Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Comprehensive Income [Member]	Total
Balance at Dec. 31, 2007 (Scenario, Previously Reported [Member])	$ 280	$ 109,235	$ 260,616	$ (2,154)	$ 3,012		$ 370,989
Balance (in Shares) at Dec. 31, 2007 (Scenario, Previously Reported [Member])	27,977,785
Foreign currency translation revision (See Note 2)				4,223			4,223
Balance at Dec. 31, 2008	280	109,235	260,616	2,069	3,012		375,212
Balance at Dec. 31, 2008 (Scenario, Previously Reported [Member])							371,000
Balance (in Shares) at Dec. 31, 2008	27,977,785
Net income			26,171		1,154	27,325	27,325
Issuance of common stock, including tax benefits (in Shares)							(74,524)
Issuance of common stock	106	130,297					130,403
Issuance of common stock (in Shares)	10,573,540
Restricted stock and stock units issued	4						4
Restricted stock and stock units issued (in Shares)	429,725
Issuance of shares pursuant to deferred stock unit awards (in Shares)	21,645
Forfeitures of restricted stock	(1)						(1)
Forfeitures of restricted stock (in Shares)	(68,751)
Equity based compensation expense		4,839					4,839
Distribution to non-controlling interests					(959)		(959)
Purchase of Insituform Linings		(1,808)			(2,171)		(3,979)
Investments by non-controlling interests					4,107		4,107
Currency translation adjustment and derivatives				16,533	327	16,860	16,860
Total comprehensive income						44,185
Total comprehensive income attributable to non-controlling interests						(1,481)
Total comprehensive income attributable to common stockholders at Jan. 01, 2009 (Scenario, Previously Reported [Member])							36,600
Total comprehensive income attributable to common stockholders						42,704	42,700
Balance at Dec. 31, 2009	389	242,563	286,787	18,602	5,470		553,811
Balance (in Shares) at Dec. 31, 2009	38,933,944
Net income			60,462		1,418	61,880	61,880
Issuance of common stock, including tax benefits (in Shares)							(132,485)
Issuance of common stock	1	2,302					2,303
Issuance of common stock (in Shares)	132,485
Restricted stock and stock units issued	2						2
Restricted stock and stock units issued (in Shares)	184,656
Issuance of shares pursuant to restricted stock units (in Shares)	32,156
Issuance of shares pursuant to deferred stock unit awards (in Shares)	9,231
Forfeitures of restricted stock (in Shares)	(46,457)
Equity based compensation expense		6,713					6,713
Distribution to non-controlling interests					(398)		(398)
Investments by non-controlling interests					2,578		2,578
Currency translation adjustment and derivatives				(489)	307	(182)	(182)
Total comprehensive income						61,698
Total comprehensive income attributable to non-controlling interests						(1,725)
Total comprehensive income attributable to common stockholders at Jan. 01, 2010 (Scenario, Previously Reported [Member])							58,700
Total comprehensive income attributable to common stockholders						59,973	60,000
Balance at Dec. 31, 2010 (Scenario, Previously Reported [Member])							615,200
Balance at Dec. 31, 2010	392	251,578	347,249	18,113	9,375		626,707
Balance (in Shares) at Dec. 31, 2010	39,246,015
Net income			26,547		1,123	27,670	27,670
Issuance of common stock, including tax benefits	1	3,610					3,611
Issuance of common stock, including tax benefits (in Shares)	128,052						(128,052)
Issuance of common stock	2	3,998					4,000
Issuance of common stock (in Shares)	246,760
Restricted stock and stock units issued	2						2
Restricted stock and stock units issued (in Shares)	168,018
Issuance of shares pursuant to restricted stock units (in Shares)	9,934
Issuance of shares pursuant to deferred stock unit awards (in Shares)	20,640
Forfeitures of restricted stock (in Shares)	(140,448)
Stock repurchase program	(3)	(4,997)					(5,000)
Stock repurchase program (in Shares)	(326,596)
Equity based compensation expense		6,491					6,491
Distribution to non-controlling interests					(1,661)		(1,661)
Investments by non-controlling interests					546		546
Currency translation adjustment and derivatives				(12,251)	(1,126)	(13,377)	(13,377)
Total comprehensive income						14,293
Total comprehensive income attributable to non-controlling interests						3
Total comprehensive income attributable to common stockholders						14,296
Balance at Dec. 31, 2011	$ 394	$ 260,680	$ 373,796	$ 5,862	$ 8,257		$ 648,989
Balance (in Shares) at Dec. 31, 2011	39,352,375