Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash flows from operating activities:
Net income	$ (35,412)		$ 45,546		$ 56,849
Loss from discontinued operations	3,847		6,461		1,713
Income from continuing operations	(31,565)		52,007		58,562
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	44,312		40,329		37,658
Gain on sale of fixed assets	(310)		(816)		(397)
Equity-based compensation expense	5,073		5,647		6,767
Deferred income taxes	(16,816)		(2,675)		(3,004)
Equity in earnings of affiliated companies	(570)	[1]	(5,159)	[2]	(6,359)	[2]
Non-cash restructuring charges	20,592		0		0
Fixed asset impairment	11,870		0		0
Definite-lived intangible asset impairment	12,116		0		0
Goodwill impairment	51,512		0		0
Debt Issuance Cost	157		1,964		0
Earnout reversal	0		(4,175)		(10,019)
Loss on sale of Ka-te Insituform AG	516		0		0
Loss on foreign currency transactions	627		2,425		1,049
Other	1,279		1,588		(4,793)
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash	(454)		(102)		(299)
Return on equity of affiliated companies	590		10,691		11,034
Receivables net, retainage and costs and estimated earnings in excess of billings	(41,211)		8,222		7,875
Inventories	(5,286)		(736)		(3,376)
Prepaid expenses and other assets	3,465		(9,685)		2,754
Accounts payable and accrued expenses	25,097		2,604		12,634
Other operating	402		(2,293)		865
Net cash provided by operating activities of continuing operations	81,868		88,065		110,951
Net cash provided by (used in) operating activities of discontinued operations	(1,045)		(3,761)		(230)
Net cash provided by operating activities	80,823		84,304		110,721
Cash flows from investing activities:
Capital expenditures	(32,899)		(26,085)		(44,738)
Proceeds from sale of fixed assets	1,547		3,435		4,401
Patent expenditures	(1,923)		(2,032)		(552)
Restricted cash related to investing activities	(1,153)		0		0
Proceeds from sale of Ka-te Insituform AG	1,123		0		0
Net cash used in investing activities of continuing operations	(23,240)		(150,145)		(82,262)
Net cash provided by (used in) investing activities of discontinued operations	1,045		845		(1,156)
Net cash used in investing activities	(22,195)		(149,300)		(83,418)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises, including tax effects	8,615		594		1,178
Repurchase of common stock	(31,085)		(27,648)		(12,308)
Investments from noncontrolling interests	0		0		4,939
Purchase of or distributions to noncontrolling interests	(617)		(287)		(5)
Payment of earnout related to acquistion of CRTS, Inc.	0		(2,112)		0
Credit facility financing fees	(783)		(5,013)		0
Proceeds on notes payable	1,284		1,541		7,160
Principal payments on notes payable	0		(183)		(2,768)
Proceeds from line of credit	18,000		0		26,000
Repayments of Lines of Credit	(8,000)		0		0
Proceeds from long-term debt	0		385,500		983
Principal payments on long-term debt	(22,039)		(253,500)		(25,000)
Net cash provided by financing activities	(34,625)		98,892		179
Effect of exchange rate changes on cash	(7,083)		(9,527)		65
Net increaes (decrease) in cash and cash equivalents for the period	16,920		24,369		27,547
Cash and cash equivalents, beginning of period	158,045		133,676		106,129
Cash and cash equivalents, end of period	174,965		158,045		133,676
Cash paid for:
Interest	9,602		8,700		7,945
Net income taxes paid	12,594		11,630		18,456
Brinderson LP [Member]
Cash flows from investing activities:
Purchase of business, net of cash acquired	1,000		(143,763)		0
Fyfe LA [Member]
Cash flows from investing activities:
Purchase of business, net of cash acquired	0		0		(3,048)
Fyfe Asia [Member]
Cash flows from investing activities:
Purchase of business, net of cash acquired	0		0		(38,841)
Fyfe NA [Member]
Cash flows from investing activities:
Purchase of business, net of cash acquired	0		0		516
Insituform Germany [Member]
Adjustments to reconcile to net cash provided by operating activities:
Gain on sale of interests in German joint venture	0		(11,771)		0
Cash flows from investing activities:
Sale of interests in German joint venture	0		18,300		0
Bayou Coating [Member]
Adjustments to reconcile to net cash provided by operating activities:
Gain on sale of interests in German joint venture	472		0		0
Cash flows from investing activities:
Sale of interests in German joint venture	$ 9,065		$ 0		$ 0

[1] Bayou Coating was sold in March 2014. Income statement data in 2014 includes only those results up to the date of its sale.

[2] Includes the financial data of Insituform-Germany through the date of its sale in June 2013.