Name:	nwpx_BusinessAcquistionIncreaseDecreaseInInventoriesMeasurementPeriodAdjustment
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Data Type:	xbrli:monetaryItemType
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In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined) due to measurement period adjustment, this element represents the increase (decrease) amount of gain recognized by the entity.

No definition available.

Name:	nwpx_BusinessCombinationBargainPurchaseIncreaseDecreaseInGainRecognizedMeasurementPeriodAdjustment
Namespace Prefix:	nwpx_
Data Type:	xbrli:monetaryItemType
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This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to trade and other receivables acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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-Section 50
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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
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