INCOME TAXES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of income tax expense attributable to income from operations [Abstract]
Federal	$ 4,413,000	$ 4,603,000	$ 1,732,000
State	280,000	395,000	124,000
Total current	4,693,000	4,998,000	1,856,000
Deferred expense/(benefit):
Federal	(136,000)	(1,126,000)	2,253,000
State	50,000	(438,000)	345,000
Remeasurement of deferred tax assets	0	0	(445,000)
Total deferred	(86,000)	(1,564,000)	2,153,000
Income tax expense	$ 4,607,000	$ 3,434,000	$ 4,009,000
Reconciliation of income tax expense [Abstract]
Statutory federal tax rate	21.00%	21.00%	21.00%
Tax computed at statutory rate	$ 5,013,000	$ 3,999,000	$ 4,963,000
Tax-exempt income	(395,000)	(424,000)	(430,000)
831(b) premium adjustment	(296,000)	(189,000)	(167,000)
Dividend exclusion	(5,000)	(7,000)	(7,000)
State taxes, net of Federal impact	118,000	(86,000)	262,000
Nondeductible interest expense	5,000	9,000	7,000
Remeasurement of deferred tax assets	0	0	(445,000)
Other items, net	167,000	132,000	(174,000)
Income tax expense	$ 4,607,000	$ 3,434,000	$ 4,009,000
Effective tax rate	19.30%	18.00%	17.00%
Deferred tax assets:
Allowance for loan losses	$ 5,393,000	$ 6,046,000
Accrual for employee benefit plans	47,000	92,000
Depreciation	681,000	379,000
Deferred compensation and directors' fees	1,045,000	765,000
Operating lease liabilities	1,831,000	2,050,000
Purchase accounting adjustment – loans	1,000	1,000
Purchase accounting adjustment – fixed assets	149,000	149,000
Gain on deemed sale of securities	54,000	71,000
Accounting for defined benefit pension and other benefit plans	2,302,000	2,448,000
Nonaccrued interest	687,000	695,000
Accrued expense	158,000	179,000
Other items, net	48,000	38,000
Total gross deferred tax assets	12,396,000	12,913,000
Deferred tax liabilities:
Deferred loan fees and costs	274,000	592,000
Prepaid pension	3,344,000	3,189,000
Net unrealized gains on securities available for sale	3,124,000	468,000
Discount accretion	50,000	24,000
Core deposit intangible	1,353,000	1,213,000
REIT dividend	616,000	922,000
Operating lease right-of-use assets	1,831,000	2,050,000
Other	168,000	103,000
Total gross deferred tax liabilities	10,760,000	8,561,000
Net deferred tax asset	1,636,000	4,352,000
Unrecognized tax benefits	0	0	$ 0
Accrued interest or penalties related to uncertain tax positions	$ 0	$ 0	$ 0