INCOME TAXES - Differences between income tax expense recognized and amount computed by applying statutory federal income tax rate to earnings before income taxes, less noncontrolling interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax on pretax income, less noncontrolling interest, at statutory rates	$ 11,441	$ 17,296	$ 9,742
State income taxes, net of federal effect	3,308	2,242	1,339
Tax-exempt interest income	(574)	(1,073)	(769)
Non-deductible interest disallowance	30	28	18
Increase in cash surrender value life insurance	(508)	(807)	(452)
Non-deductible business entertainment	156	168	106
Non-deductible merger expenses	0	65	18
Stock-based employee compensation	(50)	(62)	(35)
Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act	0	885	0
Deduction attributable to share-based payments	0	(1,854)	0
Other, net	(357)	(621)	(596)
Income tax expense	$ 13,446	$ 16,267	$ 9,371