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EMPLOYEE BENEFIT PLANS (Details) (USD $)
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12 Months Ended | ||
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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| EMPLOYEE BENEFIT PLANS [Abstract] | |||
| Percentage match of eligible employee's deferral contribution (in hundredths) | 100.00%nog_PercentageEntityMatchesOfEligibleEmployeesContributions | 100.00%nog_PercentageEntityMatchesOfEligibleEmployeesContributions | 100.00%nog_PercentageEntityMatchesOfEligibleEmployeesContributions |
| Maximum percentage of eligible employee's deferral contribution matched (in hundredths) | 8.00%nog_MaximumPercentageOfEligibleCompensationMatched | 8.00%nog_MaximumPercentageOfEligibleCompensationMatched | 8.00%nog_MaximumPercentageOfEligibleCompensationMatched |
| Matching contributions to the Plans | $ 269,000us-gaap_DefinedContributionPlanCostRecognized | $ 240,000us-gaap_DefinedContributionPlanCostRecognized | $ 189,000us-gaap_DefinedContributionPlanCostRecognized |
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- Definition
Maximum percentage of employees' eligible compensation matched. No definition available.
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- Definition
Percentage the entity matches of eligible employees' contributions. No definition available.
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- Details
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- Definition
The amount of the cost recognized during the period for defined contribution plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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