INCOME TAXES - Computation of Differences Between Financial Statement Tax Expense And Amounts (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income taxes at statutory federal rate of 21%									$ 24,663	$ 21,814	$ 22,551
Increase (decrease) in taxes resulting from:
Tax exempt income									(2,822)	(1,925)	(1,682)
Nondeductible expense									116	117	194
State income tax, net of federal tax effect									1,288	944	1,040
Captive insurance premium income									(303)	(227)	(310)
Tax credits									(578)	(540)	(548)
Bank owned life insurance									(596)	(595)	(573)
Long-term incentive plan									(274)	(58)	(421)
Nondeductible compensation expense									156	0	0
Other									61	9	87
Total income tax expense	$ 5,507	$ 5,469	$ 5,705	$ 5,030	$ 6,071	$ 5,377	$ 4,448	$ 3,643	$ 21,711	$ 19,539	$ 20,338