| Cover | Jan. 22, 2025 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 22, 2025 |
| Entity File Number | 001-35095 |
| Entity Registrant Name | UNITED COMMUNITY BANKS, INC. |
| Entity Central Index Key | 0000857855 |
| Entity Tax Identification Number | 58-1807304 |
| Entity Incorporation, State or Country Code | GA |
| Entity Address, Address Line One | 200 East Camperdown Way |
| Entity Address, City or Town | Greenville |
| Entity Address, State or Province | SC |
| Entity Address, Postal Zip Code | 29601 |
| City Area Code | 800 |
| Local Phone Number | 822-2651 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common stock, par value $1 per share |
| Trading Symbol | UCB |
| Security Exchange Name | NYSE |
| Depositary Shares [Member] | |
| Document Information [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 | UCB PRI |
| Security Exchange Name | NYSE |
