Regulatory Matters - Regulatory capital ratios and minimum amounts required (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Risk-based ratios:
Common equity tier 1 capital, Minimum	4.50%
Common equity tier 1 capital, Well Capitalized	6.50%
Common equity tier 1 capital	12.97%	12.16%
Tier 1 capital, Minimum	6.00%
Tier 1 capital, Well Capitalized	8.00%
Tier 1 capital	13.21%	12.42%
Total capital, Minimum	8.00%
Total capital, Well Capitalized	10.00%
Total capital	15.01%	14.29%
Tier 1 Leverage ratio, Minimum	4.00%
Tier 1 Leverage ratio, Well Capitalized	5.00%
Tier 1 Leverage ratio	10.34%	9.61%
Common equity tier 1 capital	$ 1,275,148	$ 1,148,355
Tier 1 capital	1,299,398	1,172,605
Total capital	1,476,302	1,348,843
Risk-weighted assets	9,834,051	9,441,622
Average total assets	$ 12,568,563	$ 12,207,986
United Community Bank
Risk-based ratios:
Common equity tier 1 capital	14.87%	12.91%
Tier 1 capital	14.87%	12.91%
Total capital	15.54%	13.60%
Tier 1 Leverage ratio	11.63%	9.98%
Common equity tier 1 capital	$ 1,458,720	$ 1,216,449
Tier 1 capital	1,458,720	1,216,449
Total capital	1,524,267	1,281,062
Risk-weighted assets	9,810,477	9,421,009
Average total assets	$ 12,545,254	$ 12,183,341

Common Equity Tier 1 Capital Required To Be Well Capitalized To Risk Weighted Assets.

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Common Equity Tier One Capital Required For Capital Adequacy To Risk Weighted Assets.

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The amount of total capital as defined in the regulations.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Amount of Common Equity Tier One Risk-based Capital, as defined by regulatory framework.

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The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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