Cover page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 22, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-12436
Entity Registrant Name	COLONY BANKCORP, INC.
Entity Incorporation, State or Country Code	GA
Entity Tax Identification Number	58-1492391
Entity Address, Address Line One	115 South Grant Street
Entity Address, City or Town	Fitzgerald
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	31750
City Area Code	229
Local Phone Number	426-6000
Title of 12(b) Security	Common Stock, Par Value $1.00 per share
Trading Symbol	CBAN
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	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 103.6
Entity Common Stock, Shares Outstanding		9,489,783
Entity Central Index Key	0000711669
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement for the 2021 Annual Meeting of Shareholders are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein. Such Proxy Statement will be filed with the Securities and Exchange Commission within 120 days after the end of the registrant’s fiscal year ended December 31, 2020.