XML 59 R48.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Derivative Instruments (Details) | 9 Months Ended
--- | ---
Sep. 30, 2018
Electricity (In MWH) [Member] | October 2018 [Member] |
Derivative [Line Items] |
Volume | 96,960
Electricity (In MWH) [Member] | November 2018 [Member] |
Derivative [Line Items] |
Volume | 68,880
Electricity (In MWH) [Member] | December 2018 [Member] |
Derivative [Line Items] |
Volume | 86,800
Electricity (In MWH) [Member] | January 2019 [Member] |
Derivative [Line Items] |
Volume | 173,360
Electricity (In MWH) [Member] | February 2019 [Member] |
Derivative [Line Items] |
Volume | 157,120
Electricity (In MWH) [Member] | March 2019 [Member] |
Derivative [Line Items] |
Volume | 36,960
Electricity (In MWH) [Member] | April 2019 [Member] |
Derivative [Line Items] |
Volume | 3,520
Electricity (In MWH) [Member] | May 2019 [Member] |
Derivative [Line Items] |
Volume | 3,520
Electricity (In MWH) [Member] | June 2019 [Member] |
Derivative [Line Items] |
Volume | 3,200
Electricity (In MWH) [Member] | July 2019 [Member] |
Derivative [Line Items] |
Volume | 7,040
Electricity (In MWH) [Member] | August 2019 [Member] |
Derivative [Line Items] |
Volume | 7,040
Electricity (In MWH) [Member] | September 2019 [Member] |
Derivative [Line Items] |
Volume | 3,200
Electricity (In MWH) [Member] | October 2019 [Member] |
Derivative [Line Items] |
Volume | 3,680
Electricity (In MWH) [Member] | November 2019 [Member] |
Derivative [Line Items] |
Volume | 3,200
Electricity (In MWH) [Member] | December 2019 [Member] |
Derivative [Line Items] |
Volume | 3,360
Electricity (In MWH) [Member] | Calendar 2020 [Member] |
Derivative [Line Items] |
Volume | -
Electricity (In MWH) [Member] | Calendar 2021 [Member] |
Derivative [Line Items] |
Volume | -
Gas (in Dth) [Member] | October 2018 [Member] |
Derivative [Line Items] |
Volume | -
Gas (in Dth) [Member] | November 2018 [Member] |
Derivative [Line Items] |
Volume | 538,650
Gas (in Dth) [Member] | December 2018 [Member] |
Derivative [Line Items] |
Volume | 554,600
Gas (in Dth) [Member] | January 2019 [Member] |
Derivative [Line Items] |
Volume | 812,530
Gas (in Dth) [Member] | February 2019 [Member] |
Derivative [Line Items] |
Volume | 694,825
Gas (in Dth) [Member] | March 2019 [Member] |
Derivative [Line Items] |
Volume | 627,875
Gas (in Dth) [Member] | April 2019 [Member] |
Derivative [Line Items] |
Volume | 36,175
Gas (in Dth) [Member] | May 2019 [Member] |
Derivative [Line Items] |
Volume | 30,450
Gas (in Dth) [Member] | June 2019 [Member] |
Derivative [Line Items] |
Volume | 24,975
Gas (in Dth) [Member] | July 2019 [Member] |
Derivative [Line Items] |
Volume | 20,100
Gas (in Dth) [Member] | August 2019 [Member] |
Derivative [Line Items] |
Volume | 18,200
Gas (in Dth) [Member] | September 2019 [Member] |
Derivative [Line Items] |
Volume | 17,750
Gas (in Dth) [Member] | October 2019 [Member] |
Derivative [Line Items] |
Volume | 16,900
Gas (in Dth) [Member] | November 2019 [Member] |
Derivative [Line Items] |
Volume | 18,575
Gas (in Dth) [Member] | December 2019 [Member] |
Derivative [Line Items] |
Volume | 18,625
Gas (in Dth) [Member] | Calendar 2020 [Member] |
Derivative [Line Items] |
Volume | 112,375
Gas (in Dth) [Member] | Calendar 2021 [Member] |
Derivative [Line Items] |
Volume | 19,850

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

X
- Definition Information that would enable users to understand the volume of the entity's derivative activity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959 + Details
Name: | us-gaap_DescriptionOfDerivativeActivityVolume
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gne_ElectricityCommodityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesFiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesSixMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesSevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesNineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesTenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesElevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesTwelveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesThirteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesFourteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesFifteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreationDateAxis=gne_SettlementDatesSixteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gne_NaturalGasReserveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |