Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Document and Entity Information [Abstract]
Document Type	10-K
Entity Central Index Key	0001090009
Document Period End Date	Dec. 31, 2020
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	000-27719
Entity Registrant Name	Southern First Bancshares, Inc.
Entity Incorporation State Country Code	SC
Entity Tax Identification Number	58-2459561
Entity Address, Address Line One	100 Verdae Boulevard
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
Security 12b Title	Common Stock
Trading Symbol	SFST
Name of Exchange on which Security is Registered	NASDAQ
Current Fiscal Year End Date	--12-31
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
Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 200,936,188
Entity Common Stock, Shares Outstanding		7,797,098
Documents Incorporated By Reference Text Block	Portions of the registrant’s Proxy Statement relating to the Annual Meeting of Shareholders to be held on May 18, 2021 are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated.