XML 54 R41.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Manufactured Methane Facilities (Narrative) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Methane Project [Line Items] |  |  |
Depreciation expense | $ 77,000 | $ 101,000 | $ 170,000
Asset Impairment Charges | 14,526,000 | 2,796,000 |
Methane Project [Member] |  |  |
Methane Project [Line Items] |  |  |
Depreciation expense | $ 60,000 | 163,000 | $ 136,000
Asset Impairment Charges |  | 2,800,000 |
Asset Impairment Charge Net Of Tax |  | $ 1,700,000 |

X
- Definition Asset Impairment Charge Net Of Tax + References No definition available. + Details
Name: | tgc_AssetImpairmentChargeNetOfTax
Namespace Prefix: | tgc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + 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 (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
Name: | us-gaap_Depreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | tgc_ExplorationAndProductionRevenueByTypeAxis=tgc_MethaneProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |