ACCUMULATED OTHER COMPREHENSIVE INCOME, CHANGES IN AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	$ 228,048	$ 218,985
Before reclassifications	3,545	5,360
Reclassifications	(175)	32
Balance at end of year	240,825	228,048
Unrealized Gains and Losses on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	857	(4,631)
Before reclassifications	3,666	5,456
Reclassifications	(175)	32
Balance at end of year	4,348	857
Changes in Pension Plan Assets and Benefit Obligations
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	(184)	(88)
Before reclassifications	(121)	(96)
Reclassifications	0	0
Balance at end of year	(305)	(184)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	673	(4,719)
Balance at end of year	$ 4,043	$ 673