Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 21, 2021
Cover [Abstract]
Entity Central Index Key	0001090009
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2021
Entity File Number	000-27719
Entity Registrant Name	Southern First Bancshares, Inc.
Entity Incorporation, State or Country Code	SC
Entity Tax Identification Number	58-2459561
Entity Address, Address Line One	100 Verdae Boulevard
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Greenville
Entity Address, State or Province	SC
Entity Address, Postal Zip Code	29607
City Area Code	864
Local Phone Number	679-9000
Title of 12(b) Security	Common Stock
Trading Symbol	SFST
Name of Exchange on which Security is Registered	NASDAQ
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 Common Stock, Shares Outstanding		7,913,381