XML 69 R57.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Supplemental Oil And Gas Information (Narrative) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2017 item $ / bbl | Dec. 31, 2016 item $ / bbl | Dec. 31, 2015 item $ / bbl | Dec. 31, 2014 item
Average Sales Price and Production Costs Per Unit of Production [Line Items] |  |  |  |
Proved undeveloped reserve locations | item | 3 | 0 | 0 | 27
Barrel Of Oil [Member] |  |  |  |
Average Sales Price and Production Costs Per Unit of Production [Line Items] |  |  |  |
Price | $ / bbl | 45.83 | 37.35 | 43.98 |

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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The revenues derived from sales of oil or gas in each geographic area during the reporting period divided by the number of barrels of oil produced or thousands of cubic feet of gas produced. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1204 -Paragraph (b) -Subparagraph (1) + Details
Name: | us-gaap_AverageSalesPrices
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis=us-gaap_CrudeOilAndNGLPerBarrelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |