Cover - USD ($)	12 Months Ended
	Dec. 31, 2022	Jan. 31, 2023	Jun. 30, 2022
Entity Listings [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-35095
Entity Registrant Name	UNITED COMMUNITY BANKS, INC.
Entity Incorporation, State or Country Code	GA
Entity Tax Identification Number	58-1807304
Entity Address, Address Line One	125 Highway 515 East
Entity Address, City or Town	Blairsville
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30512
City Area Code	706
Local Phone Number	781-2265
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3,187,685,387
Entity Common Stock, Shares Outstanding		115,031,867
Documents Incorporated by Reference	Portions of the registrant’s Proxy Statement for the 2023 Annual Meeting of Shareholders to be held on May 17, 2023 (the “2023 Proxy Statement”) are incorporated herein into Part III by reference.
Entity Central Index Key	0000857855
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Common stock, par value $1 per share
Entity Listings [Line Items]
Title of 12(b) Security	Common stock, par value $1 per share
Trading Symbol	UCBI
Security Exchange Name	NASDAQ
Depositary shares, each representing 1/1000th interest in a share of Series I Non-Cumulative Preferred Stock
Entity Listings [Line Items]
Title of 12(b) Security	Depositary shares, each representing 1/1000th interest in a share of Series I Non-Cumulative Preferred Stock
Trading Symbol	UCBIO
Security Exchange Name	NASDAQ