0001436126-21-000013 | 10-K | XBRL Viewer

Print Document View Excel Document

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2020	Mar. 11, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-34481
Entity Registrant Name	Mistras Group, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-3341267
Entity Address, Address Line One	195 Clarksville Road
Entity Address, City or Town	Princeton Junction
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08550
City Area Code	609
Local Phone Number	716-4000
Title of 12(b) Security	Common Stock, par value $.01 par value
Trading Symbol	MG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 70.1
Entity Common Stock, Shares Outstanding		29,234,143
Documents Incorporated by Reference	Information required by Part III (Items 10, 11, 12, 13 and 14) is incorporated by reference to portions of the registrant’s definitive proxy statement for its 2021 annual meeting of shareholders (the “Proxy Statement”), which is expected to be filed not later than 120 days after the registrant’s fiscal year ended December 31, 2020. Except as expressly incorporated by reference, the Proxy Statement shall not be deemed to be a part of this report on Form 10-K.
Entity Central Index Key	0001436126
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 25,760	$ 15,016
Accounts receivable, net	107,628	135,997
Inventories	13,134	13,413
Prepaid expenses and other current assets	16,066	14,729
Total current assets	162,588	179,155
Property, plant and equipment, net	92,681	98,607
Intangible assets, net	68,642	109,537
Goodwill	206,008	282,410
Deferred income taxes	2,069	1,786
Other assets	51,325	48,383
Total Assets	583,313	719,878
Current Liabilities
Accounts payable	14,240	15,033
Accrued expenses and other current liabilities	78,500	81,389
Current portion of long-term debt	10,678	6,593
Current portion of finance lease obligations	3,765	4,131
Income taxes payable	2,664	2,094
Total current liabilities	109,847	109,240
Long-term debt, net of current portion	209,538	248,120
Obligations under finance leases, net of current portion	11,115	13,043
Deferred income taxes	8,236	21,290
Other long-term liabilities	47,358	42,163
Total Liabilities	386,094	433,856
Commitments and contingencies
Equity
Preferred stock, 10,000,000 shares authorized	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized, 29,234,143 and 28,945,472 shares issued	292	289
Additional paid-in capital	234,638	229,205
Retained earnings (deficit)	(21,848)	77,613
Accumulated other comprehensive loss	(16,061)	(21,285)
Total Mistras Group, Inc. stockholders’ equity	197,021	285,822
Non-controlling interests	198	200
Total Equity	197,219	286,022
Total Liabilities and Equity	$ 583,313	$ 719,878

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	29,234,143	28,945,472

Consolidated Statements of Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 592,571	$ 748,586	$ 742,354
Cost of revenue	391,855	509,489	512,024
Depreciation	22,185	21,800	22,456
Gross profit	178,531	217,297	207,874
Selling, general and administrative expenses	156,937	168,621	165,702
Bad debt provision for troubled customers, net of recoveries	0	3,038	650
Impairment charges	106,062	0	0
Pension withdrawal expense	0	848	5,886
Gain on sale of subsidiary	0	0	(2,384)
Research and engineering	2,892	3,045	3,310
Depreciation and amortization	13,520	16,733	11,957
Acquisition-related expense, net	337	875	532
Income (loss) from operations	(101,217)	24,137	22,221
Interest expense	12,955	13,698	7,950
Income (loss) before provision for income taxes	(114,172)	10,439	14,271
Provision (benefit) for income taxes	(14,706)	4,359	7,426
Net income (loss)	(99,466)	6,080	6,845
Less: net income (loss) attributable to noncontrolling interests, net of taxes	(5)	20	9
Net income (loss) attributable to Mistras Group, Inc.	$ (99,461)	$ 6,060	$ 6,836
Earnings (loss) per common share
Basic (in dollars per share)	$ (3.41)	$ 0.21	$ 0.24
Diluted (in dollars per share)	$ (3.41)	$ 0.21	$ 0.23
Weighted average common shares outstanding:
Basic (in shares)	29,147	28,740	28,406
Diluted (in shares)	29,147	29,046	29,427

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (99,466)	$ 6,080	$ 6,845
Other comprehensive income (loss):
Foreign currency translation adjustments	5,227	6,275	(10,757)
Comprehensive income (loss)	(94,239)	12,355	(3,912)
Less: net income (loss) attributable to noncontrolling interests	(5)	20	9
Less: Foreign currency translation adjustments attributable to noncontrolling interests	3	3	(5)
Comprehensive income (loss) attributable to Mistras Group, Inc.	$ (94,237)	$ 12,332	$ (3,916)

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 235
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=120409616&loc=SL4591551-111686

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3000-108585

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 20: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=120409616&loc=SL4591552-111686

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794

+ Details

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Total Mistras Group, Inc. Stockholders’ Equity	Common Stock	Additional paid-in capital	Retained earnings (deficit)	Accumulated other comprehensive income (loss)	Noncontrolling Interest
Beginning Balance (in shares) at Dec. 31, 2017			28,295
Beginning Balance at Dec. 31, 2017	$ 270,792	$ 270,619	$ 282	$ 222,425	$ 64,717	$ (16,805)	$ 173
Increase (Decrease) in Stockholders' Equity
Net income (loss)	6,845	6,836			6,836		9
Other comprehensive income (loss)	(10,757)	(10,752)				(10,752)	(5)
Share-based payments (in shares)			243
Share-based payments	6,109	6,109	$ 3	6,106
Net settlement on vesting of restricted stock units	$ (2,188)	(2,188)		(2,188)
Exercise of stock options (in shares)	25		25
Exercise of stock options	$ 273	273		273
Ending Balance (in shares) at Dec. 31, 2018			28,563
Ending Balance at Dec. 31, 2018	271,074	270,897	$ 285	226,616	71,553	(27,557)	177
Increase (Decrease) in Stockholders' Equity
Net income (loss)	6,080	6,060			6,060		20
Other comprehensive income (loss)	6,275	6,272				6,272	3
Share-based payments (in shares)			30
Share-based payments	5,759	5,759		5,759
Net settlement on vesting of restricted stock units (in shares)			349
Net settlement on vesting of restricted stock units	$ (3,198)	(3,198)	$ 4	(3,202)
Exercise of stock options (in shares)	2,093		3
Exercise of stock options	$ 32	32		32
Ending Balance (in shares) at Dec. 31, 2019			28,945
Ending Balance at Dec. 31, 2019	286,022	285,822	$ 289	229,205	77,613	(21,285)	200
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(99,466)	(99,461)			(99,461)		(5)
Other comprehensive income (loss)	5,227	5,224				5,224	3
Share-based payments	5,930	5,930		5,930
Net settlement on vesting of restricted stock units (in shares)			289
Net settlement on vesting of restricted stock units	$ (494)	(494)	$ 3	(497)
Exercise of stock options (in shares)	0
Ending Balance (in shares) at Dec. 31, 2020			29,234
Ending Balance at Dec. 31, 2020	$ 197,219	$ 197,021	$ 292	$ 234,638	$ (21,848)	$ (16,061)	$ 198

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income (loss)	$ (99,466)	$ 6,080	$ 6,845
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation and amortization	35,705	38,533	34,413
Deferred income taxes	(13,409)	(3,599)	1,859
Share-based compensation expense	5,851	5,766	6,107
Impairment charges	106,062	0	0
Bad debt provision for troubled customers, net of recoveries	0	3,038	650
Foreign currency (gain) loss	3,010	(535)	1,311
Gain on sale of subsidiary	0	0	(2,384)
Fair value adjustments to contingent consideration	337	511	(716)
Other	2,398	1,804	462
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions
Accounts receivable	27,313	8,298	(10,349)
Inventories	84	(302)	(2,764)
Prepaid expenses and other assets	(1,288)	3,289	1,400
Accounts payable	(1,020)	1,138	2,948
Accrued expenses and other liabilities	1,841	(5,042)	5,663
Income taxes payable	384	131	(3,781)
Net cash provided by operating activities	67,802	59,110	41,664
Cash flows from investing activities
Purchase of property, plant and equipment	(15,396)	(22,047)	(20,584)
Purchase of intangible assets	(376)	(873)	(541)
Disposition of business	0	0	4,239
Acquisition of businesses, net of cash acquired	0	(4,228)	(139,980)
Proceeds from sale of equipment	803	1,868	1,416
Net cash used in investing activities	(14,969)	(25,280)	(155,450)
Cash flows from financing activities
Repayment of finance lease obligations	(4,095)	(4,545)	(5,813)
Proceeds from borrowings of long-term debt	2,284	983	2,358
Repayment of long-term debt	(5,976)	(6,857)	(2,746)
Proceeds from revolver	35,750	32,000	175,176
Repayments of revolver	(68,050)	(61,700)	(49,991)
Payments of debt issuance costs	(1,497)	0	(826)
Payment of contingent consideration for business acquisitions	(2,091)	(852)	(2,277)
Taxes paid related to net share settlement of share-based awards	(494)	(3,198)	(2,185)
Proceeds from the exercise of stock options	0	32	273
Net cash provided by (used in) financing activities	(44,169)	(44,137)	113,969
Effect of exchange rate changes on cash and cash equivalents	2,080	(221)	(2,180)
Net change in cash and cash equivalents	10,744	(10,528)	(1,997)
Cash and cash equivalents:
Beginning of period	15,016	25,544	27,541
End of period	25,760	15,016	25,544
Supplemental disclosure of cash paid
Interest, net	12,465	14,158	7,751
Income taxes, net	(543)	6,096	10,983
Noncash investing and financing
Equipment acquired through finance lease obligations	$ 2,849	$ 9,502	$ 4,845

Summary of Significant Accounting Policies and Practices	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Practices	Summary of Significant Accounting Policies and Practices Description of Business Mistras Group, Inc. and subsidiaries (the Company) is a leading “OneSource™” multinational provider of integrated technology-enabled asset protection solutions helping to maximize the safety and operational uptime for civilization's most critical industrial and civil assets. Backed by an innovative, data-driven asset protection portfolio, proprietary technologies, and decades-long legacy of industry leadership, the Company helps clients in the oil and gas, aerospace and defense, power generation, infrastructure, and manufacturing industries towards achieving and maintaining operational excellence. By supporting these organizations that help fuel our vehicles and power our society; inspecting components that are trusted for commercial, defense, and space craft; and building real-time monitoring equipment to enable safe travel across bridges, the Company helps the world at large. The Company enhances value for its clients by integrating asset protection throughout supply chains and centralizing integrity data through a suite of Industrial IoT-connected digital software and monitoring solutions. The company's core capabilities also include non-destructive testing (“NDT”) field inspections enhanced by advanced robotics, laboratory quality control and assurance testing, sensing technologies and NDT equipment, asset and mechanical integrity engineering services, and light mechanical maintenance and access services. The Company serves a global customer base of companies with asset-intensive infrastructure, including companies in the oil and gas, commercial aerospace and defense, fossil and nuclear power, alternative and renewable energy, public infrastructure, chemicals, transportation, primary metals and metalworking, pharmaceutical/biotechnology and food processing industries, and research and engineering institutions. Principles of Consolidation The Company follows guidance on the consolidation of variable interest entities (VIEs) that requires companies to utilize a qualitative approach to determine whether it is the primary beneficiary of a VIE. The process for identifying the primary beneficiary of a VIE requires consideration of the factors that indicate a party has the power to direct the activities that most significantly impact the VIE’s economic performance, including powers granted to the VIE’s program manager, powers contained in the VIE governing board and, to a certain extent, a company’s economic interest in the VIE. The Company analyzes its joint ventures and classifies them as either: •a VIE that must be consolidated because the Company is the primary beneficiary, or the joint venture is not a VIE and the Company holds the majority voting interest with no significant participative rights available to the other partners; or •a VIE that does not require consolidation and is treated as an equity method investment because the Company is not the primary beneficiary or the joint venture is not a VIE and the Company does not hold the majority voting interest. As part of the above analysis, if it is determined that the Company has the power to direct the activities that most significantly impact the joint venture’s economic performance, the Company considers whether or not it has the obligation to absorb losses or rights to receive benefits of the VIE that could potentially be significant to the VIE. The Company became the primary beneficiary in July 2020 of a VIE in which the Company has a 49% interest in a limited partnership, and a 49% shareholder in the corporate general partner of the limited partnership. The Company consolidated the financial statements of the VIE with the financial statements of the Company. As of and the for the year ended December 31, 2020, the VIE had immaterial assets and had no revenue. The Company is the primary sub-contractor of the VIE. The accompanying audited consolidated financial statements include the accounts of Mistras Group, Inc. as well as its wholly-owned subsidiaries, majority-owned subsidiaries and consolidated VIE. For subsidiaries in which the Company’s ownership interest is less than 100%, the non-controlling interests are reported in stockholders’ equity in the accompanying consolidated balance sheets. The non-controlling interests in net results, net of tax, is classified separately in the accompanying consolidated statements of income (loss). All significant intercompany accounts and transactions have been eliminated in consolidation. The results of operations of companies acquired are included from the date of acquisition. Reclassifications Certain amounts in prior periods have been reclassified to conform to the current year presentation. Such reclassifications did not have a material effect on the Company's financial condition or results of operations as previously reported. Use of Estimates The preparation of financial statements in accordance with U.S. generally accepted accounting principles (GAAP) requires that the Company make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses and disclosure of contingent assets and liabilities at the date of financial statements. The Company bases its estimates and assumptions on historical experience, known or expected trends and various other assumptions that it believes to be reasonable. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates, which may cause the Company’s future results to be significantly affected. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Accounts Receivable and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts) The Company maintains an allowance for credit losses on its accounts receivable balances, which represents its best estimate of current expected credit losses over the contractual life of the accounts receivable. Beginning January 1, 2020, when evaluating the adequacy of its allowance for credit losses each reporting period, the Company analyzes accounts receivable balances with similar risk characteristics on a collective basis, considering factors such as the aging of receivable balances, payment terms (primarily with 30 day terms), geographic location, historical loss experience, current information, and future expectations (generally considered one year which is consistent with expected collectability of the Company's trade receivables). The Company monitors and considers whether historical loss rates are consistent with expectation of supportable forward-looking estimates for its trade receivables noting no current or future economic considerations that would require adjusting the Company’s historical loss experience. Each reporting period, the Company reassesses whether any accounts receivable no longer share similar risk characteristics and should instead be evaluated as part of another pool or on an individual basis. Changes to the allowance for credit losses are adjusted through credit loss expense, which is presented within Selling, general and administrative expenses in the Consolidated statements of income. During the year ended December 31, 2020, the Company recorded a net provision for expected credit losses of $0.7 million. Concentration of Credit Risk For each of the years ended December 31, 2020 and 2019, no customer represented 10% or more of the Company's revenue. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. At times, cash deposits may exceed the limits insured by the Federal Deposit Insurance Corporation. The Company believes it is not exposed to any significant credit risk or risk of nonperformance of financial institutions. Inventories Inventories are stated at the lower of cost or net realizable value, as determined by using the first-in, first-out method, or market. Work in process and finished goods inventory include material, direct labor, variable costs and overhead. Purchased and Internal-Use Software The Company capitalizes certain costs that are incurred to purchase or to create and implement internal-use software, which includes software coding, installation and testing. Capitalized costs are amortized on a straight-line basis over three years, the estimated useful life of the software. Property, Plant and Equipment Property, plant and equipment are recorded at cost. Depreciation of property, plant and equipment is computed utilizing the straight-line method over the estimated useful lives of the assets. Amortization of leasehold improvements is computed utilizing the straight-line method over the shorter of the remaining lease term or estimated useful life. Repairs and maintenance costs are expensed as incurred. Goodwill Goodwill represents the excess purchase price of acquired businesses over the fair values attributed to underlying net tangible assets and identifiable intangible assets. The Company tests goodwill for impairment at a “reporting unit” level (which for the Company is represented by (i) our Services segment, (ii) our Products and Systems segment, and (iii) the European component of our International segment and (iv) the Brazilian component of our International segment). Our annual impairment test is conducted on the first day of our fourth quarter, which is October 1. Goodwill is also tested for impairment whenever an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. In testing for goodwill impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances lead to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company concludes that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing a quantitative impairment test is not necessary. If the Company concludes otherwise, the Company is required to perform a quantitative impairment test. If the fair value of a reporting unit is less than its carrying value, this is an indicator that the goodwill assigned to that reporting unit may be impaired. As a result of the Company adopting Accounting Standards Update ("ASU") No. 2017-04, Intangibles-Goodwill and Other (Topic 350), impairment will be recorded in the amount that fair value is less than carrying value, as the ASU eliminated step two of the goodwill impairment process. The Company considers the income and market approaches to estimating the fair value of our reporting units, which requires significant judgment in evaluation of economic and industry trends, estimated future cash flows, discount rates and other factors. See Note 8-Goodwill for additional information related to the Company's goodwill impairment tests during 2020. Impairment of Long-lived Assets The Company reviews the recoverability of its long-lived assets (or asset groups) whenever events or changes in circumstances indicate that the carrying amount of the long-lived asset (group) might not be recoverable. The assessment for potential impairment is based primarily on the Company’s ability to recover the carrying value of its long-lived assets from expected future undiscounted cash flows. If the total expected future undiscounted cash flows are less than the carrying amount of the assets, a loss is recognized for the difference between fair value (computed based upon the expected future discounted cash flows) and the carrying value of the assets. Acquisitions The Company allocates the purchase price of acquired businesses to their identifiable tangible assets and liabilities as well as identifiable intangible assets, such as customer relationships, technology, non-compete agreements and trade names. Certain estimates and judgments are required in the application of the fair value techniques, including estimates of the respective acquisition's future performance and related cash flows, selection of a discount rate and economic lives, and use of Level 3 measurements as defined in ASC No. 820, Fair Value Measurements and Disclosure. Deferred taxes are recorded for any differences between the assigned values and tax bases of assets and liabilities. Research and Engineering Research and product development costs are expensed as incurred. Advertising, Promotions and Marketing The costs for advertising, promotion and marketing programs are expensed as incurred and are included in selling, general and administrative expenses. Advertising expense was approximately $0.8 million, $2.1 million and $2.1 million for the years ended December 31, 2020, 2019 and 2018, respectively. Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and other financial current assets and liabilities approximate fair value based on the short-term nature of the items. Foreign Currency Translation The financial position and results of operations of the Company’s foreign subsidiaries are measured using their functional currencies, which are their local currencies. Assets and liabilities of foreign subsidiaries are translated into the U.S. Dollar at the exchange rates in effect at the balance sheet date. Income and expenses are translated at the average exchange rate during the period. Translation gains and losses are reported as a component of other comprehensive income (loss) for the period and included in accumulated other comprehensive income (loss) within stockholders’ equity. Foreign currency (gains) and losses arising from transactions denominated in currencies other than the functional currency are included in net income, reported in selling, general and administrative expenses, and were approximately $3.1 million, $(0.5) million, and $1.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. Self-Insurance The Company is self-insured for certain losses relating to workers’ compensation and health benefit claims. The Company maintains third-party excess insurance coverage for all workers' compensation and health benefit claims in excess of approximately $0.3 million per occurrence to reduce its exposure from such claims. Self-insured losses are accrued when it is probable that an uninsured claim has been incurred but not reported and the amount of the loss can be reasonably estimated at the balance sheet date. Share-based Compensation The value of services received from employees and directors in exchange for an award of an equity instrument is measured based on the grant-date fair value of the award. Such value is recognized as a non-cash expense on a straight-line basis over the minimum period the individual provides services, which is typically the vesting period of the award with the exception of awards with graded vesting that contain an internal performance measure where each tranche is recognized on a straight-line basis over its vesting period subject to the probability of meeting the performance requirements and adjusted for the number of shares expected to be earned. Awards to certain employees eligible for retirement prior to the award becoming fully vested are amortized to expense over the period through the date that the employee first becomes eligible to retire and is no longer required to provide service to earn the award. As share-based compensation expense is based on awards ultimately expected to vest, the amount of expense is reduced for estimated forfeitures. The cost of these awards is recorded in selling, general and administrative expense in the Company’s consolidated statements of income. Income Taxes Income taxes are accounted for under the asset and liability method. Deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax credit carry-forwards. Deferred income tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is provided if it is more likely than not that some or all of a deferred income tax asset will not be realized. A current tax liability or asset is recognized for the estimated taxes payable or refundable on tax returns for the current and prior years. US GAAP prescribes a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements. US GAAP also provides guidance on de-recognition, measurement, and classification of amounts relating to uncertain tax positions, accounting for and disclosure of interest and penalties, accounting in interim periods and disclosures required. Interest and penalties related to unrecognized tax positions are recognized as incurred within “provision for income taxes” in the consolidated statements of income. In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”) was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to deferment of employer’s social security payments, net operating loss utilization and carryback periods, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The ultimate impact of the CARES Act may differ from the estimated impact the Company recorded during this period due to changes in interpretations and guidance that may be issued and actions the Company may take in response to the CARES Act. The Company will continue to assess the impact that various provisions of the CARES Act, and how they are interpreted and effected, will have on its business. Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by eliminating certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities related to outside basis differences. The standard is effective for interim and annual periods beginning January 1, 2021, with certain amendments applied prospectively and others requiring retrospective application. Early adoption is permitted, with any adjustments reflected as of the beginning of the fiscal year of adoption. The Company did not elect early adoption and is currently evaluating the impact of this guidance on its consolidated financial position, results of operations, and cash flows. In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The guidance provides optional expedients and exceptions for applying U.S. GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another rate that is expected to be discontinued. The amendments in ASU 2020-04 are effective for all entities as of March 12, 2020 through December 31, 2022. The Company is currently evaluating the impact of this guidance on its consolidated financial position, results of operations, and cash flows.

Revenue

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Revenue

The Company derives the majority of its revenue by providing services on a time and material basis and are short-term in

nature. The Company accounts for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers.

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 ASC Topic 606. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The majority of the Company's contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. The Company provides highly integrated and bundled inspection services to its customers. Some of our contracts have multiple performance obligations, most commonly due to the contract providing both goods and services. For contracts with multiple performance obligations, the Company allocates the contract’s transaction price to each performance obligation using the Company's best estimate of the standalone selling price of each distinct good or service in the contract. The primary method used to estimate standalone selling price is a relative selling price based on price lists.

Contract modifications are not routine in the performance of the Company's contracts. Generally, when contracts are modified, the modification is to account for changes in scope to the goods and services that are provided. In most instances, contract modifications are for goods or services that are distinct, and, therefore, are accounted for as a separate contract.

The Company's performance obligations are satisfied over time as work progresses or at a point in time. The majority of the Company's revenue recognized over time as work progresses is related to the Company's service deliverables, which includes providing testing, inspection and mechanical services to our customers. Revenue is recognized over time based on time and material incurred to date which best portrays the transfer of control to the customer. The Company also utilizes an available practical expedient that provides for revenue to be recognized in an amount that corresponds directly with the value to the customer of the entity’s performance completed to date. Fixed fee arrangements are determined based on expected labor, material, and overhead to be consumed on fulfillment of such services. Revenue is recognized on a cost-to-cost method tracked on an input basis.

The majority of our revenue recognized at a point in time is related to product sales when the customer obtains control of the asset, which is generally upon shipment to the customer. Contract costs include labor, material and overhead.

The Company expects any significant remaining performance obligations to be satisfied within one year.

Contract Estimates

The majority of the Company's revenues are short-term in nature. The Company has many master service agreements (MSAs) that specify an overall framework and contract terms when the Company and customers agree upon services or products to be provided. The actual contracting to provide services or furnish products are triggered by a work order, purchase order, or some similar document issued pursuant to a MSA which sets forth the scope of services and/or identifies the products to be provided. From time-to-time, the Company may enter into long-term contracts, which can range from several months to several years. Revenue on such long-term contracts is recognized as work is performed based on total costs incurred to date in relation to the total estimated costs for the performance of the contract at completion. This includes contract estimates of costs to be incurred for the performance of the contract. Cost estimation is based upon the professional knowledge and experience of the Company's project managers, engineers and financial professionals. Factors that are considered in estimating the work to be completed include the availability of materials, the effect of any delays in the Company's project performance and the recoverability of any claims. Whenever revisions of estimates, contract costs and/or contract values indicate that the contract costs will exceed estimated revenues, thus creating a loss, a provision for the total estimated loss is recorded in that period.

Revenue by category

The following series of tables present our disaggregated revenues by segment:

Revenue by industry was as follows:


Year ended December 31, 2020	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	298,605	$	39,728	$	430	$	—	$	338,763
Aerospace & Defense	50,813		18,166		1,292		—		$	70,271
Industrials	44,919		19,657		1,852		—		$	66,428
Power generation & Transmission	30,005		7,559		2,323		—		$	39,887
Other Process Industries	24,671		10,029		171		—		$	34,871
Infrastructure, Research & Engineering	17,070		10,353		6,364		—		$	33,787
Other	10,081		2,064		4,017		(7,598)		$	8,564
Total	$	476,164	$	107,556	$	16,449	$	(7,598)	$	592,571


Year ended December 31, 2019	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	390,815	$	44,447	$	756	$	—	$	436,018
Aerospace & Defense	51,390		41,224		1,237		—		$	93,851
Industrials	64,622		21,405		3,187		—		$	89,214
Power generation & Transmission	30,300		10,289		2,726		—		$	43,315
Other Process Industries	28,495		10,196		418		—		$	39,109
Infrastructure, Research & Engineering	14,269		9,520		9,316		—		$	33,105
Other	15,239		7,190		943		(9,398)		$	13,974
Total	$	595,130	$	144,271	$	18,583	$	(9,398)	$	748,586


Year ended December 31, 2018	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	378,904	$	37,953	$	1,255	$	—	$	418,112
Aerospace & Defense	50,500		54,853		2,355		—		107,708
Industrials	60,594		26,209		3,097		—		89,900
Power generation & Transmission	30,687		8,522		4,904		—		44,113
Other Process Industries	26,425		9,497		124		—		36,046
Infrastructure, Research & Engineering	11,283		9,032		5,246		—		25,561
Other	16,226		7,382		6,445		(9,139)		20,914
Total	$	574,619	$	153,448	$	23,426	$	(9,139)	$	742,354

Revenue per key geographic location was as follows:


Year ended December 31, 2020	Services		International		Products & Systems		Corp/Elim		Total
United States	$	406,437	$	911	$	7,551	$	(3,410)	$	411,489
Other Americas	68,150		4,581		550		(446)		72,835
Europe	904		99,953		3,154		(3,470)		100,541
Asia-Pacific	673		2,111		5,194		(272)		7,706
Total	$	476,164	$	107,556	$	16,449	$	(7,598)	$	592,571


Year ended December 31, 2019	Services		International		Products & Systems		Corp/Elim		Total
United States	$	487,408	$	631	$	12,011	$	(4,918)	$	495,132
Other Americas	104,081		7,659		407		(407)		111,740
Europe	2,342		127,581		1,940		(3,978)		127,885
Asia-Pacific	1,299		8,400		4,225		(95)		13,829
Total	$	595,130	$	144,271	$	18,583	$	(9,398)	$	748,586


Year ended December 31, 2018	Services		International		Products & Systems		Corp/Elim		Total
United States	$	478,853	$	568	$	11,493	$	(3,500)	$	487,414
Other Americas	90,823		7,995		1,068		(1,638)		98,248
Europe	4,252		138,948		3,958		(3,846)		143,312
Asia-Pacific	691		5,937		6,907		(155)		13,380
Total	$	574,619	$	153,448	$	23,426	$	(9,139)	$	742,354

Contract Balances

The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) on the consolidated balance sheet. Amounts are generally billed as work progresses in accordance with agreed-upon contractual terms, generally at periodic intervals (e.g., weekly, bi-weekly or monthly). Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. However, the Company sometimes receives advances or deposits from its customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are aggregated on an individual contract basis and reported on the consolidated balance sheet at the end of each reporting period within accounts receivables or accrued expenses and other current liabilities.

Revenue recognized for 2020 and 2019, that was included in the contract liability balance at the beginning of the year was $4.6 million and $4.3 million, respectively. Changes in the contract asset and liability balances during the years ended December 31, 2020 and 2019, were not impacted by any other factors. The Company applies the practical expedient to expense incremental

costs incurred related to obtaining a contract when the asset that the Company otherwise would have recognized is one year or less.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130550-203045

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

+ Details

Earnings per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings per Share

Basic earnings (loss) per share is computed by dividing net income by the weighted average number of shares outstanding during the period. Diluted earnings per share is computed by dividing net by the sum of (1) the weighted average number of shares of common stock outstanding during the period, and (2) the dilutive effect of assumed conversion of equity awards using the treasury stock method. With respect to the number of weighted average shares outstanding (denominator), diluted shares reflect: (i) the exercise of options to acquire common stock to the extent that the options’ exercise prices are less than the average market price of common shares during the period and (ii) the pro forma vesting of restricted stock units.

The following table sets forth the computations of basic and diluted earnings per share:


	For the year ended December 31,
	2020		2019		2018
Basic earnings (loss) per share:
Numerator:
Net income (loss) attributable to Mistras Group, Inc.	$	(99,461)	$	6,060	$	6,836
Denominator
Weighted average common shares outstanding	29,147		28,740		28,406
Basic earnings (loss) per share	$	(3.41)	$	0.21	$	0.24

Diluted earnings (loss) per share:
Numerator:
Net income (loss) attributable to Mistras Group, Inc.	$	(99,461)	$	6,060	$	6,836
Denominator
Weighted average common shares outstanding	29,147		28,740		28,406
Dilutive effect of stock options outstanding	—		98		683
Dilutive effect of restricted stock units outstanding	—		208		338
	29,147		29,046		29,427
Diluted earnings (loss) per share	$	(3.41)	$	0.21	$	0.23

The following potential common shares were excluded from the computation of diluted earnings per share, as the effect would have been anti-dilutive:


	For the year ended December 31,
	2020	2019	2018
Potential common stock attributable to restricted stock units (RSUs) and performance stock units (PSUs) outstanding (1)	790	42	1
Potential common stock attributable to stock options outstanding	5	5	5
Total	795	47	6

(1) For the twelve months ended December 31, 2020, 254 shares related to RSUs/PSUs, were excluded from the calculation of diluted EPS due to the net loss for the period.

Accounts Receivable

12 Months Ended

Dec. 31, 2020

Receivables [Abstract]

Accounts Receivable

Accounts receivable consist of the following:


	December 31,
	2020		2019
Trade accounts receivable	$	115,841	$	144,282
Allowance for credit losses	(8,213)		(8,285)
Accounts receivable, net	$	107,628	$	135,997

The Company had $11.9 million and $22.2 million of unbilled revenues accrued as of December 31, 2020 and December 31, 2019, respectively, which is included within the trade accounts receivable balance above. Unbilled revenue is generally billed in the subsequent quarter to their revenue recognition.

The Company was contracted to perform inspections of welds on various pipeline projects in Texas for a customer. As of December 31, 2019, approximately $1.4 million of past due receivables were outstanding from this customer. The Company received notice from the customer in December 2019, alleging that the work performed was not in compliance with the contract. The Company filed a lawsuit to recover the $1.4 million and other amounts due to the Company and the customer filed a counterclaim, alleging breach of contract and seeking its damages. Accordingly, the Company recorded a reserve of $1.4 million during the twelve months ended December 31, 2019 for these past due receivables. The status of this situation has not changed during 2020. See Note 18-Commitments and Contingencies for additional details.

In the fourth quarter of 2018, the Company recorded a reserve of $0.7 million for a renewable energy industry customer, based in part on the available information about the financial difficulties of the customer. During the first quarter of 2019, the Company recorded an additional charge of $5.7 million to fully reserve for the amount of the exposure related to this customer. This customer filed for a voluntary insolvency proceeding on April 9, 2019. During the second quarter of 2019, the Company reversed $1.0 million of this reserve based on additional information obtained during the quarter. The status of the dispute has not changed since the second quarter of 2019.

During 2019, the Company sold to an unaffiliated third party, without recourse, its remaining outstanding receivables owed from a customer which filed for bankruptcy, and for which the Company had initially recorded a charge during the second quarter of 2017. During the first quarter of 2019, the Company recorded a recovery of $0.2 million and during the second quarter of 2019, the Company recorded a recovery $1.7 million, related to a bad debt provision for the receivables due from this customer. This matter is considered fully resolved.

Inventories

12 Months Ended

Dec. 31, 2020

Inventory Disclosure [Abstract]

Inventories

Inventories consist of the following:


	December 31,
	2020		2019
Raw materials	$	5,006	$	5,314
Work in progress	770		1,549
Finished goods	4,640		3,957
Consumable supplies	2,718		2,593
Inventories	$	13,134	$	13,413

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, plant and equipment consist of the following:


		December 31,
	Useful Life	2020		2019
	(Years)
Land		$	2,724	$	2,672
Building and improvements	30-40	25,731		24,537
Office furniture and equipment	5-8	16,980		17,227
Machinery and equipment	5-7	237,253		225,974
		282,688		270,410
Accumulated depreciation and amortization		(190,007)		(171,803)
Property, plant and equipment, net		$	92,681	$	98,607

Depreciation expense was approximately $24.7 million, $24.2 million, and $24.2 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Acquisitions and Disposition

12 Months Ended

Dec. 31, 2020

Business Combinations [Abstract]

Acquisitions and Disposition

Acquisitions

The Company did not complete any acquisitions during the year ended December 31, 2020.

During September 2019, the Company completed one acquisition that provides pipeline integrity management software and services to energy transportation companies. The Company acquired all the equity interest of the acquiree in exchange for aggregate consideration of $4.4 million in cash, contingent consideration of up to $4.3 million to be earned based upon the acquired business achieving specific performance metrics over the initial three years of operations from the acquisition date and working capital adjustments. The goodwill recorded is primarily attributable to expected synergies and is generally deductible for tax purposes. The Company accounted for this transaction in accordance with the acquisition method of accounting for business combinations.

The following table summarizes the final fair value of the assets acquired and liabilities assumed and the Company's allocation of purchase price:



	2019
Cash paid	$	4,380
Working capital adjustments	$	(152)
Fair value of contingent consideration	$	1,342
Total consideration	$	5,570

Current net assets	$	142
Other assets	$	34
Property, plant and equipment	$	65
Intangibles	$	3,594
Goodwill	$	1,735
Net assets acquired	$	5,570

The Company accounted for the acquisition completed in 2019 in accordance with the acquisition method of accounting for business combinations. Assets and liabilities of the acquired businesses were included in the consolidated balance sheet based on their respective estimated fair value on the date of acquisition as determined in a purchase price allocation, using available information and making assumptions management believes are reasonable. The amortization periods for the intangible assets acquired range from one year to eighteen years.

Disposition

During the third quarter of 2018, substantially all of the assets and liabilities of a subsidiary in the Products and Systems segment were sold for approximately $4.3 million. For the year ended December 31, 2018, the Company recognized a gain of approximately $2.4 million related to the sale, which is reported as a gain on sale of subsidiary on the consolidated statements of income (loss). The sale also included a three-year agreement to purchase products from the buyer, with a cumulative commitment of $2.3 million (see Note 18-Commitments and Contingencies).

Acquisition-Related expense

In the course of its acquisition activities, the Company incurs costs in connection with due diligence, professional fees, and other expenses. Additionally, the Company adjusts the fair value of acquisition-related contingent consideration liabilities on a quarterly basis. These amounts are recorded as acquisition-related expense, net, on the consolidated statements of income and were as follows for the years ended December 31, 2020, 2019 and 2018:


	For the year ended December 31,
	2020		2019		2018
Due diligence, professional fees and other transaction costs	$	—	$	364	$	1,248
Adjustments to fair value of contingent consideration liabilities	337		511		(716)
Acquisition-related expense, net	$	337	$	875	$	532

The Company’s contingent consideration liabilities are recorded on the consolidated balance sheets in accrued expenses and other current liabilities and Other long-term liabilities.

Goodwill

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

The changes in the carrying amount of goodwill by segment is shown below:


	Services		International		Products and Systems		Total





Balance at December 31, 2018	$	243,476	$	35,783	$	—	$	279,259
Goodwill acquired during the year	1,535		—		—		1,535
Adjustments to preliminary purchase price allocations	(2,332)		—		—		(2,332)
Foreign currency translation	4,536		(588)		—		3,948
Balance at December 31, 2019	$	247,215	$	35,195	$	—	$	282,410
Impairment charges	(57,227)		(19,862)		—		(77,089)
Adjustments to preliminary purchase price allocations	200		—		—		200
Foreign currency translation	(76)		563		—		487
Balance at December 31, 2020	$	190,112	$	15,896	$	—	$	206,008

The Company reviews goodwill for impairment on a reporting unit basis on October 1 of each year and whenever events or changes in circumstances indicate the carrying value of goodwill may not be recoverable.

During the first quarter of 2020, the Company’s market capitalization declined significantly compared to the fourth quarter of 2019. Over the same period, the equity value of the Company’s peer group, and the overall U.S. stock market also declined significantly amid market volatility. In addition, oil prices had dropped significantly. These declines were driven in large part by the uncertainty surrounding the COVID-19 pandemic and other macroeconomic events such as the geopolitical tensions between OPEC and Russia. Based on these factors, the Company concluded that multiple triggering events occurred and, accordingly, an interim quantitative goodwill impairment test was performed for each reporting unit as of March 31, 2020. During the first quarter of 2020, the Company also performed an analysis to determine any impairment of long-lived assets (see Note 9-Intangible Assets) based on the triggering events noted above.

In performing the interim quantitative goodwill impairment test and consistent with prior practice, the Company determined the fair value of each of the reporting units using a combination of the income approach and the market approach by assessing each

of these valuation methodologies based upon availability and relevance of comparable company data and determining the appropriate weighting.

Under the income approach, the fair value for each of the reporting units was determined based on the present value of estimated future cash flows, discounted at an appropriate risk-adjusted rate. The Company used internal forecasts, updated for recent events, to estimate future cash flows with cash flows beyond the specific operating plans estimated using a terminal value calculation, which incorporates historical and forecasted trends, including an estimate of long-term future growth rates, based on the Company’s most recent views of the long-term outlook for each reporting unit. The internal forecasts include assumptions about future market recovery, including the expected demand for the Company’s goods and services. Due to the inherent uncertainties involved in making estimates and assumptions, actual results may differ from those assumed in the forecasts. The Company derived the discount rates using a capital asset pricing model and analyzing published rates for industries relevant to the reporting units to estimate the cost of equity financing. The Company used discount rates that are commensurate with the risks and uncertainties inherent in the respective businesses and in the internally developed forecasts, updated for recent events.

The market approach valuations were derived from metrics of publicly traded companies or historically completed transactions of comparable businesses. The selection of comparable businesses was based on the markets in which the reporting units operate considering risk profiles, size, geography, and diversity of products and services.

Based upon the results of the interim quantitative goodwill impairment test during the first quarter of 2020, the Company recorded an aggregate impairment charge of $77.1 million, which included $57.2 million in the services reporting unit within the Services segment, and $19.3 million in the European reporting unit and $0.6 million in the Brazilian reporting unit, both within the International segment. The impairment was calculated based on the difference between the estimated fair value and the carrying value of the reporting units and are included in Impairment charges on the Consolidated Statements of Income (Loss) for the year ended December 31, 2020.

The Company's cumulative goodwill impairment as of December 31, 2020 was $100.2 million, of which $57.2 million related to the Services segment, $29.8 million related to the International segment and $13.2 million related to the Products and Systems segment. The Company's cumulative goodwill impairment as of December 31, 2019 was $23.1 million, of which $13.2 million related to the Products and Systems segment and $9.9 million related to the International segment.

The Company elected to perform a qualitative assessment of goodwill on October 1, 2020. The Company's qualitative assessment considered relevant events and circumstances occurring since the interim quantitative goodwill impairment test performed as of March 31, 2020 (see previous paragraphs). Specifically, the Company considered changes in macroeconomic conditions, industry and market conditions, internal forecasts of future revenue and expenses, the Company's stock price, any significant events affecting the Company and actual changes in the carrying values of its net assets. After considering all positive and negative evidence for the assessment as of October 1, 2020, the Company concluded that it was not more likely than not that the carrying values of each reporting unit exceeded their respective fair values and as such, no additional impairment was indicated. Subsequent to October 1, 2020 through December 31, 2020, the Company did not identify any changes in circumstances that would indicate the carrying value of goodwill may not be recoverable. Significant adverse changes in future periods could negatively affect the Company's key assumptions and may result in future goodwill impairment charges which could be material.

Intangible Assets

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

The gross carrying amount and accumulated amortization of intangible assets were as follows:


		December 31,
		2020								2019
	Useful Life (Years)	Gross Amount		Accumulated Amortization		Impairment		Net Carrying Amount		Gross Amount		Accumulated Amortization		Net Carrying Amount
Customer relationships	5-18	$	116,101	$	(75,649)	$	(2,206)	$	38,246	$	113,861	$	(67,853)	$	46,008
Software/Technology	3-15	77,326		(23,519)		(25,874)		27,933		77,914		(18,756)		59,158
Covenants not to compete	2-5	12,833		(12,162)		(212)		459		12,795		(11,630)		1,165
Other	2-12	11,120		(8,614)		(502)		2,004		10,813		(7,607)		3,206
Total		$	217,380	$	(119,944)	$	(28,794)	$	68,642	$	215,383	$	(105,846)	$	109,537

As described in Note 8- Goodwill, during the first quarter of 2020, there were negative market indicators that were determined to be triggering events indicating a potential impairment of certain long-lived assets within asset groups in the Services, International, Products and Corporate segments. The asset groups are groupings of assets and liabilities determined at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability testing indicated that certain intangible assets and right of use assets (See Note 17-Leases) were potentially impaired. For asset groups that required an impairment measurement, similar to the valuations performed to determine the goodwill impairment, the Company used income and market approaches to estimate the fair value of the long-lived assets, which requires significant judgment in evaluation of the useful lives of the assets, economic and industry trends, estimated future cash flows, discount rates, and other factors. The result of the analysis was an aggregate impairment charge of $28.8 million, which included $25.9 million to software/technology, $2.2 million to customer relationships, $0.5 million to other intangibles and $0.2 million to covenants not to compete, all of which are in the Services reporting unit within the Services segment and are included in Impairment charges on the consolidated statements of income (loss) for the year ended December 31, 2020.

Amortization expense for the years ended December 31, 2020, 2019 and 2018, was approximately $11.0 million, $14.3 million, and $10.2 million, respectively, including amortization of software/technology for these periods of $3.6 million, $5.6 million, and $1.4 million, respectively.

Amortization expense in each of the five years and thereafter subsequent to December 31, 2020 related to the Company’s intangible assets is expected to be as follows:


	Expected Amortization Expense
2021	$	9,915
2022	9,433
2023	8,719
2024	7,355
2025	5,597
Thereafter	27,623
Total	$	68,642

Accrued Expenses and Other Current Liabilities

12 Months Ended

Dec. 31, 2020

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	December 31,
	2020		2019
Accrued salaries, wages and related employee benefits	$	30,214	$	30,072
Contingent consideration	1,300		2,614
Accrued workers' compensation and health benefits	3,948		4,467
Deferred revenues	6,538		5,860

Right-of-use liability - Operating	10,348		10,133
Pension accrual	2,519		2,519
Other accrued expenses	23,633		25,724
Total accrued expenses and other current liabilities	$	78,500	$	81,389

Long-Term Debt

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Long-Term Debt

Long-term debt consists of the following:


	December 31,
	2020		2019
Senior credit facility	$	120,312	$	151,773
Senior secured term loan, net of unamortized debt issuance costs of $0.3 million and $0.1 million	89,745		94,919

Other	10,159		8,021
Total debt	220,216		254,713
Less: Current portion	(10,678)		(6,593)
Long-term debt, net of current portion	$	209,538	$	248,120

Senior Credit Facility

The Company has a credit agreement with its banking group (“Credit Agreement”) which provides the Company with a revolving line of credit and a $100 million senior secured term loan A facility. Pursuant to the Amendment described below, the revolving line of credit was reduced from $300 million to $175 million. Both the revolving line of credit and the term loan A facility under the Credit Agreement have a maturity date of December 12, 2023.

On May 15, 2020, the Company entered into the Third Amendment (the “Amendment”) to the Credit Agreement. The amendment was needed because the Company determined that as a result of the uncertain impact of the COVID-19 pandemic and the significant drop in oil prices, it would not meet the then existing financial covenants in the Credit Agreement for upcoming quarters. Accordingly, the Amendment modified the financial covenants to provide for: i) elimination of the Funded Debt Leverage Ratio (as defined in the Credit Agreement) for the quarters ended June 30 and September 30, 2020 and increased the Funded Debt Leverage ratio to no greater than 5.25 to 1 beginning for the quarter ending December 31, 2020 and decreasing each successive quarter to no greater than 3.50 to 1 for the quarter ended September 30, 2021, and all quarterly periods thereafter; ii) an elimination of the minimum Fixed Charge Coverage Ratio (as defined in the Credit Agreement for the quarters ended June 30, September 30 and December 31, 2020), a decrease to 1.0 to 1 for the quarter ending March 31, 2021 and returning to 1.25 to 1 for the quarter ending June 30, 2021 and thereafter; iii) the addition of a minimum EBITDA covenant requiring $3.44 million for the three months ending June 30, 2020, $24.25 million for the six months ending September 30, 2020, and $38.55 million for the nine months ending December 31, 2020, with no requirement thereafter; and iv) the addition of a minimum Liquidity (as defined in the Amendment) covenant of not less than $20.0 million at all times through September 30, 2020 and ceasing thereafter. In addition, the Amendment set a LIBOR floor of 1.0% applicable to all LIBOR loans, and increased the LIBOR margin range to 1.50% to 4.15%, in addition to certain other modifications of the Credit Agreement. The Amendment also requires that the Company promptly prepay the outstanding amount under the revolving credit facility in an amount equal to the difference between (a) the aggregate sum of cash and cash equivalents of the Company and its subsidiaries held in the United States minus (b) $10.0 million if, for a period of two (2) consecutive business days, (i) the outstanding amount under the revolving credit facility exceeds $75.0 million and (ii) the sum of such cash and cash equivalents exceeds $10.0 million.

The Credit Agreement, as amended, provides that the Company may not make any acquisitions prior to June 30, 2021, and thereafter only if the Company's Funded Debt Leverage Ratio is less than 2.50 to 1, and after giving effect to such acquisition, its pro forma Funded Debt Leverage Ratio will not be greater than 3.25 to 1. The Credit Agreement also limits the Company’s ability to, among other things, create liens, make investments, incur more indebtedness, merge or consolidate, make dispositions of property, pay dividends and make distributions to stockholders or repurchase its stock, enter into a new line of business, enter into transactions with affiliates and enter into burdensome agreements.

The Company may borrow up to $100 million in non-U.S. Dollar currencies and use up to $20 million of the credit limit for the issuance of letters of credit.

As of December 31, 2020, the Company had borrowings of $210.1 million and a total of $4.3 million of letters of credit outstanding under the Credit Agreement. The Company has capitalized costs associated with debt modifications of $1.1 million as of December 31, 2020, which is included in Other Assets on the consolidated balance sheet. The Amendment reduced the Company's total available loan capacity, amongst other things, and as a result, the Company expensed approximately $0.6 million in capitalized debt issuance costs during the second quarter of 2020, which is included in Selling, general and administrative expenses on the consolidated statements of income (loss).

As of December 31, 2020, the Company was in compliance with the terms of the Credit Agreement, as amended, and will continuously monitor its compliance with the covenants contained in its Credit Agreement. The Company believes that it is probable, based on the amended covenants, that the Company will be able to comply with the financial covenants in the Credit Agreement as modified by the Amendment and that sufficient credit remains available under the Credit Agreement to meet the Company's liquidity needs. However, due to the uncertainties being caused by the COVID-19 pandemic, the significant volatility in oil prices, and volatility in the aerospace production, such matters cannot be predicted with certainty.

Other Debt

The Company's other debt includes local bank financing provided at the local subsidiary levels used to support working capital requirements and fund capital expenditures. At December 31, 2020, there was approximately $10.2 million outstanding, payable at various times through 2030. Monthly payments range from $1 thousand to $18 thousand. Interest rates range from 0.4% to 3.5%.

Scheduled principal payments due under all borrowing agreements in each of the five years and thereafter subsequent to December 31, 2020 are as follows:


2021	$	10,678
2022	11,551
2023	194,191
2024	1,282
2025	799
Thereafter	1,715
Total	$	220,216

Fair Value Measurements

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurements

The Company performs fair value measurements in accordance with the guidance provided by ASC 820, Fair Value Measurements and Disclosures. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. It also establishes a three level hierarchy that prioritizes the inputs used to measure fair value. The three levels of the hierarchy are defined as follows:

Level 1 — Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level 2 — Observable inputs other than quoted prices included in Level 1, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data.

Level 3 — Unobservable inputs reflecting the Company’s own assumptions about inputs that market participants would use in pricing the asset or liability based on the best information available.

Financial instruments measured at fair value on a recurring basis

The fair value of contingent consideration liabilities was estimated using a discounted cash flow technique with significant inputs that are not observable in the market and thus represents a Level 3 fair value measurement as defined in ASC 820. The significant inputs in the Level 3 measurement not supported by market activity include the probability assessments of expected future cash flows related to the acquisitions, appropriately discounted considering the uncertainties associated with the obligation, and as calculated in accordance with the terms of the applicable acquisition agreements.

The following table represents the changes in the fair value of Level 3 contingent consideration:


	December 31,
	2020		2019
Balance at the beginning of the period:	$	3,216	$	2,365
Acquisitions	200		1,142
Payments	(2,091)		(852)
Accretion of liability	35		92
Revaluation	302		419
Foreign currency translation	(22)		50
Balance at the end of the period:	$	1,640	$	3,216

Financial instruments not measured at fair value on a recurring basis

The Company has evaluated current market conditions and borrower credit quality and has determined that the carrying value of its long-term debt approximates fair value. The fair value of the Company’s notes payable and finance and operating lease obligations approximates their carrying amounts based on anticipated interest rates which management believes would currently be available to the Company for similar issuances of debt.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Share-Based Compensation

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Share-Based Compensation

The Company has share-based incentive awards outstanding to its eligible employees and directors under two employee stock ownership plans: (i) the 2009 Long-Term Incentive Plan (the "2009 Plan") and (ii) the 2016 Long-Term Incentive Plan (the "2016 Plan"). No further awards may be granted under the 2009 Plan, although awards granted under the 2009 Plan remain outstanding in accordance with their terms. Awards granted under the 2016 Plan may be in the form of stock options, restricted stock units and other forms of share-based incentives, including performance restricted stock units, stock appreciation rights and deferred stock rights. At the annual shareholders meeting on May 19, 2020, the Company’s shareholders approved an amendment to increase the total number of shares that may be issued under the 2016 Plan by 2,000,000, for a total of 3,700,000 shares that may be issued under the 2016 Plan, of which 1,787,000 shares were available for future grants as of December 31, 2020. As of December 31, 2020, there was an aggregate of approximately 5,000 stock options outstanding under the 2009 Plan.

Stock Options

For the years ended December 31, 2020, 2019 and 2018, the Company did not have any share-based compensation expense related to stock option awards. No stock options were granted during the years ended December 31, 2020, 2019 and 2018. As of December 31, 2020, no unrecognized compensation costs remained related to stock option awards. Cash proceeds from, and the intrinsic value of, stock options exercised during the years ended December 31, 2020, 2019 and 2018 were as follows (in thousands):


	For the year ended December 31,
	2020		2019 1		2018
Cash proceeds from options exercised	$	—	$	32	$	273
Aggregate intrinsic value of options exercised	$	—	$	4,530	$	277

____________________

1 During 2019, 2.1 million stock options were net exercised, wherein the option holders surrendered a portion of the underlying stock option awards to pay the exercise price and required minimum tax withholding.

A summary of the stock option activity, weighted average exercise prices, and options outstanding and exercisable as of December 31, 2020, 2019 and 2018 is as follows (in thousands, except per share amounts and years):


	For the years ended December 31,
	2020			2019			2018
	Common Stock Options	Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price
Outstanding at beginning of year:	5	$	22.35	2,105	$	13.47	2,130	$	13.43
Granted	—	$	—	—	$	—	—	$	—
Exercised	—	$	—	(2,093)	$	13.45	(25)	$	10.75
Expired or forfeited	—	$	—	(7)	$	10.00	—	$	—
Outstanding at end of year:	5	$	22.35	5	$	22.35	2,105	$	13.47


			December 31, 2020
			Options Outstanding			Options Exercisable
Exercise Price	Total Options Outstanding		Weighted Average Remaining Life (Years)	Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
22.35	5		1.2	$	22.35	5		$	22.35


Aggregate Intrinsic Value	$	—				$	—

Restricted Stock Unit Awards

Restricted Stock Units generally vest ratably on each of the first four anniversary dates of issuance. The Company recognized approximately $4.4 million, $4.0 million and $4.2 million of share-based compensation for the years ended December 31, 2020, 2019 and 2018, respectively, related to restricted stock unit awards. As of December 31, 2020, there were approximately $4.9 million of unrecognized compensation costs, net of estimated forfeitures, related to restricted stock unit awards, which are expected to be recognized over a remaining weighted average period of 2.3 years. Upon vesting, restricted stock units are generally net share-settled to cover the required minimum withholding tax and the remaining amount is converted into an equivalent number of shares of common stock.

A summary of the vesting activity of restricted stock unit awards, with the respective fair value of the awards, is as follows: (in thousands):


	For the year ended December 31,
	2020		2019		2018
Restricted stock awards vested	208		172		258
Fair value of awards vested	$	837	$	2,495	$	5,319

A summary of the fully-vested common stock the Company issued to its six non-employee directors, in connection with its non-employee director compensation plan, is as follows (in thousands):


	For the year ended December 31,
	2020		2019		2018
Awards issued	68		30		19
Grant date fair value of awards issued	$	326	$	450	$	400

A summary of the Company's outstanding, non-vested restricted share units is presented below (in thousands, except per share amounts):


	For the year ended December 31,
	2020			2019			2018
	Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	559	$	16.92	443	$	20.55	532	$	21.05
Granted	782	$	3.79	339	$	14.04	211	$	19.20
Released	(208)	$	18.71	(172)	$	20.38	(258)	$	20.48
Forfeited	(57)	$	9.62	(51)	$	17.71	(42)	$	20.52
Outstanding at end of period:	1,076	$	7.41	559	$	16.92	443	$	20.55

Performance Restricted Stock Units

The Company maintains Performance Restricted Stock Units (PRSUs) that have been granted to select executives and senior officers whose ultimate payout is based on the Company’s performance over a one-year period based on specific metrics approved by the Compensation Committee of the Board of Directors of the Company. The PRSU awards granted in 2019 included three performance metrics, as defined: (1) Operating Income, (2) Adjusted EBITDAS (defined as net income attributable to MISTRAS Group, Inc. plus: interest expense, provision for income taxes, depreciation and amortization, share-based compensation expense and certain acquisition related costs (including transaction due diligence costs and adjustments to the fair value of contingent consideration), foreign exchange (gain) loss and, if applicable, certain special items which are noted) and (3) Revenue. There also is a discretionary portion of the 2019 PRSUs based on individual performance, granted at the discretion of the Compensation Committee (Discretionary PRSUs). PRSUs and Discretionary PRSUs generally vest ratably on each of the first four anniversary dates upon completion of the performance period, for a total requisite service period of up to five years and have no dividend rights.

For 2020 awards, the Compensation Committee changed the criteria for the PRSUs to four metrics, with no discretionary portion. Revenue and Adjusted EBITDAS were retained, and two additional metrics, free cash flow as a percentage of revenue and return on average book equity, replaced Operating Income. These two newly-added metrics are relative metrics, the performance of which are based upon how the Company performs relative to a peer group.

PRSUs are equity-classified and compensation costs are initially measured using the fair value of the underlying stock at the date of grant, assuming that the target performance conditions will be achieved. Compensation costs related to the PRSUs are subsequently adjusted for changes in the expected outcomes of the performance conditions.

Discretionary PRSUs are liability-classified and adjusted to fair value (with a corresponding adjustment to compensation expense) based upon the targeted number of shares to be awarded and the fair value of the underlying stock each reporting period until approved by the Compensation Committee, at which point they are equity-classified.

A summary of the Company's PRSU activity is presented below (in thousands, except per share amounts):


	For the year ended December 31,
	2020			2019			2018
	Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	260	$	16.77	277	$	17.80	278	$	17.00
Granted	292	$	3.68	190	$	13.63	129	$	19.46
Performance condition adjustments, net	(99)	$	3.82	(106)	$	13.77	(50)	$	19.48
Released	(120)	$	17.29	(101)	$	17.19	(68)	$	16.03
Forfeited	—	$	—	—	$	—	(12)	$	16.16
Outstanding at end of period:	333	$	8.84	260	$	16.77	277	$	17.80

For the year ended December 31, 2020, 292,000 PRSUs were granted. There was a 99,000 net unit reduction to these awards, which represents Company performance against target (including an increase of 1,000 units due to the Compensation Committee approving the final calculation of the award metrics for calendar year 2019), during the year ended December 31, 2020.

For the year ended December 31, 2019, 190,000 PRSUs were granted. There was a 103,000 unit reduction to these awards, which represents Company performance below target, during the year ended December 31, 2019. As of December 31, 2019, the aggregate liability related to 29,000 outstanding discretionary PRSUs was less than $0.1 million and is classified within Accrued expenses and other liabilities on the consolidated balance sheet.

For the year ended December 31, 2018, 129,000 PRSUs were granted. There was a 54,000 unit reduction to these awards, which represents Company performance below target, during the year ended December 31, 2018. As of December 31, 2018, the aggregate liability related to 22,000 outstanding discretionary PRSUs was less than $0.1 million and is classified within Accrued expenses and other liabilities on the consolidated balance sheet. The Compensation Committee approved these PRSUs during the first quarter of 2019, which further reduced these awards by 3,000 units. The discretionary portion of these awards were reclassified from a liability to equity on the consolidated balance sheet upon Compensation Committee approval.

Compensation expense related to all PRSUs described above was $1.2 million, $1.3 million, and $1.5 million for the years ended December 31, 2020, 2019 and 2018, respectively. At December 31, 2020, there was $1.1 million of total unrecognized compensation costs related to approximately 333,000 unvested performance restricted stock units. These costs are expected to be recognized over a weighted-average period of approximately 1.8 years.

For the years ended December 31, 2020, 2019 and 2018, the income tax benefit recognized on all share based compensation arrangements referenced above was approximately $0.6 million, $2.1 million, and $1.0 million, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Taxes

Income (loss) before provision for income taxes is as follows:


	For the year ended December 31,
	2020		2019		2018
Income (loss) before provision for income taxes from:
U.S. operations	$	(54,190)	$	7,334	$	9,853
Foreign operations	(59,982)		3,105		4,418
Income (loss) before income taxes	$	(114,172)	$	10,439	$	14,271

The provision for income taxes consists of the following:


	For the year ended December 31,
	2020		2019		2018
Current
Federal	$	(6,278)	$	2,712	$	790
States and local	528		519		533
Foreign	4,006		4,572		3,824
Reserve for uncertain tax positions	(28)		99		337
Total current provision (benefit)	(1,772)		7,902		5,484
Deferred
Federal	(2,781)		315		2,966
States and local	(1,244)		(32)		399
Foreign	(10,045)		(4,095)		(2,089)
Total deferred provision (benefit)	(14,070)		(3,812)		1,276
Net change in valuation allowance	1,136		269		666
Net deferred provision (benefit)	(12,934)		(3,543)		1,942
Total provision (benefit) for income taxes	$	(14,706)	$	4,359	$	7,426

The provision (benefit) for income taxes differs from the amount computed by applying the statutory federal tax rate to income tax as follows:


	For the years ended December 31,
	2020				2019				2018
Federal tax at statutory rate	$	(23,976)	21.0	%	$	2,192	21.0	%	$	2,997	21.0	%
State taxes, net of federal benefit	(1,175)		1.0	%	377		3.6	%	737		5.1	%
Foreign tax	(815)		0.7	%	982		9.4	%	807		5.7	%
Goodwill impairment	10,003		(8.8)	%	—		—	%	—		—	%
Nondeductible compensation	975		(0.9)	%	1,581		15.2	%	183		1.3	%
US taxation of foreign earnings	56		—	%	213		2.0	%	228		1.6	%
Permanent differences	944		(0.8)	%	464		4.4	%	361		2.5	%
Transition tax, net of foreign tax credits	—		—	%	—		—	%	1,158		8.1	%
Federal loss carryback	(1,938)		1.7	%	—		—	%	—		—	%

Change in valuation allowance	1,136		(1.0)	%	269		2.6	%	666		4.7	%
Impact of foreign tax rate changes	392		(0.3)	%	(1,882)		(18.0)	%	—		—	%
Other	(308)		0.3	%	163		1.6	%	289		2.0	%
Total provision (benefit) for income taxes	$	(14,706)	12.9	%	$	4,359	41.8	%	$	7,426	52.0	%

The permanent differences identified above include normal recurring differences, such as meals, entertainment and parking fringe benefits as well as a portion of the goodwill impairment charge.

On December 22, 2017, the United States enacted fundamental changes to the federal tax law following the passage of the Tax Cuts and Jobs Act (the "Tax Act").

The Tax Act is complex and significantly changes the U.S. corporate tax system by, among other things, (a) reducing the federal corporate tax rate from 35% to 21% for tax years beginning after December 31, 2017, (b) replacing the prior system of taxing corporations on foreign earnings of their foreign subsidiaries when the earnings are repatriated with a partial territorial tax system that provides a 100% dividends-received deduction (DRD) to domestic corporations for foreign-sourced dividends received from 10%-or-more owned foreign corporations, (c) subjecting certain unrepatriated foreign earnings to a mandatory

one-time transition tax on post-1986 earnings and profits ("the transition tax"), and (d) further limiting a public entity's ability to deduct compensation in excess of $1 million for covered employees.

During the year ended December 31, 2018, the Company completed its accounting for the effects of the Tax Act on the period ended December 31, 2017, which resulted in income tax expense of $1.7 million. This consisted primarily of $0.1 million of an increase in the Company's net deferred tax liabilities due to the reduction in the federal corporate rate from 35% to 21%, an increase of $1.3 million in tax expense attributable to the transition tax and a decrease in deferred tax assets of $0.4 million due to changes made to executive compensation.

On June 28, 2019, the Canadian province of Alberta enacted the Job Creation Tax Cut which reduced the Alberta corporate income tax rate from 12% to 11% starting in 2019 with further annual reductions to 10% in 2020, 9% in 2021, and 8% in 2022. This rate reduction had a favorable impact of approximately $1.9 million on the Company’s net deferred tax liabilities in this jurisdiction in 2019. As part of Alberta’s Recovery plan associated with the COVID-19 pandemic, Alberta accelerated the decrease in income tax rates from 10% in 2020 to 8% effective July 1, 2020. The accelerated tax rate reduction did not have a material impact on the Company’s net deferred tax liabilities but did reduce current taxes.

On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act (CARES Act). The CARES Act is an approximately $2 trillion emergency economic stimulus package in response to the Coronavirus outbreak, which among other things contains numerous income tax provisions. Some of these tax provisions are effective retroactively for years ending before the date of enactment. The CARES Act provides a five-year carryback of net operating losses generated in years 2018 through 2020. As the statutory federal income tax rate applicable to certain years within the carryback period is 35%, carryback to those years of our estimated 2020 annual federal tax loss provides a tax benefit in excess of the current federal statutory rate of 21%, resulting in an increased income tax benefit of $1.9 million. The Company expects that the income tax effects of the CARES Act will result in a cash refund of approximately $4.8 million in 2021 of taxes paid in prior years.

On December 27, 2020, the United States enacted the Consolidated Appropriations Act, 2021, (the "Appropriations Act") an additional stimulus package providing financial relief for individuals and small business. The Appropriations Act contains a variety of tax provisions, including full expensing of business meals in 2021 and 2022, and expansion of the employee retention tax credit. The Company does not currently expect the Appropriations Act to have a material impact on our consolidated financial position, results of operations, and cash flows.

In response to the COVID-19 pandemic, the American Rescue Plan Act was signed into law on March 11, 2021. This act, among other things, provides economic relief provisions to individuals and funding to certain businesses and programs. The Company is currently evaluating the impact of this guidance on its consolidated financial position, results of operations, and cash flows, but does not expect it to have a material impact.

Deferred income tax attributes resulting from differences between financial accounting amounts and income tax basis of assets and liabilities are as follows:


	December 31,
	2020		2019
Deferred income tax assets
Allowance for doubtful accounts	$	1,054	$	1,186
Inventory	459		359
Intangible assets	2,000		1,795
Accrued expenses	6,818		4,421
Net operating loss carryforward	4,190		3,832
Finance lease obligations	942		1,067
Capital losses	—		463
Deferred stock based compensation	920		1,145
Interest carryforward	—		1,372
Right-of-use liability	11,970		11,891
Credits	312		—
Other	1,507		398
Deferred income tax assets	30,172		27,929
Valuation allowance	(4,540)		(4,067)
Net deferred income tax assets	25,632		23,862
Deferred income tax liabilities
Property and equipment	(9,109)		(6,485)
Goodwill	(4,639)		(10,652)
Intangible assets	(6,058)		(14,311)
Right-of-use asset	(11,924)		(11,891)
Other	(69)		(27)
Deferred income tax liabilities	(31,799)		(43,366)
Net deferred income taxes	(6,167)		(19,504)

As of December 31, 2020, the Company had federal net operating loss carry forwards (NOLs) of approximately $0.1 million expiring in 2032 which may be used subject to limitation under Internal Revenue Code section 382. In addition, as of December 31, 2020, the Company had state and foreign NOLs of $14.8 million and $11.7 million, respectively. Approximately $8.9 million of the state NOLs expire at various times from 2031 to 2040, while the remainder of the Company's state NOLs do not expire. Approximately $0.1 million of the foreign NOLs expire at various times from 2023 to 2040, while the remainder of the Company's foreign NOLs do not expire.

In assessing the ability to realize deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will be realized. Valuation allowances are provided when management believes the Company's deferred tax assets are not recoverable based on future reversals of existing taxable temporary differences, taxable income in prior carryback year(s) if carryback is permitted under the tax law, and an assessment of estimated future taxable income, exclusive of reversing temporary differences and carryforwards, that incorporates ongoing, prudent and feasible tax planning strategies. At December 31, 2020 and December 31, 2019, the Company has a valuation allowance of approximately $4.5 million and $4.1 million, respectively, primarily against certain state and foreign NOLs and other specific deferred tax assets. The valuation allowance as of December 31, 2019, also applied against capital losses generated by the disposals of certain foreign subsidiaries. These losses expired in 2020, so no valuation allowance remains as of December 31, 2020. The net increase in the valuation allowance of approximately $0.5 million is primarily attributable to state and foreign net operating losses and changes in foreign exchange rates, offset by a reduction of expiring losses. Except for those deferred tax assets subject to the valuation allowance, management believes that it will realize all deferred tax assets as a result of sufficient future taxable income in each tax jurisdiction in which the Company has deferred tax assets.

The following table summarizes the changes in the Company’s gross unrecognized tax benefits, excluding interest and penalties:


	For the year ended December 31,
	2020		2019
Balance at beginning of period	$	393	$	723
Additions for tax positions related to the current fiscal period	—		—
Additions for tax positions related to prior years	32		217
Decreases for tax positions related to prior years	—		—
Current year acquisitions	—		—
Impact of foreign exchange fluctuation	(5)		13
Settlements	—		(465)
Reductions related to the expiration of statutes of limitations	(73)		(95)
Balance at end of period	$	347	$	393

The Company has recorded the unrecognized tax benefits in other long-term liabilities in the consolidated balance sheets. As of December 31, 2020 and December 31, 2019, there were approximately $0.3 million and $0.4 million of unrecognized tax benefits, respectively, including penalties and interest. If the Company recognized these unrecognized tax benefits, approximately $0.2 million would favorably affect the effective tax rate for both December 31, 2020 and December 31, 2019. Interest and penalties related to unrecognized tax benefits are recorded in income tax expense and are not significant for the years ended December 31, 2020, 2019 and 2018. The Company anticipates a decrease to its unrecognized tax benefits of $0.2 million excluding interest and penalties within the next 12 months.

The Company is subject to taxation in the United States and various states and foreign jurisdictions. The Company is no longer subject to U.S. federal income tax examinations for years ending before December 31, 2017 and generally is no longer subject to state, local or foreign income tax examinations by tax authorities for years ending before December 31, 2016.

Net income (loss) of foreign subsidiaries was $(55.7) million, $2.5 million, and $2.0 million for the years ended December 31, 2020, 2019 and 2018, respectively. Generally, it has been the Company's practice and intention to reinvest the earnings of its non-U.S. subsidiaries in those operations. As previously noted, the Tax Act made significant changes to the taxation of undistributed earnings, requiring that all previously untaxed earnings and profits of the Company's controlled foreign operations be subjected to the transition tax. Since these earnings have now been subjected to U.S. federal tax, they would only be potentially subject to limited other taxes, including foreign withholding and certain state taxes. As of December 31, 2020, the Company has not recognized a deferred tax liability for foreign withholdings and state taxes on its undistributed international earnings or losses of its foreign subsidiaries since it intends to indefinitely reinvest the earnings outside the United States. The Company has estimated that the amount of the unrecorded deferred tax liability related to undistributed international earnings is approximately $1.8 million.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company provides a 401(k) savings plan for eligible U.S. based employees. Employee contributions are discretionary up to the IRS limits each year and catch up contributions are allowed for employees 50 years of age or older. Under the 401(k) plan, employees become eligible to participate on the first day of the month after three months of continuous service. Under this plan, the Company matches 50% of the employee’s contributions up to 6% of the employee’s annual compensation, as defined by the plan. There is a five-year vesting schedule for the Company match. To respond to the economic downturn resulting from the COVID-19 pandemic, significant volatility in oil prices and decreased traffic in the aerospace industry, the Company temporarily suspended its 401(k) match effective with the second quarter of 2020. The Company’s contribution to the plan was $1.1 million, $4.1 million, and $3.9 million for the years ended December 31, 2020, 2019 and 2018, respectively. The Company's subsidiary participated with other employers in contributing to the Boilermaker-Blacksmith National Pension Trust (EIN 48-6168020) (“Boilermakers”) and Plumbers and Pipefitters National Pension Fund (EIN 52-6152779) (“Pipefitters”), multi-employer defined benefit pension plans, which covers certain U.S. based union employees. The plans provide multiple plan benefits with corresponding contribution rates that are collectively bargained between participating employers and their affiliated Boilermakers and Pipefitters local unions. Both the Boilermakers and Pipefitters plans are between 66 percent and 75 percent funded as of the latest Form 5500 filed. The Company did not make any contributions to the Boilermakers during the years ended December 31, 2020 and 2019 while making de minimis contributions to the Pipefitters plan during the same periods. The Company’s contributions to the Boilermakers and Pipefitters plans, collectively, were $0.6 million for the year ended December 31, 2018. See Note 18-Commitments and Contingencies, Pension Related Contingencies, for additional detail. The Company has other benefit plans covering certain employees throughout the Company. Amounts charged to expense under these plans were not significant in any year.

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company leases its headquarters under an operating lease from a shareholder and officer of the Company. On August 1, 2014, the Company extended its lease at its headquarters requiring monthly payments through October 2024. Total rent payments made during the year ended December 31, 2020 were approximately $0.7 million. See 17-Leases for further detail. The Company receives benefits consulting services from Capital Management Enterprise (“CME”). Manuel N. Stamatakis, one of the Company's non-employee directors, is the Chief Executive Officer of CME. The Company does not pay any fees to CME and, any compensation CME receives related to work for the Company is received by commissions paid by the third-party benefit providers.

Leases

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Leases

The Company leases certain office and operating facilities, machinery, equipment, and vehicles. Concurrent with the adoption of ASC 842, the Company recognized a right-of-use (ROU) asset and lease liability based on the present value of the future lease payments over the lease term for each lease agreement. The Company has elected not to recognize a ROU asset and lease liability for leases with terms of 12 months or less and will continue to recognize lease expense for these leases on a straight-line basis over the lease term. The Company has leases with both lease components and non-lease components, such as common area maintenance, utilities, or other repairs and maintenance. For all asset classes, the Company decided to utilize the practical expedient to include both fixed lease components and fixed non-lease components in calculating the ROU asset and lease liability. The Company identified variable lease payments, such as maintenance payments based on actual activities performed or costs incurred, at lease commencement by assessing the nature of the payment provisions, including whether the payments are subject to a minimum charge. Many of the Company's leases include one or more options to renew. When it is reasonably certain that the Company will exercise the option, the Company will include the impact of the option in the lease term for purposes of determining future lease payments. As the Company is unable to determine the discount rate implicit in its lease agreements, the Company uses its incremental borrowing rate on the commencement date to calculate the present value of future payments.

The Company’s Consolidated Balance Sheets include the following related to operating leases as of December 31, 2020 and 2019:


Leases	Classification	2020		2019
Assets:
ROU assets	Other Assets	$	46,728	$	45,817

Liabilities:
ROU liability - current	Accrued and other current liabilities	$	10,348	$	10,133
ROU liability - long-term	Other liabilities	37,689		36,750
Total ROU liabilities		$	48,037	$	46,883

Included within the balance of operating leases is a lease for the Company’s headquarters which is with a related party. The ROU liability for this facility is approximately $3.8 million as of December 31, 2020 and $4.5 million as of December 31,

2019. Total rent payments for this facility were approximately $0.7 million and $1.0 million during the years ended December 31, 2020 and 2019. An agreement was reached with the related party to reduce rental payments by 20% and defer payments for 90 days for the lease of the Company’s headquarters, starting in June 2020 through December 2020 as part of COVID-19 related lease concessions.

As of December 31, 2020 and 2019, the total ROU assets attributable to finance leases are approximately $15.8 million and $19.2 million, respectively, which is included in Property, plant, and equipment, net on the Consolidated Balance Sheets.

As described in Note 9-Intangible Assets, the Company performed an analysis to determine whether there was any impairment of long-lived assets, which included the ROU assets, within the Services, International, and Products and Systems operating segments as well as Corporate. The result of the analysis was a $0.2 million impairment of a ROU asset in an asset group within the Services segment which is included in Impairment charges on the consolidated statements of income (loss) for the year ended December 31, 2020.

The components of lease costs for the year ended December 31, 2020 and 2019 are as follows:


	Classification	2020		2019
Finance lease expense:
Amortization of ROU assets	Depreciation and amortization	$	4,544	$	5,091
Interest on lease liabilities	Interest expense	847		824
Operating lease expense	Cost of revenue; Selling, general & administrative expenses	13,383		12,937
Short-term lease expense	Cost of revenue; Selling, general & administrative expenses	66		43
Variable lease expense	Cost of revenue; Selling, general & administrative expenses	838		1,220
Total		$	19,678	$	20,115

Additional information related to leases as of December 31, 2020 and 2019 is as follows:


	2020			2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases:
Finance - financing cash flows	$	4,095		$	4,545
Finance - operating cash flows	847			824
Operating - operating cash flows	13,246			12,773
ROU assets obtained in the exchange for lease liabilities:
Finance leases	$	2,849		9,502
Operating leases	9,934			18,965
Weighted-average remaining lease term (in years):
Finance leases	5.7			5.9
Operating leases	5.8			6.2
Weighted-average discount rate:
Finance leases	5.7		%	5.8		%
Operating leases	5.7		%	5.9		%

Maturities of lease liabilities as of December 31, 2020 is as follows:


	Finance		Operating
2021	$	5,353	$	12,588
2022	4,087		10,495
2023	3,194		8,907
2024	2,261		7,042
2025	688		5,150
Thereafter	754		12,258
Total	16,337		56,440
Less: Present value discount	1,457		8,403
Lease liability	$	14,880	$	48,037

Leases

The Company’s Consolidated Balance Sheets include the following related to operating leases as of December 31, 2020 and 2019:


Leases	Classification	2020		2019
Assets:
ROU assets	Other Assets	$	46,728	$	45,817

Liabilities:
ROU liability - current	Accrued and other current liabilities	$	10,348	$	10,133
ROU liability - long-term	Other liabilities	37,689		36,750
Total ROU liabilities		$	48,037	$	46,883

The components of lease costs for the year ended December 31, 2020 and 2019 are as follows:


	Classification	2020		2019
Finance lease expense:
Amortization of ROU assets	Depreciation and amortization	$	4,544	$	5,091
Interest on lease liabilities	Interest expense	847		824
Operating lease expense	Cost of revenue; Selling, general & administrative expenses	13,383		12,937
Short-term lease expense	Cost of revenue; Selling, general & administrative expenses	66		43
Variable lease expense	Cost of revenue; Selling, general & administrative expenses	838		1,220
Total		$	19,678	$	20,115

Additional information related to leases as of December 31, 2020 and 2019 is as follows:


	2020			2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases:
Finance - financing cash flows	$	4,095		$	4,545
Finance - operating cash flows	847			824
Operating - operating cash flows	13,246			12,773
ROU assets obtained in the exchange for lease liabilities:
Finance leases	$	2,849		9,502
Operating leases	9,934			18,965
Weighted-average remaining lease term (in years):
Finance leases	5.7			5.9
Operating leases	5.8			6.2
Weighted-average discount rate:
Finance leases	5.7		%	5.8		%
Operating leases	5.7		%	5.9		%

Maturities of lease liabilities as of December 31, 2020 is as follows:


	Finance		Operating
2021	$	5,353	$	12,588
2022	4,087		10,495
2023	3,194		8,907
2024	2,261		7,042
2025	688		5,150
Thereafter	754		12,258
Total	16,337		56,440
Less: Present value discount	1,457		8,403
Lease liability	$	14,880	$	48,037

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings and Government Investigations The Company is subject to periodic lawsuits, investigations and claims that arise in the ordinary course of business. The Company cannot predict with certainty the ultimate resolution of lawsuits, investigations and claims asserted against it. Except possibly for certain of the matters described below, the Company does not believe that any currently pending legal proceeding to which the Company is a party will have a material adverse effect on its business, results of operations, cash flows or financial condition. The costs of defense and amounts that may be recovered against the Company may be covered by insurance for certain matters. Litigation and Commercial Claims The Company was contracted to perform inspections of welds on various pipeline projects in Texas for a customer. As of December 31, 2020 approximately $1.4 million of past due receivables were outstanding from this customer. The customer provided the Company with notice in December 2019, alleging that the Company’s inspection of 66 welds (out of approximately 16,000 welds inspected) were not in compliance with the contract, claimed approximately $7.6 million in damages, and requested that the Company pay these damages and any other damages incurred. The Company has filed a lawsuit in the District Court of Bexar County, Texas, 37th Judicial District, in an action captioned Mistras Group, Inc. v. Epic Y-Grade Pipeline LP, to recover the $1.4 million and other amounts due to the Company. The customer filed a counterclaim, alleging breach of contract and seeking recovery of its alleged damages. The Company believes that any successful claim by the customer regarding the Company’s workmanship will be covered by insurance, subject to payment of a deductible. At this time, the Company is unable to determine whether it has any liability in connection with this matter and if so, the amount or range of any such liability, and accordingly, has not established any accruals for this matter. Accordingly, the Company recorded a reserve of $1.4 million during the twelve months ended December 31, 2019 for these past due receivables. See 4-Accounts Receivable for additional details. Two proceedings have been filed in California Superior Court for the County of Los Angeles regarding alleged violations of California Labor Code. Both cases are captions Justin Price v. Mistras Group, Inc., one being a purported class action lawsuit on behalf of current and former Mistras employees in California and the other was filed on behalf of the State of California under the California Private Attorney General Act on the basis of the same alleged violations. Both cases are requesting payment of all damages, including unpaid wages, and various fines and penalties available under California law. As a result of continued legal proceedings through March 2021, the Company established a liability of $0.8 million at December 31, 2020 for a probable loss on this matter. However, no assurance can be given that this will be the limit of the loss, or that the loss will not be materially more than the $0.8 million liability. An estimate of the total possible loss or range of the total possible loss cannot be made at this time as matters are in preliminary stages. Pension Related Contingencies The workforce of certain of the Company’s subsidiaries are unionized and the terms of employment for these workers are governed by collective bargaining agreements, or CBAs. Under these CBAs, the Company’s subsidiaries are required to contribute to the national pension funds for the unions representing these employees, which are multi-employer pension plans. The Company was notified that a significant project was awarded to another contractor in January 2018, and as a result, one of the Company’s subsidiaries experienced a significant reduction in the number of its employees covered by one of the CBAs. Under certain circumstances, such a reduction in the number of employees participating in multi-employer pension plans pursuant to this CBA could result in a complete or partial withdrawal liability to these multi-employer pension plans under the Employee Retirement Income Security Act of 1974 ("ERISA"). Management explored options to retain a level of union work that would avoid withdrawal liability to the pension plans, but concluded during the third quarter of 2018 that the Company's subsidiaries probably would not obtain sufficient union work to avoid withdrawal liability. Therefore, the Company determined that it is probable that its subsidiary would incur a withdrawal liability related to these multi-employer pension plans. Accordingly, the Company recorded a charge of $5.9 million during 2018 and $0.8 million during 2019 for this potential withdrawal liability. The Company’s subsidiary reached an agreement with one of the pension funds in September 2019 and made a final payment of $0.9 million in complete satisfaction of the withdrawal liability of the subsidiary. Excluding the settlement payment, the Company made monthly payments totaling $3.3 million through the time of final settlement payment, for total payments of $4.2 million. The balance of the estimated total amount of this potential liability as of December 31, 2020 is approximately $2.5 million. Severance and labor disputes The Company’s German subsidiary provides employees to customers under temporary staff leasing arrangements. In April 2017, the German Labor Lease Act was passed in Germany limiting the duration of temporary workers to eighteen months, or longer as subsequently agreed with by a customer appropriate authority. Since the passing of the German Labor Lease Act, the Company explored selling its staff leasing services and concluded during the third quarter of 2018 that a sale would not be probable. As a result, the Company decided that it would not renew several of these leasing services contracts when they expired beginning in 2019. Due to the limit on the length of service allowed under the German Labor Lease Act, employees are being transitioned off the customer contracts. The German subsidiary has terminated, or will terminate, some these employees, creating a severance obligation to the terminated employees, and has transitioned, or will transition other employees to the Company's other customers. During December 2019, the Company executed an agreement to sell the rights of certain customer contracts for total consideration of approximately $0.1 million, effective January 1, 2020. No other assets or liabilities other than those employee benefits related to employees working on the customer contracts were included in the sale. As of December 31, 2020, the Company has approximately $0.2 million of accrued estimated severance payment obligations, which takes into account the Company's estimate with respect to the employees that have been or will be transitioned to the German subsidiaries' other customers. The $0.2 million of estimated obligations is net of $0.4 million in payments made and $1.0 million in reversals due to employees being transitioned to customer contracts. During 2018, the Company recorded approximately $1.2 million in charges related to labor claims against its Brazilian subsidiary, which are included within selling, general and administrative expenses. These claims related to employees in a company acquired by the Brazilian subsidiary in a prior period. The Company is entitled to indemnification from the sellers of the acquired company for most of these charges and won an arbitration award against the seller in 2020. The Company and the seller subsequently entered into a settlement agreement for $1.0 million, which provides for payment in two installments, the first for approximately 31% of the settlement and the second for the remaining 69%. The first installment in the amount of $0.3 million was paid by the sellers in December 31, 2020 and recognized as a gain in selling, general and administrative expenses in the same period. The remaining payment is due in the first quarter of 2021, and the recovery resulting from this second payment will be recorded upon receipt. Acquisition and disposition related contingencies The Company is liable for contingent consideration in connection with one of its acquisitions. As of December 31, 2020, total potential acquisition-related contingent consideration ranged from zero to approximately $4.3 million and would be payable upon the achievement of specific performance metrics by certain of the acquired companies over the next 1.75 years. With respect to the acquisition made in 2018, the Company filed a claim with the sellers and the Company's insurance carrier through which the Company has representations and warranty insurance. The Company received release of escrow funds from the Seller and is still pursuing its claim with the insurance carrier. During 2018, the Company sold a subsidiary in the Products and Systems segment. As part of the sale, the Company entered into a three-year agreement to purchase products from the buyer, with a cumulative commitment of $2.3 million, of which $1.2 million is remaining as of December 31, 2020. The agreement is based on third party pricing and the Company's planned purchase requirements over the three-year purchase period to meet the minimum contractual purchases.

Segment Disclosure

12 Months Ended

Dec. 31, 2020

Segment Reporting [Abstract]

Segment Disclosure

The Company’s three operating segments are:

•Services. This segment provides asset protection solutions predominantly in North America, with the largest concentration in the United States, followed by Canada, consisting primarily of NDT, inspection, mechanical and engineering services that are used to evaluate the safety, structural integrity and reliability of critical energy, industrial and public infrastructure and commercial aerospace components. PCMS software and pipeline related software and data analysis solutions are included in this segment.

•International. This segment offers services, products and systems, similar to those of the other segments, to select markets within Europe, the Middle East, Africa, Asia and South America, but not to customers in China and South Korea, which are served by the Products and Systems segment.

•Products and Systems. This segment designs, manufactures, sells, installs and services the Company’s asset protection products and systems, including equipment and instrumentation, predominantly in the United States.

Costs incurred for general corporate services, including finance, legal, and certain other costs that are provided to the segments are reported within Corporate and eliminations. Sales to the International segment from the Products and Systems segment and subsequent sales by the International segment of the same items are recorded and reflected in the operating performance of both segments. Additionally, engineering charges and royalty fees charged to the Services and International segments by the Products and Systems segment are reflected in the operating performance of each segment.

The accounting policies of the reportable segments are the same as those described in Note 1-Summary of Significant Accounting Policies and Practices. Segment income from operations is one of the primary performance measures used by the chief operating decision maker, to assess the performance of each segment and make resource allocation decisions. Certain general and administrative costs such as human resources, information technology and training are allocated to the segments. Segment income from operations excludes interest and other financial charges and income taxes. Corporate and other assets are comprised principally of cash, deposits, property, plant and equipment, domestic deferred taxes, deferred charges and other assets. Corporate loss from operations consists of administrative charges related to corporate personnel and other charges that cannot be readily identified for allocation to a particular segment.

Selected financial information by segment for the periods shown was as follows (intercompany transactions are eliminated in Corporate and eliminations):


	For the year ended December 31,
	2020		2019		2018
Revenues
Services	$	476,164	$	595,130	$	574,619
International	107,556		144,271		153,448
Products and Systems	16,449		18,583		23,426
Corporate and eliminations	(7,598)		(9,398)		(9,139)
	$	592,571	$	748,586	$	742,354


	For the year ended December 31,
	2020		2019		2018
Gross profit
Services	$	141,084	$	165,513	$	151,974
International	31,046		43,145		45,464
Products and Systems	6,826		8,639		10,560
Corporate and eliminations	(425)		—		(124)
	$	178,531	$	217,297	$	207,874

Income (loss) from operations by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations.


	For the year ended December 31,
	2020		2019		2018
Income (loss) from operations
Services	$	(44,222)	$	49,593	$	47,126
International	(21,855)		5,856		3,953
Products and Systems	(936)		(529)		2,368
Corporate and eliminations	(34,204)		(30,783)		(31,226)
	$	(101,217)	$	24,137	$	22,221


	For the year ended December 31,
	2020		2019		2018
Depreciation and amortization
Services	$	26,093	$	28,854	$	24,079
International	8,659		8,285		8,846
Products and Systems	998		1,213		1,429
Corporate and eliminations	(45)		181		59
	$	35,705	$	38,533	$	34,413


	December 31,
	2020		2019
Intangible assets, net
Services	$	58,917	$	98,284
International	8,664		9,814
Products and Systems	1,012		1,181
Corporate and eliminations	49		258
	$	68,642	$	109,537


	December 31,
	2020		2019
Total assets
Services	$	427,636	$	537,518
International	129,228		153,380
Products and Systems	10,996		16,028
Corporate and eliminations	15,453		12,952
	$	583,313	$	719,878


	December 31,
	2020		2019
Long-lived assets
United States	$	187,251	$	233,679
Other Americas	123,924		181,550
Europe	56,156		75,325
	$	367,331	$	490,554

Refer to Note 2-Revenue, for revenues by segment and by geographic area for the years ended December 31, 2020, 2019, and 2018.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8981-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 26
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8844-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8657-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-URI http://asc.fasb.org/topic&trid=2134510

+ Details

Selected Quarterly Financial Information (unaudited)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Information (unaudited)

Selected Quarterly Financial Information (unaudited)The following is a summary of the quarterly results of operations for calendar years 2020, 2019, and 2018.


Quarter ended	December 31, 2020		September 30, 2020		June 30, 2020		March 31, 2020
Revenues	$	160,777	$	147,894	$	124,435	$	159,465
Gross Profit	49,345		47,384		41,158		40,644
Income (loss) from operations	4,652		5,742		(383)		(111,228)
Net income (loss) attributable to Mistras Group, Inc.	$	181	$	1,523	$	(2,656)	$	(98,509)
Earnings (loss) per common share:
Basic	$	0.01	$	0.05	$	(0.09)	$	(3.40)
Diluted	$	0.01	$	0.05	$	(0.09)	$	(3.40)


Quarter ended	December 31, 2019		September 30, 2019		June 30, 2019		March 31, 2019
Revenues	$	178,991	$	192,192	$	200,616	$	176,787
Gross Profit	50,583		57,769		60,071		48,874
Income from operations	2,335		10,779		15,419		(4,396)
Net income (loss) attributable to Mistras Group, Inc.	$	829	$	3,093	$	7,431	$	(5,293)
Earnings (loss) per common share:
Basic	$	0.03	$	0.11	$	0.26	$	(0.19)
Diluted	$	0.03	$	0.11	$	0.26	$	(0.19)


Quarter ended	December 31, 2018		September 30, 2018		June 30, 2018		March 31, 2018
Revenues	$	180,762	$	182,169	$	191,793	$	187,630
Gross Profit	52,315		52,332		55,083		48,144
Income (loss) from operations	2,502		3,017		10,304		6,398
Net income (loss) attributable to Mistras Group, Inc.	$	(1,061)	$	(1,011)	$	6,000	$	2,908
Earnings (loss) per common share:
Basic	$	(0.04)	$	(0.04)	$	0.21	$	0.10
Diluted	$	(0.04)	$	(0.04)	$	0.20	$	0.10

Summary of Significant Accounting Policies and Practices (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Company follows guidance on the consolidation of variable interest entities (VIEs) that requires companies to utilize a qualitative approach to determine whether it is the primary beneficiary of a VIE. The process for identifying the primary beneficiary of a VIE requires consideration of the factors that indicate a party has the power to direct the activities that most significantly impact the VIE’s economic performance, including powers granted to the VIE’s program manager, powers contained in the VIE governing board and, to a certain extent, a company’s economic interest in the VIE. The Company analyzes its joint ventures and classifies them as either: •a VIE that must be consolidated because the Company is the primary beneficiary, or the joint venture is not a VIE and the Company holds the majority voting interest with no significant participative rights available to the other partners; or •a VIE that does not require consolidation and is treated as an equity method investment because the Company is not the primary beneficiary or the joint venture is not a VIE and the Company does not hold the majority voting interest. As part of the above analysis, if it is determined that the Company has the power to direct the activities that most significantly impact the joint venture’s economic performance, the Company considers whether or not it has the obligation to absorb losses or rights to receive benefits of the VIE that could potentially be significant to the VIE. The Company became the primary beneficiary in July 2020 of a VIE in which the Company has a 49% interest in a limited partnership, and a 49% shareholder in the corporate general partner of the limited partnership. The Company consolidated the financial statements of the VIE with the financial statements of the Company. As of and the for the year ended December 31, 2020, the VIE had immaterial assets and had no revenue. The Company is the primary sub-contractor of the VIE. The accompanying audited consolidated financial statements include the accounts of Mistras Group, Inc. as well as its wholly-owned subsidiaries, majority-owned subsidiaries and consolidated VIE. For subsidiaries in which the Company’s ownership interest is less than 100%, the non-controlling interests are reported in stockholders’ equity in the accompanying consolidated balance sheets. The non-controlling interests in net results, net of tax, is classified separately in the accompanying consolidated statements of income (loss). All significant intercompany accounts and transactions have been eliminated in consolidation. The results of operations of companies acquired are included from the date of acquisition.
Reclassifications	Reclassifications Certain amounts in prior periods have been reclassified to conform to the current year presentation. Such reclassifications did not have a material effect on the Company's financial condition or results of operations as previously reported.
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with U.S. generally accepted accounting principles (GAAP) requires that the Company make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses and disclosure of contingent assets and liabilities at the date of financial statements. The Company bases its estimates and assumptions on historical experience, known or expected trends and various other assumptions that it believes to be reasonable. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates, which may cause the Company’s future results to be significantly affected.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.
Accounts Receivables and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts)	Accounts Receivable and Allowance for Credit Losses (formerly Allowance for Doubtful Accounts) The Company maintains an allowance for credit losses on its accounts receivable balances, which represents its best estimate of current expected credit losses over the contractual life of the accounts receivable. Beginning January 1, 2020, when evaluating the adequacy of its allowance for credit losses each reporting period, the Company analyzes accounts receivable balances with similar risk characteristics on a collective basis, considering factors such as the aging of receivable balances, payment terms (primarily with 30 day terms), geographic location, historical loss experience, current information, and future expectations (generally considered one year which is consistent with expected collectability of the Company's trade receivables). The Company monitors and considers whether historical loss rates are consistent with expectation of supportable forward-looking estimates for its trade receivables noting no current or future economic considerations that would require adjusting the Company’s historical loss experience. Each reporting period, the Company reassesses whether any accounts receivable no longer share similar risk characteristics and should instead be evaluated as part of another pool or on an individual basis. Changes to the allowance for credit losses are adjusted through credit loss expense, which is presented within Selling, general and administrative expenses in the Consolidated statements of income.
Concentrations of Credit Risk	Concentration of Credit Risk For each of the years ended December 31, 2020 and 2019, no customer represented 10% or more of the Company's revenue. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. At times, cash deposits may exceed the limits insured by the Federal Deposit Insurance Corporation. The Company believes it is not exposed to any significant credit risk or risk of nonperformance of financial institutions.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value, as determined by using the first-in, first-out method, or market. Work in process and finished goods inventory include material, direct labor, variable costs and overhead.
Purchased and Internal-Use Software	Purchased and Internal-Use Software The Company capitalizes certain costs that are incurred to purchase or to create and implement internal-use software, which includes software coding, installation and testing. Capitalized costs are amortized on a straight-line basis over three years, the estimated useful life of the software.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are recorded at cost. Depreciation of property, plant and equipment is computed utilizing the straight-line method over the estimated useful lives of the assets. Amortization of leasehold improvements is computed utilizing the straight-line method over the shorter of the remaining lease term or estimated useful life. Repairs and maintenance costs are expensed as incurred.
Goodwill	Goodwill Goodwill represents the excess purchase price of acquired businesses over the fair values attributed to underlying net tangible assets and identifiable intangible assets. The Company tests goodwill for impairment at a “reporting unit” level (which for the Company is represented by (i) our Services segment, (ii) our Products and Systems segment, and (iii) the European component of our International segment and (iv) the Brazilian component of our International segment). Our annual impairment test is conducted on the first day of our fourth quarter, which is October 1. Goodwill is also tested for impairment whenever an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. In testing for goodwill impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances lead to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company concludes that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing a quantitative impairment test is not necessary. If the Company concludes otherwise, the Company is required to perform a quantitative impairment test. If the fair value of a reporting unit is less than its carrying value, this is an indicator that the goodwill assigned to that reporting unit may be impaired. As a result of the Company adopting Accounting Standards Update ("ASU") No. 2017-04, Intangibles-Goodwill and Other (Topic 350), impairment will be recorded in the amount that fair value is less than carrying value, as the ASU eliminated step two of the goodwill impairment process. The Company considers the income and market approaches to estimating the fair value of our reporting units, which requires significant judgment in evaluation of economic and industry trends, estimated future cash flows, discount rates and other factors.
Impairment of Long-lived Assets	Impairment of Long-lived Assets The Company reviews the recoverability of its long-lived assets (or asset groups) whenever events or changes in circumstances indicate that the carrying amount of the long-lived asset (group) might not be recoverable. The assessment for potential impairment is based primarily on the Company’s ability to recover the carrying value of its long-lived assets from expected future undiscounted cash flows. If the total expected future undiscounted cash flows are less than the carrying amount of the assets, a loss is recognized for the difference between fair value (computed based upon the expected future discounted cash flows) and the carrying value of the assets.
Acquisitions	AcquisitionsThe Company allocates the purchase price of acquired businesses to their identifiable tangible assets and liabilities as well as identifiable intangible assets, such as customer relationships, technology, non-compete agreements and trade names. Certain estimates and judgments are required in the application of the fair value techniques, including estimates of the respective acquisition's future performance and related cash flows, selection of a discount rate and economic lives, and use of Level 3 measurements as defined in ASC No. 820, Fair Value Measurements and Disclosure. Deferred taxes are recorded for any differences between the assigned values and tax bases of assets and liabilities.
Research and Engineering	Research and Engineering Research and product development costs are expensed as incurred.
Advertising, Promotions and Marketing	Advertising, Promotions and Marketing The costs for advertising, promotion and marketing programs are expensed as incurred and are included in selling, general and administrative expenses.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and other financial current assets and liabilities approximate fair value based on the short-term nature of the items.
Foreign Currency Translation	Foreign Currency Translation The financial position and results of operations of the Company’s foreign subsidiaries are measured using their functional currencies, which are their local currencies. Assets and liabilities of foreign subsidiaries are translated into the U.S. Dollar at the exchange rates in effect at the balance sheet date. Income and expenses are translated at the average exchange rate during the period. Translation gains and losses are reported as a component of other comprehensive income (loss) for the period and included in accumulated other comprehensive income (loss) within stockholders’ equity. Foreign currency (gains) and losses arising from transactions denominated in currencies other than the functional currency are included in net income, reported in selling, general and administrative expenses,
Self-Insurance	Self-Insurance The Company is self-insured for certain losses relating to workers’ compensation and health benefit claims. The Company maintains third-party excess insurance coverage for all workers' compensation and health benefit claims in excess of approximately $0.3 million per occurrence to reduce its exposure from such claims. Self-insured losses are accrued when it is probable that an uninsured claim has been incurred but not reported and the amount of the loss can be reasonably estimated at the balance sheet date.
Share-based Compensation	Share-based Compensation The value of services received from employees and directors in exchange for an award of an equity instrument is measured based on the grant-date fair value of the award. Such value is recognized as a non-cash expense on a straight-line basis over the minimum period the individual provides services, which is typically the vesting period of the award with the exception of awards with graded vesting that contain an internal performance measure where each tranche is recognized on a straight-line basis over its vesting period subject to the probability of meeting the performance requirements and adjusted for the number of shares expected to be earned. Awards to certain employees eligible for retirement prior to the award becoming fully vested are amortized to expense over the period through the date that the employee first becomes eligible to retire and is no longer required to provide service to earn the award. As share-based compensation expense is based on awards ultimately expected to vest, the amount of expense is reduced for estimated forfeitures. The cost of these awards is recorded in selling, general and administrative expense in the Company’s consolidated statements of income.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax credit carry-forwards. Deferred income tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is provided if it is more likely than not that some or all of a deferred income tax asset will not be realized. A current tax liability or asset is recognized for the estimated taxes payable or refundable on tax returns for the current and prior years. US GAAP prescribes a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements. US GAAP also provides guidance on de-recognition, measurement, and classification of amounts relating to uncertain tax positions, accounting for and disclosure of interest and penalties, accounting in interim periods and disclosures required. Interest and penalties related to unrecognized tax positions are recognized as incurred within “provision for income taxes” in the consolidated statements of income. In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”) was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to deferment of employer’s social security payments, net operating loss utilization and carryback periods, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The ultimate impact of the CARES Act may differ from the estimated impact the Company recorded during this period due to changes in interpretations and guidance that may be issued and actions the Company may take in response to the CARES Act. The Company will continue to assess the impact that various provisions of the CARES Act, and how they are interpreted and effected, will have on its business.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by eliminating certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities related to outside basis differences. The standard is effective for interim and annual periods beginning January 1, 2021, with certain amendments applied prospectively and others requiring retrospective application. Early adoption is permitted, with any adjustments reflected as of the beginning of the fiscal year of adoption. The Company did not elect early adoption and is currently evaluating the impact of this guidance on its consolidated financial position, results of operations, and cash flows. In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” The guidance provides optional expedients and exceptions for applying U.S. GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another rate that is expected to be discontinued. The amendments in ASU 2020-04 are effective for all entities as of March 12, 2020 through December 31, 2022. The Company is currently evaluating the impact of this guidance on its consolidated financial position, results of operations, and cash flows.
Revenue	Revenue The Company derives the majority of its revenue by providing services on a time and material basis and are short-term in nature. The Company accounts for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers. 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 ASC Topic 606. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The majority of the Company's contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. The Company provides highly integrated and bundled inspection services to its customers. Some of our contracts have multiple performance obligations, most commonly due to the contract providing both goods and services. For contracts with multiple performance obligations, the Company allocates the contract’s transaction price to each performance obligation using the Company's best estimate of the standalone selling price of each distinct good or service in the contract. The primary method used to estimate standalone selling price is a relative selling price based on price lists. Contract modifications are not routine in the performance of the Company's contracts. Generally, when contracts are modified, the modification is to account for changes in scope to the goods and services that are provided. In most instances, contract modifications are for goods or services that are distinct, and, therefore, are accounted for as a separate contract. The Company's performance obligations are satisfied over time as work progresses or at a point in time. The majority of the Company's revenue recognized over time as work progresses is related to the Company's service deliverables, which includes providing testing, inspection and mechanical services to our customers. Revenue is recognized over time based on time and material incurred to date which best portrays the transfer of control to the customer. The Company also utilizes an available practical expedient that provides for revenue to be recognized in an amount that corresponds directly with the value to the customer of the entity’s performance completed to date. Fixed fee arrangements are determined based on expected labor, material, and overhead to be consumed on fulfillment of such services. Revenue is recognized on a cost-to-cost method tracked on an input basis. The majority of our revenue recognized at a point in time is related to product sales when the customer obtains control of the asset, which is generally upon shipment to the customer. Contract costs include labor, material and overhead. The Company expects any significant remaining performance obligations to be satisfied within one year. Contract Estimates The majority of the Company's revenues are short-term in nature. The Company has many master service agreements (MSAs) that specify an overall framework and contract terms when the Company and customers agree upon services or products to be provided. The actual contracting to provide services or furnish products are triggered by a work order, purchase order, or some similar document issued pursuant to a MSA which sets forth the scope of services and/or identifies the products to be provided. From time-to-time, the Company may enter into long-term contracts, which can range from several months to several years. Revenue on such long-term contracts is recognized as work is performed based on total costs incurred to date in relation to the total estimated costs for the performance of the contract at completion. This includes contract estimates of costs to be incurred for the performance of the contract. Cost estimation is based upon the professional knowledge and experience of the Company's project managers, engineers and financial professionals. Factors that are considered in estimating the work to be completed include the availability of materials, the effect of any delays in the Company's project performance and the recoverability of any claims. Whenever revisions of estimates, contract costs and/or contract values indicate that the contract costs will exceed estimated revenues, thus creating a loss, a provision for the total estimated loss is recorded in that period.
Fair Value Measurements	Fair Value Measurements The Company performs fair value measurements in accordance with the guidance provided by ASC 820, Fair Value Measurements and Disclosures. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. It also establishes a three level hierarchy that prioritizes the inputs used to measure fair value. The three levels of the hierarchy are defined as follows: Level 1 — Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 — Observable inputs other than quoted prices included in Level 1, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data. Level 3 — Unobservable inputs reflecting the Company’s own assumptions about inputs that market participants would use in pricing the asset or liability based on the best information available. Financial instruments measured at fair value on a recurring basis The fair value of contingent consideration liabilities was estimated using a discounted cash flow technique with significant inputs that are not observable in the market and thus represents a Level 3 fair value measurement as defined in ASC 820. The significant inputs in the Level 3 measurement not supported by market activity include the probability assessments of expected future cash flows related to the acquisitions, appropriately discounted considering the uncertainties associated with the obligation, and as calculated in accordance with the terms of the applicable acquisition agreements.

Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregated Revenues by Segment

The following series of tables present our disaggregated revenues by segment:

Revenue by industry was as follows:


Year ended December 31, 2020	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	298,605	$	39,728	$	430	$	—	$	338,763
Aerospace & Defense	50,813		18,166		1,292		—		$	70,271
Industrials	44,919		19,657		1,852		—		$	66,428
Power generation & Transmission	30,005		7,559		2,323		—		$	39,887
Other Process Industries	24,671		10,029		171		—		$	34,871
Infrastructure, Research & Engineering	17,070		10,353		6,364		—		$	33,787
Other	10,081		2,064		4,017		(7,598)		$	8,564
Total	$	476,164	$	107,556	$	16,449	$	(7,598)	$	592,571


Year ended December 31, 2019	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	390,815	$	44,447	$	756	$	—	$	436,018
Aerospace & Defense	51,390		41,224		1,237		—		$	93,851
Industrials	64,622		21,405		3,187		—		$	89,214
Power generation & Transmission	30,300		10,289		2,726		—		$	43,315
Other Process Industries	28,495		10,196		418		—		$	39,109
Infrastructure, Research & Engineering	14,269		9,520		9,316		—		$	33,105
Other	15,239		7,190		943		(9,398)		$	13,974
Total	$	595,130	$	144,271	$	18,583	$	(9,398)	$	748,586


Year ended December 31, 2018	Services		International		Products & Systems		Corp/Elim		Total
Oil & Gas	$	378,904	$	37,953	$	1,255	$	—	$	418,112
Aerospace & Defense	50,500		54,853		2,355		—		107,708
Industrials	60,594		26,209		3,097		—		89,900
Power generation & Transmission	30,687		8,522		4,904		—		44,113
Other Process Industries	26,425		9,497		124		—		36,046
Infrastructure, Research & Engineering	11,283		9,032		5,246		—		25,561
Other	16,226		7,382		6,445		(9,139)		20,914
Total	$	574,619	$	153,448	$	23,426	$	(9,139)	$	742,354

Revenue per key geographic location was as follows:


Year ended December 31, 2020	Services		International		Products & Systems		Corp/Elim		Total
United States	$	406,437	$	911	$	7,551	$	(3,410)	$	411,489
Other Americas	68,150		4,581		550		(446)		72,835
Europe	904		99,953		3,154		(3,470)		100,541
Asia-Pacific	673		2,111		5,194		(272)		7,706
Total	$	476,164	$	107,556	$	16,449	$	(7,598)	$	592,571


Year ended December 31, 2019	Services		International		Products & Systems		Corp/Elim		Total
United States	$	487,408	$	631	$	12,011	$	(4,918)	$	495,132
Other Americas	104,081		7,659		407		(407)		111,740
Europe	2,342		127,581		1,940		(3,978)		127,885
Asia-Pacific	1,299		8,400		4,225		(95)		13,829
Total	$	595,130	$	144,271	$	18,583	$	(9,398)	$	748,586


Year ended December 31, 2018	Services		International		Products & Systems		Corp/Elim		Total
United States	$	478,853	$	568	$	11,493	$	(3,500)	$	487,414
Other Americas	90,823		7,995		1,068		(1,638)		98,248
Europe	4,252		138,948		3,958		(3,846)		143,312
Asia-Pacific	691		5,937		6,907		(155)		13,380
Total	$	574,619	$	153,448	$	23,426	$	(9,139)	$	742,354

Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Schedule of Computations of Basic and Diluted Earnings Per Share

The following table sets forth the computations of basic and diluted earnings per share:


	For the year ended December 31,
	2020		2019		2018
Basic earnings (loss) per share:
Numerator:
Net income (loss) attributable to Mistras Group, Inc.	$	(99,461)	$	6,060	$	6,836
Denominator
Weighted average common shares outstanding	29,147		28,740		28,406
Basic earnings (loss) per share	$	(3.41)	$	0.21	$	0.24

Diluted earnings (loss) per share:
Numerator:
Net income (loss) attributable to Mistras Group, Inc.	$	(99,461)	$	6,060	$	6,836
Denominator
Weighted average common shares outstanding	29,147		28,740		28,406
Dilutive effect of stock options outstanding	—		98		683
Dilutive effect of restricted stock units outstanding	—		208		338
	29,147		29,046		29,427
Diluted earnings (loss) per share	$	(3.41)	$	0.21	$	0.23

Schedule of Potential Common Shares Excluded From the Computation of Diluted Earnings Per Share

The following potential common shares were excluded from the computation of diluted earnings per share, as the effect would have been anti-dilutive:


	For the year ended December 31,
	2020	2019	2018
Potential common stock attributable to restricted stock units (RSUs) and performance stock units (PSUs) outstanding (1)	790	42	1
Potential common stock attributable to stock options outstanding	5	5	5
Total	795	47	6

(1) For the twelve months ended December 31, 2020, 254 shares related to RSUs/PSUs, were excluded from the calculation of diluted EPS due to the net loss for the period.

Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2020

Receivables [Abstract]

Schedule of Accounts Receivable, Net

Accounts receivable consist of the following:


	December 31,
	2020		2019
Trade accounts receivable	$	115,841	$	144,282
Allowance for credit losses	(8,213)		(8,285)
Accounts receivable, net	$	107,628	$	135,997

Inventories (Tables)

12 Months Ended

Dec. 31, 2020

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories consist of the following:


	December 31,
	2020		2019
Raw materials	$	5,006	$	5,314
Work in progress	770		1,549
Finished goods	4,640		3,957
Consumable supplies	2,718		2,593
Inventories	$	13,134	$	13,413

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment, Net

Property, plant and equipment consist of the following:


		December 31,
	Useful Life	2020		2019
	(Years)
Land		$	2,724	$	2,672
Building and improvements	30-40	25,731		24,537
Office furniture and equipment	5-8	16,980		17,227
Machinery and equipment	5-7	237,253		225,974
		282,688		270,410
Accumulated depreciation and amortization		(190,007)		(171,803)
Property, plant and equipment, net		$	92,681	$	98,607

Acquisitions and Disposition (Tables)

12 Months Ended

Dec. 31, 2020

Business Combinations [Abstract]

Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed at the Date of Acquisition

The following table summarizes the final fair value of the assets acquired and liabilities assumed and the Company's allocation of purchase price:



	2019
Cash paid	$	4,380
Working capital adjustments	$	(152)
Fair value of contingent consideration	$	1,342
Total consideration	$	5,570

Current net assets	$	142
Other assets	$	34
Property, plant and equipment	$	65
Intangibles	$	3,594
Goodwill	$	1,735
Net assets acquired	$	5,570

Schedule of Acquisition-related Expenses

These amounts are recorded as acquisition-related expense, net, on the consolidated statements of income and were as follows for the years ended December 31, 2020, 2019 and 2018:


	For the year ended December 31,
	2020		2019		2018
Due diligence, professional fees and other transaction costs	$	—	$	364	$	1,248
Adjustments to fair value of contingent consideration liabilities	337		511		(716)
Acquisition-related expense, net	$	337	$	875	$	532

Goodwill (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in Carrying Amount of Goodwill by Segment

The changes in the carrying amount of goodwill by segment is shown below:


	Services		International		Products and Systems		Total





Balance at December 31, 2018	$	243,476	$	35,783	$	—	$	279,259
Goodwill acquired during the year	1,535		—		—		1,535
Adjustments to preliminary purchase price allocations	(2,332)		—		—		(2,332)
Foreign currency translation	4,536		(588)		—		3,948
Balance at December 31, 2019	$	247,215	$	35,195	$	—	$	282,410
Impairment charges	(57,227)		(19,862)		—		(77,089)
Adjustments to preliminary purchase price allocations	200		—		—		200
Foreign currency translation	(76)		563		—		487
Balance at December 31, 2020	$	190,112	$	15,896	$	—	$	206,008

Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Gross Amount and Accumulated Amortization of Intangible Assets

The gross carrying amount and accumulated amortization of intangible assets were as follows:


		December 31,
		2020								2019
	Useful Life (Years)	Gross Amount		Accumulated Amortization		Impairment		Net Carrying Amount		Gross Amount		Accumulated Amortization		Net Carrying Amount
Customer relationships	5-18	$	116,101	$	(75,649)	$	(2,206)	$	38,246	$	113,861	$	(67,853)	$	46,008
Software/Technology	3-15	77,326		(23,519)		(25,874)		27,933		77,914		(18,756)		59,158
Covenants not to compete	2-5	12,833		(12,162)		(212)		459		12,795		(11,630)		1,165
Other	2-12	11,120		(8,614)		(502)		2,004		10,813		(7,607)		3,206
Total		$	217,380	$	(119,944)	$	(28,794)	$	68,642	$	215,383	$	(105,846)	$	109,537

Schedule of Expected Amortization Expense of Intangible Assets

Amortization expense in each of the five years and thereafter subsequent to December 31, 2020 related to the Company’s intangible assets is expected to be as follows:


	Expected Amortization Expense
2021	$	9,915
2022	9,433
2023	8,719
2024	7,355
2025	5,597
Thereafter	27,623
Total	$	68,642

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2020

Payables and Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	December 31,
	2020		2019
Accrued salaries, wages and related employee benefits	$	30,214	$	30,072
Contingent consideration	1,300		2,614
Accrued workers' compensation and health benefits	3,948		4,467
Deferred revenues	6,538		5,860

Right-of-use liability - Operating	10,348		10,133
Pension accrual	2,519		2,519
Other accrued expenses	23,633		25,724
Total accrued expenses and other current liabilities	$	78,500	$	81,389

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Schedule of Long-term Debt

Long-term debt consists of the following:


	December 31,
	2020		2019
Senior credit facility	$	120,312	$	151,773
Senior secured term loan, net of unamortized debt issuance costs of $0.3 million and $0.1 million	89,745		94,919

Other	10,159		8,021
Total debt	220,216		254,713
Less: Current portion	(10,678)		(6,593)
Long-term debt, net of current portion	$	209,538	$	248,120

Schedule of Principal Payments Due Under All Borrowing Agreements

Scheduled principal payments due under all borrowing agreements in each of the five years and thereafter subsequent to December 31, 2020 are as follows:


2021	$	10,678
2022	11,551
2023	194,191
2024	1,282
2025	799
Thereafter	1,715
Total	$	220,216

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Schedule of Changes in Fair Value Level 3 Contingent Consideration

The following table represents the changes in the fair value of Level 3 contingent consideration:


	December 31,
	2020		2019
Balance at the beginning of the period:	$	3,216	$	2,365
Acquisitions	200		1,142
Payments	(2,091)		(852)
Accretion of liability	35		92
Revaluation	302		419
Foreign currency translation	(22)		50
Balance at the end of the period:	$	1,640	$	3,216

Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Cash Proceeds and Aggregate Fair Value of Stock Options Exercised

Cash proceeds from, and the intrinsic value of, stock options exercised during the years ended December 31, 2020, 2019 and 2018 were as follows (in thousands):


	For the year ended December 31,
	2020		2019 1		2018
Cash proceeds from options exercised	$	—	$	32	$	273
Aggregate intrinsic value of options exercised	$	—	$	4,530	$	277

____________________

Schedule of Stock Options Activity


	For the years ended December 31,
	2020			2019			2018
	Common Stock Options	Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price
Outstanding at beginning of year:	5	$	22.35	2,105	$	13.47	2,130	$	13.43
Granted	—	$	—	—	$	—	—	$	—
Exercised	—	$	—	(2,093)	$	13.45	(25)	$	10.75
Expired or forfeited	—	$	—	(7)	$	10.00	—	$	—
Outstanding at end of year:	5	$	22.35	5	$	22.35	2,105	$	13.47

Schedule of Stock Options Outstanding and Exercisable


			December 31, 2020
			Options Outstanding			Options Exercisable
Exercise Price	Total Options Outstanding		Weighted Average Remaining Life (Years)	Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
22.35	5		1.2	$	22.35	5		$	22.35


Aggregate Intrinsic Value	$	—				$	—

Schedule of Vesting Activity of Restricted Stock Units

A summary of the vesting activity of restricted stock unit awards, with the respective fair value of the awards, is as follows: (in thousands):


	For the year ended December 31,
	2020		2019		2018
Restricted stock awards vested	208		172		258
Fair value of awards vested	$	837	$	2,495	$	5,319

Schedule of Fully-vested Common Stocks Issued to Non-employee Directors

A summary of the fully-vested common stock the Company issued to its six non-employee directors, in connection with its non-employee director compensation plan, is as follows (in thousands):


	For the year ended December 31,
	2020		2019		2018
Awards issued	68		30		19
Grant date fair value of awards issued	$	326	$	450	$	400

Schedule of Non-vested Restricted Share Units

A summary of the Company's outstanding, non-vested restricted share units is presented below (in thousands, except per share amounts):


	For the year ended December 31,
	2020			2019			2018
	Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	559	$	16.92	443	$	20.55	532	$	21.05
Granted	782	$	3.79	339	$	14.04	211	$	19.20
Released	(208)	$	18.71	(172)	$	20.38	(258)	$	20.48
Forfeited	(57)	$	9.62	(51)	$	17.71	(42)	$	20.52
Outstanding at end of period:	1,076	$	7.41	559	$	16.92	443	$	20.55

Schedule of Performance Shares Units Activity

A summary of the Company's PRSU activity is presented below (in thousands, except per share amounts):


	For the year ended December 31,
	2020			2019			2018
	Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value		Units	Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	260	$	16.77	277	$	17.80	278	$	17.00
Granted	292	$	3.68	190	$	13.63	129	$	19.46
Performance condition adjustments, net	(99)	$	3.82	(106)	$	13.77	(50)	$	19.48
Released	(120)	$	17.29	(101)	$	17.19	(68)	$	16.03
Forfeited	—	$	—	—	$	—	(12)	$	16.16
Outstanding at end of period:	333	$	8.84	260	$	16.77	277	$	17.80

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Income (Loss) Before Provision for Income Taxes

Income (loss) before provision for income taxes is as follows:


	For the year ended December 31,
	2020		2019		2018
Income (loss) before provision for income taxes from:
U.S. operations	$	(54,190)	$	7,334	$	9,853
Foreign operations	(59,982)		3,105		4,418
Income (loss) before income taxes	$	(114,172)	$	10,439	$	14,271

Schedule of Provision (Benefit) for Income Taxes

The provision for income taxes consists of the following:


	For the year ended December 31,
	2020		2019		2018
Current
Federal	$	(6,278)	$	2,712	$	790
States and local	528		519		533
Foreign	4,006		4,572		3,824
Reserve for uncertain tax positions	(28)		99		337
Total current provision (benefit)	(1,772)		7,902		5,484
Deferred
Federal	(2,781)		315		2,966
States and local	(1,244)		(32)		399
Foreign	(10,045)		(4,095)		(2,089)
Total deferred provision (benefit)	(14,070)		(3,812)		1,276
Net change in valuation allowance	1,136		269		666
Net deferred provision (benefit)	(12,934)		(3,543)		1,942
Total provision (benefit) for income taxes	$	(14,706)	$	4,359	$	7,426

Schedule of Provision (Benefit) for Income Taxes Computed by Applying Statutory Federal Tax Rate

The provision (benefit) for income taxes differs from the amount computed by applying the statutory federal tax rate to income tax as follows:


	For the years ended December 31,
	2020				2019				2018
Federal tax at statutory rate	$	(23,976)	21.0	%	$	2,192	21.0	%	$	2,997	21.0	%
State taxes, net of federal benefit	(1,175)		1.0	%	377		3.6	%	737		5.1	%
Foreign tax	(815)		0.7	%	982		9.4	%	807		5.7	%
Goodwill impairment	10,003		(8.8)	%	—		—	%	—		—	%
Nondeductible compensation	975		(0.9)	%	1,581		15.2	%	183		1.3	%
US taxation of foreign earnings	56		—	%	213		2.0	%	228		1.6	%
Permanent differences	944		(0.8)	%	464		4.4	%	361		2.5	%
Transition tax, net of foreign tax credits	—		—	%	—		—	%	1,158		8.1	%
Federal loss carryback	(1,938)		1.7	%	—		—	%	—		—	%

Change in valuation allowance	1,136		(1.0)	%	269		2.6	%	666		4.7	%
Impact of foreign tax rate changes	392		(0.3)	%	(1,882)		(18.0)	%	—		—	%
Other	(308)		0.3	%	163		1.6	%	289		2.0	%
Total provision (benefit) for income taxes	$	(14,706)	12.9	%	$	4,359	41.8	%	$	7,426	52.0	%

Schedule of Net Deferred Income Tax Assets and Liabilities

Deferred income tax attributes resulting from differences between financial accounting amounts and income tax basis of assets and liabilities are as follows:


	December 31,
	2020		2019
Deferred income tax assets
Allowance for doubtful accounts	$	1,054	$	1,186
Inventory	459		359
Intangible assets	2,000		1,795
Accrued expenses	6,818		4,421
Net operating loss carryforward	4,190		3,832
Finance lease obligations	942		1,067
Capital losses	—		463
Deferred stock based compensation	920		1,145
Interest carryforward	—		1,372
Right-of-use liability	11,970		11,891
Credits	312		—
Other	1,507		398
Deferred income tax assets	30,172		27,929
Valuation allowance	(4,540)		(4,067)
Net deferred income tax assets	25,632		23,862
Deferred income tax liabilities
Property and equipment	(9,109)		(6,485)
Goodwill	(4,639)		(10,652)
Intangible assets	(6,058)		(14,311)
Right-of-use asset	(11,924)		(11,891)
Other	(69)		(27)
Deferred income tax liabilities	(31,799)		(43,366)
Net deferred income taxes	(6,167)		(19,504)

Schedule of Changes in Company's Gross Unrecognized Tax Benefits, Excluding Interest and Penalties

The following table summarizes the changes in the Company’s gross unrecognized tax benefits, excluding interest and penalties:


	For the year ended December 31,
	2020		2019
Balance at beginning of period	$	393	$	723
Additions for tax positions related to the current fiscal period	—		—
Additions for tax positions related to prior years	32		217
Decreases for tax positions related to prior years	—		—
Current year acquisitions	—		—
Impact of foreign exchange fluctuation	(5)		13
Settlements	—		(465)
Reductions related to the expiration of statutes of limitations	(73)		(95)
Balance at end of period	$	347	$	393

Leases (Tables)

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Schedule of Supplemental Balance Sheet Information

The Company’s Consolidated Balance Sheets include the following related to operating leases as of December 31, 2020 and 2019:


Leases	Classification	2020		2019
Assets:
ROU assets	Other Assets	$	46,728	$	45,817

Liabilities:
ROU liability - current	Accrued and other current liabilities	$	10,348	$	10,133
ROU liability - long-term	Other liabilities	37,689		36,750
Total ROU liabilities		$	48,037	$	46,883

Schedule of Components of Lease Costs and Other Information Related to Leases

The components of lease costs for the year ended December 31, 2020 and 2019 are as follows:


	Classification	2020		2019
Finance lease expense:
Amortization of ROU assets	Depreciation and amortization	$	4,544	$	5,091
Interest on lease liabilities	Interest expense	847		824
Operating lease expense	Cost of revenue; Selling, general & administrative expenses	13,383		12,937
Short-term lease expense	Cost of revenue; Selling, general & administrative expenses	66		43
Variable lease expense	Cost of revenue; Selling, general & administrative expenses	838		1,220
Total		$	19,678	$	20,115

Additional information related to leases as of December 31, 2020 and 2019 is as follows:


	2020			2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases:
Finance - financing cash flows	$	4,095		$	4,545
Finance - operating cash flows	847			824
Operating - operating cash flows	13,246			12,773
ROU assets obtained in the exchange for lease liabilities:
Finance leases	$	2,849		9,502
Operating leases	9,934			18,965
Weighted-average remaining lease term (in years):
Finance leases	5.7			5.9
Operating leases	5.8			6.2
Weighted-average discount rate:
Finance leases	5.7		%	5.8		%
Operating leases	5.7		%	5.9		%

Schedule of Maturities of Operating Lease Liabilities

Maturities of lease liabilities as of December 31, 2020 is as follows:


	Finance		Operating
2021	$	5,353	$	12,588
2022	4,087		10,495
2023	3,194		8,907
2024	2,261		7,042
2025	688		5,150
Thereafter	754		12,258
Total	16,337		56,440
Less: Present value discount	1,457		8,403
Lease liability	$	14,880	$	48,037

Schedule of Maturities of Finance Lease Liabilities

Maturities of lease liabilities as of December 31, 2020 is as follows:


	Finance		Operating
2021	$	5,353	$	12,588
2022	4,087		10,495
2023	3,194		8,907
2024	2,261		7,042
2025	688		5,150
Thereafter	754		12,258
Total	16,337		56,440
Less: Present value discount	1,457		8,403
Lease liability	$	14,880	$	48,037

Segment Disclosure (Tables)

12 Months Ended

Dec. 31, 2020

Segment Reporting [Abstract]

Schedule of Financial Information by Segment

Selected financial information by segment for the periods shown was as follows (intercompany transactions are eliminated in Corporate and eliminations):


	For the year ended December 31,
	2020		2019		2018
Revenues
Services	$	476,164	$	595,130	$	574,619
International	107,556		144,271		153,448
Products and Systems	16,449		18,583		23,426
Corporate and eliminations	(7,598)		(9,398)		(9,139)
	$	592,571	$	748,586	$	742,354


	For the year ended December 31,
	2020		2019		2018
Gross profit
Services	$	141,084	$	165,513	$	151,974
International	31,046		43,145		45,464
Products and Systems	6,826		8,639		10,560
Corporate and eliminations	(425)		—		(124)
	$	178,531	$	217,297	$	207,874

Income (loss) from operations by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations.


	For the year ended December 31,
	2020		2019		2018
Income (loss) from operations
Services	$	(44,222)	$	49,593	$	47,126
International	(21,855)		5,856		3,953
Products and Systems	(936)		(529)		2,368
Corporate and eliminations	(34,204)		(30,783)		(31,226)
	$	(101,217)	$	24,137	$	22,221


	For the year ended December 31,
	2020		2019		2018
Depreciation and amortization
Services	$	26,093	$	28,854	$	24,079
International	8,659		8,285		8,846
Products and Systems	998		1,213		1,429
Corporate and eliminations	(45)		181		59
	$	35,705	$	38,533	$	34,413


	December 31,
	2020		2019
Intangible assets, net
Services	$	58,917	$	98,284
International	8,664		9,814
Products and Systems	1,012		1,181
Corporate and eliminations	49		258
	$	68,642	$	109,537


	December 31,
	2020		2019
Total assets
Services	$	427,636	$	537,518
International	129,228		153,380
Products and Systems	10,996		16,028
Corporate and eliminations	15,453		12,952
	$	583,313	$	719,878

Schedule of Long-lived Assets by Geographic Area


	December 31,
	2020		2019
Long-lived assets
United States	$	187,251	$	233,679
Other Americas	123,924		181,550
Europe	56,156		75,325
	$	367,331	$	490,554

Selected Quarterly Financial Information (unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

Schedule of Selected Quarterly Results of Operations

The following is a summary of the quarterly results of operations for calendar years 2020, 2019, and 2018.


Quarter ended	December 31, 2020		September 30, 2020		June 30, 2020		March 31, 2020
Revenues	$	160,777	$	147,894	$	124,435	$	159,465
Gross Profit	49,345		47,384		41,158		40,644
Income (loss) from operations	4,652		5,742		(383)		(111,228)
Net income (loss) attributable to Mistras Group, Inc.	$	181	$	1,523	$	(2,656)	$	(98,509)
Earnings (loss) per common share:
Basic	$	0.01	$	0.05	$	(0.09)	$	(3.40)
Diluted	$	0.01	$	0.05	$	(0.09)	$	(3.40)


Quarter ended	December 31, 2019		September 30, 2019		June 30, 2019		March 31, 2019
Revenues	$	178,991	$	192,192	$	200,616	$	176,787
Gross Profit	50,583		57,769		60,071		48,874
Income from operations	2,335		10,779		15,419		(4,396)
Net income (loss) attributable to Mistras Group, Inc.	$	829	$	3,093	$	7,431	$	(5,293)
Earnings (loss) per common share:
Basic	$	0.03	$	0.11	$	0.26	$	(0.19)
Diluted	$	0.03	$	0.11	$	0.26	$	(0.19)


Quarter ended	December 31, 2018		September 30, 2018		June 30, 2018		March 31, 2018
Revenues	$	180,762	$	182,169	$	191,793	$	187,630
Gross Profit	52,315		52,332		55,083		48,144
Income (loss) from operations	2,502		3,017		10,304		6,398
Net income (loss) attributable to Mistras Group, Inc.	$	(1,061)	$	(1,011)	$	6,000	$	2,908
Earnings (loss) per common share:
Basic	$	(0.04)	$	(0.04)	$	0.21	$	0.10
Diluted	$	(0.04)	$	(0.04)	$	0.20	$	0.10

Summary of Significant Accounting Policies and Practices (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Net provision for expected credit losses		$ 700,000
Foreign currency gains (losses)		3,100,000	$ (500,000)	$ 1,300,000
Minimum amount of excess self-insurance claims paid to reduce exposure		300,000
Limited Partnership \| Variable Interest Entity, Primary Beneficiary
Concentration Risk [Line Items]
Limited partnership ownership interest percentage	49.00%
General partnership ownership interest percentage	49.00%
Revenues		0
Selling, General and Administrative Expenses
Concentration Risk [Line Items]
Advertising expense		$ 800,000	$ 2,100,000	$ 2,100,000
Software/Technology
Concentration Risk [Line Items]
Estimated useful life of internal-use software		3 years

Revenue - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Revenue - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized that was included in contract liability balance at the beginning of the year	$ 4.6	$ 4.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction period	1 year

Revenue - Disaggregated Revenues by Segment (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 160,777	$ 147,894	$ 124,435	$ 159,465	$ 178,991	$ 192,192	$ 200,616	$ 176,787	$ 180,762	$ 182,169	$ 191,793	$ 187,630	$ 592,571	$ 748,586	$ 742,354
United States
Disaggregation of Revenue [Line Items]
Revenue													411,489	495,132	487,414
Other Americas
Disaggregation of Revenue [Line Items]
Revenue													72,835	111,740	98,248
Europe
Disaggregation of Revenue [Line Items]
Revenue													100,541	127,885	143,312
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													7,706	13,829	13,380
Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													338,763	436,018	418,112
Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													70,271	93,851	107,708
Industrials
Disaggregation of Revenue [Line Items]
Revenue													66,428	89,214	89,900
Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenue													39,887	43,315	44,113
Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													34,871	39,109	36,046
Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													33,787	33,105	25,561
Other
Disaggregation of Revenue [Line Items]
Revenue													8,564	13,974	20,914
Operating segments \| Services
Disaggregation of Revenue [Line Items]
Revenue													476,164	595,130	574,619
Operating segments \| Services \| United States
Disaggregation of Revenue [Line Items]
Revenue													406,437	487,408	478,853
Operating segments \| Services \| Other Americas
Disaggregation of Revenue [Line Items]
Revenue													68,150	104,081	90,823
Operating segments \| Services \| Europe
Disaggregation of Revenue [Line Items]
Revenue													904	2,342	4,252
Operating segments \| Services \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													673	1,299	691
Operating segments \| Services \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													298,605	390,815	378,904
Operating segments \| Services \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													50,813	51,390	50,500
Operating segments \| Services \| Industrials
Disaggregation of Revenue [Line Items]
Revenue													44,919	64,622	60,594
Operating segments \| Services \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenue													30,005	30,300	30,687
Operating segments \| Services \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													24,671	28,495	26,425
Operating segments \| Services \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													17,070	14,269	11,283
Operating segments \| Services \| Other
Disaggregation of Revenue [Line Items]
Revenue													10,081	15,239	16,226
Operating segments \| International
Disaggregation of Revenue [Line Items]
Revenue													107,556	144,271	153,448
Operating segments \| International \| United States
Disaggregation of Revenue [Line Items]
Revenue													911	631	568
Operating segments \| International \| Other Americas
Disaggregation of Revenue [Line Items]
Revenue													4,581	7,659	7,995
Operating segments \| International \| Europe
Disaggregation of Revenue [Line Items]
Revenue													99,953	127,581	138,948
Operating segments \| International \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													2,111	8,400	5,937
Operating segments \| International \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													39,728	44,447	37,953
Operating segments \| International \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													18,166	41,224	54,853
Operating segments \| International \| Industrials
Disaggregation of Revenue [Line Items]
Revenue													19,657	21,405	26,209
Operating segments \| International \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenue													7,559	10,289	8,522
Operating segments \| International \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													10,029	10,196	9,497
Operating segments \| International \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													10,353	9,520	9,032
Operating segments \| International \| Other
Disaggregation of Revenue [Line Items]
Revenue													2,064	7,190	7,382
Operating segments \| Products & Systems
Disaggregation of Revenue [Line Items]
Revenue													16,449	18,583	23,426
Operating segments \| Products & Systems \| United States
Disaggregation of Revenue [Line Items]
Revenue													7,551	12,011	11,493
Operating segments \| Products & Systems \| Other Americas
Disaggregation of Revenue [Line Items]
Revenue													550	407	1,068
Operating segments \| Products & Systems \| Europe
Disaggregation of Revenue [Line Items]
Revenue													3,154	1,940	3,958
Operating segments \| Products & Systems \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													5,194	4,225	6,907
Operating segments \| Products & Systems \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													430	756	1,255
Operating segments \| Products & Systems \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													1,292	1,237	2,355
Operating segments \| Products & Systems \| Industrials
Disaggregation of Revenue [Line Items]
Revenue													1,852	3,187	3,097
Operating segments \| Products & Systems \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenue													2,323	2,726	4,904
Operating segments \| Products & Systems \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													171	418	124
Operating segments \| Products & Systems \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													6,364	9,316	5,246
Operating segments \| Products & Systems \| Other
Disaggregation of Revenue [Line Items]
Revenue													4,017	943	6,445
Corp/Elim
Disaggregation of Revenue [Line Items]
Revenue													(7,598)	(9,398)	(9,139)
Corp/Elim \| United States
Disaggregation of Revenue [Line Items]
Revenue													(3,410)	(4,918)	(3,500)
Corp/Elim \| Other Americas
Disaggregation of Revenue [Line Items]
Revenue													(446)	(407)	(1,638)
Corp/Elim \| Europe
Disaggregation of Revenue [Line Items]
Revenue													(3,470)	(3,978)	(3,846)
Corp/Elim \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													(272)	(95)	(155)
Corp/Elim \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Industrials
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim \| Other
Disaggregation of Revenue [Line Items]
Revenue													$ (7,598)	$ (9,398)	$ (9,139)

Earnings per Share - Computations of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic earnings (loss) per share:
Net income (loss) attributable to Mistras Group, Inc.	$ 181	$ 1,523	$ (2,656)	$ (98,509)	$ 829	$ 3,093	$ 7,431	$ (5,293)	$ (1,061)	$ (1,011)	$ 6,000	$ 2,908	$ (99,461)	$ 6,060	$ 6,836
Denominator
Weighted average common shares outstanding (in shares)													29,147	28,740	28,406
Basic earnings (loss) per share (in dollars per share)	$ 0.01	$ 0.05	$ (0.09)	$ (3.40)	$ 0.03	$ 0.11	$ 0.26	$ (0.19)	$ (0.04)	$ (0.04)	$ 0.21	$ 0.10	$ (3.41)	$ 0.21	$ 0.24
Denominator
Weighted average common shares outstanding (in shares)													29,147	28,740	28,406
Dilutive effect of stock options outstanding (in shares)													0	98	683
Dilutive effect of restricted stock units outstanding (in shares)													0	208	338
Weighted average common shares outstanding, diluted (in shares)													29,147	29,046	29,427
Diluted earnings (loss) per share (in dollars per share)	$ 0.01	$ 0.05	$ (0.09)	$ (3.40)	$ 0.03	$ 0.11	$ 0.26	$ (0.19)	$ (0.04)	$ (0.04)	$ 0.20	$ 0.10	$ (3.41)	$ 0.21	$ 0.23

Earnings per Share - Potential Common Shares Excluded From Computation of Diluted Earnings (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted earnings per share (in shares)	795	47	6
RSUs/PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted earnings per share (in shares)	790	42	1
Potential common shares excluded from computation of diluted earnings per share due to net loss for the period (in shares)	254
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from computation of diluted earnings per share (in shares)	5	5	5

Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Trade accounts receivable	$ 115,841	$ 144,282
Allowance for credit losses	(8,213)	(8,285)
Accounts receivable, net	$ 107,628	$ 135,997

Accounts Receivable - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Unbilled revenues	$ 22,200				$ 11,900	$ 22,200
Concentration Risk [Line Items]
Accounts receivable, net	135,997				107,628	135,997
Credit loss reserve (reversal)					$ 0	3,038	$ 650
Texas Customer
Concentration Risk [Line Items]
Accounts receivable, net	1,400					$ 1,400
Verbal demand for damages	$ 1,400
Renewable Energy Industry Customer \| Services
Concentration Risk [Line Items]
Credit loss reserve (reversal)		$ (1,000)	$ 5,700	$ 700
Recoveries of allowance for credit losses		$ 1,700	$ 200

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 5,006	$ 5,314
Work in progress	770	1,549
Finished goods	4,640	3,957
Consumable supplies	2,718	2,593
Inventories	$ 13,134	$ 13,413

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 282,688	$ 270,410
Accumulated depreciation and amortization	(190,007)	(171,803)
Property, plant and equipment, net	92,681	98,607
Depreciation expense	24,700	24,200	$ 24,200
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	2,724	2,672
Building and improvements
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 25,731	24,537
Building and improvements \| Minimum
Property, Plant and Equipment, net
Useful Life	30 years
Building and improvements \| Maximum
Property, Plant and Equipment, net
Useful Life	40 years
Office furniture and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 16,980	17,227
Office furniture and equipment \| Minimum
Property, Plant and Equipment, net
Useful Life	5 years
Office furniture and equipment \| Maximum
Property, Plant and Equipment, net
Useful Life	8 years
Machinery and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 237,253	$ 225,974
Machinery and equipment \| Minimum
Property, Plant and Equipment, net
Useful Life	5 years
Machinery and equipment \| Maximum
Property, Plant and Equipment, net
Useful Life	7 years

Acquisitions and Disposition - Acquisition Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 entity	Dec. 31, 2019 USD ($) entity
Business Acquisition [Line Items]
Number of acquisitions \| entity	0
Acquiree That Provides Pipeline Integrity Management Software
Business Acquisition [Line Items]
Number of acquisitions \| entity		1
Cash consideration paid \| $		$ 4,380
Potential acquisition-related contingent consideration, high end of range \| $		$ 4,300
Period over which potential acquisition-related contingent consideration would be payable		3 years
Acquiree That Provides Pipeline Integrity Management Software \| Minimum
Business Acquisition [Line Items]
Amortization period of intangible assets acquired		1 year
Acquiree That Provides Pipeline Integrity Management Software \| Maximum
Business Acquisition [Line Items]
Amortization period of intangible assets acquired		18 years

Acquisitions and Disposition - Estimated Fair Value of the Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2018
Estimated fair value of the assets acquired and liabilities assumed
Goodwill	$ 282,410	$ 206,008	$ 279,259
Acquiree That Provides Pipeline Integrity Management Software
Consideration transferred:
Cash paid	4,380
Working capital adjustments	(152)
Fair value of contingent consideration	1,342
Total consideration	5,570
Estimated fair value of the assets acquired and liabilities assumed
Current net assets	142
Other assets	34
Property, plant and equipment	65
Intangibles	3,594
Goodwill	1,735
Net assets acquired	$ 5,570

Acquisitions and Disposition - Dispositions Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of subsidiary		$ 0	$ 0	$ 2,384
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Disposal of Foreign Subsidiaries \| Products and Systems
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration received on sale of subsidiary	$ 4,300
Gain on sale of subsidiary	$ 2,400
Term of agreement to purchase products from buyer on sale of subsidiary	3 years

Acquisitions and Disposition - Acquisition-Related Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Combinations [Abstract]
Due diligence, professional fees and other transaction costs	$ 0	$ 364	$ 1,248
Adjustments to fair value of contingent consideration liabilities	337	511	(716)
Acquisition-related expense, net	$ 337	$ 875	$ 532

Goodwill - Changes in Carrying Amount of Goodwill (Details) - USD ($)		12 Months Ended
	Oct. 01, 2020	Dec. 31, 2020	Dec. 31, 2019
Changes in the carrying amount of goodwill
Balance at the beginning of the period		$ 282,410,000	$ 279,259,000
Goodwill acquired during the year			1,535,000
Impairment charges	$ 0	(77,089,000)
Adjustments to preliminary purchase price allocations		200,000	(2,332,000)
Foreign currency translation		487,000	3,948,000
Balance at the end of the period		206,008,000	282,410,000
Services
Changes in the carrying amount of goodwill
Balance at the beginning of the period		247,215,000	243,476,000
Goodwill acquired during the year			1,535,000
Impairment charges		(57,227,000)
Adjustments to preliminary purchase price allocations		200,000	(2,332,000)
Foreign currency translation		(76,000)	4,536,000
Balance at the end of the period		190,112,000	247,215,000
International
Changes in the carrying amount of goodwill
Balance at the beginning of the period		35,195,000	35,783,000
Goodwill acquired during the year			0
Impairment charges		(19,862,000)
Adjustments to preliminary purchase price allocations		0	0
Foreign currency translation		563,000	(588,000)
Balance at the end of the period		15,896,000	35,195,000
Products and Systems
Changes in the carrying amount of goodwill
Balance at the beginning of the period		0	0
Goodwill acquired during the year			0
Impairment charges		0
Adjustments to preliminary purchase price allocations		0	0
Foreign currency translation		0	0
Balance at the end of the period		$ 0	$ 0

Goodwill - Narrative (Details) - USD ($)		3 Months Ended	12 Months Ended
Goodwill - Narrative (Details) - USD ($)	Oct. 01, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Goodwill
Impairment charges	$ 0		$ 77,089,000
Cumulative goodwill impairment			100,200,000	$ 23,100,000
Services
Goodwill
Cumulative goodwill impairment			57,200,000
Products and Systems
Goodwill
Cumulative goodwill impairment			13,200,000	13,200,000
International
Goodwill
Cumulative goodwill impairment			$ 29,800,000	$ 9,900,000
COVID-19
Goodwill
Impairment charges		$ 77,100,000
COVID-19 \| Services
Goodwill
Impairment charges		57,200,000
COVID-19 \| European Reporting Unit
Goodwill
Impairment charges		19,300,000
COVID-19 \| Brazilian Reporting Unit
Goodwill
Impairment charges		$ 600,000

Intangible Assets - Gross Carrying Amount and Accumulated Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 217,380	$ 215,383
Accumulated Amortization	(119,944)	(105,846)
Impairment	(28,794)
Net Carrying Amount	68,642	109,537
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	116,101	113,861
Accumulated Amortization	(75,649)	(67,853)
Impairment	(2,206)
Net Carrying Amount	$ 38,246	46,008
Customer relationships \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	5 years
Customer relationships \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	18 years
Software/Technology
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	3 years
Gross Amount	$ 77,326	77,914
Accumulated Amortization	(23,519)	(18,756)
Impairment	(25,874)
Net Carrying Amount	$ 27,933	59,158
Software/Technology \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	3 years
Software/Technology \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	15 years
Covenants not to compete
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 12,833	12,795
Accumulated Amortization	(12,162)	(11,630)
Impairment	(212)
Net Carrying Amount	$ 459	1,165
Covenants not to compete \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	2 years
Covenants not to compete \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	5 years
Other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 11,120	10,813
Accumulated Amortization	(8,614)	(7,607)
Impairment	(502)
Net Carrying Amount	$ 2,004	$ 3,206
Other \| Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	2 years
Other \| Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (Years)	12 years

Intangible Assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of expense of intangible assets		$ 11.0	$ 14.3	$ 10.2
Services \| COVID-19
Finite-Lived Intangible Assets [Line Items]
Impairment charge of long-lived assets	$ 28.8
Software/Technology
Finite-Lived Intangible Assets [Line Items]
Amortization of expense of intangible assets		$ 3.6	$ 5.6	$ 1.4
Software/Technology \| Services \| COVID-19
Finite-Lived Intangible Assets [Line Items]
Impairment charge of long-lived assets	25.9
Customer relationships \| Services \| COVID-19
Finite-Lived Intangible Assets [Line Items]
Impairment charge of long-lived assets	2.2
Other \| Services \| COVID-19
Finite-Lived Intangible Assets [Line Items]
Impairment charge of long-lived assets	0.5
Covenants not to compete \| Services \| COVID-19
Finite-Lived Intangible Assets [Line Items]
Impairment charge of long-lived assets	$ 0.2

Intangible Assets - Expected Amortization Expense (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 9,915
2022	9,433
2023	8,719
2024	7,355
2025	5,597
Thereafter	27,623
Net Carrying Amount	$ 68,642

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued salaries, wages and related employee benefits	$ 30,214	$ 30,072
Contingent consideration	1,300	2,614
Accrued workers' compensation and health benefits	3,948	4,467
Deferred revenues	6,538	5,860
Right-of-use liability - Operating	10,348	10,133
Pension accrual	2,519	2,519
Other accrued expenses	23,633	25,724
Total accrued expenses and other current liabilities	$ 78,500	$ 81,389

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total debt	$ 220,216	$ 254,713
Less: Current portion	(10,678)	(6,593)
Long-term debt, net of current portion	209,538	248,120
Senior credit facility
Debt Instrument [Line Items]
Total debt	120,312	151,773
Senior credit facility \| Senior Secured Term Loan
Debt Instrument [Line Items]
Unamortized debt issuance costs	300	100
Total debt	89,745	94,919
Other
Debt Instrument [Line Items]
Total debt	$ 10,159	$ 8,021

Long-Term Debt - Narrative (Details)		3 Months Ended	12 Months Ended
Long-Term Debt - Narrative (Details)	May 15, 2020 USD ($) d	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Other debt outstanding			$ 220,216,000	$ 254,713,000
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity in non-U.S. Dollar currencies			100,000,000
Maximum amount available for the issuance of letters of credit			20,000,000
Borrowings outstanding under line of credit			210,100,000
Outstanding letters of credit			4,300,000
Capitalized debt modification costs			1,100,000
Capitalized debt issuance costs expensed		$ 600,000
Other debt outstanding			120,312,000	151,773,000
Revolving Credit Facility \| Senior Secured Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity			100,000,000
Other debt outstanding			89,745,000	94,919,000
Revolving Credit Facility \| Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 300,000,000
Revolving Credit Facility \| Credit Agreement \| COVID-19
Debt Instrument [Line Items]
Maximum borrowing capacity			175,000,000
Amount deducted from aggregate cash and cash equivalents held by company and it's subsidiaries if prepayment of credit facility is required	$ 10,000,000.0
Number of consecutive business days \| d	2
Maximum amount outstanding under the revolving credit facility if prepayment of facility is required	$ 75,000,000.0
Cash and cash equivalents if prepayment of facility is required	$ 10,000,000.0
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Maximum
Debt Instrument [Line Items]
Funded debt leverage ratio temporarily increase due to business acquisitions	2.50
Pro forma funded debt leverage ratio	3.25
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| LIBOR
Debt Instrument [Line Items]
Margin rate (as a percent)	1.00%
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| LIBOR \| Minimum
Debt Instrument [Line Items]
Margin rate (as a percent)	1.50%
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| LIBOR \| Maximum
Debt Instrument [Line Items]
Margin rate (as a percent)	4.15%
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Quarter ending December 31, 2020 and decreasing each successive quarter
Debt Instrument [Line Items]
Funded debt leverage ratio for additional interest payment	5.25
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Quarter ending September 30, 2021 and all quarterly periods thereafter
Debt Instrument [Line Items]
Funded debt leverage ratio for additional interest payment	3.50
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Quarter ending March 31, 2021
Debt Instrument [Line Items]
Interest coverage ratio	1.0
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Quarter ending June 30, 2021
Debt Instrument [Line Items]
Interest coverage ratio	1.25
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Three months ending June 30, 2020
Debt Instrument [Line Items]
Debt covenant, minimum EBITDA, amount	$ 3,440,000
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Six months ending September 30, 2020
Debt Instrument [Line Items]
Debt covenant, minimum EBITDA, amount	24,250,000
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Nine months ending December 31, 2020
Debt Instrument [Line Items]
Debt covenant, minimum EBITDA, amount	38,550,000
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| Thereafter
Debt Instrument [Line Items]
Debt covenant, minimum EBITDA, amount	0
Revolving Credit Facility \| Credit Agreement \| COVID-19 \| At all times through September 30, 2021
Debt Instrument [Line Items]
Debt covenant, minimum EBITDA, amount	$ 20,000,000.0
Other
Debt Instrument [Line Items]
Other debt outstanding			10,159,000	$ 8,021,000
Other \| Minimum
Debt Instrument [Line Items]
Monthly debt payments			$ 1,000
Interest rate			0.40%
Other \| Maximum
Debt Instrument [Line Items]
Monthly debt payments			$ 18,000
Interest rate			3.50%

Long-Term Debt - Scheduled Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
2021	$ 10,678
2022	11,551
2023	194,191
2024	1,282
2025	799
Thereafter	1,715
Total debt	$ 220,216	$ 254,713

Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contingent Consideration Liability [Roll Forward]
Revaluation	$ 337	$ 511	$ (716)
Level 3
Contingent Consideration Liability [Roll Forward]
Contingent consideration, beginning balance	3,216	2,365
Acquisitions	200	1,142
Payments	(2,091)	(852)
Accretion of liability	35	92
Revaluation	302	419
Foreign currency translation	(22)	50
Contingent consideration, ending balance	$ 1,640	$ 3,216	$ 2,365

Share-Based Compensation - Long-term Incentive Plans (Details)		12 Months Ended
	May 19, 2020 shares	Dec. 31, 2020 plan shares	Dec. 31, 2019 shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares
Share-based compensation
Number of employee stock ownership plans \| plan		2
Stock options outstanding (in shares)		5,000	5,000	2,105,000	2,130,000
2009 Plan
Share-based compensation
Number of awards authorized for grants (in shares)		0
2016 Plan
Share-based compensation
Number of awards authorized for grants (in shares)	3,700,000
Increase in number of shares authorized for grant (in shares)	2,000,000
Number of awards available for future grants (in shares)		1,787,000
Stock options outstanding (in shares)		5,000

Share-Based Compensation - Stock Options Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based compensation
Stock options granted (in shares)	0	0	0
Unrecognized compensation costs related to stock options	$ 0
Stock Options
Share-based compensation
Recognized share-based compensation expense	$ 0	$ 0	$ 0

Share-Based Compensation - Cash Proceeds and Intrinsic Value of Stock Options Exercised (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Cash proceeds from options exercised	$ 0	$ 32	$ 273
Aggregate intrinsic value of options exercised	$ 0	$ 4,530	$ 277
Options exercised, net (in shares)		2.1

Share-Based Compensation - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Common Stock Options (shares)
Outstanding at beginning of year: (in shares)	5,000	2,105,000	2,130,000
Granted (in shares)	0	0	0
Exercised (in shares)	0	(2,093,000)	(25,000)
Expired or forfeited (in shares)	0	(7,000)	0
Outstanding at end of year: (in shares)	5,000	5,000	2,105,000
Weighted Average Exercise Price (in dollar per share)
Outstanding at beginning of year: (in dollars per share)	$ 22.35	$ 13.47	$ 13.43
Granted (in dollars per share)	0	0	0
Exercised (in dollars per share)	0	13.45	10.75
Expired or forfeited (in dollars per share)	0	10.00	0
Outstanding at end of year: (in dollars per share)	$ 22.35	$ 22.35	$ 13.47

Share-Based Compensation - Stock Options Outstanding and Exercisable (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Aggregate Intrinsic Value
Options Outstanding (in dollars) \| $	$ 0
Options Exercisable (in dollars) \| $	$ 0
22.35
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 22.35
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 22.35
Options Outstanding
Total Options Outstanding (in shares) \| shares	5
Weighted Average Remaining Life (Years)	1 year 2 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 22.35
Options Exercisable
Number Exercisable (in shares) \| shares	5
Weighted Average Exercise Price (in dollars per share)	$ 22.35

Share-Based Compensation - Restricted Stock Units Awards Narrative (Details) - Restricted Stock Units - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based compensation
Recognized share-based compensation expense	$ 4.4	$ 4.0	$ 4.2
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards	$ 4.9
Weighted-average period over which unrecognized compensation cost is expected to be recognized	2 years 3 months 18 days

Share-Based Compensation - Vesting Activity of Restricted Stock Unit Awards (Details) - Restricted Stock Units - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based compensation
Restricted stock awards vested	208	172	258
Fair value of awards vested	$ 837	$ 2,495	$ 5,319

Share-Based Compensation - Common Stock Issued to Non-employee Directors (Details) - Non-employee directors - Common Stock shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) director shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares
Share-based compensation
Number of non-employee directors to whom fully vested common stock is granted \| director	6
Awards issued (in shares) \| shares	68	30	19
Grant date fair value of awards issued (in dollars per share) \| $	$ 326	$ 450	$ 400

Share-Based Compensation - Restricted Stock Unit Awards Outstanding (Details) - Restricted Stock Units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period: (in shares)	559	443	532
Granted (in shares)	782	339	211
Released (in shares)	(208)	(172)	(258)
Forfeited (in shares)	(57)	(51)	(42)
Outstanding at end of period: (in shares)	1,076	559	443
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period: (in dollars per share)	$ 7.41	$ 16.92	$ 20.55	$ 21.05
Granted (in dollars per share)	3.79	14.04	19.20
Released (in dollars per share)	18.71	20.38	20.48
Forfeited (in dollars per share)	9.62	17.71	20.52
Outstanding at end of period: (in dollars per share)	$ 7.41	$ 16.92	$ 20.55	$ 21.05

Share-Based Compensation - Performance Restricted Stock Units Narrative (Details) - PRSUs shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019 shares	Dec. 31, 2020 USD ($) metric shares	Dec. 31, 2019 USD ($) metric shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 shares
Share-based compensation
Number of metrics \| metric		4
Number of additional metrics \| metric		2
Number of restricted stocks units granted (in shares)		292	190	129
Net reduction in number of awards with performance below target (in shares)		99	106	50
Increase in number of awards against target performance (in shares)			1
Reduction in number of awards with performance below target (in shares)	3		103	54
Unvested restricted stock units outstanding (in shares)		333	260	277	278
Accrued Expenses and Other Current Liabilities
Share-based compensation
Aggregate liability related to performance shares outstanding \| $			$ 100	$ 100
Fiscal 2019 Grants
Share-based compensation
Unvested restricted stock units outstanding (in shares)			29
Fiscal 2018 Grants
Share-based compensation
Unvested restricted stock units outstanding (in shares)				22
Executive and senior officers
Share-based compensation
Performance payout period		1 year
Number of metrics \| metric			3
Requisite service period			5 years
Recognized share-based compensation expense \| $		$ 1,200	$ 1,300	$ 1,500
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards \| $		$ 1,100
Weighted-average period over which unrecognized compensation cost is expected to be recognized		1 year 9 months 18 days
Income tax benefit recognized on share-based compensation \| $		$ 600	$ 2,100	$ 1,000

Share-Based Compensation - Performance Restricted Stock Units Activity (Details) - PRSUs - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period: (in shares)	260	277	278
Granted (in shares)	292	190	129
Performance condition adjustments, net (in shares)	(99)	(106)	(50)
Released (in shares)	(120)	(101)	(68)
Forfeited (in shares)	0	0	(12)
Outstanding at end of period: (in shares)	333	260	277
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period: (in dollars per share)	$ 8.84	$ 16.77	$ 17.80	$ 17.00
Granted (in dollars per share)	3.68	13.63	19.46
Performance condition adjustments, net (in dollars per share)	3.82	13.77	19.48
Released (in dollars per share)	17.29	17.19	16.03
Forfeited (in dollars per share)	0	0	16.16
Outstanding at end of period: (in dollars per share)	$ 8.84	$ 16.77	$ 17.80	$ 17.00

Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income (loss) before provision for income taxes from:
U.S. operations	$ (54,190)	$ 7,334	$ 9,853
Foreign operations	(59,982)	3,105	4,418
Income (loss) before provision for income taxes	(114,172)	10,439	14,271
Current
Federal	(6,278)	2,712	790
States and local	528	519	533
Foreign	4,006	4,572	3,824
Reserve for uncertain tax positions	(28)	99	337
Total current provision (benefit)	(1,772)	7,902	5,484
Deferred
Federal	(2,781)	315	2,966
States and local	(1,244)	(32)	399
Foreign	(10,045)	(4,095)	(2,089)
Total deferred provision (benefit)	(14,070)	(3,812)	1,276
Change in valuation allowance	1,136	269	666
Net deferred provision (benefit)	(12,934)	(3,543)	1,942
Total provision (benefit) for income taxes	$ (14,706)	$ 4,359	$ 7,426

Income Taxes - Provision (Benefit) for Income Taxes Computed By Applying Statutory Federal Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal tax at statutory rate	$ (23,976)	$ 2,192	$ 2,997
State taxes, net of federal benefit	(1,175)	377	737
Foreign tax	(815)	982	807
Goodwill impairment	10,003	0	0
Nondeductible compensation	975	1,581	183
US taxation of foreign earnings	56	213	228
Permanent differences	944	464	361
Transition tax, net of foreign tax credits	0	0	1,158
Federal loss carryback	(1,938)	0	0
Change in valuation allowance	1,136	269	666
Impact of foreign tax rate changes	392	(1,882)	0
Other	(308)	163	289
Total provision (benefit) for income taxes	$ (14,706)	$ 4,359	$ 7,426
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal tax at statutory rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	1.00%	3.60%	5.10%
Foreign tax	0.70%	9.40%	5.70%
Goodwill impairment	(8.80%)	0.00%	0.00%
Nondeductible compensation	(0.90%)	15.20%	1.30%
US taxation of foreign earnings	0.00%	2.00%	1.60%
Permanent differences	(0.80%)	4.40%	2.50%
Transition tax, net of foreign tax credits	0.00%	0.00%	8.10%
Federal loss carryback	0.017	0	0
Change in valuation allowance	(1.00%)	2.60%	4.70%
Impact of foreign tax rate changes	(0.30%)	(18.00%)	0.00%
Other	0.30%	1.60%	2.00%
Total provision (benefit) for income taxes	12.90%	41.80%	52.00%

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended												12 Months Ended
Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Income tax expense for effects of Tax Act																$ 1,700,000
Increase in net deferred tax liabilities due to rate reduction of Tax Act																100,000
Tax expense due to transition tax of Tax Act																1,300,000
Decrease in deferred tax asset due to changes made to executive compensation as result of Tax Act																400,000
Increase in income tax benefit as result of CARES Act														$ (1,938,000)	$ 0	0
Deferred tax assets valuation allowance	$ 4,540,000				$ 4,067,000									4,540,000	4,067,000
Net increase in valuation allowance														500,000
Unrecognized tax benefits	347,000				393,000				$ 723,000					347,000	393,000	723,000
Unrecognized tax benefits that would favorably affect the effective tax rate, if recognized	200,000				200,000									200,000	200,000
Expected decrease in unrecognized tax benefits within the next 12 months	200,000													200,000
Net income (loss) of foreign subsidiaries	181,000	$ 1,523,000	$ (2,656,000)	$ (98,509,000)	$ 829,000	$ 3,093,000	$ 7,431,000	$ (5,293,000)	$ (1,061,000)	$ (1,011,000)	$ 6,000,000	$ 2,908,000		(99,461,000)	6,060,000	6,836,000
Recognized a deferred tax liability on undistributed international earnings (losses) of foreign subsidiaries	0													0
Unrecorded deferred tax liability related to undistributed international earnings	1,800,000													1,800,000
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Deferred tax assets valuation allowance	0													0
Scenario, Forecast
Operating Loss Carryforwards [Line Items]
Projected cash refunds of taxes paid in prior years as result of CARES Act													$ 4,800,000
Federal \| Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net operating losses	100,000													100,000
State
Operating Loss Carryforwards [Line Items]
Net operating losses	14,800,000													14,800,000
Net operating losses expiring from 2023 to 2040	8,900,000													8,900,000
Foreign
Operating Loss Carryforwards [Line Items]
Net operating losses	11,700,000													11,700,000
Net operating losses expiring from 2023 to 2040	$ 100,000													100,000
Net income (loss) of foreign subsidiaries														$ (55,700,000)	2,500,000	$ 2,000,000.0
Foreign \| Canadian Province of Alberta
Operating Loss Carryforwards [Line Items]
Favorable impact foreign in tax rate from revaluation of net deferred tax liabilities															$ 1,900,000

Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets
Allowance for doubtful accounts	$ 1,054	$ 1,186
Inventory	459	359
Intangible assets	2,000	1,795
Accrued expenses	6,818	4,421
Net operating loss carryforward	4,190	3,832
Finance lease obligations	942	1,067
Capital losses	0	463
Deferred stock based compensation	920	1,145
Interest carryforward	0	1,372
Right-of-use liability	11,970	11,891
Credits	312	0
Other	1,507	398
Deferred income tax assets	30,172	27,929
Valuation allowance	(4,540)	(4,067)
Net deferred income tax assets	25,632	23,862
Deferred income tax liabilities
Property and equipment	(9,109)	(6,485)
Goodwill	(4,639)	(10,652)
Intangible assets	(6,058)	(14,311)
Right-of-use asset	(11,924)	(11,891)
Other	(69)	(27)
Deferred income tax liabilities	(31,799)	(43,366)
Net deferred income taxes	$ (6,167)	$ (19,504)

Income Taxes - Changes in Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 393	$ 723
Additions for tax positions related to the current fiscal period	0	0
Additions for tax positions related to prior years	32	217
Decreases for tax positions related to prior years	0	0
Current year acquisitions	0	0
Impact of foreign exchange fluctuation, increase		13
Impact of foreign exchange fluctuation, decrease	(5)
Settlements	0	(465)
Reductions related to the expiration of statutes of limitations	(73)	(95)
Balance at end of period	$ 347	$ 393

Employee Benefit Plans (Details)	12 Months Ended
Employee Benefit Plans (Details)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Multiemployer Plans [Line Items]
Minimum age for employees to contribute catch up contributions under IRS limits	50 years
Continuous service period required for eligibility of employees to participate under the plan	3 months
Maximum Company match amount of employee contributions matched up to 6% of annual compensation (as a percent)	50.00%
Maximum percentage of employee's annual compensation for which the company contributes a matching contribution (as a percent)	6.00%
Vesting period for employer matching contribution	5 years
Contribution under 401(k) savings plan	$ 1,100,000	$ 4,100,000	$ 3,900,000
Multiemployer Plans, Pension \| Boilermakers and Pipefitters Plans
Multiemployer Plans [Line Items]
Contributions to multi-employer defined benefit plan	$ 0	$ 0	$ 600,000
Multiemployer Plans, Pension \| Boilermakers and Pipefitters Plans \| Minimum
Multiemployer Plans [Line Items]
Multiemployer plan funded status percentage	0.66
Multiemployer Plans, Pension \| Boilermakers and Pipefitters Plans \| Maximum
Multiemployer Plans [Line Items]
Multiemployer plan funded status percentage	0.75

Related Party Transactions (Details)	12 Months Ended
Related Party Transactions (Details)	Dec. 31, 2020 USD ($) employee_director	Dec. 31, 2019 USD ($)
Related Party Transactions
Operating rental payments	$ 13,246,000	$ 12,773,000
Consulting Services \| Non-employee directors \| Capital Management Enterprise (“CME”)
Related Party Transactions
Number of non-employee director \| employee_director	1
Related party fees	$ 0

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
ROU assets	$ 46,728	$ 45,817
Liabilities:
ROU liability - current	10,348	10,133
ROU liability - long-term	37,689	36,750
Total ROU liabilities	$ 48,037	$ 46,883
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	mg:AccruedExpensesAndOtherLiabilitiesCurrent	mg:AccruedExpensesAndOtherLiabilitiesCurrent
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherNoncurrentAssetsMember	us-gaap:OtherNoncurrentAssetsMember

Leases - Narrative (Details) - USD ($) $ in Thousands	7 Months Ended	12 Months Ended
Leases - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
ROU operating lease liabilities	$ 48,037	$ 48,037	$ 46,883
Operating rental payments		13,246	12,773
ROU finance lease assets	15,800	15,800	19,200
Company's Headquarter \| Operating Lease Arrangement
Lessee, Lease, Description [Line Items]
ROU operating lease liabilities	$ 3,800	3,800	4,500
Operating rental payments		700	$ 1,000
COVID-19 \| Company's Headquarter \| Operating Lease Arrangement
Lessee, Lease, Description [Line Items]
Percentage of reduction on rental payments	20.00%
Period for reduction of rental payments	90 days
COVID-19 \| Services
Lessee, Lease, Description [Line Items]
Impairment of ROU asset		$ 200

Leases - Components of Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finance lease expense:
Amortization of ROU assets	$ 4,544	$ 5,091
Interest on lease liabilities	847	824
Operating lease expense	13,383	12,937
Short-term lease expense	66	43
Variable lease expense	838	1,220
Total	$ 19,678	$ 20,115

Leases - Other Information Related to Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash paid for amounts included in the measurement of lease liabilities for finance leases:
Finance - financing cash flows	$ 4,095	$ 4,545	$ 5,813
Finance - operating cash flows	847	824
Operating - operating cash flows	13,246	12,773
ROU assets obtained in the exchange for lease liabilities:
Finance leases	2,849	9,502
Operating leases	$ 9,934	$ 18,965
Weighted-average remaining lease term (in years):
Finance leases	5 years 8 months 12 days	5 years 10 months 24 days
Operating leases	5 years 9 months 18 days	6 years 2 months 12 days
Weighted-average discount rate:
Finance leases	5.70%	5.80%
Operating leases	5.70%	5.90%

Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finance
2021	$ 5,353
2022	4,087
2023	3,194
2024	2,261
2025	688
Thereafter	754
Total	16,337
Less: Present value discount	1,457
Lease liability	14,880
Operating
2021	12,588
2022	10,495
2023	8,907
2024	7,042
2025	5,150
Thereafter	12,258
Total	56,440
Less: Present value discount	8,403
Lease liability	$ 48,037	$ 46,883

Commitments and Contingencies (Details)	1 Months Ended				3 Months Ended	12 Months Ended
Commitments and Contingencies (Details)	Dec. 31, 2020 USD ($) installment	Dec. 31, 2019 USD ($) weld	Sep. 30, 2019 USD ($)	Apr. 30, 2017	Sep. 30, 2018 USD ($)	Dec. 31, 2020 USD ($) installment claim	Dec. 31, 2019 USD ($) weld	Dec. 31, 2018 USD ($)	Mar. 31, 2021	Jan. 01, 2020 USD ($)
Litigation
Accounts receivable, net	$ 107,628,000	$ 135,997,000				$ 107,628,000	$ 135,997,000
Credit loss reserve (reversal)						0	3,038,000	$ 650,000
Pension accrual	2,519,000	2,519,000				2,519,000	2,519,000
Products and Systems \| Disposal of Foreign Subsidiaries \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Litigation
Consideration received on sale of disposal					$ 4,300,000
Term of agreement to purchase products from buyer on sale of subsidiary					3 years
Texas Customer
Litigation
Accounts receivable, net		1,400,000					$ 1,400,000
Verbal demand for damages		$ 1,400,000
Litigation and Commercial Claims
Litigation
Number of welds alleged not in compliance \| weld		66					66
Number of welds inspected \| weld		16,000					16,000
Verbal demand for damages		$ 7,600,000
Litigation and Commercial Claims \| Texas Customer
Litigation
Accounts receivable, net	1,400,000					1,400,000
Verbal demand for damages		$ 1,400,000
Contingency accrual	0					0
Credit loss reserve (reversal)							$ 1,400,000
Class actions
Litigation
Contingency accrual	800,000					$ 800,000
Number of proceedings filed \| claim						2
Class action on behalf of current and former employees
Litigation
Number of proceedings filed \| claim						1
Class action on behalf of State of California
Litigation
Number of proceedings filed \| claim						1
Pension related contingencies
Litigation
Charge for withdrawal liability			$ 900,000				$ 800,000	5,900,000
Monthly payments, excluding settlement			3,300,000
Contingency payments			$ 4,200,000
Pension accrual	2,500,000					$ 2,500,000
Severance and labor disputes \| Right to Customer Contracts \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Litigation
Consideration received on sale of disposal										$ 100,000
Severance and labor disputes \| NDT Do Brazil, LTDA
Litigation
Contingency related charges								$ 1,200,000
Settlement amount	$ 1,000,000.0
Number of settlement installments \| installment	2					2
Percentage of settlement installments	0.31					0.31
Gain on settlement	$ 300,000
Severance and labor disputes \| NDT Do Brazil, LTDA \| Subsequent Event
Litigation
Percentage of settlement installments									0.69
Severance and labor disputes \| GERMANY \| French Subsidiary
Litigation
Contingency payments						$ 400,000
Period covered by temporary staff leasing contract				18 months
Contingency related charges						200,000
Loss contingency reversals						1,000,000.0
Acquisition-related contingencies
Litigation
Potential acquisition-related contingent consideration, low end of range	0					0
Potential acquisition-related contingent consideration, high end of range	4,300,000					$ 4,300,000
Period over which potential acquisition-related contingent consideration would be payable						1 year 9 months
Acquisition-related contingencies \| Products and Systems \| Disposal of Foreign Subsidiaries \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Litigation
Term of agreement to purchase products from buyer on sale of subsidiary								3 years
Amount of purchase agreement with buyer on sale of subsidiary					$ 2,300,000
Remaining amount of purchase agreement with buyer on sale of subsidiary	$ 1,200,000					$ 1,200,000

Segment Disclosure - Financial Information (Details) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of operating segments \| segment													3
Financial information by segment
Revenues	$ 160,777	$ 147,894	$ 124,435	$ 159,465	$ 178,991	$ 192,192	$ 200,616	$ 176,787	$ 180,762	$ 182,169	$ 191,793	$ 187,630	$ 592,571	$ 748,586	$ 742,354
Gross profit	49,345	47,384	41,158	40,644	50,583	57,769	60,071	48,874	52,315	52,332	55,083	48,144	178,531	217,297	207,874
Operating Income (Loss)	4,652	$ 5,742	$ (383)	$ (111,228)	2,335	$ 10,779	$ 15,419	$ (4,396)	$ 2,502	$ 3,017	$ 10,304	$ 6,398	(101,217)	24,137	22,221
Depreciation and amortization													35,705	38,533	34,413
Intangible assets, net	68,642				109,537								68,642	109,537
Total assets	583,313				719,878								583,313	719,878
Operating segments \| Services
Financial information by segment
Revenues													476,164	595,130	574,619
Gross profit													141,084	165,513	151,974
Operating Income (Loss)													(44,222)	49,593	47,126
Depreciation and amortization													26,093	28,854	24,079
Intangible assets, net	58,917				98,284								58,917	98,284
Total assets	427,636				537,518								427,636	537,518
Operating segments \| International
Financial information by segment
Revenues													107,556	144,271	153,448
Gross profit													31,046	43,145	45,464
Operating Income (Loss)													(21,855)	5,856	3,953
Depreciation and amortization													8,659	8,285	8,846
Intangible assets, net	8,664				9,814								8,664	9,814
Total assets	129,228				153,380								129,228	153,380
Operating segments \| Products and Systems
Financial information by segment
Revenues													16,449	18,583	23,426
Gross profit													6,826	8,639	10,560
Operating Income (Loss)													(936)	(529)	2,368
Depreciation and amortization													998	1,213	1,429
Intangible assets, net	1,012				1,181								1,012	1,181
Total assets	10,996				16,028								10,996	16,028
Corporate and eliminations
Financial information by segment
Revenues													(7,598)	(9,398)	(9,139)
Gross profit													(425)	0	(124)
Operating Income (Loss)													(34,204)	(30,783)	(31,226)
Depreciation and amortization													(45)	181	$ 59
Intangible assets, net	49				258								49	258
Total assets	$ 15,453				$ 12,952								$ 15,453	$ 12,952

Segment Disclosure - Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Revenue and long-lived assets by geographic area
Long-lived assets	$ 367,331	$ 490,554
United States
Revenue and long-lived assets by geographic area
Long-lived assets	187,251	233,679
Other Americas
Revenue and long-lived assets by geographic area
Long-lived assets	123,924	181,550
Europe
Revenue and long-lived assets by geographic area
Long-lived assets	$ 56,156	$ 75,325

Selected Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	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, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 160,777	$ 147,894	$ 124,435	$ 159,465	$ 178,991	$ 192,192	$ 200,616	$ 176,787	$ 180,762	$ 182,169	$ 191,793	$ 187,630	$ 592,571	$ 748,586	$ 742,354
Gross Profit	49,345	47,384	41,158	40,644	50,583	57,769	60,071	48,874	52,315	52,332	55,083	48,144	178,531	217,297	207,874
Income (loss) from operations	4,652	5,742	(383)	(111,228)	2,335	10,779	15,419	(4,396)	2,502	3,017	10,304	6,398	(101,217)	24,137	22,221
Net income (loss) attributable to Mistras Group, Inc.	$ 181	$ 1,523	$ (2,656)	$ (98,509)	$ 829	$ 3,093	$ 7,431	$ (5,293)	$ (1,061)	$ (1,011)	$ 6,000	$ 2,908	$ (99,461)	$ 6,060	$ 6,836
Earnings (loss) per common share:
Basic (in dollars per share)	$ 0.01	$ 0.05	$ (0.09)	$ (3.40)	$ 0.03	$ 0.11	$ 0.26	$ (0.19)	$ (0.04)	$ (0.04)	$ 0.21	$ 0.10	$ (3.41)	$ 0.21	$ 0.24
Diluted (in dollars per share)	$ 0.01	$ 0.05	$ (0.09)	$ (3.40)	$ 0.03	$ 0.11	$ 0.26	$ (0.19)	$ (0.04)	$ (0.04)	$ 0.20	$ 0.10	$ (3.41)	$ 0.21	$ 0.23

- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

+ Details

- Definition

The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(11))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1252-109256

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1337-109256

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(20))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-03(13))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868656-224227

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

+ Details

- Definition

The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1337-109256

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(11))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-03(13))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868656-224227

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1252-109256

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794

+ Details

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130543-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details