Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE (Details)

v2.4.1.9
FAIR VALUE (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Transfers between Level 1 and Level 2 $ 0us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount  
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Commodity Derivatives - Current Asset (crude oil swaps) 0nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Non - Current Asset (crude oil swaps) 0nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Current Liability (crude oil swaptions) 0nog_CommodityDerivativesCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Commodity Derivatives - Non-Current Liability (crude oil swaptions)   0nog_CommodityDerivativesNonCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Total 0us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Commodity Derivatives - Current Asset (crude oil swaps) 124,698,923nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
128,893,220nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Non - Current Asset (crude oil swaps) 14,397,517nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
25,013,011nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Current Liability (crude oil swaptions) (100,646)nog_CommodityDerivativesCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Commodity Derivatives - Non-Current Liability (crude oil swaptions)   (579,070)nog_CommodityDerivativesNonCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Total 138,995,794us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
153,327,161us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Commodity Derivatives - Current Asset (crude oil swaps) 0nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0nog_CommodityDerivativesCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Non - Current Asset (crude oil swaps) 0nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0nog_CommodityDerivativesNonCurrentAssetCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Commodity Derivatives - Current Liability (crude oil swaptions) 0nog_CommodityDerivativesCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Commodity Derivatives - Non-Current Liability (crude oil swaptions)   0nog_CommodityDerivativesNonCurrentLiabilityCrudeOilSwapsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Total $ 0us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
$ 0us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember