Erin Energy (ERINQ) 10-Q 8 Nov 17 2017 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 01, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Erin Energy Corp.
Entity Central Index Key	1,402,281
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		214,954,229

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 18,132	$ 7,177
Restricted cash	13,761	2,600
Accounts receivable - trade	14,691	0
Accounts receivable - partners	2,232	674
Accounts receivable - related party	2,821	1,956
Accounts receivable - other	5	29
Crude oil inventory	1,333	9,398
Prepaids and other current assets	2,462	872
Total current assets	55,437	22,706
Property, plant and equipment:
Oil and gas properties (successful efforts method of accounting), net	173,594	265,713
Other property, plant and equipment, net	425	716
Total property, plant and equipment, net	174,019	266,429
Other non-current assets	35	66
Total assets	229,491	289,201
Current liabilities:
Accounts payable and accrued liabilities	261,742	244,963
Accounts payable and accrued liabilities - related party	33,388	29,513
Accounts payable - partners	87	0
Short-term note payable - related party	200	0
Current portion of long-term debt, net	69,080	12,627
Derivative liability	1,751	0
Total current liabilities	366,248	287,103
Long-term notes payable - related party, net	129,821	129,796
Long-term debt, net	68,786	74,446
Asset retirement obligations	23,910	22,476
Total liabilities	588,765	513,821
Commitments and contingencies (Note 9)
Capital deficiency:
Preferred stock $0.001 par value - 50,000,000 shares authorized; none issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	0	0
Common stock $0.001 par value - 416,666,667 shares authorized; 214,954,229 and 212,622,218 shares outstanding as of September 30, 2017 and December 31, 2016, respectively	215	213
Additional paid-in capital	798,210	792,972
Accumulated deficit	(1,157,434)	(1,018,292)
Treasury stock at cost, 304,481 and 99,932 shares as of September 30, 2017 and December 31, 2016, respectively	(936)	(228)
Total deficit - Erin Energy Corporation	(359,945)	(225,335)
Non-controlling interest	671	715
Total capital deficiency	(359,274)	(224,620)
Total liabilities and capital deficiency	$ 229,491	$ 289,201

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized shares	50,000,000	50,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	416,666,667	416,666,667
Common stock, outstanding shares	214,954,229	212,622,218
Treasury stock, shares	304,481	99,932

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Crude oil sales, net of royalties	$ 33,643	$ 28,619	$ 79,509	$ 56,699
Operating costs and expenses:
Production costs	22,358	24,928	59,548	69,615
Crude oil inventory decrease	4,100	636	4,017	534
Workover expenses	0	207	(713)	7,792
Exploratory expenses	1,313	1,672	3,711	4,934
Depreciation, depletion and amortization	13,059	18,925	50,229	38,593
Accretion of asset retirement obligations	489	472	1,434	1,385
Impairment of oil and gas properties	0	0	78,711	0
Loss on settlement of asset retirement obligations	0	0	0	205
General and administrative expenses	2,354	3,596	9,026	10,950
Total operating costs and expenses	43,673	50,436	205,963	134,008
Loss on disposal of other property and equipment	0	0	149	0
Gain on sale of oil and gas properties	0	0	(2,348)	0
Operating loss	(10,030)	(21,817)	(124,255)	(77,309)
Other income (expense):
Currency transaction gain	1,542	3,282	5,027	14,610
Interest expense	(5,963)	(5,038)	(20,837)	(16,417)
Gain (loss) on fair value of derivative liability	(22)	0	15	0
Total other expense, net	(4,443)	(1,756)	(15,795)	(1,807)
Loss before income taxes	(14,473)	(23,573)	(140,050)	(79,116)
Income tax expense	0	0	0	0
Net loss before non-controlling interest	(14,473)	(23,573)	(140,050)	(79,116)
Net loss attributable to non-controlling interest	403	102	908	662
Net loss attributable to Erin Energy Corporation	$ (14,070)	$ (23,471)	$ (139,142)	$ (78,454)
Net loss attributable to Erin Energy Corporation per common share:
Basic (in dollars per share)	$ (0.07)	$ (0.11)	$ (0.65)	$ (0.37)
Diluted (in dollars per share)	$ (0.07)	$ (0.11)	$ (0.65)	$ (0.37)
Weighted average common shares outstanding:
Basic (in shares)	213,732	212,524	213,293	212,220
Diluted (in shares)	213,732	212,524	213,293	212,220

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITAL DEFIENCY - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		$ (224,620)
Common stock issued		3,621
Stock-based compensation		1,619
Transfer to treasury arising from withholding taxes upon vesting of restricted stock and exercise of stock options		(708)
Non-controlling interest		864
Net loss	$ (14,473)	(140,050)
Balance at September 30, 2017	(359,274)	(359,274)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		213
Common stock issued		2
Balance at September 30, 2017	215	215
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		792,972
Common stock issued		3,619
Stock-based compensation		1,619
Balance at September 30, 2017	798,210	798,210
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		(1,018,292)
Net loss		(139,142)
Balance at September 30, 2017	(1,157,434)	(1,157,434)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		(228)
Transfer to treasury arising from withholding taxes upon vesting of restricted stock and exercise of stock options		(708)
Balance at September 30, 2017	(936)	(936)
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2016		715
Non-controlling interest		864
Net loss		(908)
Balance at September 30, 2017	$ 671	$ 671

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net loss	$ (140,050)	$ (79,116)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation, depletion and amortization	50,229	38,593
Accretion of asset retirement obligations	1,434	1,385
Impairment of oil and gas properties	78,711	0
Amortization of debt discount and debt issuance costs	3,602	2,640
Unrealized foreign currency transaction gain	(2,372)	(10,442)
Loss on disposal of other property and equipment	149	0
Gain on sale of oil and gas properties	(2,348)	0
Gain on fair value of derivative liability	(15)	0
Settlement of accounts payable and accrued expenses	(6,934)	0
Share-based compensation	1,619	2,288
Change in operating assets and liabilities:
Decrease (increase) in accounts receivable	(12,144)	730
Decrease in crude oil inventory	4,017	534
Increase in prepaids and other current assets	(1,466)	(467)
Increase in accounts payable and accrued liabilities	40,121	54,700
Net cash provided by operating activities	14,553	10,845
Cash flows from investing activities
Capital expenditures	(41,656)	(16,475)
Net cash used in investing activities	(41,656)	(16,475)
Cash flows from financing activities
Proceeds from exercise of stock options and warrants	0	364
Payments for treasury stock arising from withholding taxes upon restricted stock vesting and exercise of stock options	(708)	(206)
Proceeds from MCB Finance Facility	63,191	0
Repayments of MCB Finance Facility	(141)	0
Repayments of term loan facility	(4,668)	(6,492)
Proceeds from short-term notes payable	0	504
Proceeds from short-term notes payable - related party	200	0
Repayment of short-term notes payable	0	(449)
Proceeds from notes payable - related party, net	0	6,829
Debt issuance costs	(8,655)	(1,040)
Funds restricted for debt service	(11,161)	0
Funds released from restricted cash	0	6,061
Net cash provided by financing activities	38,058	5,571
Net increase in cash and cash equivalents	10,955	(59)
Cash and cash equivalents at beginning of period	7,177	8,363
Cash and cash equivalents at end of period	18,132	8,304
Cash paid for:
Interest, net of amounts capitalized	7,731	10,090
Supplemental disclosure of non-cash investing and financing activities:
Discount on notes payable pursuant to issuance of warrants	1,766	53
Reduction in oil and gas properties arising from settlements of accounts payable and accrued liabilities	11,328	9,540
Shares issued from settlement of accounts payable and accrued liabilities	3,527	0
Shares issued for services	$ 94	$ 0

Company Description

Company Description	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Description	Company Description Erin Energy Corporation (NYSE American: ERN; JSE: ERN) (the "Company") is an independent oil and gas exploration and production company engaged in the acquisition and development of energy resources in Africa. The Company’s asset portfolio consists of five licenses across three countries covering an area of approximately 1.5 million acres (approximately 6,000 square kilometers). The Company owns producing properties and conducts exploration activities offshore Nigeria, and conducts exploration activities offshore Ghana and The Gambia. The Company is headquartered in Houston, Texas and has offices in Lagos, Nigeria, Nairobi, Kenya, Banjul, The Gambia, and Accra, Ghana. The Company’s operating subsidiaries include Erin Petroleum Nigeria Limited (“EPNL”), Erin Energy Kenya Limited ("EEKL"), Erin Energy Gambia Ltd., and Erin Energy Ghana Limited. The terms “we,” “us,” “our,” “the Company,” and “our Company” refer to Erin Energy Corporation and its consolidated subsidiaries. On February 16, 2017, Babatunde (Segun) Omidele informed the Company that he would resign from service as a member of the Board of Directors ("the Board") and as the Chief Executive Officer of the Company. The Board accepted his resignation effective as of February 22, 2017. The Board appointed Jean-Michel Malek, the Company’s Senior Vice President, General Counsel and Secretary, to serve as Interim Chief Executive Officer effective February 22, 2017 while the Board conducted a search for a permanent replacement for Mr. Omidele. Effective on May 18, 2017, the Board appointed Sakiru Adefemi (Femi) Ayoade as the Company’s Chief Executive Officer to replace the then Interim Chief Executive Officer, Jean-Michel Malek. Changes in Control during 2017 The Company was advised by Oltasho Nigeria Limited (“Oltasho”) and Latmol Investment Limited (“Latmol”) that on (a) April 3, 2017, an aggregate of 116,108,833 shares of the Company’s common stock previously held by Allied Energy Plc. (“Allied”), were transferred to Oltasho; and (b) April 13, 2017, an aggregate of 1,515,927 shares of the Company’s common stock previously held by CAMAC Int’l (Nigeria) Ltd. (“CAMAC International”), were transferred to Latmol. Prior to April 2017, the shares of common stock previously held by Allied and CAMAC International were beneficially owned by Dr. Kase Lawal, the Company’s former Chairman and former Chief Executive Officer, due to his ownership of equity interests in such entities and voting and dispositive control over the securities held by such entities. The shares transferred to Oltasho and Latmol represented approximately 54.6% of the Company’s outstanding voting shares ( 53.9% owned by Allied and 0.7% owned by CAMAC International) as of the dates of transfer and as such, represented a change in control of the Company. The Company has been advised that the shares held by Oltasho are beneficially owned by Alhaji Murhi Busari, its Chairman, and the shares held by Latmol are beneficially owned by Alhaji Murhi Busari, its Chairman. On July 5, 2017, Oltasho and Latmol entered into a Voting Agreement with Dr. Lawal (the “Voting Agreement”) resulting in another change in control of the Company. Pursuant to the Voting Agreement, Oltasho and Latmol provided complete authority to Dr. Lawal to vote the 117,624,760 shares foreclosed upon (and any other securities of the Company obtained by Oltasho and/or Latmol in the future) at any and all meetings of stockholders of the Company and via any written consents. Those 117,624,760 shares represent approximately 54.6% of the Company’s common stock as of the parties’ entry into the Voting Agreement. The Voting Agreement has a term of approximately 10 years , through July 31, 2027, but can be terminated at any time with the mutual consent of the parties. In connection with their entry into the Voting Agreement, Oltasho and Latmol each provided Dr. Lawal an irrevocable voting proxy to vote the shares covered by the Voting Agreement. Additionally, during the term of such agreement, Oltasho and Latmol agreed not to transfer the shares covered by the Voting Agreement except pursuant to certain limited exceptions. According to the Voting Agreement, Oltasho and Latmol have no desire to control the Company and believe that voting control of the Company was best determined by Dr. Lawal, a United States resident, who has extensive knowledge of United States laws and the assets and operations of the Company, as Dr. Lawal was, until he retired in 2015, the Chairman and Chief Executive Officer of the Company. Due to the Voting Agreement, Dr. Lawal will continue to hold voting control over the Company. The Company conducts certain business transactions with CAMAC Energy Holdings Limited (“CEHL”), and its affiliates, which include Allied, which are entities controlled by Dr. Lawal. These entities are deemed to be related parties for financial reporting purposes. See Note 8 - Related Party Transactions for further information.

Basis of Presentation and Recen

Basis of Presentation and Recently Issued Accounting Standards	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Recently Issued Accounting Standards	Basis of Presentation and Recently Issued Accounting Standards The accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly-owned and majority-owned direct and indirect subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany transactions and balances have been eliminated in consolidation. The unaudited consolidated financial statements reflect all adjustments that are, in the opinion of management, necessary for a fair presentation of the consolidated financial position and results of operations for the indicated periods. All such adjustments are of a normal recurring nature. This Form 10-Q should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 , filed with the SEC on March 16, 2017. Use of Estimates The preparation of the Company's consolidated financial statements in conformity with U.S. GAAP requires management to make estimates based on certain assumptions. Estimates affect the reported amounts of assets and liabilities, disclosure of contingent liabilities, and the reported amounts of revenues and expenses attributable to the reporting periods. Accordingly, accounting estimates in conformity with U.S. GAAP require the exercise of judgment. These estimates and assumptions used in the preparation of the Company’s consolidated financial statements are based on information available as of the date of the consolidated financial statements, and while management believes that the estimates and assumptions are appropriate, actual results could differ from management's estimates. Estimates that may have a significant effect on the Company’s financial position and results from operations include share-based compensation assumptions, oil and natural gas reserve quantities, impairments, depletion and amortization relating to oil and natural gas properties, asset retirement obligation assumptions, calculations related to derivative liabilities, and income taxes. The accounting estimates used in the preparation of the Company's consolidated financial statements may change as new events occur, more experience is acquired, additional information is obtained and our operating environment changes. Restricted Cash Restricted cash consists of cash deposits that are contractually restricted for withdrawal or required to be maintained in a reserve bank account for a specific period of time, as provided for under certain agreements with third parties. Restricted cash as of September 30, 2017 totaling $13.8 million consists of $2.6 million held in a debt service reserve account to secure certain interest and principal repayments pursuant to the Term Loan Facility in Nigeria and $11.2 million held in a debt service reserve account as required under the MCB Finance Facility (see Note 7 - Debt for further information and definitions of the Term Loan Facility and MCB Finance Facility). Restricted cash as of December 31, 2016 consists of $2.6 million held in a debt service reserve account to secure certain interest and principal repayments pursuant to the Term Loan Facility in Nigeria. Successful Efforts Method of Accounting for Oil and Gas Activities The Company follows the successful efforts method of accounting for its costs of acquisition, exploration and development of oil and gas properties. Under this method, oil and gas lease acquisition costs and intangible drilling costs associated with exploration efforts that result in the discovery of proved reserves and costs associated with development drilling, whether or not successful, are capitalized when incurred. Drilling costs of exploratory wells are capitalized pending determination that proved reserves have been found. If the determination is dependent upon the results of planned additional wells and require additional capital expenditures to develop the reserves, the drilling costs will be capitalized as long as sufficient reserves have been found to justify completion of the exploratory well as a producing well, and additional wells are underway or firmly planned to complete the evaluation of the well. Exploratory wells not meeting the criteria for continued capitalization are expensed when such a determination is made. Other exploration costs are expensed as incurred. Capitalized Interest The Company capitalizes interest costs for qualifying oil and gas properties. The capitalization period begins when expenditures are incurred on qualified properties, activities begin which are necessary to prepare the property for production, and interest costs have been incurred. The capitalization period continues as long as these events occur. Capitalized interest is added to the cost of the underlying assets and is depleted using the unit-of-production method in the same manner as the underlying assets. During the nine months ended September 30, 2017 and 2016 , the Company capitalized $2.2 million and nil , respectively, of interest costs as additions to property, plant and equipment. Treasury Stock Treasury stock is reported at cost and is included in the accompanying consolidated balance sheets. Pursuant to the Company’s withholding tax policy with respect to vested restricted stock awards, the Company may withhold, on a cashless basis, a number of shares needed to settle statutory withholding tax requirements. During the nine months ended September 30, 2017 , 204,549 shares were withheld for payroll taxes at a total cost of $0.7 million . During the nine months ended September 30, 2016 , 90,347 shares were withheld for payroll taxes at a total cost of $0.2 million . The following table sets forth certain information with respect to the withholding and related repurchases of our common stock during the nine months ended September 30, 2017 . Total Number of Average Price January 1 - January 31, 2017 12,650 $ 3.55 February 1 - February 28, 2017 158,264 3.82 May 1 - May 31, 2017 33,635 1.75 Total 204,549 $ 3.46 (1) All shares repurchased were surrendered by employees to settle tax withholding obligations upon the vesting of restricted stock awards and the exercise of stock options. The price paid was the closing price on the dates in which the shares of common stock vested or when the stock options were exercised. Net Loss Per Common Share Basic net earnings or loss per common share is computed by dividing net earnings or loss by the weighted average number of shares of common stock outstanding at the end of the reporting period. Diluted net earnings or loss per share is computed by dividing net earnings or loss by the fully dilutive common stock equivalent, which consists of shares outstanding, augmented by potentially dilutive shares issuable upon the exercise of the Company's stock options, stock warrants, non-vested restricted stock awards, as well as the conversions of the 2011 Promissory Note, the 2014 Convertible Subordinated Note and the 2016 Promissory Note (collectively, the "Convertible Notes", each defined and described in greater detail under Note 7 - Debt ), calculated using the treasury stock method. The table below sets forth the number of stock options, stock warrants, non-vested restricted stock, and shares issuable upon conversion of the Convertible Notes that were excluded from dilutive shares outstanding during the three and nine months ended September 30, 2017 and 2016 , respectively, as these securities are anti-dilutive because the Company was in a loss position during each period. Three Months Ended September 30, Nine Months Ended September 30, ( In thousands ) 2017 2016 2017 2016 Stock options 98 206 140 249 Stock warrants 4 7 7 2 Unvested restricted stock awards 1,408 2,128 1,759 1,889 1,510 2,341 1,906 2,140 Upon the occurrence of certain events, the Company is also contingently liable to make additional payments to Allied, under a Transfer Agreement entered into in November 2013 by the Company, its affiliates and Allied (the “Transfer Agreement”), up to an additional amount totaling $50.0 million in cash, or the equivalent in shares of the Company’s common stock, at Allied’s option. See Note 9 - Commitments and Contingencies for further information. Fair Value Measurements Fair value is defined as the amount at which an asset (or liability) could be bought (or incurred) or sold (or settled) in an orderly transaction between market participants at the measurement date. The established framework for measuring fair value establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and includes certain disclosure requirements. Fair value estimates are based on either (i) actual market data or (ii) assumptions that other market participants would use in pricing an asset or liability, including estimates of risk. There are three levels of valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy categorizes assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. The three levels are defined as follows: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. The Company considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an on-going basis. Level 2 - Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. Substantially all of these inputs are observable in the marketplace throughout the term, can be derived from observable data, or supported by observable levels at which transactions are executed in the marketplace. Level 3 - Inputs that are unobservable and significant to the fair value measurement (including the Company’s own assumptions in determining fair value). The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Fair Value on a Recurring Basis The Company uses discounted cash flow techniques to determine the estimated fair value of its oil and gas properties as part of the Company's analysis for impairment. Accordingly, the Company estimated the present value of expected future net cash flows from the Oyo field, discounted using risk-adjusted cost of capital. Significant Level 3 assumptions used in the calculation include the Company's estimate of future crude oil prices, production costs, development costs, and anticipated production of proved reserves, as well as appropriate risk-adjusted probable and possible reserves. As discussed under Note 7 - Debt, the Company recognized a derivative liability relating to the portion of the amount drawn from the MCB Financing Facility as of September 30, 2017 in which issuance of stock warrants is expected on the day the Company receives funds under the MCB Finance Facility. The Company utilized a combination of a lattice-binomial option-pricing model and the Black-Scholes valuation model to determine the estimated fair value of this derivative liability. The following table sets forth the Company’s oil and gas properties and derivative liability that is accounted for at fair value using Level 3 assumptions on a recurring basis as of September 30, 2017 and December 31, 2016 : Level 3 (in thousands) September 30, 2017 December 31, 2016 Liabilities: Derivative liability $ 1,751 $ — The fair value of the derivative liability is estimated using a combination of a lattice-binomial option-pricing model and the Black-Scholes valuation model with the following assumptions as of September 30, 2017 : September 30, 2017 Estimated market value of common stock on measurement date $ 2.85 Estimated exercise price $ 2.85 Risk-free interest rate (1) 1.62 % Expected warrant term (years) 3 Expected volatilities (2) 10.0% - 38.9% Expected annual dividend yield — (1 ) The risk-free rate for periods within the contractual life of the warrants is based on the U.S. Treasury yield curve in effect at the time of grant. (2 ) Expected volatilities are based on historical volatility of the Oil & Gas Exploration & Production Select Industries Index, among other factors. The following table sets forth a reconciliation of changes in the fair value of the Company's financial liability that is accounted for at fair value using Level 3 inputs, and is classified as level 3 in the fair value hierarchy: Three Months Ended Nine Months Ended (in thousands) September 30, 2017 September 30, 2017 Beginning balance $ 656 $ — Loss (gain) on fair value of derivative liability 22 (15 ) Additions 1,073 1,977 Revisions — (211 ) Transfers — — Ending balance $ 1,751 $ 1,751 Change in unrealized loss (gain) included in earnings relating to derivatives still held as of September 30, 2017 $ 22 $ (15 ) Fair Value of Financial Instruments The carrying amounts of the Company’s financial instruments, which include cash and cash equivalents, restricted cash, accounts receivable, inventory, deposits, accounts payable and accrued liabilities, and debts at floating interest rates, approximate their fair values at September 30, 2017 and December 31, 2016 , respectively, principally due to the short-term nature, maturities or nature of interest rates of the above listed items. Reclassification Certain amounts in prior periods have been reclassified to conform with current period presentation. Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842). ASU 2016-02 is aimed at making leasing activities more transparent and comparable, and requires substantially all leases be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability, including leases currently accounted for as operating leases. ASU 2016-02 is effective for the Company in the fiscal year beginning after December 15, 2018, and interim periods within those fiscal years with early adoption permitted. The Company is still evaluating the impact of this standard. However, due to the nature of its operations, the adoption of this standards update could have a material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”). This ASU clarifies 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. This guidance is to be applied using a prospective method and is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment . ASU 2017-04 eliminates step 2 of the goodwill impairment test. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In February 2017, the FASB issued ASU 2017-05, Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. This ASU clarifies the scope and application of ASC 610-20 on the sale or transfer of nonfinancial assets and in substance nonfinancial assets to noncustomers, including partial sales. The Company is required to adopt this guidance at the same time that it adopts the guidance in ASU 2014-09. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities . This ASU shortens the amortization period for certain callable debt securities held at a premium to the earliest call date. However, the amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. ASU 2017-08 is effective for the Company in the fiscal year beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting, which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. This pronouncement is effective for annual reporting periods beginning after December 15, 2017. Early adoption is permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-10, Service Concession Arrangements (Topic 853): Determining the Customer of the Operation Services . ASU No. 2017-10 provides clarity on determining the customer in a service concession arrangement. ASU No. 2017-10 is effective for interim and annual periods beginning after December 15, 2017, and the Company will adopt this standards update, as required, beginning with the first quarter of 2018. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features . ASU No. 2017-11 amendments simplify the accounting for certain financial instruments with down round features. The amendments require companies to disregard the down round feature when assessing whether the instrument is indexed to its own stock, for purposes of determining liability or equity classification. Companies that provide earnings per share (EPS) data will adjust their basic EPS calculation for the effect of the feature when triggered (i.e., when the exercise price of the related equity-linked financial instrument is adjusted downward because of the down round feature) and will also recognize the effect of the trigger within equity. ASU No. 2017-11 is effective for interim and annual periods beginning after December 15, 2018, and the Company will adopt this standards update, as required, beginning with the first quarter of 2019. The adoption of this standard update is not expected to have a material impact on the Company’s consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Improvements to Accounting for Hedging Activities . ASU No. 2017-12 amends and better aligns an entity’s risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. To meet that objective, the amendments expand and refine hedge accounting for both non-financial and financial risk components and align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. ASU No. 2017-12 is effective for interim and annual periods beginning after December 15, 2018, and the Company will adopt this standards update, as required, beginning with the first quarter of 2019. The adoption of this standard update is not expected to have a material impact on the Company’s consolidated financial statements.

Liquidity Matters and Going Con

Liquidity Matters and Going Concern	9 Months Ended
	Sep. 30, 2017
Liquidity Matters [Abstract]
Liquidity Matters and Going Concern	Liquidity Matters and Going Concern The Company incurred losses from operations for the three and nine months ended September 30, 2017 . As of September 30, 2017 , the Company's total current liabilities of $366.2 million exceeded its total current assets of $55.4 million , resulting in a working capital deficit of $310.8 million . As a result of the current low commodity prices, the Company has not been able to generate sufficient cash from operations to satisfy certain obligations as they became due. Well Oyo-7 is currently shut-in as a result of an emergency shut-in of the Oyo field production that occurred in early July 2016. This has resulted in a loss of approximately 1,400 barrels of oil per day (BOPD). The Company is currently working on relocating an existing gaslift line to well Oyo-7 to enable continuous gaslift operation to assist in restoring lost production volumes. For cost effectiveness, the relocation of the gaslift line to well Oyo-7 is now planned to be combined with the Oyo-9 subsea equipment installation scheduled for the second half of 2018. During an approximately two (2) week period starting from late June 2017 to early July 2017, the owners of the floating, production, storage, and offloading vessel (“FPSO”) Armada Perdana suspended its operations due to an impasse in contract negotiations that led to a temporary shut-in of the Oyo-8 well during this period. The FPSO operation was fully restored and the production from the Oyo-8 well was re-established on July 6, 2017. Contract negotiations have resumed. The Company is currently pursuing a number of actions, including (i) obtaining additional funds through public or private financing sources, (ii) restructuring existing debts from lenders, (iii) obtaining forbearance of debt from trade creditors, (iv) reducing ongoing operating costs, (v) minimizing projected capital costs for the remaining 2017 exploration and development campaign, (vi) farming-out a portion of its rights to certain of its oil and gas properties and (vii) exploring potential business combination transactions. There can be no assurances that sufficient liquidity can be raised from one or more of these actions or that these actions can be consummated within the period needed to meet certain obligations.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment were comprised of the following: ( In thousands ) September 30, December 31, 2016 Wells and production facilities $ 308,451 $ 318,739 Proved properties 386,196 386,196 Work in progress and exploration inventory 81,951 34,712 Oilfield assets 776,598 739,647 Accumulated depletion (609,204 ) (483,754 ) Oilfield assets, net 167,394 255,893 Unevaluated leaseholds 6,200 9,820 Oil and gas properties, net 173,594 265,713 Other property and equipment 2,895 3,040 Accumulated depreciation (2,470 ) (2,324 ) Other property and equipment, net 425 716 Total property, plant and equipment, net $ 174,019 $ 266,429 All of the Company’s oilfield assets are located offshore Nigeria in the Oil Mining Leases 120 and 121 (the "OMLs"). “Work-in-progress and exploration inventory” includes warehouse inventory items purchased as part of the redevelopment plan of the Oyo field. The Company’s unevaluated leasehold costs include costs to acquire the rights to the exploration acreage in its various oil and gas properties. The Gambia Sale Agreement In March 2017, the Company entered into a sale agreement with FAR Ltd. ("FAR"), an Australian Securities Exchange listed oil and gas company (the "Sale Agreement"), whereby FAR agreed to acquire an 80% interest and operatorship of the Company’s offshore A2 and A5 blocks in The Gambia. The Company will retain a 20% working interest in both blocks. Under the terms of the Sale Agreement, which was approved by the Government of the Republic of The Gambia in June 2017, upon closing of the transaction, FAR paid the Company the purchase price of $5.2 million and will carry $8.0 million of the Company’s share of costs in a planned exploration well to be drilled in late 2018. In addition, if the Company’s share of the exploration well is less than $8.0 million , the balance is to be paid in cash to the Company. Any amount in excess of the $8.0 million representing the Company’s share of the exploration well will be borne by the Company. Impairment of Oil and Gas Properties The Company uses discounted cash flow techniques to determine the estimated fair value of its oil and gas properties as part of the Company's analysis for impairment. Accordingly, the Company estimated the present value of expected future net cash flows from the Oyo field, discounted using risk-adjusted cost of capital. Significant Level 3 assumptions used in the calculation include the Company's estimate of future crude oil prices, production costs, development costs, and anticipated production of proved reserves, as well as appropriate risk-adjusted probable and possible reserves. In June 2017, the Company concluded that the carrying value of its oilfield assets would not be recoverable under the then current market conditions. Accordingly, the Company recorded a non-cash impairment charge of $78.1 million to reduce the carrying value of its oil and gas properties to their estimated fair values. In addition, in June 2017, the Company recorded a non-cash impairment charge of $0.6 million to write-off the carrying value of its onshore leases in Kenya.

Accounts Payable and Accrued Li

Accounts Payable and Accrued Liabilities	9 Months Ended
	Sep. 30, 2017
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities The table below sets forth a summary of the Company’s accounts payable and accrued liabilities at September 30, 2017 and December 31, 2016 : (In thousands) September 30, December 31, 2016 Accounts payable - vendors $ 179,467 $ 173,306 Amounts due to government entities 77,139 66,573 Accrued payroll and benefits 1,164 3,074 Accrued interest 3,972 1,204 Other liabilities — 806 $ 261,742 $ 244,963

Asset Retirement Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The Company’s asset retirement obligations primarily represent the estimated fair value of the amounts that will be incurred to plug, abandon and remediate its producing properties at the end of their productive lives. Significant inputs used in determining such obligations include, but are not limited to, estimates of plugging and abandonment costs, estimated future inflation rates and changes in property lives. The inputs used in the fair value determination were based on Level 3 inputs, which were essentially management's assumptions. On a quarterly basis, the Company reviews the assumptions used to estimate the expected cash flows required to settle the asset retirement obligations, including changes in estimated probabilities, amounts and timing of the settlement of the asset retirement obligations, as well as changes in the legal obligation for each of its properties. Changes in any one or more of these assumptions may cause revisions in the estimated liabilities. The following summarizes changes in the Company’s asset retirement obligations during the nine months ended September 30, 2017 ( in thousands ): Balance at January 1, 2017 $ 22,476 Accretion expense 1,434 Balance at September 30, 2017 $ 23,910

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	Debt Short-Term Debt: Short-Term Borrowing - Glencore Advance In February 2017, the Company received $13.6 million as an advance (the “February Advance”) under a stand-alone spot oil sales contract with Glencore Energy UK Ltd. ("Glencore"). Interest accrued on the February Advance at the rate of LIBOR plus 6.5% . Repayment of the February Advance was made from the February 2017 crude oil lifting. In September 2017, the Company received $23.5 million as an advance (the “September Advance”) under an exclusive off-take contract with Glencore (the “Off-take Contract”). Interest accrued on the September Advance at the rate of LIBOR plus 6.5% . Repayment of the September Advance was made from the September 2017 crude oil lifting. Short-Term Debt - Related Party On September 19, 2017, the Company, through its wholly-owned subsidiary EPNL, borrowed $0.2 million under a short-term loan agreement (the "2017 Short-Term Note") entered into with CAMAC Nigeria Limited, an affiliated company, at the flat interest rate of 5% and matures November 30, 2017. Long-Term Debt : Term Loan Facility In September 2014, the Company, through its wholly-owned subsidiary EPNL, entered into the Term Loan Facility (as amended or modified, the “Term Loan Facility”) with Zenith Bank PLC ("Zenith") for a five -year senior secured term loan providing initial borrowing capacity of up to $100.0 million . Of the total commitment provided, 90.0% of the Term Loan Facility was available in U.S. dollars, while the remaining 10% was available in Nigerian Naira. U.S. dollar borrowings under the Term Loan Facility currently bear interest at the rate of LIBOR plus 9.0% . The obligations under the Term Loan Facility include a legal charge over the OMLs and an assignment of proceeds from oil sales. The obligations of EPNL have been guaranteed by the Company and rank in priority with all its other obligations, subject to the provisions under the Override Deed (defined below). Proceeds from the Term Loan Facility were used for the further expansion and development of the Oyo field offshore Nigeria. In June 2016, the Term Loan Facility was modified contingent upon the signing of a loan agreement, which was signed in August 2016. The modification put in place a moratorium on principal payments until June 2017 and extended the term of the Term Loan Facility until February 2021. Additionally, it reduced the funding requirement of the debt service reserve account (“DSRA”) to an amount equal to one quarter of interest until the price of oil exceeds $55 per barrel, at which time an amount equal to two quarters of interest will then be required. Upon executing the Term Loan Facility, the Company paid fees totaling $2.6 million . Upon modification of the Term Loan Facility, additional fees of $1.4 million were incurred. These fees were recorded as debt issuance cost and are being amortized over the life of the Term Loan Facility using the effective interest method. As of September 30, 2017 , $1.7 million of the debt issuance costs remained unamortized. Under the Term Loan Facility, the following events, among others, constitute events of default: EPNL failing to pay any amounts due within thirty days of the due date; bankruptcy, insolvency, liquidation or dissolution of EPNL; a material breach of the Term Loan Facility by EPNL that remains unremedied within thirty days of written notice by EPNL; or a representation or warranty of EPNL proves to have been incorrect or materially inaccurate when made. Upon any event of default, all outstanding principal and interest under any loans will become immediately due and payable. Further, Zenith has the right to review the terms and conditions of the Term Loan Facility. During the nine months ended September 30, 2017 , the Company made payments of $0.4 million and $4.2 million for the principal repayment of the Naira portion of the loan and for the U.S. dollar principal, respectively. As of September 30, 2017 , the Company recognized an unrealized foreign currency gain of $5.0 million on the Naira portion of the loan, reducing the balance under the Term Loan Facility to $82.3 million , net of debt discount. Of this amount, $59.7 million was classified as long-term and $22.6 million as short-term. Accrued interest for the Term Loan Facility was $2.1 million as of September 30, 2017 . MCB Finance Facility and Related Agreements On February 6, 2017, the Company and its subsidiary, EPNL, entered into a Pre-export Finance Facility Agreement (the “MCB Finance Facility”) with The Mauritius Commercial Bank Limited, as mandated lead arranger, agent, security agent, original lender and issuing bank (“MCB”). The MCB Finance Facility provides for a total commitment of $100.0 million and is supported by a guarantee from The Standard Bank of South Africa Limited (“SBSA”), as named guarantor, which guarantee is facilitated by the South African Public Investment Corporation (SOC) Limited ("PIC"), the Company’s second largest shareholder. The PIC guarantee is made with recourse to the Company pursuant to the Company’s entry into the Financing Support Agreement with PIC (the "Financing Support Agreement"). In connection with the MCB Finance Facility, and as a condition precedent to the initial drawdown thereunder, EPNL entered into the Off-take Contract with Glencore dated January 18, 2017 for EPNL’s entire volumes of oil produced from the OMLs located offshore Nigeria. Pursuant to the MCB Finance Facility, EPNL is required to comply with the terms of the Off-take Contract, ensure payments and deliveries of oil and notify MCB of any failures under such contract and ensure that it receives a fair market price for delivered oil. The MCB Finance Facility is supported by the SBSA guarantee as facilitated by PIC, the assignment of the Off-take Contract and the assignment by way of security of certain accounts, including a debt service reserve account, as set forth in the MCB Finance Facility. EPNL was required to deposit $10.0 million (s ee Note 2 – Basis of Presentation and Recently Issued Accounting Standards - Restricted Cash) at the closing of the MCB Finance Facility into the debt service reserve account with MCB and maintain that balance for so long as borrowings are outstanding under the MCB Finance Facility. The aforementioned guarantee and security agreements were entered into by the parties thereto before the initial drawdown on the MCB Finance Facility. EPNL may make drawdowns under the MCB Finance Facility by way of loans and/or letters of credit until June 30, 2017 after which the remaining balance of MCB's commitment as of that date may be drawn and deposited into a capital expenditure reserve account for payment of invoices expected to be payable within six months after June 30, 2017. Borrowings under the MCB Finance Facility bear interest at the three-month LIBOR plus 6% . Additionally the Company is required to pay an unused commitment fee of 2% per annum. After a grace period that ended on June 30, 2017, the MCB Finance Facility will be repaid over a period starting from June 30, 2017 and ending on December 31, 2019. The MCB Finance Facility includes customary fees, including a commitment fee, structuring fee, underwriting fee, management fee, fees payable in respect of utilization of the MCB Finance Facility by way of letter of credit and other fees, and subjects EPNL to certain covenants under the terms of the MCB Finance Facility, and is subject to customary events of default. The Company did not draw down the remaining Available Facility on June 30, 2017 as expected and is currently in discussions with MCB to amend the agreement. The Company is seeking to extend the Availability period, including the Grace Period, as well as a revised repayment schedule. The Company did not make the principal payment due and a portion of interest due on September 30, 2017. Also, on June 27, 2017, a vendor filed a suit against a wholly-owned subsidiary of the Company seeking an amount in excess of $10.0 million (see Note 9 - Commitments and Contingencies for further information). These constitute events of default under the MCB Finance Facility. In October 2017, the Company obtained a waiver of default on these events from MCB. The Company made its initial drawdown under the MCB Finance Facility in March 2017 (the "March 2017 drawdown"). As part of the March 2017 drawdown, the Company incurred debt issuance costs amounting to $8.7 million . As of September 30, 2017 , $7.5 million of the debt issuance costs remained unamortized, which is shown as a discount to long-term debt on the consolidated balance sheet. As of September 30, 2017 , the amount drawn under the MBC Finance Facility was $63.2 million . Accrued interest and unused commitment fees under the MCB Finance Facility was $1.9 million as of September 30, 2017 . During the nine months ended September 30, 2017, the Company paid $0.1 million for the principal repayment of the MCB Finance Facility. Under the MCB Finance Facility, the Company is required to maintain specified financial ratios. Maintenance of these financial ratios (the "cover ratios"), including a debt service cover ratio and a life cover ratio, commenced during the quarter after the initial drawdown. As of September 30, 2017, the Company is in compliance with the cover ratios. Also on February 6, 2017, the Company and PIC also entered into the Financing Support Agreement. Pursuant to the Financing Support Agreement, PIC agrees to apply for, request and authorize SBSA, or any other reputable commercial bank acceptable to MCB, to issue a bank guarantee in favor of MCB in the amount of $100.0 million . The issuance of a guarantee in favor of MCB by SBSA or another reputable commercial bank was a condition precedent to the closing of the MCB Finance Facility. In consideration for this undertaking, the Company agreed to pay PIC an upfront fee equal to 250 basis points on the guarantee amount and issue to PIC warrants to purchase a number of shares of the Company’s common stock in an amount equal to the guarantee amount multiplied by 20% divided by the closing market price of the Company’s common stock on the day that EPNL receives the funds available under the MCB Finance Facility (the "warrants issuance date), with an exercise price equal to such closing market price. The Company recognized a derivative liability for the warrants that are expected to be issued for the portion of the amount drawn under the MCB Finance Facility at September 30, 2017 . S ee Note 2 – Basis of Presentation and Recently Issued Accounting Standards - Fair Value Measurements for further information. The Company also has agreed to indemnify PIC from and against certain claims and losses. The amount of any and all indemnifiable losses suffered by PIC agreed or otherwise required to be paid by the Company will be paid in cash or, at the option of PIC, may be paid in newly issued shares of the Company’s common stock. In March 2017, the Company paid $2.5 million to PIC in fees under the Financing Support Agreement which is recorded as debt issuance costs as discussed above and is being amortized to interest expense over the life of the MCB Financing Facility. On February 8, 2017, and in connection with the MCB Finance Facility, the Company, EPNL, MCB and Zenith, the Company’s existing secured lender, also entered into an Override Deed (the “Override Deed”). The Override Deed establishes, inter alia, pro-rata rights of MCB and Zenith in respect of the proceeds from the Off-take Contract, governs the mechanics of any enforcement action by the creditors and sets out pro-rata sharing of enforcement proceeds between MCB and Zenith. The Override Deed also grants the necessary consents to EPNL’s entry into the MCB Finance Facility and related documents. Long-Term Debt Maturities Scheduled principal repayments on the outstanding balance on the Term Loan Facility and the MCB Finance Facility are as follows ( in thousands ): Scheduled payments by year Principal 2017 (remainder) $ 24,931 2018 62,054 2019 21,277 2020 26,597 2021 and thereafter 12,198 Total principal payments 147,057 Less: Unamortized debt issuance costs (9,191 ) Total Long term debt, net $ 137,866 Long-Term Debt – Related Party: As of September 30, 2017 , the Company’s long-term related party debt was $129.8 million , consisting of $24.9 million owed under a 2011 Promissory Note, $50.0 million owed under a 2014 Convertible Subordinated Note, $48.5 million , net of discount, owed under a 2015 Convertible Note, and $6.4 million owed under a 2016 Promissory Note. Allied, a related party, was the holder of each of the 2011 Promissory Note, the 2014 Convertible Subordinated Note, and the 2015 Convertible Note (collectively the "Related Party Notes"). During the nine months ended September 30, 2017 , Oltasho became the holder of each of the Related Party Notes. Please also see Note 1 - Company Description for changes in control in the Company which occurred during 2017. Each of the Related Party Notes contains certain default and cross-default provisions, including failure to pay interest and principal amounts when due and default under other indebtedness. As of September 30, 2017 , the Company was not in compliance with certain default provisions of the Related Party Notes with respect to the payment of quarterly interest. Further, the risk of cross-default exists for each of the Related Party Notes if the holder of the Term Loan Facility exercises its right to terminate the Term Loan Facility and accelerate its maturity. In July 2017, Oltasho agreed to waive through their respective maturity dates its rights under all default provisions of each of the Related Party Notes. 2011 Promissory Note EPNL, the Company's wholly owned subsidiary, has a $25.0 million borrowing facility under a promissory note (the "2011 Promissory Note"). Interest accrues on the outstanding principal under the 2011 Promissory Note at a rate of the 30 -day LIBOR plus 2% per annum, payable quarterly. In March 2017, the 2011 Promissory Note became convertible, at the sole option of the holder, into shares of the Company’s common stock at a conversion price of $3.415 per share. In July 2017, the 2011 Promissory Note was amended to extend the maturity date to December 2019. The entire $25.0 million facility amount can be utilized for general corporate purposes. The stock of the Company’s subsidiary that holds the exploration licenses in The Gambia and Kenya were pledged as collateral to secure the 2011 Promissory Note, pursuant to an Equitable Share Mortgage arrangement. As of September 30, 2017 , the outstanding principal and accrued interest under the 2011 Promissory Note were $24.9 million and $2.2 million , respectively. As referred to above, this Note was transferred to Oltasho during the nine months ended September 30, 2017 . 2014 Convertible Subordinated Note As partial consideration in connection with the February 2014 acquisition of interests in Oil Mining Leases ("OMLs") located offshore Nigeria from Allied, the Company issued a $50.0 million Convertible Subordinated Note in favor of Allied (the “2014 Convertible Subordinated Note”). Interest on the 2014 Convertible Subordinated Note accrues at a rate per annum of one-month LIBOR plus 5% , payable quarterly in cash until the maturity of the 2014 Convertible Subordinated Note five years from the acquisition date. At the election of the holder, the 2014 Convertible Subordinated Note is convertible into shares of the Company’s common stock at an initial conversion price of $4.2984 per share, subject to anti-dilution adjustments. The 2014 Convertible Subordinated Note is subordinated to the Company’s existing and future senior indebtedness and is subject to acceleration upon an Event of Default (as defined in the 2014 Convertible Subordinated Note). The following events, among others, constitute an Event of Default under the 2014 Convertible Subordinated Note: the Company failing to pay interest within thirty days of the due date; the Company failing to pay principal when due; bankruptcy, insolvency, liquidation or dissolution of the Company; a material breach of the 2014 Convertible Subordinated Note by the Company that remains unremedied within ten days of such material breach; or a representation or warranty of the Company proves to have been incorrect or materially inaccurate when made. Upon any event of default, all outstanding principal and interest under any loans will become immediately due and payable. As of September 30, 2017 , the Company owed $10.5 million in accrued interest under the 2014 Convertible Subordinated Note. The Company may, at its option, prepay the 2014 Convertible Subordinated Note in whole or in part, at any time, without premium or penalty. Further, the 2014 Convertible Subordinated Note is subject to mandatory prepayment upon (i) the Company’s issuance of capital stock or incurrence of indebtedness, the proceeds of which the Company does not apply to repayment of senior indebtedness or (ii) any capital markets debt issuance to the extent the net proceeds of such issuance exceed $250.0 million . The holder may assign all or any part of its rights and obligations under the 2014 Convertible Subordinated Note to any person upon written notice to the Company. In July 2017, the 2014 Convertible Subordinated Note was amended to extend the maturity date to December 2019. As of September 30, 2017 , the outstanding principal under the 2014 Convertible Subordinated Note was $50.0 million . As referred to above, this Note was transferred to Oltasho during the nine months ended September 30, 2017 . 2015 Convertible Note In March 2015, the Company entered into a borrowing facility with Allied in the form of a Convertible Note (the “2015 Convertible Note”), allowing the Company to borrow up to $50.0 million for general corporate purposes. In July 2017, the maturity date of the 2015 Convertible Note was extended to December 2019. Interest accrues at the rate of LIBOR plus 5% , and is payable quarterly. The 2015 Convertible Note is convertible into shares of the Company’s common stock upon the occurrence and continuation of an event of default, at the sole option of the holder. The number of shares issuable upon conversion is equal to the sum of the principal amount and the accrued and unpaid interest divided by the conversion price, defined as the volume weighted average of the closing sales prices on the NYSE American for a share of common stock for the five complete trading days immediately preceding the conversion date. As of September 30, 2017 , the Company had borrowed $48.5 million under the note and issued to Allied warrants to purchase approximately 2.7 million shares of the Company’s common stock at prices ranging from $2.00 to $7.85 per share. The total fair market value of the warrants amounting to $5.0 million based on the Black-Scholes option pricing model was recorded as a debt discount, and is being amortized using the effective interest method over the life of the note. As of September 30, 2017 , the debt discount has been fully amortized. Additional warrants are issuable in connection with future borrowings, with the per share price for those warrants determined based on the market price of the Company’s common stock at the time of such future borrowings. As of September 30, 2017 , the outstanding balance of the 2015 Convertible Note, net of discount, was $48.5 million . Accrued interest on the 2015 Convertible Note was $7.3 million as of September 30, 2017 . As referred to above, this Note was transferred to Oltasho during the nine months ended September 30, 2017 . 2016 Promissory Note In March 2016, the Company borrowed $3.0 million under a short-term Promissory Note agreement entered into with an entity related to the Company's then majority shareholder, which accrued interest at a rate of the 30 -day LIBOR plus 7% per annum. In April 2016, the Company borrowed an additional sum of $1.0 million from the same lender, under another short-term Promissory Note, which also accrued interest at a rate of the 30 -day LIBOR plus 7% per annum. In May 2016, the Lender of the two Promissory Notes agreed to combine both notes into a $10.0 million borrowing facility (the "2016 Promissory Note"). Interest accrues at a rate of the 30 -day LIBOR plus 7% per annum. Subsequent to the combination of both notes into the 2016 Promissory Note, the Company had additional drawings under the 2016 Promissory Note totaling $2.4 million . As of September 30, 2017 , the outstanding balance under the 2016 Promissory Note was $6.4 million . Accrued interest on the 2016 Promissory Note was $0.8 million as of September 30, 2017 . In March 2017, the 2016 Promissory Note became convertible, at the sole option of the holder, into shares of the Company’s common stock at a conversion price of $3.415 per share. In July 2017, the maturity date of the 2016 Promissory Note was extended to April 2023.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Assets and Liabilities The Company has transactions in the normal course of business with its shareholders, CEHL and their affiliates. Effective April 3, 2017, Oltasho became a majority shareholder of the Company and the holder of the Related Party Notes. The following table sets forth the related party assets and liabilities as of September 30, 2017 and December 31, 2016 : ( In thousands ) September 30, December 31, 2016 Accounts receivable $ 2,821 $ 1,956 Accounts payable and accrued liabilities $ 33,388 $ 29,513 Short-term note payable - related party $ 200 $ — Long-term notes payable - related party $ 129,821 $ 129,796 As of September 30, 2017 and December 31, 2016 , the related party receivable balances of $2.8 million and $2.0 million , respectively, were for advance payments made for certain transactions on behalf of affiliates. As of September 30, 2017 and December 31, 2016 , the Company owed $33.4 million and $29.5 million , respectively, to affiliates primarily for logistical and support services in relation to the Company's oilfield operations in Nigeria, as well as accrued interest on the various related party notes payable. As of September 30, 2017 and December 31, 2016 , accrued and unpaid interest on the various related party notes payable was $21.1 million and $15.2 million , respectively. As of September 30, 2017 , the Company had a related party short term note payable balance of $0.2 million under a short term loan agreement entered into with an affiliate. As of September 30, 2017 , the Company had a combined note payable balance of $129.8 million owed to Oltasho and an affiliate, consisting of a $50.0 million 2014 Convertible Subordinated Note, $24.9 million in borrowings under the 2011 Promissory Note, a $48.5 million borrowing under the 2015 Convertible Note, net of discount, and $6.4 million under the 2016 Promissory Note. As of December 31, 2016 , the Company had a combined note payable balance of $129.8 million owed to affiliates, consisting of the $50.0 million 2014 Convertible Subordinated Note, $24.9 million in borrowings under the 2011 Promissory Note, $48.5 million borrowing under the 2015 Convertible Note, net of discount, and $6.4 million under the 2016 Promissory Note. See Note 7 – Debt for further information relating to the notes payable transactions. Results from Operations The table below sets forth a summary of transactions included in the Company's results of operations that were incurred with affiliates during the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2017 2016 2017 2016 Total operating expenses $ 2,333 $ 4,825 $ 7,058 $ 8,844 Interest expense $ 2,084 $ 1,525 $ 6,031 $ 4,987 Certain affiliates of the Company provide procurement and logistical support services to the Company’s operations. In connection therewith, during the three months ended September 30, 2017 and 2016 , the Company incurred operating costs amounting to approximately $2.3 million and $4.8 million , respectively, and during the nine months ended September 30, 2017 and 2016 , the Company incurred operating costs amounting to approximately $7.1 million and $8.8 million , respectively. During the three months ended September 30, 2017 and 2016 , the Company incurred interest expense, excluding debt discount amortization, totaling approximately $2.1 million and $1.5 million , respectively, in relation to related party notes payable. During the nine months ended September 30, 2017 and 2016 , the Company incurred interest expense totaling approximately $6.0 million and $5.0 million , respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments In February 2014, a long-term contract was signed for the floating, production, storage, and offloading vessel (“FPSO”) Armada Perdana, which is the vessel currently connected to the Company’s productive wells, Oyo-7 and Oyo-8, offshore Nigeria. The contract provides for an initial term of seven years beginning January 1, 2014, with an automatic extension for an additional term of two years unless terminated by the Company with prior notice. The FPSO can process up to 40,000 barrels of liquid per day, with a storage capacity of approximately one million barrels. The annual minimum contractual commitment per the terms of the agreement is approximately $48.4 million per year through 2020. The Company also has commitments related to four production sharing contracts with the Government of the Republic of Kenya (the “Kenya PSCs”), two Petroleum Exploration, Development & Production Licenses with the Republic of The Gambia (the “Gambia Licenses”), and one Petroleum Agreement with the Republic of Ghana (the "Ghana Petroleum Agreement"). In all cases, the Company entered into these commitments through a subsidiary. To maintain compliance and ownership, the Company is required to fulfill certain minimum work obligations and to make certain payments as stated in each of the Kenya PSCs, the Gambia Licenses, and the Ghana Petroleum Agreement. Among the Kenya PSCs in which the Company has remaining obligations, production sharing contracts related to offshore blocks L27 and L28 expired in February 2017, with the Company having no intention to renew or extend these leases. In June 2017, the Company farmed out 80% of its interest and operatorship of its offshore A2 and A5 blocks under the Gambia Licenses and will retain a 20% working interest in both blocks. See Note 4 – Property, Plant and Equipment for further information relating to the Sale Agreement. In March 2017, the Company entered into a drilling services contract with Pacific Drilling using the Pacific Bora drilling rig. The Company used this rig to drill well Oyo-9 on the Oyo field in the deepwater offshore Nigeria. Under the contract, the Company has the option to drill up to two additional wells. The option to extend the contract, if exercised, would be used to drill two of its offshore Nigeria exploration prospects in the prolific Miocene geological zone. The Pacific Bora is a highly efficient sixth generation double-hulled drillship currently in Nigeria and was mobilized to the Oyo field and on site August 1, 2017. The contract provides for a base operating rate of $195,000 per day. The rig can be used for both drilling and well completion. In October 2017, the Company successfully completed the drilling phase of the Oyo-9 well. However, due to chronic delays in the release of the remaining funds and improper interference by the guarantor of the MCB Finance Facility, the Company temporarily suspended the completion and hookup of the Oyo-9 well. Contingencies Legal Contingencies and Proceedings From time to time, the Company may be involved in various legal proceedings and claims in the ordinary course of business. As of September 30, 2017 , and through the filing date of this report, the Company does not believe the ultimate resolution of such actions or potential actions of which the Company is currently aware will have a material effect on its consolidated financial position or results of operations. On January 22, 2016, a request for arbitration was filed with the London Court of International Arbitration by Transocean Offshore Gulf of Guinea VII Limited and Indigo Drilling Limited, as Claimants, against the Company and its Nigerian subsidiary, EPNL, as Respondents (the “Arbitration”). The Arbitration was in relation to a drilling contract entered into by the Claimants and EPNL, and a parent company guarantee provided by the Company in relation thereto. On July 19, 2017, the London Court of International Arbitration issued a “First Partial Final Award by Consent” (the “Consent Award”) in a proceeding between the Claimants and Respondents to resolve claims by the Claimants arising out of a contract for oilfield services done in relation to the Company's ordinary course of business. Pursuant to the Consent Award, the Respondents are liable to pay Claimants approximately $14.0 million and 11.8 million Nigerian Naira (NGN), equal to approximately $33,000 U.S. dollars. On February 5, 2016, a class action and derivative complaint was filed in the Delaware Chancery Court purportedly on behalf of the Company and on behalf of a putative class of persons who were stockholders as of the date the Company (1) acquired interests in Oil Mining Leases located offshore Nigeria from Allied pursuant to the Transfer Agreement and (2) issued shares to PIC in a private placement (collectively the “February 2014 Transactions”). The complaint alleges the February 2014 Transactions were unfair to the Company and purports to assert derivative claims against (1) the seven individuals who served on our Board at the time of the February 2014 Transactions and (2) our then majority shareholder, CEHL. The complaint also purports to assert a direct breach of fiduciary duty claim on behalf of the putative class against the seven individuals who served on our Board at the time of the February 2014 Transactions on the grounds that they purportedly caused the Company to disseminate a false and misleading proxy statement in connection with the February 2014 Transactions, and a direct claim for aiding and abetting against Dr. Kase Lawal, the former Executive Chairman of the Board of Directors and former Chief Executive Officer of the Company. The plaintiff is seeking, on behalf of the Company and the putative class, an undisclosed amount of compensatory damages. The Company is named solely as a nominal defendant against whom the plaintiff seeks no recovery. On March 3, 2016, all of the defendants, including the Company, filed motions to dismiss the complaint, which motions were heard on January 18, 2017. The plaintiffs filed a motion to supplement their petition to include a claim relating to what Allied paid or did not pay Nigerian Agip Exploration Limited for the asset. On May 23, 2017, the court granted plaintiffs’ motion to supplement petition. On June 23, 2017, the defendants filed short motions to dismiss the supplemental allegations. The plaintiffs filed their response on July 12, 2017 and the defendants filed a reply on July 21, 2017. On June 27, 2017, BGP Kenya Limited ("BGP") filed suit against EEKL in the High Court of Kenya. BGP is seeking approximately $12.2 million , which includes interest of approximately $2.7 million for allegedly unpaid amounts in connection with BGP’s performance of seismic services in Kenya done in relation to the Company's ordinary course of business. EEKL is contesting the proceedings. On July 13, 2017, Multiplan Nigeria Limited ("Multiplan") entered into a settlement agreement and release (the “Multiplan Settlement Agreement”) with EPNL for $3.0 million , to resolve claims by Multiplan for work done in relation to the Company's ordinary course of business. As a result thereof, the Company decreased its accounts payable and accrued liabilities by $0.2 million with a corresponding decrease to its oil and gas properties as of September 30, 2017 . As part of the Multiplan Settlement Agreement, the Company paid $1.0 million to Multiplan in July 2017, and all remaining amounts claimed by Mulitiplan are due to be discharged by EPNL prior to the end of 2017. On July 14, 2017, Aker Solutions Inc. ("Aker") entered into a settlement agreement and release (the “Aker Settlement Agreement”) with EPNL for $2.5 million , to resolve claims by Aker for work done in relation to the Company's ordinary course of business. As a result thereof, the Company decreased its accounts payable and accrued liabilities by $10.2 million with a corresponding decrease to its oil and gas properties as of September 30, 2017 . As part of the Aker Settlement Agreement, EPNL paid $1.0 million to Aker in July 2017, and all remaining amounts claimed by Aker are due to be discharged by EPNL prior to the end of 2017. In September 2017, the Company entered into a Mutual Release Agreement and Stock Purchase Agreement, (collectively, the "September 2017 Settlement Agreement") with a vendor, to resolve claims by the vendor for work done in relation to the Company's ordinary course of business. As part of the September 2017 Settlement Agreement, the Company issued 1,282,355 shares of restricted common stock to the vendor at a fair value of $3.5 million . Unrecognized Loss Contingency As of September 30, 2017 , the Company has not accrued penalty and interest related to certain outstanding transactional tax obligations in Nigeria, including withholding taxes, value-added taxes, Nigerian Oil and Gas Industry Content Development Act (NCD) tax, Cabotage taxes, and Niger Delta Development Corporation taxes (NDDC). As of the date of this report, the Company believes that, based on its experience with local practices in Nigeria, the likelihood of being assessed penalty and interest is reasonably possible, with an estimated liability up to $22.1 million . Contingency under the Allied Transfer Agreement As provided for under the Transfer Agreement with Allied, the Company is required to make the following additional payments upon the occurrence of certain future events: (i) $25.0 million cash or the equivalent in shares of the Company’s common stock within fifteen days following the approval of a development plan by the Nigerian Department of Petroleum Resources ("DPR") with respect to a first new discovery of hydrocarbons in a non-Oyo field area; and (ii) $25.0 million cash or the equivalent in shares of the Company’s common stock within fifteen days starting from the commencement of the first hydrocarbon production in commercial quantities in a non-Oyo field area. The number of shares to be issued shall be determined by calculating the average closing price of the Company’s common stock over a period of thirty days, counted back from the first business day immediately prior to the approval of a development plan by DPR or the date of the first hydrocarbon production in commercial quantities, as applicable. Contingency under the 2015 Convertible Note As part of the condition to the extension of the maturity date of the 2015 Convertible Note, which extension was entered into in March 2016, the Company is required to (i) pay to Allied an amount equal to ten percent ( 10% ) towards existing liabilities of any successful debt fundraising event completed during the remaining term of the 2015 Convertible Note; and (ii) pay to Allied an amount equal to twenty percent ( 20% ) towards existing liabilities of any successful equity fundraising event completed during the remaining term of the 2015 Convertible Note. Despite the 2015 Convertible Note being transferred to Oltasho (See Note 7 - Debt ) the amounts due under the provision of this extension remain due to Allied. The execution of the MCB Financing Facility in February 2017 triggered item (i) above of which a payment is due to Allied under these provisions.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock Options The table below sets forth a summary of stock option activity for the nine months ended September 30, 2017 . Shares Weighted-Average Weighted-Average Outstanding at December 31, 2016 1,147 $2.54 2.0 Granted 745 $2.26 1.0 Exercised (511 ) $1.81 — Forfeited (639 ) $2.69 — Expired (145 ) $3.55 — Outstanding at September 30, 2017 597 $2.40 1.8 Expected to vest 145 $1.88 4.7 Exercisable at September 30, 2017 452 $2.57 0.9 During the nine months ended September 30, 2017 , the Company issued 183,160 shares of common stock as a result of the exercise of stock options, all of which were issued as a result of the cashless exercise of options to purchase 510,555 shares of common stock. Also, during the nine months ended September 30, 2017 , options to purchase 638,891 shares of common stock were forfeited and options to purchase 145,000 shares of common stock expired. The estimated fair value of stock options granted during the nine months ended September 30, 2017 was approximately $0.9 million , and was computed using the Black-Scholes option pricing model. Stock Warrants The table below sets forth a summary of stock warrant activity for the nine months ended September 30, 2017 . Shares Weighted-Average Weighted-Average Outstanding at December 31, 2016 2,983 $3.59 3.2 Granted — $— — Exercised — $— — Forfeited — $— — Expired — $— — Outstanding at September 30, 2017 2,983 $3.59 2.5 Expected to vest — $— — Exercisable at September 30, 2017 2,983 $3.59 2.5 Restricted Stock Awards The table below sets forth a summary of restricted stock awards (“RSAs”) activity for the nine months ended September 30, 2017 . Shares Weighted-Average Non-vested at December 31, 2016 2,072 $ 2.25 Granted 1,122 $ 3.00 Vested (1,038 ) $ 2.39 Forfeited (746 ) $ 2.98 Non-vested as of September 30, 2017 1,410 $ 2.36 During the nine months ended September 30, 2017 , the Company granted officers, directors, and employees a total of approximately 1.1 million shares of restricted common stock, including 0.2 million performance-based restricted stock awards ("PBRSA"), with vesting periods varying from immediate vesting to 36 months . During the same period, 0.7 million shares of restricted common stock were forfeited. The fair value of RSAs granted during the nine months ended September 30, 2017 was approximately $3.4 million , which is being amortized to expense over the respective vesting periods of each grant. With regards to the PBRSA, each grant will vest if the individuals remain employed three years from the date of grant and the Company achieves specific performance objectives at the end of the designated performance period. Up to 50% additional shares may be awarded if performance objectives are exceeded. None of the PBRSAs will vest if certain minimum performance goals are not met. The performance conditions are based on the Company’s total shareholder return over the performance period compared to an industry peer group of companies. Total estimated compensation expense is $0.1 million over three years. Issuance of Common Shares During September 2017, the Company issued 33,333 shares of restricted common stock to a consultant for services rendered with a fair value of $0.1 million . Also during September 2017, the Company issued 1,282,355 shares of restricted common stock to a vendor under the September 2017 Settlement Agreement with a fair value of $3.5 million (See Note 9 - Commitments and Contingencies ).

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Company’s current operations are based in Nigeria, Kenya, The Gambia, and Ghana. Management reviews and evaluates the operations of each geographic segment separately. Operations include exploration for and production of hydrocarbons where commercial reserves have been found and developed. Revenues and expenditures are recognized at the relevant geographical location. The Company evaluates each segment based on operating income (loss). Segment activity for the three and nine months ended September 30, 2017 and 2016 are as follows: ( In thousands ) Nigeria Kenya The Gambia Ghana Corporate and Other Total Three months ended September 30, 2017 Revenues $ 33,643 $ — $ — $ — $ — $ 33,643 Operating loss $ (6,861 ) $ (109 ) $ (207 ) $ (807 ) $ (2,046 ) $ (10,030 ) 2016 Revenues $ 28,619 $ — $ — $ — $ — $ 28,619 Operating loss $ (17,323 ) $ (434 ) $ (728 ) $ (210 ) $ (3,122 ) $ (21,817 ) Nine months ended September 30, 2017 Revenues $ 79,509 $ — $ — $ — $ — $ 79,509 Operating loss $ (114,576 ) $ (1,404 ) $ 1,591 $ (1,820 ) $ (8,046 ) $ (124,255 ) 2016 Revenues $ 56,699 $ — $ — $ — $ — $ 56,699 Operating loss $ (63,777 ) $ (1,485 ) $ (1,251 ) $ (1,328 ) $ (9,468 ) $ (77,309 ) Total assets by segment as of September 30, 2017 and December 31, 2016 , are as follows: ( In thousands ) Nigeria Kenya The Gambia Ghana Corporate and Other Total Total Assets As of September 30, 2017 $ 218,827 $ 61 $ 4,069 $ 5,230 $ 1,304 $ 229,491 As of December 31, 2016 $ 281,050 $ 698 $ 3,034 $ 3,648 $ 771 $ 289,201

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 27, 2017 the Company, through its wholly-owned subsidiary, EPNL, entered into a loan agreement, (the "2017 Loan Agreement"), with James Street Capital Partners Limited, ("JSC") as the lender, allowing the Company to borrow up to $20.0 million to be used for capital expenditures in relation to the drilling of an exploration well in the Miocene formation of the OMLs. Interest accrues on the outstanding principal of the 2017 Loan Agreement at LIBOR plus 5% per annum, payable quarterly in cash or issuance of the Company's restricted common stock. The Company is required to repay one third of the principal amount outstanding under the loan agreement, on each of December 31, 2018, 2019 and 2020. Amounts outstanding under the 2017 Loan Agreement may be paid at any time without penalty. In consideration for this undertaking, the Company issued a stock purchase warrant to JSC to purchase up to 7,017,544 shares of the Company's common stock at $2.85 per share. The warrants include a repurchase right such that upon repayment in full of the amounts borrowed under the 2017 Loan Agreement the Company may repurchase the warrants at their fair market value (as defined in the warrant agreement). The warrants expire on September 30, 2020 and include cashless exercise rights in the event the shares of common stock issuable upon exercise thereof are not registered under the Securities Act of 1933, as amended.

Basis of Presentation and Rec19

Basis of Presentation and Recently Issued Accounting Standards (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly-owned and majority-owned direct and indirect subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany transactions and balances have been eliminated in consolidation. The unaudited consolidated financial statements reflect all adjustments that are, in the opinion of management, necessary for a fair presentation of the consolidated financial position and results of operations for the indicated periods. All such adjustments are of a normal recurring nature. This Form 10-Q should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 , filed with the SEC on March 16, 2017.
Use of Estimates	The preparation of the Company's consolidated financial statements in conformity with U.S. GAAP requires management to make estimates based on certain assumptions. Estimates affect the reported amounts of assets and liabilities, disclosure of contingent liabilities, and the reported amounts of revenues and expenses attributable to the reporting periods. Accordingly, accounting estimates in conformity with U.S. GAAP require the exercise of judgment. These estimates and assumptions used in the preparation of the Company’s consolidated financial statements are based on information available as of the date of the consolidated financial statements, and while management believes that the estimates and assumptions are appropriate, actual results could differ from management's estimates. Estimates that may have a significant effect on the Company’s financial position and results from operations include share-based compensation assumptions, oil and natural gas reserve quantities, impairments, depletion and amortization relating to oil and natural gas properties, asset retirement obligation assumptions, calculations related to derivative liabilities, and income taxes. The accounting estimates used in the preparation of the Company's consolidated financial statements may change as new events occur, more experience is acquired, additional information is obtained and our operating environment changes.
Restricted Cash	Restricted Cash Restricted cash consists of cash deposits that are contractually restricted for withdrawal or required to be maintained in a reserve bank account for a specific period of time, as provided for under certain agreements with third parties.
Successful Efforts Method of Accounting for Oil and Gas Activities	Successful Efforts Method of Accounting for Oil and Gas Activities The Company follows the successful efforts method of accounting for its costs of acquisition, exploration and development of oil and gas properties. Under this method, oil and gas lease acquisition costs and intangible drilling costs associated with exploration efforts that result in the discovery of proved reserves and costs associated with development drilling, whether or not successful, are capitalized when incurred. Drilling costs of exploratory wells are capitalized pending determination that proved reserves have been found. If the determination is dependent upon the results of planned additional wells and require additional capital expenditures to develop the reserves, the drilling costs will be capitalized as long as sufficient reserves have been found to justify completion of the exploratory well as a producing well, and additional wells are underway or firmly planned to complete the evaluation of the well. Exploratory wells not meeting the criteria for continued capitalization are expensed when such a determination is made. Other exploration costs are expensed as incurred.
Capitalized Interest	Capitalized Interest The Company capitalizes interest costs for qualifying oil and gas properties. The capitalization period begins when expenditures are incurred on qualified properties, activities begin which are necessary to prepare the property for production, and interest costs have been incurred. The capitalization period continues as long as these events occur. Capitalized interest is added to the cost of the underlying assets and is depleted using the unit-of-production method in the same manner as the underlying assets.
Net Loss Per Common Share	Net Loss Per Common Share Basic net earnings or loss per common share is computed by dividing net earnings or loss by the weighted average number of shares of common stock outstanding at the end of the reporting period. Diluted net earnings or loss per share is computed by dividing net earnings or loss by the fully dilutive common stock equivalent, which consists of shares outstanding, augmented by potentially dilutive shares issuable upon the exercise of the Company's stock options, stock warrants, non-vested restricted stock awards, as well as the conversions of the 2011 Promissory Note, the 2014 Convertible Subordinated Note and the 2016 Promissory Note (collectively, the "Convertible Notes", each defined and described in greater detail under Note 7 - Debt ), calculated using the treasury stock method.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the amount at which an asset (or liability) could be bought (or incurred) or sold (or settled) in an orderly transaction between market participants at the measurement date. The established framework for measuring fair value establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and includes certain disclosure requirements. Fair value estimates are based on either (i) actual market data or (ii) assumptions that other market participants would use in pricing an asset or liability, including estimates of risk. There are three levels of valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy categorizes assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. The three levels are defined as follows: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. The Company considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an on-going basis. Level 2 - Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. Substantially all of these inputs are observable in the marketplace throughout the term, can be derived from observable data, or supported by observable levels at which transactions are executed in the marketplace. Level 3 - Inputs that are unobservable and significant to the fair value measurement (including the Company’s own assumptions in determining fair value). The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Fair Value on a Recurring Basis The Company uses discounted cash flow techniques to determine the estimated fair value of its oil and gas properties as part of the Company's analysis for impairment. Accordingly, the Company estimated the present value of expected future net cash flows from the Oyo field, discounted using risk-adjusted cost of capital. Significant Level 3 assumptions used in the calculation include the Company's estimate of future crude oil prices, production costs, development costs, and anticipated production of proved reserves, as well as appropriate risk-adjusted probable and possible reserves. As discussed under Note 7 - Debt, the Company recognized a derivative liability relating to the portion of the amount drawn from the MCB Financing Facility as of September 30, 2017 in which issuance of stock warrants is expected on the day the Company receives funds under the MCB Finance Facility. The Company utilized a combination of a lattice-binomial option-pricing model and the Black-Scholes valuation model to determine the estimated fair value of this derivative liability.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842). ASU 2016-02 is aimed at making leasing activities more transparent and comparable, and requires substantially all leases be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability, including leases currently accounted for as operating leases. ASU 2016-02 is effective for the Company in the fiscal year beginning after December 15, 2018, and interim periods within those fiscal years with early adoption permitted. The Company is still evaluating the impact of this standard. However, due to the nature of its operations, the adoption of this standards update could have a material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”). This ASU clarifies 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. This guidance is to be applied using a prospective method and is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment . ASU 2017-04 eliminates step 2 of the goodwill impairment test. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for annual reporting periods and interim reporting periods within those annual reporting periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In February 2017, the FASB issued ASU 2017-05, Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. This ASU clarifies the scope and application of ASC 610-20 on the sale or transfer of nonfinancial assets and in substance nonfinancial assets to noncustomers, including partial sales. The Company is required to adopt this guidance at the same time that it adopts the guidance in ASU 2014-09. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities . This ASU shortens the amortization period for certain callable debt securities held at a premium to the earliest call date. However, the amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. ASU 2017-08 is effective for the Company in the fiscal year beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting, which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. This pronouncement is effective for annual reporting periods beginning after December 15, 2017. Early adoption is permitted. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-10, Service Concession Arrangements (Topic 853): Determining the Customer of the Operation Services . ASU No. 2017-10 provides clarity on determining the customer in a service concession arrangement. ASU No. 2017-10 is effective for interim and annual periods beginning after December 15, 2017, and the Company will adopt this standards update, as required, beginning with the first quarter of 2018. The adoption of this standards update is not expected to have a material impact on the Company’s consolidated financial statements. In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features . ASU No. 2017-11 amendments simplify the accounting for certain financial instruments with down round features. The amendments require companies to disregard the down round feature when assessing whether the instrument is indexed to its own stock, for purposes of determining liability or equity classification. Companies that provide earnings per share (EPS) data will adjust their basic EPS calculation for the effect of the feature when triggered (i.e., when the exercise price of the related equity-linked financial instrument is adjusted downward because of the down round feature) and will also recognize the effect of the trigger within equity. ASU No. 2017-11 is effective for interim and annual periods beginning after December 15, 2018, and the Company will adopt this standards update, as required, beginning with the first quarter of 2019. The adoption of this standard update is not expected to have a material impact on the Company’s consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Improvements to Accounting for Hedging Activities . ASU No. 2017-12 amends and better aligns an entity’s risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. To meet that objective, the amendments expand and refine hedge accounting for both non-financial and financial risk components and align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. ASU No. 2017-12 is effective for interim and annual periods beginning after December 15, 2018, and the Company will adopt this standards update, as required, beginning with the first quarter of 2019. The adoption of this standard update is not expected to have a material impact on the Company’s consolidated financial statements.

Basis of Presentation and Rec20

Basis of Presentation and Recently Issued Accounting Standards (Tables)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Schedule of Shares Withholding and Repurchases of Common Stock	The following table sets forth certain information with respect to the withholding and related repurchases of our common stock during the nine months ended September 30, 2017 . Total Number of Average Price January 1 - January 31, 2017 12,650 $ 3.55 February 1 - February 28, 2017 158,264 3.82 May 1 - May 31, 2017 33,635 1.75 Total 204,549 $ 3.46 (1) All shares repurchased were surrendered by employees to settle tax withholding obligations upon the vesting of restricted stock awards and the exercise of stock options. The price paid was the closing price on the dates in which the shares of common stock vested or when the stock options were exercised.
Antidilutive Securities Excluded from Computation of Earnings Per Share	The table below sets forth the number of stock options, stock warrants, non-vested restricted stock, and shares issuable upon conversion of the Convertible Notes that were excluded from dilutive shares outstanding during the three and nine months ended September 30, 2017 and 2016 , respectively, as these securities are anti-dilutive because the Company was in a loss position during each period. Three Months Ended September 30, Nine Months Ended September 30, ( In thousands ) 2017 2016 2017 2016 Stock options 98 206 140 249 Stock warrants 4 7 7 2 Unvested restricted stock awards 1,408 2,128 1,759 1,889 1,510 2,341 1,906 2,140
Schedule of Financial Assets and Liabilities Measured on Recurring Basis	The following table sets forth the Company’s oil and gas properties and derivative liability that is accounted for at fair value using Level 3 assumptions on a recurring basis as of September 30, 2017 and December 31, 2016 : Level 3 (in thousands) September 30, 2017 December 31, 2016 Liabilities: Derivative liability $ 1,751 $ —
Schedule of Fair Value Liability Valuation Assumptions	The fair value of the derivative liability is estimated using a combination of a lattice-binomial option-pricing model and the Black-Scholes valuation model with the following assumptions as of September 30, 2017 : September 30, 2017 Estimated market value of common stock on measurement date $ 2.85 Estimated exercise price $ 2.85 Risk-free interest rate (1) 1.62 % Expected warrant term (years) 3 Expected volatilities (2) 10.0% - 38.9% Expected annual dividend yield — (1 ) The risk-free rate for periods within the contractual life of the warrants is based on the U.S. Treasury yield curve in effect at the time of grant. (2 ) Expected volatilities are based on historical volatility of the Oil & Gas Exploration & Production Select Industries Index, among other factors.
Reconciliation of Changes in Fair Value of Liabilities	The following table sets forth a reconciliation of changes in the fair value of the Company's financial liability that is accounted for at fair value using Level 3 inputs, and is classified as level 3 in the fair value hierarchy: Three Months Ended Nine Months Ended (in thousands) September 30, 2017 September 30, 2017 Beginning balance $ 656 $ — Loss (gain) on fair value of derivative liability 22 (15 ) Additions 1,073 1,977 Revisions — (211 ) Transfers — — Ending balance $ 1,751 $ 1,751 Change in unrealized loss (gain) included in earnings relating to derivatives still held as of September 30, 2017 $ 22 $ (15 )

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment were comprised of the following: ( In thousands ) September 30, December 31, 2016 Wells and production facilities $ 308,451 $ 318,739 Proved properties 386,196 386,196 Work in progress and exploration inventory 81,951 34,712 Oilfield assets 776,598 739,647 Accumulated depletion (609,204 ) (483,754 ) Oilfield assets, net 167,394 255,893 Unevaluated leaseholds 6,200 9,820 Oil and gas properties, net 173,594 265,713 Other property and equipment 2,895 3,040 Accumulated depreciation (2,470 ) (2,324 ) Other property and equipment, net 425 716 Total property, plant and equipment, net $ 174,019 $ 266,429

Accounts Payable and Accrued 22

Accounts Payable and Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2017
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	The table below sets forth a summary of the Company’s accounts payable and accrued liabilities at September 30, 2017 and December 31, 2016 : (In thousands) September 30, December 31, 2016 Accounts payable - vendors $ 179,467 $ 173,306 Amounts due to government entities 77,139 66,573 Accrued payroll and benefits 1,164 3,074 Accrued interest 3,972 1,204 Other liabilities — 806 $ 261,742 $ 244,963

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Summary of Changes in Asset Retirement Obligations	The following summarizes changes in the Company’s asset retirement obligations during the nine months ended September 30, 2017 ( in thousands ): Balance at January 1, 2017 $ 22,476 Accretion expense 1,434 Balance at September 30, 2017 $ 23,910

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt	Scheduled principal repayments on the outstanding balance on the Term Loan Facility and the MCB Finance Facility are as follows ( in thousands ): Scheduled payments by year Principal 2017 (remainder) $ 24,931 2018 62,054 2019 21,277 2020 26,597 2021 and thereafter 12,198 Total principal payments 147,057 Less: Unamortized debt issuance costs (9,191 ) Total Long term debt, net $ 137,866

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Summary of Related Party Transactions and Balances	The table below sets forth a summary of transactions included in the Company's results of operations that were incurred with affiliates during the three and nine months ended September 30, 2017 and 2016 : Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2017 2016 2017 2016 Total operating expenses $ 2,333 $ 4,825 $ 7,058 $ 8,844 Interest expense $ 2,084 $ 1,525 $ 6,031 $ 4,987 The following table sets forth the related party assets and liabilities as of September 30, 2017 and December 31, 2016 : ( In thousands ) September 30, December 31, 2016 Accounts receivable $ 2,821 $ 1,956 Accounts payable and accrued liabilities $ 33,388 $ 29,513 Short-term note payable - related party $ 200 $ — Long-term notes payable - related party $ 129,821 $ 129,796

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock and Restricted Stock Units Activity	The table below sets forth a summary of restricted stock awards (“RSAs”) activity for the nine months ended September 30, 2017 . Shares Weighted-Average Non-vested at December 31, 2016 2,072 $ 2.25 Granted 1,122 $ 3.00 Vested (1,038 ) $ 2.39 Forfeited (746 ) $ 2.98 Non-vested as of September 30, 2017 1,410 $ 2.36
Stock warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation	The table below sets forth a summary of stock warrant activity for the nine months ended September 30, 2017 . Shares Weighted-Average Weighted-Average Outstanding at December 31, 2016 2,983 $3.59 3.2 Granted — $— — Exercised — $— — Forfeited — $— — Expired — $— — Outstanding at September 30, 2017 2,983 $3.59 2.5 Expected to vest — $— — Exercisable at September 30, 2017 2,983 $3.59 2.5
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation	The table below sets forth a summary of stock option activity for the nine months ended September 30, 2017 . Shares Weighted-Average Weighted-Average Outstanding at December 31, 2016 1,147 $2.54 2.0 Granted 745 $2.26 1.0 Exercised (511 ) $1.81 — Forfeited (639 ) $2.69 — Expired (145 ) $3.55 — Outstanding at September 30, 2017 597 $2.40 1.8 Expected to vest 145 $1.88 4.7 Exercisable at September 30, 2017 452 $2.57 0.9

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of Segment Activity	Segment activity for the three and nine months ended September 30, 2017 and 2016 are as follows: ( In thousands ) Nigeria Kenya The Gambia Ghana Corporate and Other Total Three months ended September 30, 2017 Revenues $ 33,643 $ — $ — $ — $ — $ 33,643 Operating loss $ (6,861 ) $ (109 ) $ (207 ) $ (807 ) $ (2,046 ) $ (10,030 ) 2016 Revenues $ 28,619 $ — $ — $ — $ — $ 28,619 Operating loss $ (17,323 ) $ (434 ) $ (728 ) $ (210 ) $ (3,122 ) $ (21,817 ) Nine months ended September 30, 2017 Revenues $ 79,509 $ — $ — $ — $ — $ 79,509 Operating loss $ (114,576 ) $ (1,404 ) $ 1,591 $ (1,820 ) $ (8,046 ) $ (124,255 ) 2016 Revenues $ 56,699 $ — $ — $ — $ — $ 56,699 Operating loss $ (63,777 ) $ (1,485 ) $ (1,251 ) $ (1,328 ) $ (9,468 ) $ (77,309 ) Total assets by segment as of September 30, 2017 and December 31, 2016 , are as follows: ( In thousands ) Nigeria Kenya The Gambia Ghana Corporate and Other Total Total Assets As of September 30, 2017 $ 218,827 $ 61 $ 4,069 $ 5,230 $ 1,304 $ 229,491 As of December 31, 2016 $ 281,050 $ 698 $ 3,034 $ 3,648 $ 771 $ 289,201

Company Description (Details)

Company Description (Details) km² in Thousands, a in Millions	Jul. 05, 2017shares	Sep. 30, 2017a	Sep. 30, 2017	Sep. 30, 2017country	Sep. 30, 2017license	Sep. 30, 2017km²	Apr. 13, 2017shares	Apr. 03, 2017shares
Schedule of Equity Method Investments [Line Items]
Number of exploration and production licenses | license					5
Number of countries company operates in Africa | country				3
Area of land held for exploration activities (in acres and square kilometers)		1.5				6
Shares transferred, voting interest outstanding			54.60%
Allied Energy Plc
Schedule of Equity Method Investments [Line Items]
Shares transferred								116,108,833
Shares transferred, voting interest outstanding			53.90%
CAMAC International (Nigeria) Ltd.
Schedule of Equity Method Investments [Line Items]
Shares transferred							1,515,927
Shares transferred, voting interest outstanding			0.70%
Dr. Lawal
Schedule of Equity Method Investments [Line Items]
Shares transferred, voting interest transferred	117,624,760
Voting percentage owned	54.60%
Voting agreement term (in years)	10 years

Basis of Presentation and Rec29

Basis of Presentation and Recently Issued Accounting Standards - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 13,761		$ 2,600
Interest costs capitalized	$ 2,200	$ 0
Shares withheld for taxes (in shares)	204,549	90,347
Payments for treasury stock arising from withholding taxes	$ 708	$ 206
Allied
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contingent additional payment under transfer agreement (up to)	50,000
Term Loan Facility
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	2,600		$ 2,600
MCB Finance Facility, Debt Service Reserve
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 11,200

Basis of Presentation and Rec30

Basis of Presentation and Recently Issued Accounting Standards - Shares Withholding and Repurchases of Common Stock (Details) - $ / shares	1 Months Ended			9 Months Ended
	May 31, 2017	Feb. 29, 2016	Jan. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares purchased (in shares)				204,549	90,347
Average price paid per share (in dollars per share)				$ 3.46
January 1 - January 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares purchased (in shares)			12,650
Average price paid per share (in dollars per share)			$ 3.55
February 1 - February 28, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares purchased (in shares)		158,264
Average price paid per share (in dollars per share)		$ 3.82
May 1 - May 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares purchased (in shares)	33,635
Average price paid per share (in dollars per share)	$ 1.75

Basis of Presentation and Rec31

Basis of Presentation and Recently Issued Accounting Standards - Antidilutive Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	1,510	2,341	1,906	2,140
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	98	206	140	249
Stock warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	4	7	7	2
Unvested restricted stock awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	1,408	2,128	1,759	1,889

Basis of Presentation and Rec32

Basis of Presentation and Recently Issued Accounting Standards - Schedule of Liabilities on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	$ 1,751	$ 0

Basis of Presentation and Rec33

Basis of Presentation and Recently Issued Accounting Standards - Schedule of Fair Value Liability Assumptions (Details) - Recurring - Level 3	9 Months Ended
	Sep. 30, 2017$ / shares
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Estimated market value of common stock on measurement date (usd per share)	$ 2.85
Estimated exercise price (usd per share)	$ 2.85
Risk-free interest rate	1.62%
Expected warrant term (years)	3 years
Expected annual dividend yield	0.00%
Minimum
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Expected volatilities	10.00%
Maximum
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Expected volatilities	38.90%

Basis of Presentation and Rec34

Basis of Presentation and Recently Issued Accounting Standards - Reconciliation of Liability Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 656	$ 0
Loss (gain) on fair value of derivative liability	22	(15)
Additions	1,073	1,977
Revisions	0	(211)
Transfers	0	0
Ending balance	1,751	1,751
Change in unrealized loss (gain) included in earnings relating to derivatives still held as of September 30, 2017	$ 22	$ (15)

Liquidity Matters and Going C35

Liquidity Matters and Going Concern - Narrative (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)bbl	Dec. 31, 2016USD ($)
Liquidity Matters [Abstract]
Current liabilities	$ 366,248	$ 287,103
Current assets	55,437	$ 22,706
Working capital deficit	$ 310,800
Emergency shut-in, barrels of oil lost per day | bbl	1,400

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Wells and production facilities	$ 308,451	$ 318,739
Proved properties	386,196	386,196
Work in progress and exploration inventory	81,951	34,712
Oilfield assets	776,598	739,647
Accumulated depletion	(609,204)	(483,754)
Oilfield assets, net	167,394	255,893
Unevaluated leaseholds	6,200	9,820
Oil and gas properties, net	173,594	265,713
Other property and equipment	2,895	3,040
Accumulated depreciation	(2,470)	(2,324)
Other property and equipment, net	425	716
Total property, plant and equipment, net	$ 174,019	$ 266,429

Property, Plant and Equipment37

Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2017	Sep. 30, 2017
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Noncash impairment charge to reduce oil and gas properties		$ 78.1
Noncash impairment of lease		0.6
Disposal Group, Held-for-sale, Not Discontinued Operations | FAR | Gambia Farm-Out Agreement
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Project interest sold	80.00%
Project interest retained	20.00%
Sale and operatorship transfer of offshore blocks, subject to approval		5.2
Projected exploration costs		$ 8

Accounts Payable and Accrued 38

Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable - vendors	$ 179,467	$ 173,306
Amounts due to government entities	77,139	66,573
Accrued interest	1,164	3,074
Accrued interest	3,972	1,204
Other liabilities	0	806
Accounts payable and accrued liabilities	$ 261,742	$ 244,963

Asset Retirement Obligations -

Asset Retirement Obligations - Summary of Change in Asset Retirement Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning balance			$ 22,476
Accretion expense	$ 489	$ 472	1,434	$ 1,385
Asset retirement obligations, ending balance	$ 23,910		$ 23,910

Debt - Short-Term Debt (Details

Debt - Short-Term Debt (Details) - USD ($) $ in Thousands	Sep. 19, 2017	Sep. 30, 2017	Feb. 28, 2017	Sep. 30, 2017	Sep. 30, 2016
Short-term Debt [Line Items]
Proceeds from short-term notes payable - related party				$ 200	$ 0
Glencore Energy UK Ltd.
Short-term Debt [Line Items]
Proceeds from collection of advance to affiliate		$ 23,500	$ 13,600
Glencore Energy UK Ltd. | London Interbank Offered Rate (LIBOR)
Short-term Debt [Line Items]
Advance from affiliate, basis spread on variable rate		6.50%	6.50%	6.50%
2017 Short-Term Note
Short-term Debt [Line Items]
Proceeds from short-term notes payable - related party	$ 200
Interest rate	5.00%

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details)	Jun. 27, 2017USD ($)	Feb. 06, 2017USD ($)	Mar. 31, 2017USD ($)	Mar. 06, 2017	Aug. 31, 2016USD ($)$ / bbl	Jun. 30, 2016USD ($)	Mar. 31, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Foreign currency transaction gain									$ 2,372,000	$ 10,442,000
Total Long term debt, net									137,866,000
Long-term debt, net									68,786,000		$ 74,446,000
Current portion of long-term debt, net									69,080,000		12,627,000
Principal repayment									141,000	0
Damages sought	$ 10,000,000
Payments of debt issuance costs									8,655,000	1,040,000
Debt issuance costs remaining unamortized									9,191,000
Proceeds from MCB Finance Facility									63,191,000	$ 0
Term Loan Facility
Line of Credit Facility [Line Items]
Debt term (in years)								5 years
Maximum borrowing capacity								$ 100,000,000
Percent of maximum borrowing capacity available in USD								90.00%
Percent of maximum borrowing capacity available in Naira								10.00%
Price of oil per barrel, initial threshold (USD per barrel) | $ / bbl					55
Line of credit facility, commitment fee amount					$ 1,400,000	$ 2,600,000
Unamortized debt issuance costs									$ 1,700,000
Debt instrument, unremedied material breach, maximum time period (in days)									30 days
Foreign currency transaction gain									$ 5,000,000
Total Long term debt, net									82,300,000
Long-term debt, net									59,700,000
Current portion of long-term debt, net									22,600,000
Interest payable									2,100,000
Term Loan Facility | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate								9.00%
Term Loan Facility, Naira Portion
Line of Credit Facility [Line Items]
Line of credit facility, annual principal payment									400,000
Term Loan Facility, U.S. Dollar Portion
Line of Credit Facility [Line Items]
Line of credit facility, annual principal payment									4,200,000
Line of Credit | Promissory Note To Allied
Line of Credit Facility [Line Items]
Maximum borrowing capacity									25,000,000
Interest payable									2,200,000
Line of Credit | MCB Finance Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 100,000,000
Unused commitment fee (as a percentage)				2.00%
Debt instrument, upfront fee, percentage of bank guarantee		2.50%
Debt instrument, upfront fee, dividend multiplier of warrants issued		20.00%
Line of Credit | MCB Finance Facility | 60-Day London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate				6.00%
Convertible Debt | 2015 Convertible Note
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 50,000,000
Interest payable									7,300,000
Convertible Debt | 2015 Convertible Note | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate							5.00%
EPNL | Line of Credit | MCB Finance Facility
Line of Credit Facility [Line Items]
Interest payable									1,900,000
Principal repayment									100,000
Deposit requirement		$ 10,000,000
Payments of debt issuance costs									8,700,000
Debt issuance costs remaining unamortized									7,500,000
Proceeds from MCB Finance Facility									$ 63,200,000
Financial Guarantee | South African Public Investment Corporation | Line of Credit | MCB Finance Facility
Line of Credit Facility [Line Items]
Payments of debt issuance costs			$ 2,500,000
Bank guarantee, maximum		$ 100,000,000
Allied | Promissory Note To Allied
Line of Credit Facility [Line Items]
Maximum borrowing capacity											$ 25,000,000

Debt - Schedule of Maturities o

Debt - Schedule of Maturities of Long-term Debt (Details) $ in Thousands	Sep. 30, 2017USD ($)
Principal
2017 (remainder)	$ 24,931
2,018	62,054
2,019	21,277
2,020	26,597
2021 and thereafter	12,198
Total principal payments	147,057
Less: Unamortized debt issuance costs	(9,191)
Total Long term debt, net	$ 137,866

Debt - Related Party (Details)

Debt - Related Party (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term notes payable - related party, net	$ 129,821	$ 129,796
Convertible subordinate note issued	50,000
Line of Credit | Promissory Note To Allied
Debt Instrument [Line Items]
Long-term notes payable - related party, net	24,900	24,900
Line of Credit | Promissory Note to Majority Shareholder Related Party
Debt Instrument [Line Items]
Long-term notes payable - related party, net	6,400	$ 6,400
Convertible Debt | 2015 Convertible Note
Debt Instrument [Line Items]
Long-term notes payable - related party, net	48,500
Majority Shareholder | Line of Credit | Promissory Note to Majority Shareholder Related Party
Debt Instrument [Line Items]
Long-term notes payable - related party, net	$ 6,400

Debt - 2011 Promissory Note (De

Debt - 2011 Promissory Note (Details) - USD ($)	1 Months Ended	9 Months Ended
	Mar. 06, 2017	Sep. 30, 2017	Mar. 31, 2017	Feb. 06, 2017	Dec. 31, 2016	Mar. 31, 2015
Debt Instrument [Line Items]
Long-term notes payable - related party, net		$ 129,821,000			$ 129,796,000
Convertible Debt | 2015 Convertible Note
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 50,000,000
Long-term notes payable - related party, net		48,500,000
Interest payable		7,300,000
Line of Credit | MCB Finance Facility
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 100,000,000
Line of Credit | MCB Finance Facility | 60-Day London Interbank Offered Rate (LIBOR) [Member] [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	6.00%
Line of Credit | Promissory Note To Allied
Debt Instrument [Line Items]
Maximum borrowing capacity		25,000,000
Long-term notes payable - related party, net		24,900,000			24,900,000
Interest payable		$ 2,200,000
Line of Credit | Promissory Note To Allied | 30-Day London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Allied
Debt Instrument [Line Items]
Long-term notes payable - related party, net		$ 129,821,000
Allied | Promissory Note To Allied
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 25,000,000
Convertible debt conversion price (dollars per share)			$ 3.415

Debt - Convertible Subordinated

Debt - Convertible Subordinated Note (Details) - USD ($)	1 Months Ended
	Feb. 28, 2014	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Convertible subordinate note issued		$ 50,000,000
Long-term notes payable - related party, net		129,821,000	$ 129,796,000
Convertible Subordinated Debt
Debt Instrument [Line Items]
Convertible subordinate note issued	$ 50,000,000
Convertible debt conversion price (dollars per share)	$ 4.2984
Interest payable		10,500,000
Minimum proceeds from capital market debt issuance for mandatory prepayment option	$ 250,000,000
Long-term notes payable - related party, net		$ 50,000,000	$ 50,000,000
Convertible Subordinated Debt | 30-Day London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	5.00%
Debt term (in years)	5 years

Debt - Convertible Note (Detail

Debt - Convertible Note (Details) $ / shares in Units, shares in Millions	1 Months Ended	9 Months Ended
	Mar. 31, 2015USD ($)	Sep. 30, 2017USD ($)d$ / sharesshares	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Long term debt, gross		$ 147,057,000
Number of shares called by warrants issued (in shares) | shares		2.7
Long-term notes payable - related party, net		$ 129,821,000	$ 129,796,000
Convertible Debt | 2015 Convertible Note
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 50,000,000
Threshold consecutive trading days | d		5
Long term debt, gross		$ 48,500,000
Warrants issued with debt		5,000,000
Long-term notes payable - related party, net		48,500,000
Interest payable		$ 7,300,000
Convertible Debt | 2015 Convertible Note | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	5.00%
Minimum
Line of Credit Facility [Line Items]
Warrants exercise price (in dollars per share) | $ / shares		$ 2
Maximum
Line of Credit Facility [Line Items]
Warrants exercise price (in dollars per share) | $ / shares		$ 7.85

Debt - 2016 Promissory Note (De

Debt - 2016 Promissory Note (Details)	1 Months Ended			9 Months Ended		13 Months Ended
	May 31, 2016USD ($)note_payable	Apr. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017$ / shares	Dec. 31, 2016USD ($)
Short-term Debt [Line Items]
Proceeds from notes payable				$ 0	$ 504,000
Long-term notes payable - related party, net				129,821,000				$ 129,796,000
Promissory Note to Majority Shareholder Related Party | Line of Credit
Short-term Debt [Line Items]
Long-term notes payable - related party, net				6,400,000				$ 6,400,000
Promissory Note to Majority Shareholder Related Party | Majority Shareholder | Line of Credit
Short-term Debt [Line Items]
Notes payable, related parties		$ 1,000,000	$ 3,000,000
Number of outstanding notes payable | note_payable	2
Interest payable				800,000
Convertible debt conversion price (dollars per share) | $ / shares							$ 3.415
Promissory Note to Majority Shareholder Related Party | Majority Shareholder | Line of Credit | 30-Day London Interbank Offered Rate (LIBOR)
Short-term Debt [Line Items]
Basis spread on variable rate		7.00%	7.00%
Promissory Note to Majority Shareholder Related Party | Majority Shareholder | Line of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 10,000,000
Proceeds from notes payable						$ 2,400,000
Long-term notes payable - related party, net				$ 6,400,000
Promissory Note to Majority Shareholder Related Party | Majority Shareholder | Line of Credit | 30-Day London Interbank Offered Rate (LIBOR)
Short-term Debt [Line Items]
Basis spread on variable rate	7.00%

Related Party Transactions - Su

Related Party Transactions - Summary of Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Related Party Transactions [Abstract]
Accounts receivable	$ 2,821	$ 1,956
Accounts payable and accrued liabilities	33,388	29,513
Short-term note payable - related party	200	0
Long-term notes payable - related party	$ 129,821	$ 129,796

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Accounts receivable	$ 2,821		$ 2,821		$ 1,956
Accounts payable and accrued expenses	33,388		33,388		29,513
Accrued and unpaid interest on notes payable	21,100		21,100		15,200
Proceeds from short-term notes payable - related party			200	$ 0
Short-term note payable - related party	200		200		0
Long-term notes payable - related party, net	129,821		129,821		129,796
Total operating expenses	2,333	$ 4,825	7,058	8,844
Interest expense	2,084	$ 1,525	6,031	$ 4,987
Convertible Subordinated Debt
Related Party Transaction [Line Items]
Long-term notes payable - related party, net	50,000		50,000		50,000
Convertible Subordinated Debt | 2015 Convertible Note
Related Party Transaction [Line Items]
Long-term notes payable - related party, net					48,500
Line of Credit | Promissory Note To Allied
Related Party Transaction [Line Items]
Long-term notes payable - related party, net	24,900		24,900		24,900
Line of Credit | Promissory Note to Majority Shareholder Related Party
Related Party Transaction [Line Items]
Long-term notes payable - related party, net	6,400		6,400		$ 6,400
Convertible Debt | 2015 Convertible Note
Related Party Transaction [Line Items]
Long-term notes payable - related party, net	48,500		48,500
Oltasho and an affiliate
Related Party Transaction [Line Items]
Long-term notes payable - related party, net	$ 129,821		$ 129,821

Related Party Transactions - 50

Related Party Transactions - Summary of Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transactions [Abstract]
Total operating expenses	$ 2,333	$ 4,825	$ 7,058	$ 8,844
Interest expense	$ 2,084	$ 1,525	$ 6,031	$ 4,987

Commitments and Contingencies -

Commitments and Contingencies - Commitments (Details)	1 Months Ended		9 Months Ended
	Mar. 31, 2017well	Feb. 28, 2014bbl	Sep. 30, 2017USD ($)contractlicense
Long Term Floating Production Storage And Offloading System Contract
Other Commitments [Line Items]
Initial contract term (in years)		7 years
Additional contract term (in years)		2 years
Barrels processing capacity (up to) | bbl		40,000
Maximum storage capacity for the FPSO (in barrels) | bbl		1,000,000
Contractual annual minimum commitment | $			$ 48,400,000
KENYA
Other Commitments [Line Items]
Production sharing contracts | contract			4
GAMBIA
Other Commitments [Line Items]
Development and production licenses | license			2
Gambia Farm-Out Agreement | Disposal Group, Held-for-sale, Not Discontinued Operations | FAR
Other Commitments [Line Items]
Project interest retained	20.00%
Pacific Bora Drilling Rig
Other Commitments [Line Items]
Exploratory wells drilled, option | well	2
Base operating rate per day | $			$ 195,000
Pacific Bora Drilling Rig | NIGERIA
Other Commitments [Line Items]
Exploratory wells drilled, option | well	2

Commitments and Contingencies52

Commitments and Contingencies - Contingencies (Details) NGN in Millions	Sep. 30, 2017USD ($)	Jul. 19, 2017NGN	Jul. 19, 2017USD ($)	Jul. 14, 2017USD ($)	Jul. 13, 2017USD ($)	Jun. 27, 2017USD ($)	Feb. 05, 2016people	Jul. 31, 2017USD ($)	Mar. 31, 2016	Sep. 30, 2017USD ($)shares	Sep. 30, 2016USD ($)
Other Commitments [Line Items]
Damages sought						$ 10,000,000
Increase (decrease) in accounts payable and accrued liabilities										$ 40,121,000	$ 54,700,000
Shares issued for services										94,000	$ 0
NIGERIA
Other Commitments [Line Items]
Loss contingency, estimate of possible loss	$ 22,100,000									22,100,000
Approval by Nigerian Department of Petroleum Resources
Other Commitments [Line Items]
Payment of cash or the equivalent in shares	25,000,000									$ 25,000,000
Payment of cash or the equivalent of shares in period										15 days
Number of shares to be issued in period										30 days
February 2014 Transactions
Other Commitments [Line Items]
Loss contingency, number of plaintiffs | people							7
Convertible Debt | 2015 Convertible Note
Other Commitments [Line Items]
Debt instrument, convertible, percent owed on debt fundraising event									10.00%
Debt instrument, convertible, percent owed on equity fundraising event									20.00%
Judicial ruling | TransOcean Offshore Gulf of Guinea VII Limited and Indigo Drilling Limited
Other Commitments [Line Items]
Settlement amount, payment 1			$ 14,000,000
Settlement amount, payment 2		NGN 11.8	$ 33,000
Pending litigation | BGP vs EEKL
Other Commitments [Line Items]
Damages sought						12,200,000
Damages sought, interest						$ 2,700,000
Settled litigation | Multiplan vs EPNL
Other Commitments [Line Items]
Settlement amount awarded to other party					$ 3,000,000			$ 1,000,000
Increase (decrease) in accounts payable and accrued liabilities					$ 200,000
Settled litigation | Aker vs EPNL
Other Commitments [Line Items]
Settlement amount awarded to other party				$ 2,500,000				$ 1,000,000
Increase (decrease) in accounts payable and accrued liabilities	$ 10,200,000
Restricted Stock | Vendor
Other Commitments [Line Items]
Shares issued for services (in shares) | shares										1,282,355
Shares issued for services										$ 3,500,000

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Forfeited (in shares)	(638,891)
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares)	1,147,000
Granted (in shares)	745,000
Exercised (in shares)	(511,000)
Forfeited (in shares)	(639,000)
Expired (in shares)	(145,000)
Ending balance (in shares)	597,000	1,147,000
Expected to vest (in shares)	145,000
Ending balance (in shares)	452,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance (dollars per share)	$ 2.54
Granted (dollars per share)	2.26
Exercised (dollars per share)	1.81
Forfeited (dollars per share)	2.69
Expired (dollars per share)	3.55
Ending balance (dollars per share)	2.40	$ 2.54
Expected to vest (dollars per share)	1.88
Exercisable at period end (dollars per share)	$ 2.57
Outstanding at December 31, 2016 weighted-average remaining contractual term (in years)	1 year 9 months	2 years
Granted, weighted-average remaining contractual term (in years)	1 year
Expected to vest, weighted-average remaining contractual term (in years)	4 years 8 months
Exercisable at December 31, 2016 weighted-average remaining contractual term (in years)	11 months

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options forfeited (in shares)	638,891
Estimated fair value of options granted in period	$ 900
Shares issued for services	$ 94	$ 0
Cashless Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock exercised in period (in shares)	510,555
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued during period (in shares)	183,160
Common stock exercised in period (in shares)	511,000
Options forfeited (in shares)	639,000
Common stock expired in period (in shares)	145,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of grants in period (in shares)	1,122,000
Number forfeited in period	746,000
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	36 months
Stock warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of grants in period (in shares)	0
Number forfeited in period	0
Senior Officer | Performance-Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated fair value of options granted in period	$ 3,400
Number of grants in period (in shares)	200,000
Award vesting period	3 years
Maximum percentage of additional shares awarded (up to)	50.00%
Estimated compensation expense	$ 100
Estimated compensation cost not yet recognized, period of recognition	3 years
Officers, Directors, and Employees | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of grants in period (in shares)	1,100,000
Consultant | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued for services (in shares)	33,333
Shares issued for services	$ 100
Vendor | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued for services (in shares)	1,282,355
Shares issued for services	$ 3,500

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Warrants Activity (Details) - Stock warrants - $ / shares shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	2,983
Granted (in shares)	0
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Ending balance (in shares)	2,983	2,983
Expected to vest (in shares)	0
Exercisable at period end (in shares)	2,983
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per share)	$ 3.59
Granted (in dollars per share)	0
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	0
Expired (in dollars per share)	0
Ending balance (in dollars per share)	3.59	$ 3.59
Expected to vest (in dollars per share)	0
Exercisable at period end (in dollars per share)	$ 3.59
Shares outstanding, weighted average remaining contractual terms	2 years 6 months	3 years 2 months
Exercisable at period end, weighted-average remaining contractual term (years)	2 years 6 months

Stock-Based Compensation - Su56

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) - Restricted Stock shares in Thousands	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares) | shares	2,072
Granted (in shares) | shares	1,122
Vested (in shares) | shares	(1,038)
Forfeited (in shares) | shares	(746)
Ending balance (in shares) | shares	1,410
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per share) | $ / shares	$ 2.25
Granted (in dollars per share) | $ / shares	3
Vested (in dollars per share) | $ / shares	2.39
Forfeited (in dollars per share) | $ / shares	2.98
Ending balance (in dollars per share) | $ / shares	$ 2.36

Segment Information - Segment A

Segment Information - Segment Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 33,643	$ 28,619	$ 79,509	$ 56,699
Operating loss	(10,030)	(21,817)	(124,255)	(77,309)
Operating Segments | Nigeria
Segment Reporting Information [Line Items]
Revenues	33,643	28,619	79,509	56,699
Operating loss	(6,861)	(17,323)	(114,576)	(63,777)
Operating Segments | Kenya
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating loss	(109)	(434)	(1,404)	(1,485)
Operating Segments | The Gambia
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating loss	(207)	(728)	1,591	(1,251)
Operating Segments | Ghana
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating loss	(807)	(210)	(1,820)	(1,328)
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Operating loss	$ (2,046)	$ (3,122)	$ (8,046)	$ (9,468)

Segment Information - Segment58

Segment Information - Segment Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 229,491	$ 289,201
Operating Segments | Nigeria
Segment Reporting Information [Line Items]
Assets	218,827	281,050
Operating Segments | Kenya
Segment Reporting Information [Line Items]
Assets	61	698
Operating Segments | The Gambia
Segment Reporting Information [Line Items]
Assets	4,069	3,034
Operating Segments | Ghana
Segment Reporting Information [Line Items]
Assets	5,230	3,648
Corporate and Other
Segment Reporting Information [Line Items]
Assets	$ 1,304	$ 771

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	Oct. 27, 2017	Sep. 30, 2017	Sep. 30, 2016
Subsequent Event [Line Items]
Proceeds from available facility through 2017 Promissory Note		$ 63,191,000	$ 0
Subsequent event
Subsequent Event [Line Items]
Debt Instrument, Periodic Payment, Principal, Percent, Year One	33.33333%
Debt Instrument, Periodic Payment, Principal, Percent, Year Two	33.33333%
Debt Instrument, Periodic Payment, Principal, Percent, Year Three	33.33333%
Subsequent event | 2017 Promissory Note
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 20,000,000
Subsequent event | 2017 Promissory Note | London Interbank Offered Rate (LIBOR)
Subsequent Event [Line Items]
Basis spread on variable rate	5.00%
Stock Purchase Warrant [Member] | Subsequent event
Subsequent Event [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	7,017,544
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 2.85