FAIR VALUE MEASUREMENTS, Fair Value of Financial Instruments (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Loans receivable [Abstract]
Mortgage servicing rights	$ 1,347,000	$ 1,631,000
Carrying Amount [Member] | Level 1 [Member]
Financial assets [Abstract]
Cash and cash equivalents	225,104,000	111,493,000
Carrying Amount [Member] | Level 2 [Member]
Financial assets [Abstract]
Certificates of deposit	20,338,000	14,700,000
Loans receivable [Abstract]
Loans held-for-sale	1,848,000	4,130,000
Interest receivable	4,373,000	4,295,000
Financial liabilities [Abstract]
Federal Home Loan Bank advances	10,000,000	0
Interest payable	83,000	92,000
Carrying Amount [Member] | Level 3 [Member]
Financial assets [Abstract]
Stock in Federal Home Loan Bank and other equity securities	6,480,000	6,574,000
Loans receivable [Abstract]
Net loans	980,094,000	768,873,000
Mortgage servicing rights	1,347,000	1,481,000
Financial liabilities [Abstract]
Deposits	1,438,203,000	1,138,632,000
Fair Value [Member] | Level 1 [Member]
Financial assets [Abstract]
Cash and cash equivalents	225,104,000	111,493,000
Fair Value [Member] | Level 2 [Member]
Financial assets [Abstract]
Certificates of deposit	21,001,000	14,984,000
Loans receivable [Abstract]
Loans held-for-sale	1,925,000	4,213,000
Interest receivable	4,373,000	4,295,000
Financial liabilities [Abstract]
Federal Home Loan Bank advances	9,987,000	0
Interest payable	83,000	92,000
Fair Value [Member] | Level 3 [Member]
Financial assets [Abstract]
Stock in Federal Home Loan Bank and other equity securities	6,480,000	6,574,000
Loans receivable [Abstract]
Net loans	936,799,000	723,507,000
Mortgage servicing rights	1,347,000	1,631,000
Financial liabilities [Abstract]
Deposits	$ 1,400,790,000	$ 1,035,644,000