COMMITMENTS, CONTINGENCIES, AND CREDIT RISK - CREDIT RISK (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Concentration of Credit Risk
Loan portfolio	$ 1,038,885	$ 1,053,468	$ 1,040,274
Commercial real estate
Concentration of Credit Risk
Loan portfolio	520,841		$ 496,906
Bank \| Commercial real estate \| Commercial loan portfolio \| Credit risk concentration
Concentration of Credit Risk
Loan portfolio	$ 136,477	$ 141,965
Percentage of concentration risk under a specified benchmark	17.95%	18.54%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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