Concho Resources (CXO) 10-Q 1 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 30, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	CXO
Entity Registrant Name	CONCHO RESOURCES INC
Entity Central Index Key	1,358,071
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		148,696,032

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 0	$ 53
Accounts receivable, net of allowance for doubtful accounts:
Oil and natural gas	271	220
Joint operations and other	223	238
Derivative instruments	4	4
Prepaid costs and other	37	31
Total current assets	535	546
Property and equipment:
Oil and natural gas properties, successful efforts method	20,754	18,476
Accumulated depletion and depreciation	(8,167)	(7,390)
Total oil and natural gas properties, net	12,587	11,086
Other property and equipment, net	232	216
Total property and equipment, net	12,819	11,302
Funds held in escrow	0	43
Deferred loan costs, net	14	11
Intangible asset - operating rights, net	24	24
Inventory	15	16
Noncurrent derivative instruments	28	0
Other assets	47	177
Total assets	13,482	12,119
Current liabilities:
Accounts payable - trade	36	28
Bank overdrafts	68	0
Revenue payable	135	132
Accrued drilling costs	381	359
Derivative instruments	37	82
Other current liabilities	153	152
Total current liabilities	810	753
Long-term debt	2,738	2,741
Deferred income taxes	1,150	766
Noncurrent derivative instruments	6	96
Asset retirement obligations and other long-term liabilities	147	140
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 authorized; 149,297,932 and 146,488,685 shares issued at September 30, 2017 and December 31, 2016, respectively	0	0
Additional paid-in capital	7,125	6,783
Retained earnings	1,573	884
Treasury stock, at cost; 597,551 and 429,708 shares at September 30, 2017 and December 31, 2016, respectively	(67)	(44)
Total stockholders' equity	8,631	7,623
Total liabilities and stockholders' equity	$ 13,482	$ 12,119

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	149,297,932	146,488,685
Treasury shares	597,551	429,708

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenues:
Oil sales	$ 498	$ 348	$ 1,461	$ 929
Natural gas sales	129	82	345	181
Total operating revenues	627	430	1,806	1,110
Operating costs and expenses:
Oil and natural gas production	106	71	293	240
Production and ad valorem taxes	48	33	140	89
Exploration and abandonments	7	10	42	54
Depreciation, depletion and amortization	284	299	848	890
Accretion of discount on asset retirement obligations	2	2	6	5
Impairments of long-lived assets	0	0	0	1,525
General and administrative (including non-cash stock-based compensation of $17 and $15 for the three months ended September 30, 2017 and 2016, respectively, and $43 for each of the nine months ended September 30, 2017 and 2016)	64	53	180	160
(Gain) loss on derivatives	206	(41)	(289)	176
(Gain) loss on disposition of assets, net	(13)	1	(667)	(109)
Total operating costs and expenses	704	428	553	3,030
Income (loss) from operations	(77)	2	1,253	(1,920)
Other income (expense):
Interest expense	(39)	(53)	(118)	(162)
Loss on extinguishment of debt	(65)	(28)	(66)	(28)
Other, net	2	(2)	18	(9)
Total other expense	(102)	(83)	(166)	(199)
Income (loss) before income taxes	(179)	(81)	1,087	(2,119)
Income tax (expense) benefit	66	30	(398)	782
Net income (loss)	$ (113)	$ (51)	$ 689	$ (1,337)
Earnings per share:
Basic net income (loss)	$ (0.77)	$ (0.38)	$ 4.64	$ (10.18)
Diluted net income (loss)	$ (0.77)	$ (0.38)	$ 4.63	$ (10.18)

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Non-cash stock-based compensation	$ 17	$ 15	$ 43	$ 43

Consolidated Statement of Stock

Consolidated Statement of Stockholders Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Adoption of ASU No. 2016-09 (Note 2) | Accounting Standards Update 2016-09 [Member]	$ 8	$ 0	$ 8	$ 0	$ 0
BALANCE at Jan. 1, 2017	7,631	$ 0	6,791	884	$ (44)
BALANCE, Shares at Dec. 31, 2016		146,489			430
BALANCE at Dec. 31, 2016	7,623	$ 0	6,783	884	$ (44)
Net income (loss)	689	$ 0	0	689	$ 0
Common stock issued in business combination (Shares)		2,177			0
Common stock issued in business combination	291	$ 0	291	0	$ 0
Stock options exercised	0	$ 0	0	0	$ 0
Stock options exercised, shares		20			0
Grants of restricted stock, shares		445			0
Performance unit share conversion, shares		249			0
Cancellation of restricted stock, shares		(82)			0
Stock-based compensation	43	$ 0	43	0	$ 0
Purchase of treasury stock	(23)	$ 0	0	0	$ (23)
Purchase of treasury stock, shares		0			168
BALANCE, Shares at Sep. 30, 2017		149,298			598
BALANCE at Sep. 30, 2017	$ 8,631	$ 0	$ 7,125	$ 1,573	$ (67)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 689	$ (1,337)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	848	890
Accretion of discount on asset retirement obligations	6	5
Impairments of long-lived assets	0	1,525
Exploration and abandonments, including dry holes	29	47
Non-cash stock-based compensation expense	43	43
Deferred income taxes	392	(768)
(Gain) loss on disposition of assets, net	(667)	(109)
(Gain) loss on derivatives	(289)	176
Net settlements received from (paid on) derivatives	126	582
Loss on extinguishment of debt	66	28
Other non-cash items	1	10
Changes in operating assets and liabilities, net of acquisitions and dispositions:
Accounts receivable	(61)	61
Prepaid costs and other	(1)	7
Inventory	(1)	2
Accounts payable	7	9
Revenue payable	5	(57)
Other current liabilities	(8)	(95)
Net cash provided by operating activities	1,185	1,019
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures on oil and natural gas properties	(1,958)	(927)
Additions to property, equipment and other assets	(34)	(20)
Proceeds from the disposition of assets	803	296
Direct transaction costs for disposition of assets	(18)	0
Funds held in escrow	0	(81)
Contributions to equity method investments	0	(51)
Net cash used in investing activities	(1,207)	(783)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt	2,267	0
Payments of debt	(2,255)	(600)
Debt extinguishment costs	(63)	(21)
Excess tax benefit (deficiency) from stock-based compensation	0	(1)
Net proceeds from issuance of common stock	0	1,327
Payments for loan costs	(25)	0
Purchase of treasury stock	(23)	(11)
Increase (decrease) in bank overdrafts	68	0
Net cash provided by (used in) financing activities	(31)	694
Net increase (decrease) in cash and cash equivalents	(53)	930
Cash and cash equivalents at beginning of period	53	229
Cash and cash equivalents at end of period	0	1,159
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of common stock for business combinations	$ 291	$ 231

Organization and nature of oper

Organization and nature of operations	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and nature of operations	Note 1 . Organization and nature of operations Concho Resources Inc. ( the “Company” ) is a Delaware corporation formed on February 22, 2006. The Company’s principal business is the acquisition, development , exploration and production of oil and natural gas properties primarily loc ated in the Permian Basin of southeast New Mexico and w est Texas.

Summary of significant accounti

Summary of significant accounting policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of significant accounting policies	Note 2 . Summary of significant accounting policies Principles of consolidation. The consolidated financial statements of the Company include the accounts of the Company and its 100 percent owned subsidiaries. The Company consolidates the financial statements of these entities. The consolidated financial statements also include the accounts of a variable interest entity (“VIE”) where the Company is the primary beneficiary of the arrangements. See Note 4 for additional information regarding the circumstances surrounding the VIE. All material intercompany balances and transactions have been eliminated. Reclassifications. Certain prior period amounts have been reclassified to conform to the 2017 presentation. These reclassifications had no imp act on net income (loss), total stockholders’ equity or total cash flows. Use of estimates in the preparation of financial statements. Preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and e xpenses during the reporting periods. Actual results could differ from these estimates. Depletion of oil and natural gas properties is determined using estimates of proved oil and natural gas reserves. There are numerous uncertainties inherent in the estim ation of quantities of proved reserves and in the projection of future rates of production and the timing of development expenditures. Similarly, evaluations for impairment of proved and unproved oil and natural gas properties are subject to numerous uncer tainties including, among others, estimates of future recoverable reserves , commodity price outlooks and prevailing market rates of other sources of income and costs . Other significant estimates inclu de, but are not limited to, asset retirement obligations , fair value of stock-based compensation, fair value of business combinations , fair value of nonmonetary exchanges, fair value of deriva tive financial instruments and income taxes . Interim financial statements. The accompanying consolidated financial statements of the Company have not been audited by the Company’s independent registered public accounting firm, except that the consolidated balance sheet at December 31, 2016 is derived from audited consolidated financial st atements. In the opinion of management, the accompanying consolidated financial statements reflect all adjustments necessary to present fairly the Company’s consolidated financial statements . All such adjustments are of a normal , recurring nature. In prepa ring the accompanying consolidated financial statements, management has made certain estimates and assumptions that affect reported amounts in the consolidated financial statements and disclosures of contingencies. Actual results may differ from those esti mates. The results for interim periods are not necessarily indicative of annual results. Certain disclosures have been condensed in or omitted from these consolidated financial statements. Accordingly, these condensed notes to the consolidated financial s tatements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 . Cash equivalents. The Company considers all cash on hand, depository accounts held by banks, money market accounts and investments with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents are held in financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company’s counterparty risks are minimal based on the reputation and history of the institutions selec ted. At December 31, 2016, t he majority of the Company’s cash wa s invested in stable value government money market funds. Equity method investments. At December 31, 2016, the Company owned a 50 percent member ship interest in a midstream joint venture , Alpha Crude Connector, LLC (“ACC”), that operated a crude oil gathering and transportation system in the N orthern Delaware Basin. In February 2017, the Company closed on the divestiture of its ownership interest in ACC. See Note 4 for additional information regarding the di sposition of ACC. The Company account ed for its investment in ACC under the equity method of accounting for investment s in unconsolidated affiliates. The Company’s net investment in ACC was approximately $ 129 million at December 31, 2016 , and was in cluded in other assets in the Company’s consolidated balance sheet. Gains and l osses incurred from the Company’s equity investment in ACC were recorded in other income (expense) in its consolidated statement s of operations. The Company owns a 23.75 percent membership interest in Oryx Southern Delaware Holdings , LLC (“Oryx”) , an entity that operates a crude oil gathering and transportation system in the Southern Delaware Basin. The Company accounts for its investment in Oryx u nder the equity method of accounting for investments in unconsolidated affiliates. The Company’s net investment in Oryx was approximately $ 47 million and $ 42 million at September 30, 2017 and December 31, 2016 , respectively, and is included in other assets in the Company’s consolidated balance sheet s . Gains and l osses incurred from the Company’s equity investment in Oryx are recorded in other income (expense) in its consolidated statement s of operations. Revenue recognition. Oil and natural gas revenues are recorded at the time of physical transfer of such products to the purchaser, which for the Company is primarily at the wellhead. The Company follows the sales method of accounting for oil and natural gas sales, recognizing revenue s based on the Company’s actual proceeds from the oil and natural gas sold to purchasers. General and administrative expense. The Company receives fees for the operation of jointly-owned oil and natural gas properties during the drilling and production phases and records such reimbursements as reductions of general and administrative expense. The Company earned reimbursements of approximate ly $ 4 million for each of the three months ended September 30, 2017 and 2016 and approximately $ 12 million for each of the nine months ended September 30, 2017 and 2016 . Recently adopted accounting pronouncements. The Company adopted Accounting Standards Update (“ASU”) No. 2016-09 , “ Compensation–Stock Compensations (Topic 718): Improvements to Employee Share-based Payment Accounting,” on January 1, 2017. The adoption did not have an impact on prior period consolidated financial statements. The Company elect ed to account for forfeitures of share-bas ed payments as they occur. At December 31, 2016, the Company had not recorded compensation expense of a pproximately $8 million based on forecasted forfeitures nor the associated deferred tax benefit of approximately $3 million . The Company recognize d all excess tax benefits not previously recorded , which totaled approximately $5 million at December 31, 2016 . Upon adoption, the Company recorded a cumulative-effect adjustment, which decreased retained earnings by less than $1 million, increased additional paid-in capital by approximately $8 million, and decreased net deferred income taxes by approximately $8 m illion. The Company elected to prospectively classify excess tax benefits and deficiencies as operating activities on the consolidated statement s of cash flows and will prospectively record those excess tax benefits and deficiencies as d iscrete item s in th e income tax provision in the consolidated statement s of operations. Under the new standard, for the nine months ended September 30, 2017 , the Company recorded excess tax benefits of approximately $6 million as offsets to the Company’s income tax pr ovision. Also under the new standard, for the three and nine months ended September 30, 2017 , the Company recorded forfeitures of share-based payments of approximately $1 million and $7 million, respectively. New accounting pronouncements issued but not yet adopted. In May 2014, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or se rvices. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which deferred the effective date of ASU No. 2014-09 by one year. That new standard is now effective for annual reporting periods beginning after December 15, 2017. The Company expects to use the modified retrospective method to adopt the standard, meaning the cumulative effect of initially applying the standard will be recognized with an adjustment to retained earn ings on January 1, 2018. The Company has substantially completed its internal evaluation of the adoption of this standard, which included a review of all revenue-related contracts with customers and the application of the new revenue recognition model agai nst those contracts. The Company is also updating its revenue recognition policy to conform to the new standard. The Company also expects to expand its revenue recognition related disclosure. Including those changes previously discussed, the Company does n ot expect this new guidance will have a material impact on its consolidated financial statements. In Februar y 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” which supersedes current lease guidance. The new lease standard requires all leases with a term greater than one year to be recognized on the balance sheet while maintaining substantially similar classifications for financ ing and operating leases. Lease expense recognition on the consolidated statements of operations will be effectively u nchanged. This guidance is effective for reporting periods beginning after December 15, 2018 , and early adoption is permitted. The Company does not plan to early adopt the standard. The Company enters into lease agreements to support its operations. These agreements are for leases on assets such as office space, vehicles, field services , well equipment and drilling rigs. The Company is currently in the process of reviewing all contracts that could be applicable to this new guidance. The Company believes thi s new guidance will have a moderate impact to its consolidated balance sheet s due to the recognition of right-of-use assets and lease liabilities that are not currently recognized under currently applicable guidance . In Jun e 2016, the FASB issued ASU No. 2016-13, “Financial Instruments–Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which replaces the current “incurred loss” methodology for recognizing credit losses with an “expected loss” methodology. This new methodolo gy requires that a financial asset measured at amortized cost be presented at the net amount expected to be collected. This standard is intended to provide more timely decision-useful information about the expected credit losses on financial instruments. T his guidance is effective for fiscal years beginning after December 15, 2019, and early adoption is allowed as early as fiscal years beginning after December 15, 2018. The Company does not believe this new guidance will have a material impact on its consol idated financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” with the objective of adding guidance to assist in evaluating whether transactions should be accou nted for as asset acquisitions or as business combinations. The guidance provides a screen to determine when an integrated set of assets and activities is not a business. The screen requires that when substantially all of the fair value of the acquired ass ets is concentrated in a single asset or a group of similar assets, the set is not a business. If the screen is not met, to be considered a business, the set must include an input and a substantive process that together significantly contribute to the abil ity to create output. This new guidance is effective for annual periods beginning after December 15, 2017, and early adoption is allowed. The Company is evaluating the impact this new guidance will have on its consolidated financial statements.

Exploratory well costs

Exploratory well costs	9 Months Ended
	Sep. 30, 2017
Disclosure Exploratory Well Costs Capitalized Exploratory Well Activity [Abstract]
Exploratory well costs	Note 3 . Exploratory well costs The Company capitalizes exploratory well costs until a determination is made that the well has either found proved reserves or that it is impaired. After an exploratory well has been completed and found oil and natural gas reserves, a determination may be pending as to whether the oil and natural gas reserves can be classified as proved. In those circumstances, the Company continues to capitalize the well or project costs pending the determination of proved statu s if (i) the well has found a sufficient quantity of reserves to justify its completion as a producing well and (ii) the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project. The capitalized e xploratory well costs are carried in unproved oil and natural gas properties. See Note 15 for the proved and unproved components of oil and natural gas properties. If the exploratory well is determined to be impaired, the well costs are charged to exploration and abandonments expense in the consolidated statements of operations. The following table reflects the Company’s net capitalized exploratory well activity during the nine months ended September 30, 2017 : Nine Months Ended (in millions) September 30, 2017 Beginning capitalized exploratory well costs $ 151 Additions to exploratory well costs pending the determination of proved reserves 255 Reclassifications due to determination of proved reserves (136) Ending capitalized exploratory well costs $ 270 The following table provides an aging at September 30, 2017 and December 31, 2016 of capitalized exploratory well costs based on the date drilling was completed: September 30, December 31, (in millions, except number of projects) 2017 2016 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 266 $ 141 Capitalized exploratory well costs that have been capitalized for a period greater than one year 4 10 Total capitalized exploratory well costs $ 270 $ 151 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 4 8

Acquisitions and divestitures

Acquisitions and divestitures	9 Months Ended
	Sep. 30, 2017
Acquisitions and Divestitures [Abstract]
Acquisitions and divestitures	Note 4 . Acquisitions and divestitures Midland Basin acquisition. In July 2017, the Company completed an acquisition in the Midland Basin. As consideration for the acquisition, the Company paid approximately $595 million in cash. The acquisition is subject to customary post-closing adjustments. Concurrent with the acquisition, the Company entered into a transaction structured as a reverse like-kind exchange (“Reverse 1031 Exchange”) in accordance with Section 1031 of the Internal Revenue Code of 1986, as amended (the “Code”) . In connection with the Reverse 1031 Exchange, the Company assigned the ownership of the oil and natural gas properties acquired to a VIE formed by an exchange accommodation titleholder. The Company operates the properties pursuant to a management agreement with the VIE. At September 30, 2017, the Company was determined to be the primary beneficiary of the VIE, as the Company had the ability to control the activities that most significantly impact the VIE’s economic perform ance. The assets currently held by the VIE attributable to the acquisition will be conveyed to the Company or one of its subsidiaries, and the VIE structure will terminate, upon the earlier of (i) the completion of the Reverse 1031 Exchange or (ii) the exp iration of the time allowed by the treasury regulations and published Internal Revenue Service guidance to complete the Reverse 1031 Exchange , which is 180 days from commencement . At September 3 0, 2017, the VIE’s total assets and liabilities included i n the Company’s consolidated balance shee t were approximately $607 million and $605 million , respectively. Northern Delaware Basin acquisition. In April 2017, the Company closed on the remainder of its acquisition in the Northern Delaware Basin. As consideration for the entire acquisition , the C ompany paid approximately $160 million in cash , of which $43 million was held in escrow at December 31, 2016, and issued to the seller approximately 2.2 million shares of its common stock w ith an approximate value of $291 million. ACC divestiture. In February 2017, the Company closed on the divestiture of its owne rship interest in ACC. T he Company and its joint venture partner entered into separate agreements to sell 100 percent of their respective ownership interests in ACC. After adjustments for d ebt and working capital, the Company received cash proceeds from the sale of approximately $80 1 million. After direct transaction costs, the Company recorded a pre-tax gain on disposition of assets of approximately $ 655 million. The Company’s net investmen t in ACC at the time of closing was approximately $129 million.

Incentive plans

Incentive plans	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Incentive plans	Note 5 . Stock incentive plan The Company’s 20 15 Stock Incentive Plan provides for granting stock options, restricted stock awards and performance awards to directors, officers and employees of the Company. The restricted stock-based compensation awards generally vest over a period ranging from one to eight years. A summary of the Company’s Stock Incentive Plan activity for the nine months ended September 30, 2017 is presented below: Restricted Stock Performance Stock Shares Options Units Outstanding at December 31, 2016 1,157,270 20,000 331,526 Awards granted (a) 445,384 - 108,398 Options exercised - (20,000) - Awards cancelled / forfeited (82,200) - (43,333) Lapse of restrictions (389,965) - - Outstanding at September 30, 2017 1,130,489 - 396,591 (a) Weighted average grant date fair value per share/unit $ 121.77 $ - $ 183.48 The following table reflects the future stock-based compensation expense to be recorded for all the stock-based compensation awards that were outsta nding at September 30, 2017 : (in millions) Remaining 2017 $ 17 2018 47 2019 25 Thereafter 8 Total $ 97

Disclosures about fair value me

Disclosures about fair value measurements	9 Months Ended
	Sep. 30, 2017
Disclosure Fair Value Narrative [Abstract]
Disclosures about fair value measurements	Note 6 . Disclosures about fair value measurements The Company uses a valuation framework based upon inputs that market participants use in pricing an asset or liability, which are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources, whereas unobservable inputs reflect a company’s own market assumptions, which are used if observable inputs are not reasonably available without undue cost and effort. These two types of inputs are further prioritized into the following fair value input hierarchy: Level 1 : Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. The Company considers active markets to be those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 : Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. This category includes those derivative instruments that the Company values using observable market data. Substantially all of these inputs are observable in the marketplace throughout the full term of the derivative instrument, can be derived from observable data, or supported by observable levels at which transactions are executed in the marketplace. Level 2 instruments primarily include non-ex change traded derivatives such as over-the-counter commodity price swaps, basis swaps, collars and floors, investments and interest rate swaps. The Company’s valuation models are primarily industry-standard models that consider various inputs including: (i ) quoted forward prices f or commodities, (ii) time value, (iii) current market and contractual prices for the underlying instruments and (iv) volatility factors, as well as other relevant economic measures. Level 3 : Prices or valuation models that requir e inputs that are both significant to the fair value measurement and less observable from objective sources ( i.e. , supported by little or no market activity). The Company’s valuation models are primarily industry-standard models that consider various input s including: (i) quoted forward prices for commodities, (ii) time value, (iii) volatility factors and (iv) current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Financial Assets and Liabilities Measured at Fair Value The following table presents the carrying amounts and fair values of the Company’s financial instruments at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Carrying Fair Carrying Fair (in millions) Value Value Value Value Assets: Derivative instruments $ 32 $ 32 $ 4 $ 4 Liabilities: Derivative instruments $ 43 $ 43 $ 178 $ 178 Credit facility $ 368 $ 368 $ - $ - $600 million 5.5% senior notes due 2022 (a) $ - $ - $ 594 $ 620 $1,550 million 5.5% senior notes due 2023 (a) $ - $ - $ 1,555 $ 1,621 $600 million 4.375% senior notes due 2025 (a) $ 593 $ 632 $ 592 $ 599 $1,000 million 3.75% senior notes due 2027 (a) $ 988 $ 1,006 $ - $ - $800 million 4.875% senior notes due 2047 (a) $ 789 $ 834 $ - $ - (a) The carrying value includes associated deferred loan costs and any premium (discount). Credit facility. The carrying amount of the Company’s credit facility approximates its fair value, as the applicable interest rates are variable and reflective of market rates. Senior notes. The fair values of the Company’s senior notes are based on quoted market prices. The debt securities are not actively traded and, therefore, are classified as Level 2 in the fair value hierarchy. Other financial assets and liabilities . The Company has other financial instruments consisting primarily of receivable s, payables and other c urrent assets and liabilities. The carr ying amount s approximate fair value due to the short maturity of these instruments . Derivative instruments. The fair value of the Company’s derivative instruments is estimated by management considering various factors, including closing exchange and over-the-counter quotations and the time value of the underlying commitments. Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect th e valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The following table s summarize (i) the valuation of each of the Company’s financial instruments by required fair value hierarchy levels and (ii) the gross fair value by the appropriate balance sheet classification, even when the derivative instruments are subject to netting arrangements and qualify for net presentation in the Company’s consolidated balance sheets at September 30, 2017 and December 31, 2016 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. September 30, 2017 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 35 $ - $ 35 $ (31) $ 4 Noncurrent: Commodity derivatives - 44 - 44 (16) 28 Liabilities: Current: Commodity derivatives - (68) - (68) 31 (37) Noncurrent: Commodity derivatives - (22) - (22) 16 (6) Net derivative instruments $ - $ (11) $ - $ (11) $ - $ (11) December 31, 2016 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 59 $ - $ 59 $ (55) $ 4 Noncurrent: Commodity derivatives - - - - - - Liabilities: Current: Commodity derivatives - (137) - (137) 55 (82) Noncurrent: Commodity derivatives - (96) - (96) - (96) Net derivative instruments $ - $ (174) $ - $ (174) $ - $ (174) Concentrations of credit risk. At September 30, 2017 , the Company’s primary concentrations of credit risk are the risk of collecting accounts receivable and the risk of counterparties’ failure to perform under derivative obligations. The Company has entered into International Swap Dealers Association Master Agreements (“ISDA Agreements”) with each of its derivative counterparties. The terms of the ISDA Agreements provide the Company and the co unterparties with rights of set- off upon the occurrence of defined acts of default by either the Company or a counterparty to a derivative, whereby the party not in default may set off all derivative liabilities owed to the defaulting party against all derivative asset receivables from the defaulting party. See No te 7 for additional information regarding the Company ’ s derivative activities and counterparties . Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain assets and liabilities are reported at fair value on a nonrecurring basis in the Company’ s consolidated balance sheets. The following methods and assumptions were used to estimate the fair values: Impairments of long-lived assets – The Company periodically reviews its long-lived assets to be held and used, including proved oil and natural gas properties and their integrated assets, whenever events or circumstances indicat e that the carrying value of those assets may not be recoverable, for instance when there are declines in commodity prices or well performance. The Company reviews its oil and natural gas properties by depletion base. An impairment loss is indicated if the sum of the expected undiscounted future net cash flows is less than the carrying amount of the assets. If the estimated undiscounted future net cash flows are less than the carrying amount of the Company’s assets, it recognizes an impairment loss for the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company calculates the expected undiscounted future net cash flows of its long-lived assets and their integrated assets using management’s assumptions and expectations of (i) commodity prices, which are based on the New York Mercantile Exchange (“NYMEX”) strip, (ii) pricing adjustments for differentials, (iii) production costs, (iv) capital expenditures, (v) production volumes, (vi) estimated proved reserves and risk-adjusted probable and possible reserves, and (vii) prevailing market rates of income and ex penses from integrated assets. At September 30, 2017 , the Company’s estimates of commodity prices for purposes of determining undiscounted future cash flows , which are based on the NYMEX strip, ranged from a 2017 price of $52.29 per barrel of oil decreasing to a 2021 price of $50.77 per barrel of oil partially recovering to a 2024 price of $52.01 per barrel of oil. Similarly, natural gas prices ranged from a 2017 pr ice of $3.14 per Mcf of natural gas decreasing to a 2020 price of $2.85 per Mcf of natural gas partially recovering to a 2024 price of $2.88 per Mcf of natural gas. Commodity prices for this purpose were held flat after 2024. The Company calculates the es timated fair values of its long-lived assets and their integrated assets using a discounted future cash flow model. Fair value assumptions associated with the calculation of discounted future net cash flows include (i) market estimates of commodity prices, (ii) pricing adjustments for differentials, (iii) production costs, (iv) capital expenditures, (v) production volumes, (vi) estimated proved reserves and risk-adjusted probable and possible reserves, (vii) prevailing market rates of income and expenses fr om integrated assets and (viii) a discount rate. The expected future net cash flows were discounted using an annual rate of 10 percent to determine fair value . These are classified as Level 3 fair value assumptions. During the three months ended March 31, 2016, NYMEX strip prices declined as compared to December 31, 2015, and as a result the carrying amount of the Company’s Yeso field of approximately $3.4 billion exceeded the expected undiscounted future net cash flows resulting in a non-cash charge again st earnings of approximately $1.5 billion. The non-cash charge represented the amount by which the carrying amount exceeded the estimated fair value of the assets. The following table reports the carrying amount, estimated fair value and impairment expens e of long-lived assets for the indicated period : Estimated Carrying Fair Value Impairment (in millions) Amount (Level 3) Expense March 2016 $ 3,438 $ 1,913 $ 1,525 It is reasonably possible that the estimate of undiscounted future net cash flows of the Company’s long-lived assets may change in the future resulting in the need to impair carrying values. The primary factors that may affect estimates of futu re cash flows are (i) commodity prices including differentials , (ii) increases or decreases in production and capital costs , (iii) future reserve volume adjustments, both positive and negative, to proved reserves and appropriate risk-adjusted probable and possible reserves , (iv) results of f uture drilling activities and (v) changes in income and expenses from integrated assets.

Derivative financial instrument

Derivative financial instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative financial instruments	Note 7 . Derivative financial instruments The Company uses derivative financial instruments to manage its exposure to commodity price fluctuations. Commodity derivative instruments are used to (i) reduce the effect of the volatility of price changes on the oil and natural gas the Company produces and sells, (ii) support the Company’s capital budget and expenditure plans and (iii) support the economics associated with acquisitions. The Company does not enter into derivative financial instrument s for speculative or trading purposes. The Company also enters into fixed-price forward physical power purchase contracts to manage the volatility of the price of power needed for ongoing operations. The Company may also enter into physical delivery contracts to effectively provide commodity price hedges. Because these physical contracts are not expected to be net ca sh settled, the Company has elected normal purchase or normal sale treatment and are thus recorded at cost. T he Company does not designate its derivative instruments to qualify for hed ge accounting. Accordingly, the Company reflects changes in the fair value of its derivative instrum ents in its consolidated statements of operations as they occur. The following table summarizes the amounts reported in earnings related to the commodity derivative i nstruments for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Gain (loss) on derivatives: Oil derivatives $ (205) $ 36 $ 260 $ (173) Natural gas derivatives (1) 5 29 (3) Total $ (206) $ 41 $ 289 $ (176) The following table represents the Company’s net cash receipts from (payments on) derivatives for the three and nine months ended September 30, 2017 and 2016: Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Net cash receipts from (payments on) derivatives: Oil derivatives $ 28 $ 154 $ 129 $ 566 Natural gas derivatives 2 1 (3) 16 Total $ 30 $ 155 $ 126 $ 582 Commodity derivative contracts at September 30, 2017 . The following table sets forth the Company’s outstanding derivative contracts at September 30, 2017 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at September 30, 2017 are expected to settle by December 31, 2019. First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2017: Volume (Bbl) 9,370,080 9,370,080 Price per Bbl $ 51.33 $ 51.33 2018: Volume (Bbl) 8,180,629 7,546,170 7,064,318 6,676,007 29,467,124 Price per Bbl $ 51.54 $ 51.45 $ 51.36 $ 51.26 $ 51.41 2019: Volume (Bbl) 5,314,000 5,090,000 4,897,000 4,721,000 20,022,000 Price per Bbl $ 52.54 $ 52.52 $ 52.54 $ 52.55 $ 52.54 Oil Basis Swaps: (b) 2017: Volume (Bbl) 8,508,000 8,508,000 Price per Bbl $ (0.74) $ (0.74) 2018: Volume (Bbl) 7,936,000 7,521,000 6,961,000 6,684,000 29,102,000 Price per Bbl $ (1.02) $ (1.01) $ (1.01) $ (1.01) $ (1.01) 2019: Volume (Bbl) 4,581,000 4,428,000 4,262,000 4,139,000 17,410,000 Price per Bbl $ (1.17) $ (1.17) $ (1.18) $ (1.18) $ (1.17) Natural Gas Price Swaps: (c) 2017: Volume (MMBtu) 14,673,000 14,673,000 Price per MMBtu $ 3.10 $ 3.10 2018: Volume (MMBtu) 11,156,000 10,641,000 10,219,000 9,904,000 41,920,000 Price per MMBtu $ 3.06 $ 3.05 $ 3.05 $ 3.04 $ 3.05 2019: Volume (MMBtu) 2,791,533 2,681,387 2,578,537 2,489,535 10,540,992 Price per MMBtu $ 2.86 $ 2.85 $ 2.85 $ 2.85 $ 2.85 (a) The index prices for the oil price swaps are based on the NYMEX – West Texas Intermediate (“WTI”) monthly average futures price. (b) The basis differential price is between Midland – WTI and Cushing – WTI. (c) The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price. Derivative counterparties. The Company uses credit and other financial criteria to evaluate the creditworthiness of counterparties to its derivative instruments. The Company believes that all of its derivative counterparties are currently acceptable credit risks. The Company is not required to provide credit support or collateral to any counterparties under its derivative contracts, nor are they required to provide credit support to the Company. In September 2017, the Company elected to enter into an “ Investment Grade Period ” under the C redit F acility , as defined below , which had the effect of releasing all co llateral formerly securing the Credit F acility. Additionally, as a result of the Company’s Investment Grade Period election along with amendments to certain ISDA Agreements with the Company’s derivative counterparties, the Company’s derivatives are no longer secured. See Note 8 for additional information regarding the Credit F acility.

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	Note 8 . Debt The Company’s debt consisted of the following at September 30, 2017 and December 31, 2016 : September 30, December 31, (in millions) 2017 2016 Credit facility $ 368 $ - 5.5% unsecured senior notes due 2022 - 600 5.5% unsecured senior notes due 2023 - 1,550 4.375% unsecured senior notes due 2025 600 600 3.75% unsecured senior notes due 2027 1,000 - 4.875% unsecured senior notes due 2047 800 - Unamortized original issue premium (discount), net (6) 22 Senior notes issuance costs, net (24) (31) Less: current portion - - Total long-term debt $ 2,738 $ 2,741 Credit facility. The Company’s credit facility, as amended and restated (the “Credit Facility”), has a maturity date of May 9, 2022. At September 30, 2017 , the Company’s commitments from its bank group were $2.0 billion. In April 2017, the Company amended the Credit Facil ity to extend the maturity date, increase the borrowing base and decrease unused lender commitments. The amendment also lowered the corporate ratings floor sufficient to automatically terminate an Investment Grade Period under the C redit Facility from (i) “Ba1” to “Ba2” for Moody’s Investors Service, Inc. (“Moody’s”) and (ii) “BB+” to “BB” for S&P Global Ratings (“S&P”). The Company recorded a loss on extinguishment of debt of approximately $1 million during the nine months ended September 30, 2017 for the proportional amount of unamortized deferred loan costs associated with banks that are no longer in the Credit Facility syndicate as a result of the April 2017 amendment. In September 2017, the Company elected to enter into an Investment Grade Period under the Credit Facility, which had the effect of releasing all collateral formerly secu ring the Credit Facility. If the Investment Grade Period under the Credit Facility terminates (whether automatically due to a downgrade of t he Company’s credit ratings below certain thresholds or by the Company’s election), the Credit Facility will once again be secured by a first lien on substantially all of the Company’s oil and natural gas properties and by a pledge of the equity interests in its subsidiaries. At September 30, 2017 , certain of the Company’s 100 percent owned subsidiaries are guarantors under the Credit Facility. During an Investment Grade Period, advances on the Credit Facility bear interest, at the Company’s option, based o n (i) an alternative base rate, which is equal to the highest of (a) the prime rate of JPMorgan Chase Bank (4.25 percent at September 30, 2017 ) , (b) the federal funds effective rate plus 0.5 percent and (c) the London Interbank Offered Rate (“LIBOR”) plus 1 .0 percent or (ii) LIBOR . The Credit Facility’s interest rates and commitment fees on the unused portion of the available commitment vary depending on the Company’s credit ratings from Moody’s and S&P. At the Company’s current credit ratings, LIBOR Rate Lo ans and Alternate Base Rate Loans bear interest margins of 150 basis points and 50 basis points per annum, respectively, and commitment fees on the unused portion of the available commitment are 25 basis points per annum. The Credit Facility contains various restrictive covenants and compliance requirements, which include : maintenance of certain financial ratios, including maintenance of a quarterly ratio of consolidated total debt to consolidated earnings before interest expense, income taxes, deplet ion, depreciation, and amortization, exploration expense and other noncash income and expenses to be no greater than 4.25 to 1.0, and during an Investment Grade Period, if the Company does not have both a rating of “ Baa3 ” or better from Moody’s and a ratin g of “ BBB- ” or better from S&P, maintenance of a quarterly ratio of PV-9 of the Company’s oil and natural gas properties reflected in its most recently delivered reserve report to consolidated total debt to be no less than 1.50 to 1.0 ; limits on the incur rence of additional indebtedness and certain types of liens ; restrictions as to mergers, combinations and dispositions of assets; and restrictions on the payment of cash dividends . Senior notes. Interest on the Company’s senior notes is paid in arrears semi-annually. The senior notes are fully and unconditionally guaranteed on a senior unsecured basis by certain of the Company’s 100 percent owned subsidiaries , subject to customary release provisi ons as described in Note 13 . In September 2017, the Company issued $1,800 million in aggregate principal amount of unsecured senior notes, consisting of $1,000 million in aggregate principal amount of 3.75% unsecured senior notes due 2027 (the “3.75% Notes”) and $800 million in aggregate principal amount of 4.875% unsecured senior notes due 2047 (the “4.875% Notes” and, together with the 3.75% Notes, the “Notes”). The 3.75% Notes were issued at a price equal to 99.636 percent of par, and the 4.8 75% Notes were issued at a price equal to 99.749 percent of par. The Company received net proceeds of approximately $1,777 million. Additionally, in September 2017, the Company completed a cash tender offer (the “Tender Offer”) to purchase any and all of the outstanding $600 million aggregate principal amount of its 5.5% unsecured senior notes due 2022 and the outstanding $1,550 million aggregate principal amount of its 5.5% unsecured senior notes due 2023 (collectively, the “5.5% Notes”). The Company rece ived tenders from the holders of approximately $ 1,232 million in aggregate prin cipal amount, or approximately 57.3 percent, of its outstanding 5.5% Notes in connection with the Tender Offer at a price of 102.934 percent of the unpaid principal amount plus accrued and unpaid interest to the settlement date. In connection with the Tender Offer, the Company redeemed the remaining outstanding 5.5% Notes not purchased in the Tender Offer at a price, including the make-whole premium as determined in accordance with the indentures, of 102.75 percent of the unpaid principal amount plus accrued and unpaid interest . Additionally in September 2017, the Company completed a satisfaction and discharge of the redeemed notes, where the Company prepaid interest to October 13, 2017. The Company used the net proceeds from the offering of the Notes, together with cash on hand and borrowings under its Credit Facility, to fund the Tender Offer and the satisfaction and discharge of its obligations under the indentures of the 5.5% Notes. As a result of these transactions, t he Company recorded a loss on extinguishment of debt for the three and nine months ended September 30, 2017 as follows : (in millions) Tender Offer Extinguishment Total Tender premium $ 36 $ - $ 36 Make-whole premium - 25 25 Prepaid interest - 2 2 Unamortized original issue premium (11) (8) (19) Unamortized deferred loan costs 12 9 21 Total loss on extinguishment of debt $ 37 $ 28 $ 65 At September 30, 2017 , the Company was in compliance with the covenants under all of its debt instruments. Principal maturities of long-term debt. Principal maturities of long -term debt outstanding at September 30, 2017 were as follows: (in millions) Remaining 2017 $ - 2018 - 2019 - 2020 - 2021 - 2022 368 Thereafter 2,400 Total $ 2,768 Interest expense. The following amounts have been incurred and charged to interest expense for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Cash payments for interest $ 73 $ 109 $ 138 $ 215 Non-cash interest 1 3 5 7 Net changes in accruals (35) (59) (25) (60) Total interest expense $ 39 $ 53 $ 118 $ 162

Commitments and contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Note 9 . Commitments and contingencies Legal actions . The Company is a party to proceedings and clai ms incidental to its business. While many of these matters involve inherent uncertainty, the Company believes that the amount of the liability, if any, ultimately incurred with respect to any such proceedings or claims will not have a material adverse effect on the Company’s consolidated financial position as a whole or on its liquidity, capital resources or future results of operations. The Compa ny will continue to evaluate proceedings and claims involving the Company on a regular basis and will establish and adjust any reserves as appropriate to reflect its assessment of the then current status of the matters. Severance tax, royalty and joint in terest audits . The Company is subject to routine severance, royalty and joint interest audits from regulatory bodies and non-operators and makes accruals as necessary for estimated exposure when deemed probable and estimable. Additionally, the Company is subject to various possible contingencies that arise primarily from interpretations affecting the oil and natural gas industry. Such contingencies include differing interpretations as to the prices at which oil and natural gas sales may be made, the prices at which royalty owners may be paid for production from their leases, allowable costs under joint interest arrangements and other matters. At December 31, 2016 , the Company had $ 7 million accrued for estimated exposure that has since been satisfied . Although the Company believe s that it has estimated its exposure with respect to the various laws and regulations, administrative rulings and interpretations thereof, adjustments could be required as new interpre tations and regulations are issued. C ommitments. The Company periodically enters into contractual arrangements under which the Company is committed to expend funds . These contractual arrangements r elate to purchase agreements the Company has entered into including drilling commitments , water commitment agreements, through put volume delivery commitments, power commitments , fixed asset commitments and maintenance commitments . The following table s ummarizes the Company’s commitments at September 30, 2017 : (in millions) Remaining 2017 $ 10 2018 40 2019 59 2020 32 2021 31 2022 26 Thereafter 88 Total $ 286 Operating leases. The Company leases vehicles, equipment and office facilities under non-cancellable operating leases. Lease payments associated with these operating leases were approximately $ 2 million for each of the three months ended September 30, 2017 and 2016 and approximately $ 7 million and $ 6 million for the nine months ended September 30, 2017 and 2016 , respectively. Future minimum lease commitments under non-cancellable operating leases at September 30, 2017 were as follows: (in millions) Remaining 2017 $ 2 2018 9 2019 7 2020 6 2021 4 2022 - Thereafter 1 Total $ 29

Income taxes

Income taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income taxes	Note 10 . Income taxes The effective income tax rate s w ere 36.7 percent and 37.3 percent for the three months ended September 30, 2017 and 2016 , respectively, and 36.6 percent and 36.9 percent for the nine months ended September 30, 2017 and 2016 , respectively. Total income tax expense for the nine months ended September 30, 2017 differed from amounts computed by applying the United States federal statutory tax rates to pre-tax income primarily due to state income taxes and the impact of permanent differences between book and taxable income. The Company recorded a discrete income tax benefit of approximately $6 million for the nine m onths ended September 30, 2017 related to excess tax benefits on stock-based awards, which are recorded in the income tax provision pursuant to ASU No. 2016-09 , which was adopted on January 1, 2017. Total income tax benefit for the three months ended September 30, 2017 and the three and nine months ended September 30, 2016 differed from amounts computed by applying the United States federal statutory tax rates to pre-tax loss primarily due to state income taxes, partially offset by the impact of permanent differences between book and taxable loss.

Related party transactions

Related party transactions	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related party transactions	Note 11 . Related party transactions The Company paid royalties on certain properties to a partnership in which a director of the Company is the general partner and owns a 3.5 percent partnership interest. These payments were reported in the Company’s consolidated statements of operations and totaled approximately $ 1 million for each of the three months ended September 30, 2017 and 2016 and approximately $ 5 m illion and $ 3 million for the nine months ended September 30, 2017 and 2016 , respectively.

Net income per share

Net income per share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Net income per share	Note 12 . Earnings per share The Company uses the two-class method of calculating earnings per share because certain of the Company’s unvested share-based awards qualify as participating securities. The Company’s basic earnings per share attributable to common stockholders is computed as (i) net income (loss) as reported, (ii) less participating basic earnings (iii) divided by weighted average basic common shares outstanding. The Company’s diluted earnings per share attributable to common stockholders is computed as (i) basic earnings attributable to common stockholders, (ii) plus reallocation of participating earnings (iii) divided by weighted average diluted common shares outstanding. The following table reconciles the Company’s earnings from operations and earnings attributable to common stockholders to the basic and diluted earnings used to determine the Company’s earnings per share amounts for the three and nine months ended September 30, 2017 and 2016 , respectively, under the two-clas s method: Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Net income (loss) as reported $ (113) $ (51) $ 689 $ (1,337) Participating basic earnings (a) - - (5) - Basic earnings attributable to common stockholders (113) (51) 684 (1,337) Reallocation of participating earnings - - - - Diluted earnings attributable to common stockholders $ (113) $ (51) $ 684 $ (1,337) (a) Unvested restricted stock awards represent participating securities because they participate in nonforfeitable dividends or distributions with the common equity holders of the Company. Participating earnings represent the distributed earnings of the Company attributable to the participating securities. Unvested restricted stock awards do not participate in undistributed net losses as they are not contractually obligated to do so. The following table is a reconciliation of the basic weighted average common shares outstanding to diluted weighted average common shares outstanding for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Weighted average common shares outstanding: Basic 147,557 135,454 147,233 131,417 Dilutive common stock options - - 4 - Dilutive performance units - - 549 - Diluted 147,557 135,454 147,786 131,417 The following table is a summary of the performance units that were not included in the computation of diluted earnings per share, as inclusion of these items would be antidilutive: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Number of antidilutive units: Antidilutive performance units - - 107 - Performance unit awards. The number of shares of common stock that will ultimately be issued for performance units will be determined by a combination of ( i ) comparing the Company’s total shareholder return relative to the total shareholder return of a predetermined group of peer companies at the end of the performance period and (ii) the Company’s absolute total shareholder return at the end of the performance period. The performance period is 36 months. The actual payout of shares will be between zero and 300 percent .

Subsidiary guarantors

Subsidiary guarantors	9 Months Ended
	Sep. 30, 2017
Guarantees [Abstract]
Subsidiary guarantors	Note 13 . Subsidiary guarantors At September 30, 2017 , certain of the Company’s 100 percent owned subsidiaries have fully and unconditionally guaranteed the Company’s senior notes. The indentures governing the Company’s senior notes provide that the guarantees of its subsidiary guarantors will be released in certain cus tomary circumstances including (i) in connection with any sale, exchange or other disposition, whether by merger, consolidation or otherwise, of the capital stock of that guarantor to a person that is not the Company or a restricted subsidiary of the Compa ny, such that, after giving effect to such transaction, such guarantor would no longer constitute a subsidiary of the Company, (ii) in connection with any sale, exchange or other disposition (other than a lease) of all or substantially all of the assets of that guarantor to a person that is not the Company or a restricted subsidiary of the Company, (iii) upon the merger of a guarantor into the Company or any other guarantor or the liquidation or dissolution of a guarantor, (iv) if the Company designates any restricted subsidiary that is a guarantor to be an unrestricted subsidiary in accordance with the indenture, (v) upon legal defeasance or satisfaction and discharge of the indenture and (vi) upon written notice of such release or discharge by the Company to the trustee following the release or discharge of all guarantees by such guarantor of any indebtedness that resulted in the creation of such guarantee, except a discharge or release by or as a result of payment under such guarantee. See Note 8 for a summary of the Company’s senior notes. In accordance with practices accepted by the United States Securities and Exchange Commission, the Company has prepared condensed consolidating financial statements in order to quantify the assets, results of o perations and cash flows of such subsidiaries as subsidiary guarantors. In addition, two of the Company’s subsidiaries do not guarantee the Company’s senior notes and are included in the Company’s consolidated financial statements. One of such entities is a VIE that was formed to effectuate a tax-free exchange of assets, and the other entity is a 100 percent owned subsidiary that was recently acquired. These entities are referred to as “Subsidiary Non-Guarantors” in the tables below. The following condense d consolidating balance s heets at September 30, 2017 and December 31, 2016 , condensed c o nsolidating statements of o perations for the three and nine months ended September 30, 2017 and 2016 and condensed consolidating statements of cash flows for the nine months ended September 30, 2017 and 2016 , present financial information fo r Concho Resources Inc. as the p arent on a stand-alone basis ( carrying any investments in subsidiaries under the equity method), financial information for the subsidiary g uarantors on a stand-alone basis (carrying any investment in non-guarantor subsidiaries under the equity method), financial information for the subsidiary non-guarantor s on a stand-alone basis and the consolidation and elimination entries necessary to arri ve at the information for the Company on a consolidated basis. All current and deferred income taxes are recorded on Concho Resources Inc., as the subsidiaries are flow-through entities for income tax purposes. The subsidiary guarantors and subsidiary non- guarantor s are not restricted from making distributions to the Company. Condensed Consolidating Balance Sheet September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,903 $ (653) $ - $ (8,250) $ - Other current assets 14 515 6 - 535 Oil and natural gas properties, net - 11,968 619 - 12,587 Property and equipment, net - 232 - - 232 Investment in subsidiaries 2,963 - - (2,963) - Other long-term assets 42 86 - - 128 Total assets $ 11,922 $ 12,148 $ 625 $ (11,213) $ 13,482 LIABILITIES AND EQUITY Accounts payable - related parties $ (653) $ 8,290 $ 613 $ (8,250) $ - Other current liabilities 50 756 4 - 810 Long-term debt 2,738 - - - 2,738 Other long-term liabilities 1,156 141 6 - 1,303 Equity 8,631 2,961 2 (2,963) 8,631 Total liabilities and equity $ 11,922 $ 12,148 $ 625 $ (11,213) $ 13,482 Condensed Consolidating Balance Sheet December 31, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,991 $ (336) $ (8,655) $ - Other current assets 12 534 - 546 Oil and natural gas properties, net - 11,086 - 11,086 Property and equipment, net - 216 - 216 Investment in subsidiaries 1,989 - (1,989) - Other long-term assets 11 260 - 271 Total assets $ 11,003 $ 11,760 $ (10,644) $ 12,119 LIABILITIES AND EQUITY Accounts payable - related parties $ (336) $ 8,991 $ (8,655) $ - Other current liabilities 114 639 - 753 Long-term debt 2,741 - - 2,741 Other long-term liabilities 861 141 - 1,002 Equity 7,623 1,989 (1,989) 7,623 Total liabilities and equity $ 11,003 $ 11,760 $ (10,644) $ 12,119 Condensed Consolidating Statement of Operations Three Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Total operating revenues $ - $ 619 $ 8 $ - $ 627 Total operating costs and expenses (207) (491) (6) - (704) Income (loss) from operations (207) 128 2 - (77) Interest expense (39) - - - (39) Loss on extinguishment of debt (65) - - - (65) Other, net 132 2 - (132) 2 Income (loss) before income taxes (179) 130 2 (132) (179) Income tax benefit 66 - - - 66 Net income (loss) $ (113) $ 130 $ 2 $ (132) $ (113) Condensed Consolidating Statement of Operations Three Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 430 $ - $ 430 Total operating costs and expenses 41 (469) - (428) Income (loss) from operations 41 (39) - 2 Interest expense (52) (1) - (53) Loss on extinguishment of debt (28) - - (28) Other, net (42) (2) 42 (2) Loss before income taxes (81) (42) 42 (81) Income tax benefit 30 - - 30 Net loss $ (51) $ (42) $ 42 $ (51) Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Total operating revenues $ - $ 1,798 $ 8 $ - $ 1,806 Total operating costs and expenses 288 (835) (6) - (553) Income from operations 288 963 2 - 1,253 Interest expense (117) (1) - - (118) Loss on extinguishment of debt (66) - - - (66) Other, net 982 18 - (982) 18 Income before income taxes 1,087 980 2 (982) 1,087 Income tax expense (398) - - - (398) Net income $ 689 $ 980 $ 2 $ (982) $ 689 Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,110 $ - $ 1,110 Total operating costs and expenses (177) (2,853) - (3,030) Loss from operations (177) (1,743) - (1,920) Interest expense (159) (3) - (162) Loss on extinguishment of debt (28) - - (28) Other, net (1,755) (10) 1,756 (9) Loss before income taxes (2,119) (1,756) 1,756 (2,119) Income tax benefit 782 - - 782 Net loss $ (1,337) $ (1,756) $ 1,756 $ (1,337) Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Net cash flows provided by operating activities $ 99 $ 1,084 $ 2 $ - $ 1,185 Net cash flows used in investing activities - (592) (615) - (1,207) Net cash flows provided by (used in) financing activities (99) (545) 613 - (31) Net decrease in cash and cash equivalents - (53) - - (53) Cash and cash equivalents at beginning of period - 53 - - 53 Cash and cash equivalents at end of period $ - $ - $ - $ - $ - Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (694) $ 1,713 $ - $ 1,019 Net cash flows used in investing activities - (783) - (783) Net cash flows provided by financing activities 694 - - 694 Net increase in cash and cash equivalents - 930 - 930 Cash and cash equivalents at beginning of period - 229 - 229 Cash and cash equivalents at end of period $ - $ 1,159 $ - $ 1,159

Subsequent events

Subsequent events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent events	Note 14 . Subsequent events New commodity derivative contracts. After September 30, 2017 , the Com pany entered into the following oil price swaps, oil basis swaps and natural gas price swaps to hedge additional amounts of the Company’s estimated future production: First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2017: Volume (Bbl) 846,000 846,000 Price per Bbl $ 51.29 $ 51.29 2018: Volume (Bbl) 953,000 600,000 407,000 296,000 2,256,000 Price per Bbl $ 51.55 $ 51.39 $ 51.43 $ 51.28 $ 51.45 2019: Volume (Bbl) 1,035,000 1,046,500 828,000 828,000 3,737,500 Price per Bbl $ 51.25 $ 51.25 $ 51.14 $ 51.14 $ 51.20 Oil Basis Swaps: (b) 2017: Volume (Bbl) 1,499,000 1,499,000 Price per Bbl $ (0.12) $ (0.12) 2018: Volume (Bbl) 540,000 546,000 276,000 276,000 1,638,000 Price per Bbl $ (0.21) $ (0.21) $ (0.38) $ (0.38) $ (0.27) 2019: Volume (Bbl) 1,395,000 1,410,500 1,426,000 1,426,000 5,657,500 Price per Bbl $ (0.68) $ (0.68) $ (0.68) $ (0.68) $ (0.68) Natural Gas Price Swaps: (c) 2017: Volume (MMBtu) 3,660,000 3,660,000 Price per MMBtu $ 3.02 $ 3.02 2018: Volume (MMBtu) 5,400,000 5,460,000 4,600,000 4,600,000 20,060,000 Price per MMBtu $ 3.02 $ 3.02 $ 3.01 $ 3.01 $ 3.02 2019: Volume (MMBtu) 1,800,000 1,820,000 1,840,000 1,840,000 7,300,000 Price per MMBtu $ 2.86 $ 2.86 $ 2.86 $ 2.86 $ 2.86 (a) The index prices for the oil price swaps are based on the NYMEX – WTI monthly average futures price. (b) The basis differential price is between Midland – WTI and Cushing – WTI. (c) The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price.

Supplementary information

Supplementary information	9 Months Ended
	Sep. 30, 2017
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Supplementary information	Note 15 . Supplementary information Capitalized costs September 30, December 31, (in millions) 2017 2016 Oil and natural gas properties: Proved $ 17,950 $ 16,620 Unproved 2,804 1,856 Less: accumulated depletion (8,167) (7,390) Net capitalized costs for oil and natural gas properties $ 12,587 $ 11,086 Costs incurred for oil and natural gas producing activities Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Property acquisition costs: Proved $ 162 $ 1 $ 301 $ 257 Unproved 472 14 865 172 Exploration 252 177 725 513 Development 175 97 478 287 Total costs incurred for oil and natural gas properties $ 1,061 $ 289 $ 2,369 $ 1,229

Summary of significant accoun23

Summary of significant accounting policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation. The consolidated financial statements of the Company include the accounts of the Company and its 100 percent owned subsidiaries. The Company consolidates the financial statements of these entities. The consolidated financial statements also include the accounts of a variable interest entity (“VIE”) where the Company is the primary beneficiary of the arrangements. See Note 4 for additional information regarding the circumstances surrounding the VIE. All material intercompany balances and transactions have been eliminated.
Reclassifications	Reclassifications. Certain prior period amounts have been reclassified to conform to the 2017 presentation. These reclassifications had no imp act on net income (loss), total stockholders’ equity or total cash flows.
Use of estimates in the preparation of financial statements	Use of estimates in the preparation of financial statements. Preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and e xpenses during the reporting periods. Actual results could differ from these estimates. Depletion of oil and natural gas properties is determined using estimates of proved oil and natural gas reserves. There are numerous uncertainties inherent in the estim ation of quantities of proved reserves and in the projection of future rates of production and the timing of development expenditures. Similarly, evaluations for impairment of proved and unproved oil and natural gas properties are subject to numerous uncer tainties including, among others, estimates of future recoverable reserves , commodity price outlooks and prevailing market rates of other sources of income and costs . Other significant estimates inclu de, but are not limited to, asset retirement obligations , fair value of stock-based compensation, fair value of business combinations , fair value of nonmonetary exchanges, fair value of deriva tive financial instruments and income taxes .
Interim financial statements	Interim financial statements. The accompanying consolidated financial statements of the Company have not been audited by the Company’s independent registered public accounting firm, except that the consolidated balance sheet at December 31, 2016 is derived from audited consolidated financial st atements. In the opinion of management, the accompanying consolidated financial statements reflect all adjustments necessary to present fairly the Company’s consolidated financial statements . All such adjustments are of a normal , recurring nature. In prepa ring the accompanying consolidated financial statements, management has made certain estimates and assumptions that affect reported amounts in the consolidated financial statements and disclosures of contingencies. Actual results may differ from those esti mates. The results for interim periods are not necessarily indicative of annual results. Certain disclosures have been condensed in or omitted from these consolidated financial statements. Accordingly, these condensed notes to the consolidated financial s tatements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 .
Cash equivalents	Cash equivalents. The Company considers all cash on hand, depository accounts held by banks, money market accounts and investments with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents are held in financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company’s counterparty risks are minimal based on the reputation and history of the institutions selec ted. At December 31, 2016, t he majority of the Company’s cash wa s invested in stable value government money market funds.
Equity method investments	Equity method investments. At December 31, 2016, the Company owned a 50 percent member ship interest in a midstream joint venture , Alpha Crude Connector, LLC (“ACC”), that operated a crude oil gathering and transportation system in the N orthern Delaware Basin. In February 2017, the Company closed on the divestiture of its ownership interest in ACC. See Note 4 for additional information regarding the di sposition of ACC. The Company account ed for its investment in ACC under the equity method of accounting for investment s in unconsolidated affiliates. The Company’s net investment in ACC was approximately $ 129 million at December 31, 2016 , and was in cluded in other assets in the Company’s consolidated balance sheet. Gains and l osses incurred from the Company’s equity investment in ACC were recorded in other income (expense) in its consolidated statement s of operations. The Company owns a 23.75 percent membership interest in Oryx Southern Delaware Holdings , LLC (“Oryx”) , an entity that operates a crude oil gathering and transportation system in the Southern Delaware Basin. The Company accounts for its investment in Oryx u nder the equity method of accounting for investments in unconsolidated affiliates. The Company’s net investment in Oryx was approximately $ 47 million and $ 42 million at September 30, 2017 and December 31, 2016 , respectively, and is included in other assets in the Company’s consolidated balance sheet s . Gains and l osses incurred from the Company’s equity investment in Oryx are recorded in other income (expense) in its consolidated statement s of operations.
Revenue recognition	Revenue recognition. Oil and natural gas revenues are recorded at the time of physical transfer of such products to the purchaser, which for the Company is primarily at the wellhead. The Company follows the sales method of accounting for oil and natural gas sales, recognizing revenue s based on the Company’s actual proceeds from the oil and natural gas sold to purchasers.
General and administrative expense	General and administrative expense. The Company receives fees for the operation of jointly-owned oil and natural gas properties during the drilling and production phases and records such reimbursements as reductions of general and administrative expense. The Company earned reimbursements of approximate ly $ 4 million for each of the three months ended September 30, 2017 and 2016 and approximately $ 12 million for each of the nine months ended September 30, 2017 and 2016 .
Recent accounting pronouncements	Recently adopted accounting pronouncements. The Company adopted Accounting Standards Update (“ASU”) No. 2016-09 , “ Compensation–Stock Compensations (Topic 718): Improvements to Employee Share-based Payment Accounting,” on January 1, 2017. The adoption did not have an impact on prior period consolidated financial statements. The Company elect ed to account for forfeitures of share-bas ed payments as they occur. At December 31, 2016, the Company had not recorded compensation expense of a pproximately $8 million based on forecasted forfeitures nor the associated deferred tax benefit of approximately $3 million . The Company recognize d all excess tax benefits not previously recorded , which totaled approximately $5 million at December 31, 2016 . Upon adoption, the Company recorded a cumulative-effect adjustment, which decreased retained earnings by less than $1 million, increased additional paid-in capital by approximately $8 million, and decreased net deferred income taxes by approximately $8 m illion. The Company elected to prospectively classify excess tax benefits and deficiencies as operating activities on the consolidated statement s of cash flows and will prospectively record those excess tax benefits and deficiencies as d iscrete item s in th e income tax provision in the consolidated statement s of operations. Under the new standard, for the nine months ended September 30, 2017 , the Company recorded excess tax benefits of approximately $6 million as offsets to the Company’s income tax pr ovision. Also under the new standard, for the three and nine months ended September 30, 2017 , the Company recorded forfeitures of share-based payments of approximately $1 million and $7 million, respectively. New accounting pronouncements issued but not yet adopted. In May 2014, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or se rvices. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which deferred the effective date of ASU No. 2014-09 by one year. That new standard is now effective for annual reporting periods beginning after December 15, 2017. The Company expects to use the modified retrospective method to adopt the standard, meaning the cumulative effect of initially applying the standard will be recognized with an adjustment to retained earn ings on January 1, 2018. The Company has substantially completed its internal evaluation of the adoption of this standard, which included a review of all revenue-related contracts with customers and the application of the new revenue recognition model agai nst those contracts. The Company is also updating its revenue recognition policy to conform to the new standard. The Company also expects to expand its revenue recognition related disclosure. Including those changes previously discussed, the Company does n ot expect this new guidance will have a material impact on its consolidated financial statements. In Februar y 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” which supersedes current lease guidance. The new lease standard requires all leases with a term greater than one year to be recognized on the balance sheet while maintaining substantially similar classifications for financ ing and operating leases. Lease expense recognition on the consolidated statements of operations will be effectively u nchanged. This guidance is effective for reporting periods beginning after December 15, 2018 , and early adoption is permitted. The Company does not plan to early adopt the standard. The Company enters into lease agreements to support its operations. These agreements are for leases on assets such as office space, vehicles, field services , well equipment and drilling rigs. The Company is currently in the process of reviewing all contracts that could be applicable to this new guidance. The Company believes thi s new guidance will have a moderate impact to its consolidated balance sheet s due to the recognition of right-of-use assets and lease liabilities that are not currently recognized under currently applicable guidance . In Jun e 2016, the FASB issued ASU No. 2016-13, “Financial Instruments–Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which replaces the current “incurred loss” methodology for recognizing credit losses with an “expected loss” methodology. This new methodolo gy requires that a financial asset measured at amortized cost be presented at the net amount expected to be collected. This standard is intended to provide more timely decision-useful information about the expected credit losses on financial instruments. T his guidance is effective for fiscal years beginning after December 15, 2019, and early adoption is allowed as early as fiscal years beginning after December 15, 2018. The Company does not believe this new guidance will have a material impact on its consol idated financial statements. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” with the objective of adding guidance to assist in evaluating whether transactions should be accou nted for as asset acquisitions or as business combinations. The guidance provides a screen to determine when an integrated set of assets and activities is not a business. The screen requires that when substantially all of the fair value of the acquired ass ets is concentrated in a single asset or a group of similar assets, the set is not a business. If the screen is not met, to be considered a business, the set must include an input and a substantive process that together significantly contribute to the abil ity to create output. This new guidance is effective for annual periods beginning after December 15, 2017, and early adoption is allowed. The Company is evaluating the impact this new guidance will have on its consolidated financial statements.

Exploratory well costs (Tables)

Exploratory well costs (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure Exploratory Well Costs Capitalized Exploratory Well Activity [Abstract]
Company's capitalized exploratory well activity	The following table reflects the Company’s net capitalized exploratory well activity during the nine months ended September 30, 2017 : Nine Months Ended (in millions) September 30, 2017 Beginning capitalized exploratory well costs $ 151 Additions to exploratory well costs pending the determination of proved reserves 255 Reclassifications due to determination of proved reserves (136) Ending capitalized exploratory well costs $ 270
Aging of capitalized exploratory well costs based on the date drilling was completed	The following table provides an aging at September 30, 2017 and December 31, 2016 of capitalized exploratory well costs based on the date drilling was completed: September 30, December 31, (in millions, except number of projects) 2017 2016 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 266 $ 141 Capitalized exploratory well costs that have been capitalized for a period greater than one year 4 10 Total capitalized exploratory well costs $ 270 $ 151 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 4 8

Incentive plans (Tables)

Incentive plans (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the Company's stock-based compensation awards activity	A summary of the Company’s Stock Incentive Plan activity for the nine months ended September 30, 2017 is presented below: Restricted Stock Performance Stock Shares Options Units Outstanding at December 31, 2016 1,157,270 20,000 331,526 Awards granted (a) 445,384 - 108,398 Options exercised - (20,000) - Awards cancelled / forfeited (82,200) - (43,333) Lapse of restrictions (389,965) - - Outstanding at September 30, 2017 1,130,489 - 396,591 (a) Weighted average grant date fair value per share/unit $ 121.77 $ - $ 183.48
Future stock-based compensation expense to be recorded for all the stock-based compensation awards that were outstanding	The following table reflects the future stock-based compensation expense to be recorded for all the stock-based compensation awards that were outsta nding at September 30, 2017 : (in millions) Remaining 2017 $ 17 2018 47 2019 25 Thereafter 8 Total $ 97

Disclosures about fair value 26

Disclosures about fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure Fair Value Narrative [Abstract]
Carrying amounts and fair values of the Company's financial instruments	The following table presents the carrying amounts and fair values of the Company’s financial instruments at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 Carrying Fair Carrying Fair (in millions) Value Value Value Value Assets: Derivative instruments $ 32 $ 32 $ 4 $ 4 Liabilities: Derivative instruments $ 43 $ 43 $ 178 $ 178 Credit facility $ 368 $ 368 $ - $ - $600 million 5.5% senior notes due 2022 (a) $ - $ - $ 594 $ 620 $1,550 million 5.5% senior notes due 2023 (a) $ - $ - $ 1,555 $ 1,621 $600 million 4.375% senior notes due 2025 (a) $ 593 $ 632 $ 592 $ 599 $1,000 million 3.75% senior notes due 2027 (a) $ 988 $ 1,006 $ - $ - $800 million 4.875% senior notes due 2047 (a) $ 789 $ 834 $ - $ - (a) The carrying value includes associated deferred loan costs and any premium (discount).
Net basis derivative fair values as reported in the consolidated balance sheets	The following table s summarize (i) the valuation of each of the Company’s financial instruments by required fair value hierarchy levels and (ii) the gross fair value by the appropriate balance sheet classification, even when the derivative instruments are subject to netting arrangements and qualify for net presentation in the Company’s consolidated balance sheets at September 30, 2017 and December 31, 2016 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. September 30, 2017 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 35 $ - $ 35 $ (31) $ 4 Noncurrent: Commodity derivatives - 44 - 44 (16) 28 Liabilities: Current: Commodity derivatives - (68) - (68) 31 (37) Noncurrent: Commodity derivatives - (22) - (22) 16 (6) Net derivative instruments $ - $ (11) $ - $ (11) $ - $ (11) December 31, 2016 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 59 $ - $ 59 $ (55) $ 4 Noncurrent: Commodity derivatives - - - - - - Liabilities: Current: Commodity derivatives - (137) - (137) 55 (82) Noncurrent: Commodity derivatives - (96) - (96) - (96) Net derivative instruments $ - $ (174) $ - $ (174) $ - $ (174)
Carrying amounts, estimated fair values and impairment expense of long-lived assets	The following table reports the carrying amount, estimated fair value and impairment expens e of long-lived assets for the indicated period : Estimated Carrying Fair Value Impairment (in millions) Amount (Level 3) Expense March 2016 $ 3,438 $ 1,913 $ 1,525

Derivative financial instrume27

Derivative financial instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summarizes the gains and losses reported in earnings related to the commodity and interest rate derivative instruments	The following table summarizes the amounts reported in earnings related to the commodity derivative i nstruments for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Gain (loss) on derivatives: Oil derivatives $ (205) $ 36 $ 260 $ (173) Natural gas derivatives (1) 5 29 (3) Total $ (206) $ 41 $ 289 $ (176) The following table represents the Company’s net cash receipts from (payments on) derivatives for the three and nine months ended September 30, 2017 and 2016: Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Net cash receipts from (payments on) derivatives: Oil derivatives $ 28 $ 154 $ 129 $ 566 Natural gas derivatives 2 1 (3) 16 Total $ 30 $ 155 $ 126 $ 582
Company's outstanding derivative contracts	The following table sets forth the Company’s outstanding derivative contracts at September 30, 2017 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at September 30, 2017 are expected to settle by December 31, 2019. First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2017: Volume (Bbl) 9,370,080 9,370,080 Price per Bbl $ 51.33 $ 51.33 2018: Volume (Bbl) 8,180,629 7,546,170 7,064,318 6,676,007 29,467,124 Price per Bbl $ 51.54 $ 51.45 $ 51.36 $ 51.26 $ 51.41 2019: Volume (Bbl) 5,314,000 5,090,000 4,897,000 4,721,000 20,022,000 Price per Bbl $ 52.54 $ 52.52 $ 52.54 $ 52.55 $ 52.54 Oil Basis Swaps: (b) 2017: Volume (Bbl) 8,508,000 8,508,000 Price per Bbl $ (0.74) $ (0.74) 2018: Volume (Bbl) 7,936,000 7,521,000 6,961,000 6,684,000 29,102,000 Price per Bbl $ (1.02) $ (1.01) $ (1.01) $ (1.01) $ (1.01) 2019: Volume (Bbl) 4,581,000 4,428,000 4,262,000 4,139,000 17,410,000 Price per Bbl $ (1.17) $ (1.17) $ (1.18) $ (1.18) $ (1.17) Natural Gas Price Swaps: (c) 2017: Volume (MMBtu) 14,673,000 14,673,000 Price per MMBtu $ 3.10 $ 3.10 2018: Volume (MMBtu) 11,156,000 10,641,000 10,219,000 9,904,000 41,920,000 Price per MMBtu $ 3.06 $ 3.05 $ 3.05 $ 3.04 $ 3.05 2019: Volume (MMBtu) 2,791,533 2,681,387 2,578,537 2,489,535 10,540,992 Price per MMBtu $ 2.86 $ 2.85 $ 2.85 $ 2.85 $ 2.85 (a) The index prices for the oil price swaps are based on the NYMEX – West Texas Intermediate (“WTI”) monthly average futures price. (b) The basis differential price is between Midland – WTI and Cushing – WTI. (c) The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Company's debt	The Company’s debt consisted of the following at September 30, 2017 and December 31, 2016 : September 30, December 31, (in millions) 2017 2016 Credit facility $ 368 $ - 5.5% unsecured senior notes due 2022 - 600 5.5% unsecured senior notes due 2023 - 1,550 4.375% unsecured senior notes due 2025 600 600 3.75% unsecured senior notes due 2027 1,000 - 4.875% unsecured senior notes due 2047 800 - Unamortized original issue premium (discount), net (6) 22 Senior notes issuance costs, net (24) (31) Less: current portion - - Total long-term debt $ 2,738 $ 2,741
Loss on extinguishment of debt	As a result of these transactions, t he Company recorded a loss on extinguishment of debt for the three and nine months ended September 30, 2017 as follows : (in millions) Tender Offer Extinguishment Total Tender premium $ 36 $ - $ 36 Make-whole premium - 25 25 Prepaid interest - 2 2 Unamortized original issue premium (11) (8) (19) Unamortized deferred loan costs 12 9 21 Total loss on extinguishment of debt $ 37 $ 28 $ 65
Principal maturities of debt	Principal maturities of long -term debt outstanding at September 30, 2017 were as follows: (in millions) Remaining 2017 $ - 2018 - 2019 - 2020 - 2021 - 2022 368 Thereafter 2,400 Total $ 2,768
Interest expense	The following amounts have been incurred and charged to interest expense for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Cash payments for interest $ 73 $ 109 $ 138 $ 215 Non-cash interest 1 3 5 7 Net changes in accruals (35) (59) (25) (60) Total interest expense $ 39 $ 53 $ 118 $ 162

Commitments and contingencies (

Commitments and contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of the Company's future commitments	The following table s ummarizes the Company’s commitments at September 30, 2017 : (in millions) Remaining 2017 $ 10 2018 40 2019 59 2020 32 2021 31 2022 26 Thereafter 88 Total $ 286
Future minimum lease commitments under non-cancellable operating leases	Future minimum lease commitments under non-cancellable operating leases at September 30, 2017 were as follows: (in millions) Remaining 2017 $ 2 2018 9 2019 7 2020 6 2021 4 2022 - Thereafter 1 Total $ 29

Net income per share (Tables)

Net income per share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Reconciliation of earnings attributable to common shares, basic and diluted	The following table reconciles the Company’s earnings from operations and earnings attributable to common stockholders to the basic and diluted earnings used to determine the Company’s earnings per share amounts for the three and nine months ended September 30, 2017 and 2016 , respectively, under the two-clas s method: Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Net income (loss) as reported $ (113) $ (51) $ 689 $ (1,337) Participating basic earnings (a) - - (5) - Basic earnings attributable to common stockholders (113) (51) 684 (1,337) Reallocation of participating earnings - - - - Diluted earnings attributable to common stockholders $ (113) $ (51) $ 684 $ (1,337) (a) Unvested restricted stock awards represent participating securities because they participate in nonforfeitable dividends or distributions with the common equity holders of the Company. Participating earnings represent the distributed earnings of the Company attributable to the participating securities. Unvested restricted stock awards do not participate in undistributed net losses as they are not contractually obligated to do so.
Reconciliation of the basic weighted average common shares outstanding to diluted weighted average common shares outstanding	The following table is a reconciliation of the basic weighted average common shares outstanding to diluted weighted average common shares outstanding for the three and nine months ended September 30, 2017 and 2016 : Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Weighted average common shares outstanding: Basic 147,557 135,454 147,233 131,417 Dilutive common stock options - - 4 - Dilutive performance units - - 549 - Diluted 147,557 135,454 147,786 131,417
Summary of performance units which were not included in the computation of diluted net income per share	The following table is a summary of the performance units that were not included in the computation of diluted earnings per share, as inclusion of these items would be antidilutive: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Number of antidilutive units: Antidilutive performance units - - 107 -

Subsidiary guarantors (Tables)

Subsidiary guarantors (Tables)	9 Months Ended
	Sep. 30, 2017
Guarantees [Abstract]
Condensed Consolidating Balance Sheet	The following condense d consolidating balance s heets at September 30, 2017 and December 31, 2016 , condensed c o nsolidating statements of o perations for the three and nine months ended September 30, 2017 and 2016 and condensed consolidating statements of cash flows for the nine months ended September 30, 2017 and 2016 , present financial information fo r Concho Resources Inc. as the p arent on a stand-alone basis ( carrying any investments in subsidiaries under the equity method), financial information for the subsidiary g uarantors on a stand-alone basis (carrying any investment in non-guarantor subsidiaries under the equity method), financial information for the subsidiary non-guarantor s on a stand-alone basis and the consolidation and elimination entries necessary to arri ve at the information for the Company on a consolidated basis. All current and deferred income taxes are recorded on Concho Resources Inc., as the subsidiaries are flow-through entities for income tax purposes. The subsidiary guarantors and subsidiary non- guarantor s are not restricted from making distributions to the Company. Condensed Consolidating Balance Sheet September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,903 $ (653) $ - $ (8,250) $ - Other current assets 14 515 6 - 535 Oil and natural gas properties, net - 11,968 619 - 12,587 Property and equipment, net - 232 - - 232 Investment in subsidiaries 2,963 - - (2,963) - Other long-term assets 42 86 - - 128 Total assets $ 11,922 $ 12,148 $ 625 $ (11,213) $ 13,482 LIABILITIES AND EQUITY Accounts payable - related parties $ (653) $ 8,290 $ 613 $ (8,250) $ - Other current liabilities 50 756 4 - 810 Long-term debt 2,738 - - - 2,738 Other long-term liabilities 1,156 141 6 - 1,303 Equity 8,631 2,961 2 (2,963) 8,631 Total liabilities and equity $ 11,922 $ 12,148 $ 625 $ (11,213) $ 13,482 Condensed Consolidating Balance Sheet December 31, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,991 $ (336) $ (8,655) $ - Other current assets 12 534 - 546 Oil and natural gas properties, net - 11,086 - 11,086 Property and equipment, net - 216 - 216 Investment in subsidiaries 1,989 - (1,989) - Other long-term assets 11 260 - 271 Total assets $ 11,003 $ 11,760 $ (10,644) $ 12,119 LIABILITIES AND EQUITY Accounts payable - related parties $ (336) $ 8,991 $ (8,655) $ - Other current liabilities 114 639 - 753 Long-term debt 2,741 - - 2,741 Other long-term liabilities 861 141 - 1,002 Equity 7,623 1,989 (1,989) 7,623 Total liabilities and equity $ 11,003 $ 11,760 $ (10,644) $ 12,119
Condensed Consolidating Statement of Operations	The following condense d consolidating balance s heets at September 30, 2017 and December 31, 2016 , condensed c o nsolidating statements of o perations for the three and nine months ended September 30, 2017 and 2016 and condensed consolidating statements of cash flows for the nine months ended September 30, 2017 and 2016 , present financial information fo r Concho Resources Inc. as the p arent on a stand-alone basis ( carrying any investments in subsidiaries under the equity method), financial information for the subsidiary g uarantors on a stand-alone basis (carrying any investment in non-guarantor subsidiaries under the equity method), financial information for the subsidiary non-guarantor s on a stand-alone basis and the consolidation and elimination entries necessary to arri ve at the information for the Company on a consolidated basis. All current and deferred income taxes are recorded on Concho Resources Inc., as the subsidiaries are flow-through entities for income tax purposes. The subsidiary guarantors and subsidiary non- guarantor s are not restricted from making distributions to the Company. Condensed Consolidating Statement of Operations Three Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Total operating revenues $ - $ 619 $ 8 $ - $ 627 Total operating costs and expenses (207) (491) (6) - (704) Income (loss) from operations (207) 128 2 - (77) Interest expense (39) - - - (39) Loss on extinguishment of debt (65) - - - (65) Other, net 132 2 - (132) 2 Income (loss) before income taxes (179) 130 2 (132) (179) Income tax benefit 66 - - - 66 Net income (loss) $ (113) $ 130 $ 2 $ (132) $ (113) Condensed Consolidating Statement of Operations Three Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 430 $ - $ 430 Total operating costs and expenses 41 (469) - (428) Income (loss) from operations 41 (39) - 2 Interest expense (52) (1) - (53) Loss on extinguishment of debt (28) - - (28) Other, net (42) (2) 42 (2) Loss before income taxes (81) (42) 42 (81) Income tax benefit 30 - - 30 Net loss $ (51) $ (42) $ 42 $ (51) Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Total operating revenues $ - $ 1,798 $ 8 $ - $ 1,806 Total operating costs and expenses 288 (835) (6) - (553) Income from operations 288 963 2 - 1,253 Interest expense (117) (1) - - (118) Loss on extinguishment of debt (66) - - - (66) Other, net 982 18 - (982) 18 Income before income taxes 1,087 980 2 (982) 1,087 Income tax expense (398) - - - (398) Net income $ 689 $ 980 $ 2 $ (982) $ 689 Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,110 $ - $ 1,110 Total operating costs and expenses (177) (2,853) - (3,030) Loss from operations (177) (1,743) - (1,920) Interest expense (159) (3) - (162) Loss on extinguishment of debt (28) - - (28) Other, net (1,755) (10) 1,756 (9) Loss before income taxes (2,119) (1,756) 1,756 (2,119) Income tax benefit 782 - - 782 Net loss $ (1,337) $ (1,756) $ 1,756 $ (1,337)
Condensed Consolidating Statement of Cash Flows	The following condense d consolidating balance s heets at September 30, 2017 and December 31, 2016 , condensed c o nsolidating statements of o perations for the three and nine months ended September 30, 2017 and 2016 and condensed consolidating statements of cash flows for the nine months ended September 30, 2017 and 2016 , present financial information fo r Concho Resources Inc. as the p arent on a stand-alone basis ( carrying any investments in subsidiaries under the equity method), financial information for the subsidiary g uarantors on a stand-alone basis (carrying any investment in non-guarantor subsidiaries under the equity method), financial information for the subsidiary non-guarantor s on a stand-alone basis and the consolidation and elimination entries necessary to arri ve at the information for the Company on a consolidated basis. All current and deferred income taxes are recorded on Concho Resources Inc., as the subsidiaries are flow-through entities for income tax purposes. The subsidiary guarantors and subsidiary non- guarantor s are not restricted from making distributions to the Company. Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total Net cash flows provided by operating activities $ 99 $ 1,084 $ 2 $ - $ 1,185 Net cash flows used in investing activities - (592) (615) - (1,207) Net cash flows provided by (used in) financing activities (99) (545) 613 - (31) Net decrease in cash and cash equivalents - (53) - - (53) Cash and cash equivalents at beginning of period - 53 - - 53 Cash and cash equivalents at end of period $ - $ - $ - $ - $ - Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (694) $ 1,713 $ - $ 1,019 Net cash flows used in investing activities - (783) - (783) Net cash flows provided by financing activities 694 - - 694 Net increase in cash and cash equivalents - 930 - 930 Cash and cash equivalents at beginning of period - 229 - 229 Cash and cash equivalents at end of period $ - $ 1,159 $ - $ 1,159

Subsequent events (Tables)

Subsequent events (Tables)	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
New commodity derivative contracts	After September 30, 2017 , the Com pany entered into the following oil price swaps, oil basis swaps and natural gas price swaps to hedge additional amounts of the Company’s estimated future production: First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2017: Volume (Bbl) 846,000 846,000 Price per Bbl $ 51.29 $ 51.29 2018: Volume (Bbl) 953,000 600,000 407,000 296,000 2,256,000 Price per Bbl $ 51.55 $ 51.39 $ 51.43 $ 51.28 $ 51.45 2019: Volume (Bbl) 1,035,000 1,046,500 828,000 828,000 3,737,500 Price per Bbl $ 51.25 $ 51.25 $ 51.14 $ 51.14 $ 51.20 Oil Basis Swaps: (b) 2017: Volume (Bbl) 1,499,000 1,499,000 Price per Bbl $ (0.12) $ (0.12) 2018: Volume (Bbl) 540,000 546,000 276,000 276,000 1,638,000 Price per Bbl $ (0.21) $ (0.21) $ (0.38) $ (0.38) $ (0.27) 2019: Volume (Bbl) 1,395,000 1,410,500 1,426,000 1,426,000 5,657,500 Price per Bbl $ (0.68) $ (0.68) $ (0.68) $ (0.68) $ (0.68) Natural Gas Price Swaps: (c) 2017: Volume (MMBtu) 3,660,000 3,660,000 Price per MMBtu $ 3.02 $ 3.02 2018: Volume (MMBtu) 5,400,000 5,460,000 4,600,000 4,600,000 20,060,000 Price per MMBtu $ 3.02 $ 3.02 $ 3.01 $ 3.01 $ 3.02 2019: Volume (MMBtu) 1,800,000 1,820,000 1,840,000 1,840,000 7,300,000 Price per MMBtu $ 2.86 $ 2.86 $ 2.86 $ 2.86 $ 2.86 (a) The index prices for the oil price swaps are based on the NYMEX – WTI monthly average futures price. (b) The basis differential price is between Midland – WTI and Cushing – WTI. (c) The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price.

Supplementary information (Tabl

Supplementary information (Tables)	9 Months Ended
	Sep. 30, 2017
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Capitalized costs	Capitalized costs September 30, December 31, (in millions) 2017 2016 Oil and natural gas properties: Proved $ 17,950 $ 16,620 Unproved 2,804 1,856 Less: accumulated depletion (8,167) (7,390) Net capitalized costs for oil and natural gas properties $ 12,587 $ 11,086
costs incurred for oil and natural gas producing activities	Costs incurred for oil and natural gas producing activities Three Months Ended Nine Months Ended September 30, September 30, (in millions) 2017 2016 2017 2016 Property acquisition costs: Proved $ 162 $ 1 $ 301 $ 257 Unproved 472 14 865 172 Exploration 252 177 725 513 Development 175 97 478 287 Total costs incurred for oil and natural gas properties $ 1,061 $ 289 $ 2,369 $ 1,229

Summary Of Significant Accoun34

Summary Of Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Disclosure Summary Of Significant Accounting Policies Narrative [Abstract]
Fees related to operation of jointly owned oil and natural gas properties	$ 4	$ 4	$ 12	$ 12
ASU 2016-09 Cumulative Effect: Forfeiture estimate compensation expense / increase to APIC			8
ASU 2016-09 Cumulative Effect: Deferred tax benefit			3
ASU 2016-09 Cumulative Effect: Excess tax benefits			5
ASU 2016-09 Cumulative Effect: Decrease to retained earnings			0
ASU 2016-09 Cumulative Effect: Decrease to deferred income taxes			8
Excess tax benefit (deficiency) [discrete item]			6
Forfeitures expense	1		7
Alpha Crude Connector [Member]
Equity Method Investments [Line Items]
Total equity method investment					$ 129
Equity method investment ownership percentage					50.00%
Oryx Southern Delaware Holdings [Member]
Equity Method Investments [Line Items]
Total equity method investment	$ 47		$ 47		$ 42
Equity method investment ownership percentage	23.75%		23.75%

Exploratory Well Costs (Capital

Exploratory Well Costs (Capitalized Exploratory Well Activity) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Disclosure Exploratory Well Costs Capitalized Exploratory Well Activity [Abstract]
Beginning capitalized exploratory well costs	$ 151
Additions to exploratory well costs pending the determination of proved reserves	255
Reclassifications due to determination of proved reserves	(136)
Ending capitalized exploratory well costs	$ 270

Exploratory Well Costs (Aging O

Exploratory Well Costs (Aging Of Capitalized Exploratory Well Costs Based On The Date Of Drilling) (Detail) $ in Millions	Sep. 30, 2017USD ($)Number	Dec. 31, 2016USD ($)Number
Disclosure Exploratory Well Costs Aging Of Capitalized Exploratory Well Costs Based On The Date Of Drilling [Abstract]
Capitalized exploratory well costs that have been capitalized for a period of one year or less	$ 266	$ 141
Capitalized exploratory well costs that have been capitalized for a period greater than one year	4	10
Total capitalized exploratory well costs	$ 270	$ 151
Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects | Number	4	8

Acquisitions And Divestitures (

Acquisitions And Divestitures (Narrative) (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
(Gain) loss on disposition of assets, net	$ (13)	$ 1	$ (667)	$ (109)
Funds held in escrow	0		0		$ 43
Common stock issued in business combination			291	$ 231
Northern Delaware Basin [Member]
Business Acquisition [Line Items]
Total cash consideration paid for acquisition			$ 160
Funds held in escrow					$ 43
Common stock issued in business combination (Shares)			2.2
Common stock issued in business combination			$ 291
Alpha Crude Connector [Member]
Business Acquisition [Line Items]
Proceeds From Sale Of Oil And Gas Property And Equipment			801
(Gain) loss on disposition of assets, net			655
Total equity method investment	129		129
Midland Basin [Member]
Business Acquisition [Line Items]
Total cash consideration paid for acquisition			595
VIE Assets	607		607
VIE Liabilities	$ 605		$ 605

Incentive Plans (Summary of Sto

Incentive Plans (Summary of Stock-Based Award Activity) (Detail) - $ / shares		9 Months Ended
		Sep. 30, 2017	Dec. 31, 2016
Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		1,130,489	1,157,270
Awards granted	[1]	445,384
Awards cancelled / forfeited		(82,200)
Lapse of restrictions		(389,965)
Weighted average grant date fair value per share/unit		$ 121.77
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		0	20,000
Options exercised		(20,000)
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		396,591	331,526
Awards granted	[2]	108,398
Awards cancelled / forfeited		(43,333)
Lapse of restrictions		0
Weighted average grant date fair value per share/unit		$ 183.48
[1]	Weighted average grant date fair value per share is $121.77
[2]	Weighted average grant date fair value per unit is $183.48

Incentive Plans (Summary For Fu

Incentive Plans (Summary For Future Stock-Based Compensation Expense) (Detail) $ in Millions	Sep. 30, 2017USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining 2,017	$ 17
2,018	47
2,019	25
Thereafter	8
Total	$ 97

Disclosures About Fair Value 40

Disclosures About Fair Value Measurements (Narrative) (Detail) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)	Sep. 30, 2017	Dec. 31, 2024$ / bbl$ / MMBTU	Dec. 31, 2021$ / bbl	Dec. 31, 2020$ / MMBTU	Dec. 31, 2017$ / bbl$ / MMBTU
Disclosure Fair Value Narrative [Abstract]
Management Estimate of Future Oil Price | $ / bbl			52.01	50.77		52.29
Management Estimate of Future Natural Gas Price | $ / MMBTU			2.88		2.85	3.14
Annual discount rate		10.00%
Carrying Amount	$ 3,438
Impairment Expense	$ 1,525

Disclosures About Fair Value 41

Disclosures About Fair Value Measurements (Carrying Amounts And Fair Values Of The Company's Financial Instruments) (Detail) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		$ 32	$ 4
Derivative instruments, Liabilities		43	178
Credit facility		368	0
Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Two [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		$ 0	620
Interest rate		5.50%
Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Three [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		$ 0	1,621
Interest rate		5.50%
Four Point Three Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		$ 632	599
Three Point Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		$ 1,006	0
Interest rate		3.75%
Four Point Eight Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		$ 834	0
Interest rate		4.875%
Carrying Reported Amount Fair Value Disclosure [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		$ 32	4
Derivative instruments, Liabilities		43	178
Credit facility		368	0
Carrying Reported Amount Fair Value Disclosure [Member] | Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Two [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	594
Carrying Reported Amount Fair Value Disclosure [Member] | Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Three [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	1,555
Carrying Reported Amount Fair Value Disclosure [Member] | Four Point Three Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	593	592
Carrying Reported Amount Fair Value Disclosure [Member] | Three Point Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	988	0
Carrying Reported Amount Fair Value Disclosure [Member] | Four Point Eight Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	$ 789	$ 0
[1]	The carrying value includes associated deferred loan costs and any premium (discount).

Disclosures About Fair Value 42

Disclosures About Fair Value Measurements (Company's Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative, Fair Value, Net	$ (11)	$ (174)
Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	35	59
Derivative Asset, Fair Value, Gross Liability	(31)	(55)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	4	4
Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	44	0
Derivative Asset, Fair Value, Gross Liability	(16)	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	28	0
Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	(68)	(137)
Derivative Liability, Fair Value, Gross Asset	31	55
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(37)	(82)
Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	(22)	(96)
Derivative Liability, Fair Value, Gross Asset	16	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(6)	(96)
Fair Value Inputs Level 1 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative, Fair Value, Net	0	0
Fair Value Inputs Level 1 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Fair Value Inputs Level 1 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Fair Value Inputs Level 1 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Fair Value Inputs Level 1 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Fair Value Inputs Level 2 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative, Fair Value, Net	(11)	(174)
Fair Value Inputs Level 2 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	35	59
Fair Value Inputs Level 2 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	44	0
Fair Value Inputs Level 2 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	(68)	(137)
Fair Value Inputs Level 2 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	(22)	(96)
Fair Value Inputs Level 3 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative, Fair Value, Net	0	0
Fair Value Inputs Level 3 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Fair Value Inputs Level 3 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Fair Value Inputs Level 3 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Fair Value Inputs Level 3 [Member] | Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 0

Disclosures About Fair Value 43

Disclosures About Fair Value Measurements (Carrying Amounts, Estimated Fair Values And Impairment Expense Of Long-Lived Assets For Continuing And Discontinued Operations) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Disclosure Disclosures About Fair Value Of Financial Instruments Carrying Amounts Estimated Fair Values And Impairment Expense Of Long Lived Assets For Continuing And Discontinued Operations [Abstract]
Carrying Amount	$ 3,438
Estimated Fair Value (Level 3)	1,913
Impairment Expense	$ 1,525

Derivative Financial Instrume44

Derivative Financial Instruments (Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	$ 30	$ 155	$ 126	$ 582
Gain (loss) on derivatives	(206)	41	289	(176)
Oil Commodity Derivative [Member]
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	28	154	129	566
Gain (loss) on derivatives	(205)	36	260	(173)
Natural Gas Commodity Derivative [Member]
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	2	1	(3)	16
Gain (loss) on derivatives	$ (1)	$ 5	$ 29	$ (3)

Derivative Financial Instrume45

Derivative Financial Instruments (Outstanding Commodity Derivative Contracts) (Detail) - Minimum [Member]		3 Months Ended									12 Months Ended
		Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2019MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2019MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU
Oil Price Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[1]									9,370,080			9,370,080
Price - Current Year | $ / bbl	[1]									51.33			51.33
Volume - Year One | bbl	[1]					6,676,007	7,064,318	7,546,170	8,180,629			29,467,124
Price - Year One | $ / bbl	[1]					51.26	51.36	51.45	51.54			51.41
Volume - Year Two | bbl	[1]	4,721,000	4,897,000	5,090,000	5,314,000						20,022,000
Price - Year Two | $ / bbl	[1]	52.55	52.54	52.52	52.54						52.54
Oil Basis Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[2]									8,508,000			8,508,000
Price - Current Year | $ / bbl	[2]									(0.74)			(0.74)
Volume - Year One | bbl	[2]					6,684,000	6,961,000	7,521,000	7,936,000			29,102,000
Price - Year One | $ / bbl	[2]					(1.01)	(1.01)	(1.01)	(1.02)			(1.01)
Volume - Year Two | bbl	[2]	4,139,000	4,262,000	4,428,000	4,581,000						17,410,000
Price - Year Two | $ / bbl	[2]	(1.18)	(1.18)	(1.17)	(1.17)						(1.17)
Natural Gas Price Swaps [Member]
Derivative [Line Items]
Volume - Current Year | MMBTU	[3]									14,673,000			14,673,000
Price - Current Year | $ / MMBTU	[3]									3.1			3.1
Volume - Year One | MMBTU	[3]					9,904,000	10,219,000	10,641,000	11,156,000			41,920,000
Price - Year One | $ / MMBTU	[3]					3.04	3.05	3.05	3.06			3.05
Volume - Year Two | MMBTU	[3]	2,489,535	2,578,537	2,681,387	2,791,533						10,540,992
Price - Year Two | $ / MMBTU	[3]	2.85	2.85	2.85	2.86						2.85
[1]	The index prices for the oil price swaps are based on the New York Mercantile Exchange (“NYMEX”) – West Texas Intermediate (“WTI”) monthly average futures price.
[2]	The basis differential price is between Midland – WTI and Cushing – WTI.
[3]	The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price.

Debt (Summary Of Long-Term Debt

Debt (Summary Of Long-Term Debt) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Credit facility	$ 368	$ 0
Unamortized original issue premium (discount), net	(6)	22
Senior notes issuance costs, net	(24)	(31)
Less: current portion	0	0
Total long-term debt	2,738	2,741
5.5% unsecured senior notes due 2022 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	0	600
5.5% unsecured senior notes due 2023 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	0	1,550
4.375% unsecured senior notes due 2025 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	600	600
3.75% unsecured senior notes due 2027 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	1,000	0
4.875% unsecured senior notes due 2047 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 800	$ 0

Debt (Narrative) (Detail)

Debt (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Disclosure [Line Items]
Proceeds from debt, net of issuance costs			$ 1,777
Aggregate principal amount of 5.5% Notes tenders received	$ 1,232		$ 1,232
Percent of par redeemed for 5.5% Notes			102.75%
Loss on extinguishment of debt	(65)	$ (28)	$ (66)	$ (28)
Percentage of notes tendered			57.30%
Percent of par tendered			102.934%
Credit Facility [Member]
Debt Disclosure [Line Items]
Line of credit maturity date			May 9, 2022
Aggregate lender commitments	$ 2,000		$ 2,000
Loss on extinguishment of debt			$ 1
Commitment fees on unused portion of available commitment			0.25%
J.P. Morgan Chase Bank Prime Rate [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	4.25%		4.25%
Alternate Base Rate [Member] | Credit Facility [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	0.50%		0.50%
Additional percentage added to federal funds effective rate for ABR loans			0.50%
Additional percentage added to LIBOR rate for ABR loans			1.00%
London Interbank Offered Rate [Member] | Credit Facility [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	1.50%		1.50%
3.75% unsecured senior notes due 2027 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	$ 1,000		$ 1,000		$ 0
Interest rate	3.75%		3.75%
Debt Instrument Par Percentage			99.636%
4.875% unsecured senior notes due 2047 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	$ 800		$ 800		0
Interest rate	4.875%		4.875%
Debt Instrument Par Percentage			99.749%
5.5% unsecured senior notes due 2022 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	$ 0		$ 0		600
Interest rate	5.50%		5.50%
Aggregate principal amount of notes offered for tender	$ 600		$ 600
5.5% unsecured senior notes due 2023 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	$ 0		$ 0		$ 1,550
Interest rate	5.50%		5.50%
Aggregate principal amount of notes offered for tender	$ 1,550		$ 1,550

Schedule of Extinguishment of D

Schedule of Extinguishment of Debt (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Extinguishment Of Debt [Line Items]
Make-whole premium			$ 63	$ 21
Prepaid interest	$ (1)	$ (3)	(5)	(7)
Loss on extinguishment of debt	(65)	$ (28)	(66)	$ (28)
Tender Offer [Member]
Extinguishment Of Debt [Line Items]
Tender premium	36		36
Make-whole premium	0		0
Prepaid interest	0		0
Unamortized original issue premium	(11)		(11)
Unamortized deferred loan costs	12		12
Loss on extinguishment of debt	37		37
Extinguishment [Member]
Extinguishment Of Debt [Line Items]
Tender premium	0		0
Make-whole premium	25		25
Prepaid interest	2		2
Unamortized original issue premium	(8)		(8)
Unamortized deferred loan costs	9		9
Loss on extinguishment of debt	28		28
Total [Member]
Extinguishment Of Debt [Line Items]
Tender premium	36		36
Make-whole premium	25		25
Prepaid interest	2		2
Unamortized original issue premium	(19)		(19)
Unamortized deferred loan costs	21		21
Loss on extinguishment of debt	$ 65		$ 65

Debt (Principal Maturities Of D

Debt (Principal Maturities Of Debt) (Detail) $ in Millions	Sep. 30, 2017USD ($)
Disclosure Debt Principal Maturities Of Debt [Abstract]
Remaining 2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	0
2,022	368
Thereafter	2,400
Total	$ 2,768

Debt (Summary Of Interest Expen

Debt (Summary Of Interest Expense) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Disclosure Debt Summary Of Interest Expense [Abstract]
Cash payments for interest	$ 73	$ 109	$ 138	$ 215
Non-cash interest	1	3	5	7
Net changes in accruals	(35)	(59)	(25)	(60)
Total interest expense	$ 39	$ 53	$ 118	$ 162

Commitments And Contingencies51

Commitments And Contingencies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Commitments [Line Items]
Operating leases, lease payments	$ 2	$ 2	$ 7	$ 6
Accrued Exposure					$ 7

Commitments And Contingencies52

Commitments And Contingencies (Future Commitments) (Detail) $ in Millions	Sep. 30, 2017USD ($)
Disclosure Commitments And Contingencies Future Commitments [Abstract]
Remaining 2,017	$ 10
2,018	40
2,019	59
2,020	32
2,021	31
2,022	26
Thereafter	88
Total	$ 286

Commitments And Contingencies53

Commitments And Contingencies (Future Minimum Lease Commitments Under Non-Cancellable Operating Leases) (Detail) $ in Millions	Sep. 30, 2017USD ($)
Disclosure Commitments And Contingencies Future Minimum Lease Commitments Under Non Cancellable Operating Leases [Abstract]
Remaining 2,017	$ 2
2,018	9
2,019	7
2,020	6
2,021	4
2,022	0
Thereafter	1
Total	$ 29

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Disclosure Income Taxes Narrative [Abstract]
Effective tax rate	36.70%	37.30%	36.60%	36.90%
Excess tax benefit (deficiency) [discrete item]			$ 6

Related Party Transactions (Sch

Related Party Transactions (Schedule Of Related Party Transactions) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transaction [Line Items]
Ownership interest in partnership	3.50%		3.50%
Partnership (Director Ownership Interest) [Member]
Related Party Transaction [Line Items]
Amounts paid	$ 1	$ 1	$ 5	$ 3

Net Income Per Share (Narrative

Net Income Per Share (Narrative) (Detail)	9 Months Ended
	Sep. 30, 2017
Disclosure Net Income Per Share Narrative [Abstract]
Performance unit awards vesting period	36 months
Minimum Payout Value on Performance Units	0.00%
Maximum Payout Value on Performance Units	300.00%

Net Income Per Share (Reconcili

Net Income Per Share (Reconciliation Of Earnings Attributable To Common Shares Basic And Diluted) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)		$ (113)	$ (51)	$ 689	$ (1,337)
Participating basic earnings	[1]	0	0	(5)	0
Basic earnings attributable to common stockholders		(113)	(51)	684	(1,337)
Reallocation of participating earnings		0	0	0	0
Diluted earnings attributable to common stockholders		$ (113)	$ (51)	$ 684	$ (1,337)
[1]	Unvested restricted stock awards represent participating securities because they participate in nonforfeitable dividends or distributions with the common equity holders of the Company. Participating earnings represent the distributed earnings of the Company attributable to the participating securities. Unvested restricted stock awards do not participate in undistributed net losses as they are not contractually obligated to do so.

Net Income Per Share (Reconci58

Net Income Per Share (Reconciliation Of The Weighted Average Common Shares Outstanding) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Basic	147,557	135,454	147,233	131,417
Diluted	147,557	135,454	147,786	131,417
Stock Options [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	0	0	4	0
Performance Units [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	0	0	549	0

Net Income Per Share (Summary O

Net Income Per Share (Summary Of The Common Stock Options And Restricted Stock) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Performance Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive common shares	0	0	107	0

Subsidiary Guarantors (Condense

Subsidiary Guarantors (Condensed Consolidating Balance Sheet) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Accounts receivable - related parties	$ 0	$ 0
Other current assets	535	546
Oil and natural gas properties, net	12,587	11,086
Property and equipment, net	232	216
Investment in subsidiaries	0	0
Other long-term assets	128	271
Total assets	13,482	12,119
LIABILITIES AND EQUITY
Accounts payable - related parties	0	0
Other current liabilities	810	753
Long-term debt	2,738	2,741
Other long-term liabilities	1,303	1,002
Equity	8,631	7,623
Total liabilities and stockholders' equity	13,482	12,119
Consolidation Eliminations [Member]
ASSETS
Accounts receivable - related parties	(8,250)	(8,655)
Other current assets	0	0
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	(2,963)	(1,989)
Other long-term assets	0	0
Total assets	(11,213)	(10,644)
LIABILITIES AND EQUITY
Accounts payable - related parties	(8,250)	(8,655)
Other current liabilities	0	0
Long-term debt	0	0
Other long-term liabilities	0	0
Equity	(2,963)	(1,989)
Total liabilities and stockholders' equity	(11,213)	(10,644)
Parent Company [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	8,903	8,991
Other current assets	14	12
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	2,963	1,989
Other long-term assets	42	11
Total assets	11,922	11,003
LIABILITIES AND EQUITY
Accounts payable - related parties	(653)	(336)
Other current liabilities	50	114
Long-term debt	2,738	2,741
Other long-term liabilities	1,156	861
Equity	8,631	7,623
Total liabilities and stockholders' equity	11,922	11,003
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	(653)	(336)
Other current assets	515	534
Oil and natural gas properties, net	11,968	11,086
Property and equipment, net	232	216
Investment in subsidiaries	0	0
Other long-term assets	86	260
Total assets	12,148	11,760
LIABILITIES AND EQUITY
Accounts payable - related parties	8,290	8,991
Other current liabilities	756	639
Long-term debt	0	0
Other long-term liabilities	141	141
Equity	2,961	1,989
Total liabilities and stockholders' equity	12,148	$ 11,760
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	0
Other current assets	6
Oil and natural gas properties, net	619
Property and equipment, net	0
Investment in subsidiaries	0
Other long-term assets	0
Total assets	625
LIABILITIES AND EQUITY
Accounts payable - related parties	613
Other current liabilities	4
Long-term debt	0
Other long-term liabilities	6
Equity	2
Total liabilities and stockholders' equity	$ 625

Subsidiary Guarantors (Conden61

Subsidiary Guarantors (Condensed Consolidating Statement Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements Captions [Line Items]
Total operating revenues	$ 627	$ 430	$ 1,806	$ 1,110
Total operating costs and expenses	(704)	(428)	(553)	(3,030)
Income (loss) from operations	(77)	2	1,253	(1,920)
Interest expense	(39)	(53)	(118)	(162)
Loss on extinguishment of debt	(65)	(28)	(66)	(28)
Other, net	2	(2)	18	(9)
Income (loss) before income taxes	(179)	(81)	1,087	(2,119)
Income tax (expense) benefit	66	30	(398)	782
Net income (loss)	(113)	(51)	689	(1,337)
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0	0	0
Total operating costs and expenses	0	0	0	0
Income (loss) from operations	0	0	0	0
Interest expense	0	0	0	0
Loss on extinguishment of debt	0	0	0	0
Other, net	(132)	42	(982)	1,756
Income (loss) before income taxes	(132)	42	(982)	1,756
Income tax (expense) benefit	0	0	0	0
Net income (loss)	(132)	42	(982)	1,756
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0	0	0
Total operating costs and expenses	(207)	41	288	(177)
Income (loss) from operations	(207)	41	288	(177)
Interest expense	(39)	(52)	(117)	(159)
Loss on extinguishment of debt	(65)	(28)	(66)	(28)
Other, net	132	(42)	982	(1,755)
Income (loss) before income taxes	(179)	(81)	1,087	(2,119)
Income tax (expense) benefit	66	30	(398)	782
Net income (loss)	(113)	(51)	689	(1,337)
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	619	430	1,798	1,110
Total operating costs and expenses	(491)	(469)	(835)	(2,853)
Income (loss) from operations	128	(39)	963	(1,743)
Interest expense	0	(1)	(1)	(3)
Loss on extinguishment of debt	0	0	0	0
Other, net	2	(2)	18	(10)
Income (loss) before income taxes	130	(42)	980	(1,756)
Income tax (expense) benefit	0	0	0	0
Net income (loss)	130	$ (42)	980	$ (1,756)
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	8		8
Total operating costs and expenses	(6)		(6)
Income (loss) from operations	2		2
Interest expense	0		0
Loss on extinguishment of debt	0		0
Other, net	0		0
Income (loss) before income taxes	2		2
Income tax (expense) benefit	0		0
Net income (loss)	$ 2		$ 2

Subsidiary Guarantors (Conden62

Subsidiary Guarantors (Condensed Consolidating Statement Of Cash Flows) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	$ 1,185	$ 1,019
Net cash flows provided by (used in) investing activities	(1,207)	(783)
Net cash flows provided by (used in) financing activities	(31)	694
Net increase (decrease) in cash and cash equivalents	(53)	930
Cash and cash equivalents at beginning of period	53	229
Cash and cash equivalents at end of period	0	1,159
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	0	0
Net cash flows provided by (used in) investing activities	0	0
Net cash flows provided by (used in) financing activities	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	99	(694)
Net cash flows provided by (used in) investing activities	0	0
Net cash flows provided by (used in) financing activities	(99)	694
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	1,084	1,713
Net cash flows provided by (used in) investing activities	(592)	(783)
Net cash flows provided by (used in) financing activities	(545)	0
Net increase (decrease) in cash and cash equivalents	(53)	930
Cash and cash equivalents at beginning of period	53	229
Cash and cash equivalents at end of period	0	$ 1,159
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	2
Net cash flows provided by (used in) investing activities	(615)
Net cash flows provided by (used in) financing activities	613
Net increase (decrease) in cash and cash equivalents	0
Cash and cash equivalents at beginning of period	0
Cash and cash equivalents at end of period	$ 0

Subsequent Events (New Commodit

Subsequent Events (New Commodity Derivative Contracts) (Detail) - Minimum [Member]		3 Months Ended									12 Months Ended
		Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2019MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2019MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU
Oil Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[1]									9,370,080			9,370,080
Price - Current Year | $ / bbl	[1]									51.33			51.33
Volume - Year One | bbl	[1]					6,676,007	7,064,318	7,546,170	8,180,629			29,467,124
Price - Year One | $ / bbl	[1]					51.26	51.36	51.45	51.54			51.41
Volume - Year Two | bbl	[1]	4,721,000	4,897,000	5,090,000	5,314,000						20,022,000
Price - Year Two | $ / bbl	[1]	52.55	52.54	52.52	52.54						52.54
Oil Basis Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[2]									8,508,000			8,508,000
Price - Current Year | $ / bbl	[2]									(0.74)			(0.74)
Volume - Year One | bbl	[2]					6,684,000	6,961,000	7,521,000	7,936,000			29,102,000
Price - Year One | $ / bbl	[2]					(1.01)	(1.01)	(1.01)	(1.02)			(1.01)
Volume - Year Two | bbl	[2]	4,139,000	4,262,000	4,428,000	4,581,000						17,410,000
Price - Year Two | $ / bbl	[2]	(1.18)	(1.18)	(1.17)	(1.17)						(1.17)
Natural Gas Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | MMBTU	[3]									14,673,000			14,673,000
Price - Current Year | $ / MMBTU	[3]									3.1			3.1
Volume - Year One | MMBTU	[3]					9,904,000	10,219,000	10,641,000	11,156,000			41,920,000
Price - Year One | $ / MMBTU	[3]					3.04	3.05	3.05	3.06			3.05
Volume - Year Two | MMBTU	[3]	2,489,535	2,578,537	2,681,387	2,791,533						10,540,992
Price - Year Two | $ / MMBTU	[3]	2.85	2.85	2.85	2.86						2.85
Subsequent Event [Member] | Oil Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[1]									846,000			846,000
Price - Current Year | $ / bbl	[1]									51.29			51.29
Volume - Year One | bbl	[1]					296,000	407,000	600,000	953,000			2,256,000
Price - Year One | $ / bbl	[1]					51.28	51.43	51.39	51.55			51.45
Volume - Year Two | bbl	[1]	828,000	828,000	1,046,500	1,035,000						3,737,500
Price - Year Two | $ / bbl	[1]	51.14	51.14	51.25	51.25						51.2
Subsequent Event [Member] | Oil Basis Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[2]									1,499,000			1,499,000
Price - Current Year | $ / bbl	[2]									(0.12)			(0.12)
Volume - Year One | bbl	[2]					276,000	276,000	546,000	540,000			1,638,000
Price - Year One | $ / bbl	[2]					(0.38)	(0.38)	(0.21)	(0.21)			(0.27)
Volume - Year Two | bbl	[2]	1,426,000	1,426,000	1,410,500	1,395,000						5,657,500
Price - Year Two | $ / bbl	[2]	(0.68)	(0.68)	(0.68)	(0.68)						(0.68)
Subsequent Event [Member] | Natural Gas Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | MMBTU	[3]									3,660,000			3,660,000
Price - Current Year | $ / MMBTU	[3]									3.02			3.02
Volume - Year One | MMBTU	[3]					4,600,000	4,600,000	5,460,000	5,400,000			20,060,000
Price - Year One | $ / MMBTU	[3]					3.01	3.01	3.02	3.02			3.02
Volume - Year Two | MMBTU	[3]	1,840,000	1,840,000	1,820,000	1,800,000						7,300,000
Price - Year Two | $ / MMBTU	[3]	2.86	2.86	2.86	2.86						2.86
[1]	The index prices for the oil price swaps are based on the New York Mercantile Exchange (“NYMEX”) – West Texas Intermediate (“WTI”) monthly average futures price.
[2]	The basis differential price is between Midland – WTI and Cushing – WTI.
[3]	The index prices for the natural gas price swaps are based on the NYMEX – Henry Hub last trading day futures price.

Supplementary Information (Capi

Supplementary Information (Capitalized Costs) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Disclosure Supplementary Information Capitalized Costs [Abstract]
Proved	$ 17,950	$ 16,620
Unproved	2,804	1,856
Less: accumulated depletion	(8,167)	(7,390)
Net capitalized costs for oil and natural gas properties	$ 12,587	$ 11,086

Supplementary Information (Cost

Supplementary Information (Costs Incurred For Oil And Natural Gas Producing Activities) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Disclosure Supplementary Information Costs Incurred For Oil And Natural Gas Producing Activities [Abstract]
Proved	$ 162	$ 1	$ 301	$ 257
Unproved	472	14	865	172
Exploration	252	177	725	513
Development	175	97	478	287
Total costs incurred for oil and natural gas properties	$ 1,061	$ 289	$ 2,369	$ 1,229