Matador Resources (MTDR) 10-Q 6 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Matador Resources Co
Entity Central Index Key	1,520,006
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		116,365,216

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - Unaudited - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash	$ 122,450	$ 96,505
Restricted cash	21,063	5,977
Accounts receivable
Oil and natural gas revenues	74,771	65,962
Joint interest billings	71,041	67,225
Other	4,726	8,031
Derivative instruments	5,875	1,190
Lease and well equipment inventory	12,557	5,993
Prepaid expenses and other assets	8,454	6,287
Total current assets	320,937	257,170
Oil and natural gas properties, full-cost method
Evaluated	3,338,515	3,004,770
Unproved and unevaluated	692,544	637,396
Midstream and other property and equipment	360,971	281,096
Less accumulated depletion, depreciation and amortization	(2,164,013)	(2,041,806)
Net property and equipment	2,228,017	1,881,456
Other assets	6,893	7,064
Total assets	2,555,847	2,145,690
Current liabilities
Accounts payable	25,278	11,757
Accrued liabilities	133,365	174,348
Royalties payable	69,751	61,358
Amounts due to affiliates	8,108	10,302
Derivative instruments	4,016	16,429
Advances from joint interest owners	18,814	2,789
Amounts due to joint ventures	3,373	4,873
Other current liabilities	893	750
Total current liabilities	263,598	282,606
Long-term liabilities
Senior unsecured notes payable	574,164	574,073
Asset retirement obligations	26,890	25,080
Amounts due to joint ventures	5,253	0
Other long-term liabilities	6,194	6,385
Total long-term liabilities	612,501	605,538
Commitments and contingencies
Shareholders’ equity
Common stock - $0.01 par value, 160,000,000 shares authorized; 116,461,171 and 108,513,597 shares issued; and 116,357,739 and 108,510,160 shares outstanding, respectively	1,165	1,085
Additional paid-in capital	1,916,821	1,666,024
Accumulated deficit	(390,784)	(510,484)
Treasury stock, at cost, 103,432 and 3,437 shares, respectively	(2,670)	(69)
Total Matador Resources Company shareholders’ equity	1,524,532	1,156,556
Non-controlling interest in subsidiaries	155,216	100,990
Total shareholders’ equity	1,679,748	1,257,546
Total liabilities and shareholders’ equity	$ 2,555,847	$ 2,145,690

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - Unaudited - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	160,000,000	120,000,000
Common stock, shares issued	116,461,171	108,513,597
Common stock, shares outstanding	116,357,739	108,510,160
Treasury stock, shares	103,432	3,437

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Oil and natural gas revenues	$ 209,019	$ 113,764	$ 390,973	$ 228,611
Third-party midstream services revenues	3,407	2,099	6,475	3,654
Realized (loss) gain on derivatives	(2,488)	558	(6,746)	(1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Total revenues	211,367	129,611	402,547	264,425
Expenses
Production taxes, transportation and processing	20,110	12,875	37,901	24,682
Lease operating	25,006	16,040	47,154	31,797
Plant and other midstream services operating	5,676	2,942	9,896	5,283
Depletion, depreciation and amortization	66,838	41,274	122,207	75,266
Accretion of asset retirement obligations	375	314	739	614
General and administrative	19,369	17,177	37,295	33,515
Total expenses	137,374	90,622	255,192	171,157
Operating income	73,993	38,989	147,355	93,268
Other income (expense)
Net gain on asset sales and inventory impairment	0	0	0	7
Interest expense	(8,004)	(9,224)	(16,495)	(17,679)
Other (expense) income	(352)	1,922	(299)	1,991
Total other expense	(8,356)	(7,302)	(16,794)	(15,681)
Net income	65,637	31,687	130,561	77,587
Net income attributable to non-controlling interest in subsidiaries	5,831	3,178	10,861	5,094
Net income attributable to Matador Resources Company shareholders	$ 59,806	$ 28,509	$ 119,700	$ 72,493
Earnings per common share
Basic (in dollars per share)	$ 0.53	$ 0.28	$ 1.08	$ 0.72
Diluted (in dollars per share)	$ 0.53	$ 0.28	$ 1.08	$ 0.72
Weighted average common shares outstanding
Basic (shares)	112,706	100,211	110,809	100,005
Diluted (shares)	113,056	100,227	111,280	100,455

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Changes in Shareholders' Equity - Unaudited - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Accumulated deficit	Treasury Stock	Total shareholders’ equity attributable to Matador Resources Company	Non-controlling interest in subsidiaries	Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]Additional paid-in capital	Convertible Preferred Stock [Member]Total shareholders’ equity attributable to Matador Resources Company
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		717,000
Stock Issued During Period, Value, Share-based Compensation, Gross	$ 0	$ 7	$ (7)			$ 0
Beginning Balance, shares at Dec. 31, 2017	108,510,160	108,514,000			3,000
Beginning balance at Dec. 31, 2017	$ 1,257,546	$ 1,085	1,666,024	$ (510,484)	$ (69)	1,156,556	$ 100,990
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to employee stock compensation plan, shares		7,000,000
Issuance of common stock pursuant to employee stock compensation plan		$ 70						$ 226,612	$ 226,542	$ 226,612
Common stock issued to Board members and advisors, shares		76,000
Issuance of common stock pursuant to directors’ and advisors’ compensation plan	0	$ 1	(1)			0
Stock-based compensation expense related to equity-based awards including amounts capitalized	11,327		11,327			11,327
Stock options exercised, shares		154,000
Stock options exercised, net of options forfeited in net share settlements	(1,616)	$ 2	(1,618)			(1,616)
Restricted stock forfeited, shares					100,000
Restricted stock forfeited	(2,601)				$ (2,601)	(2,601)
Contributions related to formation of Joint Venture (see Note 6)	14,700		14,700			14,700	0
Contributions from non-controlling interest owners of less-than-wholly-owned subsidiaries	53,900						53,900
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(10,535)						(10,535)
Current period net income	$ 130,561			119,700		119,700	10,861
Ending Balance, shares at Jun. 30, 2018	116,357,739	116,461,000			103,000
Ending balance at Jun. 30, 2018	$ 1,679,748	$ 1,165	1,916,821	$ (390,784)	$ (2,670)	1,524,532	$ 155,216
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 146		$ 146			$ 146

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Current period net income	$ 130,561	$ 77,587
Adjustments to reconcile net income to net cash provided by operating activities
Unrealized gain on derivatives	(11,845)	(33,821)
Depletion, depreciation and amortization	122,207	75,266
Accretion of asset retirement obligations	739	614
Stock-based compensation expense	8,945	11,192
Amortization of debt issuance cost	411	64
Net gain on asset sales and inventory impairment	0	(7)
Changes in operating assets and liabilities
Accounts receivable	(9,321)	(25,642)
Lease and well equipment inventory	(8,611)	(140)
Prepaid expenses	(2,167)	(2,619)
Other assets	(149)	165
Accounts payable, accrued liabilities and other current liabilities	(883)	4,442
Royalties payable	8,393	11,435
Advances from joint interest owners	16,025	3,768
Other long-term liabilities	(97)	(1,062)
Net cash provided by operating activities	254,208	121,242
Investing activities
Oil and natural gas properties capital expenditures	(421,595)	(328,929)
Expenditures for midstream and other property and equipment	(79,560)	(41,743)
Proceeds from sale of assets	7,593	977
Net cash used in investing activities	(493,562)	(369,695)
Financing activities
Repayments of borrowings	45,000	0
Borrowings under Credit Agreement	45,000	0
Proceeds from issuance of common stock	226,612	0
Cost to issue equity	73	0
Proceeds from stock options exercised	464	2,201
Contributions related to formation of Joint Venture	14,700	171,500
Contributions from non-controlling interest owners of less-than-wholly-owned subsidiaries	53,900	14,700
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(10,535)	(1,960)
Taxes paid related to net share settlement of stock-based compensation	(4,683)	(2,970)
Purchase of non-controlling interest of less-than-wholly-owned subsidiary	0	(2,653)
Net cash provided by financing activities	280,385	180,818
Increase (decrease) in cash and restricted cash	41,031	(67,635)
Cash and restricted cash at beginning of period	102,482	214,142
Cash and restricted cash at end of period	$ 143,513	$ 146,507

Nature of Operations

Nature of Operations	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS	NATURE OF OPERATIONS Matador Resources Company, a Texas corporation (“Matador” and, collectively with its subsidiaries, the “Company”), is an independent energy company engaged in the exploration, development, production and acquisition of oil and natural gas resources in the United States, with an emphasis on oil and natural gas shale and other unconventional plays. The Company’s current operations are focused primarily on the oil and liquids-rich portion of the Wolfcamp and Bone Spring plays in the Delaware Basin in Southeast New Mexico and West Texas. The Company also operates in the Eagle Ford shale play in South Texas and the Haynesville shale and Cotton Valley plays in Northwest Louisiana and East Texas. Additionally, the Company conducts midstream operations, primarily through its midstream joint venture, San Mateo Midstream, LLC (“San Mateo” or the “Joint Venture”), in support of the Company’s exploration, development and production operations and provides natural gas processing, oil transportation services, oil, natural gas and salt water gathering services and salt water disposal services to third parties.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Interim Financial Statements, Basis of Presentation, Consolidation and Significant Estimates The interim unaudited condensed consolidated financial statements of the Company have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) but do not include all of the information and footnotes required by generally accepted accounting principles in the United States of America (“U.S. GAAP”) for complete financial statements and should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the “Annual Report”) filed with the SEC. The Company consolidates certain subsidiaries and joint ventures that are less than wholly-owned and are not involved in oil and natural gas exploration, including San Mateo, and the net income and equity attributable to the non-controlling interest in these subsidiaries have been reported separately as required by Accounting Standards Codification, Consolidation (Topic 810) . The Company proportionately consolidates certain joint ventures that are less than wholly-owned and are involved in oil and natural gas exploration. All intercompany accounts and transactions have been eliminated in consolidation. In management’s opinion, these interim unaudited condensed consolidated financial statements include all normal, recurring adjustments that are necessary for a fair presentation of the Company’s interim unaudited condensed consolidated financial statements as of June 30, 2018 . Amounts as of December 31, 2017 are derived from the Company’s audited consolidated financial statements included in the Annual Report. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates and assumptions may also affect disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company’s interim unaudited condensed consolidated financial statements are based on a number of significant estimates, including accruals for oil and natural gas revenues, accrued assets and liabilities primarily related to oil and natural gas and midstream operations, stock-based compensation, valuation of derivative instruments and oil and natural gas reserves. The estimates of oil and natural gas reserves quantities and future net cash flows are the basis for the calculations of depletion and impairment of oil and natural gas properties, as well as estimates of asset retirement obligations and certain tax accruals. While the Company believes its estimates are reasonable, changes in facts and assumptions or the discovery of new information may result in revised estimates. Actual results could differ from these estimates. Change in Accounting Principles During the first quarter of 2018, the Company adopted Accounting Standards Codification, Revenue from Contracts with Customers (Topic 606) (“ASC 606”), which specifies how and when to recognize revenue. This standard requires expanded disclosures surrounding revenue recognition and is intended to improve, and converge with international standards, the financial reporting requirements for revenue from contracts with customers. The Company adopted the new guidance using the modified retrospective approach. The adoption did not require an adjustment to opening accumulated deficit for any cumulative effect adjustment and did not have a material impact on the Company’s consolidated balance sheets, statements of operations, statement of shareholders’ equity or statements of cash flows. Prior to the adoption of ASC 606, the Company recorded oil and natural gas revenues at the time of physical transfer of such products to the purchaser. The Company followed 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 purchasers. The Company enters into contracts with customers to sell its oil and natural gas production. With the adoption of ASC 606, revenue on these contracts is recognized in accordance with the five-step revenue recognition model prescribed in ASC 606. Specifically, revenue is recognized when the Company’s performance obligations under these contracts are satisfied, which generally occurs with the transfer of control of the oil and natural gas to the purchaser. Control is generally considered transferred when the following criteria are met: (i) transfer of physical custody, (ii) transfer of title, (iii) transfer of risk of loss and (iv) relinquishment of any repurchase rights or other similar rights. Given the nature of the products sold, revenue is recognized at a point in time based on the amount of consideration the Company expects to receive in accordance with the price specified in the contract. Consideration under the oil and natural gas marketing contracts is typically received from the purchaser one to two months after production. The majority of the Company’s oil marketing contracts transfer physical custody and title at or near the wellhead, which is generally when control of the oil has been transferred to the purchaser. The majority of the oil produced is sold under contracts using market-based pricing, which price is then adjusted for differentials based upon delivery location and oil quality. To the extent the differentials are incurred at or after the transfer of control of the oil, the differentials are included in oil sales on the statements of operations as they represent part of the transaction price of the contract. If the differentials, or other related costs, are incurred prior to the transfer of control of the oil, those costs are included in production taxes, transportation and processing expenses on the Company’s consolidated statements of operations, as they represent payment for services performed outside of the contract with the customer. The Company’s natural gas is sold at the lease location, at the inlet or outlet of a natural gas plant or at an interconnect near a marketing hub following transportation from a processing plant. The majority of the Company’s natural gas is sold under fee-based contracts. When the natural gas is sold at the lease, the purchaser gathers the natural gas and transports the natural gas via pipeline to natural gas processing plants where, if necessary, natural gas liquid (“NGL”) products are extracted. The NGL products and remaining residue gas are then sold by the purchaser, or if the Company elects to repurchase the natural gas, the Company sells the natural gas to a third party. Under the fee-based contracts, the Company receives NGL and residue gas value, less the fee component, or is invoiced the fee component. To the extent control of the natural gas transfers upstream of the transportation and processing activities, revenue is recognized as the net amount received from the purchaser. To the extent that control transfers downstream of those services, revenue is recognized on a gross basis, and the related costs are included in production taxes, transportation and processing expenses on the Company’s consolidated statements of operations. The Company recognizes midstream services revenues at the time services have been rendered and the price is fixed and determinable. Third-party midstream services revenues are those revenues from midstream operations related to third parties, including working interest owners in our operated wells. All midstream services revenues related to the Company’s working interest are eliminated in consolidation. Since the Company has a right to payment from its customers in amounts that correspond directly to the value that the customer receives from the performance completed on each contract, the Company applies the practical expedient in ASC 606 that allows recognition of revenue in the amount for which there is a right to invoice the customer without estimating a transaction price for each contract and allocating that transaction price to the performance obligations within each contract. The Company determined the impact to its consolidated financial statements as a result of adoption of ASC 606 was a $2.6 million and $4.8 million decrease in oil and natural gas revenues and a $2.6 million and $4.8 million decrease in production taxes, transportation and processing expenses for the three and six months ended June 30, 2018 , respectively, which was not material. As a result of adoption of this standard, the Company is now required to disclose the following information regarding total revenues and revenues from contracts with customers on a disaggregated basis for the three and six months ended June 30, 2018 (in thousands). Three Months Ended Six Months Ended Revenues from contracts with customers $ 212,426 $ 397,448 Realized loss on derivatives (2,488 ) (6,746 ) Unrealized gain on derivatives 1,429 11,845 Total revenues $ 211,367 $ 402,547 Three Months Ended Six Months Ended Oil revenues $ 166,271 $ 314,430 Natural gas revenues 42,748 76,543 Third-party midstream services revenues 3,407 6,475 Total revenues from contracts with customers $ 212,426 $ 397,448 The Company does not disclose the value of unsatisfied performance obligations under its contracts with customers as it applies the practical expedient in accordance with ASC 606. The expedient, as described in ASC 606-10-50-14(a), applies to variable consideration that is recognized as control of the product is transferred to the customer. Since each unit of product represents a separate performance obligation, future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. During the first quarter of 2018, the Company adopted Accounting Standards Update (“ASU”) 2016-18, Statement of Cash Flows (Topic 230) , which specifies that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. The Company adopted ASU 2016-18 effective January 1, 2018 and determined that the adoption of this ASU changed the presentation of its beginning and ending cash balances and eliminated the presentation of changes in restricted cash balances from investing activities in its consolidated statements of cash flows. The Company adopted the new guidance using the retrospective transition method; as a result, approximately $6.0 million and $1.3 million of restricted cash was added to the beginning cash balance for the six months ended June 30, 2018 and 2017, respectively. During the first quarter of 2018, the Company adopted ASU 2017-01, Business Combinations (Topic 805) , which specifies the minimum inputs and processes required for an integrated set of assets and activities to meet the definition of a business. The Company adopted ASU 2017-01 prospectively, which did not have a material impact on its consolidated financial statements. Property and Equipment The Company uses the full-cost method of accounting for its investments in oil and natural gas properties. Under this method, the Company is required to perform a ceiling test each quarter that determines a limit, or ceiling, on the capitalized costs of oil and natural gas properties based primarily on the after-tax estimated future net cash flows from oil and natural gas properties using a 10% discount rate and the arithmetic average of first-day-of-the-month oil and natural gas prices for the prior 12 -month period. For both the three and six months ended June 30, 2018 and 2017 , the cost center ceiling was higher than the capitalized costs of oil and natural gas properties, and, as a result, no impairment charge was necessary. The Company capitalized approximately $6.8 million and $5.2 million of its general and administrative costs for the three months ended June 30, 2018 and 2017 , respectively, and approximately $2.6 million and $1.9 million of its interest expense for the three months ended June 30, 2018 and 2017 , respectively. The Company capitalized approximately $14.1 million and $10.8 million of its general and administrative costs for the six months ended June 30, 2018 and 2017 , respectively, and approximately $4.5 million and $3.2 million of its interest expense for the six months ended June 30, 2018 and 2017 , respectively. Earnings (Loss) Per Common Share The Company reports basic earnings attributable to Matador Resources Company shareholders per common share, which excludes the effect of potentially dilutive securities, and diluted earnings attributable to Matador Resources Company shareholders per common share, which includes the effect of all potentially dilutive securities unless their impact is anti-dilutive. The following table sets forth the computation of diluted weighted average common shares outstanding for the three and six months ended June 30, 2018 and 2017 (in thousands). Three Months Ended Six Months Ended 2018 2017 2018 2017 Weighted average common shares outstanding Basic 112,706 100,211 110,809 100,005 Dilutive effect of options and restricted stock units 350 16 471 450 Diluted weighted average common shares outstanding 113,056 100,227 111,280 100,455 Recent Accounting Pronouncements Leases . In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) , which requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous U.S. GAAP. This ASU will become effective for fiscal years beginning after December 15, 2018 with early adoption permitted. Entities are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842) , which is a land easement practical expedient. If the Company elects to use this practical expedient, the Company should evaluate new or modified land easements under this ASU beginning at the date of adoption. Adoption of ASU 2016-02 will result in increased reported assets and liabilities. The quantitative impact of the new lease standard will depend on the leases in force at the time of adoption. The Company is currently evaluating the impact of the adoption of these ASUs on its consolidated financial statements, including identifying all leases, as defined under the new lease standard, determining which practical expedients the Company will use and quantifying the impact of the new lease standard on existing leases. The Company expects to adopt these ASUs as of January 1, 2019. Stock Compensation . In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting . This ASU extends the scope of Topic 718 to include share-based payment transactions related to the acquisition of goods and services from nonemployees. Currently, the Company accounts for stock-based awards to special advisors and contractors under ASC 505-50 as liability instruments, and the fair value of the awards is recalculated each reporting period. Upon adoption, all such awards will be measured at fair value on the grant date and the resulting expense will be recognized on a straight-line basis over the awards’ vesting period. This ASU is effective for fiscal years beginning after December 15, 2018 with early adoption permitted. The transitional guidance requires entities to remeasure all unvested awards that are being accounted for under ASC 505-50 as liability instruments as of the beginning of the year in which this ASU is adopted. The Company expects to adopt this ASU as of January 1, 2019 and does not anticipate this ASU will have a material impact to the Company’s consolidated financial statements.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2018
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS	The following table summarizes the changes in the Company’s asset retirement obligations for the six months ended June 30, 2018 (in thousands). Beginning asset retirement obligations $ 26,256 Liabilities incurred during period 1,589 Liabilities settled during period (459 ) Accretion expense 739 Ending asset retirement obligations 28,125 Less: current asset retirement obligations (1) (1,235 ) Long-term asset retirement obligations $ 26,890 _______________ (1) Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at June 30, 2018 .

Debt

Debt	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
DEBT	At June 30, 2018 and August 1, 2018, the Company had $575.0 million of outstanding 6.875% senior notes due 2023 (the “Notes”), no borrowings outstanding under the Company’s revolving credit agreement (the “Credit Agreement”) and approximately $3.0 million in outstanding letters of credit issued pursuant to the Credit Agreement. Credit Agreement The borrowing base under the Credit Agreement is determined semi-annually as of May 1 and November 1 by the lenders based primarily on the estimated value of the Company’s proved oil and natural gas reserves at December 31 and June 30 of each year, respectively. Both the Company and the lenders may request an unscheduled redetermination of the borrowing base once each between scheduled redetermination dates. During the first quarter of 2018 , the lenders completed their review of the Company’s proved oil and natural gas reserves at December 31, 2017, and as a result, on March 5, 2018 , the borrowing base was increased to $725.0 million . This March 2018 redetermination constituted the regularly scheduled May 1 redetermination. The Company elected to keep the borrowing commitment at $400.0 million and the maximum facility amount remained at $500.0 million . Borrowings under the Credit Agreement are limited to the lowest of the borrowing base, the maximum facility amount and the elected commitment. The Credit Agreement matures on October 16, 2020. The Company believes that it was in compliance with the terms of the Credit Agreement at June 30, 2018 . Senior Unsecured Notes On April 14, 2015 and December 9, 2016, the Company issued $400.0 million and $175.0 million , respectively, of Notes. The Notes mature on April 15, 2023, and interes t is payable semi-annually in arrears on April 15 and October 15 of each year.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company’s deferred tax assets exceeded its deferred tax liabilities at June 30, 2018 due to the deferred tax assets generated by full-cost ceiling impairment charges recorded in prior periods. The Company established a valuation allowance against most of the deferred tax assets beginning in the third quarter of 2015 and retained a full valuation allowance at June 30, 2018 due to uncertainties regarding the future realization of its deferred tax assets. The valuation allowance will continue to be recognized until the realization of future deferred tax benefits is more likely than not to be utilized.

Equity

Equity	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
EQUITY	ased Compensation In February 2018, the Company granted awards of 667,488 shares of restricted stock and options to purchase 563,408 shares of the Company’s common stock at an exercise price of $29.68 per share to certain of its employees. The fair value of these awards was approximately $26.9 million . All of these awards vest ratably over three years. Performance Incentive In connection with the formation of San Mateo in 2017, the Company has the ability to earn a total of $73.5 million in performance incentives to be paid by its joint venture partner, a subsidiary of Five Point Energy LLC (“Five Point”), over a five -year period. The Company earned, and Five Point paid to the Company, $14.7 million in performance incentives during the six months ended June 30, 2018 , and the Company may earn an additional $58.8 million in performance incentives over the next four years. These performance incentives are recorded as an increase to additional paid-in capital when received.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	At June 30, 2018 , the Company had various costless collar, three-way costless collar and swap contracts open and in place to mitigate its exposure to oil and natural gas price volatility, each with a specific term (calculation period), notional quantity (volume hedged) and price floor and ceiling and fixed price for the swaps. Each contract is set to expire at varying times during 2018 and 2019. The following is a summary of the Company’s open costless collar contracts for oil and natural gas at June 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl or MMBtu) Weighted Average Price Floor ($/Bbl or Weighted Average Price Ceiling ($/Bbl or Fair Value of Asset (Liability) (thousands) Oil - WTI (1) 07/01/2018 - 12/31/2018 1,440,000 $ 44.27 $ 60.29 $ (15,986 ) Oil - WTI (1) 01/01/2019 - 12/31/2019 2,400,000 $ 50.00 $ 64.75 (12,208 ) Oil - LLS (2) 07/01/2018 - 12/31/2018 360,000 $ 45.00 $ 63.05 (4,381 ) Natural Gas 07/01/2018 - 12/31/2018 8,400,000 $ 2.58 $ 3.67 79 Total open costless collar contracts $ (32,496 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. (2) Argus Louisiana Light Sweet crude oil. The following is a summary of the Company’s open three-way costless collar contracts for oil at June 30, 2018 . Open three-way costless collars consist of a long put (the floor), a short call (the ceiling) and a long call that limits losses on the upside. Commodity Calculation Period Notional Quantity (Bbl) Weighted Average Price Floor ($/Bbl) Weighted Average Price, Short Call ($/Bbl) Weighted Average Price, Long Call ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil - WTI (1) 07/01/2018 - 12/31/2018 960,000 $ 50.08 $ 63.50 $ 66.68 $ (2,249 ) Total open three-way costless collar contracts $ (2,249 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. The following is a summary of the Company’s open basis swap contracts for oil at June 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl) Fixed Price ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil Basis Swaps 07/01/2018 - 12/31/2018 2,610,000 $ (1.02 ) $ 31,351 Total open swap contracts $ 31,351 Total open derivative financial instruments $ (3,394 ) The Company’s derivative financial instruments are subject to master netting arrangements, and all but one counterparty allow for cross-commodity master netting provided the settlement dates for the commodities are the same. The Company does not present different types of commodities with the same counterparty on a net basis in its interim unaudited condensed consolidated balance sheets. The following table presents the gross asset and liability fair values of the Company’s commodity price derivative financial instruments and the location of these balances in the interim unaudited condensed consolidated balance sheets as of June 30, 2018 and December 31, 2017 (in thousands). Derivative Instruments Gross Gross amounts Net amounts presented in the condensed June 30, 2018 Current assets $ 101,679 $ (95,804 ) $ 5,875 Other assets 2,749 (2,749 ) — Current liabilities (99,820 ) 95,804 (4,016 ) Other liabilities (8,002 ) 2,749 (5,253 ) Total $ (3,394 ) $ — $ (3,394 ) December 31, 2017 Current assets $ 131,092 $ (129,902 ) $ 1,190 Current liabilities (146,331 ) 129,902 (16,429 ) Total $ (15,239 ) $ — $ (15,239 ) The following table summarizes the location and aggregate fair value of all derivative financial instruments recorded in the interim unaudited condensed consolidated statements of operations for the periods presented (in thousands). These derivative financial instruments are not designated as hedging instruments. Three Months Ended Six Months Ended Type of Instrument Location in Condensed Consolidated Statement of Operations 2018 2017 2018 2017 Derivative Instrument Oil Revenues: Realized (loss) gain on derivatives $ (2,488 ) $ 581 $ (6,797 ) $ (1,053 ) Natural Gas Revenues: Realized (loss) gain on derivatives — (23 ) 51 (608 ) Realized (loss) gain on derivatives (2,488 ) 558 (6,746 ) (1,661 ) Oil Revenues: Unrealized gain on derivatives 1,829 10,643 12,956 28,422 Natural Gas Revenues: Unrealized (loss) gain on derivatives (400 ) 2,547 (1,111 ) 5,399 Unrealized gain on derivatives 1,429 13,190 11,845 33,821 Total $ (1,059 ) $ 13,748 $ 5,099 $ 32,160

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	The Company measures and reports certain financial and non-financial assets and liabilities on a fair value basis. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Fair value measurements are classified and disclosed in one of the following categories. Level 1 Unadjusted quoted prices for identical, unrestricted assets or liabilities in active markets. 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 are valued with industry standard models that consider various inputs, including: (i) quoted forward prices for commodities, (ii) time value of money and (iii) current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these inputs are observable in the marketplace throughout the full term of the derivative instrument and can be derived from observable data or supported by observable levels at which transactions are executed in the marketplace. Level 3 Unobservable inputs that are not corroborated by market data that reflect a company’s own market assumptions. Financial and non-financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. The assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The following tables summarize the valuation of the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis in accordance with the classifications provided above as of June 30, 2018 and December 31, 2017 (in thousands). Fair Value Measurements at Description Level 1 Level 2 Level 3 Total Assets (Liabilities) Natural gas derivatives $ — $ 79 $ — $ 79 Oil derivatives and basis swaps — (3,473 ) — (3,473 ) Total $ — $ (3,394 ) $ — $ (3,394 ) Fair Value Measurements at Description Level 1 Level 2 Level 3 Total Assets (Liabilities) Natural gas derivatives $ — $ 1,190 $ — $ 1,190 Oil derivatives and basis swaps — (16,429 ) — (16,429 ) Total $ — $ (15,239 ) $ — $ (15,239 ) Additional disclosures related to derivative financial instruments are provided in Note 7. Other Fair Value Measurements At June 30, 2018 and December 31, 2017 , the carrying values reported on the interim unaudited condensed consolidated balance sheets for accounts receivable, prepaid expenses and other assets, accounts payable, accrued liabilities, royalties payable, amounts due to affiliates, advances from joint interest owners, amounts due to joint ventures and other current liabilities approximated their fair values due to their short-term maturities. At June 30, 2018 and December 31, 2017 , the fair value of the Notes was $603.4 million and $614.1 million , respectively, based on quoted market prices, which represent Level 1 inputs in the fair value hierarchy.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	Processing, Transportation and Salt Water Disposal Commitments Delaware Basin — Loving County, Texas Natural Gas Processing In late 2015, the Company entered into a 15 -year, fixed-fee natural gas gathering and processing agreement whereby the Company committed to deliver the anticipated natural gas production from a significant portion of its Loving County, Texas acreage in West Texas through the counterparty’s gathering system for processing at the counterparty’s facilities. Under this agreement, if the Company does not meet the volume commitment for transportation and processing at the facilities in a contract year, it will be required to pay a deficiency fee per MMBtu of natural gas deficiency. At the end of each year of the agreement, the Company can elect to have the previous year’s actual transportation and processing volumes be the new minimum commitment for each of the remaining years of the contract. As such, the Company has the ability to unilaterally reduce the gathering and processing commitment if the Company’s production in the Loving County area is less than the Company’s minimum commitment. If the Company ceased operations in this area at June 30, 2018 , the total deficiency fee required to be paid would be approximately $10.9 million . In addition, if the Company elects to reduce the gathering and processing commitment in any year, the Company has the ability to elect to increase the committed volumes in any future year to the originally agreed gathering and processing commitment. Any quantity in excess of the volume commitment delivered in a contract year can be carried over to the next contract year for purposes of calculating that year’s natural gas deficiency. The Company paid approximately $4.0 million and $3.7 million in natural gas processing and gathering fees under this agreement during the three months ended June 30, 2018 and 2017 , respectively, and $7.4 million and $6.8 million in natural gas processing and gathering fees under this agreement during the six months ended June 30, 2018 and 2017 , respectively. The Company can elect to either sell the residue gas to the counterparty at the tailgate of its processing plants or have the counterparty deliver to the Company the residue gas in-kind to be sold to third parties downstream of the plants. Delaware Basin — Eddy County, New Mexico Natural Gas Transportation In late 2017, the Company entered into an 18 -year, fixed-fee natural gas transportation agreement whereby the Company committed to deliver a portion of the residue natural gas production at the tailgate of San Mateo’s Black River cryogenic natural gas processing plant in the Rustler Breaks asset area (the “Black River Processing Plant”) to transport through the counterparty’s pipeline. Under this agreement, if the Company does not meet the volume commitment for transportation in a contract year, the Company will owe the fees to transport the committed volume whether or not the committed volume is utilized. The minimum contractual obligation at June 30, 2018 was approximately $45.8 million . The Company paid approximately $0.9 million and $1.5 million in transportation fees under this agreement during the three and six months ended June 30, 2018 , respectively. In late 2017, the Company also entered into a fixed-fee NGL transportation and fractionation agreement whereby the Company committed to deliver its NGL production at the tailgate of the Black River Processing Plant. The Company is committed to deliver a minimum amount of NGLs to the counterparty upon construction and completion of a pipeline expansion and a fractionation facility by the counterparty, which is currently expected to be completed late in 2019. The Company has no rights to compel the counterparty to construct this pipeline extension or fractionation facility. If the counterparty does not construct the pipeline extension and fractionation facility, then the Company does not have any minimum volume commitments under the agreement. If the counterparty constructs the pipeline extension and fractionation facility on or prior to February 28, 2021, then the Company will have a commitment to deliver a minimum amount of NGLs for seven years following the completion of the pipeline extension and fractionation facility. If the Company does not meet its NGL volume commitment in any quarter during the seven -year commitment period, it will be required to pay a deficiency fee per gallon of NGL deficiency. Should the pipeline extension and fractionation facility be completed on or prior to February 28, 2021, the minimum contractual obligation during the seven -year period would be approximately $132.3 million . In April 2018, the Company entered into a short-term natural gas transportation agreement whereby the Company committed to deliver a portion of the residue natural gas production at the tailgate of the Black River Processing Plant to transport through the counterparty’s pipeline. Under this short-term agreement, the Company will owe the fees to transport the committed volume whether or not the committed volume is transported through the counterparty’s pipeline. The minimum contractual obligation under this short-term contract at June 30, 2018 is approximately $4.6 million . This short-term agreement ends on September 30, 2019. The Company paid approximately $0.2 million in transportation fees under this agreement during the three and six months ended June 30, 2018 . In addition, in April 2018, the Company entered into a 16 -year, fixed-fee natural gas transportation agreement that begins on October 1, 2019, whereby the Company committed to deliver a portion of the residue natural gas production at the tailgate of the Black River Processing Plant to transport through the counterparty’s pipeline. The Company will owe the fees to transport the committed volume whether or not the committed volume is transported through the counterparty’s pipeline. The minimum contractual obligation at June 30, 2018 was approximately $56.8 million . In May 2018, the Company also entered into a 10 -year, fixed-fee natural gas sales agreement whereby the Company committed to deliver residue natural gas through the counterparty’s pipeline to the Texas Gulf Coast beginning on the in-service date of such pipeline, which is expected to be operational in late 2019. If the Company does not meet the volume commitment specified in the natural gas sales agreement, it may be required to pay a deficiency fee per MMBtu of natural gas deficiency. The minimum contractual obligation at June 30, 2018 was approximately $200.6 million . Delaware Basin — San Mateo In February 2017, the Company dedicated its current and future leasehold interests in the Rustler Breaks and Wolf asset areas pursuant to 15 -year, fixed-fee natural gas, oil and salt water gathering agreements and salt water disposal agreements. In addition, the Company dedicated its current and future leasehold interests in the Rustler Breaks asset area pursuant to a 15 -year, fixed-fee natural gas processing agreement (collectively with the gathering and salt water disposal agreements, the “Operational Agreements”). San Mateo provides the Company with firm service under each of the Operational Agreements in exchange for certain minimum volume commitments. The minimum contractual obligation under the Operational Agreements at June 30, 2018 was approximately $222.6 million . Beginning in May 2017, a subsidiary of San Mateo entered into certain agreements with third parties for the engineering, procurement, construction and installation of an expansion of the Black River Processing Plant. The expansion was completed late in the first quarter of 2018. San Mateo’s total commitments under these agreements are $55.3 million . The subsidiary of San Mateo paid approximately $1.1 million and $3.6 million under these agreements during the three and six months ended June 30, 2018 . As of June 30, 2018 , the remaining obligations under these agreements were $2.0 million , which are expected to be paid within the next few months. During the first quarter of 2018, a subsidiary of San Mateo entered into agreements for additional field compression and an amine gas treatment unit to maximize the operation of the Black River Processing Plant. San Mateo’s total commitments under these agreements are $19.9 million . The subsidiary of San Mateo paid approximately $6.0 million and $6.5 million under these agreements during the three and six months ended June 30, 2018 . As of June 30, 2018 , the remaining obligations under these agreements were $13.5 million , which are expected to be paid within the next year. Other Commitments The Company does not own or operate its own drilling rigs, but instead enters into contracts with third parties for such drilling rigs. These contracts establish daily rates for the drilling rigs and the term of the Company’s commitment for the drilling services to be provided. The Company would incur a termination obligation if the Company elected to terminate a contract and if the drilling contractor were unable to secure replacement work for the contracted drilling rigs at the same daily rates being charged to the Company prior to the end of their respective contract terms. The Company’s undiscounted minimum outstanding aggregate termination obligations under its drilling rig contracts were approximately $32.4 million at June 30, 2018 . At June 30, 2018 , the Company had outstanding commitments to participate in the drilling and completion of various non-operated wells. If all of these wells are drilled and completed as proposed, the Company’s minimum outstanding aggregate commitments for its participation in these non-operated wells were approximately $47.2 million at June 30, 2018 . The Company expects these costs to be incurred within the next year. Legal Proceedings The Company is a party to several lawsuits encountered in the ordinary course of its business. While the ultimate outcome and impact to the Company cannot be predicted with certainty, in the opinion of management, it is remote that these lawsuits will have a material adverse impact on the Company’s financial condition, results of operations or cash flows.

Supplemental Disclosures

Supplemental Disclosures	6 Months Ended
	Jun. 30, 2018
Supplemental Disclosures [Abstract]
SUPPLEMENTAL DISCLOSURES	Accrued Liabilities The following table summarizes the Company’s current accrued liabilities at June 30, 2018 and December 31, 2017 (in thousands). June 30, December 31, Accrued evaluated and unproved and unevaluated property costs $ 79,540 $ 105,347 Accrued midstream property costs 11,459 14,823 Accrued cost to issue equity 73 — Accrued lease operating expenses 14,209 12,611 Accrued interest on debt 8,345 8,345 Accrued asset retirement obligations 1,235 1,176 Accrued partners’ share of joint interest charges 14,824 27,628 Other 3,680 4,418 Total accrued liabilities $ 133,365 $ 174,348 Supplemental Cash Flow Information The following table provides supplemental disclosures of cash flow information for the six months ended June 30, 2018 and 2017 (in thousands). Six Months Ended 2018 2017 Cash paid for interest expense, net of amounts capitalized $ 14,286 $ 15,875 Increase in asset retirement obligations related to mineral properties $ 834 $ 1,978 Increase (decrease) in asset retirement obligations related to midstream properties $ 296 $ (138 ) (Decrease) increase in liabilities for oil and natural gas properties capital expenditures $ (26,389 ) $ 43,797 (Decrease) increase in liabilities for midstream properties capital expenditures $ (2,371 ) $ 1,838 Stock-based compensation expense recognized as liability $ (93 ) $ (339 ) Increase (decrease) in liabilities for accrued cost to issue equity $ 73 $ (343 ) Transfer of inventory from (to) oil and natural gas properties $ 343 $ (228 ) Transfer of inventory to midstream and other property and equipment $ (2,390 ) $ — The following table provides a reconciliation of cash and restricted cash recorded in the interim unaudited condensed consolidated balance sheets to cash and restricted cash as presented on the interim unaudited condensed consolidated statements of cash flows (in thousands). Six Months Ended 2018 2017 Cash $ 122,450 $ 131,467 Restricted cash 21,063 15,040 Total cash and restricted cash $ 143,513 $ 146,507

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
SEGMENT INFORMATION	The Company operates in two business segments: (i) exploration and production and (ii) midstream. The exploration and production segment is engaged in the acquisition, exploration, development and production of oil and natural gas properties and is currently focused primarily on the oil and liquids-rich portion of the Wolfcamp and Bone Spring plays in the Delaware Basin in Southeast New Mexico and West Texas. The Company also operates in the Eagle Ford shale play in South Texas and the Haynesville shale and Cotton Valley plays in Northwest Louisiana and East Texas. The midstream segment conducts midstream operations in support of the Company’s exploration, development and production operations and provides natural gas processing, oil transportation services, natural gas, oil and salt water gathering services and salt water disposal services to third parties. Substantially all of the Company’s midstream operations in the Rustler Breaks and Wolf asset areas in the Delaware Basin are conducted through San Mateo. The following tables present selected financial information for the periods presented regarding the Company’s business segments on a stand-alone basis, corporate expenses that are not allocated to a segment and the consolidation and elimination entries necessary to arrive at the financial information for the Company on a consolidated basis (in thousands). On a consolidated basis, midstream services revenues consist primarily of those revenues from midstream operations related to third parties, including working interest owners in the Company’s operated wells. All midstream services revenues associated with Company-owned production are eliminated in consolidation. In evaluating the operating results of the exploration and production and midstream segments, the Company does not allocate certain expenses to the individual segments, including general and administrative expenses. Such expenses are reflected in the column labeled “Corporate.” Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Three Months Ended June 30, 2018 Oil and natural gas revenues $ 207,229 $ 1,790 $ — $ — $ 209,019 Midstream services revenues — 19,896 — (16,489 ) 3,407 Realized loss on derivatives (2,488 ) — — — (2,488 ) Unrealized gain on derivatives 1,429 — — — 1,429 Expenses (1) 126,025 9,363 18,475 (16,489 ) 137,374 Operating income (loss) (2) $ 80,145 $ 12,323 $ (18,475 ) $ — $ 73,993 Total assets $ 2,058,447 $ 354,068 $ 143,332 $ — $ 2,555,847 Capital expenditures (3) $ 199,345 $ 32,900 $ 732 $ — $ 232,977 _____________________ (1) Includes depletion, depreciation and amortization expenses of $64.5 million and $2.3 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $25,000 . (2) Includes $5.8 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $16.1 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment. Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Three Months Ended June 30, 2017 Oil and natural gas revenues $ 113,387 $ 377 $ — $ — $ 113,764 Midstream services revenues — 11,367 — (9,268 ) 2,099 Realized gain on derivatives 558 — — — 558 Unrealized gain on derivatives 13,190 — — — 13,190 Expenses (1) 78,078 5,960 15,852 (9,268 ) 90,622 Operating income (loss) (2) $ 49,057 $ 5,784 $ (15,852 ) $ — $ 38,989 Total assets $ 1,436,678 $ 192,889 $ 147,509 $ — $ 1,777,076 Capital expenditures (3) $ 165,583 $ 27,347 $ 1,752 $ — $ 194,682 _____________________ (1) Includes depletion, depreciation and amortization expenses of $39.6 million and $1.3 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.4 million . (2) Includes $3.2 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $13.4 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment. Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Six Months Ended June 30, 2018 Oil and natural gas revenues $ 387,489 $ 3,484 $ — $ — $ 390,973 Midstream services revenues — 35,708 — (29,233 ) 6,475 Realized loss on derivatives (6,746 ) — — — (6,746 ) Unrealized gain on derivatives 11,845 — — — 11,845 Expenses (1) 232,180 16,561 35,684 (29,233 ) 255,192 Operating income (loss) (2) $ 160,408 $ 22,631 $ (35,684 ) $ — $ 147,355 Total assets $ 2,058,447 $ 354,068 $ 143,332 $ — $ 2,555,847 Capital expenditures (3) $ 388,790 $ 78,617 $ 1,258 $ — $ 468,665 _____________________ (1) Includes depletion, depreciation and amortization expenses of $117.8 million and $3.9 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.6 million . (2) Includes $10.9 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $38.5 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment. Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Six Months Ended June 30, 2017 Oil and natural gas revenues $ 227,552 $ 1,059 $ — $ — $ 228,611 Midstream services revenues — 20,983 — (17,329 ) 3,654 Realized loss on derivatives (1,661 ) — — — (1,661 ) Unrealized gain on derivatives 33,821 — — — 33,821 Expenses (1) 146,416 10,462 31,608 (17,329 ) 171,157 Operating income (loss) (2) $ 113,296 $ 11,580 $ (31,608 ) $ — $ 93,268 Total assets $ 1,436,678 $ 192,889 $ 147,509 $ — $ 1,777,076 Capital expenditures (3) $ 373,956 $ 40,227 $ 3,216 $ — $ 417,399 _____________________ (1) Includes depletion, depreciation and amortization expenses of $72.1 million and $2.5 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.7 million . (2) Includes $5.1 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $18.6 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment.

Subsidiary Guarantors (Notes)

Subsidiary Guarantors (Notes)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
SUBSIDIARY GUARANTORS	Notes are jointly and severally guaranteed by certain subsidiaries of Matador (the “Guarantor Subsidiaries”) on a full and unconditional basis (except for customary release provisions). At June 30, 2018 , the Guarantor Subsidiaries were 100% owned by Matador. Matador is a parent holding company and has no independent assets or operations, and there are no significant restrictions on the ability of Matador to obtain funds from the Guarantor Subsidiaries by dividend or loan. San Mateo and its subsidiaries (the “Non-Guarantor Subsidiaries”) are not guarantors of the Notes. The following presents condensed consolidating financial information of the issuer (Matador), the Non-Guarantor Subsidiaries, the Guarantor Subsidiaries and all entities on a consolidated basis (in thousands). Elimination entries are necessary to combine the entities. This financial information is presented in accordance with the requirements of Rule 3-10 of Regulation S-X. The following financial information may not necessarily be indicative of results of operations, cash flows or financial position had the Guarantor Subsidiaries operated as independent entities. Condensed Consolidating Balance Sheet Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated ASSETS Intercompany receivable $ 811,982 $ 8,235 $ — $ (820,217 ) $ — Third-party current assets 3,031 29,358 288,548 — 320,937 Net property and equipment — 299,258 1,928,759 — 2,228,017 Investment in subsidiaries 1,285,896 — 162,418 (1,448,314 ) — Third-party long-term assets 6,433 — 3,394 (2,934 ) 6,893 Total assets $ 2,107,342 $ 336,851 $ 2,383,119 $ (2,271,465 ) $ 2,555,847 LIABILITIES AND EQUITY Intercompany payable $ — $ — $ 820,217 $ (820,217 ) $ — Third-party current liabilities 8,646 15,482 239,726 (256 ) 263,598 Senior unsecured notes payable 574,164 — — — 574,164 Other third-party long-term liabilities — 3,735 37,280 (2,678 ) 38,337 Total equity attributable to Matador Resources Company 1,524,532 162,418 1,285,896 (1,448,314 ) 1,524,532 Non-controlling interest in subsidiaries — 155,216 — — 155,216 Total liabilities and equity $ 2,107,342 $ 336,851 $ 2,383,119 $ (2,271,465 ) $ 2,555,847 Condensed Consolidating Balance Sheet Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated ASSETS Intercompany receivable $ 585,109 $ 2,912 $ — $ (588,021 ) $ — Third-party current assets 2,240 9,334 245,596 — 257,170 Net property and equipment — 223,178 1,658,278 — 1,881,456 Investment in subsidiaries 1,147,295 — 111,077 (1,258,372 ) — Third-party long-term assets 6,425 — 3,642 (3,003 ) 7,064 Total assets $ 1,741,069 $ 235,424 $ 2,018,593 $ (1,849,396 ) $ 2,145,690 LIABILITIES AND EQUITY Intercompany payable $ — $ — $ 588,021 $ (588,021 ) $ — Third-party current liabilities 8,847 19,891 254,142 (274 ) 282,606 Senior unsecured notes payable 574,073 — — — 574,073 Other third-party long-term liabilities 1,593 3,466 29,135 (2,729 ) 31,465 Total equity attributable to Matador Resources Company 1,156,556 111,077 1,147,295 (1,258,372 ) 1,156,556 Non-controlling interest in subsidiaries — 100,990 — — 100,990 Total liabilities and equity $ 1,741,069 $ 235,424 $ 2,018,593 $ (1,849,396 ) $ 2,145,690 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 21,356 $ 206,219 $ (16,208 ) $ 211,367 Total expenses 1,178 9,466 142,938 (16,208 ) 137,374 Operating (loss) income (1,178 ) 11,890 63,281 — 73,993 Interest expense (8,004 ) — — — (8,004 ) Other income (expense) — 11 (363 ) — (352 ) Earnings in subsidiaries 68,988 — 6,070 (75,058 ) — Income before income taxes 59,806 11,901 68,988 (75,058 ) 65,637 Net income attributable to non-controlling interest in subsidiaries — (5,831 ) — — (5,831 ) Net income attributable to Matador Resources Company shareholders $ 59,806 $ 6,070 $ 68,988 $ (75,058 ) $ 59,806 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 11,274 $ 127,198 $ (8,861 ) $ 129,611 Total expenses 1,586 4,814 93,083 (8,861 ) 90,622 Operating (loss) income (1,586 ) 6,460 34,115 — 38,989 Interest expense (9,224 ) — — — (9,224 ) Other (expense) income (27 ) 26 1,923 — 1,922 Earnings in subsidiaries 39,228 — 3,244 (42,472 ) — Income before income taxes 28,391 6,486 39,282 (42,472 ) 31,687 Total income tax (benefit) provision (118 ) 64 54 — — Net income attributable to non-controlling interest in subsidiaries — (3,178 ) — — (3,178 ) Net income attributable to Matador Resources Company shareholders $ 28,509 $ 3,244 $ 39,228 $ (42,472 ) $ 28,509 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 38,550 $ 392,699 $ (28,702 ) $ 402,547 Total expenses 2,412 16,394 265,088 (28,702 ) 255,192 Operating (loss) income (2,412 ) 22,156 127,611 — 147,355 Interest expense (16,495 ) — — — (16,495 ) Other income (expense) 6 11 (316 ) — (299 ) Earnings in subsidiaries 138,601 — 11,306 (149,907 ) — Income before income taxes 119,700 22,167 138,601 (149,907 ) 130,561 Net income attributable to non-controlling interest in subsidiaries — (10,861 ) — — (10,861 ) Net income attributable to Matador Resources Company shareholders $ 119,700 $ 11,306 $ 138,601 $ (149,907 ) $ 119,700 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 20,937 $ 259,846 $ (16,358 ) $ 264,425 Total expenses 2,846 8,682 175,987 (16,358 ) 171,157 Operating (loss) income (2,846 ) 12,255 83,859 — 93,268 Net gain on asset sales and inventory impairment — — 7 — 7 Interest expense (17,679 ) — — — (17,679 ) Other income — 26 1,965 — 1,991 Earnings in subsidiaries 92,900 — 7,069 (99,969 ) — Income before income taxes 72,375 12,281 92,900 (99,969 ) 77,587 Total income tax (benefit) provision (118 ) 118 — — — Net income attributable to non-controlling interest in subsidiaries — (5,094 ) — — (5,094 ) Net income attributable to Matador Resources Company shareholders $ 72,493 $ 7,069 $ 92,900 $ (99,969 ) $ 72,493 Condensed Consolidating Statement of Cash Flows Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (224,441 ) $ 10,225 $ 468,424 $ — $ 254,208 Net cash used in investing activities — (79,119 ) (454,478 ) 40,035 (493,562 ) Net cash provided by financing activities 226,539 83,400 10,481 (40,035 ) 280,385 Increase in cash and restricted cash 2,098 14,506 24,427 — 41,031 Cash and restricted cash at beginning of period 286 5,663 96,533 — 102,482 Cash and restricted cash at end of period $ 2,384 $ 20,169 $ 120,960 $ — $ 143,513 Condensed Consolidating Statement of Cash Flows Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (98,583 ) $ 1,566 $ 218,259 $ — $ 121,242 Net cash provided by (used in) investing activities 33 (38,362 ) (197,486 ) (133,880 ) (369,695 ) Net cash provided by (used in) financing activities — 47,707 (769 ) 133,880 180,818 (Decrease) increase in cash and restricted cash (98,550 ) 10,911 20,004 — (67,635 ) Cash and restricted cash at beginning of period 99,795 2,900 111,447 — 214,142 Cash and restricted cash at end of period $ 1,245 $ 13,811 $ 131,451 $ — $ 146,507

Summary of Significant Accoun19

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Interim Financial Statements, Basis of Presentation, Consolidation and Significant Estimates	Interim Financial Statements, Basis of Presentation, Consolidation and Significant Estimates The interim unaudited condensed consolidated financial statements of the Company have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) but do not include all of the information and footnotes required by generally accepted accounting principles in the United States of America (“U.S. GAAP”) for complete financial statements and should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the “Annual Report”) filed with the SEC. The Company consolidates certain subsidiaries and joint ventures that are less than wholly-owned and are not involved in oil and natural gas exploration, including San Mateo, and the net income and equity attributable to the non-controlling interest in these subsidiaries have been reported separately as required by Accounting Standards Codification, Consolidation (Topic 810) . The Company proportionately consolidates certain joint ventures that are less than wholly-owned and are involved in oil and natural gas exploration. All intercompany accounts and transactions have been eliminated in consolidation. In management’s opinion, these interim unaudited condensed consolidated financial statements include all normal, recurring adjustments that are necessary for a fair presentation of the Company’s interim unaudited condensed consolidated financial statements as of June 30, 2018 . Amounts as of December 31, 2017 are derived from the Company’s audited consolidated financial statements included in the Annual Report. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates and assumptions may also affect disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company’s interim unaudited condensed consolidated financial statements are based on a number of significant estimates, including accruals for oil and natural gas revenues, accrued assets and liabilities primarily related to oil and natural gas and midstream operations, stock-based compensation, valuation of derivative instruments and oil and natural gas reserves. The estimates of oil and natural gas reserves quantities and future net cash flows are the basis for the calculations of depletion and impairment of oil and natural gas properties, as well as estimates of asset retirement obligations and certain tax accruals. While the Company believes its estimates are reasonable, changes in facts and assumptions or the discovery of new information may result in revised estimates. Actual results could differ from these estimates.
Change in Accounting Principles and Recent Accounting Pronouncements	Change in Accounting Principles During the first quarter of 2018, the Company adopted Accounting Standards Codification, Revenue from Contracts with Customers (Topic 606) (“ASC 606”), which specifies how and when to recognize revenue. This standard requires expanded disclosures surrounding revenue recognition and is intended to improve, and converge with international standards, the financial reporting requirements for revenue from contracts with customers. The Company adopted the new guidance using the modified retrospective approach. The adoption did not require an adjustment to opening accumulated deficit for any cumulative effect adjustment and did not have a material impact on the Company’s consolidated balance sheets, statements of operations, statement of shareholders’ equity or statements of cash flows. Prior to the adoption of ASC 606, the Company recorded oil and natural gas revenues at the time of physical transfer of such products to the purchaser. The Company followed 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 purchasers. The Company enters into contracts with customers to sell its oil and natural gas production. With the adoption of ASC 606, revenue on these contracts is recognized in accordance with the five-step revenue recognition model prescribed in ASC 606. Specifically, revenue is recognized when the Company’s performance obligations under these contracts are satisfied, which generally occurs with the transfer of control of the oil and natural gas to the purchaser. Control is generally considered transferred when the following criteria are met: (i) transfer of physical custody, (ii) transfer of title, (iii) transfer of risk of loss and (iv) relinquishment of any repurchase rights or other similar rights. Given the nature of the products sold, revenue is recognized at a point in time based on the amount of consideration the Company expects to receive in accordance with the price specified in the contract. Consideration under the oil and natural gas marketing contracts is typically received from the purchaser one to two months after production. The majority of the Company’s oil marketing contracts transfer physical custody and title at or near the wellhead, which is generally when control of the oil has been transferred to the purchaser. The majority of the oil produced is sold under contracts using market-based pricing, which price is then adjusted for differentials based upon delivery location and oil quality. To the extent the differentials are incurred at or after the transfer of control of the oil, the differentials are included in oil sales on the statements of operations as they represent part of the transaction price of the contract. If the differentials, or other related costs, are incurred prior to the transfer of control of the oil, those costs are included in production taxes, transportation and processing expenses on the Company’s consolidated statements of operations, as they represent payment for services performed outside of the contract with the customer. The Company’s natural gas is sold at the lease location, at the inlet or outlet of a natural gas plant or at an interconnect near a marketing hub following transportation from a processing plant. The majority of the Company’s natural gas is sold under fee-based contracts. When the natural gas is sold at the lease, the purchaser gathers the natural gas and transports the natural gas via pipeline to natural gas processing plants where, if necessary, natural gas liquid (“NGL”) products are extracted. The NGL products and remaining residue gas are then sold by the purchaser, or if the Company elects to repurchase the natural gas, the Company sells the natural gas to a third party. Under the fee-based contracts, the Company receives NGL and residue gas value, less the fee component, or is invoiced the fee component. To the extent control of the natural gas transfers upstream of the transportation and processing activities, revenue is recognized as the net amount received from the purchaser. To the extent that control transfers downstream of those services, revenue is recognized on a gross basis, and the related costs are included in production taxes, transportation and processing expenses on the Company’s consolidated statements of operations. The Company recognizes midstream services revenues at the time services have been rendered and the price is fixed and determinable. Third-party midstream services revenues are those revenues from midstream operations related to third parties, including working interest owners in our operated wells. All midstream services revenues related to the Company’s working interest are eliminated in consolidation. Since the Company has a right to payment from its customers in amounts that correspond directly to the value that the customer receives from the performance completed on each contract, the Company applies the practical expedient in ASC 606 that allows recognition of revenue in the amount for which there is a right to invoice the customer without estimating a transaction price for each contract and allocating that transaction price to the performance obligations within each contract. The Company determined the impact to its consolidated financial statements as a result of adoption of ASC 606 was a $2.6 million and $4.8 million decrease in oil and natural gas revenues and a $2.6 million and $4.8 million decrease in production taxes, transportation and processing expenses for the three and six months ended June 30, 2018 , respectively, which was not material. As a result of adoption of this standard, the Company is now required to disclose the following information regarding total revenues and revenues from contracts with customers on a disaggregated basis for the three and six months ended June 30, 2018 (in thousands). Three Months Ended Six Months Ended Oil revenues $ 166,271 $ 314,430 Natural gas revenues 42,748 76,543 Third-party midstream services revenues 3,407 6,475 Total revenues from contracts with customers $ 212,426 $ 397,448 The Company does not disclose the value of unsatisfied performance obligations under its contracts with customers as it applies the practical expedient in accordance with ASC 606. The expedient, as described in ASC 606-10-50-14(a), applies to variable consideration that is recognized as control of the product is transferred to the customer. Since each unit of product represents a separate performance obligation, future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. During the first quarter of 2018, the Company adopted Accounting Standards Update (“ASU”) 2016-18, Statement of Cash Flows (Topic 230) , which specifies that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. The Company adopted ASU 2016-18 effective January 1, 2018 and determined that the adoption of this ASU changed the presentation of its beginning and ending cash balances and eliminated the presentation of changes in restricted cash balances from investing activities in its consolidated statements of cash flows. The Company adopted the new guidance using the retrospective transition method; as a result, approximately $6.0 million and $1.3 million of restricted cash was added to the beginning cash balance for the six months ended June 30, 2018 and 2017, respectively. During the first quarter of 2018, the Company adopted ASU 2017-01, Business Combinations (Topic 805) , which specifies the minimum inputs and processes required for an integrated set of assets and activities to meet the definition of a business. The Company adopted ASU 2017-01 prospectively, which did not have a material impact on its consolidated financial statements. Recent Accounting Pronouncements Leases . In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) , which requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous U.S. GAAP. This ASU will become effective for fiscal years beginning after December 15, 2018 with early adoption permitted. Entities are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842) , which is a land easement practical expedient. If the Company elects to use this practical expedient, the Company should evaluate new or modified land easements under this ASU beginning at the date of adoption. Adoption of ASU 2016-02 will result in increased reported assets and liabilities. The quantitative impact of the new lease standard will depend on the leases in force at the time of adoption. The Company is currently evaluating the impact of the adoption of these ASUs on its consolidated financial statements, including identifying all leases, as defined under the new lease standard, determining which practical expedients the Company will use and quantifying the impact of the new lease standard on existing leases. The Company expects to adopt these ASUs as of January 1, 2019. Stock Compensation . In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting . This ASU extends the scope of Topic 718 to include share-based payment transactions related to the acquisition of goods and services from nonemployees. Currently, the Company accounts for stock-based awards to special advisors and contractors under ASC 505-50 as liability instruments, and the fair value of the awards is recalculated each reporting period. Upon adoption, all such awards will be measured at fair value on the grant date and the resulting expense will be recognized on a straight-line basis over the awards’ vesting period. This ASU is effective for fiscal years beginning after December 15, 2018 with early adoption permitted. The transitional guidance requires entities to remeasure all unvested awards that are being accounted for under ASC 505-50 as liability instruments as of the beginning of the year in which this ASU is adopted. The Company expects to adopt this ASU as of January 1, 2019 and does not anticipate this ASU will have a material impact to the Company’s consolidated financial statements.
Property and Equipment	Property and Equipment The Company uses the full-cost method of accounting for its investments in oil and natural gas properties. Under this method, the Company is required to perform a ceiling test each quarter that determines a limit, or ceiling, on the capitalized costs of oil and natural gas properties based primarily on the after-tax estimated future net cash flows from oil and natural gas properties using a 10% discount rate and the arithmetic average of first-day-of-the-month oil and natural gas prices for the prior 12 -month period. For both the three and six months ended June 30, 2018 and 2017 , the cost center ceiling was higher than the capitalized costs of oil and natural gas properties, and, as a result, no impairment charge was necessary.
Earnings (Loss) Per Common Share	Earnings (Loss) Per Common Share The Company reports basic earnings attributable to Matador Resources Company shareholders per common share, which excludes the effect of potentially dilutive securities, and diluted earnings attributable to Matador Resources Company shareholders per common share, which includes the effect of all potentially dilutive securities unless their impact is anti-dilutive.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Disaggregation of revenue	As a result of adoption of this standard, the Company is now required to disclose the following information regarding total revenues and revenues from contracts with customers on a disaggregated basis for the three and six months ended June 30, 2018 (in thousands). Three Months Ended Six Months Ended Revenues from contracts with customers $ 212,426 $ 397,448 Realized loss on derivatives (2,488 ) (6,746 ) Unrealized gain on derivatives 1,429 11,845 Total revenues $ 211,367 $ 402,547 Three Months Ended Six Months Ended Oil revenues $ 166,271 $ 314,430 Natural gas revenues 42,748 76,543 Third-party midstream services revenues 3,407 6,475 Total revenues from contracts with customers $ 212,426 $ 397,448
Reconciliations of basic and diluted distributed and undistributed earnings (loss) per common share	The following table sets forth the computation of diluted weighted average common shares outstanding for the three and six months ended June 30, 2018 and 2017 (in thousands). Three Months Ended Six Months Ended 2018 2017 2018 2017 Weighted average common shares outstanding Basic 112,706 100,211 110,809 100,005 Dilutive effect of options and restricted stock units 350 16 471 450 Diluted weighted average common shares outstanding 113,056 100,227 111,280 100,455

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2018
Asset Retirement Obligation Disclosure [Abstract]
Schedule of changes in Company's asset retirement obligations	The following table summarizes the changes in the Company’s asset retirement obligations for the six months ended June 30, 2018 (in thousands). Beginning asset retirement obligations $ 26,256 Liabilities incurred during period 1,589 Liabilities settled during period (459 ) Accretion expense 739 Ending asset retirement obligations 28,125 Less: current asset retirement obligations (1) (1,235 ) Long-term asset retirement obligations $ 26,890 _______________ (1) Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at June 30, 2018 .

Derivative Financial Instrume22

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Open Option Contracts Written [Line Items]
Summary of gross asset balances of derivative instruments	The following table presents the gross asset and liability fair values of the Company’s commodity price derivative financial instruments and the location of these balances in the interim unaudited condensed consolidated balance sheets as of June 30, 2018 and December 31, 2017 (in thousands). Derivative Instruments Gross Gross amounts Net amounts presented in the condensed June 30, 2018 Current assets $ 101,679 $ (95,804 ) $ 5,875 Other assets 2,749 (2,749 ) — Current liabilities (99,820 ) 95,804 (4,016 ) Other liabilities (8,002 ) 2,749 (5,253 ) Total $ (3,394 ) $ — $ (3,394 ) December 31, 2017 Current assets $ 131,092 $ (129,902 ) $ 1,190 Current liabilities (146,331 ) 129,902 (16,429 ) Total $ (15,239 ) $ — $ (15,239 )
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations	The following table summarizes the location and aggregate fair value of all derivative financial instruments recorded in the interim unaudited condensed consolidated statements of operations for the periods presented (in thousands). These derivative financial instruments are not designated as hedging instruments. Three Months Ended Six Months Ended Type of Instrument Location in Condensed Consolidated Statement of Operations 2018 2017 2018 2017 Derivative Instrument Oil Revenues: Realized (loss) gain on derivatives $ (2,488 ) $ 581 $ (6,797 ) $ (1,053 ) Natural Gas Revenues: Realized (loss) gain on derivatives — (23 ) 51 (608 ) Realized (loss) gain on derivatives (2,488 ) 558 (6,746 ) (1,661 ) Oil Revenues: Unrealized gain on derivatives 1,829 10,643 12,956 28,422 Natural Gas Revenues: Unrealized (loss) gain on derivatives (400 ) 2,547 (1,111 ) 5,399 Unrealized gain on derivatives 1,429 13,190 11,845 33,821 Total $ (1,059 ) $ 13,748 $ 5,099 $ 32,160
Open costless collar contracts
Open Option Contracts Written [Line Items]
Summary of contracts for oil and natural gas	The following is a summary of the Company’s open costless collar contracts for oil and natural gas at June 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl or MMBtu) Weighted Average Price Floor ($/Bbl or Weighted Average Price Ceiling ($/Bbl or Fair Value of Asset (Liability) (thousands) Oil - WTI (1) 07/01/2018 - 12/31/2018 1,440,000 $ 44.27 $ 60.29 $ (15,986 ) Oil - WTI (1) 01/01/2019 - 12/31/2019 2,400,000 $ 50.00 $ 64.75 (12,208 ) Oil - LLS (2) 07/01/2018 - 12/31/2018 360,000 $ 45.00 $ 63.05 (4,381 ) Natural Gas 07/01/2018 - 12/31/2018 8,400,000 $ 2.58 $ 3.67 79 Total open costless collar contracts $ (32,496 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. (2) Argus Louisiana Light Sweet crude oil. The following is a summary of the Company’s open three-way costless collar contracts for oil at June 30, 2018 . Open three-way costless collars consist of a long put (the floor), a short call (the ceiling) and a long call that limits losses on the upside. Commodity Calculation Period Notional Quantity (Bbl) Weighted Average Price Floor ($/Bbl) Weighted Average Price, Short Call ($/Bbl) Weighted Average Price, Long Call ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil - WTI (1) 07/01/2018 - 12/31/2018 960,000 $ 50.08 $ 63.50 $ 66.68 $ (2,249 ) Total open three-way costless collar contracts $ (2,249 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. The following is a summary of the Company’s open basis swap contracts for oil at June 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl) Fixed Price ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil Basis Swaps 07/01/2018 - 12/31/2018 2,610,000 $ (1.02 ) $ 31,351 Total open swap contracts $ 31,351 Total open derivative financial instruments $ (3,394 ) The Company’s derivative financial instruments are subject to master netting arrangements, and all but one counterparty allow for cross-commodity master netting provided the settlement dates for the commodities are the same. The Company does not present different types of commodities with the same counterparty on a net basis in its interim unaudited condensed consolidated balance sheets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Summary of the valuation of the Company's financial assets and liabilities that were accounted for at fair value on a recurring basis	The following tables summarize the valuation of the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis in accordance with the classifications provided above as of June 30, 2018 and December 31, 2017 (in thousands). Fair Value Measurements at Description Level 1 Level 2 Level 3 Total Assets (Liabilities) Natural gas derivatives $ — $ 79 $ — $ 79 Oil derivatives and basis swaps — (3,473 ) — (3,473 ) Total $ — $ (3,394 ) $ — $ (3,394 ) Fair Value Measurements at Description Level 1 Level 2 Level 3 Total Assets (Liabilities) Natural gas derivatives $ — $ 1,190 $ — $ 1,190 Oil derivatives and basis swaps — (16,429 ) — (16,429 ) Total $ — $ (15,239 ) $ — $ (15,239 )

Supplemental Disclosures (Table

Supplemental Disclosures (Tables)	6 Months Ended
	Jun. 30, 2018
Supplemental Disclosures [Abstract]
Summary of current accrued liabilities	The following table summarizes the Company’s current accrued liabilities at June 30, 2018 and December 31, 2017 (in thousands). June 30, December 31, Accrued evaluated and unproved and unevaluated property costs $ 79,540 $ 105,347 Accrued midstream property costs 11,459 14,823 Accrued cost to issue equity 73 — Accrued lease operating expenses 14,209 12,611 Accrued interest on debt 8,345 8,345 Accrued asset retirement obligations 1,235 1,176 Accrued partners’ share of joint interest charges 14,824 27,628 Other 3,680 4,418 Total accrued liabilities $ 133,365 $ 174,348
Supplemental disclosures of cash flow information	The following table provides supplemental disclosures of cash flow information for the six months ended June 30, 2018 and 2017 (in thousands). Six Months Ended 2018 2017 Cash paid for interest expense, net of amounts capitalized $ 14,286 $ 15,875 Increase in asset retirement obligations related to mineral properties $ 834 $ 1,978 Increase (decrease) in asset retirement obligations related to midstream properties $ 296 $ (138 ) (Decrease) increase in liabilities for oil and natural gas properties capital expenditures $ (26,389 ) $ 43,797 (Decrease) increase in liabilities for midstream properties capital expenditures $ (2,371 ) $ 1,838 Stock-based compensation expense recognized as liability $ (93 ) $ (339 ) Increase (decrease) in liabilities for accrued cost to issue equity $ 73 $ (343 ) Transfer of inventory from (to) oil and natural gas properties $ 343 $ (228 ) Transfer of inventory to midstream and other property and equipment $ (2,390 ) $ — The following table provides a reconciliation of cash and restricted cash recorded in the interim unaudited condensed consolidated balance sheets to cash and restricted cash as presented on the interim unaudited condensed consolidated statements of cash flows (in thousands). Six Months Ended 2018 2017 Cash $ 122,450 $ 131,467 Restricted cash 21,063 15,040 Total cash and restricted cash $ 143,513 $ 146,507

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Selected financial information for segments	The following tables present selected financial information for the periods presented regarding the Company’s business segments on a stand-alone basis, corporate expenses that are not allocated to a segment and the consolidation and elimination entries necessary to arrive at the financial information for the Company on a consolidated basis (in thousands). On a consolidated basis, midstream services revenues consist primarily of those revenues from midstream operations related to third parties, including working interest owners in the Company’s operated wells. All midstream services revenues associated with Company-owned production are eliminated in consolidation. In evaluating the operating results of the exploration and production and midstream segments, the Company does not allocate certain expenses to the individual segments, including general and administrative expenses. Such expenses are reflected in the column labeled “Corporate.” Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Three Months Ended June 30, 2018 Oil and natural gas revenues $ 207,229 $ 1,790 $ — $ — $ 209,019 Midstream services revenues — 19,896 — (16,489 ) 3,407 Realized loss on derivatives (2,488 ) — — — (2,488 ) Unrealized gain on derivatives 1,429 — — — 1,429 Expenses (1) 126,025 9,363 18,475 (16,489 ) 137,374 Operating income (loss) (2) $ 80,145 $ 12,323 $ (18,475 ) $ — $ 73,993 Total assets $ 2,058,447 $ 354,068 $ 143,332 $ — $ 2,555,847 Capital expenditures (3) $ 199,345 $ 32,900 $ 732 $ — $ 232,977 _____________________ (1) Includes depletion, depreciation and amortization expenses of $64.5 million and $2.3 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $25,000 . (2) Includes $5.8 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $16.1 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment. Exploration and Production Consolidations and Eliminations Consolidated Company Midstream Corporate Three Months Ended June 30, 2017 Oil and natural gas revenues $ 113,387 $ 377 $ — $ — $ 113,764 Midstream services revenues — 11,367 — (9,268 ) 2,099 Realized gain on derivatives 558 — — — 558 Unrealized gain on derivatives 13,190 — — — 13,190 Expenses (1) 78,078 5,960 15,852 (9,268 ) 90,622 Operating income (loss) (2) $ 49,057 $ 5,784 $ (15,852 ) $ — $ 38,989 Total assets $ 1,436,678 $ 192,889 $ 147,509 $ — $ 1,777,076 Capital expenditures (3) $ 165,583 $ 27,347 $ 1,752 $ — $ 194,682 _____________________ (1) Includes depletion, depreciation and amortization expenses of $39.6 million and $1.3 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.4 million . (2) Includes $3.2 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $13.4 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment.

Summary of Significant Accoun26

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 212,426		$ 397,448
Realized (loss) gain on derivatives	(2,488)	$ 558	(6,746)	$ (1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Total revenue	211,367	$ 129,611	402,547	$ 264,425
Oil revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	166,271		314,430
Natural gas revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	42,748		76,543
Third-party midstream services revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,407		6,475
Total revenues from contracts with customers
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	212,426		397,448
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,600		4,800
Cost of Goods and Services Sold	$ (2,600)		$ (4,800)

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in oil and natural gas revenues	$ (212,426)		$ (397,448)
Restricted cash	21,063	$ 15,040	$ 21,063	$ 15,040	$ 5,977
Discount rate, present value of future revenue			10.00%
Impairment charges		0	$ 0
Capitalized general and administrative costs	6,800	5,200	14,100	10,800
Interest costs capitalized	2,600	1,900	4,500	3,200
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	6,000	$ 1,300	6,000	$ 1,300
Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in oil and natural gas revenues	(2,600)		(4,800)
Decrease in production taxes, transportation and processing expenses	$ 2,600		$ 4,800

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accounting Policies [Abstract]
Weighted average common shares outstanding for basic earnings (loss) per share	112,706	100,211	110,809	100,005
Dilutive effect of options and restricted stock units	350	16	471	450
Diluted weighted average common shares outstanding	113,056	100,227	111,280	100,455

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Changes in the Company's asset retirement obligations
Beginning asset retirement obligations				$ 26,256
Liabilities incurred during period				1,589
Liabilities settled during period				(459)
Accretion expense		$ 375	$ 314	739	$ 614
Ending asset retirement obligations		28,125		28,125
Less: current asset retirement obligations	[1]	(1,235)		(1,235)
Long-term asset retirement obligations		$ 26,890		$ 26,890		$ 25,080
[1]	Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at June 30, 2018.

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	Aug. 01, 2018	Jun. 30, 2018	Mar. 05, 2018	Dec. 31, 2017	Dec. 09, 2016	Apr. 14, 2015
Revolving Credit Agreement (Textual) [Abstract]
Senior unsecured notes		$ 574,164		$ 574,073
Third Amended Credit Agreement
Revolving Credit Agreement (Textual) [Abstract]
Amended maximum borrowing capacity		500,000
Senior Notes | Senior Notes Due 2023
Revolving Credit Agreement [Line Items]
Long-term Debt		$ 575,000
Revolving Credit Agreement (Textual) [Abstract]
Interest rate		6.875%			6.875%
Senior unsecured notes					$ 175,000	$ 400,000
Subsequent Event | Senior Notes | Senior Notes Due 2023
Revolving Credit Agreement [Line Items]
Long-term Debt	$ 575,000
Revolving Credit Agreement (Textual) [Abstract]
Interest rate	6.875%
Revolving Credit Facility
Revolving Credit Agreement (Textual) [Abstract]
Maximum borrowing capacity		$ 400,000	$ 725,000
Revolving Credit Facility | Third Amended Credit Agreement
Revolving Credit Agreement (Textual) [Abstract]
Borrowings under Credit Agreement		0
Revolving Credit Facility | Subsequent Event | Third Amended Credit Agreement
Revolving Credit Agreement (Textual) [Abstract]
Borrowings under Credit Agreement	$ 0
Letter of Credit
Revolving Credit Agreement (Textual) [Abstract]
Outstanding letters of credit		$ 3,000
Letter of Credit | Subsequent Event
Revolving Credit Agreement (Textual) [Abstract]
Outstanding letters of credit	$ 3,000

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	May 17, 2018	Feb. 15, 2017	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period (in shares)		563,408
Share price (in dollars per share)		$ 29.68
Fair value		$ 26,900
Cost to issue equity	$ 100			$ 73	$ 0
Repayments of Long-term Lines of Credit			$ 45,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in period (in shares)		667,488
Vesting period of shares		3 years
Corporate Joint Venture | San Mateo Midstream
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance incentives earned				14,700
Deferred performance incentives				$ 58,800		$ 73,500
Deferred performance incentives term				4 years		5 years
Public Stock Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of Stock, Consideration Received on Transaction	$ 226,500
Public Stock Offering [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	7,000,000

Derivative Financial Instrume32

Derivative Financial Instruments (Details) $ in Thousands	Jun. 30, 2018USD ($)MMBTUbbl$ / MMBTU$ / bbl	Dec. 31, 2017USD ($)
Summary of contracts for oil and natural gas
Derivative, Fair Value, Net | $	$ (3,394)	$ (15,239)
Open costless collar contracts
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability) | $	(32,496)
Open Swap Collar Contracts
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability) | $	$ 31,351
Derivative Contract, Calculation Period One | Open costless collar contracts | Oil - WTI
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | bbl	1,440,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	44.27
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	60.29
Fair Value of Asset (Liability) | $	$ (15,986)
Derivative Contract, Calculation Period One | Open costless collar contracts | Oil - LLS
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | bbl	360,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	45
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	63.05
Fair Value of Asset (Liability) | $	$ (4,381)
Derivative Contract, Calculation Period One | Open costless collar contracts | Natural Gas
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | MMBTU	8,400,000
Weighted Average Price Floor ($/Bbl or $/MMBtu) | $ / MMBTU	2.58
Weighted Average Price Ceiling ($/Bbl or $/MMBtu) | $ / MMBTU	3.67
Fair Value of Asset (Liability) | $	$ 79
Derivative Contract, Calculation Period One | Open Three-way Costless Collar Contracts | Oil - WTI
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | bbl	960,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	50.08
Fair Value of Asset (Liability) | $	$ (2,249)
Derivative Contract, Calculation Period One | Open Swap Collar Contracts | Oil Basis Swaps
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | bbl	2,610,000
Derivative, Swap Type, Average Fixed Price	(1.02)
Fair Value of Asset (Liability) | $	$ 31,351
Derivative Contract, Calculation Period One | Short Call | Open Three-way Costless Collar Contracts | Oil - WTI
Summary of contracts for oil and natural gas
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	63.50
Derivative Contract, Calculation Period One | Long Call | Open Three-way Costless Collar Contracts | Oil - WTI
Summary of contracts for oil and natural gas
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	66.68
Derivative Contract, Calculation Period Two | Open costless collar contracts | Oil - WTI
Summary of contracts for oil and natural gas
Notional Quantity (Bbl or MMBtu) | bbl	2,400,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	50
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	64.75
Fair Value of Asset (Liability) | $	$ (12,208)

Derivative Financial Instrume33

Derivative Financial Instruments (Details 2) $ in Thousands	Jun. 30, 2018USD ($)bbl$ / bbl	Dec. 31, 2017USD ($)
Summary of gross liability balances of derivative instruments
Total	$ (3,394)	$ (15,239)
Gross amounts netted in the condensed consolidated balance sheets	0	0
Net amounts presented in the condensed consolidated balance sheets	(3,394)	(15,239)
Current assets
Derivative [Line Items]
Gross amounts of recognized assets	101,679	131,092
Gross amounts netted in the condensed consolidated balance sheets	(95,804)	(129,902)
Oil, natural gas and natural gas liquids (NGL) derivatives	5,875	1,190
Other assets
Derivative [Line Items]
Gross amounts of recognized assets	2,749
Gross amounts netted in the condensed consolidated balance sheets	(2,749)
Oil, natural gas and natural gas liquids (NGL) derivatives	0
Current liabilities
Summary of gross liability balances of derivative instruments
Gross amounts of recognized liabilities	(99,820)	(146,331)
Gross amounts netted in the condensed consolidated balance sheet	95,804	129,902
Oil, natural gas and natural gas liquids (NGL) derivatives	(4,016)	$ (16,429)
Other liabilities
Summary of gross liability balances of derivative instruments
Gross amounts of recognized liabilities	(8,002)
Gross amounts netted in the condensed consolidated balance sheet	2,749
Oil, natural gas and natural gas liquids (NGL) derivatives	(5,253)
Open Costless Collar Contracts
Summary of gross liability balances of derivative instruments
Derivative Assets (Liabilities), at Fair Value, Net	$ (32,496)
Derivative Contract, Calculation Period One | Oil - WTI | Open Three-way Costless Collar Contracts
Derivative [Line Items]
Notional Quantity (Bbl or MMBtu) | bbl	960,000
Summary of gross liability balances of derivative instruments
Derivative, Floor Price | $ / bbl	50.08
Derivative Assets (Liabilities), at Fair Value, Net	$ (2,249)
Derivative Contract, Calculation Period One | Oil - WTI | Open Costless Collar Contracts
Derivative [Line Items]
Notional Quantity (Bbl or MMBtu) | bbl	1,440,000
Summary of gross liability balances of derivative instruments
Derivative, Floor Price | $ / bbl	44.27
Derivative, Cap Price | $ / bbl	60.29
Derivative Assets (Liabilities), at Fair Value, Net	$ (15,986)

Derivative Financial Instrume34

Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized (loss) gain on derivatives	$ (2,488)	$ 558	$ (6,746)	$ (1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Total	(1,059)	13,748	5,099	32,160
Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized (loss) gain on derivatives	(2,488)	558	(6,746)	(1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Oil | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized (loss) gain on derivatives	(2,488)	581	(6,797)	(1,053)
Unrealized gain on derivatives	1,829	10,643	12,956	28,422
Natural Gas | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized (loss) gain on derivatives	0	(23)	51	(608)
Unrealized gain on derivatives	$ (400)	$ 2,547	$ (1,111)	$ 5,399

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets (Liabilities)
Total	$ (3,394)	$ (15,239)
Fair value on a recurring basis
Assets (Liabilities)
Derivative Asset	79	1,190
Derivative Liability	(3,473)	(16,429)
Total	(3,394)	(15,239)
Fair value on a recurring basis | Level 1
Assets (Liabilities)
Derivative Asset	0	0
Derivative Liability	0	0
Fair value on a recurring basis | Level 2
Assets (Liabilities)
Derivative Asset	79	1,190
Derivative Liability	(3,473)	(16,429)
Total	(3,394)	(15,239)
Fair value on a recurring basis | Level 3
Assets (Liabilities)
Derivative Asset	0	0
Derivative Liability	$ 0	$ 0

Fair Value Measurements (Deta36

Fair Value Measurements (Details 1) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Senior Notes Due 2023 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of notes	$ 603.4	$ 614.1

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Feb. 17, 2017	May 31, 2018	Apr. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2015	Jun. 30, 2018	Jun. 30, 2017
Drilling Rig Commitments
Commitments and Contingencies (Textual) [Abstract]
Maximum termination outstanding obligations of contracts				$ 32,439				$ 32,439
Outside Operated Drilling Commitments
Commitments and Contingencies (Textual) [Abstract]
Maximum termination outstanding obligations of contracts				47,190				47,190
Loving County System Agreement
Commitments and Contingencies (Textual) [Abstract]
Agreement term							15 years
Deficiency fee required to be paid								10,900
Transportation and processing fee under the agreement				4,000		$ 3,700		7,400	$ 6,800
Eddy County
Commitments and Contingencies (Textual) [Abstract]
Transportation and processing fee under the agreement				900				1,500
Capital Addition Purchase Commitments
Commitments and Contingencies (Textual) [Abstract]
Remaining commitments								55,300
Payment for long-term purchase commitment				1,100				3,600
Remaining purchase obligation				2,000				2,000
Field Compression and Amine Gas Treatment
Commitments and Contingencies (Textual) [Abstract]
Remaining commitments								19,900
Payment for long-term purchase commitment				6,000				6,500
Remaining purchase obligation				13,500				13,500
Corporate Joint Venture | San Mateo Midstream
Commitments and Contingencies (Textual) [Abstract]
Contractual obligation				222,600				222,600
Rustler Breaks and Wolf Asset Area | Corporate Joint Venture | San Mateo Midstream
Commitments and Contingencies (Textual) [Abstract]
Term of contractual obligation	15 years
Rustler Breaks Asset Area | Corporate Joint Venture | San Mateo Midstream
Commitments and Contingencies (Textual) [Abstract]
Term of contractual obligation	15 years
Natural Gas Transportation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Agreement term					18 years
Contractual obligation				45,800				$ 45,800
Natural Gas Transportation and Fractionation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Agreement term								7 years
Contractual obligation				132,300				$ 132,300
16-Year Fixed Fee Natural Gas Transportation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Agreement term			16 years
Contractual obligation				56,800				56,800
10-Year Fixed Fee Natural Gas Transportation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Agreement term		10 years
Contractual obligation				200,600				200,600
Natural Gas Transportation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Transportation and processing fee under the agreement				200				200
Contractual obligation				$ 4,600				$ 4,600

Supplemental Disclosures (Detai

Supplemental Disclosures (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 133,365	$ 174,348
Accrued evaluated and unproved and unevaluated property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	79,540	105,347
Accrued midstream property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	11,459	14,823
Accrued lease operating expenses
Supplemental Disclosures [Line Items]
Total accrued liabilities	14,209	12,611
Accrued interest on debt
Supplemental Disclosures [Line Items]
Total accrued liabilities	8,345	8,345
Accrued asset retirement obligations
Supplemental Disclosures [Line Items]
Total accrued liabilities	1,235	1,176
Accrued partners’ share of joint interest charges
Supplemental Disclosures [Line Items]
Total accrued liabilities	14,824	27,628
Other
Supplemental Disclosures [Line Items]
Total accrued liabilities	3,680	4,418
Accrued Cost to Issue Equity [Member]
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 73	$ 0

Supplemental Disclosures (Det39

Supplemental Disclosures (Details 1) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Interest Paid, Net	$ 14,286	$ 15,875
(Decrease) increase in liabilities for oil and natural gas properties capital expenditures	(26,389)	43,797
(Decrease) increase in liabilities for midstream properties capital expenditures	(2,371)	1,838
Stock-based compensation expense recognized as liability	(93)	(339)
Increase (decrease) in liabilities for accrued cost to issue equity	73	(343)
Transfer of inventory from (to) oil and natural gas properties	343	(228)
Transfer of inventory to other property and equipment	(2,390)	0
Mineral Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	834	1,978
Midstream Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	$ 296	$ (138)

Supplemental Disclosures Supple

Supplemental Disclosures Supplemental Disclosures - Restricted Cash Reconciliation (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Cash	$ 122,450	$ 96,505	$ 131,467
Restricted cash	21,063	5,977	15,040
Total cash and restricted cash	$ 143,513	$ 102,482	$ 146,507	$ 214,142

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)segment	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of segments | segment			2
Oil and natural gas revenues	$ 209,019	$ 113,764	$ 390,973	$ 228,611
Third-party midstream services revenues	3,407	2,099	6,475	3,654
Realized (loss) gain on derivatives	(2,488)	558	(6,746)	(1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Expenses	137,374	90,622	255,192	171,157
Operating (loss) income	73,993	38,989	147,355	93,268
Total assets	2,555,847	1,777,076	2,555,847	1,777,076	$ 2,145,690
Capital expenditures	232,977	194,682	468,665	417,399
Depletion, depreciation and amortization	66,838	41,274	122,207	75,266
Impairment charges		0	0
Other (expense) income	(352)	1,922	(299)	1,991
Income Tax Expense (Benefit)		0		0
Income before income taxes	65,637	31,687	130,561	77,587
Net Income (Loss) Attributable to Parent	59,806	28,509	119,700	72,493
Corporate
Segment Reporting Information [Line Items]
Oil and natural gas revenues		0
Third-party midstream services revenues	0	0	0	0
Realized (loss) gain on derivatives		0
Unrealized gain on derivatives		0
Expenses	18,475	15,852	35,684	31,608
Operating (loss) income	(18,475)	(15,852)	(35,684)	(31,608)
Total assets	143,332	147,509	143,332	147,509
Capital expenditures	732	1,752	1,258	3,216
Depletion, depreciation and amortization	0	400	600	700
Consolidations and Eliminations
Segment Reporting Information [Line Items]
Oil and natural gas revenues		0
Third-party midstream services revenues	(16,489)	(9,268)	(29,233)	(17,329)
Realized (loss) gain on derivatives		0
Unrealized gain on derivatives		0
Expenses	(16,489)	(9,268)	(29,233)	(17,329)
Total assets	0	0	0	0
Capital expenditures	0	0	0	0
Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Oil and natural gas revenues	207,229	113,387	387,489	227,552
Third-party midstream services revenues	0	0	0	0
Realized (loss) gain on derivatives	(2,488)	558	(6,746)	(1,661)
Unrealized gain on derivatives	1,429	13,190	11,845	33,821
Expenses	126,025	78,078	232,180	146,416
Operating (loss) income	80,145	49,057	160,408	113,296
Total assets	2,058,447	1,436,678	2,058,447	1,436,678
Capital expenditures	199,345	165,583	388,790	373,956
Depletion, depreciation and amortization	64,500	39,600	117,800	72,100
Midstream | Operating Segments
Segment Reporting Information [Line Items]
Oil and natural gas revenues	1,790	377	3,484	1,059
Third-party midstream services revenues	19,896	11,367	35,708	20,983
Realized (loss) gain on derivatives		0
Unrealized gain on derivatives		0
Expenses	9,363	5,960	16,561	10,462
Operating (loss) income	12,323	5,784	22,631	11,580
Total assets	354,068	192,889	354,068	192,889
Capital expenditures	32,900	27,347	78,617	40,227
Depletion, depreciation and amortization	2,300	1,300	3,900	2,500
Net income attributable to non-controlling interest in subsidiaries		(3,200)	(10,900)	(5,100)
Capital expenditures	16,100	$ 13,400	$ 38,500	$ 18,600
Operating Income (Loss) | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Net income attributable to non-controlling interest in subsidiaries	$ (5,800)

Subsidiary Guarantors Consolida

Subsidiary Guarantors Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Equity Method Investment, Ownership Percentage	100.00%
Intercompany receivable	$ 0	$ 0
Third-party current assets	320,937	257,170
Net property and equipment	2,228,017	1,881,456
Investment in subsidiaries	0	0
Third-party long-term assets	6,893	7,064
Total assets	2,555,847	2,145,690	$ 1,777,076
Intercompany payable	0	0
Third-party current liabilities	263,598	282,606
Senior unsecured notes payable	574,164	574,073
Other third-party long-term liabilities	38,337	31,465
Total equity attributable to Matador Resources Company	1,524,532	1,156,556
Non-controlling interest in subsidiaries	155,216	100,990
Total liabilities and equity	2,555,847	2,145,690
Eliminating Entries
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	(820,217)	(588,021)
Third-party current assets	0	0
Net property and equipment	0	0
Investment in subsidiaries	(1,448,314)	(1,258,372)
Third-party long-term assets	(2,934)	(3,003)
Total assets	(2,271,465)	(1,849,396)
Intercompany payable	(820,217)	(588,021)
Third-party current liabilities	(256)	(274)
Senior unsecured notes payable	0	0
Other third-party long-term liabilities	(2,678)	(2,729)
Total equity attributable to Matador Resources Company	(1,448,314)	(1,258,372)
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	(2,271,465)	(1,849,396)
Matador | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	811,982	585,109
Third-party current assets	3,031	2,240
Net property and equipment	0	0
Investment in subsidiaries	1,285,896	1,147,295
Third-party long-term assets	6,433	6,425
Total assets	2,107,342	1,741,069
Intercompany payable	0	0
Third-party current liabilities	8,646	8,847
Senior unsecured notes payable	574,164	574,073
Other third-party long-term liabilities	0	1,593
Total equity attributable to Matador Resources Company	1,524,532	1,156,556
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	2,107,342	1,741,069
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	8,235	2,912
Third-party current assets	29,358	9,334
Net property and equipment	299,258	223,178
Investment in subsidiaries	0	0
Third-party long-term assets	0	0
Total assets	336,851	235,424
Intercompany payable	0	0
Third-party current liabilities	15,482	19,891
Senior unsecured notes payable	0	0
Other third-party long-term liabilities	3,735	3,466
Total equity attributable to Matador Resources Company	162,418	111,077
Non-controlling interest in subsidiaries	155,216	100,990
Total liabilities and equity	336,851	235,424
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	0	0
Third-party current assets	288,548	245,596
Net property and equipment	1,928,759	1,658,278
Investment in subsidiaries	162,418	111,077
Third-party long-term assets	3,394	3,642
Total assets	2,383,119	2,018,593
Intercompany payable	820,217	588,021
Third-party current liabilities	239,726	254,142
Senior unsecured notes payable	0	0
Other third-party long-term liabilities	37,280	29,135
Total equity attributable to Matador Resources Company	1,285,896	1,147,295
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	$ 2,383,119	$ 2,018,593

Subsidiary Guarantors Consoli43

Subsidiary Guarantors Consolidated Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Income Statements, Captions [Line Items]
Total revenues	$ 211,367	$ 129,611	$ 402,547	$ 264,425
Total expenses	137,374	90,622	255,192	171,157
Operating (loss) income	73,993	38,989	147,355	93,268
Net gain on asset sales and inventory impairment	0	0	0	7
Interest expense	(8,004)	(9,224)	(16,495)	(17,679)
Other (expense) income	(352)	1,922	(299)	1,991
Earnings in subsidiaries	0	0	0	0
Income before income taxes	65,637	31,687	130,561	77,587
Total income tax provision (benefit)		0		0
Net income attributable to non-controlling interest in subsidiaries	(5,831)	(3,178)	(10,861)	(5,094)
Net income attributable to Matador Resources Company shareholders	59,806	28,509	119,700	72,493
Eliminating Entries
Condensed Income Statements, Captions [Line Items]
Total revenues	(16,208)	(8,861)	(28,702)	(16,358)
Total expenses	(16,208)	(8,861)	(28,702)	(16,358)
Operating (loss) income	0	0	0	0
Net gain on asset sales and inventory impairment				0
Interest expense	0	0	0	0
Earnings in subsidiaries	(75,058)	(42,472)	(149,907)	(99,969)
Income before income taxes	(75,058)	(42,472)	(149,907)	(99,969)
Total income tax provision (benefit)		0		0
Net income attributable to non-controlling interest in subsidiaries	0	0	0	0
Net income attributable to Matador Resources Company shareholders	(75,058)	(42,472)	(149,907)	(99,969)
Matador | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total revenues	0		0
Total expenses	1,178	1,586	2,412	2,846
Operating (loss) income	(1,178)	(1,586)	(2,412)	(2,846)
Net gain on asset sales and inventory impairment				0
Interest expense	(8,004)	(9,224)	(16,495)	(17,679)
Other (expense) income		(27)	6
Earnings in subsidiaries	68,988	39,228	138,601	92,900
Income before income taxes	59,806	28,391	119,700	72,375
Total income tax provision (benefit)		(118)		(118)
Net income attributable to non-controlling interest in subsidiaries	0	0	0	0
Net income attributable to Matador Resources Company shareholders	59,806	28,509	119,700	72,493
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total revenues	21,356	11,274	38,550	20,937
Total expenses	9,466	4,814	16,394	8,682
Operating (loss) income	11,890	6,460	22,156	12,255
Net gain on asset sales and inventory impairment				0
Interest expense	0		0
Other (expense) income	11	26	11	26
Earnings in subsidiaries	0	0	0	0
Income before income taxes	11,901	6,486	22,167	12,281
Total income tax provision (benefit)		64		118
Net income attributable to non-controlling interest in subsidiaries	(5,831)	(3,178)	(10,861)	(5,094)
Net income attributable to Matador Resources Company shareholders	6,070	3,244	11,306	7,069
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total revenues	206,219	127,198	392,699	259,846
Total expenses	142,938	93,083	265,088	175,987
Operating (loss) income	63,281	34,115	127,611	83,859
Net gain on asset sales and inventory impairment				7
Interest expense		0		0
Other (expense) income	(363)	1,923	(316)	1,965
Earnings in subsidiaries	6,070	3,244	11,306	7,069
Income before income taxes	68,988	39,282	138,601	92,900
Total income tax provision (benefit)		54		0
Net income attributable to non-controlling interest in subsidiaries	0	0	0	0
Net income attributable to Matador Resources Company shareholders	$ 68,988	$ 39,228	$ 138,601	$ 92,900

Subsidiary Guarantors Consoli44

Subsidiary Guarantors Consolidated Cash Flow (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 254,208	$ 121,242
Net cash provided by (used in) investing activities	(493,562)	(369,695)
Net cash provided by (used in) financing activities	280,385	180,818
Increase (decrease) in cash and restricted cash	41,031	(67,635)
Cash and restricted cash at beginning of period	102,482	214,142
Cash and restricted cash at end of period	143,513	146,507
Eliminating Entries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	0	0
Net cash provided by (used in) investing activities	40,035	(133,880)
Net cash provided by (used in) financing activities	(40,035)	133,880
Increase (decrease) in cash and restricted cash	0	0
Cash and restricted cash at beginning of period	0	0
Cash and restricted cash at end of period	0	0
Matador | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(224,441)	(98,583)
Net cash provided by (used in) investing activities	0	33
Net cash provided by (used in) financing activities	226,539	0
Increase (decrease) in cash and restricted cash	2,098	(98,550)
Cash and restricted cash at beginning of period	286	99,795
Cash and restricted cash at end of period	2,384	1,245
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	10,225	1,566
Net cash provided by (used in) investing activities	(79,119)	(38,362)
Net cash provided by (used in) financing activities	83,400	47,707
Increase (decrease) in cash and restricted cash	14,506	10,911
Cash and restricted cash at beginning of period	5,663	2,900
Cash and restricted cash at end of period	20,169	13,811
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	468,424	218,259
Net cash provided by (used in) investing activities	(454,478)	(197,486)
Net cash provided by (used in) financing activities	10,481	(769)
Increase (decrease) in cash and restricted cash	24,427	20,004
Cash and restricted cash at beginning of period	96,533	111,447
Cash and restricted cash at end of period	$ 120,960	$ 131,451