Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 11, 2017
Entity [Abstract]
Entity Registrant Name	Security Federal Corporation
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Amendment Flag	false
Entity Central Index Key	0000818677
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		2,945,474
Entity Filer Category	Smaller Reporting Company
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2