Aegion 10-Q 3 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 26, 2019
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		31,342,530
Amendment Flag	false
Entity Central Index Key	0000353020
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenues	$ 276,904	$ 324,861
Cost of revenues	228,609	263,357
Gross profit	48,295	61,504
Operating expenses	47,870	56,142
Acquisition and divestiture expenses	113	392
Restructuring and related charges	1,086	1,789
Operating income (loss)	(774)	3,181
Other income (expense):
Interest expense	(3,590)	(5,443)
Interest income	285	47
Other	(674)	(262)
Total other expense	(3,979)	(5,658)
Loss before tax benefit	(4,753)	(2,477)
Tax benefit on loss	(762)	(1,001)
Net loss	(3,991)	(1,476)
Non-controlling interests income	(10)	(593)
Net loss attributable to Aegion Corporation	$ (4,001)	$ (2,069)
Loss per share attributable to Aegion Corporation:
Basic (in dollars per share)	$ (0.13)	$ (0.06)
Diluted (in dollars per share)	$ (0.13)	$ (0.06)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss		$ (3,991)	$ (1,476)
Other comprehensive income (loss):
Currency translation adjustments		1,862	2,228
Deferred gain (loss) on hedging activity, net of tax	[1]	(2,146)	494
Pension activity, net of tax	[2]	(21)	(7)
Total comprehensive income (loss)		(4,296)	1,239
Comprehensive (income) loss attributable to non-controlling interests		77	(646)
Comprehensive income (loss) attributable to Aegion Corporation		$ (4,219)	$ 593
[1]	Amounts presented net of tax of $(59) and $177 for the quarters ended March 31, 2019 and 2018, respectively.
[2]	Amounts presented net of tax of $(5) and $(2) for the quarters ended March 31, 2019 and 2018, respectively.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Deferred gain on hedging activity, tax	$ (59)	$ 177
Pension activity, tax (benefit) expense	$ (5)	$ (2)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 62,482	$ 83,527
Restricted cash	1,235	1,359
Receivables, net of allowances of $9,826 and $9,695, respectively	196,954	204,541
Retainage	31,056	33,572
Contract assets	59,422	62,467
Inventories	56,221	56,437
Prepaid expenses and other current assets	31,431	32,172
Assets held for sale	17,479	7,792
Total current assets	456,280	481,867
Property, plant & equipment, less accumulated depreciation	110,052	107,059
Other assets
Goodwill	260,760	260,633
Intangible assets, less accumulated amortization	116,260	119,696
Operating lease assets	69,042	0
Deferred income tax assets	1,797	1,561
Other assets	21,919	21,601
Total other assets	469,778	403,491
Total Assets	1,036,110	992,417
Current liabilities
Accounts payable	54,343	64,562
Accrued expenses	95,551	88,020
Contract liabilities	27,060	32,339
Current maturities of long-term debt	30,625	29,469
Liabilities held for sale	10,762	5,260
Total current liabilities	218,341	219,650
Long-term debt, less current maturities	286,417	282,003
Operating lease liabilities	54,404	0
Deferred income tax liabilities	8,669	8,361
Other non-current liabilities	13,709	12,216
Total liabilities	581,540	522,230
(See Commitments and Contingencies: Note 11)
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 31,491,872 and 31,922,409, respectively	315	319
Additional paid-in capital	111,597	122,818
Retained earnings	375,889	379,890
Accumulated other comprehensive loss	(40,508)	(40,290)
Total stockholders’ equity	447,293	462,737
Non-controlling interests	7,277	7,450
Total equity	454,570	470,187
Total Liabilities and Equity	$ 1,036,110	$ 992,417

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 9,826	$ 9,695
Preferred stock, undesignated, par (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, undesignated, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, undesignated, shares outstanding (in shares)	0	0
Common stock, par (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	125,000,000	125,000,000
Common stock, shares issues (in shares)	31,491,872	31,922,409
Common stock, shares outstanding (in shares)	31,491,872	31,922,409

Consolidated Statements of Equi

Consolidated Statements of Equity - 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, 2017		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)	(1,476)			(2,069)		593
Issuance of shares pursuant to restricted/performance stock units (in shares)								275,384		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)		4,568
Issuance of shares pursuant to deferred stock unit awards	0
Shares repurchased and retired (in shares)		(571,580)
Shares repurchased and retired	(13,676)	$ (6)	(13,670)
Equity-based compensation expense	2,158		2,158
Currency translation adjustments, derivative transactions and pension activity, net	2,715				2,662	53
Balance (in shares) at Mar. 31, 2018		32,467,823
Balance at Mar. 31, 2018	$ 495,051	$ 325	129,237	374,893	(20,860)	11,456
Balance (in shares) at Dec. 31, 2018	31,922,409	31,922,409
Balance at Dec. 31, 2018	$ 470,187	$ 319	122,818	379,890	(40,290)	7,450
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,991)			(4,001)		10
Issuance of common stock upon stock option exercises, including tax benefit (in shares)		52,783
Issuance of common stock upon stock option exercises, including tax benefit	956	$ 1	955
Issuance of shares pursuant to restricted/performance stock units (in shares)								171,575		110,656
Issuance of shares pursuant to restricted/performance stock units							$ 2	$ 2	$ 1	$ 1
Issuance of shares pursuant to deferred stock unit awards (in shares)		9,438
Issuance of shares pursuant to deferred stock unit awards	0
Shares repurchased and retired (in shares)		(774,989)
Shares repurchased and retired	(14,191)	$ (8)	(14,183)
Equity-based compensation expense	2,007		2,007
Distributions to non-controlling interests	(96)					(96)
Currency translation adjustments, derivative transactions and pension activity, net	$ (305)				(218)	(87)
Balance (in shares) at Mar. 31, 2019	31,491,872	31,491,872
Balance at Mar. 31, 2019	$ 454,570	$ 315	$ 111,597	$ 375,889	$ (40,508)	$ 7,277

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net loss	$ (3,991)	$ (1,476)
Adjustments to reconcile to net cash provided by (used in) operating activities:
Depreciation and amortization	8,655	9,554
Gain on sale of fixed assets	(308)	(105)
Equity-based compensation expense	2,007	2,158
Deferred income taxes	19	(38)
Non-cash restructuring charges	(151)	2,408
Loss on foreign currency transactions	772	315
Other	63	561
Changes in operating assets and liabilities (net of acquisitions):
Receivables net, retainage and contract assets	10,388	16,584
Inventories	(1,287)	(2,223)
Prepaid expenses and other assets	433	6,657
Accounts payable and accrued expenses	(18,017)	(24,729)
Contract liabilities	(4,307)	(8,860)
Other operating	(873)	470
Net cash provided by (used in) operating activities	(6,597)	1,276
Cash flows from investing activities:
Capital expenditures	(8,064)	(5,189)
Proceeds from sale of fixed assets	293	284
Patent expenditures	(69)	(48)
Net cash used in investing activities	(7,840)	(4,953)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises	956	0
Repurchase of common stock	(14,220)	(13,670)
Distributions to non-controlling interests	(96)	0
Credit facility amendment fees	0	(1,093)
Payments on notes payable, net	(138)	(568)
Proceeds from line of credit, net	13,000	5,000
Principal payments on long-term debt	(6,563)	(6,563)
Net cash used in financing activities	(7,061)	(16,894)
Effect of exchange rate changes on cash	329	1,870
Net decrease in cash, cash equivalents and restricted cash for the period	(21,169)	(18,701)
Cash, cash equivalents and restricted cash, beginning of year	84,886	108,545
Cash, cash equivalents and restricted cash, end of period	63,717	89,844
Cash, cash equivalents and restricted cash associated with assets held for sale, end of period	0	(813)
Cash, cash equivalents and restricted cash, end of period	$ 63,717	$ 89,031

General

General	3 Months Ended
	Mar. 31, 2019
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, 2018, 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 2018 Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 1, 2019. 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 CIPP businesses in Australia and Denmark; and (iv) reduce corporate and other operating costs. During 2018, the Company’s board of directors approved additional actions with respect to the 2017 Restructuring, which included the decisions to: (i) divest the Australia and Denmark CIPP businesses; (ii) take actions to further optimize operations within North America, including measures to reduce consolidated operating costs; and (iii) divest or otherwise exit multiple additional international businesses. See Note 4. Infrastructure Solutions Segment (“Infrastructure Solutions”) On May 14, 2018, the Company’s board of directors approved a plan to divest the Company’s CIPP business in Australia (“Insituform Australia”). While restructuring actions in Insituform Australia led to 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 Insituform Australia’s assets and liabilities as held for sale on the Consolidated Balance Sheet at March 31, 2019 and December 31, 2018. See Note 5. Corrosion Protection Segment (“Corrosion Protection”) During the first quarter of 2019, the Company initiated plans to sell its interest in its cathodic protection materials manufacturing and production joint venture in Saudi Arabia, Corrpower International Limited (“Corrpower”) and its interest in its Titeliner ® and CIPP joint venture in South Africa, Aegion South Africa Proprietary Limited (“Aegion South Africa”). Accordingly, the Company has classified the assets and liabilities of both businesses as held for sale on the Consolidated Balance Sheet at March 31, 2019. See Note 5.

Accounting Policies

Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Accounting Policies	ACCOUNTING POLICIES On January 1, 2019, the Company adopted FASB ASC 842, Leases (“FASB ASC 842”). See Note 6 for further information. Other than the adoption of FASB ASC 842, 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, 2018 . Accumulated Other Comprehensive Income (Loss) As set forth below, 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): March 31, December 31, 2018 Currency translation adjustments $ (39,158 ) $ (41,107 ) Derivative hedging activity (431 ) 1,715 Pension activity (919 ) (898 ) Total accumulated other comprehensive loss $ (40,508 ) $ (40,290 ) 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. Net foreign exchange transaction losses of $0.8 million and $0.3 million in the first quarters of 2019 and 2018 , 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. Earnings per Share Earnings per share have been calculated using the following share information: Quarters Ended 2019 2018 Weighted average number of common shares used for basic EPS 31,704,923 32,483,963 Effect of dilutive stock options and restricted and deferred stock unit awards — — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 31,704,923 32,483,963 The Company excluded 549,679 restricted and deferred stock units for the quarter ended March 31, 2019, and 710,173 restricted and deferred stock units and stock options for the quarter ended March 31, 2018 from the diluted earnings per share calculation for the Company’s common stock because of the reported net loss for the periods. 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 March 31, 2019 December 31, Cash and cash equivalents $ 62,482 $ 83,527 Restricted cash 1,235 1,359 Cash, cash equivalents and restricted cash $ 63,717 $ 84,886 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. 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 March 31, 2019 . Financial data for consolidated variable interest entities are summarized in the following tables (in thousands): Balance sheet data March 31, (1) December 31, Current assets $ 29,847 $ 33,066 Non-current assets 7,016 6,466 Current liabilities 12,006 12,953 Non-current liabilities 7,281 8,780 __________________________ (1) Includes $8.1 million of assets and $6.3 million of liabilities classified as held for sale relating to Corrpower and Aegion South Africa. See Note 5. Quarters Ended Statement of operations data 2019 2018 (1) Revenue $ 5,925 $ 16,051 Gross profit 1,635 3,310 Net income attributable to Aegion Corporation 33 1,248 __________________________ (1) Includes activity from our pipe coating and insulation joint venture in Louisiana, which was sold during the third quarter of 2018. 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 adoption of this standard is not expected to have a material impact 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 Tax Cuts and Jobs Act on items within accumulated other comprehensive income to retained earnings. 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 adopted this standard effective January 1, 2019 and elected not to reclassify the tax effects due to the immaterial impact on the Company’s consolidated financial statements. In June 2016, the FASB issued Accounting Standards Update No. 2016-13, Measurement of Credit Losses on Financial Instruments , which changes the way in which entities estimate and present credit losses for most financial assets, including accounts receivable. The guidance is effective for the Company’s fiscal year beginning January 1, 2020, including interim periods within that fiscal year. Early adoption is permitted, although the Company does not intend to do so. The Company is currently evaluating the impact this guidance will have on its consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) , which 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 Company adopted this standard, effective January 1, 2019, using the adoption-date transition provision, which recognizes and measures leases existing at January 1, 2019 but without retrospective application. See Note 6.

Revenues

Revenues	3 Months Ended
	Mar. 31, 2019
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 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. 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 generally 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 92.9% and 95.0% of revenues for the quarters ended March 31, 2019 and 2018, 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 maintenance contracts are structured such that the Company has the right to consideration from a customer in an amount that corresponds directly with the performance completed to date. Therefore, the Company utilizes the practical expedient in FASB ASC 606-55-255, which allows the Company to recognize revenue in the amount to which it has the right to invoice. Applying this practical expedient, the Company is not required to disclose the transaction price allocated to remaining performance obligations under these agreements. 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 7.1% and 5.0% of revenues for the quarters ended March 31, 2019 and 2018, respectively. On March 31, 2019 , the Company had $474.5 million of remaining performance obligations from construction, engineering and installation services. The Company estimates that approximately $445.1 million , or 93.8% , of the remaining performance obligations at March 31, 2019 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 March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 97,891 $ 30,021 $ 80,863 $ 208,775 Canada 10,611 13,457 — 24,068 Europe 12,525 3,478 — 16,003 Other foreign 10,516 17,542 — 28,058 Total revenues $ 131,543 $ 64,498 $ 80,863 $ 276,904 Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 93,845 $ 50,356 $ 92,329 $ 236,530 Canada 12,269 16,570 — 28,839 Europe 13,143 2,866 — 16,009 Other foreign 15,170 28,313 — 43,483 Total revenues $ 134,427 $ 98,105 $ 92,329 $ 324,861 The following tables summarize revenues by segment and contract type (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 118,915 $ 42,572 $ 919 $ 162,406 Time and materials — 14,977 79,944 94,921 Product sales 12,478 6,949 — 19,427 License fees 150 — 150 Total revenues $ 131,543 $ 64,498 $ 80,863 $ 276,904 Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 125,263 $ 77,901 $ 5,757 $ 208,921 Time and materials — 13,107 86,572 99,679 Product sales 9,144 7,097 — 16,241 License fees 20 — — 20 Total revenues $ 134,427 $ 98,105 $ 92,329 $ 324,861 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): March 31, (1) December 31, 2018 (2) Contract assets – current $ 59,422 $ 62,467 Contract liabilities – current (27,060 ) (32,339 ) Net contract assets $ 32,362 $ 30,128 __________________________ (1) Amounts exclude contract assets of $2.9 million and contract liabilities of less than $1.1 million that were classified as held for sale at March 31, 2019 (see Note 5). (2) Amounts exclude contract assets of $1.8 million and contract liabilities of less than $0.1 million that were classified as held for sale at December 31, 2018 (see Note 5). Included in the change of total net contract assets was a $3.0 million decrease in contract assets, primarily related to the timing between work performed on open contracts and contractual billing terms, and a $5.3 million decrease in contract liabilities, primarily related to the timing of customer advances on certain contracts. Substantially all of the $32.3 million and $51.6 million contract liabilities balances at December 31, 2018 and December 31, 2017, respectively, were recognized in revenues during the first quarters of 2019 and 2018, respectively. Impairment losses recognized on receivables and contract assets were not material during the first quarters of 2019 and 2018.

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring	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. During 2018, the Company’s board of directors approved additional actions with respect to the 2017 Restructuring, which included the decisions to: (i) divest the Australia and Denmark CIPP businesses; (ii) take actions to further optimize operations within North America, including measures to reduce consolidated operating costs; and (iii) divest or otherwise exit multiple additional international businesses, including: (a) the Company’s cathodic protection installation activities in the Middle East, including Corrpower; (b) United Pipeline de Mexico S.A. de C.V., the Company’s Tite Liner ® joint venture in Mexico; (c) the Company’s Tite Liner ® businesses in Brazil and Argentina; (d) Aegion South Africa; and (e) the Company’s CIPP contract installation operations in England. Total pre-tax 2017 Restructuring and related impairment charges since inception were $142.5 million ( $128.5 million post-tax) and consisted of cash charges totaling $28.9 million and non-cash charges totaling $113.6 million . Cash charges included employee severance, retention, extension of benefits, employment assistance programs and other restructuring costs associated with the restructuring efforts described above. Non-cash charges included (i) $86.4 million related to goodwill and long-lived asset impairment charges recorded in 2017 as part of exiting the non-pipe FRP contracting market in North America, and (ii) $27.2 million related to allowances for accounts receivable, write-offs of inventory and long-lived assets, impairment of definite-lived intangible assets, as well as net losses on the disposal of both domestic and international entities. The Company reduced headcount by approximately 440 employees as a result of these actions. The Company expects to incur additional cash and non-cash charges of $12 million to $16 million during 2019. The identified charges are primarily focused in the international operations of both Infrastructure Solutions and Corrosion Protection, but will also include certain charges in Energy Services to a lesser extent. The Company expects to reduce headcount by an additional 50 employees as a result of these further actions. During the quarters ended March 31, 2019 and 2018 , the Company recorded pre-tax expenses related to the 2017 Restructuring as follows (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 282 $ 170 $ 34 $ 9 $ 495 Lease and contract termination costs 425 17 — 98 540 Relocation and other moving costs 51 — — — 51 Other restructuring costs (1) 1,744 (211 ) — 247 1,780 Total pre-tax restructuring charges $ 2,502 $ (24 ) $ 34 $ 354 $ 2,866 __________________________ (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 the CIPP operations in the UK, exiting the cathodic protection operations in the Middle East and other cost savings initiatives. Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 780 $ 121 $ — $ 170 $ 1,071 Lease and contract termination costs 528 — — 150 678 Relocation and other moving costs 40 — — — 40 Other restructuring costs (1) 1,868 1,344 — 243 3,455 Total pre-tax restructuring charges $ 3,216 $ 1,465 $ — $ 563 $ 5,244 __________________________ (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. 2017 Restructuring costs related to severance, other termination benefit costs and early lease and contract termination costs were $1.1 million and $1.8 million for the quarters ended March 31, 2019 and 2018 , 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 quarters ended March 31, 2019 and 2018 as presented in their affected line in the Consolidated Statements of Operations (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ (25 ) $ 99 $ — $ — $ 74 Operating expenses 1,346 (63 ) — 247 1,530 Restructuring and related charges 758 187 34 107 1,086 Other expense 423 (247 ) — — 176 Total pre-tax restructuring charges $ 2,502 $ (24 ) $ 34 $ 354 $ 2,866 __________________________ (1) Total pre-tax restructuring charges include cash charges of $3.1 million and non-cash charges of $(0.2) million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Operating expenses $ 1,868 $ 1,344 $ — $ 243 $ 3,455 Restructuring and related charges 1,348 121 — 320 1,789 Total pre-tax restructuring charges $ 3,216 $ 1,465 $ — $ 563 $ 5,244 __________________________ (1) Total pre-tax restructuring charges include cash charges of $2.8 million and non-cash charges of $2.4 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 quarters of 2019 and 2018 (in thousands): Reserves at December 31, 2018 2019 Foreign Currency Translation Utilized in 2019 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 1,742 $ 495 $ (5 ) $ 1,102 $ — $ 1,130 Lease and contract termination costs 359 540 3 310 — 592 Relocation and other moving costs — 51 — — — 51 Other restructuring costs 311 1,780 (2 ) 1,852 (151 ) 388 Total pre-tax restructuring charges $ 2,412 $ 2,866 $ (4 ) $ 3,264 $ (151 ) $ 2,161 __________________________ (1) Refers to cash utilized to settle charges during the first quarter of 2019. Reserves at 2018 Foreign Currency Translation Utilized in 2018 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 3,864 $ 1,071 $ 20 $ 2,305 $ — $ 2,650 Lease and contract termination costs 650 678 — 793 — 535 Relocation and other moving costs — 40 — 40 — — Other restructuring costs 675 3,455 — 1,272 2,408 450 Total pre-tax restructuring charges $ 5,189 $ 5,244 $ 20 $ 4,410 $ 2,408 $ 3,635 __________________________ (1) Refers to cash utilized to settle charges during the first quarter of 2018.

Assets and Liabilities Held for

Assets and Liabilities Held for Sale	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Assets and Liabilities Held for Sale	ASSETS AND LIABILITIES HELD FOR SALE During the first quarter of 2019, the Company initiated plans to sell its interests in Corrpower and Aegion South Africa. The Company is currently in discussions with third parties for each of the entities and believes that it is probable that sales of each entity will occur in the second half of 2019. On May 14, 2018, the Company’s board of directors approved a plan to divest the assets and liabilities of Insituform Australia (see Note 1). The Company is currently in discussions with a third party and management believes that it is probable that a sale will occur in the first half of 2019. The relevant asset and liability balances at March 31, 2019 and December 31, 2018 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): March 31, (1) December 31, 2018 (2) Assets held for sale: Current assets Cash and cash equivalents $ — $ — Receivables, net 4,237 1,309 Retainage 234 15 Contract assets 2,920 1,777 Inventories 3,971 2,123 Prepaid expenses and other current assets 587 300 Total current assets 11,949 5,524 Property, plant & equipment, less accumulated depreciation 3,395 2,268 Operating lease assets 2,135 — Total assets held for sale $ 17,479 $ 7,792 Liabilities held for sale: Current liabilities Accounts payable $ 1,801 $ 1,331 Accrued expenses 5,516 3,891 Contract liabilities 1,100 38 Current maturities of long-term debt 895 — Total current liabilities 9,312 5,260 Operating lease liabilities 1,219 — Other non-current liabilities 231 — Total liabilities held for sale $ 10,762 $ 5,260 __________________________ (1) Includes Corrpower, Aegion South Africa and Insituform Australia. (2) Includes Insituform Australia.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	LEASES Effective January 1, 2019, the Company adopted FASB ASC 842 using the adoption-date transition provision rather than at the earliest comparative period presented in the financial statements. Therefore, the Company recognized and measured leases existing at January 1, 2019 but without retrospective application. The Company also elected the package of practical expedients not to reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs and the lessee practical expedient to combine lease and non-lease components. The Company also made a policy election to not recognize right-of-use assets and lease liabilities for short-term leases for all asset classes. The impact of FASB ASC 842 on the Consolidated Balance Sheet beginning January 1, 2019 was through the recognition of operating lease assets and corresponding operating lease liabilities of $70.5 million . No impact was recorded to the Consolidated Statement of Operations or beginning retained earnings. The Company’s operating lease portfolio includes operational field locations, administrative offices, equipment, vehicles and information technology equipment. The majority of the Company’s leases have remaining lease terms of 1 year to 20 years, some of which include options to extend the leases for 5 years or more. Right-of-use assets are presented within “Operating lease assets” on the Consolidated Balance Sheet. The current portion of operating lease liabilities are presented within “Accrued expenses”, and the non-current portion of operating lease liabilities are presented within “Operating lease liabilities” on the Consolidated Balance Sheet. Operating lease assets and liabilities are recognized based on the present value of lease payments over the lease term at inception. For purposes of calculating operating lease liabilities, lease terms may be deemed to include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating leases in effect prior to January 1, 2019 were recognized at the present value of the remaining payments on the remaining lease term as of January 1, 2019. A portion of the Company’s real estate, equipment and vehicle leases is subject to periodic changes in the Consumer Price Index, LIBOR or other market index. The changes to these indexes are treated as variable lease payments and recognized in the period in which the obligation for those payments is incurred. Because most leases do not provide an explicit rate of return, the Company utilizes its incremental secured borrowing rate on a lease-by-lease basis in determining the present value of lease payments at the commencement date of the lease. The following table presents the components of lease expense (in thousands): Quarter Ended March 31, 2019 Operating lease cost $ 5,452 Short-term lease cost 7,239 Total lease cost $ 12,691 Supplemental cash flow information related to leases was as follows (in thousands): Quarter Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 5,462 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 6,126 Supplemental balance sheet information related to leases was as follows (in thousands): March 31, (1) Operating leases: Operating lease assets $ 69,042 Accrued expenses $ 15,174 Other liabilities 54,404 Total operating lease liabilities $ 69,578 Weighted-average remaining lease term (in years) 5.78 Weighted-average discount rate 6.31 % __________________________ (1) Amounts exclude operating lease assets of $2.1 million , accrued expenses of $0.9 million , and other liabilities of $1.2 million that were classified as held for sale at March 31, 2019 (see Note 5). Operating lease liabilities under non-cancellable leases were as follows (in thousands): March 31, 2019 Nine months ended December 31, 2019 $ 14,615 2020 16,496 2021 13,954 2022 11,223 2023 8,916 Thereafter 18,891 Total undiscounted operating lease liability 84,095 Less: Imputed interest (14,517 ) Total discounted operating lease liability $ 69,578 Minimum rental commitments under non-cancellable leases as of December 31, 2018 for years 2019 through 2023 were $19.8 million , $15.1 million , $11.5 million , $8.1 million and $5.4 million , respectively, and $7.2 million thereafter.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2019
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 goodwill (in thousands): Infrastructure Corrosion Energy Total Balance, December 31, 2018: Goodwill, gross $ 244,521 $ 76,383 $ 81,504 $ 402,408 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net 181,673 30,983 47,977 260,633 2019 Activity: Foreign currency translation (15 ) 142 — 127 Balance, March 31, 2019: Goodwill, gross 244,506 76,525 81,504 402,535 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 181,658 $ 31,125 $ 47,977 $ 260,760 Intangible Assets Intangible assets consisted of the following (in thousands): March 31, 2019 December 31, 2018 Weighted Average Useful Lives (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount License agreements 1.5 $ 3,894 $ (3,751 ) $ 143 $ 3,894 $ (3,716 ) $ 178 Leases 1.8 864 (711 ) 153 864 (689 ) 175 Trademarks 9.5 15,788 (6,416 ) 9,372 15,751 (6,202 ) 9,549 Non-competes 4.1 2,527 (1,296 ) 1,231 2,529 (1,229 ) 1,300 Customer relationships 8.6 159,592 (69,329 ) 90,263 159,719 (66,753 ) 92,966 Patents and acquired technology 5.6 38,582 (23,484 ) 15,098 38,338 (22,810 ) 15,528 Total intangible assets $ 221,247 $ (104,987 ) $ 116,260 $ 221,095 $ (101,399 ) $ 119,696 Amortization expense was $3.5 million and $3.5 million for the quarters ended March 31, 2019 and 2018 , respectively. Estimated amortization expense by year is as follows (in thousands): 2019 $ 13,686 2020 13,624 2021 13,477 2022 13,398 2023 13,398

Long-Term Debt and Credit Facil

Long-Term Debt and Credit Facility	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt and Credit Facility	LONG-TERM DEBT AND CREDIT FACILITY Long-term debt consisted of the following (in thousands): March 31, December 31, Term note, due February 27, 2023, annualized rates of 4.52% and 4.59%, respectively $ 275,625 $ 282,188 Line of credit, 4.49% and 4.45%, respectively 44,000 31,000 Other notes with interest rates from 3.3% to 7.8% — 1,031 Subtotal 319,625 314,219 Less – Current maturities of long-term debt 30,625 29,469 Less – Unamortized loan costs 2,583 2,747 Total $ 286,417 $ 282,003 In October 2015, the Company entered into an amended and restated $650.0 million senior secured credit facility with a syndicate of banks. In February 2018 and December 2018, the Company amended this facility (the “amended Credit Facility”). The amended Credit Facility consists of a $275.0 million five -year revolving line of credit and a $308.4 million five -year term loan facility, each with a maturity date in February 2023. During the first quarter of 2018, the Company paid expenses of $2.4 million associated with the amended Credit Facility, $0.9 million related to up-front lending fees and $1.5 million related to third-party arranging fees and expenses, the latter of which was recorded in “Interest expense” in the Consolidated Statement of Operations. 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 quarter 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 March 31, 2019 was approximately 4.49% . The Company’s indebtedness at March 31, 2019 consisted of $275.6 million outstanding from the term loan under the amended Credit Facility and $44.0 million on the line of credit under the amended Credit Facility. Additionally, the Company had $0.9 million of debt held by its joint ventures (representing funds loaned by its joint venture partners) listed as held for sale at March 31, 2019 related to the planned sales of Corrpower and Aegion South Africa. During the first quarter of 2019, the Company borrowed $13.0 million on the line of credit for domestic working capital needs. As of March 31, 2019 , the Company had $22.6 million in letters of credit issued and outstanding under the amended Credit Facility. Of such amount, $12.3 million was collateral for the benefit of certain of our insurance carriers and $10.3 million was for letters of credit or bank guarantees of performance or payment obligations of foreign subsidiaries. The Company’s indebtedness at December 31, 2018 consisted of $282.2 million outstanding from the term loan under the amended Credit Facility, $31.0 million on the line of credit under the amended Credit Facility and $1.0 million of third-party notes and bank debt. At March 31, 2019 and December 31, 2018, the estimated fair value of the Company’s long-term debt was approximately $323.8 million and $307.7 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 13. 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 March 31, 2019 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 13. 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 13. 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 3.75 to 1.00. At March 31, 2019 , the Company’s consolidated financial leverage ratio was 3.23 to 1.00 and, using the amended Credit Facility defined income, the Company had the capacity to borrow up to $54.0 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 March 31, 2019 , the Company’s fixed charge ratio was 1.35 to 1.00. At March 31, 2019 , 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	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity and Equity Compensation	STOCKHOLDERS’ EQUITY AND EQUITY COMPENSATION Share Repurchase Plan In December 2018, the Company’s board of directors authorized the open market repurchase of up to two million shares of the Company’s common stock. The program did not establish a time period in which the repurchases had to be made. In December 2018, the Company amended its Credit Facility, which limits the open market share repurchases to $32.0 million for 2019. 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 quarter of 2019, the Company acquired 622,043 shares of the Company’s common stock for $11.1 million ( $17.82 average price per share) through the open market repurchase program discussed above, 152,946 shares of the Company’s common stock for $3.1 million ( $20.48 average price per share) in connection with the satisfaction of tax obligations in connection with the vesting of restricted stock units and performance units, and 48,409 shares of the Company’s common stock in connection with “net, net” exercises of employee stock options. Once repurchased, the Company immediately retired all such shares. During the first quarter of 2018, the Company acquired 353,831 shares of the Company’s common stock for $8.4 million ( $23.78 average price per share) through the open market repurchase program discussed above and 217,749 shares of the Company’s common stock for $5.3 million ( $24.14 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. The Company did no t acquire any of the Company’s common stock in connection with “net, net” exercises of employee stock options. 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 March 31, 2019 , 1,944,014 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 March 31, 2019 , 68,689 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: Quarter Ended Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2018 1,143,205 $ 23.26 Restricted stock units awarded 283,472 20.24 Performance stock units awarded 146,367 22.78 Restricted stock units distributed (171,073 ) 18.21 Performance stock units distributed (111,155 ) 25.85 Restricted stock units forfeited (6,655 ) 23.13 Performance stock units forfeited (42,939 ) 25.90 Outstanding at March 31, 2019 1,241,222 $ 22.88 Expense associated with stock awards was $2.0 million and $2.1 million for the quarters ended March 31, 2019 and 2018 , respectively. Unrecognized pre-tax expense of $16.7 million related to stock awards is expected to be recognized over the weighted average remaining service period of 2.96 years for awards outstanding at March 31, 2019 . 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. Historically, awards were fully vested, and fully expensed, on the date of grant. Beginning in April 2019, as a result of a recent amendment of the 2016 Director Plan, the expense related to the issuance of deferred stock units is based on the award date fair value and charged to expense ratably through the requisite service period, which is generally one year. The forfeiture of unvested deferred stock units causes the reversal of all previous expense to be recorded as a reduction of current period expense. A summary of deferred stock unit activity is as follows: Quarter Ended Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2018 287,350 $ 22.80 Awarded 2,891 16.69 Distributed (9,438 ) 18.69 Outstanding at March 31, 2019 280,803 $ 20.83 Expense associated with deferred stock unit awards was less than $0.1 million for each of the quarters ended March 31, 2019 and 2018 . Stock Options Stock options on the Company’s common stock were awarded from time to time to executive officers and certain key employees of the Company. Stock options granted generally had 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 52,783 stock options exercised during the quarter ended March 31, 2019 with a weighted average exercise price of $18.11 per share. There were no stock options outstanding at March 31, 2019.

Taxes on Income

Taxes on Income	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Taxes on Income	TAXES ON INCOME The Company’s effective tax rate in the quarter ended March 31, 2019 was a benefit of 16.0% on a pre-tax loss. The effective rate was negatively impacted by valuation allowances recorded on certain net operating losses in foreign jurisdictions for which no income tax benefits are expected to be recognized. The Company’s effective tax rate in the quarter ended March 31, 2018 was a benefit of 40.4% on a pre-tax loss. The benefit was positively impacted by a $1.5 million net tax benefit, or 60.0% benefit to the effective tax rate, related to employee share-based payments vested during the first quarter of 2018. Excluding this benefit, the Company recorded income tax expense on a pre-tax loss primarily due to valuation allowances recorded on certain net operating losses in foreign jurisdictions for which no income tax benefits are expected to be recognized.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 . 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 March 31, 2019 on its Consolidated Balance Sheet.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2019
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 and restructuring charges, if applicable. During the first quarter of 2019, the Company began reporting Corporate expenses separately rather than allocating those costs to the operating segments. The reported information for the quarter ended March 31, 2018 has been revised to conform to the current period presentation. Financial information by segment was as follows (in thousands): Quarters Ended 2019 2018 Revenues: Infrastructure Solutions $ 131,543 $ 134,427 Corrosion Protection 64,498 98,105 Energy Services 80,863 92,329 Total revenues $ 276,904 $ 324,861 Gross profit: Infrastructure Solutions $ 26,586 $ 26,709 Corrosion Protection 12,873 23,576 Energy Services 8,836 11,219 Total gross profit $ 48,295 $ 61,504 Operating income (loss): Infrastructure Solutions (1) $ 5,715 $ 3,237 Corrosion Protection (2) (1,760 ) 4,962 Energy Services 1,115 3,127 Corporate (3) (5,844 ) (8,145 ) Total operating income (loss) (774 ) 3,181 Other income (expense): Interest expense (3,590 ) (5,443 ) Interest income 285 47 Other (4) (674 ) (262 ) Total other expense (3,979 ) (5,658 ) Loss before tax benefit $ (4,753 ) $ (2,477 ) _______________________ (1) Operating income in the first quarter of 2019 includes $2.1 million of 2017 Restructuring charges (see Note 4) and $0.1 million of costs primarily related to the planned divestitures of Insituform Australia. Operating income in the first quarter of 2018 includes: (i) $3.2 million of 2017 Restructuring charges (see Note 4); and (ii) $0.1 million of costs incurred primarily related to the acquisition of Environmental Techniques. (2) Operating loss in the first quarter of 2019 includes $0.2 million of 2017 Restructuring charges (see Note 4). Operating income in the first quarter of 2018 includes $1.5 million of 2017 Restructuring charges (see Note 4). (3) Operating loss in the first quarter of 2019 includes $0.4 million of 2017 Restructuring charges (see Note 4). (4) Other expense in the first quarter of 2019 includes $0.2 million of 2017 Restructuring charges (see Note 4). The following table summarizes revenues and gross profit by geographic region (in thousands): Quarters Ended 2019 2018 Revenues: (1) United States $ 208,775 $ 236,530 Canada 24,068 28,839 Europe 16,003 16,009 Other foreign 28,058 43,483 Total revenues $ 276,904 $ 324,861 Gross profit: (1) United States $ 31,827 $ 40,707 Canada 3,454 4,775 Europe 3,519 1,134 Other foreign 9,495 14,888 Total gross profit $ 48,295 $ 61,504 __________________________ (1) Revenues and gross profit are attributed to the country of origin.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 , the Company’s cash flow hedges were in a net deferred loss position of $0.4 million compared to a net deferred gain position of $1.8 million at December 31, 2018. The change during the period was due to unfavorable 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 three months of 2019 and 2018 , a gain of $0.2 million and a loss of $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 March 31, 2019 : Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate USD/British Pound Sell £ 3,552,000 0.3 1.31 EURO/British Pound Sell £ 2,568,300 0.3 1.16 Interest Rate Swap $ 206,718,750 3.8 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 March 31, December 31, Derivatives Designated as Hedging Instruments: Interest Rate Swaps Other non-current assets $ 2,546 $ 3,648 Total Assets $ 2,546 $ 3,648 Interest Rate Swaps Other non-current liabilities $ 2,988 $ 1,885 Total Liabilities $ 2,988 $ 1,885 Derivatives Not Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ — Total Assets $ — $ — Forward Currency Contracts Accrued expenses $ 83 $ 44 Total Liabilities $ 83 $ 44 Total Derivative Assets $ 2,546 $ 3,648 Total Derivative Liabilities 3,071 1,929 Total Net Derivative Asset (Liability) $ (525 ) $ 1,719 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 March 31, 2019 . 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.

Accounting Policies (Policies)

Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Taxation	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.
Cash, Cash Equivalents and Restricted Cash	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 .
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 adoption of this standard is not expected to have a material impact 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 Tax Cuts and Jobs Act on items within accumulated other comprehensive income to retained earnings. 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 adopted this standard effective January 1, 2019 and elected not to reclassify the tax effects due to the immaterial impact on the Company’s consolidated financial statements. In June 2016, the FASB issued Accounting Standards Update No. 2016-13, Measurement of Credit Losses on Financial Instruments , which changes the way in which entities estimate and present credit losses for most financial assets, including accounts receivable. The guidance is effective for the Company’s fiscal year beginning January 1, 2020, including interim periods within that fiscal year. Early adoption is permitted, although the Company does not intend to do so. The Company is currently evaluating the impact this guidance will have on its consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) , which 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 Company adopted this standard, effective January 1, 2019, using the adoption-date transition provision, which recognizes and measures leases existing at January 1, 2019 but without retrospective application. See Note 6.
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 and restructuring charges, if applicable.
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)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Schedule of accumulated other comprehensive income (loss)	As set forth below, 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): March 31, December 31, 2018 Currency translation adjustments $ (39,158 ) $ (41,107 ) Derivative hedging activity (431 ) 1,715 Pension activity (919 ) (898 ) Total accumulated other comprehensive loss $ (40,508 ) $ (40,290 )
Schedule of weighted average number of shares	Earnings per share have been calculated using the following share information: Quarters Ended 2019 2018 Weighted average number of common shares used for basic EPS 31,704,923 32,483,963 Effect of dilutive stock options and restricted and deferred stock unit awards — — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 31,704,923 32,483,963
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 March 31, 2019 December 31, Cash and cash equivalents $ 62,482 $ 83,527 Restricted cash 1,235 1,359 Cash, cash equivalents and restricted cash $ 63,717 $ 84,886
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 March 31, (1) December 31, Current assets $ 29,847 $ 33,066 Non-current assets 7,016 6,466 Current liabilities 12,006 12,953 Non-current liabilities 7,281 8,780 __________________________ (1) Includes $8.1 million of assets and $6.3 million of liabilities classified as held for sale relating to Corrpower and Aegion South Africa. See Note 5. Quarters Ended Statement of operations data 2019 2018 (1) Revenue $ 5,925 $ 16,051 Gross profit 1,635 3,310 Net income attributable to Aegion Corporation 33 1,248 __________________________ (1) Includes activity from our pipe coating and insulation joint venture in Louisiana, which was sold during the third quarter of 2018.

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables summarize revenues by segment and geography (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 97,891 $ 30,021 $ 80,863 $ 208,775 Canada 10,611 13,457 — 24,068 Europe 12,525 3,478 — 16,003 Other foreign 10,516 17,542 — 28,058 Total revenues $ 131,543 $ 64,498 $ 80,863 $ 276,904 Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Primary geographic region: United States $ 93,845 $ 50,356 $ 92,329 $ 236,530 Canada 12,269 16,570 — 28,839 Europe 13,143 2,866 — 16,009 Other foreign 15,170 28,313 — 43,483 Total revenues $ 134,427 $ 98,105 $ 92,329 $ 324,861 The following tables summarize revenues by segment and contract type (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 118,915 $ 42,572 $ 919 $ 162,406 Time and materials — 14,977 79,944 94,921 Product sales 12,478 6,949 — 19,427 License fees 150 — 150 Total revenues $ 131,543 $ 64,498 $ 80,863 $ 276,904 Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 125,263 $ 77,901 $ 5,757 $ 208,921 Time and materials — 13,107 86,572 99,679 Product sales 9,144 7,097 — 16,241 License fees 20 — — 20 Total revenues $ 134,427 $ 98,105 $ 92,329 $ 324,861
Contract Asset and Liability	Net contract assets (liabilities) consisted of the following (in thousands): March 31, (1) December 31, 2018 (2) Contract assets – current $ 59,422 $ 62,467 Contract liabilities – current (27,060 ) (32,339 ) Net contract assets $ 32,362 $ 30,128 __________________________ (1) Amounts exclude contract assets of $2.9 million and contract liabilities of less than $1.1 million that were classified as held for sale at March 31, 2019 (see Note 5). (2) Amounts exclude contract assets of $1.8 million and contract liabilities of less than $0.1 million that were classified as held for sale at December 31, 2018 (see Note 5).

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
Summary of restructuring and related costs	The following tables summarize all charges related to the 2017 Restructuring recognized in the quarters ended March 31, 2019 and 2018 as presented in their affected line in the Consolidated Statements of Operations (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ (25 ) $ 99 $ — $ — $ 74 Operating expenses 1,346 (63 ) — 247 1,530 Restructuring and related charges 758 187 34 107 1,086 Other expense 423 (247 ) — — 176 Total pre-tax restructuring charges $ 2,502 $ (24 ) $ 34 $ 354 $ 2,866 __________________________ (1) Total pre-tax restructuring charges include cash charges of $3.1 million and non-cash charges of $(0.2) million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Operating expenses $ 1,868 $ 1,344 $ — $ 243 $ 3,455 Restructuring and related charges 1,348 121 — 320 1,789 Total pre-tax restructuring charges $ 3,216 $ 1,465 $ — $ 563 $ 5,244 __________________________ (1) Total pre-tax restructuring charges include cash charges of $2.8 million and non-cash charges of $2.4 million . Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods. During the quarters ended March 31, 2019 and 2018 , the Company recorded pre-tax expenses related to the 2017 Restructuring as follows (in thousands): Quarter Ended March 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 282 $ 170 $ 34 $ 9 $ 495 Lease and contract termination costs 425 17 — 98 540 Relocation and other moving costs 51 — — — 51 Other restructuring costs (1) 1,744 (211 ) — 247 1,780 Total pre-tax restructuring charges $ 2,502 $ (24 ) $ 34 $ 354 $ 2,866 __________________________ (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 the CIPP operations in the UK, exiting the cathodic protection operations in the Middle East and other cost savings initiatives. Quarter Ended March 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 780 $ 121 $ — $ 170 $ 1,071 Lease and contract termination costs 528 — — 150 678 Relocation and other moving costs 40 — — — 40 Other restructuring costs (1) 1,868 1,344 — 243 3,455 Total pre-tax restructuring charges $ 3,216 $ 1,465 $ — $ 563 $ 5,244 __________________________ (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.
Summary of restructuring activity	The following tables summarize the 2017 Restructuring activity during the first quarters of 2019 and 2018 (in thousands): Reserves at December 31, 2018 2019 Foreign Currency Translation Utilized in 2019 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 1,742 $ 495 $ (5 ) $ 1,102 $ — $ 1,130 Lease and contract termination costs 359 540 3 310 — 592 Relocation and other moving costs — 51 — — — 51 Other restructuring costs 311 1,780 (2 ) 1,852 (151 ) 388 Total pre-tax restructuring charges $ 2,412 $ 2,866 $ (4 ) $ 3,264 $ (151 ) $ 2,161 __________________________ (1) Refers to cash utilized to settle charges during the first quarter of 2019. Reserves at 2018 Foreign Currency Translation Utilized in 2018 Reserves at Cash (1) Non-Cash Severance and benefit related costs $ 3,864 $ 1,071 $ 20 $ 2,305 $ — $ 2,650 Lease and contract termination costs 650 678 — 793 — 535 Relocation and other moving costs — 40 — 40 — — Other restructuring costs 675 3,455 — 1,272 2,408 450 Total pre-tax restructuring charges $ 5,189 $ 5,244 $ 20 $ 4,410 $ 2,408 $ 3,635 __________________________ (1) Refers to cash utilized to settle charges during the first quarter of 2018.

Assets and Liabilities Held f_2

Assets and Liabilities Held for Sale (Tables)	3 Months Ended
	Mar. 31, 2019
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): March 31, (1) December 31, 2018 (2) Assets held for sale: Current assets Cash and cash equivalents $ — $ — Receivables, net 4,237 1,309 Retainage 234 15 Contract assets 2,920 1,777 Inventories 3,971 2,123 Prepaid expenses and other current assets 587 300 Total current assets 11,949 5,524 Property, plant & equipment, less accumulated depreciation 3,395 2,268 Operating lease assets 2,135 — Total assets held for sale $ 17,479 $ 7,792 Liabilities held for sale: Current liabilities Accounts payable $ 1,801 $ 1,331 Accrued expenses 5,516 3,891 Contract liabilities 1,100 38 Current maturities of long-term debt 895 — Total current liabilities 9,312 5,260 Operating lease liabilities 1,219 — Other non-current liabilities 231 — Total liabilities held for sale $ 10,762 $ 5,260 __________________________ (1) Includes Corrpower, Aegion South Africa and Insituform Australia. (2) Includes Insituform Australia.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lease, Cost	The following table presents the components of lease expense (in thousands): Quarter Ended March 31, 2019 Operating lease cost $ 5,452 Short-term lease cost 7,239 Total lease cost $ 12,691 Supplemental cash flow information related to leases was as follows (in thousands): Quarter Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 5,462 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 6,126
Lease, Supplemental Financial Statement Disclosures, Balance Sheet	Supplemental balance sheet information related to leases was as follows (in thousands): March 31, (1) Operating leases: Operating lease assets $ 69,042 Accrued expenses $ 15,174 Other liabilities 54,404 Total operating lease liabilities $ 69,578 Weighted-average remaining lease term (in years) 5.78 Weighted-average discount rate 6.31 % __________________________ (1) Amounts exclude operating lease assets of $2.1 million , accrued expenses of $0.9 million , and other liabilities of $1.2 million that were classified as held for sale at March 31, 2019 (see Note 5).
Lessee, Operating Lease, Liability, Maturity	Operating lease liabilities under non-cancellable leases were as follows (in thousands): March 31, 2019 Nine months ended December 31, 2019 $ 14,615 2020 16,496 2021 13,954 2022 11,223 2023 8,916 Thereafter 18,891 Total undiscounted operating lease liability 84,095 Less: Imputed interest (14,517 ) Total discounted operating lease liability $ 69,578

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The following table presents a reconciliation of the beginning and ending balances of goodwill (in thousands): Infrastructure Corrosion Energy Total Balance, December 31, 2018: Goodwill, gross $ 244,521 $ 76,383 $ 81,504 $ 402,408 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net 181,673 30,983 47,977 260,633 2019 Activity: Foreign currency translation (15 ) 142 — 127 Balance, March 31, 2019: Goodwill, gross 244,506 76,525 81,504 402,535 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 181,658 $ 31,125 $ 47,977 $ 260,760
Schedule of identified intangible assets	Intangible assets consisted of the following (in thousands): March 31, 2019 December 31, 2018 Weighted Average Useful Lives (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount License agreements 1.5 $ 3,894 $ (3,751 ) $ 143 $ 3,894 $ (3,716 ) $ 178 Leases 1.8 864 (711 ) 153 864 (689 ) 175 Trademarks 9.5 15,788 (6,416 ) 9,372 15,751 (6,202 ) 9,549 Non-competes 4.1 2,527 (1,296 ) 1,231 2,529 (1,229 ) 1,300 Customer relationships 8.6 159,592 (69,329 ) 90,263 159,719 (66,753 ) 92,966 Patents and acquired technology 5.6 38,582 (23,484 ) 15,098 38,338 (22,810 ) 15,528 Total intangible assets $ 221,247 $ (104,987 ) $ 116,260 $ 221,095 $ (101,399 ) $ 119,696
Schedule of estimated amortization expense	Estimated amortization expense by year is as follows (in thousands): 2019 $ 13,686 2020 13,624 2021 13,477 2022 13,398 2023 13,398

Long-Term Debt and Credit Fac_2

Long-Term Debt and Credit Facility (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in thousands): March 31, December 31, Term note, due February 27, 2023, annualized rates of 4.52% and 4.59%, respectively $ 275,625 $ 282,188 Line of credit, 4.49% and 4.45%, respectively 44,000 31,000 Other notes with interest rates from 3.3% to 7.8% — 1,031 Subtotal 319,625 314,219 Less – Current maturities of long-term debt 30,625 29,469 Less – Unamortized loan costs 2,583 2,747 Total $ 286,417 $ 282,003

Stockholders' Equity and Equi_2

Stockholders' Equity and Equity Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Summary of all stock award activity	A summary of the stock award activity is as follows: Quarter Ended Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2018 1,143,205 $ 23.26 Restricted stock units awarded 283,472 20.24 Performance stock units awarded 146,367 22.78 Restricted stock units distributed (171,073 ) 18.21 Performance stock units distributed (111,155 ) 25.85 Restricted stock units forfeited (6,655 ) 23.13 Performance stock units forfeited (42,939 ) 25.90 Outstanding at March 31, 2019 1,241,222 $ 22.88
Summary of all deferred stock unit activity	A summary of deferred stock unit activity is as follows: Quarter Ended Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2018 287,350 $ 22.80 Awarded 2,891 16.69 Distributed (9,438 ) 18.69 Outstanding at March 31, 2019 280,803 $ 20.83

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Financial information by segment	Financial information by segment was as follows (in thousands): Quarters Ended 2019 2018 Revenues: Infrastructure Solutions $ 131,543 $ 134,427 Corrosion Protection 64,498 98,105 Energy Services 80,863 92,329 Total revenues $ 276,904 $ 324,861 Gross profit: Infrastructure Solutions $ 26,586 $ 26,709 Corrosion Protection 12,873 23,576 Energy Services 8,836 11,219 Total gross profit $ 48,295 $ 61,504 Operating income (loss): Infrastructure Solutions (1) $ 5,715 $ 3,237 Corrosion Protection (2) (1,760 ) 4,962 Energy Services 1,115 3,127 Corporate (3) (5,844 ) (8,145 ) Total operating income (loss) (774 ) 3,181 Other income (expense): Interest expense (3,590 ) (5,443 ) Interest income 285 47 Other (4) (674 ) (262 ) Total other expense (3,979 ) (5,658 ) Loss before tax benefit $ (4,753 ) $ (2,477 ) _______________________ (1) Operating income in the first quarter of 2019 includes $2.1 million of 2017 Restructuring charges (see Note 4) and $0.1 million of costs primarily related to the planned divestitures of Insituform Australia. Operating income in the first quarter of 2018 includes: (i) $3.2 million of 2017 Restructuring charges (see Note 4); and (ii) $0.1 million of costs incurred primarily related to the acquisition of Environmental Techniques. (2) Operating loss in the first quarter of 2019 includes $0.2 million of 2017 Restructuring charges (see Note 4). Operating income in the first quarter of 2018 includes $1.5 million of 2017 Restructuring charges (see Note 4). (3) Operating loss in the first quarter of 2019 includes $0.4 million of 2017 Restructuring charges (see Note 4). (4) Other expense in the first quarter of 2019 includes $0.2 million of 2017 Restructuring charges (see Note 4).
Summary of revenues, gross profit, and operating income by geographic region	The following table summarizes revenues and gross profit by geographic region (in thousands): Quarters Ended 2019 2018 Revenues: (1) United States $ 208,775 $ 236,530 Canada 24,068 28,839 Europe 16,003 16,009 Other foreign 28,058 43,483 Total revenues $ 276,904 $ 324,861 Gross profit: (1) United States $ 31,827 $ 40,707 Canada 3,454 4,775 Europe 3,519 1,134 Other foreign 9,495 14,888 Total gross profit $ 48,295 $ 61,504 __________________________ (1) Revenues and gross profit are attributed to the country of origin.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of derivative positions	The following table summarizes the Company’s derivative positions at March 31, 2019 : Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate USD/British Pound Sell £ 3,552,000 0.3 1.31 EURO/British Pound Sell £ 2,568,300 0.3 1.16 Interest Rate Swap $ 206,718,750 3.8
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 March 31, December 31, Derivatives Designated as Hedging Instruments: Interest Rate Swaps Other non-current assets $ 2,546 $ 3,648 Total Assets $ 2,546 $ 3,648 Interest Rate Swaps Other non-current liabilities $ 2,988 $ 1,885 Total Liabilities $ 2,988 $ 1,885 Derivatives Not Designated as Hedging Instruments: Forward Currency Contracts Prepaid expenses and other current assets $ — $ — Total Assets $ — $ — Forward Currency Contracts Accrued expenses $ 83 $ 44 Total Liabilities $ 83 $ 44 Total Derivative Assets $ 2,546 $ 3,648 Total Derivative Liabilities 3,071 1,929 Total Net Derivative Asset (Liability) $ (525 ) $ 1,719

Accounting Policies - Foreign C

Accounting Policies - Foreign Currency (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Accounting Policies [Abstract]
Currency translation adjustments	$ (39,158)		$ (41,107)
Derivative hedging activity	(431)		1,715
Pension activity	(919)		(898)
Total accumulated other comprehensive loss	(40,508)		$ (40,290)
Loss on foreign currency transactions	$ 772	$ 315

Accounting Policies - Earnings

Accounting Policies - Earnings Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accounting Policies [Abstract]
Weighted average number of common shares used for basic EPS (in shares)	31,704,923	32,483,963
Effect of dilutive stock options and restricted and deferred stock unit awards (in shares)	0	0
Weighted average number of common shares and dilutive potential common stock used for dilutive EPS (in shares)	31,704,923	32,483,963
Antidilutive securities excluded from calculation of earnings per share (in shares)	549,679	710,173

Accounting Policies - Cash, Cas

Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Accounting Policies [Abstract]
Cash and cash equivalents	$ 62,482	$ 83,527
Restricted cash	1,235	1,359
Cash, cash equivalents and restricted cash	$ 63,717	$ 84,886	$ 89,031

Accounting Policies - VIE Balan

Accounting Policies - VIE Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Current assets (VIE)	$ 29,847	$ 33,066
Non-current assets (VIE)	7,016	6,466
Current liabilities (VIE)	12,006	12,953
Non-current liabilities (VIE)	7,281	$ 8,780
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Variable Interest Entity [Line Items]
Disposal group, assets	8,100
Disposal group, liabilities	$ 6,300

Accounting Policies - VIE Incom

Accounting Policies - VIE Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accounting Policies [Abstract]
Revenue	$ 5,925	$ 16,051
Gross profit	1,635	3,310
Net income attributable to Aegion Corporation	$ 33	$ 1,248

Revenues - Additional Informati

Revenues - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 268
Products and Services
Disaggregation of Revenue [Line Items]
Revenue recognized, percent	92.90%	95.00%
Product
Disaggregation of Revenue [Line Items]
Revenue recognized, percent	7.10%	5.00%
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)

Revenues - Performance Obligati

Revenues - Performance Obligation (Details) $ in Millions	Mar. 31, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	$ 474.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	$ 445.1
Revenue, remaining performance obligation, percent	93.80%
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
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 276,904	$ 324,861
Fixed fee
Disaggregation of Revenue [Line Items]
Revenues	162,406	208,921
Time and materials
Disaggregation of Revenue [Line Items]
Revenues	94,921	99,679
Product sales
Disaggregation of Revenue [Line Items]
Revenues	19,427	16,241
License fees
Disaggregation of Revenue [Line Items]
Revenues	150	20
United States
Disaggregation of Revenue [Line Items]
Revenues	208,775	236,530
Canada
Disaggregation of Revenue [Line Items]
Revenues	24,068	28,839
Europe
Disaggregation of Revenue [Line Items]
Revenues	16,003	16,009
Other foreign
Disaggregation of Revenue [Line Items]
Revenues	28,058	43,483
Infrastructure Solutions
Disaggregation of Revenue [Line Items]
Revenues	131,543	134,427
Infrastructure Solutions | Fixed fee
Disaggregation of Revenue [Line Items]
Revenues	118,915	125,263
Infrastructure Solutions | Time and materials
Disaggregation of Revenue [Line Items]
Revenues	0	0
Infrastructure Solutions | Product sales
Disaggregation of Revenue [Line Items]
Revenues	12,478	9,144
Infrastructure Solutions | License fees
Disaggregation of Revenue [Line Items]
Revenues	150	20
Infrastructure Solutions | United States
Disaggregation of Revenue [Line Items]
Revenues	97,891	93,845
Infrastructure Solutions | Canada
Disaggregation of Revenue [Line Items]
Revenues	10,611	12,269
Infrastructure Solutions | Europe
Disaggregation of Revenue [Line Items]
Revenues	12,525	13,143
Infrastructure Solutions | Other foreign
Disaggregation of Revenue [Line Items]
Revenues	10,516	15,170
Corrosion Protection
Disaggregation of Revenue [Line Items]
Revenues	64,498	98,105
Corrosion Protection | Fixed fee
Disaggregation of Revenue [Line Items]
Revenues	42,572	77,901
Corrosion Protection | Time and materials
Disaggregation of Revenue [Line Items]
Revenues	14,977	13,107
Corrosion Protection | Product sales
Disaggregation of Revenue [Line Items]
Revenues	6,949	7,097
Corrosion Protection | License fees
Disaggregation of Revenue [Line Items]
Revenues		0
Corrosion Protection | United States
Disaggregation of Revenue [Line Items]
Revenues	30,021	50,356
Corrosion Protection | Canada
Disaggregation of Revenue [Line Items]
Revenues	13,457	16,570
Corrosion Protection | Europe
Disaggregation of Revenue [Line Items]
Revenues	3,478	2,866
Corrosion Protection | Other foreign
Disaggregation of Revenue [Line Items]
Revenues	17,542	28,313
Energy Services
Disaggregation of Revenue [Line Items]
Revenues	80,863	92,329
Energy Services | Fixed fee
Disaggregation of Revenue [Line Items]
Revenues	919	5,757
Energy Services | Time and materials
Disaggregation of Revenue [Line Items]
Revenues	79,944	86,572
Energy Services | Product sales
Disaggregation of Revenue [Line Items]
Revenues	0	0
Energy Services | License fees
Disaggregation of Revenue [Line Items]
Revenues	0	0
Energy Services | United States
Disaggregation of Revenue [Line Items]
Revenues	80,863	92,329
Energy Services | Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0
Energy Services | Europe
Disaggregation of Revenue [Line Items]
Revenues	0	0
Energy Services | Other foreign
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0

Revenues - Contract Assets (Lia

Revenues - Contract Assets (Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from External Customer [Line Items]
Contract assets – current	$ 59,422	$ 62,467
Contract liabilities – current	(27,060)	(32,339)	$ (51,600)
Net contract assets	32,362	30,128
Contract assets, held-for-sale	2,900	1,800
Contract liabilities, held-for-sale	1,100	$ 100
Difference Between Work Performed On Open Contracts And Contractual Billing Terms
Revenue from External Customer [Line Items]
Changes in contract assets (liabilities)	(3,000)
Difference Related To Customer Advances On Certain Contract
Revenue from External Customer [Line Items]
Changes in contract assets (liabilities)	$ 5,300

Restructuring - Additional Info

Restructuring - Additional Information (Details) $ in Thousands	3 Months Ended		20 Months Ended
	Mar. 31, 2019USD ($)employee	Mar. 31, 2018USD ($)	Mar. 31, 2019USD ($)employee
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges	$ 1,086	$ 1,789
Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, pre tax			$ 142,500
Restructuring charges, net of tax			128,500
Restructuring reserve, settled with cash	3,264	4,410	28,900
Restructuring reserve, settled without cash	$ (151)	2,408	113,600
Goodwill and long-lived asset impairment			86,400
Allowance for doubtful accounts receivable, write-offs			$ 27,200
Headcount reduction | employee			440
Expected number of additional positions eliminated | employee	50
Restructuring and related charges	$ 2,866	$ 5,244
Minimum | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Expected restructuring cash charges	12,000		$ 12,000
Maximum | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Expected restructuring cash charges	$ 16,000		$ 16,000

Restructuring - Pre Tax Restruc

Restructuring - Pre Tax Restructuring Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,086	$ 1,789
Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,866	5,244
Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	495	1,071
Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	540	678
Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	51	40
Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,780	3,455
Operating Segments | Infrastructure Solutions | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,502	3,216
Operating Segments | Infrastructure Solutions | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	282	780
Operating Segments | Infrastructure Solutions | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	425	528
Operating Segments | Infrastructure Solutions | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	51	40
Operating Segments | Infrastructure Solutions | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,744	1,868
Operating Segments | Corrosion Protection | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(24)	1,465
Operating Segments | Corrosion Protection | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	170	121
Operating Segments | Corrosion Protection | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	17	0
Operating Segments | Corrosion Protection | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Corrosion Protection | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(211)	1,344
Operating Segments | Energy Services | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	34	0
Operating Segments | Energy Services | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	34	0
Operating Segments | Energy Services | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Energy Services | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Energy Services | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Corporate | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	354	563
Corporate | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9	170
Corporate | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	98	150
Corporate | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Corporate | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 247	$ 243

Restructuring - Recognized Cost

Restructuring - Recognized Cost Restructuring Activities (Details) - Restructuring 2017 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 2,866	$ 5,244
Restructuring charges, cash	3,100	2,800
Restructuring charges, non-cash	(200)	2,400
Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	74
Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,530	3,455
Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,086	1,789
Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	176
Operating Segments | Infrastructure Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2,502	3,216
Operating Segments | Infrastructure Solutions | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(25)
Operating Segments | Infrastructure Solutions | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,346	1,868
Operating Segments | Infrastructure Solutions | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	758	1,348
Operating Segments | Infrastructure Solutions | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	423
Operating Segments | Corrosion Protection
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(24)	1,465
Operating Segments | Corrosion Protection | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	99
Operating Segments | Corrosion Protection | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(63)	1,344
Operating Segments | Corrosion Protection | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	187	121
Operating Segments | Corrosion Protection | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(247)
Operating Segments | Energy Services
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	34	0
Operating Segments | Energy Services | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Operating Segments | Energy Services | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0	0
Operating Segments | Energy Services | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	34	0
Operating Segments | Energy Services | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	354	563
Corporate | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Corporate | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	247	243
Corporate | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	107	$ 320
Corporate | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 0

Restructuring - Restructuring A

Restructuring - Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended		20 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019
Restructuring Reserve [Roll Forward]
Restructuring and related charges	$ 1,086	$ 1,789
Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	2,412	5,189
Restructuring and related charges	2,866	5,244
Restructuring reserve, foreign currency translation gain (loss)	(4)	20
Restructuring reserve, settled with cash	3,264	4,410	$ 28,900
Restructuring reserve, settled without cash	(151)	2,408	113,600
Restructuring reserve, end	2,161	3,635	2,161
Severance and benefit related costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	1,742	3,864
Restructuring and related charges	495	1,071
Restructuring reserve, foreign currency translation gain (loss)	(5)	20
Restructuring reserve, settled with cash	1,102	2,305
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	1,130	2,650	1,130
Lease and contract termination costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	359	650
Restructuring and related charges	540	678
Restructuring reserve, foreign currency translation gain (loss)	3	0
Restructuring reserve, settled with cash	310	793
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	592	535	592
Relocation and other moving costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	0	0
Restructuring and related charges	51	40
Restructuring reserve, foreign currency translation gain (loss)	0	0
Restructuring reserve, settled with cash	0	40
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	51	0	51
Other restructuring costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	311	675
Restructuring and related charges	1,780	3,455
Restructuring reserve, foreign currency translation gain (loss)	(2)	0
Restructuring reserve, settled with cash	1,852	1,272
Restructuring reserve, settled without cash	(151)	2,408
Restructuring reserve, end	$ 388	$ 450	$ 388

Assets and Liabilities Held f_3

Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets held for sale:
Total current assets	$ 17,479	$ 7,792
Current liabilities
Total current liabilities	10,762	5,260
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale:
Cash and cash equivalents	0	0
Receivables, net	4,237	1,309
Retainage	234	15
Contract assets	2,920	1,777
Inventories	3,971	2,123
Prepaid expenses and other current assets	587	300
Total current assets	11,949	5,524
Property, plant & equipment, less accumulated depreciation	3,395	2,268
Operating lease assets	2,135	0
Total assets held for sale	17,479	7,792
Current liabilities
Accounts payable	1,801	1,331
Accrued expenses	5,516	3,891
Contract liabilities	1,100	38
Current maturities of long-term debt	895	0
Total current liabilities	9,312	5,260
Total current liabilities	1,219	0
Other non-current liabilities	231	0
Total liabilities held for sale	$ 10,762	$ 5,260

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Operating lease assets	$ 69,042		$ 0
Operating lease, liability	$ 69,578
Operating lease, renewal term	5 years
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019			19,800
2020			15,100
2021			11,500
2022			8,100
2023			5,400
2024			$ 7,200
Minimum
Lessor, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	1 year
Maximum
Lessor, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	20 years
Accounting Standards Update 2016-02
Lessor, Lease, Description [Line Items]
Operating lease assets		$ 70,500
Operating lease, liability		$ 70,500

Leases - Lease Expense (Details

Leases - Lease Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 5,452
Short-term lease cost	7,239
Total lease cost	$ 12,691

Leases - Supplemental Financial

Leases - Supplemental Financial Statement Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases	$ 5,462
Operating leases	6,126
Operating lease assets	69,042	$ 0
Accrued expenses	15,174
Other liabilities	54,404	$ 0
Total operating lease liabilities	$ 69,578
Weighted-average remaining lease term (in years)	5 years 9 months 11 days
Weighted-average discount rate	6.31%
Held-for-sale
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 2,100
Accrued expenses	900
Other liabilities	$ 1,200

Leases - Operating Lease Maturi

Leases - Operating Lease Maturities (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
2019	$ 14,615
2020	16,496
2021	13,954
2022	11,223
2023	8,916
Thereafter	18,891
Total undiscounted operating lease liability	84,095
Less: Imputed interest	(14,517)
Total discounted operating lease liability	$ 69,578

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, gross	$ 402,535	$ 402,408
Accumulated impairment losses	(141,775)	(141,775)
Goodwill, beginning balance	260,633
Foreign currency translation	127
Goodwill, ending balance	260,760
Infrastructure Solutions
Goodwill [Roll Forward]
Goodwill, gross	244,506	244,521
Accumulated impairment losses	(62,848)	(62,848)
Goodwill, beginning balance	181,673
Foreign currency translation	(15)
Goodwill, ending balance	181,658
Corrosion Protection
Goodwill [Roll Forward]
Goodwill, gross	76,525	76,383
Accumulated impairment losses	(45,400)	(45,400)
Goodwill, beginning balance	30,983
Foreign currency translation	142
Goodwill, ending balance	31,125
Energy Services
Goodwill [Roll Forward]
Goodwill, gross	81,504	81,504
Accumulated impairment losses	(33,527)	$ (33,527)
Goodwill, beginning balance	47,977
Foreign currency translation	0
Goodwill, ending balance	$ 47,977

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 221,247	$ 221,095
Accumulated Amortization	(104,987)	(101,399)
Net Carrying Amount	$ 116,260	119,696
License agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	1 year 5 months 14 days
Gross Carrying Amount	$ 3,894	3,894
Accumulated Amortization	(3,751)	(3,716)
Net Carrying Amount	$ 143	178
Leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	1 year 9 months 1 day
Gross Carrying Amount	$ 864	864
Accumulated Amortization	(711)	(689)
Net Carrying Amount	$ 153	175
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	9 years 6 months 6 days
Gross Carrying Amount	$ 15,788	15,751
Accumulated Amortization	(6,416)	(6,202)
Net Carrying Amount	$ 9,372	9,549
Non-competes
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	4 years 1 month 5 days
Gross Carrying Amount	$ 2,527	2,529
Accumulated Amortization	(1,296)	(1,229)
Net Carrying Amount	$ 1,231	1,300
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	8 years 7 months 16 days
Gross Carrying Amount	$ 159,592	159,719
Accumulated Amortization	(69,329)	(66,753)
Net Carrying Amount	$ 90,263	92,966
Patents and acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives (Years)	5 years 7 months 5 days
Gross Carrying Amount	$ 38,582	38,338
Accumulated Amortization	(23,484)	(22,810)
Net Carrying Amount	$ 15,098	$ 15,528

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 3.5	$ 3.5

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2019	$ 13,686
2020	13,624
2021	13,477
2022	13,398
2023	$ 13,398

Long-Term Debt and Credit Fac_3

Long-Term Debt and Credit Facility - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Subtotal	$ 319,625	$ 314,219
Less – Current maturities of long-term debt	30,625	29,469
Less – Unamortized loan costs	2,583	2,747
Total	286,417	282,003
Term Note
Debt Instrument [Line Items]
Term note, due February 27, 2023, annualized rates of 4.52% and 4.59%, respectively	$ 275,625	$ 282,188
Current effective interest rate	4.52%	4.59%
Line of Credit
Debt Instrument [Line Items]
Line of credit, 4.49% and 4.45%, respectively	$ 44,000	$ 31,000
Current effective interest rate	4.49%	4.45%
Other notes
Debt Instrument [Line Items]
Other notes with interest rates from 3.3% to 7.8%	$ 0	$ 1,031
Other notes | Minimum
Debt Instrument [Line Items]
Current annualized interest rate	3.30%
Other notes | Maximum
Debt Instrument [Line Items]
Current annualized interest rate	7.80%

Long-Term Debt and Credit Fac_4

Long-Term Debt and Credit Facility - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Mar. 12, 2018USD ($)	Oct. 31, 2015USD ($)
Debt Instrument [Line Items]
Fees		$ 2,400,000
Up front lending fees		900,000
Third party arrangement fees		1,500,000
Proceeds from line of credit, net	$ 13,000,000
Third-party notes and bank debt held	900,000		$ 1,000,000
Long-term debt, fair value	$ 323,800,000		307,700,000
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
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 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	275,600,000
Proceeds from line of credit, net	44,000,000
Letters of credit issued and outstanding	$ 22,600,000
Secured debt			282,200,000
Line of credit			$ 31,000,000
Portion of amortization of term loan					$ 262,500,000
Initial maximum financial leverage ratio	3.75
Actual financial leverage ratio	3.23
Remaining borrowing capacity	$ 54,000,000
Minimum permitted fixed charge coverage ratio	1.15
Actual fixed charge coverage ratio	1.35
2015 Credit Facility | Insurance Carriers Collateral
Debt Instrument [Line Items]
Letters of credit issued and outstanding	$ 12,300,000
2015 Credit Facility | Work Performance Obligations
Debt Instrument [Line Items]
Letters of credit issued and outstanding	$ 10,300,000
2015 Credit Facility | LIBOR | 2015 Interest Rate Swap
Debt Instrument [Line Items]
Interest rate at period end	4.49%
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
Debt Instrument [Line Items]
Debt instrument, term	5 years
2015 Credit Facility | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 275,000,000
Term of revolving line of credit	5 years
Unamortized loan costs		2,400,000
Interest expense, debt		$ 200,000
Line of Credit
Debt Instrument [Line Items]
Interest rate at period end	4.49%		4.45%
Line of credit	$ 44,000,000		$ 31,000,000
2018 Credit Facility
Debt Instrument [Line Items]
Notional amount				$ 170,600,000

Stockholders' Equity and Equi_3

Stockholders' Equity and Equity Compensation - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Apr. 30, 2018
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Stock repurchase program, number of shares authorized to be repurchased (in shares)			2,000,000
Options exercised (in shares)	52,783
Options exercised (per share)	$ 18.11
Options outstanding (in shares)	0
Stock Awards
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share based compensation expense	$ 2,000,000	$ 2,100,000
Unrecognized share based compensation expense	$ 16,700,000
Weighted average recognition period	2 years 11 months 15 days
Deferred Stock Units
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share based compensation expense	$ 100,000	$ 100,000
Award requisite service period	1 year
Stock Options
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Stock repurchased during period (in shares)	48,409	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)	1,944,014
2016 Director Plan
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Number of shares available for issuance (in shares)	68,689
Equity Compensation Programs
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share repurchase program, authorized amount	$ 10,000,000
Stock repurchased during period (in shares)	152,946	217,749
Stock repurchased during period, value	$ 3,100,000	$ 5,300,000
Shares repurchased, average price per share (in dollars per share)	$ 20.48	$ 24.14
Open Market Repurchase Program
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Stock repurchased during period (in shares)	622,043	353,831
Stock repurchased during period, value	$ 11,100,000	$ 8,400,000
Shares repurchased, average price per share (in dollars per share)	$ 17.82	$ 23.78
Amended Credit Facility
Stockholders' Equity and Equity Compensation (Details) [Line Items]
Share repurchase program, authorized amount			$ 32,000,000

Stockholders' Equity and Equi_4

Stockholders' Equity and Equity Compensation - Summary of Stock Award Activity (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Stock Awards
Outstanding, beginning balance (in shares) | shares	1,143,205
Outstanding, ending balance (in shares) | shares	1,241,222
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 23.26
Outstanding, ending balance (in dollars per share) | $ / shares	$ 22.88
Restricted Stock Units
Stock Awards
Awarded (in shares) | shares	283,472
Distributed (in shares) | shares	(171,073)
Forfeited (in shares) | shares	(6,655)
Weighted Average Award Date Fair Value
Awarded (in dollars per share) | $ / shares	$ 20.24
Distributed (in dollars per share) | $ / shares	18.21
Forfeited (in dollars per share) | $ / shares	$ 23.13
Performance Units
Stock Awards
Awarded (in shares) | shares	146,367
Distributed (in shares) | shares	(111,155)
Forfeited (in shares) | shares	(42,939)
Weighted Average Award Date Fair Value
Awarded (in dollars per share) | $ / shares	$ 22.78
Distributed (in dollars per share) | $ / shares	25.85
Forfeited (in dollars per share) | $ / shares	$ 25.90

Stockholders' Equity and Equi_5

Stockholders' Equity and Equity Compensation - Summary of Deferred Stock Unit Activity (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	1,143,205
Outstanding, ending balance (in shares) | shares	1,241,222
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 23.26
Outstanding, ending balance (in dollars per share) | $ / shares	$ 22.88
Deferred Stock Units
Deferred Stock Units
Outstanding, beginning balance (in shares) | shares	287,350
Awarded (in shares) | shares	2,891
Distributed (in shares) | shares	(9,438)
Outstanding, ending balance (in shares) | shares	280,803
Weighted Average Award Date Fair Value
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 22.80
Awarded (in dollars per share) | $ / shares	16.69
Distributed (in dollars per share) | $ / shares	18.69
Outstanding, ending balance (in dollars per share) | $ / shares	$ 20.83

Taxes on Income (Details)

Taxes on Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	16.00%	40.40%
Employee share-based payments, amount		$ 1.5
Employee share-based payments, percentage		60.00%

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase commitment	$ 0

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019segment
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
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 276,904	$ 324,861
Gross profit	48,295	61,504
Operating income (loss)	(774)	3,181
Interest expense	(3,590)	(5,443)
Interest income	285	47
Other	(674)	(262)
Total other expense	(3,979)	(5,658)
Loss before tax benefit	(4,753)	(2,477)
Restructuring and related charges	1,086	1,789
Restructuring 2017
Segment Reporting Information [Line Items]
Other	(200)
Restructuring and related charges	400
Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues	131,543	134,427
Infrastructure Solutions | Restructuring 2017
Segment Reporting Information [Line Items]
Restructuring and related charges	2,100	3,200
Corrosion Protection
Segment Reporting Information [Line Items]
Revenues	64,498	98,105
Corrosion Protection | Restructuring 2017
Segment Reporting Information [Line Items]
Restructuring and related charges	200	1,500
Energy Services
Segment Reporting Information [Line Items]
Revenues	80,863	92,329
Australia | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges	100
Environmental Techniques | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges		100
Operating Segments | Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues	131,543	134,427
Gross profit	26,586	26,709
Operating income (loss)	5,715	3,237
Operating Segments | Corrosion Protection
Segment Reporting Information [Line Items]
Revenues	64,498	98,105
Gross profit	12,873	23,576
Operating income (loss)	(1,760)	4,962
Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Revenues	80,863	92,329
Gross profit	8,836	11,219
Operating income (loss)	1,115	3,127
Corporate
Segment Reporting Information [Line Items]
Operating income (loss)	$ (5,844)	$ (8,145)

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
	Mar. 31, 2019	Mar. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 276,904	$ 324,861
Gross profit	48,295	61,504
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	208,775	236,530
Gross profit	31,827	40,707
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	24,068	28,839
Gross profit	3,454	4,775
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	16,003	16,009
Gross profit	3,519	1,134
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	28,058	43,483
Gross profit	$ 9,495	$ 14,888

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Mar. 12, 2018	Oct. 31, 2015
Debt Instrument [Line Items]
Gain (loss) upon settlement of cash flow hedges, (less than $0.1 million)	$ 200,000	$ (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 (liability)	$ (400,000)		$ 1,800,000

Derivative Financial Instrume_4

Derivative Financial Instruments - Summary of Derivative Positions (Details) - 3 months ended Mar. 31, 2019	USD ($)€ / £$ / £	GBP (£)€ / £$ / £
USD/British Pound | Sell
Derivative [Line Items]
Notional Amount		£ 3,552,000
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 | € / £	1.16	1.16
Interest Rate Swaps
Derivative [Line Items]
Notional Amount | $	$ 206,718,750
Weighted Average Remaining Maturity In Years	3 years 9 months

Derivative Financial Instrume_5

Derivative Financial Instruments - Summary of the Fair Value Amounts of Derivative Instruments (Details) - Significant Observable Inputs (Level 2) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative assets	$ 2,546	$ 3,648
Derivative liabilities	3,071	1,929
Net derivative asset (liability)	(525)	1,719
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	2,546	3,648
Derivative liabilities	2,988	1,885
Designated as Hedging Instrument | Interest Rate Swaps | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative assets	2,546	3,648
Designated as Hedging Instrument | Interest Rate Swaps | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	2,988	1,885
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	0	0
Derivative liabilities	83	44
Not Designated as Hedging Instrument | Forward Currency Contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0	0
Not Designated as Hedging Instrument | Forward Currency Contracts | Accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 83	$ 44