Mistras (MG) 10-Q 11 Jan 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Nov. 30, 2016	Jan. 02, 2017
Document and Entity Information
Entity Registrant Name	Mistras Group, Inc.
Entity Central Index Key	1,436,126
Document Type	10-Q
Document Period End Date	Nov. 30, 2016
Amendment Flag	false
Current Fiscal Year End Date	--05-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,796,487
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016
Current Assets
Cash and cash equivalents	$ 26,261	$ 21,188
Accounts receivable, net	141,367	137,913
Inventories	10,396	9,918
Deferred income taxes	6,174	6,216
Prepaid expenses and other current assets	16,759	12,711
Total current assets	200,957	187,946
Property, plant and equipment, net	74,580	78,676
Intangible assets, net	42,137	43,492
Goodwill	171,060	169,220
Deferred income taxes	952	1,000
Other assets	2,480	2,341
Total assets	492,166	482,675
Current Liabilities
Accounts payable	8,112	10,796
Accrued expenses and other current liabilities	64,257	62,983
Current portion of long-term debt	2,028	12,553
Current portion of capital lease obligations	6,689	7,835
Income taxes payable	3,814	2,710
Total current liabilities	84,900	96,877
Long-term debt, net of current portion	91,332	72,456
Obligations under capital leases, net of current portion	10,340	11,932
Deferred income taxes	19,670	18,328
Other long-term liabilities	7,679	6,794
Total liabilities	213,921	206,387
Commitments and contingencies
Equity
Preferred stock, 10,000,000 shares authorized	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized	292	290
Additional paid-in capital	215,956	213,737
Treasury stock, at cost	(7,000)	0
Retained earnings	96,102	82,235
Accumulated other comprehensive loss	(27,262)	(20,099)
Total Mistras Group, Inc. stockholders’ equity	278,088	276,163
Noncontrolling interests	157	125
Total equity	278,245	276,288
Total liabilities and equity	$ 492,166	$ 482,675

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Nov. 30, 2016	May 31, 2016
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

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Income Statement [Abstract]
Revenue	$ 176,642	$ 194,786	$ 345,085	$ 374,639
Cost of revenue	119,214	132,720	232,195	256,120
Depreciation	5,352	5,141	10,758	10,320
Gross profit	52,076	56,925	102,132	108,199
Selling, general and administrative expenses	36,249	34,008	71,526	69,844
Research and engineering	580	601	1,212	1,222
Depreciation and amortization	2,542	2,822	5,139	5,603
Acquisition-related expense (benefit), net	197	(75)	591	(971)
Income from operations	12,508	19,569	23,664	32,501
Interest expense	928	1,335	1,748	3,257
Income before provision for income taxes	11,580	18,234	21,916	29,244
Provision for income taxes	4,284	6,804	8,011	10,967
Net income	7,296	11,430	13,905	18,277
Less: net income (loss) attributable to noncontrolling interests, net of taxes	26	5	39	(20)
Net income attributable to Mistras Group, Inc.	$ 7,270	$ 11,425	$ 13,866	$ 18,297
Earnings per common share
Basic (in dollars per share)	$ 0.25	$ 0.40	$ 0.48	$ 0.64
Diluted (in dollars per share)	$ 0.24	$ 0.39	$ 0.46	$ 0.62
Weighted average common shares outstanding:
Basic (in shares)	29,056	28,869	29,016	28,796
Diluted (in shares)	29,998	29,594	30,139	29,641

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 7,296	$ 11,430	$ 13,905	$ 18,277
Other comprehensive loss:
Foreign currency translation adjustments	(3,580)	(384)	(7,163)	(1,036)
Comprehensive income	3,716	11,046	6,742	17,241
Less: comprehensive (loss) income attributable to noncontrolling interest	(3)	5	(7)	(20)
Comprehensive income attributable to Mistras Group, Inc.	$ 3,719	$ 11,041	$ 6,749	$ 17,261

Unaudited Condensed Consolidat6

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Cash flows from operating activities
Net income	$ 13,905	$ 18,277
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	15,897	15,923
Deferred income taxes	2,045	1,809
Share-based compensation expense	3,313	3,227
Fair value changes in contingent consideration liabilities	381	(1,068)
Other	(1,744)	(259)
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable	(5,508)	(17,641)
Inventories	742	1,496
Prepaid expenses and other current assets	(4,333)	(790)
Other assets	(145)	(9)
Accounts payable	(2,455)	(1,248)
Accrued expenses and other liabilities	2,581	5,226
Income taxes payable	1,290	1,581
Net cash provided by operating activities	25,969	26,524
Cash flows from investing activities
Purchase of property, plant and equipment	(6,846)	(7,753)
Purchase of intangible assets	(598)	(480)
Acquisition of businesses, net of cash acquired	(8,174)	(1,709)
Proceeds from sale of equipment	576	319
Net cash used in investing activities	(15,042)	(9,623)
Cash flows from financing activities
Repayment of capital lease obligations	(3,808)	(3,681)
Proceeds from borrowings of long-term debt	196	1,968
Repayment of long-term debt	(11,056)	(15,870)
Proceeds from revolver	44,900	39,200
Repayments of revolver	(25,600)	(36,800)
Payment of contingent consideration for acquisitions	(796)	(394)
Purchases of treasury stock	(7,000)	0
Taxes paid related to net share settlement of share-based awards	(2,323)	(951)
Excess tax benefit from share-based compensation	558	(303)
Proceeds from exercise of stock options	585	187
Net cash used in financing activities	(4,344)	(16,644)
Effect of exchange rate changes on cash and cash equivalents	(1,510)	(233)
Net change in cash and cash equivalents	5,073	24
Cash and cash equivalents
Beginning of period	21,188	10,555
End of period	26,261	10,579
Supplemental disclosure of cash paid
Interest	1,849	3,010
Income taxes	7,637	6,223
Noncash investing and financing
Equipment acquired through capital lease obligations	1,707	1,555
Issuance of notes payable for acquisitions	$ 481	$ 0

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Nov. 30, 2016
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) and non-destructive testing (NDT) 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, fossil and nuclear power, alternative and renewable energy, public infrastructure, chemicals, commercial aerospace and defense, 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 fiscal years ending May 31, 2017 and 2016 . Reference to a fiscal year means the fiscal year ended May 31 , which has historically been the end of the Company's fiscal year. See Note 15 regarding a change in the Company’s fiscal year. For purposes of this report, references to fiscal 2017 and 2016 shall mean to our historical fiscal year periods, without adjusting for the change in the fiscal year. 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 (“2016 Annual Report”) for fiscal 2016 , as filed with the Securities and Exchange Commission on August 15, 2016 . 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 noncontrolling interests are reported in stockholders’ equity in the accompanying condensed consolidated balance sheets. The noncontrolling 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. Mistras Group, Inc.’s and its subsidiaries’ fiscal years end on May 31 except for the subsidiaries in the International segment, which end on April 30. Accordingly, the Company’s International segment subsidiaries are consolidated on a one month lag. Therefore, in the quarter and year of acquisition, results of acquired subsidiaries in the International segment are generally included in consolidated results for one less month than the actual number of months from the acquisition date to the end of the reporting period. Management does not believe that any events occurred during the one-month lag period that would have a material effect on the Company’s condensed consolidated financial statements. 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 One customer accounted for approximately 13% of our revenues and 12% of accounts receivable for the six months ended November 30, 2016 and as of November 30, 2016, respectively, which primarily were generated from the Services segment. No customer accounted for 10% or more of our revenues or accounts receivable for the six months ended November 30, 2015. Significant Accounting Policies The Company’s significant accounting policies are disclosed in Note 2 — Summary of Significant Accounting Policies in the Company's 2016 Annual Report. On an ongoing basis, the Company evaluates its estimates and assumptions, including, among other things those related to revenue recognition, valuations of accounts receivable, long-lived assets, goodwill, deferred tax assets and uncertain tax positions. Since the date of the 2016 Annual Report, there have been no material changes to the Company's significant accounting policies. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017, as a result of a one year deferral in the standard issued by the FASB in August 2015 with ASU 2015-14, Revenue from Contracts with Customers - Deferral of the Effective Date. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its condensed consolidated financial statements and related disclosures. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. This amendment will simplify the accounting for adjustments made to provisional amounts recognized in a business combination and eliminates the requirement to retrospectively account for those adjustments in previous reporting periods. This update will require on the face of the income statement or in the notes to the financial statements the amount recorded in current-period earnings that would have previously been recorded if the adjustment to the provisional amounts had been recognized as of the acquisition date. ASU 2015-16 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2015. The Company adopted this guidance during the first quarter ended August 31, 2016. There was not a material impact on its condensed consolidated financial statements and related disclosures. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. This amendment will simplify the presentation of deferred tax assets and liabilities on the balance sheet and require all deferred tax assets and liabilities to be treated as non-current. ASU 2015-17 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2016, with early adoption permitted. The Company does not expect that ASU 2015-17 will have a material impact on its condensed consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This amendment supersedes previous accounting guidance ( Topic 840) and requires all leases, with exception of leases with a term of 12 months or less, to be recorded on the balance sheet as lease assets and lease liabilities. ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018, with early adoption permitted. The standard requires lessees and lessors to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is evaluating the effect that ASU 2016-02 will have on its condensed consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, Stock Compensation (Topic 718). This amendment will simplify certain aspects of accounting for share-based payment transactions, which include accounting for income taxes and the related impact on the statement of cash flows, an option to account for forfeitures when they occur in addition to the existing guidance to estimate the forfeitures of awards, classification of awards as either equity or liabilities and classification on the statement of cash flows for employee taxes paid to tax authorities on shares withheld for vesting. ASU 2016-09 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2016, with early adoption permitted. Upon adoption of this standard, excess tax benefits and tax deficiencies will be recognized as income tax expense, and the tax effects of exercised or vested awards will be treated as discrete items in the period in which they occur. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230). This amendment will provide guidance on the presentation and classification of specific cash flow items to improve consistency within the statement of cash flows. ASU 2016-15 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is evaluating the impact that ASU 2016-15 will have on its condensed consolidated financial statements and related disclosures. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230). This amendment will clarify the presentation of restricted cash on the statement of cash flows. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning and ending cash balances on the statement of cash flows. ASU 2016-18 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2017, with early adoption permitted. The Company does not expect that ASU 2016-18 will have a material impact on its condensed consolidated financial statements and related disclosures.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Nov. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation The Company has share-based incentive awards outstanding to its eligible employees and 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 or 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 and six months ended November 30, 2016 , the Company did not recognize any share-based compensation expense related to stock option awards. No unrecognized compensation costs remained related to stock option awards as of November 30, 2016 . For the three and six months ended November 30, 2015 , the Company recognized share-based compensation expense related to stock option awards of less than $0.1 million . No stock options were granted during the six months ended November 30, 2016 and November 30, 2015 . A summary of the stock option activity, weighted average exercise prices and options outstanding as of November 30, 2016 and 2015 is as follows: For the six months ended November 30, 2016 2015 Common Stock Options Weighted Average Exercise Price Common Stock Options Weighted Average Exercise Price Outstanding at beginning of period: 2,232 $ 13.21 2,287 $ 13.13 Granted — $ — — $ — Exercised (62 ) $ 9.42 (22 ) $ 10.18 Expired or forfeited — $ — — $ — Outstanding at end of period: 2,170 $ 13.32 2,265 $ 13.16 Restricted Stock Unit Awards For both the three months ended November 30, 2016 and November 30, 2015 , the Company recognized share-based compensation expense related to restricted stock unit awards of $1.1 million . For both the six months ended November 30, 2016 and November 30, 2015 , the Company recognized share-based compensation expense related to restricted stock unit awards of $2.2 million . As of November 30, 2016 , there was $9.8 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 2.8 years . During the six months ended November 30, 2016 and 2015 , the Company granted approximately 10,000 and 15,000 shares, respectively, of fully-vested common stock to its five non-employee directors, in connection with its non-employee director compensation plan. These shares had grant date fair values of $0.3 million and $0.2 million , respectively, which was recorded as share-based compensation expense during the six months ended November 30, 2016 and November 30, 2015 , respectively. During the six months ended November 30, 2016 and 2015 , approximately 207,000 and 217,000 restricted stock units, respectively, vested. The fair value of these units was $5.1 million and $3.4 million , respectively. 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 Company's outstanding, nonvested restricted stock units is presented below: For the six months ended November 30, 2016 2015 Units Weighted Units Weighted Outstanding at beginning of period: 575 $ 18.85 564 $ 20.47 Granted 219 $ 24.48 263 $ 16.72 Released (207 ) $ 19.40 (217 ) $ 19.80 Forfeited (17 ) $ 19.42 (8 ) $ 19.23 Outstanding at end of period: 570 $ 20.81 602 $ 18.85 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 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 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 Performance Restricted Stock Unit activity is presented below: For the six months ended November 30, 2016 Units Weighted Outstanding at beginning of period: 328 $ 17.02 Granted 105 $ 24.90 Performance condition adjustments, net (7 ) $ 24.06 Released (89 ) $ 24.50 Forfeited — $ — Outstanding at end of period: 337 $ 17.22 During the three months ended August 31, 2016, the Compensation Committee approved an additional 19,000 units pertaining to the 2016 Discretionary PRSUs. There was a 26,000 unit reduction to the fiscal 2017 awards during the three months ended November 30, 2016 . As of November 30, 2016, the aggregate liability related to 21,000 outstanding Discretionary PRSUs was less than $0.1 million , and is classified within accrued expenses and other liabilities on the condensed consolidated balance sheet. For the three months ended November 30, 2016 and November 30, 2015 , the Company recognized aggregate share-based compensation expense related to the awards described above of approximately $0.3 million and $ 0.2 million , respectively. For the six months ended November 30, 2016 and November 30, 2015 , the Company recognized aggregate share-based compensation expense related to the awards described above of approximately $0.9 million and $0.8 million , respectively. At November 30, 2016 , there was $4.7 million of total unrecognized compensation costs related to 337,000 non-vested performance restricted stock units, which are expected to be recognized over a remaining weighted average period of 3.9 years .

Earnings per Share

Earnings per Share	6 Months Ended
	Nov. 30, 2016
Earnings Per Share [Abstract]
Earnings per Share	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 Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Basic earnings per share Numerator: Net income attributable to Mistras Group, Inc. $ 7,270 $ 11,425 $ 13,866 $ 18,297 Denominator: Weighted average common shares outstanding 29,056 28,869 29,016 28,796 Basic earnings per share $ 0.25 $ 0.40 $ 0.48 $ 0.64 Diluted earnings per share: Numerator: Net income attributable to Mistras Group, Inc. $ 7,270 $ 11,425 $ 13,866 $ 18,297 Denominator: Weighted average common shares outstanding 29,056 28,869 29,016 28,796 Dilutive effect of stock options outstanding 745 592 788 610 Dilutive effect of restricted stock units outstanding 197 133 335 235 29,998 29,594 30,139 29,641 Diluted earnings per share $ 0.24 $ 0.39 $ 0.46 $ 0.62

Acquisitions

Acquisitions	6 Months Ended
	Nov. 30, 2016
Business Combinations [Abstract]
Acquisitions	Acquisitions During the six months ended November 30, 2016, the Company completed three acquisitions. The Company purchased three companies, two that provide NDT services, located in Canada and one that provides mechanical services, located in the U.S. For the Canadian acquisitions, the Company acquired 100% of the common stock of both acquirees in exchange for aggregate consideration of $1.2 million in cash, $0.3 million of notes payable and contingent consideration estimated to be $0.4 million to be earned based upon the acquired businesses achieving specific performance metrics over their initial three years of operations from their acquisition dates. For the U.S. acquisition, the Company acquired assets of the acquiree in exchange for aggregate consideration of $7.0 million in cash, $0.2 million of notes payable and contingent consideration estimated to be $1.2 million to be earned based upon the acquired businesses achieving specific performance metrics over the initial three years of operations from its acquisition date. The Company accounted for these three transactions in accordance with the acquisition method of accounting for business combinations. The assets and liabilities of the businesses acquired in fiscal 2017 were included in the Company's condensed consolidated balance sheet based upon their estimated fair values on the date of acquisition as determined in a preliminary purchase price allocation, using available information and making assumptions management believes are reasonable. The Company is still in the process of completing its valuation of the assets, both tangible and intangible, and liabilities acquired. The results of operations for these acquisitions are included in the Services segment's results from the date of acquisition. The Company's preliminary purchase price allocations are included in the table below, summarizing the estimated fair value of the assets acquired and liabilities assumed at the date of acquisition: Fiscal 2017 Number of Entities 3 Consideration transferred: Cash paid $ 8,196 Notes payable 481 Contingent consideration 1,630 Consideration transferred $ 10,307 Current assets $ 1,781 Property, plant and equipment 953 Long-term net deferred tax asset 434 Intangible assets 3,367 Goodwill 3,986 Current liabilities (214 ) Net assets acquired $ 10,307 Revenues and operating income included in the condensed consolidated statement of operations for fiscal 2017 from these acquisitions for the period subsequent to the closing of these transactions were approximately $1.7 million and less than $0.1 million , respectively. As these acquisitions were immaterial on an individual basis and in the aggregate, no unaudited pro forma financial information has been included in this report. The Company completed one acquisition in the first six months of fiscal 2016. The Company purchased a company that provides unmanned aerial systems and NDT services, located in the U.S. In this acquisition, the Company acquired 100% of the common stock of the acquiree in exchange for consideration of $1.8 million in cash and contingent consideration estimated to be $0.9 million to be earned based upon the acquired business achieving specific performance metrics over the initial four years of operations from the acquisition date. The Company accounted for this transaction in accordance with the acquisition method of accounting for business combinations. Acquisition-Related Expense During the three and six months ended November 30, 2016 and 2015 , the Company incurred acquisition-related costs of $0.2 million and less than $0.1 million , respectively, in connection with due diligence, professional fees, and other expenses for its acquisition activities. Additionally, the Company adjusted the fair value of certain previously recorded acquisition-related contingent consideration liabilities. These adjustments resulted in a net (increase) decrease of acquisition-related contingent consideration liabilities and a corresponding (decrease) increase in income from operations of less than $(0.1) million and $0.2 million , for the three months ended November 30, 2016 and 2015 , respectively and $(0.4) million and $1.1 million for the six months ended November 30, 2016 and 2015 , respectively. The Company’s aggregate acquisition-related contingent consideration liabilities were $3.2 million and $2.1 million as of November 30, 2016 and May 31, 2016 , respectively. Fair value adjustments to acquisition-related contingent consideration liabilities and acquisition-related transaction costs have been classified as acquisition-related expense, net, in the condensed consolidated statements of income for the three and six month periods ended November 30, 2016 and November 30, 2015 .

Accounts Receivable, net

Accounts Receivable, net	6 Months Ended
	Nov. 30, 2016
Receivables [Abstract]
Accounts Receivable, net	Accounts Receivable, net Accounts receivable consisted of the following: November 30, 2016 May 31, 2016 Trade accounts receivable $ 143,876 $ 140,820 Allowance for doubtful accounts (2,509 ) (2,907 ) Accounts receivable, net $ 141,367 $ 137,913

Property, Plant and Equipment,

Property, Plant and Equipment, net	6 Months Ended
	Nov. 30, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, net	Property, Plant and Equipment, net Property, plant and equipment consisted of the following: Useful Life (Years) November 30, 2016 May 31, 2016 Land $ 1,723 $ 1,735 Buildings and improvements 30-40 19,050 19,364 Office furniture and equipment 5-8 8,971 8,692 Machinery and equipment 5-7 174,119 173,053 203,863 202,844 Accumulated depreciation and amortization (129,283 ) (124,168 ) Property, plant and equipment, net $ 74,580 $ 78,676 Depreciation expense for the three months ended November 30, 2016 and November 30, 2015 was $5.7 million and $5.5 million , respectively. Depreciation expense for the six months ended November 30, 2016 and November 30, 2015 was $11.6 million and $11.1 million , respectively.

Goodwill

Goodwill	6 Months Ended
	Nov. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Changes in the carrying amount of goodwill by segment is shown below: Services International Products and Systems Total Balance at May 31, 2015 $ 117,279 $ 35,938 $ 13,197 $ 166,414 Goodwill acquired (disposed) during the year 2,728 (374 ) — 2,354 Adjustments to preliminary purchase price allocations 270 — — 270 Foreign currency translation (594 ) 776 — 182 Balance at May 31, 2016 $ 119,683 $ 36,340 $ 13,197 $ 169,220 Goodwill acquired during the year 3,986 — — 3,986 Adjustments to preliminary purchase price allocations (19 ) — — (19 ) Foreign currency translation (369 ) (1,758 ) — (2,127 ) Balance at November 30, 2016 $ 123,281 $ 34,582 $ 13,197 $ 171,060 The Company reviews goodwill for impairment on a reporting unit basis on March 1 of each year and whenever events or changes in circumstances indicate the carrying value of goodwill may not be recoverable. As of November 30, 2016 , 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 for each of the periods ended November 30, 2016 , May 31, 2016 and May 31, 2015 was $9.9 million , which is within its International segment.

Intangible Assets

Intangible Assets	6 Months Ended
	Nov. 30, 2016
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	Intangible Assets The gross amount, accumulated amortization and net carrying amount of intangible assets were as follows: November 30, 2016 May 31, 2016 Useful Life (Years) Gross Amount Accumulated Amortization Net Carrying Amount Gross Amount Accumulated Amortization Net Carrying Amount Customer relationships 5-12 $ 82,463 $ (50,111 ) $ 32,352 $ 81,262 $ (47,747 ) $ 33,515 Software/Technology 3-15 18,083 (12,504 ) 5,579 17,539 (11,855 ) 5,684 Covenants not to compete 2-5 11,148 (9,592 ) 1,556 10,791 (9,290 ) 1,501 Other 2-5 8,039 (5,389 ) 2,650 7,827 (5,035 ) 2,792 Total $ 119,733 $ (77,596 ) $ 42,137 $ 117,419 $ (73,927 ) $ 43,492 Amortization expense for the three months ended November 30, 2016 and November 30, 2015 was $2.2 million and $2.4 million , respectively. Amortization expense for the six months ended November 30, 2016 and November 30, 2015 was $4.3 million and $4.8 million , respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	6 Months Ended
	Nov. 30, 2016
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: November 30, 2016 May 31, 2016 Accrued salaries, wages and related employee benefits $ 29,400 $ 31,566 Contingent consideration, current portion 1,982 1,029 Accrued workers’ compensation and health benefits 6,848 4,834 Deferred revenue 3,092 3,332 Legal settlement accrual 6,320 6,320 Other accrued expenses 16,615 15,902 Total accrued expenses and other liabilities $ 64,257 $ 62,983

Long-Term Debt

Long-Term Debt	6 Months Ended
	Nov. 30, 2016
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following: November 30, 2016 May 31, 2016 Senior credit facility $ 88,011 $ 68,999 Notes payable 379 10,111 Other 4,970 5,899 Total debt 93,360 85,009 Less: Current portion (2,028 ) (12,553 ) Long-term debt, net of current portion $ 91,332 $ 72,456 Senior Credit Facility On October 31, 2014, the Company entered into a Third Amendment and Modification Agreement of its revolving line of credit, the Third Amended and Restated Credit Agreement (“Credit Agreement”), dated December 21, 2011, with its lending group. The Credit Agreement provides the Company with a $175.0 million revolving line of credit, which, under certain circumstances, the line of credit can be increased to $225.0 million . The Company may borrow up to $30.0 million in non-U.S. Dollar currencies and use up to $10.0 million of the credit limit for the issuance of letters of credit. The Credit Agreement has a maturity date of October 30, 2019. As of November 30, 2016 , the Company had borrowings of $88.0 million and a total of $5.7 million of letters of credit outstanding under the Credit Agreement. Loans under the Credit Agreement bear interest at LIBOR plus an applicable LIBOR margin ranging from 1% to 1.75% , 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 or minus certain other adjustments) for the period of four consecutive fiscal quarters immediately preceding the date of determination. The Company has the benefit of the lowest margin if its Funded Debt Leverage Ratio is equal to or less than 0.5 to 1, and the margin increases as the ratio increases, to the maximum margin if the ratio is greater than 2.0 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. The Credit Agreement contains financial covenants requiring that the Company maintain a Funded Debt Leverage Ratio of no greater than 3.25 to 1 and an Interest Coverage Ratio of at least 3.0 to 1. Interest Coverage Ratio means the ratio, as of any date of determination, of (a) EBITDA for the 12 month period immediately preceding the date of determination, to (b) all interest, premium payments, debt discount, fees, charges and related expenses of the Company and its 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 GAAP, paid during the 12 month period immediately preceding the date of determination. 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, 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 November 30, 2016 , the Company was in compliance with the terms of the Credit Agreement, and will continuously monitor its compliance with the covenants contained in its credit agreement. 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 that remain outstanding are three years from the date of acquisition and bear interest at the prime rate for Bank of Canada, currently 2.7% as of November 30, 2016. Interest expense is recorded in the condensed consolidated statements of income. 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

Fair Value Measurements	6 Months Ended
	Nov. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company performs fair value measurements in accordance with the guidance provided by ASC 820, Fair Value Measurements and Disclosures. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. It also establishes a three level hierarchy that prioritizes the inputs used to measure fair value. The three levels of the hierarchy are defined as follows: Level 1 — Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 — Observable inputs other than quoted prices included in Level 1, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data. Level 3 — Unobservable inputs reflecting the Company’s own assumptions about inputs that market participants would use in pricing the asset or liability based on the best information available. In accordance with the fair value hierarchy described above, the following table shows the fair value of the Company’s financial liabilities that are required to be remeasured at fair value on a recurring basis: November 30, 2016 Level 1 Level 2 Level 3 Total Liabilities: Contingent consideration $ — $ — $ 3,237 $ 3,237 Total Liabilities $ — $ — $ 3,237 $ 3,237 May 31, 2016 Level 1 Level 2 Level 3 Total Liabilities: Contingent consideration $ — $ — $ 2,075 $ 2,075 Total Liabilities $ — $ — $ 2,075 $ 2,075 The fair value of contingent consideration liabilities that was classified as Level 3 in the table above 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.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Nov. 30, 2016
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 for 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 is currently a defendant in a consolidated purported class and collective action, Edgar Viceral and David Kruger v Mistras Group, et al , pending in the U.S. District Court for the Northern District of California. This matter results from the consolidation of two cases originally filed in California state court in April 2015. The consolidated case alleges violations of California statutes, primarily the California Labor Code, and seeks to proceed as a collective action under the U.S. Fair Labor Standards Act. The case is predicated on claims for allegedly missed rest and meal periods, inaccurate wage statements, and failure to pay all wages due, as well as related unfair business practices, and is requesting payment of all damages, including unpaid wages, and various fines and penalties available under California and Federal law. The parties have reached a settlement of the case, whereby the Company agreed to pay $6 million to resolve the allegations and avoid further distraction that would result if the litigation continued. The settlement received preliminary approval by the court in October 2016. The Company recorded a pre-tax charge of $6.3 million in the fourth quarter of fiscal 2016 for the settlement and payment of payroll taxes and other costs related to the settlement. Upon final approval, the settlement will cover claims dating back to April 2011 in some cases and involves approximately 4,900 current and former employees. The Company is a defendant in the lawsuit AGL Services Company v. Mistras Group, Inc ., pending in U.S. District Court for the Northern District of Georgia, filed November 2016. The case involves radiography work performed by the Company in fiscal 2013 on the construction of a pipeline project in the U.S. The owner of the pipeline project contends that certain of the radiography images the Company’s technicians prepared regarding the project did not meet the code quality interpretation standards required by the American Petroleum Institute. The project owner is claiming damages as a result of the alleged quality defects of the Company’s radiography images. The complaint alleges damages of approximately $6 million . The Company is currently unable to determine the likely outcome or reasonably estimate the amount or range of potential liability related to this matter, and accordingly, has not established any reserves for this matter. The Company’s subsidiary in France has been involved in a dispute with a former owner of a business in France purchased by the Company’s French subsidiary. The former owner received a judgment in his favor in the amount of approximately $0.4 million for payment of the contingent consideration portion of the purchase price for the business. The judgment is being appealed, but the Company recorded a reserve for the full amount of the judgment in the fourth quarter of fiscal 2016. The Company is 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, 193 rd Judicial District, Dallas County, Texas, filed September 2016. The plaintiff alleges Mistras delivered, in fiscal 2014, a defective Ultrasonic inspection system and is alleging damages of approximately $2.3 million , the amount it paid for the system. The Company is vigorously defending the case and has not established any reserves for the matter at this time. 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. 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 reserves for this matter. Acquisition-related contingencies The Company is liable for contingent consideration in connection with certain of its acquisitions. As of November 30, 2016 , total potential acquisition-related contingent consideration ranged from zero to approximately $15.6 million and would be payable upon the achievement of specific performance metrics by certain of the acquired companies over the next 2.8 years of operations. See Note 4 - Acquisitions to these condensed consolidated financial statements for further information with respect to of the Company’s acquisitions completed in fiscal 2016 and 2017.

Segment Disclosure

Segment Disclosure	6 Months Ended
	Nov. 30, 2016
Segment Reporting [Abstract]
Segment Disclosure	Segment Disclosure The Company’s three operating segments are: • Services. This segment provides asset protection solutions primarily in North America with the largest concentration in the United States, consisting primarily of non-destructive testing and inspection and engineering services that are used to evaluate the structural integrity and reliability of critical energy, industrial and public infrastructure. • International. This segment offers services, products and systems similar to those of the Company’s other two segments to global markets, principally in 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 Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Revenues Services $ 132,418 $ 150,463 $ 259,108 $ 287,868 International 42,230 38,425 79,748 75,284 Products and Systems 6,686 7,791 12,853 16,477 Corporate and eliminations (4,692 ) (1,893 ) (6,624 ) (4,990 ) $ 176,642 $ 194,786 $ 345,085 $ 374,639 Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Gross profit Services $ 34,184 $ 41,118 $ 68,629 $ 77,687 International 14,837 12,106 27,224 22,886 Products and Systems 3,230 3,833 6,326 7,755 Corporate and eliminations (175 ) (132 ) (47 ) (129 ) $ 52,076 $ 56,925 $ 102,132 $ 108,199 Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Income (loss) from operations Services $ 12,172 $ 18,815 $ 24,641 $ 34,214 International 6,717 3,971 11,375 5,789 Products and Systems 152 1,055 289 2,239 Corporate and eliminations (6,533 ) (4,272 ) (12,641 ) (9,741 ) $ 12,508 $ 19,569 $ 23,664 $ 32,501 Income (loss) by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations. Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Depreciation and amortization Services $ 5,469 $ 5,562 $ 11,074 $ 11,084 International 1,963 1,914 3,921 3,886 Products and Systems 566 577 1,114 1,140 Corporate and eliminations (104 ) (90 ) (212 ) (187 ) $ 7,894 $ 7,963 $ 15,897 $ 15,923 November 30, 2016 May 31, 2016 Intangible assets, net Services $ 19,945 $ 19,022 International 15,807 17,703 Products and Systems 5,555 6,054 Corporate and eliminations 830 713 $ 42,137 $ 43,492 November 30, 2016 May 31, 2016 Total assets Services $ 302,920 $ 301,678 International 135,981 132,643 Products and Systems 31,247 31,596 Corporate and eliminations 22,018 16,758 $ 492,166 $ 482,675 Revenues by geographic area for the three and six months ended November 30, 2016 and 2015 , respectively, were as follows: Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Revenues United States $ 112,719 $ 132,068 $ 228,842 $ 262,411 Other Americas 19,957 23,557 35,006 35,086 Europe 37,560 36,468 71,054 71,352 Asia-Pacific 6,406 2,693 10,183 5,790 $ 176,642 $ 194,786 $ 345,085 $ 374,639

Repurchase of Common Stock

Repurchase of Common Stock	6 Months Ended
	Nov. 30, 2016
Equity [Abstract]
Repurchase of Common Stock	Repurchase of Common Stock On October 7, 2015, the Company's Board of Directors approved a $50 million stock repurchase plan. As part of this plan, on August 17, 2016, the Company entered into an agreement with its CEO, Dr. Sotirios Vahaviolos, to purchase up to 1 million of his shares, commencing in October 2016. Pursuant to the agreement, in general, the Company will purchase from Dr. Vahaviolos up to $2 million of shares each month, at a 2% discount to the average daily price of the Company's common stock for the preceding month. During the quarter ended November 30, 2016, the Company purchased approximately 181,000 shares from Dr. Vahaviolos at an average price of $22.07 per share and an aggregate cost of $4.0 million . In addition, during this same fiscal quarter, the Company repurchased approximately 146,000 shares in the open market at an average price of $20.48 per share and an aggregate cost of approximately $3.0 million . All such repurchased shares are classified as Treasury Stock on the condensed consolidated balance sheet. As of November 30, 2016, approximately $43.0 million remained available to repurchase shares under the stock repurchase plan.

Subsequent Event

Subsequent Event	6 Months Ended
	Nov. 30, 2016
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 3, 2017, the Company's Board of Directors approved a change in the Company's fiscal year from May 31 to December 31, effective December 31, 2016. As a result of this change, the Company will file a Transition Report on Form 10-K for the transition period ending December 31, 2016.

Description of Business and B22

Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Nov. 30, 2016
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 fiscal years ending May 31, 2017 and 2016 . Reference to a fiscal year means the fiscal year ended May 31 , which has historically been the end of the Company's fiscal year. See Note 15 regarding a change in the Company’s fiscal year. For purposes of this report, references to fiscal 2017 and 2016 shall mean to our historical fiscal year periods, without adjusting for the change in the fiscal year.
Use of Estimates	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.
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 noncontrolling interests are reported in stockholders’ equity in the accompanying condensed consolidated balance sheets. The noncontrolling 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. Mistras Group, Inc.’s and its subsidiaries’ fiscal years end on May 31 except for the subsidiaries in the International segment, which end on April 30. Accordingly, the Company’s International segment subsidiaries are consolidated on a one month lag. Therefore, in the quarter and year of acquisition, results of acquired subsidiaries in the International segment are generally included in consolidated results for one less month than the actual number of months from the acquisition date to the end of the reporting period. Management does not believe that any events occurred during the one-month lag period that would have a material effect on the Company’s condensed consolidated financial statements.
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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017, as a result of a one year deferral in the standard issued by the FASB in August 2015 with ASU 2015-14, Revenue from Contracts with Customers - Deferral of the Effective Date. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its condensed consolidated financial statements and related disclosures. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. This amendment will simplify the accounting for adjustments made to provisional amounts recognized in a business combination and eliminates the requirement to retrospectively account for those adjustments in previous reporting periods. This update will require on the face of the income statement or in the notes to the financial statements the amount recorded in current-period earnings that would have previously been recorded if the adjustment to the provisional amounts had been recognized as of the acquisition date. ASU 2015-16 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2015. The Company adopted this guidance during the first quarter ended August 31, 2016. There was not a material impact on its condensed consolidated financial statements and related disclosures. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. This amendment will simplify the presentation of deferred tax assets and liabilities on the balance sheet and require all deferred tax assets and liabilities to be treated as non-current. ASU 2015-17 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2016, with early adoption permitted. The Company does not expect that ASU 2015-17 will have a material impact on its condensed consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This amendment supersedes previous accounting guidance ( Topic 840) and requires all leases, with exception of leases with a term of 12 months or less, to be recorded on the balance sheet as lease assets and lease liabilities. ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2018, with early adoption permitted. The standard requires lessees and lessors to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is evaluating the effect that ASU 2016-02 will have on its condensed consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, Stock Compensation (Topic 718). This amendment will simplify certain aspects of accounting for share-based payment transactions, which include accounting for income taxes and the related impact on the statement of cash flows, an option to account for forfeitures when they occur in addition to the existing guidance to estimate the forfeitures of awards, classification of awards as either equity or liabilities and classification on the statement of cash flows for employee taxes paid to tax authorities on shares withheld for vesting. ASU 2016-09 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2016, with early adoption permitted. Upon adoption of this standard, excess tax benefits and tax deficiencies will be recognized as income tax expense, and the tax effects of exercised or vested awards will be treated as discrete items in the period in which they occur. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230). This amendment will provide guidance on the presentation and classification of specific cash flow items to improve consistency within the statement of cash flows. ASU 2016-15 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2017, with early adoption permitted. The Company is evaluating the impact that ASU 2016-15 will have on its condensed consolidated financial statements and related disclosures. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230). This amendment will clarify the presentation of restricted cash on the statement of cash flows. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning and ending cash balances on the statement of cash flows. ASU 2016-18 is effective for fiscal years, and interim periods within those fiscal years beginning after December 15, 2017, with early adoption permitted. The Company does not expect that ASU 2016-18 will have a material impact on its condensed consolidated financial statements and related disclosures.
Fair Value Measurements	Fair Value Measurements The Company performs fair value measurements in accordance with the guidance provided by ASC 820, Fair Value Measurements and Disclosures. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. It also establishes a three level hierarchy that prioritizes the inputs used to measure fair value. The three levels of the hierarchy are defined as follows: Level 1 — Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 — Observable inputs other than quoted prices included in Level 1, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs derived principally from or corroborated by observable market data. Level 3 — Unobservable inputs reflecting the Company’s own assumptions about inputs that market participants would use in pricing the asset or liability based on the best information available.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Nov. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of stock option activity, weighted average exercise prices and options outstanding	A summary of the stock option activity, weighted average exercise prices and options outstanding as of November 30, 2016 and 2015 is as follows: For the six months ended November 30, 2016 2015 Common Stock Options Weighted Average Exercise Price Common Stock Options Weighted Average Exercise Price Outstanding at beginning of period: 2,232 $ 13.21 2,287 $ 13.13 Granted — $ — — $ — Exercised (62 ) $ 9.42 (22 ) $ 10.18 Expired or forfeited — $ — — $ — Outstanding at end of period: 2,170 $ 13.32 2,265 $ 13.16
Summary of Company's outstanding, nonvested restricted share units	A summary of the Company's outstanding, nonvested restricted stock units is presented below: For the six months ended November 30, 2016 2015 Units Weighted Units Weighted Outstanding at beginning of period: 575 $ 18.85 564 $ 20.47 Granted 219 $ 24.48 263 $ 16.72 Released (207 ) $ 19.40 (217 ) $ 19.80 Forfeited (17 ) $ 19.42 (8 ) $ 19.23 Outstanding at end of period: 570 $ 20.81 602 $ 18.85 A summary of the Company's Performance Restricted Stock Unit activity is presented below: For the six months ended November 30, 2016 Units Weighted Outstanding at beginning of period: 328 $ 17.02 Granted 105 $ 24.90 Performance condition adjustments, net (7 ) $ 24.06 Released (89 ) $ 24.50 Forfeited — $ — Outstanding at end of period: 337 $ 17.22
Summary of Company's outstanding, nonvested performance restricted stock units	A summary of the Company's outstanding, nonvested restricted stock units is presented below: For the six months ended November 30, 2016 2015 Units Weighted Units Weighted Outstanding at beginning of period: 575 $ 18.85 564 $ 20.47 Granted 219 $ 24.48 263 $ 16.72 Released (207 ) $ 19.40 (217 ) $ 19.80 Forfeited (17 ) $ 19.42 (8 ) $ 19.23 Outstanding at end of period: 570 $ 20.81 602 $ 18.85 A summary of the Company's Performance Restricted Stock Unit activity is presented below: For the six months ended November 30, 2016 Units Weighted Outstanding at beginning of period: 328 $ 17.02 Granted 105 $ 24.90 Performance condition adjustments, net (7 ) $ 24.06 Released (89 ) $ 24.50 Forfeited — $ — Outstanding at end of period: 337 $ 17.22

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Nov. 30, 2016
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 Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Basic earnings per share Numerator: Net income attributable to Mistras Group, Inc. $ 7,270 $ 11,425 $ 13,866 $ 18,297 Denominator: Weighted average common shares outstanding 29,056 28,869 29,016 28,796 Basic earnings per share $ 0.25 $ 0.40 $ 0.48 $ 0.64 Diluted earnings per share: Numerator: Net income attributable to Mistras Group, Inc. $ 7,270 $ 11,425 $ 13,866 $ 18,297 Denominator: Weighted average common shares outstanding 29,056 28,869 29,016 28,796 Dilutive effect of stock options outstanding 745 592 788 610 Dilutive effect of restricted stock units outstanding 197 133 335 235 29,998 29,594 30,139 29,641 Diluted earnings per share $ 0.24 $ 0.39 $ 0.46 $ 0.62

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Nov. 30, 2016
Business Combinations [Abstract]
Schedule of Preliminary Purchase Price Allocation	The Company's preliminary purchase price allocations are included in the table below, summarizing the estimated fair value of the assets acquired and liabilities assumed at the date of acquisition: Fiscal 2017 Number of Entities 3 Consideration transferred: Cash paid $ 8,196 Notes payable 481 Contingent consideration 1,630 Consideration transferred $ 10,307 Current assets $ 1,781 Property, plant and equipment 953 Long-term net deferred tax asset 434 Intangible assets 3,367 Goodwill 3,986 Current liabilities (214 ) Net assets acquired $ 10,307

Accounts Receivable, net (Table

Accounts Receivable, net (Tables)	6 Months Ended
	Nov. 30, 2016
Receivables [Abstract]
Schedule of accounts receivable	Accounts receivable consisted of the following: November 30, 2016 May 31, 2016 Trade accounts receivable $ 143,876 $ 140,820 Allowance for doubtful accounts (2,509 ) (2,907 ) Accounts receivable, net $ 141,367 $ 137,913

Property, Plant and Equipment27

Property, Plant and Equipment, net (Tables)	6 Months Ended
	Nov. 30, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property, plant and equipment	Property, plant and equipment consisted of the following: Useful Life (Years) November 30, 2016 May 31, 2016 Land $ 1,723 $ 1,735 Buildings and improvements 30-40 19,050 19,364 Office furniture and equipment 5-8 8,971 8,692 Machinery and equipment 5-7 174,119 173,053 203,863 202,844 Accumulated depreciation and amortization (129,283 ) (124,168 ) Property, plant and equipment, net $ 74,580 $ 78,676

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Nov. 30, 2016
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 May 31, 2015 $ 117,279 $ 35,938 $ 13,197 $ 166,414 Goodwill acquired (disposed) during the year 2,728 (374 ) — 2,354 Adjustments to preliminary purchase price allocations 270 — — 270 Foreign currency translation (594 ) 776 — 182 Balance at May 31, 2016 $ 119,683 $ 36,340 $ 13,197 $ 169,220 Goodwill acquired during the year 3,986 — — 3,986 Adjustments to preliminary purchase price allocations (19 ) — — (19 ) Foreign currency translation (369 ) (1,758 ) — (2,127 ) Balance at November 30, 2016 $ 123,281 $ 34,582 $ 13,197 $ 171,060

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Nov. 30, 2016
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Schedule of gross amount, accumulated amortization and net carrying amount of intangible assets	The gross amount, accumulated amortization and net carrying amount of intangible assets were as follows: November 30, 2016 May 31, 2016 Useful Life (Years) Gross Amount Accumulated Amortization Net Carrying Amount Gross Amount Accumulated Amortization Net Carrying Amount Customer relationships 5-12 $ 82,463 $ (50,111 ) $ 32,352 $ 81,262 $ (47,747 ) $ 33,515 Software/Technology 3-15 18,083 (12,504 ) 5,579 17,539 (11,855 ) 5,684 Covenants not to compete 2-5 11,148 (9,592 ) 1,556 10,791 (9,290 ) 1,501 Other 2-5 8,039 (5,389 ) 2,650 7,827 (5,035 ) 2,792 Total $ 119,733 $ (77,596 ) $ 42,137 $ 117,419 $ (73,927 ) $ 43,492

Accrued Expenses and Other Cu30

Accrued Expenses and Other Current Liabilities (Tables)	6 Months Ended
	Nov. 30, 2016
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following: November 30, 2016 May 31, 2016 Accrued salaries, wages and related employee benefits $ 29,400 $ 31,566 Contingent consideration, current portion 1,982 1,029 Accrued workers’ compensation and health benefits 6,848 4,834 Deferred revenue 3,092 3,332 Legal settlement accrual 6,320 6,320 Other accrued expenses 16,615 15,902 Total accrued expenses and other liabilities $ 64,257 $ 62,983

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Nov. 30, 2016
Debt Disclosure [Abstract]
Schedule of long-term debt	Long-term debt consisted of the following: November 30, 2016 May 31, 2016 Senior credit facility $ 88,011 $ 68,999 Notes payable 379 10,111 Other 4,970 5,899 Total debt 93,360 85,009 Less: Current portion (2,028 ) (12,553 ) Long-term debt, net of current portion $ 91,332 $ 72,456

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Nov. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of fair value of the Company's financial liabilities that are required to be remeasured at fair value on a recurring basis	In accordance with the fair value hierarchy described above, the following table shows the fair value of the Company’s financial liabilities that are required to be remeasured at fair value on a recurring basis: November 30, 2016 Level 1 Level 2 Level 3 Total Liabilities: Contingent consideration $ — $ — $ 3,237 $ 3,237 Total Liabilities $ — $ — $ 3,237 $ 3,237 May 31, 2016 Level 1 Level 2 Level 3 Total Liabilities: Contingent consideration $ — $ — $ 2,075 $ 2,075 Total Liabilities $ — $ — $ 2,075 $ 2,075

Segment Disclosure (Tables)

Segment Disclosure (Tables)	6 Months Ended
	Nov. 30, 2016
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 Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Revenues Services $ 132,418 $ 150,463 $ 259,108 $ 287,868 International 42,230 38,425 79,748 75,284 Products and Systems 6,686 7,791 12,853 16,477 Corporate and eliminations (4,692 ) (1,893 ) (6,624 ) (4,990 ) $ 176,642 $ 194,786 $ 345,085 $ 374,639 Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Gross profit Services $ 34,184 $ 41,118 $ 68,629 $ 77,687 International 14,837 12,106 27,224 22,886 Products and Systems 3,230 3,833 6,326 7,755 Corporate and eliminations (175 ) (132 ) (47 ) (129 ) $ 52,076 $ 56,925 $ 102,132 $ 108,199 Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Income (loss) from operations Services $ 12,172 $ 18,815 $ 24,641 $ 34,214 International 6,717 3,971 11,375 5,789 Products and Systems 152 1,055 289 2,239 Corporate and eliminations (6,533 ) (4,272 ) (12,641 ) (9,741 ) $ 12,508 $ 19,569 $ 23,664 $ 32,501 Income (loss) by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations. Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Depreciation and amortization Services $ 5,469 $ 5,562 $ 11,074 $ 11,084 International 1,963 1,914 3,921 3,886 Products and Systems 566 577 1,114 1,140 Corporate and eliminations (104 ) (90 ) (212 ) (187 ) $ 7,894 $ 7,963 $ 15,897 $ 15,923 November 30, 2016 May 31, 2016 Intangible assets, net Services $ 19,945 $ 19,022 International 15,807 17,703 Products and Systems 5,555 6,054 Corporate and eliminations 830 713 $ 42,137 $ 43,492 November 30, 2016 May 31, 2016 Total assets Services $ 302,920 $ 301,678 International 135,981 132,643 Products and Systems 31,247 31,596 Corporate and eliminations 22,018 16,758 $ 492,166 $ 482,675
Schedule of revenues by geographic area	Revenues by geographic area for the three and six months ended November 30, 2016 and 2015 , respectively, were as follows: Three months ended Six months ended November 30, 2016 November 30, 2015 November 30, 2016 November 30, 2015 Revenues United States $ 112,719 $ 132,068 $ 228,842 $ 262,411 Other Americas 19,957 23,557 35,006 35,086 Europe 37,560 36,468 71,054 71,352 Asia-Pacific 6,406 2,693 10,183 5,790 $ 176,642 $ 194,786 $ 345,085 $ 374,639

Description of Business and B34

Description of Business and Basis of Presentation - Additional Information (Details)	6 Months Ended
	Nov. 30, 2016mocustomer	Nov. 30, 2015customer
Principles of Consolidation
Period lag in the consolidation of International segment subsidiaries (months)	1 month
Number of months less than the actual number of months from the acquisition date for which results of international segment subsidiaries are included in consolidation (months) | mo	1
Customer Concentration Risk | Revenues
Concentration Risk [Line Items]
Concentration risk, number of customers		0
Concentration risk, percentage		10.00%
Customer Concentration Risk | Revenues | Services
Concentration Risk [Line Items]
Concentration risk, number of customers	1
Concentration risk, percentage	13.00%
Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, number of customers		0
Concentration risk, percentage		10.00%
Customer Concentration Risk | Accounts Receivable | Services
Concentration Risk [Line Items]
Concentration risk, number of customers	1
Concentration risk, percentage	12.00%

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details)	6 Months Ended
	Nov. 30, 2016planshares
Share-based compensation
Number of employee stock ownership plans | plan	3
2007 Plan
Share-based compensation
Number of awards that may be granted (in shares)	0
2009 Plan
Share-based compensation
Number of awards that may be granted (in shares)	0

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Options (Details) - Stock Options - USD ($)	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Share-based compensation
Unrecognized compensation costs	$ 0		$ 0
Recognized share-based compensation expense (less than)	$ 0	$ 100,000	$ 0	$ 100,000
Common Stock Options (in shares)
Outstanding at the beginning of the period: (in shares)			2,232,000	2,287,000
Granted (in shares)			0	0
Exercised (in shares)			(62,000)	(22,000)
Expired of forfeited (in shares)			0	0
Outstanding at the end of the period: (in shares)	2,170,000	2,265,000	2,170,000	2,265,000
Weighted Average Exercise Price (in dollar per share)
Outstanding at the beginning of period: (in dollars per share)			$ 13.21	$ 13.13
Granted (in dollars per share)			0	0
Exercised (in dollars per share)			9.42	10.18
Expired or forfeited (in dollars per share)			0	0
Outstanding at the end of period: (in dollars per share)	$ 13.32	$ 13.16	$ 13.32	$ 13.16

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Stock Unit Awards - Narrative (Details) - Restricted Stock Units shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2016USD ($)	Nov. 30, 2015USD ($)	Nov. 30, 2016USD ($)directorshares	Nov. 30, 2015USD ($)directorshares
Share-based compensation
Recognized share-based compensation expense (benefit)	$ 1.1	$ 1.1	$ 2.2	$ 2.2
Unrecognized compensation cost, net of estimated forfeitures	$ 9.8		$ 9.8
Weighted-average period over which unrecognized compensation cost is expected to be recognized (years)			2 years 9 months 18 days
Fair value of shares vested			$ 5.1	$ 3.4
Shares vested (in shares) | shares			207	217
Non-employee directors
Share-based compensation
Fully vested common stock granted (in shares) | shares			10	15
Number of non-employee directors to whom fully vested common stock is granted (director) | director			5	5
Fair value of shares vested			$ 0.3	$ 0.2

Share-Based Compensation - Re38

Share-Based Compensation - Restricted Stock Units Awards - Activity (Details) - Restricted Stock Units - $ / shares shares in Thousands	6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Restricted Stock Units Awards (Units)
Outstanding at beginning of period: (in shares)	575	564
Granted (in shares)	219	263
Released (in shares)	(207)	(217)
Forfeited (in shares)	(17)	(8)
Outstanding at end of period: (in shares)	570	602
Weighted Average Grant-Date Fair Value (in dollars per share)
Outstanding at the beginning of period: (in dollars per share)	$ 18.85	$ 20.47
Granted (in dollars per share)	24.48	16.72
Released (in dollars per share)	19.40	19.80
Forfeited (in dollars per share)	19.42	19.23
Outstanding at end of period: (in dollars per share)	$ 20.81	$ 18.85

Share-Based Compensation - Perf

Share-Based Compensation - Performance Restricted Stock Units - Activity (Details) - Performance Restricted Stock Units shares in Thousands	6 Months Ended
	Nov. 30, 2016$ / sharesshares
Performance Restricted Stock (Units)
Outstanding at beginning of period: (in shares) | shares	328
Granted (in shares) | shares	105
Performance condition adjustments (in shares) | shares	(7)
Released (in shares) | shares	(89)
Forfeited (in shares) | shares	0
Outstanding at end of period: (in shares) | shares	337
Weighted Average Grant-Date Fair Value (in dollars per share)
Outstanding at the beginning of period: (in dollars per share) | $ / shares	$ 17.02
Granted (in dollars per share) | $ / shares	24.90
Performance condition adjustments (in dollars per share) | $ / shares	24.06
Released (in dollars per share) | $ / shares	24.50
Forfeited (in dollars per share) | $ / shares	0
Outstanding at end of period: (in dollars per share) | $ / shares	$ 17.22

Share-Based Compensation - Pe40

Share-Based Compensation - Performance Restricted Stock Units - Narrative (Details) - Performance Restricted Stock Units shares in Thousands, $ in Millions	3 Months Ended			6 Months Ended
	Nov. 30, 2016USD ($)shares	Aug. 31, 2016shares	Nov. 30, 2015USD ($)	Nov. 30, 2016USD ($)performance_metricshares	Nov. 30, 2015USD ($)	May 31, 2016shares
Share-based compensation
Nonvested shares outstanding (in shares)	337			337		328
Fiscal 2016 Grants
Share-based compensation
Nonvested shares outstanding additional shares authorized in period (in shares)		19
Nonvested shares outstanding reduction in period (in shares)	26
Nonvested number of remaining shares authorized (in shares)	21			21
Recognized share-based compensation expense (benefit) | $	$ 0.3		$ 0.2	$ 0.9	$ 0.8
Unrecognized compensation cost | $	$ 4.7			$ 4.7
Nonvested shares outstanding (in shares)	337			337
Weighted-average period over which unrecognized compensation cost is expected to be recognized (years)				3 years 10 months 24 days
Fiscal 2016 Grants | Accrued Expenses and Other Liabilities
Share-based compensation
Aggregate liability related to outstanding discretionary PRSUs, less than | $	$ 0.1			$ 0.1
Executive and Senior Officers
Share-based compensation
Performance period (years)				1 year
Number of performance award metrics | performance_metric				3
Requisite service period (years)				5 years

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Basic earnings per share
Net income attributable to Mistras Group, Inc.	$ 7,270	$ 11,425	$ 13,866	$ 18,297
Denominator:
Weighted average common shares outstanding (in shares)	29,056	28,869	29,016	28,796
Basic earnings per share (in dollars per share)	$ 0.25	$ 0.40	$ 0.48	$ 0.64
Denominator:
Weighted average common shares outstanding (in shares)	29,056	28,869	29,016	28,796
Dilutive effect of stock options outstanding (in shares)	745	592	788	610
Dilutive effect of restricted stock units outstanding (in shares)	197	133	335	235
Weighted average common shares outstanding, diluted (in shares)	29,998	29,594	30,139	29,641
Diluted earnings per share (in dollars per share)	$ 0.24	$ 0.39	$ 0.46	$ 0.62

Acquisitions (Details)

Acquisitions (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Nov. 30, 2016USD ($)	Nov. 30, 2016USD ($)Entity	Nov. 30, 2015USD ($)Entity	May 31, 2016USD ($)
Acquisitions
Contingent consideration	$ 3,200	$ 3,200		$ 2,100
Period over which potential acquisition-related contingent consideration would be payable		2 years 9 months 18 days
Fiscal 2017 Acquisitions
Acquisitions
Number of acquisitions | Entity		3
Cash paid		$ 8,196
Notes payable		481
Contingent consideration	1,630	1,630
Revenues	$ 1,700
Operating income		$ 100
Fiscal 2017 Acquisitions | Canada
Acquisitions
Percentage of common stock acquired	100.00%	100.00%
Cash paid		$ 1,200
Notes payable		300
Contingent consideration	$ 400	$ 400
Period over which potential acquisition-related contingent consideration would be payable		3 years
Fiscal 2017 Acquisitions | Canada | NDT Services
Acquisitions
Number of acquisitions | Entity		2
Fiscal 2017 Acquisitions | United States
Acquisitions
Cash paid		$ 7,000
Notes payable		200
Contingent consideration	$ 1,200	$ 1,200
Period over which potential acquisition-related contingent consideration would be payable		3 years
Fiscal 2017 Acquisitions | United States | Mechanical Services
Acquisitions
Number of acquisitions | Entity		1
Fiscal 2016 Acquisitions | United States
Acquisitions
Number of acquisitions | Entity			1
Percentage of common stock acquired			100.00%
Cash paid			$ 1,800
Contingent consideration			$ 900
Period over which potential acquisition-related contingent consideration would be payable			4 years

Acquisitions - Preliminary Purc

Acquisitions - Preliminary Purchase Price Allocation (Details) $ in Thousands	6 Months Ended
	Nov. 30, 2016USD ($)Entity	May 31, 2016USD ($)	May 31, 2015USD ($)
Acquisitions
Contingent consideration	$ 3,200	$ 2,100
Goodwill	$ 171,060	$ 169,220	$ 166,414
Fiscal 2017 Acquisitions
Acquisitions
Number of Entities | Entity	3
Cash paid	$ 8,196
Notes payable	481
Contingent consideration	1,630
Consideration transferred	10,307
Current assets	1,781
Property, plant and equipment	953
Long-term net deferred tax asset	434
Intangible assets	3,367
Goodwill	3,986
Current liabilities	(214)
Net assets acquired	$ 10,307

Acquisitions - Acquisition-Rela

Acquisitions - Acquisition-Related Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015	May 31, 2016
Acquisition-Related Expense
(Increase) decrease in acquisition-related contingent consideration liabilities			$ 381	$ (1,068)
(Decrease) increase in income (loss) from operations	$ 12,508	$ 19,569	23,664	32,501
Contingent consideration liability	3,200		3,200		$ 2,100
Fiscal 2016 Acquisitions
Acquisition-Related Expense
Acquisition related costs		200		100
(Increase) decrease in acquisition-related contingent consideration liabilities		(100)		(400)
(Decrease) increase in income (loss) from operations		$ 200		$ 1,100
Fiscal 2017 Acquisitions
Acquisition-Related Expense
Acquisition related costs	200		100
(Increase) decrease in acquisition-related contingent consideration liabilities	(100)		(400)
(Decrease) increase in income (loss) from operations	200		1,100
Contingent consideration liability	$ 1,630		$ 1,630

Accounts Receivable, net (Detai

Accounts Receivable, net (Details) - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016
Receivables [Abstract]
Trade accounts receivable	$ 143,876	$ 140,820
Allowance for doubtful accounts	(2,509)	(2,907)
Accounts receivable, net	$ 141,367	$ 137,913

Property, Plant and Equipment46

Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015	May 31, 2016
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 203,863		$ 203,863		$ 202,844
Accumulated depreciation and amortization	(129,283)		(129,283)		(124,168)
Property, plant and equipment, net	74,580		74,580		78,676
Depreciation expense	5,700	$ 5,500	11,600	$ 11,100
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	1,723		1,723		1,735
Buildings and improvements
Property, Plant and Equipment, net
Property, plant and equipment, gross	19,050		$ 19,050		19,364
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	8,971		$ 8,971		8,692
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	$ 174,119		$ 174,119		$ 173,053
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 (Details)

Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Nov. 30, 2016	May 31, 2016	May 31, 2015
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 169,220	$ 166,414
Goodwill acquired (disposed) during the year	3,986	2,354
Adjustments to preliminary purchase price allocations	(19)	270
Foreign currency translation	(2,127)	182
Goodwill, ending balance	171,060	169,220
Services
Goodwill [Roll Forward]
Goodwill, beginning balance	119,683	117,279
Goodwill acquired (disposed) during the year	3,986	2,728
Adjustments to preliminary purchase price allocations	(19)	270
Foreign currency translation	(369)	(594)
Goodwill, ending balance	123,281	119,683
International
Goodwill [Roll Forward]
Goodwill, beginning balance	36,340	35,938
Goodwill acquired (disposed) during the year	0	(374)
Adjustments to preliminary purchase price allocations	0	0
Foreign currency translation	(1,758)	776
Goodwill, ending balance	34,582	36,340
Goodwill, cumulative impairment loss	9,900	9,900	$ 9,900
Products and Systems
Goodwill [Roll Forward]
Goodwill, beginning balance	13,197	13,197
Goodwill acquired (disposed) during the year	0	0
Adjustments to preliminary purchase price allocations	0	0
Foreign currency translation	0	0
Goodwill, ending balance	$ 13,197	$ 13,197

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015	May 31, 2016
Intangible assets
Gross Amount	$ 119,733		$ 119,733		$ 117,419
Accumulated Amortization	(77,596)		(77,596)		(73,927)
Net Carrying Amount	42,137		42,137		43,492
Amortization expense	2,200	$ 2,400	4,300	$ 4,800
Customer relationships
Intangible assets
Gross Amount	82,463		82,463		81,262
Accumulated Amortization	(50,111)		(50,111)		(47,747)
Net Carrying Amount	32,352		$ 32,352		33,515
Customer relationships | Minimum
Intangible assets
Useful Life (Years)			5 years
Customer relationships | Maximum
Intangible assets
Useful Life (Years)			12 years
Software/Technology
Intangible assets
Gross Amount	18,083		$ 18,083		17,539
Accumulated Amortization	(12,504)		(12,504)		(11,855)
Net Carrying Amount	5,579		$ 5,579		5,684
Software/Technology | Minimum
Intangible assets
Useful Life (Years)			3 years
Software/Technology | Maximum
Intangible assets
Useful Life (Years)			15 years
Covenants not to compete
Intangible assets
Gross Amount	11,148		$ 11,148		10,791
Accumulated Amortization	(9,592)		(9,592)		(9,290)
Net Carrying Amount	1,556		$ 1,556		1,501
Covenants not to compete | Minimum
Intangible assets
Useful Life (Years)			2 years
Covenants not to compete | Maximum
Intangible assets
Useful Life (Years)			5 years
Other
Intangible assets
Gross Amount	8,039		$ 8,039		7,827
Accumulated Amortization	(5,389)		(5,389)		(5,035)
Net Carrying Amount	$ 2,650		$ 2,650		$ 2,792
Other | Minimum
Intangible assets
Useful Life (Years)			2 years
Other | Maximum
Intangible assets
Useful Life (Years)			5 years

Accrued Expenses and Other Cu49

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016
Payables and Accruals [Abstract]
Accrued salaries, wages and related employee benefits	$ 29,400	$ 31,566
Contingent consideration, current portion	1,982	1,029
Accrued workers’ compensation and health benefits	6,848	4,834
Deferred revenue	3,092	3,332
Legal settlement accrual	6,320	6,320
Other accrued expenses	16,615	15,902
Total accrued expenses and other liabilities	$ 64,257	$ 62,983

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 93,360	$ 85,009
Less: Current portion	(2,028)	(12,553)
Long-term debt, net of current portion	91,332	72,456
Senior credit facility
Debt Instrument [Line Items]
Long-term debt	88,011	68,999
Notes payable
Debt Instrument [Line Items]
Long-term debt	379	10,111
Other
Debt Instrument [Line Items]
Long-term debt	$ 4,970	$ 5,899

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details)	Nov. 30, 2016USD ($)	Oct. 31, 2014USD ($)Quarter
Senior credit facility
Senior Credit Facility
Maximum borrowing capacity		$ 175,000,000
Line of credit facility, higher borrowing capacity option		225,000,000
Maximum borrowing capacity in non-U.S. Dollar currencies		30,000,000
Maximum amount available for the issuance of letters of credit		$ 10,000,000
Outstanding borrowings	$ 88,000,000
Outstanding letters of credit	$ 5,700,000
Number of consecutive fiscal quarters used for calculating Funded Debt Leverage Ratio | Quarter		4
Funded Debt Leverage Ratio at which the entity will have the benefit of lowest interest margin (less than or equal to)		0.5
Funded Debt Leverage Ratio at which the entity will bear the maximum interest rate margin (greater than)		2
Additional interest rate margin if Funded Debt Leverage Ratio exceeds threshold (as a percent)		2.00%
Funded Debt Leverage Ratio for additional interest payment (less than)		3.25
Interest Coverage Ratio (greater than)		3
Preceding period used for calculating Interest Coverage Ratio		12 months
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)		1.75%
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%)
Notes payable
Notes Payable and Other
Interest rate (as a percent)	2.70%
Notes payable | Minimum
Notes Payable and Other
Maturity term from the date of acquisition	3 years

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016
Liabilities:
Contingent consideration	$ 3,200	$ 2,100
Recurring basis
Liabilities:
Contingent consideration	3,237	2,075
Total Liabilities	3,237	2,075
Recurring basis | Level 1
Liabilities:
Contingent consideration	0	0
Total Liabilities	0	0
Recurring basis | Level 2
Liabilities:
Contingent consideration	0	0
Total Liabilities	0	0
Recurring basis | Level 3
Liabilities:
Contingent consideration	3,237	2,075
Total Liabilities	$ 3,237	$ 2,075

Commitments and Contingencies (

Commitments and Contingencies (Details)	1 Months Ended		3 Months Ended	6 Months Ended
	Nov. 30, 2016USD ($)	Sep. 30, 2016USD ($)	May 31, 2016USD ($)	Nov. 30, 2016USD ($)plaintiff
Litigation
Period over which potential acquisition-related contingent consideration would be payable				2 years 9 months 18 days
French subsidiary
Litigation
Litigation settlement				$ 400,000
Consolidated class and collective action lawsuit
Litigation
Litigation settlement				$ 6,000,000
Payroll taxes and other costs related to settlement			$ 6,300,000
Number of plaintiffs | plaintiff				4,900
Damages from products defects | Quality of Radiography Images
Litigation
Verbal demand for damages	$ 6,000,000
Damages from products defects | Ultrasonic Inspection System
Litigation
Verbal demand for damages		$ 2,300,000
Acquisition-related contingencies
Litigation
Potential acquisition-related contingent consideration, low end of range	0			$ 0
Potential acquisition-related contingent consideration, high end of range	$ 15,600,000			$ 15,600,000

Segment Disclosure - Financial

Segment Disclosure - Financial Information by Segment (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016USD ($)	Nov. 30, 2015USD ($)	Nov. 30, 2016USD ($)segment	Nov. 30, 2015USD ($)	May 31, 2016USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			3
Financial information by segment
Revenues	$ 176,642	$ 194,786	$ 345,085	$ 374,639
Gross profit	52,076	56,925	102,132	108,199
Income (loss) from operations	12,508	19,569	23,664	32,501
Depreciation and amortization	7,894	7,963	15,897	15,923
Intangible assets, net	42,137		42,137		$ 43,492
Total assets	492,166		492,166		482,675
Operating segments | Services
Financial information by segment
Revenues	132,418	150,463	259,108	287,868
Gross profit	34,184	41,118	68,629	77,687
Income (loss) from operations	12,172	18,815	24,641	34,214
Depreciation and amortization	5,469	5,562	11,074	11,084
Intangible assets, net	19,945		19,945		19,022
Total assets	302,920		302,920		301,678
Operating segments | International
Financial information by segment
Revenues	42,230	38,425	79,748	75,284
Gross profit	14,837	12,106	27,224	22,886
Income (loss) from operations	6,717	3,971	11,375	5,789
Depreciation and amortization	1,963	1,914	3,921	3,886
Intangible assets, net	15,807		15,807		17,703
Total assets	135,981		135,981		132,643
Operating segments | Products and Systems
Financial information by segment
Revenues	6,686	7,791	12,853	16,477
Gross profit	3,230	3,833	6,326	7,755
Income (loss) from operations	152	1,055	289	2,239
Depreciation and amortization	566	577	1,114	1,140
Intangible assets, net	5,555		5,555		6,054
Total assets	31,247		31,247		31,596
Corporate and eliminations
Financial information by segment
Revenues	(4,692)	(1,893)	(6,624)	(4,990)
Gross profit	(175)	(132)	(47)	(129)
Income (loss) from operations	(6,533)	(4,272)	(12,641)	(9,741)
Depreciation and amortization	(104)	$ (90)	(212)	$ (187)
Intangible assets, net	830		830		713
Total assets	$ 22,018		$ 22,018		$ 16,758

Segment Disclosure - Revenues b

Segment Disclosure - Revenues by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Revenue and long-lived assets by geographic area
Revenues	$ 176,642	$ 194,786	$ 345,085	$ 374,639
United States
Revenue and long-lived assets by geographic area
Revenues	112,719	132,068	228,842	262,411
Other Americas
Revenue and long-lived assets by geographic area
Revenues	19,957	23,557	35,006	35,086
Europe
Revenue and long-lived assets by geographic area
Revenues	37,560	36,468	71,054	71,352
Asia-Pacific
Revenue and long-lived assets by geographic area
Revenues	$ 6,406	$ 2,693	$ 10,183	$ 5,790

Repurchase of Common Stock (Det

Repurchase of Common Stock (Details) - Stock Repurchase Plan - USD ($) $ / shares in Units, shares in Thousands	Aug. 17, 2016	Nov. 30, 2016	Oct. 07, 2015
Class of Stock [Line Items]
Stock repurchase plan, amount approved			$ 50,000,000
Treasury stock repurchased (in shares)		146
Treasury stock acquired, average price (in dollars per share)		$ 20.48
Treasury stock acquired, aggregate cost		$ 3,000,000
Stock repurchase plan, remaining amount approved		$ 43,000,000
CEO Dr. Sotirios Vahaviolos
Class of Stock [Line Items]
Stock repurchase plan, amount approved (in shares)	1,000
Stock repurchase plan, amount approved each month from CEO	$ 2,000,000
Average daily price of common stock for the preceding month discount, percent	2.00%
Treasury stock repurchased (in shares)		181
Treasury stock acquired, average price (in dollars per share)		$ 22.07
Treasury stock acquired, aggregate cost		$ 4,000,000