XML 113 R84.htm IDEA: XBRL DOCUMENT
v3.20.4

Supplemental Oil And Gas Information (Narrative) (FY) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) Item $ / bbl | Dec. 31, 2018 Item $ / bbl | Dec. 31, 2017 Item $ / bbl
Oil and Gas, Average Sale Price and Production Cost Per Unit [Line Items] |  |  |
Proved undeveloped reserve locations | Item | 0 | 7 | 3
Depreciation, depletion, or any indirect cost | $ | $ 0 |  |
Barrel Of Oil [Member] |  |  |
Oil and Gas, Average Sale Price and Production Cost Per Unit [Line Items] |  |  |
Price | $ / bbl | 50.65 | 60.21 | 45.83

X
- Definition Sales price per unit of oil and gas produced. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1204 -Paragraph (b) -Subparagraph (1) + Details
Name: | srt_AverageSalesPrices
Namespace Prefix: | srt_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Oil and Gas, Average Sale Price and Production Cost Per Unit [Line Items] + References No definition available. + Details
Name: | tgc_OilAndGasAverageSalePriceAndProductionCostPerUnitLineItems
Namespace Prefix: | tgc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proved Undeveloped Reserve Locations + References No definition available. + Details
Name: | tgc_ProvedUndevelopedReserveLocations
Namespace Prefix: | tgc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Depreciation, depletion, amortization, and accretion related to oil and gas producing activities. + References No definition available. + Details
Name: | us-gaap_ResultsOfOperationsDepreciationDepletionAmortizationAndAccretion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_EnergyAxis=srt_CrudeOilAndNGLPerBarrelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |