Document and entity information Document (USD $)	12 Months Ended
	Jan. 31, 2015	Apr. 07, 2015	Jul. 31, 2014
Entity Information [Line Items]
Entity Registrant Name	MFRI INC.
Entity Central Index Key	0000914122
Current Fiscal Year End Date	--01-31
Entity Filer Category	Smaller Reporting Company
Document Type	10-K
Document Period End Date	Jan. 31, 2015
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		7,246,010
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 69,518,913