Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 02, 2017
Document and Entity Information
Entity Registrant Name	Mistras Group, Inc.
Entity Central Index Key	0001436126
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,250,751
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2