LOANS AND ALLOWANCE FOR CREDIT LOSSES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred interest on loans, allowance for credit losses	$ 170		$ 214
Interest income on nonaccrual loans	0	$ 0
Loans modified that are not troubled debt restructurings	132,000	$ 118,000
Loan Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	50,600		54,800
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring	50,000		76,600
Troubled debt restructurings, previous charge-offs, excluding purchased loans	654		654
Allowance for loan losses allocated to troubled debt restructuring	$ 3,400		$ 10,500