Mistras (MG) 10-Q 9 Jan 15 2015 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Nov. 30, 2014	Jan. 01, 2015
Document and Entity Information
Entity Registrant Name	Mistras Group, Inc.
Entity Central Index Key	1436126
Document Type	10-Q
Document Period End Date	30-Nov-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-26
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,623,549
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Nov. 30, 2014	31-May-14
In Thousands, unless otherwise specified
Current Assets
Cash and cash equivalents	$19,599	$10,020
Accounts receivable, net	164,888	137,824
Inventories	12,188	11,376
Deferred income taxes	3,775	3,283
Prepaid expenses and other current assets	15,536	12,626
Total current assets	215,986	175,129
Property, plant and equipment, net	82,266	77,811
Intangible assets, net	61,543	57,875
Goodwill	169,088	130,516
Deferred income taxes	1,301	1,344
Other assets	1,887	1,297
Total assets	532,071	443,972
Current Liabilities
Accounts payable	15,558	14,978
Accrued expenses and other current liabilities	54,594	54,650
Current portion of long-term debt	17,988	8,058
Current portion of capital lease obligations	6,968	7,251
Income taxes payable	2,133	1,854
Total current liabilities	97,241	86,791
Long-term debt, net of current portion	137,080	68,590
Obligations under capital leases, net of current portion	12,968	13,664
Deferred income taxes	20,369	15,521
Other long-term liabilities	14,699	17,014
Total liabilities	282,357	201,580
Commitments and contingencies
Equity
Preferred stock, 10,000,000 shares authorized	0	0
Common stock, $0.01 par value, 200,000,000 shares authorized	286	284
Additional paid-in capital	204,987	201,831
Retained earnings	53,593	41,500
Accumulated other comprehensive loss	-9,427	-1,511
Total Mistras Group, Inc. stockholders’ equity	249,439	242,104
Noncontrolling interests	275	288
Total equity	249,714	242,392
Total liabilities and equity	$532,071	$443,972

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Nov. 30, 2014	31-May-14
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	200,000,000	200,000,000

Unaudited_Condensed_Consolidat

Unaudited Condensed Consolidated Statements of Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Income Statement [Abstract]
Revenue	$206,893	$156,755	$373,466	$292,593
Cost of revenue	142,940	104,494	262,662	196,747
Depreciation	4,914	4,284	9,771	8,592
Gross profit	59,039	47,977	101,033	87,254
Selling, general and administrative expenses	37,180	29,849	72,400	58,548
Research and engineering	629	786	1,278	1,429
Depreciation and amortization	3,472	2,501	6,894	4,958
Acquisition-related expense (benefit), net	-434	-411	-1,395	-2,508
Income from operations	18,192	15,252	21,856	24,827
Interest expense	1,352	772	2,257	1,517
Income before provision for income taxes	16,840	14,480	19,599	23,310
Provision for income taxes	6,428	5,196	7,516	8,391
Net income	10,412	9,284	12,083	14,919
Less: net loss (income) attributable to noncontrolling interests, net of taxes	15	-27	10	-21
Net income attributable to Mistras Group, Inc.	$10,427	$9,257	$12,093	$14,898
Earnings per common share
Basic (in dollars per share)	$0.36	$0.33	$0.42	$0.53
Diluted (in dollars per share)	$0.35	$0.32	$0.41	$0.51
Weighted average common shares outstanding:
Basic (in shares)	28,619	28,378	28,547	28,309
Diluted (in shares)	29,397	29,102	29,551	29,147

Unaudited_Condensed_Consolidat1

Unaudited Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$10,412	$9,284	$12,083	$14,919
Other comprehensive (loss)/income:
Foreign currency translation adjustments	-6,011	2,697	-7,916	2,432
Comprehensive income	4,401	11,981	4,167	17,351
less: comprehensive (income) loss attributable to noncontrolling interest	15	-27	10	-21
Comprehensive income attributable to Mistras Group, Inc.	$4,416	$11,954	$4,177	$17,330

Unaudited_Condensed_Consolidat2

Unaudited Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013
Cash flows from operating activities
Net income	$12,083	$14,919
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	16,665	13,550
Deferred income taxes	1,192	695
Share-based compensation expense	4,257	2,747
Fair value adjustment to contingent consideration liabilities	-808	-2,976
Other	968	211
Changes in operating assets and liabilities, net of effect of acquisitions of businesses:
Accounts receivable	-24,196	-12,498
Inventories	601	-265
Prepaid expenses and other current assets	-2,952	-2,802
Other assets	-478	-22
Accounts payable	-666	2,524
Accrued expenses and other current liabilities	-3,041	124
Income taxes payable	-395	-573
Net cash provided by operating activities	3,230	15,634
Cash flows from investing activities
Purchase of property, plant and equipment	-7,862	-8,189
Purchase of intangible assets	-433	-275
Acquisition of businesses, net of cash acquired	-32,967	-1,507
Proceeds from sale of equipment	596	734
Acquisition-related deposit	0	-11,000
Net cash used in investing activities	-40,666	-20,237
Cash flows from financing activities
Repayment of capital lease obligations	-4,183	-3,757
Repayment of long-term debt	-9,854	-4,105
Net borrowings against revolver	62,648	22,013
Payment of contingent consideration for business acquisitions	-700	-500
Taxes paid related to net share settlement of share-based awards	-1,384	-1,005
Excess tax benefit from share-based compensation	283	122
Proceeds from the exercise of stock options	0	362
Net cash provided by (used in) financing activities	46,810	13,130
Effect of exchange rate changes on cash and cash equivalents	205	-89
Net change in cash and cash equivalents	9,579	8,438
Cash and cash equivalents
Beginning of period	10,020	7,802
End of period	19,599	16,240
Supplemental disclosure of cash paid
Interest	1,815	1,666
Income taxes	8,028	7,570
Noncash investing and financing
Equipment acquired through capital lease obligations	3,533	3,443
Issuance of notes payable	$20,500	$0

Description_of_Business_and_Ba

Description of Business and Basis of Presentation	6 Months Ended
	Nov. 30, 2014
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, aerospace and defense, transportation, primary metals and metalworking, pharmaceuticals and food processing industries.
	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, 2015 and 2014. Reference to a fiscal year means the fiscal year ended May 31. 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 consolidated financial statements contained in the Company’s Annual Report on Form 10-K (“Annual Report”) for fiscal 2014, as filed with the Securities and Exchange Commission on August 8, 2014.
	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 consolidated balance sheets. The noncontrolling interests in net income, net of tax, is classified separately in the accompanying 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 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.
	Significant Accounting Policies
	The Company’s significant accounting policies are disclosed in Note 2 — Summary of Significant Accounting Policies in our Annual Report. On an ongoing basis, we evaluate 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 2014 Annual Report, there have been no material changes to our significant accounting policies.
	Recent Accounting Pronouncements
	On May 28, 2014, the Financial Accounting Standards Board issued Accounting Standards Update (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. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017. 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 consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

ShareBased_Compensation

Share-Based Compensation	6 Months Ended
	Nov. 30, 2014
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 two employee stock ownership plans: (i) the 2007 Stock Option Plan (the 2007 Plan), and (ii) the 2009 Long-Term Incentive Plan (the 2009 Plan). No further awards may be granted under the 2007 Plan, although awards granted under the 2007 Plan remain outstanding in accordance with their terms. Awards granted under the 2009 Plan may be in the form of stock options, restricted stock units and other forms of share-based incentives, including performance restricted stock units, stock appreciation rights and deferred stock rights.
	Stock Options
	For the three months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to stock option awards of less than $0.1 million and $0.1 million, respectively. For the six months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to stock option awards of less than $0.1 million and $0.7 million respectively. As of November 30, 2014, there was less than $0.1 million of unrecognized compensation costs, net of estimated forfeitures, related to stock option awards, which are expected to be recognized over a remaining weighted average period of 1.3 years.
	No stock options were granted during the six months ended November 30, 2014 and 2013.
	Restricted Stock Unit Awards
	For each of the three months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to restricted stock unit awards of $1.2 million and $1.1 million, respectively. For the six months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to restricted stock unit awards of $2.3 million and $1.9 million, respectively. As of November 30, 2014, there was $10.2 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 2.6 years.
	During the first quarter of fiscal 2015 and 2014, the Company granted approximately 10,000 shares 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 $0.2 million for each period respectively, which was recorded as share-based compensation expense during the six months ended November 30, 2014 and 2013.
	During the first half of fiscal 2015 and 2014, approximately 226,000 and 175,000 restricted stock units, respectively, vested. The fair value of these units was $4.9 million and $3.2 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.
	Performance Restricted Stock Units
	In the second quarter of fiscal 2015, the company granted performance restricted stock units to its executive and certain other senior officers. These units have requisite service (vesting) periods of three years and have no dividend rights. For the three months ended November 30, 2014, the Company recognized share-based compensation expense related to performance restricted stock units of $0.1 million. At November 30, 2014, there was $1.8 million of total unrecognized compensation costs related to approximately 115,000 non-vested performance restricted stock units. These costs are expected to be recognized over a weighted-average period of approximately 2.8 years. The actual payout of these units will vary based on the Company’s performance over a three -year period (based on pre-established targets) and a market condition modifier based on total shareholder return (TSR) compared to an industry peer group. Compensation cost is initially measured assuming that the target performance condition will be achieved. However, compensation cost related to the performance condition is adjusted for subsequent changes in the expected outcome of the performance condition. Compensation cost related to the TSR condition is fixed at the measurement date, and not subsequently adjusted.
	In the second quarter of fiscal 2014, the company granted performance restricted stock units to its executive and certain other senior officers. These units have requisite service (vesting) periods of three years and have no dividend rights.
	For the three months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to performance restricted stock units of $0.8 million and less than $0.1 million, respectively. For the six months ended November 30, 2014 and 2013, the Company recognized share-based compensation expense related to performance restricted stock units of $1.6 million and less than $0.1 million , respectively. At November 30, 2014, there was $5.7 million of total unrecognized compensation costs related to approximately 423,000 non-vested performance restricted stock units. These costs are expected to be recognized over a weighted-average period of approximately 1.8 years. The actual payout of these units will vary based on the Company’s performance over one, two and three-year periods (based on pre-established targets) and a market condition modifier based on TSR compared to an industry peer group. Compensation cost is initially measured assuming that the target performance condition will be achieved. However, compensation cost related to the performance condition is adjusted for subsequent changes in the expected outcome of the performance condition. Compensation cost related to the TSR condition is fixed at the measurement date, and not subsequently adjusted. The one-year performance condition of the fiscal 2014 awards was not achieved. The one-year market condition of the fiscal 2014 awards was achieved and will payout at 170% of target once the requisite service period is complete.

Earnings_per_Share

Earnings per Share	6 Months Ended
	Nov. 30, 2014
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) only 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 November 30,				Six months ended November 30,
		2014		2013		2014		2013
	Basic earnings per share
	Numerator:
	Net income attributable to Mistras Group, Inc.	$	10,427	$	9,257	$	12,093	$	14,898
	Denominator:
	Weighted average common shares outstanding	28,619		28,378		28,547		28,309
	Basic earnings per share	$	0.36	$	0.33	$	0.42	$	0.53
	Diluted earnings per share:
	Numerator:
	Net income attributable to Mistras Group, Inc.	$	10,427	$	9,257	$	12,093	$	14,898
	Denominator:
	Weighted average common shares outstanding	28,619		28,378		28,547		28,309
	Dilutive effect of stock options outstanding	675		697		763		702
	Dilutive effect of restricted stock units outstanding	103		27		241		136
		29,397		29,102		29,551		29,147
	Diluted earnings per share	$	0.35	$	0.32	$	0.41	$	0.51

Acquisitions

Acquisitions	6 Months Ended
	Nov. 30, 2014
Business Combinations [Abstract]
Acquisitions	Acquisitions
	In the first half of fiscal 2015, the Company completed three acquisitions. The Company purchased The NACHER Corporation, located in Louisiana, a provider of maintenance and inspection services primarily on offshore platforms. This acquisition expands the service offerings within the Services segment, allowing the Company to provide services to the upstream operations of its customers. The Company also purchased a group of asset protection businesses located in Quebec, Canada to continue its market expansion strategy. The Company’s International Segment completed an acquisition of an asset inspection business located in the United Kingdom.
	In these acquisitions, the Company acquired 100% of the common stock or certain assets of each acquiree in exchange for aggregate consideration of approximately $33.7 million in cash and $20.5 million in notes payable issued as part of the acquisition and other liabilities assumed. The Company accounted for these transactions in accordance with the acquisition method of accounting for business combinations. In addition, the acquisition in Quebec provides for contingent consideration of up to $2.7 million to be earned based upon the acquired business achieving specific performance metrics over the next three years of operation. The Company is in the process of completing the preliminary purchase price allocations.
	In the first half of fiscal 2014, the Company completed an acquisition of a professional engineering consulting and technical training services company located in the U.S. serving the hydrocarbon processing and other energy-related industries. This company was acquired to complement service offerings within the Company’s Services segment and expand its technical capabilities. The Company acquired 100% of the common stock in exchange for $1.5 million in cash.
	The Company is continuing its review of the fair value estimate of assets acquired and liabilities assumed for one entity acquired in fiscal 2014. This process will conclude as soon as the Company finalizes information regarding facts and circumstances that existed as of the acquisition date. Goodwill and intangibles for this entity totaled $0.6 million and $1.6 million, respectively. This measurement period will not exceed one year from the acquisition date.
	The assets and liabilities of the businesses acquired in fiscal 2015 were included in the Company’s 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 each respective operating segment’s results of operations from the date of acquisition. For acquisitions in fiscal 2015 and 2014 for which the final purchase accounting has yet to be completed, 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
		2015			2014
	Number of Entities	2			1
	Consideration transferred:
	Cash paid	$	32,529		$	2,300
	Notes payable issued to seller	20,000			—
	Contingent consideration	1,373			297
	Consideration transferred	53,902			2,597
	Current assets	9,996			346
	Property, plant and equipment	6,764			68
	Current deferred tax asset	481			—
	Intangibles	11,561			1,600
	Goodwill	42,042			583
	Current liabilities	(12,570		)	—
	Long-term deferred tax liability	(4,372		)	—
	Net assets acquired	$	53,902		$	2,597
	The amortization period of intangible assets acquired in fiscal 2015 ranges from 3 to 10 years. The Company recorded $42.9 million of goodwill in connection with these acquisitions, reflecting the strategic fit and revenue and earnings growth potential of these business.
	Revenues and operating income from these acquisitions for the period subsequent to the closing of these transactions were $25.9 million and $2.7 million, respectively, for the six month period ended November 30, 2014. No unaudited pro forma financial information is required as these acquisitions are not significant to the Company.
	During the three and six month periods ended November 30, 2014, the Company incurred acquisition-related costs of $0.2 million, in connection with due diligence, professional fees, and other expenses related to its acquisition activity. Additionally, the Company adjusted the fair value of certain previously recorded acquisition-related contingent consideration liabilities. For the three and six month periods ended November 30, 2014, these adjustments resulted in a net decrease of acquisition-related contingent consideration liabilities and a corresponding increase in income from operations of $0.6 million and $1.6 million, respectively. The Company’s aggregate acquisition-related contingent consideration liabilities were $12.5 million and $14.1 million as of November 30, 2014 and May 31, 2014, respectively.
	During the three and six month period ended November 30, 2013, the Company incurred acquisition-related costs of $0.4 million and $0.5 million in connection with due diligence, professional fees, and other expenses for its acquisition activity. Additionally, the Company adjusted the fair value of certain acquisition-related contingent consideration liabilities. For the three and six month periods ended November 30, 2013, these adjustments resulted in a net decrease of acquisition-related contingent consideration liabilities and a corresponding increase in income from operations of approximately $0.8 million and $3.0 million, respectively.
	The fair value adjustments to acquisition-related contingent consideration liabilities and the 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, 2014 and 2013.

Accounts_Receivable_net

Accounts Receivable, net	6 Months Ended
	Nov. 30, 2014
Receivables [Abstract]
Accounts Receivable, net	Accounts Receivable, net
	Accounts receivable consisted of the following:
		November 30, 2014			May 31, 2014
	Trade accounts receivable	$	167,518		$	140,120
	Allowance for doubtful accounts	(2,630		)	(2,296		)
	Account receivable, net	$	164,888		$	137,824

Inventories

Inventories	6 Months Ended
	Nov. 30, 2014
Inventory Disclosure [Abstract]
Inventories	Inventories
	Inventories consisted of the following:
		November 30, 2014		May 31, 2014
	Raw materials	$	3,832	$	3,663
	Work in process	1,897		2,069
	Finished goods	3,991		3,462
	Services-related consumable supplies	2,468		2,182
	Inventory	$	12,188	$	11,376

Property_Plant_and_Equipment_n

Property, Plant and Equipment, net	6 Months Ended
	Nov. 30, 2014
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	30-Nov-14			31-May-14
		(Years)
	Land		$	1,905		$	1,938
	Buildings and improvements	30-40	17,948			22,983
	Office furniture and equipment	8-May	7,731			7,169
	Machinery and equipment	7-May	156,979			144,798
			184,563			176,888
	Accumulated depreciation and amortization		(102,297		)	(99,077		)
	Property, plant and equipment, net		$	82,266		$	77,811
	Depreciation expense for the three months ended November 30, 2014 and 2013 was $5.5 million and $4.6 million, respectively. Depreciation expense for the six months ended November 30, 2014 and 2013 was $10.9 million and $9.2 million, respectively.

Intangible_Assets

Intangible Assets	6 Months Ended
	Nov. 30, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	Intangible Assets
	The gross amount, accumulated amortization and net carrying amount of intangible assets are as follows:
			30-Nov-14							31-May-14
		Useful Life	Gross		Accumulated			Net		Gross		Accumulated			Net
		(Years)	Amount		Amortization			Carrying		Amount		Amortization			Carrying
								Amount							Amount
	Customer relationships	12-May	$	87,595	$	(38,261	)	$	49,334	$	82,395	$	(34,636	)	$	47,759
	Software/Technology	15-Mar	15,447		(9,684		)	5,763		15,328		(9,172		)	6,156
	Covenants not to compete	5-Feb	10,408		(8,266		)	2,142		9,471		(7,882		)	1,589
	Other	5-Feb	8,212		(3,908		)	4,304		5,869		(3,498		)	2,371
	Total		$	121,662	$	(60,119	)	$	61,543	$	113,063	$	(55,188	)	$	57,875
	Amortization expense for the three months ended November 30, 2014 and 2013 was $2.9 million and $2.2 million, respectively. Amortization expense for the six months ended November 30, 2014 and 2013 was $5.8 million and $4.3 million, respectively.

Accrued_Expenses_and_Other_Cur

Accrued Expenses and Other Current Liabilities	6 Months Ended
	Nov. 30, 2014
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities
	Accrued expenses and other current liabilities consist of the following:
		30-Nov-14		31-May-14
	Accrued salaries, wages and related employee benefits	$	24,677	$	26,236
	Contingent consideration, current portion	4,382		4,778
	Accrued workers’ compensation and health benefits	6,893		3,661
	Deferred revenue	2,447		2,659
	Other accrued expenses	16,195		17,316
	Total accrued expenses and other liabilities	$	54,594	$	54,650

LongTerm_Debt

Long-Term Debt	6 Months Ended
	Nov. 30, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt
	Long-term debt consists of the following:
		30-Nov-14			31-May-14
	Senior credit facility	$	123,796		$	61,148
	Notes payable	26,335			10,512
	Other	4,937			4,988
	Total debt	155,068			76,648
	Less: Current portion	(17,988		)	(8,058		)
	Long-term debt, net of current portion	$	137,080		$	68,590
	Senior Credit Facility
	On October 31, 2014, the Company entered into a Third Amendment and Modification Agreement (the “Amendment”), to its revolving line of credit, the Third Amended and Restated Credit Agreement (“Credit Agreement”), dated December 21, 2011, with Bank of America, N.A., as agent for the lenders and a lender, and JPMorgan Chase Bank, N.A., Keybank, National Association and TD Bank, N.A., as lenders. The Amendment increased the Company’s revolving line of credit to from $125.0 million to $175.0 million and provides that under certain circumstances the line of credit can be increased to $225.0 million. The Company may continue to 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 Amendment also extended the original maturity date of the Credit Agreement from December 20, 2016 to October 30, 2019. As of November 30, 2014, the Company had borrowings of $123.8 million and a total of $4.2 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, or 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 3.0 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 its 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, 2014, 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 through fiscal 2015, the Company issued subordinated notes payable to the sellers. The maturity of these notes range from two to five years from the date of acquisition with stated interest rates ranging from 0% to 4%. The Company has discounted these obligations to reflect a 2% to 4% market interest. Unamortized discount on the notes was de minimis as of November 30, 2014 and May 31, 2014. Amortization is recorded as interest expense in the 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 issues of debt.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Nov. 30, 2014
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, 2014
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Contingent consideration	$	—	$	—	$	12,531	$	12,531
	Total Liabilities	$	—	$	—	$	12,531	$	12,531
		May 31, 2014
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Contingent consideration	$	—	$	—	$	14,145	$	14,145
	Total Liabilities	$	—	$	—	$	14,145	$	14,145
	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, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Litigation
	The Company is subject to periodic lawsuits, investigations and claims that arise in the ordinary course of business. Although the Company cannot predict with certainty the ultimate resolution of lawsuits, investigations and claims asserted against it, 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 in such matters may be covered by insurance.
	In January 2012, the Company received notice of a governmental investigation concerning an environmental incident which occurred in February 2011 outside on the premises of its Cudahy, California location. No human injury or property damage was reported or appears to have been caused as a result of this incident. While management cannot predict the ultimate outcome of this matter, based on its internal investigation to date, the Company does not believe the outcome will have a material effect on its financial condition or results of operations.
	During fiscal 2012 and 2013, the Company performed radiography work on the construction of pipeline projects in Georgia. The Company has received notice that the owner of the pipeline projects contends that certain of the x-ray images the Company’s technicians prepared did not meet the code quality interpretation standards required by API (American Petroleum Institute) 1104. The owner of the projects is claiming damages as a result of the alleged quality defects of the Company’s x-ray images. No lawsuit has been filed at this time.  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 has received a notice from an insurance company of a chemical plant alleging that the Company is liable due to faulty inspections for all or part of $46 million of damages paid by the insurance company as a result of an explosion at the facility. The Company believes it was not involved in inspecting the portion of the plant where the explosion occurred and therefore has no liability for the claim.  Accordingly, the Company has not established a reserve for this matter.
	Acquisition-related contingencies
	The Company is liable for contingent consideration in connection with certain of its acquisitions. As of November 30, 2014, total potential acquisition-related contingent consideration ranged from zero to approximately $26.9 million and would be payable upon the achievement of specific performance metrics by certain of the acquired companies over the next three years of operations. See Note 4 - Acquisitions to these consolidated financial statements for further discussion of the Company’s acquisitions.

Segment_Disclosure

Segment Disclosure	6 Months Ended
	Nov. 30, 2014
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 and the Canadian services business, 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.
	Allocations for general corporate services, including accounting, audit, and contract management, 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.
	The accounting policies of the reportable segments are the same as those described in Note 1 — Description of Business and Basis of Presentation. Segment income from operations is determined based on internal performance measures used by the Chief Executive Officer, who is the chief operating decision maker, to assess the performance of each business in a given period and to make decisions as to resource allocations. In connection with that assessment, the Chief Executive Officer may exclude matters such as charges for share-based compensation and certain other acquisition-related charges and balances, technology and product development costs, certain gains and losses from dispositions, and litigation settlements or other charges. Certain general and administrative costs such as human resources, information technology and training are allocated to the segments. Segment income from operations also excludes interest and other financial charges and income taxes. Corporate and other assets are comprised principally of cash, deposits, property, plant and equipment, domestic deferred taxes, deferred charges and other assets. Corporate loss from operations consists of depreciation on the corporate office facilities and equipment, administrative charges related to corporate personnel and other charges that cannot be readily identified for allocation to a particular segment.
	Selected consolidated financial information by segment for the periods shown was as follows:
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Revenues
	Services	$	160,874		$	108,862		$	282,806		$	204,672
	International	41,018			43,209			81,056			80,968
	Products and Systems	7,495			8,604			14,062			15,189
	Corporate and eliminations	(2,494		)	(3,920		)	(4,458		)	(8,236		)
		$	206,893		$	156,755		$	373,466		$	292,593
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Gross profit
	Services	$	44,252		$	30,918		$	74,023		$	57,665
	International	11,309			13,293			20,777			23,413
	Products and Systems	3,328			3,718			5,992			6,102
	Corporate and eliminations	150			48			241			74
		$	59,039		$	47,977		$	101,033		$	87,254
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Income (loss) from operations
	Services	$	20,071		$	14,400		$	28,951		$	25,246
	International	3,177			7,293			2,478			9,108
	Products and Systems	417			469			(16		)	1,060
	Corporate and eliminations	(5,473		)	(6,910		)	(9,557		)	(10,587		)
		$	18,192		$	15,252		$	21,856		$	24,827
	Income (loss) by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations.
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Depreciation and amortization
	Services	$	5,579		$	4,156		$	10,964		$	8,391
	International	2,050			1,983			4,211			3,905
	Products and Systems	605			583			1,201			1,166
	Corporate and eliminations	152			63			289			88
		$	8,386		$	6,785		$	16,665		$	13,550
		November 30, 2014			May 31, 2014
	Goodwill
	Services	$	115,039		$	73,767
	International	40,852			43,552
	Products and Systems	13,197			13,197
		$	169,088		$	130,516
		November 30, 2014			May 31, 2014
	Total assets
	Services	$	345,133		$	249,378
	International	143,527			155,571
	Products and Systems	35,697			38,041
	Corporate and eliminations	7,714			982
		$	532,071		$	443,972
	Revenues by geographic area for the three and six months ended November 30, 2014 and 2013, respectively, were as follows:
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Revenues
	United States	$	140,308		$	99,497		$	252,248		$	182,654
	Other Americas	25,266			13,752			39,564			27,172
	Europe	38,081			37,399			74,726			72,805
	Asia-Pacific	3,238			6,107			6,928			9,962
		$	206,893		$	156,755		$	373,466		$	292,593

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Nov. 30, 2014
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, 2015 and 2014. Reference to a fiscal year means the fiscal year ended May 31. 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 consolidated financial statements contained in the Company’s Annual Report on Form 10-K (“Annual Report”) for fiscal 2014, as filed with the Securities and Exchange Commission on August 8, 2014.
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 consolidated balance sheets. The noncontrolling interests in net income, net of tax, is classified separately in the accompanying 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 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
	On May 28, 2014, the Financial Accounting Standards Board issued Accounting Standards Update (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. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017. 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 consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

Earnings_per_Share_Tables

Earnings per Share (Tables)	6 Months Ended
	Nov. 30, 2014
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 November 30,				Six months ended November 30,
		2014		2013		2014		2013
	Basic earnings per share
	Numerator:
	Net income attributable to Mistras Group, Inc.	$	10,427	$	9,257	$	12,093	$	14,898
	Denominator:
	Weighted average common shares outstanding	28,619		28,378		28,547		28,309
	Basic earnings per share	$	0.36	$	0.33	$	0.42	$	0.53
	Diluted earnings per share:
	Numerator:
	Net income attributable to Mistras Group, Inc.	$	10,427	$	9,257	$	12,093	$	14,898
	Denominator:
	Weighted average common shares outstanding	28,619		28,378		28,547		28,309
	Dilutive effect of stock options outstanding	675		697		763		702
	Dilutive effect of restricted stock units outstanding	103		27		241		136
		29,397		29,102		29,551		29,147
	Diluted earnings per share	$	0.35	$	0.32	$	0.41	$	0.51

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended
	Nov. 30, 2014
Business Combinations [Abstract]
Summary of estimated fair value of assets acquired and liabilities assumed at 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
		2015			2014
	Number of Entities	2			1
	Consideration transferred:
	Cash paid	$	32,529		$	2,300
	Notes payable issued to seller	20,000			—
	Contingent consideration	1,373			297
	Consideration transferred	53,902			2,597
	Current assets	9,996			346
	Property, plant and equipment	6,764			68
	Current deferred tax asset	481			—
	Intangibles	11,561			1,600
	Goodwill	42,042			583
	Current liabilities	(12,570		)	—
	Long-term deferred tax liability	(4,372		)	—
	Net assets acquired	$	53,902		$	2,597

Accounts_Receivable_net_Tables

Accounts Receivable, net (Tables)	6 Months Ended
	Nov. 30, 2014
Receivables [Abstract]
Schedule of accounts receivable	Accounts receivable consisted of the following:
		November 30, 2014			May 31, 2014
	Trade accounts receivable	$	167,518		$	140,120
	Allowance for doubtful accounts	(2,630		)	(2,296		)
	Account receivable, net	$	164,888		$	137,824

Inventories_Tables

Inventories (Tables)	6 Months Ended
	Nov. 30, 2014
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories consisted of the following:
		November 30, 2014		May 31, 2014
	Raw materials	$	3,832	$	3,663
	Work in process	1,897		2,069
	Finished goods	3,991		3,462
	Services-related consumable supplies	2,468		2,182
	Inventory	$	12,188	$	11,376

Property_Plant_and_Equipment_n1

Property, Plant and Equipment, net (Tables)	6 Months Ended
	Nov. 30, 2014
Property, Plant and Equipment [Abstract]
Schedule of Property, plant and equipment	Property, plant and equipment consisted of the following:
		Useful Life	30-Nov-14			31-May-14
		(Years)
	Land		$	1,905		$	1,938
	Buildings and improvements	30-40	17,948			22,983
	Office furniture and equipment	8-May	7,731			7,169
	Machinery and equipment	7-May	156,979			144,798
			184,563			176,888
	Accumulated depreciation and amortization		(102,297		)	(99,077		)
	Property, plant and equipment, net		$	82,266		$	77,811

Intangible_Assets_Tables

Intangible Assets (Tables)	6 Months Ended
	Nov. 30, 2014
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 are as follows:
			30-Nov-14							31-May-14
		Useful Life	Gross		Accumulated			Net		Gross		Accumulated			Net
		(Years)	Amount		Amortization			Carrying		Amount		Amortization			Carrying
								Amount							Amount
	Customer relationships	12-May	$	87,595	$	(38,261	)	$	49,334	$	82,395	$	(34,636	)	$	47,759
	Software/Technology	15-Mar	15,447		(9,684		)	5,763		15,328		(9,172		)	6,156
	Covenants not to compete	5-Feb	10,408		(8,266		)	2,142		9,471		(7,882		)	1,589
	Other	5-Feb	8,212		(3,908		)	4,304		5,869		(3,498		)	2,371
	Total		$	121,662	$	(60,119	)	$	61,543	$	113,063	$	(55,188	)	$	57,875

Accrued_Expenses_and_Other_Cur1

Accrued Expenses and Other Current Liabilities (Tables)	6 Months Ended
	Nov. 30, 2014
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following:
		30-Nov-14		31-May-14
	Accrued salaries, wages and related employee benefits	$	24,677	$	26,236
	Contingent consideration, current portion	4,382		4,778
	Accrued workers’ compensation and health benefits	6,893		3,661
	Deferred revenue	2,447		2,659
	Other accrued expenses	16,195		17,316
	Total accrued expenses and other liabilities	$	54,594	$	54,650

LongTerm_Debt_Tables

Long-Term Debt (Tables)	6 Months Ended
	Nov. 30, 2014
Debt Disclosure [Abstract]
Schedule of long-term debt	Long-term debt consists of the following:
		30-Nov-14			31-May-14
	Senior credit facility	$	123,796		$	61,148
	Notes payable	26,335			10,512
	Other	4,937			4,988
	Total debt	155,068			76,648
	Less: Current portion	(17,988		)	(8,058		)
	Long-term debt, net of current portion	$	137,080		$	68,590

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Nov. 30, 2014
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	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, 2014
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Contingent consideration	$	—	$	—	$	12,531	$	12,531
	Total Liabilities	$	—	$	—	$	12,531	$	12,531
		May 31, 2014
		Level 1		Level 2		Level 3		Total
	Liabilities:
	Contingent consideration	$	—	$	—	$	14,145	$	14,145
	Total Liabilities	$	—	$	—	$	14,145	$	14,145

Segment_Disclosure_Tables

Segment Disclosure (Tables)	6 Months Ended
	Nov. 30, 2014
Segment Reporting [Abstract]
Schedule of consolidated financial information by segment	Selected consolidated financial information by segment for the periods shown was as follows:
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Revenues
	Services	$	160,874		$	108,862		$	282,806		$	204,672
	International	41,018			43,209			81,056			80,968
	Products and Systems	7,495			8,604			14,062			15,189
	Corporate and eliminations	(2,494		)	(3,920		)	(4,458		)	(8,236		)
		$	206,893		$	156,755		$	373,466		$	292,593
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Gross profit
	Services	$	44,252		$	30,918		$	74,023		$	57,665
	International	11,309			13,293			20,777			23,413
	Products and Systems	3,328			3,718			5,992			6,102
	Corporate and eliminations	150			48			241			74
		$	59,039		$	47,977		$	101,033		$	87,254
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Income (loss) from operations
	Services	$	20,071		$	14,400		$	28,951		$	25,246
	International	3,177			7,293			2,478			9,108
	Products and Systems	417			469			(16		)	1,060
	Corporate and eliminations	(5,473		)	(6,910		)	(9,557		)	(10,587		)
		$	18,192		$	15,252		$	21,856		$	24,827
	Income (loss) by operating segment includes intercompany transactions, which are eliminated in Corporate and eliminations.
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Depreciation and amortization
	Services	$	5,579		$	4,156		$	10,964		$	8,391
	International	2,050			1,983			4,211			3,905
	Products and Systems	605			583			1,201			1,166
	Corporate and eliminations	152			63			289			88
		$	8,386		$	6,785		$	16,665		$	13,550
		November 30, 2014			May 31, 2014
	Goodwill
	Services	$	115,039		$	73,767
	International	40,852			43,552
	Products and Systems	13,197			13,197
		$	169,088		$	130,516
		November 30, 2014			May 31, 2014
	Total assets
	Services	$	345,133		$	249,378
	International	143,527			155,571
	Products and Systems	35,697			38,041
	Corporate and eliminations	7,714			982
		$	532,071		$	443,972
Schedule of revenues by geographic area	Revenues by geographic area for the three and six months ended November 30, 2014 and 2013, respectively, were as follows:
		Three months ended November 30,						Six months ended November 30,
		2014			2013			2014			2013
	Revenues
	United States	$	140,308		$	99,497		$	252,248		$	182,654
	Other Americas	25,266			13,752			39,564			27,172
	Europe	38,081			37,399			74,726			72,805
	Asia-Pacific	3,238			6,107			6,928			9,962
		$	206,893		$	156,755		$	373,466		$	292,593

Description_of_Business_and_Ba2

Description of Business and Basis of Presentation (Details)	6 Months Ended
	Nov. 30, 2014
	item
Principles of Consolidation
Difference of period between the consolidation of International segment subsidiaries	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	1

ShareBased_Compensation_Detail

Share-Based Compensation (Details) (USD $)	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2013	Nov. 30, 2014	Aug. 31, 2014	Aug. 31, 2013
	item				item	item
Share-based compensation
Number of employee stock ownership plans	2
Stock Options
Share-based compensation
Recognized share-based compensation expense		$0.10	$0.70
Weighted-average period over which unrecognized compensation cost is expected to be recognized	1 year 3 months
Stock options granted (in shares)	0		0
Stock Options | Maximum
Share-based compensation
Recognized share-based compensation expense	0.1			0.1
Unrecognized compensation costs, net of estimated forfeitures, related to stock option awards	0.1			0.1
Restricted Stock Unit Awards
Share-based compensation
Recognized share-based compensation expense	2.3	1.1	1.9	1.2
Weighted-average period over which unrecognized compensation cost is expected to be recognized	2 years 7 months 10 days
Additional disclosures
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards	10.2			10.2
Fair value of shares vested	4.9		3.2
Shares vested	226,000		175,000
Non-employee directors
Additional disclosures
Number of fully vested common stock granted					10,000	10,000
Number of non-employee directors to whom fully vested common stock is granted					5	5
Fair value of shares vested			$0.20	$0.20
2007 Plan
Share-based compensation
Number of awards that may be granted (in shares)	0			0

ShareBased_Compensation_Detail1

Share-Based Compensation (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Fiscal 2015 Grants | Performance Restricted Stock Units
Share-based compensation
Requisite service period	3 years
Recognized share-based compensation expense	$0.10
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards	1.8		1.8
Unvested restricted stock units outstanding (in shares)	115,000		115,000
Weighted-average period over which unrecognized compensation cost is expected to be recognized			2 years 9 months 18 days
Performance period			3 years
Fiscal 2014 Grants
Share-based compensation
Payout for the fiscal 2014 market condition awards, percentage of target			170.00%
Fiscal 2014 Grants | Performance Restricted Stock Units
Share-based compensation
Requisite service period		3 years
Recognized share-based compensation expense	0.8	0.1	1.6	0.1
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards	$5.70		$5.70
Unvested restricted stock units outstanding (in shares)	423,000		423,000
Weighted-average period over which unrecognized compensation cost is expected to be recognized			1 year 9 months 18 days
Fiscal 2014 Grants | Performance Restricted Stock Units with one year EPS performance condition
Share-based compensation
Performance period			1 year
Fiscal 2014 Grants | Performance Restricted Stock Units with two year EPS performance condition
Share-based compensation
Performance period				2 years
Fiscal 2014 Grants | Performance Restricted Stock Units with three year EPS performance condition
Share-based compensation
Performance period			3 years

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Numerator:
Net income attributable to Mistras Group, Inc.	$10,427	$9,257	$12,093	$14,898
Denominator:
Weighted average common shares outstanding	28,619	28,378	28,547	28,309
Basic earnings per share (in dollars per share)	$0.36	$0.33	$0.42	$0.53
Numerator:
Net income attributable to Mistras Group, Inc.	$10,427	$9,257	$12,093	$14,898
Denominator:
Weighted average common shares outstanding	28,619	28,378	28,547	28,309
Dilutive effect of stock options outstanding (in shares)	675	697	763	702
Dilutive effect of restricted stock units outstanding (in shares)	103	27	241	136
Weighted average common shares outstanding, diluted	29,397	29,102	29,551	29,147
Diluted earnings per share (in dollars per share)	$0.35	$0.32	$0.41	$0.51

Acquisitions_Details

Acquisitions (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	31-May-14
	Entity		Entity
Consideration transferred:
Contingent consideration	$12,500		$14,100
Goodwill	169,088		130,516
Fiscal 2015 acquisitions
Estimated fair value of the assets acquired and liabilities assumed
Number of Entities	3
Consideration transferred:
Cash paid	33,700
Notes payable issued to seller	20,500
Fiscal 2014 acquisitions
Estimated fair value of the assets acquired and liabilities assumed
Number of Entities			1
Consideration transferred:
Cash paid		1,500
Intangibles			1,600
Preliminary
Consideration transferred:
Notes payable issued to seller			0
Current deferred tax asset			0
Preliminary | Fiscal 2015 acquisitions
Estimated fair value of the assets acquired and liabilities assumed
Number of Entities	2
Consideration transferred:
Cash paid	32,529
Notes payable issued to seller	20,000
Contingent consideration	1,373
Consideration transferred	53,902
Current assets	9,996
Property, plant and equipment	6,764
Current deferred tax asset	481
Intangibles	11,561
Goodwill	42,042
Current liabilities	-12,570
Long-term deferred tax liability	-4,372
Net assets acquired	53,902
Preliminary | Fiscal 2014 acquisitions
Estimated fair value of the assets acquired and liabilities assumed
Number of Entities			1
Consideration transferred:
Cash paid			2,300
Contingent consideration			297
Consideration transferred			2,597
Current assets			346
Property, plant and equipment			68
Intangibles			1,600
Goodwill			583
Current liabilities			0
Long-term deferred tax liability			0
Net assets acquired			$2,597

Acquisitions_Details_2

Acquisitions (Details 2) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
					Entity
Acquisitions
Fair value of contingent consideration liabilities	$12,500,000		$12,500,000		$14,100,000
Period over which potential acquisition-related contingent consideration would be payable			3 years
Other acquisition information
Acquisition-related costs	-434,000	-411,000	-1,395,000	-2,508,000
Increase (decrease) in income from operations	600,000	800,000	1,600,000	3,000,000
Fair value adjustment to contingent consideration liabilities			-808,000	-2,976,000
Fiscal 2015 acquisitions
Acquisitions
Number of Entities			3
Percentage of common stock acquired	100.00%		100.00%
Cash paid			33,700,000
Notes payable issued to seller			20,500,000
Period over which potential acquisition-related contingent consideration would be payable			3 years
Goodwill from acquisitions after purchase accounting adjustments	42,900,000		42,900,000
Pro forma information of the results of operations
Revenues			25,900,000
Operating income			2,700,000
Other acquisition information
Acquisition-related costs	200,000		200,000
Fair value adjustment to contingent consideration liabilities	-600,000		-1,600,000
Fiscal 2014 acquisitions
Acquisitions
Number of Entities					1
Percentage of common stock acquired		100.00%		100.00%
Cash paid				1,500,000
Goodwill from acquisitions after purchase accounting adjustments					600,000
Intangibles					1,600,000
Maximum fair value measurement period from the acquisition date					1 year
Other acquisition information
Acquisition-related costs		400,000		500,000
Fair value adjustment to contingent consideration liabilities		-800,000		-3,000,000
Minimum | Fiscal 2015 acquisitions
Acquisitions
Amortization period of intangible assets acquired			3 years
Maximum | Fiscal 2015 acquisitions
Acquisitions
Fair value of contingent consideration liabilities	$2,700,000		$2,700,000
Amortization period of intangible assets acquired			10 years

Accounts_Receivable_net_Detail

Accounts Receivable, net (Details) (USD $)	Nov. 30, 2014	31-May-14
In Thousands, unless otherwise specified
Receivables [Abstract]
Trade accounts receivable	$167,518	$140,120
Allowance for doubtful accounts	-2,630	-2,296
Account receivable, net	$164,888	$137,824

Inventories_Details

Inventories (Details) (USD $)	Nov. 30, 2014	31-May-14
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$3,832	$3,663
Work in process	1,897	2,069
Finished goods	3,991	3,462
Services-related consumable supplies	2,468	2,182
Inventory	$12,188	$11,376

Property_Plant_and_Equipment_n2

Property, Plant and Equipment, net (Details) (USD $)	3 Months Ended		6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
Property, Plant and Equipment, net
Property, plant and equipment, gross	$184,563,000		$184,563,000		$176,888,000
Accumulated depreciation and amortization	-102,297,000		-102,297,000		-99,077,000
Property, plant and equipment, net	82,266,000		82,266,000		77,811,000
Depreciation expense	5,500,000	4,600,000	10,900,000	9,200,000
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	1,905,000		1,905,000		1,938,000
Buildings and improvements
Property, Plant and Equipment, net
Property, plant and equipment, gross	17,948,000		17,948,000		22,983,000
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	7,731,000		7,731,000		7,169,000
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	$156,979,000		$156,979,000		$144,798,000
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

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	3 Months Ended		6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
Intangible assets
Gross Amount	$121,662,000		$121,662,000		$113,063,000
Accumulated Amortization	-60,119,000		-60,119,000		-55,188,000
Net Carrying Amount	61,543,000		61,543,000		57,875,000
Amortization expense	2,900,000	2,200,000	5,800,000	4,300,000
Customer relationships
Intangible assets
Gross Amount	87,595,000		87,595,000		82,395,000
Accumulated Amortization	-38,261,000		-38,261,000		-34,636,000
Net Carrying Amount	49,334,000		49,334,000		47,759,000
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	15,447,000		15,447,000		15,328,000
Accumulated Amortization	-9,684,000		-9,684,000		-9,172,000
Net Carrying Amount	5,763,000		5,763,000		6,156,000
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	10,408,000		10,408,000		9,471,000
Accumulated Amortization	-8,266,000		-8,266,000		-7,882,000
Net Carrying Amount	2,142,000		2,142,000		1,589,000
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	8,212,000		8,212,000		5,869,000
Accumulated Amortization	-3,908,000		-3,908,000		-3,498,000
Net Carrying Amount	$4,304,000		$4,304,000		$2,371,000
Other | Minimum
Intangible assets
Useful Life (Years)			2 years
Other | Maximum
Intangible assets
Useful Life (Years)			5 years

Accrued_Expenses_and_Other_Cur2

Accrued Expenses and Other Current Liabilities (Details) (USD $)	Nov. 30, 2014	31-May-14
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accrued salaries, wages and related employee benefits	$24,677	$26,236
Contingent consideration, current portion	4,382	4,778
Accrued workers’ compensation and health benefits	6,893	3,661
Deferred revenue	2,447	2,659
Other accrued expenses	16,195	17,316
Total accrued expenses and other liabilities	$54,594	$54,650

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	0 Months Ended	3 Months Ended	6 Months Ended
	Oct. 31, 2014	Nov. 30, 2014	Nov. 30, 2014	31-May-14	Oct. 30, 2014
	item
Long-Term Debt
Long-term debt		$155,068,000	$155,068,000	$76,648,000
Less: Current portion		-17,988,000	-17,988,000	-8,058,000
Long-term debt, net of current portion		137,080,000	137,080,000	68,590,000
Senior credit facility
Long-Term Debt
Long-term debt		123,796,000	123,796,000	61,148,000
Senior Credit Facility
Maximum borrowing capacity	175,000,000				125,000,000
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		123,800,000	123,800,000
Outstanding letters of credit		4,200,000	4,200,000
Number of consecutive fiscal quarters used for calculating Funded Debt Leverage Ratio	4
Additional interest rate margin if Funded Debt Leverage Ratio exceeds threshold (as a percent)	2.00%
Preceding period used for calculating Interest Coverage Ratio	12 months
Senior credit facility | Minimum
Senior Credit Facility
Funded Debt Leverage Ratio at which the entity will bear the maximum interest rate margin	2
Interest Coverage Ratio	3
Senior credit facility | Maximum
Senior Credit Facility
Funded Debt Leverage Ratio at which the entity will have the benefit of lowest interest margin	0.5
Funded Debt Leverage Ratio for additional interest payment	3
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)	-0.38%
Senior credit facility | Base rate | Maximum
Senior Credit Facility
Margin (as a percent)	-1.25%
Notes payable
Long-Term Debt
Long-term debt		26,335,000	26,335,000	10,512,000
Notes Payable and Other
Interest rate, minimum (as a percent)			0.00%
Interest rate, maximum (as a percent)		4.00%
Notes payable | Minimum
Notes Payable and Other
Maturity term from the date of acquisition		2 years
Market interest rate (as a percent)			2.00%
Notes payable | Maximum
Notes Payable and Other
Maturity term from the date of acquisition		5 years
Market interest rate (as a percent)			4.00%
Other
Long-Term Debt
Long-term debt		$4,937,000	$4,937,000	$4,988,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Nov. 30, 2014	31-May-14
In Thousands, unless otherwise specified
Liabilities:
Contingent consideration	$12,500	$14,100
Recurring basis
Liabilities:
Contingent consideration	12,531	14,145
Total Liabilities	12,531	14,145
Recurring basis | Level 3
Liabilities:
Contingent consideration	12,531	14,145
Total Liabilities	$12,531	$14,145

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	6 Months Ended
	Nov. 30, 2014
Litigation
Period over which potential acquisition-related contingent consideration would be payable	3 years
Lawsuits for alleged quality defects
Litigation
Number of claims filed	0
Lawsuit for liability due to faulty inspections
Litigation
Expected maximum possible liability	46,000,000
Acquisition-related contingencies
Litigation
Potential acquisition-related contingent consideration, low end of range	0
Potential acquisition-related contingent consideration, high end of range	26,900,000

Segment_Disclosure_Details

Segment Disclosure (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
			Operating_Segment
Segment Reporting [Abstract]
Number of operating segments			3
Financial information by segment
Revenues	$206,893	$156,755	$373,466	$292,593
Gross profit	59,039	47,977	101,033	87,254
Income (loss) from operations	18,192	15,252	21,856	24,827
Depreciation and amortization	8,386	6,785	16,665	13,550
Goodwill	169,088		169,088		130,516
Total assets	532,071		532,071		443,972
Operating segments | Services
Financial information by segment
Revenues	160,874	108,862	282,806	204,672
Gross profit	44,252	30,918	74,023	57,665
Income (loss) from operations	20,071	14,400	28,951	25,246
Depreciation and amortization	5,579	4,156	10,964	8,391
Goodwill	115,039		115,039		73,767
Total assets	345,133		345,133		249,378
Operating segments | International
Financial information by segment
Revenues	41,018	43,209	81,056	80,968
Gross profit	11,309	13,293	20,777	23,413
Income (loss) from operations	3,177	7,293	2,478	9,108
Depreciation and amortization	2,050	1,983	4,211	3,905
Goodwill	40,852		40,852		43,552
Total assets	143,527		143,527		155,571
Operating segments | Products and Systems
Financial information by segment
Revenues	7,495	8,604	14,062	15,189
Gross profit	3,328	3,718	5,992	6,102
Income (loss) from operations	417	469	-16	1,060
Depreciation and amortization	605	583	1,201	1,166
Goodwill	13,197		13,197		13,197
Total assets	35,697		35,697		38,041
Corporate and eliminations
Financial information by segment
Revenues	-2,494	-3,920	-4,458	-8,236
Gross profit	150	48	241	74
Income (loss) from operations	-5,473	-6,910	-9,557	-10,587
Depreciation and amortization	152	63	289	88
Total assets	$7,714		$7,714		$982

Segment_Disclosure_Details_2

Segment Disclosure (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Revenue and long-lived assets by geographic area
Revenues	$206,893	$156,755	$373,466	$292,593
United States
Revenue and long-lived assets by geographic area
Revenues	140,308	99,497	252,248	182,654
Other Americas
Revenue and long-lived assets by geographic area
Revenues	25,266	13,752	39,564	27,172
Europe
Revenue and long-lived assets by geographic area
Revenues	38,081	37,399	74,726	72,805
Asia-Pacific
Revenue and long-lived assets by geographic area
Revenues	$3,238	$6,107	$6,928	$9,962