XML 11 R1.htm IDEA: XBRL DOCUMENT v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Oct. 31, 2017
Dec. 06, 2017
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Oct. 31, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
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