Document and Entity Information - USD ($)	12 Months Ended
	Jan. 31, 2017	Apr. 05, 2017	Jul. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	MIND
Entity Registrant Name	MITCHAM INDUSTRIES INC
Entity Central Index Key	0000926423
Current Fiscal Year End Date	--01-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		12,089,758
Entity Public Float			$ 43,106,000