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v3.8.0.1

Significant accounting policies - Revenue recognition (Details) | 12 Months Ended
--- | ---
Dec. 31, 2017
Minimum |
Property, Plant and Equipment [Line Items] |
Term of contract (less than one year) | 1 year
Dene North Site Services |
Property, Plant and Equipment [Line Items] |
Undivided ownership interest, percentage | 49.00%

X
- Definition Jointly Owned Partnership, Proportionate Ownership Share + References No definition available. + Details
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Namespace Prefix: | noa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Term of Contract + References No definition available. + Details
Name: | noa_TermOfContract
Namespace Prefix: | noa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OwnershipAxis=noa_DeneNorthSiteServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |