Document and Entity Information	3 Months Ended
	Mar. 31, 2015	May 13, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	BFFI
Entity Registrant Name	BEN FRANKLIN FINANCIAL, INC.
Entity Central Index Key	0001618798
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		696,339