XML 35 R50.htm IDEA: XBRL DOCUMENT v2.4.1.9

Goodwill and Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 30, 2014
Goodwill [Line Items]
Goodwill	$ 5,282us-gaap_Goodwill	$ 25,760us-gaap_Goodwill	$ 20,478us-gaap_Goodwill
Goodwill written off related to sale of business	4,412us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Amortization expense	540us-gaap_AmortizationOfIntangibleAssets	27us-gaap_AmortizationOfIntangibleAssets	27us-gaap_AmortizationOfIntangibleAssets
Tubular Products [Member]
Goodwill [Line Items]
Goodwill	16,100us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = us-gaap_PublicUtilitiesInventoryTubularGoodsMember
Water Transmission [Member]
Goodwill [Line Items]
Goodwill	5,300us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = us-gaap_WaterTransmissionMember
Disposal of OCTG Business [Member]
Goodwill [Line Items]
Goodwill written off related to sale of business	$ 4,400us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit / us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis = nwpx_OilCountryTubularGoodsMember			$ 4,400us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit / us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis = nwpx_OilCountryTubularGoodsMember

X

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ 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 350

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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Balance Type:	debit
Period Type:	duration

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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X

- Details

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X

- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

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X

- Details

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Namespace Prefix:
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X

- Details

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X

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