Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 14, 2021
Entity [Abstract]
Entity Registrant Name	Security Federal Corporation
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Central Index Key	0000818677
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		3,252,884
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Document Quarterly Report	true
Document Transition Report	false