Document and Entity Information [Abstract] Document And Entity Information [Abstract]. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Trading Symbol Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Filer Category Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Ex Transition Period Entity Common Stock Shares Outstanding Entity Common Stock, Shares Outstanding Balance Sheets [Abstract] Balance Sheets Assets [Abstract] Assets Current [Abstract] Current assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Total Cash, cash equivalents and restricted cash - beginning of period Cash, cash equivalents and restricted cash - end of period Deposits Assets Current Fixed short term bank deposits - restricted Fixed short-term bank deposits - restricted Fixed short term bank deposits - restricted Prepaid Expense And Other Assets Current Prepaid expenses and other Prepaid Expense and Other Assets, Current, Total Other Assets, Current Other deposits Governmental Receivables Governmental receivables Governmental receivables amount The amount of receivables that are derived from government. Accounts and Other Receivables, Net, Current Other receivables Assets Current Total current assets Oil and Gas Property, Full Cost Method, Net Total unproved oil and gas properties, full cost method Unproved oil and gas properties, full cost method (see Note 4) Property Plant And Equipment Cost [Abstract] Property and equipment at cost Property Plant And Equipment Net Property and equipment at cost Net of accumulated depreciation of $468 and $455 Property, Plant and Equipment, Net, Total Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Ending Balance Net of accumulated depreciation of $468 and $455 Operating Lease, Right-of-Use Asset Right of Use Lease Assets (see Note 7) Operating lease assets Other Assets Noncurrent [Abstract] Other assets Deposits Assets, Noncurrent Fixed short term bank deposits - restricted Assets Held-in-trust, Noncurrent Assets held for severance benefits Other Assets, Noncurrent Assets held for severance benefits Funds deposited in financial institutions Total other assets Assets Total assets Liabilities And Stockholders Equity [Abstract] Liabilities and Stockholders' Equity Liabilities Current [Abstract] Current liabilities Accounts Payable Current Accounts payable Accounts Payable, Current, Total Lease Obligations Current Lease obligation - current (see Note 7) Amount of lease obligation due within one year or the normal operating cycle, if longer. Asset Retirement Obligation, Current Asset retirement obligation Asset Retirement Obligations, Beginning Balance Retirement Obligations, Ending Balance Derivative Liability, Current Derivative liability (see Note 6) Accrued Liabilities Current Accrued liabilities Accrued liabilities Total accrued liabilities Liabilities Current Total current liabilities Liabilities, Noncurrent [Abstract] Long-term liabilities Senior Convertible Bonds 10% Senior convertible bonds, net of unamortized deferred financing cost of $57 and $63 and unamortized debt discount of $900 and $993 at March 31, 2019 and December 31, 2018 respectively (see Note 5) 10% senior Convertible bonds - Long Term Liability 10% senior Convertible bonds - Long Term Liability Carrying value as of the balance sheet date of the portion of senior convertible bonds. Lease Obligations Noncurrent Lease obligation - non-current (see Note 7) Amount of lease obligation due to be paid more than one year (or one operating cycle, if longer) after the balance sheet date. Capital Lease Obligations, Current Obligation under capital lease, net of current maturities of $10 Lease obligation - current (see Note 7) Employee Related Liabilities Noncurrent Provision for severance pay Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. For classified balance sheets, used to reflect the noncurrent portion of the liabilities (due beyond one year or one operating cycle, if longer); for unclassified balance sheets, used to reflect the total liabilities (regardless of due date). Liabilities, Noncurrent Total long-term liabilities Liabilities Total liabilities Commitments And Contingencies Commitments and contingencies (see Note 8) Stockholders Equity [Abstract] Stockholders' equity Common Stock, Value, Issued Common stock, par value $.01; Authorized: 200,000,000 shares at March 31, 2019: Issued and outstanding: 71,065,742 and 66,405,180 shares at March 31, 2019 and December 31, 2018 respectively Common Stock, Value, Issued, Total Common Stock, Value, Issued, Beginning Balance Common Stock, Value, Issued, Ending Balance Additional Paid in Capital, Common Stock Additional paid-in capital Additional Paid in Capital, Common Stock, Beginning Balance Additional Paid in Capital, Common Stock, Ending Balance Retained Earnings (Accumulated Deficit) Accumulated deficit Stockholders' Equity Attributable to Parent Total stockholders' equity Beginning Balances Ending Balances Liabilities And Stockholders Equity Total liabilities and stockholders' equity Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Property and equipment, accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Deferred Costs, Noncurrent Unamortized deferred financing cost, net Debt Instrument, Unamortized Discount Debt discount on derivative liability Unamortized debt discount Maturities Capital Lease Obligation under capital lease of current maturities The amount of maturities capital Lease. Common Stock Par Or Stated Value Per Share Common stock, par value Common Stock Shares Authorized Common stock, authorized Common Stock Shares Issued Common stock, issued Common stock issued Common Stock, Shares, Issued, Total Common Stock Shares Outstanding Common stock, outstanding Common Stock, Shares, Outstanding, Beginning Balance Common Stock, Shares, Outstanding, Ending Balance Statements of Operations [Abstract] Statements of Operations General and Administrative Expense General and administrative Impairment Of Unproved Oil And Gas Properties Impairment of unproved oil and gas properties The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced. Other Cost And Expense Operating Other Other Cost and Expense, Operating, Total Operating Income Loss Loss from operations Nonoperating Income Expense [Abstract] Other income (expense), net Derivative, Loss on Derivative (Loss) on derivative liability (Loss) on derivative liability Foreign Currency Transaction Gain Loss Before Tax Foreign exchange (loss) Foreign exchange (loss) gain Foreign Currency Transaction Gain (Loss), before Tax, Total Interest Income Expense Nonoperating Net Financial (expenses), net Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Pre-tax loss as reported Loss before income taxes Income Tax Expense Benefit Income taxes Income tax expense Income taxes Net Income (Loss) Attributable to Parent Net loss Net loss Earnings Per Share, Basic and Diluted Net loss per share of common stock - basic and diluted (in US$) Weighted Average Number of Shares Outstanding, Basic and Diluted Weighted-average shares outstanding-basic and diluted (in thousands) Statement of Stockholders' Equity [Abstract] Statement of Changes in Stockholders' Equity Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Common Stock Additional Paid-in Capital [Member] Additional paid-In capital [Member] Additional paid-in Capital Retained Earnings [Member] Deficit Accumulated In Development Stage [Member] Accumulated deficit Statement [Line Items] Statement [Line Items] Shares, Outstanding Beginning Balances (in shares) Ending Balances (in shares) Stock Issued During Period Value Stock Dividend Reinvestment And Direct Stock Purchase Plan Funds received from sale of DSPP units and shares Value stock issued during the period as a result of dividend reinvestment and direct stock purchase plan. Stock Issued During Period Shares Stock Dividend Reinvestment And Direct Stock Purchase Plan Funds received from sale of DSPP units and shares (in shares) Number of shares issued during the period as a result of dividend reinvestment and direct stock purchase plan. Debt Conversion, Converted Instrument, Amount Value of bonds converted to shares Debt Conversion, Converted Instrument, Shares Issued Value of bonds converted to shares (in shares) Stock Issued During Period, Value, Stock Options Exercised Funds received from option exercises Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Funds received from option exercises (in shares) Exercised Stock option plan, award to purchase common stock Exercised Adjustments To Additional Paid In Capital Option Issued Value of options granted to employees, directors and others as non-cash compensation Adjustments to Additional Paid in Capital, Option Issued Statements Of Cash Flows [Abstract] Statement of Cash Flows Net Cash Provided By Used In Operating Activities [Abstract] Cash flows from operating activities Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Adjustments required to reconcile net loss to net cash used in operating activities: Depreciation Depreciation Depreciation, Total Gain (Loss) on Disposition of Property Plant Equipment Capital gain on sale of property and equipment Capital gain on sale of property and equipment Adjustment Of Options Granted For Services Cost of options issued to employees, directors and others Cost of options issued to employees, directors and others as non-cash compensation Adjustment for noncash service expenses paid for by granting of options. Amortization of Debt Discount (Premium) Amortization of debt discount related to convertible bonds Derivative, Gain (Loss) on Derivative, Net Change in derivative liability Gain, (loss) on derivative liability Change in derivative liability Increase Decrease In Operating Capital [Abstract] Change in assets and liabilities, net: Increase (Decrease) in Deposit Assets Other deposits Other deposits Increase Decrease In Prepaid Deferred Expense And Other Assets Increase (Decrease) in Prepaid Expense and Other Assets, Total Prepaid expenses and other Increase (Decrease) in Other Current Assets Governmental receivables Increase Decrease In Lease Obligation Current Lease obligation - current Amount of increase (decrease) in lease obligation current. Increase Decrease In Lease Obligation Non Current Lease obligation - non current Amount of increase (decrease) in lease obligation non current. Increase Decrease In Right Of Use Lease Assets Right of Use Lease Assets Amount of increase (decrease) in right of use lease assets. Right of Use Lease Assets Increase (Decrease) in Other Receivables Other receivables Increase Decrease In Accrued Severance Pay Net Of Severance Pay Fund Severance pay Increase Decrease In Accrued Severance Pay Net Of Severance Pay Fund Increase Decrease In Accounts Payable Accounts payable Increase (Decrease) in Accounts Payable, Total Increase (Decrease) in Asset Retirement Obligations Asset retirement obligation Increase Decrease In Accrued Liabilities Accrued liabilities Increase (Decrease) in Accrued Liabilities, Total Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Net Cash Provided By Used In Investing Activities [Abstract] Cash flows from investing activities Payments To Acquire Property Plant And Equipment Payments to Acquire Property, Plant, and Equipment, Total Acquisition of property and equipment Payments to Acquire Oil and Gas Property Investment in unproved oil and gas properties Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided By Used In Financing Activities [Abstract] Cash flows from financing activities Repayments Of Capital Loan The cash outflow during the period from the repayment of aggregate long-term debt. Payments related to capital lease Proceeds from Stock Options Exercised Proceeds from exercise of stock options Proceeds From Deferred Offering Cost Deferred offering costs The cash inflow from deferred offering cost. Proceeds From Issuance Of Common Stock And Warrants Net Proceeds from issuance of stock and exercise of warrants Proceeds from warrant and options exercise The cash inflow from the additional capital contribution to the entity including any warrants issued. Proceeds are net of cash outflows for issuance costs related to the transaction. Cash proceeds from common stock Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Cash And Cash Equivalents Period Increase Decrease Net (decrease), increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash Restricted cash Cash, cash equivalents and restricted cash Cash, cash equivalents and restricted cash - beginning of period Cash, cash equivalents and restricted cash - end of period Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Non-cash investing and financing activities: Capitalized Costs Of Options Related To Oil And Gas Properties Cost of options capitalized to oil & gas properties Capitalized costs of options related to oil and gas properties. Noncash Or Part Noncash Acquisition Investments Acquired 1 Unpaid investments in oil & gas properties Convertible Bond Interest Paid In Shares Convertible Bond interest paid in shares Amount of convertible bond interest paid in shares. Convertible Shares Related To Senior Convertible Bonds 10% Senior Convertible Bonds converted to shares Convertible shares related to senior convertible bonds in noncash investing and financing activities. Acquisition Of Property And Equipment Under Capital Lease Acquisition of property and equipment under capital lease Acquisition of property and equipment under capital lease. Capitalized Convertible Bond Interest Attributed To Oil And Gas Properties Capitalized convertible bond interest attributed to oil and gas properties Amount of increase (decrease) in lease obligation non current. Restricted Cash and Cash Equivalents Cash and cash equivalents Cash and cash equivalents Restricted Cash and Investments, Current Restricted cash included in fixed short-term bank deposits Restricted Cash and Investments, Noncurrent Restricted cash included in fixed long-term bank deposits Nature of Operations, Basis of Presentation and Going Concern [Abstract] Nature of Operations [Text Block] Nature of Operations, Basis of Presentation and Going Concern Summary of Significant Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies Stockholders' Equity [Abstract] Stockholders Equity Note Disclosure [Text Block] Stockholders' Equity Unproved Oil and Gas Properties, Full Cost Method [Abstract] Oil and Gas Properties [Text Block] Unproved Oil and Gas Properties, Full Cost Method Senior Convertible Bonds [Abstract] Debt Disclosure [Text Block] Senior Convertible Bonds Derivative Liability [Abstract] Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivative Liability Leases [Abstract] Lessee, Operating Leases [Text Block] Right of use leases assets and leases obligations Commitments and Contingencies [Abstract] Commitments And Contingencies Disclosure [Text Block] Commitments and Contingencies Subsequent Events [Abstract] Subsequent Events [Text Block] Subsequent Events Earnings Per Share Policy [Text Block] Net Gain (Loss) per Share Data Use of Estimates, Policy [Policy Text Block] Use of Estimates Oil And Gas Properties Policy Policy [Text Block] Oil and Gas Properties and Impairment Fair Value Measurement, Policy [Policy Text Block] Fair Value Measurements Derivatives, Policy [Policy Text Block] Derivative Liabilities Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Stock-Based Compensation Related Parties [Policy Text Block] Related parties Disclosure of accounting policy for related parties. New Accounting Pronouncements, Policy [Policy Text Block] Recently Adopted Accounting Pronouncements Financial Statements In United States Dollars [Policy Text Block] Financial Statements in United States Dollars Disclosure of financial statements in United States dollars. Cash and Cash Equivalents, Policy [Policy Text Block] Cash and Cash Equivalents Fixed Short Term Time Deposits [Policy Text Block] Fixed Short-Term Time Deposits Disclosure of fixed short term time deposits. Fixed Long Term Time Deposits [Policy Text Block] Fixed Long-Term Time Deposits Disclosure of fixed long term time deposits. Property, Plant and Equipment, Policy [Policy Text Block] Property and Equipment Compensation Related Costs, Policy [Policy Text Block] Assets Held For Severance Benefits Income Tax, Policy [Policy Text Block] Income Taxes Environmental Cost, Expense Policy [Policy Text Block] Environmental Costs and Loss Contingencies Asset Retirement Obligations, Policy [Policy Text Block] Asset Retirement Obligations Reclassification, Policy [Policy Text Block] Reclassifications Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Relationship to Entity [Domain] Title of Individual with Relationship to Entity [Domain] Non Employee [Member] Non-Employees [Member] Granted to non-employees [Member] Non Employee [Member] Non-employees [Member] Employees And Directors [Member] Employees and Directors [Member] Employees and Directors [Member] Employee [Member] Employees [Member] Granted to employees [Member] Employee [Member]. Employees And Non Employees [Member] Employees and and Non-employees and Capitalized [Member] Award Type [Axis] Award Type [Axis] Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Award Type [Domain] Warrants And Options [Member] Warrants and Options [Member] Warrants And Options [Member]. Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Dividend Reinvestment And Stock Purchase Plan [Member] Dividend Reinvestment and Stock Purchase Plan [Member] Dividend Reinvestment and Stock Purchase Plan Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Schedule Of Warrants And Options Exercise Prices And Expiration Dates Table Text Block Schedule of warrants and options exercise prices and expiration dates Schedule of warrants and options exercise prices and expiration dates. Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Schedule of stock option transactions Schedule Of Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Text Block] Schedule of stock options outstanding Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Schedule of assumptions used to estimate fair value of warrants granted using black-scholes option pricing model Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Schedule of compensation cost of warrant and option issuances Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] Schedule of warrants description Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization [Table Text Block] Schedule of unproved oil and gas properties, full cost method Unproved Properties Disclosure [Table Text Block] Schedule of changes in unproved oil and gas properties Convertible Debt [Table Text Block] Schedule of senior convertible bonds Schedule of Derivative Liabilities at Fair Value [Table Text Block] Schedule of fair value of derivative liabilities Schedule of Derivative Instruments [Table Text Block] Schedule of change in fair value of derivative liability Schedule of Assumptions Used [Table Text Block] Schedule of assumption used for the model of derivatives liabilities Schedule Of Operating Lease Assets And Liabilities [Table Text Block] Schedule of operating lease assets and liabilities Tabular disclosure of operating lease assets and liabilities. Schedule Of Weighted Average Lease Term And Discount Rate [Table Text Block] Schedule of weighted average remaining lease term and weighted average discount rate for operating leases Tabular disclosure of weighted average lease term and discount rate. Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of future minimum lease payments under non-cancelable operating leases Nature of Operations and Going Concern [Table] Nature Of Operations And Going Concern [Table]. Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Other Types [Member] Property, Plant and Equipment, Other Types [Member] Megiddo Jezreel License [Member] Megiddo-Jezreel License [Member] Megiddo Jezreel License [Member]. Jordan Valley License [Member] Jordan Valley License [Member] Jordan Valley License [Member]. Range [Axis] Range [Domain] Maximum [Member] Minimum [Member] Nature of Operations and Going Concern [Line Items] Nature Of Operations And Going Concern [Line Items]. Nature Of Operations Basis Of Presentation And Going Concern Textual [Abstract] Nature of Operations, Basis of Presentation and Going Concern (Textual) Land Purchase Options, Description Area of land depth, description Area of Land Area of land, approximate Initial Length Lease Term Initial length of lease Initial length of lease. Impairment of Oil and Gas Properties Impairment of unproved oil and gas properties Impairment of oil and gas properties Impairment of unproved oil and gas properties Impairment of oil and gas properties Impairment Charge on Reclassified Assets Post-impairment charge Property, Plant and Equipment [Table] Property, Plant and Equipment [Line Items] Summary Of Significant Accounting Policies Textual [Abstract] Summary of Significant Accounting Policies (Textual) Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Common stock equivalents excluded from EPS as the inclusion would be anti-dilutive Capitalized Costs of Unproved Properties Excluded from Amortization, Period Cost Capitalized exploration costs Total unproved oil and gas properties, full cost method Other Asset Impairment Charges Post-impairment charge Deferred Costs, Current Offering cost, net Deferred offering costs Deferred offering costs Offering cost, net Employee Stock Option [Member] Stock Options [Member] Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding [Roll Forward] Number of shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Number of Shares Outstanding options and warrants, shares Outstanding, December 31, 2018 Outstanding, March 31, 2019 Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Value of shares granted (in shares) Stock option plan, award to purchase common stock Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total Granted to employees, officers, directors and others Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Expired/Cancelled/Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Total Expired/Cancelled/Forfeited Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Exercisable Stock options exercisable, shares Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Exercise Price [Abstract] Weighted Average exercise price Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted Average Exercise price Outstanding, December 31, 2018 Outstanding, March 31, 2019 Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Granted Stock option plan, award to purchase common stock, exercise price Granted to employees, officers, directors and others Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Weighted Average Exercise Price Expired/Cancelled/Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price, Total Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Exercisable Stock option plan, exercise price Schedule Of Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Vested [Member] Fully Vested [Member] Vested [Member] Non Vested [Member] Non-vested [Member] Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Axis] Exercise Price Range [Axis] Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Ranges One [Member] Range One [Member] Range One [Member] Ranges Two [Member] Range Two [Member] Range Two [Member] Ranges Three [Member] Range Three [Member] Range Three [Member] Ranges Four [Member] Range Four [Member] Range Four [Member] Ranges Five [Member] Range Five [Member] Range Five [Member] Ranges Six [Member] Range Six [Member] Range Six [Member]. Ranges Seven [Member] Range Seven [Member] Range Seven [Member] Ranges Eight [Member] Range Eight [Member] Range Eight [Member]. Ranges Nine [Member] Range Nine [Member] Range Nine [Member] Ranges Ten [Member] Range Ten [Member] Ranges Eleven [Member] Range Eleven [Member] Range Eleven [Member]. Ranges Twelve [Member] Range Twelve [Member] Ranges Thirteen [Member] Ranges Fourteen [Member] Ranges Fifteen [Member] Ranges Sixteen [Member] Ranges Seventeen [Member] Ranges Eighteen [Member] Ranges Nineteen [Member] Ranges Twenty [Member] Ranges Twenty One [Member] Ranges Twenty Two [Member] Ranges Twenty Three [Member] Ranges Twenty Four [Member] Ranges Twenty Five [Member] Ranges Twenty Six [Member] Ranges Twenty Seven [Member] Ranges Twenty Eight [Member] Ranges Twenty Nine [Member] Ranges Thirty [Member] Ranges Thirty One [Member] Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Shares Underlying Outstanding Options [Abstract] Shares underlying outstanding options Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range of exercise price Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price. Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Range of exercise price, lower range Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Range of exercise price, upper range Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Number Outstanding Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term Weighted average remaining contractual life (years) Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Grant Date Intrinsic Value Weighted-average fair value of underlying stock at grant date Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Dividend yields Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Risk-free interest rates Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term 1 Expected lives (in years) Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value Weighted-average grant date fair value Stock options par value Oil and Gas Properties [Member] Unproved Oil and Gas Properties [Member] Share Based Compensation Compensation cost of warrant and option issuances Cost of options issued to employees, directors & others Share-based Compensation, Total Class of Warrant or Right [Table] Related Party [Axis] Related Party [Domain] Investor [Member] Investors [Member] Class of Warrant or Right [Axis] Class Of Warrant Or Right [Domain] Class of Warrant or Right [Domain] Znwaa Warrants [Member] ZNWAA Warrants [Member] ZNWAA [Member] Znwaa Warrants [Member]. Znwad Warrants [Member] ZNWAD [Member] ZNWAD Warrants [Member] Znwad Warrants [Member]. Znwae Warrants [Member] ZNWAE Warrants [Member] ZNWAE [Member] Znwae warrants. Znwaf [Member] ZNWAF [Member] ZNWAF Warrants [Member] Znwag [Member] ZNWAG Warrants [Member] ZNWAG [Member] Znwah [Member] ZNWAH Warrants [Member] ZNWAH [Member] Znwai Warrants [Member] ZNWAI Warrants [Member] ZNWAI [Member] Znwaj Warrants [Member] ZNWAJ Warrants [Member] ZNWAJ [Member] Znwak Warrants [Member] ZNWAK Warrants [Member] ZNWAK [Member] Reporting Date [Axis] Reporting Date [Domain] Beginning Date [Member] Beginning Date [Member] Beginning Date [Member]. Ending Date [Member] Ending Date [Member] Ending Date [Member]. February Two Zero One Eight [Member] February 2018 [Member] Class of Warrant or Right [Line Items] Class of Warrant or Right, Title of Security Warrants or Rights Outstanding Warrant name Name Class of Warrant or Right, Date from which Warrants or Rights Exercisable Period of Grant Class of Warrant or Right, Exercise Price of Warrants or Rights Warrant exercise price Exercise Price Exercise Price Purchase warrants unit price Class Of Warrant Or Right Expiry Date Of Warrants Or Right Exercisable Expiration Date Warrant Termination Date Class of warrant or right, expiry date of warrants or rights exercisable. Transaction Type [Axis] Transaction [Domain] Warrant Transactions [Member] Warrant Termination Date Its represented warrant termination date. Class of Warrant or Right, Outstanding Warrants outstanding Outstanding warrants, Beginning Balance Outstanding warrants, Ending Balance Warrants Issued Warrants issued Warrants Issued Warrants issued. Class Of Warrants Exercised Warrants Exercised Class of warrant exercised Number of warrants exercised in during the period. Class Of Warrants Expired Warrants Expired lts represented class of warrant expired. Senior Officers Staff Members And Consultants [Member] 23 Senior officers, staff members and consultants [Member] Senior officers, staff members and consultants. Senior Officer [Member] Five Senior officers [Member] Consultant [Member] Three Consultants [Member] Consultant [Member] Consultants [Member]. Eight Board Members [Member] Stock Option Plan Twenty Eleven [Member] Equity Incentive Stock Option Plan 2011 [Member] 2011 Equity Incentive Stock Option Plan [Member] Stock Option Plan 2011 [Member] Non Employee Directors Stock Option Plan [Member] 2011 Non-Employee Directors Stock Option Plan [Member] 2011 Directors' Plan [Member] Non-employee directors stock option plan. Award Date [Axis] Award Date [Domain] Exercisable Through June Thirty Two Thousand Eighteen [Member] June 30, 2018 [Member] Exercisable Through December Thirty One Two Thousand Eighteen [Member] December 31, 2018 [Member] Exercisable Through June Three Zero Two Zero One Nine [Member] June 30, 2019 [Member] Stockholders Equity Textual [Abstract] Stockholders' Equity (Textual) Stock Issued During Period, Shares, Employee Stock Purchase Plans Shares purchased under option plan (in share) Shares purchased under option plan (in share) Share Price Exercise price per unit Share Based Compensation Arrangement By Sharebased Payment Award Options Grants In Period Grant Date Fair Value Stock options granted, fair value on dates of grant Fair value of stock options granted Share Based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date Stock option plan, expiration date Expiration date Stock option plan, expiration date Share Based Compensation Arrangement By Share Based Payment Award Options Vested Description Stock option vested, description Share based Compensation Arrangement By Share based Payment Award Options Vested Description. Financial Instrument [Axis] Financial Instruments [Domain] Warrant [Member] Warrant [Member] Warrants [Member] New Unit Program [Member] New Unit Program [Member] Unit Option Program [Member] Unit Option Program [Member] Subscription Rights Offering [Member] 2018 Subscription Rights Offering [Member] Unrecognized compensation cost related to non vested stock Unrecognized compensation cost related to non vested stock Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Total Unit Option Description Unit option, description Unit option description. Warrant Termination Date Description Warrant termination date description Warrants termination, description Warrants termination date. Sale of Stock, Description of Transaction New unit program, description Proceeds from Issuance or Sale of Equity Amount of funds raised under the DSPP program Amount of funds received from DSPP Subscription Rights Offering Subscription rights offering, description Subscription Rights Offering. Proceeds from Issuance Initial Public Offering Proceeds from the sale of the rights Expenses From Rights Offering Expenses from rights offering Expenses from rights offering. Capitalized Costs of Unproved Properties Excluded from Amortization [Table] Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items] Excluded From Amortization Base [Abstract] Excluded from amortization base: Operational Costs Drilling costs, and other operational related costs Operational costs excluded from amortization base related to unproved oil and gas properties. Capitalized Salary Costs Unproved Properties Capitalized salary costs Salary costs excluded from amortization base related to unproved oil and gas properties. Interest Costs Capitalized Capitalized interest costs Legal Costs License Fees And Preparation Costs Legal costs, license fees and other preparation costs Legal costs, license fees and other preparation costs excluded from amortization base related to unproved oil and gas properties. Other Utility Cost Other costs Other utility cost incurred related to oil and gas produced and sold during the reporting period. Changes In Drilling Costs, And Other Operational Related Costs Drilling costs, and other operational related costs Changes in operational costs excluded from amortization base related to unproved oil and gas properties. Changes In Capitalized Salary Costs Unproved Properties Capitalized salary costs Changes in salary costs excluded from amortization base related to unproved oil and gas properties. Increase Decrease In Interest Costs Capitalized Capitalized interest costs Increase decrease in amount of interest capitalized during the period. Increase Decrease In Legal Costs License Fees And Preparation Costs Legal costs, license fees and other preparation costs Increase decrease in legal costs, license fees and other preparation costs excluded from amortization base related to unproved oil and gas properties. Increase Decrease In Other Utility Costs Other costs Increase decrease in other utility cost incurred related to oil and gas produced and sold during the reporting period. Increase Decrease In Capitalized Costs Of Unproved Properties Excluded From Amortization Period Cost Changes in Unproved oil and gas properties Increase decrease in the sum of the capitalized costs incurred during the period of unproved properties excluded from amortization including acquisition costs, exploration costs, development costs, and production costs. Unproved Oil And Gas Properties, Full Cost Method Textual [Abstract] Unproved Oil and Gas Properties, Full Cost Method (Textual) Inclusive Non Cash Amount Inclusive of non-cash amounts Increase decrease in the sum of the inclusive of non cash amounts. Unproved Oil And Gas Properties Unpaid Amount Unproved oil and gas properties unpaid amount Unproved oil and gas properties unpaid amount. Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Debt Instrument Textual [Abstract] Senior Convertible Bonds (Textual) Senior Convertible Bonds [Abstract] Convertible Debt 10% Senior Convertible Bonds, on the day of issuance Convertible bonds Debt Instrument, Unamortized Discount (Premium), Net Unamortized Debt discount, net Debt discount amortization, net Bonds Converted To Shares Bonds converted to shares Bonds converted to shares. Bonds converted to shares Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Convertible Debt [Member] 10% Senior Convertible Bonds [Member] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Issue [Member] Debt issuance [Member] Sale of Stock [Axis] Sale of Stock [Domain] IPO [Member] Rights offering [Member] Rights Offering Senior Convertible Bonds Rights Offering [Member] Debt Instrument, Maturity Date Debt instrument, maturity date Debt Instrument, Payment Terms Debt instrument payment description Debt Instrument, Redemption, Description Description of note redeemption Debt Instrument, Convertible, Conversion Price Convertible bonds purchase price Debt Instrument, Interest Rate, Stated Percentage Convertible senior bonds percentage Senior unsecured notes interest rate Annual interest paid Debt Conversion, Description Debt conversion, description Amortization of Debt Issuance Costs Amortization expense Interest Expense Interest expense Debt Instrument, Face Amount Principal amount Convertible Notes Face Value Debt Instrument, Convertible, Number of Equity Instruments Number of convertible bonds Convertible Bonds Amount Convertible bond price Convertible bond price per instrument. Conversion of Stock, Shares Converted Common stock issued Financial Expenses Financial expenses Amount ov financial expenses. Conversion of Stock, Amount Converted Financing costs associated notes converted to shares Sale of Stock, Price Per Share Average Company stock price Stock Issued During Period, Shares, Other Stock issued to bondholders Proceeds from Issuance of Unsecured Debt Net proceeds from sale of the Notes Debt Discount On Derivative Liability Debt discount on derivative liability Debt discount on derivative liability. Fair Value Option Qualitative Disclosures [Table] Summarization of information required and determined to be disclosed concerning the election to apply the fair value option for measurement and reporting of eligible financial assets and liabilities (as defined), as well as certain other eligible items (as defined) included in the statement of financial position, whether such option is elected for a single eligible item or a group of similar eligible items. Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 3 [Member] Level 3 [Member] Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] Derivative Liability, Fair Value, Gross Liability Fair value of derivative liability Derivative Liability Derivative liability fair value, beginning balance Derivative liability fair value, ending balance Derivative, Gain on Derivative Loss on derivative liability Convertible Debt, Fair Value Disclosures Convertible Option Fair Value of approximately Fair Value Assumption Risk Free Interest Rate Annual Risk-free Rate Risk-free interest rate assumption used in valuing an instrument. Fair Value Assumption Expected Volatility Rate Volatility Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price. Fair Value Assumption Expected Term Expected Term (years) Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Fair Value Assumptions Expected Yield Rate Expected annual yield on Regular Notes Fair value assumptions expected yield rate. Fair Value Assumption Exercise Price Price of the Underlying Stock Agreed upon price for the exchange of the underlying asset. Derivative Liability Textual [Abstract] Derivative Liability (Textual) Derivative liability textual. Operating Lease Liabilities [Abstract] Operating lease liabilities: Operating Lease, Liability, Current Current operating lease liabilities Operating Lease, Liability, Noncurrent Non-current operating lease liabilities Operating Lease, Liability Total undiscounted future minimum lease payments Total operating lease liabilities Operating Lease, Weighted Average Remaining Lease Term Weighted average remaining lease term (years) Operating Lease, Weighted Average Discount Rate, Percent Weighted average discount rate Operating Lease Liabilities, Payments Due [Abstract] Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months April 1, 2019 through December 31, 2019 Lessee, Operating Lease, Liability, Payments, Due Year Two 2020 Lessee, Operating Lease, Liability, Payments, Due Year Three 2021 Lessee, Operating Lease, Liability, Payments, Due Year Four 2022 Lessee, Operating Lease, Liability, Payments, Due Year Five 2023 Lessee, Operating Lease, Liability, Payments, Due after Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due Total undiscounted future minimum lease payments Lessee, Operating Lease, Liability, Undiscounted Excess Amount Less: portion representing imputed interest Less: portion representing imputed interest Right Of Use Leases Assets And Leases Obligations Textual [Abstract] Operating Lease, Cost Operating lease costs Operating Lease, Payments Operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Right-of-use assets obtained in exchange for new operating lease liabilities Commitments And Contingencies Textual [Abstract] Commitments and Contingencies (Textual) Bank Guarantees To Government Bank guarantees to government bodies Bank guarantees to government. Other Commitment Aggregate guarantee amount Bank guarantees to others Guarantor Obligations, Current Carrying Value Aggregate guarantee amount Loss Contingency Accrual Advanced deposit Cash And Cash Equivalents Weighted Average Interest Rate Cash and cash equivalents weighted average interest rate The percentage af cash and cash equivalents weighted average interest rate. Foreign Currency Transactions, Description Foreign currency exchange rate risks, description Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event [Member] Two Thousand Eleven Non Employee Directors Stock Option Plan [Member] 2011 Non-Employee Directors Stock Option Plan [Member] Subsequent Event [Line Items] Subsequent Events Textual [Abstract] Subsequent Events (Textual) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Shares granted under stock option plan (in shares) Common Stock Exercise Price Exercise price of common stock Common stock exercise price. Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights Description of options vesting Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Outstanding options and warrants, Intrinsic value Fair value of stock options Shares granted under stock option plan (in shares) Shares granted under stock option plan (in values) Proceeds from Stock Plans Amount collected from DSPP Subscription Price Subscription price per share subscription price per share. Board Members Staff members Board members. Stock Issued Description Stock issued, description Stock issued description. Shares Issued, Price Per Share Stock price Shares, Issued Shares issued Agency And Setup Costs Agency and setup costs Agency and setup costs. Subsequent Event, Description