Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 15, 2021
Entity [Abstract]
Entity Registrant Name	SECURITY FEDERAL CORPORATION
Document Type	10-Q
Document Period End Date	Sep. 30, 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	Q3
Document Quarterly Report	true
Document Transition Report	false
Entity Shell Company	false
Entity Address, Address Line One	238 Richland Avenue Northwest
Entity Address, City or Town	A
Entity Address, State or Province	SC
Entity Address, Postal Zip Code	29801
Entity Tax Identification Number	57-0858504
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Local Phone Number	641-3000
Entity File Number	000-16120
Entity Incorporation, State or Country Code	SC
City Area Code	803