INCOME TAXES - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	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, 2019	Dec. 31, 2018	Dec. 31, 2017
Amount
Federal income tax expense computed by applying the statutory rate to income before income taxes									$ 13,808	$ 10,157	$ 13,820
Tax exempt interest									(920)	(1,002)	(1,808)
State taxes, net of federal income tax benefit									1,425	1,999	725
Deferred tax asset remeasurement											7,572
Other									(253)	(2,013)	(1,363)
Total income tax expense	$ 3,934	$ 3,852	$ 2,859	$ 3,415	$ 2,878	$ 1,381	$ 1,701	$ 3,181	$ 14,060	$ 9,141	$ 18,946
Percentage of Pre-tax Earnings
Federal income tax expense computed by applying the statutory rate to income before income taxes (as a percent)									21.00%	21.00%	35.00%
Tax exempt interest (as a percent)									(1.00%)	(2.00%)	(5.00%)
State taxes, net of federal income tax benefit (as a percent)									2.00%	4.00%	2.00%
Deferred tax asset remeasurement (as a percent)											19.00%
Other (as a percent)									(1.00%)	(4.00%)	(3.00%)
Income tax expense (as a percent)									21.00%	19.00%	48.00%