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Assets held for sale (Details) (CAD) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013
Property, Plant and Equipment [Line Items] |  |
Contract-related assets held for sale | 29,400 noa_AssetsHeldforsaleNotPartofDisposalGroupContractrelatedAssetsCurrent |
Gain (loss) on disposal of assets held for sale | 86 noa_GainLossOnDispositionOfAssetsHeldForSale | (2,212)noa_GainLossOnDispositionOfAssetsHeldForSale
Equipment |  |
Property, Plant and Equipment [Line Items] |  |
Gain (loss) on disposal of assets held for sale | 86 noa_GainLossOnDispositionOfAssetsHeldForSale / us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis = us-gaap_EquipmentMember | (2,212)noa_GainLossOnDispositionOfAssetsHeldForSale / us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis = us-gaap_EquipmentMember
Equipment | Depreciation expense |  |
Property, Plant and Equipment [Line Items] |  |
Impairment of equipment assets held for sale | 3,461 us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf / us-gaap_IncomeStatementLocationAxis = noa_DepreciationExpenseMember / us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis = us-gaap_EquipmentMember | 3,097 us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf / us-gaap_IncomeStatementLocationAxis = noa_DepreciationExpenseMember / us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis = us-gaap_EquipmentMember

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- Definition Assets Held-for-sale, Not Part of Disposal Group, Contract-related Assets, Current + References No definition available. + Details
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Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Gain (Loss) on Disposition of Assets Held for Sale + References No definition available. + Details
Name: | noa_GainLossOnDispositionOfAssetsHeldForSale
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2611-110228 + Details
Name: | us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
Name: | us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis=us-gaap_EquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |