Quarterly Data - Summary of Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Line Items]
Net sales	$ 102,158us-gaap_SalesRevenueNet	$ 116,505us-gaap_SalesRevenueNet	$ 101,988us-gaap_SalesRevenueNet	$ 82,647us-gaap_SalesRevenueNet	$ 85,641us-gaap_SalesRevenueNet	$ 78,527us-gaap_SalesRevenueNet	$ 87,942us-gaap_SalesRevenueNet	$ 107,335us-gaap_SalesRevenueNet	$ 403,298us-gaap_SalesRevenueNet	$ 359,445us-gaap_SalesRevenueNet	$ 388,902us-gaap_SalesRevenueNet
Gross profit	9,125us-gaap_GrossProfit	15,820us-gaap_GrossProfit	11,317us-gaap_GrossProfit	4,314us-gaap_GrossProfit	10,853us-gaap_GrossProfit	11,254us-gaap_GrossProfit	15,210us-gaap_GrossProfit	22,919us-gaap_GrossProfit	40,576us-gaap_GrossProfit	60,236us-gaap_GrossProfit	59,108us-gaap_GrossProfit
Operating income (loss)	(13,410)us-gaap_OperatingIncomeLoss	9,331us-gaap_OperatingIncomeLoss	5,399us-gaap_OperatingIncomeLoss	(1,126)us-gaap_OperatingIncomeLoss	5,679us-gaap_OperatingIncomeLoss	5,698us-gaap_OperatingIncomeLoss	9,269us-gaap_OperatingIncomeLoss	16,889us-gaap_OperatingIncomeLoss	194us-gaap_OperatingIncomeLoss	37,535us-gaap_OperatingIncomeLoss	31,286us-gaap_OperatingIncomeLoss
Net income (loss)	(13,996)us-gaap_NetIncomeLoss	5,021us-gaap_NetIncomeLoss	3,192us-gaap_NetIncomeLoss	(12,104)us-gaap_NetIncomeLoss	(17,006)us-gaap_NetIncomeLoss	1,016us-gaap_NetIncomeLoss	5,561us-gaap_NetIncomeLoss	9,506us-gaap_NetIncomeLoss	(17,887)us-gaap_NetIncomeLoss	(923)us-gaap_NetIncomeLoss	16,244us-gaap_NetIncomeLoss
Basic earnings (loss) per share
Continuing operations	$ (1.47)	$ 0.62	$ 0.34	$ (0.13)	$ 0.26	$ 0.29	$ 0.59	$ 1.16	$ (0.65)	$ 2.29	$ 1.87
Discontinued operations		$ (0.09)		$ (1.14)	$ (2.06)	$ (0.18)		$ (0.15)	$ (1.23)	$ (2.39)	$ (0.14)
Total	$ (1.47)us-gaap_EarningsPerShareBasic	$ 0.53us-gaap_EarningsPerShareBasic	$ 0.34us-gaap_EarningsPerShareBasic	$ (1.27)us-gaap_EarningsPerShareBasic	$ (1.80)us-gaap_EarningsPerShareBasic	$ 0.11us-gaap_EarningsPerShareBasic	$ 0.59us-gaap_EarningsPerShareBasic	$ 1.01us-gaap_EarningsPerShareBasic	$ (1.88)us-gaap_EarningsPerShareBasic	$ (0.10)us-gaap_EarningsPerShareBasic	$ 1.73us-gaap_EarningsPerShareBasic
Diluted earnings (loss) per share
Continuing operations	$ (1.47)	$ 0.61	$ 0.33	$ (0.13)	$ 0.25	$ 0.29	$ 0.59	$ 1.16	$ (0.65)	$ 2.27	$ 1.85
Discontinued operations		$ (0.09)		$ (1.14)	$ (2.03)	$ (0.18)		$ (0.16)	$ (1.23)	$ (2.37)	$ (0.13)
Total	$ (1.47)us-gaap_EarningsPerShareDiluted	$ 0.52us-gaap_EarningsPerShareDiluted	$ 0.33us-gaap_EarningsPerShareDiluted	$ (1.27)us-gaap_EarningsPerShareDiluted	$ (1.78)us-gaap_EarningsPerShareDiluted	$ 0.11us-gaap_EarningsPerShareDiluted	$ 0.59us-gaap_EarningsPerShareDiluted	$ 1.00us-gaap_EarningsPerShareDiluted	$ (1.88)us-gaap_EarningsPerShareDiluted	$ (0.10)us-gaap_EarningsPerShareDiluted	$ 1.72us-gaap_EarningsPerShareDiluted
Operating Segments [Member]
Quarterly Financial Data [Line Items]
Operating income (loss)									14,813	52,286	48,339
Corporate [Member]
Quarterly Financial Data [Line Items]
Operating income (loss)	(4,000)	(3,943)	(3,555)	(3,121)	(3,309)	(3,559)	(4,004)	(3,879)	(14,619)	(14,751)	(17,053)
Water Transmission [Member] \| Operating Segments [Member]
Quarterly Financial Data [Line Items]
Net sales	56,484	76,857	62,205	42,999	42,831	46,835	58,148	78,613	238,545	226,427	269,203
Gross profit	9,883	16,559	11,491	1,668	7,026	7,932	12,125	19,870	39,601	46,953	45,051
Operating income (loss)	7,817	14,429	9,543	(299)	5,505	6,306	10,499	18,033	31,490	40,343	36,278
Tubular Products [Member] \| Operating Segments [Member]
Quarterly Financial Data [Line Items]
Net sales	45,674	39,648	39,783	39,648	42,810	31,692	29,794	28,722	164,753	133,018	119,699
Gross profit	(758)	(739)	(174)	2,646	3,827	3,322	3,085	3,049	975	13,283	14,057
Operating income (loss)	$ (17,227)	$ (1,155)	$ (589)	$ 2,294	$ 3,483	$ 2,951	$ 2,774	$ 2,735	$ (16,677)	$ 11,943	$ 12,061

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