LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired loans (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Recorded Investment
Total	$ 16,093,000		$ 16,093,000		$ 15,054,000
Unpaid Principal Balance
Total	19,093,000		19,093,000		18,100,000
Related Allowance
With an allowance recorded	1,000		1,000
Total					8,000
Average Recorded Investment
Total	15,523,000	$ 13,693,000	15,261,000	$ 13,462,000
Interest Income Recognized
Total	160,000	81,000	256,000	165,000
Commercial and Industrial [Member]
Recorded Investment
With no related allowance recorded	1,047,000		1,047,000		1,095,000
With an allowance recorded	0		0		0
Total	1,047,000		1,047,000		1,095,000
Unpaid Principal Balance
With no related allowance recorded	1,047,000		1,047,000		1,095,000
With an allowance recorded	0		0		0
Total	1,047,000		1,047,000		1,095,000
Related Allowance
With no related allowance recorded	0		0		0
With an allowance recorded	0		0		0
Total	0		0		0
Average Recorded Investment
With no related allowance recorded	1,057,000	1,068,000	1,071,000	1,074,000
With an allowance recorded	0	0
Total	1,057,000	1,068,000	1,071,000	1,074,000
Interest Income Recognized
With no related allowance recorded	13,000	2,000	15,000	8,000
With an allowance recorded	0	0
Total	13,000	2,000	15,000	8,000
Commercial Real Estate. [Member]
Recorded Investment
With no related allowance recorded	13,378,000		13,378,000		12,438,000
With an allowance recorded	483,000		483,000		485,000
Total	13,861,000		13,861,000		12,923,000
Unpaid Principal Balance
With no related allowance recorded	16,311,000		16,311,000		15,400,000
With an allowance recorded	483,000		483,000		485,000
Total	16,794,000		16,794,000		15,885,000
Related Allowance
With no related allowance recorded	0		0		0
With an allowance recorded	1,000		1,000		8,000
Total	1,000		1,000		8,000
Average Recorded Investment
With no related allowance recorded	12,750,000	11,300,000	12,564,000	11,217,000
With an allowance recorded	483,000	217,000	484,000	166,000
Total	13,233,000	11,517,000	13,048,000	11,383,000
Interest Income Recognized
With no related allowance recorded	147,000	75,000	240,000	151,000
With an allowance recorded	0	3,000		4,000
Total	147,000	78,000	240,000	155,000
Residential Real Estate. [Member]
Recorded Investment
With no related allowance recorded	1,185,000		1,185,000		1,036,000
With an allowance recorded	0		0		0
Total	1,185,000		1,185,000		1,036,000
Unpaid Principal Balance
With no related allowance recorded	1,252,000		1,252,000		1,120,000
With an allowance recorded	0		0		0
Total	1,252,000		1,252,000		1,120,000
Related Allowance
With no related allowance recorded	0		0		0
With an allowance recorded	0		0		0
Total					$ 0
Average Recorded Investment
With no related allowance recorded	1,233,000	1,088,000	1,142,000	984,000
With an allowance recorded	0	20,000		21,000
Total	1,233,000	1,108,000	1,142,000	1,005,000
Interest Income Recognized
With no related allowance recorded	0	0	1,000
With an allowance recorded	0	1,000		2,000
Total	$ 0	$ 1,000	$ 1,000	$ 2,000