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Shares - Share Purchase Program (Details) (CAD) In Thousands, except Share data, unless otherwise specified | 0 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 18, 2014 | Dec. 31, 2014 | Dec. 31, 2013
Equity, Class of Treasury Stock [Line Items] |  |  |
Retired through Share Purchase Program (shares) |  | 500,000 noa_StockRepurchaseProgramNumberofSharestobePurchasedandRetired | 1,800,000 noa_StockRepurchaseProgramNumberofSharestobePurchasedandRetired
Stock purchase program |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |
Retired through Share Purchase Program (shares) | 1,771,195 noa_StockRepurchaseProgramNumberofSharestobePurchasedandRetired / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember |  |
Percentage of issued and outstanding common shares purchased under Purchase Program | 5.00%noa_StockRepurchaseProgramCommonVotingSharesPurchasedPercentage / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember |  |
Shares retired during period |  | 500,000 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember | 1,800,000 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember
Shares retired during period, percentage of issued and outstanding shares |  |  | 5.00%noa_StockRepurchasedandRetiredDuringPeriodPercentageofIssuedandOutstandingShares / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember
Common stock | Stock purchase program |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |
Increase (decrease) as a result of the retirement of shares |  | (4,238)us-gaap_StockRepurchasedAndRetiredDuringPeriodValue / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember | (16,133)us-gaap_StockRepurchasedAndRetiredDuringPeriodValue / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember
Additional paid in capital | Stock purchase program |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |
Increase (decrease) as a result of the retirement of shares |  | 2,297 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember / us-gaap_StatementEquityComponentsAxis = us-gaap_AdditionalPaidInCapitalMember | 4,393 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue / us-gaap_ShareRepurchaseProgramAxis = noa_StockPurchaseProgramMember / us-gaap_StatementEquityComponentsAxis = us-gaap_AdditionalPaidInCapitalMember

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- Definition Stock Repurchased and Retired During Period, Percentage of Issued and Outstanding Shares + References No definition available. + Details
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- Definition Stock Repurchase Program, Common Voting Shares Purchased, Percentage + References No definition available. + Details
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- Definition Stock Repurchase Program, Number of Shares to be Purchased and Retired + References No definition available. + Details
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- Definition Number of shares that have been repurchased and retired during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
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- Definition Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
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