Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2019	May 02, 2019
Document and Entity Information
Entity Registrant Name	Mistras Group, Inc.
Entity Central Index Key	0001436126
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,646,123
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 24,600	$ 25,544
Accounts receivable, net	138,505	148,324
Inventories	13,571	13,053
Prepaid expenses and other current assets	21,029	15,870
Total current assets	197,705	202,791
Property, plant and equipment, net	93,916	93,895
Intangible assets, net	109,055	111,395
Goodwill	280,696	279,259
Deferred income taxes	2,861	1,930
Other assets	41,204	4,767
Total assets	725,437	694,037
Current Liabilities
Accounts payable	13,275	13,863
Accrued expenses and other current liabilities	79,641	73,895
Current portion of long-term debt	6,787	6,833
Current portion of finance lease obligations	3,764
Current portion of finance lease obligations		3,922
Income taxes payable	3,911	1,958
Total current liabilities	107,378	100,471
Long-term debt, net of current portion	280,919	283,787
Obligations under finance leases, net of current portion	9,046
Obligations under finance leases, net of current portion		9,075
Deferred income taxes	24,571	23,148
Other long-term liabilities	34,427	6,482
Total liabilities	456,341	422,963
Commitments and contingencies
Equity
Preferred stock, 10,000,000 shares authorized	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized, 28,626,687 and 28,562,608 shares issued	286	285
Additional paid-in capital	227,790	226,616
Retained earnings	66,260	71,553
Accumulated other comprehensive loss	(25,426)	(27,557)
Total Mistras Group, Inc. stockholders’ equity	268,910	270,897
Non-controlling interests	186	177
Total equity	269,096	271,074
Total liabilities and equity	$ 725,437	$ 694,037

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
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)	28,626,687	28,562,608

Unaudited Condensed Consolidated Statements of (Loss) Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 176,787	$ 187,630
Cost of revenue	122,417	133,787
Depreciation	5,496	5,698
Gross profit	48,874	48,145
Selling, general and administrative expenses	41,763	39,034
Bad debt provision for troubled customers, net of recoveries	5,491	0
Pension withdrawal expense	534	0
Research and engineering	857	756
Depreciation and amortization	4,172	2,950
Acquisition-related expense (benefit), net	453	(994)
(Loss) income from operations	(4,396)	6,399
Interest expense	3,527	1,792
(Loss) income before (benefit) provision for income taxes	(7,923)	4,607
(Benefit) provision for income taxes	(2,637)	1,688
Net (loss) income	(5,286)	2,919
Less: net income attributable to non-controlling interests, net of taxes	7	12
Net (loss) income attributable to Mistras Group, Inc.	$ (5,293)	$ 2,907
(Loss) earnings per common share:
Basic (in dollars per share)	$ (0.19)	$ 0.10
Diluted (in dollars per share)	$ (0.19)	$ 0.10
Weighted average common shares outstanding:
Basic (in shares)	28,574	28,304
Diluted (in shares)	28,574	29,362

Unaudited Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (5,286)	$ 2,919
Other comprehensive income:
Foreign currency translation adjustments	2,131	1,500
Comprehensive (loss) income	(3,155)	4,419
Less: comprehensive income attributable to non-controlling interest	9	14
Comprehensive (loss) income attributable to Mistras Group, Inc.	$ (3,164)	$ 4,405

Unaudited Condensed 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	Accumulated other comprehensive income (loss)	Noncontrolling Interest
Balance (in shares) at Dec. 31, 2017			28,295
Balance at Dec. 31, 2017	$ 270,792	$ 270,619	$ 282	$ 222,425	$ 64,717	$ (16,805)	$ 173
Increase (Decrease) in Stockholders' Equity
Net (loss) income	2,919	2,907			2,907		12
Other comprehensive income (loss), net of tax	1,502	1,500				1,500	2
Share-based payments (in shares)			19
Share-based payments	1,194	1,194		1,194
Net settlement on vesting of restricted stock units	$ (43)	(43)		(43)
Exercise of stock options (in shares)	0
Balance (in shares) at Mar. 31, 2018			28,314
Balance at Mar. 31, 2018	$ 276,364	276,177	$ 282	223,576	67,624	(15,305)	187
Balance (in shares) at Dec. 31, 2018			28,563
Balance at Dec. 31, 2018	271,074	270,897	$ 285	226,616	71,553	(27,557)	177
Increase (Decrease) in Stockholders' Equity
Net (loss) income	(5,286)	(5,293)			(5,293)		7
Other comprehensive income (loss), net of tax	2,133	2,131				2,131	2
Share-based payments (in shares)			61
Share-based payments	1,427	1,427	$ 1	1,426
Net settlement on vesting of restricted stock units	$ (284)	(284)		(284)
Exercise of stock options (in shares)	4		3
Exercise of stock options	$ 32	32		32
Balance (in shares) at Mar. 31, 2019			28,627
Balance at Mar. 31, 2019	$ 269,096	$ 268,910	$ 286	$ 227,790	$ 66,260	$ (25,426)	$ 186

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net (loss) income	$ (5,286)	$ 2,919
Adjustments to reconcile net (loss) income to net cash provided by operating activities
Depreciation and amortization	9,668	8,648
Deferred income taxes	244	260
Share-based compensation expense	1,356	1,126
Bad debt provision for troubled customers, net of recoveries	5,491	0
Fair value adjustments to contingent consideration	305	(1,033)
Foreign currency (gain) loss	(647)	45
Other	(163)	(167)
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions
Accounts receivable	4,904	(15)
Inventories	(505)	(468)
Prepaid expenses and other assets	(5,425)	(437)
Accounts payable	(541)	(732)
Accrued expenses and other liabilities	(3,189)	(3,703)
Income taxes payable	1,965	(625)
Net cash provided by operating activities	8,177	5,818
Cash flows from investing activities
Purchase of property, plant and equipment	(5,637)	(5,182)
Purchase of intangible assets	(88)	(165)
Proceeds from sale of equipment	724	575
Net cash used in investing activities	(5,001)	(4,772)
Cash flows from financing activities
Repayment of capital lease obligations	(1,124)	(1,630)
Proceeds from borrowings of long-term debt	121	371
Repayment of long-term debt	(1,694)	(834)
Proceeds from revolver	6,500	18,600
Repayment of revolver	(7,500)	(10,700)
Payment of contingent consideration for business acquisitions	0	(1,503)
Taxes paid related to net share settlement of share-based awards	(284)	(43)
Proceeds from exercise of stock options	32	0
Net cash (used in) provided by financing activities	(3,949)	4,261
Effect of exchange rate changes on cash and cash equivalents	(171)	284
Net change in cash and cash equivalents	(944)	5,591
Cash and cash equivalents at beginning of period	25,544	27,541
Cash and cash equivalents at end of period	24,600	33,132
Supplemental disclosure of cash paid
Interest	3,428	1,590
Income taxes	1,091	2,136
Noncash investing and financing
Equipment acquired through capital lease obligations	$ 1,086	$ 587

Description of Business and Basis of Presentation	3 Months Ended
Description of Business and Basis of Presentation	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Description of Business Mistras Group, Inc. and subsidiaries ("the Company") is a leading “one source” global provider of technology-enabled asset protection solutions used to evaluate the structural integrity and reliability of critical energy, industrial and public infrastructure. The Company combines industry-leading products and technologies, expertise in mechanical integrity (MI), non-destructive testing (NDT) and mechanical services and proprietary data analysis software to deliver a comprehensive portfolio of customized solutions, ranging from routine inspections to complex, plant-wide asset integrity assessments and management. These mission critical solutions enhance customers’ ability to extend the useful life of their assets, increase productivity, minimize repair costs, comply with governmental safety and environmental regulations, manage risk and avoid catastrophic disasters. 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. Basis of Presentation The condensed consolidated financial statements contained in this report are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, necessary for a fair presentation of the results for the interim periods of the years ending December 31, 2019 and 2018. Certain items included in these statements are based on management’s estimates. Actual results may differ from those estimates. The results of operations for any interim period are not necessarily indicative of the results expected for the year. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the notes to the audited consolidated financial statements contained in the Company’s Annual Report on Form 10-K (“2018 Annual Report”) for the year ended December 31, 2018, as filed with the Securities and Exchange Commission on March 15, 2019. Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of Mistras Group, Inc. and its wholly and majority-owned subsidiaries. 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 condensed consolidated balance sheets. The non-controlling interests in net income, net of tax, is classified separately in the accompanying condensed consolidated statements of income. All significant intercompany accounts and transactions have been eliminated in consolidation. Reclassification 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. Customers There were no customers that represented 10% of our revenues for either of the three months ended March 31, 2019 or 2018, respectively. Significant Accounting Policies The Company’s significant accounting policies are disclosed in Note 1 — Summary of Significant Accounting Policies and Practices in the 2018 Annual Report. On an ongoing basis, the Company evaluates its estimates and assumptions, including among other things, those related to revenue recognition, long-lived assets, goodwill and acquisitions. Since the date of the 2018 Annual Report, there have been no material changes to the Company's significant accounting policies, other than its adoption of the new leasing standard on January 1, 2019. Income Taxes On December 22, 2017, the United States enacted fundamental changes to federal tax law following the passage of the Tax Cuts and Jobs Act (the “Tax Act”). The Company’s financial statements for the periods ended March 31, 2019 and March 31, 2018 reflected provisions of the Tax Act effective for periods beginning after December 31, 2017, which includes the reduced federal corporate tax rate of from 35% to 21%, adjustments made to executive compensation and meals and entertainment rules, and the inclusion of new categories of income, global intangible low-taxes income (“GILTI”) and foreign derived intangible income (“FDII”). The Company’s effective income tax rate was approximately 33% and 37% for the three months ended March 31, 2019 and 2018, respectively. The effective income tax rate for the first quarter of 2019 and 2018 was higher than the statutory rate due to the impact of discrete items, GILTI and executive compensation provisions resulting from the passage of the Tax Act, and foreign tax rates different than statutory rates in the U.S. The Company has completed the accounting for the adoption of the Tax Act, but the amounts recorded in 2019 for the Tax Act related to the calculations of the GILTI, FDII, executive compensation and meals and entertainment are the Company’s best estimates based on the current data and guidance available. The Company is continuing to evaluate the state tax conformity to the Tax Act, including the GILTI provisions. Given the complexity of the new GILTI tax rules, the Company is continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under U.S. GAAP, the Company is allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). In 2018, the Company made an accounting policy election to account for these effects under the period cost method. Mistras and its subsidiaries file tax returns in the U.S., including various state and local returns and in other foreign jurisdictions. The Company believes adequate provision has been made for all income tax uncertainties. Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842), which the Company adopted as of January 1, 2019. Topic 842 requires the recognition of lease rights and obligations as assets and liabilities on the balance sheet. The Company elected the modified retrospective method permitted by the standard, upon which prior-period information has not been restated. The standard provided for several practical expedient options for use in transition. The Company elected to utilize the “package of practical expedients,” which permits the Company not to reassess previous conclusions reached on lease identification, lease classification and initial direct costs. The Company also elected to utilize the practical expedient available to not separate lease and non-lease components within the lease and have therefore accounted for all lease components as a single lease component. Adoption of the new standard resulted in the recording of a right-of-use (ROU) asset and liability related to the Company’s operating leases of approximately $38 million as of January 1, 2019. The new standard did not have a material impact to our statements of (loss) income or cash flows. In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350). This amendment eliminates Step Two of the goodwill impairment test. Under the amendments in this update, entities should perform the annual goodwill impairment test by comparing the carrying value of its reporting units to their fair value. An entity should record an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. Tax deductibility of goodwill should be considered in evaluating any reporting unit's impairment loss to be taken. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, with early adoption permitted. The Company early adopted ASU 2017-04 in the third quarter of 2017 for its condensed consolidated financial statements and related disclosures.

Revenue

3 Months Ended

Mar. 31, 2019

Revenue from Contract with Customer [Abstract]

Revenue

The majority of the Company's revenues are derived from 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, which was adopted on January 1, 2018.

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 our 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 our 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 our 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.

Our performance obligations are satisfied over time as work progresses or at a point in time. The majority of our revenue recognized over time as work progresses is related to our 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 our revenues are short-term in nature. The Company has many Master Service Agreements (MSAs) that specify an overall framework and terms of contract 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 our 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 our 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:

Revenue by industry was as follows:



Three months ended March 31, 2019	Services		International		Products		Corp/Elim			Total
Oil & Gas	$	91,666	$	9,704	$	15	$	—		$	101,385
Aerospace & Defense	12,794		11,654		307		—			24,755
Industrials	16,123		5,075		432		—			21,630
Power generation & Transmission	6,262		1,422		1,380		—			9,064
Other Process Industries	6,319		2,242		5		—			8,566
Infrastructure, Research & Engineering	2,590		2,733		847		—			6,170
Other	4,544		2,332		446		(2,105		)	5,217
Total	$	140,298	$	35,162	$	3,432	$	(2,105	)	$	176,787



Three months ended March 31, 2018	Services		International		Products		Corp/Elim			Total
Oil & Gas	$	103,290	$	8,108	$	563	$	—		$	111,961
Aerospace & Defense	12,457		14,465		667		—			27,589
Industrials	11,717		6,400		540		—			18,657
Power generation & Transmission	6,359		720		1,556		—			8,635
Other Process Industries	5,407		1,790		5		—			7,202
Infrastructure, Research & Engineering	2,180		2,519		500		—			5,199
Other	4,185		4,454		2,353		(2,605		)	8,387
Total	$	145,595	$	38,456	$	6,184	$	(2,605	)	$	187,630

Revenue per key geographic location was as follows:



Three months ended March 31, 2019	Services		International		Products		Corp/Elim			Total
United States	$	113,136	$	276	$	1,970	$	(1,282	)	$	114,100
Other Americas	26,708		2,229		66		(56		)	28,947
Europe	428		31,540		421		(763		)	31,626
Asia-Pacific	26		1,117		975		(4		)	2,114
Total	$	140,298	$	35,162	$	3,432	$	(2,105	)	$	176,787



Three months ended March 31, 2018	Services		International		Products		Corp/Elim			Total
United States	$	123,562	$	267	$	3,258	$	(1,097	)	$	125,990
Other Americas	21,783		1,902		81		(253		)	23,513
Europe	155		34,219		1,120		(1,226		)	34,268
Asia-Pacific	95		2,068		1,725		(29		)	3,859
Total	$	145,595	$	38,456	$	6,184	$	(2,605	)	$	187,630

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 condensed 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 receive advances or deposits from our customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are aggregated on an individual contract basis and reported on the condensed consolidated balance sheet at the end of each reporting period within accrued expenses and other current liabilities.

Revenue recognized in 2019, that was included in the contract liability balance at the beginning of the year was $1.8 million. Changes in the contract asset and liability balances during the quarter ended March 31, 2019, were not materially impacted by any other factors. The Company has elected to utilize a practical expedient to expense incremental costs incurred related to obtaining a contract. The Company’s expenses are expected to be amortized over a period less than one year.

Share-Based Compensation

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-Based Compensation

The Company has share-based incentive awards outstanding to its eligible employees and non-employee directors under three equity incentive plans: (i) the 2007 Stock Option Plan (the "2007 Plan"), (ii) the 2009 Long-Term Incentive Plan (the "2009 Plan") and (iii) the 2016 Long-Term Incentive Plan (the "2016 Plan"). No further awards may be granted under the 2007 and 2009 Plans, although awards granted under the 2007 and 2009 Plans 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.

Stock Options

For the three months ended March 31, 2019 and 2018, the Company did not recognize any share-based compensation expense related to stock option awards, as all outstanding stock options awards are fully vested.

No unrecognized compensation costs remained related to stock option awards as of March 31, 2019.

No stock options were granted during the three months ended March 31, 2019 and March 31, 2018.

The following table sets forth a summary of the stock option activity, weighted average exercise prices and options outstanding as of March 31, 2019 and March 31, 2018:



	For the three months ended March 31,
	2019				2018
	Common Stock Options		Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price
Outstanding at beginning of period:	2,105		$	13.47	2,130	$	13.43
Granted	—		$	—	—	$	—
Exercised	(4	)	$	10.00	—	$	—
Expired or forfeited	—		$	—	—	$	—
Outstanding at end of period:	2,101		$	13.47	2,130	$	13.43

Restricted Stock Unit Awards

For the three months ended March 31, 2019 and March 31, 2018, the Company recognized share-based compensation expense related to restricted stock unit awards of $0.9 million and $0.8 million, respectively. As of March 31, 2019, there was $10.0 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 2.9 years.

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



	For the three months ended March 31,
	2019		2018
Restricted stock awards vested	50		4
Fair value of awards vested	$	0.7	$	0.1

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 fully-vested common stock the Company issued to its five non-employee directors, in connection with its non-employee director compensation plan, is as follows: (awards in thousands, fair value in millions)



	For the three months ended March 31,
	2019		2018
Awards issued	14		10
Grant date fair value of awards issued	$	0.2	$	0.2

A summary of the Company's outstanding, non-vested restricted share units is as follows:



	For the three months ended March 31,
	2019				2018
	Units		Weighted Average Grant-Date Fair Value		Units		Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	443		$	20.55	532		$	21.05
Granted	334		$	14.04	211		$	19.20
Released	(50	)	$	19.21	(4	)	$	24.08
Forfeited	(8	)	$	20.78	(16	)	$	19.82
Outstanding at end of period:	719		$	17.61	723		$	20.52

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 three metrics, as defined: (1) Operating Income, (2) Adjusted EBITDAS and (3) Revenue. There also is a discretionary portion of the PRSUs based on individual performance, 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.

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 classified as equity.

A summary of the Company's PRSU activity is as follows:



	For the three months ended March 31,
	2019				2018
	Units		Weighted Average Grant-Date Fair Value		Units		Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	277		$	17.80	278		$	17.00
Granted	—		$	—	123		$	19.46
Performance condition adjustments	(3	)	$	18.46	5		$	18.36
Released	(17	)	$	20.22	—		$	—
Forfeited	—		$	—	(12	)	$	16.16
Outstanding at end of period:	257		$	17.35	394		$	17.71

During the three months ended March 31, 2019 and March 31, 2018, the Compensation Committee approved the final calculation of the award metrics for calendar year 2018 and calendar year 2017, respectively. As a result, the calendar year 2018 PRSUs decreased by approximately 3,000 units and the calendar year 2017 PRSUs increased by approximately 5,000 units.

For the three months ended March 31, 2019 and March 31, 2018, the Company recognized aggregate share-based compensation expense related to the awards described above of approximately $0.2 million and $0.1 million, respectively. At March 31, 2019, there was $1.5 million of total unrecognized compensation costs related to approximately 257,000 non-vested PRSUs, which are expected to be recognized over a remaining weighted average period of 1.8 years.

The Company is still in the process of reviewing the key terms and metrics related to the long-term executive compensation plan for calendar year 2019 PRSUs. As such, no shares have been granted, as noted in the table above. The Company expects these awards to be finalized and approved by its Compensation Committee during the second quarter of 2019.

Earnings per Share

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Earnings per Share

Basic earnings 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 income 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 reflects: (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:



	Three months ended
	March 31, 2019				March 31, 2018

Basic earnings per share:
Numerator:
Net (loss) income attributable to Mistras Group, Inc.	$	(5,293	)		$	2,907
Denominator:
Weighted average common shares outstanding	28,574				28,304
Basic earnings per share	$	(0.19	)		$	0.10

Diluted earnings per share:
Numerator:
Net (loss) income attributable to Mistras Group, Inc.	$	(5,293	)		$	2,907
Denominator:
Weighted average common shares outstanding	28,574				28,304
Dilutive effect of stock options outstanding	n/a			⁽¹⁾	745
Dilutive effect of restricted stock units outstanding	n/a			⁽²⁾	313
	28,574				29,362
Diluted earnings per share	$	(0.19	)		$	0.10

(1) - For the three months ended March 31, 2019, 212 shares were excluded from the calculation of diluted EPS due to the net loss for the period.

(2) - For the three months ended March 31, 2019, 168 shares were excluded from the calculation of diluted EPS due to the net loss for the period.

Acquisitions

3 Months Ended

Mar. 31, 2019

Business Combinations [Abstract]

Acquisitions

During the three months ended March 31, 2019 and March 31, 2018, the Company did not complete any acquisitions.

The Company accounts for acquisitions in accordance with the acquisition method of accounting for business combinations. The assets and liabilities of one of the businesses acquired in 2018 were included in the Company's condensed consolidated balance sheet based upon its estimated fair value on the date of acquisition as determined in a preliminary purchase price allocation, using available information and making assumptions management believed were reasonable. The Company is still in the process of completing its valuation of the assets, both tangible and intangible, and liabilities acquired for the acquisition completed during 2018. The results of operations for this acquisition have been included in the Services segment's results from the date of acquisition. Goodwill of $83.2 million primarily relates to expected synergies and assembled workforce, and is not deductible for tax purposes. Other intangible assets, primarily related to technology, customer relationships and covenants not to compete, were $59.6 million.

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 (benefit), net, on the condensed consolidated statements of income and were as follows for the three months ended March 31, 2019 and 2018:



	Three months ended March 31,
	2019		2018
Due diligence, professional fees and other transaction costs	$	148	$	39
Adjustments to fair value of contingent consideration liabilities	305		(1,033		)
Acquisition-related expense (benefit), net	$	453	$	(994	)

The Company's contingent consideration liabilities are recorded on the balance sheet in accrued expenses and other liabilities.

Accounts Receivable, net

3 Months Ended

Mar. 31, 2019

Receivables [Abstract]

Accounts Receivable, net

Accounts receivable consisted of the following:



	March 31, 2019			December 31, 2018

Trade accounts receivable	$	148,070		$	152,511
Allowance for doubtful accounts	(9,565		)	(4,187		)
Accounts receivable, net	$	138,505		$	148,324

The Company had $25.9 million and $16.1 million of unbilled revenues accrued as of March 31, 2019 and December 31, 2018, respectively and such amounts are included within the trade accounts receivable balances above. Unbilled revenues are generally billed in the subsequent quarter to their revenue recognition.

In the fourth quarter of 2018, the Company recorded a reserve of $0.7 million for a renewable energy industry customer of the Company’s Services Division, based in part on the available information about the financial difficulties of the customer. This customer filed for a voluntary insolvency proceeding on April 9, 2019 at which time payments under the previously agreed upon payment plan ceased. As a result, 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. During the first quarter of 2019 the Company also recorded a net $0.2 million recovery of an unrelated bad debt provision which the Company had initially recorded as a charge during the second quarter of 2017.

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Property, Plant and Equipment, net

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment, net

Property, plant and equipment consisted of the following:



	Useful Life (Years)	March 31, 2019			December 31, 2018

Land		$	2,671		$	2,680
Buildings and improvements	30-40	24,200			24,338
Office furniture and equipment	5-8	16,427			16,170
Machinery and equipment	5-7	212,114			208,245
		255,412			251,433
Accumulated depreciation and amortization		(161,496		)	(157,538		)
Property, plant and equipment, net		$	93,916		$	93,895

Depreciation expense for both the three months ended March 31, 2019 and March 31, 2018 was approximately $6.1 million.

Goodwill

3 Months Ended

Mar. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

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 period	—		—			—		—
Adjustments to preliminary purchase price allocations	—		—			—		—
Foreign currency translation	2,020		(583		)	—		1,437
Balance at March 31, 2019	$	245,496	$	35,200		$	—	$	280,696

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. As of March 31, 2019, the Company did not identify any changes in circumstances that would indicate the carrying value of goodwill may not be recoverable.

The Company's cumulative goodwill impairment as of March 31, 2019 and December 31, 2018 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.

Intangible Assets

3 Months Ended

Mar. 31, 2019

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets

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



		March 31, 2019							December 31, 2018
	Useful Life (Years)	Gross Amount		Accumulated Amortization			Net Carrying Amount		Gross Amount		Accumulated Amortization			Net Carrying Amount

Customer relationships	5-14	$	112,544	$	(62,631	)	$	49,913	$	112,624	$	(60,993	)	$	51,631
Software/Technology	3-15	68,391		(14,556		)	53,835		67,240		(13,319		)	53,921
Covenants not to compete	2-5	12,632		(11,055		)	1,577		12,593		(10,825		)	1,768
Other	2-12	10,344		(6,614		)	3,730		10,317		(6,242		)	4,075
Total		$	203,911	$	(94,856	)	$	109,055	$	202,774	$	(91,379	)	$	111,395

Amortization expense for the three months ended March 31, 2019 and March 31, 2018 was approximately $3.6 million and $2.5 million, respectively.

Accrued Expenses and Other Current Liabilities

3 Months Ended

Mar. 31, 2019

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:



	March 31, 2019		December 31, 2018

Accrued salaries, wages and related employee benefits	$	28,688	$	29,959
Contingent consideration, current portion	1,997		1,687
Accrued workers’ compensation and health benefits	4,750		5,086
Deferred revenue	4,963		5,046
Pension accrual	4,913		5,585
Right-of-use liability - operating	8,700		—
Other accrued expenses	25,630		26,532
Total accrued expenses and other current liabilities	$	79,641	$	73,895

Long-Term Debt

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Long-Term Debt

Long-term debt consisted of the following:



	March 31, 2019			December 31, 2018

Senior credit facility	$	180,475		$	181,656
Senior secured term loan, net of debt issuance costs of $0.1 million	98,652			99,897
Notes payable	70			68
Other	8,509			8,999
Total debt	287,706			290,620
Less: Current portion	(6,787		)	(6,833		)
Long-term debt, net of current portion	$	280,919		$	283,787

Senior Credit Facility

The Company's revolving credit agreement with its banking group ("Credit Agreement") provides the Company with a $300 million revolving line of credit, which, under certain circumstances, can be increased to $450 million with the approval of the banks. In addition, the Credit Agreement provided the Company with a $100 million senior secured term loan A facility. Both the revolving line of credit and the term loan A facility under the Credit Agreement have a maturity date of December 12, 2023. 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 March 31, 2019, the Company had borrowings of $279.2 million and a total of $5.4 million of letters of credit outstanding under the Credit Agreement. The Company has capitalized costs associated with debt modifications of $1.0 million as of March 31, 2019, which amount is included in other long-term assets within the accompanying condensed consolidated balance sheet.

Loans under the Credit Agreement bear interest at the London Interbank Offered Rate ("LIBOR") plus an applicable LIBOR margin ranging from 1% to 2%, or a base rate less a margin of 1.25% to 0.375%, at the option of the Company, based upon the Company’s Funded Debt Leverage Ratio. Funded Debt Leverage Ratio is generally the ratio of (1) all outstanding indebtedness for borrowed money and other interest-bearing indebtedness as of the date of determination to (2) EBITDA (which is (a) net income, less (b) income (or plus loss) from discontinued operations and extraordinary items, plus (c) income tax expenses, plus (d) interest expense, plus (e) depreciation, depletion, and amortization (including non-cash loss on retirement of assets), plus (f) stock compensation expense, less (g) cash expense related to stock compensation, plus (h) certain amounts of EBITDA of acquired business for the prior twelve months, plus (i) certain expenses related to the closing of the Credit Agreement, plus (j) non-cash expenses which do not (in the current or any future period) represent a cash item (excluding non-cash gains which increase net income), plus (k) non-recurring charges (not to exceed $10.0 million in the four consecutive quarters immediately preceding the date of determination) for items such as severance, lease termination charges, asset write-offs and litigation settlements paid, and multi-employer pension plan withdrawal liabilities, all determined for the period of four consecutive fiscal quarters immediately preceding the date of determination of EBITDA. The Company has the benefit of the lowest margin if its Funded Debt Leverage Ratio is equal to or less than 1.0 to 1, and the margin increases as the ratio increases, to the maximum margin if the ratio is greater than 3.25 to 1. The Company will also bear additional costs for market disruption, regulatory changes effecting the lenders’ funding costs, and default pricing of an additional 2% interest rate margin on any amounts not paid when due. Amounts borrowed under the Credit Agreement are secured by liens on substantially all of the assets of the Company and is guaranteed by some of our subsidiaries.

The Credit Agreement contains financial covenants requiring that the Company maintain a Funded Debt Leverage Ratio of no greater than 4.25 to 1 through December 31, 2018, reducing to a maximum permitted ratio of 4.0 to 1 as of March 31, 2019 to September 30, 2019, a maximum permitted ratio of 3.75 to 1 as of December 31, 2019 and a maximum permitted ratio of 3.50 to 1 as of March 31, 2020 and all quarterly periods thereafter, and a Fixed Charge Coverage Ratio of at least 1.25 to 1. Fixed Charge Coverage Ratio means the ratio, as of any date of determination, of (a) (i) EBITDA for the 12 month period immediately preceding the date of determination, taken together as one accounting period, less (ii) the aggregate amount of all capital expenditures made during the period, less (iii) taxes paid in cash during the period, less (iv) Restricted Payments (as defined in the Credit Agreement) paid in cash during the period, -to- (b) the sum of (i) all interest, premium payments, debt discount, fees, charges and related expenses of us and our subsidiaries in connection with borrowed money (including capitalized interest) or in connection with the deferred purchase price of assets, in each case, to the extent treated as interest in accordance with U.S. generally accepted accounting principles ("GAAP") and to the extent paid in cash during the period, (ii) the aggregate principal amount of all redemptions or similar acquisitions for value of outstanding debt for borrowed money or regularly scheduled principal payments made during the period, but excluding any such payments to the extent refinanced through the incurrence of additional Indebtedness otherwise expressly permitted under the Credit Agreement, and (iii) payments made during the period under all leases that have been or should be, in accordance with GAAP as in effect for the Company's 2017 audited financial statement, recorded as capitalized leases. Beginning in 2020, the Company can elect to increase the maximum Funded Debt Leverage Ratio to 4.0 to 1 for four fiscal quarters immediately following the fiscal quarter in which the Company acquires another business, with the maximum permitted ratio reducing back to 3.5 to 1 in the fifth fiscal quarter following such acquisition. The Company can make this election twice during the term of the Credit Agreement.

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 our stock, enter into a new line of business, enter into transactions with affiliates and enter into burdensome agreements. The Credit Agreement does not limit the Company’s ability to acquire other businesses or companies except that the acquired business or company must be in the Company's line of business, the Company must be in compliance with the financial covenants on a pro forma basis after taking into account the acquisition, and, if the acquired business is a separate subsidiary, in certain circumstances the lenders will receive the benefit of a guaranty of the subsidiary and liens on its assets and a pledge of its stock.

As of March 31, 2019, the Company was in compliance with its Fixed Charge Coverage Ratio, but was not in compliance with its Funded Debt Leverage Ratio and obtained a waiver for such non-compliance.

Notes Payable and Other

In connection with certain of its acquisitions, the Company issued subordinated notes payable to the sellers. The maturity of the notes remain outstanding through June 30, 2019 and bear interest at the prime rate for the Bank of Canada, currently 3.95% as of March 31, 2019. Interest expense is recorded in the condensed consolidated statements of income.

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 March 31, 2019, there was approximately $8.5 million outstanding, payable at various times from 2019 to 2029. Monthly payments range from $1 thousand to $17 thousand. Interest rates range from 0.4% to 6.2%.

Fair Value Measurements

3 Months Ended

Mar. 31, 2019

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.

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:



	Three months ended March 31,
	2019		2018
Beginning balance	$	2,365	$	5,508
Acquisitions	—		—
Payments	—		(1,503		)
Accretion of liability	44		65
Revaluation	261		(1,098		)
Foreign currency translation	29		(63		)
Ending balance	$	2,699	$	2,909

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 capital 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

Leases

3 Months Ended

Mar. 31, 2019

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 our leases include one or more options to renew. When it is reasonably certain that we will exercise the option, we 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 Condensed Consolidated Balance Sheet includes the following related to operating leases:



Leases	Classification	As of March 31, 2019
Assets
Right-of-use assets	Other Assets	$	36,289

Liabilities
Right-of use liability - current	Accrued and other current liabilities	$	8,700
Right-of-use liability - long term	Other liabilities	28,340
Total right-of-use liabilities		$	37,040

Included within the balance of operating leases is a lease for the Company’s headquarters which is with a related party. The right-of use liability for this facility is approximately $5.0 million as of March 31, 2019 and total rent payments made during the quarter ended March 31, 2019 were approximately $0.2 million.

As of March 31, 2019, the total right-of-use assets attributable to finance leases is approximately $14.9 million, which is classified within Property, Plant, & Equipment on the accompanying condensed consolidated balance sheet.

The components of lease costs were as follows:



	Classification	For the three months ended March 31, 2019
Finance lease expense
Amortization of ROU assets	Depreciation and amortization	$	1,292
Interest on lease liabilities	Interest expense	197
Operating lease expense	Costs of goods sold or Selling, General & Administrative expenses	3,023
Short-term lease expense	Costs of goods sold or Selling, General & Administrative expenses	133
Variable lease expense	Costs of goods sold or Selling, General & Administrative expenses	272
Total		$	4,917

Other information related to leases was as follows:



	March 31, 2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases
Finance - financing cash flows	$	1,249
Finance - operating cash flows	$	197
Operating - operating cash flows	$	3,079
ROU assets obtained in the exchange for lease liabilities
Finance leases	$	1,086
Operating leases	$	1,348
Weighted average remaining lease term (in years)
Finance leases	5.8
Operating leases	6.0
Weighted average discount rate
Finance leases	6.45		%
Operating leases	5.97		%

Maturities of lease liabilities as of March 31, 2019 were as follows:



	Finance			Operating
Remaining of 2019	$	4,916		$	8,212
2020	3,694			9,162
2021	2,415			6,666
2022	1,546			5,064
2023	637			4,526
Thereafter	821			11,003
Total	14,029			44,633
Less: Present value discount	(1,219		)	(7,593		)
Lease liability	$	12,810		$	37,040

Pursuant to the Company’s adoption of the new lease accounting guidance using a modified retrospective transition approach, as permitted, comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. As previously disclosed in its 2018 Annual Report, the following table presents the Company’s future minimum operating lease commitments as of December 31, 2018:



2019	$	10,939
2020	8,764
2021	6,327
2022	4,826
2023	4,239
Thereafter	10,667
Total	$	45,762

Leases

The Company’s Condensed Consolidated Balance Sheet includes the following related to operating leases:



Leases	Classification	As of March 31, 2019
Assets
Right-of-use assets	Other Assets	$	36,289

Liabilities
Right-of use liability - current	Accrued and other current liabilities	$	8,700
Right-of-use liability - long term	Other liabilities	28,340
Total right-of-use liabilities		$	37,040

The components of lease costs were as follows:



	Classification	For the three months ended March 31, 2019
Finance lease expense
Amortization of ROU assets	Depreciation and amortization	$	1,292
Interest on lease liabilities	Interest expense	197
Operating lease expense	Costs of goods sold or Selling, General & Administrative expenses	3,023
Short-term lease expense	Costs of goods sold or Selling, General & Administrative expenses	133
Variable lease expense	Costs of goods sold or Selling, General & Administrative expenses	272
Total		$	4,917

Other information related to leases was as follows:



	March 31, 2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases
Finance - financing cash flows	$	1,249
Finance - operating cash flows	$	197
Operating - operating cash flows	$	3,079
ROU assets obtained in the exchange for lease liabilities
Finance leases	$	1,086
Operating leases	$	1,348
Weighted average remaining lease term (in years)
Finance leases	5.8
Operating leases	6.0
Weighted average discount rate
Finance leases	6.45		%
Operating leases	5.97		%

Maturities of lease liabilities as of March 31, 2019 were as follows:



	Finance			Operating
Remaining of 2019	$	4,916		$	8,212
2020	3,694			9,162
2021	2,415			6,666
2022	1,546			5,064
2023	637			4,526
Thereafter	821			11,003
Total	14,029			44,633
Less: Present value discount	(1,219		)	(7,593		)
Lease liability	$	12,810		$	37,040



2019	$	10,939
2020	8,764
2021	6,327
2022	4,826
2023	4,239
Thereafter	10,667
Total	$	45,762

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2019
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’s subsidiary in France has been involved in a dispute with a former owner of a business purchased by the Company’s French subsidiary. The former owner received a judgment in his favor in the amount of $0.4 million for payment of the contingent consideration portion of the purchase price for the business. The Company recorded an accrual for this judgment during 2016. The Company's subsidiary appealed the judgment and the entire judgment was overturned on appeal. The appeal process was completed in July 2018 in the Company's favor, and accordingly, the Company reversed the accrual as of June 30, 2018. The Company was a defendant in a lawsuit, Triumph Aerostructures, LLC d/b/a Triumph Aerostructures-Vought Aircraft Division v. Mistras Group, Inc., pending in Texas State district court, 193rd Judicial District, Dallas County, Texas, filed September 2016. The plaintiff alleged that in 2014 Mistras delivered a defective Ultrasonic inspection system and alleged damages of approximately $2.3 million, the amount it paid for the system. In January 2018, the Company agreed to settle this matter for a payment of $1.6 million and Mistras subsequently obtained ownership of the underlying ultrasonic inspection components. A charge for $1.6 million was recorded in 2017 and payment was made in February 2018. A Company vehicle was involved in an accident in which individuals were injured, property was damaged, and businesses alleged impacted by the accident have claimed economic losses. One lawsuit has been filed by one of the injured individuals in the U.S. District Court for the District of Colorado, McAllister v. Mistras Group, Inc. The Company has insurance for these types of matters and believes its insurance is sufficient to cover all claims resulting from this accident. However, the possibility exists that the insurance ultimately will not be sufficient to satisfy all claims or insurance coverage is denied, in which case the Company would be responsible for the amount of claims in excess of insurance coverage. Government Investigations In May 2015, the Company received a notice from the U.S. Environmental Protection Agency (“EPA”) that it performed a preliminary assessment at a leased facility the Company operates in Cudahy, California. Based upon the preliminary assessment, the EPA is conducting an investigation of the site, which includes taking groundwater and soil samples. The purpose of the investigation is to determine whether any hazardous materials were released from the facility. The Company has been informed that certain hazardous materials and pollutants have been found in the ground water in the general vicinity of the site and the EPA is attempting to ascertain the origination or source of these materials and pollutants. Given the historic industrial use of the site, the EPA determined that the site of the Cudahy facility should be examined, along with numerous other sites in the vicinity. In addition, in 2018, the California Department of Toxic Substances Control notified the owner of the property that it will be performing an additional investigation at the property. 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. 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 has 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 will incur a withdrawal liability related to these multi-employer pension plans. Accordingly, the Company recorded a charge of $5.9 million during the third quarter of 2018 and $0.5 million during the three months ended March 31, 2019 for this potential withdrawal liability. The balance of the estimated total amount of this potential liability as of March 31, 2019 is approximately $4.9 million, which is net of $1.5 million of payments made to one of the pension plans. Severance and labor disputes During 2018, the Company recorded approximately $1.2 million in charges related to labor claims for 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 believes it is entitled to indemnification from the sellers of the acquired company for most of these charges, but has not recorded the expected recovery of indemnification for these labor claims as the amount and timing of collection is uncertain as of March 31, 2019. 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 will not renew several of these leasing services contracts when they expire beginning in 2019. Due to the cap on the length of service allowed under the German Labor Lease Act, employees will have to be transitioned off the customer contracts. It is expected that the German subsidiary then will either terminate these employees, creating a severance obligation to the terminated employees, or transition them to the Company's other customers. As of March 31, 2019, the Company estimated approximately $1.6 million in severance payment obligations, which takes into account the Company's estimate with respect to the employees that would be transitioned to the German subsidiaries' other customers. Acquisition and disposition related contingencies The Company is liable for contingent consideration in connection with certain of its acquisitions. As of March 31, 2019, total potential acquisition-related contingent consideration ranged from zero to approximately $5.8 million and would be payable upon the achievement of specific performance metrics by certain of the acquired companies over the next 1.3 years of operations. See Note 5 - Acquisitions to these condensed consolidated financial statements for further discussion of the Company’s acquisitions. During the third quarter of 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 $2.0 million is remaining as of March 31, 2019. The agreement is based on third party pricing and the Company's planned purchase requirements over the next three years to meet the minimum contractual purchases.

Segment Disclosure

3 Months Ended

Mar. 31, 2019

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 and inspection 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.


•	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. All such intersegment transactions are eliminated in the Company’s consolidated financial reporting.

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



	Three months ended
	March 31, 2019			March 31, 2018
Revenues
Services	$	140,298		$	145,595
International	35,162			38,456
Products and Systems	3,432			6,184
Corporate and eliminations	(2,105		)	(2,605		)
	$	176,787		$	187,630



	Three months ended
	March 31, 2019			March 31, 2018
Gross profit
Services	$	37,365		$	34,710
International	10,360			10,707
Products and Systems	1,239			2,890
Corporate and eliminations	(90		)	(162		)
	$	48,874		$	48,145



	Three months ended
	March 31, 2019			March 31, 2018
Income (loss) from operations
Services	$	4,053		$	12,275
International	(215		)	920
Products and Systems	(1,328		)	273
Corporate and eliminations	(6,906		)	(7,069		)
	$	(4,396	)	$	6,399

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



	Three months ended
	March 31, 2019		March 31, 2018
Depreciation and amortization
Services	$	7,268	$	5,970
International	2,089		2,281
Products and Systems	290		362
Corporate and eliminations	21		35
	$	9,668	$	8,648



	March 31, 2019		December 31, 2018
Intangible assets, net
Services	$	96,893	$	98,362
International	10,437		11,143
Products and Systems	1,317		1,438
Corporate and eliminations	408		452
	$	109,055	$	111,395



	March 31, 2019		December 31, 2018
Total assets
Services	$	536,346	$	523,506
International	153,077		146,535
Products and Systems	12,832		12,264
Corporate and eliminations	23,182		11,732
	$	725,437	$	694,037

Revenues by geographic area for the three months ended March 31, 2019 and 2018, respectively, were as follows:



	Three months ended
	March 31, 2019		March 31, 2018
Revenues
United States	$	114,100	$	125,990
Other Americas	28,947		23,513
Europe	31,626		34,268
Asia-Pacific	2,114		3,859
	$	176,787	$	187,630

Repurchase of Common Stock	3 Months Ended
Repurchase of Common Stock	Mar. 31, 2019
Equity [Abstract]
Repurchase of Common Stock	Repurchase of Common Stock The Company's Board of Directors approved a $50 million stock repurchase plan in 2015. The Company retired all its repurchased shares during the fourth quarter of 2017. There were no repurchases of common stock during the three months ended March 31, 2019, and the Board of Directors approved the termination of the stock repurchase plan on April 1, 2019.

Description of Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements contained in this report are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, necessary for a fair presentation of the results for the interim periods of the years ending December 31, 2019 and 2018. Certain items included in these statements are based on management’s estimates. Actual results may differ from those estimates. The results of operations for any interim period are not necessarily indicative of the results expected for the year. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the notes to the audited consolidated financial statements contained in the Company’s Annual Report on Form 10-K (“2018 Annual Report”) for the year ended December 31, 2018, as filed with the Securities and Exchange Commission on March 15, 2019.
Principles of Consolidation	Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of Mistras Group, Inc. and its wholly and majority-owned subsidiaries. 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 condensed consolidated balance sheets. The non-controlling interests in net income, net of tax, is classified separately in the accompanying condensed consolidated statements of income. All significant intercompany accounts and transactions have been eliminated in consolidation.
Reclassification	Reclassification 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.
Income Taxes	The Company has completed the accounting for the adoption of the Tax Act, but the amounts recorded in 2019 for the Tax Act related to the calculations of the GILTI, FDII, executive compensation and meals and entertainment are the Company’s best estimates based on the current data and guidance available. The Company is continuing to evaluate the state tax conformity to the Tax Act, including the GILTI provisions. Given the complexity of the new GILTI tax rules, the Company is continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under U.S. GAAP, the Company is allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). In 2018, the Company made an accounting policy election to account for these effects under the period cost method. Mistras and its subsidiaries file tax returns in the U.S., including various state and local returns and in other foreign jurisdictions. The Company believes adequate provision has been made for all income tax uncertainties. Income Taxes On December 22, 2017, the United States enacted fundamental changes to federal tax law following the passage of the Tax Cuts and Jobs Act (the “Tax Act”).
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842), which the Company adopted as of January 1, 2019. Topic 842 requires the recognition of lease rights and obligations as assets and liabilities on the balance sheet. The Company elected the modified retrospective method permitted by the standard, upon which prior-period information has not been restated. The standard provided for several practical expedient options for use in transition. The Company elected to utilize the “package of practical expedients,” which permits the Company not to reassess previous conclusions reached on lease identification, lease classification and initial direct costs. The Company also elected to utilize the practical expedient available to not separate lease and non-lease components within the lease and have therefore accounted for all lease components as a single lease component. Adoption of the new standard resulted in the recording of a right-of-use (ROU) asset and liability related to the Company’s operating leases of approximately $38 million as of January 1, 2019. The new standard did not have a material impact to our statements of (loss) income or cash flows. In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350). This amendment eliminates Step Two of the goodwill impairment test. Under the amendments in this update, entities should perform the annual goodwill impairment test by comparing the carrying value of its reporting units to their fair value. An entity should record an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. Tax deductibility of goodwill should be considered in evaluating any reporting unit's impairment loss to be taken. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, with early adoption permitted. The Company early adopted ASU 2017-04 in the third quarter of 2017 for its condensed consolidated financial statements and related disclosures.
Revenue	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 condensed 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 receive advances or deposits from our customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are aggregated on an individual contract basis and reported on the condensed consolidated balance sheet at the end of each reporting period within accrued expenses and other current liabilities. Revenue The majority of the Company's revenues are derived from 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, which was adopted on January 1, 2018. 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 our 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 our 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 our 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. Our performance obligations are satisfied over time as work progresses or at a point in time. The majority of our revenue recognized over time as work progresses is related to our 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 our revenues are short-term in nature. The Company has many Master Service Agreements (MSAs) that specify an overall framework and terms of contract 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 our 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 our 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	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 capital 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. 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. 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.
Leases	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 our leases include one or more options to renew. When it is reasonably certain that we will exercise the option, we 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.

- Definition

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

+ References + Details

Revenue (Tables)

3 Months Ended

Mar. 31, 2019

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregated Revenues by Industry and Key Geographic Location

The following series of tables present our disaggregated revenues:

Revenue by industry was as follows:



Three months ended March 31, 2019	Services		International		Products		Corp/Elim			Total
Oil & Gas	$	91,666	$	9,704	$	15	$	—		$	101,385
Aerospace & Defense	12,794		11,654		307		—			24,755
Industrials	16,123		5,075		432		—			21,630
Power generation & Transmission	6,262		1,422		1,380		—			9,064
Other Process Industries	6,319		2,242		5		—			8,566
Infrastructure, Research & Engineering	2,590		2,733		847		—			6,170
Other	4,544		2,332		446		(2,105		)	5,217
Total	$	140,298	$	35,162	$	3,432	$	(2,105	)	$	176,787



Three months ended March 31, 2018	Services		International		Products		Corp/Elim			Total
Oil & Gas	$	103,290	$	8,108	$	563	$	—		$	111,961
Aerospace & Defense	12,457		14,465		667		—			27,589
Industrials	11,717		6,400		540		—			18,657
Power generation & Transmission	6,359		720		1,556		—			8,635
Other Process Industries	5,407		1,790		5		—			7,202
Infrastructure, Research & Engineering	2,180		2,519		500		—			5,199
Other	4,185		4,454		2,353		(2,605		)	8,387
Total	$	145,595	$	38,456	$	6,184	$	(2,605	)	$	187,630

Revenue per key geographic location was as follows:



Three months ended March 31, 2019	Services		International		Products		Corp/Elim			Total
United States	$	113,136	$	276	$	1,970	$	(1,282	)	$	114,100
Other Americas	26,708		2,229		66		(56		)	28,947
Europe	428		31,540		421		(763		)	31,626
Asia-Pacific	26		1,117		975		(4		)	2,114
Total	$	140,298	$	35,162	$	3,432	$	(2,105	)	$	176,787



Three months ended March 31, 2018	Services		International		Products		Corp/Elim			Total
United States	$	123,562	$	267	$	3,258	$	(1,097	)	$	125,990
Other Americas	21,783		1,902		81		(253		)	23,513
Europe	155		34,219		1,120		(1,226		)	34,268
Asia-Pacific	95		2,068		1,725		(29		)	3,859
Total	$	145,595	$	38,456	$	6,184	$	(2,605	)	$	187,630

Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock Option Activity

The following table sets forth a summary of the stock option activity, weighted average exercise prices and options outstanding as of March 31, 2019 and March 31, 2018:



	For the three months ended March 31,
	2019				2018
	Common Stock Options		Weighted Average Exercise Price		Common Stock Options	Weighted Average Exercise Price
Outstanding at beginning of period:	2,105		$	13.47	2,130	$	13.43
Granted	—		$	—	—	$	—
Exercised	(4	)	$	10.00	—	$	—
Expired or forfeited	—		$	—	—	$	—
Outstanding at end of period:	2,101		$	13.47	2,130	$	13.43

Schedule of Vesting Activity of Restricted Stock Unit Awards

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



	For the three months ended March 31,
	2019		2018
Restricted stock awards vested	50		4
Fair value of awards vested	$	0.7	$	0.1

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



	For the three months ended March 31,
	2019		2018
Awards issued	14		10
Grant date fair value of awards issued	$	0.2	$	0.2

Schedule of Company's Outstanding, Nonvested Restricted Share Units and Performance Restricted Stock Units

A summary of the Company's outstanding, non-vested restricted share units is as follows:



	For the three months ended March 31,
	2019				2018
	Units		Weighted Average Grant-Date Fair Value		Units		Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	443		$	20.55	532		$	21.05
Granted	334		$	14.04	211		$	19.20
Released	(50	)	$	19.21	(4	)	$	24.08
Forfeited	(8	)	$	20.78	(16	)	$	19.82
Outstanding at end of period:	719		$	17.61	723		$	20.52

A summary of the Company's PRSU activity is as follows:



	For the three months ended March 31,
	2019				2018
	Units		Weighted Average Grant-Date Fair Value		Units		Weighted Average Grant-Date Fair Value
Outstanding at beginning of period:	277		$	17.80	278		$	17.00
Granted	—		$	—	123		$	19.46
Performance condition adjustments	(3	)	$	18.46	5		$	18.36
Released	(17	)	$	20.22	—		$	—
Forfeited	—		$	—	(12	)	$	16.16
Outstanding at end of period:	257		$	17.35	394		$	17.71

- Definition

Tabular disclosure of an equity-based arrangement (such as stock or unit options and stock or unit awards) with an individual employee, which is generally an employment contract between the entity and a selected officer or key employee containing a promise by the employer to pay certain equity-based awards at future dates, sometimes including a period after retirement, upon compliance with stipulated requirements. This type of arrangement is distinguished from broader based employee benefit plans as it is usually tailored to the employee. Disclosure also typically includes the amount of related compensation expense recognized during the reporting period, the number of shares or units issued during the period under such arrangements, and the carrying amount as of the balance sheet date of the related liability.

+ References + Details

Earnings per Share (Tables)

3 Months Ended

Mar. 31, 2019

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:



	Three months ended
	March 31, 2019				March 31, 2018

Basic earnings per share:
Numerator:
Net (loss) income attributable to Mistras Group, Inc.	$	(5,293	)		$	2,907
Denominator:
Weighted average common shares outstanding	28,574				28,304
Basic earnings per share	$	(0.19	)		$	0.10

Diluted earnings per share:
Numerator:
Net (loss) income attributable to Mistras Group, Inc.	$	(5,293	)		$	2,907
Denominator:
Weighted average common shares outstanding	28,574				28,304
Dilutive effect of stock options outstanding	n/a			⁽¹⁾	745
Dilutive effect of restricted stock units outstanding	n/a			⁽²⁾	313
	28,574				29,362
Diluted earnings per share	$	(0.19	)		$	0.10

(1) - For the three months ended March 31, 2019, 212 shares were excluded from the calculation of diluted EPS due to the net loss for the period.

(2) - For the three months ended March 31, 2019, 168 shares were excluded from the calculation of diluted EPS due to the net loss for the period.

Acquisitions (Tables)

3 Months Ended

Mar. 31, 2019

Business Combinations [Abstract]

Schedule of Acquisition-Related Expenses



	Three months ended March 31,
	2019		2018
Due diligence, professional fees and other transaction costs	$	148	$	39
Adjustments to fair value of contingent consideration liabilities	305		(1,033		)
Acquisition-related expense (benefit), net	$	453	$	(994	)

Accounts Receivable, net (Tables)

3 Months Ended

Mar. 31, 2019

Receivables [Abstract]

Schedule of Accounts Receivable, Net

Accounts receivable consisted of the following:



	March 31, 2019			December 31, 2018

Trade accounts receivable	$	148,070		$	152,511
Allowance for doubtful accounts	(9,565		)	(4,187		)
Accounts receivable, net	$	138,505		$	148,324

Property, Plant and Equipment, net (Tables)

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment, Net

Property, plant and equipment consisted of the following:



	Useful Life (Years)	March 31, 2019			December 31, 2018

Land		$	2,671		$	2,680
Buildings and improvements	30-40	24,200			24,338
Office furniture and equipment	5-8	16,427			16,170
Machinery and equipment	5-7	212,114			208,245
		255,412			251,433
Accumulated depreciation and amortization		(161,496		)	(157,538		)
Property, plant and equipment, net		$	93,916		$	93,895

Goodwill (Tables)

3 Months Ended

Mar. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

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 period	—		—			—		—
Adjustments to preliminary purchase price allocations	—		—			—		—
Foreign currency translation	2,020		(583		)	—		1,437
Balance at March 31, 2019	$	245,496	$	35,200		$	—	$	280,696

Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2019

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Schedule of Gross Amount, Accumulated Amortization and Net Carrying Amount of Intangibles

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



		March 31, 2019							December 31, 2018
	Useful Life (Years)	Gross Amount		Accumulated Amortization			Net Carrying Amount		Gross Amount		Accumulated Amortization			Net Carrying Amount

Customer relationships	5-14	$	112,544	$	(62,631	)	$	49,913	$	112,624	$	(60,993	)	$	51,631
Software/Technology	3-15	68,391		(14,556		)	53,835		67,240		(13,319		)	53,921
Covenants not to compete	2-5	12,632		(11,055		)	1,577		12,593		(10,825		)	1,768
Other	2-12	10,344		(6,614		)	3,730		10,317		(6,242		)	4,075
Total		$	203,911	$	(94,856	)	$	109,055	$	202,774	$	(91,379	)	$	111,395

Accrued Expenses and Other Current Liabilities (Tables)

3 Months Ended

Mar. 31, 2019

Payables and Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:



	March 31, 2019		December 31, 2018

Accrued salaries, wages and related employee benefits	$	28,688	$	29,959
Contingent consideration, current portion	1,997		1,687
Accrued workers’ compensation and health benefits	4,750		5,086
Deferred revenue	4,963		5,046
Pension accrual	4,913		5,585
Right-of-use liability - operating	8,700		—
Other accrued expenses	25,630		26,532
Total accrued expenses and other current liabilities	$	79,641	$	73,895

Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Schedule of Long-Term Debt

Long-term debt consisted of the following:



	March 31, 2019			December 31, 2018

Senior credit facility	$	180,475		$	181,656
Senior secured term loan, net of debt issuance costs of $0.1 million	98,652			99,897
Notes payable	70			68
Other	8,509			8,999
Total debt	287,706			290,620
Less: Current portion	(6,787		)	(6,833		)
Long-term debt, net of current portion	$	280,919		$	283,787

- 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://www.xbrl.org/2003/role/presentationRef
-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=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-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 4: http://www.xbrl.org/2003/role/presentationRef
-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=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21521-112644

+ Details

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Changes in Fair Value of Level 3 Contingent Consideration

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



	Three months ended March 31,
	2019		2018
Beginning balance	$	2,365	$	5,508
Acquisitions	—		—
Payments	—		(1,503		)
Accretion of liability	44		65
Revaluation	261		(1,098		)
Foreign currency translation	29		(63		)
Ending balance	$	2,699	$	2,909

Leases (Tables)

3 Months Ended

Mar. 31, 2019

Leases [Abstract]

Schedule of Supplemental Balance Sheet Information

The Company’s Condensed Consolidated Balance Sheet includes the following related to operating leases:



Leases	Classification	As of March 31, 2019
Assets
Right-of-use assets	Other Assets	$	36,289

Liabilities
Right-of use liability - current	Accrued and other current liabilities	$	8,700
Right-of-use liability - long term	Other liabilities	28,340
Total right-of-use liabilities		$	37,040

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

The components of lease costs were as follows:



	Classification	For the three months ended March 31, 2019
Finance lease expense
Amortization of ROU assets	Depreciation and amortization	$	1,292
Interest on lease liabilities	Interest expense	197
Operating lease expense	Costs of goods sold or Selling, General & Administrative expenses	3,023
Short-term lease expense	Costs of goods sold or Selling, General & Administrative expenses	133
Variable lease expense	Costs of goods sold or Selling, General & Administrative expenses	272
Total		$	4,917

Other information related to leases was as follows:



	March 31, 2019
Cash paid for amounts included in the measurement of lease liabilities for finance leases
Finance - financing cash flows	$	1,249
Finance - operating cash flows	$	197
Operating - operating cash flows	$	3,079
ROU assets obtained in the exchange for lease liabilities
Finance leases	$	1,086
Operating leases	$	1,348
Weighted average remaining lease term (in years)
Finance leases	5.8
Operating leases	6.0
Weighted average discount rate
Finance leases	6.45		%
Operating leases	5.97		%

Schedule of Maturities of Finance Lease Liabilities

Maturities of lease liabilities as of March 31, 2019 were as follows:



	Finance			Operating
Remaining of 2019	$	4,916		$	8,212
2020	3,694			9,162
2021	2,415			6,666
2022	1,546			5,064
2023	637			4,526
Thereafter	821			11,003
Total	14,029			44,633
Less: Present value discount	(1,219		)	(7,593		)
Lease liability	$	12,810		$	37,040

Schedule of Maturities of Finance Lease Liabilities

Maturities of lease liabilities as of March 31, 2019 were as follows:



	Finance			Operating
Remaining of 2019	$	4,916		$	8,212
2020	3,694			9,162
2021	2,415			6,666
2022	1,546			5,064
2023	637			4,526
Thereafter	821			11,003
Total	14,029			44,633
Less: Present value discount	(1,219		)	(7,593		)
Lease liability	$	12,810		$	37,040

Schedule of Future Minimum Operating Lease Commitments Under Previous Lease Accounting Guidance



2019	$	10,939
2020	8,764
2021	6,327
2022	4,826
2023	4,239
Thereafter	10,667
Total	$	45,762

Segment Disclosure (Tables)

3 Months Ended

Mar. 31, 2019

Segment Reporting [Abstract]

Schedule of Consolidated Financial Information by Segment

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



	Three months ended
	March 31, 2019			March 31, 2018
Revenues
Services	$	140,298		$	145,595
International	35,162			38,456
Products and Systems	3,432			6,184
Corporate and eliminations	(2,105		)	(2,605		)
	$	176,787		$	187,630



	Three months ended
	March 31, 2019			March 31, 2018
Gross profit
Services	$	37,365		$	34,710
International	10,360			10,707
Products and Systems	1,239			2,890
Corporate and eliminations	(90		)	(162		)
	$	48,874		$	48,145



	Three months ended
	March 31, 2019			March 31, 2018
Income (loss) from operations
Services	$	4,053		$	12,275
International	(215		)	920
Products and Systems	(1,328		)	273
Corporate and eliminations	(6,906		)	(7,069		)
	$	(4,396	)	$	6,399

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



	Three months ended
	March 31, 2019		March 31, 2018
Depreciation and amortization
Services	$	7,268	$	5,970
International	2,089		2,281
Products and Systems	290		362
Corporate and eliminations	21		35
	$	9,668	$	8,648



	March 31, 2019		December 31, 2018
Intangible assets, net
Services	$	96,893	$	98,362
International	10,437		11,143
Products and Systems	1,317		1,438
Corporate and eliminations	408		452
	$	109,055	$	111,395



	March 31, 2019		December 31, 2018
Total assets
Services	$	536,346	$	523,506
International	153,077		146,535
Products and Systems	12,832		12,264
Corporate and eliminations	23,182		11,732
	$	725,437	$	694,037

Schedule of Revenues by Geographic Areas

Revenues by geographic area for the three months ended March 31, 2019 and 2018, respectively, were as follows:



	Three months ended
	March 31, 2019		March 31, 2018
Revenues
United States	$	114,100	$	125,990
Other Americas	28,947		23,513
Europe	31,626		34,268
Asia-Pacific	2,114		3,859
	$	176,787	$	187,630

Description of Business and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019
Concentration Risk [Line Items]
Effective income tax rate	33.00%	37.00%
ROU assets	$ 36,289
Operating lease liabilities	$ 37,040
ASU 2016-02
Concentration Risk [Line Items]
ROU assets			$ 38,000
Operating lease liabilities			$ 38,000

Revenue - Additional Information (Details) $ in Millions	3 Months Ended
Revenue - Additional Information (Details) $ in Millions	Mar. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, expected timing of satisfaction period	1 year
Revenue recognized that was included in contract liability balance at the beginning of the year	$ 1.8
Revenue, practical expedient, incremental cost of obtaining a contract, maximum period	1 year

Revenue - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 176,787	$ 187,630
United States
Disaggregation of Revenue [Line Items]
Revenues	114,100	125,990
Other Americas
Disaggregation of Revenue [Line Items]
Revenues	28,947	23,513
Europe
Disaggregation of Revenue [Line Items]
Revenues	31,626	34,268
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	2,114	3,859
Oil & Gas
Disaggregation of Revenue [Line Items]
Revenues	101,385	111,961
Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenues	24,755	27,589
Industrials
Disaggregation of Revenue [Line Items]
Revenues	21,630	18,657
Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenues	9,064	8,635
Other Process Industries
Disaggregation of Revenue [Line Items]
Revenues	8,566	7,202
Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenues	6,170	5,199
Other
Disaggregation of Revenue [Line Items]
Revenues	5,217	8,387
Operating segments \| Services
Disaggregation of Revenue [Line Items]
Revenues	140,298	145,595
Operating segments \| Services \| United States
Disaggregation of Revenue [Line Items]
Revenues	113,136	123,562
Operating segments \| Services \| Other Americas
Disaggregation of Revenue [Line Items]
Revenues	26,708	21,783
Operating segments \| Services \| Europe
Disaggregation of Revenue [Line Items]
Revenues	428	155
Operating segments \| Services \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	26	95
Operating segments \| Services \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenues	91,666	103,290
Operating segments \| Services \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenues	12,794	12,457
Operating segments \| Services \| Industrials
Disaggregation of Revenue [Line Items]
Revenues	16,123	11,717
Operating segments \| Services \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenues	6,262	6,359
Operating segments \| Services \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenues	6,319	5,407
Operating segments \| Services \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenues	2,590	2,180
Operating segments \| Services \| Other
Disaggregation of Revenue [Line Items]
Revenues	4,544	4,185
Operating segments \| International
Disaggregation of Revenue [Line Items]
Revenues	35,162	38,456
Operating segments \| International \| United States
Disaggregation of Revenue [Line Items]
Revenues	276	267
Operating segments \| International \| Other Americas
Disaggregation of Revenue [Line Items]
Revenues	2,229	1,902
Operating segments \| International \| Europe
Disaggregation of Revenue [Line Items]
Revenues	31,540	34,219
Operating segments \| International \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	1,117	2,068
Operating segments \| International \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenues	9,704	8,108
Operating segments \| International \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenues	11,654	14,465
Operating segments \| International \| Industrials
Disaggregation of Revenue [Line Items]
Revenues	5,075	6,400
Operating segments \| International \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenues	1,422	720
Operating segments \| International \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenues	2,242	1,790
Operating segments \| International \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenues	2,733	2,519
Operating segments \| International \| Other
Disaggregation of Revenue [Line Items]
Revenues	2,332	4,454
Operating segments \| Products
Disaggregation of Revenue [Line Items]
Revenues	3,432	6,184
Operating segments \| Products \| United States
Disaggregation of Revenue [Line Items]
Revenues	1,970	3,258
Operating segments \| Products \| Other Americas
Disaggregation of Revenue [Line Items]
Revenues	66	81
Operating segments \| Products \| Europe
Disaggregation of Revenue [Line Items]
Revenues	421	1,120
Operating segments \| Products \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	975	1,725
Operating segments \| Products \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenues	15	563
Operating segments \| Products \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenues	307	667
Operating segments \| Products \| Industrials
Disaggregation of Revenue [Line Items]
Revenues	432	540
Operating segments \| Products \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenues	1,380	1,556
Operating segments \| Products \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenues	5	5
Operating segments \| Products \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenues	847	500
Operating segments \| Products \| Other
Disaggregation of Revenue [Line Items]
Revenues	446	2,353
Corp/Elim
Disaggregation of Revenue [Line Items]
Revenues	(2,105)	(2,605)
Corp/Elim \| United States
Disaggregation of Revenue [Line Items]
Revenues	(1,282)	(1,097)
Corp/Elim \| Other Americas
Disaggregation of Revenue [Line Items]
Revenues	(56)	(253)
Corp/Elim \| Europe
Disaggregation of Revenue [Line Items]
Revenues	(763)	(1,226)
Corp/Elim \| Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	(4)	(29)
Corp/Elim \| Oil & Gas
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Industrials
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Power generation & Transmission
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Other Process Industries
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corp/Elim \| Other
Disaggregation of Revenue [Line Items]
Revenues	$ (2,105)	$ (2,605)

Share-Based Compensation - Equity Incentive Plans (Details)	3 Months Ended
	Mar. 31, 2019 plan shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employee stock ownership plans (plan) \| plan	3
2007 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards that may be granted (in shares)	0
2009 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards that may be granted (in shares)	0

Share-Based Compensation - Stock Options (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 0
Common Stock Options (in shares)
Outstanding at the beginning of the period: (in shares)	2,105,000	2,130,000
Granted (in shares)	0	0
Exercised (in shares)	(4,000)	0
Expired or forfeited (in shares)	0	0
Outstanding at the end of the period: (in shares)	2,101,000	2,130,000
Weighted Average Exercise Price (in dollar per share)
Outstanding at the beginning of period: (in dollars per share)	$ 13.47	$ 13.43
Granted (in dollars per share)	0.00	0.00
Exercised (in dollars per share)	10.00	0.00
Expired or forfeited (in dollars per share)	0.00	0.00
Outstanding at the end of period: (in dollars per share)	$ 13.47	$ 13.43
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense	$ 0	$ 0

Share-Based Compensation - Restricted Stock Unit Awards - Narrative (Details) - Restricted Stock Units - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share-based compensation expense (benefit)	$ 0.9	$ 0.8
Unrecognized compensation cost, net of estimated forfeitures	$ 10.0
Weighted-average period over which unrecognized compensation cost is expected to be recognized (years)	2 years 11 months

Share-Based Compensation - Vesting Activity of Restricted Stock Unit Awards (Details) - Restricted Stock Units - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards vested (in shares)	50	4
Fair value of awards vested	$ 0.7	$ 0.1

Share-Based Compensation - Fully-vested Common Stock Issued to Non-employee Directors (Details) - Common Stock - Non-employee directors shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) director shares	Mar. 31, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of non-employee directors to whom fully vested common stock is granted \| director	5
Awards issued (in shares) \| shares	14	10
Grant date fair value of awards issued \| $	$ 0.2	$ 0.2

Share-Based Compensation - Restricted Stock Units Awards - Activity (Details) - Restricted Stock Units - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restricted Stock Units Awards (Units)
Outstanding at beginning of period: (in shares)	443	532
Granted (in shares)	334	211
Released (in shares)	(50)	(4)
Forfeited (in shares)	(8)	(16)
Outstanding at end of period: (in shares)	719	723
Weighted Average Grant-Date Fair Value (in dollars per share)
Outstanding at the beginning of period: (in dollars per share)	$ 20.55	$ 21.05
Granted (in dollars per share)	14.04	19.20
Released (in dollars per share)	19.21	24.08
Forfeited (in dollars per share)	20.78	19.82
Outstanding at end of period: (in dollars per share)	$ 17.61	$ 20.52

Share-Based Compensation - Performance Restricted Stock Units - Narrative (Details) - PRSUs shares in Thousands, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019 USD ($) performance_metric shares	Mar. 31, 2018 USD ($) shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units increased (decreased) during the period (in shares)			(3)	5
Recognized share-based compensation expense (benefit) \| $	$ 0.2	$ 0.1
Unrecognized compensation cost \| $	$ 1.5
Nonvested shares outstanding (in shares)	257	394	277	278
Weighted-average period over which unrecognized compensation cost is expected to be recognized (years)	1 year 9 months 12 days
Awards granted (in shares)	0	123
Executive and Senior Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period (years)	1 year
Number of performance award metrics \| performance_metric	3
Requisite service period (years)	5 years
Executive and Senior Officers \| Anniversary 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
Executive and Senior Officers \| Anniversary 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
Executive and Senior Officers \| Anniversary 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
Executive and Senior Officers \| Anniversary 4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%

Share-Based Compensation - Performance Restricted Stock Units - Activity (Details) - PRSUs - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Performance Restricted Stock (Units)
Outstanding at beginning of period: (in shares)	277	278
Granted (in shares)	0	123
Performance condition adjustments (in shares)	(3)	5
Released (in shares)	(17)	0
Forfeited (in shares)	0	(12)
Outstanding at end of period: (in shares)	257	394
Weighted Average Grant-Date Fair Value (in dollars per share)
Outstanding at the beginning of period: (in dollars per share)	$ 17.80	$ 17.00
Granted (in dollars per share)	0.00	19.46
Performance condition adjustments (in dollars per share)	18.46	18.36
Released (in dollars per share)	20.22	0.00
Forfeited (in dollars per share)	0.00	16.16
Outstanding at end of period: (in dollars per share)	$ 17.35	$ 17.71

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic earnings per share:
Net (loss) income attributable to Mistras Group, Inc.	$ (5,293)	$ 2,907
Denominator:
Weighted average common shares outstanding (in shares)	28,574	28,304
Basic earnings (loss) per share (in dollars per share)	$ (0.19)	$ 0.10
Denominator:
Weighted average common shares outstanding (in shares)	28,574	28,304
Dilutive effect of stock options outstanding (in shares)		745
Dilutive effect of restricted stock units outstanding (in shares)		313
Weighted average common shares outstanding, diluted (in shares)	28,574	29,362
Diluted earnings (loss) per share (in dollars per share)	$ (0.19)	$ 0.10
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares excluded from calculation of diluted EPS due to net loss position (in shares)	212
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares excluded from calculation of diluted EPS due to net loss position (in shares)	168

Acquisitions - Additional Information (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019 entity	Mar. 31, 2018 entity	Dec. 31, 2018 USD ($) entity
Acquisitions
Number of acquisitions \| entity	0	0	1
Business deductible for tax purposes			$ 83.2
Customer Relationships and Covenants Not To Compete
Acquisitions
Intangible assets acquired			$ 59.6

Acquisitions - Acquisition-Related Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Combinations [Abstract]
Due diligence, professional fees and other transaction costs	$ 148	$ 39
Adjustments to fair value of contingent consideration liabilities	305	(1,033)
Acquisition-related expense (benefit), net	$ 453	$ (994)

Accounts Receivable, net (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Trade accounts receivable	$ 148,070	$ 152,511
Allowance for doubtful accounts	(9,565)	(4,187)
Accounts receivable, net	138,505	148,324
Unbilled revenues accrued	$ 25,900	$ 16,100

Accounts Receivable, net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled revenues accrued	$ 25,900	$ 16,100
Bad debt provision for troubled customers, net of recoveries	5,491		$ 0
Recovery from unrelated bad debt provision	200
Renewable Energy Industry Customer \| Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Bad debt provision for troubled customers, net of recoveries	$ 5,700	$ 700

Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 255,412		$ 251,433
Accumulated depreciation and amortization	(161,496)		(157,538)
Property, plant and equipment, net	93,916		93,895
Depreciation expense	6,100	$ 6,100
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	2,671		2,680
Buildings and improvements
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 24,200		24,338
Buildings and improvements \| Minimum
Property, Plant and Equipment, net
Useful Life (Years)	30 years
Buildings and improvements \| Maximum
Property, Plant and Equipment, net
Useful Life (Years)	40 years
Office furniture and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 16,427		16,170
Office furniture and equipment \| Minimum
Property, Plant and Equipment, net
Useful Life (Years)	5 years
Office furniture and equipment \| Maximum
Property, Plant and Equipment, net
Useful Life (Years)	8 years
Machinery and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 212,114		$ 208,245
Machinery and equipment \| Minimum
Property, Plant and Equipment, net
Useful Life (Years)	5 years
Machinery and equipment \| Maximum
Property, Plant and Equipment, net
Useful Life (Years)	7 years

Goodwill - Changes in Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2018	$ 279,259
Goodwill acquired during the period	0
Adjustments to preliminary purchase price allocations	0
Foreign currency translation	1,437
Balance at March 31, 2019	280,696
Services
Goodwill [Roll Forward]
Balance at December 31, 2018	243,476
Goodwill acquired during the period	0
Adjustments to preliminary purchase price allocations	0
Foreign currency translation	2,020
Balance at March 31, 2019	245,496
International
Goodwill [Roll Forward]
Balance at December 31, 2018	35,783
Goodwill acquired during the period	0
Adjustments to preliminary purchase price allocations	0
Foreign currency translation	(583)
Balance at March 31, 2019	35,200
Products and Systems
Goodwill [Roll Forward]
Balance at December 31, 2018	0
Goodwill acquired during the period	0
Adjustments to preliminary purchase price allocations	0
Foreign currency translation	0
Balance at March 31, 2019	$ 0

Goodwill - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill cumulative impairment loss	$ 23.1	$ 23.1
Products and Systems
Goodwill [Line Items]
Goodwill cumulative impairment loss	13.2	13.2
International
Goodwill [Line Items]
Goodwill cumulative impairment loss	$ 9.9	$ 9.9

Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 203,911		$ 202,774
Accumulated Amortization	(94,856)		(91,379)
Net Carrying Amount	109,055		111,395
Amortization expense	3,600	$ 2,500
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	112,544		112,624
Accumulated Amortization	(62,631)		(60,993)
Net Carrying Amount	$ 49,913		51,631
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)	14 years
Software/Technology
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 68,391		67,240
Accumulated Amortization	(14,556)		(13,319)
Net Carrying Amount	$ 53,835		53,921
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	$ 12,632		12,593
Accumulated Amortization	(11,055)		(10,825)
Net Carrying Amount	$ 1,577		1,768
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	$ 10,344		10,317
Accumulated Amortization	(6,614)		(6,242)
Net Carrying Amount	$ 3,730		$ 4,075
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

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued salaries, wages and related employee benefits	$ 28,688	$ 29,959
Contingent consideration, current portion	1,997	1,687
Accrued workers’ compensation and health benefits	4,750	5,086
Deferred revenue	4,963	5,046
Pension accrual	4,913	5,585
Right-of use liability - current	8,700
Other accrued expenses	25,630	26,532
Total accrued expenses and other current liabilities	$ 79,641	$ 73,895

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total debt	$ 287,706	$ 290,620
Less: Current portion	(6,787)	(6,833)
Long-term debt, net of current portion	280,919	283,787
Senior credit facility
Debt Instrument [Line Items]
Total debt	180,475	181,656
Senior credit facility \| Term A Loan Facility
Debt Instrument [Line Items]
Total debt	98,652	99,897
Debt issuance costs	100	100
Notes payable
Debt Instrument [Line Items]
Total debt	70	68
Other
Debt Instrument [Line Items]
Total debt	$ 8,509	$ 8,999

Long-Term Debt - Additional Information (Details)			3 Months Ended
Long-Term Debt - Additional Information (Details)	Dec. 08, 2017 USD ($) quarter	Oct. 31, 2014 quarter	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Notes Payable and Other
Debt outstanding			$ 287,706,000	$ 290,620,000
Senior credit facility
Senior Credit Facility
Maximum borrowing capacity			300,000,000
Line of credit facility, higher borrowing capacity option			450,000,000
Maximum borrowing capacity in non-U.S. Dollar currencies			100,000,000.0
Maximum amount available for the issuance of letters of credit			20,000,000.0
Outstanding borrowings			279,200,000
Outstanding letters of credit			5,400,000
Capitalized debt modification costs			1,000,000
Amount of non-recurring charges used as threshold used for calculation of funded debt leverage ratio	$ 10,000,000.0
Number of consecutive fiscal quarters used for calculating funded debt leverage ratio \| quarter	4	4
Funded debt leverage ratio at which the entity will have the benefit of lowest interest margin (less than or equal to)		1.0
Funded debt leverage ratio at which the entity will bear the maximum interest rate margin (greater than)		3.25
Additional interest rate margin if funded debt leverage ratio exceeds threshold (as a percent)		2.00%
Interest coverage ratio (greater than)		1.25
Preceding period used for calculating interest coverage ratio		12 months
Number of fiscal quarters to temporary increase funded debt leverage ratio \| quarter	4
Notes Payable and Other
Debt outstanding			180,475,000	181,656,000
Senior credit facility \| Through December 31, 2018
Senior Credit Facility
Funded debt leverage ratio for additional interest payment (less than)		4.25
Senior credit facility \| From March 31, 2019 to September 30, 2019
Senior Credit Facility
Funded debt leverage ratio for additional interest payment (less than)		4.0
Senior credit facility \| As of December 31, 2019
Senior Credit Facility
Funded debt leverage ratio for additional interest payment (less than)		3.75
Senior credit facility \| Minimum
Senior Credit Facility
Temporary increase in funded debt leverage ratio	3.5
Senior credit facility \| Minimum \| As of March 31, 2020 and all quarterly periods thereafter
Senior Credit Facility
Funded debt leverage ratio for additional interest payment (less than)	3.50
Senior credit facility \| Maximum
Senior Credit Facility
Temporary increase in funded debt leverage ratio	4.0
Senior credit facility \| LIBOR
Senior Credit Facility
Reference rate, description		"LIBOR"
Senior credit facility \| LIBOR \| Minimum
Senior Credit Facility
Margin (as a percent)		1.00%
Senior credit facility \| LIBOR \| Maximum
Senior Credit Facility
Margin (as a percent)		2.00%
Senior credit facility \| Base rate
Senior Credit Facility
Reference rate, description		base rate
Senior credit facility \| Base rate \| Minimum
Senior Credit Facility
Margin (as a percent)		(0.375%)
Senior credit facility \| Base rate \| Maximum
Senior Credit Facility
Margin (as a percent)		(1.25%)
Senior credit facility \| Term A Loan Facility
Senior Credit Facility
Maximum borrowing capacity			100,000,000
Notes Payable and Other
Debt outstanding			$ 98,652,000	99,897,000
Notes payable
Notes Payable and Other
Interest rate (as a percent)			3.95%
Debt outstanding			$ 70,000	68,000
Other
Notes Payable and Other
Debt outstanding			$ 8,509,000	$ 8,999,000
Other \| Minimum
Notes Payable and Other
Interest rate (as a percent)			0.40%
Debt monthly periodic payments			$ 1,000
Other \| Maximum
Notes Payable and Other
Interest rate (as a percent)			6.20%
Debt monthly periodic payments			$ 17,000

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended
Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Contingent Consideration Liability [Roll Forward]
Revaluation	$ 305	$ (1,033)
Level 3
Contingent Consideration Liability [Roll Forward]
Beginning balance	2,365	5,508
Acquisitions	0	0
Payments	0	(1,503)
Accretion of liability	44	65
Revaluation	261	(1,098)
Foreign currency translation	29	(63)
Ending balance	$ 2,699	$ 2,909

Leases - Supplemental Balance Sheet Information (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Leases [Abstract]
Right-of-use assets	$ 36,289
Right-of use liability - current	8,700
Right-of-use liability - long term	28,340
Total right-of-use liabilities	$ 37,040

Leases - Additional Information (Details) $ in Thousands	3 Months Ended
Leases - Additional Information (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease liabilities	$ 37,040
Operating - operating cash flows	3,079
Finance lease, right-of-use assets	14,900
Operating Lease Arrangement \| Company's Headquarters
Lessee, Lease, Description [Line Items]
Operating lease liabilities	5,000
Operating - operating cash flows	$ 200

Leases - Lease Cost (Details) $ in Thousands	3 Months Ended
Leases - Lease Cost (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Finance lease expense
Amortization of ROU assets	$ 1,292
Interest on lease liabilities	197
Operating lease expense	3,023
Short-term lease expense	133
Variable lease expense	272
Total	$ 4,917

Leases - Other Information Related to Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Cash paid for amounts included in the measurement of lease liabilities for finance leases
Finance - financing cash flows	$ 1,249
Finance - operating cash flows	197
Operating - operating cash flows	3,079
ROU assets obtained in the exchange for lease liabilities
Finance leases	1,086
Operating leases	$ 1,348
Weighted average remaining lease term (in years)
Finance leases	5 years 9 months 18 days
Operating leases	6 years
Weighted average discount rate
Finance leases	6.45%
Operating leases	5.97%

Leases - Maturity of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Finance
Remaining of 2019	$ 4,916
2020	3,694
2021	2,415
2022	1,546
2023	637
Thereafter	821
Total	14,029
Less: Present value discount	(1,219)
Lease liability	12,810
Operating
Remaining of 2019	8,212
2020	9,162
2021	6,666
2022	5,064
2023	4,526
Thereafter	11,003
Total	44,633
Less: Present value discount	(7,593)
Lease liability	$ 37,040

Leases - Future Minimum Operating Lease Commitments Under Previous Accounting Guidance (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Leases [Abstract]
2019	$ 10,939
2020	8,764
2021	6,327
2022	4,826
2023	4,239
Thereafter	10,667
Total	$ 45,762

Commitments and Contingencies (Details)	1 Months Ended			3 Months Ended			12 Months Ended
Commitments and Contingencies (Details)	Jan. 31, 2018 USD ($)	Apr. 30, 2017	Sep. 30, 2016 USD ($)	Mar. 31, 2019 USD ($) arrangement subsidiary	Sep. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Litigation
Charges related to potential liability for withdrawal from multi-employer pension plan				$ 534,000		$ 0
Pension accrual				4,913,000			$ 5,585,000
Payment to pension plan				1,500,000
Dispute with former owner of company's French subsidiary \| Settled Litigation \| AGL Services Company v. Mistras Group \| Affiliated Entity
Litigation
Litigation settlement, amount awarded to other party									$ 400,000
Defective ultrasound inspection system \| Settled Litigation
Litigation
Amount of damages claimed			$ 2,300,000
Defective ultrasound inspection system \| Settled Litigation \| Triumph Aerostructures-Vought Aircraft Division v. Mistras Group
Litigation
Litigation settlement, amount awarded to other party	$ 1,600,000
Litigation expenses								$ 1,600,000
Pension related contingencies
Litigation
Charges related to potential liability for withdrawal from multi-employer pension plan				$ 500,000	$ 5,900,000
Pension related contingencies \| Pending Litigation
Litigation
Number of Company's subsidiaries that could experience significant decline in employees covered by collective-bargaining arrangement \| subsidiary				1
Number of collective-bargaining agreements with significant decline in employees covered \| arrangement				1
Severance and labor disputes \| Affiliated Entity \| GERMANY \| Selling, General and Administrative Expenses
Litigation
Estimated severance				$ 1,600,000
Severance and labor disputes \| Pending Litigation \| NDT Do Brazil, LTDA \| Selling, General and Administrative Expenses
Litigation
Contingency charges							$ 1,200,000
Severance and labor disputes \| Pending Litigation \| Affiliated Entity \| GERMANY
Litigation
Temporary employment contract period		18 months
Acquisition-related contingencies
Litigation
Potential acquisition-related contingent consideration, low end of range				0
Potential acquisition-related contingent consideration, high end of range				$ 5,800,000
Remaining period over which potential acquisition-related contingent consideration would be payable				1 year 3 months 1 day
Products and Systems \| Foreign Subsidiaries \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Litigation
Term of agreement to purchase products from the buyer on sale of subsidiary					3 years
Amount of purchased commitment to buy products from the buyer on sale of subsidiary					$ 2,300,000
Remaining balance under purchase commitment agreement				$ 2,000,000

Segment Disclosure - Financial Information by Segment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) segment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting [Abstract]
Number of operating segments \| segment	3
Financial information by segment
Revenues	$ 176,787	$ 187,630
Gross profit	48,874	48,145
Income (loss) from operations	(4,396)	6,399
Depreciation and amortization	9,668	8,648
Intangible assets, net	109,055		$ 111,395
Total assets	725,437		694,037
Operating segments \| Services
Financial information by segment
Revenues	140,298	145,595
Gross profit	37,365	34,710
Income (loss) from operations	4,053	12,275
Depreciation and amortization	7,268	5,970
Intangible assets, net	96,893		98,362
Total assets	536,346		523,506
Operating segments \| International
Financial information by segment
Revenues	35,162	38,456
Gross profit	10,360	10,707
Income (loss) from operations	(215)	920
Depreciation and amortization	2,089	2,281
Intangible assets, net	10,437		11,143
Total assets	153,077		146,535
Operating segments \| Products and Systems
Financial information by segment
Revenues	3,432	6,184
Gross profit	1,239	2,890
Income (loss) from operations	(1,328)	273
Depreciation and amortization	290	362
Intangible assets, net	1,317		1,438
Total assets	12,832		12,264
Corporate and eliminations
Financial information by segment
Revenues	(2,105)	(2,605)
Gross profit	(90)	(162)
Income (loss) from operations	(6,906)	(7,069)
Depreciation and amortization	21	$ 35
Intangible assets, net	408		452
Total assets	$ 23,182		$ 11,732

Segment Disclosure - Revenues by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue and long-lived assets by geographic area
Revenues	$ 176,787	$ 187,630
United States
Revenue and long-lived assets by geographic area
Revenues	114,100	125,990
Other Americas
Revenue and long-lived assets by geographic area
Revenues	28,947	23,513
Europe
Revenue and long-lived assets by geographic area
Revenues	31,626	34,268
Asia-Pacific
Revenue and long-lived assets by geographic area
Revenues	$ 2,114	$ 3,859

Repurchase of Common Stock (Details) - Stock Repurchase Plan - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2015
Class of Stock [Line Items]
Stock repurchase plan, amount approved		$ 50,000,000
Repurchases of common stock (in shares)	0