INCOME TAXES - Reconciliation of Federal Income Tax Statutory Rates (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
Income taxes at statutory rate													$ 13,244	$ 11,854	$ 5,674
Tax-exempt income													(1,868)	(1,176)	(867)
Bargain purchase gain													$ (1,645)	$ 0	$ 0
Bargain purchase gain													(3.00%)	0.00%	0.00%
Nondeductible expenses													$ 188	$ 348	$ 403
State income tax, net of federal tax effect													1,600	1,969	1,058
Tax credits, net													(715)	(334)	(334)
Other, net													(241)	40	(142)
Total income tax expense	$ 3,642	$ 2,993	$ 2,241	$ 1,687	$ 3,353	$ 3,491	$ 3,823	$ 2,034	$ 1,982	$ 1,383	$ 1,419	$ 1,008	$ 10,563	$ 12,701	$ 5,792
Income taxes at statutory rate, Percent													21.00%	21.00%	21.00%
Tax-exempt income, Percent													(2.00%)	(2.00%)	(3.00%)
Nondeductible expenses, Percent														1.00%	1.00%
State income tax, net of federal tax effect, Percent													3.00%	4.00%	4.00%
Tax credits, Percent													(1.00%)	(1.00%)	(1.00%)
Other, net, Percent													(1.00%)	0.00%	(1.00%)
Effective Income Tax Rate Reconciliation, Percent													17.00%	23.00%	21.00%