Segment Information - Segment Information Report of Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Net sales	$ 116,505	$ 78,527	$ 301,140	$ 273,804
Gross profit (loss)	15,820	11,254	31,451	49,383
Operating income (loss)	9,331	5,698	13,604	31,856
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(3,943)	(3,559)	(10,619)	(11,442)
Water Transmission [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	76,857	46,835	182,061	183,596
Gross profit (loss)	16,559	7,932	29,718	39,927
Operating income (loss)	14,429	6,306	23,673	34,838
Tubular Products [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	39,648	31,692	119,079	90,208
Gross profit (loss)	(739)	3,322	1,733	9,456
Operating income (loss)	$ (1,155)	$ 2,951	$ 550	$ 8,460

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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