Quarterly report pursuant to Section 13 or 15(d)

STOCK OPTIONS/STOCK-BASED COMPENSATION AND WARRANTS (Details)

v2.4.1.9
STOCK OPTIONS/STOCK-BASED COMPENSATION AND WARRANTS (Details) (USD $)
3 Months Ended
Mar. 31, 2015
2006 Incentive Stock Option Plan [Member]  
Stock Option Awards [Abstract]  
Shares granted (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_PlanNameAxis
= nog_IncentiveStockOptionPlanMember
2013 Equity Incentive Plan [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Additional shares were authorized for grant (in shares) 1,500,000nog_ShareBasedCompensationArrangementAdditionalSharesWereAuthorizedForGrant
/ us-gaap_PlanNameAxis
= nog_EquityIncentivePlan2013Member
Restricted Stock Awards [Member]  
Restricted Stock Awards [Abstract]  
Unrecognized compensation expense 8,200,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Unrecognized compensation expense, recognized period 2 years 4 months 24 days
Percent of forfeiture rate assumed for restricted stock (in hundredths) 0.00%nog_ShareBasedCompensationArrangementsFairValueAwardExpectedForfeitureRate
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Restricted Stock Awards Activity [Roll forward]  
Restricted Shares Outstanding at the Beginning of Period (in shares) 538,499us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Shares Granted (in shares) 497,854us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Lapse of Restrictions (in shares) (64,759)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Restricted Shares Outstanding at the End of Period (in shares) 971,594us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Restricted Stock Awards, Additional Disclosures [Abstract]  
Restricted Shares Outstanding, Weighted-Average Price at the Beginning of Period (in dollars per share) 13.54us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Shares Granted, Weighted-Average Price (in dollars per share) 8.61us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Lapse of Restrictions, Weighted-Average Price (in dollars per share) 14.67us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Restricted Shares Outstanding, Weighted-Average Price at the End of Period (in dollars per share) 10.94us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Currently Outstanding Options [Abstract]  
Unvested options outstanding (in shares) 971,594us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Stock Option Awards [Member]  
Restricted Stock Awards Activity [Roll forward]  
Restricted Shares Outstanding at the End of Period (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Stock Option Awards [Abstract]  
Options remain outstanding but unexercised (in shares) 141,872us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Currently Outstanding Options [Abstract]  
Forfeited (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options expired during period (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Exercisable (in shares) 141,872us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Share-based compensation expense 0us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Unvested options outstanding (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Stock Option Awards [Member] | 2006 Incentive Stock Option Plan [Member]  
Stock Option Awards [Abstract]  
Shares granted (in shares) 560,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= nog_IncentiveStockOptionPlanMember
Shares granted (in dollars per share) 5.18us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= nog_IncentiveStockOptionPlanMember
Stock Option Awards [Member] | Directors [Member] | 2006 Incentive Stock Option Plan [Member]  
Stock Option Awards [Abstract]  
Shares granted (in shares) 500,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= nog_IncentiveStockOptionPlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_DirectorMember
Stock Option Awards [Member] | Employee [Member] | 2006 Incentive Stock Option Plan [Member]  
Stock Option Awards [Abstract]  
Shares granted (in shares) 60,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= nog_IncentiveStockOptionPlanMember
/ us-gaap_TitleOfIndividualAxis
= nog_EmployeeMember