Segment Information - Segment Information Report of Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Net sales	$ 101,988	$ 87,942	$ 184,635	$ 195,277
Gross profit (loss)	11,317	15,210	15,631	38,129
Operating income (loss)	5,399	9,269	4,273	26,158
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(3,555)	(4,004)	(6,676)	(7,883)
Water Transmission [Member]
Segment Reporting Information [Line Items]
Net sales	62,205	58,148	105,204	136,761
Gross profit (loss)	11,491	12,125	13,159	31,995
Operating income (loss)	9,543	10,499	9,244	28,532
Tubular Products [Member]
Segment Reporting Information [Line Items]
Net sales	39,783	29,794	79,431	58,516
Gross profit (loss)	(174)	3,085	2,472	6,134
Operating income (loss)	$ (589)	$ 2,774	$ 1,705	$ 5,509

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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- Details

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