Document and Entity Information - shares	6 Months Ended
	Jul. 31, 2017	Sep. 06, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Trading Symbol	MIND
Entity Registrant Name	MITCHAM INDUSTRIES INC
Entity Central Index Key	0000926423
Current Fiscal Year End Date	--01-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		12,089,339