XML 92 R84.htm IDEA: XBRL DOCUMENT v2.4.1.9

Subsequent events (Details) (Subsequent event, CAD) In Thousands, unless otherwise specified	Jan. 02, 2015
Subsequent event
Subsequent Event [Line Items]
Net proceeds from sale of contract-related assets	36,347noa_DisposalGroupIncludingDiscontinuedOperationConsideration / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

X

- Definition

Disposal Group, Including Discontinued Operation, Consideration

+ References

No definition available.

+ Details

Name:	noa_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix:	noa_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration