LOANS AND ALLOWANCE FOR LOAN LOSSES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans to related parties	$ 28,300,000	$ 32,200,000
Nonaccrual loans, no allowance	1,200,000	2,200,000
Collateral-dependent loans	8,500,000	11,500,000
Mortgage Loans in Process of Foreclosure, Amount	21,000	1,200,000
Commitments to lend additional funds on TDRs	$ 0	$ 0	$ 0
Related party loans as a percent of stockholders' equity	3.10%	3.70%
Loans, Nonaccrual, Interest Income Reversal	$ 15,000	$ 193,000
Accrued interest receivable on our loan portfolio	13,300,000	16,400,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	321,000
COVID-19 Payment Deferral
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans	$ 0	47,200,000
1-4 family residential real estate loans | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
General loan term	15 years
1-4 family residential real estate loans | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
General loan term	30 years
Commercial real estate loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans secured by owner and non-owner occupied commercial real estate	$ 1,370,000,000
Loans secured by multi-family properties	209,700,000
Loans secured by farmland	$ 21,800,000
General loan term	20 years
Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans	$ 31,000,000	$ 214,800,000