BORROWED FUNDS - Long-term Borrowings (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Borrowed funds
Borrowings from the FHLB	$ 0	$ 30,800,000
Fixed Interest Rate Notes, Originating In November 2019, Due Between November 2022 and November 2024, With Interest Of Between 1.74% and 1.81% Payable Monthly
Borrowed funds
Borrowings from the FHLB		$ 30,000,000.0
Fixed Interest Rate Notes, Originating In November 2019, Due Between November 2022 and November 2024, With Interest Of Between 1.74% and 1.81% Payable Monthly | Minimum
Borrowed funds
Interest rate on debt security		1.70%
Fixed Interest Rate Notes, Originating In November 2019, Due Between November 2022 and November 2024, With Interest Of Between 1.74% and 1.81% Payable Monthly | Maximum
Borrowed funds
Interest rate on debt security		1.80%
Fixed Interest Rate Notes, Originating Between October 2006 and April 2007, Due Between October 2021 and April 2022
Borrowed funds
Borrowings from the FHLB		$ 800,000
Fixed Interest Rate Notes, Originating Between October 2006 and April 2007, Due Between October 2021 and April 2022 | Minimum
Borrowed funds
Interest rate on debt security		5.18%
Fixed Interest Rate Notes, Originating Between October 2006 and April 2007, Due Between October 2021 and April 2022 | Maximum
Borrowed funds
Interest rate on debt security		5.20%