Aegion 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 26, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Aegion Corp
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		32,313,990
Amendment Flag	false
Entity Central Index Key	353,020
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 339,679	$ 341,872	$ 999,570	$ 1,021,520
Cost of revenues	267,006	268,430	794,340	800,898
Gross profit	72,673	73,442	205,230	220,622
Operating expenses	51,386	54,872	161,750	165,812
Goodwill impairment	1,389	45,390	1,389	45,390
Definite-lived intangible asset impairment	870	41,032	870	41,032
Acquisition and divestiture expenses	4,800	1,980	6,024	2,513
Restructuring and related charges	1,219	5,439	4,548	5,439
Operating income (loss)	13,009	(75,271)	30,649	(39,564)
Other income (expense):
Interest expense	(3,870)	(3,962)	(13,236)	(12,014)
Interest income	130	33	239	117
Other	(9,281)	(798)	(10,049)	(1,593)
Total other expense	(13,021)	(4,727)	(23,046)	(13,490)
Income (loss) before taxes on income	(12)	(79,998)	7,603	(53,054)
Taxes (benefit) on income (loss)	(153)	(5,954)	1,740	1,144
Net income (loss)	141	(74,044)	5,863	(54,198)
Non-controlling interests (income) loss	(588)	546	(458)	(2,414)
Net income (loss) attributable to Aegion Corporation	$ (447)	$ (73,498)	$ 5,405	$ (56,612)
Earnings (loss) per share attributable to Aegion Corporation:
Net income (loss) per share, basic (in dollars per share)	$ (0.01)	$ (2.23)	$ 0.17	$ (1.70)
Net income (loss) per share, diluted (in dollars per share)	$ (0.01)	$ (2.23)	$ 0.16	$ (1.70)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 141	$ (74,044)	$ 5,863	$ (54,198)
Other comprehensive income (loss):
Currency translation adjustments		(6,701)	359	(10,983)	17,637
Deferred gain on hedging activity, net of tax	[1]	477	89	1,655	265
Pension activity, net of tax	[2]	2	(9)	7	(25)
Total comprehensive loss		(6,081)	(73,605)	(3,458)	(36,321)
Comprehensive (income) loss attributable to non-controlling interests		(660)	480	(283)	(2,500)
Comprehensive loss attributable to Aegion Corporation		$ (6,741)	$ (73,125)	$ (3,741)	$ (38,821)
[1]	Amounts presented net of tax of $171 and $59 for the quarters ended September 30, 2018 and 2017, respectively, and $593 and $176 for the nine months ended September 30, 2018 and 2017, respectively.
[2]	Amounts presented net of tax of $1 and $(2) for the quarters ended September 30, 2018 and 2017, respectively, and $2 and $(6) for the nine months ended September 30, 2018 and 2017, respectively.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) - Parenthetical - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Deferred gain on hedging activity, tax	$ 171	$ 59	$ 593	$ 176
Pension activity, tax (benefit) expense	$ 1	$ (2)	$ 2	$ (6)

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 67,410	$ 105,717
Restricted cash	1,835	1,839
Receivables, net of allowances of $5,967 and $5,775, respectively	194,941	201,570
Retainage	33,751	33,002
Contract assets	88,348	75,371
Inventories	63,144	63,969
Prepaid expenses and other current assets	33,435	35,282
Assets held for sale	10,173	70,314
Total current assets	493,037	587,064
Property, plant & equipment, less accumulated depreciation	107,792	109,040
Other assets
Goodwill	261,757	260,715
Intangible assets, less accumulated amortization	124,449	132,345
Deferred income tax assets	1,641	1,666
Other assets	26,362	16,269
Total other assets	414,209	410,995
Total Assets	1,015,038	1,107,099
Current liabilities
Accounts payable	75,654	70,611
Accrued expenses	83,682	92,011
Contract liabilities	35,297	51,597
Current maturities of long-term debt	26,548	26,555
Liabilities held for sale	6,423	20,900
Total current liabilities	227,604	261,674
Long-term debt, less current maturities	279,269	318,240
Deferred income tax liabilities	9,749	9,211
Other non-current liabilities	12,332	12,918
Total liabilities	528,954	602,043
(See Commitments and Contingencies: Note 10)
Equity
Preferred stock, undesignated, $.10 par – shares authorized 2,000,000; none outstanding	0	0
Common stock, $.01 par – shares authorized 125,000,000; shares issued and outstanding 32,313,990 and 32,462,542, respectively	323	325
Additional paid-in capital	128,330	140,749
Retained earnings	382,367	376,694
Accumulated other comprehensive loss	(32,668)	(23,522)
Total stockholders’ equity	478,352	494,246
Non-controlling interests	7,732	10,810
Total equity	486,084	505,056
Total Liabilities and Equity	$ 1,015,038	$ 1,107,099

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 5,967	$ 5,775
Preferred stock, undesignated, par (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, undesignated, shares authorized	2,000,000	2,000,000
Preferred stock, undesignated, shares outstanding	0	0
Common stock, par (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issues	32,313,990	32,462,542
Common stock, shares outstanding	32,313,990	32,462,542

Consolidated Statements of Equi

Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Non- Controlling Interests	Restricted Stock Units	Restricted Stock UnitsCommon Stock	Performance Units	Performance UnitsCommon Stock
Balance (in shares) at Dec. 31, 2016		33,956,304
Balance at Dec. 31, 2016	$ 576,183	$ 340	$ 167,700	$ 446,095	$ (45,635)	$ 7,683
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(54,198)			(56,612)		2,414
Issuance of shares pursuant to restricted/performance stock units (in shares)								90,663		49,672
Issuance of shares pursuant to restricted/performance stock units							$ 1	$ 1
Issuance of shares pursuant to deferred stock unit awards (in shares)		30,559
Forfeitures of restricted shares (in shares)		(1,084)
Shares repurchased and retired (in shares)		(1,452,296)
Shares repurchased and retired	(31,730)	$ (14)	(31,716)
Equity-based compensation expense	8,104		8,104
Investments from non-controlling interests	158					158
Distributions/Sale of to non-controlling interests	(71)					(71)
Currency translation adjustments, derivative transactions and pension activity, net	17,877				17,791	86
Balance (in shares) at Sep. 30, 2017		32,673,818
Balance at Sep. 30, 2017	516,324	$ 327	144,088	389,483	(27,844)	10,270
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment	$ 268			268
Balance (in shares) at Dec. 31, 2017	32,462,542	32,462,542
Balance at Dec. 31, 2017	$ 505,056	$ 325	140,749	376,694	(23,522)	10,810
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	5,863			5,405		458
Issuance of shares pursuant to restricted/performance stock units (in shares)								301,041		296,909
Issuance of shares pursuant to restricted/performance stock units							$ 3	$ 3	$ 3	$ 3
Issuance of shares pursuant to deferred stock unit awards (in shares)		26,396
Shares repurchased and retired (in shares)		(772,898)
Shares repurchased and retired	(18,628)	$ (8)	(18,620)
Equity-based compensation expense	6,201		6,201
Distributions/Sale of to non-controlling interests	(3,361)					(3,361)
Currency translation adjustments, derivative transactions and pension activity, net	$ (9,321)				(9,146)	(175)
Balance (in shares) at Sep. 30, 2018	32,313,990	32,313,990
Balance at Sep. 30, 2018	$ 486,084	$ 323	$ 128,330	$ 382,367	$ (32,668)	$ 7,732

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ 5,863	$ (54,198)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	27,692	34,410
Gain on sale of fixed assets	(423)	(6)
Equity-based compensation expense	6,201	8,104
Deferred income taxes	647	(4,511)
Non-cash restructuring charges	5,891	102
Goodwill impairment	1,389	45,390
Definite-lived intangible asset impairment	870	41,032
Loss on sale of businesses	8,729	0
Loss on foreign currency transactions	1,231	1,659
Other	(119)	(1,129)
Changes in operating assets and liabilities (net of acquisitions):
Receivables net, retainage and contract assets	(19,247)	(54,040)
Inventories	(3,188)	(4,645)
Prepaid expenses and other assets	678	6,562
Accounts payable and accrued expenses	(256)	23,726
Contract liabilities	(21,537)	(9,869)
Other operating	(396)	(79)
Net cash provided by operating activities	14,025	32,508
Cash flows from investing activities:
Capital expenditures	(22,230)	(22,515)
Proceeds from sale of fixed assets	955	423
Patent expenditures	(197)	(340)
Other acquisition activity	(9,000)	(9,045)
Sale of Bayou, net of cash disposed	37,942	0
Net cash provided by (used in) investing activities	7,470	(31,477)
Cash flows from financing activities:
Repurchase of common stock	(18,622)	(31,730)
Investments from non-controlling interests	0	158
Distributions to non-controlling interests	0	(71)
Payment of contingent consideration	0	(500)
Credit facility amendment fees	(1,093)	0
Principal payments on notes payable	(26)	150
Proceeds from line of credit, net	(19,000)	14,000
Principal payments on long-term debt	(19,688)	(15,085)
Net cash used in financing activities	(58,429)	(33,078)
Effect of exchange rate changes on cash	(2,366)	3,289
Net decrease in cash, cash equivalents and restricted cash for the period	(39,300)	(28,758)
Cash, cash equivalents and restricted cash, beginning of year	108,545	134,392
Cash, cash equivalents and restricted cash, end of period	69,245	105,634
Cash, cash equivalents and restricted cash associated with assets held for sale, end of period	0	(8,909)
Cash, cash equivalents and restricted cash, end of period	$ 69,245	$ 96,725

Accounting Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Accounting Policies	ACCOUNTING POLICIES On January 1, 2018, the Company adopted FASB ASC 606, Revenue from Contracts with Customers (“FASB ASC 606”). See Note 3 for further information. Other than the adoption of FASB ASC 606, t here were no material changes in accounting policies from those disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Foreign Currency Translation For the Company’s international subsidiaries, the local currency is generally the functional currency. Assets and liabilities of these subsidiaries are translated into U.S. dollars using rates in effect at the balance sheet date while revenues and expenses are translated into U.S. dollars using average exchange rates. The cumulative translation adjustment resulting from changes in exchange rates are included in the Consolidated Balance Sheets as a component of “Accumulated other comprehensive loss” in total stockholders’ equity. The Company’s accumulated other comprehensive loss is comprised of three main components: (i) currency translation; (ii) derivatives; and (iii) gains and losses associated with the Company’s defined benefit plan in the United Kingdom (in thousands): September 30, December 31, 2017 Currency translation adjustments $ (38,017 ) $ (26,614 ) Derivative hedging activity 5,584 3,336 Pension activity (235 ) (244 ) Total accumulated other comprehensive loss $ (32,668 ) $ (23,522 ) Net foreign exchange transaction losses of $0.4 million and $0.8 million in the third quarters of 2018 and 2017 , respectively, and $1.2 million and $1.7 million for the nine months ended September 30, 2018 and 2017 , respectively, are included in “Other expense” in the Consolidated Statements of Operations. Taxation The Company provides for estimated income taxes payable or refundable on current year income tax returns as well as the estimated future tax effects attributable to temporary differences and carryforwards, based upon enacted tax laws and tax rates, and in accordance with FASB ASC 740, Income Taxes (“FASB ASC 740”). FASB ASC 740 also requires that a valuation allowance be recorded against any deferred tax assets that are not likely to be realized in the future. The determination is based on the Company’s ability to generate future taxable income and, at times, is dependent on its ability to implement strategic tax initiatives to ensure full utilization of recorded deferred tax assets. Should the Company not be able to implement the necessary tax strategies, it may need to record valuation allowances for certain deferred tax assets, including those related to foreign income tax benefits. Significant management judgment is required in determining the provision for income taxes, deferred tax assets and liabilities and any valuation allowances recorded against net deferred tax assets. As a result of the reduction in the U.S. corporate income tax rate from 35% to 21% under the Tax Cuts and Jobs Act (“TCJA”), FASB ASC 740 required the Company to remeasure its deferred tax assets and liabilities based on tax rates at which the balances are expected to reverse in the future. The provisional amount recorded for the remeasurement of the Company’s deferred tax balances resulted in no adjustment to income tax expense in 2017 or 2018. The remeasurement of the deferred tax assets gave rise to an additional income tax expense of $5.1 million in 2017, which was offset by an equal reduction in the valuation allowance of $5.1 million . The Company continues to analyze certain aspects of the TCJA, including consideration of additional forthcoming technical guidance, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. In 2017, in connection with its initial analysis of the TCJA, the Company recorded a provisional estimated net income tax expense of $2.4 million , which consisted of a charge of $10.4 million for the deemed mandatory repatriation less $7.1 million related to the release of deferred tax liabilities on unremitted foreign earnings and $0.9 million associated with other TCJA related impacts. On December 22, 2017, the SEC issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”), directing a taxpayer to consider the impact of the U.S. legislation as “provisional” when it does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for income tax effects of the TCJA. In accordance with SAB 118, the additional estimated income tax of $2.4 million represented the Company’s best estimate at the time it was made, but also understanding that the provisional amount is subject to further adjustments under SAB 118. During the third quarter of 2018, the Company revised its estimate of the deemed mandatory repatriation tax on foreign earnings downward by $1.5 million primarily due to further refinement of the earnings and profits and cash and cash equivalent balances within the computation pursuant to guidance issued during the quarter. This adjustment was recorded as a reduction to income tax expense in the quarter and nine-month period ended September 30, 2018. The Company continues to refine its estimated balances, and adjustments may be made under SAB 118 during the measurement period as a result of future changes in interpretation, issuance of additional regulatory guidance from the U.S. federal and state tax authorities, or its own assumption changes. All accounting will be completed within the one-year measurement period allowed under SAB 118. The ultimate impact of the TCJA may differ from the current estimated amounts and the adjustments could be material. Earnings per Share Earnings per share have been calculated using the following share information: Quarters Ended Nine Months Ended 2018 2017 2018 2017 Weighted average number of common shares used for basic EPS 32,312,000 32,905,142 32,390,777 33,363,472 Effect of dilutive stock options and restricted and deferred stock unit awards — — 667,229 — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 32,312,000 32,905,142 33,058,006 33,363,472 The Company excluded 664,661 stock options and restricted and deferred stock units for the quarter ended September 30, 2018, and 737,423 and 702,544 stock options and restricted and deferred stock units for the quarter and nine-month period ended September 30, 2017, respectively, from the diluted earnings per share calculation for the Company’s common stock because of the reported net loss for the periods. The Company excluded 77,807 stock options for the quarter and nine months ended September 30, 2017, respectively, from the diluted earnings per share calculations for the Company’s common stock because they were anti-dilutive as their exercise prices were greater than the average market price of common shares for each period. Cash, Cash Equivalents and Restricted Cash The Company classifies highly liquid investments with original maturities of 90 days or less as cash equivalents. Recorded book values are reasonable estimates of fair value for cash and cash equivalents. Cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets and Consolidated Statements of Cash Flows are as follows (in thousands): Balance sheet data September 30, 2018 December 31, (1) Cash and cash equivalents $ 67,410 $ 105,717 Restricted cash 1,835 1,839 Cash, cash equivalents and restricted cash $ 69,245 $ 107,556 __________________________ (1) Amounts exclude $1.0 million of cash and cash equivalents classified as held for sale at December 31, 2017 (see Note 5). Restricted cash held in escrow primarily relates to funds reserved for legal requirements, deposits made in lieu of retention on specific projects performed for municipalities and state agencies, or advance customer payments and compensating balances for bank undertakings in Europe. Restricted cash related to operations is similar to retainage, and is, therefore, classified as a current asset, consistent with the Company’s policy on retainage. Long-Lived Assets Property, plant and equipment and other identified intangibles (primarily customer relationships, patents and acquired technologies, trademarks, licenses and non-compete agreements) are recorded at cost, net of accumulated depreciation and impairment, and, except for goodwill and certain trademarks, are depreciated or amortized on a straight-line basis over their estimated useful lives. Changes in circumstances such as technological advances, changes to the Company’s business model or changes in the Company’s capital strategy can result in the actual useful lives differing from the Company’s estimates. If the Company determines that the useful life of its property, plant and equipment or its identified intangible assets should be changed, the Company would depreciate or amortize the net book value in excess of the salvage value over its revised remaining useful life, thereby increasing or decreasing depreciation or amortization expense. Long-lived assets, including property, plant and equipment and other intangibles, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Such impairment tests are based on a comparison of undiscounted cash flows to the recorded value of the asset. The estimate of cash flow is based upon, among other things, assumptions about expected future operating performance. The Company’s estimates of undiscounted cash flow may differ from actual cash flow due to, among other things, technological changes, economic conditions, changes to its business model or changes in its operating performance. If the sum of the undiscounted cash flows is less than the carrying value, the Company recognizes an impairment loss, measured as the amount by which the carrying value exceeds the fair value of the asset. Impairment Review – Third Quarter 2017 As part of the 2017 Restructuring, which was approved by the Company’s board of directors on July 28, 2017, the Company exited all non-pipe related contract applications for the Tyfo ® system in North America. As a result of this action, the Company evaluated the long-lived assets of its Fyfe reporting unit, which caused the Company to review the financial performance of at-risk asset groups within the Fyfe reporting unit in accordance with FASB ASC 360, Property, Plant and Equipment (“FASB ASC 360”). The results of the Fyfe reporting unit and its related asset groups are reported within the Infrastructure Solutions reportable segment. The assets of an asset group represent the lowest level for which identifiable cash flows can be determined independent of other groups of assets and liabilities. The Fyfe North America asset group was the only at-risk asset group reviewed for impairment. The Company developed internal forward business plans under the guidance of local and regional leadership to determine the undiscounted expected future cash flows derived from Fyfe North America’s long-lived assets. Such were based on management’s best estimates considering the likelihood of various outcomes. Based on the internal projections, the Company determined that the sum of the undiscounted expected future cash flows for the Fyfe North America asset group was less than the carrying value of the assets, and as a result, engaged a third-party valuation firm to assist management in determining the fair value of long-lived assets for the Fyfe North America asset group. In order to determine the impairment amount of long-lived assets, the Company first determined the fair value of each key component of its long-lived assets for the Fyfe North America asset group. The fair values were derived using various income-based approaches, which utilize discounted cash flows to evaluate the net earnings attributable to the asset being measured. Key assumptions used in assessment include the discount rate (based on weighted-average cost of capital), revenue growth rates, contributory asset charges, customer attrition, income tax rates and working capital needs, which were based on current market conditions and were consistent with internal management projections. Based on the results of the valuation, the carrying amount of certain long-lived assets for the Fyfe North America asset group exceeded the fair value. Accordingly, the Company recorded impairment charges of $3.4 million to trademarks, $20.8 million to customer relationships and $16.8 million to patents and acquired technology in the third quarter of 2017. The impairment charges were recorded to “Definite-lived intangible asset impairment” in the Consolidated Statement of Operations. Property, plant and equipment were determined to have a fair value that exceeded carrying value; thus, no impairment was recorded. The fair value estimates described above were determined using observable inputs and significant unobservable inputs, which are based on level 3 inputs as defined in Note 12. Goodwill Under FASB ASC 350, Intangibles – Goodwill and Other (“FASB ASC 350”), the Company assesses recoverability of goodwill on an annual basis or when events or changes in circumstances indicate that the carrying amount of goodwill may not be recoverable. An impairment charge will be recognized to the extent that the fair value of a reporting unit is less than its carrying value. Factors that could potentially trigger an impairment review include (but are not limited to): • significant underperformance of a segment relative to expected, historical or forecasted operating results; • significant negative industry or economic trends; • significant changes in the strategy for a segment including extended slowdowns in the segment’s market; • a decrease in market capitalization below the Company’s book value; and • a significant change in regulations. Whether during the annual impairment assessment or during a trigger-based impairment review, the Company determines the fair value of its reporting units and compares such fair value to the carrying value of those reporting units to determine if there are any indications of goodwill impairment. Fair value of reporting units is determined using a combination of two valuation methods: a market approach and an income approach with each method given equal weight in determining the fair value assigned to each reporting unit. Absent an indication of fair value from a potential buyer or similar specific transaction, the Company believes the use of these two methods provides a reasonable estimate of a reporting unit’s fair value. Assumptions common to both methods are operating plans and economic outlooks, which are used to forecast future revenues, earnings and after-tax cash flows for each reporting unit. These assumptions are applied consistently for both methods. The market approach estimates fair value by first determining earnings before interest, taxes, depreciation and amortization (“EBITDA”) multiples for comparable publicly-traded companies with similar characteristics of the reporting unit. The EBITDA multiples for comparable companies are based upon current enterprise value. The enterprise value is based upon current market capitalization and includes a control premium. The Company believes this approach is appropriate because it provides a fair value estimate using multiples from entities with operations and economic characteristics comparable to its reporting units. The income approach is based on forecasted future (debt-free) cash flows that are discounted to present value using factors that consider timing and risk of future cash flows. The Company believes this approach is appropriate because it provides a fair value estimate based upon the reporting unit’s expected long-term operating cash flow performance. Discounted cash flow projections are based on financial forecasts developed from operating plans and economic outlooks, growth rates, estimates of future expected changes in operating margins, terminal value growth rates, future capital expenditures and changes in working capital requirements. Estimates of discounted cash flows may differ from actual cash flows due to, among other things, changes in economic conditions, changes to business models, changes in the Company’s weighted average cost of capital, or changes in operating performance. The discount rate applied to the estimated future cash flows is one of the most significant assumptions utilized under the income approach. The Company determines the appropriate discount rate for each of its reporting units based on the weighted average cost of capital (“WACC”) for each individual reporting unit. The WACC takes into account both the pre-tax cost of debt and cost of equity (including the risk-free rate on 20-year U.S. Treasury bonds), and certain other company-specific and market-based factors. As each reporting unit has a different risk profile based on the nature of its operations, the WACC for each reporting unit is adjusted, as appropriate, to account for company-specific risks. Accordingly, the WACC for each reporting unit may differ. Impairment Review – Third Quarter 2017 As part of the 2017 Restructuring, which was approved by the Company’s board of directors on July 28, 2017, the Company exited all non-pipe related contract applications for the Tyfo ® system in North America. As a result of this action, the Company evaluated the goodwill of its Fyfe reporting unit and determined that a triggering event occurred. As such, the Company engaged a third-party valuation firm to assist management in performing a goodwill impairment review for its Fyfe reporting unit during the third quarter of 2017. In accordance with the provisions of FASB ASC 350, the Company determined the fair value of the reporting unit and compared such fair value to the carrying value of the reporting unit. For the Fyfe reporting unit, carrying value, as adjusted for the long-lived asset impairments discussed previously, exceeded fair value by approximately 45% . As of January 1, 2017, the Company adopted FASB Accounting Standards Update No. 2017-04, Simplifying the Test for Goodwill Impairment , which states that an impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value. Based on the impairment analysis, the Company determined that recorded goodwill at the Fyfe reporting unit was impaired by $45.4 million , which was recorded to “Goodwill impairment” in the Consolidated Statement of Operations during the third quarter of 2017. As of December 31, 2017, the Company had remaining Fyfe goodwill of $9.6 million . Projected cash flows were based, in part, on the ability to grow third-party product sales and pressure pipe contracting in North America, and maintaining a presence in other international markets. Investments in Variable Interest Entities The Company evaluates all transactions and relationships with variable interest entities (“VIE”) to determine whether the Company is the primary beneficiary of the entities in accordance with FASB ASC 810, Consolidation . There were no changes in the Company’s VIEs during the quarter ended September 30, 2018 . Financial data for consolidated variable interest entities are summarized in the following tables (in thousands): Balance sheet data September 30, December 31, (1) Current assets $ 39,022 $ 42,732 Non-current assets 5,098 26,346 Current liabilities 14,514 12,449 Non-current liabilities 11,341 30,675 __________________________ (1) Amounts included $25.4 million of assets and $9.8 million of liabilities classified as held for sale relating to our pipe coating and insulation joint venture in Louisiana, Bayou Wasco Insulation, LLC, which was divested on August 31, 2018. See Note 5. Quarters Ended Nine Months Ended Income statement data (1) 2018 2017 2018 2017 (1) Revenue $ 16,405 $ 11,457 $ 39,179 $ 72,916 Gross profit 3,238 1,984 6,982 11,704 Net income (loss) attributable to Aegion Corporation (946 ) 1,121 (886 ) 3,071 __________________________ (1) During the nine months ended September 30, 2017, increased activity was primarily driven from our joint venture in Louisiana, which performed work on a large deepwater pipe coating and insulation project. Newly Issued Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update No. 2018-13, Fair Value Measurement: Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements for Level 1, Level 2 and Level 3 instruments in the fair value hierarchy. The guidance is effective for the Company’s fiscal year beginning January 1, 2020, including interim periods within that fiscal year. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In February 2018, the FASB issued Accounting Standards Update No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which permits a company to reclassify the income tax effects of the TCJA on items within accumulated other comprehensive income to retained earnings. The guidance is effective for the Company’s fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Companies may adopt the new guidance using one of two transition methods: (i) retrospective to each period (or periods) in which the income tax effects are recognized, or (ii) at the beginning of the period of adoption. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities , which amends the recognition and presentation requirements for hedge accounting activities. The standard improves the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and reduces the complexity of applying hedge accounting. This new guidance is effective for the Company’s fiscal year beginning January 1, 2019, but the Company early-adopted this standard, effective January 1, 2018. The adoption of this standard did not have a material impact on its consolidated financial statements. In November 2016, the FASB issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash. As a result, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This new guidance was effective for the Company’s fiscal year beginning January 1, 2018 and applied retrospectively. The Company’s adoption of this standard, effective January 1, 2018, did not have a material impact on its consolidated financial statements, other than the classification of restricted cash on the Consolidated Statement of Cash Flows. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which addresses diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The standard was effective for the Company’s fiscal year beginning January 1, 2018, the adoption of which did not have a material impact on its consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) , that requires lessees to present right-of-use assets and lease liabilities on the balance sheet for all leases with lease terms longer than twelve months. The standard is effective for the Company’s fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Early adoption is permitted, although the Company does not intend to do so. The Company intends to adopt the new guidance using the cumulative effect method, which would apply to all new lease contracts initiated on or after January 1, 2019. For existing lease contracts that have remaining obligations as of January 1, 2019, the difference between the recognition criteria in the new guidance and the Company’s current practices would be recognized using a cumulative effect adjustment to the opening balance of retained earnings. In early 2017, the Company identified a project manager as well as a cross-functional implementation team responsible for identifying and assessing the impact on its lease contracts. During 2017 and 2018, the implementation team completed the assessment phase, which included data retrieval from the Company’s key third-party lease administration vendors and the identification of the Company’s known lease contracts throughout the world. Additionally, the Company is currently implementing a third-party software solution to support recognition and disclosure under the new standard, including customization and migration of existing data into the new software solution. During the fourth quarter of 2018, the Company will: (i) test the data output from the software solution in accordance with the new standard; (ii) calculate opening balances and determine the cumulative effect adjustment; and (iii) identify any further potential changes to business processes, systems and controls. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaces revenue recognition requirements regarding contracts with customers to transfer goods or services with a single revenue recognition model for recognizing revenue. Under the new guidance, entities are required to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides a five-step analysis to be performed on transactions to determine when and how revenue is recognized. The Company adopted this standard, effective January 1, 2018, using the modified retrospective transition method. See Note 3.

General

General	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	GENERAL The accompanying unaudited consolidated financial statements of Aegion Corporation and its subsidiaries (collectively, “Aegion” or the “Company”) reflect all adjustments (consisting only of normal recurring adjustments) that are, in the opinion of management, necessary for a fair statement of the Company’s financial position, results of operations and cash flows for the dates and periods presented. Results for interim periods are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period. All significant intercompany related accounts and transactions have been eliminated in consolidation. The Consolidated Balance Sheet as of December 31, 2017, which is derived from the audited consolidated financial statements, and the interim unaudited consolidated financial statements included herein have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”), the requirements of Form 10-Q and Article 10 of Regulation S-X and, consequently, do not include all information or footnotes required by GAAP for complete financial statements or all the disclosures normally made in an Annual Report on Form 10-K. Accordingly, the unaudited consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and footnotes included in the Company’s 2017 Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 1, 2018. Revision The Company identified errors related primarily to intercompany accounts and stock compensation prior to December 31, 2016 of approximately $9.0 million and corrected this error as a cumulative decrease to beginning retained earnings of $9.0 million with a corresponding increase to additional paid-in capital and accumulated other comprehensive loss of $1.1 million and $7.9 million , respectively, as of December 31, 2016. The Company also revised the results for the quarter and nine-month period ended September 30, 2017 to reflect the correction of these errors, resulting in: (i) a net increase to operating expenses of $0.3 million for both periods and a corresponding decrease in net income; and (ii) an increase to currency translation adjustments of $0.6 million and $1.4 million , respectively, which is a component of accumulated other comprehensive income. The Company also revised the results for the period ended September 30, 2017, which resulted in a decrease of $1.1 million to additional paid-in capital related to equity-based compensation expense. The Company evaluated the impact of these errors on the prior period quarterly and annual financial statements, assessing materiality both quantitatively and qualitatively. The Company determined that these errors were not material to any of the Company’s prior annual and interim period consolidated financial statements and therefore, amendments of previously filed reports were not required. As such, the revision for the corrections is reflected in the financial information of the applicable prior periods in this Form 10-Q filing and disclosure of the revised amount on other prior periods will be reflected in future filings containing the applicable period. Acquisitions/Strategic Initiatives/Divestitures 2017 Restructuring On July 28, 2017, the Company’s board of directors approved a realignment and restructuring plan (the “2017 Restructuring”). As part of the 2017 Restructuring, the Company announced plans to: (i) divest the Company’s pipe coating and insulation businesses in Louisiana, The Bayou Companies, LLC and Bayou Wasco Insulation, LLC (collectively “Bayou”); (ii) exit all non-pipe related contract applications for the Tyfo ® system in North America; (iii) right-size the cathodic protection services operation in Canada and the cured-in-place pipe (“CIPP”) businesses in Australia and Denmark; and (iv) reduce corporate and other operating costs. These decisions reflected the Company’s: (a) desire to reduce further its exposure in the North American upstream oil and gas markets; (b) assessment of its ability to drive sustainable, profitable growth in the non-pipe fiber reinforced polymer ( “FRP” ) contracting market in North America; and (c) assessment of continuing weak conditions in the Canadian oil and gas markets. See Note 4. See Note 13 for additional restructuring activities approved by the Company’s board of directors on October 26, 2018. Infrastructure Solutions Segment (“Infrastructure Solutions”) On July 25, 2018, the Company’s board of directors approved a plan to exit the CIPP operation in Denmark to address continued underperformance in the business. As a result of this decision, the Company is seeking to divest assets, where possible. Accordingly, the Company has classified Denmark’s assets and liabilities as held for sale on the Consolidated Balance Sheet at September 30, 2018. See Note 5. Additionally, see Note 13 for additional information on the executed asset sale agreement, effective November 1, 2018. On May 14, 2018, the Company’s board of directors approved a plan to divest the Company’s CIPP business in Australia. While restructuring actions in Australia have led to year-over-year improvements in operating results, an assessment of the long-term fit within the Company’s portfolio led to the decision to divest the business. Accordingly, the Company has classified Australia’s assets and liabilities as held for sale on the Consolidated Balance Sheet at September 30, 2018. See Note 5. Corrosion Protection Segment (“Corrosion Protection”) On August 31, 2018, the Company sold substantially all of the assets of its wholly-owned subsidiary, The Bayou Companies, LLC and its fifty-one percent ( 51% ) interest in Bayou Wasco Insulation, LLC. The sale price was $46 million , consisting of $38 million paid in cash at closing and $8 million in a fully secured, two -year loan payable to Aegion. Aegion is also eligible to receive an additional $4 million in total earn-out payments based on performance of the divested businesses in 2019 and 2020. Cash proceeds, net of customary closing costs, were used to repay outstanding borrowings on the Company’s line of credit. The sale resulted in a pre-tax, non-cash loss of $8.7 million during the third quarter of 2018, which is included in “Other expense” in the Consolidated Statements of Operations. On May 4, 2018, the Company acquired the operations of Hebna Inc., Hebna Canada Inc. and Hebna Corporation (collectively “Hebna”), for a total purchase price of $6.0 million ( $3.0 million was paid during the second quarter of 2018 and $3.0 million was paid during the third quarter of 2018). The transaction was funded from a combination of domestic and international cash balances, with fifty percent ( 50% ) of the purchase price being paid by the Company’s joint venture in Oman, in which the Company is a fifty-one percent ( 51% ) partner. Hebna provides pipeline lining services, including compressed-fit lining, slip-lining, liner and free-standing pipe fusing, pipeline assessment and integrity management, pipeline pigging and calibration, and roto-lining services primarily in the United States, Canada and Middle East . In September 2017, the Company organized Aegion South Africa Proprietary Limited, a joint venture in South Africa between Aegion International Holdings Limited, a subsidiary of the Company (“Aegion International”), and Robor Proprietary Limited (“Robor”), for the purpose of providing Aegion’s Corrosion Protection and Infrastructure Solutions products and services to sub-Saharan Africa. Aegion International owns sixty percent ( 60% ) of the joint venture and Robor owns the remaining forty percent ( 40% ). Energy Services Segment (“Energy Services”) On July 20, 2018, the Company acquired the operations of Plant Performance Services LLC and P2S LLC (collectively “P2S”), for a total purchase price of $3.0 million . The transaction was funded from domestic cash balances. P2S specializes in general mechanical turnaround services, specialty welding services and field fabrication services primarily for the downstream oil and gas industry.

Revenues

Revenues	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenues	REVENUES On January 1, 2018, the Company adopted FASB ASC 606 for all contracts that were not completed using the modified retrospective transition method. The Company recognized the cumulative effect of initially applying FASB ASC 606 as an adjustment to the opening balance of retained earnings. Prior period information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company recorded a net reduction to opening retained earnings of $0.3 million as of January 1, 2018 due to the cumulative impact of adopting FASB ASC 606, with the impact primarily related to royalty license fee revenues. The impact to revenues for the nine months ended September 30, 2018 was an increase of $1.9 million as a result of applying FASB ASC 606. Performance Obligations A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in FASB ASC 606. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. For contracts in which construction, engineering and installation services are provided, there is a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. The bundle of goods and services represents the combined output for which the customer has contracted. For product sales contracts with multiple performance obligations where each product is distinct, the Company allocates the contract’s transaction price to each performance obligation using its best estimate of the standalone selling price of each distinct good in the contract. For royalty license agreements whereby intellectual property is transferred to the customer, there is a single performance obligation as the license is not separately identifiable from the other goods and services in the contract. The Company’s performance obligations are satisfied over time as work progresses or at a point in time. Revenues from products and services transferred to customers over time accounted for 92.6% and 93.3% of revenues for the quarters ended September 30, 2018 and 2017, respectively, and 93.6% and 93.3% of revenues for the nine months ended September 30, 2018 and 2017, respectively. Revenues from construction, engineering and installation services are recognized over time using an input measure (e.g., costs incurred to date relative to total estimated costs at completion) to measure progress toward satisfying performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, overhead and, when appropriate, general and administrative expenses. Revenues from royalty license arrangements are recognized either at contract inception when the license is transferred or when the royalty has been earned, depending on whether the contract contains fixed consideration. Revenues from stand-alone product sales are recognized at a point in time, when control of the product is transferred to the customer. Revenues from these types of contracts accounted for 7.4% and 6.7% of revenues for the quarters ended September 30, 2018 and 2017, respectively, and 6.4% and 6.7% for the nine months ended September 30, 2018 and 2017, respectively. On September 30, 2018 , the Company had $670.7 million of remaining performance obligations. The Company estimates that approximately $654.7 million , or 97.6% , of the remaining performance obligations at September 30, 2018 will be realized as revenues in the next 12 months. Contract Estimates Accounting for long-term contracts involves the use of various techniques to estimate total contract revenue and costs. For long-term contracts, the Company estimates the profit on a contract as the difference between the total estimated revenue and expected costs to complete a contract, and recognizes that profit over the life of the contract. Contract estimates are based on various assumptions to project the outcome of future events that sometimes span multiple years. These assumptions include labor productivity and availability; the complexity of the work to be performed; the cost and availability of materials; the performance of subcontractors; and the availability and timing of funding from the customer. The Company’s contracts do not typically contain variable consideration or other provisions that increase or decrease the transaction price. In rare situations where the transaction price is not fixed, the Company estimates variable consideration at the most likely amount to which it expects to be entitled. The Company includes estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. For royalty license agreements, the Company applies the sales-based and usage-based royalty exception and recognizes royalties at the later of: (i) when the subsequent sale or usage occurs; or (ii) the satisfaction or partial satisfaction of the performance obligation to which some or all of the sales-or usage-based royalty has been allocated. For contracts in which a portion of the transaction price is retained and paid after the good or service has been transferred to the customer, the Company does not recognize a significant financing component. The primary purpose of the retainage payment is often to provide the customer with assurance that the Company will perform its obligations under the contract, rather than to provide financing to the customer. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of anticipated performance and all information (historical, current and forecasted) that is reasonably available. Revenue by Category The following tables summarize revenues by segment and geography (in thousands): Quarter Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 111,902 $ 72,022 $ 78,374 $ 262,298 Canada 16,153 19,767 — 35,920 Europe 13,460 2,821 — 16,281 Other foreign 14,166 11,014 — 25,180 Total revenues $ 155,681 $ 105,624 $ 78,374 $ 339,679 Nine Months Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 323,327 $ 207,267 $ 248,612 $ 779,206 Canada 44,028 51,157 — 95,185 Europe 39,600 8,535 — 48,135 Other foreign 43,885 33,159 — 77,044 Total revenues $ 450,840 $ 300,118 $ 248,612 $ 999,570 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 128,356 $ 57,024 $ 65,435 $ 250,815 Canada 17,936 24,003 — 41,939 Europe 13,900 3,467 — 17,367 Other foreign 13,969 17,782 — 31,751 Total revenues $ 174,161 $ 102,276 $ 65,435 $ 341,872 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 328,627 $ 241,620 $ 216,799 $ 787,046 Canada 42,170 55,883 — 98,053 Europe 41,196 10,460 — 51,656 Other foreign 39,347 45,418 — 84,765 Total revenues $ 451,340 $ 353,381 $ 216,799 $ 1,021,520 The following tables summarize revenues by segment and contract type (in thousands): Quarter Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 141,598 $ 68,935 $ 2,069 $ 212,602 Time and materials — 25,612 76,305 101,917 Product sales 11,679 11,077 — 22,756 License fees 2,404 — — 2,404 Total revenues $ 155,681 $ 105,624 $ 78,374 $ 339,679 Nine Months Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 416,392 $ 210,819 $ 13,793 $ 641,004 Time and materials — 60,160 234,819 294,979 Product sales 32,011 29,139 — 61,150 License fees 2,437 — — 2,437 Total revenues $ 450,840 $ 300,118 $ 248,612 $ 999,570 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 163,043 $ 76,419 $ 1,548 $ 241,010 Time and materials — 14,188 63,887 78,075 Product sales 10,987 11,669 — 22,656 License fees 131 — — 131 Total revenues $ 174,161 $ 102,276 $ 65,435 $ 341,872 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 419,991 $ 276,431 $ 4,216 $ 700,638 Time and materials — 40,325 212,583 252,908 Product sales 30,905 36,625 — 67,530 License fees 444 — — 444 Total revenues $ 451,340 $ 353,381 $ 216,799 $ 1,021,520 Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable, contract assets and contract liabilities on the Consolidated Balance Sheets. Contract assets represent work performed that could not be billed either due to contract stipulations or the required contractual documentation has not been finalized. Substantially all unbilled amounts are expected to be billed and collected within one year. For fixed fee and time-and-materials based contracts, amounts are billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. For some royalty license arrangements, minimum amounts are billed over the license term as quarterly royalty amounts are determined. This results in contract assets as the Company recognizes revenue for the license when the license is transferred to the customer at contract inception. The Company’s contract liabilities consist of advance payments, billings in excess of revenue recognized and deferred revenue. The Company’s contract assets and contract liabilities are reported in a net position on a contract-by-contract basis at the end of each reporting period. Advance payments, billings in excess of revenue recognized and deferred revenue are each classified as current. Net contract assets (liabilities) consisted of the following (in thousands): September 30, (1) December 31, 2017 (2) Contract assets – current $ 88,348 $ 75,371 Contract liabilities – current (35,297 ) (51,597 ) Net contract assets $ 53,051 $ 23,774 __________________________ (1) Amounts exclude contract assets of $2.2 million and contract liabilities of less than $0.1 million that were classified as held for sale at September 30, 2018 (see Note 5). (2) Amounts exclude contract assets of $1.3 million and contract liabilities of $5.5 million that were classified as held for sale at December 31, 2017 (see Note 5). Included in the change of total net contract assets was a $13.0 million increase in contract assets, primarily related to the timing between work performed on open contracts and contractual billing terms, and a $16.3 million decrease in contract liabilities, primarily related to the timing of customer advances on certain contracts. Substantially all of the $51.6 million and $62.7 million contract liabilities balances at December 31, 2017 and December 31, 2016, respectively, were recognized in revenues during the first nine months of 2018 and 2017, respectively. Impairment losses recognized on receivables and contract assets were not material during the first nine months of 2018 and 2017.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring	RESTRUCTURING 2017 Restructuring On July 28, 2017, the Company’s board of directors approved the 2017 Restructuring. As part of the 2017 Restructuring, the Company announced plans to: (i) divest Bayou; (ii) exit all non-pipe related contract applications for the Tyfo ® system in North America; (iii) right-size the cathodic protection services operation in Canada and the CIPP businesses in Australia and Denmark; and (iv) reduce corporate and other operating costs. These decisions reflected the Company’s: (a) desire to reduce further its exposure in the North American upstream oil and gas markets; (b) assessment of its ability to drive sustainable, profitable growth in the non-pipe FRP contracting market in North America; and (c) assessment of continuing weak conditions in the Canadian oil and gas markets. In May 2018 and July 2018, the Company’s board of directors approved subsequent actions to divest the Australia CIPP business and divest assets, where possible, from the Denmark CIPP business, respectively (see Note 5). During the first nine months of 2018, total pre-tax 2017 Restructuring charges recorded were $15.6 million ( $14.0 million post-tax) and consisted of employee severance, retention, extension of benefits, employment assistance programs, early lease and contract termination and other restructuring costs associated with the restructuring efforts described above. Total pre-tax 2017 Restructuring and related impairment charges since inception were $125.7 million ( $115.6 million post-tax), including cash charges of $21.1 million and non-cash charges of $104.6 million , of which $86.4 million relates to goodwill and long-lived asset impairment charges recorded in 2017 as part of exiting the non-pipe FRP contracting market in North America. The Company reduced headcount by approximately 320 employees as a result of these actions. Management expects total restructuring and impairment charges for actions approved on July 28, 2017, and including the subsequent actions for Australia and Denmark, to be approximately $130 million . See Note 13 for additional restructuring activities approved by the Company’s board of directors on October 26, 2018. During the quarter and nine months ended September 30, 2018 and 2017 , the Company recorded pre-tax expenses related to the 2017 Restructuring as follows (in thousands): Quarter Ended September 30, 2018 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total Infrastructure Solutions Corrosion Protection Total Severance and benefit related costs $ 914 $ 35 $ 949 $ 3,140 $ 1,930 $ 5,070 Lease and contract termination costs 215 — 215 250 90 340 Relocation and other moving costs 55 — 55 — 29 29 Other restructuring costs (1) 5,085 1,119 6,204 1,183 115 1,298 Total pre-tax restructuring charges (2) $ 6,269 $ 1,154 $ 7,423 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Includes charges primarily related to certain wind-down costs, allowances for accounts receivable, fixed asset disposals and other restructuring-related costs in connection with exiting non-pipe-related contract applications for the Tyfo ® system in North America and right-sizing the CIPP operations in Australia and Denmark. Amounts also include goodwill and definite-lived intangible asset impairments related to Denmark. (2) Includes $0.3 million and $0.8 million of corporate-related restructuring charges in the third quarter of 2018 and 2017 , respectively, that have been allocated to the Infrastructure Solutions and Corrosion Protection reportable segments. Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total Infrastructure Solutions Corrosion Protection Total Severance and benefit related costs $ 2,780 $ 437 $ 3,217 $ 3,140 $ 1,930 $ 5,070 Lease and contract termination costs 1,052 150 1,202 250 90 340 Relocation and other moving costs 129 — 129 — 29 29 Other restructuring costs (1) 8,395 2,637 11,032 1,183 115 1,298 Total pre-tax restructuring charges (2) $ 12,356 $ 3,224 $ 15,580 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Includes charges primarily related to certain wind-down costs, allowances for accounts receivable, fixed asset disposals and other restructuring-related costs in connection with exiting non-pipe-related contract applications for the Tyfo ® system in North America and right-sizing the CIPP operations in Australia and Denmark. Amounts also include goodwill and definite-lived intangible asset impairments related to Denmark. (2) Includes $0.9 million and $0.8 million of corporate-related restructuring charges in the first nine months of 2018 and 2017 , respectively, that have been allocated to the Infrastructure Solutions and Corrosion Protection reportable segments. 2017 Restructuring costs related to severance, other termination benefit costs and early lease and contract termination costs were $1.2 million and $5.4 million for the quarters ended September 30, 2018 and 2017 , respectively, and $4.5 million and $5.4 million for the nine months ended September 30, 2018 and 2017 , respectively, and are reported on a separate line in the Consolidated Statements of Operations. The following tables summarize all charges related to the 2017 Restructuring recognized in the quarter and nine month periods ended September 30, 2018 and 2017 as presented in their affected line in the Consolidated Statements of Operations (in thousands): Quarter Ended September 30, 2018 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total (1) Infrastructure Solutions Corrosion Protection Total (2) Cost of Revenues $ 138 $ 567 $ 705 $ 30 $ 15 $ 45 Operating expenses 2,466 552 3,018 1,153 100 1,253 Goodwill impairment 1,389 — 1,389 — — — Definite-lived intangible asset impairment 870 — 870 — — — Restructuring and related charges 1,184 35 1,219 3,390 2,049 5,439 Other expense 222 — 222 — — — Total pre-tax restructuring charges $ 6,269 $ 1,154 $ 7,423 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Total pre-tax restructuring charges include cash charges of $2.3 million and non-cash charges of $5.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. (2) Total pre-tax restructuring charges include cash charges of $6.6 million and non-cash charges of $0.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total (1) Infrastructure Solutions Corrosion Protection Total (2) Cost of Revenues $ 138 $ 567 $ 705 $ 30 $ 15 $ 45 Operating expenses 5,776 2,070 7,846 1,153 100 1,253 Goodwill impairment 1,389 — 1,389 — — — Definite-lived intangible asset impairment 870 — 870 — — — Restructuring and related charges 3,961 587 4,548 3,390 2,049 5,439 Other expense 222 — 222 — — — Total pre-tax restructuring charges $ 12,356 $ 3,224 $ 15,580 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Total pre-tax restructuring charges include cash charges of $7.4 million and non-cash charges of $8.2 million . Cash charges consist of charges incurred during the period that will be settled in cash, either during the current period or future periods. (2) Total pre-tax restructuring charges include cash charges of $6.6 million and non-cash charges of $0.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. The following tables summarize the 2017 Restructuring activity during the first nine months of 2018 and 2017 (in thousands): Reserves at December 31, 2017 2018 Foreign Currency Translation Utilized in 2018 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 3,864 $ 3,217 $ (30 ) $ 4,754 $ — $ 2,297 Lease and contract termination costs 650 1,202 (4 ) 1,337 — 511 Relocation and other moving costs — 129 — 129 — — Other restructuring costs 675 11,032 — 3,204 8,150 353 Total pre-tax restructuring charges $ 5,189 $ 15,580 $ (34 ) $ 9,424 $ 8,150 $ 3,161 __________________________ (1) Refers to cash utilized to settle charges during the first nine months of 2018. 2017 Utilized in 2017 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 5,070 $ 1,639 $ — $ 3,431 Lease and contract termination costs 340 264 — 76 Relocation and other moving costs 29 29 — — Other restructuring costs 1,298 521 77 700 Total pre-tax restructuring charges $ 6,737 $ 2,453 $ 77 $ 4,207 __________________________ (1) Refers to cash utilized to settle charges during the first nine months of 2017.

Assets and Liabilities Held for

Assets and Liabilities Held for Sale	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Assets and Liabilities Held for Sale	ASSETS AND LIABILITIES HELD FOR SALE On May 14, 2018 and July 25, 2018, the Company’s board of directors approved plans to divest the assets and liabilities of Australia and Denmark, respectively (see Notes 1 and 4). For Australia, a sales process is under way and management believes that it is probable that a sale will occur before the end of the first quarter of 2019. For Denmark, see Note 13 for additional information on the executed asset sale agreement, effective November 1, 2018. On July 28, 2017, the Company’s board of directors approved a plan to sell the assets and liabilities of Bayou. The Company completed a sale transaction during the third quarter of 2018. See Note 1. The relevant asset and liability balances at September 30, 2018 and December 31, 2017 are accounted for as held for sale and measured at the lower of carrying value or fair value less cost to sell. No impairment charges were recorded on these assets as the net carrying value approximated or was less than management’s current expectation of fair value less cost to sell. In the event the Company is unable to sell the assets and liabilities or sells them at a price or on terms that are less favorable, or at a higher cost than currently anticipated, the Company could incur impairment charges or a loss on disposal. The following table provides the components of assets and liabilities held for sale (in thousands): September 30, 2018 December 31, Australia Denmark Total Bayou Assets held for sale: Current assets Cash and cash equivalents $ — $ — $ — $ 989 Receivables, net 2,003 — 2,003 6,368 Retainage 16 — 16 — Contract assets 2,185 — 2,185 1,299 Inventories 1,769 35 1,804 3,727 Prepaid expenses and other current assets 250 — 250 827 Total current assets 6,223 35 6,258 13,210 Property, plant & equipment, less accumulated depreciation 2,315 1,600 3,915 53,887 Identified intangible assets, less accumulated amortization — — — 3,217 Total assets held for sale $ 8,538 $ 1,635 $ 10,173 $ 70,314 Liabilities held for sale: Current liabilities Accounts payable $ 985 $ — $ 985 $ 5,763 Accrued expenses 5,399 — 5,399 1,805 Contract liabilities 39 — 39 5,478 Total current liabilities 6,423 — 6,423 13,046 Long-term debt — — — 7,757 Other non-current liabilities — — — 97 Total liabilities held for sale $ 6,423 $ — $ 6,423 $ 20,900

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS Goodwill The following table presents a reconciliation of the beginning and ending balances of the Company’s goodwill (in thousands): Infrastructure Corrosion Energy Total Balance, December 31, 2017: Goodwill, gross $ 246,486 $ 74,369 $ 80,246 $ 401,101 Accumulated impairment losses (61,459 ) (45,400 ) (33,527 ) (140,386 ) Goodwill, net 185,027 28,969 46,719 260,715 2018 Activity: Acquisitions (1) (2) — 2,715 1,258 3,973 Impairments (3) (1,389 ) — — (1,389 ) Foreign currency translation (1,363 ) (179 ) — (1,542 ) Balance, September 30, 2018: Goodwill, gross 245,123 76,905 81,504 403,532 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 182,275 $ 31,505 $ 47,977 $ 261,757 __________________________ (1) During the second quarter of 2018, the Company recorded goodwill of $2.7 million related to the acquisition of Hebna (see Note 1). (2) During the third quarter of 2018, the Company recorded goodwill of $1.3 million related to the acquisition of P2S (see Note 1). (3) During the third quarter of 2018, the Company recorded a $1.4 million goodwill impairment related to restructuring activities in Denmark (see Note 4). Intangible Assets Intangible assets consisted of the following (in thousands): September 30, 2018 December 31, 2017 Weighted Average Useful Lives (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount License agreements (3) 1.8 $ 3,899 $ (3,686 ) $ 213 $ 4,497 $ (3,623 ) $ 874 Leases 2.3 796 (599 ) 197 796 (534 ) 262 Trademarks (2) (3) 9.6 15,739 (7,132 ) 8,607 15,464 (6,184 ) 9,280 Non-competes (1) (2) 4.8 2,548 (1,107 ) 1,441 1,197 (1,048 ) 149 Customer relationships (1) (2) (3) 9.2 161,745 (64,876 ) 96,869 160,423 (56,907 ) 103,516 Patents and acquired technology 6.1 38,699 (21,577 ) 17,122 39,285 (21,021 ) 18,264 $ 223,426 $ (98,977 ) $ 124,449 $ 221,662 $ (89,317 ) $ 132,345 __________________________ (1) During the second quarter of 2018, the Company recorded non-competes of $1.1 million and customer relationships of $1.3 million related to the acquisition of Hebna (see Note 1). (2) During the third quarter of 2018, the Company recorded trademarks of $0.3 million , non-competes of $0.2 million and customer relationships of $0.7 million related to the acquisition of P2S (see Note 1). (3) During the third quarter of 2018, the Company recorded intangible asset impairments related to restructuring activities in Denmark of $0.5 million for license agreements, $0.1 million for trademarks, and $0.3 million for customer relationships (see Note 4). Amortization expense was $3.5 million and $3.8 million for the quarters ended September 30, 2018 and 2017 , respectively, and $10.4 million and $12.5 million for the nine months ended September 30, 2018 and 2017 , respectively. Estimated amortization expense by year is as follows (in thousands): 2018 $ 13,848 2019 13,738 2020 13,691 2021 13,485 2022 13,287

Long-Term Debt and Credit Facil

Long-Term Debt and Credit Facility	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Long-Term Debt and Credit Facility	LONG-TERM DEBT AND CREDIT FACILITY Financing Arrangements Long-term debt consisted of the following (in thousands): September 30, December 31, Term note, due February 27, 2023, annualized rates of 4.53% and 3.60%, respectively $ 288,750 $ 308,437 Line of credit, 4.39% and 3.50%, respectively 19,000 38,000 Other notes with interest rates from 3.3% to 7.8% 780 875 Subtotal 308,530 347,312 Less – Current maturities of long-term debt 26,548 26,555 Less – Unamortized loan costs 2,713 2,517 Total $ 279,269 $ 318,240 In October 2015, the Company entered into an amended and restated $650.0 million senior secured credit facility with a syndicate of banks. On February 27, 2018, the Company amended this facility (the “amended Credit Facility”). Bank of America, N.A. served as the sole administrative agent and U.S. Bank National Association, PNC Bank, National Association and Compass Bank acted as co-syndication agents. Merrill Lynch Pierce Fenner & Smith Incorporated, U.S. Bank National Association, PNC Capital Markets, LLC and Compass Bank acted as joint lead arrangers and joint book managers in the syndication of the amended Credit Facility. The amended Credit Facility consists of a $300.0 million five -year revolving line of credit and a $308.4 million five -year term loan facility. Interest terms from the Company’s original credit facility did not change under the amendment. The amended Credit Facility also: (i) extended the expiration date of the original credit facility and the amortization period for the term loan facility from October 2020 to February 2023; (ii) approved the sale of Bayou; and (iii) updated the defined terms to allow for the add-back of certain charges related to the 2017 Restructuring when calculating the Company’s compliance with the financial covenants. As required by the amended Credit Facility, net cash proceeds of $35 million from the sale of Bayou were applied against the outstanding borrowings on the revolving line of credit during the third quarter of 2018. Additionally, and in conjunction with the sale, the maximum aggregate principal amount of the revolving line of credit was permanently reduced from $300.0 million to $275.0 million . The Company paid expenses of $2.5 million associated with the amended Credit Facility, $0.9 million related to up-front lending fees and $1.6 million related to third-party arranging fees and expenses, the latter of which was recorded in “Interest expense” in the Consolidated Statement of Operations during the first nine months of 2018. In addition, the Company had $2.4 million in unamortized loan costs associated with the original Credit Facility, of which $0.2 million was written off and recorded in “Interest expense” in the Consolidated Statement of Operations during the first nine months of 2018. Generally, interest is charged on the principal amounts outstanding under the amended Credit Facility at the British Bankers Association LIBOR rate plus an applicable rate ranging from 1.25% to 2.25% depending on the Company’s consolidated leverage ratio. The Company can also opt for an interest rate equal to a base rate (as defined in the credit documents) plus an applicable rate, which also is based on the Company’s consolidated leverage ratio. The applicable LIBOR borrowing rate (LIBOR plus Company’s applicable rate) as of September 30, 2018 was approximately 4.39% . The Company’s indebtedness at September 30, 2018 consisted of $288.8 million outstanding from the $308.4 million term loan under the amended Credit Facility, $19.0 million on the line of credit under the amended Credit Facility and $0.8 million of third-party notes and bank debt. During the first nine months of 2018, the Company had net repayments on the line of credit of $19.0 million , which included a $35.0 million repayment from the proceeds on the Bayou sale, net of borrowings of $16.0 million for domestic working capital needs. As of September 30, 2018 , the Company had $29.3 million in letters of credit issued and outstanding under the amended Credit Facility. Of such amount, $13.7 million was collateral for the benefit of certain of our insurance carriers and $15.6 million was for letters of credit or bank guarantees of performance or payment obligations of foreign subsidiaries. The Company’s indebtedness at December 31, 2017 consisted of $308.4 million outstanding from the term loan under the Credit Facility, $38.0 million on the line of credit under the Credit Facility and $0.9 million of third-party notes and bank debt. Additionally, the Company had $7.8 million of debt held by a joint venture (representing funds loaned by its joint venture partner) listed as held for sale at December 31, 2017 related to the planned sale of Bayou. At September 30, 2018 and December 31, 2017, the estimated fair value of the Company’s long-term debt was approximately $305.6 million and $356.0 million , respectively. Fair value was estimated using market rates for debt of similar risk and maturity and a discounted cash flow model, which are based on Level 3 inputs as defined in Note 12. In October 2015, the Company entered into an interest rate swap agreement for a notional amount of $262.5 million , which is set to expire in October 2020. The notional amount of this swap mirrors the amortization of a $262.5 million portion of the Company’s $350.0 million term loan drawn from the original Credit Facility. The swap requires the Company to make a monthly fixed rate payment of 1.46% calculated on the amortizing $262.5 million notional amount, and provides for the Company to receive a payment based upon a variable monthly LIBOR interest rate calculated on the same amortizing $262.5 million notional amount. The receipt of the monthly LIBOR-based payment offsets a variable monthly LIBOR-based interest cost on a corresponding $262.5 million portion of the Company’s term loan from the original Credit Facility. After considering the impact of the interest rate swap agreement, the effective borrowing rate on the Company’s term note as of September 30, 2018 was approximately 3.74% . This interest rate swap is used to partially hedge the interest rate risk associated with the volatility of monthly LIBOR rate movement and is accounted for as a cash flow hedge. See Note 12. On March 12, 2018, the Company entered into an interest rate swap forward agreement that begins in October 2020 and expires in February 2023 to coincide with the amortization period of the amended Credit Facility. The swap will require the Company to make a monthly fixed rate payment of 2.937% calculated on the then amortizing $170.6 million notional amount, and provides for the Company to receive a payment based upon a variable monthly LIBOR interest rate calculated on the same amortizing $170.6 million notional amount. The receipt of the monthly LIBOR-based payment will offset the variable monthly LIBOR-based interest cost on a corresponding $170.6 million portion of the Company’s term loan from the amended Credit Facility. This interest rate swap will be used to partially hedge the interest rate risk associated with the volatility of monthly LIBOR rate movement and accounted for as a cash flow hedge. See Note 12. The amended Credit Facility is subject to certain financial covenants, including a consolidated financial leverage ratio and consolidated fixed charge coverage ratio. Subject to the specifically defined terms and methods of calculation as set forth in the amended Credit Facility’s credit agreement, the financial covenant requirements, as of each quarterly reporting period end, are defined as follows: • Consolidated financial leverage ratio compares consolidated funded indebtedness to amended Credit Facility defined income with a maximum amount not to exceed 3.5 to 1.00. At September 30, 2018 , the Company’s consolidated financial leverage ratio was 2.88 to 1.00 and, using the amended Credit Facility defined income, the Company had the capacity to borrow up to $68.8 million of additional debt. • Consolidated fixed charge coverage ratio compares amended Credit Facility defined income to amended Credit Facility defined fixed charges with a minimum permitted ratio of not less than 1.15 to 1.00. At September 30, 2018 , the Company’s fixed charge ratio was 1.45 to 1.00. At September 30, 2018 , the Company was in compliance with all of its debt and financial covenants as required under the amended Credit Facility.

Stockholders' Equity and Equity

Stockholders' Equity and Equity Compensation	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity and Equity Compensation	STOCKHOLDERS’ EQUITY AND EQUITY COMPENSATION Share Repurchase Plan Under the terms of the amended Credit Facility, the Company is authorized to purchase up to $30.0 million of shares of its common stock in open market purchases during 2018. In October 2017, the Company’s board of directors authorized the open market repurchase of up to $40.0 million of the Company’s common stock to be made during 2018. That authorization was reduced to $30 million in 2018 in connection with the execution of the amended Credit Facility. The Company began repurchasing shares under this program in January 2018. Once repurchased, the Company promptly retires such shares. The Company is also authorized to repurchase up to $10.0 million of the Company’s common stock in each calendar year in connection with the Company’s equity compensation programs for employees. The participants in the Company’s equity plans may surrender shares of common stock in satisfaction of tax obligations arising from the vesting of restricted stock, restricted stock unit awards and performance unit awards under such plans and in connection with the exercise of stock option awards. The deemed price paid is the closing price of the Company’s common stock on the Nasdaq Global Select Market on the date that the restricted stock, restricted stock unit or performance unit vests or the shares of the Company’s common stock are surrendered in exchange for stock option exercises. With regard to stock option awards, the option holder may elect a “net, net” exercise in connection with the exercise of employee stock options such that the option holder receives a number of shares equal to the built-in gain in the option shares divided by the market price of the Company’s common stock on the date of exercise, less a number of shares equal to the taxes due upon the exercise of the option divided by the market price of the Company’s common stock on the date of exercise. The shares of common stock surrendered for taxes due on the exercise of the option are deemed repurchased by the Company. During the first nine months of 2018, the Company acquired 548,198 shares of the Company’s common stock for $13.2 million ( $24.07 average price per share) through the open market repurchase program discussed above and 224,700 shares of the Company’s common stock for $5.4 million ( $24.15 average price per share) in connection with the satisfaction of tax obligations in connection with the vesting of restricted stock units and performance units. Once repurchased, the Company immediately retired all such shares. During the first nine months of 2017, the Company acquired 1,346,132 shares of the Company’s common stock for $29.4 million ( $21.81 average price per share) through the open market repurchase program discussed above and 106,164 shares of the Company’s common stock for $2.4 million ( $22.25 average price per share) in connection with the satisfaction of tax obligations in connection with the vesting of restricted stock, restricted stock units and performance units. Once repurchased, the Company immediately retired all such shares. Equity-Based Compensation Plans In April 2016, the Company’s stockholders approved the 2016 Employee Equity Incentive Plan, which was amended in 2017 by the First Amendment to the 2016 Employee Equity Incentive Plan (as amended, the “2016 Employee Plan”). In April 2018, the Company’s stockholders approved the Second Amendment to the 2016 Employee Equity Incentive Plan, which increased by 1,700,000 the number of shares of the Company’s common stock reserved and available for issuance in connection with awards issued under the 2016 Employee Plan. The 2016 Employee Plan, which replaced the 2013 Employee Equity Incentive Plan, provides for equity-based compensation awards, including restricted shares of common stock, performance awards, stock options, stock units and stock appreciation rights. The 2016 Employee Plan is administered by the Compensation Committee of the board of directors, which determines eligibility, timing, pricing, amount and other terms or conditions of awards. As of September 30, 2018 , 2,667,104 shares of the Company’s common stock were available for issuance under the 2016 Employee Plan. In April 2016, the Company’s stockholders also approved the 2016 Non-Employee Director Equity Incentive Plan (the “2016 Director Plan”), which replaced the 2011 Non-Employee Director Equity Incentive Plan. The 2016 Director Plan provides for equity-based compensation awards, including non-qualified stock options and stock units. The board of directors administers the 2016 Director Plan and has the authority to establish, amend and rescind any rules and regulations related to the 2016 Director Plan. As of September 30, 2018 , 73,532 shares of the Company’s common stock were available for issuance under the 2016 Director Plan. Stock Awards Stock awards, which include shares of restricted stock, restricted stock units and performance stock units, are awarded from time to time to executive officers and certain key employees of the Company. Stock award compensation is recorded based on the award date fair value and charged to expense ratably through the requisite service period. The forfeiture of unvested restricted stock, restricted stock units and performance stock units causes the reversal of all previous expense to be recorded as a reduction of current period expense. A summary of the stock award activity is as follows: Nine Months Ended Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2017 1,428,878 $ 21.53 Restricted stock units awarded 279,459 24.14 Performance stock units awarded 219,943 23.25 Restricted stock units distributed (301,041 ) 17.37 Performance stock units distributed (296,909 ) 21.55 Restricted stock units forfeited (78,171 ) 21.52 Performance stock units forfeited (61,952 ) 26.42 Outstanding at September 30, 2018 1,190,207 $ 23.26 Expense associated with stock awards was $1.1 million and $2.2 million for the quarters ended September 30, 2018 and 2017 , respectively, and $5.2 million and $7.0 million for the nine months ended September 30, 2018 and 2017 , respectively. Unrecognized pre-tax expense of $12.4 million related to stock awards is expected to be recognized over the weighted average remaining service period of 1.91 years for awards outstanding at September 30, 2018 . Deferred Stock Unit Awards Deferred stock units are generally awarded to directors of the Company and represent the Company’s obligation to transfer one share of the Company’s common stock to the grantee at a future date and are generally fully vested on the date of grant. The expense related to the issuance of deferred stock units is recorded as of the date of the award. A summary of deferred stock unit activity is as follows: Nine Months Ended Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2017 269,977 $ 20.14 Awarded 43,729 23.67 Distributed (26,396 ) 19.32 Outstanding at September 30, 2018 287,310 $ 20.76 Expense associated with deferred stock unit awards was less than $0.1 million for each of the quarters ended September 30, 2018 and 2017 , and $1.0 million and $1.1 million for the nine months ended September 30, 2018 and 2017 , respectively. Stock Options Stock options on the Company’s common stock are awarded from time to time to executive officers and certain key employees of the Company. Stock options granted generally have a term of seven to ten years and an exercise price equal to the market value of the underlying common stock on the date of grant. There were 73,897 stock options forfeited during the nine months ended September 30, 2018 with a weighted average exercise price of $26.60 per share. Stock options outstanding and exercisable at September 30, 2018 were 52,783 , with a weighted average exercise price of $18.11 per share. There was no expense associated with stock option grants for both quarters and nine months ended September 30, 2018 and 2017 and no unrecognized pre-tax expense related to stock option grants at September 30, 2018 . Financial data for stock option exercises are summarized as follows (in thousands): Nine Months Ended 2018 2017 Aggregate intrinsic value of outstanding stock options $ 384 $ 478 Aggregate intrinsic value of exercisable stock options 384 478 The intrinsic value calculations are based on the Company’s closing stock price of $25.38 and $23.28 on September 30, 2018 and 2017 , respectively. The Company uses a binomial option-pricing model for valuation purposes to reflect the features of stock options granted. Volatility, expected term and dividend yield assumptions are based on the Company’s historical experience. The risk-free rate is based on a U.S. treasury note with a maturity similar to the option grant’s expected term. There were no stock options awarded during 2018 or 2017 .

Taxes on Income

Taxes on Income	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Taxes on Income	TAXES ON INCOME The Company’s effective tax rate in the quarter and nine-month period ended September 30, 2018 was a benefit of 1,275.0% on a pre-tax loss and an expense of 22.9% on pre-tax income, respectively. These effective rates were positively impacted by a $1.5 million adjustment to the mandatory deemed repatriation tax on foreign earnings and a $1.5 million net tax benefit related to employee share-based awards that vested during the first quarter of 2018. In total, these two adjustments had a 39.3% benefit to the effective tax rate during the first nine months of 2018. Offsetting these positive impacts were valuation allowances recorded on certain net operating losses in foreign jurisdictions for which no income tax benefit can be recognized. For the quarter and nine-month period ended September 30, 2017 , the Company’s effective tax rate was a benefit of 7.4% on a pre-tax loss and an expense of 2.2% on a pre-tax loss, respectively. The low effective tax rates, as compared to the U.S. federal statutory income tax rate, were unfavorably impacted by: (i) significant pre-tax charges related to goodwill and definite-lived intangible asset impairments, certain of which are not deductible for tax purposes; and (ii) the impact of establishing a $14.9 million valuation allowance on net operating losses and other deferred tax assets in jurisdictions, primarily in the United States, where the Company is unlikely to recognize these benefits. The effective tax rate for the first nine months of 2017 was also unfavorably impacted by a higher mix of earnings in the United States, primarily from income generated on a large deepwater project in the Company’s pipe coating and insulation operation.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Litigation The Company is involved in certain litigation incidental to the conduct of its business and affairs. Management, after consultation with legal counsel, does not believe that the outcome of any such litigation, individually or in the aggregate, will have a material adverse effect on the Company’s consolidated financial condition, results of operations or cash flows. Purchase Commitments The Company had no material purchase commitments at September 30, 2018 . Guarantees The Company has many contracts that require the Company to indemnify the other party against loss from claims, including claims of patent or trademark infringement or other third-party claims for injuries, damages or losses. The Company has agreed to indemnify its surety against losses from third-party claims of subcontractors. The Company has not previously experienced material losses under these provisions and, while there can be no assurances, currently does not anticipate any future material adverse impact on its consolidated financial position, results of operations or cash flows. The Company regularly reviews its exposure under all its engagements, including performance guarantees by contractual joint ventures and indemnification of its surety. As a result of the most recent review, the Company has determined that the risk of material loss is remote under these arrangements and has not recorded a liability for these risks at September 30, 2018 on its Consolidated Balance Sheet.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING The Company has three operating segments, which are also its reportable segments: Infrastructure Solutions; Corrosion Protection; and Energy Services. The Company’s operating segments correspond to its management organizational structure. Each operating segment has a president who reports to the Company’s chief executive officer, who is also the chief operating decision manager (“CODM”). The operating results and financial information reported by each segment are evaluated separately, regularly reviewed and used by the CODM to evaluate segment performance, allocate resources and determine management incentive compensation. The following disaggregated financial results have been prepared using a management approach that is consistent with the basis and manner with which management internally disaggregates financial information for the purpose of making internal operating decisions. The Company evaluates performance based on stand-alone operating income (loss), which includes acquisition and divestiture expenses, restructuring charges and an allocation of corporate-related expenses. Financial information by segment was as follows (in thousands): Quarters Ended Nine Months Ended 2018 2017 2018 2017 Revenues: Infrastructure Solutions $ 155,681 $ 174,161 $ 450,840 $ 451,340 Corrosion Protection 105,624 102,276 300,118 353,381 Energy Services 78,374 65,435 248,612 216,799 Total revenues $ 339,679 $ 341,872 $ 999,570 $ 1,021,520 Gross profit: Infrastructure Solutions $ 38,135 $ 41,189 $ 100,793 $ 106,803 Corrosion Protection 26,411 23,063 74,524 86,663 Energy Services 8,127 9,190 29,913 27,156 Total gross profit $ 72,673 $ 73,442 $ 205,230 $ 220,622 Operating income (loss): Infrastructure Solutions (1) $ 10,398 $ (74,025 ) $ 19,563 $ (60,224 ) Corrosion Protection (2) 2,463 (2,703 ) 6,184 15,803 Energy Services 148 1,457 4,902 4,857 Total operating income (loss) 13,009 (75,271 ) 30,649 (39,564 ) Other income (expense): Interest expense (3,870 ) (3,962 ) (13,236 ) (12,014 ) Interest income 130 33 239 117 Other (3) (9,281 ) (798 ) (10,049 ) (1,593 ) Total other expense (13,021 ) (4,727 ) (23,046 ) (13,490 ) Income (loss) before taxes on income $ (12 ) $ (79,998 ) $ 7,603 $ (53,054 ) _______________________ (1) Operating income in the third quarter of 2018 includes $6.0 million of 2017 Restructuring charges (see Note 4) and $0.2 million of costs primarily related to the planned divestitures of Australia and Denmark. Operating loss in the third quarter of 2017 includes: (i) $4.5 million of 2017 Restructuring charges (see Note 3); (ii) $45.4 million of goodwill impairment charges (see Note 2); (iii) $41.0 million of definite-lived intangible asset impairment charges (see Note 2); and (iv) $0.1 million of costs incurred primarily related to the acquisition of Environmental Techniques. Operating income in the first nine months of 2018 includes $12.1 million of 2017 Restructuring charges (see Note 4) and $0.5 million of costs primarily related to the planned divestitures of Australia and Denmark. Operating loss in the nine months ended September 30, 2017 includes: (i) $4.7 million of 2017 Restructuring charges (see Note 3); (ii) $45.4 million of goodwill impairment charges (see Note 2); (iii) $41.0 million of definite-lived intangible asset impairment charges (see Note 2); and (iv) $0.7 million of costs incurred primarily related to the acquisition of Environmental Techniques. (2) Operating income in the third quarter of 2018 includes $1.2 million of 2017 Restructuring charges (see Note 4) and $4.6 million of costs incurred primarily related to the divestiture of Bayou. Operating loss in the third quarter of 2017 includes $2.2 million of 2017 Restructuring charges (see Note 3) and $1.9 million of costs incurred primarily related to the planned divestiture of Bayou. Operating income in the first nine months of 2018 includes $3.2 million of 2017 Restructuring charges (see Note 4) and $5.5 million of costs incurred primarily related to the acquisition of Hebna and the divestiture of Bayou. Operating income in the first nine months of 2017 includes $2.2 million of 2017 Restructuring charges (see Note 3) and $1.9 million of costs incurred primarily related to the planned divestiture of Bayou. (3) Other expense for the quarter and nine months ended September 30, 2018 includes charges of $8.7 million related to the loss on the sale of Bayou and $0.2 million related to 2017 Restructuring charges (see Note 4). The following table summarizes revenues, gross profit and operating income (loss) by geographic region (in thousands): Quarters Ended Nine Months Ended 2018 2017 2018 2017 Revenues (1) : United States $ 262,298 $ 250,815 $ 779,206 $ 787,046 Canada 35,920 41,939 95,185 98,053 Europe 16,281 17,367 48,135 51,656 Other foreign 25,180 31,751 77,044 84,765 Total revenues $ 339,679 $ 341,872 $ 999,570 $ 1,021,520 Gross profit: United States $ 57,043 $ 56,295 $ 165,203 $ 179,029 Canada 7,265 9,099 17,494 19,703 Europe 2,931 2,989 5,467 9,414 Other foreign 5,434 5,059 17,066 12,476 Total gross profit $ 72,673 $ 73,442 $ 205,230 $ 220,622 Operating income (loss): United States $ 12,604 $ (57,799 ) $ 32,983 $ (25,752 ) Canada 4,055 1,148 7,170 5,086 Europe (4,423 ) (2,860 ) (10,473 ) (2,672 ) Other foreign 773 (15,760 ) 969 (16,226 ) Total operating income (loss) $ 13,009 $ (75,271 ) $ 30,649 $ (39,564 ) __________________________ (1) Revenues are attributed to the country of origin for the Company’s legal entities. For a significant majority of its legal entities, the country of origin relates to the country or geographic area that it services.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	DERIVATIVE FINANCIAL INSTRUMENTS As a matter of policy, the Company uses derivatives for risk management purposes, and does not use derivatives for speculative purposes. From time to time, the Company may enter into foreign currency forward contracts to hedge foreign currency cash flow transactions. For cash flow hedges, a gain or loss is recorded in the Consolidated Statements of Operations upon settlement of the hedge. All of the Company’s hedges that are designated as hedges for accounting purposes were highly effective; therefore, no notable amounts of hedge ineffectiveness were recorded in the Company’s Consolidated Statements of Operations for either the settlement of cash flow hedges or the outstanding hedged balance. At September 30, 2018 , the Company’s cash flow hedges were in a net deferred gain position of $5.6 million due to favorable movements in short-term interest rates relative to the hedged position. The Company presents derivative instruments in the consolidated financial statements on a gross basis. Deferred gains and losses were recorded in other non-current assets and other non-current liabilities, respectively, and other comprehensive income on the Consolidated Balance Sheets. The net periodic change of the Company’s cash flow hedges was recorded on the foreign currency translation adjustment and derivative transactions line of the Consolidated Statements of Equity. The Company also engages in regular inter-company trade activities and receives royalty payments from certain of its wholly-owned entities, paid in local currency, rather than the Company’s functional currency, U.S. dollars. The Company utilizes foreign currency forward exchange contracts to mitigate the currency risk associated with the anticipated future payments from certain of its international entities. During the first nine months of 2018 and 2017 , losses of $0.4 million and $0.1 million , respectively, were recorded upon settlement of foreign currency forward exchange contracts. Gains and losses of this nature are recorded to “Other income (expense)” in the Consolidated Statements of Operations. In October 2015, the Company entered into an interest rate swap agreement for a notional amount of $262.5 million , which is set to expire in October 2020. The notional amount of this swap mirrored the amortization of a $262.5 million portion of the Company’s $350.0 million term loan drawn from the original Credit Facility. The swap requires the Company to make a monthly fixed rate payment of 1.46% calculated on the amortizing $262.5 million notional amount and provides for the Company to receive a payment based upon a variable monthly LIBOR interest rate calculated by amortizing the $262.5 million same notional amount. The receipt of the monthly LIBOR-based payment offsets a variable monthly LIBOR-based interest cost on a corresponding $262.5 million portion of the Company’s term loan from the original Credit Facility. This interest rate swap is used to partially hedge the interest rate risk associated with the volatility of monthly LIBOR rate movement and is accounted for as a cash flow hedge. On March 12, 2018, the Company entered into an interest rate swap forward agreement that begins in October 2020 and expires in February 2023 to coincide with the amortization period of the amended Credit Facility. The swap will require the Company to make a monthly fixed rate payment of 2.937% calculated on the then amortizing $170.6 million notional amount, and provides for the Company to receive a payment based upon a variable monthly LIBOR interest rate calculated on the same amortizing $170.6 million notional amount. The receipt of the monthly LIBOR-based payment will offset the variable monthly LIBOR-based interest cost on a corresponding $170.6 million portion of the Company’s term loan from the amended Credit Facility. This interest rate swap will be used to partially hedge the interest rate risk associated with the volatility of monthly LIBOR rate movement and accounted for as a cash flow hedge. The following table summarizes the Company’s derivative positions at September 30, 2018 : Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate USD/British Pound Sell £ 1,962,900 0.3 1.31 EURO/British Pound Sell £ 2,568,300 0.3 1.12 Interest Rate Swap $ 216,562,500 4.3 The following table provides a summary of the fair value amounts of our derivative instruments, all of which are Level 2 inputs as defined below (in thousands): Designation of Derivatives Balance Sheet Location September 30, December 31, Derivatives Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ 176 Interest Rate Swaps Other non-current assets 5,584 3,193 Total Assets $ 5,584 $ 3,369 Forward Currency Contracts Accrued expenses $ — $ 33 Total Liabilities $ — $ 33 Derivatives Not Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ 10 Total Assets $ — $ 10 Forward Currency Contracts Accrued expenses $ 61 $ — Total Liabilities $ 61 $ — Total Derivative Assets $ 5,584 $ 3,379 Total Derivative Liabilities 61 33 Total Net Derivative Asset (Liability) $ 5,523 $ 3,346 FASB ASC 820, Fair Value Measurements (“FASB ASC 820”), defines fair value and establishes a framework for measuring and disclosing fair value instruments. The guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: • Level 1 – defined as quoted prices in active markets for identical instruments; • Level 2 – defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; • Level 3 – defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. In accordance with FASB ASC 820, the Company determined that the value of all of its derivative instruments, which are measured at fair value on a recurring basis, are derived from significant observable inputs, referred to as Level 2 inputs. The Company had no transfers between Level 1, 2 or 3 inputs during the quarter ended September 30, 2018 . Certain financial instruments are required to be recorded at fair value. Changes in assumptions or estimation methods could affect the fair value estimates; however, the Company does not believe any such changes would have a material impact on its financial condition, results of operations or cash flows. Other financial instruments including cash and cash equivalents and short-term borrowings, including notes payable, are recorded at cost, which approximates fair value, which is based on Level 2 inputs as previously defined.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Additional Restructuring Actions On October 26, 2018, the Company’s board of directors approved additional actions with respect to the 2017 Restructuring, which included the decision to: (i) exit multiple additional international locations; and (ii) take actions to further optimize operations within North America. Total pre-tax charges associated with the additional actions are expected to be approximately $25 million , including pre-tax cash charges of approximately $8 million to $10 million . Most charges are expected to be incurred by mid-2019 and relate to employee severance, retention, extension of benefits, employment assistance programs, early lease and contract termination and other restructuring related costs. The identified charges are primarily focused in the international operations of both Infrastructure Solutions and Corrosion Protection, but also include certain other measures to reduce consolidated operating costs. The Company expects to reduce headcount by approximately 150 employees as a result of these additional actions. As the Company completes these actions over the coming months, additional charges and headcount reductions could occur. Asset Sale Agreement On November 1, 2018, the Company executed a sale agreement for substantially all of the fixed assets and inventory from its CIPP operations in Denmark for a sale price of DKK 10.5 million (approximately $1.6 million ). The transfer of ownership is expected to occur in early November 2018. In connection with the sale, the Company entered into a five -year exclusive tube-supply agreement whereby the buyers will purchase liners from the Company. The buyers will also be entitled to use the Insituform ® trade name based on a trade mark license granted for the same five -year time period. No impairment charges are expected to be recorded as the net carrying value approximated or was less than the sale price.

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Foreign Currency Translation	Foreign Currency Translation For the Company’s international subsidiaries, the local currency is generally the functional currency. Assets and liabilities of these subsidiaries are translated into U.S. dollars using rates in effect at the balance sheet date while revenues and expenses are translated into U.S. dollars using average exchange rates. The cumulative translation adjustment resulting from changes in exchange rates are included in the Consolidated Balance Sheets as a component of “Accumulated other comprehensive loss” in total stockholders’ equity.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents	Cash, Cash Equivalents and Restricted Cash The Company classifies highly liquid investments with original maturities of 90 days or less as cash equivalents. Recorded book values are reasonable estimates of fair value for cash and cash equivalents.
Investments in Variable Interest Entities	Investments in Variable Interest Entities The Company evaluates all transactions and relationships with variable interest entities (“VIE”) to determine whether the Company is the primary beneficiary of the entities in accordance with FASB ASC 810, Consolidation . There were no changes in the Company’s VIEs during the quarter ended September 30, 2018 .
Newly Issued Accounting Pronouncements	Newly Issued Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update No. 2018-13, Fair Value Measurement: Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements for Level 1, Level 2 and Level 3 instruments in the fair value hierarchy. The guidance is effective for the Company’s fiscal year beginning January 1, 2020, including interim periods within that fiscal year. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In February 2018, the FASB issued Accounting Standards Update No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which permits a company to reclassify the income tax effects of the TCJA on items within accumulated other comprehensive income to retained earnings. The guidance is effective for the Company’s fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Companies may adopt the new guidance using one of two transition methods: (i) retrospective to each period (or periods) in which the income tax effects are recognized, or (ii) at the beginning of the period of adoption. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities , which amends the recognition and presentation requirements for hedge accounting activities. The standard improves the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and reduces the complexity of applying hedge accounting. This new guidance is effective for the Company’s fiscal year beginning January 1, 2019, but the Company early-adopted this standard, effective January 1, 2018. The adoption of this standard did not have a material impact on its consolidated financial statements. In November 2016, the FASB issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash. As a result, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This new guidance was effective for the Company’s fiscal year beginning January 1, 2018 and applied retrospectively. The Company’s adoption of this standard, effective January 1, 2018, did not have a material impact on its consolidated financial statements, other than the classification of restricted cash on the Consolidated Statement of Cash Flows. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which addresses diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The standard was effective for the Company’s fiscal year beginning January 1, 2018, the adoption of which did not have a material impact on its consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) , that requires lessees to present right-of-use assets and lease liabilities on the balance sheet for all leases with lease terms longer than twelve months. The standard is effective for the Company’s fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Early adoption is permitted, although the Company does not intend to do so. The Company intends to adopt the new guidance using the cumulative effect method, which would apply to all new lease contracts initiated on or after January 1, 2019. For existing lease contracts that have remaining obligations as of January 1, 2019, the difference between the recognition criteria in the new guidance and the Company’s current practices would be recognized using a cumulative effect adjustment to the opening balance of retained earnings. In early 2017, the Company identified a project manager as well as a cross-functional implementation team responsible for identifying and assessing the impact on its lease contracts. During 2017 and 2018, the implementation team completed the assessment phase, which included data retrieval from the Company’s key third-party lease administration vendors and the identification of the Company’s known lease contracts throughout the world. Additionally, the Company is currently implementing a third-party software solution to support recognition and disclosure under the new standard, including customization and migration of existing data into the new software solution. During the fourth quarter of 2018, the Company will: (i) test the data output from the software solution in accordance with the new standard; (ii) calculate opening balances and determine the cumulative effect adjustment; and (iii) identify any further potential changes to business processes, systems and controls. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaces revenue recognition requirements regarding contracts with customers to transfer goods or services with a single revenue recognition model for recognizing revenue. Under the new guidance, entities are required to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides a five-step analysis to be performed on transactions to determine when and how revenue is recognized. The Company adopted this standard, effective January 1, 2018, using the modified retrospective transition method. See Note 3.
Segment Reporting	The Company has three operating segments, which are also its reportable segments: Infrastructure Solutions; Corrosion Protection; and Energy Services. The Company’s operating segments correspond to its management organizational structure. Each operating segment has a president who reports to the Company’s chief executive officer, who is also the chief operating decision manager (“CODM”). The operating results and financial information reported by each segment are evaluated separately, regularly reviewed and used by the CODM to evaluate segment performance, allocate resources and determine management incentive compensation. The following disaggregated financial results have been prepared using a management approach that is consistent with the basis and manner with which management internally disaggregates financial information for the purpose of making internal operating decisions. The Company evaluates performance based on stand-alone operating income (loss), which includes acquisition and divestiture expenses, restructuring charges and an allocation of corporate-related expenses.
Derivative Financial Instruments	As a matter of policy, the Company uses derivatives for risk management purposes, and does not use derivatives for speculative purposes. From time to time, the Company may enter into foreign currency forward contracts to hedge foreign currency cash flow transactions. For cash flow hedges, a gain or loss is recorded in the Consolidated Statements of Operations upon settlement of the hedge. All of the Company’s hedges that are designated as hedges for accounting purposes were highly effective; therefore, no notable amounts of hedge ineffectiveness were recorded in the Company’s Consolidated Statements of Operations for either the settlement of cash flow hedges or the outstanding hedged balance.

Accounting Policies (Tables)

Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule of accumulated other comprehensive income (loss)	The Company’s accumulated other comprehensive loss is comprised of three main components: (i) currency translation; (ii) derivatives; and (iii) gains and losses associated with the Company’s defined benefit plan in the United Kingdom (in thousands): September 30, December 31, 2017 Currency translation adjustments $ (38,017 ) $ (26,614 ) Derivative hedging activity 5,584 3,336 Pension activity (235 ) (244 ) Total accumulated other comprehensive loss $ (32,668 ) $ (23,522 )
Schedule of weighted average number of shares	Earnings per share have been calculated using the following share information: Quarters Ended Nine Months Ended 2018 2017 2018 2017 Weighted average number of common shares used for basic EPS 32,312,000 32,905,142 32,390,777 33,363,472 Effect of dilutive stock options and restricted and deferred stock unit awards — — 667,229 — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 32,312,000 32,905,142 33,058,006 33,363,472
Restrictions on cash and cash equivalents	Cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets and Consolidated Statements of Cash Flows are as follows (in thousands): Balance sheet data September 30, 2018 December 31, (1) Cash and cash equivalents $ 67,410 $ 105,717 Restricted cash 1,835 1,839 Cash, cash equivalents and restricted cash $ 69,245 $ 107,556 __________________________ (1) Amounts exclude $1.0 million of cash and cash equivalents classified as held for sale at December 31, 2017 (see Note 5).
Financial data for consolidated variable interest entities	Financial data for consolidated variable interest entities are summarized in the following tables (in thousands): Balance sheet data September 30, December 31, (1) Current assets $ 39,022 $ 42,732 Non-current assets 5,098 26,346 Current liabilities 14,514 12,449 Non-current liabilities 11,341 30,675 __________________________ (1) Amounts included $25.4 million of assets and $9.8 million of liabilities classified as held for sale relating to our pipe coating and insulation joint venture in Louisiana, Bayou Wasco Insulation, LLC, which was divested on August 31, 2018. See Note 5. Quarters Ended Nine Months Ended Income statement data (1) 2018 2017 2018 2017 (1) Revenue $ 16,405 $ 11,457 $ 39,179 $ 72,916 Gross profit 3,238 1,984 6,982 11,704 Net income (loss) attributable to Aegion Corporation (946 ) 1,121 (886 ) 3,071 __________________________ (1) During the nine months ended September 30, 2017, increased activity was primarily driven from our joint venture in Louisiana, which performed work on a large deepwater pipe coating and insulation project.

Revenues (Tables)

Revenues (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables summarize revenues by segment and geography (in thousands): Quarter Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 111,902 $ 72,022 $ 78,374 $ 262,298 Canada 16,153 19,767 — 35,920 Europe 13,460 2,821 — 16,281 Other foreign 14,166 11,014 — 25,180 Total revenues $ 155,681 $ 105,624 $ 78,374 $ 339,679 Nine Months Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 323,327 $ 207,267 $ 248,612 $ 779,206 Canada 44,028 51,157 — 95,185 Europe 39,600 8,535 — 48,135 Other foreign 43,885 33,159 — 77,044 Total revenues $ 450,840 $ 300,118 $ 248,612 $ 999,570 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 128,356 $ 57,024 $ 65,435 $ 250,815 Canada 17,936 24,003 — 41,939 Europe 13,900 3,467 — 17,367 Other foreign 13,969 17,782 — 31,751 Total revenues $ 174,161 $ 102,276 $ 65,435 $ 341,872 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 328,627 $ 241,620 $ 216,799 $ 787,046 Canada 42,170 55,883 — 98,053 Europe 41,196 10,460 — 51,656 Other foreign 39,347 45,418 — 84,765 Total revenues $ 451,340 $ 353,381 $ 216,799 $ 1,021,520 The following tables summarize revenues by segment and contract type (in thousands): Quarter Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 141,598 $ 68,935 $ 2,069 $ 212,602 Time and materials — 25,612 76,305 101,917 Product sales 11,679 11,077 — 22,756 License fees 2,404 — — 2,404 Total revenues $ 155,681 $ 105,624 $ 78,374 $ 339,679 Nine Months Ended September 30, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 416,392 $ 210,819 $ 13,793 $ 641,004 Time and materials — 60,160 234,819 294,979 Product sales 32,011 29,139 — 61,150 License fees 2,437 — — 2,437 Total revenues $ 450,840 $ 300,118 $ 248,612 $ 999,570 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 163,043 $ 76,419 $ 1,548 $ 241,010 Time and materials — 14,188 63,887 78,075 Product sales 10,987 11,669 — 22,656 License fees 131 — — 131 Total revenues $ 174,161 $ 102,276 $ 65,435 $ 341,872 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 419,991 $ 276,431 $ 4,216 $ 700,638 Time and materials — 40,325 212,583 252,908 Product sales 30,905 36,625 — 67,530 License fees 444 — — 444 Total revenues $ 451,340 $ 353,381 $ 216,799 $ 1,021,520
Contract Asset and Liability	Net contract assets (liabilities) consisted of the following (in thousands): September 30, (1) December 31, 2017 (2) Contract assets – current $ 88,348 $ 75,371 Contract liabilities – current (35,297 ) (51,597 ) Net contract assets $ 53,051 $ 23,774 __________________________ (1) Amounts exclude contract assets of $2.2 million and contract liabilities of less than $0.1 million that were classified as held for sale at September 30, 2018 (see Note 5). (2) Amounts exclude contract assets of $1.3 million and contract liabilities of $5.5 million that were classified as held for sale at December 31, 2017 (see Note 5).

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Summary of restructuring and related costs	During the quarter and nine months ended September 30, 2018 and 2017 , the Company recorded pre-tax expenses related to the 2017 Restructuring as follows (in thousands): Quarter Ended September 30, 2018 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total Infrastructure Solutions Corrosion Protection Total Severance and benefit related costs $ 914 $ 35 $ 949 $ 3,140 $ 1,930 $ 5,070 Lease and contract termination costs 215 — 215 250 90 340 Relocation and other moving costs 55 — 55 — 29 29 Other restructuring costs (1) 5,085 1,119 6,204 1,183 115 1,298 Total pre-tax restructuring charges (2) $ 6,269 $ 1,154 $ 7,423 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Includes charges primarily related to certain wind-down costs, allowances for accounts receivable, fixed asset disposals and other restructuring-related costs in connection with exiting non-pipe-related contract applications for the Tyfo ® system in North America and right-sizing the CIPP operations in Australia and Denmark. Amounts also include goodwill and definite-lived intangible asset impairments related to Denmark. (2) Includes $0.3 million and $0.8 million of corporate-related restructuring charges in the third quarter of 2018 and 2017 , respectively, that have been allocated to the Infrastructure Solutions and Corrosion Protection reportable segments. Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total Infrastructure Solutions Corrosion Protection Total Severance and benefit related costs $ 2,780 $ 437 $ 3,217 $ 3,140 $ 1,930 $ 5,070 Lease and contract termination costs 1,052 150 1,202 250 90 340 Relocation and other moving costs 129 — 129 — 29 29 Other restructuring costs (1) 8,395 2,637 11,032 1,183 115 1,298 Total pre-tax restructuring charges (2) $ 12,356 $ 3,224 $ 15,580 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Includes charges primarily related to certain wind-down costs, allowances for accounts receivable, fixed asset disposals and other restructuring-related costs in connection with exiting non-pipe-related contract applications for the Tyfo ® system in North America and right-sizing the CIPP operations in Australia and Denmark. Amounts also include goodwill and definite-lived intangible asset impairments related to Denmark. (2) Includes $0.9 million and $0.8 million of corporate-related restructuring charges in the first nine months of 2018 and 2017 , respectively, that have been allocated to the Infrastructure Solutions and Corrosion Protection reportable segments. The following tables summarize all charges related to the 2017 Restructuring recognized in the quarter and nine month periods ended September 30, 2018 and 2017 as presented in their affected line in the Consolidated Statements of Operations (in thousands): Quarter Ended September 30, 2018 Quarter Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total (1) Infrastructure Solutions Corrosion Protection Total (2) Cost of Revenues $ 138 $ 567 $ 705 $ 30 $ 15 $ 45 Operating expenses 2,466 552 3,018 1,153 100 1,253 Goodwill impairment 1,389 — 1,389 — — — Definite-lived intangible asset impairment 870 — 870 — — — Restructuring and related charges 1,184 35 1,219 3,390 2,049 5,439 Other expense 222 — 222 — — — Total pre-tax restructuring charges $ 6,269 $ 1,154 $ 7,423 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Total pre-tax restructuring charges include cash charges of $2.3 million and non-cash charges of $5.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. (2) Total pre-tax restructuring charges include cash charges of $6.6 million and non-cash charges of $0.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Infrastructure Solutions Corrosion Protection Total (1) Infrastructure Solutions Corrosion Protection Total (2) Cost of Revenues $ 138 $ 567 $ 705 $ 30 $ 15 $ 45 Operating expenses 5,776 2,070 7,846 1,153 100 1,253 Goodwill impairment 1,389 — 1,389 — — — Definite-lived intangible asset impairment 870 — 870 — — — Restructuring and related charges 3,961 587 4,548 3,390 2,049 5,439 Other expense 222 — 222 — — — Total pre-tax restructuring charges $ 12,356 $ 3,224 $ 15,580 $ 4,573 $ 2,164 $ 6,737 __________________________ (1) Total pre-tax restructuring charges include cash charges of $7.4 million and non-cash charges of $8.2 million . Cash charges consist of charges incurred during the period that will be settled in cash, either during the current period or future periods. (2) Total pre-tax restructuring charges include cash charges of $6.6 million and non-cash charges of $0.1 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.
Summary of restructuring activity	The following tables summarize the 2017 Restructuring activity during the first nine months of 2018 and 2017 (in thousands): Reserves at December 31, 2017 2018 Foreign Currency Translation Utilized in 2018 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 3,864 $ 3,217 $ (30 ) $ 4,754 $ — $ 2,297 Lease and contract termination costs 650 1,202 (4 ) 1,337 — 511 Relocation and other moving costs — 129 — 129 — — Other restructuring costs 675 11,032 — 3,204 8,150 353 Total pre-tax restructuring charges $ 5,189 $ 15,580 $ (34 ) $ 9,424 $ 8,150 $ 3,161 __________________________ (1) Refers to cash utilized to settle charges during the first nine months of 2018. 2017 Utilized in 2017 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 5,070 $ 1,639 $ — $ 3,431 Lease and contract termination costs 340 264 — 76 Relocation and other moving costs 29 29 — — Other restructuring costs 1,298 521 77 700 Total pre-tax restructuring charges $ 6,737 $ 2,453 $ 77 $ 4,207 __________________________ (1) Refers to cash utilized to settle charges during the first nine months of 2017.

Assets and Liabilities Held f_2

Assets and Liabilities Held for Sale (Tables)	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Schedule of assets and liabilities held for sale	The following table provides the components of assets and liabilities held for sale (in thousands): September 30, 2018 December 31, Australia Denmark Total Bayou Assets held for sale: Current assets Cash and cash equivalents $ — $ — $ — $ 989 Receivables, net 2,003 — 2,003 6,368 Retainage 16 — 16 — Contract assets 2,185 — 2,185 1,299 Inventories 1,769 35 1,804 3,727 Prepaid expenses and other current assets 250 — 250 827 Total current assets 6,223 35 6,258 13,210 Property, plant & equipment, less accumulated depreciation 2,315 1,600 3,915 53,887 Identified intangible assets, less accumulated amortization — — — 3,217 Total assets held for sale $ 8,538 $ 1,635 $ 10,173 $ 70,314 Liabilities held for sale: Current liabilities Accounts payable $ 985 $ — $ 985 $ 5,763 Accrued expenses 5,399 — 5,399 1,805 Contract liabilities 39 — 39 5,478 Total current liabilities 6,423 — 6,423 13,046 Long-term debt — — — 7,757 Other non-current liabilities — — — 97 Total liabilities held for sale $ 6,423 $ — $ 6,423 $ 20,900

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The following table presents a reconciliation of the beginning and ending balances of the Company’s goodwill (in thousands): Infrastructure Corrosion Energy Total Balance, December 31, 2017: Goodwill, gross $ 246,486 $ 74,369 $ 80,246 $ 401,101 Accumulated impairment losses (61,459 ) (45,400 ) (33,527 ) (140,386 ) Goodwill, net 185,027 28,969 46,719 260,715 2018 Activity: Acquisitions (1) (2) — 2,715 1,258 3,973 Impairments (3) (1,389 ) — — (1,389 ) Foreign currency translation (1,363 ) (179 ) — (1,542 ) Balance, September 30, 2018: Goodwill, gross 245,123 76,905 81,504 403,532 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 182,275 $ 31,505 $ 47,977 $ 261,757 __________________________ (1) During the second quarter of 2018, the Company recorded goodwill of $2.7 million related to the acquisition of Hebna (see Note 1). (2) During the third quarter of 2018, the Company recorded goodwill of $1.3 million related to the acquisition of P2S (see Note 1). (3) During the third quarter of 2018, the Company recorded a $1.4 million goodwill impairment related to restructuring activities in Denmark (see Note 4).
Schedule of identified intangible assets	Intangible assets consisted of the following (in thousands): September 30, 2018 December 31, 2017 Weighted Average Useful Lives (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount License agreements (3) 1.8 $ 3,899 $ (3,686 ) $ 213 $ 4,497 $ (3,623 ) $ 874 Leases 2.3 796 (599 ) 197 796 (534 ) 262 Trademarks (2) (3) 9.6 15,739 (7,132 ) 8,607 15,464 (6,184 ) 9,280 Non-competes (1) (2) 4.8 2,548 (1,107 ) 1,441 1,197 (1,048 ) 149 Customer relationships (1) (2) (3) 9.2 161,745 (64,876 ) 96,869 160,423 (56,907 ) 103,516 Patents and acquired technology 6.1 38,699 (21,577 ) 17,122 39,285 (21,021 ) 18,264 $ 223,426 $ (98,977 ) $ 124,449 $ 221,662 $ (89,317 ) $ 132,345 __________________________ (1) During the second quarter of 2018, the Company recorded non-competes of $1.1 million and customer relationships of $1.3 million related to the acquisition of Hebna (see Note 1). (2) During the third quarter of 2018, the Company recorded trademarks of $0.3 million , non-competes of $0.2 million and customer relationships of $0.7 million related to the acquisition of P2S (see Note 1). (3) During the third quarter of 2018, the Company recorded intangible asset impairments related to restructuring activities in Denmark of $0.5 million for license agreements, $0.1 million for trademarks, and $0.3 million for customer relationships (see Note 4).
Schedule of estimated amortization expense	Estimated amortization expense by year is as follows (in thousands): 2018 $ 13,848 2019 13,738 2020 13,691 2021 13,485 2022 13,287

Long-Term Debt and Credit Fac_2

Long-Term Debt and Credit Facility (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in thousands): September 30, December 31, Term note, due February 27, 2023, annualized rates of 4.53% and 3.60%, respectively $ 288,750 $ 308,437 Line of credit, 4.39% and 3.50%, respectively 19,000 38,000 Other notes with interest rates from 3.3% to 7.8% 780 875 Subtotal 308,530 347,312 Less – Current maturities of long-term debt 26,548 26,555 Less – Unamortized loan costs 2,713 2,517 Total $ 279,269 $ 318,240

Stockholders' Equity and Equi_2

Stockholders' Equity and Equity Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Summary of all stock award activity	A summary of the stock award activity is as follows: Nine Months Ended Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2017 1,428,878 $ 21.53 Restricted stock units awarded 279,459 24.14 Performance stock units awarded 219,943 23.25 Restricted stock units distributed (301,041 ) 17.37 Performance stock units distributed (296,909 ) 21.55 Restricted stock units forfeited (78,171 ) 21.52 Performance stock units forfeited (61,952 ) 26.42 Outstanding at September 30, 2018 1,190,207 $ 23.26
Summary of all deferred stock unit activity	A summary of deferred stock unit activity is as follows: Nine Months Ended Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2017 269,977 $ 20.14 Awarded 43,729 23.67 Distributed (26,396 ) 19.32 Outstanding at September 30, 2018 287,310 $ 20.76
Financial data for stock option exercises	Financial data for stock option exercises are summarized as follows (in thousands): Nine Months Ended 2018 2017 Aggregate intrinsic value of outstanding stock options $ 384 $ 478 Aggregate intrinsic value of exercisable stock options 384 478

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Financial information by segment	Financial information by segment was as follows (in thousands): Quarters Ended Nine Months Ended 2018 2017 2018 2017 Revenues: Infrastructure Solutions $ 155,681 $ 174,161 $ 450,840 $ 451,340 Corrosion Protection 105,624 102,276 300,118 353,381 Energy Services 78,374 65,435 248,612 216,799 Total revenues $ 339,679 $ 341,872 $ 999,570 $ 1,021,520 Gross profit: Infrastructure Solutions $ 38,135 $ 41,189 $ 100,793 $ 106,803 Corrosion Protection 26,411 23,063 74,524 86,663 Energy Services 8,127 9,190 29,913 27,156 Total gross profit $ 72,673 $ 73,442 $ 205,230 $ 220,622 Operating income (loss): Infrastructure Solutions (1) $ 10,398 $ (74,025 ) $ 19,563 $ (60,224 ) Corrosion Protection (2) 2,463 (2,703 ) 6,184 15,803 Energy Services 148 1,457 4,902 4,857 Total operating income (loss) 13,009 (75,271 ) 30,649 (39,564 ) Other income (expense): Interest expense (3,870 ) (3,962 ) (13,236 ) (12,014 ) Interest income 130 33 239 117 Other (3) (9,281 ) (798 ) (10,049 ) (1,593 ) Total other expense (13,021 ) (4,727 ) (23,046 ) (13,490 ) Income (loss) before taxes on income $ (12 ) $ (79,998 ) $ 7,603 $ (53,054 ) _______________________ (1) Operating income in the third quarter of 2018 includes $6.0 million of 2017 Restructuring charges (see Note 4) and $0.2 million of costs primarily related to the planned divestitures of Australia and Denmark. Operating loss in the third quarter of 2017 includes: (i) $4.5 million of 2017 Restructuring charges (see Note 3); (ii) $45.4 million of goodwill impairment charges (see Note 2); (iii) $41.0 million of definite-lived intangible asset impairment charges (see Note 2); and (iv) $0.1 million of costs incurred primarily related to the acquisition of Environmental Techniques. Operating income in the first nine months of 2018 includes $12.1 million of 2017 Restructuring charges (see Note 4) and $0.5 million of costs primarily related to the planned divestitures of Australia and Denmark. Operating loss in the nine months ended September 30, 2017 includes: (i) $4.7 million of 2017 Restructuring charges (see Note 3); (ii) $45.4 million of goodwill impairment charges (see Note 2); (iii) $41.0 million of definite-lived intangible asset impairment charges (see Note 2); and (iv) $0.7 million of costs incurred primarily related to the acquisition of Environmental Techniques. (2) Operating income in the third quarter of 2018 includes $1.2 million of 2017 Restructuring charges (see Note 4) and $4.6 million of costs incurred primarily related to the divestiture of Bayou. Operating loss in the third quarter of 2017 includes $2.2 million of 2017 Restructuring charges (see Note 3) and $1.9 million of costs incurred primarily related to the planned divestiture of Bayou. Operating income in the first nine months of 2018 includes $3.2 million of 2017 Restructuring charges (see Note 4) and $5.5 million of costs incurred primarily related to the acquisition of Hebna and the divestiture of Bayou.
Summary of revenues, gross profit, and operating income by geographic region	The following table summarizes revenues, gross profit and operating income (loss) by geographic region (in thousands): Quarters Ended Nine Months Ended 2018 2017 2018 2017 Revenues (1) : United States $ 262,298 $ 250,815 $ 779,206 $ 787,046 Canada 35,920 41,939 95,185 98,053 Europe 16,281 17,367 48,135 51,656 Other foreign 25,180 31,751 77,044 84,765 Total revenues $ 339,679 $ 341,872 $ 999,570 $ 1,021,520 Gross profit: United States $ 57,043 $ 56,295 $ 165,203 $ 179,029 Canada 7,265 9,099 17,494 19,703 Europe 2,931 2,989 5,467 9,414 Other foreign 5,434 5,059 17,066 12,476 Total gross profit $ 72,673 $ 73,442 $ 205,230 $ 220,622 Operating income (loss): United States $ 12,604 $ (57,799 ) $ 32,983 $ (25,752 ) Canada 4,055 1,148 7,170 5,086 Europe (4,423 ) (2,860 ) (10,473 ) (2,672 ) Other foreign 773 (15,760 ) 969 (16,226 ) Total operating income (loss) $ 13,009 $ (75,271 ) $ 30,649 $ (39,564 ) __________________________ (1) Revenues are attributed to the country of origin for the Company’s legal entities. For a significant majority of its legal entities, the country of origin relates to the country or geographic area that it services.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of derivative positions	The following table summarizes the Company’s derivative positions at September 30, 2018 : Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate USD/British Pound Sell £ 1,962,900 0.3 1.31 EURO/British Pound Sell £ 2,568,300 0.3 1.12 Interest Rate Swap $ 216,562,500 4.3
Summary of fair value amounts of derivative instruments	The following table provides a summary of the fair value amounts of our derivative instruments, all of which are Level 2 inputs as defined below (in thousands): Designation of Derivatives Balance Sheet Location September 30, December 31, Derivatives Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ 176 Interest Rate Swaps Other non-current assets 5,584 3,193 Total Assets $ 5,584 $ 3,369 Forward Currency Contracts Accrued expenses $ — $ 33 Total Liabilities $ — $ 33 Derivatives Not Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ 10 Total Assets $ — $ 10 Forward Currency Contracts Accrued expenses $ 61 $ — Total Liabilities $ 61 $ — Total Derivative Assets $ 5,584 $ 3,379 Total Derivative Liabilities 61 33 Total Net Derivative Asset (Liability) $ 5,523 $ 3,346

General - Additional Informatio

General - Additional Information (Details) - USD ($) $ in Millions	Aug. 31, 2018	Jul. 20, 2018	May 04, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2016	Dec. 31, 2014
General [Line Items]
Increase in foreign currency adjustment, error adjustment				$ 0.6			$ 1.4
Decrease in equity-based compensation expense, error adjustment							$ 1.1
Hebna
General [Line Items]
Total consideration recorded			$ 6	$ 3	$ 3
Energy Services
General [Line Items]
Total consideration recorded		$ 3
Aegion South Africa Proprietary Limited
General [Line Items]
Ownership percentage by noncontrolling owners						40.00%
OMAN | Co-venturer
General [Line Items]
Purchase price paid, percentage			50.00%
Aegion International | Aegion South Africa Proprietary Limited
General [Line Items]
Ownership percentage by parent						60.00%
Aegion International | OMAN | Co-venturer
General [Line Items]
Ownership percentage by parent				51.00%			51.00%
Restatement Adjustment
General [Line Items]
Intercompany accounts and stock compensation, error, net									$ 9
Decrease in retained earnings, error adjustment								$ 9
Increase in additional paid-in capital, error adjustment								1.1
Increase in accumulated other comprehensive income loss, error adjustment								$ 7.9
Increase in operating expense, error adjustment						$ 0.3	$ 0.3
Bayou
General [Line Items]
Ownership percentage by parent	51.00%
Proceeds from divestiture of businesses	$ 46			$ 35
Consideration received, cash	38
Consideration received, performance based, additional earn-out payments	4
Gain (loss) on disposition of business, non-cash				$ 8.7
Loans Payable | Bayou
General [Line Items]
Consideration received, loans receivable	$ 8
Debt instrument, term	2 years

Accounting Policies - Foreign C

Accounting Policies - Foreign Currency (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Accounting Policies [Abstract]
Currency translation adjustments	$ (38,017)		$ (38,017)		$ (26,614)
Derivative hedging activity	5,584		5,584		3,336
Pension activity	(235)		(235)		(244)
Total accumulated other comprehensive loss	(32,668)		(32,668)		$ (23,522)
Loss on foreign currency transactions	$ 400	$ 800	$ 1,231	$ 1,659

Accounting Policies - Taxation

Accounting Policies - Taxation (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Income tax expense			$ 5.1
Valuation allowance			5.1
Provisional income tax expense (benefit)			2.4
Transition tax for accumulated foreign earnings, provisional income tax expense			10.4
Change in tax rate			7.1
Other provisional income tax expense (benefit)			$ 0.9
Change in tax rate, adjustment	$ (1.5)	$ (1.5)

Accounting Policies - Earnings

Accounting Policies - Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of common shares used for basic EPS (in shares)	32,312,000	32,905,142	32,390,777	33,363,472
Effect of dilutive stock options and restricted and deferred stock unit awards (in shares)	0	0	667,229	0
Weighted average number of common shares and dilutive potential common stock used for dilutive EPS (in shares)	32,312,000	32,905,142	33,058,006	33,363,472
Antidilutive securities excluded from calculation of earnings per share (in shares)	664,661	737,423	702,544
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share (in shares)		77,807	77,807

Accounting Policies - Cash, Cas

Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 67,410	$ 105,717
Restricted cash	1,835	1,839
Cash, cash equivalents and restricted cash	69,245	107,556
Held for sale, cash and cash equivalents	$ 0	$ 1,000	$ 8,909

Accounting Policies - Additiona

Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Accounting Policies [Abstract]
Net foreign exchange transaction gains (loss)	$ (400)	$ (800)	$ (1,231)	$ (1,659)
Finite-Lived Intangible Assets [Line Items]
Definite-lived intangible asset impairment	870	41,032	870	41,032
Goodwill impairment	1,389	$ 45,390	1,389	$ 45,390
Goodwill	$ 261,757		$ 261,757		$ 260,715
Fyfe
Finite-Lived Intangible Assets [Line Items]
Percentage of fair value in excess of carrying value		45.00%		45.00%
Goodwill impairment		$ 45,400
Goodwill					$ 9,600
Fyfe | Trademarks
Finite-Lived Intangible Assets [Line Items]
Definite-lived intangible asset impairment		3,400
Fyfe | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Definite-lived intangible asset impairment		20,800
Fyfe | Patents
Finite-Lived Intangible Assets [Line Items]
Definite-lived intangible asset impairment		$ 16,800

Accounting Policies - VIE Balan

Accounting Policies - VIE Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Current assets (VIE)	$ 39,022	$ 42,732
Non-current assets (VIE)	5,098	26,346
Current liabilities (VIE)	14,514	12,449
Non-current liabilities (VIE)	$ 11,341	30,675
Bayou Perma-Pipe Canada, Ltd | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Variable Interest Entity [Line Items]
Disposal group, assets		25,400
Disposal group, liabilities		$ 9,800

Accounting Policies - VIE Incom

Accounting Policies - VIE Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Revenue	$ 16,405	$ 11,457	$ 39,179	$ 72,916
Gross profit	3,238	1,984	6,982	11,704
Net income (loss) attributable to Aegion Corporation	$ (946)	$ 1,121	$ (886)	$ 3,071

Revenues - Additional Informati

Revenues - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Cumulative effect of new accounting principle in period of adoption						$ 268
Contract with customer, liability, current	$ 35,297		$ 35,297			51,597	$ 62,700
Difference Between Work Performed On Open Contracts And Contractual Billing Terms
Disaggregation of Revenue [Line Items]
Changes in contract assets (liabilities)			(13,000)
Difference Related To Customer Advances On Certain Contract
Disaggregation of Revenue [Line Items]
Changes in contract assets (liabilities)			$ 16,300
Products and Services
Disaggregation of Revenue [Line Items]
Revenue recognized, percent	92.60%	93.30%	93.60%	93.30%
Product
Disaggregation of Revenue [Line Items]
Revenue recognized, percent	7.40%	6.70%	6.40%	6.70%
Retained Earnings
Disaggregation of Revenue [Line Items]
Cumulative effect of new accounting principle in period of adoption						$ 268
Accounting Standards Update 2014-09 | Retained Earnings
Disaggregation of Revenue [Line Items]
Cumulative effect of new accounting principle in period of adoption					$ 300
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Changes in revenues			$ 1,900

Revenues - Performance Obligati

Revenues - Performance Obligation (Details) $ in Millions	Sep. 30, 2018USD ($)
Revenue, remaining performance obligation	$ 670.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, remaining performance obligation	$ 654.7
Revenue, remaining performance obligation, percent	97.60%
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months

Revenues - Disaggreation of Rev

Revenues - Disaggreation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 339,679	$ 341,872	$ 999,570	$ 1,021,520
Fixed fee
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	212,602	241,010	641,004	700,638
Time and materials
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	101,917	78,075	294,979	252,908
Product sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	22,756	22,656	61,150	67,530
License fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,404	131	2,437	444
United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	262,298	250,815	779,206	787,046
Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	35,920	41,939	95,185	98,053
Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	16,281	17,367	48,135	51,656
Other foreign
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	25,180	31,751	77,044	84,765
Infrastructure Solutions
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	155,681	174,161	450,840	451,340
Infrastructure Solutions | Fixed fee
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	141,598	163,043	416,392	419,991
Infrastructure Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Infrastructure Solutions | Product sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11,679	10,987	32,011	30,905
Infrastructure Solutions | License fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,404	131	2,437	444
Infrastructure Solutions | United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	111,902	128,356	323,327	328,627
Infrastructure Solutions | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	16,153	17,936	44,028	42,170
Infrastructure Solutions | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13,460	13,900	39,600	41,196
Infrastructure Solutions | Other foreign
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	14,166	13,969	43,885	39,347
Corrosion Protection
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	105,624	102,276	300,118	353,381
Corrosion Protection | Fixed fee
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	68,935	76,419	210,819	276,431
Corrosion Protection | Time and materials
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	25,612	14,188	60,160	40,325
Corrosion Protection | Product sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11,077	11,669	29,139	36,625
Corrosion Protection | License fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Corrosion Protection | United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	72,022	57,024	207,267	241,620
Corrosion Protection | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	19,767	24,003	51,157	55,883
Corrosion Protection | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,821	3,467	8,535	10,460
Corrosion Protection | Other foreign
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11,014	17,782	33,159	45,418
Energy Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	78,374	65,435	248,612	216,799
Energy Services | Fixed fee
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,069	1,548	13,793	4,216
Energy Services | Time and materials
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	76,305	63,887	234,819	212,583
Energy Services | Product sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Energy Services | License fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Energy Services | United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	78,374	65,435	248,612	216,799
Energy Services | Canada
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Energy Services | Europe
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Energy Services | Other foreign
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 0	$ 0	$ 0

Revenues - Contract Assets (Lia

Revenues - Contract Assets (Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from Contract with Customer [Abstract]
Contract assets – current	$ 88,348	$ 75,371
Contract liabilities – current	(35,297)	(51,597)	$ (62,700)
Net contract assets	53,051	23,774
Contract assets, held-for-sale	2,200	1,300
Contract liabilities, held-for-sale	$ 100	$ 5,500

Restructuring - Additional Info

Restructuring - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended		14 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)employee	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)
Restructuring Cost and Reserve [Line Items]
Goodwill and long-lived asset impairment	$ 870	$ 41,032	$ 870	$ 41,032
Expected restructuring cash charges	130,000		130,000		$ 130,000
Restructuring and related charges	1,219	5,439	4,548	5,439
Restructuring 2,017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, pre tax			15,600		125,700
Restructuring charges, net of tax			14,000		115,600
Payments for restructuring			9,424	2,453	21,100
Restructuring reserve, settled without cash			$ 8,150	77	104,600
Goodwill and long-lived asset impairment					$ 86,400
Headcount reduction | employee			320
Restructuring and related charges	$ 7,423	$ 6,737	$ 15,580	$ 6,737

Restructuring - Pre Tax Restruc

Restructuring - Pre Tax Restructuring Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,219	$ 5,439	$ 4,548	$ 5,439
Restructuring 2,017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	7,423	6,737	15,580	6,737
Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	949	5,070	3,217	5,070
Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	215	340	1,202	340
Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	55	29	129	29
Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6,204	1,298	11,032	1,298
Infrastructure Solutions | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6,269	4,573	12,356	4,573
Infrastructure Solutions | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	914	3,140	2,780	3,140
Infrastructure Solutions | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	215	250	1,052	250
Infrastructure Solutions | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	55	0	129	0
Infrastructure Solutions | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	5,085	1,183	8,395	1,183
Corrosion Protection | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,154	2,164	3,224	2,164
Corrosion Protection | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	35	1,930	437	1,930
Corrosion Protection | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	90	150	90
Corrosion Protection | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	29	0	29
Corrosion Protection | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,119	115	2,637	115
Corporate, Non-Segment | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 300	$ 800	$ 900	$ 800

Restructuring - Recognized Cost

Restructuring - Recognized Cost Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		14 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Goodwill impairment	$ 1,389	$ 45,390	$ 1,389	$ 45,390
Definite-lived intangible asset impairment	870	41,032	870	41,032
Restructuring 2,017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	7,423	6,737	15,580	6,737
Definite-lived intangible asset impairment					$ 86,400
Restructuring charges, cash	2,300	6,600	7,400	6,600
Restructuring charges, non-cash	5,100	100	8,200	100
Restructuring 2017 | Cost of Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	705	45	705	45
Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	3,018	1,253	7,846	1,253
Goodwill impairment	1,389	0	1,389	0
Definite-lived intangible asset impairment	870	0	870	0
Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,219	5,439	4,548	5,439
Restructuring 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	222	0	222	0
Infrastructure Solutions
Restructuring Cost and Reserve [Line Items]
Goodwill impairment		45,400	1,389	45,400
Definite-lived intangible asset impairment		41,000		41,000
Infrastructure Solutions | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	6,269	4,573	12,356	4,573
Infrastructure Solutions | Restructuring 2017 | Cost of Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	138	30	138	30
Infrastructure Solutions | Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2,466	1,153	5,776	1,153
Goodwill impairment	1,389	0	1,389	0
Definite-lived intangible asset impairment	870	0	870	0
Infrastructure Solutions | Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,184	3,390	3,961	3,390
Infrastructure Solutions | Restructuring 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	222	0	222	0
Corrosion Protection
Restructuring Cost and Reserve [Line Items]
Goodwill impairment			0
Corrosion Protection | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,154	2,164	3,224	2,164
Corrosion Protection | Restructuring 2017 | Cost of Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	567	15	567	15
Corrosion Protection | Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	552	100	2,070	100
Goodwill impairment	0	0	0	0
Definite-lived intangible asset impairment	0	0	0	0
Corrosion Protection | Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	35	2,049	587	2,049
Corrosion Protection | Restructuring 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 0	$ 0	$ 0	$ 0

Restructuring - Restructuring A

Restructuring - Restructuring Activities (Details) - Restructuring 2017 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		14 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Restructuring reserve, start			$ 5,189
Restructuring and related cost, incurred cost	$ 7,423	$ 6,737	15,580	$ 6,737
Restructuring reserve, foreign currency translation gain (loss)			(34)
Payments for restructuring			9,424	2,453	$ 21,100
Restructuring reserve, settled without cash			8,150	77	104,600
Restructuring reserve, end	3,161	4,207	3,161	4,207	3,161
Severance and benefit related costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start			3,864
Restructuring and related cost, incurred cost			3,217	5,070
Restructuring reserve, foreign currency translation gain (loss)			(30)
Payments for restructuring			4,754	1,639
Restructuring reserve, settled without cash			0	0
Restructuring reserve, end	2,297	3,431	2,297	3,431	2,297
Lease and contract termination costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start			650
Restructuring and related cost, incurred cost			1,202	340
Restructuring reserve, foreign currency translation gain (loss)			(4)
Payments for restructuring			1,337	264
Restructuring reserve, settled without cash			0	0
Restructuring reserve, end	511	76	511	76	511
Relocation and other moving costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start			0
Restructuring and related cost, incurred cost			129	29
Restructuring reserve, foreign currency translation gain (loss)			0
Payments for restructuring			129	29
Restructuring reserve, settled without cash			0	0
Restructuring reserve, end	0	0	0	0	0
Other restructuring costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start			675
Restructuring and related cost, incurred cost			11,032	1,298
Restructuring reserve, foreign currency translation gain (loss)			0
Payments for restructuring			3,204	521
Restructuring reserve, settled without cash			8,150	77
Restructuring reserve, end	$ 353	$ 700	$ 353	$ 700	$ 353

Assets and Liabilities Held f_3

Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Assets held for sale:
Cash and cash equivalents	$ 0	$ 1,000	$ 8,909
Total current assets	10,173	70,314
Liabilities held for sale:
Total current liabilities	6,423	20,900
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents	0
Receivables, net	2,003
Retainage	16
Contract assets	2,185
Inventories	1,804
Prepaid expenses and other current assets	250
Total current assets	6,258
Property, plant & equipment, less accumulated depreciation	3,915
Identified intangible assets, less accumulated amortization	0
Total assets held for sale	10,173
Liabilities held for sale:
Accounts payable	985
Accrued expenses	5,399
Contract liabilities	39
Total current liabilities	6,423
Long-term debt	0
Other non-current liabilities	0
Total liabilities held for sale	6,423
Bayou | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents		989
Receivables, net		6,368
Retainage		0
Contract assets		1,299
Inventories		3,727
Prepaid expenses and other current assets		827
Total current assets		13,210
Property, plant & equipment, less accumulated depreciation		53,887
Identified intangible assets, less accumulated amortization		3,217
Total assets held for sale		70,314
Liabilities held for sale:
Accounts payable		5,763
Accrued expenses		1,805
Contract liabilities		5,478
Total current liabilities		13,046
Long-term debt		7,757
Other non-current liabilities		97
Total liabilities held for sale		$ 20,900
Australia | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents	0
Receivables, net	2,003
Retainage	16
Contract assets	2,185
Inventories	1,769
Prepaid expenses and other current assets	250
Total current assets	6,223
Property, plant & equipment, less accumulated depreciation	2,315
Identified intangible assets, less accumulated amortization	0
Total assets held for sale	8,538
Liabilities held for sale:
Accounts payable	985
Accrued expenses	5,399
Contract liabilities	39
Total current liabilities	6,423
Long-term debt	0
Other non-current liabilities	0
Total liabilities held for sale	6,423
Denmark | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents	0
Receivables, net	0
Retainage	0
Contract assets	0
Inventories	35
Prepaid expenses and other current assets	0
Total current assets	35
Property, plant & equipment, less accumulated depreciation	1,600
Identified intangible assets, less accumulated amortization	0
Total assets held for sale	1,635
Liabilities held for sale:
Accounts payable	0
Accrued expenses	0
Contract liabilities	0
Total current liabilities	0
Long-term debt	0
Other non-current liabilities	0
Total liabilities held for sale	$ 0

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, gross	$ 403,532			$ 403,532		$ 401,101
Accumulated impairment losses	(141,775)			(141,775)		(140,386)
Goodwill, beginning balance				260,715
Acquisitions				3,973
Goodwill impairment	1,389		$ 45,390	1,389	$ 45,390
Foreign currency translation				(1,542)
Goodwill, ending balance	261,757			261,757
Infrastructure Solutions
Goodwill [Roll Forward]
Goodwill, gross	245,123			245,123		246,486
Accumulated impairment losses	(62,848)			(62,848)		(61,459)
Goodwill, beginning balance				185,027
Acquisitions				0
Goodwill impairment			$ 45,400	1,389	$ 45,400
Foreign currency translation				(1,363)
Goodwill, ending balance	182,275			182,275
Corrosion Protection
Goodwill [Roll Forward]
Goodwill, gross	76,905			76,905		74,369
Accumulated impairment losses	(45,400)			(45,400)		(45,400)
Goodwill, beginning balance				28,969
Acquisitions				2,715
Goodwill impairment				0
Foreign currency translation				(179)
Goodwill, ending balance	31,505			31,505
Energy Services
Goodwill [Roll Forward]
Goodwill, gross	81,504			81,504		80,246
Accumulated impairment losses	(33,527)			(33,527)		$ (33,527)
Goodwill, beginning balance				46,719
Goodwill impairment				0
Foreign currency translation				0
Goodwill, ending balance	47,977			$ 47,977
Hebna | Corrosion Protection
Goodwill [Roll Forward]
Acquisitions		$ 2,700
Energy Services
Goodwill [Roll Forward]
Acquisitions	1,258
Denmark | Infrastructure Solutions
Goodwill [Roll Forward]
Goodwill impairment	$ 1,400

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 223,426			$ 223,426		$ 221,662
Accumulated Amortization	(98,977)			(98,977)		(89,317)
Net Carrying Amount	124,449			124,449		132,345
Goodwill and long-lived asset impairment	870		$ 41,032	$ 870	$ 41,032
License agreements (3)
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				1 year 9 months 25 days
Gross Carrying Amount	3,899			$ 3,899		4,497
Accumulated Amortization	(3,686)			(3,686)		(3,623)
Net Carrying Amount	213			$ 213		874
Leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				2 years 3 months
Gross Carrying Amount	796			$ 796		796
Accumulated Amortization	(599)			(599)		(534)
Net Carrying Amount	197			$ 197		262
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				9 years 7 months 5 days
Gross Carrying Amount	15,739			$ 15,739		15,464
Accumulated Amortization	(7,132)			(7,132)		(6,184)
Net Carrying Amount	8,607			$ 8,607		9,280
Non-competes
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				4 years 9 months 10 days
Gross Carrying Amount	2,548			$ 2,548		1,197
Accumulated Amortization	(1,107)			(1,107)		(1,048)
Net Carrying Amount	1,441			$ 1,441		149
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				9 years 1 month 30 days
Gross Carrying Amount	161,745			$ 161,745		160,423
Accumulated Amortization	(64,876)			(64,876)		(56,907)
Net Carrying Amount	96,869			$ 96,869		103,516
Patents and acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)				6 years 1 month 10 days
Gross Carrying Amount	38,699			$ 38,699		39,285
Accumulated Amortization	(21,577)			(21,577)		(21,021)
Net Carrying Amount	17,122			17,122		$ 18,264
Hebna | Non-competes
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 1,100
Hebna | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 1,300
Energy Services | Trademarks
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	300
Energy Services | Non-competes
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	200
Energy Services | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 700
Denmark | License agreements (3)
Finite-Lived Intangible Assets [Line Items]
Goodwill and long-lived asset impairment				500
Denmark | Trademarks
Finite-Lived Intangible Assets [Line Items]
Goodwill and long-lived asset impairment				100
Denmark | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Goodwill and long-lived asset impairment				$ 300

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 3.5	$ 3.8	$ 10.4	$ 12.5

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Future Amortization Expense (Details) $ in Thousands	Sep. 30, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 13,848
2,019	13,738
2,020	13,691
2,021	13,485
2,022	$ 13,287

Long-Term Debt and Credit Fac_3

Long-Term Debt and Credit Facility - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Subtotal	$ 308,530	$ 347,312
Less – Current maturities of long-term debt	26,548	26,555
Less – Unamortized loan costs	2,713	2,517
Total	279,269	318,240
Term Note
Debt Instrument [Line Items]
Term note, due February 27, 2023, annualized rates of 4.53% and 3.60%, respectively	$ 288,750	$ 308,437
Current effective interest rate	4.53%	3.60%
Line of Credit
Debt Instrument [Line Items]
Line of credit, 4.39% and 3.50%, respectively	$ 19,000	$ 38,000
Current effective interest rate	4.39%	3.50%
Other notes
Debt Instrument [Line Items]
Other notes with interest rates from 3.3% to 7.8%	$ 780	$ 875
Other notes | Minimum
Debt Instrument [Line Items]
Current annualized interest rate	3.30%	3.30%
Other notes | Maximum
Debt Instrument [Line Items]
Current annualized interest rate	7.80%	7.80%

Long-Term Debt and Credit Fac_4

Long-Term Debt and Credit Facility - Additional Information (Details)	Aug. 31, 2018USD ($)	Feb. 27, 2018	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Mar. 12, 2018USD ($)	Dec. 31, 2017USD ($)	Oct. 31, 2017USD ($)	Oct. 31, 2015USD ($)
Debt Instrument [Line Items]
Fees				$ 2,500,000
Up front lending fees				900,000
Third party arrangement fees				1,600,000
Third-party notes and bank debt held			$ 800,000	800,000		$ 900,000
Repayments of lines of credit				(19,000,000)
Debt designated as third-party debt						7,800,000
Long-term debt, fair value			305,600,000	305,600,000		356,000,000
2015 Interest Rate Swap
Debt Instrument [Line Items]
Interest rate at period end								3.74%
Notional amount								$ 262,500,000
Fixed interest rate								1.46%
2018 Interest Rate Swap
Debt Instrument [Line Items]
Notional amount					$ 170,600,000
Portion of amortization of term loan					$ 170,600,000
Fixed interest rate					2.937%
Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			308,400,000	308,400,000
2015 Credit Facility
Debt Instrument [Line Items]
Senior secured credit facility								$ 650,000,000
Maximum borrowing capacity							$ 350,000,000
Secured debt outstanding			288,800,000	288,800,000		308,400,000
Proceeds from line of credit, net				19,000,000
Letters of credit issued and outstanding			$ 29,300,000	$ 29,300,000
Line of credit						$ 38,000,000
Portion of amortization of term loan								$ 262,500,000
Initial maximum financial leverage ratio			3.5	3.5
Actual financial leverage ratio			2.88	2.88
Remaining borrowing capacity			$ 68,800,000	$ 68,800,000
Minimum permitted fixed charge coverage ratio			1.15	1.15
Actual fixed charge coverage ratio			1.45	1.45
2015 Credit Facility | Insurance Carriers Collateral
Debt Instrument [Line Items]
Letters of credit issued and outstanding			$ 13,700,000	$ 13,700,000
2015 Credit Facility | Work Performance Obligations
Debt Instrument [Line Items]
Letters of credit issued and outstanding			$ 15,600,000	$ 15,600,000
2015 Credit Facility | LIBOR | 2015 Interest Rate Swap
Debt Instrument [Line Items]
Interest rate at period end			4.39%	4.39%
2015 Credit Facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				1.25%
2015 Credit Facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate				2.25%
2015 Credit Facility | Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Term				5 years
2015 Credit Facility | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 300,000,000	$ 300,000,000
Term of revolving line of credit		5 years
Maximum borrowing capacity, post sale			$ 275,000,000	275,000,000
Unamortized loan costs				2,400,000
Interest expense, debt				200,000
Proceeds from line of credit, net				$ 16,000,000
Line of Credit
Debt Instrument [Line Items]
Interest rate at period end			4.39%	4.39%		3.50%
Line of credit			$ 19,000,000	$ 19,000,000		$ 38,000,000
2018 Credit Facility
Debt Instrument [Line Items]
Notional amount					$ 170,600,000
Bayou
Debt Instrument [Line Items]
Proceeds from divestiture of businesses	$ 46,000,000		$ 35,000,000
Repayment from proceeds from divestiture of businesses				$ (35,000,000)

Stockholders' Equity and Equi_3

Stockholders' Equity and Equity Compensation - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Apr. 30, 2018	Oct. 31, 2017
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share repurchase program, authorized amount	$ 30,000,000		$ 30,000,000			$ 40,000,000
Options forfeited (in shares)			73,897
Options forfeited (in dollars per share)			$ 26.60
Options outstanding (in shares)	52,783		52,783
Weighted average exercise price (in dollars per share)	$ 18.11		$ 18.11
Closing stock price (in dollars per share)	$ 25.38	$ 23.28	$ 25.38	$ 23.28
Stock options awarded during period (in shares)			0	0
Stock Awards
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share based compensation expense	$ 1,100,000	$ 2,200,000	$ 5,200,000	$ 7,000,000
Unrecognized share based compensation expense	12,400,000		$ 12,400,000
Weighted average recognition period			1 year 10 months 28 days
Deferred Stock Units
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share based compensation expense	100,000	$ 500,000	$ 1,000,000	1,100,000
Stock Options
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share based compensation expense			0	$ 0
Unrecognized pre-tax expense related to stock option grants	$ 0		$ 0
Stock Options | Minimum
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Award vesting period			7 years
Stock Options | Maximum
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Award vesting period			10 years
2016 Employee Plan
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Stock repurchase program, number of shares authorized to be repurchased (in shares)					1,700,000
Number of shares available for issuance (in shares)	2,667,104		2,667,104
2016 Director Plan
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Number of shares available for issuance (in shares)	73,532		73,532
Equity Compensation Programs
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share repurchase program, authorized amount	$ 10,000,000		$ 10,000,000
Stock repurchased during period (in shares)			224,700	106,164
Stock repurchased during period, value			$ 5,400,000	$ 2,400,000
Shares repurchased, average price per share (in dollars per share)			$ 24.15	$ 22.25
Open Market Repurchase Program
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Stock repurchased during period (in shares)			548,198	1,346,132
Stock repurchased during period, value			$ 13,200,000	$ 29,400,000
Shares repurchased, average price per share (in dollars per share)			$ 24.07	$ 21.81

Stockholders' Equity and Equi_4

Stockholders' Equity and Equity Compensation - Summary of Stock Award Activity (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Stock Awards
Outstanding, beginning balance (in shares) | shares	1,428,878
Outstanding, ending balance (in shares) | shares	1,190,207
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 21.53
Outstanding, ending balance (in dollars per share) | $ / shares	$ 23.26
Restricted Stock Units
Stock Awards
Awarded (in shares) | shares	279,459
Distributed (in shares) | shares	(301,041)
Forfeited (in shares) | shares	(78,171)
Weighted Average Award Date Fair Value
Awarded (in dollars per share) | $ / shares	$ 24.14
Distributed (in dollars per share) | $ / shares	17.37
Forfeited (in dollars per share) | $ / shares	$ 21.52
Performance Units
Stock Awards
Awarded (in shares) | shares	219,943
Distributed (in shares) | shares	(296,909)
Forfeited (in shares) | shares	(61,952)
Weighted Average Award Date Fair Value
Awarded (in dollars per share) | $ / shares	$ 23.25
Distributed (in dollars per share) | $ / shares	21.55
Forfeited (in dollars per share) | $ / shares	$ 26.42

Stockholders' Equity and Equi_5

Stockholders' Equity and Equity Compensation - Summary of Deferred Stock Unit Activity (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	1,428,878
Outstanding, ending balance (in shares) | shares	1,190,207
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 21.53
Outstanding, ending balance (in dollars per share) | $ / shares	$ 23.26
Deferred Stock Units
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	269,977
Awarded (in shares) | shares	43,729
Distributed (in shares) | shares	(26,396)
Outstanding, ending balance (in shares) | shares	287,310
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 20.14
Awarded (in dollars per share) | $ / shares	23.67
Distributed (in dollars per share) | $ / shares	19.32
Outstanding, ending balance (in dollars per share) | $ / shares	$ 20.76

Stockholders' Equity and Equi_6

Stockholders' Equity and Equity Compensation - Financial Data for Stock Option Exercises (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Equity [Abstract]
Aggregate intrinsic value of outstanding stock options	$ 384	$ 478
Aggregate intrinsic value of exercisable stock options	$ 384	$ 478

Taxes on Income (Details)

Taxes on Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Effective income tax rate	1275.00%	7.40%	22.90%	(2.20%)
Change in tax rate, adjustment	$ (1.5)		$ (1.5)
Employee share-based payments, amount			$ 1.5
Employee share-based payments, percentage			39.30%
Operating loss carryforwards, valuation allowance	$ 14.9		$ 14.9

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	9 Months Ended
	Sep. 30, 2018segment
Segment Reporting [Abstract]
Number of operating segments	3
Number of reportable segments	3

Segment Reporting - Financial I

Segment Reporting - Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenues	$ 339,679	$ 341,872	$ 999,570	$ 1,021,520
Gross profit	72,673	73,442	205,230	220,622
Operating income (loss)	13,009	(75,271)	30,649	(39,564)
Interest expense	(3,870)	(3,962)	(13,236)	(12,014)
Interest income	130	33	239	117
Other	(9,281)	(798)	(10,049)	(1,593)
Total other expense	(13,021)	(4,727)	(23,046)	(13,490)
Income (loss) before taxes on income	(12)	(79,998)	7,603	(53,054)
Restructuring and related charges	1,219	5,439	4,548	5,439
Goodwill impairment	1,389	45,390	1,389	45,390
Definite-lived intangible asset impairment	870	41,032	870	41,032
Restructuring 2,017
Segment Reporting Information [Line Items]
Restructuring and related charges	200		200
Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues	155,681	174,161	450,840	451,340
Gross profit	38,135	41,189	100,793	106,803
Operating income (loss)	10,398	(74,025)	19,563	(60,224)
Goodwill impairment		45,400	1,389	45,400
Definite-lived intangible asset impairment		41,000		41,000
Infrastructure Solutions | Restructuring 2017
Segment Reporting Information [Line Items]
Restructuring and related charges	6,000	4,500	12,100	4,700
Corrosion Protection
Segment Reporting Information [Line Items]
Revenues	105,624	102,276	300,118	353,381
Gross profit	26,411	23,063	74,524	86,663
Operating income (loss)	2,463	(2,703)	6,184	15,803
Goodwill impairment			0
Corrosion Protection | Restructuring 2017
Segment Reporting Information [Line Items]
Restructuring and related charges	1,200	2,200	3,200	2,200
Energy Services
Segment Reporting Information [Line Items]
Revenues	78,374	65,435	248,612	216,799
Gross profit	8,127	9,190	29,913	27,156
Operating income (loss)	148	1,457	4,902	4,857
Goodwill impairment			0
Australia and Denmark | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges	200		500
Bayou
Segment Reporting Information [Line Items]
Gain (loss) on disposition of business	(8,700)		8,700
Bayou | Corrosion Protection
Segment Reporting Information [Line Items]
Restructuring costs	$ 4,600	1,900		1,900
Environmental Techniques | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges		$ 100		$ 700
Hebna | Bayou | Corrosion Protection
Segment Reporting Information [Line Items]
Restructuring and related charges			$ 5,500

Segment Reporting - Summary of

Segment Reporting - Summary of Revenues, Gross Profit and Operating Income (Loss) by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 339,679	$ 341,872	$ 999,570	$ 1,021,520
Gross profit	72,673	73,442	205,230	220,622
Operating income (loss)	13,009	(75,271)	30,649	(39,564)
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	262,298	250,815	779,206	787,046
Gross profit	57,043	56,295	165,203	179,029
Operating income (loss)	12,604	(57,799)	32,983	(25,752)
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	35,920	41,939	95,185	98,053
Gross profit	7,265	9,099	17,494	19,703
Operating income (loss)	4,055	1,148	7,170	5,086
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	16,281	17,367	48,135	51,656
Gross profit	2,931	2,989	5,467	9,414
Operating income (loss)	(4,423)	(2,860)	(10,473)	(2,672)
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	25,180	31,751	77,044	84,765
Gross profit	5,434	5,059	17,066	12,476
Operating income (loss)	$ 773	$ (15,760)	$ 969	$ (16,226)

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Mar. 12, 2018	Oct. 31, 2017	Oct. 31, 2015
Debt Instrument [Line Items]
Gain upon settlement of cash flow hedges, (less than $0.1 million)	$ (400,000)	$ (100,000)
2015 Credit Facility
Debt Instrument [Line Items]
Amount of hedged item					$ 262,500,000
Maximum borrowing capacity				$ 350,000,000
2018 Credit Facility
Debt Instrument [Line Items]
Notional amount			$ 170,600,000
2015 Interest Rate Swap
Debt Instrument [Line Items]
Notional amount					$ 262,500,000
Fixed interest rate					1.46%
2018 Interest Rate Swap
Debt Instrument [Line Items]
Notional amount			170,600,000
Amount of hedged item			$ 170,600,000
Fixed interest rate			2.937%
Recurring | Designated as Hedging Instrument
Debt Instrument [Line Items]
Net derivative asset	$ 5,600,000

Derivative Financial Instrume_4

Derivative Financial Instruments - Summary of Derivative Positions (Details) - 9 months ended Sep. 30, 2018	USD ($)€ / £$ / £	GBP (£)€ / £$ / £
USD/British Pound | Sell
Derivative [Line Items]
Notional Amount		£ 1,962,900
Weighted Average Remaining Maturity In Years	3 months 19 days
Average Exchange Rate | $ / £	1.31	1.31
EURO/British Pound | Sell
Derivative [Line Items]
Notional Amount		£ 2,568,300
Weighted Average Remaining Maturity In Years	3 months 19 days
Average Exchange Rate | € / £	1.12	1.12
Interest Rate Swaps
Derivative [Line Items]
Notional Amount | $	$ 216,562,500
Weighted Average Remaining Maturity In Years	4 years 3 months

Derivative Financial Instrume_5

Derivative Financial Instruments - Summary of the Fair Value Amounts of Derivative Instruments (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Significant Observable Inputs (Level 2)
Derivatives, Fair Value [Line Items]
Derivative assets	$ 5,584	$ 3,379
Derivative liabilities	61	33
Net derivative asset (liability)	5,523	3,346
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Net derivative asset (liability)	5,600
Designated as Hedging Instrument | Significant Observable Inputs (Level 2)
Derivatives, Fair Value [Line Items]
Derivative assets	5,584	3,369
Derivative liabilities	0	33
Designated as Hedging Instrument | Significant Observable Inputs (Level 2) | Forward Currency Contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0	176
Designated as Hedging Instrument | Significant Observable Inputs (Level 2) | Forward Currency Contracts | Accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	0	33
Designated as Hedging Instrument | Significant Observable Inputs (Level 2) | Interest Rate Swaps | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative assets	5,584	3,193
Not Designated as Hedging Instrument | Significant Observable Inputs (Level 2)
Derivatives, Fair Value [Line Items]
Derivative assets	0	10
Derivative liabilities	61	0
Not Designated as Hedging Instrument | Significant Observable Inputs (Level 2) | Forward Currency Contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0	10
Not Designated as Hedging Instrument | Significant Observable Inputs (Level 2) | Forward Currency Contracts | Accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 61	$ 0

Subsequent Events (Details)

Subsequent Events (Details) $ in Thousands, kr in Millions	Nov. 01, 2018USD ($)	Nov. 01, 2018DKK (kr)	Oct. 26, 2018USD ($)employee	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Subsequent Event [Line Items]
Restructuring charges				$ 1,219	$ 5,439	$ 4,548	$ 5,439
Restructuring 2,017
Subsequent Event [Line Items]
Restructuring charges				$ 7,423	$ 6,737	$ 15,580	$ 6,737
Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of productive assets	$ 1,600	kr 10.5
Tube-supply agreement, term (years)	5 years	5 years
Trade Name Entitlement Agreement, Term	5 years	5 years
Subsequent Event | Restructuring 2017
Subsequent Event [Line Items]
Restructuring charges			$ 25,000
Reduction of headcount | employee			150
Subsequent Event | Restructuring 2017 | Minimum
Subsequent Event [Line Items]
Restructuring charges			$ 8,000
Subsequent Event | Restructuring 2017 | Maximum
Subsequent Event [Line Items]
Restructuring charges			$ 10,000