Concho Resources (CXO) 10-K 22 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Feb. 17, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		148,162,936
Entity Public Float	$ 15,544,307,866

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 53,261,000	$ 228,550,000
Accounts receivable, net of allowance for doubtful accounts:
Oil and natural gas	220,152,000	203,972,000
Joint operations and other	238,217,000	190,608,000
Derivative instruments	3,551,000	652,498,000
Prepaid costs and other	31,313,000	38,922,000
Total current assets	546,494,000	1,314,550,000
Property and equipment:
Oil and natural gas properties, successful efforts method	18,476,279,000	15,846,307,000
Accumulated depletion and depreciation	(7,389,844,000)	(5,047,810,000)
Total oil and natural gas properties, net	11,086,435,000	10,798,497,000
Other property and equipment, net	215,998,000	178,450,000
Total property and equipment, net	11,302,433,000	10,976,947,000
Funds held in escrow	43,000,000	0
Deferred loan costs, net	10,909,000	15,585,000
Intangible asset - operating rights, net	24,232,000	25,693,000
Inventory	16,303,000	19,118,000
Noncurrent derivative instruments	0	167,038,000
Other assets	175,955,000	122,945,000
Total assets	12,119,326,000	12,641,876,000
Accounts payable:
Trade	28,450,000	13,200,000
Related parties	0	0
Revenue payable	131,592,000	169,787,000
Accrued and prepaid drilling costs	359,495,000	228,523,000
Derivative instruments	82,079,000	0
Other current liabilities	151,570,000	184,910,000
Total current liabilities	753,186,000	596,420,000
Long-term debt	2,740,580,000	3,332,188,000
Deferred income taxes	766,032,000	1,630,373,000
Noncurrent derivative instruments	95,870,000	0
Asset retirement obligations and other long-term liabilities	140,965,000	140,344,000
Commitments and contingencies (Note 10)
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 authorized; 146,488,685 and 129,444,042 shares issued at December 31, 2016 and 2015, respectively	146,000	129,000
Additional paid-in capital	6,782,914,000	4,628,390,000
Retained earnings	883,195,000	2,345,641,000
Treasury stock, at cost; 429,708 and 306,061 shares at December 31, 2016 and 2015, respectively	(43,562,000)	(31,609,000)
Total stockholders' equity	7,622,693,000	6,942,551,000
Total liabilities and stockholders' equity	$ 12,119,326,000	$ 12,641,876,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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	146,488,685	129,444,042
Treasury shares	429,708	306,061

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating revenues:
Oil sales	$ 1,350,367	$ 1,539,917	$ 2,189,072
Natural gas sales	284,621	263,656	471,075
Total operating revenues	1,634,988	1,803,573	2,660,147
Operating costs and expenses:
Oil and natural gas production	451,304	541,359	538,374
Exploration and abandonments	77,454	58,847	284,821
Depreciation, depletion and amortization	1,167,208	1,223,253	979,740
Accretion of discount on asset retirement obligations	7,133	7,600	7,072
Impairments of long-lived assets	1,524,645	60,529	447,151
General and administrative (including non-cash stock-based compensation of $58,927, $63,073 and $47,130 for the years ended December 31, 2016, 2015 and 2014, respectively)	225,565	230,734	204,161
(Gain) loss on derivatives	368,684	(699,752)	(890,917)
(Gain) loss on disposition of assets, net	(117,561)	53,789	9,308
Total operating costs and expenses	3,704,432	1,476,359	1,579,710
Income (loss) from operations	(2,069,444)	327,214	1,080,437
Other income (expense):
Interest expense	(203,518)	(215,384)	(216,661)
Loss on extinguishment of debt	(56,436)	0	(4,316)
Other, net	(9,138)	(14,559)	(3,500)
Total other expense	(269,092)	(229,943)	(224,477)
Income (loss) from operations before income taxes	(2,338,536)	97,271	855,960
Income tax (expense) benefit	876,090	(31,371)	(317,785)
Net income (loss)	$ (1,462,446)	$ 65,900	$ 538,175
Earnings per share:
Basic net income (loss)	$ (10.85)	$ 0.54	$ 4.89
Diluted net income (loss)	$ (10.85)	$ 0.54	$ 4.88

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Non-cash stock-based compensation	$ 58,927	$ 63,073	$ 47,130

Consolidated Statement of Stock

Consolidated Statement of Stockholders Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
BALANCE at Dec. 31, 2013	$ 3,757,949	$ 105	$ 2,027,162	$ 1,741,566	$ (10,884)
BALANCE, Shares at Dec. 31, 2013		105,223			127
Net income (loss)	538,175	$ 0	0	538,175	$ 0
Issuance of common stock (Shares)		7,475			0
Issuance of common stock	931,989	$ 7	931,982	0	$ 0
Common stock issued in business combinations	0
Stock options exercised	4,659	$ 1	4,658	0	$ 0
Stock options exercised, shares		208			0
Grants of restricted stock, shares		448			0
Cancellation of restricted stock, shares		(89)			0
Stock-based compensation	47,130	$ 0	47,130	0	$ 0
Excess tax deficiency (benefit) related to stock-based compensation	16,480	0	16,480	0	0
Purchase of treasury stock	(15,594)	$ 0	0	0	$ (15,594)
Purchase of treasury stock, shares		0			133
BALANCE at Dec. 31, 2014	5,280,788	$ 113	3,027,412	2,279,741	$ (26,478)
BALANCE, Shares at Dec. 31, 2014		113,265			260
Net income (loss)	65,900	$ 0	0	65,900	$ 0
Issuance of common stock (Shares)		15,755			0
Issuance of common stock	1,535,712	$ 16	1,535,696	0	$ 0
Common stock issued in business combinations	0
Stock options exercised	59	$ 0	59	0	$ 0
Stock options exercised, shares		5			0
Grants of restricted stock, shares		452			0
Cancellation of restricted stock, shares		(33)			0
Stock-based compensation	63,073	$ 0	63,073	0	$ 0
Excess tax deficiency (benefit) related to stock-based compensation	2,150	0	2,150	0	0
Purchase of treasury stock	(5,131)	$ 0	0	0	$ (5,131)
Purchase of treasury stock, shares		0			46
BALANCE at Dec. 31, 2015	6,942,551	$ 129	4,628,390	2,345,641	$ (31,609)
BALANCE, Shares at Dec. 31, 2015		129,444			306
Net income (loss)	(1,462,446)	$ 0	0	(1,462,446)	$ 0
Issuance of common stock (Shares)		10,350			0
Issuance of common stock	1,327,444	$ 10	1,327,434	0	$ 0
Common stock issued in business combinations (Shares)		6,134			0
Common stock issued in business combinations	768,368	$ 6	768,362	0	$ 0
Stock options exercised	471	$ 1	470	0	$ 0
Stock options exercised, shares		23			0
Grants of restricted stock, shares		451			0
Performance unit share conversion, shares		180			0
Cancellation of restricted stock, shares		(93)			0
Stock-based compensation	58,927	$ 0	58,927	0	$ 0
Excess tax deficiency (benefit) related to stock-based compensation	(669)	0	(669)	0	0
Purchase of treasury stock	(11,953)	$ 0	0	0	$ (11,953)
Purchase of treasury stock, shares		0			124
BALANCE at Dec. 31, 2016	$ 7,622,693	$ 146	$ 6,782,914	$ 883,195	$ (43,562)
BALANCE, Shares at Dec. 31, 2016		146,489			430

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (1,462,446)	$ 65,900	$ 538,175
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	1,167,208	1,223,253	979,740
Accretion of discount on asset retirement obligations	7,133	7,600	7,072
Impairments of long-lived assets	1,524,645	60,529	447,151
Exploration and abandonments, including dry holes	66,621	43,737	265,064
Non-cash stock-based compensation expense	58,927	63,073	47,130
Deferred income taxes	(864,341)	29,622	296,167
(Gain) loss on disposition of assets, net	(117,561)	53,789	9,308
(Gain) loss on derivatives	368,684	(699,752)	(890,917)
Net settlements received from (paid on) derivatives	625,250	632,916	71,983
Loss on extinguishment of debt	56,436	0	4,316
Other non-cash items	13,942	14,639	14,063
Changes in operating assets and liabilities, net of acquisitions and dispositions:
Accounts receivable	21,958	117,716	(104,988)
Prepaid costs and other	6,063	(3,726)	(23,628)
Inventory	1,891	(5,154)	2,441
Accounts payable	15,246	(17,689)	1,566
Revenue payable	(37,588)	(68,311)	60,481
Other current liabilities	(67,620)	12,279	20,646
Net cash provided by (used in) operating activities	1,384,448	1,530,421	1,745,770
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures on oil and natural gas properties	(2,397,217)	(2,443,704)	(2,554,914)
Additions to property, equipment and other assets	(60,655)	(67,699)	(34,320)
Proceeds from the disposition of assets	331,966	104	1,305
Funds held in escrow	(43,000)	0	0
Contributions to equity method investments	(55,750)	(91,342)	(30,050)
Net cash provided by (used in) investing activities	(2,224,656)	(2,602,641)	(2,617,979)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt	600,000	1,490,900	2,081,000
Payments of debt	(1,200,000)	(1,630,400)	(2,191,500)
Debt extinguishment costs	(42,450)	0	0
Exercise of stock options	471	59	4,659
Excess tax benefit (deficiency) from stock-based compensation	(669)	2,150	16,480
Net proceeds from issuance of common stock	1,327,444	1,535,712	931,989
Payments for loan costs	(7,924)	0	(10,648)
Purchase of treasury stock	(11,953)	(5,131)	(15,594)
Increase (decrease) in bank overdrafts	0	(92,541)	55,823
Net cash provided by (used in) financing activities	664,919	1,300,749	872,209
Net increase (decrease) in cash and cash equivalents	(175,289)	228,529	0
Cash and cash equivalents at beginning of period	228,550	21	21
Cash and cash equivalents at end of period	53,261	228,550	21
SUPPLEMENTAL CASH FLOWS:
Cash paid for interest	232,173	211,443	211,342
Cash paid for income taxes	0	3,950	27,844
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of common stock for business combinations	$ 768,368	$ 0	$ 0

Organization and nature of oper

Organization and nature of operations	12 Months Ended
	Dec. 31, 2016
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 t he acquisition, development, exploration and production of oil and natural gas properties primarily located in the Permian Basin of Southeast New Mexico and West Texas.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of significant accounting policies	Note 2 . Summary of significant accounting policies Principles of consolidation. The consolidated financial statements of the Company include the accounts of the Company and its 100 percent owned subsidiaries. The Company consolidates the financial statements of these entities. All material intercompany balances and transactions have been eliminated. R eclassifications. Certain prior period amounts have been reclassified to conform to the 2016 presentation. These reclassifications had no im pact on net income (loss), total stockholders’ equity or total cash flows. Use of estimates in the preparation of financial statements. Preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from the se estimates. Depletion of oi l 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 rat es of production and the timing of development expenditures. Similarly, evaluations for impairment of proved and unproved oil and natural gas properties are subject to numerous 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 inclu de, but are not limited to, asset retirement obligations, fair value of stock-based compensation , fair value of business combinati ons, fair value of nonmonetary exchanges, fair value of de rivative financial instruments and income taxes . Cash equivalents. The Company considers all cash on hand, depository accounts held by banks, money market accounts and investments with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents are held in financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company’s cou nterparty risks are minimal based on the reputation and history of the institutions selected. Accounts receivable. The Company sells oil and natural gas to various customers and participates with other parties in the drilling, completion and operation of oil and natural gas wells. Joint interest and oil and natural gas sales receivables related to these operations are generally unsecured. The Company determines joint interest operations accounts receivable allowances based on management’s assessment of the creditworthiness of the joint interest owners and the Company’s ability to realize the receivables through netting of anticipated future production revenues. Receivables are considered past due if full payment is not received by the contr actual due date. Past due accounts are generally written off against the allowance for doubtful accounts only after all collection attempts have been exhausted. The Company had an allowance for doubtful accounts of approximately $ 1.2 million for ea ch of the years ended December 31, 2016 and 2015 . Oil and natural gas properties. The Company utilizes the successful efforts method of accounting for its oil and natural gas properties. Under this method all costs associated with productive wells and nonproductive development wells are capitalized, while nonproductive exploration costs are expensed. Capitalized acquisition costs relating to proved properties are depleted using the unit-of-production method based on proved reserves. The depletion of capitalized drilling and development costs and integ rated assets is based on the unit-of-production method using proved dev eloped reserves . During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized depletion expense from operations of $ 1,145.2 million, $ 1,203.5 million and $ 960.9 million, respectively. The Company generally does not carry the costs of drilling an exploratory well as an asset in its consolidated balance sheets following the completion of drilling unless both of the follow ing conditions are met: the well has found a sufficient quantity of reserves to justify its completion as a producing well; and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project. Due t o the capital intensive nature and the geographical location of certain projects, it may take the Company longer than one year to evaluate the future potential of the exploration well and economics associated with making a determination on its commercial v iability. In these instances, the project ’ s feasibility is not contingent upon price improvements or advances in technology, but rather the C ompany’ s ongoing efforts and expenditures related to accurately predicting the hydrocarbon recoverability based on well information, ga ining access to other companies’ production, transportation or processing facilities and/or getting partner approval to drill additional appraisal wells. These activities are ongoing and being pursued consta ntly. Consequently, the Compa ny’ s assessment of suspended exploratory well costs is continuous until a decision can be made that the well has found proved reserves or is noncommercial and is charged to exploration and abandonments expense. See Note 3 for additional in forma tion regarding the Company’ s suspended exploratory well costs. Proceeds from the sales of individual properties and the capitalized costs of individual properties sold or abandoned are credited and charged, respectively, to accumulated depletion. Generall y, no gain or loss is recognized until the entire depletion base is sold. However, gain or loss is recognized from the sale of less than an entire depletion base if the disposition is significant enough to materially impact the depletion rate of the remain ing properties in the depletion base. Ordinary maintenance and repair costs are expensed as incurred. Costs of significant nonproducing properties, wells in the process of being drilled and completed and development projects are excluded from depletion un til the related project is completed and proved developed reserves are established or , if unsuccessful, impairment is determined. The Company capitalizes interest, if debt is outstanding, on expenditures for significant development projects until such proj ects ar e ready for their intended use. The Company did not have capitalized interest related to significant oil and natural gas development projects for the year ended December 31, 2016 . During the y ears ended December 31, 2015 and 2014 , the Comp any had capitalized interest of $ 0.7 million and $ 1.4 million, respectively. The Company reviews its long-lived assets to be held and used, including proved oil and natural gas properties, whenever events or circumstances indicate that the carrying value of those assets may not be recoverable. An impairment loss is indicated if the sum of the expected future cash flows is less than the carrying amount of the assets. In this circumstance, the Company recognizes an impairment loss fo r the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company reviews its oil and natural gas properties by depletion base or by individual well for those wells not constituting part of a depletion b ase. For each property determined to be impaired, an impairment loss equal to the difference between the carrying value of the properties and the estimated fair value (discounted future cash flows) of the properties and integrated assets would be recognized at that time. Estimating future cash flows involves the use of judgments, including estimation of the proved and risk-adjusted unproved oil and natural gas reserve quantities, timing of development and production, expected future commodity prices, capital exp enditures and production costs and cash flows from integrated assets . The Compan y recognized impairment expense of $ 1,524.6 million, $ 60.5 million and $ 447.2 million during the years ended December 31, 2016 , 2015 and 2014 , respectively, related to its proved oil and natural gas properties. See Note 7 for additional in formation regarding the Company’ s impairment expense . Unproved oil and natural gas properties are periodically assessed for imp airment by consid ering future drilling and exploration plans, results of exploration activities, commodity price outlooks, planned future sales and expiration of all or a portion of the projects. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized expense of $ 59.8 million, $ 34.5 million and $ 217.3 million, respectively, related to abandoned prospects , expiring acreage and abandoned well costs , which is included in exploration an d abandonments expense in the accompanying consolidated statements of operations. Other property and equipment. Other capital assets include buildings, transportation equipment, computer equipment and software, telecommunications equipment, leasehold impr ovements and furniture and fixtures. These items are recorded at cost, or fair value if acquired, and are depreciated using the straight-line method based on expected lives of the individual assets or group of assets ranging from two to 39 years. The Compa ny had other capital assets of $ 216.0 million and $ 178.5 million, net of accumulated depreciation of $ 73.7 million and $ 54.4 million, at December 31, 2016 and December 31, 2015 , respectively. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized depreciation expense of $ 20.6 million, $ 18.3 million and $ 17.3 million, respectively. Additionally, during the year ended December 31, 2016 , the Company had capitalized interest of $0.3 million related to other property and equipment. Funds held in escrow. At December 31, 2016 , the Company’s funds held in escrow totaled $43.0 million, which consists of a deposit paid by the Company that was held in escrow for the Northern Delaware Basin acquisition that partially closed in January 2017. See Note 17 for additional information regarding the acquisition . Deferred loan costs. Deferred loan costs are stated at cost, net of amortization, which is computed using the straight-line method. The Company had deferred loan costs related to its credit facility of $ 10.9 million and $ 15.6 million, net of accumulated amortization of $ 55.7 million and $ 51.0 million, in noncurrent assets at December 31, 2016 and 2015 , respectively. Intangible assets. The Company has capitalized certain operating rights acquired in an acquisition. The gross operating rights, which have no residual value, are amortized over the estimated economic life of 25 years. Impairment will be assessed if indicators of potential impairment exist or when there is a material change in the remaining useful economic life . The following table reflects the gross and net intangible assets at December 31, 2016 and 2015 , respectively : December 31, (in thousands) 2016 2015 Gross intangible - operating rights $ 36,557 $ 36,557 Accumulated amortization (12,325) (10,864) Net intangible - operating rights $ 24,232 $ 25,693 The following table reflects amortization expense from operations for the years ended December 31, 2016 , 2015 and 2014 : Years Ending December 31, (in thousands) 2016 2015 2014 Amortization expense $ 1,461 $ 1,461 $ 1,461 The following table reflects the estimated aggregate amortization expense for each of the periods presented below at December 31, 2016 : (in thousands) 2017 $ 1,461 2018 1,461 2019 1,461 2020 1,461 2021 1,461 Thereafter 16,927 Total $ 24,232 Inventory. Inventory consists primarily of tubular goods, water and other oilfield equipment that the Company plans to utilize in its ongoing exploration and development activities and is carried at the lower of cost or market value, on a weighted average cost basis. Equity method investment s . At December 31, 2016 , the Company owned a 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 n orthern Delaware Basin. ACC commenced partial operations in late 2015 and completed construction of the pipelin e in April 2016. The Company has the option to purchase the membership interest of the other investor in ACC. This purchase option became exercis able in July 2016 and will expire after one year. During January 2017, the Company and its joint venture partner entered into separate agreements to sell 100 percent of their respective ownership interests in ACC. See Note 17 for additional in formation regarding the disposition of ACC. The Company accounts for its investment in ACC under the equity method of accounting for investments in unconsolidated affiliates. The Co mpany’s net investment in ACC was approximately $ 128.7 million and $ 98.9 million at December 31, 2016 and 2015 , respectively, and is included in other assets in the Company’s consolidated balance sheet s . The equity loss for the years ended December 31, 2016 , 2015 and 2014 was approximate ly $ 2.1 million , $ 4.1 million and $ 1.3 million , respectively, and is included in other expense in the Company’s consolidated statement s of operations. During the year ended 2016 , the Company did not capitalize any interest on its investment in ACC. During the years ended 2015 and 2014 , the Company recorded approximately $ 2.9 million and $ 0.7 million, respectively, of capitalized interest on its investment in ACC. During the year ended 2015, the Company purchased a 25 percent membership interest in an entity constructing a crude oil gathering and transportation system in the southern Delaware Basin . The initial system is operational and was substantially completed d uring 2016. The Company accounts for its investment under the equity method of accounting for investments in unconsolidated affiliates. The Company’s net investment was approximately $ 42.5 million and $ 20.8 million at December 31, 2016 and 2015 , respectively, and is included in other assets in the Company’s consolidated balance sheets. The equity loss for the year ended December 31, 2016 was approximately $ 2.1 million , and is included in other expense in the Company’s consolidated statements of operations. Environmental. The Company is subject to extensive federal, state and local environmental laws and regulations. These laws, which are often changing, regulate the discharge of materials into the environmen t and may require the Company to remove or mitigate the environmental effects of the disposal or release of petroleum or chemical substances at various sites. Environmental expenditures are expensed. Expenditures that relate to an existing condition caused by past operations and that have no future economic benefits are expensed. Liabilities for expenditures of a noncapital nature are recorded when environmental assessment and/or remediation is probable and the costs can be reasonably estimated. Such liabil ities are generally undiscounted unless the timing of cash paymen ts is fixed and readily determinable. At December 31, 2016 and 2015 , the Company has accrued approximately $ 1.4 million and $ 1.0 million, respectively, r elated to environmental liabilities. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized environmental charges of approximately $ 7.0 million, $ 2.7 million and $ 4.0 million, respectively. Senior note deferred loan costs. Deferred loan costs are stated at cost, net of amortization, which is computed using the effective interest method. The Company had deferred loan costs related to its senior notes of $ 31.6 million and $ 42.9 million, net of accumulated amortization of $ 12.1 million and $ 18.7 million, as a reduction of long-term debt at December 31, 2016 and 2015 , respectively. See Note 9 for additional information regarding 2016 activity related to the Company’s senior notes. Income taxes. The Company recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial state ment carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expe cted to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in income in the period that includes the enactment date. A valuation allowance is established to reduce deferred tax assets if it is m ore likely than not that the related tax benefits will not be realized. The Company evaluates uncertain tax positions for recognition and measurement in the cons olidated financial statements. To recognize a tax position, the Company determines whether it is more likely than not that the tax positions will be sustained upon examination, including resolution of any related appeals or litigation, based on the te chnical merits of the position. A tax position that meets the more likely than not threshold is mea sured to determine the amount of benefit to be recognized in the consol idated financial statements. The amount of tax benefit recognized with respect to any tax position is measured as the largest amount of benefit that is greater than 50 percent likely of b eing realized upon settlement. The Company had no material uncertain tax positions that required recognition in the consolidated financial statements at December 31, 2016 and 2015 . Any interest or penalties would be recognized as a component of inc ome tax expense. Derivative instruments. The Company recognizes its derivative instruments , other than any commodity derivative contracts that are designated as normal purchase and normal sale, as either assets or liabilities measured at fair value. The C ompany netted the fair value of derivative instruments by counterparty in the accompanying consolidated balance sheets where the right of offset exists. The Company does not have any derivatives designated as fair value or cash flow hedges. The Company may also enter into physical delivery contracts to effectively provide commodity price hedges. Because these contracts are not expec ted to be net cash settled, they are considered to be normal sales contracts and not derivatives. Therefore, these contracts ar e not recorded in the Company’s consolidated financial statements. Asset retirement obligations. The Company records the fair value of a liability for an asset retirement obligation in the period in which it is incurred and a corresponding increase in the carrying amount of the related long-lived asset. Subsequently, the asset retirement cost included in the carrying amount of the related asset is allocated to expense through depletion of the asset. Changes in the liability due to passage of time are gener ally recognized as an increase in the carrying amount of the liability and as corresponding accretion expense. Based on certain factors including commodity prices and costs, the Company may revise its previous estimates related to the liability, which woul d also increase or decrease the associated oil and natural gas property asset. Treasury stock. Treasury stock purchases are recorded at cost. Revenue recognition. Oil and natural gas revenues are recorded at the time of physical transfer of such products to the purchaser , which for the Company is primarily at the wellhead . The Company follows the sales method of accounting for oil and natural gas sales, recognizing revenues based on the Company’s actual proceeds from the oil and natural gas sold to purcha sers. Oil and natural gas imbalances. Oil and n atural gas imbalances are generated on properties for which two or more owners have the right to take production “in-kind” and, in doing so, take more or less than their respective entitled percentage. I mbalances are tracked by well , but the Company does not record any receivable from or payable to the other owners unless the imbalance has reached a level at which it exceeds the remaining reserves in the respective well. If reserves are insufficient to of fset the imbalance and the Company is in an overtake position, a liability is recorded for the amount of shortfall in reserves valued at a contract price or the market price in effect at the time the imbalance is generated. If the Company is in an undertak e position, a receivable is recorded for an amount that is reasonably expected to be received, not to exceed the current market value of such imbalance. The Company had no significant imbalances at December 31, 2016 or 2015 . General and administrati ve expense . The Company receives fees for the operation of jointly-owned oil and natural gas properties during the drilling and production phases and records such reimbursements as reductions of general and administrative expense. Such fees totaled approxi mately $ 16.9 million, $ 19.2 million and $ 18.9 million for the years e nded December 31, 2016 , 2015 and 2014 , respectively. Stock-based compensation. S tock-based compensation expense is recognized in the Company’ s financial statements on a n accelerated basis over the awards’ vesting periods based on their fair values on the dates of grant , net of an estimate for forfeitures . S tock-based compensation awards generally vest over a period ranging from one to eight years. The Company utilizes (i) the Black-Scholes option pricing model to measure the fair value of stock options, (ii) the average of the grant date’s high and low stock price s for the fair value of restricted stock and (iii) the Monte Carlo simulation m ethod for the fair value of performance unit awards. Recent accounting pronouncements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how rev enue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which deferred the effective date of ASU 2014-09 by one year. That new standard is now effective for annual reporting periods beginning after December 15, 2017. The Company expects to use the modified retrospective method to adopt the standard , meaning the cumulative effect of initially applying the standard will be recognized in the most current period presented in the financia l statements. The Company is substantially complete with its internal evaluation of the adoption of this standard and does not expect this new guidance will have a material impact o n its consolidated financial statements. In February 2016, the FASB issue d ASU No. 2016-02, “Leases (Topic 842),” which supersedes current lease guidance. The new lease standard requires all leases with a term greater than one year to be recognized on the balance sheet while maintaining substantially similar classifications for finance and operating leases. Lease expense recognition on the income statement 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 into lease agreements to support its operations. These agreements are for leases on assets such as office space, vehicles, field services and well equipment and drilling rigs. The Company is currently in the process of reviewing all contracts that could be applicable to this new guidance. The Company believes this new guidance will have a moderate impact to its consolidated balance sheet due to the recognition of lease-related assets and liabilities that were not previously recognized. In March 2016, the FASB issued ASU No. 2016-09, “Compensation–Stock Compensations (Topic 718): Improvements to Employee Share-based Payment Accounting,” which changes the accounting and presentation for share-based payment arrangements in the following areas: (i) recognition in the statement of operations of excess tax benefits and deficiencies; (ii) cash flow presentation of excess tax benefits and deficiencies; (iii) minimum statutory withholding thresholds and the classi fication on the cash flow statement of the withheld amounts; and (iv) an accounting policy election to recognize forfeitures as they occur. This guidance is effective for reporting periods beginning after December 15, 2016 and early adoption is permitted. The Company will adopt ASU No. 2016-09 during the first quarter of 2017. The adoption will not have a material impact on prior period consolidated financial statements. The Company will elect to account for forfeitures of share-based payments as they occ ur. As of December 31, 2016, the Company had not recorded compen sation expense of approximately $8.2 million for its forfeiture estimate. The Company will prospectively classify excess tax benefits and deficiencies as operating activities on the consolidat ed statement of cash flows and will prospectively record as a discrete item in the income tax provision in the consolidated income statement. The Company will also recognize all excess tax benefits not previously realized, which totaled approximately $4.7 million as of December 31, 2016. Upon adoption, the Company will record a cumulative-effect adjustment, which will decrease retained earnings by approximately $0.5 million, increase additional paid-in capital by approximately $8.2 million, and decrease net deferred income taxes by approximately $7.7 million. In June 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” meth odology for recognizing credit losses with an “expected loss” methodology. This new methodology 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 ti mely decision-useful information about the expected credit losses on financial instruments. This 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, 2 018. The Company does not believe this new guidance will have a material impact on its consolidated financial statements.

Exploratory well costs

Exploratory well costs	12 Months Ended
	Dec. 31, 2016
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. The capitalized explo ratory well costs are carried in unproved oil and natural gas properties. See Unaudited Supplementary Data 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 ch arged to exploration and abandonments expense in the consolidated statements of operations. The following table reflects the Company’s net capitalized exploratory well activity during each of the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Beginning capitalized exploratory well costs $ 116,198 $ 241,657 $ 144,504 Additions to exploratory well costs pending the determination of proved reserves 143,981 102,846 234,057 Reclassifications due to determination of proved reserves (85,985) (227,746) (99,657) Exploratory well costs charged to expense (5,707) (559) (37,247) Disposition of wells (17,339) - - Ending capitalized exploratory well costs $ 151,148 $ 116,198 $ 241,657 The following table provides an aging at December 31, 2016 and 2015 of capitalized exploratory well costs based on the date drilling was completed: December 31, (dollars in thousands) 2016 2015 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 141,595 $ 98,764 Capitalized exploratory well costs that have been capitalized for a period greater than one year 9,553 17,434 Total capitalized exploratory well costs $ 151,148 $ 116,198 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 8 8 Northern Delaware Basin project . At December 31, 2016 , the Company had approximately $ 4.9 million of suspended well costs grea ter than one year recorded for a well drilled in the third quarter of 2015. The Company expects to complete this well in the first quarter of 2017. Midland Basin project . At December 31, 2016 , the Company had approximately $ 1.7 million of suspended well costs grea ter than one year recorded for a well drilled in the third quarter of 2015. The Company expects to complete this well in 2017. Projects operated by others. At December 31, 2016 , the Company had approximately $ 3.0 million of suspended well costs greater than one year recorded for six wells that are operated by others and waiti ng on completion. Two of these wells completed drilling in 2014 and the remaining four wells completed drilling in 2015.

Acquisitions and divestitures

Acquisitions and divestitures	12 Months Ended
	Dec. 31, 2016
Acquisitions and Divestitures [Abstract]
Acquisitions and divestitures	Note 4 . Acquisitions and divestitures Reliance acquisition. In October 2016, the Company completed an acquisition of approxi mately 40,000 net acres in the n orthern Midland Basin and other assets from Reliance Energy, Inc. (collectively, the “Reliance Acquisition”) for approximately $1.7 billion. As consideration for the acquisition, the Company paid approximately $1.2 billion in cash and issued to the seller approximately 3.9 million shares of common stock with an approxima te value of $0.5 billion. Approximately $29.2 million of operating revenues and approximately $9.6 million of income from operations attributed to the Reliance Acquisition are included in the Company’s results of operations since the closing date in Octob er 2016. The following table reflects the fair value of the acquired assets and liabilities associated with the Reliance Acquisition: (in thousands) Fair value of net assets: Proved oil and natural gas properties $ 729,814 Unproved oil and natural gas properties 972,236 Other assets 34,000 Total assets acquired 1,736,050 Current liabilities, including current portion of asset retirement obligations (8,225) Asset retirement obligations assumed (12,250) Fair value of net assets acquired $ 1,715,575 Fair value of consideration paid for net assets: Cash consideration $ 1,175,708 Non-cash consideration, including equity 539,867 Total consideration paid for net assets $ 1,715,575 Southern Delaware Basin acquisition. In March 2016, the Company completed an acquisition of 80 percent of a third-party seller’s interest in certain oil and natural gas properties and related assets in the southern Delaware Basin. As consideration for the acquisition, the Company issued to the seller approximately 2.2 million shares of common stock with an approximate value of $230.8 million, $145.7 million in cash and $40.0 million to carry a portion of the seller’s future development costs in these prope rties. Pro forma data. The following unaudited pro forma combined condensed financial data for the years ended December 31, 2016 and 2015 , were derived from the historical financial statements of the Company giving effect to the Reliance Acquisitio n, as if it had occurred on January 1, 2015 . The results of operations for the Reliance Acquisition are included in the Company’s results of operations since the closing in October 2016 through December 31, 2016 . The pro forma financial data does not include the results of operations for the southern Delaware Basin acquisition, as it was primarily an acreage acquisition and its results were not deemed material. The unaudited pro forma combined condensed financial data has been included for comparative purposes only and is not necessarily indicative of the results that might have occurred had the Reliance Acquisition taken place as of the date indicated and is not intended to be a projection of future results . Years Ended December 31, (in thousands, except per share amounts) 2016 2015 (unaudited) Operating revenues $ 1,717,460 $ 1,976,356 Net income (loss) $ (1,396,250) $ 97,354 Earnings per common share: Basic net income (loss) $ (10.36) $ 0.81 Diluted net income (loss) $ (10.36) $ 0.80 Asset divestiture. In February 2016, the Company sold certain assets in the northern Delaware Basin for proceeds of approximately $292.0 million and recognized a pre-tax gain of approximately $110.1 million. Clayton Williams Acreage Exchange. In December 2015, the Company completed a nonmonetary acreage exchange with Clayton Williams Energy, Inc. that consolidated acres into a concentrated, operated position in the southern Delaware Basin. The Company recognized a loss on disposition of assets of approxim ately $50.0 million related to the acreage exchange based on the fair value of the assets surrendered.

Asset retirement obligations

Asset retirement obligations	12 Months Ended
	Dec. 31, 2016
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligations	Note 5 . Asset retirement obligations The Company’s asset retirement obligations represent the estimated present value of the estimated cash flows the Company will incur to plug, abandon and remediate its producing properties at the end of their productive lives, in accordance with applicable state laws . Market risk premiums associated with asset retirement obligations are estimated to repre sent a component of the Company’ s credit-adjusted risk-free rate that is utilized in the calculations o f ass et retirement obligations. The Company’s asset retirement obligation transactions during the years ended December 31, 2016 , 2015 and 2014 are summarized in the table below: Years Ended December 31, (in thousands) 2016 2015 2014 Asset retirement obligations, beginning of period $ 119,945 $ 119,881 $ 101,593 Liabilities incurred from new wells 2,113 4,052 5,324 Liabilities assumed in acquisitions 13,217 2,434 4,065 Accretion expense 7,133 7,600 7,072 Disposition of wells (10,955) - - Liabilities settled upon plugging and abandoning wells (1,063) (2,736) (2,926) Revision of estimates (a) - (11,286) 4,753 Asset retirement obligations, end of period $ 130,390 $ 119,945 $ 119,881 (a) The downward revision to the Companyʼs asset retirement obligation estimates for the year ended December 31, 2015 is primarily due to a reduction in the future estimated abandonment costs.

Incentive plans

Incentive plans	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Incentive plans	Note 6 . Incentive plans Defined contribution plan. The Company sponsors a 401(k) defined contribution plan for the benefit of substantially all employees. During the years ended December 31, 2016 , 2015 and 2014 , the Company matched 100 percent of employee contributions, not to exceed 10 percent of the employee’s annual salary. The Company’s contributions to the plan were approximately $ 9.5 million for each of the years ended December 31, 2016 and 2015 and approximately $ 8.1 million for the year ended December 31, 2014 , of which a portion was recoverable from other working interest owners. Stock incentive plan. The Company’s 2015 Stock Incentiv e Plan (the “Plan”) provides for granting stock options, restricted stock awards and performance awards to directors, officers and employees of the Company. A total of 10.5 million shares of common stock have been authorized for issuance under the Plan. At December 31, 2016 , the Company had 2.4 million shares of common stock available for future grant. Restricted stock awards. All restricted shares are legally issued and outstanding . If an employee terminates employment prior to the restriction lapse date, the awarded shares are forfeited and cancelled and are no longer considered issued and outstanding. A summary of the Company’s restricted stock award activity for the year ended D ecember 31, 2016 is presented below: Weighted Average Number of Grant Date Restricted Fair Value Shares Per Share Restricted stock: Outstanding at December 31, 2015 1,199,647 $ 110.14 Shares granted 450,981 $ 112.78 Shares cancelled / forfeited (93,018) $ 117.70 Lapse of restrictions (400,340) $ 96.48 Outstanding at December 31, 2016 1,157,270 $ 115.29 For restricted stock awards granted, stock-based compensation expense is being recognized in the Company’ s financial statements on a n accelerated basis over the awards’ vesting periods based on their fair values on the dates of grant. The restricted stock-based compensation awards generally vest over a period ranging from one to five years . The Company utilizes the average of the grant date’s high and low stock price s for the fair value of restricted stock. The following table summarizes information about stock-based compensation for the Company’s restricted stock awards activity under the Plan for years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Fair value for awards granted during the period (a) $ 50,863 $ 49,659 $ 57,940 Fair value for awards vested during the period $ 44,881 $ 35,700 $ 59,226 Stock-based compensation expense from restricted stock $ 40,801 $ 43,185 $ 36,585 Income tax benefit related to restricted stock $ 14,970 $ 16,049 $ 13,672 (a) The weighted average grant date fair value per share amounts were $112.78, $109.76, and $129.12 for the years ended December 31, 2016, 2015 and 2014, respectively. Stock option awards. A summary of the Company’s stock option award activity under the Plan for the year ended December 31, 2016 is presented below: Weighted Average Number of Exercise Options Price Stock options: Outstanding at December 31, 2015 42,901 $ 18.10 Options exercised (22,901) $ 20.52 Outstanding at December 31, 2016 20,000 $ 15.33 Vested and exercisable at December 31, 2016 20,000 $ 15.33 The intrinsic value of options exercised during 2016 , 2015 and 2014 was approximately $ 2.3 million , $ 0.4 million and $ 23.2 million, respectively, based on the difference between the market price at the exercise date and the option exercise price. The following table summarizes information about the Company’s vested and exercisable stock options outstanding at December 31, 2016 : December 31, 2016 Weighted Intrinsic Average Weighted Value Remaining Average of Exercise Number Contractual Exercise Options Prices Vested Life Price (in thousands) Vested and exercisable options: $12.85 15,000 0.62 years $ 12.85 $ 1,812 $22.77 5,000 1.81 years $ 22.77 554 20,000 0.92 years $ 15.33 $ 2,366 The following table shows the deductions in current taxable income related to stock options exercised for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Deductions in current taxable income related to stock options exercised $ 271 $ 415 $ 23,208 Performance unit awards. During the years ended December 31, 2016 , 2015 and 2014 , the Company awarded performance units to its officers under the Plan. The number of shares of common stock that will ultimately be issued 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 grant date fair value was determined using the Monte Carlo simulation method and is being expensed ratably over the performance period. Expected volatilities utilized in the model were es timated using a historical period consistent with the remaining performance period of approximately three years. The risk-free interest rate was based on the United States Treasury rate for a term commensurate with the expected life of the grant. The Company used the following assumptions to estimate the fair value of performance unit awards granted during the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, 2016 2015 2014 Risk-free interest rate 1.31% 1.07% 0.76% Range of volatilities 31.6% - 59.0% 26.1% - 43.0% 29.2% - 42.2% The following table summarizes the performance unit activity for the year ended December 31, 2016 : Number of Grant Date Units Fair Value Performance units: Outstanding at December 31, 2015 315,755 $ 149.21 Units granted (a) 161,361 $ 114.81 Units forfeited (9,285) 140.66 Units vested (b) (136,305) $ 139.54 Outstanding at December 31, 2016 331,526 $ 136.68 (a) Reflects the amount of performance units granted. The actual payout of shares will be between zero and 300 percent of the performance units granted depending on the Company’s performance at the end of the performance period. (b) On December 31, 2016, the performance period ended for these performance units. Each unit converted into 1.825 shares representing 248,763 shares of common stock issued on January 2, 2017. The following table summarizes information about stock-based compensation expense for performance units for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Fair value for awards granted during the period (a) $ 18,526 $ 27,659 $ 19,455 Fair value for awards vested during the period $ 33,247 $ 16,458 $ - Stock-based compensation expense from performance units $ 18,126 $ 19,888 $ 10,545 Income tax benefit related to performance units $ 6,650 $ 7,391 $ 3,941 (a) The weighted average grant date fair value per unit amounts were $114.81, $156.86 and $139.54 for the years ended December 31, 2016, 2015 and 2014, respectively. Future stock-based compensation expense. The following table reflects the future stock-based compensation expense to be recorded for all the stock-bas ed compensation awards that we re outstanding at December 31, 2016 : Restricted Performance (in thousands) Stock Units Total 2017 $ 31,622 $ 13,369 $ 44,991 2018 17,140 5,469 22,609 2019 5,341 - 5,341 2020 423 - 423 2021 85 - 85 Thereafter 197 - 197 Total $ 54,808 $ 18,838 $ 73,646

Disclosures about fair value of

Disclosures about fair value of financial instruments	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Disclosures about fair value of financial instruments	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 for 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 : P rices or valuation m odels that require 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 consi der various inputs 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 December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 Carrying Fair Carrying Fair (in thousands) Value Value Value Value Assets: Derivative instruments $ 3,551 $ 3,551 $ 819,536 $ 819,536 Liabilities: Derivative instruments $ 177,949 $ 177,949 $ - $ - $600 million 7.0% senior notes due 2021 (a) $ - $ - $ 592,414 $ 595,500 $600 million 6.5% senior notes due 2022 (a) $ - $ - $ 591,549 $ 579,000 $600 million 5.5% senior notes due 2022 (a) $ 593,787 $ 619,500 $ 592,899 $ 553,500 $1,550 million 5.5% senior notes due 2023 (a) $ 1,554,710 $ 1,621,382 $ 1,555,326 $ 1,453,005 $600 million 4.375% senior notes due 2025 (a) $ 592,083 $ 598,800 $ - $ - (a) The carrying value includes associated deferred loan costs and any premium. Cash and cash equivalents, accounts receivable, other current assets, accounts payable, interest payable and other current liabilities. The carrying amounts approximate fair value due to the short maturity of these instruments. 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. 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 tables 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 December 31, 2016 and 2015 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. December 31, 2016 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in thousands) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets Current: Commodity derivatives $ - $ 58,351 $ - $ 58,351 $ (54,800) $ 3,551 Noncurrent: Commodity derivatives - 62 - 62 (62) - Liabilities Current: Commodity derivatives - (136,879) - (136,879) 54,800 (82,079) Noncurrent: Commodity derivatives - (95,932) - (95,932) 62 (95,870) Net derivative instruments $ - $ (174,398) $ - $ (174,398) $ - $ (174,398) December 31, 2015 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in thousands) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets Current: Commodity derivatives $ - $ 684,029 $ - $ 684,029 $ (31,531) $ 652,498 Noncurrent: Commodity derivatives - 175,267 - 175,267 (8,229) 167,038 Liabilities Current: Commodity derivatives - (31,531) - (31,531) 31,531 - Noncurrent: Commodity derivatives - (8,229) - (8,229) 8,229 - Net derivative instruments $ - $ 819,536 $ - $ 819,536 $ - $ 819,536 Concentrations of credit risk. At December 31, 2016 , the Company ’ s primary concentration s of credit risk are the risk of collec ting accounts receivable and the risk of counterparties ’ failure to perform under de rivative obligations. See Note 12 for in formation regarding the Company’ s major customers and derivative counterparties . The Company has entered into International Swap Dealers Association Master Agreements ( “ ISDA Agreements ” ) with each of its derivative counterparties. The te rms 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 Note 8 for additional information regarding the Company ’ s derivative activities. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain assets and liabilities are reported at fair value on a nonrecurring basis in the Company’s consolidated balance sheets. The following methods and assumptions were used to estimate the fair values: Impairments of long-lived assets – The Company periodical ly reviews its long-lived assets to be held and used, including proved oil and natural gas properties and their integrated assets, whenever events or circumstances indicate that the carrying value of those assets may not be recoverable, for instance when t here are declines in commodity prices or well performance. The Company reviews its oil and natural gas properties by depletion base. An impairment loss is indicated if the sum of the expected undiscounted future net cash flows is less than the carrying amo unt of the assets. If the estimated undiscounted future net cash flows are less than the carrying amount of the Company’s assets, it recognizes an impairment loss for the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company calculates the expected undiscounted future net cash flows of its long-lived assets and their integrated assets using management’s assumptions and expectations of (i) commodity prices, which are based on the New York Mercantile Exc hange (“NYMEX”) strip, (ii) pricing adjustments for differentials, (iii) production costs, (iv) capital expenditures, (v) production volumes, (vi) estimated proved reserves and risk-adjusted probable and possible reserves, and (vii) prevailing market rates of income and expenses from integrated assets. At December 31, 2016 , the Company’s estimates of commodity prices for purposes of determining undiscounted future cash flows, which are based on the NYMEX strip, ranged from a 2017 price of $ 56.19 per barr el of oil to a 2024 price of $ 57.41 per barrel of oil . Similarly, gas prices ranged from a 2017 price of $ 3.61 per Mcf of natural gas decreasing to a 2020 price of $2.88 per Mcf partially recovering to a 2024 price of $ 3.38 per Mcf of natural gas. Commodit y prices for this p urpose were held flat after 2024 . The Company calculates the estimated fair values of its long-lived assets and their integrated assets using a discounted future cash flow model. Fair value assumptions associated with the calculation o f discounted future net cash flows include (i) market estimates of commodity prices, (ii) pricing adjustments for differentials, (iii) production costs, (iv) capital expenditures, (v) production volumes, (vi) estimated proved reserves and risk-adjusted pro bable and possible reserves, (vii) prevailing market rates of income and expenses from integrated assets and (viii) discount rate. The expected future net cash flows were discounted using an annual rate of 10 percent to determine fair value. These are clas sified as Level 3 fair value assumptions. During the three months ended March 31, 2016, NYMEX strip prices declined as compared to December 31, 2015, and as a result the carrying amount of the Company’s Yeso field of approximately $3.4 billion exceeded t he expected undiscounted future net cash flows resulting in a non-cash charge against earnings of approximately $ 1.5 billion. The non-cash charge represented the amount by which the carrying amount exceeded the estimated fair value of the asse ts. The following table reports the carrying amount, estimated fair value and impairment expense of long-lived assets for the indicated period s : Estimated Carrying Fair Value Impairment (in thousands) Amount (Level 3) Expense March 2016 $ 3,437,612 $ 1,912,967 $ 1,524,645 December 2015 $ 104,982 $ 52,041 $ 52,941 September 2015 $ 18,023 $ 10,435 $ 7,588 December 2014 $ 677,021 $ 245,346 $ 431,675 September 2014 $ 26,790 $ 11,314 $ 15,476 It is reasonably possible that the estimate of undiscounted future net cash flows of the Company’s long-lived assets may change in the future resulting in the need to impair carrying values. The primary factors that may affect estimates of future cash flows are (i) commodity prices including differentials, (ii) increases or decreases in production and capital costs, (iii) future reserve volume adjustments, both positive and negative, to proved reserves and appropriate risk-adjusted probable and possible reserves, (iv) results of future drilling activities and (v) changes in income and expenses from integrated assets.

Derivative financial instrument

Derivative financial instruments	12 Months Ended
	Dec. 31, 2016
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 may also enter into physical delivery contracts to effectively provide commodity price hedges. Because these physical delivery contracts are not expected to be net cash settled, they are considered to be n ormal sales contracts and not derivatives. Therefore, these contracts are not recorded in the Company’s consolidated financial statements. The 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 statem ents of operations as they occur. The followin g table summarizes the amounts r eported in earnings related to the commodity derivative instruments for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Gain (loss) on derivatives: Oil derivatives $ (337,175) $ 675,303 $ 869,421 Natural gas derivatives (31,509) 24,449 21,496 Total $ (368,684) $ 699,752 $ 890,917 The following table represents the Company’s net cash receipts from (payments on) derivatives for the years ended December 31, 2016, 2015 and 2014: Years Ended December 31, (in thousands) 2016 2015 2014 Net cash receipts from (payments on) derivatives: Oil derivatives $ 608,847 $ 597,297 $ 76,335 Natural gas derivatives 16,403 35,619 (4,352) Total $ 625,250 $ 632,916 $ 71,983 Commodity derivative contracts at December 31, 2016 . The following table sets forth the Company’s outstanding derivative contracts at December 31, 2016 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at December 31, 2016 are expected to settle by December 31, 2018 . First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Swaps: (a) 2017: Volume (Bbl) 7,020,870 6,348,480 5,854,370 5,465,080 24,688,800 Price per Bbl $ 57.00 $ 57.66 $ 51.25 $ 51.48 $ 54.58 2018: Volume (Bbl) 5,139,629 4,864,170 4,624,318 4,418,007 19,046,124 Price per Bbl $ 51.63 $ 51.46 $ 51.28 $ 51.12 $ 51.38 Oil Basis Swaps: (b) 2017: Volume (Bbl) 6,603,000 6,141,500 5,290,000 5,290,000 23,324,500 Price per Bbl $ (1.00) $ (1.03) $ (0.49) $ (0.49) $ (0.78) 2018: Volume (Bbl) 2,340,000 2,366,000 2,392,000 2,392,000 9,490,000 Price per Bbl $ (0.98) $ (0.98) $ (0.98) $ (0.98) $ (0.98) Natural Gas Swaps: (c) 2017: Volume (MMBtu) 14,461,315 13,289,642 12,365,441 11,743,000 51,859,398 Price per MMBtu $ 3.07 $ 3.05 $ 3.05 $ 3.04 $ 3.06 2018: Volume (MMBtu) 5,506,000 5,216,000 5,029,000 4,844,000 20,595,000 Price per MMBtu $ 3.04 $ 3.04 $ 3.03 $ 3.03 $ 3.03 (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. Other than prov ided by the Company’s credit facility, 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. Un der the terms of the Company’s credit f acility, certain events could occur that would cause any obligations under the Company’s credit f acility to no longer be secured by the Company’s oil and natural gas properties. In this circumstance, the Company has c ertain agreements in place with the Company’s derivative counterparties that would regulate collateral related to derivative transactions. See additional information in Note 12.

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt	Note 9 . Debt The Company’s debt consisted of the following at December 31, 2016 and 2015 : December 31, (in thousands) 2016 2015 Credit facility $ - $ - 7.0% unsecured senior notes due 2021 - 600,000 6.5% unsecured senior notes due 2022 - 600,000 5.5% unsecured senior notes due 2022 600,000 600,000 5.5% unsecured senior notes due 2023 1,550,000 1,550,000 4.375% unsecured senior notes due 2025 600,000 - Unamortized original issue premium 22,173 25,073 Senior notes issuance costs, net (31,593) (42,885) Less: current portion - - Total long-term debt $ 2,740,580 $ 3,332,188 Credit facility. The Company’s credit facility, as amended and restated (the “Credit Facility”), has a maturity date of May 9 , 2019 . A t December 31, 2016 , the Company’s commitments from its bank group were $2.5 billion. The Company expects it will maintain its $2.5 billion in commitments until its next schedul ed redetermination in May 2017. At December 31, 2016 , t he Company’s borrowing base wa s $ 2.8 billion. Between scheduled borrowing base redeterminations, the Company and the lenders (requiring a 66 2/3 percent vote), may each request one special redetermination. Advances on the Credit Facility bear interest, at the Company’s option, based on (i) the prime rate of JPMorgan Cha se Bank (“JPM Prime Rate”) (3.75 percent at December 31, 2016 ) or (ii) a Eurodollar rate (substantially equal to the LIBOR ). At December 31, 2016 , the interest rates of Eurodollar rate advances and JPM Prime Rate advances varied, with i nterest margins ranging from 125 to 225 basis points and 25 to 1 25 basis points pe r annum, respectively, depending on the balance outstanding on the Credit Facility . During the years ended December 31, 2016 , 2015 and 2014 , the Company incurred commitment fees on the unused portion of the available commitments of $ 7.6 million, $ 7.0 million and $ 7.7 million, respectively. Under the current Credit Facility, commitment fees range from 3 0 to 37.5 basis points per annum. The Company had $ 2.5 billion of unused commitments under it s credit facility at December 31, 2016 . The Company’s obligations under the Credit Facility are secured by a first lien on substantially all of its oil and natural gas properties. Under the terms of the Credit Facility , if the Compa ny receives certain upgrades to its credit rating, any obligations under the Credit Facility could no longer be secured by the Company’s oil and natural gas properties based on certain provisions. At December 31, 2016 , certain of the Company’s subsidiaries are guarantors and have had their equity pledged to secure borrowings under the Credit Facility. The Credit Facility contains various restrictive covenants and compliance requirements which include: maintenance of a quarterly ratio of total debt to consolidated earnings before interest expense , income taxes, depletion, depreciation, and amortization, exploration expense and other noncash income and ex penses to be no greater than 4.25 to 1.0 ; limits on the incurrence of certain indebtedness and certain types of liens; restrictions as to mergers, combinations and dispositions of assets; and limits on the payment of cash dividends. Senior notes. Interest on the Company’s senior notes is paid in arrears semi-annually. The senior no tes are fully and unconditionally guaranteed on a senior unsecured basis by certain subsidiaries of the Company, subject to customary release provisions as described in Note 16. In December 2016, the Company issued $600 million in aggregate pri ncipal amount of 4.375% senior notes due 2025 at par, for which it received net proceeds of approximately $592.1 million. The Company used the net proceeds from the offering to fund the satisfaction and discharge of its obligations under the indenture of t he $600 million outstanding principal amount of its 6.5% unsecured senior notes due 2022 (the “6.5% Notes”) at a price equal to 103.25 percent of par. The early extinguishment price included the make-whole premium as determined in accordance with the inden ture governing the 6.5% Notes. In December 2016, the Company also paid interest of approximately $19.6 million on the 6.5% Notes through January 16, 2017 . The Company recorded a loss on exting uishment of debt related to the 6.5% Notes of approximately $28. 7 million for the year ended December 31, 2016 . This amount includes $19.5 million associated with the make-whole premium paid for the early extinguishment of th e notes, approximately $7.3 million of unamortized deferred loan costs and approximately $1 .9 million of additional interest on the 6.5% Notes through January 16, 2017 , which was paid in December 2016. In September 2016, the Company redeemed the $600 million outstanding principal amount of its 7.0% unsecured senior notes due 2021 (the “7.0% Not es”) at a price equal to 103.5 percent of par. The redemption price included the make-whole premium for the early redemption, as determined in accordance with the indenture governing the 7.0% Notes. The Company also paid accrued and unpaid interest on the 7.0% Notes through September 19, 2016, the redemption date. The Company recorded a loss on extinguishment of debt related to the redemption of the 7.0% Notes of approximately $ 27.7 million for the year ended December 31, 2016 . This amount includes $21.0 million associated with the make-whole premium paid for the early redemption of the notes and approximately $6.7 million of unamortized deferred loan costs. At December 31, 2016 , the C ompany was in compliance with the covenants u nder all of its debt instruments . Principal maturities of long-term debt. Principal maturities of long -term debt outstanding at December 31, 2016 were as follows: (in thousands) 2017 $ - 2018 - 2019 - 2020 - 2021 - Thereafter 2,750,000 Total $ 2,750,000 Interest expense. The following amounts have been incurred and charged to interest expense for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Cash payments for interest $ 232,173 $ 211,443 $ 211,342 Amortization of original issue premium (2,900) (2,747) (2,599) Amortization of deferred loan origination costs 9,937 9,971 10,937 Accretion expense 1,939 1,795 - Net changes in accruals (37,379) (165) (737) Interest costs incurred 203,770 220,297 218,943 Less: capitalized interest (252) (4,913) (2,282) Total interest expense $ 203,518 $ 215,384 $ 216,661

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Note 10 . Commitments and contingencies Severance agreements. The Company has entered into severance and change in control agreements with all of its officers. The current annual salaries for the Company’s officers covered under such agreements total approximately $ 7.4 million. Indemnifications . The Company has agreed to indemnify its directors and officers with respect to claims and damages arising from certain acts or omi ssions taken in such capacity. Legal actions . The Company is a party to proceedings and claims 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 Company will continue to evaluate proceedings and cla ims 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 interest audits . The Company is subject to routin e 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 a rise 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 product ion from their leases, allowable costs under joint interest arrangements and other matters. At December 31, 2016 and 2015 , the Company h ad $ 7.1 million and $ 13.4 million, respectively , accrued for estimated exposure. Al though the Company believes 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 relate to purchase agreements the Company has entered into including drilling commitments, water commitment agreements, throughput volume delivery commitments, power commitments , fixed asset commitment s and maintenance commitments. The following table summariz es the Company’s commitments at December 31, 2016 : (in thousands) 2017 $ 56,649 2018 69,195 2019 49,327 2020 24,669 2021 20,770 Thereafter 97,869 Total $ 318,479 Operating leases. The Company leases vehicles, equipment and office facilities under non-cancellable operating leases. Lease payments associated with these operating leases for the years ended December 31, 2016 , 2015 and 2014 were approximately $ 8.4 million , $ 8.0 million and $ 7.2 million, respectively . Future minimu m lease commitments under non-cancellable operating leases at December 31, 2016 were as follows: (in thousands) 2017 $ 8,988 2018 7,945 2019 6,419 2020 4,966 2021 4,088 Thereafter 1,002 Total $ 33,408

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income taxes	Note 11 . Income taxes The Company uses an asset and liability approach for financial accounting and reporting for income taxes. The Company’s objectives of accounting for income taxes are to recognize (i) the amount of taxes payable or refundable for the current year and (ii) deferred tax liabilities and assets for the future tax consequences of events that have been recognized in its financial statements or tax returns. The Company and its subsidiaries file a federal corporate income tax return o n a consolidated basis. The tax returns and the amount of taxable income or loss are subject to examination by federal and state taxing authorities. At December 31, 2016 , the Company had current income taxes receivable of approximately $ 4.5 million. At December 31, 2015 , the Company had current income taxes receivable of approximately $ 37.3 million and current income taxes payable of approximately $ 1.0 million. At December 31, 2016 , the Company did not have any significant uncertain tax positions requiring recognition in the financial statements. The tax years 2013 through 2016 remain subject to examination by the major tax jurisdictions. Income tax expense (benefit) . The Company’s income tax expense (benefit) and amounts separately allocated were attributable to the following items for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Consolidated statements of operations: Income tax expense (benefit) from operations $ (876,090) $ 31,371 $ 317,785 Consolidated statements of stockholders' equity: Excess tax deficiency (benefit) related to stock-based compensation 669 (2,150) (16,480) $ (875,421) $ 29,221 $ 301,305 The Company’s income tax expense (benefit) attributable to income (loss) from operations consisted of the following for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Current: U.S. federal $ (11,579) $ 127 $ 16,621 U.S. state and local (170) 1,622 4,997 Total current income tax expense (benefit) (11,749) 1,749 21,618 Deferred: U.S. federal (770,734) 40,364 278,615 U.S. state and local (93,607) (10,742) 17,552 Total deferred income tax expense (benefit) (864,341) 29,622 296,167 Total income tax expense (benefit) attributable to income from operations $ (876,090) $ 31,371 $ 317,785 The reconciliation between the income tax expense (benefit) computed by multiplying pre-tax income (loss) from operations by the United States federal statutory rate and the reported amounts of income tax expense (benefit) from operations is as follows: Years Ended December 31, (in thousands) 2016 2015 2014 Income (loss) at U.S. federal statutory rate $ (818,488) $ 34,045 $ 299,586 State income taxes (net of federal tax effect) (40,015) 3,071 22,826 Revisions of previous estimates 746 (631) 738 Change in estimated effective statutory state income tax (20,909) (9,026) (7,945) Nondeductible expense & other 2,576 3,912 2,580 Income tax expense (benefit) $ (876,090) $ 31,371 $ 317,785 Effective tax rate (37.5)% 32.3% 37.1% The Company monitors changes in enacted tax rates for the jurisdictions in which it operates. The Company monitors its state tax apportionment footprint and makes updates for changes in its projected activity, including changes in budgets and drilling plans. During 2013, the state of New Mexico passed legislation to phase in a tax rate reduction over the next five years. In June of 2015, the State of Texas enacted legislation to reduce its rate. In October 2016, the Company purchased Texas-based assets in the Reliance Acquisition for approximately $1.7 billion, which caused a shift in the Company’s projected future apportion ment from New Mexico to Texas. Therefore, based upon the Company’s projected future activity for the states in which it conducts bus iness, the timing for when it anticipates its deferred tax items to become taxable and enacted tax rates at such time deferred items become taxable, the Company has revised its estimated state rate and recorded an additional deferred state tax benefit of $ 20.9 million, $9.0 million and $7.9 million during 2016, 2015 and 2014, respectively. The Company’s effective tax rate increased in 2016 as compared with 2015 primarily due to a shift from pre-tax earnings of $97.3 million in 2015 to a pre-tax loss of $2. 3 billion in 2016, resulting in a less pronounced effect on the effective tax r ate for each reconciling item. In particular, the reduction in the Company’s effective statutory state rate caused a 0.9 percent increase in 2016 as compared to a 9.3 percent re duction in 2015, partially offset by other reconciling and non-deductible items for a net rate increase of 5.2 percent over 2015. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities were as follows: December 31, (in thousands) 2016 2015 Deferred tax assets: Stock-based compensation $ 39,192 $ 36,738 Derivative instruments 63,986 - Asset retirement obligation 47,840 44,573 Net operating losses and credits 177,264 194 Other 23,850 29,380 Total deferred tax assets 352,132 110,885 Deferred tax liabilities: Oil and natural gas properties, principally due to differences in basis and depreciation and the deduction of intangible drilling costs for tax purposes (1,095,173) (1,420,275) Intangible assets - operating rights (8,891) (9,548) Derivative instruments - (304,550) Other (14,100) (6,885) Total deferred tax liability (1,118,164) (1,741,258) Net deferred tax liability $ (766,032) $ (1,630,373) The Company ha d net deferred tax liabilities of approximately $766.0 million and $1.6 billion as of December 31, 2016 and December 31, 2015, respectively. At De cember 31, 2016, the Company had approximately $477.7 million of federal net operating losses (“NOLs”) expiring in 2036, of which $12.6 million is due to st ock-based compensation awards. The Company has estimate d an apportioned New Mexico NOL of $248.2 million expiring in 2035 through 2036, of which $8.5 million is due to st ock-based compensation awards. In accordance with applicable accounting standards as of December 31, 2016, a financial statement benefit has not been recorded for the NOLs related to the st ock-based compensation awards. As discussed in Note 2, upon th e adoption of ASU 2016-09 , the Company will record this tax benefit during the first quarter of 2017 . In addition, the Company’s tax attributes at December 31, 2016 include $4.8 million of alternative minimum tax credits that are not subject to expiration and $6.0 million of charitable contribution carryforwards first expiring after 2020. Pursuant to management’s assessment, the Company do es not believe a cumulative ownership change has o ccurred as of December 31, 2016. As such, Section 382 of the Internal Revenue Code of 1986, as amended , is not expected to limit the Company’s ability to utilize its NOL carryfo rward as of December 31, 2016. Management monitors company-specific, oil and natural gas industry and worldwide economic factors and assesses the l ik elihood that the Company’s NOLs and other deferred tax attributes will be utilized prior to their expiration. At December 31, 2016, management considered all factors including the expected reversal of deferred tax liabilities (includi ng the impact of available carry back and carryforward periods), historical operating income, tax planning strategies and pr ojected future taxable income. Based on the results of the assessment, management determined that it is more likely than not that the Company will rea li ze its deferred tax assets.

Major customers and derivative

Major customers and derivative counterparties	12 Months Ended
	Dec. 31, 2016
Major Customer Disclosure [Abstract]
Major Customers and Derivative Counterparties [Text Block]	Note 12 . Major customers and derivative counterparties Sales to major customers. The Company’s share of oil and natural gas production is sold to various purchasers. The Company is of the opinion that the loss of any one purchaser would not have a material adverse effect on the ability of the Company to sell its oil and natural gas production. The following purchasers individually accounted for 10 percent or more of the consolidated oil and natural gas revenues during the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, 2016 2015 2014 Plains Marketing and Transportation, Inc. 29% 11% 6% Holly Frontier Refining and Marketing, LLC 16% 25% 17% Enterprise Crude Oil LLC 7% 12% 12% Western Refining Company LP - 5% 12% At December 31, 2016 , the Company had receivables from Plains Marketing & Transportation Inc., Holly Frontier Refining and Marketing, LLC, Enterprise Crude Oil LLC, and Western Refining Company LP of $ 48.1 million, $ 26.5 million, $ 23.7 million and $ 0.4 million, respectively, which are reflected in a ccounts receivable — oil and natural gas in the accompanying consolidated balance sheets. Derivative counterparties. The Company uses credit and other financial criteria to evaluate the creditworthiness of counterparties to its derivative instruments. The Credit Facility require s that the senior unsecured debt ratings of the Company’s derivative counterparties be (i) not less than either A- by S&P Global Ratings rating system or A3 by Moody’s Investors Service, Inc. r ating system or (ii) a lender or related affiliate under the Credit F acility. At December 31, 2016 and 2015 , the counterparties with whom the Company had outstanding derivative contract s met or exceeded the se criteria . Although the Company does not obtain collateral or otherwise secure the fair value of its derivative instruments, management believes the associated credit risk is mitigated by the Company’s credit risk policies and proced ures and by the criteria of the Credit F acility . Under the terms of the Credit Facility, certain events could occur that would cause any obligations under the Credit Facility to no longer be secured by the Company’s oil and natural gas properties. In this circumstance, the Company has certain agreements in place with the Company’s derivative counterparties that would regulate collateral related to derivative transactions.

Related party transactions

Related party transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related party transactions	Note 13 . Related party transactions The following table summarizes amounts paid to and received from related parties and reported in the Company’s consolidated statements of operations for the periods presented : Years Ended December 31, (in thousands) 2016 2015 2014 Amounts paid to a partnership in which a director has an ownership interest (a) $ 4,374 $ 5,745 $ 15,181 Amounts paid to a director and certain officers of the Company (b) $ 349 $ 593 $ 383 Amounts received from certain officers of the Company (c) $ 36 $ 237 $ 169 (a) Amounts include royalties on certain properties and lease bonus payments paid to a partnership in which a director of the Company is the general partner and owns a 3.5 percent partnership interest. (b) Amounts include revenue interests, overriding royalty interests and net profits interests in properties owned by the Company made to a director and certain officers (or affiliated entities). Amounts also include payments for an acreage acquisition and lease bonuses to an affiliated entity of an office r . (c) Amounts include payments to the Company as a result of activity on oil and natural gas properties in which certain officers (or affiliated entities) have an interest .

Net income per share

Net income per share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Net income per share	Note 14 . Earnings per share T he Company uses the two-class method of calculating earnings per share because certain of the Company’s unvested share-based awards qualify as participating secu rities. The following table reconcile s 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 shar e amounts for the years ended December 31, 2016 , 2015 a nd 2014 , respectively, under the two-class method : Years Ended December 31, (in thousands, except per share amounts) 2016 2015 2014 Net income (loss) as reported $ (1,462,446) $ 65,900 $ 538,175 Participating basic earnings (a) - (635) (5,961) Basic earnings attributable to common stockholders (1,462,446) 65,265 532,214 Reallocation of participating earnings - 2 16 Diluted earnings attributable to common stockholders $ (1,462,446) $ 65,267 $ 532,230 Earnings per common share: Basic $ (10.85) $ 0.54 $ 4.89 Diluted $ (10.85) $ 0.54 $ 4.88 (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 years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Weighted average common shares outstanding: Basic 134,755 119,926 108,844 Dilutive common stock options - 25 83 Dilutive performance units - 422 205 Diluted 134,755 120,373 109,132

Other current liabilities

Other current liabilities	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Other current liabilities	Note 15 . Other current liabilities The following table provides the components of the Company’s other current liabilities at December 31, 2016 and 2015 : December 31, (in thousands) 2016 2015 Other current liabilities: Accrued production costs $ 62,573 $ 70,876 Payroll related matters 34,647 29,411 Accrued interest 31,719 68,925 Asset retirement obligations 10,035 8,626 Other 12,596 7,072 Other current liabilities $ 151,570 $ 184,910

Subsidiary guarantors

Subsidiary guarantors	12 Months Ended
	Dec. 31, 2016
Guarantees [Abstract]
Subsidiary guarantors	Note 16 . Subsidiary guarantors At December 31, 2016 , c ertain 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 customary circumstances including (i) in connection with any sale, exchange or other disposition, whether by merger, co nsolidation or otherwise, of the capital stock of that guarantor to a person that is not the Company or a restricted subsidiary of the Company, such that, after giving effect to such transaction, such guarantor would no longer constitute a subsidiary of th e 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) up on 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 resul ted 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 United States Securities and Exchange Commission (“ SEC ”) , the Company has prepared condensed consolidating financial statements in order to quantify the assets, results of operations and cash flows of such subsidi aries as subsidiary guarantors. The following condensed consolidating balance s heets at December 31, 2016 and 2015 , condensed c o nsolidating statements of o perations and condensed consolidating statements of cash flows for the years ended December 31, 2016 , 2015 and 2014 , present financial inform ation 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 basis and the consolidation and elimination entrie s 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 are not restricted from making distributions to the Company. Condensed Consolidating Balance Sheet December 31, 2016 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,991,238 $ (335,771) $ (8,655,467) $ - Other current assets 12,519 533,975 - 546,494 Oil and natural gas properties, net - 11,086,435 - 11,086,435 Property and equipment, net - 215,998 - 215,998 Investment in subsidiaries 1,988,962 - (1,988,962) - Other long-term assets 10,909 259,490 - 270,399 Total assets $ 11,003,628 $ 11,760,127 $ (10,644,429) $ 12,119,326 LIABILITIES AND EQUITY Accounts payable - related parties $ (335,771) $ 8,991,238 $ (8,655,467) $ - Other current liabilities 114,224 638,962 - 753,186 Long-term debt 2,740,580 - - 2,740,580 Other long-term liabilities 861,902 140,965 - 1,002,867 Equity 7,622,693 1,988,962 (1,988,962) 7,622,693 Total liabilities and equity $ 11,003,628 $ 11,760,127 $ (10,644,429) $ 12,119,326 Condensed Consolidating Balance Sheet December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,502,099 $ 1,162,297 $ (9,664,396) $ - Other current assets 753,716 560,834 - 1,314,550 Oil and natural gas properties, net - 10,798,497 - 10,798,497 Property and equipment, net - 178,450 - 178,450 Investment in subsidiaries 3,698,485 - (3,698,485) - Other long-term assets 182,623 167,756 - 350,379 Total assets $ 13,136,923 $ 12,867,834 $ (13,362,881) $ 12,641,876 LIABILITIES AND EQUITY Accounts payable - related parties $ 1,162,297 $ 8,502,099 $ (9,664,396) $ - Other current liabilities 69,514 526,906 - 596,420 Long-term debt 3,332,188 - - 3,332,188 Other long-term liabilities 1,630,373 140,344 - 1,770,717 Equity 6,942,551 3,698,485 (3,698,485) 6,942,551 Total liabilities and equity $ 13,136,923 $ 12,867,834 $ (13,362,881) $ 12,641,876 Condensed Consolidating Statement of Operations For the Year Ended December 31, 2016 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,634,988 $ - $ 1,634,988 Total operating costs and expenses (370,824) (3,333,608) - (3,704,432) Loss from operations (370,824) (1,698,620) - (2,069,444) Interest expense (201,753) (1,765) - (203,518) Loss on extinguishment of debt (56,436) - - (56,436) Other, net (1,709,523) (9,138) 1,709,523 (9,138) Loss before income taxes (2,338,536) (1,709,523) 1,709,523 (2,338,536) Income tax benefit 876,090 - - 876,090 Net loss $ (1,462,446) $ (1,709,523) $ 1,709,523 $ (1,462,446) Condensed Consolidating Statement of Operations For the Year Ended December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,803,573 $ - $ 1,803,573 Total operating costs and expenses 697,247 (2,173,606) - (1,476,359) Income (loss) from operations 697,247 (370,033) - 327,214 Interest expense (213,416) (1,968) - (215,384) Other, net (386,560) (14,559) 386,560 (14,559) Income (loss) before income taxes 97,271 (386,560) 386,560 97,271 Income tax expense (31,371) - - (31,371) Net income (loss) $ 65,900 $ (386,560) $ 386,560 $ 65,900 Condensed Consolidating Statement of Operations For the Year Ended December 31, 2014 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 2,660,147 $ - $ 2,660,147 Total operating costs and expenses 888,632 (2,468,342) - (1,579,710) Income from operations 888,632 191,805 - 1,080,437 Interest expense (216,661) - - (216,661) Loss on extinguishment of debt (4,316) - - (4,316) Other, net 188,305 (3,501) (188,304) (3,500) Income before income taxes 855,960 188,304 (188,304) 855,960 Income tax expense (317,785) - - (317,785) Net income $ 538,175 $ 188,304 $ (188,304) $ 538,175 Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2016 Parent Issuer Subsidiary Guarantors Consolidating Entries (in thousands) Total Net cash flows provided by (used in) operating activities $ (664,870) $ 2,049,318 $ - $ 1,384,448 Net cash flows used in investing activities - (2,224,656) - (2,224,656) Net cash flows provided by financing activities 664,919 - - 664,919 Net increase (decrease) in cash and cash equivalents 49 (175,338) - (175,289) Cash and cash equivalents at beginning of period - 228,550 - 228,550 Cash and cash equivalents at end of period $ 49 $ 53,212 $ - $ 53,261 Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (1,393,290) $ 2,923,711 $ - $ 1,530,421 Net cash flows used in investing activities - (2,602,641) - (2,602,641) Net cash flows provided by (used in) financing activities 1,393,290 (92,541) - 1,300,749 Net increase in cash and cash equivalents - 228,529 - 228,529 Cash and cash equivalents at beginning of period - 21 - 21 Cash and cash equivalents at end of period $ - $ 228,550 $ - $ 228,550 Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2014 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (816,386) $ 2,562,156 $ - $ 1,745,770 Net cash flows used in investing activities - (2,617,979) - (2,617,979) Net cash flows provided by financing activities 816,386 55,823 - 872,209 Net increase (decrease) in cash and cash equivalents - - - - Cash and cash equivalents at beginning of period - 21 - 21 Cash and cash equivalents at end of period $ - $ 21 $ - $ 21

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent events	Note 17 . Subsequent events ACC divestiture. In January 2017, the Company and its joint venture partner entered into separate agreements to sell 100 percent of their respective ownership interests in ACC for a combined total of $1.215 billion. After adjustments for debt and working capital, the Company received net cash proceeds from the sale of approximately $802.8 million. The Company’s net investment in ACC was approximately $128.7 million at December 31, 2016. The transaction closed in February 2017 and is subject to customary post-closing adjustments. Northern Delaware Basin acquisition. In January 2017, the Company completed a portion of the previously announced acquisition of approximately 16,400 net acres in the northern Delawar e Basin. As consi deration for the entire acquisition, the Company agreed to issue to the seller approxi mately 2.2 million shares of its common stock and $150.0 million in cash. The Company expect s to close on the remainder of the acquisition during the fir st half of 2017 and the acquisition, in its entirety, is subject to customary closing and post-closing adjustments . N ew commodity derivative contracts. After December 31, 2016 , the Company entered into the following additional oil price swaps to hedge additional amounts of the Company’s estimated future production: First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Swaps: (a) 2017: Volume (Bbl) 403,000 1,360,000 1,044,000 868,000 3,675,000 Price per Bbl $ 55.32 $ 55.20 $ 55.36 $ 55.56 $ 55.34 2018: Volume (Bbl) 736,000 652,000 580,000 523,000 2,491,000 Price per Bbl $ 55.47 $ 55.48 $ 55.54 $ 55.61 $ 55.52 2019: Volume (Bbl) 2,355,000 2,253,000 2,163,000 2,083,000 8,854,000 Price per Bbl $ 55.15 $ 55.11 $ 55.14 $ 55.16 $ 55.14 (a) The index prices for the oil price swaps are based on the NYMEX – WTI monthly average futures price.

Summary of significant accoun25

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation. The consolidated financial statements of the Company include the accounts of the Company and its 100 percent owned subsidiaries. The Company consolidates the financial statements of these entities. All material intercompany balances and transactions have been eliminated.
Reclassification	R eclassifications. Certain prior period amounts have been reclassified to conform to the 2016 presentation. These reclassifications had no im pact on net income (loss), total stockholders’ equity or total cash flows.
Use of estimates in the preparation of financial statements	Use of estimates in the preparation of financial statements. Preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from the se estimates. Depletion of oi l 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 rat es of production and the timing of development expenditures. Similarly, evaluations for impairment of proved and unproved oil and natural gas properties are subject to numerous 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 inclu de, but are not limited to, asset retirement obligations, fair value of stock-based compensation , fair value of business combinati ons, fair value of nonmonetary exchanges, fair value of de rivative financial instruments and income taxes .
Cash equivalents	Cash equivalents. The Company considers all cash on hand, depository accounts held by banks, money market accounts and investments with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents are held in financial institutions in amounts that exceed the insurance limits of the Federal Deposit Insurance Corporation. However, management believes that the Company’s cou nterparty risks are minimal based on the reputation and history of the institutions selected.
Accounts receivable	Accounts receivable. The Company sells oil and natural gas to various customers and participates with other parties in the drilling, completion and operation of oil and natural gas wells. Joint interest and oil and natural gas sales receivables related to these operations are generally unsecured. The Company determines joint interest operations accounts receivable allowances based on management’s assessment of the creditworthiness of the joint interest owners and the Company’s ability to realize the receivables through netting of anticipated future production revenues. Receivables are considered past due if full payment is not received by the contr actual due date. Past due accounts are generally written off against the allowance for doubtful accounts only after all collection attempts have been exhausted. The Company had an allowance for doubtful accounts of approximately $ 1.2 million for ea ch of the years ended December 31, 2016 and 2015 .
Oil and natural gas properties	Oil and natural gas properties. The Company utilizes the successful efforts method of accounting for its oil and natural gas properties. Under this method all costs associated with productive wells and nonproductive development wells are capitalized, while nonproductive exploration costs are expensed. Capitalized acquisition costs relating to proved properties are depleted using the unit-of-production method based on proved reserves. The depletion of capitalized drilling and development costs and integ rated assets is based on the unit-of-production method using proved dev eloped reserves . During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized depletion expense from operations of $ 1,145.2 million, $ 1,203.5 million and $ 960.9 million, respectively. The Company generally does not carry the costs of drilling an exploratory well as an asset in its consolidated balance sheets following the completion of drilling unless both of the follow ing conditions are met: the well has found a sufficient quantity of reserves to justify its completion as a producing well; and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project. Due t o the capital intensive nature and the geographical location of certain projects, it may take the Company longer than one year to evaluate the future potential of the exploration well and economics associated with making a determination on its commercial v iability. In these instances, the project ’ s feasibility is not contingent upon price improvements or advances in technology, but rather the C ompany’ s ongoing efforts and expenditures related to accurately predicting the hydrocarbon recoverability based on well information, ga ining access to other companies’ production, transportation or processing facilities and/or getting partner approval to drill additional appraisal wells. These activities are ongoing and being pursued consta ntly. Consequently, the Compa ny’ s assessment of suspended exploratory well costs is continuous until a decision can be made that the well has found proved reserves or is noncommercial and is charged to exploration and abandonments expense. See Note 3 for additional in forma tion regarding the Company’ s suspended exploratory well costs. Proceeds from the sales of individual properties and the capitalized costs of individual properties sold or abandoned are credited and charged, respectively, to accumulated depletion. Generall y, no gain or loss is recognized until the entire depletion base is sold. However, gain or loss is recognized from the sale of less than an entire depletion base if the disposition is significant enough to materially impact the depletion rate of the remain ing properties in the depletion base. Ordinary maintenance and repair costs are expensed as incurred. Costs of significant nonproducing properties, wells in the process of being drilled and completed and development projects are excluded from depletion un til the related project is completed and proved developed reserves are established or , if unsuccessful, impairment is determined. The Company capitalizes interest, if debt is outstanding, on expenditures for significant development projects until such proj ects ar e ready for their intended use. The Company did not have capitalized interest related to significant oil and natural gas development projects for the year ended December 31, 2016 . During the y ears ended December 31, 2015 and 2014 , the Comp any had capitalized interest of $ 0.7 million and $ 1.4 million, respectively. The Company reviews its long-lived assets to be held and used, including proved oil and natural gas properties, whenever events or circumstances indicate that the carrying value of those assets may not be recoverable. An impairment loss is indicated if the sum of the expected future cash flows is less than the carrying amount of the assets. In this circumstance, the Company recognizes an impairment loss fo r the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company reviews its oil and natural gas properties by depletion base or by individual well for those wells not constituting part of a depletion b ase. For each property determined to be impaired, an impairment loss equal to the difference between the carrying value of the properties and the estimated fair value (discounted future cash flows) of the properties and integrated assets would be recognized at that time. Estimating future cash flows involves the use of judgments, including estimation of the proved and risk-adjusted unproved oil and natural gas reserve quantities, timing of development and production, expected future commodity prices, capital exp enditures and production costs and cash flows from integrated assets . The Compan y recognized impairment expense of $ 1,524.6 million, $ 60.5 million and $ 447.2 million during the years ended December 31, 2016 , 2015 and 2014 , respectively, related to its proved oil and natural gas properties. See Note 7 for additional in formation regarding the Company’ s impairment expense . Unproved oil and natural gas properties are periodically assessed for imp airment by consid ering future drilling and exploration plans, results of exploration activities, commodity price outlooks, planned future sales and expiration of all or a portion of the projects. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized expense of $ 59.8 million, $ 34.5 million and $ 217.3 million, respectively, related to abandoned prospects , expiring acreage and abandoned well costs , which is included in exploration an d abandonments expense in the accompanying consolidated statements of operations.
Other property and equipment	Other property and equipment. Other capital assets include buildings, transportation equipment, computer equipment and software, telecommunications equipment, leasehold impr ovements and furniture and fixtures. These items are recorded at cost, or fair value if acquired, and are depreciated using the straight-line method based on expected lives of the individual assets or group of assets ranging from two to 39 years. The Compa ny had other capital assets of $ 216.0 million and $ 178.5 million, net of accumulated depreciation of $ 73.7 million and $ 54.4 million, at December 31, 2016 and December 31, 2015 , respectively. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized depreciation expense of $ 20.6 million, $ 18.3 million and $ 17.3 million, respectively. Additionally, during the year ended December 31, 2016 , the Company had capitalized interest of $0.3 million related to other property and equipment.
Funds held in escrow	Funds held in escrow. At December 31, 2016 , the Company’s funds held in escrow totaled $43.0 million, which consists of a deposit paid by the Company that was held in escrow for the Northern Delaware Basin acquisition that partially closed in January 2017. See Note 17 for additional information regarding the acquisition .
Deferred loan costs	Deferred loan costs. Deferred loan costs are stated at cost, net of amortization, which is computed using the straight-line method. The Company had deferred loan costs related to its credit facility of $ 10.9 million and $ 15.6 million, net of accumulated amortization of $ 55.7 million and $ 51.0 million, in noncurrent assets at December 31, 2016 and 2015 , respectively.
Intangible assets	Intangible assets. The Company has capitalized certain operating rights acquired in an acquisition. The gross operating rights, which have no residual value, are amortized over the estimated economic life of 25 years. Impairment will be assessed if indicators of potential impairment exist or when there is a material change in the remaining useful economic life . The following table reflects the gross and net intangible assets at December 31, 2016 and 2015 , respectively : December 31, (in thousands) 2016 2015 Gross intangible - operating rights $ 36,557 $ 36,557 Accumulated amortization (12,325) (10,864) Net intangible - operating rights $ 24,232 $ 25,693 The following table reflects amortization expense from operations for the years ended December 31, 2016 , 2015 and 2014 : Years Ending December 31, (in thousands) 2016 2015 2014 Amortization expense $ 1,461 $ 1,461 $ 1,461 The following table reflects the estimated aggregate amortization expense for each of the periods presented below at December 31, 2016 : (in thousands) 2017 $ 1,461 2018 1,461 2019 1,461 2020 1,461 2021 1,461 Thereafter 16,927 Total $ 24,232
Inventory	Inventory. Inventory consists primarily of tubular goods, water and other oilfield equipment that the Company plans to utilize in its ongoing exploration and development activities and is carried at the lower of cost or market value, on a weighted average cost basis.
Equity method investments	Equity method investment s . At December 31, 2016 , the Company owned a 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 n orthern Delaware Basin. ACC commenced partial operations in late 2015 and completed construction of the pipelin e in April 2016. The Company has the option to purchase the membership interest of the other investor in ACC. This purchase option became exercis able in July 2016 and will expire after one year. During January 2017, the Company and its joint venture partner entered into separate agreements to sell 100 percent of their respective ownership interests in ACC. See Note 17 for additional in formation regarding the disposition of ACC. The Company accounts for its investment in ACC under the equity method of accounting for investments in unconsolidated affiliates. The Co mpany’s net investment in ACC was approximately $ 128.7 million and $ 98.9 million at December 31, 2016 and 2015 , respectively, and is included in other assets in the Company’s consolidated balance sheet s . The equity loss for the years ended December 31, 2016 , 2015 and 2014 was approximate ly $ 2.1 million , $ 4.1 million and $ 1.3 million , respectively, and is included in other expense in the Company’s consolidated statement s of operations. During the year ended 2016 , the Company did not capitalize any interest on its investment in ACC. During the years ended 2015 and 2014 , the Company recorded approximately $ 2.9 million and $ 0.7 million, respectively, of capitalized interest on its investment in ACC. During the year ended 2015, the Company purchased a 25 percent membership interest in an entity constructing a crude oil gathering and transportation system in the southern Delaware Basin . The initial system is operational and was substantially completed d uring 2016. The Company accounts for its investment under the equity method of accounting for investments in unconsolidated affiliates. The Company’s net investment was approximately $ 42.5 million and $ 20.8 million at December 31, 2016 and 2015 , respectively, and is included in other assets in the Company’s consolidated balance sheets. The equity loss for the year ended December 31, 2016 was approximately $ 2.1 million , and is included in other expense in the Company’s consolidated statements of operations.
Environmental	Environmental. The Company is subject to extensive federal, state and local environmental laws and regulations. These laws, which are often changing, regulate the discharge of materials into the environmen t and may require the Company to remove or mitigate the environmental effects of the disposal or release of petroleum or chemical substances at various sites. Environmental expenditures are expensed. Expenditures that relate to an existing condition caused by past operations and that have no future economic benefits are expensed. Liabilities for expenditures of a noncapital nature are recorded when environmental assessment and/or remediation is probable and the costs can be reasonably estimated. Such liabil ities are generally undiscounted unless the timing of cash paymen ts is fixed and readily determinable. At December 31, 2016 and 2015 , the Company has accrued approximately $ 1.4 million and $ 1.0 million, respectively, r elated to environmental liabilities. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized environmental charges of approximately $ 7.0 million, $ 2.7 million and $ 4.0 million, respectively.
Deferred loan costs, senior notes	Senior note deferred loan costs. Deferred loan costs are stated at cost, net of amortization, which is computed using the effective interest method. The Company had deferred loan costs related to its senior notes of $ 31.6 million and $ 42.9 million, net of accumulated amortization of $ 12.1 million and $ 18.7 million, as a reduction of long-term debt at December 31, 2016 and 2015 , respectively. See Note 9 for additional information regarding 2016 activity related to the Company’s senior notes.
Income taxes	Income taxes. The Company recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial state ment carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expe cted to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in income in the period that includes the enactment date. A valuation allowance is established to reduce deferred tax assets if it is m ore likely than not that the related tax benefits will not be realized.
Income taxes uncertainties	The Company evaluates uncertain tax positions for recognition and measurement in the cons olidated financial statements. To recognize a tax position, the Company determines whether it is more likely than not that the tax positions will be sustained upon examination, including resolution of any related appeals or litigation, based on the te chnical merits of the position. A tax position that meets the more likely than not threshold is mea sured to determine the amount of benefit to be recognized in the consol idated financial statements. The amount of tax benefit recognized with respect to any tax position is measured as the largest amount of benefit that is greater than 50 percent likely of b eing realized upon settlement. The Company had no material uncertain tax positions that required recognition in the consolidated financial statements at December 31, 2016 and 2015 . Any interest or penalties would be recognized as a component of inc ome tax expense.
Derivative instruments	Derivative instruments. The Company recognizes its derivative instruments , other than any commodity derivative contracts that are designated as normal purchase and normal sale, as either assets or liabilities measured at fair value. The C ompany netted the fair value of derivative instruments by counterparty in the accompanying consolidated balance sheets where the right of offset exists. The Company does not have any derivatives designated as fair value or cash flow hedges. The Company may also enter into physical delivery contracts to effectively provide commodity price hedges. Because these contracts are not expec ted to be net cash settled, they are considered to be normal sales contracts and not derivatives. Therefore, these contracts ar e not recorded in the Company’s consolidated financial statements.
Asset retirement obligations	Asset retirement obligations. The Company records the fair value of a liability for an asset retirement obligation in the period in which it is incurred and a corresponding increase in the carrying amount of the related long-lived asset. Subsequently, the asset retirement cost included in the carrying amount of the related asset is allocated to expense through depletion of the asset. Changes in the liability due to passage of time are gener ally recognized as an increase in the carrying amount of the liability and as corresponding accretion expense. Based on certain factors including commodity prices and costs, the Company may revise its previous estimates related to the liability, which woul d also increase or decrease the associated oil and natural gas property asset.
Treasury stock	Treasury stock. Treasury stock purchases are recorded at cost.
Revenue recognition	Revenue recognition. Oil and natural gas revenues are recorded at the time of physical transfer of such products to the purchaser , which for the Company is primarily at the wellhead . The Company follows the sales method of accounting for oil and natural gas sales, recognizing revenues based on the Company’s actual proceeds from the oil and natural gas sold to purcha sers.
Oil and natural gas imbalances	Oil and natural gas imbalances. Oil and n atural gas imbalances are generated on properties for which two or more owners have the right to take production “in-kind” and, in doing so, take more or less than their respective entitled percentage. I mbalances are tracked by well , but the Company does not record any receivable from or payable to the other owners unless the imbalance has reached a level at which it exceeds the remaining reserves in the respective well. If reserves are insufficient to of fset the imbalance and the Company is in an overtake position, a liability is recorded for the amount of shortfall in reserves valued at a contract price or the market price in effect at the time the imbalance is generated. If the Company is in an undertak e position, a receivable is recorded for an amount that is reasonably expected to be received, not to exceed the current market value of such imbalance. The Company had no significant imbalances at December 31, 2016 or 2015 .
General and administrative expense	General and administrati ve expense . The Company receives fees for the operation of jointly-owned oil and natural gas properties during the drilling and production phases and records such reimbursements as reductions of general and administrative expense. Such fees totaled approxi mately $ 16.9 million, $ 19.2 million and $ 18.9 million for the years e nded December 31, 2016 , 2015 and 2014 , respectively.
Stock-based compensation	Stock-based compensation. S tock-based compensation expense is recognized in the Company’ s financial statements on a n accelerated basis over the awards’ vesting periods based on their fair values on the dates of grant , net of an estimate for forfeitures . S tock-based compensation awards generally vest over a period ranging from one to eight years. The Company utilizes (i) the Black-Scholes option pricing model to measure the fair value of stock options, (ii) the average of the grant date’s high and low stock price s for the fair value of restricted stock and (iii) the Monte Carlo simulation m ethod for the fair value of performance unit awards.
Recent accounting pronouncements	Recent accounting pronouncements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how rev enue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which deferred the effective date of ASU 2014-09 by one year. That new standard is now effective for annual reporting periods beginning after December 15, 2017. The Company expects to use the modified retrospective method to adopt the standard , meaning the cumulative effect of initially applying the standard will be recognized in the most current period presented in the financia l statements. The Company is substantially complete with its internal evaluation of the adoption of this standard and does not expect this new guidance will have a material impact o n its consolidated financial statements. In February 2016, the FASB issue d ASU No. 2016-02, “Leases (Topic 842),” which supersedes current lease guidance. The new lease standard requires all leases with a term greater than one year to be recognized on the balance sheet while maintaining substantially similar classifications for finance and operating leases. Lease expense recognition on the income statement 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 into lease agreements to support its operations. These agreements are for leases on assets such as office space, vehicles, field services and well equipment and drilling rigs. The Company is currently in the process of reviewing all contracts that could be applicable to this new guidance. The Company believes this new guidance will have a moderate impact to its consolidated balance sheet due to the recognition of lease-related assets and liabilities that were not previously recognized. In March 2016, the FASB issued ASU No. 2016-09, “Compensation–Stock Compensations (Topic 718): Improvements to Employee Share-based Payment Accounting,” which changes the accounting and presentation for share-based payment arrangements in the following areas: (i) recognition in the statement of operations of excess tax benefits and deficiencies; (ii) cash flow presentation of excess tax benefits and deficiencies; (iii) minimum statutory withholding thresholds and the classi fication on the cash flow statement of the withheld amounts; and (iv) an accounting policy election to recognize forfeitures as they occur. This guidance is effective for reporting periods beginning after December 15, 2016 and early adoption is permitted. The Company will adopt ASU No. 2016-09 during the first quarter of 2017. The adoption will not have a material impact on prior period consolidated financial statements. The Company will elect to account for forfeitures of share-based payments as they occ ur. As of December 31, 2016, the Company had not recorded compen sation expense of approximately $8.2 million for its forfeiture estimate. The Company will prospectively classify excess tax benefits and deficiencies as operating activities on the consolidat ed statement of cash flows and will prospectively record as a discrete item in the income tax provision in the consolidated income statement. The Company will also recognize all excess tax benefits not previously realized, which totaled approximately $4.7 million as of December 31, 2016. Upon adoption, the Company will record a cumulative-effect adjustment, which will decrease retained earnings by approximately $0.5 million, increase additional paid-in capital by approximately $8.2 million, and decrease net deferred income taxes by approximately $7.7 million. In June 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” meth odology for recognizing credit losses with an “expected loss” methodology. This new methodology 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 ti mely decision-useful information about the expected credit losses on financial instruments. This 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, 2 018. The Company does not believe this new guidance will have a material impact on its consolidated financial statements.

Summary of significant accoun26

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following table reflects the gross and net intangible assets at December 31, 2016 and 2015 , respectively : December 31, (in thousands) 2016 2015 Gross intangible - operating rights $ 36,557 $ 36,557 Accumulated amortization (12,325) (10,864) Net intangible - operating rights $ 24,232 $ 25,693
Schedule Of Amortization Expense [Table Text Block]	The following table reflects amortization expense from operations for the years ended December 31, 2016 , 2015 and 2014 : Years Ending December 31, (in thousands) 2016 2015 2014 Amortization expense $ 1,461 $ 1,461 $ 1,461
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The following table reflects the estimated aggregate amortization expense for each of the periods presented below at December 31, 2016 : (in thousands) 2017 $ 1,461 2018 1,461 2019 1,461 2020 1,461 2021 1,461 Thereafter 16,927 Total $ 24,232

Exploratory well costs (Tables)

Exploratory well costs (Tables)	12 Months Ended
	Dec. 31, 2016
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 each of the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Beginning capitalized exploratory well costs $ 116,198 $ 241,657 $ 144,504 Additions to exploratory well costs pending the determination of proved reserves 143,981 102,846 234,057 Reclassifications due to determination of proved reserves (85,985) (227,746) (99,657) Exploratory well costs charged to expense (5,707) (559) (37,247) Disposition of wells (17,339) - - Ending capitalized exploratory well costs $ 151,148 $ 116,198 $ 241,657
Aging of capitalized exploratory well costs based on the date drilling was completed	The following table provides an aging at December 31, 2016 and 2015 of capitalized exploratory well costs based on the date drilling was completed: December 31, (dollars in thousands) 2016 2015 Capitalized exploratory well costs that have been capitalized for a period of one year or less $ 141,595 $ 98,764 Capitalized exploratory well costs that have been capitalized for a period greater than one year 9,553 17,434 Total capitalized exploratory well costs $ 151,148 $ 116,198 Number of projects with exploratory well costs that have been capitalized for a period greater than one year 8 8

Acquisitions and business combi

Acquisitions and business combinations (Tables)	12 Months Ended
	Dec. 31, 2016
Acquisitions and Divestitures [Abstract]
Estimated fair value of the acquired assets and liabilities	The following table reflects the fair value of the acquired assets and liabilities associated with the Reliance Acquisition: (in thousands) Fair value of net assets: Proved oil and natural gas properties $ 729,814 Unproved oil and natural gas properties 972,236 Other assets 34,000 Total assets acquired 1,736,050 Current liabilities, including current portion of asset retirement obligations (8,225) Asset retirement obligations assumed (12,250) Fair value of net assets acquired $ 1,715,575 Fair value of consideration paid for net assets: Cash consideration $ 1,175,708 Non-cash consideration, including equity 539,867 Total consideration paid for net assets $ 1,715,575
Business Acquisition, Pro Forma Information [Table Text Block]	The following unaudited pro forma combined condensed financial data for the years ended December 31, 2016 and 2015 , were derived from the historical financial statements of the Company giving effect to the Reliance Acquisitio n, as if it had occurred on January 1, 2015 . The results of operations for the Reliance Acquisition are included in the Company’s results of operations since the closing in October 2016 through December 31, 2016 . The pro forma financial data does not include the results of operations for the southern Delaware Basin acquisition, as it was primarily an acreage acquisition and its results were not deemed material. The unaudited pro forma combined condensed financial data has been included for comparative purposes only and is not necessarily indicative of the results that might have occurred had the Reliance Acquisition taken place as of the date indicated and is not intended to be a projection of future results . Years Ended December 31, (in thousands, except per share amounts) 2016 2015 (unaudited) Operating revenues $ 1,717,460 $ 1,976,356 Net income (loss) $ (1,396,250) $ 97,354 Earnings per common share: Basic net income (loss) $ (10.36) $ 0.81 Diluted net income (loss) $ (10.36) $ 0.80

Asset retirement obligations (T

Asset retirement obligations (Tables)	12 Months Ended
	Dec. 31, 2016
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligations	The Company’s asset retirement obligation transactions during the years ended December 31, 2016 , 2015 and 2014 are summarized in the table below: Years Ended December 31, (in thousands) 2016 2015 2014 Asset retirement obligations, beginning of period $ 119,945 $ 119,881 $ 101,593 Liabilities incurred from new wells 2,113 4,052 5,324 Liabilities assumed in acquisitions 13,217 2,434 4,065 Accretion expense 7,133 7,600 7,072 Disposition of wells (10,955) - - Liabilities settled upon plugging and abandoning wells (1,063) (2,736) (2,926) Revision of estimates (a) - (11,286) 4,753 Asset retirement obligations, end of period $ 130,390 $ 119,945 $ 119,881 (a) The downward revision to the Companyʼs asset retirement obligation estimates for the year ended December 31, 2015 is primarily due to a reduction in the future estimated abandonment costs.

Incentive plans (Tables)

Incentive plans (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the Company's restricted stock awards activity	A summary of the Company’s restricted stock award activity for the year ended D ecember 31, 2016 is presented below: Weighted Average Number of Grant Date Restricted Fair Value Shares Per Share Restricted stock: Outstanding at December 31, 2015 1,199,647 $ 110.14 Shares granted 450,981 $ 112.78 Shares cancelled / forfeited (93,018) $ 117.70 Lapse of restrictions (400,340) $ 96.48 Outstanding at December 31, 2016 1,157,270 $ 115.29
Summarizes information about stock-based compensation for the Company's restricted stock awards activity under the Plan	The following table summarizes information about stock-based compensation for the Company’s restricted stock awards activity under the Plan for years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Fair value for awards granted during the period (a) $ 50,863 $ 49,659 $ 57,940 Fair value for awards vested during the period $ 44,881 $ 35,700 $ 59,226 Stock-based compensation expense from restricted stock $ 40,801 $ 43,185 $ 36,585 Income tax benefit related to restricted stock $ 14,970 $ 16,049 $ 13,672 (a) The weighted average grant date fair value per share amounts were $112.78, $109.76, and $129.12 for the years ended December 31, 2016, 2015 and 2014, respectively.
Summary of the Company's stock option awards activity under the Plan	Stock option awards. A summary of the Company’s stock option award activity under the Plan for the year ended December 31, 2016 is presented below: Weighted Average Number of Exercise Options Price Stock options: Outstanding at December 31, 2015 42,901 $ 18.10 Options exercised (22,901) $ 20.52 Outstanding at December 31, 2016 20,000 $ 15.33 Vested and exercisable at December 31, 2016 20,000 $ 15.33
Summarizes information about the Company's vested and exercisable stock options outstanding	The following table summarizes information about the Company’s vested and exercisable stock options outstanding at December 31, 2016 : December 31, 2016 Weighted Intrinsic Average Weighted Value Remaining Average of Exercise Number Contractual Exercise Options Prices Vested Life Price (in thousands) Vested and exercisable options: $12.85 15,000 0.62 years $ 12.85 $ 1,812 $22.77 5,000 1.81 years $ 22.77 554 20,000 0.92 years $ 15.33 $ 2,366
Summarizes information about stock-based compensation for stock options	The following table shows the deductions in current taxable income related to stock options exercised for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Deductions in current taxable income related to stock options exercised $ 271 $ 415 $ 23,208
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 years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, 2016 2015 2014 Risk-free interest rate 1.31% 1.07% 0.76% Range of volatilities 31.6% - 59.0% 26.1% - 43.0% 29.2% - 42.2%
Summary of the Company's performance unit activity	The following table summarizes the performance unit activity for the year ended December 31, 2016 : Number of Grant Date Units Fair Value Performance units: Outstanding at December 31, 2015 315,755 $ 149.21 Units granted (a) 161,361 $ 114.81 Units forfeited (9,285) 140.66 Units vested (b) (136,305) $ 139.54 Outstanding at December 31, 2016 331,526 $ 136.68 (a) Reflects the amount of performance units granted. The actual payout of shares will be between zero and 300 percent of the performance units granted depending on the Company’s performance at the end of the performance period. (b) On December 31, 2016, the performance period ended for these performance units. Each unit converted into 1.825 shares representing 248,763 shares of common stock issued on January 2, 2017.
Summarizes information about stock-based compensation for the Company's performance unit awards activity under the Plan	The following table summarizes information about stock-based compensation expense for performance units for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Fair value for awards granted during the period (a) $ 18,526 $ 27,659 $ 19,455 Fair value for awards vested during the period $ 33,247 $ 16,458 $ - Stock-based compensation expense from performance units $ 18,126 $ 19,888 $ 10,545 Income tax benefit related to performance units $ 6,650 $ 7,391 $ 3,941 (a) The weighted average grant date fair value per unit amounts were $114.81, $156.86 and $139.54 for the years ended December 31, 2016, 2015 and 2014, respectively.
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-bas ed compensation awards that we re outstanding at December 31, 2016 : Restricted Performance (in thousands) Stock Units Total 2017 $ 31,622 $ 13,369 $ 44,991 2018 17,140 5,469 22,609 2019 5,341 - 5,341 2020 423 - 423 2021 85 - 85 Thereafter 197 - 197 Total $ 54,808 $ 18,838 $ 73,646

Disclosures about fair value 31

Disclosures about fair value of financial instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [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 December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 Carrying Fair Carrying Fair (in thousands) Value Value Value Value Assets: Derivative instruments $ 3,551 $ 3,551 $ 819,536 $ 819,536 Liabilities: Derivative instruments $ 177,949 $ 177,949 $ - $ - $600 million 7.0% senior notes due 2021 (a) $ - $ - $ 592,414 $ 595,500 $600 million 6.5% senior notes due 2022 (a) $ - $ - $ 591,549 $ 579,000 $600 million 5.5% senior notes due 2022 (a) $ 593,787 $ 619,500 $ 592,899 $ 553,500 $1,550 million 5.5% senior notes due 2023 (a) $ 1,554,710 $ 1,621,382 $ 1,555,326 $ 1,453,005 $600 million 4.375% senior notes due 2025 (a) $ 592,083 $ 598,800 $ - $ - (a) The carrying value includes associated deferred loan costs and any premium.
Net basis derivative fair values as reported in the consolidated balance sheets	The following tables 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 December 31, 2016 and 2015 . The Company nets the fair value of derivative instruments by counterparty in the Company’s consolidated balance sheets. December 31, 2016 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in thousands) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets Current: Commodity derivatives $ - $ 58,351 $ - $ 58,351 $ (54,800) $ 3,551 Noncurrent: Commodity derivatives - 62 - 62 (62) - Liabilities Current: Commodity derivatives - (136,879) - (136,879) 54,800 (82,079) Noncurrent: Commodity derivatives - (95,932) - (95,932) 62 (95,870) Net derivative instruments $ - $ (174,398) $ - $ (174,398) $ - $ (174,398) December 31, 2015 Fair Value Measurements Using Net Quoted Prices Gross Fair Value in Active Significant Amounts Presented Markets for Other Significant Offset in the in the Identical Observable Unobservable Consolidated Consolidated Assets Inputs Inputs Total Balance Balance (in thousands) (Level 1) (Level 2) (Level 3) Fair Value Sheet Sheet Assets Current: Commodity derivatives $ - $ 684,029 $ - $ 684,029 $ (31,531) $ 652,498 Noncurrent: Commodity derivatives - 175,267 - 175,267 (8,229) 167,038 Liabilities Current: Commodity derivatives - (31,531) - (31,531) 31,531 - Noncurrent: Commodity derivatives - (8,229) - (8,229) 8,229 - Net derivative instruments $ - $ 819,536 $ - $ 819,536 $ - $ 819,536
Carrying amounts, estimated fair values and impairment expense of long-lived assets	Estimated Carrying Fair Value Impairment (in thousands) Amount (Level 3) Expense March 2016 $ 3,437,612 $ 1,912,967 $ 1,524,645 December 2015 $ 104,982 $ 52,041 $ 52,941 September 2015 $ 18,023 $ 10,435 $ 7,588 December 2014 $ 677,021 $ 245,346 $ 431,675 September 2014 $ 26,790 $ 11,314 $ 15,476

Derivative financial instrume32

Derivative financial instruments (Tables)	12 Months Ended
	Dec. 31, 2016
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 followin g table summarizes the amounts r eported in earnings related to the commodity derivative instruments for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Gain (loss) on derivatives: Oil derivatives $ (337,175) $ 675,303 $ 869,421 Natural gas derivatives (31,509) 24,449 21,496 Total $ (368,684) $ 699,752 $ 890,917 The following table represents the Company’s net cash receipts from (payments on) derivatives for the years ended December 31, 2016, 2015 and 2014: Years Ended December 31, (in thousands) 2016 2015 2014 Net cash receipts from (payments on) derivatives: Oil derivatives $ 608,847 $ 597,297 $ 76,335 Natural gas derivatives 16,403 35,619 (4,352) Total $ 625,250 $ 632,916 $ 71,983
Company's outstanding derivative contracts	Commodity derivative contracts at December 31, 2016 . The following table sets forth the Company’s outstanding derivative contracts at December 31, 2016 . When aggregating multiple contracts, the weighted average contract price is disclosed. All of the Company’s derivative contracts at December 31, 2016 are expected to settle by December 31, 2018 . First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Swaps: (a) 2017: Volume (Bbl) 7,020,870 6,348,480 5,854,370 5,465,080 24,688,800 Price per Bbl $ 57.00 $ 57.66 $ 51.25 $ 51.48 $ 54.58 2018: Volume (Bbl) 5,139,629 4,864,170 4,624,318 4,418,007 19,046,124 Price per Bbl $ 51.63 $ 51.46 $ 51.28 $ 51.12 $ 51.38 Oil Basis Swaps: (b) 2017: Volume (Bbl) 6,603,000 6,141,500 5,290,000 5,290,000 23,324,500 Price per Bbl $ (1.00) $ (1.03) $ (0.49) $ (0.49) $ (0.78) 2018: Volume (Bbl) 2,340,000 2,366,000 2,392,000 2,392,000 9,490,000 Price per Bbl $ (0.98) $ (0.98) $ (0.98) $ (0.98) $ (0.98) Natural Gas Swaps: (c) 2017: Volume (MMBtu) 14,461,315 13,289,642 12,365,441 11,743,000 51,859,398 Price per MMBtu $ 3.07 $ 3.05 $ 3.05 $ 3.04 $ 3.06 2018: Volume (MMBtu) 5,506,000 5,216,000 5,029,000 4,844,000 20,595,000 Price per MMBtu $ 3.04 $ 3.04 $ 3.03 $ 3.03 $ 3.03 (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)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Company's debt	Note 9 . Debt The Company’s debt consisted of the following at December 31, 2016 and 2015 : December 31, (in thousands) 2016 2015 Credit facility $ - $ - 7.0% unsecured senior notes due 2021 - 600,000 6.5% unsecured senior notes due 2022 - 600,000 5.5% unsecured senior notes due 2022 600,000 600,000 5.5% unsecured senior notes due 2023 1,550,000 1,550,000 4.375% unsecured senior notes due 2025 600,000 - Unamortized original issue premium 22,173 25,073 Senior notes issuance costs, net (31,593) (42,885) Less: current portion - - Total long-term debt $ 2,740,580 $ 3,332,188
Principal maturities of debt	Principal maturities of long -term debt outstanding at December 31, 2016 were as follows: (in thousands) 2017 $ - 2018 - 2019 - 2020 - 2021 - Thereafter 2,750,000 Total $ 2,750,000
Interest expense	The following amounts have been incurred and charged to interest expense for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Cash payments for interest $ 232,173 $ 211,443 $ 211,342 Amortization of original issue premium (2,900) (2,747) (2,599) Amortization of deferred loan origination costs 9,937 9,971 10,937 Accretion expense 1,939 1,795 - Net changes in accruals (37,379) (165) (737) Interest costs incurred 203,770 220,297 218,943 Less: capitalized interest (252) (4,913) (2,282) Total interest expense $ 203,518 $ 215,384 $ 216,661

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Summary of the Company's future commitments	Company periodically enters into contractual arrangements under which the Company is committed to expend funds. These contractual arrangements relate to purchase agreements the Company has entered into including drilling commitments, water commitment agreements, throughput volume delivery commitments, power commitments , fixed asset commitment s and maintenance commitments. The following table summariz es the Company’s commitments at December 31, 2016 : (in thousands) 2017 $ 56,649 2018 69,195 2019 49,327 2020 24,669 2021 20,770 Thereafter 97,869 Total $ 318,479
Future minimum lease commitments under non-cancellable operating leases	Future minimu m lease commitments under non-cancellable operating leases at December 31, 2016 were as follows: (in thousands) 2017 $ 8,988 2018 7,945 2019 6,419 2020 4,966 2021 4,088 Thereafter 1,002 Total $ 33,408

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
The Company's income tax expense (benefit)	The Company’s income tax expense (benefit) and amounts separately allocated were attributable to the following items for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Consolidated statements of operations: Income tax expense (benefit) from operations $ (876,090) $ 31,371 $ 317,785 Consolidated statements of stockholders' equity: Excess tax deficiency (benefit) related to stock-based compensation 669 (2,150) (16,480) $ (875,421) $ 29,221 $ 301,305
Company's income tax expense (benefit) attributable to income from continuing operations	The Company’s income tax expense (benefit) attributable to income (loss) from operations consisted of the following for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Current: U.S. federal $ (11,579) $ 127 $ 16,621 U.S. state and local (170) 1,622 4,997 Total current income tax expense (benefit) (11,749) 1,749 21,618 Deferred: U.S. federal (770,734) 40,364 278,615 U.S. state and local (93,607) (10,742) 17,552 Total deferred income tax expense (benefit) (864,341) 29,622 296,167 Total income tax expense (benefit) attributable to income from operations $ (876,090) $ 31,371 $ 317,785
reconciliation between the income tax expense (benefit) computed by multiplying pretax income (loss) from operations	The reconciliation between the income tax expense (benefit) computed by multiplying pre-tax income (loss) from operations by the United States federal statutory rate and the reported amounts of income tax expense (benefit) from operations is as follows: Years Ended December 31, (in thousands) 2016 2015 2014 Income (loss) at U.S. federal statutory rate $ (818,488) $ 34,045 $ 299,586 State income taxes (net of federal tax effect) (40,015) 3,071 22,826 Revisions of previous estimates 746 (631) 738 Change in estimated effective statutory state income tax (20,909) (9,026) (7,945) Nondeductible expense & other 2,576 3,912 2,580 Income tax expense (benefit) $ (876,090) $ 31,371 $ 317,785 Effective tax rate (37.5)% 32.3% 37.1%
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities were as follows: December 31, (in thousands) 2016 2015 Deferred tax assets: Stock-based compensation $ 39,192 $ 36,738 Derivative instruments 63,986 - Asset retirement obligation 47,840 44,573 Net operating losses and credits 177,264 194 Other 23,850 29,380 Total deferred tax assets 352,132 110,885 Deferred tax liabilities: Oil and natural gas properties, principally due to differences in basis and depreciation and the deduction of intangible drilling costs for tax purposes (1,095,173) (1,420,275) Intangible assets - operating rights (8,891) (9,548) Derivative instruments - (304,550) Other (14,100) (6,885) Total deferred tax liability (1,118,164) (1,741,258) Net deferred tax liability $ (766,032) $ (1,630,373)

Major customers and derivativ36

Major customers and derivative counterparties (Tables)	12 Months Ended
	Dec. 31, 2016
Major Customer Disclosure [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	The following purchasers individually accounted for 10 percent or more of the consolidated oil and natural gas revenues during the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, 2016 2015 2014 Plains Marketing and Transportation, Inc. 29% 11% 6% Holly Frontier Refining and Marketing, LLC 16% 25% 17% Enterprise Crude Oil LLC 7% 12% 12% Western Refining Company LP - 5% 12%

Related party transactions (Tab

Related party transactions (Tables)	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Summary of charges incurred with and payments made to and received from the Company's related parties and reported in the consolidated statements of operations	The following table summarizes amounts paid to and received from related parties and reported in the Company’s consolidated statements of operations for the periods presented : Years Ended December 31, (in thousands) 2016 2015 2014 Amounts paid to a partnership in which a director has an ownership interest (a) $ 4,374 $ 5,745 $ 15,181 Amounts paid to a director and certain officers of the Company (b) $ 349 $ 593 $ 383 Amounts received from certain officers of the Company (c) $ 36 $ 237 $ 169 (a) Amounts include royalties on certain properties and lease bonus payments paid to a partnership in which a director of the Company is the general partner and owns a 3.5 percent partnership interest. (b) Amounts include revenue interests, overriding royalty interests and net profits interests in properties owned by the Company made to a director and certain officers (or affiliated entities). Amounts also include payments for an acreage acquisition and lease bonuses to an affiliated entity of an office r . (c) Amounts include payments to the Company as a result of activity on oil and natural gas properties in which certain officers (or affiliated entities) have an interest .

Net income per share (Tables)

Net income per share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Reconciliation of earnings attributable to common shares, basic and diluted	The following table reconcile s 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 shar e amounts for the years ended December 31, 2016 , 2015 a nd 2014 , respectively, under the two-class method : Years Ended December 31, (in thousands, except per share amounts) 2016 2015 2014 Net income (loss) as reported $ (1,462,446) $ 65,900 $ 538,175 Participating basic earnings (a) - (635) (5,961) Basic earnings attributable to common stockholders (1,462,446) 65,265 532,214 Reallocation of participating earnings - 2 16 Diluted earnings attributable to common stockholders $ (1,462,446) $ 65,267 $ 532,230 Earnings per common share: Basic $ (10.85) $ 0.54 $ 4.89 Diluted $ (10.85) $ 0.54 $ 4.88 (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 years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31, (in thousands) 2016 2015 2014 Weighted average common shares outstanding: Basic 134,755 119,926 108,844 Dilutive common stock options - 25 83 Dilutive performance units - 422 205 Diluted 134,755 120,373 109,132

Other current liabilities (Tabl

Other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
components of the Company's other current liabilities	The following table provides the components of the Company’s other current liabilities at December 31, 2016 and 2015 : December 31, (in thousands) 2016 2015 Other current liabilities: Accrued production costs $ 62,573 $ 70,876 Payroll related matters 34,647 29,411 Accrued interest 31,719 68,925 Asset retirement obligations 10,035 8,626 Other 12,596 7,072 Other current liabilities $ 151,570 $ 184,910

Subsidiary guarantors (Tables)

Subsidiary guarantors (Tables)	12 Months Ended
	Dec. 31, 2016
Guarantees [Abstract]
Condensed Consolidating Balance Sheet	The following condensed consolidating balance s heets at December 31, 2016 and 2015 , condensed c o nsolidating statements of o perations and condensed consolidating statements of cash flows for the years ended December 31, 2016 , 2015 and 2014 , present financial inform ation 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 basis and the consolidation and elimination entrie s 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 are not restricted from making distributions to the Company. Condensed Consolidating Balance Sheet December 31, 2016 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,991,238 $ (335,771) $ (8,655,467) $ - Other current assets 12,519 533,975 - 546,494 Oil and natural gas properties, net - 11,086,435 - 11,086,435 Property and equipment, net - 215,998 - 215,998 Investment in subsidiaries 1,988,962 - (1,988,962) - Other long-term assets 10,909 259,490 - 270,399 Total assets $ 11,003,628 $ 11,760,127 $ (10,644,429) $ 12,119,326 LIABILITIES AND EQUITY Accounts payable - related parties $ (335,771) $ 8,991,238 $ (8,655,467) $ - Other current liabilities 114,224 638,962 - 753,186 Long-term debt 2,740,580 - - 2,740,580 Other long-term liabilities 861,902 140,965 - 1,002,867 Equity 7,622,693 1,988,962 (1,988,962) 7,622,693 Total liabilities and equity $ 11,003,628 $ 11,760,127 $ (10,644,429) $ 12,119,326 Condensed Consolidating Balance Sheet December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total ASSETS Accounts receivable - related parties $ 8,502,099 $ 1,162,297 $ (9,664,396) $ - Other current assets 753,716 560,834 - 1,314,550 Oil and natural gas properties, net - 10,798,497 - 10,798,497 Property and equipment, net - 178,450 - 178,450 Investment in subsidiaries 3,698,485 - (3,698,485) - Other long-term assets 182,623 167,756 - 350,379 Total assets $ 13,136,923 $ 12,867,834 $ (13,362,881) $ 12,641,876 LIABILITIES AND EQUITY Accounts payable - related parties $ 1,162,297 $ 8,502,099 $ (9,664,396) $ - Other current liabilities 69,514 526,906 - 596,420 Long-term debt 3,332,188 - - 3,332,188 Other long-term liabilities 1,630,373 140,344 - 1,770,717 Equity 6,942,551 3,698,485 (3,698,485) 6,942,551 Total liabilities and equity $ 13,136,923 $ 12,867,834 $ (13,362,881) $ 12,641,876
Condensed Consolidating Statement of Operations	The following condensed consolidating balance s heets at December 31, 2016 and 2015 , condensed c o nsolidating statements of o perations and condensed consolidating statements of cash flows for the years ended December 31, 2016 , 2015 and 2014 , present financial inform ation 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 basis and the consolidation and elimination entrie s 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 are not restricted from making distributions to the Company. Condensed Consolidating Statement of Operations For the Year Ended December 31, 2016 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,634,988 $ - $ 1,634,988 Total operating costs and expenses (370,824) (3,333,608) - (3,704,432) Loss from operations (370,824) (1,698,620) - (2,069,444) Interest expense (201,753) (1,765) - (203,518) Loss on extinguishment of debt (56,436) - - (56,436) Other, net (1,709,523) (9,138) 1,709,523 (9,138) Loss before income taxes (2,338,536) (1,709,523) 1,709,523 (2,338,536) Income tax benefit 876,090 - - 876,090 Net loss $ (1,462,446) $ (1,709,523) $ 1,709,523 $ (1,462,446) Condensed Consolidating Statement of Operations For the Year Ended December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 1,803,573 $ - $ 1,803,573 Total operating costs and expenses 697,247 (2,173,606) - (1,476,359) Income (loss) from operations 697,247 (370,033) - 327,214 Interest expense (213,416) (1,968) - (215,384) Other, net (386,560) (14,559) 386,560 (14,559) Income (loss) before income taxes 97,271 (386,560) 386,560 97,271 Income tax expense (31,371) - - (31,371) Net income (loss) $ 65,900 $ (386,560) $ 386,560 $ 65,900 Condensed Consolidating Statement of Operations For the Year Ended December 31, 2014 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Total operating revenues $ - $ 2,660,147 $ - $ 2,660,147 Total operating costs and expenses 888,632 (2,468,342) - (1,579,710) Income from operations 888,632 191,805 - 1,080,437 Interest expense (216,661) - - (216,661) Loss on extinguishment of debt (4,316) - - (4,316) Other, net 188,305 (3,501) (188,304) (3,500) Income before income taxes 855,960 188,304 (188,304) 855,960 Income tax expense (317,785) - - (317,785) Net income $ 538,175 $ 188,304 $ (188,304) $ 538,175
Condensed Consolidating Statement of Cash Flows	The following condensed consolidating balance s heets at December 31, 2016 and 2015 , condensed c o nsolidating statements of o perations and condensed consolidating statements of cash flows for the years ended December 31, 2016 , 2015 and 2014 , present financial inform ation 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 basis and the consolidation and elimination entrie s 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 are not restricted from making distributions to the Company. Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2016 Parent Issuer Subsidiary Guarantors Consolidating Entries (in thousands) Total Net cash flows provided by (used in) operating activities $ (664,870) $ 2,049,318 $ - $ 1,384,448 Net cash flows used in investing activities - (2,224,656) - (2,224,656) Net cash flows provided by financing activities 664,919 - - 664,919 Net increase (decrease) in cash and cash equivalents 49 (175,338) - (175,289) Cash and cash equivalents at beginning of period - 228,550 - 228,550 Cash and cash equivalents at end of period $ 49 $ 53,212 $ - $ 53,261 Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2015 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (1,393,290) $ 2,923,711 $ - $ 1,530,421 Net cash flows used in investing activities - (2,602,641) - (2,602,641) Net cash flows provided by (used in) financing activities 1,393,290 (92,541) - 1,300,749 Net increase in cash and cash equivalents - 228,529 - 228,529 Cash and cash equivalents at beginning of period - 21 - 21 Cash and cash equivalents at end of period $ - $ 228,550 $ - $ 228,550 Condensed Consolidating Statement of Cash Flows For the Year Ended December 31, 2014 Parent Subsidiary Consolidating (in thousands) Issuer Guarantors Entries Total Net cash flows provided by (used in) operating activities $ (816,386) $ 2,562,156 $ - $ 1,745,770 Net cash flows used in investing activities - (2,617,979) - (2,617,979) Net cash flows provided by financing activities 816,386 55,823 - 872,209 Net increase (decrease) in cash and cash equivalents - - - - Cash and cash equivalents at beginning of period - 21 - 21 Cash and cash equivalents at end of period $ - $ 21 $ - $ 21

Subsequent events (Tables)

Subsequent events (Tables)	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
New commodity derivative contracts	After December 31, 2016 , the Company entered into the following additional oil price swaps to hedge additional amounts of the Company’s estimated future production: First Second Third Fourth Quarter Quarter Quarter Quarter Total Oil Swaps: (a) 2017: Volume (Bbl) 403,000 1,360,000 1,044,000 868,000 3,675,000 Price per Bbl $ 55.32 $ 55.20 $ 55.36 $ 55.56 $ 55.34 2018: Volume (Bbl) 736,000 652,000 580,000 523,000 2,491,000 Price per Bbl $ 55.47 $ 55.48 $ 55.54 $ 55.61 $ 55.52 2019: Volume (Bbl) 2,355,000 2,253,000 2,163,000 2,083,000 8,854,000 Price per Bbl $ 55.15 $ 55.11 $ 55.14 $ 55.16 $ 55.14 (a) The index prices for the oil price swaps are based on the NYMEX – WTI monthly average futures price.

Summary Of Significant Accoun42

Summary Of Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Summary Of Significant Accounting Policies Narrative [Abstract]
Senior notes issuance costs, net		$ 31,593	$ 42,885
Allowance for Doubtful Accounts Receivable		1,200	1,200
Accumulated amortization of senior note deferred loan costs		12,100	18,700
Credit Facility deferred loan costs, net		10,909	15,585
Accumulated amortization of Credit Facility deferred loan costs		$ 55,700	51,000
Estimated economic life of gross operating rights in years		25 years
Depletion expense from operations		$ 1,145,200	1,203,500	$ 960,900
Impairments of long-lived assets		1,524,645	60,529	447,151
Impairment of Leasehold		59,800	34,500	217,300
Other property and equipment, net		215,998	178,450
Other property and equipment, accumulated depreciation		73,700	54,400
Depreciation expense on other property and equipment		20,600	18,300	17,300
Interest costs capitalized on other property and equipment		300	0	0
Funds held in escrow		43,000	0
Environmental liability accrued		1,400	1,000
Environmental libility expensed		7,000	2,700	4,000
Fees related to operation of jointly owned oil and natural gas properties		16,900	19,200	18,900
Interest costs capitalized on oil and gas properties		0	700	1,400
ASU 2016-09 Forfeiture estimate compensation expense	$ 8,200
ASU 2016-09 Excess tax benefit related to stock-based compensation	4,700	(669)	2,150	16,480
ASU 2016-09 Decrease to retained earnings	500
ASU 2016-09 Decrease to deferred income taxes	$ 7,700
Alpha Crude Connector [Member]
Equity Method Investments [Line Items]
Income (loss) from equity method investments		(2,100)	(4,100)	(1,300)
Interest costs capitalized on equity method investment		0	2,900	700
Total equity method investment		$ 128,700	98,900
Equity method investment ownership percentage		50.00%
Other [Member]
Equity Method Investments [Line Items]
Income (loss) from equity method investments		$ (2,100)	0	$ 0
Total equity method investment		$ 42,500	$ 20,800
Equity method investment ownership percentage		25.00%

Summary Of Significant Accoun43

Summary Of Significant Accounting Policies (Gross And Net Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Disclosure Summary Of Significant Accounting Policies Gross And Net Intangible Assets [Abstract]
Gross intangible - operating rights	$ 36,557	$ 36,557
Accumulated amortization	(12,325)	(10,864)
Net intangible - operating rights	$ 24,232	$ 25,693

Summary Of Significant Accoun44

Summary Of Significant Accounting Policies (Amortization Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Summary Of Significant Accounting Policies Amortization Expense [Abstract]
Amortization expense	$ 1,461	$ 1,461	$ 1,461

Summary Of Significant Accoun45

Summary Of Significant Accounting Policies (Estimated Future Aggregate Amortization Expense) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Disclosure Summary Of Significant Accounting Policies Estimated Future Aggregate Amortization Expense [Abstract]
2,017	$ 1,461
2,018	1,461
2,019	1,461
2,020	1,461
2,021	1,461
Thereafter	16,927
Net intangible - operating rights	$ 24,232	$ 25,693

Exploratory Well Costs (Capital

Exploratory Well Costs (Capitalized Exploratory Well Activity) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Exploratory Well Costs Capitalized Exploratory Well Activity [Abstract]
Beginning capitalized exploratory well costs	$ 116,198	$ 241,657	$ 144,504
Additions to exploratory well costs pending the determination of proved reserves	143,981	102,846	234,057
Reclassifications due to determination of proved reserves	(85,985)	(227,746)	(99,657)
Exploratory well costs charged to expense	(5,707)	(559)	(37,247)
Disposition of wells	(17,339)	0	0
Ending capitalized exploratory well costs	$ 151,148	$ 116,198	$ 241,657

Exploratory Well Costs (Aging O

Exploratory Well Costs (Aging Of Capitalized Exploratory Well Costs Based On The Date Of Drilling) (Detail) $ in Thousands	Dec. 31, 2016USD ($)Number	Dec. 31, 2015USD ($)Number	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
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	$ 141,595	$ 98,764
Capitalized exploratory well costs that have been capitalized for a period greater than one year	9,553	17,434
Total capitalized exploratory well costs	$ 151,148	$ 116,198	$ 241,657	$ 144,504
Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects | Number	8	8

Exploratory Well Costs (Narrati

Exploratory Well Costs (Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Oil And Gas In Process Activities [Line Items]
Capitalized Exploratory Well Costs That Have Been Capitalized For Period Greater Than One Year	$ 9,553	$ 17,434
Northern Delaware Basin Project [Member]
Oil And Gas In Process Activities [Line Items]
Capitalized Exploratory Well Costs That Have Been Capitalized For Period Greater Than One Year	4,900
Midland Basin Project [Member]
Oil And Gas In Process Activities [Line Items]
Capitalized Exploratory Well Costs That Have Been Capitalized For Period Greater Than One Year	1,700
Projects Operated by Others [Member]
Oil And Gas In Process Activities [Line Items]
Capitalized Exploratory Well Costs That Have Been Capitalized For Period Greater Than One Year	$ 3,000

Acquisitions And Divestitures (

Acquisitions And Divestitures (Narrative) (Detail) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total consideration paid for net assets	$ 1,700,000
Clayton Williams [Member]
Business Acquisition [Line Items]
Gain (loss) on disposition of assets		$ (50,000)
Reliance [Member]
Business Acquisition [Line Items]
Total consideration paid for net assets	1,715,575
Cash consideration	$ 1,175,708
Common stock issued in business combinations (Shares)	3.9
Equity consideration	$ 539,867
Revenues since acquisition date	29,200
Income from operations since acquisition date	9,600
Southern Delaware Basin [Member]
Business Acquisition [Line Items]
Cash consideration	$ 145,700
Common stock issued in business combinations (Shares)	2.2
Equity consideration	$ 230,800
Future Carry Amount	40,000
Northern Delaware Basin [Member]
Business Acquisition [Line Items]
Net Proceeds	292,000
Pre-tax gain on asset divestiture	$ 110,100

Acquisitions And Business Com50

Acquisitions And Business Combinations (Fair Value of Net Assets) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Total consideration paid for net assets	$ 1,700,000
Reliance [Member]
Business Acquisition [Line Items]
Proved oil and natural gas properties	729,814
Unproved oil and natural gas properties	972,236
Other assets	34,000
Total assets acquired	1,736,050
Current liabilities, including current portion of asset retirement obligations	(8,225)
Asset retirement obligations assumed	(12,250)
Fair value of net assets acquired	1,715,575
Cash consideration	1,175,708
Non-cash consideration, including equity	539,867
Total consideration paid for net assets	$ 1,715,575

Acquisitions And Business Com51

Acquisitions And Business Combinations (Pro Forma Data) (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition, Pro Forma Information [Abstract]
Business Acquisition, Pro Forma Revenue	$ 1,717,460	$ 1,976,356
Business Acquisition, Pro Forma Net Income (Loss)	$ (1,396,250)	$ 97,354
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ (10.36)	$ 0.81
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ (10.36)	$ 0.8

Asset Retirement Obligations (S

Asset Retirement Obligations (Schedule Of Asset Retirement Obligation Transactions) (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Asset Retirement Obligations Schedule Of Asset Retirement Obligation Transactions [Abstract]
Asset retirement obligations, beginning of period		$ 119,945	$ 119,881	$ 101,593
Liabilities incurred from new wells		2,113	4,052	5,324
Liabilities assumed in acquisitions		13,217	2,434	4,065
Accretion expense		7,133	7,600	7,072
Disposition of wells		(10,955)	0	0
Liabilities settled upon plugging and abandoning wells		(1,063)	(2,736)	(2,926)
Revision of estimates	[1]	0	(11,286)	4,753
Asset retirement obligations, end of period		$ 130,390	$ 119,945	$ 119,881
[1]	The downward revision to the Companyʼs asset retirement obligation estimates for the year ended December 31, 2015 is primarily due to a reduction in the future estimated abandonment costs.

Incentive Plans (Narrative) (De

Incentive Plans (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, employers contribution	$ 9.5	$ 9.5	$ 8.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 2.3	$ 0.4	$ 23.2
Performance unit awards vesting period	3 years
Approved and authorized awards	10,500,000
Awards available for future grant	2,400,000
Plan 401 k [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan employer's contribution match percentage	100.00%
Defined contribution plan, employee contribution	10.00%

Incentive Plans (Schedule Of Re

Incentive Plans (Schedule Of Restricted Stock Awards Activity) (Detail) - 2015 Stock Incentive Plan [Member] - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding at beginning of period	1,199,647
Shares granted	450,981
Shares cancelled / forfeited	(93,018)
Lapse of restrictions	(400,340)
Outstanding at end of period	1,157,270	1,199,647
Weighted Average Grant Date Fair Value, Outstanding at beginning of year	$ 110.14
Shares Granted - Weighted Average Grant Date Fair Value Per Share	112.78	$ 109.76	$ 129.12
Shares cancelled / forfeited - Weighted Average Grant Date Fair Value per share	117.7
Lapse of Restrictions - Weighted Average Grant Date Fair Value per share	96.48
Weighted Average Grant Date Fair Value, Outstanding at end of year	$ 115.29	$ 110.14

Incentive Plans (Summary Inform

Incentive Plans (Summary Information For Stock-Based Compensation For Restricted Stock Awards) (Detail) - Restricted Stock [Member] - 2015 Stock Incentive Plan [Member] - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value for awards granted during the period	[1]	$ 50,863	$ 49,659	$ 57,940
Fair value for awards vested during the period		44,881	35,700	59,226
Stock-based compensation expense from restricted stock		40,801	43,185	36,585
Income tax benefit related to restricted stock		$ 14,970	$ 16,049	$ 13,672
Shares Granted - Weighted Average Grant Date Fair Value Per Share		$ 112.78	$ 109.76	$ 129.12
[1]	The weighted average grant date fair value per share amounts were $112.78, $109.76, and $129.12 for the years ended December 31, 2016, 2015 and 2014, respectively.

Incentive Plans (Schedule Of St

Incentive Plans (Schedule Of Stock Option Awards Activity) (Detail) - 2015 Stock Incentive Plan [Member] - Stock Options [Member]	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding at beginning of period (Shares) | shares	42,901
Options exercised (Shares) | shares	(22,901)
Outstanding at end of period (Shares) | shares	20,000
Vested and exercisable at end of period (Shares) | shares	20,000
Outstanding at beginning of period | $ / shares	$ 18.1
Options exercised | $ / shares	20.52
Outstanding at end of period | $ / shares	15.33
Vested and exercisable at end of period - weighted average exercise price | $ / shares	$ 15.33

Incentive Plans (Summary Info57

Incentive Plans (Summary Information For Vested And Exercisable Stock Options Outstanding) (Detail) - 2015 Stock Incentive Plan [Member] - Stock Options [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Vested and exercisable at end of period (Shares) | shares	20,000
Weighted Average Remaining Contractual Life, Vested and exercisable options, years	11 months
Vested and exercisable at end of period - weighted average exercise price	$ 15.33
Intrinsic Value, Vested and exercisable options | $	$ 2,366
Range Three [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price	$ 12.85
Vested and exercisable at end of period (Shares) | shares	15,000
Weighted Average Remaining Contractual Life, Vested and exercisable options, years	7 months
Vested and exercisable at end of period - weighted average exercise price	$ 12.85
Intrinsic Value, Vested and exercisable options | $	$ 1,812
Range Four [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price	$ 22.77
Vested and exercisable at end of period (Shares) | shares	5,000
Weighted Average Remaining Contractual Life, Vested and exercisable options, years	1 year 10 months
Vested and exercisable at end of period - weighted average exercise price	$ 22.77
Intrinsic Value, Vested and exercisable options | $	$ 554

Incentive Plans (Summary Info58

Incentive Plans (Summary Information For Stock-Based Compensation For Stock Options) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options [Member] | 2015 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Deductions in current taxable income related to stock options exercised	$ 271	$ 415	$ 23,208

Incentive Plans (Summary Of Ass

Incentive Plans (Summary Of Assumptions To Estimate Fair Value of Performance Unit Awards) (Detail) - 2015 Stock Incentive Plan [Member] - Performance Units [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	1.31%	1.07%	0.76%
Volatility assumption - minimum	31.60%	26.10%	29.20%
Volatility assumption - maximum	59.00%	43.00%	42.20%

Incentive Plans (Schedule Of Pe

Incentive Plans (Schedule Of Performance Unit Awards Activity) (Detail) - 2015 Stock Incentive Plan [Member] - Performance Units [Member] - $ / shares		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance units outstanding at beginning of period (Shares)		315,755
Units granted	[1]	161,361
Units forfeited		(9,285)
Units vested	[2]	(136,305)
Performance units outstanding at end of period (Shares)		331,526	315,755
Weighted Average Grant Date Fair Value, Outstanding at beginning of year		$ 149.21
Shares Granted - Grant Date Fair Value - Performance Units		114.81	$ 156.86	$ 139.54
Shares Forfeited - Grant Date Fair Value - Performance Units		140.66
Shares Vested - Grant Date Fair Value - Performance Units		139.54
Weighted Average Grant Date Fair Value, Outstanding at end of year		$ 136.68	$ 149.21
Performance Percentage Of Actual Payout Minimum		0.00%
Performance Percentage Of Actual Payout Maximum		300.00%
Number Of Shares Earned For Each Vested Award		248,763
[1]	Reflects the amount of performance units granted. The actual payout of shares will be between zero and 300 percent of the performance units granted depending on the Company’s performance at the end of the performance period.
[2]	On December 31, 2016, the performance period ended for these performance units. Each unit converted into 1.825 shares representing 248,763 shares of common stock issued on January 2, 2017.

Incentive Plans (Summary Info61

Incentive Plans (Summary Information For Stock-Based Compensation For Performance Units) (Detail) - Performance Units [Member] - 2015 Stock Incentive Plan [Member] - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value for awards granted during the period	[1]	$ 18,526	$ 27,659	$ 19,455
Fair value for awards vested during the period		33,247	16,458	0
Stock-based compensation expense from performance units		18,126	19,888	10,545
Income tax benefit related to performance units		$ 6,650	$ 7,391	$ 3,941
Shares Granted - Grant Date Fair Value - Performance Units		$ 114.81	$ 156.86	$ 139.54
[1]	The weighted average grant date fair value per unit amounts were $114.81, $156.86 and $139.54 for the years ended December 31, 2016, 2015 and 2014, respectively.

Incentive Plans (Summary For Fu

Incentive Plans (Summary For Future Stock-Based Compensation Expense) (Detail) - 2015 Stock Incentive Plan [Member] $ in Thousands	Dec. 31, 2016USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
2,017	$ 44,991
2,018	22,609
2,019	5,341
2,020	423
2,021	85
Thereafter	197
Total	73,646
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
2,017	31,622
2,018	17,140
2,019	5,341
2,020	423
2,021	85
Thereafter	197
Total	54,808
Performance Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
2,017	13,369
2,018	5,469
2,019	0
2,020	0
2,021	0
Thereafter	0
Total	$ 18,838

Disclosures about Fair Value Me

Disclosures about Fair Value Measurements (Narrative) (Detail) $ in Thousands	3 Months Ended					12 Months Ended
	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2024$ / bbl$ / Mcf	Dec. 31, 2020$ / Mcf	Dec. 31, 2017$ / bbl$ / Mcf	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Management Estimate of Future Oil Price | $ / bbl						57.41		56.19
Management Estimate of Future Natural Gas Price | $ / Mcf						3.38	2.88	3.61
Annual discount rate									10.00%
Carrying Amount	$ 3,437,612	$ 104,982	$ 18,023	$ 677,021	$ 26,790
Impairment Expense	$ 1,524,645	$ 52,941	$ 7,588	$ 431,675	$ 15,476

Disclosures About Fair Value 64

Disclosures About Fair Value Of Financial Instruments (Carrying Amounts And Fair Values Of The Company's Financial Instruments) (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		$ 3,551	$ 819,536
Derivative instruments, Liabilities		177,949	0
Credit facility		0	0
Seven Point Zero Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	595,500
Six Point Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	579,000
Five Point Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	619,500	553,500
Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Three [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	1,621,382	1,453,005
Four Point Three Seven Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	598,800	0
Carrying Reported Amount Fair Value Disclosure [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, Assets		3,551	819,536
Derivative instruments, Liabilities		177,949	0
Carrying Reported Amount Fair Value Disclosure [Member] | Seven Point Zero Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	592,414
Carrying Reported Amount Fair Value Disclosure [Member] | Six Point Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	0	591,549
Carrying Reported Amount Fair Value Disclosure [Member] | Five Point Five Percent Unsecured Senior Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	593,787	592,899
Carrying Reported Amount Fair Value Disclosure [Member] | Five Point Five Percent Unsecured Senior Notes Due Twenty Twenty Three [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unsecured senior notes	[1]	1,554,710	1,555,326
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]	$ 592,083	$ 0
[1]	The carrying value includes associated deferred loan costs and any premium.

Disclosures About Fair Value 65

Disclosures About Fair Value Measurements (Company's Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	$ 3,551	$ 652,498
Noncurrent derivative contracts, assets	0	167,038
Current derivative contracts, liabilities	(82,079)	0
Noncurrent derivative contracts, liabilities	(95,870)	0
Net financial assets (liabilities)	(174,398)	819,536
Estimate Of Fair Value Fair Value Disclosure [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	58,351	684,029
Noncurrent derivative contracts, assets	62	175,267
Current derivative contracts, liabilities	(136,879)	(31,531)
Noncurrent derivative contracts, liabilities	(95,932)	(8,229)
Net financial assets (liabilities)	(174,398)	819,536
Gross Amounts Offset in Consolidated Balance Sheet [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	(54,800)	(31,531)
Noncurrent derivative contracts, assets	(62)	(8,229)
Current derivative contracts, liabilities	54,800	31,531
Noncurrent derivative contracts, liabilities	62	8,229
Net financial assets (liabilities)	0	0
Fair Value Inputs Level 1 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	0	0
Noncurrent derivative contracts, assets	0	0
Current derivative contracts, liabilities	0	0
Noncurrent derivative contracts, liabilities	0	0
Net financial assets (liabilities)	0	0
Fair Value Inputs Level 2 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	58,351	684,029
Noncurrent derivative contracts, assets	62	175,267
Current derivative contracts, liabilities	(136,879)	(31,531)
Noncurrent derivative contracts, liabilities	(95,932)	(8,229)
Net financial assets (liabilities)	(174,398)	819,536
Fair Value Inputs Level 3 [Member]
Fair Value Of Derivatives Disclosure Information [Line Items]
Current derivative contracts, assets	0	0
Noncurrent derivative contracts, assets	0	0
Current derivative contracts, liabilities	0	0
Noncurrent derivative contracts, liabilities	0	0
Net financial assets (liabilities)	$ 0	$ 0

Disclosures About Fair Value 66

Disclosures About Fair Value Of Financial Instruments (Carrying Amounts, Estimated Fair Values And Impairment Expense Of Long-Lived Assets For Continuing And Discontinued Operations) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 3,437,612	$ 104,982	$ 18,023	$ 677,021	$ 26,790
Estimated Fair Value (Level 3)	1,912,967	52,041	10,435	245,346	11,314
Impairment Expense	$ 1,524,645	$ 52,941	$ 7,588	$ 431,675	$ 15,476

Derivative Financial Instrume67

Derivative Financial Instruments (Gains And Losses Reported In Earnings Related To Commodity Derivative Instruments) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity And Interest Rate Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	$ 625,250	$ 632,916	$ 71,983
Gain (loss) on derivatives	(368,684)	699,752	890,917
Oil Commodity Derivative [Member]
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity And Interest Rate Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	608,847	597,297	76,335
Gain (loss) on derivatives	(337,175)	675,303	869,421
Natural Gas Commodity Derivative [Member]
Derivative Financial Instruments Gains And Losses Reported In Earnings Related To Commodity And Interest Rate Derivative Instruments [Line Items]
Net settlements received from (paid on) derivatives	16,403	35,619	(4,352)
Gain (loss) on derivatives	$ (31,509)	$ 24,449	$ 21,496

Derivative Financial Instrume68

Derivative Financial Instruments (Outstanding Commodity Derivative Contracts) (Detail) - Minimum [Member]		3 Months Ended								12 Months Ended
		Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2018MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU	Sep. 30, 2017MMBTUbbl$ / bbl$ / MMBTU	Jun. 30, 2017MMBTUbbl$ / bbl$ / MMBTU	Mar. 31, 2017MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2018MMBTUbbl$ / bbl$ / MMBTU	Dec. 31, 2017MMBTUbbl$ / bbl$ / MMBTU
Oil Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[1]					5,465,080	5,854,370	6,348,480	7,020,870		24,688,800
Price - Current Year | $ / bbl	[1]					51.48	51.25	57.66	57		54.58
Volume - Year One | bbl	[1]	4,418,007	4,624,318	4,864,170	5,139,629					19,046,124
Price - Year One | $ / bbl	[1]	51.12	51.28	51.46	51.63					51.38
Oil Basis Swaps [Member]
Derivative [Line Items]
Volume - Current Year | bbl	[2]					5,290,000	5,290,000	6,141,500	6,603,000		23,324,500
Price - Current Year | $ / bbl	[2]					(0.49)	(0.49)	(1.03)	(1)		(0.78)
Volume - Year One | bbl	[2]	2,392,000	2,392,000	2,366,000	2,340,000					9,490,000
Price - Year One | $ / bbl	[2]	(0.98)	(0.98)	(0.98)	(0.98)					(0.98)
Natural Gas Swap [Member]
Derivative [Line Items]
Volume - Current Year | MMBTU	[3]					11,743,000	12,365,441	13,289,642	14,461,315		51,859,398
Price - Current Year | $ / MMBTU	[3]					3.04	3.05	3.05	3.07		3.06
Volume - Year One | MMBTU	[3]	4,844,000	5,029,000	5,216,000	5,506,000					20,595,000
Price - Year One | $ / MMBTU	[3]	3.03	3.03	3.04	3.04					3.03
[1]	The index prices for the oil price swaps are based on the 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 Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Credit facility	$ 0	$ 0
Unamortized original issue premium	22,173	25,073
Senior notes issuance costs, net	(31,593)	(42,885)
Less: current portion	0	0
Total long-term debt	2,740,580	3,332,188
7.0% unsecured senior notes due 2021
Debt Instrument [Line Items]
Unsecured senior notes	0	600,000
6.5% unsecured senior notes due 2022
Debt Instrument [Line Items]
Unsecured senior notes	0	600,000
5.5% unsecured senior notes due 2022
Debt Instrument [Line Items]
Unsecured senior notes	600,000	600,000
5.5% unsecured senior notes due 2023
Debt Instrument [Line Items]
Unsecured senior notes	1,550,000	1,550,000
4.375% unsecured senior notes due 2025
Debt Instrument [Line Items]
Unsecured senior notes	$ 600,000	$ 0

Debt (Narrative) (Detail)

Debt (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Line Items]
Line of credit maturity date	May 9, 2019
Aggregate lender commitments	$ 2,500,000
Aggregate maximum borrowing base	2,800,000
Unused lender commitments	$ 2,500,000
Line of credit interest rate	3.75%
Debt Related Commitment Fees	$ 7,600	$ 7,000	$ 7,700
Loss on extinguishment of debt	(56,436)	0	(4,316)
Senior notes issuance costs, net	31,593	42,885
Make-whole premium for early redemption	$ 42,450	0	$ 0
Minimum [Member]
Debt Disclosure [Line Items]
Commitment fees on unused portion of available commitment	0.30%
Maximum [Member]
Debt Disclosure [Line Items]
Commitment fees on unused portion of available commitment	0.375%
JPM Prime Rate [Member] | Minimum [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	0.25%
JPM Prime Rate [Member] | Maximum [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	1.25%
Eurodollar Future [Member] | Minimum [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	1.25%
Eurodollar Future [Member] | Maximum [Member]
Debt Disclosure [Line Items]
Line Of Credit Facility Interest Rate At Period End	2.25%
4.375% unsecured senior notes due 2025
Debt Disclosure [Line Items]
Unsecured senior notes	$ 600,000	0
Interest rate	4.375%
Debt instrument percent of par value issued	100.00%
Proceeds from Debt, Net of Issuance Costs	$ 592,100
7.0% unsecured senior notes due 2021
Debt Disclosure [Line Items]
Unsecured senior notes	$ 0	600,000
Percent of par redeemed	103.50%
Loss on extinguishment of debt	$ 27,700
Make-whole premium for early redemption	21,000
Write-off of unamortized deferred loan costs	6,700
Outstanding principal amount redeemed	600,000
6.5% unsecured senior notes due 2022
Debt Disclosure [Line Items]
Unsecured senior notes	0	600,000
Loss on extinguishment of debt	28,700
Outstanding principal amount satisfied and discharged	$ 600,000
Percent of par satisfied and discharged	103.25%
Make-whole premium for early redemption	$ 19,500
Write-off of unamortized deferred loan costs	7,300
Interest paid on senior notes	19,600
5.5% unsecured senior notes due 2022
Debt Disclosure [Line Items]
Unsecured senior notes	600,000	600,000
5.5% unsecured senior notes due 2023
Debt Disclosure [Line Items]
Unsecured senior notes	$ 1,550,000	$ 1,550,000

Debt (Principal Maturities Of D

Debt (Principal Maturities Of Debt) (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Disclosure Debt Principal Maturities Of Debt [Abstract]
2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	0
Thereafter	2,750,000
Total	$ 2,750,000

Debt (Summary Of Interest Expen

Debt (Summary Of Interest Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Debt Summary Of Interest Expense [Abstract]
Cash payments for interest	$ (232,173)	$ (211,443)	$ (211,342)
Amortization of original issue discount (premium)	(2,900)	(2,747)	(2,599)
Amortization of deferred loan origination costs	9,937	9,971	10,937
Accretion expense	1,939	1,795	0
Net changes in accruals	(37,379)	(165)	(737)
Interest costs incurred	203,770	220,297	218,943
Less: capitalized interest	(252)	(4,913)	(2,282)
Total interest expense	$ 203,518	$ 215,384	$ 216,661

Commitments And Contingencies73

Commitments And Contingencies (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments [Line Items]
Annual officers' salaries	$ 7.4
Accrued Exposure	7.1	$ 13.4
Operating leases, lease payments	$ 8.4	$ 8	$ 7.2

Commitments And Contingencies74

Commitments And Contingencies (Future Commitments) (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Disclosure Commitments And Contingencies Future Commitments [Abstract]
2,017	$ 56,649
2,018	69,195
2,019	49,327
2,020	24,669
2,021	20,770
Thereafter	97,869
Total	$ 318,479

Commitments And Contingencies75

Commitments And Contingencies (Future Minimum Lease Commitments Under Non-Cancellable Operating Leases) (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Disclosure Commitments And Contingencies Future Minimum Lease Commitments Under Non Cancellable Operating Leases [Abstract]
2,017	$ 8,988
2,018	7,945
2,019	6,419
2,020	4,966
2,021	4,088
Thereafter	1,002
Total	$ 33,408

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Income Taxes Narrative [Abstract]
Income taxes receivable, current	$ 4,500	$ 37,300
Income taxes payable, current	0	1,000
Total consideration paid for net assets	1,700,000
Change in estimated effective statutory state income tax	(20,909)	(9,026)	$ (7,945)
Income (loss) from operations before income taxes	$ (2,338,536)	$ 97,271	$ 855,960
State Tax Rate Increase (Reduction)	0.90%	(9.30%)
Income Tax Rate Increase (Reduction)	5.20%
Net deferred tax liabilities	$ 766,032	$ 1,630,373
Federal Net Operating Loss	477,700
Federal NOL due to stock-based compensation	12,600
State Net Operating Loss	248,800
State NOL due to stock-based compensation	8,500
AMT credits	4,800
Charitable contribution carryforwards	$ 6,000

Income Taxes (Company's Income

Income Taxes (Company's Income Tax Expense (Benefit)) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Income Taxes Companys Income Tax Expense (Benefit) [Abstract]
Income tax expense (benefit) from continuing operations		$ (876,090)	$ 31,371	$ 317,785
Excess tax deficiency (benefit) related to stock-based compensation	$ (4,700)	669	(2,150)	(16,480)
Income Tax Expense (Benefit) Net Of Excess Tax Benefits, Total		$ (875,421)	$ 29,221	$ 301,305

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense (Benefit) Attributable To Income (Loss) From Continuing Operations) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Income Taxes Income Tax Expense (Benefit) Attributable To Income Loss From Continuing Operations [Abstract]
U.S. federal, current	$ (11,579)	$ 127	$ 16,621
U.S. state and local, current	(170)	1,622	4,997
Total current income tax expense (benefit)	(11,749)	1,749	21,618
U.S. federal, deferred	(770,734)	40,364	278,615
U.S. state and local, deferred	(93,607)	(10,742)	17,552
Total deferred income tax expense (benefit)	(864,341)	29,622	296,167
Total income tax expense (benefit) attributable to income from continuing operations	$ (876,090)	$ 31,371	$ 317,785

Income Taxes (Reconciliation Be

Income Taxes (Reconciliation Between The Income Tax Expense (Benefit) And The Reported Amounts Of Income Tax Expense (Benefiit)) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Income Taxes Reconciliation Between The Income Tax Expense Benefit And The Reported Amounts Of Income Tax Expense (Benefit) [Abstract]
Income (loss) at U.S. federal statutory rate	$ (818,488)	$ 34,045	$ 299,586
State income taxes (net of federal tax effect)	(40,015)	3,071	22,826
Revisions of previous estimates	746	(631)	738
Change in estimated effective statutory state income tax	(20,909)	(9,026)	(7,945)
Nondeductible expense & other	2,576	3,912	2,580
Total income tax expense (benefit) attributable to income from continuing operations	$ (876,090)	$ 31,371	$ 317,785
Effective tax rate	(37.50%)	32.30%	37.10%

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets and Liabilities [Abstract]
Stock Based Compensation	$ 39,192	$ 36,738
Derivative Instruments	63,986	0
Asset retirement obligation	47,840	44,573
Net operating losses and credits	177,264	194
Other	23,850	29,380
Total Deferred tax assets	352,132	110,885
Oil and Natural Gas Properties deduction of intangible drilling cost due to tax purpose	(1,095,173)	(1,420,275)
Intangible Assets - Operating rights	(8,891)	(9,548)
Derivative instruments	0	(304,550)
Other	(14,100)	(6,885)
Deferred Tax Liabilities, Gross	(1,118,164)	(1,741,258)
Net deferred tax liabilities	$ (766,032)	$ (1,630,373)

Major Customers and Derivativ81

Major Customers and Derivative Counterparties (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Plains Marketing and Transportation Inc [Member]
Revenue, Major Customer [Line Items]
Entity Wide Receivables Major Customer	$ 48.1
Plains Marketing and Transportation Inc [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Major Customer Percentage	29.00%	11.00%	6.00%
Holly Frontier Refining and Marketing LLC [Member]
Revenue, Major Customer [Line Items]
Entity Wide Receivables Major Customer	$ 26.5
Holly Frontier Refining and Marketing LLC [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Major Customer Percentage	16.00%	25.00%	17.00%
Enterprise Crude Oil LLC [Member]
Revenue, Major Customer [Line Items]
Entity Wide Receivables Major Customer	$ 23.7
Enterprise Crude Oil LLC [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Major Customer Percentage	7.00%	12.00%	12.00%
Western Refining Company LP [Member]
Revenue, Major Customer [Line Items]
Entity Wide Receivables Major Customer	$ 0.4
Western Refining Company LP [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Major Customer Percentage	0.00%	5.00%	12.00%

Related Party Transactions (Sch

Related Party Transactions (Schedule Of Related Party Transactions) (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Ownership interest in partnership		3.50%
Partnership (Director Ownership Interest) [Member]
Related Party Transaction [Line Items]
Amounts paid	[1]	$ 4,374,000	$ 5,745,000	$ 15,181,000
Director And Certain Officers [Member]
Related Party Transaction [Line Items]
Amounts paid	[2]	349,000	593,000	383,000
Payments From Officers	[3]	$ 36,000	$ 237,000	$ 169,000
[1]	Amounts include royalties on certain properties and lease bonus payments paid to a partnership in which a director of the Company is the general partner and owns a 3.5 percent partnership interest.
[2]	Amounts include revenue interests, overriding royalty interests and net profits interests in properties owned by the Company made to a director and certain officers (or affiliated entities). Amounts also include payments for an acreage acquisition and lease bonuses to an affiliated entity of an office r .
[3]	Amounts include payments to the Company as a result of activity on oil and natural gas properties in which certain officers (or affiliated entities) have an interest .

Net Income Per Share (Reconcili

Net Income Per Share (Reconciliation Of Earnings Attributable To Common Shares Basic And Diluted) (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss) as reported		$ (1,462,446)	$ 65,900	$ 538,175
Participating basic earnings	[1]	0	(635)	(5,961)
Basic earnings attributable to common stockholders		(1,462,446)	65,265	532,214
Reallocation of participating earnings		0	2	16
Diluted earnings attributable to common stockholders		$ (1,462,446)	$ 65,267	$ 532,230
Basic net income (loss)		$ (10.85)	$ 0.54	$ 4.89
Diluted net income (loss)		$ (10.85)	$ 0.54	$ 4.88
[1]	Unvested restricted stock awards represent participating securities because they participate in nonforfeitable dividends or distributions with the common equity holders of the Company. Participating earnings represent the distributed earnings of the Company attributable to the participating securities. Unvested restricted stock awards do not participate in undistributed net losses as they are not contractually obligated to do so.

Net Income Per Share (Reconci84

Net Income Per Share (Reconciliation Of The Weighted Average Common Shares Outstanding) (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Basic	134,755	119,926	108,844
Diluted	134,755	120,373	109,132
Stock Options [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	0	25	83
Performance Units [Member]
Reconciliation Of Basic Weighted Average Common Shares Outstanding To Diluted Weighted Average Common Shares Outstanding [Line Items]
Dilutive shares	0	422	205

Other Current Liabilities (Sche

Other Current Liabilities (Schedule Of Other Current Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Accrued production costs	$ 62,573	$ 70,876
Payroll related matters	34,647	29,411
Accrued interest	31,719	68,925
Asset retirement obligations	10,035	8,626
Other	12,596	7,072
Other current liabilities	$ 151,570	$ 184,910

Subsidiary Guarantors (Condense

Subsidiary Guarantors (Condensed Consolidating Balance Sheet) (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Accounts receivable - related parties	$ 0	$ 0
Other current assets	546,494,000	1,314,550,000
Oil and natural gas properties, net	11,086,435,000	10,798,497,000
Property and equipment, net	215,998,000	178,450,000
Investment in subsidiaries	0	0
Other long-term assets	270,399,000	350,379,000
Total assets	12,119,326,000	12,641,876,000
LIABILITIES AND EQUITY
Accounts payable - related parties	0	0
Other current liabilities	753,186,000	596,420,000
Long-term debt	2,740,580,000	3,332,188,000
Other long-term liabilities	1,002,867,000	1,770,717,000
Equity	7,622,693,000	6,942,551,000	$ 5,280,788,000	$ 3,757,949,000
Total liabilities and stockholders' equity	12,119,326,000	12,641,876,000
Consolidation Eliminations [Member]
ASSETS
Accounts receivable - related parties	(8,655,467,000)	(9,664,396,000)
Other current assets	0	0
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	(1,988,962,000)	(3,698,485,000)
Other long-term assets	0	0
Total assets	(10,644,429,000)	(13,362,881,000)
LIABILITIES AND EQUITY
Accounts payable - related parties	(8,655,467,000)	(9,664,396,000)
Other current liabilities	0	0
Long-term debt	0	0
Other long-term liabilities	0	0
Equity	(1,988,962,000)	(3,698,485,000)
Total liabilities and stockholders' equity	(10,644,429,000)	(13,362,881,000)
Parent Company [Member]
ASSETS
Accounts receivable - related parties	8,991,238,000	8,502,099,000
Other current assets	12,519,000	753,716,000
Oil and natural gas properties, net	0	0
Property and equipment, net	0	0
Investment in subsidiaries	1,988,962,000	3,698,485,000
Other long-term assets	10,909,000	182,623,000
Total assets	11,003,628,000	13,136,923,000
LIABILITIES AND EQUITY
Accounts payable - related parties	(335,771,000)	1,162,297,000
Other current liabilities	114,224,000	69,514,000
Long-term debt	2,740,580,000	3,332,188,000
Other long-term liabilities	861,902,000	1,630,373,000
Equity	7,622,693,000	6,942,551,000
Total liabilities and stockholders' equity	11,003,628,000	13,136,923,000
Guarantor Subsidiaries [Member]
ASSETS
Accounts receivable - related parties	(335,771,000)	1,162,297,000
Other current assets	533,975,000	560,834,000
Oil and natural gas properties, net	11,086,435,000	10,798,497,000
Property and equipment, net	215,998,000	178,450,000
Investment in subsidiaries	0	0
Other long-term assets	259,490,000	167,756,000
Total assets	11,760,127,000	12,867,834,000
LIABILITIES AND EQUITY
Accounts payable - related parties	8,991,238,000	8,502,099,000
Other current liabilities	638,962,000	526,906,000
Long-term debt	0	0
Other long-term liabilities	140,965,000	140,344,000
Equity	1,988,962,000	3,698,485,000
Total liabilities and stockholders' equity	$ 11,760,127,000	$ 12,867,834,000

Subsidiary Guarantors (Conden87

Subsidiary Guarantors (Condensed Consolidating Statement Of Operations) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements Captions [Line Items]
Total operating revenues	$ 1,634,988	$ 1,803,573	$ 2,660,147
Total operating costs and expenses	(3,704,432)	(1,476,359)	(1,579,710)
Income (loss) from operations	(2,069,444)	327,214	1,080,437
Interest expense	(203,518)	(215,384)	(216,661)
Loss on extinguishment of debt	(56,436)	0	(4,316)
Other, net	(9,138)	(14,559)	(3,500)
Income (loss) from operations before income taxes	(2,338,536)	97,271	855,960
Income tax (expense) benefit	876,090	(31,371)	(317,785)
Net income (loss)	(1,462,446)	65,900	538,175
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0	0
Total operating costs and expenses	0	0	0
Income (loss) from operations	0	0	0
Interest expense	0	0	0
Loss on extinguishment of debt	0	0	0
Other, net	1,709,523	386,560	(188,304)
Income (loss) from operations before income taxes	1,709,523	386,560	(188,304)
Income tax (expense) benefit	0	0	0
Net income (loss)	1,709,523	386,560	(188,304)
Parent Company [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	0	0	0
Total operating costs and expenses	(370,824)	697,247	888,632
Income (loss) from operations	(370,824)	697,247	888,632
Interest expense	(201,753)	(213,416)	(216,661)
Loss on extinguishment of debt	(56,436)	0	(4,316)
Other, net	(1,709,523)	(386,560)	188,305
Income (loss) from operations before income taxes	(2,338,536)	97,271	855,960
Income tax (expense) benefit	876,090	(31,371)	(317,785)
Net income (loss)	(1,462,446)	65,900	538,175
Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
Total operating revenues	1,634,988	1,803,573	2,660,147
Total operating costs and expenses	(3,333,608)	(2,173,606)	(2,468,342)
Income (loss) from operations	(1,698,620)	(370,033)	191,805
Interest expense	(1,765)	(1,968)	0
Loss on extinguishment of debt	0	0	0
Other, net	(9,138)	(14,559)	(3,501)
Income (loss) from operations before income taxes	(1,709,523)	(386,560)	188,304
Income tax (expense) benefit	0	0	0
Net income (loss)	$ (1,709,523)	$ (386,560)	$ 188,304

Subsidiary Guarantors (Conden88

Subsidiary Guarantors (Condensed Consolidating Statement Of Cash Flows) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements Captions [Line Items]
Net cash provided by (used in) operating activities	$ 1,384,448,000	$ 1,530,421,000	$ 1,745,770,000
Net cash flows provided by (used in) investing activities	(2,224,656,000)	(2,602,641,000)	(2,617,979,000)
Net cash flows provided by (used in) financing activities	664,919,000	1,300,749,000	872,209,000
Net increase (decrease) in cash and cash equivalents	(175,289,000)	228,529,000	0
Cash and cash equivalents at beginning of period	228,550,000	21,000	21,000
Cash and cash equivalents at end of period	53,261,000	228,550,000	21,000
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Net cash provided by (used in) operating activities	0	0	0
Net cash flows provided by (used in) investing activities	0	0	0
Net cash flows provided by (used in) financing activities	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
Parent Company [Member]
Condensed Financial Statements Captions [Line Items]
Net cash provided by (used in) operating activities	(664,870,000)	(1,393,290,000)	(816,386,000)
Net cash flows provided by (used in) investing activities	0	0	0
Net cash flows provided by (used in) financing activities	664,919,000	1,393,290,000	816,386,000
Net increase (decrease) in cash and cash equivalents	49,000	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	49,000	0	0
Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
Net cash provided by (used in) operating activities	2,049,318,000	2,923,711,000	2,562,156,000
Net cash flows provided by (used in) investing activities	(2,224,656,000)	(2,602,641,000)	(2,617,979,000)
Net cash flows provided by (used in) financing activities	0	(92,541,000)	55,823,000
Net increase (decrease) in cash and cash equivalents	(175,338,000)	228,529,000	0
Cash and cash equivalents at beginning of period	228,550,000	21,000	21,000
Cash and cash equivalents at end of period	$ 53,212,000	$ 228,550,000	$ 21,000

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Detail) - USD ($) shares in Millions, $ in Millions	1 Months Ended
	Feb. 28, 2017	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Alpha Crude Connector [Member]
Subsequent Event [Line Items]
Total equity method investment			$ 128.7	$ 98.9
Subsequent Event [Member]
Subsequent Event [Line Items]
Total joint venture proceeds from divestiture of equity method investment	$ 1,215
Proceeds From Sale Of Oil And Gas Property And Equipment	$ 802.8
Number of common stock issued		2.2
Cash paid to acquire		$ 150

Subsequent Events (New Commodit

Subsequent Events (New Commodity Derivative Contracts) (Detail) - Oil Swaps [Member] - Subsequent Event [Member] - Minimum [Member]		3 Months Ended												12 Months Ended
		Dec. 31, 2019bbl$ / bbl	Sep. 30, 2019bbl$ / bbl	Jun. 30, 2019bbl$ / bbl	Mar. 31, 2019bbl$ / bbl	Dec. 31, 2018bbl$ / bbl	Sep. 30, 2018bbl$ / bbl	Jun. 30, 2018bbl$ / bbl	Mar. 31, 2018bbl$ / bbl	Dec. 31, 2017bbl$ / bbl	Sep. 30, 2017bbl$ / bbl	Jun. 30, 2017bbl$ / bbl	Mar. 31, 2017bbl$ / bbl	Dec. 31, 2019bbl$ / bbl	Dec. 31, 2018bbl$ / bbl	Dec. 31, 2017bbl$ / bbl
Subsequent Event [Line Items]
Volume - Current Year | bbl	[1]									868,000	1,044,000	1,360,000	403,000			3,675,000
Price - Current Year | $ / bbl	[1]									55.56	55.36	55.2	55.32			55.34
Volume - Year One | bbl	[1]					523,000	580,000	652,000	736,000						2,491,000
Price - Year One | $ / bbl	[1]					55.61	55.54	55.48	55.47						55.52
Volume - Year Two | bbl	[1]	2,083,000	2,163,000	2,253,000	2,355,000									8,854,000
Price - Year Two | $ / bbl	[1]	55.16	55.14	55.11	55.15									55.14
[1]	The index prices for the oil price swaps are based on the NYMEX – West Texas Intermediate (“WTI”) monthly average futures price.