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Stock-based compensation - Plan activity (Details) (CAD)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Exercised (options)   (295,230)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Share option plan    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Beginning balance (options) 2,213,280us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
3,029,734us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Granted (options)   177,400us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Exercised (options) (385,880)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
[1] (295,230)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
[1]
Forfeited (options) (61,480)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
(698,624)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Ending balance (options) 1,765,920us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
2,213,280us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]    
Beginning balance (CAD per share) 5.51us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
5.70us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Granted (CAD per share)   5.91us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Exercised (CAD per share) 3.49us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
[1] 3.98us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
[1]
Forfeited (CAD per share) 7.83us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
7.12us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Ending balance (CAD per share) 5.87us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
5.51us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]    
Number of options granted   177,400us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_ShareOptionPlanMember
Senior executive stock option plan    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Granted (options) 258,200us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
550,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Exercised (options) (291,800)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]    
Number of options granted 258,200us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
550,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Weighted average fair value per option granted (CAD per share) 0.08us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
1.71us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Senior executive stock option plan | Stock options    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]    
Dividend yield 2.20%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
 
Expected volatility 49.68%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
39.12%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Risk-free interest rate 0.25%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
0.22%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= noa_SeniorExecutiveStockOptionPlanMember
Expected life (years) 0 years 5 months 1 year 5 months
Liability classified restricted share unit plan | Restricted share units (RSUs)    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]    
Beginning balance (units) 1,023,944us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
1,110,275us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
Granted/issued (units)   555,204us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
Dividend equivalents granted/issued (units) 695noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGranted
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
 
Vested (units) (350,271)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
(154,330)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
Forfeited (units) (58,865)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
(487,205)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
Ending balance (units) 615,503us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
1,023,944us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedRestrictedShareUnitPlanMember
Equity classified restricted share unit plan | Restricted share units (RSUs)    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]    
Beginning balance (units) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Granted/issued (units) 274,256us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Dividend equivalents granted/issued (units) 11,557noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGranted
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Vested (units) (605)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
Forfeited (units) (22,300)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Ending balance (units) 262,908us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]    
Outstanding, beginning of period (CAD per unit) 0.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Granted/Issued, Weighted average exercise price (CAD per unit) 7.98us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Dividend equivalents granted/issued, Weighted average exercise price (CAD per unit) 6.15noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGrantedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Vested, Weighted average exercise price (CAD per unit) 7.75us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Forfeited, Weighted average exercise price (CAD per unit) 7.87us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
 
Outstanding, end of period (CAD per unit) 7.91us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
0.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedRestrictedShareUnitPlanMember
Liability classified deferred stock unit plan | Deferred stock units (DSUs)    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]    
Beginning balance (units) 586,834us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
625,156us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
Granted/issued (units) 7,674us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
141,509us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
Vested (units) (63,886)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
(179,831)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
Ending balance (units) 530,622us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
586,834us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_LiabilityClassifiedDeferredStockUnitPlanMember
Equity classified deferred stock unit plan | Deferred stock units (DSUs)    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]    
Beginning balance (units) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Granted/issued (units) 161,007us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Dividend equivalents granted/issued (units) 8,721noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGranted
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Ending balance (units) 169,728us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]    
Outstanding, beginning of period (CAD per unit) 0.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Granted/Issued, Weighted average exercise price (CAD per unit) 6.52us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Dividend equivalents granted/issued, Weighted average exercise price (CAD per unit) 6.10noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGrantedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
Outstanding, end of period (CAD per unit) 6.50us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= noa_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= noa_EquityClassifiedDeferredStockUnitPlanMember
 
[1] All stock options exercised resulted in new common shares being issued (note 17(a))