XML 62 R50.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stock And Stock Options (Narrative) (Details) |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Mar. 21, 2016 | Feb. 01, 2008 shares | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 USD ($) shares | Dec. 31, 2015 USD ($) | Oct. 25, 2000 shares
Stock Options [Line Items] |  |  |  |  |  |
Number of shares that may be granted |  |  |  |  |  | 7,000,000
Number of additional shares that may be granted |  | 3,500,000 |  |  |  |
Stock Incentive Plan term |  |  | 10 years |  |  |
Purchase price floor of fair market value |  |  | 85.00% |  |  |
Stock based compensation | $ |  |  | $ 14,000 | $ 17,000 | $ 12,000 |
Expected volatility |  |  |  | 122.70% | 61.70% |
Risk free interest rate |  |  |  | 2.67% | 2.53% |
Reverse stock split | 0.1 |  |  |  |  |
Common stock, shares issued |  |  | 10,619,924 | 6,097,723 |  |
Stock Options [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Stock based compensation | $ |  |  |  | $ 3,000 | $ 12,000 |
Directors And CEO [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Stock based compensation | $ |  |  | $ 14,000 | $ 14,000 |  |
Common stock, shares issued |  |  | 23,503 | 12,641 |  |
Four Non-Executive Directors [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Number of additional shares that may be granted |  |  | 0 |  |  |
Minimum [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Option life remaining |  |  |  | 3 months 18 days | 3 months 18 days |
Maximum [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Option life remaining |  |  |  | 4 years 9 months 18 days | 4 years 9 months 18 days |
Voluntary Resignation [Member] |  |  |  |  |  |
Stock Options [Line Items] |  |  |  |  |  |
Stock Incentive Plan exercisable period |  |  | 3 months |  |  |

X
- Definition Share Based Compensation Arrangement By Share Based Payment Award, Exercisable Period + References No definition available. + Details
Name: | tgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisablePeriod
Namespace Prefix: | tgc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price Floor Of Fair Market Value + References No definition available. + Details
Name: | tgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePriceFloorOfFairMarketValue
Namespace Prefix: | tgc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Term + References No definition available. + Details
Name: | tgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardTerm
Namespace Prefix: | tgc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Options [Line Items] + References No definition available. + Details
Name: | tgc_StockOptionsLineItems
Namespace Prefix: | tgc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Risk-free interest rate assumption used in valuing an instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
Name: | us-gaap_ShareBasedCompensation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of additional shares authorized for issuance under an established share-based compensation plan. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB TOPIC 4.C) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Stock Split -URI http://asc.fasb.org/extlink&oid=6525746 + Details
Name: | us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=tgc_DirectorsAndChiefExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=tgc_FourNonExecutiveDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=tgc_VoluntaryResignationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |