XML 48 R61.htm IDEA: XBRL DOCUMENT v2.4.1.9

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

X

- 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_
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Balance Type:	debit
Period Type:	instant

X

- Definition

Gain (Loss) on Disposition of Assets Held for Sale

+ References

No definition available.

+ Details

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Namespace Prefix:	noa_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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X

- 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

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- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Details

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