FAIR VALUE - Fair Value of Foreclosed Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Carrying Value | Other real estate owned remeasured at initial recognition
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	$ 42	$ 147	$ 542
Carrying Value | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	62	35	599
Charge-offs | Other real estate owned remeasured at initial recognition
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	(9)	(11)	(25)
Charge-offs | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	(1)	(10)	(56)
Fair Value | Other real estate owned remeasured at initial recognition
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	33	136	517
Fair Value | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	$ 61	$ 25	$ 543