Quarterly report pursuant to Section 13 or 15(d)

CRUDE OIL AND NATURAL GAS PROPERTIES (Details)

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CRUDE OIL AND NATURAL GAS PROPERTIES (Details) (USD $)
3 Months Ended 12 Months Ended
Mar. 31, 2015
acre
Mar. 31, 2014
Dec. 31, 2014
acre
Acquisitions [Abstract]      
Capital expenditures incurred but not yet paid $ 155,500,000us-gaap_CapitalExpendituresIncurredButNotYetPaid   $ 221,300,000us-gaap_CapitalExpendituresIncurredButNotYetPaid
Mineral acres acquired, net (in acres) 899nog_GasAndOilAcreageNetAcresAcquired    
Average acquisition cost per net acre 1,363nog_AverageAcquisitionCostPerNetAcre    
Proceeds from sale of oil and gas properties 160,944us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment 0us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment  
Unproved Properties [Abstract]      
Unproven leasehold interests (in net acres) 52,631nog_UnprovenLeaseholdInterests   55,743nog_UnprovenLeaseholdInterests
Anticipated future period over which excluded costs will become subject to depletion 5 years    
Impairment costs related to expired leases subject to depletion 23,600,000nog_ImpairmentCostsRelatedToExpiredLeasesSubjectToDepletion 0nog_ImpairmentCostsRelatedToExpiredLeasesSubjectToDepletion  
North Dakota and Montana Properties [Member]      
Acquisitions [Abstract]      
Gas and Oil acreage, net acres sold 383nog_GasAndOilAcreageNetAcresSold
/ dei_LegalEntityAxis
= nog_NorthDakotaAndMontanaPropertiesMember
   
Proceeds from sale of oil and gas properties $ 200,000us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment
/ dei_LegalEntityAxis
= nog_NorthDakotaAndMontanaPropertiesMember