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v2.4.1.9

Supplemental Oil And Gas Information (Schedule Of Net Proved Oil And Gas Reserves And The Changes In Net Proved Oil And Gas Reserves) (Details) | 12 Months Ended
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Dec. 31, 2014 MBbls MBoe | Dec. 31, 2013 MBbls MBoe | Dec. 31, 2012 MBbls MBoe | Dec. 31, 2011 MBoe MBbls
Reserve Quantities [Line Items] |  |  |  |
Proved reserves | 2,040,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet | 2,217,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet | 2,592,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet |
Revisions of previous estimates | (253,000)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease | (151,000)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease | (327,000)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease |
Extensions and discoveries | 164,000 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions | 170,000 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions | 186,000 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions |
Production | (154,000)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction | (172,000)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction | (234,000)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction |
Sales of reserves in place |  | (24,000)us-gaap_ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace |  |
Proved reserves | 1,797,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet | 2,040,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet | 2,217,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet | 2,592,000 us-gaap_ProvedDevelopedAndUndevelopedReservesNet
Proved developed reserves (equivalent) | 1,438,000 tgc_ProvedDevelopedReservesBoe1 | 1,575,000 tgc_ProvedDevelopedReservesBoe1 | 1,826,000 tgc_ProvedDevelopedReservesBoe1 | 1,940,000 tgc_ProvedDevelopedReservesBoe1
Proved undeveloped reserves (equivalent) | 359,000 tgc_ProvedUndevelopedReserveBoe1 | 465,000 tgc_ProvedUndevelopedReserveBoe1 | 391,000 tgc_ProvedUndevelopedReserveBoe1 | 652,000 tgc_ProvedUndevelopedReserveBoe1
Oil [Member] |  |  |  |
Reserve Quantities [Line Items] |  |  |  |
Proved reserves | 2,040 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 2,213 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 2,591 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |
Revisions of previous estimates | (253)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | (153)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | (337)us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |
Extensions and discoveries | 164 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 170 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 186 us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |
Production | (154)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | (166)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | (227)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |
Sales of reserves in place |  | (24)us-gaap_ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |  |
Proved reserves | 1,797 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 2,040 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 2,213 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember |
Proved developed reserves (volume) | 1,438 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 1,575 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 1,822 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 1,939 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember
Proved undeveloped reserves (volume) | 359 us-gaap_ProvedUndevelopedReserveVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 465 us-gaap_ProvedUndevelopedReserveVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 391 us-gaap_ProvedUndevelopedReserveVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember | 652 us-gaap_ProvedUndevelopedReserveVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_OilReservesMember
Gas [Member] |  |  |  |
Reserve Quantities [Line Items] |  |  |  |
Proved reserves |  | 22 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember | 4 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember |
Revisions of previous estimates |  | 16 us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember | 61 us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember |
Production |  | (38)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember | (43)us-gaap_ProvedDevelopedAndUndevelopedReservesProduction / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember |
Proved reserves |  |  | 22 us-gaap_ProvedDevelopedAndUndevelopedReservesNet / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember |
Proved developed reserves (volume) |  |  | 22 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember | 4 us-gaap_ProvedDevelopedReservesVolume / us-gaap_ReserveQuantitiesByTypeOfReserveAxis = us-gaap_NaturalGasReservesMember

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- Definition Energy measure of interests in proved developed reserves of crude oil, including condensate and natural gas liquids, natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas. + References No definition available. + Details
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- Definition Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61831-109447 + Details
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- Definition The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61831-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-10.(a)(2)) -URI http://asc.fasb.org/extlink&oid=27015464&loc=d3e511914-122862 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 10 -Paragraph a -Subparagraph 2 -Article 4 + Details
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- Definition Revisions represent changes in previous estimates of proved reserves, either upward or downward, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from change in economic factors. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61831-109447 + Details
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- Definition Net quantities of an enterprise's interests in proved developed reserves of either crude oil (including condensate and natural gas liquids), natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas as of the beginning and the end of the year. "Net" quantities of reserves include those relating to the enterprise's operating and nonoperating interests in properties. Quantities of reserves relating to royalty interests owned are included in "net" quantities if the necessary information is available to the enterprise. "Net" quantities does not include reserves relating to interests of others in properties owned by the enterprise. The unit of measure for reserve quantities is defined as "barrels" for oil and synthetic oil reserves or "cubic feet" or "cubic meters" for natural gas and synthetic gas reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61797-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61884-109447 + Details
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