Annual report pursuant to Section 13 and 15(d)

CRUDE OIL AND NATURAL GAS PROPERTIES (Details)

v2.4.1.9
CRUDE OIL AND NATURAL GAS PROPERTIES (Details) (USD $)
12 Months Ended 3 Months Ended
Dec. 31, 2014
acre
Dec. 31, 2013
acre
Dec. 31, 2012
Dec. 31, 2012
acre
Dec. 31, 2011
Acquisitions [Abstract]          
Capital expenditures incurred but not yet paid $ 221,000,000us-gaap_CapitalExpendituresIncurredButNotYetPaid $ 163,000,000us-gaap_CapitalExpendituresIncurredButNotYetPaid      
Divestitures [Abstract]          
Proceeds from sale of oil and gas properties 0us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment 908,000us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment 0us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment    
Unproved Properties [Abstract]          
Unproven leasehold interests (in net acres) 55,743nog_UnprovenLeaseholdInterests 60,600nog_UnprovenLeaseholdInterests      
Anticipated future period over which excluded costs will become subject to depletion 5 years        
Impairment costs related to expired leases subject to depletion 21,400,000nog_ImpairmentCostsRelatedToExpiredLeasesSubjectToDepletion 5,100,000nog_ImpairmentCostsRelatedToExpiredLeasesSubjectToDepletion 0nog_ImpairmentCostsRelatedToExpiredLeasesSubjectToDepletion    
Capitalized Costs of Unproved Properties Excluded from Amortization, Period Cost [Abstract]          
Property Acquisition 23,919,268us-gaap_AcquisitionCosts 13,085,405us-gaap_AcquisitionCosts 3,356,715us-gaap_AcquisitionCosts    
Development 0us-gaap_DevelopmentCosts 0us-gaap_DevelopmentCosts 0us-gaap_DevelopmentCosts    
Total 23,919,268us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization 13,085,405us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization 3,356,715us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization    
Capitalized Costs of Unproved Properties Excluded from Amortization, Cumulative [Abstract]          
Property Acquisition, Cumulative         10,281,045us-gaap_AcquisitionCostsCumulative
Development, Cumulative         0us-gaap_DevelopmentCostsCumulative
Total, Cumulative         10,281,045us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationCumulative
2012 Acquisitions [Member]          
Acquisitions [Abstract]          
Mineral acres acquired, net (in acres) 17,590nog_GasAndOilAcreageNetAcresAcquired
/ nog_AcquisitionsByYearAxis
= nog_AcquisitionsMember
       
Average acquisition cost per net acre 1,788nog_AverageAcquisitionCostPerNetAcre
/ nog_AcquisitionsByYearAxis
= nog_AcquisitionsMember
       
Number of acres earned through farm-in arrangements (in acres) 6,450nog_NumberOfAcresEarnedThroughFarmInArrangements
/ nog_AcquisitionsByYearAxis
= nog_AcquisitionsMember
       
2013 Acquisitions [Member]          
Acquisitions [Abstract]          
Mineral acres acquired, net (in acres) 20,900nog_GasAndOilAcreageNetAcresAcquired
/ nog_AcquisitionsByYearAxis
= nog_Year2013Member
       
Average acquisition cost per net acre 1,279nog_AverageAcquisitionCostPerNetAcre
/ nog_AcquisitionsByYearAxis
= nog_Year2013Member
       
Productive oil and gas wells number of wells gross 70nog_ProductiveOilAndGasWellsNumberOfWellsGross
/ nog_AcquisitionsByYearAxis
= nog_Year2013Member
       
Productive oil and gas wells number of wells net 7.0nog_ProductiveOilAndGasWellsNumberOfWellsNet
/ nog_AcquisitionsByYearAxis
= nog_Year2013Member
       
Productive Oil and Gas Wells, Cost 9,000,000nog_ProductiveOilAndGasWellsCost
/ nog_AcquisitionsByYearAxis
= nog_Year2013Member
       
2014 Acquisitions [Member]          
Acquisitions [Abstract]          
Mineral acres acquired, net (in acres) 22,668nog_GasAndOilAcreageNetAcresAcquired
/ nog_AcquisitionsByYearAxis
= nog_Year2014Member
       
Average acquisition cost per net acre 1,534nog_AverageAcquisitionCostPerNetAcre
/ nog_AcquisitionsByYearAxis
= nog_Year2014Member
       
Productive oil and gas wells number of wells gross 125nog_ProductiveOilAndGasWellsNumberOfWellsGross
/ nog_AcquisitionsByYearAxis
= nog_Year2014Member
       
Productive oil and gas wells number of wells net 10.3nog_ProductiveOilAndGasWellsNumberOfWellsNet
/ nog_AcquisitionsByYearAxis
= nog_Year2014Member
       
Productive Oil and Gas Wells, Cost 10,600,000nog_ProductiveOilAndGasWellsCost
/ nog_AcquisitionsByYearAxis
= nog_Year2014Member
       
North Dakota and Montana Properties [Member]          
Divestitures [Abstract]          
Proceeds from sale of oil and gas properties       $ 900,000us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment
/ dei_LegalEntityAxis
= nog_NorthDakotaAndMontanaPropertiesMember
 
Gas and Oil acreage, net acres sold       835nog_GasAndOilAcreageNetAcresSold
/ dei_LegalEntityAxis
= nog_NorthDakotaAndMontanaPropertiesMember