Concho Resources (CXO) 10-Q 2 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
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		149,071,775

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 0	$ 0
Accounts receivable, net of allowance for doubtful accounts:
Oil and natural gas	392	331
Joint operations and other	260	212
Inventory	11	14
Derivative instruments	23	0
Prepaid costs and other	33	35
Total current assets	719	592
Property and equipment:
Oil and natural gas properties, successful efforts method	22,023	21,267
Accumulated depletion and depreciation	(8,658)	(8,460)
Total oil and natural gas properties, net	13,365	12,807
Other property and equipment, net	246	234
Total property and equipment, net	13,611	13,041
Deferred loan costs, net	12	13
Intangible asset, net	22	26
Noncurrent derivative instruments	2	0
Other assets	15	60
Total assets	14,381	13,732
Current liabilities:
Accounts payable - trade	33	43
Bank overdrafts	72	116
Revenue payable	185	183
Accrued drilling costs	307	330
Derivative instruments	248	277
Other current liabilities	264	216
Total current liabilities	1,109	1,165
Long-term debt	2,370	2,691
Deferred income taxes	941	687
Noncurrent derivative instruments	79	102
Asset retirement obligations and other long-term liabilities	144	172
Commitments and contingencies (Note 10)
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 authorized; 149,870,242 and 149,324,849 shares issued at March 31, 2018 and December 31, 2017, respectively	0	0
Additional paid-in capital	7,159	7,142
Retained earnings	2,675	1,840
Treasury stock, at cost; 799,644 and 598,049 shares at March 31, 2018 and December 31, 2017, respectively	(96)	(67)
Total stockholders' equity	9,738	8,915
Total liabilities and stockholders' equity	$ 14,381	$ 13,732

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
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	149,870,242	149,324,849
Treasury shares	799,644	598,049

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating revenues:
Oil sales	$ 793	$ 502
Natural gas sales	154	110
Total operating revenues	947	612
Operating costs and expenses:
Oil and natural gas production	130	87
Production and ad valorem taxes	70	48
Gathering, processing and transportation	11	0
Exploration and abandonments	18	15
Depreciation, depletion and amortization	317	283
Accretion of discount on asset retirement obligations	2	2
General and administrative (including non-cash stock-based compensation of $17 and $12 for the three months ended March 31, 2018 and 2017, respectively)	65	56
(Gain) loss on derivatives	35	(286)
(Gain) loss on disposition of assets, net	(723)	(654)
Total operating costs and expenses	(75)	(449)
Income (loss) from operations	1,022	1,061
Other income (expense):
Interest expense	(30)	(40)
Other, net	97	0
Total other income (expense)	67	(40)
Income (loss) before income taxes	1,089	1,021
Income tax (expense) benefit	(254)	(371)
Net income (loss)	$ 835	$ 650
Earnings per share:
Basic net income (loss)	$ 5.6	$ 4.39
Diluted net income (loss)	$ 5.58	$ 4.37

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Non-cash stock-based compensation	$ 17	$ 12

Consolidated Statement of Stock

Consolidated Statement of Stockholders Equity - 3 months ended Mar. 31, 2018 - USD ($) shares in Thousands, $ in Millions	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
BALANCE, Shares at Dec. 31, 2017		149,325			598
BALANCE at Dec. 31, 2017	$ 8,915	$ 0	$ 7,142	$ 1,840	$ (67)
Net income (loss)	835	$ 0	0	835	$ 0
Grants of restricted stock, shares		112			0
Performance unit share conversion, shares		446			0
Cancellation of restricted stock, shares		(13)			0
Stock-based compensation	17	$ 0	17	0	$ 0
Purchase of treasury stock	(29)	$ 0	0	0	$ (29)
Purchase of treasury stock, shares		0			202
BALANCE, Shares at Mar. 31, 2018		149,870			800
BALANCE at Mar. 31, 2018	$ 9,738	$ 0	$ 7,159	$ 2,675	$ (96)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 835	$ 650
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	317	283
Accretion of discount on asset retirement obligations	2	2
Exploration and abandonments, including dry holes	10	6
Non-cash stock-based compensation expense	17	12
Deferred income taxes	254	363
(Gain) loss on disposition of assets, net	(723)	(654)
(Gain) loss on derivatives	35	(286)
Net settlements received from (paid on) derivatives	(112)	28
Other	(96)	1
Changes in operating assets and liabilities, net of acquisitions and dispositions:
Accounts receivable	(81)	(6)
Prepaid costs and other	(2)	(8)
Inventory	3	0
Accounts payable	(12)	7
Revenue payable	2	8
Other current liabilities	39	1
Net cash provided by (used in) operating activities	488	407
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to oil and natural gas properties	(474)	(286)
Acquisitions of oil and natural gas properties	(13)	(171)
Additions to property, equipment and other assets	(6)	(2)
Proceeds from the disposition of assets	255	806
Direct transaction costs for disposition of assets	(3)	(17)
Distribution from equity method investment	148	0
Net cash provided by (used in) investing activities	(93)	330
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt	662	105
Payments of debt	(984)	(105)
Purchase of treasury stock	(29)	(19)
Increase (decrease) in bank overdrafts	(44)	0
Net cash provided by (used in) financing activities	(395)	(19)
Net increase (decrease) in cash and cash equivalents	0	718
Cash and cash equivalents at beginning of period	0	53
Cash and cash equivalents at end of period	0	771
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of common stock for business combinations	$ 0	$ 258

Organization and nature of oper

Organization and nature of operations	3 Months Ended
	Mar. 31, 2018
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	3 Months Ended
	Mar. 31, 2018
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 consolidated financial statements also included the accounts of a variable interest entity (“VIE”) where the Company was the primary beneficiary of the arrangements until the VIE structure dissolved. See Note 5 for additional information regarding the circumstances surro unding the VIE. The Company consolidates the financial statements of these entities. All material intercompany balances and transactions have been eliminated. Reclassifications. Certain prior period amounts have been reclassified to conform to the 2018 presentation. These reclassifications had no impact 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 accept ed 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 stat ements and the reported amounts of revenues and expenses 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 estimation 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 nat ural gas properties are subject to numerous uncertainties 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 include, but are not limited to, asset retirement obligations, fair value of stock-based compensation, fair value of business combinations, fair value of nonmonetary transactions, fair value of derivative financial instruments and income taxes. Interim financial stat ements. 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, 2017 is derived from audited consolidated fina ncial statements. 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 preparing 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 th ose estimates. 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 fin ancial statements 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, 2017 . Cash equivalents. The Company considers all cash on hand, deposi tory 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 may 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 selected. Equity method investments. The Company accounts for its equity method investments under the equity method of accounting and includes the investment balance in other assets on the consolidated balance sheets. Gains and losses incurred from the Company’s equity investments are recorded in o ther income on the con solidated statements of operations. The Company owns a 23.75 perce nt 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. During the three months ended March 31, 2018 , Oryx obtained a term loan of $800 million. The proceeds were used in part to fund a cash distribution to its equity holders, of which the Company received a distribution of approximately $157 million. Of this amount, a pproximately $54 million fully offset the Company’s net investment in Oryx. The remaining distribution of approximately $103 million was recorded in other income on the Company’s consolidated statement of operations for the three months ended March 31, 2018 since the lenders to the term loan do not have recourse against the Company , and the Company has no contractual obligation to repay the distribution . The Company’s net investment in Oryx was approximately $ 49 million at December 31, 2017 . During the three months ended March 31, 2018 and 2017 , the Company recorded income of approximately $ 5 million and $ 1 million, respectively. In February 2017, the Company closed on the divestiture of its 50 percent membership interest in a midstream joint venture, Alpha Crude Connector, LLC (“ACC”), that constructed a crude oil gathering and transportation system in the Northern Delaware Basin. See Note 5 for additional information regarding the disposition of ACC. Revenue recognition . On January 1, 2018, the Company adopted Accounting Standards Codification (“ASC ”) Topic 606 , “Revenue from Contrac ts with Customers,” (“ ASC 606 ”) using the modified retrospective approach, which only applies to contracts that were not completed as of the date of initial application. The adoption did not require an adjustment to opening retained earnings for the cumula tive effect adjustment and does not have a material impact on the Company’s ong oing consolidated balance sheets, statements of operat ions, statement of stockholders’ equity, or statement s of cash flows. The C ompany recognizes revenues from the sales of o il and natural gas to its customers and presents them disaggregated on the Company’s consolidated statements of operations. All revenues are recognized in the geographical region of the Permian Basin. P rior to the adoption of ASC 606, the Company recorded oil and natural gas revenues at the time of physical transfer of such products to the purchaser, which for the Company is primarily at the wellhead. The Company followed the sales method of accounting for oil and natural gas sales, recognizing revenues bas ed on the Company’s actual proceeds from the oil and natural gas sold to purchasers. The Company enters into contracts with customers to sell its oil and natural gas production. Revenue on these contracts is recognized in accordance with the five-step rev enue recognition model prescribed in ASC 606 . Specifically, revenue is recognized when the Company’s performance obligations under these contracts are satisfied, which generally occurs with the transfer of control of the oil and natural gas to the purchase r. Control is generally considered transfe rred when the following criteria are met: (i) transfer of physical custody, (ii) transfer of title, (iii) transfer of risk of loss and (iv) relinquishment of any repurchase rights or other similar rights. Given the nature of the products sold, reve nue is recognized at a point in time based on the amount of consideration the Company expects to receive in accordance with the price specified in the contract. Consideration under the oil and natural gas marketing contrac ts is typically received from the purchaser one to two months after production. At March 31, 2018 , the Company had receivables related to contracts with customers of $ 392 million. The following table shows the impact of the adoption of ASC 606 on the Company’s current period results as compared to the previous revenue recognition standard, ASC Topic 605, “Revenue recognition ” (“ASC 605”): Three Months Ended March 31, 2018 (in millions) Under ASC 606 Under ASC 605 Increase (Decrease) Operating revenues: Oil sales $ 793 $ 791 $ 2 Natural gas sales 154 148 6 Operating costs and expenses: Oil and natural gas production 130 133 (3) Gathering, processing and transportation 11 - 11 Net income $ 835 $ 835 $ - Oil Contracts. The majority of the Company’s oil marketing contracts transfer physical custody and title at or near the wellhead, which is generally when control of the oil has been transferred to the purchaser. The majority of the oil produced is sold under contracts u sing market-based pricing, which price is then adjusted for differentials based upon delivery location and oil quality. To the extent the differentials are incurred after the transfer of control of the oil, the differentials are included in o il sales o n th e statement s of operations as they represent part of the transaction price of the contract. If the differentials, or other related costs, are incurred prior to the transfer of control of the oil, those costs are included in g athering, processing and transp ortation o n the Company’s consolidated statement s of operations as they represent payment for services performed outside of the contract with the customer. Natural Gas Contracts. The majority of the Company’s natural gas is sold at the lease location, wh ich is generally when control of the natural gas has been transferred to the purchaser. The natural gas is sold under (i) percent age of proceeds processing contr acts, (ii) fee-based contracts or ( iii) a hybrid of percentage of proceeds and fee-based contra cts. Under these contracts, the purchaser gathers the natural gas in the field where it is produced and transports it via pipeline to natural gas processing plants where natural gas liquid products are extracted. The natural gas liquid products and remaini ng residue gas are then sold by the purchaser. Under the percentage of proceeds and hybrid percentage of proceeds and fee-based contracts, the Company receives a percentage of the value for the extracted liquids and the residue gas. Under the fee - based co ntracts, the Company receives natural gas liquids and residue gas value, less the fee component, or is invoiced the fee component. To the extent control of the natural gas transfers upstream of the transportation and processing activities, revenue is recog nized as the net amount r eceived from the purchaser. To the extent that control transfers downstream of those costs, revenue is recognized on a gross basis , and the related costs are classified in g athering, processing and transportation o n the Company’s c onsolidated statement s of operations. The Company does not disclose the value of unsatisfied performance obligations under its contracts with customers as it applies the practical exemption in accordance with ASC 606. Th e exemption , as described in ASC 60 6-10-50-14(a), applies to variable consideration that is recognized as control of the product is transferred to the customer. Since each unit of product represents a separate performance obligation, future volumes are wholly unsatisfied and disclosure of t he transaction price allocated to remaining performance obligations is not required. 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 redu ctions to general and administrative expense. Such fees totaled approximate ly $ 4 million for each of the three months ended March 31, 2018 and 2017 . New accounting pronouncements issued but not yet adopted. In Februar y 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, “Leases (Topic 842) ” (“ASU 2016-02”), 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 consol idated statements of operations will be effectively unchanged. 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 in to 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 ha s substantially completed the process of reviewing and determining t he contracts to which this new guidance applies . The Company is currently enhancing its accounting system in order to track and calculate additional information necessary for adoption of this standard. The Company believes this new guidance will have a mod erate impact on its consolidated balance sheet s due to the recognition of right-of-use assets and lease liabilities that are not recognized under currently applicable guidance . In January 2018, the FASB issued ASU No. 2018-01, “Land Easement Practical Ex pedie nt for Transition to Topic 842,” which provides an optional practical expedient to not evaluate land easements that exist ed or expired before the adoption of ASU 2016-02 and that were not previously accounted for as leases under the original “Leases ( Topic 840 )” accounting standard (“Topic 840”) . The Company enters into land easements on a routine basis as part of its ongoing operations and has many such agreements currently in place; however, the Company does not currently account for any land easemen ts under Topic 840. As this guidance serves as an amendment to ASU 2016-02, t he Company will elect this practical expedient , which becomes effective upon the date of adoption of ASU 2016-02 . After the adoption of ASU 2016-02 , the Company will assess any ne w land easements to determine whether the arrangement should be accounted for as a lease. 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 methodolog y 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. Th is 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 consoli dated financial statements.

Exploratory well costs

Exploratory well costs	3 Months Ended
	Mar. 31, 2018
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 stat us 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 exploratory well costs are carried in unproved oil and natural gas properties . See Note 16 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 e xploration and abandonments expense in the consolidated statements of operations. The following table reflects the Company’s net capitalized exploratory well activity during the three months ended March 31, 2018 : Three Months Ended (in millions) March 31, 2018 Beginning capitalized exploratory well costs $ 182 Additions to exploratory well costs pending the determination of proved reserves 163 Reclassifications due to determination of proved reserves (76) Disposition of wells (16) Ending capitalized exploratory well costs $ 253 The following table provides an aging at March 31, 2018 and December 31, 2017 of capitalized exploratory well costs based on the date drilling was completed: March 31, December 31, (in millions, except number of projects) 2018 2017 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 239 $ 180 Capitalized exploratory well costs that have been capitalized for a period greater than one year 14 2 Total capitalized exploratory well costs $ 253 $ 182 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 2 2 Northern Delaware Basin project . At March 31, 2018 , the Company had approximately $ 12 million of suspended well costs greater than one year recorded for a well drilled in the first quarter of 2017. This well is part of a multi-well pad project. This well was completed during the three months ended March 31, 2018 and began economically producing subsequent to March 31, 2018 .

RSP Permian Acquisition

RSP Permian Acquisition	3 Months Ended
	Mar. 31, 2018
RSP Permian Acquisition [Abstract]
RSP Permian Acquisition	Note 4 . RSP Acquisition On March 27 , 2018, the Company and RSP Permia n, Inc. (“RSP”) entered into an Agreement and Plan of Merger (the “Acquisition Agreement”) under which the Company will acquire RSP through an all-stock transaction (the “RSP Acquisition”). T he Company expects the RSP Acquisition to be completed during the t hird quarter of 2018, subject to the satisfaction of certain regulatory approvals and other customary closing conditions , and wil l account for the RSP Acquisition as a business combination using the acquisition method of accounting . If the RSP Acquisition is completed, RSP shareholders will automatically receive 0.320 of a share of the Company’s common stock in exchange for one sh are of RSP common stock . This exchange ratio is fixed and will not be adjusted for changes in the Company’s or RSP’s stock price. The Company estimates that it will issue up to approximately 51 million shares in connection with the RSP Acquisition. The Ac quisition Agreement also provides the Company certain termination rights under which it may exercise and effectively terminate the Acquisition Agreement. Should certain unlikely events occur under the specified circumstances outlined in the Acquisition Agr eement, the Company will be required to pay RSP a termination fee of $350 million.

Acquisitions, divestitures and

Acquisitions, divestitures and nonmonetary transactions	3 Months Ended
	Mar. 31, 2018
Acquisitions, divestitures and nonmonetary transactions [Abstract]
Acquisitions, divestitures and nonmonetary transactions	Note 5 . Acquisitions, divestitures and nonmonetary transactions During the three months ended March 31, 2018 , the Company entered into the following transactions: February 2018 acquisition and divestiture. In February 2018, the Company closed on an acquisition treated as a business combination where it received producing wells with approximately 5 M B oepd along with approximately 21,000 net acres, primarily located in the Midland Basin. As consideration for the non-cash acquisition, the C ompany divested of approximately 34,000 net acres, primarily comprised of approximately 32,000 net acres in the N orthern Delaware Basin, with current production of 3 MBoepd. The business acquired was valued at approximately $755 million as compared to the historical book value of the divested assets of approximately $180 million, which resulted in a preliminary non-cash gain of approximately $575 million, subject to customary post-closing adjustments. The approximately $7 5 5 million fair value of assets acquired comprised of approximately $245 million of proved properties, approximately $480 million of unproved properties and approximately $30 million of other assets. The fair value of the assets received in the business combination approximated the fair value of assets disposed. Southern Delaware B asin divestitures. In January 2018, the Company closed on two asset sales transactions of certain non-core assets in Reeves and Ward Counties with combined preliminar y proceeds of approximately $280 million, subject to customary post-closing adjustments. After direct transaction costs, the Company recorded a pre-tax gain of approximately $134 million, which is included in g ain on disposition of assets, net on its consolidated statement of operations for the three months ended March 31, 2018 . The assets divested included proved and unproved oil and natural gas properties on approximately 20,000 net acres. These divestitures completed a transaction structured as a reverse like-kind exchange (“Reverse 1031 Exchange”) in accordance with Section 1031 of the Internal Re venue Code of 1986, as amended, that the Company entered into concurrent with a July 2017 acquisition in the Midland Basin. In connection with the Reverse 1031 Exchange, the Company assigned the ownership of the oil and natural gas prope rties acquired to a VIE formed by an exchange accommodation titleholder. The Company operated the properties pursuant to a management agreement with the VIE. At December 31, 2017 and prior to the completion of the reverse like-kind exchange in January 2018 , 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 performance. Upon completion of the Reverse 1031 Exchange in January 2018 , t he assets and liabilities attributable to the acquisition that were held by the VIE were conveyed to the Company, and the VIE structure was dissolved . Nonmonetary transactions. During the three months ended March 31, 201 8 , the Company completed multiple nonmonetary transactions. These transactions include d the exchange of both proved and unproved oil and natural gas properties. Certain of these transactions were accounted for at fair value and , as a result , the Company recorded pre-tax gains of approximat ely $14 million. During the three months ended March 31, 2017 , the Company entered into the following transactions: Northern Delaware Basin acquisition. In January and April 2017, the Company closed on the two-part acquisition in the Northern Delaware Basin. As consideration for the entire acquisition, the Company paid approximately $160 million in cash and issued to the seller approximately 2.2 million shares of its common stock with an approximate value of $291 million. ACC divestiture. In February 2017, the Company closed on the divestiture of its ownership interest in ACC. The Company and its joint venture partner entered into separate agreements to sell 100 percent of their respective ownership interests in ACC. After adjustments for debt and working capita l, the Company received cash proceeds fro m the sale of approximately $803 million. After direct transaction costs, the Company recorded a pre-tax gain of approximately $656 million, which is included in gain on disposition of assets, net o n its consolidate d statement of operations for the three months ended March 31, 2017 . The Company’s net investment in ACC at the time of closing was approximately $129 million.

Stock incentive plan

Stock incentive plan	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock incentive plan	Note 6 . Stock incentive plan The Company’s 20 15 Stock Incentive Plan (“the 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. Performance unit award s vest over a period of three years. Shares issued as a result of awards granted under the Plan are generally new common shares. A summary of the Company’s restricted stock shares and performance unit activity under the Plan for the three months ended March 31, 2018 is presented below: Restricted Performance Stock Shares Units Outstanding at December 31, 2017 1,149,246 247,647 Awards granted (a) 112,024 111,490 Awards cancelled / forfeited (13,463) - Lapse of restrictions (106,094) - Outstanding at March 31, 2018 1,141,713 359,137 (a) Weighted average grant date fair value per share/unit $ 151.37 $ 216.03 The Company used the following assumptions to estimate the fair value of performance unit awards granted during the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 Risk-free interest rate 2.00% 1.47% Range of volatilities 23.5% - 64.0% 24.8% - 60.2% 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 March 31, 2018 : (in millions) Remaining 2018 $ 50 2019 37 2020 17 Thereafter 3 Total $ 107

Disclosures about fair value me

Disclosures about fair value measurements	3 Months Ended
	Mar. 31, 2018
Disclosure Fair Value Narrative [Abstract]
Disclosures about fair value measurements	Note 7 . 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 March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 Carrying Fair Carrying Fair (in millions) Value Value Value Value Assets: Derivative instruments $ 25 $ 25 $ - $ - Liabilities: Derivative instruments $ 327 $ 327 $ 379 $ 379 Credit facility $ - $ - $ 322 $ 322 $600 million 4.375% senior notes due 2025 (a) $ 593 $ 604 $ 593 $ 624 $1,000 million 3.75% senior notes due 2027 (a) $ 988 $ 971 $ 987 $ 1,012 $800 million 4.875% senior notes due 2047 (a) $ 789 $ 838 $ 789 $ 874 (a) The carrying value includes associated deferred loan costs and any discount. Credit facility. The carrying amount of the Company’s credit facility, as amended and restated (the “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 ot her financial instruments consisting primarily of receivables, payables and other current assets and liabilities. The carrying amounts 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 March 31, 2018 and December 31, 2017 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. March 31, 2018 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 Total Consolidated Consolidated Assets Inputs Inputs Fair Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 111 $ - $ 111 $ (88) $ 23 Noncurrent: Commodity derivatives - 29 - 29 (27) 2 Liabilities: Current: Commodity derivatives - (336) - (336) 88 (248) Noncurrent: Commodity derivatives - (106) - (106) 27 (79) Net derivative instruments $ - $ (302) $ - $ (302) $ - $ (302) December 31, 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 Total Consolidated Consolidated Assets Inputs Inputs Fair Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 13 $ - $ 13 $ (13) $ - Noncurrent: Commodity derivatives - 1 - 1 (1) - Liabilities: Current: Commodity derivatives - (290) - (290) 13 (277) Noncurrent: Commodity derivatives - (103) - (103) 1 (102) Net derivative instruments $ - $ (379) $ - $ (379) $ - $ (379) Concentrations of credit risk. At March 31, 2018 , 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 8 for additional information regarding the Company ’ s derivative activities and counterparties .

Derivative financial instrument

Derivative financial instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative financial instruments	Note 8 . 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 contra cts to effectively provide commodity price hedges. Because these physical contracts are not expected to be net cash settled, the Company has elected normal purchase or normal sale treatment and such contracts are thus recorded at cost. T he Company does not designate its derivative instruments to qualify for hedge accounting. Accordingly, the Company reflects changes in the fair value of its derivative instruments 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 months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in millions) 2018 2017 Gain (loss) on derivatives: Oil derivatives $ (33) $ 266 Natural gas derivatives (2) 20 Total $ (35) $ 286 The following table represents the Company’s net cash receipts from (payments on) derivatives for the three months ended March 31, 2018 and 2017: Three Months Ended March 31, (in millions) 2018 2017 Net cash receipts from (payments on) derivatives: Oil derivatives $ (113) $ 31 Natural gas derivatives 1 (3) Total $ (112) $ 28 Commodity derivative contracts at March 31, 2018 . The following table sets forth the Company’s outstanding derivative contracts at March 31, 2018 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at March 31, 2018 are expected to settle by December 31, 2020 . First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2018: Volume (Bbl) 10,724,170 9,496,318 8,658,007 28,878,495 Price per Bbl $ 53.79 $ 53.56 $ 53.20 $ 53.54 2019: Volume (Bbl) 7,849,000 7,366,500 6,950,000 6,601,000 28,766,500 Price per Bbl $ 53.28 $ 53.21 $ 53.21 $ 53.18 $ 53.22 2020: Volume (Bbl) 1,482,000 1,416,000 1,357,000 1,309,000 5,564,000 Price per Bbl $ 54.59 $ 54.60 $ 54.62 $ 54.62 $ 54.61 Oil Basis Swaps: (b) 2018: Volume (Bbl) 9,492,000 8,465,000 7,757,000 25,714,000 Price per Bbl $ (0.81) $ (0.85) $ (0.89) $ (0.85) 2019: Volume (Bbl) 7,050,000 6,687,500 6,394,000 5,933,000 26,064,500 Price per Bbl $ (0.95) $ (0.96) $ (0.97) $ (1.01) $ (0.97) 2020: Volume (Bbl) 2,730,000 2,730,000 2,760,000 2,760,000 10,980,000 Price per Bbl $ (0.08) $ (0.08) $ (0.08) $ (0.08) $ (0.08) Natural Gas Price Swaps: (c) 2018: Volume (MMBtu) 16,979,000 15,740,000 14,778,000 47,497,000 Price per MMBtu $ 3.04 $ 3.04 $ 3.03 $ 3.04 2019: Volume (MMBtu) 4,591,533 4,501,387 4,418,537 4,329,535 17,840,992 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 – 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.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	Note 9 . Debt The Company’s debt consisted of the following at March 31, 2018 and December 31, 2017 : March 31, December 31, (in millions) 2018 2017 Credit facility $ - $ 322 4.375% unsecured senior notes due 2025 (a) 600 600 3.75% unsecured senior notes due 2027 1,000 1,000 4.875% unsecured senior notes due 2047 800 800 Unamortized original issue discount (5) (6) Senior notes issuance costs, net (25) (25) Less: current portion - - Total long-term debt $ 2,370 $ 2,691 (a) For each of the twelve-month periods beginning on January 15, 2020, 2021, 2022, 2023 and thereafter, these notes are callable at 103.281%, 102.188%, 101.094% and 100%, respectively. Credit facility. The Company’s Credit Facility has a maturity date of May 9, 2022. At March 31, 2018 , the Company’s commitments from it s bank group were $2.0 billion. 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 14 . At March 31, 2018 , 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 March 31, 2018 were as follows: (in millions) Remaining 2018 $ - 2019 - 2020 - 2021 - 2022 - 2023 - Thereafter 2,400 Total $ 2,400 Interest expense. The following amounts have been incurred and charged to interest expense for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in millions) 2018 2017 Cash payments for interest $ 18 $ 61 Non-cash interest 1 3 Net changes in accruals 12 (24) Interest costs incurred 31 40 Less: capitalized interest (1) - Total interest expense $ 30 $ 40

Commitments and contingencies

Commitments and contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Note 10 . 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. Although the Company beli eve 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 interpretations 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, fixed and variable power commitments , sand commitment agreements, fixed asset commitments and maintenance commitments . The following table s ummarizes the Company’s commitments at March 31, 2018 : (in millions) Remaining 2018 $ 32 2019 64 2020 55 2021 52 2022 21 2023 17 Thereafter 56 Total $ 297 Operating leases. The Company leases vehicles, equipment and office facilities under non-cancellable operating leases. Lease payments associated with these operating leases were approximately $ 3 million for each of the three months ended March 31, 2018 and 2017 . Future minimum lease commitments under non-cancellable operating leases at March 31, 2018 were as follows: (in millions) Remaining 2018 $ 8 2019 9 2020 8 2021 6 2022 1 2023 - Thereafter 1 Total $ 33

Income taxes

Income taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes	Note 11 . Income taxes The Company’s provision for income taxes for the three months ended March 31, 2018 and 2017 is based on the estimated annual effective tax rate plus discrete items. The effective income tax rate s w ere 23 percent and 36 percent for the three months ended March 31, 2018 and 2017 , respectively. The difference between the Company’s effective tax rates for the three months ended March 31, 2018 and 2017 is primarily due to (i) the reduc tion of the U . S . federal statutory corporate income tax rate from 35 percent to 21 percent, (ii) the impact of changes in non-deductible e xpenses and (iii) state income taxes, ne t of federal income tax benefits . The Company recorded a disc rete income tax benefit related to stock-based awards of approximately $2 million and $7 million for the three months ended March 31, 2018 and 2017 , respectively. On December 22, 2017, the President of the United States signed into law the “Tax Cuts and Job s Act” (“TCJA”) , which enacted significant changes to federal income tax laws, including a decrease in the federal corporate income tax rat e from 35 percent to 21 percent, which was effective January 1, 2018 . In accordance wit h Staff Accounting Bulletin No. 118, “Income Tax Accounting Implicatio ns of the Tax Cuts and Jobs Act ” (“SAB 118”) , the Company recorded, based on reasonable est imates, a $398 million decrease to its income tax provision at December 31, 2017. Th is provisional amount related to the re-measurement of certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future. At March 31, 2018 , the Company has not completed its accounting for all of the ta x effects of the TCJA and has not made an adjustment to the provisional tax benefit recorded under SAB 118 at December 31, 2017. In addition, the Company has considered in its estimated annual effective tax rate for 2018 the impact of the statutory changes enacted by the TCJA, including reasonable estimates of those provisions effective for the 2018 tax year.

Related party transactions

Related party transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related party transactions	Note 12 . 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 and $ 2 million for the three months ended March 31, 2018 and 2017 , respectively.

Earnings per share

Earnings per share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Earnings per share	Note 13 . 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 months ended March 31, 2018 and 2017 , respectively, under th e two-class method: Three Months Ended March 31, (in millions) 2018 2017 Net income as reported $ 835 $ 650 Participating basic earnings (a) (6) (5) Basic earnings attributable to common stockholders 829 645 Reallocation of participating earnings - - Diluted earnings attributable to common stockholders $ 829 $ 645 (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 months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in thousands) 2018 2017 Weighted average common shares outstanding: Basic 147,925 146,838 Dilutive common stock options - 12 Dilutive performance units 537 701 Diluted 148,462 147,551 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 March 31, (in thousands) 2018 2017 Number of antidilutive units: Antidilutive performance units - 108 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	3 Months Ended
	Mar. 31, 2018
Guarantees [Abstract]
Subsidiary guarantors	Note 14 . Subsidiary guarantors At March 31, 2018 , 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 9 for a summary of the Company’s senior notes. In accordance with practices accepted by the SEC, the Company has prepared condensed consolidating financial statements in order to quantify the assets, results of operations and cash flows of such subsidiaries as subsidiary guarantors. In addition, one of the Company’s subsidiaries does not guarantee the Company’s senior notes and is included in the Company’s consolidated financial statements. This entity is a 100 percent owned subsidiary that was recently acquired, and is referred to as a “Subsidiary Non-Guarantor” in the tables below . An additional entity did not guarantee the Company’s senior notes at December 31, 2017 . This entity wa s a VIE that was formed to effectuate a tax-free exchange of assets . During the three months ended March 31, 2018 , the Reverse 1031 Exchange was completed and all assets and liabilities attributable to the VIE wer e conveyed to the Company. This entity did not guarantee the Company’s seni or notes until t he conveyance was completed. See Note 5 for additional information regarding the completion of the Reverse 1031 Exchange . The following condensed consolida ting balance s heets at March 31, 2018 and December 31, 2017 , condensed c o nsolidating statements of o perations for the three months ended March 31, 2018 and 2017 and condensed consolidating statements of cash flows for the three months ended March 31, 2018 and 2017 , 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 guarantors on a stand-alone bas is (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 arrive 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 March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total ASSETS Accounts receivable - related parties $ 8,390 $ (657) $ - $ (7,733) $ - Other current assets 28 691 - - 719 Oil and natural gas properties, net - 13,348 17 - 13,365 Property and equipment, net - 246 - - 246 Investment in subsidiaries 4,355 - - (4,355) - Other long-term assets 25 26 - - 51 Total assets $ 12,798 $ 13,654 $ 17 $ (12,088) $ 14,381 LIABILITIES AND EQUITY Accounts payable - related parties $ (657) $ 8,373 $ 17 $ (7,733) $ - Other current liabilities 327 782 - - 1,109 Long-term debt 2,370 - - - 2,370 Other long-term liabilities 1,020 144 - - 1,164 Equity 9,738 4,355 - (4,355) 9,738 Total liabilities and equity $ 12,798 $ 13,654 $ 17 $ (12,088) $ 14,381 Condensed Consolidating Balance Sheet December 31, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,836 $ (669) $ - $ (8,167) $ - Other current assets 6 576 10 - 592 Oil and natural gas properties, net - 12,192 615 - 12,807 Property and equipment, net - 234 - - 234 Investment in subsidiaries 3,202 - - (3,202) - Other long-term assets 23 76 - - 99 Total assets $ 12,067 $ 12,409 $ 625 $ (11,369) $ 13,732 LIABILITIES AND EQUITY Accounts payable - related parties $ (669) $ 8,223 $ 613 $ (8,167) $ - Other current liabilities 341 821 3 - 1,165 Long-term debt 2,691 - - - 2,691 Other long-term liabilities 789 166 6 - 961 Equity 8,915 3,199 3 (3,202) 8,915 Total liabilities and equity $ 12,067 $ 12,409 $ 625 $ (11,369) $ 13,732 Condensed Consolidating Statement of Operations Three Months Ended March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total Total operating revenues $ - $ 942 $ 5 $ - $ 947 Total operating costs and expenses (34) 112 (3) - 75 Income (loss) from operations (34) 1,054 2 - 1,022 Interest expense (30) - - - (30) Other, net 1,153 97 - (1,153) 97 Income before income taxes 1,089 1,151 2 (1,153) 1,089 Income tax expense (254) - - - (254) Net income $ 835 $ 1,151 $ 2 $ (1,153) $ 835 Condensed Consolidating Statement of Operations Three Months Ended March 31, 2017 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 612 $ - $ 612 Total operating costs and expenses 285 164 - 449 Income from operations 285 776 - 1,061 Interest expense (40) - - (40) Other, net 776 - (776) - Income before income taxes 1,021 776 (776) 1,021 Income tax expense (371) - - (371) Net income $ 650 $ 776 $ (776) $ 650 Condensed Consolidating Statement of Cash Flows Three Months Ended March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total Net cash flows provided by operating activities $ 351 $ 137 $ - $ - $ 488 Net cash flows used in investing activities - (93) - - (93) Net cash flows used in financing activities (351) (44) - - (395) Net increase in cash and cash equivalents - - - - - Cash and cash equivalents at beginning of period - - - - - Cash and cash equivalents at end of period $ - $ - $ - $ - $ - Condensed Consolidating Statement of Cash Flows Three Months Ended March 31, 2017 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Net cash flows provided by operating activities $ 19 $ 388 $ - $ 407 Net cash flows provided by investing activities - 330 - 330 Net cash flows used in financing activities (19) - - (19) Net increase in cash and cash equivalents - 718 - 718 Cash and cash equivalents at beginning of period - 53 - 53 Cash and cash equivalents at end of period $ - $ 771 $ - $ 771

Subsequent events

Subsequent events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent events	Note 15 . Subsequent events New commodity derivative contracts. After March 31, 2018 , the Com pany enter ed into th e 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) 2018: Volume (Bbl) 729,000 659,000 417,000 1,805,000 Price per Bbl $ 64.92 $ 64.76 $ 64.54 $ 64.77 2019: Volume (Bbl) 443,000 328,000 257,000 217,000 1,245,000 Price per Bbl $ 59.81 $ 59.71 $ 59.46 $ 59.34 $ 59.63 2020: Volume (Bbl) 1,244,000 1,185,000 1,131,000 1,104,000 4,664,000 Price per Bbl $ 56.05 $ 56.01 $ 55.95 $ 55.92 $ 55.98 Oil Basis Swaps: (b) 2019: Volume (Bbl) 630,000 637,000 644,000 644,000 2,555,000 Price per Bbl $ (3.26) $ (3.26) $ (3.26) $ (3.26) $ (3.26) Natural Gas Price Swaps: (c) 2018: Volume (MMBtu) 1,200,000 3,680,000 3,680,000 8,560,000 Price per MMBtu $ 2.88 $ 2.88 $ 2.88 $ 2.88 2019: Volume (MMBtu) 2,700,000 2,730,000 2,760,000 2,760,000 10,950,000 Price per MMBtu $ 2.75 $ 2.75 $ 2.75 $ 2.75 $ 2.75 2020: Volume (MMBtu) 1,820,000 1,820,000 1,840,000 1,840,000 7,320,000 Price per MMBtu $ 2.70 $ 2.70 $ 2.70 $ 2.70 $ 2.70 (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	3 Months Ended
	Mar. 31, 2018
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Supplementary information	Note 16 . Supplementary information Capitalized costs March 31, December 31, (in millions) 2018 2017 Oil and natural gas properties: Proved $ 18,907 $ 18,565 Unproved 3,116 2,702 Less: accumulated depletion (8,658) (8,460) Net capitalized costs for oil and natural gas properties $ 13,365 $ 12,807 (a) (a) Approximately $135 million of the balance at December 31, 2017 relates to assets held for sale that were disposed of during January 2018. Costs incurred for oil and natural gas producing activities Three Months Ended March 31, (in millions) 2018 2017 Property acquisition costs: Proved $ - $ 127 Unproved 13 306 Exploration 243 235 Development 207 158 Total costs incurred for oil and natural gas properties $ 463 $ 826

Summary of significant accoun24

Summary of significant accounting policies (Policies)	3 Months Ended
	Mar. 31, 2018
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 consolidated financial statements also included the accounts of a variable interest entity (“VIE”) where the Company was the primary beneficiary of the arrangements until the VIE structure dissolved. See Note 5 for additional information regarding the circumstances surro unding the VIE. The Company consolidates the financial statements of these entities. All material intercompany balances and transactions have been eliminated.
Reclassifications	Reclassifications. Certain prior period amounts have been reclassified to conform to the 2018 presentation. These reclassifications had no impact 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 accept ed 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 stat ements and the reported amounts of revenues and expenses 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 estimation 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 nat ural gas properties are subject to numerous uncertainties 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 include, but are not limited to, asset retirement obligations, fair value of stock-based compensation, fair value of business combinations, fair value of nonmonetary transactions, fair value of derivative financial instruments and income taxes.
Interim financial statements	Interim financial stat ements. 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, 2017 is derived from audited consolidated fina ncial statements. 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 preparing 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 th ose estimates. 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 fin ancial statements 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, 2017 .
Cash equivalents	Cash equivalents. The Company considers all cash on hand, deposi tory 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 may 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 selected.
Equity method investments	Equity method investments. The Company accounts for its equity method investments under the equity method of accounting and includes the investment balance in other assets on the consolidated balance sheets. Gains and losses incurred from the Company’s equity investments are recorded in o ther income on the con solidated statements of operations. The Company owns a 23.75 perce nt 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. During the three months ended March 31, 2018 , Oryx obtained a term loan of $800 million. The proceeds were used in part to fund a cash distribution to its equity holders, of which the Company received a distribution of approximately $157 million. Of this amount, a pproximately $54 million fully offset the Company’s net investment in Oryx. The remaining distribution of approximately $103 million was recorded in other income on the Company’s consolidated statement of operations for the three months ended March 31, 2018 since the lenders to the term loan do not have recourse against the Company , and the Company has no contractual obligation to repay the distribution . The Company’s net investment in Oryx was approximately $ 49 million at December 31, 2017 . During the three months ended March 31, 2018 and 2017 , the Company recorded income of approximately $ 5 million and $ 1 million, respectively. In February 2017, the Company closed on the divestiture of its 50 percent membership interest in a midstream joint venture, Alpha Crude Connector, LLC (“ACC”), that constructed a crude oil gathering and transportation system in the Northern Delaware Basin. See Note 5 for additional information regarding the disposition of ACC.
Revenue recognition	Revenue recognition . On January 1, 2018, the Company adopted Accounting Standards Codification (“ASC ”) Topic 606 , “Revenue from Contrac ts with Customers,” (“ ASC 606 ”) using the modified retrospective approach, which only applies to contracts that were not completed as of the date of initial application. The adoption did not require an adjustment to opening retained earnings for the cumula tive effect adjustment and does not have a material impact on the Company’s ong oing consolidated balance sheets, statements of operat ions, statement of stockholders’ equity, or statement s of cash flows. The C ompany recognizes revenues from the sales of o il and natural gas to its customers and presents them disaggregated on the Company’s consolidated statements of operations. All revenues are recognized in the geographical region of the Permian Basin. P rior to the adoption of ASC 606, the Company recorded oil and natural gas revenues at the time of physical transfer of such products to the purchaser, which for the Company is primarily at the wellhead. The Company followed the sales method of accounting for oil and natural gas sales, recognizing revenues bas ed on the Company’s actual proceeds from the oil and natural gas sold to purchasers. The Company enters into contracts with customers to sell its oil and natural gas production. Revenue on these contracts is recognized in accordance with the five-step rev enue recognition model prescribed in ASC 606 . Specifically, revenue is recognized when the Company’s performance obligations under these contracts are satisfied, which generally occurs with the transfer of control of the oil and natural gas to the purchase r. Control is generally considered transfe rred when the following criteria are met: (i) transfer of physical custody, (ii) transfer of title, (iii) transfer of risk of loss and (iv) relinquishment of any repurchase rights or other similar rights. Given the nature of the products sold, reve nue is recognized at a point in time based on the amount of consideration the Company expects to receive in accordance with the price specified in the contract. Consideration under the oil and natural gas marketing contrac ts is typically received from the purchaser one to two months after production. At March 31, 2018 , the Company had receivables related to contracts with customers of $ 392 million. The following table shows the impact of the adoption of ASC 606 on the Company’s current period results as compared to the previous revenue recognition standard, ASC Topic 605, “Revenue recognition ” (“ASC 605”): Three Months Ended March 31, 2018 (in millions) Under ASC 606 Under ASC 605 Increase (Decrease) Operating revenues: Oil sales $ 793 $ 791 $ 2 Natural gas sales 154 148 6 Operating costs and expenses: Oil and natural gas production 130 133 (3) Gathering, processing and transportation 11 - 11 Net income $ 835 $ 835 $ - Oil Contracts. The majority of the Company’s oil marketing contracts transfer physical custody and title at or near the wellhead, which is generally when control of the oil has been transferred to the purchaser. The majority of the oil produced is sold under contracts u sing market-based pricing, which price is then adjusted for differentials based upon delivery location and oil quality. To the extent the differentials are incurred after the transfer of control of the oil, the differentials are included in o il sales o n th e statement s of operations as they represent part of the transaction price of the contract. If the differentials, or other related costs, are incurred prior to the transfer of control of the oil, those costs are included in g athering, processing and transp ortation o n the Company’s consolidated statement s of operations as they represent payment for services performed outside of the contract with the customer. Natural Gas Contracts. The majority of the Company’s natural gas is sold at the lease location, wh ich is generally when control of the natural gas has been transferred to the purchaser. The natural gas is sold under (i) percent age of proceeds processing contr acts, (ii) fee-based contracts or ( iii) a hybrid of percentage of proceeds and fee-based contra cts. Under these contracts, the purchaser gathers the natural gas in the field where it is produced and transports it via pipeline to natural gas processing plants where natural gas liquid products are extracted. The natural gas liquid products and remaini ng residue gas are then sold by the purchaser. Under the percentage of proceeds and hybrid percentage of proceeds and fee-based contracts, the Company receives a percentage of the value for the extracted liquids and the residue gas. Under the fee - based co ntracts, the Company receives natural gas liquids and residue gas value, less the fee component, or is invoiced the fee component. To the extent control of the natural gas transfers upstream of the transportation and processing activities, revenue is recog nized as the net amount r eceived from the purchaser. To the extent that control transfers downstream of those costs, revenue is recognized on a gross basis , and the related costs are classified in g athering, processing and transportation o n the Company’s c onsolidated statement s of operations. The Company does not disclose the value of unsatisfied performance obligations under its contracts with customers as it applies the practical exemption in accordance with ASC 606. Th e exemption , as described in ASC 60 6-10-50-14(a), applies to variable consideration that is recognized as control of the product is transferred to the customer. Since each unit of product represents a separate performance obligation, future volumes are wholly unsatisfied and disclosure of t he transaction price allocated to remaining performance obligations is not required.
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 redu ctions to general and administrative expense. Such fees totaled approximate ly $ 4 million for each of the three months ended March 31, 2018 and 2017 .
Recent accounting pronouncements	New accounting pronouncements issued but not yet adopted. In Februar y 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, “Leases (Topic 842) ” (“ASU 2016-02”), 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 consol idated statements of operations will be effectively unchanged. 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 in to 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 ha s substantially completed the process of reviewing and determining t he contracts to which this new guidance applies . The Company is currently enhancing its accounting system in order to track and calculate additional information necessary for adoption of this standard. The Company believes this new guidance will have a mod erate impact on its consolidated balance sheet s due to the recognition of right-of-use assets and lease liabilities that are not recognized under currently applicable guidance . In January 2018, the FASB issued ASU No. 2018-01, “Land Easement Practical Ex pedie nt for Transition to Topic 842,” which provides an optional practical expedient to not evaluate land easements that exist ed or expired before the adoption of ASU 2016-02 and that were not previously accounted for as leases under the original “Leases ( Topic 840 )” accounting standard (“Topic 840”) . The Company enters into land easements on a routine basis as part of its ongoing operations and has many such agreements currently in place; however, the Company does not currently account for any land easemen ts under Topic 840. As this guidance serves as an amendment to ASU 2016-02, t he Company will elect this practical expedient , which becomes effective upon the date of adoption of ASU 2016-02 . After the adoption of ASU 2016-02 , the Company will assess any ne w land easements to determine whether the arrangement should be accounted for as a lease. 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 methodolog y 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. Th is 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 consoli dated financial statements.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure Revenue Recognition Impact of ASC 606 Adoption [Abstract]
Impact of the adoption of ASC 606 on current period results	The following table shows the impact of the adoption of ASC 606 on the Company’s current period results as compared to the previous revenue recognition standard, ASC Topic 605, “Revenue recognition ” (“ASC 605”): Three Months Ended March 31, 2018 (in millions) Under ASC 606 Under ASC 605 Increase (Decrease) Operating revenues: Oil sales $ 793 $ 791 $ 2 Natural gas sales 154 148 6 Operating costs and expenses: Oil and natural gas production 130 133 (3) Gathering, processing and transportation 11 - 11 Net income $ 835 $ 835 $ -

Exploratory well costs (Tables)

Exploratory well costs (Tables)	3 Months Ended
	Mar. 31, 2018
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 three months ended March 31, 2018 : Three Months Ended (in millions) March 31, 2018 Beginning capitalized exploratory well costs $ 182 Additions to exploratory well costs pending the determination of proved reserves 163 Reclassifications due to determination of proved reserves (76) Disposition of wells (16) Ending capitalized exploratory well costs $ 253
Aging of capitalized exploratory well costs based on the date drilling was completed	The following table provides an aging at March 31, 2018 and December 31, 2017 of capitalized exploratory well costs based on the date drilling was completed: March 31, December 31, (in millions, except number of projects) 2018 2017 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 239 $ 180 Capitalized exploratory well costs that have been capitalized for a period greater than one year 14 2 Total capitalized exploratory well costs $ 253 $ 182 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 2 2

Stock incentive plan (Tables)

Stock incentive plan (Tables)	3 Months Ended
	Mar. 31, 2018
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 restricted stock shares and performance unit activity under the Plan for the three months ended March 31, 2018 is presented below: Restricted Performance Stock Shares Units Outstanding at December 31, 2017 1,149,246 247,647 Awards granted (a) 112,024 111,490 Awards cancelled / forfeited (13,463) - Lapse of restrictions (106,094) - Outstanding at March 31, 2018 1,141,713 359,137 (a) Weighted average grant date fair value per share/unit $ 151.37 $ 216.03
Summarizes the assumptions to estimate the fair value of performance units granted	The Company used the following assumptions to estimate the fair value of performance unit awards granted during the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 Risk-free interest rate 2.00% 1.47% Range of volatilities 23.5% - 64.0% 24.8% - 60.2%
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 March 31, 2018 : (in millions) Remaining 2018 $ 50 2019 37 2020 17 Thereafter 3 Total $ 107

Disclosures about fair value 28

Disclosures about fair value measurements (Tables)	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 Carrying Fair Carrying Fair (in millions) Value Value Value Value Assets: Derivative instruments $ 25 $ 25 $ - $ - Liabilities: Derivative instruments $ 327 $ 327 $ 379 $ 379 Credit facility $ - $ - $ 322 $ 322 $600 million 4.375% senior notes due 2025 (a) $ 593 $ 604 $ 593 $ 624 $1,000 million 3.75% senior notes due 2027 (a) $ 988 $ 971 $ 987 $ 1,012 $800 million 4.875% senior notes due 2047 (a) $ 789 $ 838 $ 789 $ 874 (a) The carrying value includes associated deferred loan costs and any 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 March 31, 2018 and December 31, 2017 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. March 31, 2018 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 Total Consolidated Consolidated Assets Inputs Inputs Fair Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 111 $ - $ 111 $ (88) $ 23 Noncurrent: Commodity derivatives - 29 - 29 (27) 2 Liabilities: Current: Commodity derivatives - (336) - (336) 88 (248) Noncurrent: Commodity derivatives - (106) - (106) 27 (79) Net derivative instruments $ - $ (302) $ - $ (302) $ - $ (302) December 31, 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 Total Consolidated Consolidated Assets Inputs Inputs Fair Balance Balance (in millions) (Level 1) (Level 2) (Level 3) Value Sheet Sheet Assets: Current: Commodity derivatives $ - $ 13 $ - $ 13 $ (13) $ - Noncurrent: Commodity derivatives - 1 - 1 (1) - Liabilities: Current: Commodity derivatives - (290) - (290) 13 (277) Noncurrent: Commodity derivatives - (103) - (103) 1 (102) Net derivative instruments $ - $ (379) $ - $ (379) $ - $ (379)

Derivative financial instrume29

Derivative financial instruments (Tables)	3 Months Ended
	Mar. 31, 2018
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 months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in millions) 2018 2017 Gain (loss) on derivatives: Oil derivatives $ (33) $ 266 Natural gas derivatives (2) 20 Total $ (35) $ 286 The following table represents the Company’s net cash receipts from (payments on) derivatives for the three months ended March 31, 2018 and 2017: Three Months Ended March 31, (in millions) 2018 2017 Net cash receipts from (payments on) derivatives: Oil derivatives $ (113) $ 31 Natural gas derivatives 1 (3) Total $ (112) $ 28
Company's outstanding derivative contracts	The following table sets forth the Company’s outstanding derivative contracts at March 31, 2018 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at March 31, 2018 are expected to settle by December 31, 2020 . First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Price Swaps: (a) 2018: Volume (Bbl) 10,724,170 9,496,318 8,658,007 28,878,495 Price per Bbl $ 53.79 $ 53.56 $ 53.20 $ 53.54 2019: Volume (Bbl) 7,849,000 7,366,500 6,950,000 6,601,000 28,766,500 Price per Bbl $ 53.28 $ 53.21 $ 53.21 $ 53.18 $ 53.22 2020: Volume (Bbl) 1,482,000 1,416,000 1,357,000 1,309,000 5,564,000 Price per Bbl $ 54.59 $ 54.60 $ 54.62 $ 54.62 $ 54.61 Oil Basis Swaps: (b) 2018: Volume (Bbl) 9,492,000 8,465,000 7,757,000 25,714,000 Price per Bbl $ (0.81) $ (0.85) $ (0.89) $ (0.85) 2019: Volume (Bbl) 7,050,000 6,687,500 6,394,000 5,933,000 26,064,500 Price per Bbl $ (0.95) $ (0.96) $ (0.97) $ (1.01) $ (0.97) 2020: Volume (Bbl) 2,730,000 2,730,000 2,760,000 2,760,000 10,980,000 Price per Bbl $ (0.08) $ (0.08) $ (0.08) $ (0.08) $ (0.08) Natural Gas Price Swaps: (c) 2018: Volume (MMBtu) 16,979,000 15,740,000 14,778,000 47,497,000 Price per MMBtu $ 3.04 $ 3.04 $ 3.03 $ 3.04 2019: Volume (MMBtu) 4,591,533 4,501,387 4,418,537 4,329,535 17,840,992 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 – 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)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Company's debt	The Company’s debt consisted of the following at March 31, 2018 and December 31, 2017 : March 31, December 31, (in millions) 2018 2017 Credit facility $ - $ 322 4.375% unsecured senior notes due 2025 (a) 600 600 3.75% unsecured senior notes due 2027 1,000 1,000 4.875% unsecured senior notes due 2047 800 800 Unamortized original issue discount (5) (6) Senior notes issuance costs, net (25) (25) Less: current portion - - Total long-term debt $ 2,370 $ 2,691 (a) For each of the twelve-month periods beginning on January 15, 2020, 2021, 2022, 2023 and thereafter, these notes are callable at 103.281%, 102.188%, 101.094% and 100%, respectively.
Principal maturities of debt	Principal maturities of long -term debt outstanding at March 31, 2018 were as follows: (in millions) Remaining 2018 $ - 2019 - 2020 - 2021 - 2022 - 2023 - Thereafter 2,400 Total $ 2,400
Interest expense	The following amounts have been incurred and charged to interest expense for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in millions) 2018 2017 Cash payments for interest $ 18 $ 61 Non-cash interest 1 3 Net changes in accruals 12 (24) Interest costs incurred 31 40 Less: capitalized interest (1) - Total interest expense $ 30 $ 40

Commitments and contingencies (

Commitments and contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Summary of the Company's future commitments	The following table s ummarizes the Company’s commitments at March 31, 2018 : (in millions) Remaining 2018 $ 32 2019 64 2020 55 2021 52 2022 21 2023 17 Thereafter 56 Total $ 297
Future minimum lease commitments under non-cancellable operating leases	Future minimum lease commitments under non-cancellable operating leases at March 31, 2018 were as follows: (in millions) Remaining 2018 $ 8 2019 9 2020 8 2021 6 2022 1 2023 - Thereafter 1 Total $ 33

Earnings per share (Tables)

Earnings per share (Tables)	3 Months Ended
	Mar. 31, 2018
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 months ended March 31, 2018 and 2017 , respectively, under th e two-class method: Three Months Ended March 31, (in millions) 2018 2017 Net income as reported $ 835 $ 650 Participating basic earnings (a) (6) (5) Basic earnings attributable to common stockholders 829 645 Reallocation of participating earnings - - Diluted earnings attributable to common stockholders $ 829 $ 645 (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 months ended March 31, 2018 and 2017 : Three Months Ended March 31, (in thousands) 2018 2017 Weighted average common shares outstanding: Basic 147,925 146,838 Dilutive common stock options - 12 Dilutive performance units 537 701 Diluted 148,462 147,551
Summary of performance units which were not included in the computation of diluted earnings 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 March 31, (in thousands) 2018 2017 Number of antidilutive units: Antidilutive performance units - 108

Subsidiary guarantors (Tables)

Subsidiary guarantors (Tables)	3 Months Ended
	Mar. 31, 2018
Guarantees [Abstract]
Condensed Consolidating Balance Sheet	The following condensed consolida ting balance s heets at March 31, 2018 and December 31, 2017 , condensed c o nsolidating statements of o perations for the three months ended March 31, 2018 and 2017 and condensed consolidating statements of cash flows for the three months ended March 31, 2018 and 2017 , 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 guarantors on a stand-alone bas is (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 arrive 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 March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total ASSETS Accounts receivable - related parties $ 8,390 $ (657) $ - $ (7,733) $ - Other current assets 28 691 - - 719 Oil and natural gas properties, net - 13,348 17 - 13,365 Property and equipment, net - 246 - - 246 Investment in subsidiaries 4,355 - - (4,355) - Other long-term assets 25 26 - - 51 Total assets $ 12,798 $ 13,654 $ 17 $ (12,088) $ 14,381 LIABILITIES AND EQUITY Accounts payable - related parties $ (657) $ 8,373 $ 17 $ (7,733) $ - Other current liabilities 327 782 - - 1,109 Long-term debt 2,370 - - - 2,370 Other long-term liabilities 1,020 144 - - 1,164 Equity 9,738 4,355 - (4,355) 9,738 Total liabilities and equity $ 12,798 $ 13,654 $ 17 $ (12,088) $ 14,381 Condensed Consolidating Balance Sheet December 31, 2017 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,836 $ (669) $ - $ (8,167) $ - Other current assets 6 576 10 - 592 Oil and natural gas properties, net - 12,192 615 - 12,807 Property and equipment, net - 234 - - 234 Investment in subsidiaries 3,202 - - (3,202) - Other long-term assets 23 76 - - 99 Total assets $ 12,067 $ 12,409 $ 625 $ (11,369) $ 13,732 LIABILITIES AND EQUITY Accounts payable - related parties $ (669) $ 8,223 $ 613 $ (8,167) $ - Other current liabilities 341 821 3 - 1,165 Long-term debt 2,691 - - - 2,691 Other long-term liabilities 789 166 6 - 961 Equity 8,915 3,199 3 (3,202) 8,915 Total liabilities and equity $ 12,067 $ 12,409 $ 625 $ (11,369) $ 13,732
Condensed Consolidating Statement of Operations	The following condensed consolida ting balance s heets at March 31, 2018 and December 31, 2017 , condensed c o nsolidating statements of o perations for the three months ended March 31, 2018 and 2017 and condensed consolidating statements of cash flows for the three months ended March 31, 2018 and 2017 , 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 guarantors on a stand-alone bas is (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 arrive 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 March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total Total operating revenues $ - $ 942 $ 5 $ - $ 947 Total operating costs and expenses (34) 112 (3) - 75 Income (loss) from operations (34) 1,054 2 - 1,022 Interest expense (30) - - - (30) Other, net 1,153 97 - (1,153) 97 Income before income taxes 1,089 1,151 2 (1,153) 1,089 Income tax expense (254) - - - (254) Net income $ 835 $ 1,151 $ 2 $ (1,153) $ 835 Condensed Consolidating Statement of Operations Three Months Ended March 31, 2017 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Total operating revenues $ - $ 612 $ - $ 612 Total operating costs and expenses 285 164 - 449 Income from operations 285 776 - 1,061 Interest expense (40) - - (40) Other, net 776 - (776) - Income before income taxes 1,021 776 (776) 1,021 Income tax expense (371) - - (371) Net income $ 650 $ 776 $ (776) $ 650
Condensed Consolidating Statement of Cash Flows	The following condensed consolida ting balance s heets at March 31, 2018 and December 31, 2017 , condensed c o nsolidating statements of o perations for the three months ended March 31, 2018 and 2017 and condensed consolidating statements of cash flows for the three months ended March 31, 2018 and 2017 , 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 guarantors on a stand-alone bas is (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 arrive 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 Three Months Ended March 31, 2018 Parent Subsidiary Subsidiary Consolidating (in millions) Issuer Guarantors Non-Guarantor Entries Total Net cash flows provided by operating activities $ 351 $ 137 $ - $ - $ 488 Net cash flows used in investing activities - (93) - - (93) Net cash flows used in financing activities (351) (44) - - (395) Net increase in cash and cash equivalents - - - - - Cash and cash equivalents at beginning of period - - - - - Cash and cash equivalents at end of period $ - $ - $ - $ - $ - Condensed Consolidating Statement of Cash Flows Three Months Ended March 31, 2017 Parent Subsidiary Consolidating (in millions) Issuer Guarantors Entries Total Net cash flows provided by operating activities $ 19 $ 388 $ - $ 407 Net cash flows provided by investing activities - 330 - 330 Net cash flows used in financing activities (19) - - (19) Net increase in cash and cash equivalents - 718 - 718 Cash and cash equivalents at beginning of period - 53 - 53 Cash and cash equivalents at end of period $ - $ 771 $ - $ 771

Subsequent events (Tables)

Subsequent events (Tables)	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
New commodity derivative contracts	After March 31, 2018 , the Com pany enter ed into th e 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) 2018: Volume (Bbl) 729,000 659,000 417,000 1,805,000 Price per Bbl $ 64.92 $ 64.76 $ 64.54 $ 64.77 2019: Volume (Bbl) 443,000 328,000 257,000 217,000 1,245,000 Price per Bbl $ 59.81 $ 59.71 $ 59.46 $ 59.34 $ 59.63 2020: Volume (Bbl) 1,244,000 1,185,000 1,131,000 1,104,000 4,664,000 Price per Bbl $ 56.05 $ 56.01 $ 55.95 $ 55.92 $ 55.98 Oil Basis Swaps: (b) 2019: Volume (Bbl) 630,000 637,000 644,000 644,000 2,555,000 Price per Bbl $ (3.26) $ (3.26) $ (3.26) $ (3.26) $ (3.26) Natural Gas Price Swaps: (c) 2018: Volume (MMBtu) 1,200,000 3,680,000 3,680,000 8,560,000 Price per MMBtu $ 2.88 $ 2.88 $ 2.88 $ 2.88 2019: Volume (MMBtu) 2,700,000 2,730,000 2,760,000 2,760,000 10,950,000 Price per MMBtu $ 2.75 $ 2.75 $ 2.75 $ 2.75 $ 2.75 2020: Volume (MMBtu) 1,820,000 1,820,000 1,840,000 1,840,000 7,320,000 Price per MMBtu $ 2.70 $ 2.70 $ 2.70 $ 2.70 $ 2.70 (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)	3 Months Ended
	Mar. 31, 2018
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Capitalized costs	Capitalized costs March 31, December 31, (in millions) 2018 2017 Oil and natural gas properties: Proved $ 18,907 $ 18,565 Unproved 3,116 2,702 Less: accumulated depletion (8,658) (8,460) Net capitalized costs for oil and natural gas properties $ 13,365 $ 12,807 (a) (a) Approximately $135 million of the balance at December 31, 2017 relates to assets held for sale that were disposed of during January 2018.
costs incurred for oil and natural gas producing activities	Costs incurred for oil and natural gas producing activities Three Months Ended March 31, (in millions) 2018 2017 Property acquisition costs: Proved $ - $ 127 Unproved 13 306 Exploration 243 235 Development 207 158 Total costs incurred for oil and natural gas properties $ 463 $ 826

Summary Of Significant Accoun36

Summary Of Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disclosure Summary Of Significant Accounting Policies Narrative [Abstract]
Fees related to operation of jointly owned oil and natural gas properties	$ 4	$ 4
Receivables related to contracts with customers	392		$ 331
Equity Method Investments [Line Items]
Total distribution from equity method investment	$ 148	0
Oryx Southern Delaware Holdings [Member]
Equity Method Investments [Line Items]
Equity method investment ownership percentage	23.75%
Term loan obtained by Oryx	$ 800
Total distribution from equity method investment	157
Portion of equity method investment distribution that offset Company's net investment	54
Portion of equity method investment distribution recognized in other income	103
Total equity method investment	0		$ 49
Income from equity method investments	$ 5	$ 1
Alpha Crude Connector [Member]
Equity Method Investments [Line Items]
Equity method investment ownership percentage			50.00%

Summary Of Significant Accoun37

Summary Of Significant Accounting Policies (Adoption of ASC 606) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue Recognition Standard Adoption [Line Items]
Oil sales	$ 793	$ 502
Natural gas sales	154	110
Oil and natural gas production	130	87
Gathering, processing and transportation	11	0
Net income (loss)	835	$ 650
ASC 606 [Member]
Revenue Recognition Standard Adoption [Line Items]
Oil sales	793
Natural gas sales	154
Oil and natural gas production	130
Gathering, processing and transportation	11
Net income (loss)	835
ASC 605 [Member]
Revenue Recognition Standard Adoption [Line Items]
Oil sales	791
Natural gas sales	148
Oil and natural gas production	133
Gathering, processing and transportation	0
Net income (loss)	835
Increase (Decrease) due to ASC 606 Adoption [Member]
Revenue Recognition Standard Adoption [Line Items]
Oil sales	2
Natural gas sales	6
Oil and natural gas production	(3)
Gathering, processing and transportation	11
Net income (loss)	$ 0

Exploratory Well Costs (Capital

Exploratory Well Costs (Capitalized Exploratory Well Activity) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Disclosure Exploratory Well Costs Capitalized Exploratory Well Activity [Abstract]
Beginning capitalized exploratory well costs	$ 182
Additions to exploratory well costs pending the determination of proved reserves	163
Reclassifications due to determination of proved reserves	(76)
Disposition of wells	(16)
Ending capitalized exploratory well costs	$ 253

Exploratory Well Costs (Aging O

Exploratory Well Costs (Aging Of Capitalized Exploratory Well Costs Based On The Date Of Drilling) (Detail) $ in Millions	Mar. 31, 2018USD ($)Number	Dec. 31, 2017USD ($)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	$ 239	$ 180
Capitalized exploratory well costs that have been capitalized for a period greater than one year	14	2
Total capitalized exploratory well costs	$ 253	$ 182
Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects | Number	2	2

Exploratory Well Costs (Narrati

Exploratory Well Costs (Narrative) (Detail) $ in Millions	Mar. 31, 2018USD ($)
Northern Delaware Basin Project [Member]
Oil And Gas In Process Activities [Line Items]
Suspended well costs greater than one year	12

RSP Permian Acquisition (Narrat

RSP Permian Acquisition (Narrative) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)shares
RSP Permian Acquisition Narrative [Abstract]
Acquisition Agreement Date	Mar. 27, 2018
Ratio of Company's common stock in exchange for RSP common stock	0.32
Termination fee owed if the Company terminates Acquisition Agreement | $	$ 350
Common stock, number of shares to be issued | shares	51,000,000

Acquisitions, divestitures an42

Acquisitions, divestitures and nonmonetary transactions (Narrative) (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
(Gain) loss on disposition of assets, net	$ (723)	$ (654)
Common stock issued in business combination	0	258
February 2018 Acquisition and Divestiture [Member]
Business Acquisition [Line Items]
Fair value of acquired assets	755
Book value of divested assets	180
Pre-tax gain on acquisition/divestiture or nonmonetary transaction	(575)
Fair value of proved acquired assets	245
Fair value of unproved acquired assets	480
Fair value of other acquired assets	30
Southern Delaware Basin [Member]
Business Acquisition [Line Items]
Net proceeds from asset divestiture	280
Pre-tax gain on asset divestiture	(134)
Nonmonetary Transactions [Member]
Business Acquisition [Line Items]
Pre-tax gain on acquisition/divestiture or nonmonetary transaction	$ (14)
Northern Delaware Basin [Member]
Business Acquisition [Line Items]
Total cash consideration paid for acquisition		$ 160
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		803
Pre-tax gain on asset divestiture		$ (656)
Total equity method investment			$ 129

Incentive Plans (Summary of Sto

Incentive Plans (Summary of Stock-Based Award Activity) (Detail) - $ / shares		3 Months Ended
		Mar. 31, 2018	Dec. 31, 2017
Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		1,141,713	1,149,246
Awards granted	[1]	112,024
Awards cancelled / forfeited		(13,463)
Lapse of restrictions		(106,094)
Weighted average grant date fair value per share/unit		$ 151.37
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		359,137	247,647
Awards granted	[2]	111,490
Awards cancelled / forfeited		0
Lapse of restrictions		0
Weighted average grant date fair value per share/unit		$ 216.03
[1]	Weighted average grant date fair value per share is $151.37
[2]	Weighted average grant date fair value per unit is $216.03

Incentive Plans (Summary Of Ass

Incentive Plans (Summary Of Assumptions To Estimate Fair Value of Performance Unit Awards) (Detail)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure Incentive Plans Schedule Of Performance Unit Awards Fair Value Assumptions [Abstract]
Risk-free interest rate	2.00%	1.47%
Volatility assumption - minimum	23.50%	24.80%
Volatility assumption - maximum	64.00%	60.20%

Incentive Plans (Summary For Fu

Incentive Plans (Summary For Future Stock-Based Compensation Expense) (Detail) $ in Millions	Mar. 31, 2018USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining 2,018	$ 50
2,019	37
2,020	17
Thereafter	3
Total	$ 107

Disclosures About Fair Value 46

Disclosures About Fair Value Measurements (Carrying Amounts And Fair Values Of The Company's Financial Instruments) (Detail) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		$ 25	$ 0
Derivative instruments, Liabilities		327	379
Credit facility		0	322
Four Point Three Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		604	624
Three Point Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		971	1,012
Four Point Eight Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes		838	874
Carrying Reported Amount Fair Value Disclosure [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		25	0
Derivative instruments, Liabilities		327	379
Credit facility		0	322
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	593
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	987
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	$ 789
[1]	The carrying value includes associated deferred loan costs and any discount.

Disclosures About Fair Value 47

Disclosures About Fair Value Measurements (Company's Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative, Fair Value, Net	$ (302)	$ (379)
Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Current [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	111	13
Derivative Asset, Fair Value, Gross Liability	(88)	(13)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	23	0
Commodity Derivative Price Swap Contracts [Member] | Derivative Asset Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Asset, Fair Value, Gross Asset	29	1
Derivative Asset, Fair Value, Gross Liability	(27)	(1)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	2	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	(336)	(290)
Derivative Liability, Fair Value, Gross Asset	88	13
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(248)	(277)
Commodity Derivative Price Swap Contracts [Member] | Derivative Liability Noncurrent [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Derivative Liability, Fair Value, Gross Liability	(106)	(103)
Derivative Liability, Fair Value, Gross Asset	27	1
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(79)	(102)
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	(302)	(379)
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	111	13
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	29	1
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	(336)	(290)
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	(106)	(103)
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

Derivative Financial Instrume48

Derivative Financial Instruments (Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	$ (112)	$ 28
Gain (loss) on derivatives	(35)	286
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	(113)	31
Gain (loss) on derivatives	(33)	266
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	1	(3)
Gain (loss) on derivatives	$ (2)	$ 20

Derivative Financial Instrume49

Derivative Financial Instruments (Outstanding Commodity Derivative Contracts) (Detail) - Minimum [Member]		3 Months Ended											12 Months Ended
		Dec. 31, 2020bbl$ / bbl	Sep. 30, 2020bbl$ / bbl	Jun. 30, 2020bbl$ / bbl	Mar. 31, 2020bbl$ / bbl	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	Dec. 31, 2020bbl$ / bbl	Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU
Oil Price Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[1]									8,658,007	9,496,318	10,724,170			28,878,495
Price - Current Year | $ / bbl	[1]									53.2	53.56	53.79			53.54
Volume - Year One | bbl	[1]					6,601,000	6,950,000	7,366,500	7,849,000					28,766,500
Price - Year One | $ / bbl	[1]					53.18	53.21	53.21	53.28					53.22
Volume - Year Two | bbl	[1]	1,309,000	1,357,000	1,416,000	1,482,000								5,564,000
Price - Year Two | $ / bbl	[1]	54.62	54.62	54.6	54.59								54.61
Oil Basis Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[2]									7,757,000	8,465,000	9,492,000			25,714,000
Price - Current Year | $ / bbl	[2]									(0.89)	(0.85)	(0.81)			(0.85)
Volume - Year One | bbl	[2]					5,933,000	6,394,000	6,687,500	7,050,000					26,064,500
Price - Year One | $ / bbl	[2]					(1.01)	(0.97)	(0.96)	(0.95)					(0.97)
Volume - Year Two | bbl	[2]	2,760,000	2,760,000	2,730,000	2,730,000								10,980,000
Price - Year Two | $ / bbl	[2]	(0.08)	(0.08)	(0.08)	(0.08)								(0.08)
Natural Gas Price Swaps [Member]
Derivative [Line Items]
Volume - Current Year | MMBTU	[3]									14,778,000	15,740,000	16,979,000			47,497,000
Price - Current Year | $ / MMBTU	[3]									3.03	3.04	3.04			3.04
Volume - Year One | MMBTU	[3]					4,329,535	4,418,537	4,501,387	4,591,533					17,840,992
Price - Year One | $ / 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.

Debt (Summary Of Long-Term Debt

Debt (Summary Of Long-Term Debt) (Detail) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Credit facility		$ 0	$ 322
Unamortized original issue premium (discount), net		(5)	(6)
Senior notes issuance costs, net		(25)	(25)
Less: current portion		0	0
Total long-term debt		2,370	2,691
4.375% unsecured senior notes due 2025 [Member]
Debt Instrument [Line Items]
Unsecured senior notes	[1]	600	600
3.75% unsecured senior notes due 2027 [Member]
Debt Instrument [Line Items]
Unsecured senior notes		1,000	1,000
4.875% unsecured senior notes due 2047 [Member]
Debt Instrument [Line Items]
Unsecured senior notes		$ 800	$ 800
[1]	For each of the twelve month periods beginning on January 15, 2020, 2021, 2022, 2023 and thereafter, these notes are callable at 103.281%, 102.188%, 101.094% and 100%, respectively.

Debt (Narrative) (Detail)

Debt (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Credit Facility [Member]
Debt Disclosure [Line Items]
Line of credit maturity date	May 9, 2022
Aggregate lender commitments	$ 2,000
3.75% unsecured senior notes due 2027 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	1,000	$ 1,000
4.875% unsecured senior notes due 2047 [Member]
Debt Disclosure [Line Items]
Unsecured senior notes	$ 800	$ 800

Debt (Principal Maturities Of D

Debt (Principal Maturities Of Debt) (Detail) $ in Millions	Mar. 31, 2018USD ($)
Disclosure Debt Principal Maturities Of Debt [Abstract]
Remaining 2,018	$ 0
2,019	0
2,020	0
2,021	0
2,022	0
2,023	0
Thereafter	2,400
Total	$ 2,400

Debt (Summary Of Interest Expen

Debt (Summary Of Interest Expense) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure Debt Summary Of Interest Expense [Abstract]
Cash payments for interest	$ 18	$ 61
Net changes in accruals	12	(24)
Interest costs incurred	31	40
Less: capitalized interest	(1)	0
Total interest expense	$ 30	$ 40

Commitments And Contingencies54

Commitments And Contingencies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commitments [Line Items]
Operating leases, lease payments	$ 3	$ 3

Commitments And Contingencies55

Commitments And Contingencies (Future Commitments) (Detail) $ in Millions	Mar. 31, 2018USD ($)
Disclosure Commitments And Contingencies Future Commitments [Abstract]
Remaining 2,018	$ 32
2,019	64
2,020	55
2,021	52
2,022	21
2,023	17
Thereafter	56
Total	$ 297

Commitments And Contingencies56

Commitments And Contingencies (Future Minimum Lease Commitments Under Non-Cancellable Operating Leases) (Detail) $ in Millions	Mar. 31, 2018USD ($)
Disclosure Commitments And Contingencies Future Minimum Lease Commitments Under Non Cancellable Operating Leases [Abstract]
Remaining 2,018	$ 8
2,019	9
2,020	8
2,021	6
2,022	1
2,023	0
Thereafter	1
Total	$ 33

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disclosure Income Taxes Narrative [Abstract]
Effective tax rate	23.00%	36.00%
Previous Corporate Income Tax Rate		35.00%
Corporate Income Tax Rate, As Amended	21.00%
Excess tax benefit (deficiency) [discrete item]	$ 2	$ 7
Provisional change in deferred tax assets and liabilities			$ 398

Related Party Transactions (Sch

Related Party Transactions (Schedule Of Related Party Transactions) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Related Party Transaction [Line Items]
Ownership interest in partnership	3.50%
Partnership (Director Ownership Interest) [Member]
Related Party Transaction [Line Items]
Amounts paid	$ 1	$ 2

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Detail)	3 Months Ended
	Mar. 31, 2018
Disclosure Earnings 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%

Earnings Per Share (Reconciliat

Earnings Per Share (Reconciliation Of Earnings Attributable To Common Shares Basic And Diluted) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)		$ 835	$ 650
Participating basic earnings	[1]	(6)	(5)
Basic earnings attributable to common stockholders		829	645
Reallocation of participating earnings		0	0
Diluted earnings attributable to common stockholders		$ 829	$ 645
[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.

Earnings Per Share (Reconcili61

Earnings Per Share (Reconciliation Of The Weighted Average Common Shares Outstanding) (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Basic	147,925	146,838
Diluted	148,462	147,551
Stock Options [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	0	12
Performance Units [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	537	701

Earnings Per Share (Summary Of

Earnings Per Share (Summary Of The Common Stock Options And Restricted Stock) (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Performance Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive common shares	0	108

Subsidiary Guarantors (Condense

Subsidiary Guarantors (Condensed Consolidating Balance Sheet) (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Accounts receivable - related parties	$ 0	$ 0
Other current assets	719	592
Oil and natural gas properties, net	13,365	12,807
Property and equipment, net	246	234
Investment in subsidiaries	0	0
Other long-term assets	51	99
Total assets	14,381	13,732
LIABILITIES AND EQUITY
Accounts payable - related parties	0	0
Other current liabilities	1,109	1,165
Long-term debt	2,370	2,691
Other long-term liabilities	1,164	961
Equity	9,738	8,915
Total liabilities and stockholders' equity	14,381	13,732
Consolidation Eliminations [Member]
ASSETS
Accounts receivable - related parties	(7,733)	(8,167)
Other current assets	0	0
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	(4,355)	(3,202)
Other long-term assets	0	0
Total assets	(12,088)	(11,369)
LIABILITIES AND EQUITY
Accounts payable - related parties	(7,733)	(8,167)
Other current liabilities	0	0
Long-term debt	0	0
Other long-term liabilities	0	0
Equity	(4,355)	(3,202)
Total liabilities and stockholders' equity	(12,088)	(11,369)
Parent Company [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	8,390	8,836
Other current assets	28	6
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	4,355	3,202
Other long-term assets	25	23
Total assets	12,798	12,067
LIABILITIES AND EQUITY
Accounts payable - related parties	(657)	(669)
Other current liabilities	327	341
Long-term debt	2,370	2,691
Other long-term liabilities	1,020	789
Equity	9,738	8,915
Total liabilities and stockholders' equity	12,798	12,067
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	(657)	(669)
Other current assets	691	576
Oil and natural gas properties, net	13,348	12,192
Property and equipment, net	246	234
Investment in subsidiaries	0	0
Other long-term assets	26	76
Total assets	13,654	12,409
LIABILITIES AND EQUITY
Accounts payable - related parties	8,373	8,223
Other current liabilities	782	821
Long-term debt	0	0
Other long-term liabilities	144	166
Equity	4,355	3,199
Total liabilities and stockholders' equity	13,654	12,409
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
ASSETS
Accounts receivable - related parties	0	0
Other current assets	0	10
Oil and natural gas properties, net	17	615
Property and equipment, net	0	0
Investment in subsidiaries	0	0
Other long-term assets	0	0
Total assets	17	625
LIABILITIES AND EQUITY
Accounts payable - related parties	17	613
Other current liabilities	0	3
Long-term debt	0	0
Other long-term liabilities	0	6
Equity	0	3
Total liabilities and stockholders' equity	$ 17	$ 625

Subsidiary Guarantors (Conden64

Subsidiary Guarantors (Condensed Consolidating Statement Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements Captions [Line Items]
Total operating revenues	$ 947	$ 612
Total operating costs and expenses	75	449
Income (loss) from operations	1,022	1,061
Interest expense	(30)	(40)
Other, net	97	0
Income (loss) before income taxes	1,089	1,021
Income tax (expense) benefit	(254)	(371)
Net income (loss)	835	650
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0
Total operating costs and expenses	0	0
Income (loss) from operations	0	0
Interest expense	0	0
Other, net	(1,153)	(776)
Income (loss) before income taxes	(1,153)	(776)
Income tax (expense) benefit	0	0
Net income (loss)	(1,153)	(776)
Parent Company [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0
Total operating costs and expenses	(34)	285
Income (loss) from operations	(34)	285
Interest expense	(30)	(40)
Other, net	1,153	776
Income (loss) before income taxes	1,089	1,021
Income tax (expense) benefit	(254)	(371)
Net income (loss)	835	650
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	942	612
Total operating costs and expenses	112	164
Income (loss) from operations	1,054	776
Interest expense	0	0
Other, net	97	0
Income (loss) before income taxes	1,151	776
Income tax (expense) benefit	0	0
Net income (loss)	1,151	$ 776
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	5
Total operating costs and expenses	(3)
Income (loss) from operations	2
Interest expense	0
Other, net	0
Income (loss) before income taxes	2
Income tax (expense) benefit	0
Net income (loss)	$ 2

Subsidiary Guarantors (Conden65

Subsidiary Guarantors (Condensed Consolidating Statement Of Cash Flows) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	$ 488	$ 407
Net cash flows provided by (used in) investing activities	(93)	330
Net cash flows provided by (used in) financing activities	(395)	(19)
Net increase (decrease) in cash and cash equivalents	0	718
Cash and cash equivalents at beginning of period	0	53
Cash and cash equivalents at end of period	0	771
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	351	19
Net cash flows provided by (used in) investing activities	0	0
Net cash flows provided by (used in) financing activities	(351)	(19)
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	137	388
Net cash flows provided by (used in) investing activities	(93)	330
Net cash flows provided by (used in) financing activities	(44)	0
Net increase (decrease) in cash and cash equivalents	0	718
Cash and cash equivalents at beginning of period	0	53
Cash and cash equivalents at end of period	0	$ 771
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Financial Statements Captions [Line Items]
Net cash flows provided by (used in) operating activities	0
Net cash flows provided by (used in) investing activities	0
Net cash flows provided by (used in) financing activities	0
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, 2020MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2020MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2020MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2020MMBTUbbl$ / bbl$ / MMBTU	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	Dec. 31, 2020MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2019MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU
Oil Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[1]									8,658,007	9,496,318	10,724,170			28,878,495
Price - Current Year | $ / bbl	[1]									53.2	53.56	53.79			53.54
Volume - Year One | bbl	[1]					6,601,000	6,950,000	7,366,500	7,849,000					28,766,500
Price - Year One | $ / bbl	[1]					53.18	53.21	53.21	53.28					53.22
Volume - Year Two | bbl	[1]	1,309,000	1,357,000	1,416,000	1,482,000								5,564,000
Price - Year Two | $ / bbl	[1]	54.62	54.62	54.6	54.59								54.61
Oil Basis Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[2]									7,757,000	8,465,000	9,492,000			25,714,000
Price - Current Year | $ / bbl	[2]									(0.89)	(0.85)	(0.81)			(0.85)
Volume - Year One | bbl	[2]					5,933,000	6,394,000	6,687,500	7,050,000					26,064,500
Price - Year One | $ / bbl	[2]					(1.01)	(0.97)	(0.96)	(0.95)					(0.97)
Volume - Year Two | bbl	[2]	2,760,000	2,760,000	2,730,000	2,730,000								10,980,000
Price - Year Two | $ / bbl	[2]	(0.08)	(0.08)	(0.08)	(0.08)								(0.08)
Natural Gas Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | MMBTU	[3]									14,778,000	15,740,000	16,979,000			47,497,000
Price - Current Year | $ / MMBTU	[3]									3.03	3.04	3.04			3.04
Volume - Year One | MMBTU	[3]					4,329,535	4,418,537	4,501,387	4,591,533					17,840,992
Price - Year One | $ / MMBTU	[3]					2.86	2.86	2.86	2.86					2.86
Subsequent Event [Member] | Oil Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | bbl	[1]									417,000	659,000	729,000			1,805,000
Price - Current Year | $ / bbl	[1]									64.54	64.76	64.92			64.77
Volume - Year One | bbl	[1]					217,000	257,000	328,000	443,000					1,245,000
Price - Year One | $ / bbl	[1]					59.34	59.46	59.71	59.81					59.63
Volume - Year Two | bbl	[1]	1,104,000	1,131,000	1,185,000	1,244,000								4,664,000
Price - Year Two | $ / bbl	[1]	55.92	55.95	56.01	56.05								55.98
Subsequent Event [Member] | Oil Basis Swaps [Member]
Subsequent Event [Line Items]
Volume - Year One | bbl	[2]					644,000	644,000	637,000	630,000					2,555,000
Price - Year One | $ / bbl	[2]					(3.26)	(3.26)	(3.26)	(3.26)					(3.26)
Subsequent Event [Member] | Natural Gas Price Swaps [Member]
Subsequent Event [Line Items]
Volume - Current Year | MMBTU	[3]									3,680,000	3,680,000	1,200,000			8,560,000
Price - Current Year | $ / MMBTU	[3]									2.88	2.88	2.88			2.88
Volume - Year One | MMBTU	[3]					2,760,000	2,760,000	2,730,000	2,700,000					10,950,000
Price - Year One | $ / MMBTU	[3]					2.75	2.75	2.75	2.75					2.75
Volume - Year Two | MMBTU	[3]	1,840,000	1,840,000	1,820,000	1,820,000								7,320,000
Price - Year Two | $ / MMBTU	[3]	2.7	2.7	2.7	2.7								2.7
[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	Mar. 31, 2018	Dec. 31, 2017
Disclosure Supplementary Information Capitalized Costs [Abstract]
Proved	$ 18,907	$ 18,565
Unproved	3,116	2,702
Less: accumulated depletion	(8,658)	(8,460)
Net capitalized costs for oil and natural gas properties	$ 13,365	$ 12,807	[1]
[1]	Approximately $135 million of the balance at December 31, 2017 relates to assets held for sale that were disposed of during January 2018.

Supplementary Information (Cost

Supplementary Information (Costs Incurred For Oil And Natural Gas Producing Activities) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure Supplementary Information Costs Incurred For Oil And Natural Gas Producing Activities [Abstract]
Proved	$ 0	$ 127
Unproved	13	306
Exploration	243	235
Development	207	158
Total costs incurred for oil and natural gas properties	$ 463	$ 826