Condensed Financial Statements of United Community Banks, Inc. (Holding Company Only) - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Other assets	$ 211,199	$ 226,405
Total assets	20,946,771	17,794,374
LIABILITIES AND SHAREHOLDERS’ EQUITY
Long-term debt	247,360	326,956
Total liabilities	18,724,526	15,786,844
Shareholders’ equity	2,222,245	2,007,530	$ 1,635,692	$ 1,457,554
Total liabilities and shareholders’ equity	20,946,771	17,794,374
Holding Company
ASSETS
Cash and cash equivalents	298,316	289,243
Investment in Bank	2,150,683	2,028,965
Investment in other subsidiaries	23,194	752
Other assets	46,432	34,661
Total assets	2,518,625	2,353,621
LIABILITIES AND SHAREHOLDERS’ EQUITY
Long-term debt	247,360	311,956
Other liabilities	49,020	34,135
Total liabilities	296,380	346,091
Shareholders’ equity	2,222,245	2,007,530
Total liabilities and shareholders’ equity	$ 2,518,625	$ 2,353,621