for income taxes (3) (20) – – (20)  Assets 4,015 1,253 1,622 (4) 6,890  Capital investments (5) 372 3 1 376   Nine months ended September 30, 2015:  Revenues from external customers $ 1,647 $ 798 $ 1 $ 2,446  Intersegment revenues (14) 1,653 – 1,639  Depreciation, depletion and amortization expense 824 52 – 876  Impairment of natural gas and oil properties 4,374 – – 4,374  Operating income (loss) (4,471) 511 (6) (1) (3,961)  Interest expense (3) 45 7 – 52  Gain (loss) on derivatives 32 – (2) 30  Other income, net 2 – – 2  Provision (benefit) for income taxes (3) (1,724) 193 (1) (1,532)  Assets 9,159 1,329 215 10,703  Capital investments (5) 1,880 164 10 2,054 (1) Operating income (loss) for the E&P segment includes $2 million and $74 million related to restructuri ng charges for the three and nine months ended September 30, 2016, respectively. (2) Operating income (loss) for the Midstream segment includes $3 million related to restructuring charges for the nine months e nded September 30, 2016 . (3) Interest expense and the provision for income taxes by segment are an allocation of corporate amounts as they are incurred at the corporate level. (4) Other assets represent corporate assets not allocated to segments and assets for non-reportable segments. At September 30, 2016, other assets includes approximately $1,443 million in marketable securities. (5) Capital investments includes increases of $27 million and $6 million for the three months ended September 30, 2016 and 2015 , respectively, and decreases of $24 million and $5 million for the nine months ended September 30, 2016 and 2015, respectively, relating to the change in accrued expenditures between periods. E&P capital for t he nine month period ended September 30, 2015 includes approximately $516 million related to the WPX Property and Statoil Property Acquisitions. Midstream capit al for the nine months ended September 30, 2015 includes approximately $119 million associated with the intangible asset related to the firm transportation acquired through the WPX Property Acquisition. (6) Operating income (loss) for the Midstream segment includes $277 million gain on sale of assets for the nine months e nded September 30, 2015 .  Included in intersegment revenues of the Midstream segment are $ 355 million and $ 414 million for the three months ended September 30 , 2016 and 2015, respectively , and $941 million and $1.4 billion for the nine months ended September 30, 2016 and 2015, respectively, for marketing of the Company’s E&P sales. Corporate assets include cash and cash equivalents, furniture and fixtures and other costs. Corporate general and administrative costs, depreciation expense and taxes other than income are allocated to the segments.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Taxes [Abstract]
Income Taxes	(15) INCOME TAXES  The Company’s effective tax rate was approximately 3% and 1% for the three and nine months ended September 30, 2016, respectively, primarily as a result of the recognition of a valuation allowance. A $20 million tax benefit was recognized in the third quarter of 2016 primarily due to the laps e of the statute of limitations on uncertain tax positions associated with alternative minimum tax .  A valuation allowance for deferred tax assets, including net operating losses, is recognized when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. To assess that likelihood, the Company uses estimates and judgment regarding future taxable income, and considers the tax consequences in the jurisdiction where such taxable income is generated, to determine whether a valuation allowance is required. Such evidence can include current financial position, results of operations, both actual and forecasted, the reversal of deferred tax liabilities, and tax planning strategies as well as the current and forecasted business economic s of the oil and gas industry.  Due to the material write-downs of the carrying value of natural gas and oil properties and operating results, the Company is in a net deferred tax asset po sition. The Company believes it is more likely than not that these deferred tax assets will not be realized and recorded a $256 million and $903 million tax expense for the increase in our valuation allowance for the three and nine months ended September 30, 2016, respectively . Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit the use of deferred tax assets. A significant piece of objective negative evidence evaluated is the projected cumulative loss incurred over the three -year period ending December 31, 2016. Such objective negative evidence limits the ability to consider other subjective positive evidence, such as projections for future growth. The amount of the deferred tax asset considered realizable, however, could be adjusted if estimates of future taxable income are reduced or increased or if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as future expected growth. 

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
New Accounting Pronouncements [Abstract]
New Accounting Pronouncements	(1 6 ) NEW ACCOUNTI NG PRONOUNCEMENTS  New Accounting Standards Implemented  In September 2015, the FASB issued Accounting Standards Update No. 2015-16, Business Combinations (Topic 805) (“Update 2015-16”), which seeks to reduce the complexity of amounts recognized in a business combination. The amendments in Update 2015-16 require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The amendments in Update 2015-16 require that the acquirer record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The amendments in Update 2015-16 require an entity to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. The amendments in Update 2015-16 were effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The Company adopted this update in the first quarter of 2016 resulting in no impact on its unaudited condensed consolidated results of operations, financial position and cash flows.  In May 2015, the FASB issued Accounting Standards Update No. 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (Or Its Equivalent) (“Update 2015-07”), which amends ASC 820, Fair Value Measurement. The standard removes the requirement to categorize within the fair value hierarchy investments for which fair value is measured using the net asset value per share practical expedient and removes certain related disclosure requirements. The amendments in Update 2015-07 are effective for reporting periods beginning after December 15, 2015, with early adoption permitted. The Company adopted this update in the first quarter of 2016 resulting in no impact on its unaudited condensed consolidated results of operations, financial position and cash flows.  In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) (“Update 2015-03”), in an effort to simplify presentation of debt issuance costs. Update 2015-03 required that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs was not affected by the amendments in this Update. Entities were required to apply the amendments in Update 2015-03 on a retrospective basis, with the balance sheet of each individual period presented adjusted to reflect the period-specific effects of applying the new guidance. In August 2015, the FASB issued Accounting Standards Update No. 2015-15, Interest-Imputation of Interest (Subtopic 835-30) (“Update 2015-15”), which addressed the presentation or subsequent measurement of debt issuance costs related to line-of-credit arrangements, given the absence of authoritative guidance within Update 2015-03 for debt issuance costs related to line-of-credit arrangements. For public entities, Update 2015-03 and Update 2015-15 were effective for annual reporting periods beginning after December 15, 2015, including interim periods within that reporting period. The Company adopted this update in the first quarter of 2016 resulting in an immaterial impact on its unaudited condensed consolidated results of operations, financial position and cash flows. At December 31, 2015, the Company had $24 million in unamortized debt expense that was classified as a long-term asset which is now presented as a contra liability as a result of adoption.  In November 2014, the FASB issued Accounting Standards Update No. 2014-16, Derivatives and Hedging – Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share is More Akin to Debt or to Equity (Subtopic 815-15) (“Update 2014-16”), addresses diversity in practice related to the determination of whether derivative features embedded in hybrid instruments issued in the form of a share should be bifurcated and accounted for separately. For public entities, Update 2014-16 was effective for annual reporting periods beginning after December 15, 2015, including interim periods within that reporting period. The Company adopted this update in the first quarter of 2016 resulting in no impact on its unaudited condensed consolidated results of operations, financial position and cash flows.  New Accounting Standards Not Yet Implemented  In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230) (“Update 2016-15”), which seeks to reduce the existing diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. For public entities, Update 2016-15 becomes effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the provisions of Update 2016-15 and assessing the impact, if any, it may have on its consolidated results of operations, financial position or cash flows.  In March 2016, the FASB issued Accounting Standards Update No. 2016-09, Compensation - Stock Compensation (Topic 718) (“Update 2016-09”), which seeks to simplify accounting for share-based payment transactions including income tax consequences, classification of awards as either equity or liabilities, and the classification on the statement of cash flows. For public entities, Update 2016-09 becomes effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the provisions of Update 2016-09 and assessing the impact, if any, it may have on its consolidated results of operations, financial position or cash flows.  In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) (“Update 2016-02”), which seeks to increase transparency and comparability among organizations by, among other things, recognizing lease assets and lease liabilities on the balance sheet for leases classified as operating leases under previous GAAP and disclosing key information about leasing arrangements. For public entities, Update 2016-02 becomes effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the provisions of Update 2016-02 and assessing the impact, if any, it may have on its consolidated results of operations, financial position or cash flows.  In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Inventory (Topic 330) (“Update 2015-11”), which seeks to simplify the measurement of inventory. Update 2015-11 requires that an entity should measure inventory at the lower of cost and net realizable value, where net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. For public entities, the amendments in Update 2015-11 are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the provisions of Update 2015-11 and assessing the impact, if any, it may have on its consolidated results of operations, financial position or cash flows.  In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“Update 2014-09”), which seeks to provide clarity for recognizing revenue. Topic 606 Revenue from Contracts with Customers will supersede the revenue recognition requirement as in Topic 605 Revenue Recognition. Update 2014-09 requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to those goods or services. Entities may apply the amendments in Update 2014-09 either (a) retrospectively to each reporting period presented, and the entity may elect a practical expedient per the update, or (b) retrospectively with the cumulative effect of initially applying Update 2014-09 recognized at the date of initial application – if an entity elects this transition method it also should provide the additional disclosures in reporting periods. In August 2015, the FASB issued Accounting Standards Update No. 2015-14, Revenue from Contracts with Customers (Topic 606) (“Update 2015-14”). Deferral of the Effective Date, which finalized proposed ASU No. 2015-240 of the same name and responds to stakeholders’ request to defer the effective date of the guidance in ASU No. 2014-09. In March 2016, the FASB issued Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606) – Principal versus Agent Considerations (Reporting Revenue Gross versus Net ) (“Update 2016-08”), which finalized proposed ASU No. 2015-290 of the same name and clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued Accounting Standards Update No. 2016-10, Revenue from Contracts with Customers (Topic 606) (“Update 2016-10”), which clarifies multiple aspects of Topic 606. In May 2016, the FASB issued Accounting Standards Update No. 2016-12, Revenue from Contracts with Customers (Topic 606) – Narrow-Scope Improvements and Practical Expedients (“Update 2016-12”), which provides clarifying guidance in a few narrow areas and adds some practical expedients to the guidance. For public entities, Upda te 2014-09, Update 2015-14, Update 2016-08 , Update 2016-10 and Update 2016-12 are effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is currently evaluating the provisions of Upd ate 2014-09, Update 2015-14, Update 2016-08 , Update 2016-10 and Update 2016-12 and assessing the impact, if any, they may have on its consolidated results of operations, financial position or cash flows.

Cash And Cash Equivalents (Tabl

Cash And Cash Equivalents (Tables)	9 Months Ended
	Sep. 30, 2016
Cash And Cash Equivalents [Abstract]
Summary Of Cash And Cash Equivalents	  September 30, December 31,  2016 2015  (in millions)   Cash $ 31 $ 15  Marketable securities (1) 1,443 –  Total cash and cash equivalents $ 1,474 $ 15 (1) Consists of government stable value money market funds .

Reduction In Workforce (Tables)

Reduction In Workforce (Tables)	9 Months Ended
	Sep. 30, 2016
Reduction In Workforce [Abstract]
Summary Of Restructuring Charges	  For the three months ended For the nine months ended  September 30, 2016 September 30, 2016  (in millions)  Severance (including payroll taxes) (1) $ – $ 44  Stock-based compensation (2) – 24 Pension and other postretirement benefits (3) 2 5  Other benefits – 3  Outplacement services, other – 1  Total restructuring charges (4) $ 2 $ 77 (1) Includes $1 million related to executive management res tructuring for the nine months ended September 30, 2016. (2) Includes $3 million related to executive management restructuring for the nine months ended September 30, 2016. (3) Includes non-cash charges related to the curtailment and settlement of the pension and other postretirement benefit plans. See Note 12 for additional details regarding the Company’s retirement and employee benefit plans. (4) Total restructuring charges were $2 million for the Company’s E&P segment for the three months ended September 30, 2016. For the nine months ended September 30, 2016, restructuring charges were $74 million and $3 million for the Company’s E&P and Midstream segments, respectively.
Summary Of Liabilities Associated With Restructuring Activities	  Liability at June 3 0 , 2016 $ 2  Additions −  Distributions (1)  Liability at September 30, 2016 $ 1 

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share	  For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions, except share/per share amounts)  Net loss $ (708) $ (1,739) $ (2,433) $ (2,449)  Mandatory convertible preferred stock dividend 27 27 81 79  Net loss attributable to common stock $ (735) $ (1,766) $ (2,514) $ (2,528)   Number of common shares:  Weighted average outstanding 482,485,150 382,098,080 417,222,661 379,909,748  Issued upon assumed exercise of outstanding stock options (1) – – – –  Effect of issuance of non-vested restricted common stock (2) – – – –  Effect of issuance of non-vested performance units (3) – – – –  Effect of issuance of mandatory convertible preferred stock (4) – – – –  Effect of declaration of preferred stock dividends (5) – – – –  Weighted average and potential dilutive outstanding 482,485,150 382,098,080 417,222,661 379,909,748   Loss per common share:  Basic $ (1.52) $ (4.62) $ (6.02) $ (6.65)  Diluted $ (1.52) $ (4.62) $ (6.02) $ (6.65) (1) Due to the net loss for the three and nine months ended September 30 , 2016 and 2015 , the unvested stock options were not recognized in diluted earnings per share calculations as they would have had an antidilutive effect . Options for 3,409,596 shares and 3,714,095 shares were excluded from the calculation of diluted shares for the three and nine months ended September 30, 2016, respectively, because they would have had an antidilutive effect. Options for 3,796,778 shares and 3,778,140 shares were excluded from the calculation of diluted shares for the three and nine months ended September 30, 2015, respectively, because they would have had an antidilutive effect. (2) Due to the net loss for the three and nine months ended September 30, 2016 and 2015 , the unvested share-based payments were not recognized in diluted earnings per share calculations as they would have had an antidilutive effect. The calculation excluded 599,372 shares and 993,576 sh ares of restricted stock for the three and nine months ended September 30, 2016, respectively, because they would have had an antidilutive effect. The calculation excluded 1,469,380 shares and 1,472,379 shares of restricted stock for the three and nine months ended September 30, 2015, respectively, because they would have had an antidilutive effect . (3) Due to the net loss f or the three and nine months ended September 30 , 2016, 935,330 shares and 762,171 shares , respectively, of performance units were excluded from the calculation of diluted earnings per share as they would have had an antidilutive effect. Due to the net loss for the three and nine months ended September 30, 2015, the calculation excluded 89,802 shares and 135,836 shares , respectively, of performance units as they would have had an antidilutive effect. (4) Due to the net loss f or the three and nine months ended September 30 , 2016 , 74,999,895 of weighted average common shares issuable upon the assumed conversion of the mandatory convertible preferred stock were excluded from the diluted earnings per sh are calculation as they would have had an antidilutive effect. Due to the net loss for the three and nine months ended September 30, 2015, 74,999,895 and 69,505,397 of weighted average common shares issuable upon the assumed conversion of the mandatory convertible preferred stock were excluded from the diluted earnings per sh are calculation , respectively, as they would have had an antidilutive effect. (5) Due to the net loss for the three months ended September 30, 2016, the 2,043,780 shares of common stock declared as preferred stock dividends were excluded from the diluted earnings per share calculations as they would have had an antidilutive effect.

Derivatives And Risk Manageme29

Derivatives And Risk Management (Tables)	9 Months Ended
	Sep. 30, 2016
Derivatives And Risk Management [Abstract]
Schedule Of Derivative Instruments, Notional Amount In BCF, Weighted Average Contract Prices And Fair Value	  Weighted Average Price per MMBtu  Volume (Bcf) Swaps Sold Puts Purchased Puts Sold Calls Basis Differential Fair value at September 30, 2016 ($ in millions)  Financial protection on production  2016  Fixed price swaps 51 $ 2.81 $ – $ – $ – $ – $ (8)  Purchased put options 4 $ – $ – $ 2.34 $ – $ – $ –  Two-way costless-collars 40 $ – $ – $ 2.93 $ 3.33 $ – $ 2  Three-way costless-collars 5 $ – $ 2.30 $ 3.00 $ 3.25 $ – $ –  Basis swaps 16 $ – $ – $ – $ – $ 0.02 $ 18  Total 116 $ 12  2017  Fixed price swaps 296 $ 3.04 $ – $ – $ – $ – $ (9)  Two-way costless-collars 103 $ – $ – $ 2.94 $ 3.38 $ – $ (1)  Three-way costless-collars 135 $ – $ 2.29 $ 2.97 $ 3.30 $ – $ (5)  Basis swaps 76 $ – $ – $ – $ – $ (0.59) $ 13  Total 610 $ (2) 2018  Two-way costless-collars 14 $ – $ – $ 3.00 $ 3.46 $ – $ (1)  Three-way costless-collars 73 $ – $ 2.28 $ 2.93 $ 3.37 $ – $ 4  Basis swaps 2 $ – $ – $ – $ – $ 0.83 $ (1)  Total 89 $ 2   Sold call options  2016 30 $ – $ – $ – $ 5.00 $ – $ –  2017 86 $ – $ – $ – $ 3.25 $ – $ (23)  2018 63 $ – $ – $ – $ 3.50 $ – $ (13)  2019 52 $ – $ – $ – $ 3.50 $ – $ (11)  2020 32 $ – $ – $ – $ 3.75 $ – $ (7)  Total 263 $ (54) 
Balance Sheet Classification Of Derivative Financial Instruments	  Derivative Assets  Balance Sheet Classification Fair Value  September 30, 2016 December 31, 2015  (in millions)  Derivatives not designated as hedging instruments: Fixed price swaps Derivative assets $ 9 $ –  Two-way costless collars Derivative assets 20 –  Three-way costless collars Derivative assets 27 –  Basis swaps Derivative assets 37 3  Fixed price swaps Other long-term assets 1 –  Two-way costless collars Other long-term assets 14 –  Three-way costless collars Other long-term assets 42 – Basis swaps Other long-term assets 4 –  Total derivative assets $ 154 $ 3   Derivative Liabilities  Balance Sheet Classification Fair Value  September 30, 2016 December 31, 2015  (in millions)  Derivatives not designated as hedging instruments:  Fixed price swaps Derivative liabilities $ 23 $ –  Two-way costless collars Derivative liabilities 20 –  Three-way costless collars Derivative liabilities 29 –  Basis swaps Derivative liabilities 10 –  Sold call options Derivative liabilities 15 –  Interest rate swaps Derivative liabilities 3 3  Fixed price swaps Other long-term liabilities 4 –  Two-way costless collars Other long-term liabilities 14 –  Three-way costless collars Other long-term liabilities 41 – Basis swaps Other long-term liabilities 1 –  Sold call options Other long-term liabilities 39 –  Interest rate swaps Other long-term liabilities 5 2  Total derivative liabilities $ 204 $ 5 
Summary Of Before Tax Effect Of Cash Flow Hedges On Consolidated Financial Statements	   Gain (Loss) on Derivatives, Unsettled  Recognized in Earnings  Consolidated Statement of Operations For the three months ended For the nine months ended  Classification of Gain (Loss) September 30, September 30,  Derivative Instrument on Derivatives, Unsettled 2016 2015 2016 2015  (in millions)  Fixed price swaps Gain (Loss) on Derivatives $ 23 $ (37) $ (17) $ (110)  Purchased put options Gain (Loss) on Derivatives – – – –  Two-way costless collars Gain (Loss) on Derivatives 5 – – –  Three-way costless collars Gain (Loss) on Derivatives 1 – (1) –  Basis swaps Gain (Loss) on Derivatives 31 1 27 (4)  Sold call options Gain (Loss) on Derivatives 21 3 (54) 11  Interest rate swaps Gain (Loss) on Derivatives – (1) (3) (2)  Total gain (loss) on unsettled derivatives $ 81 $ (34) $ (48) $ (105)   Gain (Loss) on Derivatives, Settled (1)  Recognized in Earnings  Consolidated Statement of Operations For the three months ended For the nine months ended  Classification of Gain (Loss) September 30, September 30,  Derivative Instrument on Derivatives, Settled 2016 2015 2016 2015  (in millions)  Fixed price swaps Gain (Loss) on Derivatives $ (9) $ 49 $ 7 $ 143  Purchased put options Gain (Loss) on Derivatives – – 11 –  Basis swaps Gain (Loss) on Derivatives – – 4 (6)  Interest rate swaps Gain (Loss) on Derivatives (1) – (2) (2)  Total gain (loss) on settled derivatives (2) $ (10) $ 49 $ 20 $ 135   Total gain (loss) on derivatives $ 71 $ 15 $ (28) $ 30  (1) T he Company calculates gain (loss) on derivatives, settled, as the summation of gains and losses on positions that have settled within the period . (2) Excluding interest rate swaps, t hese amounts are included, along with gas sales revenues, in the calculation of the Company’s realized natural gas price .

Reclassifications From Accumu30

Reclassifications From Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2016
Reclassifications From Accumulated Other Comprehensive Income (Loss) [Abstract]
Components Of Accumulated Other Comprehensive Income (Loss)	    September 30, 2016  Pension and Other Postretirement Foreign Currency Total  (in millions) (1)  Beginning balance at December 31, 2015 $ (25) $ (23) $ (48)  Other comprehensive income before reclassifications 5 3 8  Amounts reclassified from/to other comprehensive income (loss) (2) 1 – 1  Net current-period other comprehensive income (loss) 6 3 9  Ending balance at September 30, 2016 $ (19) $ (20) $ (39) (1) All amounts are net of tax. (2) See separate table below for details about these reclassifications . 1
Amounts Reclassified From Accumulated Other Comprehensive Income (Loss)	  Details about Accumulated Other Comprehensive Income Affected Line Item in the Consolidated Statement of Operations Amount Reclassified from Accumulated Other Comprehensive Income  For the nine months ended September 30, 2016  (in millions)  Pension and other postretirement  Amortization of prior service cost and net loss (1) General and administrative expenses $ 2  Provision (benefit) for income taxes 1  Total reclassifications for the period Net loss $ 1  (1) See Note 12 for additional details regarding the Company’s retirement and employee benefit plans.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Measurements [Abstract]
Carrying Amount And Estimated Fair Values Of Financial Instruments	  September 30, 2016 December 31, 2015  Carrying Fair Carrying Fair  Amount Value Amount Value  (in millions)  Cash and cash equivalents $ 1,474 $ 1,474 $ 15 $ 15  Credit facility – – 116 116  Term loan facility due Dec ember 2020 (1) 325 325 747 747  Term loan facility due December 2020 (1) 1,180 1,180 – –  Senior notes 3,147 3,093 3,842 2,651  Derivative instruments, net (50) (50) (2) (2)  (1) The maturity date will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes.
Summary Of Assets And Liabilities Measured At Fair Value On Recurring Basis	  September 30, 2016  Fair Value Measurements Using:  Quoted Prices Significant  in Active Significant Other Unobservable  Markets Observable Inputs Inputs Assets (Liabilities)  (Level 1) (Level 2) (Level 3) at Fair Value Fixed price swap assets $ – $ 10 $ – $ 10  Two-way costless collars assets – – 34 34  Three-way costless collars assets – – 69 69  Basis swap assets – – 41 41  Fixed price swap liabilities – (27) – (27) Two-way costless collars liabilities – – (34) (34)  Three-way costless collars liabilities – – (70) (70)  Basis swap liabilities – – (11) (11)  Sold call option liabilities – – (54) (54)  Interest rate swap liabilities – (8) – (8)  Total $ – $ (25) $ (25) $ (50)   December 31, 2015  Fair Value Measurements Using:  Quoted Prices Significant Other Significant  in Active Markets Observable Inputs Unobservable Inputs Assets (Liabilities)  (Level 1) (Level 2) (Level 3) at Fair Value  Basis swap assets $ – $ – $ 3 $ 3  Interest rate swap liabilities – (5) – (5)  Total $ – $ (5) $ 3 $ (2) 
Reconciliations For Change In Net Fair Value Of Derivative Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)	  For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Balance at beginning of period $ (83) $ (5) $ 3 $ (8)  Total gains (losses):  Included in earnings 58 4 (13) 1  Purchases, issuances, and settlements:  Settlements – – (15) 6  Transfers into/out of Level 3 – – – –  Balance at end of period $ (25) $ (1) $ (25) $ (1)  Change in gains (losses) included in earnings relating to derivativ es still held as of September 30 $ 58 $ 4 $ (28) $ 7 

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt [Abstract]
Components Of Debt	   September 30, 2016  Debt Instrument Unamortized Issuance Cost Unamortized Debt Discount Total  (in millions) Short-term debt:  7.15% Senior Notes due June 2018 $ 1 $ – $ – $ 1  Total short-term debt $ 1 $ – $ – $ 1   Long-term debt:  Variable rate ( 2.960% at September 30, 2016) term loan facility, due December 2020 (1) $ 327 $ (2) $ – $ 325  Variable rate ( 2.960% at September 30, 2016) term loan facility, due December 2020 (2) 1,191 (11) – 1,180  7.35% Senior Notes due October 2017 15 – – 15  7.125% Senior Notes due October 2017 25 – – 25  3.30% Senior Notes due January 2018 (3) ( 4 ) 38 – – 38  7.50% Senior Notes due February 2018 ( 3 ) 212 – – 212  7.15% Senior Notes due June 2018 26 – – 26  4.05% Senior Notes due January 2020 ( 4 ) 850 (5) – 845  4.10% Senior Notes due March 2022 1,000 (5) (1) 994  4.95% Senior Notes due January 2025 ( 4 ) 1,000 (7) (2) 991  Total long-term debt $ 4,684 $ (30) $ (3) $ 4,651   Total debt $ 4,685 $ (30) $ (3) $ 4,652  (1) In July 2016, $375 million was repaid on the term loan facility, extending the maturity from November 2018 to December 2020 , which will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes. In September 2016, an additional $48 million was repaid.  (2) The maturity date will accelerate to October 2019 if, by that date, the Company has not amended, redeemed or refinanced at least $765 million of its 2020 Senior Notes.  (3) In July 2016, the Company purchased approximately $312 million of the 3.3 0 % Senior Notes due January 2018 and $388 million of the 7.5 0 % Senior Notes due February 2018.  (4) In February and June 2016, Moody’s and S&P downgraded certain senior n otes, increasing the interest rates by 175 basis points effective July 2016. As a result of the downgrades, interest rates increased to 5.05% for the 2018 Notes, 5.80% for the 2020 Notes and 6.70% for the 2025 Notes .   December 31, 2015  Debt Instrument Unamortized Issuance Cost Unamortized Debt Discount Total  (in millions) Short-term debt:  7.15% Senior Notes due June 2018 $ 1 $ – $ – $ 1  Total short-term debt $ 1 $ – $ – $ 1   Long-term debt:  Variable rate ( 1.886% at December 31, 2015) credit facility, expires December 2018 $ 116 $ – $ – $ 116  Variable rate ( 1.775% at December 31, 2015) term loan facility, due November 2018 750 (3) – 747  7.35% Senior Notes due October 2017 15 – – 15  7.125% Senior Notes due October 2017 25 – – 25  3.30% Senior Notes due January 2018 350 (2) – 348  7.50% Senior Notes due February 2018 600 (2) – 598  7.15% Senior Notes due June 2018 26 – – 26  4.05% Senior Notes due January 2020 850 (5) (1) 844  4.10% Senior Notes due March 2022 1,000 (5) (1) 994  4.95% Senior Notes due January 2025 1,000 (7) (2) 991  Total long-term debt $ 4,732 $ (24) $ (4) $ 4,704   Total debt $ 4,733 $ (24) $ (4) $ 4,705 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies [Abstract]
Schedule Of Future Obligation Under Transportation Agreements	  Payments Due by Period  Total Less than 1 Year 1 to 3 Years 3 to 5 Years 5 to 8 Years More than 8 Years  (in millions)  Infrastructure currently in service $ 5,157 $ 545 $ 1,140 $ 865 $ 851 $ 1,756  Pending regulatory approval and/or construction (1) 3,429 14 294 465 694 1,962  Total transportation charges $ 8,586 $ 559 $ 1,434 $ 1,330 $ 1,545 $ 3,718  (1) Based on the estim ated in-service dates as of September 30, 2016.

Pension Plan And Other Postre34

Pension Plan And Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2016
Pension Plan And Other Postretirement Benefits [Abstract]
Pension And Other Postretirement Benefit Costs	  Pension Benefits  For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Service cost $ 3 $ 4 $ 9 $ 12  Interest cost 1 1 4 4  Expected return on plan assets (2) (2) (5) (6)  Amortization of prior service cost – – – –  Amortization of net loss – 1 1 2 Curtailment loss – – 1 –  Settlement loss 2 – 10 –  Net periodic benefit cost $ 4 $ 4 $ 20 $ 12 

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Stock-Based Compensation [Abstract]
Schedule Of Stock-Based Compensation Costs	  For the three months ended For the nine months ended  September 30, September 30,  2016 2015 2016 2015  (in millions)  Stock-based compensation cost – expensed (1) $ 6 $ 6 $ 43 $ 18  Stock-based compensation cost – capitalized $ 2 $ 6 $ 7 $ 17 (1) Includes $16 million and $3 million related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016.
Summary Of Stock Option Activity	  Number Weighted Average  of Options Exercise Price  (in thousands) (per share)  Outstanding at December 31, 2015 5,623 $ 24.57  Granted 156 8.60  Exercised – –  Forfeited or expired (63) 27.81  Outstanding at September 30, 2016 5,716 24.10  Exercisable at September 30, 2016 2,627 $ 35.80 
Summary Of Restricted Stock Activity	  Number Weighted Average  of Shares Fair Value  (in thousands) (per share)  Unvested shares at December 31, 2015 7,222 $ 13.24  Granted 79 8.41  Vested (1) (2,525) 9.24  Forfeited (138) 12.20  Unvested shares at September 30, 2016 4,638 $ 12.86 (1) I ncludes 2,041,877 shares related to the reduction in workforce and 151,575 shares related to the executive management restructuring for the nine months ended September 30, 2016.
Summary Of Performance Unit Activity	  Number Weighted Average  of Units (1) Fair Value  (in thousands) (per share)  Unvested units at December 31, 2015 407 $ 36.65  Granted 1,502 8.60  Vested (2 ) (414) 7.62  Forfeited (3) (290) 11.32  Unvested units at September 30, 2016 1,205 $ 13.70 (1) These amounts reflect the number of performance units granted in thousands. The actual payout of shares may range from a minimum of zero shares to a maximum of two shares contingent upon the actual performance against the applicable Performance Measures. (2) Includes 15,632 units and 37,590 units related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016. (3) Includes 76,281 units and 195,834 units related to the reduction in workforce and executive management restructuring, respectively, for the nine months ended September 30, 2016. 

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Information [Abstract]
Summary Financial Information For Company's Reportable Segments	   Exploration and  Production Midstream Other Total  (in millions)  Three months ended September 30, 2016:  Revenues from external customers $ 381 $ 270 $ – $ 651  Intersegment revenues (3) 412 – 409  Depreciation, depletion and amortization expense 83 16 – 99  Impairment of natural gas and oil properties 817 – – 817  Operating income (loss) (777) (1) 52 – (725)  Interest expense (3) 26 – – 26  Gain on derivatives 71 – – 71  Loss on early extinguishment of debt – – (51) (51)  Other income, net 2 1 – 3 Benefit for income taxes (3) (20) – – (20)  Assets 4,015 1,253 1,622 (4) 6,890  Capital investments (5) 179 1 – 180   Three months ended September 30, 2015:  Revenues from external customers $ 491 $ 258 $ – $ 749  Intersegment revenues (3) 489 – 486  Depreciation, depletion and amortization expense 255 20 – 275  Impairment of natural gas and oil properties 2,839 – – 2,839  Operating income (loss) (2,910) 68 – (2,842)  Gain on derivatives 15 – – 15  Provision (benefit) for income taxes (3) (1,112) 24 – (1,088)  Assets 9,159 1,329 215 10,703  Capital investments (5) 461 7 – 468     Exploration and  Production Midstream Other Total  (in millions)  Nine months ended September 30, 2016:  Revenues from external customers $ 1,015 $ 737 $ – $ 1,752  Intersegment revenues (17) 1,125 – 1,108  Depreciation, depletion and amortization expense 300 49 – 349  Impairment of natural gas and oil properties 2,321 – – 2,321  Operating income (loss) (2,486) (1) 169 (2) – (2,317)  Interest expense (3) 56 1 – 57  Loss on derivatives (27) (1) – (28)  Loss on early extinguishment of debt – – (51) (51)  Other income (loss), net 3 (2) (1) – Benefit for income taxes (3) (20) – – (20)  Assets 4,015 1,253 1,622 (4) 6,890  Capital investments (5) 372 3 1 376   Nine months ended September 30, 2015:  Revenues from external customers $ 1,647 $ 798 $ 1 $ 2,446  Intersegment revenues (14) 1,653 – 1,639  Depreciation, depletion and amortization expense 824 52 – 876  Impairment of natural gas and oil properties 4,374 – – 4,374  Operating income (loss) (4,471) 511 (6) (1) (3,961)  Interest expense (3) 45 7 – 52  Gain (loss) on derivatives 32 – (2) 30  Other income, net 2 – – 2  Provision (benefit) for income taxes (3) (1,724) 193 (1) (1,532)  Assets 9,159 1,329 215 10,703  Capital investments (5) 1,880 164 10 2,054 (1) Operating income (loss) for the E&P segment includes $2 million and $74 million related to restructuri ng charges for the three and nine months ended September 30, 2016, respectively. (2) Operating income (loss) for the Midstream segment includes $3 million related to restructuring charges for the nine months e nded September 30, 2016 . (3) Interest expense and the provision for income taxes by segment are an allocation of corporate amounts as they are incurred at the corporate level. (4) Other assets represent corporate assets not allocated to segments and assets for non-reportable segments. At September 30, 2016, other assets includes approximately $1,443 million in marketable securities. (5) Capital investments includes increases of $27 million and $6 million for the three months ended September 30, 2016 and 2015 , respectively, and decreases of $24 million and $5 million for the nine months ended September 30, 2016 and 2015, respectively, relating to the change in accrued expenditures between periods. E&P capital for t he nine month period ended September 30, 2015 includes approximately $516 million related to the WPX Property and Statoil Property Acquisitions. Midstream capit al for the nine months ended September 30, 2015 includes approximately $119 million associated with the intangible asset related to the firm transportation acquired through the WPX Property Acquisition. (6) Operating income (loss) for the Midstream segment includes $277 million gain on sale of assets for the nine months e nded September 30, 2015 .

Basis Of Presentation (Narrativ

Basis Of Presentation (Narrative) (Details)	9 Months Ended
	Sep. 30, 2016segment
Basis Of Presentation [Abstract]
Number of segments	2

Cash And Cash Equivalents (Summ

Cash And Cash Equivalents (Summary Of Cash And Cash Equivalents) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Abstract]
Cash	$ 31	$ 15
Marketable securities	1,443
Total cash and cash equivalents	$ 1,474	$ 15	$ 15	$ 53

Reduction In Workforce (Narrati

Reduction In Workforce (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jan. 31, 2016employee	Sep. 30, 2016USD ($)	Sep. 30, 2016USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 2	$ 77
Workforce Reduction [Member]
Restructuring Cost and Reserve [Line Items]
Positions eliminated, percent	40.00%
Positions eliminated | employee	1,100
Restructuring charges		$ 2	$ 77

Reduction In Workforce (Summary

Reduction In Workforce (Summary Of Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 2	$ 77
Exploration and Production [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	2	74
Midstream Services [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charges		3
Workforce Reduction [Member]
Restructuring Cost and Reserve [Line Items]
Severance (including payroll taxes)		44
Stock-based compensation		24
Pension and other postretirement benefits	2	5
Other benefits		3
Outplacement services, other		1
Total restructuring charges	2	77
Workforce Reduction [Member] | Executive Management [Member]
Restructuring Cost and Reserve [Line Items]
Severance (including payroll taxes)		1
Stock-based compensation		3
Workforce Reduction [Member] | Exploration and Production [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 2	74
Workforce Reduction [Member] | Midstream Services [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charges		$ 3

Reduction In Workforce (Summa41

Reduction In Workforce (Summary Of Liabilities Associated With Restructuring Activities) (Details) - Workforce Reduction [Member] $ in Millions	3 Months Ended
	Sep. 30, 2016USD ($)
Restructuring Cost and Reserve [Line Items]
Liability at June 30, 2016	$ 2
Additions
Distributions	(1)
Liability at September 30, 2016	$ 1

Acquisitions And Divestitures (

Acquisitions And Divestitures (Narrative) (Details) $ in Millions

1 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2016USD ($)a

Jul. 31, 2016USD ($)

Nov. 30, 2015USD ($)

May 31, 2015USD ($)

Apr. 30, 2015USD ($)miMMcf

Jan. 31, 2015USD ($)aMMcf

Dec. 31, 2014USD ($)aMMcf

Sep. 30, 2016a

Jun. 30, 2016

Sep. 30, 2016USD ($)a

Sep. 30, 2015USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2014USD ($)aitemMMcf

Business Acquisition [Line Items]

Payments on long-term debt

$ 1,175

$ 500

Capital spending

$ 391

$ 1,392

Bridge Loan [Member]

Business Acquisition [Line Items]

Bridge loan

$ 4,500

$ 4,500

$ 4,500

$ 4,500

Debt instrument, term

364 days

364 days

364 days

Debt issuance costs

$ 47

Long-term Debt [Member] | 2015 Term Facility [Member]

Business Acquisition [Line Items]

Payments on long-term debt

$ 48

$ 375

Loans payable

$ 750

Maturity date, year and month

2020-12

2018-11

2018-11

Debt instrument, term

3 years

Long-term Debt [Member] | Term Loan due December 2016 [Member]

Business Acquisition [Line Items]

Loans payable

$ 500

$ 500

Maturity date, year and month

2016-12

Debt instrument, term

2 years

WPX Property Acquisition [Member]

Business Acquisition [Line Items]

Area of land purchased | a

46,700

Cash consideration

$ 270

Net production per day of acreage sold in MMcf | MMcf

50

50

Number of horizontal wells operated | item

63

Firm transportation capacity assumed, per day | MMcf

260

Firm transportation, useful life

19 years

Amortization

$ 15

$ 8

Statoil Property Acquisition [Member]

Business Acquisition [Line Items]

Area of land purchased | a

30,000

Percentage of interest acquired

20.00%

Cost to acquire property

$ 357

Chesapeake Property Acquisition [Member]

Business Acquisition [Line Items]

Area of land purchased | a

413,000

413,000

Cash consideration

$ 5,000

West Virginia [Member]

Business Acquisition [Line Items]

Area of land sold | a

55,000

55,000

55,000

Proceeds from sale of oil and gas property and equipment

$ 426

East Texas and Arkoma Basin [Member]

Business Acquisition [Line Items]

Proceeds from sale of oil and gas property and equipment

$ 211

Reduction in capitalized costs relating to proceeds

$ (205)

Bradford And Lycoming Counties, Pennsylvania [Member]

Business Acquisition [Line Items]

Proceeds from sale of oil and gas property and equipment

$ 489

Net book value

206

Gain on sale of property

$ 283

Number of miles of natural gas gathering pipeline | mi

100

Pipeline capacity per day | MMcf

600

Natural Gas And Oil Properties

Natural Gas And Oil Properties (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)$ / bbl$ / MMBTU	Sep. 30, 2015USD ($)$ / bbl$ / MMBTU	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)
Natural Gas and Oil Properties [Line Items]
Natural gas, oil and NGL reserves discount	10.00%
Period of time needed to calculate ceiling value of reserves	12 months	12 months
Cash flow hedges impact on ceiling value, net of tax | $		$ 40
Impairment of natural gas and oil properties, net of tax | $	$ 506	$ 1,746	$ 297	$ 641
Natural Gas [Member] | Henry Hub [Member]
Natural Gas and Oil Properties [Line Items]
Full cost ceiling test, price | $ / MMBTU	2.28	3.06
Oil [Member] | West Texas Intermediate [Member]
Natural Gas and Oil Properties [Line Items]
Full cost ceiling test, price | $ / bbl	38.17	55.73
NGL [Member]
Natural Gas and Oil Properties [Line Items]
Full cost ceiling test, price | $ / bbl	6.46	8.62

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 17, 2016	Sep. 30, 2016	Jul. 31, 2016	Nov. 30, 2015	Jan. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Payments on long-term debt							$ 1,175	$ 500
Debt instrument		$ 4,685					$ 4,685		$ 4,733
Bridge Loan [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Bridge loan					$ 4,500	$ 4,500			$ 4,500
Debt instrument, term					364 days	364 days			364 days
Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued			98,900,000		30,000,000
Price per share			$ 13		$ 23
Proceeds from issuance of shares			$ 1,247		$ 669
Depositary Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued					34,500,000
Proceeds from issuance of shares					$ 1,700
Depositary shares conversion rate					5.00%
Liquidation preference per share					$ 50
Series B Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Liquidation preference per share		$ 1,000			$ 1,000		$ 1,000		$ 1,000
Trading day period							20 days
Long-term Debt [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Debt instrument		$ 4,684					$ 4,684		$ 4,732
Long-term Debt [Member] | 2015 Term Facility [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Payments on long-term debt		48	375
Debt instrument		$ 750					$ 750		$ 750
Debt instrument, term				3 years
Senior Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Purchase of note principal			$ 700
Proceeds from issuance of debt					$ 2,200
Minimum [Member] | Depositary Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued upon conversion		1.85014					1.85014
Minimum [Member] | Series B Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued upon conversion		37.0028					37.0028
Potential number of shares issued upon conversion							63,829,830
Maximum [Member] | Depositary Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued upon conversion		2.17391					2.17391
Maximum [Member] | Series B Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares issued upon conversion		43.4782					43.4782
Potential number of shares issued upon conversion							74,999,895
Subsequent Event [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock, shares issued as stock dividend	2,043,780

Earnings Per Share (Schedule Of

Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Line Items]
Net loss	$ (708)	$ (1,739)	$ (2,433)	$ (2,449)
Mandatory convertible preferred stock dividend	27	27	81	79
Net Loss Attributable to Common Stock	$ (735)	$ (1,766)	$ (2,514)	$ (2,528)
Number of common shares: Weighted average outstanding	482,485,150	382,098,080	417,222,661	379,909,748
Number of common shares: Issued upon assumed exercise of outstanding stock options
Number of common shares: Effect of issuance of non-vested restricted common stock
Number of common shares: Effect of issuance of non-vested performance units
Number of common shares: Effect of issuance of mandatory convertible preferred stock
Number of common shares: Effect of declaration of preferred stock dividends
Number of common shares: Weighted average and potential dilutive outstanding	482,485,150	382,098,080	417,222,661	379,909,748
Basic	$ (1.52)	$ (4.62)	$ (6.02)	$ (6.65)
Diluted	$ (1.52)	$ (4.62)	$ (6.02)	$ (6.65)
Common stock, shares declared as stock dividend	2,043,780		2,043,780
Stock Options [Member]
Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	3,409,596	3,796,778	3,714,095	3,778,140
Restricted Stock [Member]
Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	599,372	1,469,380	993,576	1,472,379
Performance Units [Member]
Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	935,330	89,802	762,171	135,836
Mandatory Convertible Preferred Stock [Member]
Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	74,999,895	74,999,895	74,999,895	69,505,397

Derivatives And Risk Manageme46

Derivatives And Risk Management (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative [Line Items]
Gas sales	$ 340	$ 458	$ 906	$ 1,540
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative liabilities	8		8		$ 5
Fixed Price Swaps [Member]
Derivative [Line Items]
Derivative liabilities	27		27
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative liabilities	8		8
Notional amount	170		$ 170
Derivative, expiration			Jun. 30, 2020
Designated as Hedging Instrument [Member] | Fixed Price Swaps [Member]
Derivative [Line Items]
Derivative gain (loss) in other comprehensive income		14		35
Gas sales		$ 50		$ 145
Natural Gas [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative liabilities	$ 42		$ 42

Derivatives And Risk Manageme47

Derivatives And Risk Management (Schedule Of Derivative Instruments, Notional Amount In BCF, Weighted Average Contract Prices And Fair Value) (Details) $ in Millions, ft³ in Billions	9 Months Ended
	Sep. 30, 2016USD ($)$ / MMBTUft³
Derivative [Line Items]
Cap price per MMBtu
Fixed Price Swaps -2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	51
Average price per MMBtu	2.81
Fair value | $	$ (8)
Purchased Put Options - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	4
Floor price per MMBtu	2.34
Fair value | $
Two-way Costless-collars - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	40
Fair value | $	$ 2
Two-way Costless-collars - 2016 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.93
Two-way Costless-collars - 2016 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.33
Three-way Costless-collars - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	5
Fair value | $
Three-way Costless-collars - 2016 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	3
Three-way Costless-collars - 2016 Sold Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.30
Three-way Costless-collars - 2016 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.25
Basis Swap - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	16
Basis differential per MMBtu	0.02
Fair value | $	$ 18
Financial protection on production - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	116
Fair value | $	$ 12
Fixed Price Swaps - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	296
Average price per MMBtu	3.04
Fair value | $	$ (9)
Two-way Costless-collars - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	103
Fair value | $	$ (1)
Two-way Costless-collars - 2017 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.94
Two-way Costless-collars - 2017 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.38
Three-way Costless-collars - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	135
Fair value | $	$ (5)
Three-way Costless-collars - 2017 Sold Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.29
Three-way Costless-collars - 2017 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.97
Three-way Costless-collars - 2017 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.30
Basis Swap - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	76
Basis differential per MMBtu	(0.59)
Fair value | $	$ 13
Financial protection on production - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	610
Fair value | $	$ (2)
Two-way Costless-collars - 2018 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	14
Fair value | $	$ (1)
Two-way Costless-collars - 2018 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	3
Two-way Costless-collars - 2018 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.46
Three-way Costless-collars - 2018 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	73
Fair value | $	$ 4
Three-way Costless-collars - 2018 Sold Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.28
Three-way Costless-collars - 2018 Purchased Puts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Floor price per MMBtu	2.93
Three-way Costless-collars - 2018 Sold Calls [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cap price per MMBtu	3.37
Basis Swap - 2018 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	2
Basis differential per MMBtu	0.83
Fair value | $	$ (1)
Financial protection on production - 2018 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	89
Fair value | $	$ 2
Sold Call Options - 2016 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	30
Cap price per MMBtu	5
Fair value | $
Sold Call Options - 2017 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	86
Cap price per MMBtu	3.25
Fair value | $	$ (23)
Sold Call Options - 2018 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	63
Cap price per MMBtu	3.50
Fair value | $	$ (13)
Sold Call Options - 2019 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	52
Cap price per MMBtu	3.50
Fair value | $	$ (11)
Sold Call Options - 2020 [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	32
Cap price per MMBtu	3.75
Fair value | $	$ (7)
Sold Call Options [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume (Bcf) | ft³	263
Fair value | $	$ (54)

Derivatives And Risk Manageme48

Derivatives And Risk Management (Balance Sheet Classification Of Derivative Financial Instruments) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative assets	$ 154	$ 3
Derivative liabilities	204	5
Fixed Price Swaps [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	9
Fixed Price Swaps [Member] | Other Long-Term Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1
Fixed Price Swaps [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	23
Fixed Price Swaps [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	4
Two-way Costless-collars [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	20
Two-way Costless-collars [Member] | Other Long-Term Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	14
Two-way Costless-collars [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	20
Two-way Costless-collars [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	14
Three-way Costless-collars [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	27
Three-way Costless-collars [Member] | Other Long-Term Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	42
Three-way Costless-collars [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	29
Three-way Costless-collars [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	41
Basis Swaps [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	37	3
Basis Swaps [Member] | Other Long-Term Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	4
Basis Swaps [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	10
Basis Swaps [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	1
Sold Call Options [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	15
Sold Call Options [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	39
Interest Rate Swaps [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	3	3
Interest Rate Swaps [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 5	$ 2

Derivatives And Risk Manageme49

Derivatives And Risk Management (Summary Of Before Tax Effect Of Cash Flow Hedges On Consolidated Financial Statements) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	$ 81	$ (34)	$ (48)	$ (105)
Derivative Instrument, Gain (Loss) on Derivatives, Settled	(10)	49	20	135
Total gain (loss) on derivatives	71	15	(28)	30
Fixed Price Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	23	(37)	(17)	(110)
Derivative Instrument, Gain (Loss) on Derivatives, Settled	(9)	49	7	143
Purchased Put Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Settled			11
Two-way Costless-collars [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	5
Three-way Costless-collars [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	1		(1)
Basis Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	31	1	27	(4)
Derivative Instrument, Gain (Loss) on Derivatives, Settled			4	(6)
Sold Call Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled	21	3	(54)	11
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) on Derivatives, Unsettled		$ (1)	(3)	(2)
Derivative Instrument, Gain (Loss) on Derivatives, Settled	$ (1)		$ (2)	$ (2)

Reclassifications From Accumu50

Reclassifications From Accumulated Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, December 31, 2015	$ (48)
Other comprehensive income before reclassifications	8
Amounts reclassified from/to other comprehensive income (loss)	1
Net current-period other comprehensive income (loss)	9
Ending balance, September 30, 2016	(39)
Pension And Other Postretirement [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, December 31, 2015	(25)
Other comprehensive income before reclassifications	5
Amounts reclassified from/to other comprehensive income (loss)	1
Net current-period other comprehensive income (loss)	6
Ending balance, September 30, 2016	(19)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, December 31, 2015	(23)
Other comprehensive income before reclassifications	3
Amounts reclassified from/to other comprehensive income (loss)
Net current-period other comprehensive income (loss)	3
Ending balance, September 30, 2016	$ (20)

Reclassifications From Accumu51

Reclassifications From Accumulated Other Comprehensive Income (Loss) (Amounts Reclassified From Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
General and administrative expenses	$ 61	$ 60	$ 171	$ 188
Provision (benefit) for income taxes	(20)	(1,088)	(20)	(1,532)
Net Loss	$ (708)	$ (1,739)	(2,433)	$ (2,449)
Pension And Other Postretirement [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
General and administrative expenses			2
Provision (benefit) for income taxes			1
Net Loss			$ 1

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments, net	$ (50)	$ (2)
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,474	15
Credit facility		116
Senior notes	3,147	3,842
Derivative instruments, net	(50)	(2)
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,474	15
Credit facility		116
Senior notes	3,093	2,651
Derivative instruments, net	$ (50)	(2)
Long-term Debt [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity date, year and month	2020-12
Long-term Debt [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity date, year and month	2020-12
Long-term Debt [Member] | 2020 Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accelerated maturity date, year and month if not amended, redeemed or refinanced	2019-10
Amount to be amended, redeemed or refinanced to avoid acceleration	$ 765
Long-term Debt [Member] | Carrying Amount [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	325	747
Long-term Debt [Member] | Carrying Amount [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	1,180
Long-term Debt [Member] | Fair Value [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	325	$ 747
Long-term Debt [Member] | Fair Value [Member] | Term Loan due December 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	$ 1,180

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ (50)	$ (2)
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	(25)	(5)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	(25)	3
Fixed Price Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	10
Derivative liabilities	(27)
Fixed Price Swaps [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets
Derivative liabilities
Fixed Price Swaps [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	10
Derivative liabilities	(27)
Two-way Costless-collars [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	34
Derivative liabilities	(34)
Two-way Costless-collars [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets
Derivative liabilities
Two-way Costless-collars [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	34
Derivative liabilities	(34)
Three-way Costless-collars [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	69
Derivative liabilities	(70)
Three-way Costless-collars [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets
Derivative liabilities
Three-way Costless-collars [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	69
Derivative liabilities	(70)
Basis Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	41	3
Derivative liabilities	(11)
Basis Swaps [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets
Derivative liabilities
Basis Swaps [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	41	3
Derivative liabilities	(11)
Sold Call Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(54)
Sold Call Options [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities
Sold Call Options [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(54)
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(8)	(5)
Interest Rate Swaps [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities
Interest Rate Swaps [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	$ (8)	$ (5)

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliations For Change In Net Fair Value Of Derivative Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value Measurements [Abstract]
Balance at beginning of period	$ (83)	$ (5)	$ 3	$ (8)
Included in earnings	58	4	(13)	1
Purchases, issuances, and settlements:
Settlements			(15)	6
Transfers into/out of Level 3
Balance at end of period	(25)	(1)	(25)	(1)
Change in gains (losses) included in earnings relating to derivatives still held as of September 30	$ 58	$ 4	$ (28)	$ 7

Debt (2016 Credit Facility - Na

Debt (2016 Credit Facility - Narrative) (Details)	1 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015USD ($)	Dec. 31, 2013USD ($)
Debt Instrument [Line Items]
Debt instrument		$ 4,685,000,000			$ 4,733,000,000
Long-term Debt [Member]
Debt Instrument [Line Items]
Debt instrument		4,684,000,000			$ 4,732,000,000
Long-term Debt [Member] | 2013 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 66,000,000					$ 2,000,000,000
Repayment of line of credit	285,000,000
Amount outstanding		0
Long-term Debt [Member] | 2016 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	743,000,000
Long-term Debt [Member] | 2013 & 2016 Credit Facilities [Member]
Debt Instrument [Line Items]
Amount outstanding		0
Long-term Debt [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Amount outstanding		$ 174,000,000
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,934,000,000
Maturity date, year and month	2020-12
Incremental increase EBITDAX to interest expense ratio		0.25
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
EBITDAX to interest expense ratio		0.75
Liquidity requirement		$ 300,000,000
Anti-hoarding provision, required unrestricted cash		$ 100,000,000
Collateral coverage ratio		1.50
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Minimum [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
EBITDAX to interest expense ratio			1.50	1.50
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Liquidity requirement		$ 500,000,000
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Eurodollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points		1.75%
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Eurodollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points		2.50%
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis points		0.75%
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis points		1.50%
Revolving Credit Facility And Term Loan Facility [Member] | Long-term Debt [Member] | Over LIBOR [Member]
Debt Instrument [Line Items]
Basis points		2.50%
Term Loan due December 2020 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,191,000,000
Debt instrument	$ 1,191,000,000	$ 1,191,000,000
Maturity date, year and month		2020-12
2020 Senior Notes [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Amount to be amended, redeemed or refinanced to avoid acceleration		$ 765,000,000

Debt (2013 Credit Facility - Na

Debt (2013 Credit Facility - Narrative) (Details) - Long-term Debt [Member] - USD ($)	9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2013
2013 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 66,000,000	$ 2,000,000,000
Credit facility, maturity date	Dec. 1, 2018
Amount outstanding	$ 0
Debt percentage of adjusted book capital structure covenant	60.00%
2016 Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		743,000,000
Term Loan due December 2020 [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,191,000,000

Debt (2015 Credit Facility - Na

Debt (2015 Credit Facility - Narrative) (Details) $ in Millions	1 Months Ended			3 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2016USD ($)a	Jul. 31, 2016USD ($)	Nov. 30, 2015USD ($)	Sep. 30, 2016USD ($)a	Jun. 30, 2016	Sep. 30, 2016USD ($)a	Sep. 30, 2015USD ($)	Dec. 31, 2015
Debt Instrument [Line Items]
Payments on long-term debt						$ 1,175	$ 500
Net loss on extinguishment of debt				$ (51)		(51)
2015 Term Facility [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Loans payable			$ 750
Debt instrument, term			3 years
Payments on long-term debt	$ 48	$ 375
Maturity date, year and month				2020-12	2018-11			2018-11
Net loss on extinguishment of debt	$ (0.4)					$ (3)
2020 Senior Notes [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Accelerated maturity date, year and month if not amended, redeemed or refinanced						2019-10
Amount to be amended, redeemed or refinanced to avoid acceleration						$ 765
Over LIBOR [Member] | 2015 Term Facility [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Basis points	2.50%
West Virginia [Member]
Debt Instrument [Line Items]
Area of land sold | a	55,000			55,000		55,000

Debt (Senior Notes - Narrative)

Debt (Senior Notes - Narrative) (Details) - USD ($) $ in Millions	1 Months Ended			3 Months Ended	9 Months Ended		12 Months Ended
	Jul. 31, 2016	Jan. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Net loss on extinguishment of debt				$ (51)	$ (51)
Unamortized debt expense				30	30		$ 24
Long-term Debt [Member]
Debt Instrument [Line Items]
Unamortized debt expense				$ 30	$ 30		24
Senior Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of debt		$ 2,200
Purchase of note principal	$ 700
Net loss on extinguishment of debt	(51)
Premium	50
Unamortized debt expense	$ 2
Senior Notes [Member] | Over LIBOR [Member]
Debt Instrument [Line Items]
Incremental increase in basis points resulting from downgrades					0.25%
Incremental decrease in basis points resulting from upgrades					0.25%
Increase in basis spread	1.75%
Bridge Loan [Member]
Debt Instrument [Line Items]
Bridge loan		$ 4,500	$ 4,500				$ 4,500
Debt instrument, term		364 days	364 days				364 days
Debt issuance costs		$ 47
3.30% Senior Notes due January 2018 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior notes		$ 350
Stated interest rate	5.05%	3.30%		3.30%	3.30%		3.30%
Maturity date, year		2,018
Percentage of face amount, sold to public		99.949%
Unamortized debt expense							$ 2
4.05% Senior Notes due January 2020 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior notes		$ 850
Stated interest rate	5.80%	4.05%		4.05%	4.05%		4.05%
Maturity date, year		2,020
Percentage of face amount, sold to public		99.897%
Unamortized debt expense				$ 5	$ 5		$ 5
4.95% Senior Notes due January 2025 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior notes		$ 1,000
Stated interest rate	6.70%	4.95%		4.95%	4.95%		4.95%
Maturity date, year		2,025
Percentage of face amount, sold to public		99.782%
Unamortized debt expense				$ 7	$ 7		$ 7
Maximum [Member] | 3.30% Senior Notes due January 2018 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Stated interest rate				5.30%	5.30%
Maximum [Member] | 4.05% Senior Notes due January 2020 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Stated interest rate				6.05%	6.05%
Maximum [Member] | 4.95% Senior Notes due January 2025 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Stated interest rate				6.95%	6.95%

Debt (Components Of Debt) (Deta

Debt (Components Of Debt) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Jul. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Jan. 31, 2015
Debt Instrument [Line Items]
Debt Instrument	$ 4,685		$ 4,685		$ 4,685		$ 4,733
Unamortized Issuance Cost	(30)		(30)		(30)		(24)
Unamortized Debt Discount	(3)		(3)		(3)		(4)
Total	4,652		4,652		4,652		4,705
Payments on long-term debt					1,175	$ 500
Short-term Debt [Member]
Debt Instrument [Line Items]
Debt Instrument	1		1		1		1
Unamortized Issuance Cost
Unamortized Debt Discount
Total	1		1		1		1
Short-term Debt [Member] | 7.15% Senior Notes due June 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument	1		1		1		1
Unamortized Issuance Cost
Unamortized Debt Discount
Total	$ 1		$ 1		$ 1		$ 1
Stated interest rate	7.15%		7.15%		7.15%		7.15%
Maturity date, year and month					2018-06		2018-06
Long-term Debt [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 4,684		$ 4,684		$ 4,684		$ 4,732
Unamortized Issuance Cost	(30)		(30)		(30)		(24)
Unamortized Debt Discount	(3)		(3)		(3)		(4)
Total	4,651		4,651		4,651		4,704
Long-term Debt [Member] | Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument							116
Total							$ 116
Credit facility, variable interest rate							1.886%
Credit facility, maturity date							Dec. 1, 2018
Long-term Debt [Member] | 7.35% Senior Notes due October 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument	15		15		15		$ 15
Unamortized Issuance Cost
Unamortized Debt Discount
Total	$ 15		$ 15		$ 15		$ 15
Stated interest rate	7.35%		7.35%		7.35%		7.35%
Maturity date, year and month					2017-10		2017-10
Long-term Debt [Member] | 7.125% Senior Notes due October 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 25		$ 25		$ 25		$ 25
Unamortized Issuance Cost
Unamortized Debt Discount
Total	$ 25		$ 25		$ 25		$ 25
Stated interest rate	7.125%		7.125%		7.125%		7.125%
Maturity date, year and month					2017-10		2017-10
Long-term Debt [Member] | 3.30% Senior Notes due January 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 38		$ 38		$ 38		$ 350
Unamortized Issuance Cost							(2)
Unamortized Debt Discount
Total	$ 38		$ 38		$ 38		$ 348
Stated interest rate	3.30%	5.05%	3.30%		3.30%		3.30%	3.30%
Maturity date, year and month					2018-01		2018-01
Payments on long-term debt		$ 312
Long-term Debt [Member] | 7.50% Senior Notes due February 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 212		$ 212		$ 212		$ 600
Unamortized Issuance Cost							(2)
Unamortized Debt Discount
Total	$ 212		$ 212		$ 212		$ 598
Stated interest rate	7.50%		7.50%		7.50%		7.50%
Maturity date, year and month					2018-02		2018-02
Payments on long-term debt		$ 388
Long-term Debt [Member] | 7.15% Senior Notes due June 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 26		$ 26		$ 26		$ 26
Unamortized Issuance Cost
Unamortized Debt Discount
Total	$ 26		$ 26		$ 26		$ 26
Stated interest rate	7.15%		7.15%		7.15%		7.15%
Maturity date, year and month					2018-06		2018-06
Long-term Debt [Member] | 4.05% Senior Notes due January 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 850		$ 850		$ 850		$ 850
Unamortized Issuance Cost	(5)		(5)		(5)		(5)
Unamortized Debt Discount							(1)
Total	$ 845		$ 845		$ 845		$ 844
Stated interest rate	4.05%	5.80%	4.05%		4.05%		4.05%	4.05%
Maturity date, year and month					2020-01		2020-01
Long-term Debt [Member] | 4.10% Senior Notes due March 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 1,000		$ 1,000		$ 1,000		$ 1,000
Unamortized Issuance Cost	(5)		(5)		(5)		(5)
Unamortized Debt Discount	(1)		(1)		(1)		(1)
Total	$ 994		$ 994		$ 994		$ 994
Stated interest rate	4.10%		4.10%		4.10%		4.10%
Maturity date, year and month					2022-03		2022-03
Long-term Debt [Member] | 4.95% Senior Notes due January 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 1,000		$ 1,000		$ 1,000		$ 1,000
Unamortized Issuance Cost	(7)		(7)		(7)		(7)
Unamortized Debt Discount	(2)		(2)		(2)		(2)
Total	$ 991		$ 991		$ 991		$ 991
Stated interest rate	4.95%	6.70%	4.95%		4.95%		4.95%	4.95%
Maturity date, year and month					2025-01		2025-01
Long-term Debt [Member] | Term Loan due December 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument	$ 327		$ 327		$ 327
Unamortized Issuance Cost	(2)		(2)		(2)
Unamortized Debt Discount
Total	325		325		$ 325
Variable interest rate					2.96%
Maturity date, year and month					2020-12
Long-term Debt [Member] | 2015 Term Facility [Member]
Debt Instrument [Line Items]
Debt Instrument	750		$ 750		$ 750		$ 750
Unamortized Issuance Cost							(3)
Total							$ 747
Variable interest rate							1.775%
Maturity date, year and month			2020-12	2018-11			2018-11
Payments on long-term debt	48	$ 375
Long-term Debt [Member] | Term Loan due December 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument	1,191		$ 1,191	$ 1,191	1,191
Unamortized Issuance Cost	(11)		(11)		(11)
Unamortized Debt Discount
Total	$ 1,180		$ 1,180		$ 1,180
Variable interest rate					2.96%
Maturity date, year and month					2020-12
Long-term Debt [Member] | 2020 Senior Notes [Member]
Debt Instrument [Line Items]
Accelerated maturity date, year and month if not amended, redeemed or refinanced					2019-10
Amount to be amended, redeemed or refinanced to avoid acceleration					$ 765
Senior Notes [Member]
Debt Instrument [Line Items]
Unamortized Issuance Cost		$ (2)
Over LIBOR [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Increase in basis spread		1.75%

Commitments And Contingencies60

Commitments And Contingencies (Narrative) (Details)	1 Months Ended
	Sep. 30, 2015plaintiffitem	Jul. 31, 2013USD ($)	Sep. 30, 2016USD ($)item
Commitments And Contingencies [Line Items]
Obligation under transportation agreements			$ 8,586,000,000
Guarantee obligations relative to the firms transportation agreements and gathering project and services			862,000,000
Actual damages recoverable by plaintiff to be reversed		$ 11,000,000
Disgorgement recoverable by plaintiff to be reversed		$ 24,000,000
Indemnification liability			$ 0
Arkansas Royalty Litigation [Member]
Commitments And Contingencies [Line Items]
Number of cases | item			3
Arkansas Royalty Litigation [Member] | Arkansas State Court 2010 and 2013 [Member]
Commitments And Contingencies [Line Items]
Number of cases | item			2
Arkansas Royalty Litigation [Member] | Federal Court 2014 [Member]
Commitments And Contingencies [Line Items]
Number of cases | item			1
Arkansas Royalty Litigation [Member] | Arkansas State Court 2015 [Member]
Commitments And Contingencies [Line Items]
Number of cases | item	3
Number of plaintiffs | plaintiff	248
Arkansas Royalty Litigation [Member] | Federal Court [Member]
Commitments And Contingencies [Line Items]
Number of cases removed to federal court | item	2
Minimum [Member] | Arkansas Royalty Litigation [Member] | Federal Court 2014 [Member]
Commitments And Contingencies [Line Items]
Loss contingency, range of possible loss, minimum			$ 100,000,000
Pending Regulatory Approval and/or Construction [Member]
Commitments And Contingencies [Line Items]
Obligation under transportation agreements			$ 3,429,000,000

Commitments And Contingencies61

Commitments And Contingencies (Schedule Of Future Obligation Under Transportation Agreements) (Details) $ in Millions	Sep. 30, 2016USD ($)
Other Commitments [Line Items]
Less than 1 year	$ 559
1 to 3 years	1,434
3 to 5 years	1,330
5 to 8 years	1,545
More than 8 years	3,718
Total transportation charges	8,586
Infrastructure Currently in Service [Member]
Other Commitments [Line Items]
Less than 1 year	545
1 to 3 years	1,140
3 to 5 years	865
5 to 8 years	851
More than 8 years	1,756
Total transportation charges	5,157
Pending Regulatory Approval and/or Construction [Member]
Other Commitments [Line Items]
Less than 1 year	14
1 to 3 years	294
3 to 5 years	465
5 to 8 years	694
More than 8 years	1,962
Total transportation charges	$ 3,429

Pension Plan And Other Postre62

Pension Plan And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended		12 Months Ended
		Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (gain)		$ 4		$ 4	$ 20	$ 12
Net gain incurred in period	[1]	$ 1			5
Employer contributions					8
Company's expected additional annual contribution					$ 3
Common Stock in Treasury, Shares		31,269			31,269		47,149
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-cash curtailment gain (loss)			$ (1)		$ (1)
Settlement loss		$ (2)			(10)
Benefit obligation		$ 40			$ 40		$ 31
Discount rate		4.20%			4.20%			4.60%
Pension Benefits [Member] | One-time Termination Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Lump-sum payment		$ 35	$ 35
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-cash curtailment gain (loss)					$ 6
Net periodic benefit cost (gain)		1		$ 1	(4)	$ 3
Benefit obligation		$ 12			$ 12		$ 20
Discount rate		4.20%			4.20%			4.60%
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Common stock purchased under the terms of the Non-Qualified Plan presented as treasury stock					31,269		47,149
[1]	Net of $1 million and $2 million in taxes for the three and nine months ended September 30, 2016, respectively.

Pension Plan And Other Postre63

Pension Plan And Other Postretirement Benefits (Pension And Other Postretirement Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 4		$ 4	$ 20	$ 12
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3		4	9	12
Interest cost	1		1	4	4
Expected return on plan assets	(2)		(2)	(5)	(6)
Amortization of prior service cost
Amortization of net loss			$ 1	1	$ 2
Curtailment loss		$ 1		1
Settlement loss	$ 2			$ 10

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to the Company's unvested stock option grants, restricted stock grants, and performance units		$ 55		$ 55
Weighted average period over which cost is recognized, years				2 years
Stock-based compensation costs - expensed		$ 6	$ 6	$ 43	$ 18
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, exercised, number of options
Liability-Classified Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock awards from grant date				3 years
Workforce Reduction [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Positions eliminated, percent	40.00%
Stock-based compensation costs - expensed				$ 16

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Stock-Based Compensation Costs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation costs - expensed	$ 6	$ 6	$ 43	$ 18
Stock-based compensation costs - capitalized	$ 2	$ 6	7	$ 17
Workforce Reduction [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation costs - expensed			16
Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation costs - expensed			$ 3

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Stock Option Activity) (Details) - Stock Options [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, Outstanding at December 31, Number of Options | shares	5,623
Stock options, Granted, Number of Options | shares	156
Stock options, Exercised, Number of Options | shares
Stock options, Forfeited or expired, Number of Options | shares	(63)
Stock options, Outstanding at September 30, Number of Options | shares	5,716
Stock options, Exercisable at September 30, Number of Options | shares	2,627
Stock options, Outstanding at December 31, Weighted Average Exercise Price | $ / shares	$ 24.57
Stock options, Granted, Weighted Average Exercise Price | $ / shares	8.60
Stock options, Exercised, Weighted Average Exercise Price | $ / shares
Stock options, Forfeited or expired, Weighted Average Exercise Price | $ / shares	27.81
Stock options, Outstanding at September 30, Weighted Average Exercise Price | $ / shares	24.10
Stock options, Exercisable at September 30, Weighted Average Exercise Price | $ / shares	$ 35.80

Stock-Based Compensation (Sum67

Stock-Based Compensation (Summary Of Restricted Stock Activity) (Details) - Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested shares/units at December 31, Number of Shares	7,222,000
Granted, Number of Shares/Units	79,000
Vested, Number of Shares/Units	(2,525,000)
Forfeited, Number of Shares/Units	(138,000)
Unvested shares/units at September 30, Number of Shares	4,638,000
Unvested shares/units at December 31, Weighted Average Fair Value | $ / shares	$ 13.24
Granted, Weighted Average Fair Value | $ / shares	8.41
Vested, Weighted Average Fair Value | $ / shares	9.24
Forfeited, Weighted Average Fair Value | $ / shares	12.20
Unvested shares at September 30, Weighted Average Fair Value | $ / shares	$ 12.86
Workforce Reduction [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, Number of Shares/Units	(2,041,877)
Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, Number of Shares/Units	(151,575)

Stock-Based Compensation (Sum68

Stock-Based Compensation (Summary Of Performance Unit Activity) (Details) - Performance Units [Member]	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested shares/units at December 31, Number of Shares	407,000
Granted, Number of Shares/Units	1,502,000
Vested, Number of Shares/Units	(414,000)
Forfeited, Number of Shares/Units	(290,000)
Unvested shares/units at September 30, Number of Shares	1,205,000
Unvested shares/units at December 31, Weighted Average Fair Value | $ / shares	$ 36.65
Granted, Weighted Average Fair Value | $ / shares	8.60
Vested, Weighted Average Fair Value | $ / shares	7.62
Forfeited, Weighted Average Fair Value | $ / shares	11.32
Unvested shares at September 30, Weighted Average Fair Value | $ / shares	$ 13.70
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Number of Shares/Units	0
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Number of Shares/Units	2
Workforce Reduction [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, Number of Shares/Units	(15,632)
Forfeited, Number of Shares/Units	(76,281)
Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, Number of Shares/Units	(37,590)
Forfeited, Number of Shares/Units	(195,834)

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 651	$ 749	$ 1,752	$ 2,446
Depreciation, depletion and amortization expense	99	275	349	876
Impairment of natural gas and oil properties	817	2,839	2,321	4,374
Operating income (loss)	(725)	(2,842)	(2,317)	(3,961)
Interest expense	26		57	52
Gain (loss) on derivatives	71	15	(28)	30
Loss on early extinguishment of debt	(51)		(51)
Other income (loss), net	3			2
Provision (benefit) for income taxes	(20)	(1,088)	(20)	(1,532)
Assets	6,890	10,703	6,890	10,703	$ 8,086
Capital investments	180	468	376	2,054
Restructuring charges	2		77
Change in accrued expenditures	27	6	(24)	(5)
Gain on sale of assets, net		(1)		276
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(409)	(486)	(1,108)	(1,639)
Exploration and Production [Member]
Segment Reporting Information [Line Items]
Revenues	381	491	1,015	1,647
Depreciation, depletion and amortization expense	83	255	300	824
Impairment of natural gas and oil properties	817	2,839	2,321	4,374
Operating income (loss)	(777)	(2,910)	(2,486)	(4,471)
Interest expense	26		56	45
Gain (loss) on derivatives	71	15	(27)	32
Other income (loss), net	2		3	2
Provision (benefit) for income taxes	(20)	(1,112)	(20)	(1,724)
Assets	4,015	9,159	4,015	9,159
Capital investments	179	461	372	1,880
Restructuring charges	2		74
Exploration and Production [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	3	3	17	14
Midstream Services [Member]
Segment Reporting Information [Line Items]
Revenues	270	258	737	798
Depreciation, depletion and amortization expense	16	20	49	52
Operating income (loss)	52	68	169	511
Interest expense			1	7
Gain (loss) on derivatives			(1)
Other income (loss), net	1		(2)
Provision (benefit) for income taxes		24		193
Assets	1,253	1,329	1,253	1,329
Capital investments	1	7	3	164
Restructuring charges			3
Gain on sale of assets, net			277
Midstream Services [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(412)	(489)	(1,125)	(1,653)
Other [Member]
Segment Reporting Information [Line Items]
Revenues				1
Operating income (loss)				(1)
Gain (loss) on derivatives				(2)
Loss on early extinguishment of debt	(51)		(51)
Other income (loss), net			(1)
Provision (benefit) for income taxes				(1)
Assets	1,622	215	1,622	215
Capital investments			1	10
Marketable securities	1,443		1,443
Marketing [Member] | Midstream Services [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	$ (355)	(414)	$ (941)	(1,400)
WPX and Statoil Property Acquisitions [Member] | Exploration and Production [Member]
Segment Reporting Information [Line Items]
Capital investments		$ 516
WPX Property Acquisition [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Capital investments				$ 119

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Taxes [Abstract]
Effective tax rate	3.00%		1.00%
Income tax benefit	$ 20	$ 1,088	$ 20	$ 1,532
Increase in valuation allowance	$ 256		$ 903
Projected cumulative loss period evaluated for objective negative evidence			3 years

New Accounting Pronouncements (

New Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
New Accounting Pronouncements [Abstract]
Unamortized debt expense	$ 30	$ 24