Unaudited Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Total Mistras Group, Inc. Stockholders’ Equity	Common Stock	Additional paid-in capital	Retained earnings (deficit)	Accumulated other comprehensive income (loss)	Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2018			28,563
Beginning balance at Dec. 31, 2018	$ 271,074	$ 270,897	$ 285	$ 226,616	$ 71,553	$ (27,557)	$ 177
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(5,286)	(5,293)			(5,293)		7
Other comprehensive loss, net of tax	2,133	2,131				2,131	2
Share-base payments (in shares)			61
Share-based payments	1,427	1,427	$ 1	1,426
Net settlement of restricted stock units	$ (284)	(284)		(284)
Exercise of stock options (in shares)	4		3
Exercise of stock options	$ 32	32		32
Ending balance (in shares) at Mar. 31, 2019			28,627
Ending balance at Mar. 31, 2019	269,096	268,910	$ 286	227,790	66,260	(25,426)	186
Beginning balance (in shares) at Dec. 31, 2019			28,945
Beginning balance at Dec. 31, 2019	286,022	285,822	$ 289	229,205	77,613	(21,285)	200
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(98,522)	(98,509)			(98,509)		(13)
Other comprehensive loss, net of tax	(17,015)	(17,009)				(17,009)	(6)
Share-based payments	1,425	1,425		1,425
Net settlements of restricted stock units (in shares)			97
Net settlement of restricted stock units	$ (157)	(157)	$ 1	(158)
Exercise of stock options (in shares)	0
Ending balance (in shares) at Mar. 31, 2020			29,042
Ending balance at Mar. 31, 2020	$ 171,753	$ 171,572	$ 290	$ 230,472	$ (20,896)	$ (38,294)	$ 181