Commitments and Contingencies	6 Months Ended
Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 8 - Commitments and Contingencies A. Securities and Exchange Commission (“SEC”) Investigation As previously disclosed by the Company, on June 21, 2018, Zion received a subpoena to produce documents from the Fort Worth office of the SEC informing the Company of the existence of a non-public, fact-finding inquiry into the Company. Prior to the receipt of the subpoena on June 21, 2018, Zion had no previous communication with the SEC on this issue and was unaware of this investigation. The SEC stated that “the investigation and the subpoena do not mean that we have concluded that [Zion] or anyone else has violated the law.” To date, Zion has furnished all required documents to the SEC and will continue to fully cooperate with the investigation. The Company cannot predict when this matter will be resolved or what further action, if any, the SEC may take in connection with it. B. Litigation Following the commencement of the SEC investigation, on August 9, 2018, a putative class action (the “class action”) Complaint was filed against Zion, Victor G. Carrillo, the Company’s Chief Executive Officer at such time, and Michael B. Croswell Jr., the Company’s Chief Financial Officer (collectively, the “Defendants”) in the U.S. District Court for the Northern District of Texas. On November 16, 2018, the Court entered an Order in the class action appointing lead plaintiffs and approving lead counsel and on January 22, 2019, an Amended Complaint was filed. On February 1, 2019, a Corrected Amended Class Action Complaint was filed. The suit alleges violations of Section 10(b) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Rule 10b-5 promulgated thereunder by the SEC and Section 11 of the Securities Act of 1933 (the “Securities Act”) against all defendants and alleges violations of Section 20(a) of the Exchange Act and Section 15 of the Securities Act against the individual defendants. The alleged class period is from February 13, 2018 through November 20, 2018. On March 13, 2019, a Motion to Dismiss Plaintiffs’ Corrected Amended Complaint was filed on behalf of Zion, Victor Carrillo and Michael B. Croswell, Jr., pleading numerous grounds in support of their Motion to Dismiss. On April 29, 2019 Plaintiffs filed a Response to Defendants’ Motion to Dismiss, and on May 29, 2019 Defendants filed a Reply to Plaintiffs’ Response. By Verified Consolidated Stockholder Derivative Complaint filed on March 4, 2019, three (3) stockholder derivative lawsuits previously filed in federal district court in Delaware on September 10, 2018, November 1, 2018, and November 21, 2018 were consolidated into one lawsuit filed derivatively and purportedly on behalf of the Company against Victor G. Carrillo, Michael B. Croswell, Jr., John M. Brown, Dustin L. Guinn, Forest A. Garb, Kent S. Siegel, Paul Oroian, William H. Avery, the Estate of Yehezkel Druckman, Lee Russell, Justin W. Furnace, Gene Scammahorn, Ralph F. DeVore, and Martin M. van Brauman. The suit alleges breach of fiduciary duty, unjust enrichment, violations of Section 14(a) of the Exchange Act and conspiracy to “facilitate and disguise” other alleged wrongdoings. The “Relevant Period” of alleged wrongdoing spans from February 13, 2018 and continues through the present. The suit seeks unspecified damages to be awarded to the Company, orders directing the Company and individual defendants to make certain corporate governance reforms, restitution, and fees and costs. On April 18, 2019, a Motion to Dismiss Plaintiffs’ Complaint was filed on behalf of all defendants pleading numerous grounds in support of their Motion to Dismiss. On June 3, 2019 Plaintiffs filed a Response to Defendants’ Motion to Dismiss, and on July 3, 2019 Defendants filed a Reply to Plaintiffs’ Response. On September 25, 2018, another lawsuit was filed in the 68^th district court, Dallas County, Texas derivatively and purportedly on behalf of the Company against John M. Brown, Forrest A. Garb, Kent S. Siegel, Michael B. Croswell, Jr., Dustin L. Guinn, Victor G. Carrillo, Paul Oroian, William H. Avery, Justin W. Furnace, Gene Scammahorn, Martin M. van Brauman, and Lee R. Russell and the Company as a nominal defendant. This suit alleges claims for breaches of fiduciary duty and unjust enrichment against the individual defendants in connection with certain public statements made by the Company from March 12, 2018 to May 30, 2018. On March 29, 2019, this lawsuit was voluntarily dismissed by Plaintiff without prejudice to its subsequent refiling. On October 29, 2018, Zion received a shareholder request to inspect books and records pursuant to Section 220 of the Delaware General Corporation Law for the purpose of investigating potential corporate mismanagement and breaches of fiduciary duty in connection with public statements made by the Company from March 12, 2018 to May 30, 2018. The Company responded to this request. The Company disputes the above claims and has made an advanced deposit of $500,000 to defense counsel for the cost of defending the litigation. The Company carries insurance that is applicable to these claims. Because of the uncertainties of litigation, it is not feasible to predict or determine the outcome of these matters, to guarantee that there will be no liability, or to reasonably estimate any loss in excess of its coverage. However, the Company intends to pursue a vigorous defense to the claims. From time to time, the Company may also be subject to routine litigation, claims or disputes in the ordinary course of business. The Company defends itself vigorously in all such matters. However, we cannot predict the outcome or effect of any of the litigation or any other pending litigation or claims. C. Environmental and Onshore Licensing Regulatory Matters The Company is engaged in oil and gas exploration and production and may become subject to certain liabilities as they relate to environmental cleanup of well sites or other environmental restoration procedures and other obligations as they relate to the drilling of oil and gas wells or the operation thereof. Various guidelines have been published in Israel by the State of Israel’s Petroleum Commissioner and Energy and Environmental Ministries as it pertains to oil and gas activities. Mention of these older guidelines was included in previous Zion filings. On March 15, 2018, the Energy Ministry issued new guidelines regarding a uniform reporting manner by which the operator must submit to the Commissioner data and materials regarding lawful exploration and production activities. The guidelines detail the timeline, data, forms, format, media and materials (such as rock cuttings, cores, gas and oil samples) that must be submitted for seismic and drilling activities. On April 8, 2019 the Energy Ministry issued new procedural guidelines regarding a uniform reporting manner by which the rights holder in a license must submit a quarterly report regarding a summary of license history, the nature, scope, location and results of the exploration work, specification of the amounts expended for the exploration work, and the results and interpretation of the exploration work and basic data on which these results and interpretation are based. The guidelines will be binding as from the date of submission of the report for the third quarter 2019. The Company believes that these new regulations are likely to continue to increase the expenditures associated with obtaining new exploration rights and drilling new wells. The Company expects that an additional financial burden could occur as a result of requiring cash reserves that could otherwise be used for operational purposes. In addition, these new regulations are likely to continue to increase the time needed to obtain all of the necessary authorizations and approvals to drill and production test exploration wells. D. Bank Guarantees As of June 30, 2019, the Company provided Israeli-required bank guarantees to various governmental bodies (approximately $1,010,000) and others (approximately $85,000) with respect to its drilling operation in an aggregate amount of approximately $1,095,000. The (cash) funds backing these guarantees and additional amounts added to support currency fluctuations as required by the bank are held in restricted interest-bearing accounts and are reported on the Company’s balance sheets as fixed short-term bank deposits – restricted, and fixed long-term bank deposits – restricted. E. Risks Market risk is a broad term for the risk of economic loss due to adverse changes in the fair value of a financial instrument. These changes may be the result of various factors, including interest rates, foreign exchange rates, commodity prices and/or equity prices. In the normal course of doing business, we are exposed to the risks associated with foreign currency exchange rates and changes in interest rates. Foreign Currency Exchange Rate Risks. A portion of our expenses, primarily labor expenses and certain supplier contracts, are denominated in New Israeli Shekels (“NIS”). As a result, we have significant exposure to the risk of fluctuating exchange rates with the U.S. Dollar (“USD”), our primary reporting currency. During the period January 1, 2019 through June 30, 2019, the USD has fluctuated by approximately 4.9% against the NIS (the USD has weakened relative to the NIS). By contrast, during the period January 1, 2018 through December 31, 2018, the USD fluctuated by approximately 8.1% against the NIS (the USD strengthened relative to the NIS). Continued weakening of the US dollar against the NIS will result in higher operating costs from NIS denominated expenses. To date, we have not hedged any of our currency exchange rate risks, but we may do so in the future. Interest Rate Risk. Our exposure to market risk relates to our cash and investments. We maintain an investment portfolio of short-term bank deposits and money market funds. The securities in our investment portfolio are not leveraged, and are, due to their very short-term nature, subject to minimal interest rate risk. We currently do not hedge interest rate exposure. Because of the short-term maturities of our investments, we do not believe that a change in market interest rates would have a significant negative impact on the value of our investment portfolio except for reduced income in a low interest rate environment. At June 30, 2019, we had cash, cash equivalents and short-term bank deposits, inclusive of restricted cash, of approximately $4,180,000. The weighted average annual interest rate related to our cash and cash equivalents for the six months ended June 30, 2019 was approximately 0.13%. The primary objective of our investment activities is to preserve principal while at the same time maximizing yields without significantly increasing risk. To achieve this objective, we invest our excess cash in short-term bank deposits and money market funds that may invest in high quality debt instruments.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2019

Commitments and Contingencies Disclosure [Abstract]

Note 8 - Commitments and Contingencies

A. Securities and Exchange Commission (“SEC”) Investigation

As previously disclosed by the Company, on June 21, 2018, Zion received a subpoena to produce documents from the Fort Worth office of the SEC informing the Company of the existence of a non-public, fact-finding inquiry into the Company. Prior to the receipt of the subpoena on June 21, 2018, Zion had no previous communication with the SEC on this issue and was unaware of this investigation. The SEC stated that “the investigation and the subpoena do not mean that we have concluded that [Zion] or anyone else has violated the law.” To date, Zion has furnished all required documents to the SEC and will continue to fully cooperate with the investigation.

The Company cannot predict when this matter will be resolved or what further action, if any, the SEC may take in connection with it.

B. Litigation

Following the commencement of the SEC investigation, on August 9, 2018, a putative class action (the “class action”) Complaint was filed against Zion, Victor G. Carrillo, the Company’s Chief Executive Officer at such time, and Michael B. Croswell Jr., the Company’s Chief Financial Officer (collectively, the “Defendants”) in the U.S. District Court for the Northern District of Texas. On November 16, 2018, the Court entered an Order in the class action appointing lead plaintiffs and approving lead counsel and on January 22, 2019, an Amended Complaint was filed. On February 1, 2019, a Corrected Amended Class Action Complaint was filed. The suit alleges violations of Section 10(b) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Rule 10b-5 promulgated thereunder by the SEC and Section 11 of the Securities Act of 1933 (the “Securities Act”) against all defendants and alleges violations of Section 20(a) of the Exchange Act and Section 15 of the Securities Act against the individual defendants. The alleged class period is from February 13, 2018 through November 20, 2018. On March 13, 2019, a Motion to Dismiss Plaintiffs’ Corrected Amended Complaint was filed on behalf of Zion, Victor Carrillo and Michael B. Croswell, Jr., pleading numerous grounds in support of their Motion to Dismiss. On April 29, 2019 Plaintiffs filed a Response to Defendants’ Motion to Dismiss, and on May 29, 2019 Defendants filed a Reply to Plaintiffs’ Response.

By Verified Consolidated Stockholder Derivative Complaint filed on March 4, 2019, three (3) stockholder derivative lawsuits previously filed in federal district court in Delaware on September 10, 2018, November 1, 2018, and November 21, 2018 were consolidated into one lawsuit filed derivatively and purportedly on behalf of the Company against Victor G. Carrillo, Michael B. Croswell, Jr., John M. Brown, Dustin L. Guinn, Forest A. Garb, Kent S. Siegel, Paul Oroian, William H. Avery, the Estate of Yehezkel Druckman, Lee Russell, Justin W. Furnace, Gene Scammahorn, Ralph F. DeVore, and Martin M. van Brauman. The suit alleges breach of fiduciary duty, unjust enrichment, violations of Section 14(a) of the Exchange Act and conspiracy to “facilitate and disguise” other alleged wrongdoings. The “Relevant Period” of alleged wrongdoing spans from February 13, 2018 and continues through the present. The suit seeks unspecified damages to be awarded to the Company, orders directing the Company and individual defendants to make certain corporate governance reforms, restitution, and fees and costs. On April 18, 2019, a Motion to Dismiss Plaintiffs’ Complaint was filed on behalf of all defendants pleading numerous grounds in support of their Motion to Dismiss. On June 3, 2019 Plaintiffs filed a Response to Defendants’ Motion to Dismiss, and on July 3, 2019 Defendants filed a Reply to Plaintiffs’ Response.

On September 25, 2018, another lawsuit was filed in the 68^th district court, Dallas County, Texas derivatively and purportedly on behalf of the Company against John M. Brown, Forrest A. Garb, Kent S. Siegel, Michael B. Croswell, Jr., Dustin L. Guinn, Victor G. Carrillo, Paul Oroian, William H. Avery, Justin W. Furnace, Gene Scammahorn, Martin M. van Brauman, and Lee R. Russell and the Company as a nominal defendant. This suit alleges claims for breaches of fiduciary duty and unjust enrichment against the individual defendants in connection with certain public statements made by the Company from March 12, 2018 to May 30, 2018. On March 29, 2019, this lawsuit was voluntarily dismissed by Plaintiff without prejudice to its subsequent refiling.

On October 29, 2018, Zion received a shareholder request to inspect books and records pursuant to Section 220 of the Delaware General Corporation Law for the purpose of investigating potential corporate mismanagement and breaches of fiduciary duty in connection with public statements made by the Company from March 12, 2018 to May 30, 2018. The Company responded to this request.

The Company disputes the above claims and has made an advanced deposit of $500,000 to defense counsel for the cost of defending the litigation. The Company carries insurance that is applicable to these claims. Because of the uncertainties of litigation, it is not feasible to predict or determine the outcome of these matters, to guarantee that there will be no liability, or to reasonably estimate any loss in excess of its coverage. However, the Company intends to pursue a vigorous defense to the claims.

From time to time, the Company may also be subject to routine litigation, claims or disputes in the ordinary course of business. The Company defends itself vigorously in all such matters. However, we cannot predict the outcome or effect of any of the litigation or any other pending litigation or claims.

C. Environmental and Onshore Licensing Regulatory Matters

The Company is engaged in oil and gas exploration and production and may become subject to certain liabilities as they relate to environmental cleanup of well sites or other environmental restoration procedures and other obligations as they relate to the drilling of oil and gas wells or the operation thereof. Various guidelines have been published in Israel by the State of Israel’s Petroleum Commissioner and Energy and Environmental Ministries as it pertains to oil and gas activities. Mention of these older guidelines was included in previous Zion filings.

On March 15, 2018, the Energy Ministry issued new guidelines regarding a uniform reporting manner by which the operator must submit to the Commissioner data and materials regarding lawful exploration and production activities. The guidelines detail the timeline, data, forms, format, media and materials (such as rock cuttings, cores, gas and oil samples) that must be submitted for seismic and drilling activities.

On April 8, 2019 the Energy Ministry issued new procedural guidelines regarding a uniform reporting manner by which the rights holder in a license must submit a quarterly report regarding a summary of license history, the nature, scope, location and results of the exploration work, specification of the amounts expended for the exploration work, and the results and interpretation of the exploration work and basic data on which these results and interpretation are based. The guidelines will be binding as from the date of submission of the report for the third quarter 2019.

The Company believes that these new regulations are likely to continue to increase the expenditures associated with obtaining new exploration rights and drilling new wells. The Company expects that an additional financial burden could occur as a result of requiring cash reserves that could otherwise be used for operational purposes. In addition, these new regulations are likely to continue to increase the time needed to obtain all of the necessary authorizations and approvals to drill and production test exploration wells.

D. Bank Guarantees

As of June 30, 2019, the Company provided Israeli-required bank guarantees to various governmental bodies (approximately $1,010,000) and others (approximately $85,000) with respect to its drilling operation in an aggregate amount of approximately $1,095,000. The (cash) funds backing these guarantees and additional amounts added to support currency fluctuations as required by the bank are held in restricted interest-bearing accounts and are reported on the Company’s balance sheets as fixed short-term bank deposits – restricted, and fixed long-term bank deposits – restricted.

E. Risks

Market risk is a broad term for the risk of economic loss due to adverse changes in the fair value of a financial instrument. These changes may be the result of various factors, including interest rates, foreign exchange rates, commodity prices and/or equity prices. In the normal course of doing business, we are exposed to the risks associated with foreign currency exchange rates and changes in interest rates.

Foreign Currency Exchange Rate Risks. A portion of our expenses, primarily labor expenses and certain supplier contracts, are denominated in New Israeli Shekels (“NIS”). As a result, we have significant exposure to the risk of fluctuating exchange rates with the U.S. Dollar (“USD”), our primary reporting currency. During the period January 1, 2019 through June 30, 2019, the USD has fluctuated by approximately 4.9% against the NIS (the USD has weakened relative to the NIS). By contrast, during the period January 1, 2018 through December 31, 2018, the USD fluctuated by approximately 8.1% against the NIS (the USD strengthened relative to the NIS). Continued weakening of the US dollar against the NIS will result in higher operating costs from NIS denominated expenses. To date, we have not hedged any of our currency exchange rate risks, but we may do so in the future.

Interest Rate Risk. Our exposure to market risk relates to our cash and investments. We maintain an investment portfolio of short-term bank deposits and money market funds. The securities in our investment portfolio are not leveraged, and are, due to their very short-term nature, subject to minimal interest rate risk. We currently do not hedge interest rate exposure. Because of the short-term maturities of our investments, we do not believe that a change in market interest rates would have a significant negative impact on the value of our investment portfolio except for reduced income in a low interest rate environment. At June 30, 2019, we had cash, cash equivalents and short-term bank deposits, inclusive of restricted cash, of approximately $4,180,000. The weighted average annual interest rate related to our cash and cash equivalents for the six months ended June 30, 2019 was approximately 0.13%.

The primary objective of our investment activities is to preserve principal while at the same time maximizing yields without significantly increasing risk. To achieve this objective, we invest our excess cash in short-term bank deposits and money market funds that may invest in high quality debt instruments.