XML 15 R1.htm IDEA: XBRL DOCUMENT v3.20.4
Document And Entity Information - USD ($)
12 Months Ended
Dec. 31, 2020
Mar. 01, 2021
Jun. 30, 2020
Document Information [Line Items]      
Entity Central Index Key 0001046203    
Entity Registrant Name Guaranty Federal Bancshares Inc    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2020    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Document Transition Report false    
Entity File Number 0-23325    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 43-1792717    
Entity Address, Address Line One 2144 E Republic Rd, Suite F200    
Entity Address, City or Town Springfield    
Entity Address, State or Province MO    
Entity Address, Postal Zip Code 65804    
City Area Code 833    
Local Phone Number 875-2492    
Title of 12(b) Security Common Stock, Par Value $0.10 per share    
Trading Symbol GFED    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 45,600,000
Entity Common Stock, Shares Outstanding   4,381,352