XML 81 R62.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Acquisitions - Heavy construction fleet and related assets (Details) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Nov. 23, 2018 CAD ($) installment | Dec. 31, 2018 CAD ($) | Dec. 31, 2017 CAD ($)
Schedule of Asset Acquisition [Line Items] |  |  |
Payments for asset acquisitions |  | $ 151,180 | $ 0
Acquisition Of Aecon Construction Group Inc.'s Heavy Construction Equipment Fleet And Related Assets |  |  |
Schedule of Asset Acquisition [Line Items] |  |  |
Payments for asset acquisitions | $ 198,000 |  |
Initial payment | 150,800 |  |
Capital leases and equipment related promissory notes | $ 12,600 |  |
Number of installment payments | installment | 3 |  |
Transaction costs | $ 400 |  |

X
- Definition Asset Acquisition, Capital Leases And Equipment Related Promissory Notes + References No definition available. + Details
Name: | noa_AssetAcquisitionCapitalLeasesAndEquipmentRelatedPromissoryNotes
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Asset Acquisition, Initial Payment + References No definition available. + Details
Name: | noa_AssetAcquisitionInitialPayment
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Asset Acquisition, Number Of Installment Payments + References No definition available. + Details
Name: | noa_AssetAcquisitionNumberOfInstallmentPayments
Namespace Prefix: | noa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Asset Acquisition, Transaction Costs + References No definition available. + Details
Name: | noa_AssetAcquisitionTransactionCosts
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Payments for Asset Acquisitions + References No definition available. + Details
Name: | noa_PaymentsforAssetAcquisitions
Namespace Prefix: | noa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition [Line Items] for Schedule of Asset Acquisition [Table] + References No definition available. + Details
Name: | noa_ScheduleofAssetAcquisitionLineItems
Namespace Prefix: | noa_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | noa_AssetAcquisitionAxis=noa_AcquisitionOfAeconConstructionGroupInc.sHeavyConstructionEquipmentFleetAndRelatedAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |