Debt instrument minimum principal withdrawal limit.

No definition available.

Name:	teng_DebtInstrumentMinimumPrincipalWithdrawalLimit
Namespace Prefix:	teng_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum amount received by lenders to share sale proceeds.

+ References

No definition available.

+ Details

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Namespace Prefix:	teng_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Sales percentage to borrowers.

+ References

No definition available.

+ Details

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Namespace Prefix:	teng_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Sales percentage to lenders.

+ References

No definition available.

+ Details

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Namespace Prefix:	teng_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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-Name Accounting Standards Codification
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-Subparagraph (SX 210.9-04(8))
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ 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 210.5-02.22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ References

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-Name Accounting Standards Codification
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+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Expenses paid for obtaining loans which includes expenses such as application and origination fees.

+ References

No definition available.

+ Details

Name:	us-gaap_LoanProcessingFee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=teng_CommittedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=teng_UncommittedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_PaymentInKindPIKNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=teng_FirstOptionTargetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=teng_SecondOptionTargetsMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=teng_ThirdOptionTargetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Notes Payable (Morgan Stanley Credit Agreement) - Additional Information (Detail) - USD ($)		3 Months Ended		12 Months Ended
	Aug. 17, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	May 21, 2014
Debt Instrument [Line Items]
Debt issuance costs		$ 2,662,638		$ 3,550,184
Morgan Stanley [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate description		Interest at a per annum rate equal to 9% plus the greater of 1% or LIBOR, for a three month interest period.
Debt instrument, additional interest rate		1.00%
Debt instrument interest rate		9.00%
Interest expense related to credit agreement		$ 5,370,581	$ 2,967,969
American Shale [Member] \| Morgan Stanley [Member]
Debt Instrument [Line Items]
Initial withdrawal amount					$ 102,500,000
Remaining borrowing capacity		47,500,000
Debt origination fees		6,242,874
Debt issuance costs		2,662,638		3,550,184
Interest expense related to amortization of the loan costs		3,580,236		$ 2,692,690
American Shale [Member] \| Morgan Stanley [Member] \| Committed [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity					47,500,000
American Shale [Member] \| Morgan Stanley [Member] \| Uncommitted [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity					50,000,000
American Shale [Member] \| Morgan Stanley [Member] \| Payment in Kind (PIK) Note [Member]
Debt Instrument [Line Items]
Credit Agreement fee					593,750
American Shale [Member] \| Credit Agreement [Member]
Debt Instrument [Line Items]
Obligations outstanding under credit facility		$ 135,000,000
American Shale [Member] \| Subsequent Event [Member] \| First Option Targets [Member]
Debt Instrument [Line Items]
Lender's percentage to share sale proceeds	100.00%
Minimum amount that the lender received to share sale proceeds	$ 80,000,000
Debt instrument interest rate	12.00%
American Shale [Member] \| Subsequent Event [Member] \| Second Option Targets [Member]
Debt Instrument [Line Items]
Lender's percentage to share sale proceeds	78.75%
Minimum amount that the lender received to share sale proceeds	$ 57,167,819
Debt instrument interest rate	15.00%
Borrower's percentage to share sale proceeds	21.25%
American Shale [Member] \| Subsequent Event [Member] \| Third Option Targets [Member]
Debt Instrument [Line Items]
Lender's percentage to share sale proceeds	15.00%
Borrower's percentage to share sale proceeds	85.00%
American Shale [Member] \| Maximum [Member] \| Morgan Stanley [Member]
Debt Instrument [Line Items]
Credit facility, face amount					$ 200,000,000