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Claims revenue (Details) - CAD CAD in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Contractors [Abstract] |  |  |
Claims revenue recognized | CAD 7,635 | CAD 8,230 | CAD 17,053
Claims revenue uncollected (classified as unbilled revenue) | CAD 7,088 | CAD 4,622 | CAD 8,074

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- Definition Revenues, Contract Claims + References No definition available. + Details
Name: | noa_RevenuesContractClaims
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_ContractorsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Amount of billed or unbilled claims or other similar items subject to uncertainty concerning their determination or ultimate realization under long-term contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3(c)(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_ContractsReceivableClaimsAndUncertainAmounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant