FAIR VALUE - Fair Value of Foreclosed Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
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	$ 0	$ 42	$ 0
Carrying Value | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	0	62	62
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	0	(9)	0
Charge-offs | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	0	(1)	(1)
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	0	33	0
Fair Value | Revision of Prior Period, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	$ 0	$ 61	$ 61