XML 49 R45.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Long-Term Debt (Narrative) (Details) (USD $) | 12 Months Ended | 0 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2014 | Mar. 27, 2014 | Dec. 31, 2013 | Mar. 16, 2015 | Mar. 15, 2015
Maximum [Member] |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Interest rate per annum | 8.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |
Minimum [Member] |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Interest rate per annum | 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |
F&M Bank [Member] |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum line of credit | $ 40,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  |  |  |
Borrowing base | 14,300,000 tgc_LineOfCreditFacilityBorrowingBase / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  |  |  |
Interest rate per annum | 3.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  |  |  |
Variable interest rate | 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  |  |  |
Loans and letters of credit amount outstanding | 734,000 us-gaap_LineOfCreditFacilityAmountOutstanding / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  | 3,300,000 us-gaap_LineOfCreditFacilityAmountOutstanding / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember |  |
F&M Bank [Member] | Subsequent Event [Member] |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Credit facility current borrowing capacity |  |  |  | 40,000,000 us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |
Borrowing base |  |  |  | $ 7,800,000 tgc_LineOfCreditFacilityBorrowingBase / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | $ 14,300,000 tgc_LineOfCreditFacilityBorrowingBase / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Variable interest rate |  | 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = tgc_FAndMBankMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |

X
- Definition Line Of Credit Facility Borrowing Base + References No definition available. + Details
Name: | tgc_LineOfCreditFacilityBorrowingBase
Namespace Prefix: | tgc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount borrowed under the credit facility as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + 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 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + 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 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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