Aegion 10-K 2 Mar 20 2019 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 28, 2019
Document Information [Line Items]
Entity Central Index Key	0000353020
Entity Registrant Name	Aegion Corp
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2019
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-35328
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3117900
Entity Address, Address Line One	17988 Edison Avenue
Entity Address, City or Town	Chesterfield
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63005-1195
City Area Code	636
Local Phone Number	530-8000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Class A Common Shares, $.01 par value
Trading Symbol	AEGN
Security Exchange Name	NASDAQ
Entity Public Float			$ 563,133,402
Entity Common Stock, Shares Outstanding		30,714,860

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Revenues	[1]	$ 1,213,935	$ 1,333,568		$ 1,359,019
Cost of revenues		967,700	1,066,642		1,074,207
Gross profit	[1]	246,235	266,926		284,812
Operating expenses		199,430	219,823		226,173
Goodwill impairment		0	1,389	[2]	45,390
Definite-lived intangible asset impairment		0	2,169		41,032
Impairment of assets held for sale		23,427	0		0
Acquisition and divestiture expenses		3,375	7,004		2,923
Restructuring and related charges		9,030	6,894		12,814
Operating income (loss)	[1]	10,973	29,647		(43,520)
Other income (expense):
Interest expense		(14,002)	(17,327)		(16,001)
Interest income		1,038	516		145
Other	[3]	(10,893)	(9,881)		(2,201)
Total other expense		(23,857)	(26,692)		(18,057)
Income (loss) before taxes on income		(12,884)	2,955		(61,577)
Taxes (benefit) on income (loss)		6,564	(132)		5,005
Net income (loss)		(19,448)	3,087		(66,582)
Non-controlling interests income		(1,444)	(159)		(2,819)
Net income (loss) attributable to Aegion Corporation		$ (20,892)	$ 2,928		$ (69,401)
Earnings (loss) per share attributable to Aegion Corporation:
Basic (in dollars per share)		$ (0.67)	$ 0.09		$ (2.09)
Diluted (in dollars per share)		$ (0.67)	$ 0.09		$ (2.09)
[1]	Attributed to the country of origin.
[2]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).
[3]	Other expense for 2019 includes $10.2 million of restructuring charges (see Note 4). Other expense for 2018 includes charges of $7.0 million related to the loss on the sale of Bayou (see Note 1) and $4.0 million of restructuring charges (see Note 4).

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income (loss)		$ (19,448)	$ 3,087	$ (66,582)
Other comprehensive income (loss):
Currency translation adjustments		13,915	(14,651)	20,839
Deferred gain (loss) on hedging activity, net of tax	[1]	(6,237)	(1,621)	1,402
Pension activity, net of tax	[2]	(33)	(654)	93
Total comprehensive loss		(11,803)	(13,839)	(44,248)
Comprehensive income attributable to non-controlling interests		(1,493)	(1)	(3,040)
Comprehensive loss attributable to Aegion Corporation		$ (13,296)	$ (13,840)	$ (47,288)
[1]	Amounts presented net of tax of $164, $(48) and $930 for the years ended December 31, 2019, 2018 and 2017, respectively.
[2]	Amounts presented net of tax of $8, $(134) and $22 for the years ended December 31, 2019, 2018 and 2017, respectively.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred gain (loss) on hedging activity, tax	$ 164	$ (48)	$ 930
Pension activity, tax	$ 8	$ (134)	$ 22

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019		Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 64,874		$ 83,527
Restricted cash	1,348		1,359
Receivables, net of allowances of $7,224 and $9,695, respectively	192,604		204,541
Retainage	33,103		33,572
Contract assets	51,092	[1]	62,467	[2]
Inventories	57,193		56,437	[3]
Prepaid expenses and other current assets	33,909		32,172
Assets held for sale	16,092		7,792
Total current assets	450,215		481,867
Property, plant & equipment, less accumulated depreciation	101,091		107,059
Other assets
Goodwill, net	256,835		260,633
Intangible assets, less accumulated amortization	104,828		119,696
Operating lease assets	71,466	[4]	0
Deferred income tax assets	1,216		1,561
Other non-current assets	9,862		21,601
Total other assets	444,207		403,491
Total Assets	995,513		992,417
Current liabilities
Accounts payable	60,614		64,562
Accrued expenses	96,577		88,020
Contract liabilities	37,562	[1]	32,339	[2]
Current maturities of long-term debt	32,803		29,469
Liabilities held for sale	6,485		5,260
Total current liabilities	234,041		219,650
Long-term debt, less current maturities	243,629		282,003
Other liabilities
Operating lease liabilities	56,253		0
Deferred income tax liabilities	11,254		8,361
Other non-current liabilities	15,243		12,216
Total other liabilities	82,750		20,577
Total liabilities	560,420		522,230
(See Commitments and Contingencies: Note 13)
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 30,715,959 and 31,922,409, respectively	307		319
Additional paid-in capital	101,148		122,818
Retained earnings	358,998		379,890
Accumulated other comprehensive loss	(32,694)		(40,290)
Total stockholders’ equity	427,759		462,737
Non-controlling interests	7,334		7,450
Total equity	435,093		470,187
Total Liabilities and Equity	$ 995,513		$ 992,417
[1]	Amounts exclude contract assets of $5.4 million and contract liabilities of $0.1 million that were classified as held for sale at December 31, 2019 (see Note 6).
[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 6).
[3]	During 2018, the Company incurred non-cash charges of $2.8 million related to estimates for inventory obsolescence within its cathodic protection operations. The charges were recorded to cost of revenues in the Consolidated Statement of Operations.
[4]	Amounts exclude operating lease assets of $0.3 million, accrued expenses of $0.2 million and other liabilities of $0.2 million that were classified as held for sale at December 31, 2019 (see Note 5).

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts receivable	$ 7,224	$ 9,695
Preferred stock, undesignated, par value (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 value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	125,000,000	125,000,000
Common stock, shares issued (in shares)	30,715,959	31,922,409
Common stock, shares outstanding (in shares)	30,715,959	31,922,409

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock [Member]Restricted Stock Units (RSUs) [Member]	Common Stock [Member]Performance Shares [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Restricted Stock Units (RSUs) [Member]	Performance Shares [Member]	Total
Balance (in shares) at Dec. 31, 2016			33,956,304
Issuance of common stock upon stock option exercises (in shares)			43,573							43,573
Issuance of shares pursuant to restricted stock units (in shares)	95,510	49,672
Issuance of shares pursuant to deferred stock units (in shares)			30,559
Forfeitures of restricted shares (in shares)			(1,084)
Shares repurchased and retired (in shares)			(1,711,992)
Balance (in shares) at Dec. 31, 2017			32,462,542
Balance at Dec. 31, 2016			$ 340	$ 167,700	$ 446,095	$ (45,635)	$ 7,683			$ 576,183
Issuance of common stock upon stock option exercises			0	822						822
Issuance of shares pursuant to restricted stock units	$ 1	$ 0						$ 1	$ 0
Issuance of shares pursuant to deferred stock units			0							0
Shares repurchased and retired			(16)	(37,833)						(37,849)
Balance at Dec. 31, 2017			$ 325	140,749	376,694	(23,522)	10,810			505,056
Equity-based compensation expense				10,060						10,060
Cumulative effect adjustment (see Revenues: Note 3)					0					0
Net income (loss)					(69,401)		2,819			(66,582)
Currency translation adjustment and derivative transactions, net						22,113	221			22,334
Investments from non-controlling interest							158			158
Distributions to non-controlling interests							(71)			(71)
Sale of non-controlling interests							0			0
Investments from non-controlling interest							158			$ 158
Issuance of common stock upon stock option exercises (in shares)			0							0
Issuance of shares pursuant to restricted stock units (in shares)	312,182	296,909
Issuance of shares pursuant to deferred stock units (in shares)			28,308
Forfeitures of restricted shares (in shares)			0
Shares repurchased and retired (in shares)			(1,177,532)
Balance (in shares) at Dec. 31, 2018			31,922,409							31,922,409
Issuance of common stock upon stock option exercises			$ 0	0						$ 0
Issuance of shares pursuant to restricted stock units	$ 3	$ 3						3	3
Issuance of shares pursuant to deferred stock units			0							0
Shares repurchased and retired			(12)	(25,769)						(25,781)
Balance at Dec. 31, 2018			$ 319	122,818	379,890	(40,290)	7,450			470,187
Equity-based compensation expense				7,838						7,838
Cumulative effect adjustment (see Revenues: Note 3)					268					268
Net income (loss)					2,928		159			3,087
Currency translation adjustment and derivative transactions, net						(16,768)	(158)			(16,926)
Investments from non-controlling interest							0			0
Distributions to non-controlling interests							0			0
Sale of non-controlling interests							(3,361)			(3,361)
Investments from non-controlling interest							0			$ 0
Issuance of common stock upon stock option exercises (in shares)			52,783							52,783
Issuance of shares pursuant to restricted stock units (in shares)	237,416	111,158
Issuance of shares pursuant to deferred stock units (in shares)			84,184
Forfeitures of restricted shares (in shares)			0
Shares repurchased and retired (in shares)			(1,691,991)
Balance (in shares) at Dec. 31, 2019			30,715,959							30,715,959
Issuance of common stock upon stock option exercises			$ 1	955						$ 956
Issuance of shares pursuant to restricted stock units	$ 2	$ 1						$ 2	$ 1
Issuance of shares pursuant to deferred stock units			1							1
Shares repurchased and retired			(17)	(30,376)						(30,393)
Balance at Dec. 31, 2019			$ 307	101,148	358,998	(32,694)	7,334			435,093
Equity-based compensation expense				$ 7,751						7,751
Cumulative effect adjustment (see Revenues: Note 3)					0					0
Net income (loss)					$ (20,892)		1,444			(19,448)
Currency translation adjustment and derivative transactions, net						$ 7,596	49			7,645
Investments from non-controlling interest										0
Distributions to non-controlling interests							(1,609)			(1,609)
Sale of non-controlling interests							$ 0			0
Investments from non-controlling interest										$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ (19,448)	$ 3,087		$ (66,582)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	36,163	37,855		44,419
(Gain) loss on sale of fixed assets	(662)	143		(59)
Equity-based compensation expense	7,751	7,838		10,060
Deferred income taxes	3,146	(648)		(9,376)
Non-cash restructuring charges	12,782	13,814		10,080
Goodwill impairment	0	1,389	[1]	45,390
Definite-lived intangible asset impairment	0	2,169		41,032
Impairment of assets held for sale	23,427	0		0
Loss on sale of business	0	7,048		0
Loss on foreign currency transactions	503	623		2,152
Other	(744)	1,278		(1,562)
Changes in operating assets and liabilities (net of acquisitions):
Receivables net, retainage and contract assets	16,416	(6,821)		(29,847)
Inventories	(3,413)	2,306		(1,926)
Prepaid expenses and other assets	4,578	614		8,732
Accounts payable and accrued expenses	(6,711)	(7,339)		18,803
Contract liabilities	5,091	(24,144)		(5,924)
Other operating	(65)	457		(1,798)
Net cash provided by operating activities	78,814	39,669		63,594
Cash flows from investing activities:
Capital expenditures	(28,772)	(30,514)		(30,830)
Proceeds from sale of fixed assets	1,339	3,036		707
Patent expenditures	(293)	(299)		(379)
Other acquisition activity	0	(9,000)		(9,045)
Sale of Bayou, net of cash disposed	0	37,942		0
Net cash provided by (used in) investing activities	(27,726)	1,165		(39,547)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises	956	0		823
Repurchase of common stock	(30,393)	(25,775)		(37,849)
Investments from non-controlling interest	0	0		158
Distributions to non-controlling interests	(1,609)	0		(71)
Payment of contingent consideration	0	0		(500)
Credit facility amendment fees	0	(1,657)		0
Proceeds from (payments on) notes payable, net	(273)	234		639
Proceeds from (payments on) line of credit, net	(7,000)	(7,000)		2,000
Principal payments on long-term debt	(28,438)	(26,250)		(21,647)
Net cash used in financing activities	(66,757)	(60,448)		(56,447)
Effect of exchange rate changes on cash	(2,995)	(4,045)		6,553
Net decrease in cash, cash equivalents and restricted cash for the year	(18,664)	(23,659)		(25,847)
Cash, cash equivalents and restricted cash, beginning of year	84,886	108,545		134,392
Cash, cash equivalents and restricted cash, end of year	66,222	84,886		108,545
Cash, cash equivalents and restricted cash, assets held for sale, end of year	0	0		(989)
Cash, cash equivalents and restricted cash, end of year	66,222	84,886		107,556
Supplemental disclosures of cash flow information:
Interest	14,977	15,622		14,998
Income taxes	$ (1,579)	$ 4,625		$ 5,649
[1]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).

Note 1 - Description of Busines

Note 1 - Description of Business	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. Aegion Corporation combines innovative technologies with market leading expertise to maintain, rehabilitate and strengthen pipelines and other infrastructure around the world. For nearly 50 ® The Company is primarily built on the premise that it is possible to use technology to extend the structural design life and maintain, if not The Company’s predecessor was originally incorporated in Delaware in 1980 ® 1971. ® first 50 In order to strengthen the Company’s ability to service the emerging demands of the infrastructure protection market and to better position the Company for sustainable growth, the Company embarked on a diversification strategy in 2009 Recognizing that the breadth of offerings expanded beyond the Company’s flagship Insituform ® 2011, October 2011. Strategic Initiatives/Acquisitions/Divestitures Restructuring Activities On July 28, 2017, ® During 2018 2019, ® ® ® The Company completed the divestitures of Bayou and the Denmark CIPP business in 2018. ® 2019, 2020 17 first 2020. second 2020 As part of efforts to optimize the cathodic protection operations in North America, the Company’s management initiated plans during the fourth 2019 2019. fourth 2019, 4. Infrastructure Solutions Segment (“Infrastructure Solutions”) During 2019, , and Spain, Insituform Technologies Iberica SA (“Insituform Spain”). December 31, 2019. 6. 17 February 13, 2020. In October 2019, five During 2018, December 31, 2019 2018. 6. 17 January 24, 2020. In November 2018, five ® ® five In March 2017, £6.5 Corrosion Protection Segment (“Corrosion Protection”) In October 2019, fifty-five ® forty-five In August 2018, fifty-one two 2019 2020. 2018, In May 2018, fifty fifty-one Energy Services Segment (“Energy Services”) In July 2018, P2S “P2S” P2S Purchase Price Accounting The Company finalized its accounting for P2S 2019 2018. no P2S, P2S not The Company’s acquisition of Environmental Techniques contributed revenues of $9.5 million, $7.5 million and $4.0 million, and net income (loss) of $(0.1) million, $0.1 million and $(0.7) million in 2019, 2018 2017, P2S 2019 2018.

Note 2 - Accounting Policies

Note 2 - Accounting Policies	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Significant Accounting Policies [Text Block]	2. Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and majority-owned subsidiaries in which the Company is deemed to be the primary beneficiary. All significant intercompany transactions and balances have been eliminated. Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Accumulated Other Comprehensive Loss As set forth below, the Company’s accumulated other comprehensive loss is comprised of three December 31, 2019 2018 Currency translation adjustments (1) $ (27,241 ) $ (41,107 ) Derivative hedging activity (4,522 ) 1,715 Pension activity (931 ) (898 ) Total accumulated other comprehensive loss $ (32,694 ) $ (40,290 ) ( 1 During 2019, $10.9 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 $0.5 million, $0.6 million and $2.2 million for 2019, 2018 2017, Research and Development The Company expenses research and development costs as incurred. Research and development costs of $6.4 million, $5.6 million and $4.2 million for the years ended December 31, 2019, 2018 2017, 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 740” 740 not not may In accordance with FASB ASC 740, may not 50% 740. The Company recognizes tax liabilities in accordance with FASB ASC 740 not may December 31, 2019 2018 740, Refer to Note 12 Earnings per Share Earnings per share have been calculated using the following share information: Years Ended December 31, 2019 2018 2017 Weighted average number of common shares used for basic EPS 31,130,222 32,345,382 33,150,949 Effect of dilutive stock options and restricted and deferred stock unit awards — 652,621 — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 31,130,222 32,998,003 33,150,949 The Company excluded 529,539 restricted and deferred stock units in 2019 2017 2018 2017, Purchase Price Accounting The Company accounts for its acquisitions in accordance with FASB ASC 805, Business Combinations The Company typically determines the fair value of tangible and intangible assets acquired in a business combination using independent valuations that rely on management’s estimates of inputs and assumptions that a market participant would use. Key assumptions include cash flow projections, growth rates, asset lives, and discount rates based on an analysis of weighted average cost of capital. Classification of Current Assets and Current Liabilities The Company includes in current assets and current liabilities certain amounts realizable and payable under construction contracts that may one one 24 Cash, Cash Equivalents and Restricted Cash The Company classifies highly liquid investments with original maturities of 90 Cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets and Consolidated Statements of Cash Flows are as follows (in thousands): December 31, Balance sheet data 2019 2018 Cash and cash equivalents $ 64,874 $ 83,527 Restricted cash 1,348 1,359 Cash, cash equivalents and restricted cash $ 66,222 $ 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. Inventories Inventories are stated at the lower of cost ( first first Retainage Many of the contracts under which the Company performs work contain retainage provisions. Retainage refers to that portion of revenue earned by the Company but held for payment by the customer pending satisfactory completion of the project. The Company generally invoices its customers periodically as work is completed. Under ordinary circumstances, collection from municipalities is made within 60 90 30 45 one one December 31, 2019, 365 Allowance for Doubtful Accounts Management makes estimates of the uncollectibility of accounts receivable and retainage. The Company records an allowance based on specific accounts to reduce receivables, including retainage, to the amount that is expected to be collected. The specific allowances are reevaluated and adjusted as additional information is received. After all reasonable attempts to collect the receivable or retainage have been explored, the account is written off against the allowance. The Company also includes reserves related to certain accounts receivable that may Long-Lived Assets Property, plant and equipment and other identified intangibles (primarily customer relationships, patents and acquired technologies, trademarks, licenses and non-compete agreements) are recorded at cost, net of accumulated depreciation, amortization and impairment, and, except for goodwill, are depreciated or amortized on a straight-line basis over their estimated useful lives. Changes in circumstances such as technological advances, changes to the Company’s business model or changes in the Company’s capital strategy can result in the actual useful lives differing from the Company’s estimates. If the Company determines that the useful life of its property, plant and equipment or its identified intangible assets should be shortened, the Company would depreciate or amortize the net book value in excess of the salvage value over its revised remaining useful life, thereby increasing depreciation or amortization expense. Long-lived assets, including property, plant and equipment and other intangibles, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not may Impairment Review – 2017 As part of the Restructuring, the Company exited all non-pipe related contract applications for the Tyfo ® 360, Property, Plant and Equipment 360” Based on the results of the valuation, the carrying amount of certain long-lived assets for the Fyfe North America asset group exceeded the fair value. Accordingly, the Company recorded impairment charges of $3.4 million to trademarks, $20.8 million to customer relationships and $16.8 million to patents and acquired technology in 2017. no The fair value estimates described above were determined using observable inputs and significant unobservable inputs, which are based on level 3 Goodwill Under FASB ASC 350, may not not • significant underperformance of a segment relative to expected, historical or forecasted operating results; • significant negative industry or economic trends; • significant changes in the strategy for a segment including extended slowdowns in the segment’s market; • a decrease in market capitalization below the Company’s book value; and • a significant change in regulations. Whether during the annual impairment assessment or during a trigger-based impairment review, the Company estimates the fair value of its reporting units and compares such fair value to the carrying value of those reporting units to determine if there are any indications of goodwill impairment. Fair value of reporting units is estimated using a combination of two two The market approach estimates fair value by first The income approach is based on forecasted future (debt-free) cash flows that are discounted to present value using factors that consider timing and risk of future cash flows. The Company believes this approach is appropriate because it provides a fair value estimate based upon the reporting unit’s expected long-term operating cash flow performance. Discounted cash flow projections are based on financial forecasts developed from operating plans and economic outlooks, growth rates, estimates of future expected changes in operating margins, terminal value growth rates, future capital expenditures and changes in working capital requirements. Estimates of discounted cash flows may The discount rate applied to the estimated future cash flows is one twenty may Annual Impairment Assessment – October 1, 2019 The Company had six reporting units for purposes of assessing goodwill at October 1, 2019 Significant assumptions used in the Company’s October 2019 16.0%; 4.9%; The Company’s assessment of each reporting unit’s fair value in relation to its respective carrying value yielded no reporting units with a fair value below carrying value or within 10 percent of its carrying value. The Energy Services reporting unit had a fair value only slightly above 10 not Impairment Review – 2017 As part of the Restructuring, the Company exited all non-pipe related contract applications for the Tyfo ® 2017. December 31, 2017, third not Fair Value Measurements FASB ASC 820, Fair Value Measurements 820” three • Level 1 • Level 2 • Level 3 no The Company uses these levels of hierarchy to measure the fair value of certain financial instruments on a recurring basis, such as for derivative instruments; on a non-recurring basis, such as for acquisitions and impairment testing; for disclosure purposes, such as for long-term debt; and for other applications, as discussed in their respective footnotes. Changes in assumptions or estimation methods could affect the fair value estimates; however, the Company does not 2 no 1, 2 3 2019, 2018 2017. 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. no 2019. Financial data for consolidated variable interest entities are summarized in the following tables (in thousands): December 31, Balance sheet data 2019 2018 Current assets $ 18,304 $ 33,066 Non-current assets 7,635 6,466 Current liabilities 8,261 12,953 Non-current liabilities 1,962 8,780 Years Ended December 31, Statement of operations data 2019 (1) 2018 (2) 2017 Revenue $ 28,403 $ 49,809 $ 91,947 Gross profit 9,508 9,898 15,194 Net (income) loss attributable to Aegion Corporation (1,100 ) (1,374 ) 3,432 ( 1 Includes activity from our Tite Liner ® fourth 2019. ( 2 Includes activity from our pipe coating and insulation joint venture in Louisiana, which was sold during the third 2018. Accounting Standards Updates In December 2019, No. 2019 12, Simplifying the Accounting for Income Taxes 740 January 1, 2021, not In August 2018, No. 2018 13, Fair Value Measurement: Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 1, 2 3 January 1, 2020, not In February 2018, No. 2018 02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income may one two January 1, 2019 not In June 2016, No. 2016 13, Measurement of Credit Losses on Financial Instruments January 1, 2020, January 1, 2020, not In February 2016, No. 2016 02, Leases (Topic 842 twelve January 1, 2019, January 1, 2019 7.

Note 3 - Revenues

Note 3 - Revenues	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. On January 1, 2018, 606, Revenue from Contracts with Customers 606” not 606 not The Company recorded a net reduction to opening retained earnings of $0.3 million as of January 1, 2018 606, December 31, 2019 2018 606. Performance Obligations A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in FASB ASC 606. not not not 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 92.3%, 93.5% and 93.5% of revenues for the years ended December 31, 2019, 2018 2017, 606 55 255, not December 31, 2019, 2018 2017, On December 31, 2019, December 31, 2019 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 not not not 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): Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 427,220 $ 159,408 $ 328,048 $ 914,676 Canada 65,370 57,663 — 123,033 Europe 49,157 15,121 — 64,278 Other foreign 49,050 62,898 — 111,948 Total revenues $ 590,797 $ 295,090 $ 328,048 $ 1,213,935 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 430,187 $ 200,397 $ 335,707 $ 966,291 Canada 62,292 71,320 — 133,612 Europe 54,567 12,227 — 66,794 Other foreign 57,075 109,796 — 166,871 Total revenues $ 604,121 $ 393,740 $ 335,707 $ 1,333,568 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 437,944 $ 299,643 $ 290,726 $ 1,028,313 Canada 60,675 79,059 — 139,734 Europe 58,520 13,319 — 71,839 Other foreign 55,015 64,118 — 119,133 Total revenues $ 612,154 $ 456,139 $ 290,726 $ 1,359,019 The following tables summarize revenues by segment and contract type (in thousands): Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 523,042 $ 203,887 $ 704 $ 727,633 Time and materials — 65,084 327,344 392,428 Product sales 67,512 26,119 — 93,631 License fees 243 — — 243 Total revenues $ 590,797 $ 295,090 $ 328,048 $ 1,213,935 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 556,642 $ 296,217 $ 16,134 $ 868,993 Time and materials — 58,372 319,573 377,945 Product sales 45,030 39,151 — 84,181 License fees 2,449 — — 2,449 Total revenues $ 604,121 $ 393,740 $ 335,707 $ 1,333,568 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 569,701 $ 353,480 $ 9,225 $ 932,406 Time and materials — 56,288 281,501 337,789 Product sales 41,878 46,371 — 88,249 License fees 575 — — 575 Total revenues $ 612,154 $ 456,139 $ 290,726 $ 1,359,019 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 not one 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): December 31, 2019 (1) 2018 (2) Contract assets – current $ 51,092 $ 62,467 Contract liabilities – current (37,562 ) (32,339 ) Net contract assets $ 13,530 $ 30,128 ( 1 Amounts exclude contract assets of $5.4 million and contract liabilities of $0.1 million that were classified as held for sale at December 31, 2019 ( 6 ( 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 ( 6 Included in the change of total net contract assets was a $11.4 million decrease in contract assets, primarily related to the timing between work performed on open contracts and contractual billing terms, and a $5.2 million increase 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 December 31, 2017, 2019 2018, Impairment losses recognized on receivables and contract assets were not 2019, 2018 2017.

Note 4 - Restructuring

Note 4 - Restructuring	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Restructuring, Impairment, and Other Activities Disclosure [Text Block]	4. On July 28, 2017, ® During 2018 2019, ® ® ® The Company completed the divestitures of Bayou and the Denmark CIPP business in 2018. ® 2019, 2020 17 first 2020. second 2020 As part of efforts to optimize the cathodic protection operations in North America, management initiated plans during the fourth 2019 three 2019. fourth 2019, Total pre-tax restructuring and related impairment charges since the Restructuring’s inception were $171.9 million ($155.7 million post-tax) and consisted of cash charges totaling $45.3 million and non-cash charges totaling $126.6 million. Cash charges included employee severance, retention, extension of benefits, employment assistance programs, early lease and contract termination costs and other restructuring charges 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 650 The Company is substantially complete with respect to its restructuring efforts and expects to incur additional cash charges of between $2 million and $4 million. Also, the Company could incur additional non-cash charges primarily associated with the release of cumulative currency translation adjustments and losses on the closure or liquidation of international entities. 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 and Corporate to a lesser extent. During 2019, 2018 2017, Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 938 $ 3,179 $ 553 $ 1,685 $ 6,355 Contract termination costs 601 1,089 234 98 2,022 Relocation and other moving costs 190 408 55 — 653 Other restructuring costs (1) 13,642 4,592 819 4,258 23,311 Total pre-tax restructuring charges $ 15,371 $ 9,268 $ 1,661 $ 6,041 $ 32,341 ( 1 Includes charges primarily related to certain wind-down costs, inventory obsolescence, fixed asset disposals, release of cumulative currency translation adjustments and other restructuring-related costs in connection with exiting or divesting the CIPP operations in Europe and Australia, exiting the cathodic protection operations in the Middle East and right-sizing the cathodic protection services operation in North America. Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 3,038 $ 1,094 $ 234 $ 170 $ 4,536 Contract termination costs 1,999 25 — 150 2,174 Relocation and other moving costs 184 — — — 184 Other restructuring costs (1) 13,311 7,936 28 1,317 22,592 Total pre-tax restructuring charges $ 18,532 $ 9,055 $ 262 $ 1,637 $ 29,486 ( 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 ® Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Corporate Total Severance and benefit related costs $ 4,274 $ 2,442 $ 629 $ 7,345 Contract termination costs 4,545 775 — 5,320 Relocation and other moving costs 26 121 — 147 Other restructuring costs (1) 8,434 1,522 975 10,931 Total pre-tax restructuring charges $ 17,279 $ 4,860 $ 1,604 $ 23,743 ( 1 Includes charges primarily related to exiting non-pipe-related applications for the Tyfo ® Restructuring costs related to severance, other termination benefit costs and early lease and contract termination costs were $9.0 million, $6.9 million and $12.8 million in 2019, 2018 2017, The following tables summarize restructuring charges recognized in 2019, 2018 2017 Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ 469 $ 1,869 $ — $ — $ 2,338 Operating expenses 5,349 1,131 819 3,444 10,743 Restructuring and related charges 1,729 4,676 842 1,783 9,030 Other expense (2) 7,824 1,592 — 814 10,230 Total pre-tax restructuring charges $ 15,371 $ 9,268 $ 1,661 $ 6,041 $ 32,341 ( 1 Total pre-tax restructuring charges include cash charges of $19.5 million and non-cash charges of $12.8 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods. ( 2 Includes charges related to the loss on disposal of restructured entities, including the release of cumulative currency translation adjustments resulting from those disposals. Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ 1,281 $ 600 $ — $ — $ 1,881 Operating expenses 7,291 4,547 28 1,317 13,183 Goodwill impairment 1,389 — — — 1,389 Definite-lived intangible asset impairment 870 1,299 — — 2,169 Restructuring and related charges 5,221 1,119 234 320 6,894 Other expense (2) 2,480 1,490 — — 3,970 Total pre-tax restructuring charges $ 18,532 $ 9,055 $ 262 $ 1,637 $ 29,486 ( 1 Total pre-tax restructuring charges include cash charges of $12.1 million and non-cash charges of $17.4 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods. ( 2 Includes charges related to the loss on disposal of restructured entities, including the release of cumulative currency translation adjustments resulting from those disposals. Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Corporate Total (1) Cost of revenues $ 30 $ 15 $ — $ 45 Operating expenses 8,404 1,507 973 10,884 Restructuring and related charges 8,845 3,338 631 12,814 Total pre-tax restructuring charges $ 17,279 $ 4,860 $ 1,604 $ 23,743 ( 1 Total pre-tax restructuring charges include cash charges of $13.6 million and non-cash charges of $10.1 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods. The following tables summarize restructuring activity during 2019, 2018 2017 Utilized in 2019 Reserves at December 31, 2018 2019 Charge to Income Foreign Currency Translation Cash(1) Non-Cash Reserves at December 31, 2019 Severance and benefit related costs $ 1,742 $ 6,355 $ (11 ) $ 3,697 $ — $ 4,389 Contract termination costs 359 2,022 (20 ) 1,408 — 953 Relocation and other moving costs — 653 (3 ) 283 — 367 Other restructuring costs 311 23,311 (4 ) 8,457 12,782 2,379 Total pre-tax restructuring charges $ 2,412 $ 32,341 $ (38 ) $ 13,845 $ 12,782 $ 8,088 Utilized in 2018 Reserves at December 31, 2017 2018 Charge to Income Foreign Currency Translation Cash(1) Non-Cash Reserves at December 31, 2018 Severance and benefit related costs $ 3,864 $ 4,536 $ (69 ) $ 6,589 $ — $ 1,742 Contract termination costs 650 2,174 (19 ) 2,446 — 359 Relocation and other moving costs — 184 — 184 — — Other restructuring costs 675 22,592 (3 ) 5,581 17,372 311 Total pre-tax restructuring charges $ 5,189 $ 29,486 $ (91 ) $ 14,800 $ 17,372 $ 2,412 Utilized in 2017 2017 Charge to Income Cash(1) Non-Cash Reserves at December 31, 2017 Severance and benefit related costs $ 7,345 $ 3,481 $ — $ 3,864 Contract termination costs 5,320 2,706 1,964 650 Relocation and other moving costs 147 147 — — Other restructuring costs 10,931 2,140 8,116 675 Total pre-tax restructuring charges $ 23,743 $ 8,474 $ 10,080 $ 5,189 ( 1 Refers to cash utilized to settle charges during the year.

Note 5 - Supplemental Balance S

Note 5 - Supplemental Balance Sheet Information	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Supplemental Balance Sheet Disclosures [Text Block]	5. Allowance for Doubtful Accounts Activity in the allowance for doubtful accounts is summarized as follows (in thousands): Years Ended December 31, 2019 2018 2017 Balance, beginning of year $ 9,695 $ 5,775 $ 6,098 Bad debt expense (1) (1,259 ) 8,188 3,155 Write-offs and adjustments (1,212 ) (4,268 ) (3,478 ) Balance, end of year $ 7,224 $ 9,695 $ 5,775 ( 1 The Company recorded bad debt expense (reversals) of less than ($0.1) million, $5.3 million and $0.4 million in 2019, 2018 2017, 4 Inventories Inventories are summarized as follows (in thousands): December 31, 2019 2018 (1) Raw materials and supplies $ 27,415 $ 29,343 Work-in-process 5,739 2,510 Finished products 14,937 15,205 Construction materials 9,102 9,379 Total $ 57,193 $ 56,437 ( 1 During 2018, Property, Plant and Equipment Property, plant and equipment consisted of the following (in thousands): Estimated Useful Lives December 31, (Years) 2019 2018 Land and land improvements $ 5,359 $ 10,521 Buildings and improvements 5 — 40 50,589 47,430 Machinery and equipment 4 — 10 143,128 147,918 Furniture and fixtures 3 — 10 35,440 37,471 Autos and trucks 3 — 10 47,197 51,129 Construction in progress 7,475 14,626 289,188 309,095 Less – Accumulated depreciation (188,097 ) (202,036 ) Property, plant & equipment, less accumulated depreciation $ 101,091 $ 107,059 Depreciation expense was $22.2 million, $23.9 million and $29.3 million for the years ended December 31, 2019, 2018 2017, 2018 2018. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2019 2018 Vendor and other accrued expenses $ 30,730 $ 35,450 Estimated casualty and healthcare liabilities 13,138 17,419 Job costs 12,041 9,878 Accrued compensation 23,089 23,882 Operating lease liabilities 15,828 — Income taxes payable 1,751 1,391 Total $ 96,577 $ 88,020

Note 6 - Assets and Liabilities

Note 6 - Assets and Liabilities Held for Sale	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	6. During the first 2019, 1 17 1 fourth 2019, The Company is currently in various stages of discussions with third first 2020. 2020. During 2018, 17 January 24, 2020. The relevant asset and liability balances at December 31, 2019 2018 2019. second 2019, fourth 2019, fourth 2019 The following table provides the components of assets and liabilities held for sale (in thousands): December 31, 2019(1) 2018(2) Assets held for sale: Current assets Receivables, net $ 4,136 $ 1,309 Retainage 518 15 Contract assets 5,350 1,777 Inventories 2,097 2,123 Prepaid expenses and other current assets 799 300 Total current assets 12,900 5,524 Property, plant & equipment, less accumulated depreciation 10,962 2,268 Goodwill 4,224 — Intangible assets, less accumulated amortization 1,528 — Operating lease assets 326 — Other non-current assets 130 — Impairment of assets held for sale (13,978 ) — Total assets held for sale $ 16,092 $ 7,792 Liabilities held for sale: Current liabilities Accounts payable $ 2,174 $ 1,331 Accrued expenses 3,961 3,891 Contract liabilities 122 38 Total current liabilities 6,257 5,260 Operating lease liabilities 174 — Other non-current liabilities 54 — Total liabilities held for sale $ 6,485 $ 5,260 ( 1 Includes Insituform Australia, Insituform Spain, Environmental Techniques and land held at Corporate. ( 2 Includes Insituform Australia.

Note 7 - Leases

Note 7 - Leases	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	7. Effective January 1, 2019, 842 January 1, 2019 not not 842 January 1, 2019 No 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 January 1, 2019 January 1, 2019. not The following table presents the components of lease expense (in thousands): Year Ended December 31, 2019 Operating lease cost $ 22,235 Short-term lease cost 25,382 Total lease cost $ 47,617 Supplemental cash flow information related to leases was as follows (in thousands): Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 22,144 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18,879 Supplemental balance sheet information related to leases was as follows (in thousands): December 31, 2019(1) Operating leases: Operating lease assets $ 71,466 Accrued expenses $ 15,828 Other liabilities 56,253 Total operating lease liabilities $ 72,081 Weighted-average remaining lease term (in years) 5.74 Weighted-average discount rate 5.71 % ( 1 Amounts exclude operating lease assets of $0.3 million, accrued expenses of $0.2 million and other liabilities of $0.2 million that were classified as held for sale at December 31, 2019 5 Operating lease liabilities under non-cancellable leases were as follows (in thousands): December 31, 2019 2020 $ 18,739 2021 16,287 2022 13,509 2023 10,950 2024 7,845 Thereafter 16,358 Total undiscounted operating lease liabilities 83,688 Less: Imputed interest (11,607 ) Total discounted operating lease liabilities $ 72,081 Minimum rental commitments under non-cancellable leases as of December 31, 2018 2019 2023

Note 8 - Goodwill and Intangibl

Note 8 - Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Goodwill and Intangible Assets Disclosure [Text Block]	8. Goodwill The following table presents a reconciliation of the beginning and ending balances of goodwill (in thousands): Infrastructure Solutions Corrosion Protection Energy Services Total Balance, December 31, 2017 Goodwill, gross $ 246,486 $ 74,369 $ 80,246 $ 401,101 Accumulated impairment losses (61,459 ) (45,400 ) (33,527 ) (140,386 ) Goodwill, net 185,027 28,969 46,719 260,715 2018 Activity: Acqusitions (1) — 2,715 1,258 3,973 Impairments (2) (1,389 ) — — (1,389 ) Foreign currency translation (1,965 ) (701 ) — (2,666 ) 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 (137 ) 563 — 426 Reclassification to assets held for sale (3) (4,224 ) — — (4,224 ) Balance, December 31, 2019 Goodwill, gross 240,160 76,946 81,504 398,610 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 177,312 $ 31,546 $ 47,977 $ 256,835 ( 1 During 2018, P2S, 1 ( 2 During 2018, 4 ( 3 During 2019, 6 Intangible Assets Intangible assets consisted of the following (in thousands): December 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 0.7 $ 3,894 $ (3,825 ) $ 70 $ 3,894 $ (3,716 ) $ 178 Leases 1.0 864 (777 ) 87 864 (689 ) 175 Trademarks 8.3 15,699 (6,911 ) 8,788 15,751 (6,202 ) 9,549 Non-competes 3.3 2,301 (1,354 ) 947 2,529 (1,229 ) 1,300 Customer relationships 7.2 157,576 (76,832 ) 80,744 159,719 (66,753 ) 92,966 Patents and acquired technology 9.0 39,288 (25,097 ) 14,192 38,338 (22,810 ) 15,528 Total intangible assets — $ 219,622 $ (114,795 ) $ 104,828 $ 221,095 $ (101,399 ) $ 119,696 Amortization expense was $13.7 million, $14.0 million and $16.1 million for the years ended December 31, 2019, 2018 2017, December 31, 2020, 2021, 2022, 2023 2024

Note 9 - Long-term Debt and Cre

Note 9 - Long-term Debt and Credit Facility	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Debt Disclosure [Text Block]	9. Long-term debt consisted of the following (in thousands): December 31, 2019 2018 Term note, due February 27, 2023, annualized rates of 4.09% and 4.59%, respectively $ 253,750 $ 282,188 Line of credit, 4.01% and 4.45%, respectively 24,000 31,000 Other notes with interest rates from 3.3% to 7.8% 770 1,031 Subtotal 278,520 314,219 Less – Current maturities of long-term debt 32,803 29,469 Less – Unamortized loan costs 2,088 2,747 Total $ 243,629 $ 282,003 Required principal payments for each of the next five December 31, 2019 2020 $ 32,803 2021 25,060 2022 30,844 2023 189,813 2024 — Thereafter — Total $ 278,520 Financing Arrangements In October 2015, February 2018 December 2018, February 2023. During 2018, third 2018. 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 is also based on the Company’s consolidated leverage ratio. The applicable LIBOR borrowing rate (LIBOR plus Company’s applicable rate) as of December 31, 2019 The Company’s indebtedness at December 31, 2019 2019, As of December 31, 2019, The Company’s indebtedness at December 31, 2018 third 2018, At December 31, 2019 2018, 3 2. In October 2015, October 2020. $262.5 $262.5 $262.5 $262.5 December 31, 2019 15. In March 2018, October 2020 February 2023 $170.6 15. 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, as amended, compares consolidated funded indebtedness to amended Credit Facility defined income with a maximum amount not 1.00. December 31, 2019, 1.00 • Consolidated fixed charge coverage ratio, as amended, compares amended Credit Facility defined income to amended Credit Facility defined fixed charges with a minimum permitted ratio of not 1.00. December 31, 2019, 1.00. At December 31, 2019,

Note 10 - Stockholders' Equity

Note 10 - Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	10. Share Repurchase Plan In December 2018, two million one 10b5 1 1934. not December 2018, 2019. January 2019. December 2019, two million not 2020 1.00. 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 may During 2019, During 2018, 2018, not During 2017, 2017, not Equity-Based Compensation Plans Employee Plans In April 2016, 2016 2017 2016 “2016 April 2018, 2016 2016 2016 2013 2016 December 31, 2019, 2016 Director Plans In April 2016, 2016 “2016 2011 April 2019, 2016 2016 2016 2016 2016 December 31, 2019, 2016 Prior to the 2016 2011 “2011 2006 “2006 2001 “2001 December 31, 2019, 2011 2006 2001 Activity and related expense associated with these plans are described in Note 11.

Note 11 - Equity-based Compensa

Note 11 - Equity-based Compensation	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	11. 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 recorded as a reduction of current period expense. A summary of stock award activity is as follows: Years Ended December 31, 2019 2018 2017 Stock Awards Weighted Average Award Date Fair Value Stock Awards Weighted Average Award Date Fair Value Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2018 1,143,205 $ 23.26 1,428,878 $ 21.53 1,501,021 $ 20.58 Period Activity: Restricted stock units awarded 325,321 20.02 281,567 24.13 257,532 23.06 Performance stock units awarded 146,367 22.78 219,943 23.25 213,436 28.18 Restricted shares distributed (76,686 ) 18.26 — — (179,169 ) 22.44 Restricted stock units distributed (237,416 ) 18.83 (312,182 ) 17.47 (95,510 ) 20.71 Performance stock units distributed (111,155 ) 25.85 (296,909 ) 21.55 (49,672 ) 21.95 Restricted shares forfeited — — — — (1,084 ) 23.01 Restricted stock units forfeited (74,075 ) 22.09 (90,896 ) 21.79 (81,626 ) 20.36 Performance stock units forfeited (80,597 ) 25.30 (87,196 ) 25.95 (136,050 ) 24.29 Outstanding at December 31, 2019 1,034,964 $ 23.20 1,143,205 $ 23.26 1,428,878 $ 21.53 Expense associated with stock awards was $7.0 million, $6.8 million and $9.0 million in 2019, 2018 2017, December 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 April 2019, 2016 one A summary of deferred stock unit activity is as follows: Years Ended December 31, 2019 2018 2017 Deferred Stock Units Weighted Average Award Date Fair Value Deferred Stock Units Weighted Average Award Date Fair Value Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2018 287,350 $ 20.80 269,977 $ 20.14 253,445 $ 19.93 Period Activity: Awarded 50,174 19.64 45,681 23.72 47,091 23.53 Distributed (84,184 ) 20.38 (28,308 ) 19.22 (30,559 ) 23.57 Outstanding at December 31, 2019 253,340 $ 20.71 287,350 $ 20.80 269,977 $ 20.14 Expense associated with awards of deferred stock units was $0.7 million, $1.1 million and $1.1 million in 2019, 2018 2017, December 31, 2019. Stock Options Stock options on the Company’s common stock are awarded from time to time to executive officers and certain key employees of the Company. Stock options granted generally have a term of seven ten A summary of stock option activity is as follows: Years Ended December 31, 2019 2018 2017 Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Outstanding, beginning of year 52,783 $ 18.11 126,680 $ 23.06 170,253 $ 21.99 Exercised (52,783 ) 18.11 — — (43,573 ) 18.87 Canceled/Expired — — (73,897 ) 26.60 — — Outstanding, end of year — $ — 52,783 $ 18.11 126,680 $ 23.06 Exercisable, end of year — $ — 52,783 $ 18.11 126,680 $ 23.06 In 2019, 2018 2017, Financial data for stock option exercises are summarized in the following table (in thousands): Years Ended December 31, 2019 2018 2017 Amount received from stock option exercises $ 956 $ — $ 823 Total intrinsic value of stock option exercises (1) 129 — 370 Tax expense (benefit) of stock option exercises recorded in income tax expense 312 (1,556 ) (63 ) Aggregate intrinsic value of outstanding stock options — — 386 Aggregate intrinsic value of exercisable stock options — — 386 ( 1 December 31, 2019 2017,

Note 12 - Taxes on Income

Note 12 - Taxes on Income	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Income Tax Disclosure [Text Block]	12. Income (loss) before taxes on income was as follows (in thousands): Years Ended December 31, 2019 2018 2017 Domestic $ 3,627 $ 8,142 $ (40,007 ) Foreign (16,511 ) (5,187 ) (21,570 ) Total $ (12,884 ) $ 2,955 $ (61,577 ) 97 Provisions for taxes on income (loss) consisted of the following components (in thousands): Years Ended December 31, 2019 2018 2017 Current: Federal $ (2,775 ) $ (4,765 ) $ 3,764 Foreign 5,705 6,025 7,512 State 460 (651 ) 3,351 Subtotal 3,390 609 14,627 Deferred: Federal 538 947 (8,706 ) Foreign (199 ) (1,531 ) (1,099 ) State 2,835 (157 ) 183 Subtotal 3,174 (741 ) (9,622 ) Total tax provision $ 6,564 $ (132 ) $ 5,005 Income tax expense differed from the amounts computed by applying the U.S. federal income tax rate of 21% for 2019 2018 2017 Years Ended December 31, 2019 2018 2017 Income taxes (benefit) at U.S. federal statutory tax rate $ (2,706 ) $ 621 $ (21,552 ) Increase (decrease) in taxes resulting from: Change in the balance of the valuation allowance for deferred tax assets allocated to foreign income tax expense 806 590 4,598 Change in the balance of the valuation allowance for deferred tax assets allocated to domestic income tax expense 2,960 (944 ) 12,755 State income taxes, net of federal income tax benefit 2,603 (798 ) 2,270 Divestitures 5,613 2,133 — Meals and entertainment 470 517 785 Changes in taxes previously accrued (1,070 ) (536 ) (1,339 ) Foreign tax rate differences (643 ) 1,301 913 Share-based compensation 358 (1,427 ) 131 Goodwill impairment — 291 6,359 Recognition of uncertain tax positions (717 ) (218 ) (62 ) Deemed mandatory repatriation — (842 ) 10,406 Release of deferred tax liability on foreign earnings — — (7,051 ) Domestic Production Activities deduction — — (1,921 ) Other matters (1,110 ) (820 ) (1,287 ) Total tax provision $ 6,564 $ (132 ) $ 5,005 Effective tax rate (50.9 %) (4.5 %) (8.1 %) On December 22, 2017, 35% 21%; one not 2018, no no In its reporting since the TCJA was enacted, the Company had been recording provisional amounts for certain enactment-date effects of the TCJA by applying the guidance in SAB 118 not 2018 2017, one not The one 1986 2017 2015 2016. 2017, 2018. December 31, 2017 2018, The transition tax liability, as filed on the 2017 2018, eight eight April 2018 first December 2018 no 2017 2018 no Net deferred taxes consisted of the following (in thousands): December 31, 2019 2018 Deferred income tax assets: Foreign tax credit carryforwards $ 4,101 $ 507 Net operating loss carryforwards 19,079 22,909 Accrued expenses 15,281 12,987 Other 8,431 8,652 Total gross deferred income tax assets 46,892 45,055 Less valuation allowance (34,247 ) (28,451 ) Net deferred income tax assets 12,645 16,604 Deferred income tax liabilities: Property, plant and equipment (5,689 ) (6,038 ) Intangible assets (12,203 ) (10,609 ) Other (4,791 ) (6,757 ) Total deferred income tax liabilities (22,683 ) (23,404 ) Net deferred income tax liabilities $ (10,038 ) $ (6,800 ) The Company’s tax assets and liabilities, netted by taxing location, are in the following captions in the balance sheets (in thousands): December 31, 2019 2018 Noncurrent deferred income tax assets, net $ 1,216 $ 1,561 Noncurrent deferred income tax liabilities, net (11,254 ) (8,361 ) Net deferred income tax liabilities $ (10,038 ) $ (6,800 ) The Company’s deferred tax assets at December 31, 2019 not 2020 2039, no 2026 not 2029 not no For financial reporting purposes, a valuation allowance of $34.2 million has been recognized at December 31, 2019 not not December 31, 2018 As of December 31, 2019, not no may Activity in the valuation allowance is summarized as follows (in thousands): Years Ended December 31, 2019 2018 2017 Balance, at beginning of year $ 28,451 $ 29,782 $ 15,428 Additions 8,789 1,879 19,260 Reversals (6,776 ) (2,102 ) (183 ) Remeasurement of U.S. deferred tax balances — — (5,141 ) Other adjustments 3,783 (1,108 ) 418 Balance, at end of year $ 34,247 $ 28,451 $ 29,782 As a result of the deemed mandatory repatriation provisions in the TCJA, the Company included $206.7 million of undistributed earnings in income subject to U.S. tax at reduced tax rates. Certain provisions within the TCJA effectively transition the U.S. to a territorial system and eliminates deferral on U.S. taxation for certain amounts of income that are not not 100 not not December 31, 2019. FASB ASC 740, Income Taxes 740” not 740 A reconciliation of the beginning and ending balance of unrecognized tax benefits is as follows (in thousands): Years Ended December 31, 2019 2018 2017 Balance, at beginning of year $ 1,955 $ 2,229 $ 2,465 Additions for tax positions of prior years 9 8 12 Lapse in statute of limitations (587 ) (264 ) (274 ) Foreign currency translation 7 (18 ) 26 Balance, at end of year, total tax provision $ 1,384 $ 1,955 $ 2,229 The total amount of unrecognized tax benefits, if recognized, that would affect the effective tax rate was $0.3 million at December 31, 2019. The Company recognizes interest and penalties, if any, related to unrecognized tax benefits in income tax expense. During the years ended December 31, 2019, 2018 2017, The Company believes that it is reasonably possible that the total amount of unrecognized tax benefits will change in 2020. twelve The Company is subject to taxation in the United States, various states and foreign jurisdictions. With few exceptions, the Company is no 2015

Note 13 - Commitments and Conti

Note 13 - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	13. 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 Contingencies In connection with the Brinderson acquisition, certain pre-acquisition matters were identified in 2014 No. 450 20, Contingencies - Loss Contingencies December 31, 2016, 2017, one 2017 third 2017. 2018, one December 31, 2018, 2019, Purchase Commitments The Company had no December 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 third not no not 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 December 31, 2019 Retirement Plans Approximately 1,050 of our U.S. employees participate in multi-employer retirement plans. Substantially all of the Company’s remaining U.S. employees are eligible to participate in one 401 December 31, 2019, 2018 2017, Certain foreign subsidiaries maintain various other defined contribution retirement plans. Company contributions to such plans for the years ended December 31, 2019, 2018 2017 In connection with the Company’s 2009 no December 31, 2019, 2018 2017 December 31, 2019 December 31, 2018 2 2.

Note 14 - Segment and Geographi

Note 14 - Segment and Geographic Information	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	14. The Company has three 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. In 2019, 2018 2017 Financial information by segment was as follows (in thousands): Years Ended December 31, 2019 2018 2017 Revenues: Infrastructure Solutions $ 590,797 $ 604,121 $ 612,154 Corrosion Protection 295,090 393,740 456,139 Energy Services 328,048 335,707 290,726 Total revenues $ 1,213,935 $ 1,333,568 $ 1,359,019 Gross profit: Infrastructure Solutions $ 144,074 $ 132,411 $ 140,823 Corrosion Protection 60,927 92,968 108,240 Energy Services 41,234 41,547 35,749 Total gross profit $ 246,235 $ 266,926 $ 284,812 Operating income (loss): Infrastructure Solutions (1) $ 42,079 $ 37,509 $ (47,316 ) Corrosion Protection (2) (5,635 ) 16,283 32,222 Energy Services (3) 9,740 9,638 7,736 Corporate (4) (35,211 ) (33,783 ) (36,162 ) Total operating income (loss) 10,973 29,647 (43,520 ) Other income (expense): Interest expense (14,002 ) (17,327 ) (16,001 ) Interest income 1,038 516 145 Other (5) (10,893 ) (9,881 ) (2,201 ) Total other expense (23,857 ) (26,692 ) (18,057 ) Income (loss) before taxes on income $ (12,884 ) $ 2,955 $ (61,577 ) Total assets: Infrastructure Solutions $ 508,226 $ 500,977 $ 531,746 Corrosion Protection 278,694 279,106 329,848 Energy Services 161,165 163,109 152,416 Corporate 31,336 41,432 22,775 Assets held for sale 16,092 7,793 70,314 Total assets $ 995,513 $ 992,417 $ 1,107,099 Capital expenditures: Infrastructure Solutions $ 10,679 $ 12,730 $ 16,680 Corrosion Protection 11,437 9,754 8,603 Energy Services 3,437 3,053 2,713 Corporate 3,219 4,977 2,834 Total capital expenditures $ 28,772 $ 30,514 $ 30,830 Depreciation and amortization: Infrastructure Solutions $ 13,773 $ 16,758 $ 18,731 Corrosion Protection 12,487 11,874 15,598 Energy Services 7,490 7,111 6,726 Corporate 2,413 2,112 3,364 Total depreciation and amortization $ 36,163 $ 37,855 $ 44,419 ( 1 Operating income for 2019 4 6 2018 4 2017 4 2 2 ( 2 Operating loss for 2019 4 6 2018 4 2017 4 ( 3 Operating income for 2019 4 2018 4 ( 4 Operating loss for 2019 4 6 2018 4 2017 4 ( 5 Other expense for 2019 4 2018 1 4 The following table summarizes revenues, gross profit, operating income (loss) and long-lived assets by geographic region (in thousands): Years Ended December 31, 2019 2018 2017 Revenues: (1) United States $ 914,676 $ 966,291 $ 1,028,313 Canada 123,033 133,612 139,734 Europe 64,278 66,794 71,839 Other foreign 111,948 166,871 119,133 Total revenues $ 1,213,935 $ 1,333,568 $ 1,359,019 Gross profit: (1) United States $ 175,705 $ 178,024 $ 226,026 Canada 22,183 22,823 31,173 Europe 14,849 8,379 11,997 Other foreign 33,498 57,700 15,616 Total gross profit $ 246,235 $ 266,926 $ 284,812 Operating income (loss): (1) United States $ 6,212 $ 174 $ (33,583 ) Canada 7,460 9,482 12,220 Europe (11,363 ) (10,599 ) (3,771 ) Other foreign 8,664 30,590 (18,386 ) Total operating income (loss) $ 10,973 $ 29,647 $ (43,520 ) Long-lived assets: (1)(2) United States $ 80,910 $ 105,978 $ 93,472 Canada 7,462 7,725 8,816 Europe 2,499 8,295 13,435 Other foreign 10,220 6,662 9,586 Total long-lived assets $ 101,091 $ 128,660 $ 125,309 ( 1 Attributed to the country of origin. ( 2 Long-lived assets do not

Note 15 - Derivative Financial

Note 15 - Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Derivative Instruments and Hedging Activities Disclosure [Text Block]	15. As a matter of policy, the Company uses derivatives for risk management purposes, and does not may no December 31, 2019, December 31, 2018. 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 2019, 2018 2017, In October 2015, October 2020. $262.5 $262.5 In March 2018, October 2020 February 2023 The following table summarizes the Company’s derivative positions at December 31, 2019: Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate Interest Rate Swap — $ 190,312,500 3.2 — The following table summarizes the fair value amounts of the Company’s derivative instruments, all of which are Level 2 2 December 31, Designation of Derivatives Balance Sheet Location 2019 2018 Derivatives Designated as Hedging Instruments: Interest Rate Swaps Other non-current assets $ 261 $ 3,648 Total Assets $ 261 $ 3,648 Interest Rate Swaps Other non-current liabilities $ 4,899 $ 1,885 Total Liabilities $ 4,899 $ 1,885 Forward Currency Contracts Accrued expenses $ — $ 44 Total Liabilities $ — $ 44 Total Derivative Assets $ 261 $ 3,648 Total Derivative Liabilities 4,899 1,929 Total Net Derivative Asset (Liability) $ (4,638 ) $ 1,719

Note 16 - Selected Quarterly Fi

Note 16 - Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Quarterly Financial Information [Text Block]	16. Unaudited quarterly financial data was as follows (in thousands, except per share data): First Quarter(1) Second Quarter(2) Third Quarter(3) Fourth Quarter(4) Year Ended December 31, 2019: Revenues $ 276,904 $ 318,740 $ 308,789 $ 309,502 Gross profit 48,295 67,437 66,792 63,711 Operating income (loss) (774 ) 459 14,649 (3,361 ) Net income (loss) (3,991 ) (8,147 ) 6,349 (13,659 ) Earnings (loss) per share attributable to Aegion Corporation: Basic $ (0.13 ) $ (0.27 ) $ 0.20 $ (0.47 ) Diluted $ (0.13 ) $ (0.27 ) $ 0.19 $ (0.47 ) ( 1 Includes pre-tax expenses of $2.9 million related to our restructuring efforts (see Note 4 ( 2 Includes pre-tax expenses of $6.5 million related to our restructuring efforts (see Note 4 ( 3 Includes pre-tax expenses of $8.6 million related to our restructuring efforts (see Note 4 ( 4 Includes pre-tax expenses of $14.3 million related to our restructuring efforts (see Note 4 First Quarter(1) Second Quarter(2) Third Quarter(3) Fourth Quarter(4) Year Ended December 31, 2018: Revenues $ 324,861 $ 335,030 $ 339,679 $ 333,998 Gross profit 61,504 71,053 72,673 61,696 Operating income (loss) 3,181 14,459 13,009 (1,002 ) Net income (loss) (1,476 ) 7,198 141 (2,776 ) Earnings (loss) per share attributable to Aegion Corporation: Basic $ (0.06 ) $ 0.24 $ (0.01 ) $ (0.08 ) Diluted $ (0.06 ) $ 0.24 $ (0.01 ) $ (0.08 ) ( 1 Includes pre-tax expenses of $5.2 million related to our restructuring efforts (see Note 4 ( 2 Includes pre-tax expenses of $2.9 million related to our restructuring efforts (see Note 4 ( 3 Includes pre-tax expenses of $7.4 million related to our restructuring efforts (see Note 4 ( 4 Includes pre-tax expenses of $13.9 million related to our restructuring efforts (see Note 4

Note 17 - Subsequent Events

Note 17 - Subsequent Events	12 Months Ended
	Dec. 31, 2019
Notes to Financial Statements
Subsequent Events [Text Block]	17. Sale of Insituform Australia On January 24, 2020, five ® five second 2019, No Sale of Insituform Spain On February 13, 2020, five ® five fourth 2019, No

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and majority-owned subsidiaries in which the Company is deemed to be the primary beneficiary. All significant intercompany transactions and balances have been eliminated.
Use of Estimates, Policy [Policy Text Block]	Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Accumulated Other Comprehensive Loss As set forth below, the Company’s accumulated other comprehensive loss is comprised of three December 31, 2019 2018 Currency translation adjustments (1) $ (27,241 ) $ (41,107 ) Derivative hedging activity (4,522 ) 1,715 Pension activity (931 ) (898 ) Total accumulated other comprehensive loss $ (32,694 ) $ (40,290 ) ( 1 During 2019, $10.9 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 $0.5 million, $0.6 million and $2.2 million for 2019, 2018 2017,
Research and Development Expense, Policy [Policy Text Block]	Research and Development The Company expenses research and development costs as incurred. Research and development costs of $6.4 million, $5.6 million and $4.2 million for the years ended December 31, 2019, 2018 2017,
Income Tax, Policy [Policy Text Block]	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 740” 740 not not may In accordance with FASB ASC 740, may not 50% 740. The Company recognizes tax liabilities in accordance with FASB ASC 740 not may December 31, 2019 2018 740, Refer to Note 12
Earnings Per Share, Policy [Policy Text Block]	Earnings per Share Earnings per share have been calculated using the following share information: Years Ended December 31, 2019 2018 2017 Weighted average number of common shares used for basic EPS 31,130,222 32,345,382 33,150,949 Effect of dilutive stock options and restricted and deferred stock unit awards — 652,621 — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 31,130,222 32,998,003 33,150,949 The Company excluded 529,539 restricted and deferred stock units in 2019 2017 2018 2017,
Business Combinations Policy [Policy Text Block]	Purchase Price Accounting The Company accounts for its acquisitions in accordance with FASB ASC 805, Business Combinations The Company typically determines the fair value of tangible and intangible assets acquired in a business combination using independent valuations that rely on management’s estimates of inputs and assumptions that a market participant would use. Key assumptions include cash flow projections, growth rates, asset lives, and discount rates based on an analysis of weighted average cost of capital.
Classification of Current Assets and Liabilities [Policy Text Block]	Classification of Current Assets and Current Liabilities The Company includes in current assets and current liabilities certain amounts realizable and payable under construction contracts that may one one 24
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash, Cash Equivalents and Restricted Cash The Company classifies highly liquid investments with original maturities of 90 Cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets and Consolidated Statements of Cash Flows are as follows (in thousands): December 31, Balance sheet data 2019 2018 Cash and cash equivalents $ 64,874 $ 83,527 Restricted cash 1,348 1,359 Cash, cash equivalents and restricted cash $ 66,222 $ 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.
Inventory, Policy [Policy Text Block]	Inventories Inventories are stated at the lower of cost ( first first
Retainage [Policy Text Block]	Retainage Many of the contracts under which the Company performs work contain retainage provisions. Retainage refers to that portion of revenue earned by the Company but held for payment by the customer pending satisfactory completion of the project. The Company generally invoices its customers periodically as work is completed. Under ordinary circumstances, collection from municipalities is made within 60 90 30 45 one one December 31, 2019, 365
Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block]	Allowance for Doubtful Accounts Management makes estimates of the uncollectibility of accounts receivable and retainage. The Company records an allowance based on specific accounts to reduce receivables, including retainage, to the amount that is expected to be collected. The specific allowances are reevaluated and adjusted as additional information is received. After all reasonable attempts to collect the receivable or retainage have been explored, the account is written off against the allowance. The Company also includes reserves related to certain accounts receivable that may
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Long-Lived Assets Property, plant and equipment and other identified intangibles (primarily customer relationships, patents and acquired technologies, trademarks, licenses and non-compete agreements) are recorded at cost, net of accumulated depreciation, amortization and impairment, and, except for goodwill, are depreciated or amortized on a straight-line basis over their estimated useful lives. Changes in circumstances such as technological advances, changes to the Company’s business model or changes in the Company’s capital strategy can result in the actual useful lives differing from the Company’s estimates. If the Company determines that the useful life of its property, plant and equipment or its identified intangible assets should be shortened, the Company would depreciate or amortize the net book value in excess of the salvage value over its revised remaining useful life, thereby increasing depreciation or amortization expense. Long-lived assets, including property, plant and equipment and other intangibles, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not may Impairment Review – 2017 As part of the Restructuring, the Company exited all non-pipe related contract applications for the Tyfo ® 360, Property, Plant and Equipment 360” Based on the results of the valuation, the carrying amount of certain long-lived assets for the Fyfe North America asset group exceeded the fair value. Accordingly, the Company recorded impairment charges of $3.4 million to trademarks, $20.8 million to customer relationships and $16.8 million to patents and acquired technology in 2017. no The fair value estimates described above were determined using observable inputs and significant unobservable inputs, which are based on level 3
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill Under FASB ASC 350, may not not • significant underperformance of a segment relative to expected, historical or forecasted operating results; • significant negative industry or economic trends; • significant changes in the strategy for a segment including extended slowdowns in the segment’s market; • a decrease in market capitalization below the Company’s book value; and • a significant change in regulations. Whether during the annual impairment assessment or during a trigger-based impairment review, the Company estimates the fair value of its reporting units and compares such fair value to the carrying value of those reporting units to determine if there are any indications of goodwill impairment. Fair value of reporting units is estimated using a combination of two two The market approach estimates fair value by first The income approach is based on forecasted future (debt-free) cash flows that are discounted to present value using factors that consider timing and risk of future cash flows. The Company believes this approach is appropriate because it provides a fair value estimate based upon the reporting unit’s expected long-term operating cash flow performance. Discounted cash flow projections are based on financial forecasts developed from operating plans and economic outlooks, growth rates, estimates of future expected changes in operating margins, terminal value growth rates, future capital expenditures and changes in working capital requirements. Estimates of discounted cash flows may The discount rate applied to the estimated future cash flows is one twenty may Annual Impairment Assessment – October 1, 2019 The Company had six reporting units for purposes of assessing goodwill at October 1, 2019 Significant assumptions used in the Company’s October 2019 16.0%; 4.9%; The Company’s assessment of each reporting unit’s fair value in relation to its respective carrying value yielded no reporting units with a fair value below carrying value or within 10 percent of its carrying value. The Energy Services reporting unit had a fair value only slightly above 10 not Impairment Review – 2017 As part of the Restructuring, the Company exited all non-pipe related contract applications for the Tyfo ® 2017. December 31, 2017, third not
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Measurements FASB ASC 820, Fair Value Measurements 820” three • Level 1 • Level 2 • Level 3 no The Company uses these levels of hierarchy to measure the fair value of certain financial instruments on a recurring basis, such as for derivative instruments; on a non-recurring basis, such as for acquisitions and impairment testing; for disclosure purposes, such as for long-term debt; and for other applications, as discussed in their respective footnotes. Changes in assumptions or estimation methods could affect the fair value estimates; however, the Company does not 2 no 1, 2 3 2019, 2018 2017.
Consolidation, Variable Interest Entity, Policy [Policy Text Block]	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. no 2019. Financial data for consolidated variable interest entities are summarized in the following tables (in thousands): December 31, Balance sheet data 2019 2018 Current assets $ 18,304 $ 33,066 Non-current assets 7,635 6,466 Current liabilities 8,261 12,953 Non-current liabilities 1,962 8,780 Years Ended December 31, Statement of operations data 2019 (1) 2018 (2) 2017 Revenue $ 28,403 $ 49,809 $ 91,947 Gross profit 9,508 9,898 15,194 Net (income) loss attributable to Aegion Corporation (1,100 ) (1,374 ) 3,432 ( 1 Includes activity from our Tite Liner ® fourth 2019. ( 2 Includes activity from our pipe coating and insulation joint venture in Louisiana, which was sold during the third 2018.
New Accounting Pronouncements, Policy [Policy Text Block]	Accounting Standards Updates In December 2019, No. 2019 12, Simplifying the Accounting for Income Taxes 740 January 1, 2021, not In August 2018, No. 2018 13, Fair Value Measurement: Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 1, 2 3 January 1, 2020, not In February 2018, No. 2018 02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income may one two January 1, 2019 not In June 2016, No. 2016 13, Measurement of Credit Losses on Financial Instruments January 1, 2020, January 1, 2020, not In February 2016, No. 2016 02, Leases (Topic 842 twelve January 1, 2019, January 1, 2019 7.

Note 2 - Accounting Policies (T

Note 2 - Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	December 31, 2019 2018 Currency translation adjustments (1) $ (27,241 ) $ (41,107 ) Derivative hedging activity (4,522 ) 1,715 Pension activity (931 ) (898 ) Total accumulated other comprehensive loss $ (32,694 ) $ (40,290 )
Schedule of Weighted Average Number of Shares [Table Text Block]	Years Ended December 31, 2019 2018 2017 Weighted average number of common shares used for basic EPS 31,130,222 32,345,382 33,150,949 Effect of dilutive stock options and restricted and deferred stock unit awards — 652,621 — Weighted average number of common shares and dilutive potential common stock used for dilutive EPS 31,130,222 32,998,003 33,150,949
Restrictions on Cash and Cash Equivalents [Table Text Block]	December 31, Balance sheet data 2019 2018 Cash and cash equivalents $ 64,874 $ 83,527 Restricted cash 1,348 1,359 Cash, cash equivalents and restricted cash $ 66,222 $ 84,886
Schedule of Variable Interest Entities [Table Text Block]	December 31, Balance sheet data 2019 2018 Current assets $ 18,304 $ 33,066 Non-current assets 7,635 6,466 Current liabilities 8,261 12,953 Non-current liabilities 1,962 8,780 Years Ended December 31, Statement of operations data 2019 (1) 2018 (2) 2017 Revenue $ 28,403 $ 49,809 $ 91,947 Gross profit 9,508 9,898 15,194 Net (income) loss attributable to Aegion Corporation (1,100 ) (1,374 ) 3,432

Note 3 - Revenues (Tables)

Note 3 - Revenues (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Disaggregation of Revenue [Table Text Block]	Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 427,220 $ 159,408 $ 328,048 $ 914,676 Canada 65,370 57,663 — 123,033 Europe 49,157 15,121 — 64,278 Other foreign 49,050 62,898 — 111,948 Total revenues $ 590,797 $ 295,090 $ 328,048 $ 1,213,935 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 430,187 $ 200,397 $ 335,707 $ 966,291 Canada 62,292 71,320 — 133,612 Europe 54,567 12,227 — 66,794 Other foreign 57,075 109,796 — 166,871 Total revenues $ 604,121 $ 393,740 $ 335,707 $ 1,333,568 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Geographic region: United States $ 437,944 $ 299,643 $ 290,726 $ 1,028,313 Canada 60,675 79,059 — 139,734 Europe 58,520 13,319 — 71,839 Other foreign 55,015 64,118 — 119,133 Total revenues $ 612,154 $ 456,139 $ 290,726 $ 1,359,019 Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 523,042 $ 203,887 $ 704 $ 727,633 Time and materials — 65,084 327,344 392,428 Product sales 67,512 26,119 — 93,631 License fees 243 — — 243 Total revenues $ 590,797 $ 295,090 $ 328,048 $ 1,213,935 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 556,642 $ 296,217 $ 16,134 $ 868,993 Time and materials — 58,372 319,573 377,945 Product sales 45,030 39,151 — 84,181 License fees 2,449 — — 2,449 Total revenues $ 604,121 $ 393,740 $ 335,707 $ 1,333,568 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Energy Services Total Contract type: Fixed fee $ 569,701 $ 353,480 $ 9,225 $ 932,406 Time and materials — 56,288 281,501 337,789 Product sales 41,878 46,371 — 88,249 License fees 575 — — 575 Total revenues $ 612,154 $ 456,139 $ 290,726 $ 1,359,019
Contract Asset and Liability [Table Text Block]	December 31, 2019 (1) 2018 (2) Contract assets – current $ 51,092 $ 62,467 Contract liabilities – current (37,562 ) (32,339 ) Net contract assets $ 13,530 $ 30,128

Note 4 - Restructuring (Tables)

Note 4 - Restructuring (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Restructuring and Related Costs [Table Text Block]	Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 938 $ 3,179 $ 553 $ 1,685 $ 6,355 Contract termination costs 601 1,089 234 98 2,022 Relocation and other moving costs 190 408 55 — 653 Other restructuring costs (1) 13,642 4,592 819 4,258 23,311 Total pre-tax restructuring charges $ 15,371 $ 9,268 $ 1,661 $ 6,041 $ 32,341 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total Severance and benefit related costs $ 3,038 $ 1,094 $ 234 $ 170 $ 4,536 Contract termination costs 1,999 25 — 150 2,174 Relocation and other moving costs 184 — — — 184 Other restructuring costs (1) 13,311 7,936 28 1,317 22,592 Total pre-tax restructuring charges $ 18,532 $ 9,055 $ 262 $ 1,637 $ 29,486 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Corporate Total Severance and benefit related costs $ 4,274 $ 2,442 $ 629 $ 7,345 Contract termination costs 4,545 775 — 5,320 Relocation and other moving costs 26 121 — 147 Other restructuring costs (1) 8,434 1,522 975 10,931 Total pre-tax restructuring charges $ 17,279 $ 4,860 $ 1,604 $ 23,743 Year Ended December 31, 2019 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ 469 $ 1,869 $ — $ — $ 2,338 Operating expenses 5,349 1,131 819 3,444 10,743 Restructuring and related charges 1,729 4,676 842 1,783 9,030 Other expense (2) 7,824 1,592 — 814 10,230 Total pre-tax restructuring charges $ 15,371 $ 9,268 $ 1,661 $ 6,041 $ 32,341 Year Ended December 31, 2018 Infrastructure Solutions Corrosion Protection Energy Services Corporate Total (1) Cost of revenues $ 1,281 $ 600 $ — $ — $ 1,881 Operating expenses 7,291 4,547 28 1,317 13,183 Goodwill impairment 1,389 — — — 1,389 Definite-lived intangible asset impairment 870 1,299 — — 2,169 Restructuring and related charges 5,221 1,119 234 320 6,894 Other expense (2) 2,480 1,490 — — 3,970 Total pre-tax restructuring charges $ 18,532 $ 9,055 $ 262 $ 1,637 $ 29,486 Year Ended December 31, 2017 Infrastructure Solutions Corrosion Protection Corporate Total (1) Cost of revenues $ 30 $ 15 $ — $ 45 Operating expenses 8,404 1,507 973 10,884 Restructuring and related charges 8,845 3,338 631 12,814 Total pre-tax restructuring charges $ 17,279 $ 4,860 $ 1,604 $ 23,743
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	Utilized in 2019 Reserves at December 31, 2018 2019 Charge to Income Foreign Currency Translation Cash(1) Non-Cash Reserves at December 31, 2019 Severance and benefit related costs $ 1,742 $ 6,355 $ (11 ) $ 3,697 $ — $ 4,389 Contract termination costs 359 2,022 (20 ) 1,408 — 953 Relocation and other moving costs — 653 (3 ) 283 — 367 Other restructuring costs 311 23,311 (4 ) 8,457 12,782 2,379 Total pre-tax restructuring charges $ 2,412 $ 32,341 $ (38 ) $ 13,845 $ 12,782 $ 8,088 Utilized in 2018 Reserves at December 31, 2017 2018 Charge to Income Foreign Currency Translation Cash(1) Non-Cash Reserves at December 31, 2018 Severance and benefit related costs $ 3,864 $ 4,536 $ (69 ) $ 6,589 $ — $ 1,742 Contract termination costs 650 2,174 (19 ) 2,446 — 359 Relocation and other moving costs — 184 — 184 — — Other restructuring costs 675 22,592 (3 ) 5,581 17,372 311 Total pre-tax restructuring charges $ 5,189 $ 29,486 $ (91 ) $ 14,800 $ 17,372 $ 2,412 Utilized in 2017 2017 Charge to Income Cash(1) Non-Cash Reserves at December 31, 2017 Severance and benefit related costs $ 7,345 $ 3,481 $ — $ 3,864 Contract termination costs 5,320 2,706 1,964 650 Relocation and other moving costs 147 147 — — Other restructuring costs 10,931 2,140 8,116 675 Total pre-tax restructuring charges $ 23,743 $ 8,474 $ 10,080 $ 5,189

Note 5 - Supplemental Balance_2

Note 5 - Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Allowance for Doubtful Accounts [Table Text Block]	Years Ended December 31, 2019 2018 2017 Balance, beginning of year $ 9,695 $ 5,775 $ 6,098 Bad debt expense (1) (1,259 ) 8,188 3,155 Write-offs and adjustments (1,212 ) (4,268 ) (3,478 ) Balance, end of year $ 7,224 $ 9,695 $ 5,775
Schedule of Inventory, Current [Table Text Block]	December 31, 2019 2018 (1) Raw materials and supplies $ 27,415 $ 29,343 Work-in-process 5,739 2,510 Finished products 14,937 15,205 Construction materials 9,102 9,379 Total $ 57,193 $ 56,437
Property, Plant and Equipment [Table Text Block]	Estimated Useful Lives December 31, (Years) 2019 2018 Land and land improvements $ 5,359 $ 10,521 Buildings and improvements 5 — 40 50,589 47,430 Machinery and equipment 4 — 10 143,128 147,918 Furniture and fixtures 3 — 10 35,440 37,471 Autos and trucks 3 — 10 47,197 51,129 Construction in progress 7,475 14,626 289,188 309,095 Less – Accumulated depreciation (188,097 ) (202,036 ) Property, plant & equipment, less accumulated depreciation $ 101,091 $ 107,059
Schedule of Accrued Liabilities [Table Text Block]	December 31, 2019 2018 Vendor and other accrued expenses $ 30,730 $ 35,450 Estimated casualty and healthcare liabilities 13,138 17,419 Job costs 12,041 9,878 Accrued compensation 23,089 23,882 Operating lease liabilities 15,828 — Income taxes payable 1,751 1,391 Total $ 96,577 $ 88,020

Note 6 - Assets and Liabiliti_2

Note 6 - Assets and Liabilities Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Disposal Groups, Including Discontinued Operations [Table Text Block]	December 31, 2019(1) 2018(2) Assets held for sale: Current assets Receivables, net $ 4,136 $ 1,309 Retainage 518 15 Contract assets 5,350 1,777 Inventories 2,097 2,123 Prepaid expenses and other current assets 799 300 Total current assets 12,900 5,524 Property, plant & equipment, less accumulated depreciation 10,962 2,268 Goodwill 4,224 — Intangible assets, less accumulated amortization 1,528 — Operating lease assets 326 — Other non-current assets 130 — Impairment of assets held for sale (13,978 ) — Total assets held for sale $ 16,092 $ 7,792 Liabilities held for sale: Current liabilities Accounts payable $ 2,174 $ 1,331 Accrued expenses 3,961 3,891 Contract liabilities 122 38 Total current liabilities 6,257 5,260 Operating lease liabilities 174 — Other non-current liabilities 54 — Total liabilities held for sale $ 6,485 $ 5,260

Note 7 - Leases (Tables)

Note 7 - Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Lease, Cost [Table Text Block]	Year Ended December 31, 2019 Operating lease cost $ 22,235 Short-term lease cost 25,382 Total lease cost $ 47,617 Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 22,144 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18,879
Lease, Supplemental Financial Statement Disclosures, Balance Sheet [Table Text Block]	December 31, 2019(1) Operating leases: Operating lease assets $ 71,466 Accrued expenses $ 15,828 Other liabilities 56,253 Total operating lease liabilities $ 72,081 Weighted-average remaining lease term (in years) 5.74 Weighted-average discount rate 5.71 %
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	December 31, 2019 2020 $ 18,739 2021 16,287 2022 13,509 2023 10,950 2024 7,845 Thereafter 16,358 Total undiscounted operating lease liabilities 83,688 Less: Imputed interest (11,607 ) Total discounted operating lease liabilities $ 72,081

Note 8 - Goodwill and Intangi_2

Note 8 - Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Goodwill [Table Text Block]	Infrastructure Solutions Corrosion Protection Energy Services Total Balance, December 31, 2017 Goodwill, gross $ 246,486 $ 74,369 $ 80,246 $ 401,101 Accumulated impairment losses (61,459 ) (45,400 ) (33,527 ) (140,386 ) Goodwill, net 185,027 28,969 46,719 260,715 2018 Activity: Acqusitions (1) — 2,715 1,258 3,973 Impairments (2) (1,389 ) — — (1,389 ) Foreign currency translation (1,965 ) (701 ) — (2,666 ) 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 (137 ) 563 — 426 Reclassification to assets held for sale (3) (4,224 ) — — (4,224 ) Balance, December 31, 2019 Goodwill, gross 240,160 76,946 81,504 398,610 Accumulated impairment losses (62,848 ) (45,400 ) (33,527 ) (141,775 ) Goodwill, net $ 177,312 $ 31,546 $ 47,977 $ 256,835
Schedule of Finite-Lived Intangible Assets [Table Text Block]	December 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 0.7 $ 3,894 $ (3,825 ) $ 70 $ 3,894 $ (3,716 ) $ 178 Leases 1.0 864 (777 ) 87 864 (689 ) 175 Trademarks 8.3 15,699 (6,911 ) 8,788 15,751 (6,202 ) 9,549 Non-competes 3.3 2,301 (1,354 ) 947 2,529 (1,229 ) 1,300 Customer relationships 7.2 157,576 (76,832 ) 80,744 159,719 (66,753 ) 92,966 Patents and acquired technology 9.0 39,288 (25,097 ) 14,192 38,338 (22,810 ) 15,528 Total intangible assets — $ 219,622 $ (114,795 ) $ 104,828 $ 221,095 $ (101,399 ) $ 119,696

Note 9 - Long-term Debt and C_2

Note 9 - Long-term Debt and Credit Facility (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Long-term Debt Instruments [Table Text Block]	December 31, 2019 2018 Term note, due February 27, 2023, annualized rates of 4.09% and 4.59%, respectively $ 253,750 $ 282,188 Line of credit, 4.01% and 4.45%, respectively 24,000 31,000 Other notes with interest rates from 3.3% to 7.8% 770 1,031 Subtotal 278,520 314,219 Less – Current maturities of long-term debt 32,803 29,469 Less – Unamortized loan costs 2,088 2,747 Total $ 243,629 $ 282,003
Schedule of Maturities of Long-term Debt [Table Text Block]	December 31, 2019 2020 $ 32,803 2021 25,060 2022 30,844 2023 189,813 2024 — Thereafter — Total $ 278,520

Note 11 - Equity-based Compen_2

Note 11 - Equity-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]	Years Ended December 31, 2019 2018 2017 Stock Awards Weighted Average Award Date Fair Value Stock Awards Weighted Average Award Date Fair Value Stock Awards Weighted Average Award Date Fair Value Outstanding at December 31, 2018 1,143,205 $ 23.26 1,428,878 $ 21.53 1,501,021 $ 20.58 Period Activity: Restricted stock units awarded 325,321 20.02 281,567 24.13 257,532 23.06 Performance stock units awarded 146,367 22.78 219,943 23.25 213,436 28.18 Restricted shares distributed (76,686 ) 18.26 — — (179,169 ) 22.44 Restricted stock units distributed (237,416 ) 18.83 (312,182 ) 17.47 (95,510 ) 20.71 Performance stock units distributed (111,155 ) 25.85 (296,909 ) 21.55 (49,672 ) 21.95 Restricted shares forfeited — — — — (1,084 ) 23.01 Restricted stock units forfeited (74,075 ) 22.09 (90,896 ) 21.79 (81,626 ) 20.36 Performance stock units forfeited (80,597 ) 25.30 (87,196 ) 25.95 (136,050 ) 24.29 Outstanding at December 31, 2019 1,034,964 $ 23.20 1,143,205 $ 23.26 1,428,878 $ 21.53
Share-based Payment Arrangement, Outstanding Award, Activity, Excluding Option [Table Text Block]	Years Ended December 31, 2019 2018 2017 Deferred Stock Units Weighted Average Award Date Fair Value Deferred Stock Units Weighted Average Award Date Fair Value Deferred Stock Units Weighted Average Award Date Fair Value Outstanding at December 31, 2018 287,350 $ 20.80 269,977 $ 20.14 253,445 $ 19.93 Period Activity: Awarded 50,174 19.64 45,681 23.72 47,091 23.53 Distributed (84,184 ) 20.38 (28,308 ) 19.22 (30,559 ) 23.57 Outstanding at December 31, 2019 253,340 $ 20.71 287,350 $ 20.80 269,977 $ 20.14
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Years Ended December 31, 2019 2018 2017 Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Outstanding, beginning of year 52,783 $ 18.11 126,680 $ 23.06 170,253 $ 21.99 Exercised (52,783 ) 18.11 — — (43,573 ) 18.87 Canceled/Expired — — (73,897 ) 26.60 — — Outstanding, end of year — $ — 52,783 $ 18.11 126,680 $ 23.06 Exercisable, end of year — $ — 52,783 $ 18.11 126,680 $ 23.06
Cash Proceeds Received and Tax Benefit from Share-based Payment Awards [Table Text Block]	Years Ended December 31, 2019 2018 2017 Amount received from stock option exercises $ 956 $ — $ 823 Total intrinsic value of stock option exercises (1) 129 — 370 Tax expense (benefit) of stock option exercises recorded in income tax expense 312 (1,556 ) (63 ) Aggregate intrinsic value of outstanding stock options — — 386 Aggregate intrinsic value of exercisable stock options — — 386

Note 12 - Taxes on Income (Tabl

Note 12 - Taxes on Income (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]	Years Ended December 31, 2019 2018 2017 Domestic $ 3,627 $ 8,142 $ (40,007 ) Foreign (16,511 ) (5,187 ) (21,570 ) Total $ (12,884 ) $ 2,955 $ (61,577 )
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	Years Ended December 31, 2019 2018 2017 Current: Federal $ (2,775 ) $ (4,765 ) $ 3,764 Foreign 5,705 6,025 7,512 State 460 (651 ) 3,351 Subtotal 3,390 609 14,627 Deferred: Federal 538 947 (8,706 ) Foreign (199 ) (1,531 ) (1,099 ) State 2,835 (157 ) 183 Subtotal 3,174 (741 ) (9,622 ) Total tax provision $ 6,564 $ (132 ) $ 5,005
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Years Ended December 31, 2019 2018 2017 Income taxes (benefit) at U.S. federal statutory tax rate $ (2,706 ) $ 621 $ (21,552 ) Increase (decrease) in taxes resulting from: Change in the balance of the valuation allowance for deferred tax assets allocated to foreign income tax expense 806 590 4,598 Change in the balance of the valuation allowance for deferred tax assets allocated to domestic income tax expense 2,960 (944 ) 12,755 State income taxes, net of federal income tax benefit 2,603 (798 ) 2,270 Divestitures 5,613 2,133 — Meals and entertainment 470 517 785 Changes in taxes previously accrued (1,070 ) (536 ) (1,339 ) Foreign tax rate differences (643 ) 1,301 913 Share-based compensation 358 (1,427 ) 131 Goodwill impairment — 291 6,359 Recognition of uncertain tax positions (717 ) (218 ) (62 ) Deemed mandatory repatriation — (842 ) 10,406 Release of deferred tax liability on foreign earnings — — (7,051 ) Domestic Production Activities deduction — — (1,921 ) Other matters (1,110 ) (820 ) (1,287 ) Total tax provision $ 6,564 $ (132 ) $ 5,005 Effective tax rate (50.9 %) (4.5 %) (8.1 %)
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	December 31, 2019 2018 Deferred income tax assets: Foreign tax credit carryforwards $ 4,101 $ 507 Net operating loss carryforwards 19,079 22,909 Accrued expenses 15,281 12,987 Other 8,431 8,652 Total gross deferred income tax assets 46,892 45,055 Less valuation allowance (34,247 ) (28,451 ) Net deferred income tax assets 12,645 16,604 Deferred income tax liabilities: Property, plant and equipment (5,689 ) (6,038 ) Intangible assets (12,203 ) (10,609 ) Other (4,791 ) (6,757 ) Total deferred income tax liabilities (22,683 ) (23,404 ) Net deferred income tax liabilities $ (10,038 ) $ (6,800 ) December 31, 2019 2018 Noncurrent deferred income tax assets, net $ 1,216 $ 1,561 Noncurrent deferred income tax liabilities, net (11,254 ) (8,361 ) Net deferred income tax liabilities $ (10,038 ) $ (6,800 )
Summary of Valuation Allowance [Table Text Block]	Years Ended December 31, 2019 2018 2017 Balance, at beginning of year $ 28,451 $ 29,782 $ 15,428 Additions 8,789 1,879 19,260 Reversals (6,776 ) (2,102 ) (183 ) Remeasurement of U.S. deferred tax balances — — (5,141 ) Other adjustments 3,783 (1,108 ) 418 Balance, at end of year $ 34,247 $ 28,451 $ 29,782
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	Years Ended December 31, 2019 2018 2017 Balance, at beginning of year $ 1,955 $ 2,229 $ 2,465 Additions for tax positions of prior years 9 8 12 Lapse in statute of limitations (587 ) (264 ) (274 ) Foreign currency translation 7 (18 ) 26 Balance, at end of year, total tax provision $ 1,384 $ 1,955 $ 2,229

Note 14 - Segment and Geograp_2

Note 14 - Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Years Ended December 31, 2019 2018 2017 Revenues: Infrastructure Solutions $ 590,797 $ 604,121 $ 612,154 Corrosion Protection 295,090 393,740 456,139 Energy Services 328,048 335,707 290,726 Total revenues $ 1,213,935 $ 1,333,568 $ 1,359,019 Gross profit: Infrastructure Solutions $ 144,074 $ 132,411 $ 140,823 Corrosion Protection 60,927 92,968 108,240 Energy Services 41,234 41,547 35,749 Total gross profit $ 246,235 $ 266,926 $ 284,812 Operating income (loss): Infrastructure Solutions (1) $ 42,079 $ 37,509 $ (47,316 ) Corrosion Protection (2) (5,635 ) 16,283 32,222 Energy Services (3) 9,740 9,638 7,736 Corporate (4) (35,211 ) (33,783 ) (36,162 ) Total operating income (loss) 10,973 29,647 (43,520 ) Other income (expense): Interest expense (14,002 ) (17,327 ) (16,001 ) Interest income 1,038 516 145 Other (5) (10,893 ) (9,881 ) (2,201 ) Total other expense (23,857 ) (26,692 ) (18,057 ) Income (loss) before taxes on income $ (12,884 ) $ 2,955 $ (61,577 ) Total assets: Infrastructure Solutions $ 508,226 $ 500,977 $ 531,746 Corrosion Protection 278,694 279,106 329,848 Energy Services 161,165 163,109 152,416 Corporate 31,336 41,432 22,775 Assets held for sale 16,092 7,793 70,314 Total assets $ 995,513 $ 992,417 $ 1,107,099 Capital expenditures: Infrastructure Solutions $ 10,679 $ 12,730 $ 16,680 Corrosion Protection 11,437 9,754 8,603 Energy Services 3,437 3,053 2,713 Corporate 3,219 4,977 2,834 Total capital expenditures $ 28,772 $ 30,514 $ 30,830 Depreciation and amortization: Infrastructure Solutions $ 13,773 $ 16,758 $ 18,731 Corrosion Protection 12,487 11,874 15,598 Energy Services 7,490 7,111 6,726 Corporate 2,413 2,112 3,364 Total depreciation and amortization $ 36,163 $ 37,855 $ 44,419 Years Ended December 31, 2019 2018 2017 Revenues: (1) United States $ 914,676 $ 966,291 $ 1,028,313 Canada 123,033 133,612 139,734 Europe 64,278 66,794 71,839 Other foreign 111,948 166,871 119,133 Total revenues $ 1,213,935 $ 1,333,568 $ 1,359,019 Gross profit: (1) United States $ 175,705 $ 178,024 $ 226,026 Canada 22,183 22,823 31,173 Europe 14,849 8,379 11,997 Other foreign 33,498 57,700 15,616 Total gross profit $ 246,235 $ 266,926 $ 284,812 Operating income (loss): (1) United States $ 6,212 $ 174 $ (33,583 ) Canada 7,460 9,482 12,220 Europe (11,363 ) (10,599 ) (3,771 ) Other foreign 8,664 30,590 (18,386 ) Total operating income (loss) $ 10,973 $ 29,647 $ (43,520 ) Long-lived assets: (1)(2) United States $ 80,910 $ 105,978 $ 93,472 Canada 7,462 7,725 8,816 Europe 2,499 8,295 13,435 Other foreign 10,220 6,662 9,586 Total long-lived assets $ 101,091 $ 128,660 $ 125,309

Note 15 - Derivative Financia_2

Note 15 - Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	Position Notional Amount Weighted Average Remaining Maturity In Years Average Exchange Rate Interest Rate Swap — $ 190,312,500 3.2 —
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	December 31, Designation of Derivatives Balance Sheet Location 2019 2018 Derivatives Designated as Hedging Instruments: Interest Rate Swaps Other non-current assets $ 261 $ 3,648 Total Assets $ 261 $ 3,648 Interest Rate Swaps Other non-current liabilities $ 4,899 $ 1,885 Total Liabilities $ 4,899 $ 1,885 Forward Currency Contracts Accrued expenses $ — $ 44 Total Liabilities $ — $ 44 Total Derivative Assets $ 261 $ 3,648 Total Derivative Liabilities 4,899 1,929 Total Net Derivative Asset (Liability) $ (4,638 ) $ 1,719

Note 16 - Selected Quarterly _2

Note 16 - Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Notes Tables
Quarterly Financial Information [Table Text Block]	First Quarter(1) Second Quarter(2) Third Quarter(3) Fourth Quarter(4) Year Ended December 31, 2019: Revenues $ 276,904 $ 318,740 $ 308,789 $ 309,502 Gross profit 48,295 67,437 66,792 63,711 Operating income (loss) (774 ) 459 14,649 (3,361 ) Net income (loss) (3,991 ) (8,147 ) 6,349 (13,659 ) Earnings (loss) per share attributable to Aegion Corporation: Basic $ (0.13 ) $ (0.27 ) $ 0.20 $ (0.47 ) Diluted $ (0.13 ) $ (0.27 ) $ 0.19 $ (0.47 ) First Quarter(1) Second Quarter(2) Third Quarter(3) Fourth Quarter(4) Year Ended December 31, 2018: Revenues $ 324,861 $ 335,030 $ 339,679 $ 333,998 Gross profit 61,504 71,053 72,673 61,696 Operating income (loss) 3,181 14,459 13,009 (1,002 ) Net income (loss) (1,476 ) 7,198 141 (2,776 ) Earnings (loss) per share attributable to Aegion Corporation: Basic $ (0.06 ) $ 0.24 $ (0.01 ) $ (0.08 ) Diluted $ (0.06 ) $ 0.24 $ (0.01 ) $ (0.08 )

Note 1 - Description of Busin_2

Note 1 - Description of Business (Details Textual) $ in Thousands, £ in Millions, kr in Millions	Aug. 31, 2018USD ($)	Oct. 31, 2019	Nov. 30, 2018USD ($)	Aug. 31, 2018USD ($)	Jul. 31, 2018USD ($)	May 31, 2018USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2017GBP (£)	Dec. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Oct. 30, 2019	Nov. 30, 2018DKK (kr)
Proceeds from Divestiture of Businesses										$ 0	$ 37,942	$ 0
Goodwill, Ending Balance									$ 256,835	256,835	260,633	260,715
Net Income (Loss) Attributable to Parent, Total										(20,892)	2,928	(69,401)
United Mexico [Member] | Miller Pipeline de Mexico, S.A. de C.V. [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners													45.00%
Environmental Techniques [Member]
Business Combination, Consideration Transferred, Total							$ 8,000	£ 6.5
Revenues, Total										9,500	7,500	4,000
Net Income (Loss) Attributable to Parent, Total										(100)	100	(700)
Hebna [Member]
Business Combination, Consideration Transferred, Total						$ 6,000
P2S [Member]
Business Combination, Consideration Transferred, Total					$ 3,000
P2S, Hebna and Environmental Techniques [Member]
Business Combination, Consideration Transferred, Total										17,000
Goodwill, Ending Balance									7,300	7,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total									5,500	5,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment, Total									3,500	3,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Working Capital									700	700
Discontinued Operations, Disposed of by Sale [Member] | CIPP Operations [Member]
Disposal Group, Including Discontinued Operation, Consideration			$ 1,600
Discontinued Operations, Disposed of by Sale [Member] | Bayou Companies, LLC [Member]
Disposal Group, Including Discontinued Operation, Consideration	$ 46,000			$ 46,000
Joint Venture Ownership Percentage Sold	51.00%
Proceeds from Divestiture of Businesses				38,000
Noncash or Part Noncash Divestiture, Amount of Consideration Received				8,000
Disposal Group, Including Discontinued Operation, Additional Earn-out Payments				$ 4,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal											7,000
Discontinued Operations, Disposed of by Sale [Member] | Bayou Companies, LLC [Member] | Notes Receivable [Member]
Notes Receivable, Term				2 years
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | United Mexico [Member] | Miller Pipeline de Mexico, S.A. de C.V. [Member]
Noncontrolling Interest, Ownership Percentage Sold by Parent													55.00%
DENMARK | Discontinued Operations, Disposed of by Sale [Member] | CIPP Operations [Member]
Disposal Group, Including Discontinued Operation, Consideration | kr														kr 10.5
OMAN | Aegion International [Member]
Business Acquisition, Percentage of Voting Interests Acquired						50.00%
Noncontrolling Interest, Ownership Percentage by Parent						51.00%
Infrastructure Solutions [Member]
Trade Name Entitlement Agreement, Term		5 years	5 years
Goodwill, Ending Balance									$ 177,312	$ 177,312	$ 181,673	$ 185,027
Downsize Operation in US [Member]
Restructuring and Related Cost, Number of Office Closed									3
Restructuring and Related Cost, Number of Offices Exiting Capital Intensive Drilling Activities									4
Restructuring and Related Cost, Number of Positions Eliminated, Period Percent										20.00%
Restructuring and Related Cost, Contributed To Cathodic Protection Domestic Revenue, Percentage										20.00%

Note 2 - Accounting Policies (D

Note 2 - Accounting Policies (Details Textual) $ in Thousands	Oct. 01, 2019USD ($)	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares		Dec. 31, 2017USD ($)shares
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax, Total		$ 10,900
Foreign Currency Transaction Gain (Loss), Realized		(503)	$ (623)		$ (2,152)
Research and Development Expense, Total		$ 6,400	5,600		4,200
Retainage Collection Period Upon Completion of Contract		1 year
Percentage of Retainage Balance, Retainage Receivables Aged Greater than 365 Days		18.00%
Impairment of Intangible Assets, Finite-lived		$ 0	2,169		41,032
Number of Reporting Units	6
Reporting Unit, Fair Value in Below of Carrying Amount, Number of Reporting Units	0
Reporting Unit, Percentage of Fair Value in Below of Carrying Amount	10.00%
Goodwill, Ending Balance		256,835	260,633		260,715
Goodwill, Impairment Loss		$ 0	$ 1,389	[1]	45,390
Fyfe [Member]
Goodwill, Ending Balance					9,600
Goodwill, Impairment Loss					45,400
Energy Services [Member]
Goodwill, Ending Balance	$ 48,000
Trademarks [Member] | Fyfe [Member]
Impairment of Intangible Assets, Finite-lived					3,400
Customer Relationships [Member] | Fyfe [Member]
Impairment of Intangible Assets, Finite-lived					20,800
Patents and Acquired Technology [Member] | Fyfe [Member]
Impairment of Intangible Assets, Finite-lived					$ 16,800
Minimum [Member]
Construction Period		1 month
Collection Period for Municipalities		60 days
Retainage, Percent of Contract Value Withheld		5.00%
Collection Period for Other than Municipalities		30 days
Minimum [Member] | Measurement Input, Discount Rate [Member]
Goodwill, Measurement Input	0.120
Minimum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]
Goodwill, Measurement Input	0.016
Maximum [Member]
Construction Period		24 months
Collection Period for Municipalities		90 days
Retainage, Percent of Contract Value Withheld		15.00%
Collection Period for Other than Municipalities		45 days
Maximum [Member] | Measurement Input, Discount Rate [Member]
Goodwill, Measurement Input	0.160
Maximum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]
Goodwill, Measurement Input	0.049
Stock Options and Restricted and Deferred Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares		529,539			735,577
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares			4,049		73,897
Other Expense [Member]
Foreign Currency Transaction Gain (Loss), Realized		$ 500	$ (600)		$ (2,200)
[1]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).

Note 2 - Accounting Policies -

Note 2 - Accounting Policies - Accumulated Other Comprehensive Income Loss (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Currency translation adjustments	[1]	$ (27,241)	$ (41,107)
Derivative hedging activity		(4,522)	1,715
Pension activity		(931)	(898)
Total accumulated other comprehensive loss		$ (32,694)	$ (40,290)
[1]	During 2019, as a result of selling or disposing of certain international entities, $10.9 million was reclassified out of accumulated other comprehensive loss to "Other expense" in the Consolidated Statements of Operations.

Note 2 - Accounting Policies _2

Note 2 - Accounting Policies - Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted average number of common shares used for basic EPS (in shares)	31,130,222	32,345,382	33,150,949
Effect of dilutive stock options and restricted and deferred stock unit awards (in shares)	0	652,621	0
Weighted average number of common shares and dilutive potential common stock used for dilutive EPS (in shares)	31,130,222	32,998,003	33,150,949

Note 2 - Accounting Policies _3

Note 2 - Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents	$ 64,874	$ 83,527
Restricted cash	1,348	1,359
Cash, cash equivalents and restricted cash	$ 66,222	$ 84,886	$ 107,556

Note 2 - Accounting Policies _4

Note 2 - Accounting Policies - Investments in Variable Interest Entities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Current assets	$ 450,215		$ 481,867
Current liabilities	234,041		219,650
Variable Entity [Member]
Current assets	18,304		33,066
Non-current assets	7,635		6,466
Current liabilities	8,261		12,953
Non-current liabilities	1,962		8,780
Revenue	28,403	[1]	49,809	[2]	$ 91,947
Gross profit	9,508	[1]	9,898	[2]	15,194
Net (income) loss attributable to Aegion Corporation	$ (1,100)	[1]	$ (1,374)	[2]	$ 3,432
[1]	Includes activity from our Tite Liner joint venture in Mexico, which was sold during the fourth quarter of 2019.
[2]	Includes activity from our pipe coating and insulation joint venture in Louisiana, which was sold during the third quarter of 2018.

Note 3 - Revenues 1 (Details Te

Note 3 - Revenues 1 (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Disposal Group, Including Discontinued Operation, Contract Assets, Current	$ 5,400	$ 1,800
Disposal Group, Including Discontinued Operation, Contract Liabilities, Current	100	100
Increase (Decrease) in Contract with Customer, Liability	5,091	(24,144)	$ (5,924)
Contract with Customer, Liability, Total		$ 32,300	$ 51,600
Construction, Engineering and Installation Services [Member]
Revenue, Remaining Performance Obligation, Amount	464,600
Difference Between Work Performed On Open Contracts And Contractual Billing Terms [Member]
Increase (Decrease) in Contract with Customer, Asset	(11,400)
Increase (Decrease) in Contract with Customer, Liability	$ 5,200
Product and Services [Member]
Revenue Recognized, Percent	92.30%	93.50%	93.50%
Product [Member]
Revenue Recognized, Percent	7.70%	6.50%	6.50%
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract	$ (400)	$ 1,800
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ (300)

Note 3 - Revenues 2 (Details Te

Note 3 - Revenues 2 (Details Textual) - Construction, Engineering and Installation Services [Member] $ in Millions	Dec. 31, 2019USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 464.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Amount	$ 452.8
Revenue, Remaining Performance Obligation, Percentage	97.50%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months

Note 3 - Revenues - Disaggregat

Note 3 - Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2019	[1]	Sep. 30, 2019	[2]	Jun. 30, 2019	[3]	Mar. 31, 2019	[4]	Dec. 31, 2018	[1]	Sep. 30, 2018	[2]	Jun. 30, 2018	[4]	Mar. 31, 2018	[4]	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Revenues		$ 309,502		$ 308,789		$ 318,740		$ 276,904		$ 333,998		$ 339,679		$ 335,030		$ 324,861		$ 1,213,935	[5]	$ 1,333,568	[5]	$ 1,359,019	[5]
Fixed-price Contract [Member]
Revenues																		727,633		868,993		932,406
Time-and-materials Contract [Member]
Revenues																		392,428		377,945		337,789
Product Sales [Member]
Revenues																		93,631		84,181		88,249
License Fees [Member]
Revenues																		243		2,449		575
Infrastructure Solutions [Member]
Revenues																		590,797		604,121		612,154
Infrastructure Solutions [Member] | Fixed-price Contract [Member]
Revenues																		523,042		556,642		569,701
Infrastructure Solutions [Member] | Time-and-materials Contract [Member]
Revenues																		0		0		0
Infrastructure Solutions [Member] | Product Sales [Member]
Revenues																		67,512		45,030		41,878
Infrastructure Solutions [Member] | License Fees [Member]
Revenues																		243		2,449		575
Corrosion Protection [Member]
Revenues																		295,090		393,740		456,139
Corrosion Protection [Member] | Fixed-price Contract [Member]
Revenues																		203,887		296,217		353,480
Corrosion Protection [Member] | Time-and-materials Contract [Member]
Revenues																		65,084		58,372		56,288
Corrosion Protection [Member] | Product Sales [Member]
Revenues																		26,119		39,151		46,371
Corrosion Protection [Member] | License Fees [Member]
Revenues																		0		0		0
Energy Services [Member]
Revenues																		328,048		335,707		290,726
Energy Services [Member] | Fixed-price Contract [Member]
Revenues																		704		16,134		9,225
Energy Services [Member] | Time-and-materials Contract [Member]
Revenues																		327,344		319,573		281,501
Energy Services [Member] | Product Sales [Member]
Revenues																		0		0		0
Energy Services [Member] | License Fees [Member]
Revenues																		0		0		0
UNITED STATES
Revenues	[5]																	914,676		966,291		1,028,313
UNITED STATES | Infrastructure Solutions [Member]
Revenues																		427,220		430,187		437,944
UNITED STATES | Corrosion Protection [Member]
Revenues																		159,408		200,397		299,643
UNITED STATES | Energy Services [Member]
Revenues																		328,048		335,707		290,726
CANADA
Revenues	[5]																	123,033		133,612		139,734
CANADA | Infrastructure Solutions [Member]
Revenues																		65,370		62,292		60,675
CANADA | Corrosion Protection [Member]
Revenues																		57,663		71,320		79,059
CANADA | Energy Services [Member]
Revenues																		0		0		0
Europe [Member]
Revenues	[5]																	64,278		66,794		71,839
Europe [Member] | Infrastructure Solutions [Member]
Revenues																		49,157		54,567		58,520
Europe [Member] | Corrosion Protection [Member]
Revenues																		15,121		12,227		13,319
Europe [Member] | Energy Services [Member]
Revenues																		0		0		0
Other Foreign Countries [Member]
Revenues	[5]																	111,948		166,871		119,133
Other Foreign Countries [Member] | Infrastructure Solutions [Member]
Revenues																		49,050		57,075		55,015
Other Foreign Countries [Member] | Corrosion Protection [Member]
Revenues																		62,898		109,796		64,118
Other Foreign Countries [Member] | Energy Services [Member]
Revenues																		$ 0		$ 0		$ 0
[1]	Includes pre-tax expenses of $13.9 million related to our restructuring efforts (see Note 4).
[2]	Includes pre-tax expenses of $7.4 million related to our restructuring efforts (see Note 4).
[3]	Includes pre-tax expenses of $6.5 million related to our restructuring efforts (see Note 4).
[4]	Includes pre-tax expenses of $5.2 million related to our restructuring efforts (see Note 4).
[5]	Attributed to the country of origin.

Note 3 - Revenues- Contract Ass

Note 3 - Revenues- Contract Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	[1]	Dec. 31, 2018	[2]
Contract assets – current	$ 51,092		$ 62,467
Contract liabilities – current	(37,562)		(32,339)
Net contract assets	$ 13,530		$ 30,128
[1]	Amounts exclude contract assets of $5.4 million and contract liabilities of $0.1 million that were classified as held for sale at December 31, 2019 (see Note 6).
[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 6).

Note 4 - Restructuring (Details

Note 4 - Restructuring (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Restructuring Charges, Non-Cash		$ 12,782	$ 13,814	$ 10,080
Restructuring 2017 [Member]
Restructuring Charges Pre Tax		171,900
Restructuring Charges, Net of Tax		155,700
Payments for Restructuring		45,300
Restructuring Reserve, Settled without Cash		$ 126,600
Restructuring and Related Cost, Expected Number of Additional Positions Eliminated		4
Restructuring Charges, Cash		$ 19,500	12,100	13,600
Restructuring Charges, Non-Cash		12,800	17,400	10,100
Restructuring 2017 [Member] | Minimum [Member]
Restructuring and Related Cost, Expected Cost, Total	$ 2,000	$ 2,000
Downsize Operation in US [Member]
Restructuring and Related Cost, Number of Office Closed	3
Restructuring and Related Cost, Number of Offices Exiting Capital Intensive Drilling Activities	4
Restructuring and Related Cost, Number of Positions Eliminated, Period Percent		20.00%
Restructuring and Related Cost, Contributed To Cathodic Protection Domestic Revenue, Percentage		20.00%
Restructuring Charges Related to Goodwill and Long-lived Asset Impairment Charges [Member] | Restructuring 2017 [Member]
Restructuring Reserve, Settled without Cash				86,400
Allowance, Write-offs and Long-lived Assets, Impairment of Intangible Assets and Net Losses On Disposal of Entities [Member] | Restructuring 2017 [Member]
Restructuring Reserve, Settled without Cash				40,200
Severance, Other Termination Benefit Costs and Contract Termination Costs [Member] | Restructuring 2017 [Member]
Restructuring and Related Costs, Incurred Cost, Total		$ 9,000	$ 6,900	$ 12,800

Note 4 - Restructuring - Pre-ta

Note 4 - Restructuring - Pre-tax Restructuring Cost (Details) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Restructuring charges

$ 14,300

$ 8,600

$ 6,500

$ 2,900

$ 13,900

$ 7,400

$ 2,900

$ 5,200

Restructuring 2017 [Member]

Restructuring charges

$ 32,341

$ 29,486

[1]

$ 23,743

[2]

Restructuring 2017 [Member] | Cost of Revenues [Member]

Restructuring charges

1,881

[1]

45

[2]

Restructuring 2017 [Member] | Operating Expense [Member]

Restructuring charges

13,183

[1]

10,884

[2]

Restructuring 2017 [Member] | Restructuring and Related Charges [Member]

Restructuring charges

6,894

[1]

12,814

[2]

Restructuring 2017 [Member] | Other Expense [Member]

Restructuring charges

[1],[3]

3,970

Restructuring 2017 [Member] | Goodwill Impairment [Member]

Restructuring charges

[1]

1,389

Restructuring 2017 [Member] | Definite-lived Intangible Asset Impairment [Member]

Restructuring charges

[1]

2,169

Restructuring 2017 [Member] | Employee Severance [Member]

Restructuring charges

6,355

4,536

Restructuring 2017 [Member] | Contract Termination [Member]

Restructuring charges

2,022

2,174

Restructuring 2017 [Member] | Employee Relocation [Member]

Restructuring charges

653

184

Restructuring 2017 [Member] | Other Restructuring [Member]

Restructuring charges

23,311

[4]

22,592

[5]

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member]

Restructuring charges

15,371

18,532

17,279

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Cost of Revenues [Member]

Restructuring charges

1,281

30

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Operating Expense [Member]

Restructuring charges

7,291

8,404

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Restructuring and Related Charges [Member]

Restructuring charges

5,221

8,845

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Other Expense [Member]

Restructuring charges

[1],[3]

2,480

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Goodwill Impairment [Member]

Restructuring charges

1,389

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Definite-lived Intangible Asset Impairment [Member]

Restructuring charges

870

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Employee Severance [Member]

Restructuring charges

938

3,038

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Contract Termination [Member]

Restructuring charges

601

1,999

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Employee Relocation [Member]

Restructuring charges

190

184

Restructuring 2017 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Other Restructuring [Member]

Restructuring charges

13,642

[4]

13,311

[5]

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member]

Restructuring charges

9,268

9,055

4,860

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Cost of Revenues [Member]

Restructuring charges

600

15

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Operating Expense [Member]

Restructuring charges

4,547

1,507

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Restructuring and Related Charges [Member]

Restructuring charges

1,119

3,338

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Other Expense [Member]

Restructuring charges

[1],[3]

1,490

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Goodwill Impairment [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Definite-lived Intangible Asset Impairment [Member]

Restructuring charges

1,299

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Employee Severance [Member]

Restructuring charges

3,179

1,094

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Contract Termination [Member]

Restructuring charges

1,089

25

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Employee Relocation [Member]

Restructuring charges

408

0

Restructuring 2017 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Other Restructuring [Member]

Restructuring charges

4,592

[4]

7,936

[5]

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member]

Restructuring charges

1,661

262

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Cost of Revenues [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Operating Expense [Member]

Restructuring charges

28

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Restructuring and Related Charges [Member]

Restructuring charges

234

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Other Expense [Member]

Restructuring charges

[1],[3]

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Goodwill Impairment [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Definite-lived Intangible Asset Impairment [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Employee Severance [Member]

Restructuring charges

553

234

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Contract Termination [Member]

Restructuring charges

234

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Employee Relocation [Member]

Restructuring charges

55

0

Restructuring 2017 [Member] | Operating Segments [Member] | Energy Services [Member] | Other Restructuring [Member]

Restructuring charges

819

[4]

28

[5]

Restructuring 2017 [Member] | Corporate, Non-Segment [Member]

Restructuring charges

6,041

1,637

1,604

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Cost of Revenues [Member]

Restructuring charges

0

0

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Operating Expense [Member]

Restructuring charges

1,317

973

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Restructuring and Related Charges [Member]

Restructuring charges

320

631

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Other Expense [Member]

Restructuring charges

[1],[3]

0

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Goodwill Impairment [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Definite-lived Intangible Asset Impairment [Member]

Restructuring charges

0

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Employee Severance [Member]

Restructuring charges

1,685

170

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Contract Termination [Member]

Restructuring charges

98

150

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Employee Relocation [Member]

Restructuring charges

0

0

Restructuring 2017 [Member] | Corporate, Non-Segment [Member] | Other Restructuring [Member]

Restructuring charges

4,258

[4]

1,317

[5]

Restructuring 2016 [Member]

Restructuring charges

32,341

[6]

29,486

23,743

Restructuring 2016 [Member] | Cost of Revenues [Member]

Restructuring charges

[6],[7]

2,338

Restructuring 2016 [Member] | Operating Expense [Member]

Restructuring charges

[6]

10,743

Restructuring 2016 [Member] | Restructuring and Related Charges [Member]

Restructuring charges

[6]

9,030

Restructuring 2016 [Member] | Other Expense [Member]

Restructuring charges

[6],[7]

10,230

Restructuring 2016 [Member] | Employee Severance [Member]

Restructuring charges

6,355

4,536

7,345

Restructuring 2016 [Member] | Contract Termination [Member]

Restructuring charges

2,022

2,174

5,320

Restructuring 2016 [Member] | Employee Relocation [Member]

Restructuring charges

653

184

147

Restructuring 2016 [Member] | Other Restructuring [Member]

Restructuring charges

23,311

$ 22,592

10,931

[8]

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member]

Restructuring charges

15,371

17,279

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Cost of Revenues [Member]

Restructuring charges

469

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Operating Expense [Member]

Restructuring charges

5,349

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Restructuring and Related Charges [Member]

Restructuring charges

1,729

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Other Expense [Member]

Restructuring charges

[7]

7,824

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Employee Severance [Member]

Restructuring charges

4,274

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Contract Termination [Member]

Restructuring charges

4,545

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Employee Relocation [Member]

Restructuring charges

26

Restructuring 2016 [Member] | Operating Segments [Member] | Infrastructure Solutions [Member] | Other Restructuring [Member]

Restructuring charges

[8]

8,434

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member]

Restructuring charges

9,268

4,860

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Cost of Revenues [Member]

Restructuring charges

1,869

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Operating Expense [Member]

Restructuring charges

1,131

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Restructuring and Related Charges [Member]

Restructuring charges

4,676

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Other Expense [Member]

Restructuring charges

[7]

1,592

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Employee Severance [Member]

Restructuring charges

2,442

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Contract Termination [Member]

Restructuring charges

775

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Employee Relocation [Member]

Restructuring charges

121

Restructuring 2016 [Member] | Operating Segments [Member] | Corrosion Protection [Member] | Other Restructuring [Member]

Restructuring charges

[8]

1,522

Restructuring 2016 [Member] | Operating Segments [Member] | Energy Services [Member]

Restructuring charges

1,661

Restructuring 2016 [Member] | Operating Segments [Member] | Energy Services [Member] | Cost of Revenues [Member]

Restructuring charges

0

Restructuring 2016 [Member] | Operating Segments [Member] | Energy Services [Member] | Operating Expense [Member]

Restructuring charges

819

Restructuring 2016 [Member] | Operating Segments [Member] | Energy Services [Member] | Restructuring and Related Charges [Member]

Restructuring charges

842

Restructuring 2016 [Member] | Operating Segments [Member] | Energy Services [Member] | Other Expense [Member]

Restructuring charges

[7]

0

Restructuring 2016 [Member] | Corporate, Non-Segment [Member]

Restructuring charges

6,041

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Cost of Revenues [Member]

Restructuring charges

0

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Operating Expense [Member]

Restructuring charges

3,444

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Restructuring and Related Charges [Member]

Restructuring charges

1,783

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Other Expense [Member]

Restructuring charges

[7]

$ 814

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Energy Services [Member]

Restructuring charges

1,604

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Energy Services [Member] | Employee Severance [Member]

Restructuring charges

629

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Energy Services [Member] | Contract Termination [Member]

Restructuring charges

0

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Energy Services [Member] | Employee Relocation [Member]

Restructuring charges

0

Restructuring 2016 [Member] | Corporate, Non-Segment [Member] | Energy Services [Member] | Other Restructuring [Member]

Restructuring charges

[8]

$ 975

[1]

Total pre-tax restructuring charges include cash charges of $12.1 million and non-cash charges of $17.4 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.

[2]

Total pre-tax restructuring charges include cash charges of $13.6 million and non-cash charges of $10.1 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.

[3]

Includes charges related to the loss on disposal of restructured entities, including the release of cumulative currency translation adjustments resulting from those disposals.

[4]

Includes charges primarily related to certain wind-down costs, inventory obsolescence, fixed asset disposals, release of cumulative currency translation adjustments and other restructuring-related costs in connection with exiting or divesting the CIPP operations in Europe and Australia, exiting the cathodic protection operations in the Middle East and right-sizing the cathodic protection services operation in North America.

[5]

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, divesting the CIPP operations in Australia and Denmark, and exiting the cathodic protection operations in the Middle East. Amounts also include goodwill and definite-lived intangible asset impairments related to Denmark and definite-lived intangible asset impairments related to the cathodic protection operations in the Middle East.

[6]

Total pre-tax restructuring charges include cash charges of $19.5 million and non-cash charges of $12.8 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.

[7]

Includes charges related to the loss on disposal of restructured entities, including the release of cumulative currency translation adjustments resulting from those disposals.

[8]

Includes charges primarily related to exiting non-pipe-related applications for the Tyfo system in North America and right-sizing the cathodic protection services operation in Canada, inclusive of wind-down costs, professional fees, patent write offs, fixed asset disposals and certain other restructuring and related charges.

Note 4 - Restructuring - Recogn

Note 4 - Restructuring - Recognized Cost Restructuring Activities (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Restructuring charges		$ 14,300	$ 8,600	$ 6,500	$ 2,900	$ 13,900	$ 7,400	$ 2,900	$ 5,200
Restructuring reserve, settled without cash										$ 12,782		$ 13,814	$ 10,080
Restructuring 2016 [Member]
Restructuring reserve, balance					2,412				5,189	2,412		5,189
Restructuring charges										32,341	[1]	29,486	23,743
Restructuring reserve, foreign currency translation										(38)		(91)
Restructuring reserve, settled with cash	[2]									13,845		14,800	8,474
Restructuring reserve, settled without cash										12,782		17,372	10,080
Restructuring reserve, balance		8,088				2,412				8,088		2,412	5,189
Employee Severance [Member] | Restructuring 2016 [Member]
Restructuring reserve, balance					1,742				3,864	1,742		3,864
Restructuring charges										6,355		4,536	7,345
Restructuring reserve, foreign currency translation										(11)		(69)
Restructuring reserve, settled with cash	[2]									3,697		6,589	3,481
Restructuring reserve, settled without cash										0		0	0
Restructuring reserve, balance		4,389				1,742				4,389		1,742	3,864
Contract Termination [Member] | Restructuring 2016 [Member]
Restructuring reserve, balance					359				650	359		650
Restructuring charges										2,022		2,174	5,320
Restructuring reserve, foreign currency translation										(20)		(19)
Restructuring reserve, settled with cash	[2]									1,408		2,446	2,706
Restructuring reserve, settled without cash										0		0	1,964
Restructuring reserve, balance		953				359				953		359	650
Employee Relocation [Member] | Restructuring 2016 [Member]
Restructuring reserve, balance					0				0	0		0
Restructuring charges										653		184	147
Restructuring reserve, foreign currency translation										(3)		0
Restructuring reserve, settled with cash	[2]									283		184	147
Restructuring reserve, settled without cash										0		0	0
Restructuring reserve, balance		367				0				367		0	0
Other Restructuring [Member] | Restructuring 2016 [Member]
Restructuring reserve, balance					$ 311				$ 675	311		675
Restructuring charges										23,311		22,592	10,931	[3]
Restructuring reserve, foreign currency translation										(4)		(3)
Restructuring reserve, settled with cash	[2]									8,457		5,581	2,140
Restructuring reserve, settled without cash										12,782		17,372	8,116
Restructuring reserve, balance		$ 2,379				$ 311				$ 2,379		$ 311	$ 675
[1]	Total pre-tax restructuring charges include cash charges of $19.5 million and non-cash charges of $12.8 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.
[2]	Refers to cash utilized to settle charges during the year.
[3]	Includes charges primarily related to exiting non-pipe-related applications for the Tyfo system in North America and right-sizing the cathodic protection services operation in Canada, inclusive of wind-down costs, professional fees, patent write offs, fixed asset disposals and certain other restructuring and related charges.

Note 5 - Supplemental Balance_3

Note 5 - Supplemental Balance Sheet Information (Details Textual) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Credit Loss Expense (Reversal)	[1]	$ (1,259)	$ 8,188	$ 3,155
Inventory Write-down			2,800
Depreciation, Total		22,200	23,900	29,300
Restructuring 2016 and 2017 [Member]
Accounts Receivable, Credit Loss Expense (Reversal)		$ (100)	$ 5,300	$ 400
[1]	The Company recorded bad debt expense (reversals) of less than ($0.1) million, $5.3 million and $0.4 million in 2019, 2018 and 2017, respectively, as part of the restructuring efforts (see Note 4) and was primarily due to the exiting of certain low-return businesses mainly in foreign locations.

Note 5 - Supplemental Balance_4

Note 5 - Supplemental Balance Sheet Information - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance, beginning of year		$ 9,695	$ 5,775	$ 6,098
Bad debt expense (1)	[1]	(1,259)	8,188	3,155
Write-offs and adjustments		(1,212)	(4,268)	(3,478)
Balance, end of year		$ 7,224	$ 9,695	$ 5,775
[1]	The Company recorded bad debt expense (reversals) of less than ($0.1) million, $5.3 million and $0.4 million in 2019, 2018 and 2017, respectively, as part of the restructuring efforts (see Note 4) and was primarily due to the exiting of certain low-return businesses mainly in foreign locations.

Note 5 - Supplemental Balance_5

Note 5 - Supplemental Balance Sheet Information - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	[1]
Raw materials and supplies	$ 27,415	$ 29,343
Work-in-process	5,739	2,510
Finished products	14,937	15,205
Construction materials	9,102	9,379
Total	$ 57,193	$ 56,437
[1]	During 2018, the Company incurred non-cash charges of $2.8 million related to estimates for inventory obsolescence within its cathodic protection operations. The charges were recorded to cost of revenues in the Consolidated Statement of Operations.

Note 5 - Supplemental Balance_6

Note 5 - Supplemental Balance Sheet Information - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment, Gross	$ 289,188	$ 309,095
Less – Accumulated depreciation	(188,097)	(202,036)
Property, plant & equipment, less accumulated depreciation	101,091	107,059
Land and Land Improvements [Member]
Property, Plant and Equipment, Gross	$ 5,359	10,521
Land and Land Improvements [Member] | Minimum [Member]
Estimated Useful Lives (Year)	5 years
Land and Land Improvements [Member] | Maximum [Member]
Estimated Useful Lives (Year)	40 years
Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Gross	$ 50,589	47,430
Land, Buildings and Improvements [Member] | Minimum [Member]
Estimated Useful Lives (Year)	4 years
Land, Buildings and Improvements [Member] | Maximum [Member]
Estimated Useful Lives (Year)	10 years
Machinery and Equipment [Member]
Property, Plant and Equipment, Gross	$ 143,128	147,918
Machinery and Equipment [Member] | Minimum [Member]
Estimated Useful Lives (Year)	3 years
Machinery and Equipment [Member] | Maximum [Member]
Estimated Useful Lives (Year)	10 years
Furniture and Fixtures [Member]
Property, Plant and Equipment, Gross	$ 35,440	37,471
Furniture and Fixtures [Member] | Minimum [Member]
Estimated Useful Lives (Year)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Estimated Useful Lives (Year)	10 years
Vehicles [Member]
Property, Plant and Equipment, Gross	$ 47,197	51,129
Construction in Progress [Member]
Property, Plant and Equipment, Gross	$ 7,475	$ 14,626

Note 5 - Supplemental Balance_7

Note 5 - Supplemental Balance Sheet Information - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019		Dec. 31, 2018
Vendor and other accrued expenses	$ 30,730		$ 35,450
Estimated casualty and healthcare liabilities	13,138		17,419
Job costs	12,041		9,878
Accrued compensation	23,089		23,882
Income taxes payable	1,751		1,391
Total	96,577		88,020
Accrued Expense [Member]
Operating lease liabilities	$ 15,828	[1]	$ 0
[1]	Amounts exclude operating lease assets of $0.3 million, accrued expenses of $0.2 million and other liabilities of $0.2 million that were classified as held for sale at December 31, 2019 (see Note 5).

Note 6 - Assets and Liabiliti_3

Note 6 - Assets and Liabilities Held for Sale (Details Textual) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Impairment of Long-Lived Assets to be Disposed of			$ 23,427	$ 0	$ 0
Corporate, Non-Segment [Member]
Impairment of Long-Lived Assets to be Disposed of	$ 2,900		2,900
Infrastructure Solutions [Member]
Impairment of Long-Lived Assets to be Disposed of			17,600
Corrosion Protection [Member]
Impairment of Long-Lived Assets to be Disposed of			$ 2,900
Insituform Australia [Member] | Infrastructure Solutions [Member]
Impairment of Long-Lived Assets to be Disposed of		$ 5,100
Insituform Netherlands [Member] | Infrastructure Solutions [Member]
Impairment of Long-Lived Assets to be Disposed of	2,600	3,900
Corrpower [Member] | Corrosion Protection [Member]
Impairment of Long-Lived Assets to be Disposed of		1,100
United Mexico [Member] | Corrosion Protection [Member]
Impairment of Long-Lived Assets to be Disposed of		$ 1,800
Insituform Spain [Member] | Infrastructure Solutions [Member]
Impairment of Long-Lived Assets to be Disposed of	$ 6,000

Note 6 - Assets and Liabiliti_4

Note 6 - Assets and Liabilities Held for Sale - Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Disposal Group, Including Discontinued Operation, Contract Assets, Current	$ 5,400		$ 1,800
Total current assets	16,092		7,792
Impairment of assets held for sale	(23,427)		0		$ 0
Disposal Group, Including Discontinued Operation, Contract Liabilities, Current	100		100
Total current liabilities	6,485		5,260
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Receivables, net	4,136	[1]	1,309	[2]
Retainage	518	[1]	15	[2]
Disposal Group, Including Discontinued Operation, Contract Assets, Current	5,350	[1]	1,777	[2]
Inventories	2,097	[1]	2,123	[2]
Prepaid expenses and other current assets	799	[1]	300	[2]
Total current assets	12,900	[1]	5,524	[2]
Property, plant & equipment, less accumulated depreciation	10,962	[1]	2,268	[2]
Goodwill	4,224	[1]	0	[2]
Intangible assets, less accumulated amortization	1,528	[1]	0	[2]
Disposal Group, Including Discontinued Operation, Operating Lease, Right-of-Use Asset	326	[1]	0	[2]
Other non-current assets	130	[1]	0	[2]
Impairment of assets held for sale	(13,978)	[1]	0	[2]
Total assets held for sale	16,092	[1]	7,792	[2]
Accounts payable	2,174	[1]	1,331	[2]
Accrued expenses	3,961	[1]	3,891	[2]
Disposal Group, Including Discontinued Operation, Contract Liabilities, Current	122	[1]	38	[2]
Total current liabilities	6,257	[1]	5,260	[2]
Disposal Group, Including Discontinued Operation, Operating Lease, Liability, Noncurrent	174	[1]	0	[2]
Other non-current liabilities	54	[1]	0	[2]
Total liabilities held for sale	$ 6,485	[1]	$ 5,260	[2]
[1]	Includes Insituform Australia, Insituform Spain, Environmental Techniques and land held at Corporate.
[2]	Includes Insituform Australia.

Note 7 - Leases (Details Textua

Note 7 - Leases (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018	[2]
Lessee, Operating Lease, Renewal Term	5 years
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 19,800
Operating Leases, Future Minimum Payments, Due in Two Years	15,100
Operating Leases, Future Minimum Payments, Due in Three Years	11,500
Operating Leases, Future Minimum Payments, Due in Four Years	8,100
Operating Leases, Future Minimum Payments, Due in Five Years	5,400
Operating Leases, Future Minimum Payments, Due Thereafter	7,200
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Disposal Group, Including Discontinued Operation, Operating Lease, Right-of-Use Asset	326	[1]		$ 0
Disposal Group Including Discontinued Operation, Operating Lease Liability Current	200
Disposal Group, Including Discontinued Operation, Operating Lease, Liability, Noncurrent	$ 174	[1]		$ 0
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term	1 year
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term	20 years
Accounting Standards Update 2016-02 [Member]
Operating Lease, Liability, Total			$ 70,500
[1]	Includes Insituform Australia, Insituform Spain, Environmental Techniques and land held at Corporate.
[2]	Includes Insituform Australia.

Note 7 - Leases - Lease Expense

Note 7 - Leases - Lease Expenses (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Operating lease cost	$ 22,235
Short-term lease cost	25,382
Total lease cost	47,617
Operating cash flows from operating leases	22,144
Operating leases	$ 18,879

Note 7 - Leases - Supplement Fi

Note 7 - Leases - Supplement Financial Statement Disclosure (Details) - USD ($) $ in Thousands		Dec. 31, 2019		Dec. 31, 2018
Operating lease assets		$ 71,466	[1]	$ 0
Other liabilities		$ 56,253		0
Weighted-average remaining lease term (Year)	[1]	5 years 8 months 26 days
Weighted-average discount rate	[1]	5.71%
Accrued Expense [Member]
Accrued expenses		$ 15,828	[1]	$ 0
Other Liabilities [Member]
Other liabilities	[1]	56,253
Accrued Expense and Other Liabilities [Member]
Total operating lease liabilities	[1]	$ 72,081
[1]	Amounts exclude operating lease assets of $0.3 million, accrued expenses of $0.2 million and other liabilities of $0.2 million that were classified as held for sale at December 31, 2019 (see Note 5).

Note 7 - Leases - Operating Lea

Note 7 - Leases - Operating Lease Liabilities (Details) $ in Thousands	Dec. 31, 2019USD ($)
2020	$ 18,739
2021	16,287
2022	13,509
2023	10,950
2024	7,845
Thereafter	16,358
Total undiscounted operating lease liabilities	83,688
Less: Imputed interest	(11,607)
Accrued Expense and Other Liabilities [Member]
Total discounted operating lease liabilities	$ 72,081	[1]
[1]	Amounts exclude operating lease assets of $0.3 million, accrued expenses of $0.2 million and other liabilities of $0.2 million that were classified as held for sale at December 31, 2019 (see Note 5).

Note 8 - Goodwill and Intangi_3

Note 8 - Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Goodwill, Acquired During Period	[1]		$ 3,973
Goodwill, Impairment Loss		$ 0	1,389	[1]	$ 45,390
Amortization of Intangible Assets, Total		13,700	14,000		16,100
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		13,500
Finite-Lived Intangible Assets, Amortization Expense, Year Two		13,500
Finite-Lived Intangible Assets, Amortization Expense, Year Three		13,300
Finite-Lived Intangible Assets, Amortization Expense, Year Four		13,300
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 13,300
Infrastructure Solutions [Member]
Goodwill, Acquired During Period	[1]		0
Goodwill, Impairment Loss			1,389	[1]	$ 45,400
Denmark 1 [Member] | Infrastructure Solutions [Member]
Goodwill, Impairment Loss			1,400
Hebna [Member]
Goodwill, Acquired During Period			2,700
P2S [Member]
Goodwill, Acquired During Period			$ 1,300
[1]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).

Note 8 - Goodwill and Intangi_4

Note 8 - Goodwill and Intangible Assets - Reconciliation Goodwill (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Goodwill, gross		$ 398,610	$ 402,408		$ 401,101
Accumulated impairment losses		(141,775)	(141,775)		(140,386)
Goodwill, Ending Balance		256,835	260,633		260,715
Acqusitions (1)	[1]		3,973
Impairments (2)		0	(1,389)	[1]	(45,390)
Foreign currency translation		426	(2,666)
Reclassification to assets held for sale (3)	[2]	(4,224)
Goodwill, net		256,835	260,633		260,715
Infrastructure Solutions [Member]
Goodwill, gross		240,160	244,521		246,486
Accumulated impairment losses		(62,848)	(62,848)		(61,459)
Goodwill, Ending Balance		177,312	181,673		185,027
Acqusitions (1)	[1]		0
Impairments (2)			(1,389)	[1]	(45,400)
Foreign currency translation		(137)	(1,965)
Reclassification to assets held for sale (3)	[2]	(4,224)
Goodwill, net		177,312	181,673		185,027
Corrosion Protection [Member]
Goodwill, gross		76,946	76,383		74,369
Accumulated impairment losses		(45,400)	(45,400)		(45,400)
Goodwill, Ending Balance		31,546	30,983		28,969
Acqusitions (1)	[1]		2,715
Impairments (2)	[1]		0
Foreign currency translation		563	(701)
Reclassification to assets held for sale (3)	[2]	0
Goodwill, net		31,546	30,983		28,969
Energy Services [Member]
Goodwill, gross		81,504	81,504		80,246
Accumulated impairment losses		(33,527)	(33,527)		(33,527)
Goodwill, Ending Balance		47,977	47,977		46,719
Acqusitions (1)	[1]		1,258
Impairments (2)	[1]		0
Foreign currency translation		0	0
Reclassification to assets held for sale (3)	[2]	0
Goodwill, net		$ 47,977	$ 47,977		$ 46,719
[1]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).
[2]	During 2019, the Company classified certain assets of its CIPP contracting operation in Europe as held for sale (see Note 6).

Note 8 - Goodwill and Intangi_5

Note 8 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Gross carrying amount	$ 219,622	$ 221,095
Accumulated amortization	(114,795)	(101,399)
Net carrying amount	$ 104,828	119,696
Licensing Agreements [Member]
Weighted average useful lives (Year)	8 months 12 days
Gross carrying amount	$ 3,894	3,894
Accumulated amortization	(3,825)	(3,716)
Net carrying amount	$ 70	178
Lease Agreements [Member]
Weighted average useful lives (Year)	1 year
Gross carrying amount	$ 864	864
Accumulated amortization	(777)	(689)
Net carrying amount	$ 87	175
Trademarks [Member]
Weighted average useful lives (Year)	8 years 3 months 18 days
Gross carrying amount	$ 15,699	15,751
Accumulated amortization	(6,911)	(6,202)
Net carrying amount	$ 8,788	9,549
Noncompete Agreements [Member]
Weighted average useful lives (Year)	3 years 3 months 18 days
Gross carrying amount	$ 2,301	2,529
Accumulated amortization	(1,354)	(1,229)
Net carrying amount	$ 947	1,300
Customer Relationships [Member]
Weighted average useful lives (Year)	7 years 2 months 12 days
Gross carrying amount	$ 157,576	159,719
Accumulated amortization	(76,832)	(66,753)
Net carrying amount	$ 80,744	92,966
Patents [Member]
Weighted average useful lives (Year)	9 years
Gross carrying amount	$ 39,288	38,338
Accumulated amortization	(25,097)	(22,810)
Net carrying amount	$ 14,192	$ 15,528

Note 9 - Long-term Debt and C_3

Note 9 - Long-term Debt and Credit Facility (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Mar. 12, 2018	Oct. 31, 2015
Line of Credit Facility, Fees		$ 3,100
Line of Credit Facility, Up Front Lending Fee		1,400
Line of Credit Facility, Third Party Arrangement Fees		1,700
Long-term Debt, Total	$ 278,520	314,219
Repayments of Lines of Credit	7,000	7,000
Long-term Debt, Fair Value	286,800	307,700
Derivative, Fixed Interest Rate			2.937%
Bayou [Member]
Repayment of (Proceeds From) Divestiture of Businesses		35,000
A 2015 Interest Rate Swap [Member]
Derivative Asset, Notional Amount				$ 262,500
Derivative, Fixed Interest Rate				1.46%
A 2018 Interest Rate Swap [Member]
Derivative Asset, Notional Amount			$ 170,600
Derivative, Fixed Interest Rate			2.937%
Derivative, Amount of Hedged Item			$ 170,600
Term Loan [Member]
Long-term Debt, Total	253,800
A 2015 Credit Facility [Member]
Debt Instrument, Face Amount				$ 650,000
Line of Credit Facility, Maximum Borrowing Capacity				350,000
Line Of Credit Facility, Unamortized Loan Costs		2,400
Interest Expense, Debt, Total		600
Long-term Line of Credit, Total	24,000	31,000
Other Loans Payable, Total	800	1,000
Letters of Credit Outstanding, Amount	$ 26,100
Proceeds from Lines of Credit, Total		$ 28,000
Derivative, Amount of Hedged Item				262,500
Credit Facility Maximum Consolidated Leverage Ratio	3.25
Credit Facility Actual Consolidated Leverage Ratio	2.88
Line of Credit Facility, Remaining Borrowing Capacity	$ 37,500
Credit Facility Minimum Consolidated Fixed Charge Ratio	1.25
Credit Facility Actual Consolidated Fixed Charge Ratio	1.38
A 2015 Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | A 2015 Interest Rate Swap [Member]
Debt Instrument, Interest Rate, Effective Percentage	4.09%
A 2015 Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate		1.25%
A 2015 Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate		2.25%
A 2015 Credit Facility [Member] | Term Loan [Member]
Debt Instrument, Face Amount		$ 308,400
Debt Instrument, Interest Rate, Effective Percentage	3.83%
Long-term Debt, Total		$ 282,200
A 2015 Credit Facility [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 225,000
A 2015 Credit Facility [Member] | Insurance Carries Collateral [Member]
Letters of Credit Outstanding, Amount	$ 12,200
A 2015 Credit Facility [Member] | Working Performance Obligation [Member]
Letters of Credit Outstanding, Amount	$ 13,900

Note 9 - Long-term Debt and C_4

Note 9 - Long-term Debt and Credit Facility - Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Long term debt	$ 278,520	$ 314,219
Less – Current maturities of long-term debt	32,803	29,469
Less – Unamortized loan costs	2,088	2,747
Total	243,629	282,003
Medium-term Notes [Member]
Long term debt	253,750	282,188
Line of Credit [Member]
Long term debt	24,000	31,000
Notes Payable, Other Payables [Member]
Long term debt	$ 770	$ 1,031

Note 9 - Long-term Debt and C_5

Note 9 - Long-term Debt and Credit Facility - Long-term Debt (Details) (Parentheticals)	Dec. 31, 2019	Dec. 31, 2018
Medium-term Notes [Member]
Current effective interest rate	4.09%	4.59%
Line of Credit [Member]
Current effective interest rate	4.01%	4.45%
Notes Payable, Other Payables [Member] | Minimum [Member]
Current effective interest rate	3.30%	3.30%
Notes Payable, Other Payables [Member] | Maximum [Member]
Current effective interest rate	7.80%	7.80%

Note 9 - Long-term Debt and C_6

Note 9 - Long-term Debt and Credit Facility - Debt Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
2020	$ 32,803
2021	25,060
2022	30,844
2023	189,813
2024	0
Thereafter	0
Total	$ 278,520	$ 314,219

Note 10 - Stockholders' Equity

Note 10 - Stockholders' Equity (Details Textual) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Apr. 30, 2018shares	Dec. 31, 2016shares
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	2,000,000	2,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	1,034,964	1,143,205	1,428,878		1,501,021
A 2016 Employee Plan [Member]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	300,000			1,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,099,380
Share-based Payment Arrangement, Option [Member]
Stock Repurchased During Period, Shares	48,409
Stock Repurchased During Period, Value | $	$ 1
Treasury Stock Acquired, Average Cost Per Share | $ / shares	$ 20.52
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	253,340	287,350	269,977		253,445
Deferred Stock Units [Member] | A 2016 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	321,406
Deferred Stock Units [Member] | A 2011 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	52,296
Deferred Stock Units [Member] | A 2006 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	39,109
Deferred Stock Units [Member] | A 2001 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	31,850
In Connection With Equity Compensation Programs [Member]
Stock Repurchase Program, Authorized Amount | $	$ 10
Stock Repurchased During Period, Shares	151,234	228,068	112,899
Stock Repurchased During Period, Value | $	$ 3.1	$ 5.5	$ 2.5
Treasury Stock Acquired, Average Cost Per Share | $ / shares	$ 20.26	$ 24.08	$ 22.15
Through The Open Market Repurchase Program [Member]
Stock Repurchased During Period, Shares	1,492,348,000,000	949,464	1,599,093
Stock Repurchased During Period, Value | $	$ 26.3	$ 20.3	$ 35.3
Treasury Stock Acquired, Average Cost Per Share | $ / shares	$ 17.64	$ 21.36	$ 22.10
Amended Credit Facility [Member]
Stock Repurchase Program, Authorized Amount | $	$ 40	$ 32
Credit Facility Minimum Consolidated Leverage Ratio	2.50

Note 11 - Equity-based Compen_3

Note 11 - Equity-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 9,600
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days
Weighted Average [Member]
Share Price	$ 20.55		$ 27.35
Current Stock Awards [Member]
Share-based Payment Arrangement, Expense	$ 7,000	$ 6,800	$ 9,000
Deferred Stock Units [Member]
Share-based Payment Arrangement, Expense	$ 700	1,100	1,100
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	3 months 18 days
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 400
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense	$ 0	$ 0	$ 0
Share-based Payment Arrangement, Option [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	7 years
Share-based Payment Arrangement, Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years

Note 11 - Equity-based Compen_4

Note 11 - Equity-based Compensation - Summary of Stock Award Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Awards, Outstanding (in shares)	1,143,205	1,428,878	1,501,021
Weighted average award date fair value (in dollars per share)	$ 23.26	$ 21.53	$ 20.58
Stock Awards, Outstanding (in shares)	1,034,964	1,143,205	1,428,878
Weighted average award date fair value (in dollars per share)	$ 23.20	$ 23.26	$ 21.53
Restricted Stock Units (RSUs) [Member]
Awards, grants during period (in shares)	325,321	281,567	257,532
Weighted average award date fair value, award granted (in dollars per share)	$ 20.02	$ 24.13	$ 23.06
Awards, distributed during period (in shares)	(237,416)	(312,182)	(95,510)
Weighted average award date fair value, award distributed (in dollars per share)	$ 18.83	$ 17.47	$ 20.71
Awards, forfeited during period (in shares)	(74,075)	(90,896)	(81,626)
Weighted average award date fair value, award forfeited (in dollars per share)	$ 22.09	$ 21.79	$ 20.36
Performance Shares [Member]
Awards, grants during period (in shares)	146,367	219,943	213,436
Weighted average award date fair value, award granted (in dollars per share)	$ 22.78	$ 23.25	$ 28.18
Awards, distributed during period (in shares)	(111,155)	(296,909)	(49,672)
Weighted average award date fair value, award distributed (in dollars per share)	$ 25.85	$ 21.55	$ 21.95
Awards, forfeited during period (in shares)	(80,597)	(87,196)	(136,050)
Weighted average award date fair value, award forfeited (in dollars per share)	$ 25.30	$ 25.95	$ 24.29
Restricted Stock [Member]
Awards, distributed during period (in shares)	(76,686)	0	(179,169)
Weighted average award date fair value, award distributed (in dollars per share)	$ 18.26	$ 0	$ 22.44
Awards, forfeited during period (in shares)	0	0	(1,084)
Weighted average award date fair value, award forfeited (in dollars per share)	$ 0	$ 0	$ 23.01

Note 11 - Equity-based Compen_5

Note 11 - Equity-based Compensation - Deferred Stock Unit Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Awards, Outstanding (in shares)	1,143,205	1,428,878	1,501,021
Weighted average award date fair value (in dollars per share)	$ 23.26	$ 21.53	$ 20.58
Stock Awards, Outstanding (in shares)	1,034,964	1,143,205	1,428,878
Weighted average award date fair value (in dollars per share)	$ 23.20	$ 23.26	$ 21.53
Deferred Stock Units [Member]
Stock Awards, Outstanding (in shares)	287,350	269,977	253,445
Weighted average award date fair value (in dollars per share)	$ 20.80	$ 20.14	$ 19.93
Awards, grants during period (in shares)	50,174	45,681	47,091
Weighted average award date fair value, award granted (in dollars per share)	$ 19.64	$ 23.72	$ 23.53
Awards, distributed during period (in shares)	(84,184)	(28,308)	(30,559)
Weighted average award date fair value, award distributed (in dollars per share)	$ 20.38	$ 19.22	$ 23.57
Stock Awards, Outstanding (in shares)	253,340	287,350	269,977
Weighted average award date fair value (in dollars per share)	$ 20.71	$ 20.80	$ 20.14

Note 11 - Equity-based Compen_6

Note 11 - Equity-based Compensation - Summary of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Outstanding, shares (in shares)	52,783	126,680	170,253
Outstanding, weighted average exercise price (in dollars per share)	$ 18.11	$ 23.06	$ 21.99
Exercised, shares (in shares)	(52,783)	0	(43,573)
Exercised, weighted average exercise price (in dollars per share)	$ 18.11	$ 0	$ 18.87
Canceled/Expired, shares (in shares)	0	(73,897)	0
Canceled/Expired, weighted average exercise price (in dollars per share)	$ 0	$ 26.60	$ 0
Outstanding,, shares (in shares)	0	52,783	126,680
Outstanding, weighted average exercise price (in dollars per share)	$ 0	$ 18.11	$ 23.06
Exercisable, shares (in shares)	0	52,783	126,680
Exercisable, weighted average exercise price (in dollars per share)	$ 0	$ 18.11	$ 23.06

Note 11 - Equity-based Compen_7

Note 11 - Equity-based Compensation - Stock Option Exercises (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Proceeds from issuance of common stock upon stock option exercises		$ 956	$ 0	$ 823
Total intrinsic value of stock option exercises (1)	[1]	129	0	370
Tax expense (benefit) of stock option exercises recorded in income tax expense		312	(1,556)	(63)
Aggregate intrinsic value of outstanding stock options		0	0	386
Aggregate intrinsic value of exercisable stock options		$ 0	$ 0	$ 386
[1]	Calculations based on a weighted average market price of the Company's stock at the time of exercise of $20.55 and $27.35 for the years ended December 31, 2019 and 2017, respectively.

Note 12 - Taxes on Income (Deta

Note 12 - Taxes on Income (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	35.00%
Tax Cuts and Jobs Act, Incomplete Accounting, Provisional Income Tax Expense (Benefit), Total			$ 2,400
Tax Cuts and Jobs Act, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense			10,400
Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax Benefit			7,100
Tax Cuts and Jobs Act, Incomplete Accounting, Other Adjustments, Provisional Income Tax Benefit			900
Tax Cuts and Jobs Act, Transition Tax for Accumulated Foreign Earnings, Income Tax Expense			9,600
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Tax Benefit			7,100
Tax Cuts and Jobs Act, Change in Tax Rate, Other Adjustments, Income Tax Benefit			2,000
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)		$ (1,900)
Tax Cuts and Jobs Act, Transition Tax for Accumulated Foreign Earnings, Liability, Total		1,100
Deferred Tax Assets, Operating Loss Carryforwards, Total	$ 19,079	22,909
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	11,900
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	7,200
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	4,101	507
Deferred Tax Assets, Tax Credit Carryforwards, Foreign, Subject to Expiration	400
Deferred Tax Assets, Tax Credit Carryforwards, Foreign, Not Subject to Expiration	3,600	100
Deferred Tax Assets, Valuation Allowance, Total	34,247	28,451
Undistributed Earnings of Foreign Subsidiaries	206,700
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	300
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total	200	$ 200	$ 200
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 700
Open Tax Year	2015 2016 2017 2018 2019

Note 12 - Taxes on Income - Inc

Note 12 - Taxes on Income - Income (Loss) Before Taxes on Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Domestic	$ 3,627	$ 8,142	$ (40,007)
Foreign	(16,511)	(5,187)	(21,570)
Total	$ (12,884)	$ 2,955	$ (61,577)

Note 12 - Taxes on Income - Pro

Note 12 - Taxes on Income - Provisions for Taxes on Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal	$ (2,775)	$ (4,765)	$ 3,764
Foreign	5,705	6,025	7,512
State	460	(651)	3,351
Subtotal	3,390	609	14,627
Federal	538	947	(8,706)
Foreign	(199)	(1,531)	(1,099)
State	2,835	(157)	183
Subtotal	3,174	(741)	(9,622)
Total tax provision	$ 6,564	$ (132)	$ 5,005

Note 12 - Taxes on Income - Eff

Note 12 - Taxes on Income - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income taxes (benefit) at U.S. federal statutory tax rate	$ (2,706)	$ 621	$ (21,552)
State income taxes, net of federal income tax benefit	2,603	(798)	2,270
Divestitures	5,613	2,133	0
Meals and entertainment	470	517	785
Changes in taxes previously accrued	(1,070)	(536)	(1,339)
Foreign tax rate differences	(643)	1,301	913
Share-based compensation	358	(1,427)	131
Goodwill impairment	0	291	6,359
Recognition of uncertain tax positions	(717)	(218)	(62)
Deemed mandatory repatriation	0	(842)	10,406
Release of deferred tax liability on foreign earnings	0	0	(7,051)
Domestic Production Activities deduction	0	0	(1,921)
Other matters	(1,110)	(820)	(1,287)
Total tax provision	$ 6,564	$ (132)	$ 5,005
Effective tax rate	(50.90%)	(4.50%)	(8.10%)
Foreign Tax Authority [Member]
Change in the balance of the valuation allowance for deferred tax assets allocated to foreign income tax expense	$ 806	$ 590	$ 4,598
Domestic Tax Authority [Member]
Change in the balance of the valuation allowance for deferred tax assets allocated to foreign income tax expense	$ 2,960	$ (944)	$ 12,755

Note 12 - Taxes on Income - Net

Note 12 - Taxes on Income - Net Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Foreign tax credit carryforwards	$ 4,101	$ 507
Net operating loss carryforwards	19,079	22,909
Accrued expenses	15,281	12,987
Other	8,431	8,652
Total gross deferred income tax assets	46,892	45,055
Less valuation allowance	(34,247)	(28,451)
Net deferred income tax assets	12,645	16,604
Property, plant and equipment	(5,689)	(6,038)
Intangible assets	(12,203)	(10,609)
Other	4,791	6,757
Total deferred income tax liabilities	(22,683)	(23,404)
Net deferred income tax liabilities	(10,038)	(6,800)
Deferred income tax assets	1,216	1,561
Noncurrent deferred income tax liabilities, net	(11,254)	(8,361)
Net deferred income tax liabilities	$ 10,038	$ 6,800

Note 12 - Taxes on Income - Act

Note 12 - Taxes on Income - Activity in the Valuation Allowance (Details) - SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 28,451	$ 29,782	$ 15,428
Additions	8,789	1,879	19,260
Reversals	(6,776)	(2,102)	(183)
Remeasurement of U.S. deferred tax balances	0	0	(5,141)
Other adjustments	3,783	(1,108)	418
Balance	$ 34,247	$ 28,451	$ 29,782

Note 12 - Taxes on Income - Unr

Note 12 - Taxes on Income - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 1,955	$ 2,229	$ 2,465
Additions for tax positions of prior years	9	8	12
Lapse in statute of limitations	(587)	(264)	(274)
Foreign currency translation	7		26
Foreign currency translation		(18)
Balance	$ 1,384	$ 1,955	$ 2,229

Note 13 - Commitments and Con_2

Note 13 - Commitments and Contingencies (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Multiemployer Plans, Number of Participants	1,050
Corrpro [Member]
Defined Benefit Plan, Benefit Obligation, Ending Balance	$ 6.9	$ 7.9
Defined Benefit Plan, Plan Assets, Amount, Ending Balance	$ 6.2	7.1
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.10%
Corrpro [Member] | Overfunded Plan [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total	$ 0.7
UNITED STATES
Defined Contribution Plan, Cost	5.2	5.7	$ 6.3
Foreign Plan [Member]
Defined Contribution Plan, Cost	0.8	1.1	1
Brinderson L.P. [Member] | Pre-Acquisition Matters [Member]
Loss Contingency Accrual, Ending Balance		4		$ 6
Loss Contingency Accrual, Payments	4.3	$ 0.2	0.3
Loss Contingency Accrual, Period Increase (Decrease), Total			$ 1.5
Loss Contingency Accrual, Provision	$ 0.3

Note 14 - Segment and Geograp_3

Note 14 - Segment and Geographic Information (Details Textual) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)		Dec. 31, 2017USD ($)
Number of Reportable Segments										3
Restructuring Charges, Total		$ 14,300	$ 8,600	$ 6,500	$ 2,900	$ 13,900	$ 7,400	$ 2,900	$ 5,200
Impairment of Long-Lived Assets to be Disposed of										$ 23,427	$ 0		$ 0
Goodwill, Impairment Loss										0	1,389	[1]	45,390
Corporate, Non-Segment [Member]
Impairment of Long-Lived Assets to be Disposed of		$ 2,900								2,900
Infrastructure Solutions [Member]
Impairment of Long-Lived Assets to be Disposed of										17,600
Goodwill, Impairment Loss											1,389	[1]	45,400
Impairment of Intangible Assets (Excluding Goodwill), Total													41,000
Infrastructure Solutions [Member] | Environmental Techniques [Member]
Business Combination, Acquisition Related Costs													100
Corrosion Protection [Member]
Impairment of Long-Lived Assets to be Disposed of										2,900
Goodwill, Impairment Loss	[1]										0
Energy Services [Member]
Goodwill, Impairment Loss	[1]										0
Restructuring 2017 [Member]
Restructuring Charges, Total										32,341	29,486	[2]	23,743	[3]
Restructuring 2017 [Member] | Corporate, Non-Segment [Member]
Restructuring Charges, Total										6,041	1,637		1,604
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Corporate, Non-Segment [Member]
Restructuring Charges, Total										5,200	1,600		1,600
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Divestiture of International Operations [Member] | Corporate, Non-Segment [Member]
Restructuring Charges, Total										2,200	4,100		1,200
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Infrastructure Solutions [Member]
Restructuring Charges, Total										7,500	16,100		17,500
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Infrastructure Solutions [Member] | Divestiture of International Operations [Member]
Restructuring Charges, Total										1,000	400
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Corrosion Protection [Member]
Restructuring Charges, Total										7,700	7,600		4,900
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Corrosion Protection [Member] | Divestiture of International Operations [Member]
Restructuring Charges, Total										100	2,500		1,600
Restructuring 2017 [Member] | Operating Income (Loss) [Member] | Energy Services [Member]
Restructuring Charges, Total										1,700	300
Restructuring 2017 [Member] | Other Nonoperating Income (Expense) [Member]
Restructuring Charges, Total										$ 10,200			$ 4,000
Restructuring 2017 [Member] | Other Nonoperating Income (Expense) [Member] | Bayou [Member]
Restructuring Charges, Total											$ 7,000
[1]	During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).
[2]	Total pre-tax restructuring charges include cash charges of $12.1 million and non-cash charges of $17.4 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.
[3]	Total pre-tax restructuring charges include cash charges of $13.6 million and non-cash charges of $10.1 million. Cash charges consist of charges incurred during the year that will be settled in cash, either during the current period or future periods.

Note 14 - Segment and Geograp_4

Note 14 - Segment and Geographic Information - Summary of Revenues (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2019		Sep. 30, 2019	[2]	Jun. 30, 2019	[3]	Mar. 31, 2019	[4]	Dec. 31, 2018		Sep. 30, 2018	[2]	Jun. 30, 2018	[4]	Mar. 31, 2018	[4]	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Revenues		$ 309,502	[1]	$ 308,789		$ 318,740		$ 276,904		$ 333,998	[1]	$ 339,679		$ 335,030		$ 324,861		$ 1,213,935	[5]	$ 1,333,568	[5]	$ 1,359,019	[5]
Gross profit		63,711	[1]	66,792		67,437		48,295		61,696	[1]	72,673		71,053		61,504		246,235	[5]	266,926	[5]	284,812	[5]
Operating income (loss)		(3,361)	[1]	$ 14,649		$ 459		$ (774)		(1,002)	[1]	$ 13,009		$ 14,459		$ 3,181		10,973	[5]	29,647	[5]	(43,520)	[5]
Interest expense																		(14,002)		(17,327)		(16,001)
Interest income																		1,038		516		145
Other	[6]																	(10,893)		(9,881)		(2,201)
Total other expense																		(23,857)		(26,692)		(18,057)
Income (loss) before taxes on income																		(12,884)		2,955		(61,577)
Total assets		995,513								992,417								995,513		992,417		1,107,099
Capital expenditures																		28,772		30,514		30,830
Depreciation and amortization																		36,163		37,855		44,419
Long-lived assets	[5],[7]	101,091								128,660								101,091		128,660		125,309
UNITED STATES
Revenues	[5]																	914,676		966,291		1,028,313
Gross profit	[5]																	175,705		178,024		226,026
Operating income (loss)	[5]																	6,212		174		(33,583)
Long-lived assets	[5],[7]	80,910								105,978								80,910		105,978		93,472
CANADA
Revenues	[5]																	123,033		133,612		139,734
Gross profit	[5]																	22,183		22,823		31,173
Operating income (loss)	[5]																	7,460		9,482		12,220
Long-lived assets	[5],[7]	7,462								7,725								7,462		7,725		8,816
Europe [Member]
Revenues	[5]																	64,278		66,794		71,839
Gross profit	[5]																	14,849		8,379		11,997
Operating income (loss)	[5]																	(11,363)		(10,599)		(3,771)
Long-lived assets	[5],[7]	2,499								8,295								2,499		8,295		13,435
Other Foreign Countries [Member]
Revenues	[5]																	111,948		166,871		119,133
Gross profit	[5]																	33,498		57,700		15,616
Operating income (loss)	[5]																	8,664		30,590		(18,386)
Long-lived assets	[5],[7]	10,220								6,662								10,220		6,662		9,586
Infrastructure Solutions [Member]
Revenues																		590,797		604,121		612,154
Infrastructure Solutions [Member] | UNITED STATES
Revenues																		427,220		430,187		437,944
Infrastructure Solutions [Member] | CANADA
Revenues																		65,370		62,292		60,675
Infrastructure Solutions [Member] | Europe [Member]
Revenues																		49,157		54,567		58,520
Infrastructure Solutions [Member] | Other Foreign Countries [Member]
Revenues																		49,050		57,075		55,015
Corrosion Protection [Member]
Revenues																		295,090		393,740		456,139
Corrosion Protection [Member] | UNITED STATES
Revenues																		159,408		200,397		299,643
Corrosion Protection [Member] | CANADA
Revenues																		57,663		71,320		79,059
Corrosion Protection [Member] | Europe [Member]
Revenues																		15,121		12,227		13,319
Corrosion Protection [Member] | Other Foreign Countries [Member]
Revenues																		62,898		109,796		64,118
Energy Services [Member]
Revenues																		328,048		335,707		290,726
Energy Services [Member] | UNITED STATES
Revenues																		328,048		335,707		290,726
Energy Services [Member] | CANADA
Revenues																		0		0		0
Energy Services [Member] | Europe [Member]
Revenues																		0		0		0
Energy Services [Member] | Other Foreign Countries [Member]
Revenues																		0		0		0
Operating Segments [Member] | Infrastructure Solutions [Member]
Revenues																		590,797		604,121		612,154
Gross profit																		144,074		132,411		140,823
Operating income (loss)	[8]																	42,079		37,509		(47,316)
Total assets		508,226								500,977								508,226		500,977		531,746
Capital expenditures																		10,679		12,730		16,680
Depreciation and amortization																		13,773		16,758		18,731
Operating Segments [Member] | Corrosion Protection [Member]
Revenues																		295,090		393,740		456,139
Gross profit																		60,927		92,968		108,240
Operating income (loss)	[9]																	(5,635)		16,283		32,222
Total assets		278,694								279,106								278,694		279,106		329,848
Capital expenditures																		11,437		9,754		8,603
Depreciation and amortization																		12,487		11,874		15,598
Operating Segments [Member] | Energy Services [Member]
Revenues																		328,048		335,707		290,726
Gross profit																		41,234		41,547		35,749
Operating income (loss)	[10]																	9,740		9,638		7,736
Total assets		161,165								163,109								161,165		163,109		152,416
Capital expenditures																		3,437		3,053		2,713
Depreciation and amortization																		7,490		7,111		6,726
Corporate, Non-Segment [Member]
Operating income (loss)	[11]																	(35,211)		(33,783)		(36,162)
Total assets		31,336								41,432								31,336		41,432		22,775
Capital expenditures																		3,219		4,977		2,834
Depreciation and amortization																		2,413		2,112		3,364
Segment Reconciling Items [Member]
Total assets		$ 16,092								$ 7,793								$ 16,092		$ 7,793		$ 70,314
[1]	Includes pre-tax expenses of $13.9 million related to our restructuring efforts (see Note 4).
[2]	Includes pre-tax expenses of $7.4 million related to our restructuring efforts (see Note 4).
[3]	Includes pre-tax expenses of $6.5 million related to our restructuring efforts (see Note 4).
[4]	Includes pre-tax expenses of $5.2 million related to our restructuring efforts (see Note 4).
[5]	Attributed to the country of origin.
[6]	Other expense for 2019 includes $10.2 million of restructuring charges (see Note 4). Other expense for 2018 includes charges of $7.0 million related to the loss on the sale of Bayou (see Note 1) and $4.0 million of restructuring charges (see Note 4).
[7]	Long-lived assets do not include goodwill, intangible assets, operating lease assets or deferred tax assets.
[8]	Operating income for 2019 includes: (i) $7.5 million of restructuring charges (see Note 4); (ii) $1.0 million of costs primarily related to the planned divestiture of certain international operations; and (iii) $17.6 million of impairment charges to assets held for sale (see Note 6). Operating income for 2018 includes: (i) $16.1 million of restructuring charges (see Note 4); and (ii) $0.4 million of cost incurred related to the disposition of Denmark. Operating loss for 2017 includes: (i) $17.5 million of restructuring charges (see Note 4); (ii) $45.4 million of goodwill impairment charges (see Note 2); (iii) $41.0 million of definite-lived intangible asset impairment charges (see Note 2); and (iv) $0.1 million of costs incurred related to the acquisition of Environmental Techniques.
[9]	Operating loss for 2019 includes: (i) $7.7 million of restructuring charges (see Note 4); (ii) $0.1 million of divestiture costs; and (iii) $2.9 million of impairment charges to assets held for sale (see Note 6). Operating income for 2018 includes: (i) $7.6 million of restructuring charges (see Note 4); and (ii) $2.5 million of costs incurred related to the divestiture of Bayou. Operating income for 2017 includes $4.9 million of restructuring charges (see Note 4) and (ii) $1.6 million of costs incurred related to the planned divestiture of Bayou.
[10]	Operating income for 2019 includes $1.7 million of restructuring charges (see Note 4). Operating income for 2018 includes $0.3 million of restructuring charges (see Note 4).
[11]	Operating loss for 2019 includes: (i) $5.2 million of restructuring charges (see Note 4); (ii) $2.2 million of costs primarily related to the planned divestiture of certain international operations; and (iii) $2.9 million of impairment charges to assets held for sale (see Note 6). Operating loss for 2018 includes $1.6 million of restructuring charges (see Note 4) and $4.1 million of divestiture costs. Operating loss for 2017 includes $1.6 million of restructuring charges (see Note 4) and $1.2 million of divestiture costs.

Note 15 - Derivative Financia_3

Note 15 - Derivative Financial Instruments (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 12, 2018	Oct. 31, 2015
Derivative Assets (Liabilities), at Fair Value, Net, Total	$ (4,638)	$ 1,719
Gain (Loss) on Foreign Currency Derivatives Recorded in Earnings, Net	(200)	(500)	$ (100)
Derivative, Fixed Interest Rate				2.937%
A 2015 Interest Rate Swap [Member]
Derivative, Fixed Interest Rate					1.46%
Derivative Asset, Notional Amount					$ 262,500
A 2018 Interest Rate Swap [Member]
Derivative, Amount of Hedged Item				$ 170,600
Derivative, Fixed Interest Rate				2.937%
Derivative Asset, Notional Amount				$ 170,600
A 2015 Credit Facility [Member]
Derivative, Amount of Hedged Item					262,500
Line of Credit Facility, Maximum Borrowing Capacity					$ 350,000
A 2018 Credit Facility [Member]
Derivative Asset, Notional Amount				$ 170,600
Fair Value, Recurring [Member] | Designated as Hedging Instrument [Member]
Derivative Assets (Liabilities), at Fair Value, Net, Total	$ (4,600)	$ 1,800

Note 15 - Derivative Financia_4

Note 15 - Derivative Financial Instruments - Summary of Derivative Positions (Details) - Interest Rate Swap [Member]	12 Months Ended
	Dec. 31, 2019USD ($)
Notional amount	$ 190,312,500
Weighted average remaining maturities (Year)	3 years 2 months 12 days

Note 15 - Derivative Financia_5

Note 15 - Derivative Financial Instruments - Summary of Fair Value Amounts of Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative assets	$ 261	$ 3,648
Derivative liabilities	4,899	1,929
Net derivative assets (liabilities)	(4,638)	1,719
Designated as Hedging Instrument [Member]
Derivative assets	261	3,648
Derivative liabilities	4,899	1,885
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Interest Rate Swap [Member]
Derivative assets	261	3,648
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Interest Rate Swap [Member]
Derivative liabilities	4,899	1,885
Not Designated as Hedging Instrument [Member]
Derivative liabilities	0	44
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member] | Foreign Exchange Forward [Member]
Derivative liabilities	$ 0	$ 44

Note 16 - Selected Quarterly _3

Note 16 - Selected Quarterly Financial Data (Unaudited) (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Restructuring Charges, Total	$ 14.3	$ 8.6	$ 6.5	$ 2.9	$ 13.9	$ 7.4	$ 2.9	$ 5.2

Note 16 - Selected Quarterly _4

Note 16 - Selected Quarterly Financial Data (Unaudited) - Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2019	[1]	Sep. 30, 2019	[2]	Jun. 30, 2019	[3]	Mar. 31, 2019	[4]	Dec. 31, 2018	[1]	Sep. 30, 2018	[2]	Jun. 30, 2018	[4]	Mar. 31, 2018	[4]	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Revenues	$ 309,502		$ 308,789		$ 318,740		$ 276,904		$ 333,998		$ 339,679		$ 335,030		$ 324,861		$ 1,213,935	[5]	$ 1,333,568	[5]	$ 1,359,019	[5]
Gross profit	63,711		66,792		67,437		48,295		61,696		72,673		71,053		61,504		246,235	[5]	266,926	[5]	284,812	[5]
Operating income (loss)	(3,361)		14,649		459		(774)		(1,002)		13,009		14,459		3,181		10,973	[5]	29,647	[5]	(43,520)	[5]
Net income (loss)	$ (13,659)		$ 6,349		$ (8,147)		$ (3,991)		$ (2,776)		$ 141		$ 7,198		$ (1,476)		$ (19,448)		$ 3,087		$ (66,582)
Basic (in dollars per share)	$ (0.47)		$ 0.20		$ (0.27)		$ (0.13)		$ (0.08)		$ (0.01)		$ 0.24		$ (0.06)		$ (0.67)		$ 0.09		$ (2.09)
Diluted (in dollars per share)	$ (0.47)		$ 0.19		$ (0.27)		$ (0.13)		$ (0.08)		$ (0.01)		$ 0.24		$ (0.06)		$ (0.67)		$ 0.09		$ (2.09)
[1]	Includes pre-tax expenses of $13.9 million related to our restructuring efforts (see Note 4).
[2]	Includes pre-tax expenses of $7.4 million related to our restructuring efforts (see Note 4).
[3]	Includes pre-tax expenses of $6.5 million related to our restructuring efforts (see Note 4).
[4]	Includes pre-tax expenses of $5.2 million related to our restructuring efforts (see Note 4).
[5]	Attributed to the country of origin.

Note 17 - Subsequent Events (De

Note 17 - Subsequent Events (Details Textual) - USD ($) $ in Millions	Feb. 13, 2020	Jan. 24, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019
Insituform Pacific Pty Limited ("IPPL") [Member] | Discontinued Operations, Disposed of by Sale [Member]
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down				$ 5.1
Insituform Spain [Member] | Discontinued Operations, Disposed of by Sale [Member]
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down			$ 6
Trademarks [Member]
Finite-Lived Intangible Asset, Useful Life					8 years 3 months 18 days
Insituform Pacific Pty Limited ("IPPL") [Member] | Subsequent Event [Member]
Tube-Supply Agreement, Term		5 years
Insituform Pacific Pty Limited ("IPPL") [Member] | Subsequent Event [Member] | Trademarks [Member]
Finite-Lived Intangible Asset, Useful Life		5 years
Insituform Spain [Member] | Subsequent Event [Member]
Tube-Supply Agreement, Term	5 years
Insituform Spain [Member] | Subsequent Event [Member] | Trademarks [Member]
Finite-Lived Intangible Asset, Useful Life	5 years