Variable interest entity option exercise loan forgiveness.

No definition available.

Name:	gne_VariableInterestEntityOptionExerciseLoanForgiveness
Namespace Prefix:	gne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Variable interest entity payment to owner to acquire option.

+ References

No definition available.

+ Details

Name:	gne_VariableInterestEntityPaymentToOwnerToAcquireOption
Namespace Prefix:	gne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	gne_VariableInterestEntityTextualAbstract
Namespace Prefix:	gne_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Expiration date of the option.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Footnote 5

+ Details

Name:	invest_InvestmentOptionsExpirationDate
Namespace Prefix:	invest_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the amount of activity, consisting of a transaction or a measure not described elsewhere in the taxonomy, occurring during the period between the reporting entity and the Variable Interest Entity (VIE) or potential VIE. Such description provides an understanding of the nature of the other measure of activity being disclosed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph d
-URI http://asc.fasb.org/extlink&oid=52262685&loc=d3e5747-111685

+ Details

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

- Definition

The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=52262685&loc=SL6759159-111685

+ Details

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

- Details

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=gne_CitizensChoiceEnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Variable Interest Entities (Details Textual) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity Textual [Abstract]
Loan amount		$ 950	$ (266)	$ 4,126
CCE [Member]
Variable Interest Entity Textual [Abstract]
Payment to owner of limited liability company	$ 200
Loan amount	$ 500
Variable interest entity, Description	GRE paid $0.2 million to the owner of the limited liability company interests in CCE, and loaned CCE $0.5 million in exchange for an option to purchase 100% of the issued and outstanding limited liability company interests of CCE for one dollar plus the forgiveness of the $0.5 million loan.
Forgiveness of loan	$ 500
Options expiration date	Oct. 22, 2023