Matador Resources (MTDR) 10-Q 1 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 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	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		116,333,766

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - Unaudited - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash	$ 45,942	$ 96,505
Restricted cash	7,066	5,977
Accounts receivable
Oil and natural gas revenues	81,422	65,962
Joint interest billings	55,390	67,225
Other	10,060	8,031
Derivative instruments	4	1,190
Lease and well equipment inventory	18,758	5,993
Prepaid expenses and other assets	6,790	6,287
Total current assets	225,432	257,170
Oil and natural gas properties, full-cost method
Evaluated	3,506,479	3,004,770
Unproved and unevaluated	1,241,529	637,396
Midstream and other property and equipment	408,436	281,096
Less accumulated depletion, depreciation and amortization	(2,234,470)	(2,041,806)
Net property and equipment	2,921,974	1,881,456
Other assets	6,796	7,064
Total assets	3,154,202	2,145,690
Current liabilities
Accounts payable	32,491	11,757
Accrued liabilities	178,830	174,348
Royalties payable	67,023	61,358
Amounts due to affiliates	12,998	10,302
Derivative instruments	19,740	16,429
Advances from joint interest owners	12,354	2,789
Amounts due to joint ventures	2,373	4,873
Other current liabilities	942	750
Total current liabilities	326,751	282,606
Long-term liabilities
Borrowings under Credit Agreement	325,000	0
Senior unsecured notes payable	740,063	574,073
Asset retirement obligations	28,706	25,080
Amounts due to joint ventures	4,996	0
Other long-term liabilities	6,243	6,385
Total long-term liabilities	1,105,008	605,538
Commitments and contingencies
Shareholders’ equity
Common stock - $0.01 par value, 160,000,000 shares authorized; 116,506,743 and 108,513,597 shares issued; and 116,348,548 and 108,510,160 shares outstanding, respectively	1,165	1,085
Additional paid-in capital	1,923,030	1,666,024
Accumulated deficit	(372,990)	(510,484)
Treasury stock, at cost, 158,195 and 3,437 shares, respectively	(4,039)	(69)
Total Matador Resources Company shareholders’ equity	1,547,166	1,156,556
Non-controlling interest in subsidiaries	175,277	100,990
Total shareholders’ equity	1,722,443	1,257,546
Total liabilities and shareholders’ equity	$ 3,154,202	$ 2,145,690

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - Unaudited - $ / shares	Sep. 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	160,000,000
Common stock, shares issued	116,506,743	108,513,597
Common stock, shares outstanding	116,348,548	108,510,160
Treasury stock, shares	158,195	3,437

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues
Revenues	$ 223,091		$ 620,539
Realized gain (loss) on derivatives	5,424	$ 485	(1,322)	$ (1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Total revenues	207,178	126,279	609,725	390,703
Expenses
Production taxes, transportation and processing	20,215	15,666	58,116	40,348
Lease operating	22,531	16,689	69,685	48,486
Plant and other midstream services operating	7,291	3,096	17,187	8,379
Depletion, depreciation and amortization	70,457	47,800	192,664	123,066
Accretion of asset retirement obligations	387	323	1,126	937
General and administrative	18,444	16,156	55,739	49,671
Total expenses	139,325	99,730	394,517	270,887
Operating income	67,853	26,549	215,208	119,816
Other income (expense)
Net (loss) gain on asset sales and inventory impairment	(196)	16	(196)	23
Interest expense	(10,340)	(8,550)	(26,835)	(26,229)
Prepayment premium on extinguishment of debt	(31,226)	0	(31,226)	0
Other (expense) income	(976)	(36)	(1,275)	1,956
Total other expense	(42,738)	(8,570)	(59,532)	(24,250)
Net income	25,115	17,979	155,676	95,566
Net income attributable to non-controlling interest in subsidiaries	7,321	2,940	18,182	8,034
Net income attributable to Matador Resources Company shareholders	$ 17,794	$ 15,039	$ 137,494	$ 87,532
Earnings per common share
Basic (in dollars per share)	$ 0.15	$ 0.15	$ 1.22	$ 0.87
Diluted (in dollars per share)	$ 0.15	$ 0.15	$ 1.21	$ 0.87
Weighted average common shares outstanding
Basic (shares)	116,358	100,365	112,659	100,141
Diluted (shares)	116,912	100,504	113,208	100,580
Oil and natural gas revenues
Revenues
Revenues	$ 216,282	$ 134,948	$ 607,255	$ 363,559
Third-party midstream services revenues
Revenues
Revenues	$ 6,809	$ 3,218	$ 13,284	$ 6,871

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Shareholders' Equity - Unaudited - 9 months ended Sep. 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		736,000
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		79,000
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	17,174		17,174			17,174
Stock options exercised, shares		178,000
Stock options exercised, net of options forfeited in net share settlements	(1,254)	$ 2	(1,256)			(1,254)
Restricted stock forfeited, shares					155,000
Restricted stock forfeited	(3,970)				$ (3,970)	(3,970)
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	73,500						73,500
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(17,395)						(17,395)
Current period net income	$ 155,676			137,494		137,494	18,182
Ending Balance, shares at Sep. 30, 2018	116,348,548	116,507,000			158,000
Ending balance at Sep. 30, 2018	$ 1,722,443	$ 1,165	1,923,030	$ (372,990)	$ (4,039)	1,547,166	$ 175,277
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 146		$ 146			$ 146

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Current period net income	$ 155,676	$ 95,566
Adjustments to reconcile net income to net cash provided by operating activities
Unrealized loss (gain) on derivatives	9,492	(21,449)
Depletion, depreciation and amortization	192,664	123,066
Accretion of asset retirement obligations	1,126	937
Stock-based compensation expense	13,787	12,488
Prepayment premium on extinguishment of debt	31,226	0
Amortization of debt issuance cost	851	103
Net loss (gain) on asset sales and inventory impairment	196	(23)
Changes in operating assets and liabilities
Accounts receivable	(5,654)	(50,343)
Lease and well equipment inventory	(15,347)	(1,666)
Prepaid expenses	(502)	(2,224)
Other assets	0	217
Accounts payable, accrued liabilities and other current liabilities	20,823	35,068
Royalties payable	5,665	29,651
Advances from joint interest owners	9,565	2,646
Other long-term liabilities	(250)	(1,521)
Net cash provided by operating activities	419,318	222,516
Investing activities
Oil and natural gas properties capital expenditures	(1,106,556)	(517,270)
Expenditures for midstream and other property and equipment	(122,239)	(80,560)
Proceeds from sale of assets	8,267	977
Net cash used in investing activities	(1,220,528)	(596,853)
Financing activities
Repayments of borrowings	45,000	0
Borrowings under Credit Agreement	370,000	0
Proceeds from issuance of senior unsecured notes	750,000	0
Cost to issue senior unsecured notes	9,531	0
Purchase of senior unsecured notes	(605,780)	0
Proceeds from issuance of common stock	226,612	0
Cost to issue equity	146	0
Proceeds from stock options exercised	827	2,920
Contributions related to formation of Joint Venture	14,700	171,500
Contributions from non-controlling interest owners of less-than-wholly-owned subsidiaries	73,500	29,400
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(17,395)	(5,635)
Taxes paid related to net share settlement of stock-based compensation	(6,051)	(4,415)
Purchase of non-controlling interest of less-than-wholly-owned subsidiary	0	(2,653)
Net cash provided by financing activities	751,736	191,117
Decrease in cash and restricted cash	(49,474)	(183,220)
Cash and restricted cash at beginning of period	102,482	214,142
Cash and restricted cash at end of period	$ 53,008	$ 30,922

Nature of Operations

Nature of Operations	9 Months Ended
	Sep. 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	9 Months Ended
	Sep. 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 September 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 Update 2014-09, 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 from 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 the Company’s 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 on its consolidated financial statements as a result of adoption of ASC 606 was a $2.8 million and $7.6 million decrease in oil and natural gas revenues and a $2.8 million and $7.6 million decrease in production taxes, transportation and processing expenses for the three and nine months ended September 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 nine months ended September 30, 2018 (in thousands). Three Months Ended Nine Months Ended Revenues from contracts with customers $ 223,091 $ 620,539 Realized gain (loss) on derivatives 5,424 (1,322 ) Unrealized loss on derivatives (21,337 ) (9,492 ) Total revenues $ 207,178 $ 609,725 Three Months Ended Nine Months Ended Oil revenues $ 169,913 $ 484,343 Natural gas revenues 46,369 122,912 Third-party midstream services revenues 6,809 13,284 Total revenues from contracts with customers $ 223,091 $ 620,539 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 nine months ended September 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 nine months ended September 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 $8.5 million and $6.1 million of its general and administrative costs for the three months ended September 30, 2018 and 2017 , respectively, and approximately $1.7 million and $2.1 million of its interest expense for the three months ended September 30, 2018 and 2017 , respectively. The Company capitalized approximately $22.6 million and $16.9 million of its general and administrative costs for the nine months ended September 30, 2018 and 2017 , respectively, and approximately $6.2 million and $5.2 million of its interest expense for the nine months ended September 30, 2018 and 2017 , respectively. On September 12, 2018, the Company announced the successful acquisition of 8,400 gross ( 8,400 net) leasehold acres in Lea and Eddy Counties, New Mexico for approximately $387 million in the Bureau of Land Management New Mexico Oil and Gas Lease Sale on September 5 and 6, 2018 (the “BLM Acquisition”). 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 nine months ended September 30, 2018 and 2017 (in thousands). Three Months Ended Nine Months Ended 2018 2017 2018 2017 Weighted average common shares outstanding Basic 116,358 100,365 112,659 100,141 Dilutive effect of options and restricted stock units 554 139 549 439 Diluted weighted average common shares outstanding 116,912 100,504 113,208 100,580 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. The Company plans to use this practical expedient, and as a result, the Company will evaluate new or modified land easements under this ASU beginning at the date of adoption. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842) , which is a targeted improvement for comparative reporting requirements for initial adoption of ASU 2016-02. The Company plans to use the optional transition method to adopt ASU 2016-02, and the amendments provided for in ASU 2018-11 will allow the Company to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period 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, 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 on the Company’s consolidated financial statements.

Asset Retirement Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 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 nine months ended September 30, 2018 (in thousands). Beginning asset retirement obligations $ 26,256 Liabilities incurred during period 2,473 Liabilities settled during period (663 ) Revisions in estimated cash flows 442 Accretion expense 1,126 Ending asset retirement obligations 29,634 Less: current asset retirement obligations (1) (928 ) Long-term asset retirement obligations $ 28,706 _______________ (1) Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at September 30, 2018 .

Debt

Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
DEBT	At September 30, 2018 , the Company had $750.0 million of outstanding 5.875% senior notes due 2026 (the “Original 2026 Notes”), $325.0 million in 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. At October 31, 2018 , the Company had $1.05 billion of outstanding Notes (as defined below), $25.0 million in borrowings outstanding under 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, in March 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 at September 30, 2018 . In October 2018, the lenders completed their review of the Company’s proved oil and natural gas reserves at June 30, 2018. In connection with such review, the Company amended the Credit Agreement to, among other items, increase the maximum facility amount to $1.5 billion , increase the borrowing base to $850.0 million , increase the elected borrowing commitment to $500.0 million , extend the maturity to October 31, 2023 and reduce borrowing rates by 0.25% per annum. This October 2018 redetermination constituted the regularly scheduled November 1 redetermination. Borrowings under the Credit Agreement are limited to the lowest of the borrowing base, the maximum facility amount and the elected borrowing commitment. The Company believes that it was in compliance with the terms of the Credit Agreement at September 30, 2018 . Senior Unsecured Notes As of June 30, 2018, the Company had $575.0 million of outstanding 6.875% senior notes due 2023 (the “2023 Notes”). On August 21, 2018, the Company issued $750.0 million of Original 2026 Notes in a private placement (the “2026 Notes Offering”). The Original 2026 Notes were issued at par value with a coupon rate of 5.875% , and the Company received net proceeds of approximately $740.0 million , after deducting the initial purchasers’ discounts and offering expenses. In conjunction with the 2026 Notes Offering, in August and September 2018, respectively, the Company completed a tender offer to purchase for cash and subsequent redemption of all of the Company’s $575.0 million aggregate principal amount of 2023 Notes (the “2023 Notes Tender Offer and Redemption”). The Company used a portion of the net proceeds from the 2026 Notes Offering to fund the 2023 Notes Tender Offer and Redemption. In connection with the 2023 Notes Tender Offer and Redemption, the Company incurred a loss of $31.2 million , including total payments of $30.4 million to holders of the 2023 Notes as a result of the tender premium and the required 105.156% redemption price payable pursuant to the 2023 Notes indenture. On October 4, 2018, the Company issued an additional $300.0 million of 5.875% senior unsecured notes due 2026 (the “Additional 2026 Notes” and, collectively with the Original 2026 Notes, the “Notes”). The Additional 2026 Notes were issued pursuant to, and are governed by, the same indenture governing the Original 2026 Notes (the “Indenture”). The Additional 2026 Notes were issued at 100.5% of par, plus accrued interest from August 21, 2018. The Company received net proceeds from this offering of approximately $297.6 million , after deducting the initial purchasers’ discounts and estimated offering expenses but excluding accrued interest from August 21, 2018 paid by the initial purchasers of the Additional 2026 Notes. The proceeds from this offering were used to repay a portion of the outstanding borrowings under the Credit Agreement, which were incurred in connection with the BLM Acquisition. The Notes will mature September 15, 2026, and interest is payable on the Notes semi-annually in arrears on each March 15 and September 15. The Notes are guaranteed on a senior unsecured basis by certain subsidiaries of the Company (the “Guarantors”). On or after September 15, 2021, the Company may redeem all or a part of the Notes at any time or from time to time at the following redemption prices (expressed as percentages of principal amount) plus accrued and unpaid interest, if any, to the applicable redemption date, if redeemed during the twelve-month period beginning on September 15 of the years indicated below: Year Redemption Price 2021 104.406% 2022 102.938% 2023 101.469% 2024 and thereafter 100.000% At any time prior to September 15, 2021, the Company may redeem up to 35% of the aggregate principal amount of the Notes with net proceeds from certain equity offerings at a redemption price of 105.875% of the principal amount thereof, plus accrued and unpaid interest, if any, to the redemption date, provided that (i) at least 65% in aggregate principal amount of the Notes (including any additional notes) originally issued remains outstanding immediately after the occurrence of such redemption (excluding Notes held by the Company and its subsidiaries) and (ii) each such redemption occurs within 180 days of the date of the closing of the related equity offering. In addition, at any time prior to September 15, 2021, the Company may redeem all or part of the Notes at a redemption price equal to the sum of: (i) the principal amount thereof, plus (ii) the excess, if any, of (a) the present value at such time of (1) the redemption price of such Notes at September 15, 2021 plus (2) any required interest payments due on such Notes through September 15, 2021, discounted to the redemption date on a semi-annual basis using a discount rate equal to the Treasury Rate (as defined in the Indenture) plus 50 basis points, over (b) the principal amount of such Notes, plus (iii) accrued and unpaid interest, if any, to the redemption date. Subject to certain exceptions, the Indenture contains various covenants that limit the Company’s ability to take certain actions, including, but not limited to, the following: • incur additional indebtedness; • sell assets; • pay dividends or make certain investments; • create liens that secure indebtedness; • enter into transactions with affiliates; and • merge or consolidate with another company. In the case of an event of default arising from certain events of bankruptcy or insolvency with respect to Matador, any Restricted Subsidiary (as defined in the Indenture) that is a Significant Subsidiary (as defined in the Indenture) or any group of Restricted Subsidiaries that, taken together, would constitute a Significant Subsidiary, all outstanding Notes will become due and payable immediately without further action or notice. If any other event of default occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the then outstanding Notes may declare all the Notes to be due and payable immediately. Events of default include, but are not limited to, the following events: • default for 30 days in the payment when due of interest on the Notes; • default in the payment when due of the principal of, or premium, if any, on the Notes; • failure by the Company to comply with its obligations to offer to purchase or purchase notes pursuant to the change of control or asset sale covenants of the Indenture or to comply with the covenant relating to mergers; • failure by the Company for 180 days after notice to comply with its reporting obligations under the Indenture; • failure by the Company for 60 days after notice to comply with any of the other agreements in the Indenture; • payment defaults and accelerations with respect to other indebtedness of the Company and its Restricted Subsidiaries in the aggregate principal amount of $50.0 million or more; • failure by the Company or any Restricted Subsidiary to pay certain final judgments aggregating in excess of $50.0 million within 60 days; • any subsidiary guarantee by a Guarantor ceases to be in full force and effect, is declared null and void in a judicial proceeding or is denied or disaffirmed by its maker; and • certain events of bankruptcy or insolvency with respect to the Company or any Restricted Subsidiary that is a Significant Subsidiary or any group of Restricted Subsidiaries that, taken together, would constitute a Significant Subsidiary.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company’s deferred tax assets exceeded its deferred tax liabilities at September 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 September 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	9 Months Ended
	Sep. 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 Incentives 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 nine months ended September 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. These performance incentives for the nine months ended September 30, 2018 are also denoted as “Contributions related to formation of Joint Venture” under “Financing activities” in the Company’s condensed consolidated statements of cash flows.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	At September 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 September 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) 10/01/2018 - 12/31/2018 720,000 $ 44.27 $ 60.29 $ (9,240 ) Oil - WTI (1) 01/01/2019 - 12/31/2019 2,400,000 $ 50.00 $ 64.75 (21,287 ) Oil - LLS (2) 10/01/2018 - 12/31/2018 180,000 $ 45.00 $ 63.05 (2,973 ) Natural Gas 10/01/2018 - 12/31/2018 4,200,000 $ 2.58 $ 3.67 (18 ) Total open costless collar contracts $ (33,518 ) _____________________ (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 September 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) 10/01/2018 - 12/31/2018 480,000 $ 50.08 $ 63.50 $ 66.68 $ (1,369 ) Total open three-way costless collar contracts $ (1,369 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. The following is a summary of the Company’s open basis swap contracts for oil at September 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl) Fixed Price ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil Basis Swaps 10/01/2018 - 12/31/2018 1,305,000 $ (1.02 ) $ 10,155 Total open swap contracts $ 10,155 At September 30, 2018, the Company had an aggregate liability for open derivative financial instruments of $24.7 million . 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 September 30, 2018 and December 31, 2017 (in thousands). Derivative Instruments Gross Gross amounts Net amounts presented in the condensed September 30, 2018 Current assets $ 49,723 $ (49,719 ) $ 4 Other assets 654 (654 ) — Current liabilities (69,459 ) 49,719 (19,740 ) Long-term liabilities (5,650 ) 654 (4,996 ) Total $ (24,732 ) $ — $ (24,732 ) 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 Nine Months Ended Type of Instrument Location in Condensed Consolidated Statement of Operations 2018 2017 2018 2017 Derivative Instrument Oil Revenues: Realized gain (loss) on derivatives $ 5,424 $ 485 $ (1,373 ) $ (568 ) Natural Gas Revenues: Realized gain (loss) on derivatives — — 51 (608 ) Realized gain (loss) on derivatives 5,424 485 (1,322 ) (1,176 ) Oil Revenues: Unrealized (loss) gain on derivatives (21,240 ) (12,479 ) (8,284 ) 15,949 Natural Gas Revenues: Unrealized (loss) gain on derivatives (97 ) 115 (1,208 ) 5,508 NGL Revenues: Unrealized loss on derivatives — (8 ) — (8 ) Unrealized (loss) gain on derivatives (21,337 ) (12,372 ) (9,492 ) 21,449 Total $ (15,913 ) $ (11,887 ) $ (10,814 ) $ 20,273

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 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 September 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 $ — $ (18 ) $ — $ (18 ) Oil derivatives and basis swaps — (24,714 ) — (24,714 ) Total $ — $ (24,732 ) $ — $ (24,732 ) 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 September 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 September 30, 2018 , the carrying value of borrowings under the Credit Agreement approximated its fair value as it is subject to short-term floating interest rates that reflect market rates available to the Company at the time and is classified at Level 2. At September 30, 2018 and December 31, 2017 , the fair value of the Original 2026 Notes and the 2023 Notes was $761.3 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	9 Months Ended
	Sep. 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 September 30, 2018 , the total deficiency fee required to be paid would be approximately $12.5 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 $4.8 million and $4.0 million in natural gas processing and gathering fees under this agreement during the three months ended September 30, 2018 and 2017 , respectively, and $12.2 million and $10.8 million in natural gas processing and gathering fees under this agreement during the nine months ended September 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 September 30, 2018 was approximately $45.2 million . The Company paid approximately $1.0 million and $2.5 million in transportation fees under this agreement during the three and nine months ended September 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 in late 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 September 30, 2018 was approximately $3.6 million . This short-term agreement ends on September 30, 2019. The Company paid approximately $0.9 million and $1.1 million in transportation fees under this agreement during the three and nine months ended September 30, 2018 , respectively. In April 2018, the Company also 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 September 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 September 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 with subsidiaries of San Mateo. 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 September 30, 2018 was approximately $222.0 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. Since inception, San Mateo’s commitments under these agreements totaled $55.3 million . The subsidiary of San Mateo paid approximately $2.0 million and $5.6 million under these agreements during the three and nine months ended September 30, 2018 . As of September 30, 2018 , there was no remaining obligation under these agreements. 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. Since inception, San Mateo’s commitments under these agreements totaled $24.8 million . The subsidiary of San Mateo paid approximately $6.3 million and $12.8 million under these agreements during the three and nine months ended September 30, 2018 . As of September 30, 2018 , the remaining obligations under these agreements were $12.0 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 $32.8 million at September 30, 2018 . At September 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 $44.2 million at September 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 on 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	9 Months Ended
	Sep. 30, 2018
Supplemental Disclosures [Abstract]
SUPPLEMENTAL DISCLOSURES	Accrued Liabilities The following table summarizes the Company’s current accrued liabilities at September 30, 2018 and December 31, 2017 (in thousands). September 30, December 31, Accrued evaluated and unproved and unevaluated property costs $ 108,420 $ 105,347 Accrued midstream property costs 16,996 14,823 Accrued lease operating expenses 18,651 12,611 Accrued interest on debt 5,407 8,345 Accrued asset retirement obligations 928 1,176 Accrued partners’ share of joint interest charges 22,114 27,628 Other 6,314 4,418 Total accrued liabilities $ 178,830 $ 174,348 Supplemental Cash Flow Information The following table provides supplemental disclosures of cash flow information for the nine months ended September 30, 2018 and 2017 (in thousands). Nine Months Ended 2018 2017 Cash paid for interest expense, net of amounts capitalized $ 29,773 $ 14,542 Increase in asset retirement obligations related to mineral properties $ 1,705 $ 2,484 Increase (decrease) in asset retirement obligations related to midstream properties $ 547 $ (138 ) Increase in liabilities for oil and natural gas properties capital expenditures $ 5,157 $ 35,940 Increase (decrease) in liabilities for midstream properties capital expenditures $ 1,864 $ (247 ) Stock-based compensation expense recognized as liability $ (107 ) $ 150 Decrease in liabilities for accrued cost to issue equity $ — $ (343 ) Increase in liabilities for accrued cost to issue senior notes $ 510 $ — Transfer of inventory from oil and natural gas properties $ 305 $ 74 Transfer of inventory to midstream and other property and equipment $ (2,691 ) $ — 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). Nine Months Ended 2018 2017 Cash $ 45,942 $ 20,178 Restricted cash 7,066 10,744 Total cash and restricted cash $ 53,008 $ 30,922

Segment Information

Segment Information	9 Months Ended
	Sep. 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 September 30, 2018 Oil and natural gas revenues $ 215,248 $ 1,034 $ — $ — $ 216,282 Midstream services revenues — 24,950 — (18,141 ) 6,809 Realized gain on derivatives 5,424 — — — 5,424 Unrealized loss on derivatives (21,337 ) — — — (21,337 ) Expenses (1) 128,263 10,162 19,041 (18,141 ) 139,325 Operating income (loss) (2) $ 71,072 $ 15,822 $ (19,041 ) $ — $ 67,853 Total assets $ 2,697,685 $ 391,323 $ 65,194 $ — $ 3,154,202 Capital expenditures (3) $ 716,751 $ 47,153 $ 312 $ — $ 764,216 _____________________ (1) Includes depletion, depreciation and amortization expenses of $67.2 million and $2.6 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.6 million . (2) Includes $7.3 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $554.9 million attributable to land and seismic acquisition expenditures related to the exploration and production segment and $23.1 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 September 30, 2017 Oil and natural gas revenues $ 134,488 $ 460 $ — $ — $ 134,948 Midstream services revenues — 11,261 — (8,043 ) 3,218 Realized gain on derivatives 485 — — — 485 Unrealized loss on derivatives (12,372 ) — — — (12,372 ) Expenses (1) 86,728 5,598 15,447 (8,043 ) 99,730 Operating income (loss) (2) $ 35,873 $ 6,123 $ (15,447 ) $ — $ 26,549 Total assets $ 1,590,677 $ 222,274 $ 35,586 $ — $ 1,848,537 Capital expenditures (3) $ 180,686 $ 35,008 $ 1,494 $ — $ 217,188 _____________________ (1) Includes depletion, depreciation and amortization expenses of $46.1 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 $2.9 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $17.2 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 Nine Months Ended September 30, 2018 Oil and natural gas revenues $ 602,737 $ 4,518 $ — $ — $ 607,255 Midstream services revenues — 60,658 — (47,374 ) 13,284 Realized loss on derivatives (1,322 ) — — — (1,322 ) Unrealized loss on derivatives (9,492 ) — — — (9,492 ) Expenses (1) 359,830 26,723 55,338 (47,374 ) 394,517 Operating income (loss) (2) $ 232,093 $ 38,453 $ (55,338 ) $ — $ 215,208 Total assets $ 2,697,685 $ 391,323 $ 65,194 $ — $ 3,154,202 Capital expenditures (3) $ 1,105,541 $ 125,770 $ 1,570 $ — $ 1,232,881 _____________________ (1) Includes depletion, depreciation and amortization expenses of $184.4 million and $6.5 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $1.8 million . (2) Includes $18.2 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $613.8 million attributable to land and seismic acquisition expenditures related to the exploration and production segment and $61.6 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 Nine Months Ended September 30, 2017 Oil and natural gas revenues $ 362,040 $ 1,519 $ — $ — $ 363,559 Midstream services revenues — 32,244 — (25,373 ) 6,871 Realized loss on derivatives (1,176 ) — — — (1,176 ) Unrealized gain on derivatives 21,449 — — — 21,449 Expenses (1) 233,145 16,060 47,055 (25,373 ) 270,887 Operating income (loss) (2) $ 149,168 $ 17,703 $ (47,055 ) $ — $ 119,816 Total assets $ 1,590,677 $ 222,274 $ 35,586 $ — $ 1,848,537 Capital expenditures (3) $ 554,642 $ 75,235 $ 4,710 $ — $ 634,587 _____________________ (1) Includes depletion, depreciation and amortization expenses of $118.2 million and $3.8 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $1.1 million . (2) Includes $8.0 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $35.8 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment.

Subsidiary Guarantors (Notes)

Subsidiary Guarantors (Notes)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
SUBSIDIARY GUARANTORS	The 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 September 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 $ 939,294 $ 26,382 $ — $ (965,676 ) $ — Third-party current assets 827 23,159 201,446 — 225,432 Net property and equipment — 343,371 2,578,603 — 2,921,974 Investment in subsidiaries 1,346,446 — 183,297 (1,529,743 ) — Third-party long-term assets 6,425 — 3,305 (2,934 ) 6,796 Total assets $ 2,292,992 $ 392,912 $ 2,966,651 $ (2,498,353 ) $ 3,154,202 LIABILITIES AND EQUITY Intercompany payable $ — $ — $ 965,676 $ (965,676 ) $ — Third-party current liabilities 5,763 30,335 290,909 (256 ) 326,751 Senior unsecured notes payable 740,063 — — — 740,063 Other third-party long-term liabilities — 4,003 363,620 (2,678 ) 364,945 Total equity attributable to Matador Resources Company 1,547,166 183,297 1,346,446 (1,529,743 ) 1,547,166 Non-controlling interest in subsidiaries — 175,277 — — 175,277 Total liabilities and equity $ 2,292,992 $ 392,912 $ 2,966,651 $ (2,498,353 ) $ 3,154,202 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 $ — $ 25,640 $ 199,386 $ (17,848 ) $ 207,178 Total expenses 1,184 10,708 145,281 (17,848 ) 139,325 Operating (loss) income (1,184 ) 14,932 54,105 — 67,853 Net loss on asset sales and inventory impairment — — (196 ) — (196 ) Interest expense (10,340 ) — — — (10,340 ) Prepayment premium on extinguishment of debt (31,226 ) — — — (31,226 ) Other (expense) income (6 ) 8 (978 ) — (976 ) Earnings in subsidiaries 60,550 — 7,619 (68,169 ) — Income before income taxes 17,794 14,940 60,550 (68,169 ) 25,115 Net income attributable to non-controlling interest in subsidiaries — (7,321 ) — — (7,321 ) Net income attributable to Matador Resources Company shareholders $ 17,794 $ 7,619 $ 60,550 $ (68,169 ) $ 17,794 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 11,242 $ 122,675 $ (7,638 ) $ 126,279 Total expenses 1,175 5,253 100,940 (7,638 ) 99,730 Operating (loss) income (1,175 ) 5,989 21,735 — 26,549 Net gain on asset sales and inventory impairment — — 16 — 16 Interest expense (8,550 ) — — — (8,550 ) Other income 27 11 (74 ) — (36 ) Earnings in subsidiaries 24,674 — 2,997 (27,671 ) — Income before income taxes 14,976 6,000 24,674 (27,671 ) 17,979 Total income tax (benefit) provision (63 ) 63 — — — Net income attributable to non-controlling interest in subsidiaries — (2,940 ) — — (2,940 ) Net income attributable to Matador Resources Company shareholders $ 15,039 $ 2,997 $ 24,674 $ (27,671 ) $ 15,039 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 64,190 $ 592,085 $ (46,550 ) $ 609,725 Total expenses 3,596 27,102 410,369 (46,550 ) 394,517 Operating (loss) income (3,596 ) 37,088 181,716 — 215,208 Net loss on asset sales and inventory impairment — — (196 ) — (196 ) Interest expense (26,835 ) — — — (26,835 ) Other (expense) income — 19 (1,294 ) — (1,275 ) Prepayment premium on extinguishment of debt (31,226 ) — — — (31,226 ) Earnings in subsidiaries 199,151 — 18,925 (218,076 ) — Income before income taxes 137,494 37,107 199,151 (218,076 ) 155,676 Net income attributable to non-controlling interest in subsidiaries — (18,182 ) — — (18,182 ) Net income attributable to Matador Resources Company shareholders $ 137,494 $ 18,925 $ 199,151 $ (218,076 ) $ 137,494 Condensed Consolidating Statement of Operations Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Total revenues $ — $ 32,179 $ 382,520 $ (23,996 ) $ 390,703 Total expenses 4,021 13,935 276,927 (23,996 ) 270,887 Operating (loss) income (4,021 ) 18,244 105,593 — 119,816 Net gain on asset sales and inventory impairment — — 23 — 23 Interest expense (26,229 ) — — — (26,229 ) Other income 27 37 1,892 — 1,956 Earnings in subsidiaries 117,574 — 10,066 (127,640 ) — Income before income taxes 87,351 18,281 117,574 (127,640 ) 95,566 Total income tax (benefit) provision (181 ) 181 — — — Net income attributable to non-controlling interest in subsidiaries — (8,034 ) — — (8,034 ) Net income attributable to Matador Resources Company shareholders $ 87,532 $ 10,066 $ 117,574 $ (127,640 ) $ 87,532 Condensed Consolidating Statement of Cash Flows Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (361,016 ) $ 12,318 $ 768,016 $ — $ 419,318 Net cash used in investing activities — (120,836 ) (1,152,987 ) 53,295 (1,220,528 ) Net cash provided by financing activities 361,155 109,400 334,476 (53,295 ) 751,736 Increase (decrease) in cash and restricted cash 139 882 (50,495 ) — (49,474 ) Cash and restricted cash at beginning of period 286 5,663 96,533 — 102,482 Cash and restricted cash at end of period $ 425 $ 6,545 $ 46,038 $ — $ 53,008 Condensed Consolidating Statement of Cash Flows Matador Non-Guarantor Subsidiaries Guarantor Subsidiaries Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (99,546 ) $ 24,075 $ 297,987 $ — $ 222,516 Net cash provided by (used in) investing activities 33 (75,749 ) (387,257 ) (133,880 ) (596,853 ) Net cash provided by (used in) financing activities — 58,732 (1,495 ) 133,880 191,117 (Decrease) increase in cash and restricted cash (99,513 ) 7,058 (90,765 ) — (183,220 ) Cash and restricted cash at beginning of period 99,795 2,900 111,447 — 214,142 Cash and restricted cash at end of period $ 282 $ 9,958 $ 20,682 $ — $ 30,922

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 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 September 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	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. The Company plans to use this practical expedient, and as a result, the Company will evaluate new or modified land easements under this ASU beginning at the date of adoption. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842) , which is a targeted improvement for comparative reporting requirements for initial adoption of ASU 2016-02. The Company plans to use the optional transition method to adopt ASU 2016-02, and the amendments provided for in ASU 2018-11 will allow the Company to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period 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, 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 on the Company’s consolidated financial statements. Change in Accounting Principles During the first quarter of 2018, the Company adopted Accounting Standards Update 2014-09, 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 from 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 the Company’s 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 on its consolidated financial statements as a result of adoption of ASC 606 was a $2.8 million and $7.6 million decrease in oil and natural gas revenues and a $2.8 million and $7.6 million decrease in production taxes, transportation and processing expenses for the three and nine months ended September 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 nine months ended September 30, 2018 (in thousands). Three Months Ended Nine Months Ended Oil revenues $ 169,913 $ 484,343 Natural gas revenues 46,369 122,912 Third-party midstream services revenues 6,809 13,284 Total revenues from contracts with customers $ 223,091 $ 620,539 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 nine months ended September 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	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 nine months ended September 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 Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 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 nine months ended September 30, 2018 (in thousands). Three Months Ended Nine Months Ended Revenues from contracts with customers $ 223,091 $ 620,539 Realized gain (loss) on derivatives 5,424 (1,322 ) Unrealized loss on derivatives (21,337 ) (9,492 ) Total revenues $ 207,178 $ 609,725 Three Months Ended Nine Months Ended Oil revenues $ 169,913 $ 484,343 Natural gas revenues 46,369 122,912 Third-party midstream services revenues 6,809 13,284 Total revenues from contracts with customers $ 223,091 $ 620,539
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 nine months ended September 30, 2018 and 2017 (in thousands). Three Months Ended Nine Months Ended 2018 2017 2018 2017 Weighted average common shares outstanding Basic 116,358 100,365 112,659 100,141 Dilutive effect of options and restricted stock units 554 139 549 439 Diluted weighted average common shares outstanding 116,912 100,504 113,208 100,580

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 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 nine months ended September 30, 2018 (in thousands). Beginning asset retirement obligations $ 26,256 Liabilities incurred during period 2,473 Liabilities settled during period (663 ) Revisions in estimated cash flows 442 Accretion expense 1,126 Ending asset retirement obligations 29,634 Less: current asset retirement obligations (1) (928 ) Long-term asset retirement obligations $ 28,706 _______________ (1) Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at September 30, 2018 .

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt Instrument Redemption	On or after September 15, 2021, the Company may redeem all or a part of the Notes at any time or from time to time at the following redemption prices (expressed as percentages of principal amount) plus accrued and unpaid interest, if any, to the applicable redemption date, if redeemed during the twelve-month period beginning on September 15 of the years indicated below: Year Redemption Price 2021 104.406% 2022 102.938% 2023 101.469% 2024 and thereafter 100.000%

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 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 September 30, 2018 and December 31, 2017 (in thousands). Derivative Instruments Gross Gross amounts Net amounts presented in the condensed September 30, 2018 Current assets $ 49,723 $ (49,719 ) $ 4 Other assets 654 (654 ) — Current liabilities (69,459 ) 49,719 (19,740 ) Long-term liabilities (5,650 ) 654 (4,996 ) Total $ (24,732 ) $ — $ (24,732 ) 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 Nine Months Ended Type of Instrument Location in Condensed Consolidated Statement of Operations 2018 2017 2018 2017 Derivative Instrument Oil Revenues: Realized gain (loss) on derivatives $ 5,424 $ 485 $ (1,373 ) $ (568 ) Natural Gas Revenues: Realized gain (loss) on derivatives — — 51 (608 ) Realized gain (loss) on derivatives 5,424 485 (1,322 ) (1,176 ) Oil Revenues: Unrealized (loss) gain on derivatives (21,240 ) (12,479 ) (8,284 ) 15,949 Natural Gas Revenues: Unrealized (loss) gain on derivatives (97 ) 115 (1,208 ) 5,508 NGL Revenues: Unrealized loss on derivatives — (8 ) — (8 ) Unrealized (loss) gain on derivatives (21,337 ) (12,372 ) (9,492 ) 21,449 Total $ (15,913 ) $ (11,887 ) $ (10,814 ) $ 20,273
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 September 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) 10/01/2018 - 12/31/2018 720,000 $ 44.27 $ 60.29 $ (9,240 ) Oil - WTI (1) 01/01/2019 - 12/31/2019 2,400,000 $ 50.00 $ 64.75 (21,287 ) Oil - LLS (2) 10/01/2018 - 12/31/2018 180,000 $ 45.00 $ 63.05 (2,973 ) Natural Gas 10/01/2018 - 12/31/2018 4,200,000 $ 2.58 $ 3.67 (18 ) Total open costless collar contracts $ (33,518 ) _____________________ (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 September 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) 10/01/2018 - 12/31/2018 480,000 $ 50.08 $ 63.50 $ 66.68 $ (1,369 ) Total open three-way costless collar contracts $ (1,369 ) _____________________ (1) NYMEX West Texas Intermediate crude oil. The following is a summary of the Company’s open basis swap contracts for oil at September 30, 2018 . Commodity Calculation Period Notional Quantity (Bbl) Fixed Price ($/Bbl) Fair Value of Asset (Liability) (thousands) Oil Basis Swaps 10/01/2018 - 12/31/2018 1,305,000 $ (1.02 ) $ 10,155 Total open swap contracts $ 10,155 At September 30, 2018, the Company had an aggregate liability for open derivative financial instruments of $24.7 million . 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)	9 Months Ended
	Sep. 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 September 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 $ — $ (18 ) $ — $ (18 ) Oil derivatives and basis swaps — (24,714 ) — (24,714 ) Total $ — $ (24,732 ) $ — $ (24,732 ) 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)	9 Months Ended
	Sep. 30, 2018
Supplemental Disclosures [Abstract]
Summary of current accrued liabilities	The following table summarizes the Company’s current accrued liabilities at September 30, 2018 and December 31, 2017 (in thousands). September 30, December 31, Accrued evaluated and unproved and unevaluated property costs $ 108,420 $ 105,347 Accrued midstream property costs 16,996 14,823 Accrued lease operating expenses 18,651 12,611 Accrued interest on debt 5,407 8,345 Accrued asset retirement obligations 928 1,176 Accrued partners’ share of joint interest charges 22,114 27,628 Other 6,314 4,418 Total accrued liabilities $ 178,830 $ 174,348
Supplemental disclosures of cash flow information	The following table provides supplemental disclosures of cash flow information for the nine months ended September 30, 2018 and 2017 (in thousands). Nine Months Ended 2018 2017 Cash paid for interest expense, net of amounts capitalized $ 29,773 $ 14,542 Increase in asset retirement obligations related to mineral properties $ 1,705 $ 2,484 Increase (decrease) in asset retirement obligations related to midstream properties $ 547 $ (138 ) Increase in liabilities for oil and natural gas properties capital expenditures $ 5,157 $ 35,940 Increase (decrease) in liabilities for midstream properties capital expenditures $ 1,864 $ (247 ) Stock-based compensation expense recognized as liability $ (107 ) $ 150 Decrease in liabilities for accrued cost to issue equity $ — $ (343 ) Increase in liabilities for accrued cost to issue senior notes $ 510 $ — Transfer of inventory from oil and natural gas properties $ 305 $ 74 Transfer of inventory to midstream and other property and equipment $ (2,691 ) $ — 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). Nine Months Ended 2018 2017 Cash $ 45,942 $ 20,178 Restricted cash 7,066 10,744 Total cash and restricted cash $ 53,008 $ 30,922

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 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 September 30, 2018 Oil and natural gas revenues $ 215,248 $ 1,034 $ — $ — $ 216,282 Midstream services revenues — 24,950 — (18,141 ) 6,809 Realized gain on derivatives 5,424 — — — 5,424 Unrealized loss on derivatives (21,337 ) — — — (21,337 ) Expenses (1) 128,263 10,162 19,041 (18,141 ) 139,325 Operating income (loss) (2) $ 71,072 $ 15,822 $ (19,041 ) $ — $ 67,853 Total assets $ 2,697,685 $ 391,323 $ 65,194 $ — $ 3,154,202 Capital expenditures (3) $ 716,751 $ 47,153 $ 312 $ — $ 764,216 _____________________ (1) Includes depletion, depreciation and amortization expenses of $67.2 million and $2.6 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $0.6 million . (2) Includes $7.3 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $554.9 million attributable to land and seismic acquisition expenditures related to the exploration and production segment and $23.1 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 September 30, 2017 Oil and natural gas revenues $ 134,488 $ 460 $ — $ — $ 134,948 Midstream services revenues — 11,261 — (8,043 ) 3,218 Realized gain on derivatives 485 — — — 485 Unrealized loss on derivatives (12,372 ) — — — (12,372 ) Expenses (1) 86,728 5,598 15,447 (8,043 ) 99,730 Operating income (loss) (2) $ 35,873 $ 6,123 $ (15,447 ) $ — $ 26,549 Total assets $ 1,590,677 $ 222,274 $ 35,586 $ — $ 1,848,537 Capital expenditures (3) $ 180,686 $ 35,008 $ 1,494 $ — $ 217,188 _____________________ (1) Includes depletion, depreciation and amortization expenses of $46.1 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 $2.9 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $17.2 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 Nine Months Ended September 30, 2018 Oil and natural gas revenues $ 602,737 $ 4,518 $ — $ — $ 607,255 Midstream services revenues — 60,658 — (47,374 ) 13,284 Realized loss on derivatives (1,322 ) — — — (1,322 ) Unrealized loss on derivatives (9,492 ) — — — (9,492 ) Expenses (1) 359,830 26,723 55,338 (47,374 ) 394,517 Operating income (loss) (2) $ 232,093 $ 38,453 $ (55,338 ) $ — $ 215,208 Total assets $ 2,697,685 $ 391,323 $ 65,194 $ — $ 3,154,202 Capital expenditures (3) $ 1,105,541 $ 125,770 $ 1,570 $ — $ 1,232,881 _____________________ (1) Includes depletion, depreciation and amortization expenses of $184.4 million and $6.5 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $1.8 million . (2) Includes $18.2 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $613.8 million attributable to land and seismic acquisition expenditures related to the exploration and production segment and $61.6 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 Nine Months Ended September 30, 2017 Oil and natural gas revenues $ 362,040 $ 1,519 $ — $ — $ 363,559 Midstream services revenues — 32,244 — (25,373 ) 6,871 Realized loss on derivatives (1,176 ) — — — (1,176 ) Unrealized gain on derivatives 21,449 — — — 21,449 Expenses (1) 233,145 16,060 47,055 (25,373 ) 270,887 Operating income (loss) (2) $ 149,168 $ 17,703 $ (47,055 ) $ — $ 119,816 Total assets $ 1,590,677 $ 222,274 $ 35,586 $ — $ 1,848,537 Capital expenditures (3) $ 554,642 $ 75,235 $ 4,710 $ — $ 634,587 _____________________ (1) Includes depletion, depreciation and amortization expenses of $118.2 million and $3.8 million for the exploration and production and midstream segments, respectively. Also includes corporate depletion, depreciation and amortization expenses of $1.1 million . (2) Includes $8.0 million in net income attributable to non-controlling interest in subsidiaries related to the midstream segment. (3) Includes $35.8 million in capital expenditures attributable to non-controlling interest in subsidiaries related to the midstream segment.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 223,091		$ 620,539
Realized gain (loss) on derivatives	5,424	$ 485	(1,322)	$ (1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Total revenue	207,178	$ 126,279	609,725	$ 390,703
Oil revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	169,913		484,343
Natural gas revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	46,369		122,912
Third-party midstream services revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	6,809		13,284
Total revenues from contracts with customers
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	223,091		620,539
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	2,800		7,600
Cost of Goods and Services Sold	$ (2,800)		$ (7,600)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details Textual) $ in Thousands	Sep. 12, 2018USD ($)a	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in oil and natural gas revenues		$ (223,091)		$ (620,539)
Restricted cash		7,066	$ 10,744	$ 7,066	$ 10,744	$ 5,977
Discount rate, present value of future revenue				10.00%
Impairment charges			0	$ 0
Capitalized general and administrative costs		8,500	6,100	22,600	16,900
Interest costs capitalized		1,700	2,100	6,200	5,200
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		(2,800)		(7,600)
Decrease in production taxes, transportation and processing expenses		$ 2,800		$ 7,600
BLM Acquisition
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Leasehold acres | a	8,400
Leasehold acres, net | a	8,400
Consideration transferred	$ 387,000

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Weighted average common shares outstanding for basic earnings (loss) per share	116,358	100,365	112,659	100,141
Dilutive effect of options and restricted stock units	554	139	549	439
Diluted weighted average common shares outstanding	116,912	100,504	113,208	100,580

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Changes in the Company's asset retirement obligations
Beginning asset retirement obligations				$ 26,256
Liabilities incurred during period				2,473
Liabilities settled during period				(663)
Revisions in estimated cash flows				442
Accretion expense		$ 387	$ 323	1,126	$ 937
Ending asset retirement obligations		29,634		29,634
Less: current asset retirement obligations	[1]	(928)		(928)
Long-term asset retirement obligations		$ 28,706		$ 28,706		$ 25,080
[1]	Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at September 30, 2018.

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Revolving Credit Agreement [Line Items]
Line of credit facility		$ 325,000	$ 0
Senior Notes | Senior Notes Due 2026
Revolving Credit Agreement [Line Items]
Long-term debt outstanding		$ 750,000
Interest rate		5.875%
Revolving Credit Facility | Third Amended Credit Agreement
Revolving Credit Agreement [Line Items]
Line of credit facility		$ 325,000
Letter of Credit
Revolving Credit Agreement [Line Items]
Outstanding letters of credit		$ 3,000
Subsequent Event | Senior Notes | Senior Notes Due 2026
Revolving Credit Agreement [Line Items]
Long-term debt outstanding	$ 1,050,000
Subsequent Event | Revolving Credit Facility | Third Amended Credit Agreement
Revolving Credit Agreement [Line Items]
Line of credit facility	25,000
Subsequent Event | Letter of Credit
Revolving Credit Agreement [Line Items]
Outstanding letters of credit	$ 3,000

Debt Credit Agreement (Details)

Debt Credit Agreement (Details) - Revolving Credit Facility - Third Amended Credit Agreement - USD ($)	1 Months Ended
	Oct. 31, 2018	Sep. 30, 2018	Mar. 31, 2018
Debt Instrument [Line Items]
Increase in borrowing base			$ 725,000,000
Maximum borrowing commitment		$ 400,000,000
Maximum facility amount		$ 500,000,000
Subsequent Event
Debt Instrument [Line Items]
Increase in borrowing base	$ 850,000,000
Maximum borrowing commitment	500,000,000
Increase in maximum credit facility	$ 1,500,000,000
Annual reduction in borrowing rate	0.25%

Debt Senior Unsecured Notes (De

Debt Senior Unsecured Notes (Details) - USD ($)	Oct. 04, 2018	Aug. 21, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Oct. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt issued			$ 740,063,000		$ 740,063,000				$ 574,073,000
Proceeds from issuance of debt					750,000,000	$ 0
Prepayment premium on extinguishment of debt			(31,226,000)	$ 0	(31,226,000)	$ 0
Senior Notes | Senior Notes Due 2023
Debt Instrument [Line Items]
Long-term debt outstanding								$ 575,000,000
Interest rate								6.875%
Payments on debt			$ 30,400,000
Senior Notes | Senior Notes Due 2023 | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage of principal amount			105.156%
Senior Notes | 2026 Notes Offering
Debt Instrument [Line Items]
Interest rate		5.875%
Debt issued		$ 750,000,000
Proceeds from issuance of debt		$ 740,000,000
Senior Notes | Senior Notes Due 2026
Debt Instrument [Line Items]
Long-term debt outstanding			$ 750,000,000		$ 750,000,000
Interest rate			5.875%		5.875%
Subsequent Event | Senior Notes | Additional 2026 Notes
Debt Instrument [Line Items]
Interest rate	5.875%
Debt issued	$ 300,000,000
Proceeds from issuance of debt	$ 297,600,000
Redemption price, percentage of principal amount	100.50%
Subsequent Event | Senior Notes | Additional 2026 Notes | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Basis spread on variable rate	5.00%
Debt covenant, threshold percentage of principal	25.00%
Debt covenant, default period, when due of interest	30 days
Debt covenant, failure to comply with reporting obligations, period after notice	180 days
Debt covenant, failure to comply with other agreements, period after notice	60 days
Debt covenant, maximum aggregate payment defaults and accelerations	$ 50,000,000
Debt covenant, maximum outstanding judgements	$ 50,000,000
Debt covenant, maximum outstanding judgements, payment period	60 days
Subsequent Event | Senior Notes | Senior Notes Due 2026
Debt Instrument [Line Items]
Long-term debt outstanding							$ 1,050,000,000
Subsequent Event | Senior Notes | Senior Notes Due 2026 | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage of principal amount	35.00%
Redemption price, percentage	105.875%
Redemption price, threshold percentage of outstanding principal	65.00%
Subsequent Event | Senior Notes | Senior Notes Due 2026 | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Redemption price, percentage	104.406%
Redemption period	180 days

Debt Redemption Price Schedule

Debt Redemption Price Schedule (Details) - Subsequent Event - Senior Notes - Senior Notes Due 2026	Oct. 04, 2018
2,021
Debt Instrument, Redemption [Line Items]
Redemption price, percentage	104.406%
2,022
Debt Instrument, Redemption [Line Items]
Redemption price, percentage	102.938%
2,023
Debt Instrument, Redemption [Line Items]
Redemption price, percentage	101.469%
2024 and thereafter
Debt Instrument, Redemption [Line Items]
Redemption price, percentage	100.00%

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	May 17, 2018	Feb. 15, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 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			$ 146	$ 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 Instrume_3

Derivative Financial Instruments (Details) $ in Thousands	Sep. 30, 2018USD ($)MMBTUbbl$ / MMBTU$ / bbl
Open costless collar contracts
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability) | $	$ (33,518)
Open Swap Collar Contracts
Summary of contracts for oil and natural gas
Fair Value of Asset (Liability) | $	$ 10,155
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	720,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	44.27
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	60.29
Fair Value of Asset (Liability) | $	$ (9,240)
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	180,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	45
Weighted Average Price Ceiling ($/Bbl or $/MMBtu)	63.05
Fair Value of Asset (Liability) | $	$ (2,973)
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	4,200,000
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) | $	$ (18)
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	480,000
Weighted Average Price Floor ($/Bbl or $/MMBtu)	50.08
Fair Value of Asset (Liability) | $	$ (1,369)
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	1,305,000
Derivative, Swap Type, Average Fixed Price	(1.02)
Fair Value of Asset (Liability) | $	$ 10,155
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) | $	$ (21,287)

Derivative Financial Instrume_4

Derivative Financial Instruments Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative liability	$ 24,732	$ 15,239

Derivative Financial Instrume_5

Derivative Financial Instruments (Details 2) $ in Thousands	Sep. 30, 2018USD ($)bbl$ / bbl	Dec. 31, 2017USD ($)
Summary of gross liability balances of derivative instruments
Total	$ (24,732)	$ (15,239)
Gross amounts netted in the condensed consolidated balance sheets	0	0
Net amounts presented in the condensed consolidated balance sheets	(24,732)	(15,239)
Current assets
Derivative [Line Items]
Gross amounts of recognized assets	49,723	131,092
Gross amounts netted in the condensed consolidated balance sheets	(49,719)	(129,902)
Oil, natural gas and natural gas liquids (NGL) derivatives	4	1,190
Other assets
Derivative [Line Items]
Gross amounts of recognized assets	654
Gross amounts netted in the condensed consolidated balance sheets	(654)
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	(69,459)	(146,331)
Gross amounts netted in the condensed consolidated balance sheet	49,719	129,902
Oil, natural gas and natural gas liquids (NGL) derivatives	(19,740)	$ (16,429)
Other liabilities
Summary of gross liability balances of derivative instruments
Gross amounts of recognized liabilities	(5,650)
Gross amounts netted in the condensed consolidated balance sheet	654
Oil, natural gas and natural gas liquids (NGL) derivatives	(4,996)
Open Costless Collar Contracts
Summary of gross liability balances of derivative instruments
Derivative Assets (Liabilities), at Fair Value, Net	$ (33,518)
Derivative Contract, Calculation Period One | Oil - WTI | Open Three-way Costless Collar Contracts
Derivative [Line Items]
Notional Quantity (Bbl or MMBtu) | bbl	480,000
Summary of gross liability balances of derivative instruments
Derivative, Floor Price | $ / bbl	50.08
Derivative Assets (Liabilities), at Fair Value, Net	$ (1,369)
Derivative Contract, Calculation Period One | Oil - WTI | Open Costless Collar Contracts
Derivative [Line Items]
Notional Quantity (Bbl or MMBtu) | bbl	720,000
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	$ (9,240)

Derivative Financial Instrume_6

Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	$ 5,424	$ 485	$ (1,322)	$ (1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Total	(15,913)	(11,887)	(10,814)	20,273
Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	5,424	485	(1,322)	(1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Oil | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	5,424	485	(1,373)	(568)
Unrealized (loss) gain on derivatives	(21,240)	(12,479)	(8,284)	15,949
Natural Gas | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	0	0	51	(608)
Unrealized (loss) gain on derivatives	(97)	115	(1,208)	5,508
NGL | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Unrealized (loss) gain on derivatives	$ 0	$ (8)	$ 0	$ (8)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets (Liabilities)
Total	$ (24,732)	$ (15,239)
Fair value on a recurring basis
Assets (Liabilities)
Derivative Asset	(18)	1,190
Derivative Liability	(24,714)	(16,429)
Total	(24,732)	(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	(18)	1,190
Derivative Liability	(24,714)	(16,429)
Total	(24,732)	(15,239)
Fair value on a recurring basis | Level 3
Assets (Liabilities)
Derivative Asset	0	0
Derivative Liability	$ 0	$ 0

Fair Value Measurements (Deta_2

Fair Value Measurements (Details 1) - USD ($) $ in Millions	Sep. 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	$ 761.3	$ 614.1

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Feb. 17, 2017	May 31, 2018	Apr. 30, 2018	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2015	Sep. 30, 2018	Sep. 30, 2017
Drilling Rig Commitments
Commitments and Contingencies (Textual) [Abstract]
Maximum termination outstanding obligations of contracts				$ 32,790				$ 32,790
Outside Operated Drilling Commitments
Commitments and Contingencies (Textual) [Abstract]
Maximum termination outstanding obligations of contracts				44,234				44,234
Loving County System Agreement
Commitments and Contingencies (Textual) [Abstract]
Agreement term							15 years
Deficiency fee required to be paid								12,500
Capital Addition Purchase Commitments
Commitments and Contingencies (Textual) [Abstract]
Remaining commitments								55,300
Payment for long-term purchase commitment				2,000				5,600
Remaining purchase obligation				0				0
Field Compression and Amine Gas Treatment
Commitments and Contingencies (Textual) [Abstract]
Remaining commitments								24,800
Payment for long-term purchase commitment				6,300				12,800
Remaining purchase obligation				12,000				12,000
Corporate Joint Venture | San Mateo Midstream
Commitments and Contingencies (Textual) [Abstract]
Contractual obligation				222,000				222,000
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				45,200				$ 45,200
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]
Contractual obligation				3,600				3,600
Natural Gas, Gathering, Transportation, Marketing and Processing [Member] | Loving County System Agreement
Commitments and Contingencies (Textual) [Abstract]
Cost of Goods and Services Sold				4,800		$ 4,000		12,200	$ 10,800
Transportation Fees [Member] | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Cost of Goods and Services Sold				1,000				2,500
Transportation Fees [Member] | Natural Gas Transportation Agreement | Eddy County
Commitments and Contingencies (Textual) [Abstract]
Cost of Goods and Services Sold				$ 900				$ 1,100

Supplemental Disclosures (Detai

Supplemental Disclosures (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 178,830	$ 174,348
Accrued evaluated and unproved and unevaluated property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	108,420	105,347
Accrued midstream property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	16,996	14,823
Accrued lease operating expenses
Supplemental Disclosures [Line Items]
Total accrued liabilities	18,651	12,611
Accrued interest on debt
Supplemental Disclosures [Line Items]
Total accrued liabilities	5,407	8,345
Accrued asset retirement obligations
Supplemental Disclosures [Line Items]
Total accrued liabilities	928	1,176
Accrued partners’ share of joint interest charges
Supplemental Disclosures [Line Items]
Total accrued liabilities	22,114	27,628
Other
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 6,314	$ 4,418

Supplemental Disclosures (Det_2

Supplemental Disclosures (Details 1) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Cash paid for interest expense, net of amounts capitalized	$ 29,773	$ 14,542
Increase in liabilities for oil and natural gas properties capital expenditures	5,157	35,940
Increase (decrease) in liabilities for midstream properties capital expenditures	1,864	(247)
Stock-based compensation expense recognized as liability	(107)	150
Decrease in liabilities for accrued cost to issue equity	0	(343)
Increase in liabilities for accrued cost to issue senior notes	510	0
Transfer of inventory from oil and natural gas properties	305	74
Transfer of inventory to midstream and other property and equipment	(2,691)	0
Mineral Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	1,705	2,484
Midstream Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	$ 547	$ (138)

Supplemental Disclosures Supple

Supplemental Disclosures Supplemental Disclosures - Restricted Cash Reconciliation (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Cash	$ 45,942	$ 96,505	$ 20,178
Restricted cash	7,066	5,977	10,744
Total cash and restricted cash	$ 53,008	$ 102,482	$ 30,922	$ 214,142

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 223,091		$ 620,539
Number of segments | segment			2
Realized gain (loss) on derivatives	5,424	$ 485	$ (1,322)	$ (1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Expenses	139,325	99,730	394,517	270,887
Operating (loss) income	67,853	26,549	215,208	119,816
Total assets	3,154,202	1,848,537	3,154,202	1,848,537	$ 2,145,690
Capital expenditures	764,216	217,188	1,232,881	634,587
Depletion, depreciation and amortization	70,457	47,800	192,664	123,066
Impairment charges		0	0
Other (expense) income	(976)	(36)	(1,275)	1,956
Income before income taxes	25,115	17,979	155,676	95,566
Corporate
Segment Reporting Information [Line Items]
Realized gain (loss) on derivatives		0
Unrealized (loss) gain on derivatives		0
Expenses	19,041	15,447	55,338	47,055
Operating (loss) income	(19,041)	(15,447)	(55,338)	(47,055)
Total assets	65,194	35,586	65,194	35,586
Capital expenditures	312	1,494	1,570	4,710
Depletion, depreciation and amortization	600	400	1,800	1,100
Consolidations and Eliminations
Segment Reporting Information [Line Items]
Realized gain (loss) on derivatives		0
Unrealized (loss) gain on derivatives		0
Expenses	(18,141)	(8,043)	(47,374)	(25,373)
Total assets	0	0	0	0
Capital expenditures	0	0	0	0
Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Realized gain (loss) on derivatives	5,424	485	(1,322)	(1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Expenses	128,263	86,728	359,830	233,145
Operating (loss) income	71,072	35,873	232,093	149,168
Total assets	2,697,685	1,590,677	2,697,685	1,590,677
Capital expenditures	716,751	180,686	1,105,541	554,642
Depletion, depreciation and amortization	67,200	46,100	184,400	118,200
Midstream | Operating Segments
Segment Reporting Information [Line Items]
Realized gain (loss) on derivatives		0
Unrealized (loss) gain on derivatives		0
Expenses	10,162	5,598	26,723	16,060
Operating (loss) income	15,822	6,123	38,453	17,703
Total assets	391,323	222,274	391,323	222,274
Capital expenditures	47,153	35,008	125,770	75,235
Depletion, depreciation and amortization	2,600	1,300	6,500	3,800
Net income attributable to non-controlling interest in subsidiaries		(2,900)	(18,200)	(8,000)
Capital expenditures attributable to non-controlling interest	23,100	17,200	61,600	35,800
Capital expenditures attributable to land and seismic acquisition expenditures	554,900		613,800
Operating Income (Loss) | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Net income attributable to non-controlling interest in subsidiaries	(7,300)
Oil and natural gas revenues
Segment Reporting Information [Line Items]
Revenues	216,282	134,948	607,255	363,559
Oil and natural gas revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues	215,248	134,488	602,737	362,040
Oil and natural gas revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,034	460	4,518	1,519
Third-party midstream services revenues
Segment Reporting Information [Line Items]
Revenues	6,809	3,218	13,284	6,871
Third-party midstream services revenues | Corporate
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Third-party midstream services revenues | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues	(18,141)	(8,043)	(47,374)	(25,373)
Third-party midstream services revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Third-party midstream services revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues	$ 24,950	$ 11,261	$ 60,658	$ 32,244

Subsidiary Guarantors Consolida

Subsidiary Guarantors Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Equity Method Investment, Ownership Percentage	100.00%
Intercompany receivable	$ 0	$ 0
Third-party current assets	225,432	257,170
Net property and equipment	2,921,974	1,881,456
Investment in subsidiaries	0	0
Third-party long-term assets	6,796	7,064
Total assets	3,154,202	2,145,690	$ 1,848,537
Intercompany payable	0	0
Third-party current liabilities	326,751	282,606
Senior unsecured notes payable	740,063	574,073
Other third-party long-term liabilities	364,945	31,465
Total equity attributable to Matador Resources Company	1,547,166	1,156,556
Non-controlling interest in subsidiaries	175,277	100,990
Total liabilities and equity	3,154,202	2,145,690
Eliminating Entries
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	(965,676)	(588,021)
Third-party current assets	0	0
Net property and equipment	0	0
Investment in subsidiaries	(1,529,743)	(1,258,372)
Third-party long-term assets	(2,934)	(3,003)
Total assets	(2,498,353)	(1,849,396)
Intercompany payable	(965,676)	(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	(1,529,743)	(1,258,372)
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	(2,498,353)	(1,849,396)
Matador | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	939,294	585,109
Third-party current assets	827	2,240
Net property and equipment	0	0
Investment in subsidiaries	1,346,446	1,147,295
Third-party long-term assets	6,425	6,425
Total assets	2,292,992	1,741,069
Intercompany payable	0	0
Third-party current liabilities	5,763	8,847
Senior unsecured notes payable	740,063	574,073
Other third-party long-term liabilities	0	1,593
Total equity attributable to Matador Resources Company	1,547,166	1,156,556
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	2,292,992	1,741,069
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	26,382	2,912
Third-party current assets	23,159	9,334
Net property and equipment	343,371	223,178
Investment in subsidiaries	0	0
Third-party long-term assets	0	0
Total assets	392,912	235,424
Intercompany payable	0	0
Third-party current liabilities	30,335	19,891
Senior unsecured notes payable	0	0
Other third-party long-term liabilities	4,003	3,466
Total equity attributable to Matador Resources Company	183,297	111,077
Non-controlling interest in subsidiaries	175,277	100,990
Total liabilities and equity	392,912	235,424
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Balance Sheet Statements, Captions [Line Items]
Intercompany receivable	0	0
Third-party current assets	201,446	245,596
Net property and equipment	2,578,603	1,658,278
Investment in subsidiaries	183,297	111,077
Third-party long-term assets	3,305	3,642
Total assets	2,966,651	2,018,593
Intercompany payable	965,676	588,021
Third-party current liabilities	290,909	254,142
Senior unsecured notes payable	0	0
Other third-party long-term liabilities	363,620	29,135
Total equity attributable to Matador Resources Company	1,346,446	1,147,295
Non-controlling interest in subsidiaries	0	0
Total liabilities and equity	$ 2,966,651	$ 2,018,593

Subsidiary Guarantors Consoli_2

Subsidiary Guarantors Consolidated Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Income Statements, Captions [Line Items]
Prepayment premium on extinguishment of debt	$ (31,226)	$ 0	$ (31,226)	$ 0
Total revenues	207,178	126,279	609,725	390,703
Total expenses	139,325	99,730	394,517	270,887
Operating (loss) income	67,853	26,549	215,208	119,816
Net gain on asset sales and inventory impairment	(196)	16	(196)	23
Interest expense	(10,340)	(8,550)	(26,835)	(26,229)
Other (expense) income	(976)	(36)	(1,275)	1,956
Earnings in subsidiaries	0	0	0	0
Income before income taxes	25,115	17,979	155,676	95,566
Total income tax provision (benefit)		0		0
Net income attributable to non-controlling interest in subsidiaries	(7,321)	(2,940)	(18,182)	(8,034)
Net income attributable to Matador Resources Company shareholders	17,794	15,039	137,494	87,532
Eliminating Entries
Condensed Income Statements, Captions [Line Items]
Total revenues	(17,848)	(7,638)	(46,550)	(23,996)
Total expenses	(17,848)	(7,638)	(46,550)	(23,996)
Operating (loss) income	0	0	0	0
Net gain on asset sales and inventory impairment	0	0	0	0
Interest expense	0	0	0	0
Earnings in subsidiaries	(68,169)	(27,671)	(218,076)	(127,640)
Income before income taxes	(68,169)	(27,671)	(218,076)	(127,640)
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	(68,169)	(27,671)	(218,076)	(127,640)
Matador | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Prepayment premium on extinguishment of debt	(31,226)		(31,226)
Total revenues	0		0
Total expenses	1,184	1,175	3,596	4,021
Operating (loss) income	(1,184)	(1,175)	(3,596)	(4,021)
Net gain on asset sales and inventory impairment	0	0	0	0
Interest expense	(10,340)	(8,550)	(26,835)	(26,229)
Other (expense) income	(6)	27		27
Earnings in subsidiaries	60,550	24,674	199,151	117,574
Income before income taxes	17,794	14,976	137,494	87,351
Total income tax provision (benefit)		(63)		(181)
Net income attributable to non-controlling interest in subsidiaries	0	0	0	0
Net income attributable to Matador Resources Company shareholders	17,794	15,039	137,494	87,532
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Prepayment premium on extinguishment of debt	0		0
Total revenues	25,640	11,242	64,190	32,179
Total expenses	10,708	5,253	27,102	13,935
Operating (loss) income	14,932	5,989	37,088	18,244
Net gain on asset sales and inventory impairment	0	0	0	0
Interest expense	0		0
Other (expense) income	8	11	19	37
Earnings in subsidiaries	0	0	0	0
Income before income taxes	14,940	6,000	37,107	18,281
Total income tax provision (benefit)		63		181
Net income attributable to non-controlling interest in subsidiaries	(7,321)	(2,940)	(18,182)	(8,034)
Net income attributable to Matador Resources Company shareholders	7,619	2,997	18,925	10,066
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Total revenues	199,386	122,675	592,085	382,520
Total expenses	145,281	100,940	410,369	276,927
Operating (loss) income	54,105	21,735	181,716	105,593
Net gain on asset sales and inventory impairment	(196)	16	(196)	23
Interest expense		0		0
Other (expense) income	(978)	(74)	(1,294)	1,892
Earnings in subsidiaries	7,619	2,997	18,925	10,066
Income before income taxes	60,550	24,674	199,151	117,574
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	$ 60,550	$ 24,674	$ 199,151	$ 117,574

Subsidiary Guarantors Consoli_3

Subsidiary Guarantors Consolidated Cash Flow (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 419,318	$ 222,516
Net cash used in investing activities	(1,220,528)	(596,853)
Net cash provided by financing activities	751,736	191,117
Decrease in cash and restricted cash	(49,474)	(183,220)
Cash and restricted cash at beginning of period	102,482	214,142
Cash and restricted cash at end of period	53,008	30,922
Eliminating Entries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	0	0
Net cash used in investing activities	53,295	(133,880)
Net cash provided by financing activities	(53,295)	133,880
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	(361,016)	(99,546)
Net cash used in investing activities	0	33
Net cash provided by financing activities	361,155	0
Decrease in cash and restricted cash	139	(99,513)
Cash and restricted cash at beginning of period	286	99,795
Cash and restricted cash at end of period	425	282
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	12,318	24,075
Net cash used in investing activities	(120,836)	(75,749)
Net cash provided by financing activities	109,400	58,732
Decrease in cash and restricted cash	882	7,058
Cash and restricted cash at beginning of period	5,663	2,900
Cash and restricted cash at end of period	6,545	9,958
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	768,016	297,987
Net cash used in investing activities	(1,152,987)	(387,257)
Net cash provided by financing activities	334,476	(1,495)
Decrease in cash and restricted cash	(50,495)	(90,765)
Cash and restricted cash at beginning of period	96,533	111,447
Cash and restricted cash at end of period	$ 46,038	$ 20,682