Gastar Exploration (GST) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 07, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	Gastar Exploration Inc.
Trading Symbol	GST
Entity Central Index Key	1,431,372
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		220,105,332

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 100,215	$ 13,266
Accounts receivable, net of allowance for doubtful accounts of $1,953	22,148	38,575
Commodity derivative contracts	542	1,370
Prepaid expenses	928	960
Total current assets	123,833	54,171
Oil and natural gas properties, full cost method of accounting:
Unproved properties, excluded from amortization	136,178	131,955
Proved properties	1,276,638	1,344,329
Total oil and natural gas properties	1,412,816	1,476,284
Furniture and equipment	3,849	3,838
Total property, plant and equipment	1,416,665	1,480,122
Accumulated depreciation, depletion and amortization	(1,164,005)	(1,155,027)
Total property, plant and equipment, net	252,660	325,095
OTHER ASSETS:
Restricted cash	370	370
Advances to operators	81	82
Other	150	405
Total other assets	601	857
TOTAL ASSETS	377,094	380,123
CURRENT LIABILITIES:
Accounts payable	8,537	24,382
Revenue payable	17,676	11,823
Accrued interest	7,317	7,298
Accrued drilling and operating costs	15,885	9,381
Advances from non-operators	1,502	1,445
Commodity derivative contracts	6,278	4,416
Commodity derivative premium payable	102	135
Other accrued liabilities	7,569	2,706
Total current liabilities	64,866	61,586
LONG-TERM LIABILITIES:
Long-term debt	352,758	342,952
Commodity derivative contracts	3,289	2,572
Asset retirement obligation	2,361	4,841
Total long-term liabilities	358,408	350,365
Commitments and contingencies (Note 11)	0	0
STOCKHOLDERS’ DEFICIT:
Common stock, par value $0.001 per share; 800,000,000 shares authorized at March 31, 2018 and December 31, 2017, respectively; 221,544,464 and 218,874,418 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	222	219
Additional paid-in capital	820,710	819,554
Accumulated deficit	(867,174)	(851,663)
Total stockholders’ deficit	(46,180)	(31,828)
TOTAL LIABILITIES AND STOCKHOLDERS’ DEFICIT	377,094	380,123
Series A Preferred Stock
STOCKHOLDERS’ DEFICIT:
Preferred stock	41	41
Series B Preferred Stock
STOCKHOLDERS’ DEFICIT:
Preferred stock	$ 21	$ 21

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts	$ 1,953	$ 1,953
Preferred stock, shares authorized	40,000,000	40,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	221,544,464	218,874,418
Common stock, shares outstanding	221,544,464	218,874,418
Series A Preferred Stock
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued	4,045,000	4,045,000
Preferred stock, shares outstanding	4,045,000	4,045,000
Liquidation preference per share	$ 25	$ 25
Series B Preferred Stock
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued	2,140,000	2,140,000
Preferred stock, shares outstanding	2,140,000	2,140,000
Liquidation preference per share	$ 25	$ 25

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Operations - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES:
Oil and condensate	$ 20,982,000	$ 12,190,000
Natural gas	2,181,000	2,588,000
NGLs	3,275,000	2,591,000
Total oil, condensate, natural gas and NGLs revenues	26,438,000	17,369,000
(Loss) gain on commodity derivatives contracts	(5,529,000)	1,300,000	[1]
Total revenues and other (loss) gain	20,909,000	18,669,000	[1]
EXPENSES:
Production taxes	989,000	485,000
Lease operating expenses	7,509,000	5,072,000
Transportation, treating and gathering	0	311,000
Depreciation, depletion and amortization	8,978,000	4,652,000
Accretion of asset retirement obligation	56,000	51,000
General and administrative expense	8,968,000	3,824,000
Total expenses	26,500,000	14,395,000
(LOSS) INCOME FROM OPERATIONS	(5,591,000)	4,274,000
OTHER INCOME (EXPENSE):
Interest expense	(9,937,000)	(10,849,000)
Loss on early extinguishment of debt	0	(12,172,000)
Investment income and other	17,000	49,000
LOSS BEFORE PROVISION FOR INCOME TAXES	(15,511,000)	(18,698,000)
Provision for income taxes	0	0
NET LOSS	(15,511,000)	(18,698,000)
Dividends on preferred stock	0	(3,618,000)
Undeclared cumulative dividends on preferred stock	(3,618,000)	0
NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ (19,129,000)	$ (22,316,000)
NET LOSS PER SHARE OF COMMON STOCK ATTRIBUTABLE TO COMMON STOCKHOLDERS:
Basic (in dollars per share)	$ (0.09)	$ (0.14)
Diluted (in dollars per share)	$ (0.09)	$ (0.14)
WEIGHTED AVERAGE SHARES OF COMMON STOCK OUTSTANDING:
Basic (shares)	209,903,482	162,829,221
Diluted (shares)	209,903,482	162,829,221
[1]	Prior period amounts have not been adjusted under the modified retrospective method.

Condensed Consolidated Stateme5

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (15,511)	$ (18,698)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	8,978	4,652
Stock-based compensation	1,724	996
Total loss (gain) on commodity derivatives contracts	5,529	(1,300)	[1]
Cash settlements of matured commodity derivatives contracts, net	(1,347)	1,683
Cash premiums paid for commodity derivatives contracts	(552)	0
Amortization of deferred financing costs and debt discount	3,177	1,710
Paid-in-kind interest	6,629	0
Accretion of asset retirement obligation	56	51
Loss on early extinguishment of debt	0	12,172
Changes in operating assets and liabilities:
Accounts receivable	16,172	(9,897)
Prepaid expenses	(56)	103
Accounts payable and accrued liabilities	7,439	972
Net cash provided by (used in) operating activities	32,238	(7,556)
CASH FLOWS FROM INVESTING ACTIVITIES:
Development and purchase of oil and natural gas properties	(42,341)	(21,613)
Acquisition of oil and natural gas properties	0	(54,498)
Proceeds from sale of oil and natural gas properties	97,571	13,150
Proceeds from (application of proceeds from) non-operators	57	(729)
Purchase of furniture and equipment	(11)	(41)
Net cash provided by (used in) investing activities	55,276	(63,731)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from term loan	0	250,000
Proceeds from convertible notes	0	200,000
Repayment of senior secured notes	0	(325,000)
Repayment of revolving credit facility	0	(84,630)
Loss on early extinguishment of debt	0	(7,011)
Proceeds from issuance of common stock, net of issuance costs	0	56,366
Dividends on preferred stock	0	(14,473)
Deferred financing charges	0	(9,945)
Increase in restricted cash	0	(369)
Tax withholding related to restricted stock award vestings	(565)	(585)
Net cash (used in) provided by financing activities	(565)	64,353
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	86,949	(6,934)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	13,266	71,529
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 100,215	$ 64,595
[1]	Prior period amounts have not been adjusted under the modified retrospective method.

Description of Business

Description of Business	3 Months Ended
	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of Business Gastar Exploration Inc. (the “Company” or “Gastar”) is a pure play Mid-Continent independent energy company engaged in the exploration, development and production of oil, condensate, natural gas and NGLs in the United States. Gastar’s principal business activities include the identification, acquisition, and subsequent exploration and development of oil and natural gas properties with an emphasis on unconventional reserves, such as shale resource plays. Gastar holds a concentrated acreage position in the normally pressured oil window of the STACK Play, an area of central Oklahoma which is home to multiple oil and natural gas-rich reservoirs including the Oswego limestone, Meramec and Osage bench formations within the Mississippi Lime, the Woodford shale and Hunton limestone formations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accounting policies followed by the Company are set forth in the notes to the Company’s audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Form 10-K”) filed with the SEC. Please refer to the notes to the consolidated financial statements included in the 2017 Form 10-K for additional details of the Company’s financial condition, results of operations and cash flows. No material item included in those notes has changed except as a result of normal transactions in the interim or as disclosed within this report. The unaudited interim condensed consolidated financial statements of the Company included herein are stated in U.S. dollars and were prepared from the records of the Company by management in accordance with U.S. GAAP applicable to interim financial statements and reflect all normal and recurring adjustments, which are, in the opinion of management, necessary to provide a fair presentation of the results of operations and financial position for the interim periods. Such financial statements conform to the presentation reflected in the 2017 Form 10-K except for revenue which, for the three months ended March 31, 2018, is presented net of treating, transportation and gathering costs pursuant to current authoritative accounting guidance. The current interim period reported herein should be read in conjunction with the financial statements and accompanying notes, including Item 8. “Financial Statements and Supplementary Data, Note 2 – Summary of Significant Accounting Policies,” included in the 2017 Form 10-K. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and 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. Actual results could differ from those estimates. Significant estimates with regard to these financial statements include the valuation of convertible debt, estimate of proved oil and natural gas reserve quantities and the related present value of estimated future net cash flows. The unaudited interim condensed consolidated financial statements of the Company include the consolidated accounts of all of its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The results of operations for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. Subsequent Events In preparing these financial statements, the Company has evaluated events and transactions for potential recognition or disclosure through the date the financial statements were issued and has disclosed certain subsequent events in these condensed consolidated financial statements, as appropriate. Accounts Receivable Accounts receivable are reported net of the allowance for doubtful accounts. The allowance for doubtful accounts is determined based on a review of the Company’s receivables. Receivable accounts are charged off when collection efforts have failed or the account is deemed uncollectible. During 2016, the Company determined that a receivable account from a third-party natural gas and NGLs purchaser would no longer be collectible as a result of the third-party purchaser filing for bankruptcy. A summary of the activity related to the allowance for doubtful accounts is as follows: March 31, 2018 December 31, 2017 (in thousands) Allowance for doubtful accounts, beginning of period $ 1,953 $ 1,953 Expense — — Reductions/write-offs — — Allowance for doubtful accounts, end of period $ 1,953 $ 1,953 Recent Accounting Developments Business Combinations. In January 2017, the FASB issued updated guidance to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments in this update provide a screen to determine when a set is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. The amendments in this update affect all reporting entities that must determine whether they have acquired or sold a business and are effective for public business entities for annual reporting periods beginning after December 15, 2017, including interim periods within those periods. The amendments should be applied prospectively on or after the effective date and no disclosures are required at transition. The Company adopted this updated guidance for the fiscal year beginning January 1, 2018. The application of this guidance to future acquisitions and disposals could have an immediate effect on the Company’s financial position or results of operations. Statement of Cash Flows. In August 2016, the FASB issued updated guidance associated with the classification of certain cash receipts and cash payments on the statement of cash flows. The amended guidance addresses specific cash flow issues with the objective of reducing existing diversity in practice. The amendment provides guidance on the following eight specific cash flow issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The amendments in this update apply to all entities required to present a statement of cash flows. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. Amendments should be applied using a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. The Company adopted this update guidance for the fiscal year beginning January 1, 2018 and has determined that such adoption does not have a material effect on its statement of cash flows nor does it affect the Company’s financial position or results of operations. Leases. In February 2016, the FASB issued updated guidance to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and enhance disclosures regarding key information about leasing arrangements. Under the new guidance, lessees will be required to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplified the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Additionally, in January 2018, the FASB issued an amendment to the updated guidance to permit an entity to elect an optional transition practical expedient to not evaluate under the new guidance land easements that exist or expire before the adoption of the updated guidance and that were not previously accounted for as leases under previous guidance. The amendments in this update are effective beginning on January 1, 2019 and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. The Company has commenced analyzing its lease contracts but has not yet determined what the effects of adopting this updated guidance will be on its consolidated financial statements. Revenue Recognition. In May 2014, the FASB issued an amendment to previously issued guidance regarding the recognition of revenue, which supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, “Revenue Recognition,” (“ASC 605”) and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this core principle, an entity should apply the following steps: (1) identify the contract(s) with the customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. In 2015, the FASB delayed the effective date one year, beginning in fiscal year 2018. On January 1, 2018, the Company adopted Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“ASC 606”) using the modified retrospective method of transition. Under the modified retrospective approach, the standard has been applied to all existing contracts as of the date of initial application with the cumulative effect of applying the standard, if any, recognized in retained earnings. In order to determine the impact of adoption, the Company evaluated a representative sample of revenue contracts related to its oil, natural gas and NGLs revenues. For these contracts, the Company reviewed the contract provisions and evaluated the contracts under the new standard to assess the impact on the quantum and timing of revenue recognition and presentation of revenues on adoption of the new guidance. The Company believes that it has identified all material contract types and contractual features that represent the Company’s revenue. The impact of adoption on our current period results is as follows: Three Months Ended March 31, 2018 Under ASC 606 Under ASC 605 Increase (Decrease) (in thousands) Revenues: Oil and condensate $ 20,982 $ 20,992 $ (10 ) Natural gas 2,181 2,756 (575 ) NGLs 3,275 3,623 (348 ) Total oil and condensate, natural gas and NGLs revenues $ 26,438 $ 27,371 $ (933 ) Expenses: Transportation, treating and gathering $ — 933 $ (933 ) Net income (loss) $ 26,438 $ 26,438 $ — Retained earnings $ 26,438 $ 26,438 $ — The primary impact to our revenues as a result of the adoption of ASC 606 is the recording of transportation, treating, gathering and compression expenses (“Post-Production Expenses”) as a direct reduction to revenues instead of our historical practice of presenting such expenses gross in transportation, treating and gathering. These changes are due to the conclusion that the Company represents the agent in the sale of natural gas and NGLs under its gas processing and marketing agreements with midstream entities in accordance with the control model in ASC 606. As a result, the Company is required to record revenue on a net basis for amounts expected to be received from third-party customers through the marketing process, with Post-Production Expenses incurred subsequent to control of the product(s) transferring to the midstream entity at the wellhead being netted against revenue.

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2018
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	3. Property, Plant and Equipment The amount capitalized as oil and natural gas properties was incurred for the purchase and development of various properties in the U.S., specifically the state of Oklahoma. The following table summarizes the components of unproved properties excluded from amortization at the dates indicated: March 31, 2018 December 31, 2017 (in thousands) Unproved properties, excluded from amortization: Drilling in progress costs $ 6,410 $ 4,772 Acreage acquisition costs 113,531 113,191 Capitalized interest 16,237 13,992 Total unproved properties excluded from amortization $ 136,178 $ 131,955 The full cost method of accounting for oil and natural gas properties requires a quarterly calculation of a limitation on capitalized costs, often referred to as a full cost ceiling calculation. The ceiling is the present value (discounted at 10% per annum) of estimated future cash flow from proved oil, condensate, natural gas and NGLs reserves reduced by future operating expenses, development expenditures, abandonment costs (net of salvage) to the extent not included in oil and natural gas properties pursuant to authoritative guidance and estimated future income taxes thereon. To the extent that the Company's capitalized costs (net of accumulated depletion and deferred taxes) exceed the ceiling at the end of each reporting period, the excess must be written off to expense for such period. Once incurred, this impairment of oil and natural gas properties is not reversible at a later date even if oil and natural gas prices increase. The ceiling calculation is determined using a mandatory trailing 12-month unweighted arithmetic average of the first-day-of-the-month commodities pricing and costs in effect at the end of the period, each of which are held constant indefinitely (absent specific contracts with respect to future prices and costs) with respect to valuing future net cash flows from proved reserves for this purpose. The 12-month unweighted arithmetic average of the first-day-of-the-month commodities prices are adjusted for basis and quality differentials in determining the present value of the proved reserves. The table below sets forth relevant pricing assumptions utilized in the quarterly ceiling test computations for the respective periods noted before adjustment for basis and quality differentials: 2018 Total Year to Date Impairment March 31 Henry Hub natural gas price (per MMBtu) (1) $ 3.00 WTI oil price (per Bbl) (1) $ 53.49 Impairment recorded (pre-tax) (in thousands) $ — $ — 2017 Total Year to Date Impairment March 31 Henry Hub natural gas price (per MMBtu) (1) $ 2.73 WTI oil price (per Bbl) (1) $ 47.61 Impairment recorded (pre-tax) (in thousands) $ — $ — (1) For the respective periods, oil and natural gas prices are calculated using the trailing 12-month unweighted arithmetic average of the first-day-of-the-month prices based on Henry Hub spot natural gas prices and WTI spot oil prices. The Company could potentially incur ceiling test impairments in the future should commodities prices decline. However, it is difficult to project future impairment charges in light of numerous variables involved. The Company’s proved reserves estimates and their estimated discounted value and standardized measure will also be impacted by changes in lease operating costs, future development costs, production, exploration and development activities and estimated future income taxes. The ceiling limitation calculation is not intended to be indicative of the fair market value of the Company’s proved reserves or future results. WEHLU Sale On January 23, 2018, the Company entered into a definitive agreement of sale and purchase (the “Sale Agreement”) to divest its interest in the West Edmund Hunton Lime Unit (“WEHLU”) and adjacent undeveloped acreage to Revolution Resources, LLC, for $107.5 million, subject to, among other customary adjustments, adjustments for a property sale effective date of October 1, 2017 (the “WEHLU Sale”). Pursuant to the Sale Agreement, the WEHLU Sale closed on February 28, 2018. After effective date and other adjustments of approximately $8.7 million primarily related to revenues and direct operating expenses, net cash proceeds from the WEHLU Sale were approximately $97.6 million, subject to certain additional adjustments for final closing. The WEHLU Sale was reflected as a reduction to the full cost pool and no gain or loss was recorded related to the divestiture as such divestiture did not result in a significant change to the depletion rate. WEHLU Sale Pro Forma Operating Results The following unaudited pro forma results for the three months ended March 31, 2018 and 2017 show the effect on the Company's consolidated results of operations as if the WEHLU Sale had occurred at the beginning of the periods presented. The pro forma results are the result of excluding from the statement of operations of the Company the revenues and direct operating expenses for the properties divested adjusted for (1) the reduction in asset retirement obligation liabilities and accretion expense for the properties divested and (2) the reduction in depreciation, depletion and amortization expense as a result of the divestiture. As a result, certain estimates and judgments were made in preparing the pro forma adjustments. For the Three Months Ended March 31, 2018 2017 (in thousands, except (Unaudited) Revenues $ 14,173 $ 8,579 Net Loss $ (21,382 ) $ (26,397 ) Loss per share: Basic $ (0.10 ) $ (0.16 ) Diluted $ (0.10 ) $ (0.16 ) STACK Leasehold Acquisition On March 22, 2017, the Company completed the acquisition of additional working and net revenue interests in approximately 66 gross (9.5 net) producing wells and 5,670 net acres of additional undeveloped STACK Play leasehold in Kingfisher County, Oklahoma, effective March 1, 2017, for $51.4 million (the “STACK Leasehold Acquisition”). Prior to the completion of the STACK Leasehold Acquisition, the Company held an interest in the majority of acquired producing wells and acreage. The Company accounted for the STACK Leasehold Acquisition as an asset acquisition. Development Agreement On October 14, 2016, the Company executed an agreement with STACK Exploration LLC (the “Investor”) (the “Development Agreement”) to jointly develop up to 60 Gastar operated wells in the STACK Play in Kingfisher County, Oklahoma (the “Drilling Program”). The Drilling Program targeted the Meramec and Osage formations within the Mississippi Lime in a contract area within three townships covering approximately 32,900 gross (21,200 net) undeveloped mineral acres under leases held by the Company. The Company serves as the operator of all Drilling Program wells. Under the Development Agreement, the Investor funded 90% of the Company’s working interest portion of drilling and completion costs to initially earn 80% of the Company’s working interest in each new well (in each case, proportionately reduced by other participating working interests in the well). As a result, the Company paid 10% of its working interest portion of such costs for 20% of its original working interest. The proposed Drilling Program wells were to be mutually developed in three tranches of 20 wells each. The locations of the first 20 wells, comprised of 18 Meramec formation wells and two Osage formation wells, were mutually agreed upon by the Company and the Investor. Participation in the second tranche of 20 Drilling Program wells was to be at the election of the Investor and the third tranche of 20 wells would require mutual consent. On July 31, 2017, the Investor elected not to participate in the second tranche of wells. With respect to each 20-well tranche, when the Investor has achieved an aggregate 15% internal rate of return for its investment in the tranche, Investor’s interest will be reduced from 80% to 40% of the Company’s original working interest and the Company’s working interest increases from 20% to 60% of the original working interest. When a tranche internal rate of return of 20% is achieved by the Investor, Investor’s working interest decreases to 10% and the Company’s working interest increases to 90% of the working interest originally owned by the Company. If and when the final reversion of working interest in the completed 20 well tranche should occur, the Investor has the right, but not the obligation, for a period of six months to cause the Company to purchase the Investor’s remaining interest in the 20 wells in the Drilling Program (the “WI Tail”) for such tranche (the “Investor Put Right”) for fair market value by applying the methodology to determine a 15% discounted present value as defined by the Development Agreement. If the Investor fails to exercise the Investor Put Right within the six-month period after achieving final reversion, then for a period of six months thereafter, the Company shall have the right, but not the obligation, to purchase the WI Tail from the Investor on the same fair market value approach of the Investor Put Right. If final reversion has not been achieved by August 19, 2024, Investor will, for a period of six months thereafter, have the right to cause us to buy Investor’s then-current interest in the Drilling Program wells at an agreed upon valuation. Based on current commodity prices, well cost and production performance of the completed wells drilled in the first tranche, the 15% of internal rate of return is not anticipated to be achieved. By December 31, 2017, the Company and the Investor had completed all 20 gross (15.8 net; 3.2 net to the Company) wells within the first tranche of the Drilling Program.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Long-Term Debt	4. Long-Term Debt The table below provides a reconciliation of the Company’s long-term debt balance as presented in the condensed consolidated balance sheets for the periods presented: March 31, 2018 December 31, 2017 (in thousands) Term Loan, principal balance (1) $ 263,229 $ 256,599 Less: Unamortized deferred financing costs (2) (4,493 ) (4,724 ) Unamortized debt discount (2) (21,676 ) (22,464 ) Term Loan, net $ 237,060 $ 229,411 Notes, principal balance $ 162,500 $ 162,500 Less: Unamortized deferred financing costs (2) (2,496 ) (2,631 ) Unamortized debt discount (2) (44,306 ) (46,328 ) Notes, net $ 115,698 $ 113,541 Total long-term debt $ 352,758 $ 342,952 (1) Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end. (2) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method. Ares Investment Transactions On March 3, 2017, certain funds (the “Purchasers”) managed indirectly by Ares Management LLC (“Ares”) purchased from the Company for cash (i) $125.0 million aggregate principal amount of its Convertible Notes due 2022 (“Notes”) sold at par, which Notes, subject to the receipt of approval of the Company’s stockholders which was obtained on May 2, 2017, are convertible into common stock or, in certain circumstances, cash in lieu of common stock or a combination of cash and shares of common stock as described below and (ii) 29,408,305 shares of common stock for a purchase price of $50.0 million. In addition, an affiliate of Ares concurrently loaned the Company $250.0 million pursuant to the Third Amended and Restated Credit Agreement among the Company (the “Term Loan”), as borrower, the guarantors party thereto, AF V Energy I Holdings, L.P., a fund managed indirectly by Ares, as lender, and Wilmington Trust, National Association, as Administrative Agent as further described below. The proceeds from the sale of the Notes, the common stock and the Term Loan were used to fully repay and redeem the Company’s prior Revolving Credit Facility (as defined below) and to satisfy and discharge its $325.0 million of 8.625% senior secured notes due May 2018, which were satisfied and discharged on March 3, 2017 by irrevocably calling for redemption and depositing with the indenture trustee cash in the amount of the redemption price of 102.156% of their principal amount plus accrued and unpaid interest to the redemption date of March 24, 2017, and to pay the expenses from the Ares transactions. In order to provide funding for the STACK Leasehold Acquisition and a portion of the Company’s 2017 capital budget, on March 21, 2017, the Purchasers purchased from the Company for cash an additional $75.0 million aggregate principal amount of its Notes sold at par (the “Additional Notes”). The Notes, including the Additional Notes, were issued with conversion rights that were subject to the approval of holders of issued and outstanding common stock (other than the Purchasers), which approval was obtained May 2, 2017 (the “Requisite Stockholder Approval”). Pursuant to the purchase agreement for the Additional Notes, upon receipt of Requisite Stockholder Approval, Purchasers and the Company exchanged $37.5 million principal amount of the Additional Notes for (a) 25,456,521 newly issued shares of common stock (the “Repurchase Shares”) and (b) 2,000 shares of the Company’s Special Voting Preferred Stock, par value $0.01 per share (the “Mandatory Repurchase”). The terms of Mandatory Repurchase, which was effected May 5, 2017, provided for one Repurchase Share issued for each $1.4731 of outstanding principal of the repurchased Notes, which was based on the 10-day volume weighted average trading price (“VWAP”) of the common stock for the period ended March 17, 2017. The exchange reduced the aggregate principal amount of issued and outstanding Notes from $200.0 million to $162.5 million at June 30, 2017, which principal amount remains outstanding at March 31, 2018. Term Loan On March 3, 2017, the Company entered into a credit agreement for the Term Loan. The Term Loan bears interest at a per annum rate equal to 8.5%, payable on a quarterly basis on each March 31, June 30, September 30 and December 31 of each year, commencing March 31, 2017. The Term Loan has a scheduled maturity of March 3, 2022. In addition, the Term Loan is subject to an interest “make-whole” and repayment premium, such that any repayment or prepayment of the loans thereunder prior to the stated maturity date shall be subject to the payment of a repayment premium, and depending on the date of such repayment or prepayment, the applicable interest “make-whole” amount, with the amount of such repayment premium decreasing over the life of the Term Loan. The Term Loan is guaranteed by the Company’s sole domestic subsidiary and will be guaranteed by all of the Company's future domestic subsidiaries formed during the term of the Term Loan. The Term Loan is secured by a first-priority lien on substantially all of the assets of the Company and its subsidiaries, excluding certain assets as customary exceptions. The Term Loan contains various customary covenants for credit facilities of this type, including, among others, restrictions on granting liens, incurrence of other indebtedness, payments of certain dividends and other restricted payments, engaging in transactions with affiliates, dispositions of assets and other, in each case subject to certain baskets and exceptions. At March 31, 2018, the Company was in compliance with such covenants. All outstanding amounts owed become due and payable upon the occurrence of certain usual and customary events of default, including among others (i) failure to make payments; (ii) non-performance of covenants and obligations continuing beyond any applicable grace period; and (iii) the occurrence of a change in control of the Company, as defined in the Term Loan. At March 31, 2018, no events of default had occurred. The Company accounted for the Term Loan in accordance with guidance relating to “ Debt with Conversion and Other Options On March 20, 2017, the Company, together with the parties thereto, entered into an Amendment No. 1 to the Term Loan which amendment permitted the issuance of the Additional Notes. On August 2, 2017, the Company, together with the parties thereto, entered into an Amendment No. 2 to Term Loan (“Amendment No. 2”). Amendment No. 2 amended the Term Loan, to among other things, (i) allow for the payment of pay in kind (“PIK”) interest on the Term Loan at the applicable PIK percentage and (ii) increased the applicable rate for periods ending after June 30, 2017 from 8.5% per annum to 10.25% per annum. Amendment No. 2 allows the Company to elect to PIK upon proper notice 100% of interest payments due after June 30, 2017 and prior to December 31, 2018 and at the Company’s election, PIK between 0% and 50% of any interest payments occurring after December 31, 2018 (other than interest due on the maturity date or the date of any repayment or prepayment). The Term Loan interest rate increased to 10.25% for all interest periods post June 30, 2017 and the PIK interest shall be payable by capitalizing and adding such amounts to the outstanding principal amount of the Term Loan on the applicable interest payment date. On September 18, 2017, the Company, together with the parties thereto, entered into an Amendment No. 3 to the Term Loan (“Amendment No. 3”). Amendment No. 3 amended the Term Loan to, among other things, expressly provide that certain assignments of oil and natural gas properties made or to be made by the Company to Red Bluff Resources Operating, LLC (“Red Bluff”), pursuant to the Red Bluff Purchase and Sale Agreement dated October 19, 2016 between the Company and Red Bluff (“Red Bluff PSA”), are permitted by the Term Loan and are not subject to the mandatory prepayment provisions applicable to “Asset Sales” under the Term Loan. The carrying amount of the Term Loan for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Term Loan, principal balance (1) $ 263,229 $ 256,599 Less: Unamortized deferred financing costs (2) (4,493 ) (4,724 ) Unamortized debt discount (2) (21,676 ) (22,464 ) Term loan, net $ 237,060 $ 229,411 (1) Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end. (2) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan based on the effective interest method. Indenture and Notes On March 3, 2017, the Company entered into an indenture (the “Indenture”) by and among the Company, the subsidiary guarantor named therein, and Wilmington Trust, National Association, as trustee (the “Trustee”) and collateral trustee, with respect to the Notes. The principal terms of the Notes are governed by the Indenture. Pursuant to the Indenture, the Notes were issued for cash at par, bear interest at 6.0% per annum and will mature on March 1, 2022, unless earlier repurchased, redeemed or converted in accordance with the terms of the Indenture. Interest is payable on the Notes on each March 1, June 1, September 1 and December 1 of each year, commencing on June 1, 2017. Pursuant to the Indenture, Requisite Stockholder Approval was required on or before July 3, 2017 to approve the conversion rights of the Notes (including the Additional Notes) to be convertible at the option of the holder into shares of common stock based on the terms of the Indenture. Requisite Stockholder Approval was obtained on May 2, 2017 at a special meeting of stockholders. The interest rate on the Notes was subject to an increase in certain circumstances if the Company fails to comply with certain obligations under a Registration Rights Agreement and on the Notes in the case of certain issuances of common stock by the Company at a price below $1.7002 per share (subject to adjustment). The Notes are secured by a second-priority lien on substantially all of the assets of the Company and its sole subsidiary. If at least a majority of the Notes issued pursuant to the Securities Purchase Agreement dated February 16, 2017 (the “Purchase Agreement”) cease to be held by affiliates of Ares as provided in the Indenture, the liens securing the Notes will be released and substantially all of the restrictive covenants in the Indenture will terminate. The Indenture restricts the ability of the Company and certain of its subsidiaries to, among other things: (i) pay dividends or make other distributions in respect of the Company’s capital stock or make other restricted payments; (ii) incur additional indebtedness and issue preferred stock; (iii) make certain dispositions and transfers of assets; (iv) engage in transactions with affiliates; (v) create liens; (vi) engage in certain business activities that are not related to oil and gas; and (vii) impair any security interest. These covenants are subject to a number of exceptions and qualifications. The Indenture provides that a number of events will constitute an Event of Default (as defined in the Indenture), including, among other things: (i) a failure to pay the Notes when due at maturity, upon redemption or repurchase; (ii) failure to pay interest for 30 days; (iii) the Company’s failure to deliver certain notices; (iv) a default in the Company’s obligation to convert the Notes; (v) the Company’s failure to comply with certain covenants relating to merger, consolidation or sale of assets; (vi) the Company’s failure to comply, for 60 days following notice, with any of the other covenants or agreements in the Indenture; (vii) a default, which is not cured within 30 days, by the Company or any Restricted Subsidiaries (as defined in the Indenture) with respect to any mortgages or any indebtedness for money borrowed of at least $15 million; (viii) one or more final judgments against the Company or any of its Restricted Subsidiaries for the payment of at least $15 million; (ix) the Company’s failure to make any payments required under that certain development agreement, which is not cured within 30 days; (x) causing any Guarantee (as defined in the Indenture) to cease to be in full force and effect; (xi) the cessation to be in full force and effect of any of the collateral agreements entered into with respect to the Notes; and (xii) certain events of bankruptcy or insolvency. In the case of an Event of Default arising from certain events of bankruptcy or insolvency with respect to the Company, 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 aggregate principal amount of the then outstanding Notes may declare all the Notes to be due and payable immediately. At March 31, 2018, no Event of Default had occurred. In accordance with accounting guidance relating to “ Debt with Conversion and Other Options” The carrying amount of the liability component of the Notes for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Notes, principal balance $ 162,500 $ 162,500 Less: Unamortized deferred financing costs (1) (2,496 ) (2,631 ) Unamortized debt discount (1) (44,306 ) (46,328 ) Notes, net $ 115,698 $ 113,541 (1) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Notes based on the effective interest method. The carrying amount of the equity components of the Notes recorded in additional paid in capital for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Value of conversion option $ 77,626 $ 77,626 Debt issuance costs attributable to conversion option $ (2,164 ) $ (2,164 ) Total $ 75,462 $ 75,462 Second Amended and Restated Revolving Credit Facility On June 7, 2013, the Company entered into the Second Amended and Restated Credit Agreement among the Company, Wells Fargo Bank, National Association, as Administrative Agent, Collateral Agent, Swing Line Lender and Issuing Lender and the lenders named therein (the “Revolving Credit Facility”). The Revolving Credit Facility had a scheduled maturity of November 14, 2017. On January 10, 2017, the Company, together with the parties thereto, entered into an amendment to the Revolving Credit Facility (“Amendment No. 10”), which amended the Revolving Credit Facility to, among other things, permit the payment of certain cash dividends on its preferred stock, including the dividends declared payable on January 31, 2017, provided that (i) the Company’s borrowing base was correspondingly reduced in the amount of any such dividend payment and (ii) the Company paid down its outstanding indebtedness under the Revolving Credit Facility in the amount of any resulting borrowing base deficiency. Under Amendment No. 10, payment of the declared January 2017 dividend and monthly preferred stock cash dividends through May 2017 was permitted contingent upon the satisfaction of certain conditions, including but not limited to, (i) the absence of any defaults or borrowing base deficiency, (ii) for any dividends declared and paid in respect of April 2017 and May 2017, having cash liquidity (including any available borrowings under the Revolving Credit Facility) of more than $30.0 million and (iii) paying any permitted dividends solely from proceeds received by the Company from sales of equity since November 30, 2016 (including through the Company’s at-the-market issuance sales agreement with a third-party sales agent to sell, from time to time, shares of the Company’s common stock (the “ATM Program”). Under Amendment No. 10, the Company also agreed to pay down indebtedness under its Revolving Credit Facility by at least an additional $8.1 million by April 30, 2017. On March 3, 2017, the Company used a portion of the net proceeds from the transactions described in this Note 4 under the caption “Ares Investment Transactions” above to fully repay all of the $69.2 million borrowings outstanding under the Revolving Credit Facility (which was terminated on such date). Senior Secured Notes At December 31, 2016, the Company had $325.0 million aggregate principal amount of 8 5/8% Senior Secured Notes due May 15, 2018 (the “Former Notes”) outstanding under an indenture by and among the Company, the Guarantors named therein (the “Guarantors”), Wells Fargo Bank, National Association, as Trustee (in such capacity, the “Former Notes Trustee”) and Collateral Agent. The Notes bore interest at a rate of 8.625% per year, payable semi-annually in arrears on May 15 and November 15 of each year. Effective May 17, 2016, Wells Fargo Bank, National Association resigned as Former Notes Trustee and Collateral Agent and Wilmington Trust, National Association was appointed Trustee and Collateral Agent pursuant to the Indenture. On March 3, 2017, the redemption price plus interest on all of the Company’s outstanding $325.0 million principal of the Former Notes was funded to satisfy and discharge the Former Notes from a portion of the net proceeds from the transactions described in this Note 4 under the caption “Ares Investment Transactions” above. All of the Former Notes were satisfied and discharged on March 3, 2017 by irrevocably calling for redemption and depositing with the indenture trustee cash in the amount of the redemption price of 102.156% of the principal amount, or principal plus an additional $7.0 million, plus accrued and unpaid interest to the redemption date of March 24, 2017. Additionally, the Company wrote-off $5.2 million of remaining unamortized deferred financing costs related to the Former Notes upon redemption.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements The Company’s financial assets and liabilities are measured at fair value on a recurring basis. The Company discloses its recognized non-financial assets and liabilities, such as asset retirement obligations, unproved properties and other property and equipment, at fair value on a non-recurring basis. For non-financial assets and liabilities, the Company is required to disclose information that enables users of its financial statements to assess the inputs used to develop these measurements. The Company assesses its unproved properties for impairment whenever events or circumstances indicate the carrying value of those properties may not be recoverable. The fair value of the unproved properties is measured using an income approach based upon internal estimates of future production levels, current and future prices, drilling and operating costs, discount rates, current drilling plans and favorable and unfavorable drilling activity on the properties being evaluated and/or adjacent properties, which are Level 3 (as defined below) inputs. Should an impairment of unproved properties occur, the value of the impaired properties would be reclassified into proved properties in the full cost pool subject to depletion. As no other fair value measurements are required to be recognized on a non-recurring basis at March 31, 2018, no additional disclosures are provided. As defined in the guidance, fair value is the amount 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 (an exit price). To estimate fair value, the Company utilizes market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. The guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets or liabilities (“Level 1”) and the lowest priority to unobservable inputs (“Level 3”). The three levels of the fair value hierarchy are as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. The Company’s cash equivalents consist of short-term, highly liquid investments, which have maturities of 90 days or less, including sweep investments and money market funds. • Level 2 inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. • Level 3 inputs are measured based on prices or valuation models that require inputs that are both significant to the fair value measurement and less observable from objective sources. These inputs may be used with internally developed methodologies or third party broker quotes that result in management’s best estimate of fair value. The Company’s valuation models consider various inputs including (a) quoted forward prices for commodities, (b) time value, (c) volatility factors and (d) current market and contractual prices for the underlying instruments. Significant increases or decreases in any of these inputs in isolation would result in a significantly higher or lower fair value measurement. Level 3 instruments are commodity costless collars, index swaps, basis and fixed price swaps and put and call options to hedge oil, natural gas and NGLs price risk. At each balance sheet date, the Company performs an analysis of all applicable instruments and includes in Level 3 all of those whose fair value is based on significant unobservable inputs. The fair values derived from counterparties and third-party brokers are verified by the Company using publicly available values for relevant NYMEX futures contracts and exchange traded contracts for each derivative settlement location. Although such counterparty and third-party broker quotes are used to assess the fair value of its commodity derivative instruments, the Company does not have access to the specific assumptions used in its counterparties valuation models. Consequently, additional disclosures regarding significant Level 3 unobservable inputs were not provided and the Company does not currently have sufficient corroborating market evidence to support classifying these contracts as Level 2 instruments. As required, financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values below incorporates various factors, including the impact of the counterparty’s non-performance risk with respect to the Company’s financial assets and the Company’s non-performance risk with respect to the Company’s financial liabilities. The Company has not elected to offset the fair value amounts recognized for multiple derivative instruments executed with the same counterparty, but reports them gross on its consolidated balance sheets. Transfers between levels are recognized at the end of the reporting period. There were no transfers between levels during the 2018 and 2017 periods. The following tables set forth by level within the fair value hierarchy the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of March 31, 2018 and December 31, 2017: Fair value as of March 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets: Commodity derivative contracts — — 542 542 Liabilities: Commodity derivative contracts — — (9,567 ) (9,567 ) Total $ — $ — $ (9,025 ) $ (9,025 ) Fair value as of December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Assets: Commodity derivative contracts — — 1,370 1,370 Liabilities: Commodity derivative contracts — — (6,988 ) (6,988 ) Total $ — $ — $ (5,618 ) $ (5,618 ) The table below presents a reconciliation of the assets and liabilities classified as Level 3 in the fair value hierarchy for the three months ended March 31, 2018 and 2017. Level 3 instruments presented in the table consist of net derivatives that, in management’s opinion, reflect the assumptions a marketplace participant would have used at March 31, 2018 and 2017. Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ (5,618 ) $ 7,512 Total (losses) gains included in earnings (5,529 ) 1,300 Purchases 552 470 Issuances — — Settlements (1) 1,570 (2,805 ) Balance at end of period $ (9,025 ) $ 6,477 The amount of total losses for the period included in earnings attributable to the change in mark to market of commodity derivatives contracts still held at March 31, 2018 and 2017 $ (3,326 ) $ (582 ) (1) Included in gain (loss) on commodity derivatives contracts on the condensed consolidated statements of operations. At March 31, 2018, the estimated fair value of accounts receivable and accounts and revenue payables approximates their carrying value due to their short-term nature. The estimated fair value of the Notes excluding the conversion feature at March 31, 2018 was $127.7 million calculated based on the fair value of similar non-convertible debt instruments (Level 2) since an observable quoted price of the Notes or a similar asset or liability is not readily available. The estimated fair value of the Term Loan at March 31, 2018 was $242.5 million calculated based on the fair value of similar debt instruments (Level 2) since an observable price of the Term Loan or a similar asset or liability is not readily available. The Company has consistently applied the valuation techniques discussed above in all periods presented.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue from Contracts with Customers	6. Revenue from Contracts with Customers Disaggregation of Revenue The following represents a disaggregation of revenues and a reconciliation of total revenues as reported in the condensed consolidated statement of operations to revenue from contracts with customers: For the Three Months Ended March 31, 2018 March 31, 2017 (1) (in thousands) Revenues Oil and condensate $ 20,982 $ 12,190 Natural gas 2,181 2,588 NGLs 3,275 2,591 Total revenues from contracts with customers $ 26,438 $ 17,369 (Loss) gain on commodity derivatives contracts (5,529 ) 1,300 Total revenues and other (loss) gain $ 20,909 $ 18,669 (1) Prior period amounts have not been adjusted under the modified retrospective method. Revenue Recognition Oil, condensate, natural gas and NGLs revenues are recognized at the point in time that control of the product is transferred to the customer and collectability is reasonably assured. A more detailed summary of the underlying contracts that give rise to revenue and method of recognition are included below. Oil and Condensate Sales Under the Company’s oil and condensate sales contracts, the Company delivers all or a specified percentage of the crude oil production from specified leases to the nominated delivery point which is the outlet flange of the Company’s lease facility or at unit storage tanks. The Company sells oil and condensate production at the delivery point and collects an agreed-upon index price, net of applicable transport differential. The Company recognizes revenue when control transfers to the purchaser at the delivery point at the net price received. Natural Gas and NGLs Sales Under the Company’s gas processing contracts, the Company delivers all or a specified percentage of natural gas production to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity processes the natural gas, sells the resulting NGLs and residue gas to third parties and pays the Company for the NGLs and residue gas with deductions for Post-Production Expenses. The NGLs are subject to an incremental NGLs pricing formula based upon a percentage of NGLs extracted from the Company’s wet gas. For the Company’s gas processing contracts, the Company evaluates whether it is the principal or the agent. For the Company’s existing contracts, it has concluded that it is the agent and the midstream processing entity is the Company’s customer, and therefore, the Company recognizes revenue when control transfers to the midstream processing entity for the net amount of the proceeds received. If for future contracts the Company was to conclude that it is the principal with the ultimate third party being the customer, the Company would recognize revenue for those contracts on a gross basis, with Post-Production Expenses presented gross as expenses. Imbalances The Company recognizes revenue for all oil, condensate, natural gas and NGLs sold to purchasers regardless of whether the sales are proportionate to the Company’s ownership interest in the property. Production imbalances are recognized as a liability to the extent an imbalance on a specific property exceeds the Company’s share of remaining proved oil and natural gas reserves. The Company had no material imbalances at March 31, 2018 or 2017. Significant Judgments Principal versus Agent The Company engages in various types of transactions in which midstream entities process its wet gas and, in some scenarios, subsequently market resulting NGLs and residue gas to third-party customers on the Company’s behalf, such as gas processing contracts. These types of transactions require judgment to determine whether the Company is the principal or the agent in the contract and, as a result, whether revenues are recorded gross or net. For the Company’s existing contracts, the Company has determined that it represents the agent in the sale of products under certain gas processing and marketing agreements with midstream entities in accordance with the control model in ASC 606. As a result, the Company presents revenue on a net basis for amounts expected to be received from third-party customers through the marketing process, with Post-Production Expenses incurred subsequent to control of the product(s) transferring to the midstream entity being netted against revenue. Transaction Price Allocated to Remaining Performance Obligations A significant number of the Company’s product sales are short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient in ASC 606-10-50-14 that exempts it from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less. For the Company’s product sales that have a contract term greater than one year, the Company has utilized the practical expedient in ASC 606-10-50-14A that states that it is not required to disclose the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Under these sales contracts, each unit of product generally represents a separate performance obligation; therefore future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. Contract Balances Under the Company’s customer contracts, the Company receives a remittance advice confirming purchased volumes and pricing from its customers once the Company’s performance obligations have been satisfied, at which point payment is unconditional. Accordingly, the Company’s contracts do not give rise to contract assets or liabilities under ASC 606. All of the Company’s revenue accounts receivable balances are attributable to revenues from contracts with customers. Prior-period Performance Obligations The Company records revenue in the month its production is delivered to the purchaser. However, settlement statements and payment may not be received for 30 to 90 days after the date production is delivered, and as a result, the Company is required to estimate the amount of production that was delivered to the purchaser and the price that will be received for the sale of the product including any transportation and other deductions. The Company uses its knowledge of its properties, historical performance, contractual data, the anticipated effect of weather conditions during the month of production and prevailing market as the basis for these estimates. The Company records the variances between its estimates and the actual amounts received in the month payment is received and such variances have historically not been material. For the three months ended March 31, 2018, revenue recognized in the reporting period related to performance obligations satisfied in prior reporting periods was not material.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activity	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activity	7. Derivative Instruments and Hedging Activity The Company maintains a commodity price risk management strategy that uses derivative instruments to minimize significant, unanticipated earnings fluctuations that may arise from volatility in commodity prices. The Company uses costless collars, index, basis and fixed price swaps and put and call options to hedge oil, condensate, natural gas and NGLs price risk. All derivative contracts are carried at their fair value on the balance sheet and all changes in value are recorded in the condensed consolidated statements of operations in (loss) gain on commodity derivatives contracts. For the three months ended March 31, 2018 and 2017, the Company reported losses of $3.3 million and $582,000, respectively, in the condensed consolidated statements of operations related to the change in the fair value of its commodity derivative contracts still held at March 31, 2018 and 2017. As of March 31, 2018, the following crude derivative transactions were outstanding with the associated notional volumes and weighted average underlying hedge prices: Settlement Period Derivative Instrument Average Daily Volume (1) Total of Notional Volume Base Fixed Price Floor (Long) Short Put Ceiling (Short) (in Bbls) April to June 2018 Costless three-way collar 1,700 154,700 $ — $ 47.50 $ 37.50 $ 57.85 July to September 2018 Costless three-way collar 1,600 147,200 $ — $ 47.50 $ 37.50 $ 57.85 October to December 2018 Costless three-way collar 1,700 156,400 $ — $ 47.50 $ 37.50 $ 57.85 April 2018 Fixed price swap 125 3,750 $ 66.45 $ — $ — $ — April 2018 Fixed price swap 477 14,310 $ 51.20 $ — $ — $ — April to December 2018 Fixed price swap 500 137,500 $ 61.60 $ — $ — $ — May 2018 Fixed price swap 325 10,075 $ 66.45 $ — $ — $ — May 2018 Fixed price swap 492 15,252 $ 51.20 $ — $ — $ — June 2018 Fixed price swap 600 18,000 $ 51.20 $ — $ — $ — June to August 2018 Fixed price swap 425 39,100 $ 66.45 $ — $ — $ — July to September 2018 Fixed price swap 500 46,000 $ 51.20 $ — $ — $ — October to December 2018 Fixed price swap 600 55,200 $ 51.20 $ — $ — $ — January to September 2019 Costless three-way collar 2,000 546,000 $ — $ 47.50 $ 37.50 $ 59.70 October to December 2019 Costless three-way collar 1,900 174,800 $ — $ 47.50 $ 37.50 $ 59.70 January to September 2019 Fixed price swap 700 191,100 $ 50.40 $ — $ — $ — October to November 2019 Fixed price swap 600 36,600 $ 50.40 $ — $ — $ — December 2019 Fixed price swap 416 12,896 $ 50.40 $ — $ — $ — (1) Crude volumes hedged include oil, condensate and certain components of our NGLs production. As of March 31, 2018, the following natural gas derivative transactions were outstanding with the associated notional volumes and weighted average underlying hedge prices: Settlement Period Derivative Instrument Average Daily Volume Total of Notional Volume Base Fixed Price Floor (Long) Short Put Ceiling (Short) (in MMBtus) April to December 2018 Costless three-way collar 5,000 1,375,000 $ — $ 3.00 $ 2.35 $ 4.00 April to December 2018 Fixed price swap 1,550 426,250 $ 3.01 $ — $ — $ — As of March 31, 2018, all of the Company’s economic derivative hedge positions were with large institutions, which are not known to the Company to be in default on their derivative positions. The Company is exposed to credit risk to the extent of non-performance by the counterparties in the derivative contracts discussed above; however, the Company does not anticipate non-performance by such counterparties. None of the Company’s derivative instruments contain credit-risk related contingent features. In conjunction with certain derivative hedging activity, the Company deferred the payment of certain put premiums for the production month period April 2018 through December 2018. The put premium liabilities become payable monthly as the hedge production month becomes the prompt production month. The Company amortizes the deferred put premium liabilities as they become payable. The following table provides information regarding the deferred put premium liabilities for the periods indicated: March 31, 2018 December 31, 2017 (in thousands) Current commodity derivative put premium payable $ 102 $ 135 Total unamortized put premium liabilities $ 102 $ 135 For the Three Months Ended March 31, 2018 (in thousands) Put premium liabilities, beginning balance $ 135 Settlement of put premium liabilities (33 ) Additional put premium liabilities — Put premium liabilities, ending balance $ 102 Additional Disclosures about Derivative Instruments and Hedging Activities The tables below provide information on the location and amounts of derivative fair values in the condensed consolidated statement of financial position and derivative gains and losses in the condensed consolidated statement of operations for derivative instruments that are not designated as hedging instruments: Fair Values of Derivative Instruments Derivative Assets (Liabilities) Fair Value Balance Sheet Location March 31, 2018 December 31, 2017 (in thousands) Derivatives not designated as hedging instruments Commodity derivative contracts Current assets $ 542 $ 1,370 Commodity derivative contracts Current liabilities (6,278 ) (4,416 ) Commodity derivative contracts Long-term liabilities (3,289 ) (2,572 ) Total derivatives not designated as hedging instruments $ (9,025 ) $ (5,618 ) Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended March 31, Location of Loss Recognized in Income on Derivatives 2018 2017 (in thousands) Derivatives not designated as hedging instruments Commodity derivative contracts Loss on commodity derivatives contracts $ (5,529 ) $ 1,300 Total $ (5,529 ) $ 1,300

Capital Stock

Capital Stock	3 Months Ended
	Mar. 31, 2018
Stockholders Equity Note [Abstract]
Capital Stock	8. Capital Stock Common Stock On May 7, 2015, the Company entered into the ATM Program. The shares were issued pursuant to the Company’s then-existing effective shelf registration statement on Form S-3, as amended (Registration No. 333-193832). The Company registered shares having an aggregate offering price of up to $50.0 million. For the period January 1, 2017 to February 20, 2017, the Company sold 5,447,919 shares through the ATM Program for net proceeds of $8.3 million. The ATM Program expired on February 24, 2017. On March 3, 2017, the Purchasers purchased for cash (i) $125.0 million aggregate principal amount of Notes sold at par and (ii) 29,408,305 shares of common stock for a purchase price of $50.0 million before offering costs and expenses. The common stock sale was priced based on a 30-trading day VWAP of $1.7002 determined on February 15, 2017 the date immediately prior to the signing date of the Purchase Agreement with Purchasers in respect to such sale. On March 21, 2017, the Company sold to the Purchasers an additional $75.0 million aggregate principal amount of Notes. Pursuant to the purchase agreement for the Additional Notes, after obtaining the Requisite Stockholder Approval, on May 5, 2017, the Company and the Purchasers exchanged $37.5 million aggregate principal amount of the outstanding Additional Notes for the issuance of 25,456,521 shares of common stock to Purchasers of the Mandatory Repurchase. The Notes are convertible into shares of common stock as described in more detail in Note 4. On June 27, 2017, the Company’s stockholders approved an amendment to the Company’s certificate of incorporation to increase the number of authorized shares of common stock from 550,000,000 to 800,000,000, which amendment became effective on July 24, 2017. Preferred Stock Pursuant to the Company’s certificate of incorporation, the Company has 40,000,000 shares of preferred stock authorized with a par value of $0.01 per share. The Company has designated 10,000,000 of such shares to constitute its 8.625% Series A Cumulative Preferred Stock (the “Series A Preferred Stock”) and 10,000,000 of such shares to constitute its 10.75% Series B Cumulative Preferred Stock (the “Series B Preferred Stock”). The Series A Preferred Stock and the Series B Preferred Stock each have a liquidation preference of $25.00 per share. On March 22, 2017, the Company designated 2,000 of such shares as Special Voting Preferred Stock with a liquidation preference of $0.01 for each share, which is junior and subordinate to the right of the holders of any shares of any other existing or future series of preferred stock. Series A Preferred Stock At March 31, 2018, there were 4,045,000 shares of the Series A Preferred Stock issued and outstanding with a $25.00 per share liquidation preference. The Series A Preferred Stock ranks senior to the Company's common stock and on parity with the Series B Preferred Stock with respect to the payment of dividends and distribution of assets upon liquidation, dissolution or winding up. The Series A Preferred Stock is subordinated to all of the Company’s existing and future debt and all future capital stock designated as senior to the Series A Preferred Stock. The Series A Preferred Stock cannot be converted into common stock, but may be redeemed, at the Company’s option for $25.00 per share plus any accrued and unpaid dividends. There is no mandatory redemption of the Series A Preferred Stock. The Company paid monthly dividends on the Series A Preferred Stock at a fixed rate of 8.625% per annum of the $25.00 per share liquidation preference through March 2016. Effective March 9, 2016, the Revolving Credit Facility prohibited the payment of cash dividends on the Company’s preferred stock commencing April 2016. Pursuant to Amendment No. 10 to the Company’s Revolving Credit Facility, on January 10, 2017, the Company declared a special cash dividend on the Series A Preferred Stock to pay in full all accumulated and unpaid cash dividends accrued since April 1, 2016 at an annualized 8.625% through the payment date. The Series A Preferred Stock January 2017 dividend of $7.3 million was paid on January 31, 2017 to holders of record at the close of business on January 20, 2017, which paid all unpaid dividends that accumulated in respect to the Series A Preferred Stock at such time. Thereafter, all monthly cash dividends on the Series A Preferred Stock were paid for each month through July 2017. On August 1, 2017, primarily in response to the decline in oil prices and to preserve liquidity, the Company elected to suspend Series A Preferred Stock dividends commencing August 2017, which suspension remained in effect through March 2018. Dividends on the Series A Preferred Stock accumulate regardless of whether any such dividends are declared. If the Company has accumulated, accrued and unpaid cash dividends in any calendar month within four calendar quarters, then commencing in the calendar month following the first month in such fourth calendar quarter in which cash dividends are not paid in full, and until accumulated dividends are paid in full for four calendar quarters with the last two calendar quarters’ dividends paid in cash, (i) the fixed dividend rate of Series A Preferred Stock each increases by 2.00% per annum, (ii) the Company will be required to issue a dividend of common stock to pay accrued and unpaid dividends based on then current market value determined in accordance with the certificate of designations applicable to the Series A Preferred Stock, if such dividends are not paid in cash, provided it has sufficient capital surplus to pay such a dividend and can otherwise pay a dividend under state law, and (iii) the holders of Series A Preferred Stock and Series B Preferred Stock, voting as a single class, will have the right to elect up to two additional directors to the board of directors of the Company. If the Company’s common stock ceases to be listed on a national securities exchange or a national securities market, “pay in kind” dividends of additional shares of Series A Preferred Stock may be payable in lieu of cash or common stock dividends. For the three months ended March 31, 2018, the Company recognized undeclared cumulative dividends of $2.2 million for the Series A Preferred Stock. For the three months ended March 31, 2017, the Company paid cash dividends of $8.7 million, including $6.5 million of 2016 undeclared dividends, for the Series A Preferred Stock. As of March 31, 2018, accumulated and unpaid dividends on the outstanding Series A Preferred Stock aggregated to $5.8 million, or $1.4375 per shares. On April 9, 2018, the Company declared a special cash dividend on the Series A Preferred Stock to pay in full all accumulated and unpaid cash dividends accrued since August 1, 2017 at an annualized 8.625% through the payment date. The Series A Preferred Stock April 2018 dividend of $6.5 million was paid on April 30, 2018 to holders of record at the close of business on April 20, 2018, which paid all unpaid dividends that accumulated in respect to the Series A Preferred Stock at such time. Series B Preferred Stock At March 31, 2018, there were 2,140,000 shares of the Series B Preferred Stock issued and outstanding with a $25.00 per share liquidation preference. The Series B Preferred Stock ranks senior (to the extent of its stated liquidation preference and any accumulated and unpaid dividends) to the Company’s common stock and on parity with Series A Preferred Stock with respect to the payment of dividends and distribution of assets upon liquidation, dissolution or winding up. The Series B Preferred Stock are subordinated to all of the Company’s existing and future debt and all future capital stock designated as senior to the Series B Preferred Stock. Except upon a change in ownership or control, the Series B Preferred Stock may not be redeemed before November 15, 2018, at or after which time it may be redeemed at the Company’s option for $25.00 per share in cash. Following a change in ownership or control, the Company will have the option to redeem the Series B Preferred Stock within 90 days of the occurrence of the change in control, in whole but not in part for $25.00 per share in cash, plus accrued and unpaid dividends (whether or not declared), up to, but not including the redemption date. If the Company does not exercise its option to redeem the Series B Preferred Stock upon a change of ownership or control, the holders of the Series B Preferred Stock have the option to convert the shares of Series B Preferred Stock into the Company's common stock based upon on an average common stock trading price then in effect but limited to an aggregate of 11.5207 shares of the Company’s common stock per share of Series B Preferred Stock, subject to certain adjustments. If the Company exercises any of its redemption rights relating to shares of Series B Preferred Stock, the holders of Series B Preferred Stock will not have the conversion right described above with respect to the shares of Series B Preferred Stock called for redemption. There is no mandatory redemption of the Series B Preferred Stock. The Company paid monthly dividends on the Series B Preferred Stock at a fixed rate of 10.75% per annum of the $25.00 per share liquidation preference through March 2016. Effective March 9, 2016, the Revolving Credit Facility prohibited the payment of cash dividends on the Company’s preferred stock commencing April 2016. Pursuant to Amendment No. 10 to the Company’s Revolving Credit Facility, on January 10, 2017, the Company declared a special cash dividend on the Series B Preferred Stock to pay in full all accumulated and unpaid cash dividends since April 1, 2016 at an annualized 10.75% through the payment date. The Series B Preferred Stock January 2017 dividend in the amount of $4.8 million was paid on January 31, 2017 to holders of record at the close of business on January 20, 2017, which paid all unpaid dividends that accumulated in respect to the Series B Preferred Stock at such time. Thereafter, all monthly cash dividends on the Series B Preferred Stock were paid for each month through July 2017. On August 1, 2017, primarily in response to the decline in oil prices and to preserve liquidity, the Company elected to suspend Series B Preferred Stock dividends commencing August 2017, which suspension remained in effect through March 2018. Dividends on the Series B Preferred Stock will accumulate regardless of whether any such dividends are declared. If the Company has accumulated, accrued and unpaid cash dividends in any calendar month within four calendar quarters, then commencing in the calendar month following the first month in such fourth calendar quarter in which cash dividends are not paid in full, and until accumulated dividends are paid in full for four calendar quarters with the last two calendar quarters’ dividends paid in cash, (i) the fixed dividend rate of Series B Preferred Stock each increases by 2.00% per annum, (ii) the Company will be required to issue a dividend of common stock to pay accrued and unpaid dividends based on then current market value determined in accordance with the certificate of designations applicable to the Series B Preferred Stock, if such dividends are not paid in cash, provided it has sufficient capital surplus to pay such a dividend and can otherwise pay a dividend under state law, and (iii) the holders of Series A Preferred Stock and Series B Preferred Stock, voting as a single class, will have the right to elect up to two additional directors to the board of directors of the Company. If the Company’s common stock ceases to be listed on a national securities exchange or a national securities market, “pay in kind” dividends of additional shares of Series B Preferred Stock may be payable in lieu of cash or common stock dividends. For the three months ended March 31, 2018, the Company recognized undeclared cumulative dividends of $1.4 million for the Series B Preferred Stock. For the three months ended March 31, 2017, the Company paid cash dividends of $5.8 million, including $4.3 million of 2016 undeclared dividends. As of March 31, 2018, accumulated and unpaid dividends on the outstanding Series B Preferred Stock aggregated to $3.8 million, or $1.7916667 per shares. On April 9, 2018, the Company declared a special cash dividend on the Series B Preferred Stock to pay in full all accumulated and unpaid cash dividends accrued since August 1, 2017 at an annualized 10.75% through the payment date. The Series B Preferred Stock April 2018 dividend of $4.3 million was paid on April 30, 2018 to holders of record at the close of business on April 20, 2018, which paid all unpaid dividends that accumulated in respect to the Series A Preferred Stock at such time. Other Share Issuances The following table provides information regarding the issuances and forfeitures of common stock pursuant to the Company's long-term incentive plan for the periods indicated: For the Three Months Ended March 31, 2018 Other share issuances: Shares of restricted common stock granted 3,162,699 Shares of restricted common stock vested 1,598,644 Shares of restricted common stock surrendered upon vesting/exercise (1) 489,478 Shares of restricted common stock forfeited 3,175 _________________ (1) Represents shares of common stock forfeited in connection with the payment of estimated withholding taxes on shares of restricted common stock that vested during the period. On June 27, 2017, the Company’s stockholders approved an amendment to the Gastar Exploration Inc. Long-Term Incentive Plan (the “LTIP”), effective May 2, 2017, to, among other things, increase the number of shares of common stock reserved for issuance under the LTIP by 14,000,000 shares of common stock. There were 4,717,198 shares of common stock available for issuance under the LTIP at March 31, 2018. Shares Reserved At March 31, 2018, the Company had 164,400 common shares reserved for the exercise of stock options and 1,477,095 shares reserved for the settlement of performance based units.

Interest Expense

Interest Expense	3 Months Ended
	Mar. 31, 2018
Interest Expense [Abstract]
Interest Expense	9. Interest Expense The following table summarizes the components of interest expense for the periods indicated: For the Three Months Ended March 31, 2018 2017 (in thousands) Interest expense: Cash and accrued $ 2,459 $ 9,759 Paid in kind 6,629 — Amortization of deferred financing costs and debt discount 3,177 1,710 Capitalized interest (2,328 ) (620 ) Total interest expense $ 9,937 $ 10,849

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes For the three months ended March 31, 2018 and 2017, respectively, the Company did not recognize a current income tax benefit or provision as the Company has a full valuation allowance against assets created by net operating losses generated. The Company believes it more likely than not that the assets will not be utilized. The Company had no deferred income tax expense (benefit) for the three months ended March 31, 2018 and 2017. In connection with the Company’s recent equity and convertible debt transactions during 2017, the Company determined that the utilization of net operating losses in future years is subject to limitations by reason of an “ownership change” as defined under Section 382 of the Internal Revenue Code (“Section 382 Limitation”). Any utilization of the Company’s net operating loss carryforwards and other tax credit carryforwards will be subject to the Section 382 Limitation.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per Share	11. Earnings per Share In accordance with the provisions of current authoritative guidance, basic earnings or loss per share is computed on the basis of the weighted average number of common shares outstanding during the periods. Diluted earnings or loss per share is computed based upon the weighted average number of common shares outstanding plus the assumed issuance of common shares for all potentially dilutive securities. For the Three Months Ended March 31, 2018 2017 (in thousands, except per share and share data) Net loss attributable to common stockholders $ (19,129 ) $ (22,316 ) Weighted average common shares outstanding - basic 209,903,482 162,829,221 Weighted average common shares outstanding - diluted 209,903,482 162,829,221 Net loss per share of common stock attributable to common stockholders: Basic $ (0.09 ) $ (0.14 ) Diluted $ (0.09 ) $ (0.14 ) Common shares excluded from denominator as anti-dilutive: Unvested restricted shares 3,984,569 510,465 Unvested PBUs 952,579 170,858 Convertible notes 73,520,769 98,977,920 Total 78,457,917 99,659,243

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Litigation Gastar Exploration Inc. v. Christopher McArthur (Cause No.: 2015-77605) 157th Judicial District Court, Harris County, Texas. On December 29, 2015, Gastar filed suit against Christopher McArthur (“McArthur”) in the District Court of Harris County, Texas. The lawsuit arises from a demand letter sent by McArthur to Gastar in which he claimed to be party to an agreement with Gastar that entitled him to be paid $2.75 million for services rendered. In August 2016, McArthur filed an amended answer admitting he had no agreement with the Company. As a result, Gastar believes McArthur’s claim has been effectively resolved. Gastar has continued to pursue a counterclaim in this action against McArthur for tortious interference with an existing contract. McArthur has filed a general denial. Torchlight Energy Resources, Inc., Torchlight Energy, Inc. v. Husky Ventures, Inc., et al., (Cause No. 429-01961-2016) 429th Judicial District Court in Collin County, Texas. Torchlight Energy Resources, Inc. and Torchlight Energy, Inc. (collectively “Torchlight”) brought a lawsuit against the Company, two of its executive officers, its chairman of the board of directors and a former director of the Company on May 3, 2016 in Collin County, Texas (the “Torchlight Lawsuit”). The Torchlight Lawsuit arises primarily out of Torchlight’s business dealings with Husky Ventures, Inc. (“Husky”) in Oklahoma. Husky and several of its employees and affiliates are also defendants in the Torchlight Lawsuit. As part of settlement negotiations between Husky and the Company in a separate lawsuit, Husky informed the Company that it had agreed to repurchase assets from Torchlight that Husky had previously sold to Torchlight (the “Torchlight Assets”). Husky offered to sell those Torchlight Assets to the Company. In the Purchase and Sale Agreement between Torchlight and Husky (the “Purchase and Sale Agreement”), Torchlight expressly acknowledged that the Torchlight Assets were to be sold to the Company and released the Company from any claims arising out of the sale of the Torchlight Assets. Despite this release, Torchlight alleged multiple causes of action against the Company and its officers and directors arising out of the sale of the Torchlight Assets and Torchlight’s other business dealings it had with Husky. On August 17, 2016, plaintiffs nonsuited, without prejudice, their claims against the former chairman of the board. On May 22, 2017, the court granted the Company’s motion for summary judgment and dismissed all of the plaintiffs’ claims against the Company and the Company’s other officers and directors in their entirety. The Company has also filed a counterclaim against Torchlight for breach of the release in the Purchase and Sale Agreement which is still pending. PennMarc Resources II, LP, et al v. Gastar Exploration USA, Inc., et al, (Civil Action No. 17-C-214) Circuit Court of Marshall County, West Virginia. PennMarc Resources II, LP and others filed suit against the Company on October 23, 2017 in the Circuit Court of Marshall County, West Virginia. The plaintiffs are royalty owners under various leases taken by or assigned to the Company. The leases cover property in Marshall County, West Virginia. The leases are among other assets that were assigned to THQ Appalachia, LLC pursuant to a purchase and sale agreement dated February 12, 2016. The plaintiffs allege that the Company breached the leases by making deductions for post-production costs that were not authorized by the terms of the leases. The plaintiffs also allege that the unauthorized deductions were not shown on the monthly royalty statements and the failure to detail the deduction of these costs was a further breach of the leases and fraud. The plaintiffs claim of breach of contract, breach of fiduciary duty and fraudulent concealment. The plaintiffs seek compensatory damages and punitive damages. The Company is still assessing this claim and has not yet filed a response. The Company has moved to dismiss the plaintiffs’ claims and has requested that discovery be stayed until the motion is ruled on. The motion to dismiss was heard on March 23, 2018, but the court has not yet issued a ruling. Eagle Natrium LLC v. Gastar Exploration USA, Inc., Cause No. GD-14-7208, In the Court of Common Pleas of Allegheny County, Pennsylvania. On April 22, 2014, Eagle Natrium LLC (“Eagle”), a wholly-owned subsidiary of Axiall Corporation, filed a complaint against the Company in the Court of Common Pleas of Allegheny County, Pennsylvania seeking to enjoin Gastar’s hydraulic fracturing and completion operations on three wells drilled from Gastar’s Goudy pad in Marshall County, West Virginia, or conducting any activity that poses a substantial risk of harm to Eagle’s brine operations. Gastar was the operator of approximately 16,000 acres in Marshall County, West Virginia, including a 3,300 gross acre oil and gas lease adjacent to Eagle’s facilities. Eagle asserted its right to relief based on certain of the lessor’s rights which were assigned to Eagle by the lessor solely as they relate to the brine and related facilities. A hearing on the request for preliminary injunction was held in the summer of 2014. After considering the evidence presented at the hearing and the party’s briefing, the court issued an order on October 21, 2014 denying the request for a preliminary injunction. In January 2015, Gastar began completion operations and has since completed the three wells drilled from its Goudy pad that formed the basis of Eagle’s complaint. In 2016, the Company amended its answer and has added counterclaims seeking damages from Eagle as a result of the proceedings. Specifically, Gastar has asserted a breach of contract claim, seeking damages for lost revenues, rig up and rig down costs and attorney’s fees relating to the Pennsylvania lawsuit filed by Eagle. Eagle has also maintained its breach of contract claim against the Company. The Court held a hearing on competing motions for summary judgment on April 27, 2018 and has taken those motions under advisement. The Court bifurcated liability and damages and the liability trial is scheduled to begin on June 25, 2018. The Company has been expensing legal costs on these proceedings as they are incurred. The Company is party to various legal proceedings arising in the normal course of business. The ultimate outcome of each of these matters cannot be absolutely determined, and the liability the Company may ultimately incur with respect to any one of these matters in the event of a negative outcome may be in excess of amounts currently accrued for with respect to such matters. Net of available insurance and performance of contractual defense and indemnity obligations, where applicable, management does not believe any such matters will have a material adverse effect on the Company’s financial position, results of operations or cash flows.

Statement of Cash Flows - Suppl

Statement of Cash Flows - Supplemental Information	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Statement of Cash Flows - Supplemental Information	13. Statement of Cash Flows – Supplemental Information The following is a summary of the supplemental cash paid and non-cash transactions for the periods indicated: For the Three Months Ended March 31, 2018 2017 (in thousands) Cash paid for interest, net of capitalized amounts $ 111 $ 11,721 Non-cash transactions: Capital expenditures included in accounts payable and accrued drilling costs $ (6,046 ) $ 3,072 Capital expenditures excluded from prepaid expenses $ (88 ) $ — Asset retirement obligation included in oil and natural gas properties $ 45 $ 230 Asset retirement obligation sold $ (2,581 ) $ (1,533 ) Application of advances to operators $ 1 $ 16 Non-cash financing charges excluded from accounts payable and accrued liabilities $ — $ 585 Undeclared cumulative dividends on preferred stock $ 3,618 $ —

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Pursuant to Amendment No. 2 to the Term Loan, on April 2, 2018, the Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 2, 2018 in the amount of $6.7 million, thus increasing the outstanding principal balance of the Term Loan to $269.7 million at such time. On April 9, 2018, the Company declared a special cash dividend on the Series A Preferred Stock and Series B Preferred Stock to pay in full all accumulated and unpaid cash dividends accrued since August 1, 2017 at an annualized 8.625% and 10.75%, respectively, through the payment date. The Series A Preferred Stock April 2018 dividend of $6.5 million was paid on April 30, 2018 to holders of record at the close of business on April 20, 2018, which paid all unpaid dividends that accumulated in respect to the Series A Preferred Stock at such time. The Series B Preferred Stock April 2018 dividend of $4.3 million was paid on April 30, 2018 to holders of record at the close of business on April 20, 2018, which paid all unpaid dividends that accumulated in respect to the Series A Preferred Stock at such time.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Accounting	The unaudited interim condensed consolidated financial statements of the Company included herein are stated in U.S. dollars and were prepared from the records of the Company by management in accordance with U.S. GAAP applicable to interim financial statements and reflect all normal and recurring adjustments, which are, in the opinion of management, necessary to provide a fair presentation of the results of operations and financial position for the interim periods. Such financial statements conform to the presentation reflected in the 2017 Form 10-K except for revenue which, for the three months ended March 31, 2018, is presented net of treating, transportation and gathering costs pursuant to current authoritative accounting guidance. The current interim period reported herein should be read in conjunction with the financial statements and accompanying notes, including Item 8. “Financial Statements and Supplementary Data, Note 2 – Summary of Significant Accounting Policies,” included in the 2017 Form 10-K.
Subsequent Events	Subsequent Events In preparing these financial statements, the Company has evaluated events and transactions for potential recognition or disclosure through the date the financial statements were issued and has disclosed certain subsequent events in these condensed consolidated financial statements, as appropriate.
Accounts Receivable	Accounts Receivable Accounts receivable are reported net of the allowance for doubtful accounts. The allowance for doubtful accounts is determined based on a review of the Company’s receivables. Receivable accounts are charged off when collection efforts have failed or the account is deemed uncollectible. During 2016, the Company determined that a receivable account from a third-party natural gas and NGLs purchaser would no longer be collectible as a result of the third-party purchaser filing for bankruptcy. A summary of the activity related to the allowance for doubtful accounts is as follows: March 31, 2018 December 31, 2017 (in thousands) Allowance for doubtful accounts, beginning of period $ 1,953 $ 1,953 Expense — — Reductions/write-offs — — Allowance for doubtful accounts, end of period $ 1,953 $ 1,953
Recent Accounting Developments	Recent Accounting Developments Business Combinations. In January 2017, the FASB issued updated guidance to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments in this update provide a screen to determine when a set is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. The amendments in this update affect all reporting entities that must determine whether they have acquired or sold a business and are effective for public business entities for annual reporting periods beginning after December 15, 2017, including interim periods within those periods. The amendments should be applied prospectively on or after the effective date and no disclosures are required at transition. The Company adopted this updated guidance for the fiscal year beginning January 1, 2018. The application of this guidance to future acquisitions and disposals could have an immediate effect on the Company’s financial position or results of operations. Statement of Cash Flows. In August 2016, the FASB issued updated guidance associated with the classification of certain cash receipts and cash payments on the statement of cash flows. The amended guidance addresses specific cash flow issues with the objective of reducing existing diversity in practice. The amendment provides guidance on the following eight specific cash flow issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The amendments in this update apply to all entities required to present a statement of cash flows. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. Amendments should be applied using a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. The Company adopted this update guidance for the fiscal year beginning January 1, 2018 and has determined that such adoption does not have a material effect on its statement of cash flows nor does it affect the Company’s financial position or results of operations. Leases. In February 2016, the FASB issued updated guidance to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and enhance disclosures regarding key information about leasing arrangements. Under the new guidance, lessees will be required to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplified the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Additionally, in January 2018, the FASB issued an amendment to the updated guidance to permit an entity to elect an optional transition practical expedient to not evaluate under the new guidance land easements that exist or expire before the adoption of the updated guidance and that were not previously accounted for as leases under previous guidance. The amendments in this update are effective beginning on January 1, 2019 and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. The Company has commenced analyzing its lease contracts but has not yet determined what the effects of adopting this updated guidance will be on its consolidated financial statements. Revenue Recognition. In May 2014, the FASB issued an amendment to previously issued guidance regarding the recognition of revenue, which supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, “Revenue Recognition,” (“ASC 605”) and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this core principle, an entity should apply the following steps: (1) identify the contract(s) with the customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. In 2015, the FASB delayed the effective date one year, beginning in fiscal year 2018. On January 1, 2018, the Company adopted Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“ASC 606”) using the modified retrospective method of transition. Under the modified retrospective approach, the standard has been applied to all existing contracts as of the date of initial application with the cumulative effect of applying the standard, if any, recognized in retained earnings. In order to determine the impact of adoption, the Company evaluated a representative sample of revenue contracts related to its oil, natural gas and NGLs revenues. For these contracts, the Company reviewed the contract provisions and evaluated the contracts under the new standard to assess the impact on the quantum and timing of revenue recognition and presentation of revenues on adoption of the new guidance. The Company believes that it has identified all material contract types and contractual features that represent the Company’s revenue. The impact of adoption on our current period results is as follows: Three Months Ended March 31, 2018 Under ASC 606 Under ASC 605 Increase (Decrease) (in thousands) Revenues: Oil and condensate $ 20,982 $ 20,992 $ (10 ) Natural gas 2,181 2,756 (575 ) NGLs 3,275 3,623 (348 ) Total oil and condensate, natural gas and NGLs revenues $ 26,438 $ 27,371 $ (933 ) Expenses: Transportation, treating and gathering $ — 933 $ (933 ) Net income (loss) $ 26,438 $ 26,438 $ — Retained earnings $ 26,438 $ 26,438 $ — The primary impact to our revenues as a result of the adoption of ASC 606 is the recording of transportation, treating, gathering and compression expenses (“Post-Production Expenses”) as a direct reduction to revenues instead of our historical practice of presenting such expenses gross in transportation, treating and gathering. These changes are due to the conclusion that the Company represents the agent in the sale of natural gas and NGLs under its gas processing and marketing agreements with midstream entities in accordance with the control model in ASC 606. As a result, the Company is required to record revenue on a net basis for amounts expected to be received from third-party customers through the marketing process, with Post-Production Expenses incurred subsequent to control of the product(s) transferring to the midstream entity at the wellhead being netted against revenue.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Summary of the activity related to the allowance for doubtful accounts	A summary of the activity related to the allowance for doubtful accounts is as follows: March 31, 2018 December 31, 2017 (in thousands) Allowance for doubtful accounts, beginning of period $ 1,953 $ 1,953 Expense — — Reductions/write-offs — — Allowance for doubtful accounts, end of period $ 1,953 $ 1,953
ASU 2014-09
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Schedule of Impact of Adoption	The impact of adoption on our current period results is as follows: Three Months Ended March 31, 2018 Under ASC 606 Under ASC 605 Increase (Decrease) (in thousands) Revenues: Oil and condensate $ 20,982 $ 20,992 $ (10 ) Natural gas 2,181 2,756 (575 ) NGLs 3,275 3,623 (348 ) Total oil and condensate, natural gas and NGLs revenues $ 26,438 $ 27,371 $ (933 ) Expenses: Transportation, treating and gathering $ — 933 $ (933 ) Net income (loss) $ 26,438 $ 26,438 $ — Retained earnings $ 26,438 $ 26,438 $ —

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization	The following table summarizes the components of unproved properties excluded from amortization at the dates indicated: March 31, 2018 December 31, 2017 (in thousands) Unproved properties, excluded from amortization: Drilling in progress costs $ 6,410 $ 4,772 Acreage acquisition costs 113,531 113,191 Capitalized interest 16,237 13,992 Total unproved properties excluded from amortization $ 136,178 $ 131,955
Schedule Of Relevant Assumptions Used In Ceiling Test Computations	The table below sets forth relevant pricing assumptions utilized in the quarterly ceiling test computations for the respective periods noted before adjustment for basis and quality differentials: 2018 Total Year to Date Impairment March 31 Henry Hub natural gas price (per MMBtu) (1) $ 3.00 WTI oil price (per Bbl) (1) $ 53.49 Impairment recorded (pre-tax) (in thousands) $ — $ — 2017 Total Year to Date Impairment March 31 Henry Hub natural gas price (per MMBtu) (1) $ 2.73 WTI oil price (per Bbl) (1) $ 47.61 Impairment recorded (pre-tax) (in thousands) $ — $ — (1) For the respective periods, oil and natural gas prices are calculated using the trailing 12-month unweighted arithmetic average of the first-day-of-the-month prices based on Henry Hub spot natural gas prices and WTI spot oil prices.
WEHLU
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information	As a result, certain estimates and judgments were made in preparing the pro forma adjustments. For the Three Months Ended March 31, 2018 2017 (in thousands, except (Unaudited) Revenues $ 14,173 $ 8,579 Net Loss $ (21,382 ) $ (26,397 ) Loss per share: Basic $ (0.10 ) $ (0.16 ) Diluted $ (0.10 ) $ (0.16 )

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Summary of Reconciliation of Long-Term Debt Balance	The table below provides a reconciliation of the Company’s long-term debt balance as presented in the condensed consolidated balance sheets for the periods presented: March 31, 2018 December 31, 2017 (in thousands) Term Loan, principal balance (1) $ 263,229 $ 256,599 Less: Unamortized deferred financing costs (2) (4,493 ) (4,724 ) Unamortized debt discount (2) (21,676 ) (22,464 ) Term Loan, net $ 237,060 $ 229,411 Notes, principal balance $ 162,500 $ 162,500 Less: Unamortized deferred financing costs (2) (2,496 ) (2,631 ) Unamortized debt discount (2) (44,306 ) (46,328 ) Notes, net $ 115,698 $ 113,541 Total long-term debt $ 352,758 $ 342,952 (1) Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end. (2) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method.
Summary of Carrying Amount of Equity Components of Notes Recorded in Additional Paid in Capital	The carrying amount of the equity components of the Notes recorded in additional paid in capital for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Value of conversion option $ 77,626 $ 77,626 Debt issuance costs attributable to conversion option $ (2,164 ) $ (2,164 ) Total $ 75,462 $ 75,462
Notes
Summary of Carrying Amount of Long-Term debt	The carrying amount of the liability component of the Notes for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Notes, principal balance $ 162,500 $ 162,500 Less: Unamortized deferred financing costs (1) (2,496 ) (2,631 ) Unamortized debt discount (1) (44,306 ) (46,328 ) Notes, net $ 115,698 $ 113,541 (1) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Notes based on the effective interest method.
Term Loan
Summary of Carrying Amount of Long-Term debt	The carrying amount of the Term Loan for the periods indicated are as follows: March 31, 2018 December 31, 2017 (in thousands) Term Loan, principal balance (1) $ 263,229 $ 256,599 Less: Unamortized deferred financing costs (2) (4,493 ) (4,724 ) Unamortized debt discount (2) (21,676 ) (22,464 ) Term loan, net $ 237,060 $ 229,411 (1) Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end. (2) The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan based on the effective interest method.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following tables set forth by level within the fair value hierarchy the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of March 31, 2018 and December 31, 2017: Fair value as of March 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets: Commodity derivative contracts — — 542 542 Liabilities: Commodity derivative contracts — — (9,567 ) (9,567 ) Total $ — $ — $ (9,025 ) $ (9,025 ) Fair value as of December 31, 2017 Level 1 Level 2 Level 3 Total (in thousands) Assets: Commodity derivative contracts — — 1,370 1,370 Liabilities: Commodity derivative contracts — — (6,988 ) (6,988 ) Total $ — $ — $ (5,618 ) $ (5,618 )
Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation	The table below presents a reconciliation of the assets and liabilities classified as Level 3 in the fair value hierarchy for the three months ended March 31, 2018 and 2017. Level 3 instruments presented in the table consist of net derivatives that, in management’s opinion, reflect the assumptions a marketplace participant would have used at March 31, 2018 and 2017. Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ (5,618 ) $ 7,512 Total (losses) gains included in earnings (5,529 ) 1,300 Purchases 552 470 Issuances — — Settlements (1) 1,570 (2,805 ) Balance at end of period $ (9,025 ) $ 6,477 The amount of total losses for the period included in earnings attributable to the change in mark to market of commodity derivatives contracts still held at March 31, 2018 and 2017 $ (3,326 ) $ (582 ) (1) Included in gain (loss) on commodity derivatives contracts on the condensed consolidated statements of operations.

Revenue from Contracts with C25

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Disaggregation of Revenues and Reconciliation of Total Revenues	The following represents a disaggregation of revenues and a reconciliation of total revenues as reported in the condensed consolidated statement of operations to revenue from contracts with customers: For the Three Months Ended March 31, 2018 March 31, 2017 (1) (in thousands) Revenues Oil and condensate $ 20,982 $ 12,190 Natural gas 2,181 2,588 NGLs 3,275 2,591 Total revenues from contracts with customers $ 26,438 $ 17,369 (Loss) gain on commodity derivatives contracts (5,529 ) 1,300 Total revenues and other (loss) gain $ 20,909 $ 18,669 (1) Prior period amounts have not been adjusted under the modified retrospective method.

Derivative Instruments and He26

Derivative Instruments and Hedging Activity (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative [Line Items]
Summary of Information Regarding Deferred Put Premium Liabilities	The following table provides information regarding the deferred put premium liabilities for the periods indicated: March 31, 2018 December 31, 2017 (in thousands) Current commodity derivative put premium payable $ 102 $ 135 Total unamortized put premium liabilities $ 102 $ 135 For the Three Months Ended March 31, 2018 (in thousands) Put premium liabilities, beginning balance $ 135 Settlement of put premium liabilities (33 ) Additional put premium liabilities — Put premium liabilities, ending balance $ 102
Summary of Information on the Location and Amounts of Commodity Derivative Fair Values and Commodity Derivative Gains and Losses	The tables below provide information on the location and amounts of derivative fair values in the condensed consolidated statement of financial position and derivative gains and losses in the condensed consolidated statement of operations for derivative instruments that are not designated as hedging instruments: Fair Values of Derivative Instruments Derivative Assets (Liabilities) Fair Value Balance Sheet Location March 31, 2018 December 31, 2017 (in thousands) Derivatives not designated as hedging instruments Commodity derivative contracts Current assets $ 542 $ 1,370 Commodity derivative contracts Current liabilities (6,278 ) (4,416 ) Commodity derivative contracts Long-term liabilities (3,289 ) (2,572 ) Total derivatives not designated as hedging instruments $ (9,025 ) $ (5,618 ) Amount of Gain (Loss) Recognized in Income on Derivatives For the Three Months Ended March 31, Location of Loss Recognized in Income on Derivatives 2018 2017 (in thousands) Derivatives not designated as hedging instruments Commodity derivative contracts Loss on commodity derivatives contracts $ (5,529 ) $ 1,300 Total $ (5,529 ) $ 1,300
Natural Gas
Derivative [Line Items]
Schedule of Notional Amounts and Weighted Average Underlying Hedge Prices of Outstanding Derivative Positions	As of March 31, 2018, the following natural gas derivative transactions were outstanding with the associated notional volumes and weighted average underlying hedge prices: Settlement Period Derivative Instrument Average Daily Volume Total of Notional Volume Base Fixed Price Floor (Long) Short Put Ceiling (Short) (in MMBtus) April to December 2018 Costless three-way collar 5,000 1,375,000 $ — $ 3.00 $ 2.35 $ 4.00 April to December 2018 Fixed price swap 1,550 426,250 $ 3.01 $ — $ — $ —
Crude Oil
Derivative [Line Items]
Schedule of Notional Amounts and Weighted Average Underlying Hedge Prices of Outstanding Derivative Positions	As of March 31, 2018, the following crude derivative transactions were outstanding with the associated notional volumes and weighted average underlying hedge prices: Settlement Period Derivative Instrument Average Daily Volume (1) Total of Notional Volume Base Fixed Price Floor (Long) Short Put Ceiling (Short) (in Bbls) April to June 2018 Costless three-way collar 1,700 154,700 $ — $ 47.50 $ 37.50 $ 57.85 July to September 2018 Costless three-way collar 1,600 147,200 $ — $ 47.50 $ 37.50 $ 57.85 October to December 2018 Costless three-way collar 1,700 156,400 $ — $ 47.50 $ 37.50 $ 57.85 April 2018 Fixed price swap 125 3,750 $ 66.45 $ — $ — $ — April 2018 Fixed price swap 477 14,310 $ 51.20 $ — $ — $ — April to December 2018 Fixed price swap 500 137,500 $ 61.60 $ — $ — $ — May 2018 Fixed price swap 325 10,075 $ 66.45 $ — $ — $ — May 2018 Fixed price swap 492 15,252 $ 51.20 $ — $ — $ — June 2018 Fixed price swap 600 18,000 $ 51.20 $ — $ — $ — June to August 2018 Fixed price swap 425 39,100 $ 66.45 $ — $ — $ — July to September 2018 Fixed price swap 500 46,000 $ 51.20 $ — $ — $ — October to December 2018 Fixed price swap 600 55,200 $ 51.20 $ — $ — $ — January to September 2019 Costless three-way collar 2,000 546,000 $ — $ 47.50 $ 37.50 $ 59.70 October to December 2019 Costless three-way collar 1,900 174,800 $ — $ 47.50 $ 37.50 $ 59.70 January to September 2019 Fixed price swap 700 191,100 $ 50.40 $ — $ — $ — October to November 2019 Fixed price swap 600 36,600 $ 50.40 $ — $ — $ — December 2019 Fixed price swap 416 12,896 $ 50.40 $ — $ — $ — (1) Crude volumes hedged include oil, condensate and certain components of our NGLs production.

Capital Stock (Tables)

Capital Stock (Tables)	3 Months Ended
	Mar. 31, 2018
Stockholders Equity Note [Abstract]
Schedule of Issuances And Forfeitures Of Common Shares	The following table provides information regarding the issuances and forfeitures of common stock pursuant to the Company's long-term incentive plan for the periods indicated: For the Three Months Ended March 31, 2018 Other share issuances: Shares of restricted common stock granted 3,162,699 Shares of restricted common stock vested 1,598,644 Shares of restricted common stock surrendered upon vesting/exercise (1) 489,478 Shares of restricted common stock forfeited 3,175 _________________ (1) Represents shares of common stock forfeited in connection with the payment of estimated withholding taxes on shares of restricted common stock that vested during the period.

Interest Expense (Tables)

Interest Expense (Tables)	3 Months Ended
	Mar. 31, 2018
Interest Expense [Abstract]
Schedule Of Components Of Interest Expense	The following table summarizes the components of interest expense for the periods indicated: For the Three Months Ended March 31, 2018 2017 (in thousands) Interest expense: Cash and accrued $ 2,459 $ 9,759 Paid in kind 6,629 — Amortization of deferred financing costs and debt discount 3,177 1,710 Capitalized interest (2,328 ) (620 ) Total interest expense $ 9,937 $ 10,849

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	For the Three Months Ended March 31, 2018 2017 (in thousands, except per share and share data) Net loss attributable to common stockholders $ (19,129 ) $ (22,316 ) Weighted average common shares outstanding - basic 209,903,482 162,829,221 Weighted average common shares outstanding - diluted 209,903,482 162,829,221 Net loss per share of common stock attributable to common stockholders: Basic $ (0.09 ) $ (0.14 ) Diluted $ (0.09 ) $ (0.14 ) Common shares excluded from denominator as anti-dilutive: Unvested restricted shares 3,984,569 510,465 Unvested PBUs 952,579 170,858 Convertible notes 73,520,769 98,977,920 Total 78,457,917 99,659,243

Statement of Cash Flows - Sup30

Statement of Cash Flows - Supplemental Information (Tables)	3 Months Ended
	Mar. 31, 2018
Supplemental Cash Flow Information [Abstract]
Statement of Cash Flows Supplemental Information	The following is a summary of the supplemental cash paid and non-cash transactions for the periods indicated: For the Three Months Ended March 31, 2018 2017 (in thousands) Cash paid for interest, net of capitalized amounts $ 111 $ 11,721 Non-cash transactions: Capital expenditures included in accounts payable and accrued drilling costs $ (6,046 ) $ 3,072 Capital expenditures excluded from prepaid expenses $ (88 ) $ — Asset retirement obligation included in oil and natural gas properties $ 45 $ 230 Asset retirement obligation sold $ (2,581 ) $ (1,533 ) Application of advances to operators $ 1 $ 16 Non-cash financing charges excluded from accounts payable and accrued liabilities $ — $ 585 Undeclared cumulative dividends on preferred stock $ 3,618 $ —

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Schedule of Allowance for Doubtful Accounts) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for doubtful accounts, beginning of period	$ 1,953	$ 1,953
Expense	0	0
Reductions/write-offs	0	0
Allowance for doubtful accounts, end of period	$ 1,953	$ 1,953

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Schedule of Impact of Adoption) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES:
Oil and condensate	$ 20,982	$ 12,190
Natural gas	2,181	2,588
NGLs	3,275	2,591
Total oil, condensate, natural gas and NGLs revenues	26,438	17,369
EXPENSES:
Transportation, treating and gathering	0	$ 311
Net income (loss)	26,438
Retained earnings	26,438
Under ASC 605 | ASU 2014-09
REVENUES:
Oil and condensate	20,992
Natural gas	2,756
NGLs	3,623
Total oil, condensate, natural gas and NGLs revenues	27,371
EXPENSES:
Transportation, treating and gathering	933
Net income (loss)	26,438
Retained earnings	26,438
Increase (Decrease) | ASU 2014-09
REVENUES:
Oil and condensate	(10)
Natural gas	(575)
NGLs	(348)
Total oil, condensate, natural gas and NGLs revenues	(933)
EXPENSES:
Transportation, treating and gathering	$ (933)

Property, Plant and Equipment33

Property, Plant and Equipment (Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Unproved properties, excluded from amortization:
Drilling in progress costs	$ 6,410	$ 4,772
Acreage acquisition costs	113,531	113,191
Capitalized interest	16,237	13,992
Total unproved properties excluded from amortization	$ 136,178	$ 131,955

Property, Plant and Equipment34

Property, Plant and Equipment (Narrative) (Details) $ in Thousands	Jan. 23, 2018USD ($)	Oct. 02, 2017USD ($)	Mar. 22, 2017USD ($)awell	Oct. 14, 2016awellTownshipTranche	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017well
Property, Plant and Equipment [Line Items]
Fair market value, discounted present rate					10.00%
Proceeds from sale of natural gas and oil properties | $					$ 97,571	$ 13,150
Acquisition of oil and natural gas properties | $					$ 0	$ 54,498
STACK Leasehold Acquisition
Property, Plant and Equipment [Line Items]
Gross wells			66
Net wells			9.5
Net acres | a			5,670
Acquisition of oil and natural gas properties | $			$ 51,400
Sale Agreement
Property, Plant and Equipment [Line Items]
Consideration on sale of property | $	$ 107,500
Proceeds from sale of natural gas and oil properties | $		$ 97,600
Development Agreement
Property, Plant and Equipment [Line Items]
Number of wells completed							20
Number of wells completed, net							15.8
Development Agreement | Parent Company
Property, Plant and Equipment [Line Items]
Number of wells completed, net							3.2
Development Agreement | Investor
Property, Plant and Equipment [Line Items]
Fair market value, discounted present rate					15.00%
Development Agreement | Oklahoma
Property, Plant and Equipment [Line Items]
Investor funding percentage on working interest portion of drilling and completion cost				90.00%
Investors percentage of Gastar's working interest in each new well				80.00%
Percentage of costs paid to obtain 20% working interest				10.00%
Percentage on working interest in each new well				20.00%
Number of tranches | Tranche				3
Number of wells in each tranche				20
Number of wells in Meramec formation				18
Number of wells in Osage formation				2
Percentage of internal rate of return one				15.00%
Percentage of working interest on achievement of 15% internal rate of return				60.00%
Percentage of internal rate of return two				20.00%
Percentage of working interest on achievement of 20% internal rate of return				90.00%
Description of working interest on achievement of internal rate of returns				With respect to each 20-well tranche, when the Investor has achieved an aggregate 15% internal rate of return for its investment in the tranche, Investor’s interest will be reduced from 80% to 40% of the Company’s original working interest and the Company’s working interest increases from 20% to 60% of the original working interest. When a tranche internal rate of return of 20% is achieved by the Investor, Investor’s working interest decreases to 10% and the Company’s working interest increases to 90% of the working interest originally owned by the Company.
Development Agreement | Oklahoma | Investor
Property, Plant and Equipment [Line Items]
Percentage of working interest on achievement of 15% internal rate of return				40.00%
Percentage of working interest on achievement of 20% internal rate of return				10.00%
Development Agreement | Oklahoma | Investor
Property, Plant and Equipment [Line Items]
Net acres | a				21,200
Number of townships covered | Township				3
Gross acres | a				32,900
Development Agreement | Oklahoma | Investor | Maximum
Property, Plant and Equipment [Line Items]
Number of operated wells				60
Revenues and Direct Operating Expenses | Sale Agreement
Property, Plant and Equipment [Line Items]
Adjustments related to revenues and direct operating expenses | $		$ 8,700

Property, Plant and Equipment35

Property, Plant and Equipment (Average Sales Price and Production Costs Per Unit of Production) (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2018USD ($)$ / MMBTU$ / bbl	Mar. 31, 2017USD ($)$ / MMBTU$ / bbl
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Impairment recorded (pre-tax) | $		$ 0	$ 0
Natural Gas Per Thousand Cubic Feet
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average price | $ / MMBTU	[1]	3	2.73
Crude Oil And N G L Per Barrel
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average price | $ / bbl	[1]	53.49	47.61
[1]	For the respective periods, oil and natural gas prices are calculated using the trailing 12-month unweighted arithmetic average of the first-day-of-the-month prices based on Henry Hub spot natural gas prices and WTI spot oil prices.

Property, Plant And Equipment36

Property, Plant And Equipment (Schedule of Pro Forma Information) (Details) - WEHLU - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Revenues	$ 14,173	$ 8,579
Net Loss	$ (21,382)	$ (26,397)
Loss per share, Basic	$ (0.10)	$ (0.16)
Loss per share, Diluted	$ (0.10)	$ (0.16)

Long-Term Debt - Reconciliation

Long-Term Debt - Reconciliation of Long-Term Debt Balance (Details) - USD ($) $ in Thousands		Mar. 31, 2018		Dec. 31, 2017		Mar. 03, 2017
Line of Credit Facility [Line Items]
Total long-term debt		$ 352,758		$ 342,952
Notes
Line of Credit Facility [Line Items]
Principal balance		162,500		162,500
Unamortized deferred financing costs		(2,496)	[1]	(2,631)	[1]	$ (5,400)
Unamortized debt discount		(44,306)	[1]	(46,328)	[1]	(52,400)
Long term loan, net		115,698		113,541
Term Loan
Line of Credit Facility [Line Items]
Principal balance	[2],[3]	263,229		256,599
Unamortized deferred financing costs		(4,493)	[1]	(4,724)	[1]	(5,500)
Unamortized debt discount		(21,676)	[1]	(22,464)	[1]	$ (25,200)
Long term loan, net		$ 237,060		$ 229,411
[1]	The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method.
[2]	Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.
[3]	Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.

Long-Term Debt - Reconciliati38

Long-Term Debt - Reconciliation of Long-Term Debt Balance (Parenthetical) (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended	18 Months Ended
		Apr. 02, 2018	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Jan. 02, 2018	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Kind interest due, amount				$ 6,629	$ 0
Term Loan
Line of Credit Facility [Line Items]
Principal balance	[1],[2]			$ 263,229				$ 256,599
Term Loan | Amendment No. 2
Line of Credit Facility [Line Items]
Percentage of interest pay in kind						100.00%
Kind interest due, amount						$ 13,200
Principal balance						$ 263,200
Term Loan | Amendment No. 2 | Subsequent Event
Line of Credit Facility [Line Items]
Percentage of interest pay in kind		100.00%	100.00%
Kind interest due, amount		$ 6,700	$ 6,500
Principal balance		$ 269,700
Term Loan | Amendment No. 2 | Scenario, Forecast
Line of Credit Facility [Line Items]
Percentage of interest pay in kind							100.00%
[1]	Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.
[2]	Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)

Aug. 02, 2017

May 05, 2017

May 02, 2017

Mar. 03, 2017

Mar. 31, 2018

Mar. 31, 2017

Jan. 02, 2018

Dec. 31, 2016

Dec. 31, 2017

Jun. 30, 2017

May 04, 2017

Apr. 30, 2017

Mar. 21, 2017

Feb. 15, 2017

Jan. 10, 2017

Line of Credit Facility [Line Items]

Proceeds from issuance of common stock, net of issuance costs

$ 0

$ 56,366,000

Common stock volume weighted average trading price per share

$ 1.7002

Revolving Credit Facility

Line of Credit Facility [Line Items]

Repayment of debt

$ 69,200,000

Convertible Notes due 2022

Line of Credit Facility [Line Items]

Aggregate principal amount

162,500,000

$ 162,500,000

Term loan amount

$ 115,698,000

113,541,000

Interest rate

6.00%

Debt instrument maturity date

Mar. 1, 2022

Debt instrument fair value

$ 147,800,000

Debt discount

52,400,000

$ 44,306,000

[1]

46,328,000

[1]

Debt issuance costs

5,400,000

$ 2,496,000

[1]

2,631,000

[1]

Debt instrument, default, description

The Indenture provides that a number of events will constitute an Event of Default (as defined in the Indenture), including, among other things: (i) a failure to pay the Notes when due at maturity, upon redemption or repurchase; (ii) failure to pay interest for 30 days; (iii) the Company’s failure to deliver certain notices; (iv) a default in the Company’s obligation to convert the Notes; (v) the Company’s failure to comply with certain covenants relating to merger, consolidation or sale of assets; (vi) the Company’s failure to comply, for 60 days following notice, with any of the other covenants or agreements in the Indenture; (vii) a default, which is not cured within 30 days, by the Company or any Restricted Subsidiaries (as defined in the Indenture) with respect to any mortgages or any indebtedness for money borrowed of at least $15 million; (viii) one or more final judgments against the Company or any of its Restricted Subsidiaries for the payment of at least $15 million; (ix) the Company’s failure to make any payments required under that certain development agreement, which is not cured within 30 days; (x) causing any Guarantee (as defined in the Indenture) to cease to be in full force and effect; (xi) the cessation to be in full force and effect of any of the collateral agreements entered into with respect to the Notes; and (xii) certain events of bankruptcy or insolvency.

Debt instrument, debt default, amount

$ 15,000,000

Aggregate principal amount of the then outstanding notes, percentage

25.00%

Value of conversion option

$ 77,600,000

$ 77,626,000

77,626,000

Debt issuance costs related to liability component notes

3,200,000

Debt issuance costs related to equity component notes

$ 2,200,000

$ 2,164,000

2,164,000

Amortization of debt issuance costs percentage

16.00%

Senior Secured Notes Due 2018

Line of Credit Facility [Line Items]

Aggregate principal amount

$ 325,000,000

Interest rate

8.625%

Debt instrument redemption price percentage

102.156%

Redemption date

Mar. 24, 2017

Debt instrument maturity date

May 15, 2018

Additional amount paid on redemption over principle

$ 7,000,000

Wrote-off of remaining unamortized deferred financing costs

$ 5,200,000

Second Amended and Restated Revolving Credit Facility

Line of Credit Facility [Line Items]

Revolving credit facility scheduled maturity date

Nov. 14, 2017

Amendment No. 10

Line of Credit Facility [Line Items]

Preferred dividends payment, minimum required cash liquidity

$ 30,000,000

Agreed additional indebtedness to pay down

$ 8,100,000

First Lien Secured Term Loan

Line of Credit Facility [Line Items]

Aggregate principal amount

[2],[3]

$ 263,229,000

256,599,000

Term loan amount

$ 237,060,000

229,411,000

Interest rate

8.50%

Frequency of interest payment

quarterly

Debt instrument maturity date

Mar. 3, 2022

Debt instrument fair value

$ 224,800,000

Debt discount

25,200,000

$ 21,676,000

[1]

22,464,000

[1]

Debt issuance costs

$ 5,500,000

$ 4,493,000

[1]

$ 4,724,000

[1]

Debt instrument effective interest rate percentage

13.00%

First Lien Secured Term Loan | Amendment No. 2

Line of Credit Facility [Line Items]

Aggregate principal amount

$ 263,200,000

Interest rate

10.25%

8.50%

Debt instrument, payment terms

Amendment No. 2 amended the Term Loan, to among other things, (i) allow for the payment of pay in kind (“PIK”) interest on the Term Loan at the applicable PIK percentage and (ii) increased the applicable rate for periods ending after June 30, 2017 from 8.5% per annum to 10.25% per annum. Amendment No. 2 allows the Company to elect to PIK upon proper notice 100% of interest payments due after June 30, 2017 and prior to December 31, 2018 and at the Company’s election, PIK between 0% and 50% of any interest payments occurring after December 31, 2018 (other than interest due on the maturity date or the date of any repayment or prepayment).

Percentage of interest pay in kind

100.00%

First Lien Secured Term Loan | Amendment No. 2 | June 30, 2017 to December 31, 2018

Line of Credit Facility [Line Items]

Percentage of interest pay in kind

100.00%

First Lien Secured Term Loan | Amendment No. 2 | Minimum | After December 31, 2018

Line of Credit Facility [Line Items]

Percentage of interest pay in kind

0.00%

First Lien Secured Term Loan | Amendment No. 2 | Maximum | After December 31, 2018

Line of Credit Facility [Line Items]

Percentage of interest pay in kind

50.00%

Securities Purchase Agreement | Common Stock

Line of Credit Facility [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

25,456,521

Ares Management, LLC | Senior Secured Notes Due 2018

Line of Credit Facility [Line Items]

Aggregate principal amount

$ 325,000,000

Ares Management, LLC | Securities Purchase Agreement

Line of Credit Facility [Line Items]

Aggregate principal amount

$ 75,000,000

Interest rate

8.625%

Debt instrument redemption price percentage

102.156%

Redemption date

Mar. 24, 2017

Aggregate principal amount, exchanged

$ 37,500,000

Repurchase share, issued

$ 1.4731

Aggregate principle amount of issued and outstanding notes

$ 162,500,000

$ 200,000,000

Common stock volume weighted average trading price per share

$ 1.7002

Ares Management, LLC | Securities Purchase Agreement | Common Stock

Line of Credit Facility [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

25,456,521

29,408,305

Proceeds from issuance of common stock, net of issuance costs

$ 50,000,000

Ares Management, LLC | Securities Purchase Agreement | Special Voting Preferred Stock

Line of Credit Facility [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

2,000

Preferred stock, par value

$ 0.01

Ares Management, LLC | Securities Purchase Agreement | Convertible Notes due 2022

Line of Credit Facility [Line Items]

Aggregate principal amount

125,000,000

Ares Management, LLC | Securities Purchase Agreement | Senior Secured Notes Due 2018

Line of Credit Facility [Line Items]

Repayment of debt

325,000,000

Ares Management, LLC | Securities Purchase Agreement | First Lien Secured Term Loan

Line of Credit Facility [Line Items]

Term loan amount

$ 250,000,000

[1]

The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method.

[2]

Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.

[3]

Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.

Long-Term Debt - Summary of Car

Long-Term Debt - Summary of Carrying Amount of Term Loan (Details) - Term Loan - USD ($) $ in Thousands		Mar. 31, 2018		Dec. 31, 2017		Mar. 03, 2017
Line of Credit Facility [Line Items]
Principal balance	[1],[2]	$ 263,229		$ 256,599
Unamortized deferred financing costs		(4,493)	[3]	(4,724)	[3]	$ (5,500)
Unamortized debt discount		(21,676)	[3]	(22,464)	[3]	$ (25,200)
Long term loan, net		$ 237,060		$ 229,411
[1]	Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.
[2]	Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.
[3]	The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method.

Long-Term Debt - Summary of C41

Long-Term Debt - Summary of Carrying Amount of Term Loan (Parenthetical) (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended	18 Months Ended
		Apr. 02, 2018	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Jan. 02, 2018	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Kind interest due, amount				$ 6,629	$ 0
Term Loan
Line of Credit Facility [Line Items]
Principal balance	[1],[2]			$ 263,229				$ 256,599
Term Loan | Amendment No. 2
Line of Credit Facility [Line Items]
Percentage of interest pay in kind						100.00%
Kind interest due, amount						$ 13,200
Principal balance						$ 263,200
Term Loan | Amendment No. 2 | Subsequent Event
Line of Credit Facility [Line Items]
Percentage of interest pay in kind		100.00%	100.00%
Kind interest due, amount		$ 6,700	$ 6,500
Principal balance		$ 269,700
Term Loan | Amendment No. 2 | Scenario, Forecast
Line of Credit Facility [Line Items]
Percentage of interest pay in kind							100.00%
[1]	Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.
[2]	Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.

Long-Term Debt - Summary of C42

Long-Term Debt - Summary of Carrying Amount of Liability Component of Notes (Details) - Notes - USD ($) $ in Thousands	Mar. 31, 2018		Dec. 31, 2017		Mar. 03, 2017
Line of Credit Facility [Line Items]
Principal balance	$ 162,500		$ 162,500
Unamortized deferred financing costs	(2,496)	[1]	(2,631)	[1]	$ (5,400)
Unamortized debt discount	(44,306)	[1]	(46,328)	[1]	$ (52,400)
Long term loan, net	$ 115,698		$ 113,541
[1]	The unamortized deferred financing costs and debt discount will be amortized over the remaining life of the Term Loan and Notes (as defined below), respectively, based on the effective interest method.

Long-Term Debt - Summary of C43

Long-Term Debt - Summary of Carrying Amount of Equity Components of Notes Recorded in Additional Paid in Capital (Details) - Notes - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 03, 2017
Line of Credit Facility [Line Items]
Value of conversion option	$ 77,626	$ 77,626	$ 77,600
Debt issuance costs attributable to conversion option	(2,164)	(2,164)	$ (2,200)
Fair value of conversion option, net	$ 75,462	$ 75,462

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurements, Recurring and Nonrecurring) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Assets, Commodity derivative contracts	$ 542	$ 1,370
Liabilities:
Liabilities, Commodity derivative contracts	(9,567)	(6,988)
Total	(9,025)	(5,618)
Level 3
Assets:
Assets, Commodity derivative contracts	542	1,370
Liabilities:
Liabilities, Commodity derivative contracts	(9,567)	(6,988)
Total	$ (9,025)	$ (5,618)

Fair Value Measurements (Net Ch

Fair Value Measurements (Net Change in Assets and Liabilities Measured at Fair Value on a Recurring Basis and Included in the Level 3 Fair Value Category) (Details) - USD ($)		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
The amount of total losses for the period included in earnings attributable to the change in mark to market of commodity derivatives contracts still held at March 31, 2018 and 2017		$ (3,300,000)	$ (582,000)
Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		(5,618,000)	7,512,000
Total (losses) gains included in earnings		(5,529,000)	1,300,000
Purchases		552,000	470,000
Settlements	[1]	1,570,000	(2,805,000)
Balance at end of period		(9,025,000)	6,477,000
The amount of total losses for the period included in earnings attributable to the change in mark to market of commodity derivatives contracts still held at March 31, 2018 and 2017		$ (3,326,000)	$ (582,000)
[1]	Included in gain (loss) on commodity derivatives contracts on the condensed consolidated statements of operations.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - Level 2 $ in Millions	Mar. 31, 2018USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of notes excluding conversion feature	$ 127.7
Fair value of term loan	$ 242.5

Revenue from Contract with Cust

Revenue from Contract with Customers (Disaggregation of Revenues and Reconciliation of Total Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	[1]
Revenues
Total revenues from contracts with customers	$ 26,438	$ 17,369
(Loss) gain on commodity derivatives contracts	(5,529)	1,300
Total revenues and other (loss) gain	20,909	18,669
Oil and Condensate
Revenues
Total revenues from contracts with customers	20,982	12,190
Natural Gas
Revenues
Total revenues from contracts with customers	2,181	2,588
Natural Gas Liquids
Revenues
Total revenues from contracts with customers	$ 3,275	$ 2,591
[1]	Prior period amounts have not been adjusted under the modified retrospective method.

Revenue from Contract with Cu48

Revenue from Contract with Customers (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Significant judgments	Principal versus Agent The Company engages in various types of transactions in which midstream entities process its wet gas and, in some scenarios, subsequently market resulting NGLs and residue gas to third-party customers on the Company’s behalf, such as gas processing contracts. These types of transactions require judgment to determine whether the Company is the principal or the agent in the contract and, as a result, whether revenues are recorded gross or net. For the Company’s existing contracts, the Company has determined that it represents the agent in the sale of products under certain gas processing and marketing agreements with midstream entities in accordance with the control model in ASC 606. As a result, the Company presents revenue on a net basis for amounts expected to be received from third-party customers through the marketing process, with Post-Production Expenses incurred subsequent to control of the product(s) transferring to the midstream entity being netted against revenue.
Revenue, practical expedient, nondisclosure of transaction price allocation to remaining performance obligation	true
Performance obligation, description of timing	The Company records revenue in the month its production is delivered to the purchaser. However, settlement statements and payment may not be received for 30 to 90 days after the date production is delivered, and as a result, the Company is required to estimate the amount of production that was delivered to the purchaser and the price that will be received for the sale of the product including any transportation and other deductions.

Derivative Instruments and He49

Derivative Instruments and Hedging Activity (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Losses related to change in fair value of commodity derivative contracts	$ (3,300,000)	$ (582,000)

Derivative Instruments and He50

Derivative Instruments and Hedging Activity (Schedule of Notional Amounts and Weighted Average Underlying Hedge Prices of Outstanding Derivative Positions) (Details)	3 Months Ended
	Mar. 31, 2018MMBTU$ / MMBTU$ / bblbbl
Fixed Price Swap - April to December 2018 | Natural Gas
Derivative [Line Items]
Base Fixed Price (Price per MMBtu or Bbl) | $ / MMBTU	3.01
Average Daily Volume (MMBtu or Bbl) | MMBTU	1,550
Total of Notional Volume (MMBtu) | MMBTU	426,250
Costless Three-Way Collar - April to December 2018 | Natural Gas
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl) | MMBTU	5,000
Total of Notional Volume (MMBtu) | MMBTU	1,375,000
Costless Three-Way Collar - April to December 2018 | Long | Natural Gas
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / MMBTU	3
Costless Three-Way Collar - April to December 2018 | Short | Natural Gas
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / MMBTU	2.35
Ceiling (Short) (Price per MMBtu or Bbl) | $ / MMBTU	4
Crude Oil | Costless Three-Way Collar - April to June 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	1,700	[1]
Total of Notional Volume (Bbl)	154,700
Crude Oil | Costless Three-Way Collar - April to June 2018 | Long
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / bbl	47.50
Crude Oil | Costless Three-Way Collar - April to June 2018 | Short
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / bbl	37.50
Ceiling (Short) (Price per MMBtu or Bbl) | $ / bbl	57.85
Crude Oil | Costless Three-Way Collar - July to September 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	1,600	[1]
Total of Notional Volume (Bbl)	147,200
Crude Oil | Costless Three-Way Collar - July to September 2018 | Long
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / bbl	47.50
Crude Oil | Costless Three-Way Collar - July to September 2018 | Short
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / bbl	37.50
Ceiling (Short) (Price per MMBtu or Bbl) | $ / bbl	57.85
Crude Oil | Costless Three-Way Collar - October to December 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	1,700	[1]
Total of Notional Volume (Bbl)	156,400
Crude Oil | Costless Three-Way Collar - October to December 2018 | Long
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / bbl	47.50
Crude Oil | Costless Three-Way Collar - October to December 2018 | Short
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / bbl	37.50
Ceiling (Short) (Price per MMBtu or Bbl) | $ / bbl	57.85
Crude Oil | Fixed Price Swap One - April 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	125	[1]
Total of Notional Volume (Bbl)	3,750
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	66.45
Crude Oil | Fixed Price Swap Two - April 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	477	[1]
Total of Notional Volume (Bbl)	14,310
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	51.20
Crude Oil | Fixed Price Swap - April to December 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	500	[1]
Total of Notional Volume (Bbl)	137,500
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	61.60
Crude Oil | Fixed Price Swap One - May 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	325	[1]
Total of Notional Volume (Bbl)	10,075
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	66.45
Crude Oil | Fixed Price Swap Two - May 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	492	[1]
Total of Notional Volume (Bbl)	15,252
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	51.20
Crude Oil | Fixed Price Swap - June 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	600	[1]
Total of Notional Volume (Bbl)	18,000
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	51.20
Crude Oil | Fixed Price Swap - June to August 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	425	[1]
Total of Notional Volume (Bbl)	39,100
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	66.45
Crude Oil | Fixed Price Swap - July to September 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	500	[1]
Total of Notional Volume (Bbl)	46,000
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	51.20
Crude Oil | Fixed Price Swap - October to December 2018
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	600	[1]
Total of Notional Volume (Bbl)	55,200
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	51.20
Crude Oil | Costless Three-Way Collar - January to September 2019
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	2,000	[1]
Total of Notional Volume (Bbl)	546,000
Crude Oil | Costless Three-Way Collar - January to September 2019 | Long
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / bbl	47.50
Crude Oil | Costless Three-Way Collar - January to September 2019 | Short
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / bbl	37.50
Ceiling (Short) (Price per MMBtu or Bbl) | $ / bbl	59.70
Crude Oil | Costless Three-Way Collar - October to December 2019
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	1,900	[1]
Total of Notional Volume (Bbl)	174,800
Crude Oil | Costless Three-Way Collar - October to December 2019 | Long
Derivative [Line Items]
Floor (Long) (Price per MMBtu or Bbl) | $ / bbl	47.50
Crude Oil | Costless Three-Way Collar - October to December 2019 | Short
Derivative [Line Items]
Put (Short) (Price per MMBtu or Bbl) | $ / bbl	37.50
Ceiling (Short) (Price per MMBtu or Bbl) | $ / bbl	59.70
Crude Oil | Fixed Price Swap - January to September 2019
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	700	[1]
Total of Notional Volume (Bbl)	191,100
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	50.40
Crude Oil | Fixed Price Swap - October to November 2019
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	600	[1]
Total of Notional Volume (Bbl)	36,600
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	50.40
Crude Oil | Fixed Price Swap - December 2019
Derivative [Line Items]
Average Daily Volume (MMBtu or Bbl)	416	[1]
Total of Notional Volume (Bbl)	12,896
Base Fixed Price (Price per MMBtu or Bbl) | $ / bbl	50.40
[1]	Crude volumes hedged include oil, condensate and certain components of our NGLs production.

Derivative Instruments and He51

Derivative Instruments and Hedging Activity (Summary of Information Regarding Deferred Put Premium Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Current commodity derivative put premium payable		$ 102	$ 135
Total unamortized put premium liabilities	$ 102	$ 102	$ 135
Put Premium Liabilities [Roll Forward]
Put premium liabilities, beginning balance	135
Settlement of put premium liabilities	(33)
Put premium liabilities, ending balance	$ 102

Derivative Instruments and He52

Derivative Instruments and Hedging Activity (Summary of Information on the Location and Amounts of Derivative Fair Values and Derivative Gains and Losses) (Details) - Commodity Contract - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives contracts	$ (5,529)	$ 1,300
Gain (loss) on commodity derivatives contracts
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives contracts	(5,529)	$ 1,300
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Total derivatives not designated as hedging instruments	(9,025)		$ (5,618)
Derivatives not designated as hedging instruments | Current assets
Derivatives, Fair Value [Line Items]
Commodity derivative contracts, Assets	542		1,370
Derivatives not designated as hedging instruments | Current liabilities
Derivatives, Fair Value [Line Items]
Commodity derivative contracts, Liabilities	(6,278)		(4,416)
Derivatives not designated as hedging instruments | Long-term liabilities
Derivatives, Fair Value [Line Items]
Commodity derivative contracts, Liabilities	$ (3,289)		$ (2,572)

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details) - USD ($)

Apr. 30, 2018

Apr. 09, 2018

May 05, 2017

May 02, 2017

Mar. 03, 2017

Feb. 15, 2017

Jan. 31, 2017

Mar. 09, 2016

Jan. 31, 2017

Apr. 30, 2016

Feb. 20, 2017

Mar. 31, 2018

Mar. 31, 2017

Dec. 31, 2016

Dec. 31, 2017

Jul. 24, 2017

Mar. 22, 2017

Mar. 21, 2017

May 07, 2015

Class Of Stock [Line Items]

Aggregate offering price

$ 50,000,000

Proceeds from issuance of common stock, net of issuance costs

$ 0

$ 56,366,000

Volume-weighted average trading price of the common shares

$ 1.7002

Common stock, shares authorized

800,000,000

550,000,000

800,000,000

800,000,000

Preferred stock, shares authorized

40,000,000

40,000,000

Cash dividends on preferred stock

$ 0

14,473,000

Undeclared cumulative dividends on preferred stock

$ 3,618,000

0

Preferred stock dividends payment conditions applied commencement period

2016-04

Stock options

Class Of Stock [Line Items]

Common shares reserved for future issuance

164,400

PBUs

Class Of Stock [Line Items]

Common shares reserved for future issuance

1,477,095

2006 Long-Term Stock Incentive Plan

Class Of Stock [Line Items]

Shares reserved for issuance under LTIP

14,000,000

Shares available for future issuance (no more than) (shares)

4,717,198

Series A Preferred Stock

Class Of Stock [Line Items]

Preferred stock, shares authorized

10,000,000

10,000,000

Preferred stock, dividend rate, percentage (percentage)

8.625%

Preferred stock, par value

$ 0.01

$ 0.01

Redemption price

$ 25

$ 25

Preferred stock, shares issued

4,045,000

4,045,000

Preferred stock, shares outstanding

4,045,000

4,045,000

Dividends payable, date declared

Apr. 9, 2018

Dividends payable, date paid

Apr. 30, 2018

Dividends payable record date

Apr. 20, 2018

Cash dividends on preferred stock

8,700,000

Fixed rate preferred dividend increases percentage if suspension more than one year

2.00%

Undeclared cumulative dividends on preferred stock

$ 2,200,000

Undeclared dividends paid

$ 6,500,000

Accumulated and unpaid dividends on preferred stock transferred to liquidation preference

$ 5,800

Accumulated and unpaid dividends on preferred stock transferred to liquidation preference per share

$ 1.4375

Series A Preferred Stock | Subsequent Event

Class Of Stock [Line Items]

Preferred stock, dividend rate, percentage (percentage)

8.625%

Cash dividends on preferred stock

$ 6,500,000

$ 6,500,000

Series B Preferred Stock

Class Of Stock [Line Items]

Preferred stock, shares authorized

10,000,000

10,000,000

Preferred stock, dividend rate, percentage (percentage)

10.75%

Preferred stock, par value

$ 0.01

$ 0.01

Redemption price

$ 25

$ 25

Preferred stock, shares issued

2,140,000

2,140,000

Preferred stock, shares outstanding

2,140,000

2,140,000

Dividends payable, date declared

Apr. 9, 2018

Dividends payable, date paid

Apr. 30, 2018

Dividends payable record date

Apr. 20, 2018

Cash dividends on preferred stock

$ 4,800,000

5,800,000

Fixed rate preferred dividend increases percentage if suspension more than one year

2.00%

Undeclared cumulative dividends on preferred stock

$ 1,400,000

Undeclared dividends paid

$ 4,300,000

Accumulated and unpaid dividends on preferred stock transferred to liquidation preference

$ 3,800,000

Accumulated and unpaid dividends on preferred stock transferred to liquidation preference per share

$ 1.7916667

Preferred stock redemption price per share

$ 25

Period after change in control to redeem preferred stock

90 days

Option to convert shares of Series B Preferred Stock

$ 11.5207

Dividend declared or paid

$ 0

Series B Preferred Stock | Subsequent Event

Class Of Stock [Line Items]

Preferred stock, dividend rate, percentage (percentage)

10.75%

Cash dividends on preferred stock

$ 4,300,000

$ 4,300,000

Special Voting Preferred Stock

Class Of Stock [Line Items]

Preferred stock, shares authorized

2,000

Redemption price

$ 0.01

Convertible Notes due 2022

Class Of Stock [Line Items]

Aggregate principal amount

$ 162,500,000

$ 162,500,000

Amendment No. 10 | Series A Preferred Stock

Class Of Stock [Line Items]

Dividends payable, date declared

Jan. 10, 2017

Dividends payable, date paid

Jan. 31, 2017

Dividends payable record date

Jan. 20, 2017

Cash dividends on preferred stock

$ 7,300,000

Amendment No. 10 | Series B Preferred Stock

Class Of Stock [Line Items]

Dividends payable, date declared

Jan. 10, 2017

Dividends payable record date

Jan. 20, 2017

Dividend payable date

Jan. 31, 2017

Securities Purchase Agreement | Additional Notes

Class Of Stock [Line Items]

Aggregate principal amount

$ 75,000,000

Aggregate principal amount, exchanged

$ 37,500,000

Securities Purchase Agreement | Common Stock

Class Of Stock [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

25,456,521

Ares Management, LLC | Securities Purchase Agreement

Class Of Stock [Line Items]

Aggregate principal amount

$ 75,000,000

Number of consecutive trading days used in volume-weighted average trading price

30 days

Volume-weighted average trading price of the common shares

$ 1.7002

Aggregate principal amount, exchanged

$ 37,500,000

Ares Management, LLC | Securities Purchase Agreement | Convertible Notes due 2022

Class Of Stock [Line Items]

Aggregate principal amount

$ 125,000,000

Ares Management, LLC | Securities Purchase Agreement | Common Stock

Class Of Stock [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

25,456,521

29,408,305

Proceeds from issuance of common stock, net of issuance costs

$ 50,000,000

Sales price of underwritten public offering before offering costs and expenses

$ 50,000,000

ATM Program

Class Of Stock [Line Items]

Issuance of common shares - cash, net of offering costs (shares)

5,447,919

Proceeds from issuance of common stock, net of issuance costs

$ 8,300,000

Expiration date

Feb. 24, 2017

Capital Stock (Schedule of Issu

Capital Stock (Schedule of Issuances and Forfeitures of Common Shares) (Details) - Restricted shares	3 Months Ended
	Mar. 31, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of restricted common stock granted	3,162,699
Shares of restricted common stock vested	1,598,644
Shares of restricted common stock surrendered upon vesting/exercise	489,478	[1]
Shares of restricted common stock forfeited	3,175
[1]	Represents shares of common stock forfeited in connection with the payment of estimated withholding taxes on shares of restricted common stock that vested during the period.

Interest Expense (Schedule of C

Interest Expense (Schedule of Components of Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest Expense [Abstract]
Cash and accrued	$ 2,459	$ 9,759
Paid-in-kind interest	6,629	0
Amortization of deferred financing costs and debt discount	3,177	1,710
Capitalized interest	(2,328)	(620)
Total interest expense	$ 9,937	$ 10,849

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Current income tax benefit or provision	$ 0	$ 0
Deferred income tax expense (benefit)	$ 0	$ 0

Earnings per Share (Schedule of

Earnings per Share (Schedule of Earnings per Share, Basic and Diluted, by Common Class, Including Two Class Method) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders	$ (19,129)	$ (22,316)
Weighted average common shares outstanding basic (shares)	209,903,482	162,829,221
Weighted average common shares outstanding diluted (shares)	209,903,482	162,829,221
Basic (dollars per share)	$ (0.09)	$ (0.14)
Diluted (dollars per share)	$ (0.09)	$ (0.14)
Common shares excluded from denominator as anti-dilutive (shares)	78,457,917	99,659,243
Unvested restricted shares
Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Common shares excluded from denominator as anti-dilutive (shares)	3,984,569	510,465
Unvested PBUs
Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Common shares excluded from denominator as anti-dilutive (shares)	952,579	170,858
Convertible notes
Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Common shares excluded from denominator as anti-dilutive (shares)	73,520,769	98,977,920

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)	May 03, 2016Officer	Mar. 31, 2018	Dec. 29, 2015USD ($)	Apr. 22, 2014awell
Gastar Exploration Inc V Christopher Mc Arthur | Maximum
Loss Contingencies [Line Items]
Damages sought in arbitration matter | $			$ 2,750,000
Torchlight Energy Resources, Inc., Torchlight Energy, Inc. v. Husky Ventures, Inc.
Loss Contingencies [Line Items]
Number of executive officers filed lawsuit | Officer	2
Loss contingency, actions taken by plaintiff		On August 17, 2016, plaintiffs nonsuited, without prejudice, their claims against the former chairman of the board.
Loss contingency, date of dismissal of plantiff claims		May 22, 2017
PennMarc Resources II, Limited Partners and Others
Loss Contingencies [Line Items]
Loss contingency, date of lawsuit filed		October 23, 2017
Eagle Natrium LLC In the Court of Common Pleas of Allegheny County Pennsylvania [Member]
Loss Contingencies [Line Items]
Number of wells completed | well				3
Area of gastar operator				16,000
Gross area for oil and gas lease adjacent to eagles facilitties				3,300

Statement of Cash Flows - Sup59

Statement of Cash Flows - Supplemental Information (Schedule of Supplemental Cash Paid and Non-cash Transactions) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Supplemental Cash Flow Information [Abstract]
Cash paid for interest, net of capitalized amounts	$ 111	$ 11,721
Non-cash transactions:
Capital expenditures included in accounts payable and accrued drilling costs	(6,046)	3,072
Capital expenditures excluded from prepaid expenses	(88)
Asset retirement obligation included in oil and natural gas properties	45	230
Asset retirement obligation sold	(2,581)	(1,533)
Application of advances to operators	1	16
Non-cash financing charges excluded from accounts payable and accrued liabilities		585
Undeclared cumulative dividends on preferred stock	$ 3,618	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands		Apr. 30, 2018	Apr. 09, 2018	Jan. 31, 2017	Apr. 02, 2018	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Jan. 02, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Kind interest due, amount							$ 6,629	$ 0
Cash dividends on preferred stock							$ 0	14,473
Series A Preferred Stock
Subsequent Event [Line Items]
Dividends payable, date declared							Apr. 9, 2018
Dividends payable, date paid							Apr. 30, 2018
Dividends payable record date							Apr. 20, 2018
Cash dividends on preferred stock								8,700
Preferred stock, dividend rate, percentage (percentage)							8.625%
Series B Preferred Stock
Subsequent Event [Line Items]
Dividends payable, date declared							Apr. 9, 2018
Dividends payable, date paid							Apr. 30, 2018
Dividends payable record date							Apr. 20, 2018
Cash dividends on preferred stock				$ 4,800				$ 5,800
Preferred stock, dividend rate, percentage (percentage)							10.75%
Subsequent Event | Series A Preferred Stock
Subsequent Event [Line Items]
Cash dividends on preferred stock		$ 6,500	$ 6,500
Preferred stock, dividend rate, percentage (percentage)			8.625%
Subsequent Event | Series B Preferred Stock
Subsequent Event [Line Items]
Cash dividends on preferred stock		$ 4,300	$ 4,300
Preferred stock, dividend rate, percentage (percentage)			10.75%
First Lien Secured Term Loan
Subsequent Event [Line Items]
Principal balance	[1],[2]						$ 263,229			$ 256,599
First Lien Secured Term Loan | Amendment No. 2
Subsequent Event [Line Items]
Percentage of interest pay in kind									100.00%
Kind interest due, amount									$ 13,200
Principal balance									$ 263,200
First Lien Secured Term Loan | Subsequent Event | Amendment No. 2
Subsequent Event [Line Items]
Percentage of interest pay in kind					100.00%	100.00%
Kind interest due, amount					$ 6,700	$ 6,500
Principal balance					$ 269,700
[1]	Pursuant to Amendment No. 2 (as defined below), the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million. The Company elected to pay in kind 100% of the interest due for the period January 2, 2018 to April 1, 2018 in the amount of $6.5 million and such was accrued at March 31, 2018 due to the interest payment date falling on a weekend outside of quarter end.
[2]	Pursuant to Amendment No. 2, the Company can elect to pay in kind 100% of the interest due after June 30, 2017 to December 31, 2018. The Company elected to pay in kind 100% of the interest due for the period June 30, 2017 to January 1, 2018 in the amount of $13.2 million, thus increasing the outstanding principal balance of the Term Loan to $263.2 million.