LOANS AND THE ALLOWANCE FOR CREDIT LOSSES - Narrative (Details)	12 Months Ended
	Dec. 31, 2025 USD ($) loan	Dec. 31, 2024 USD ($) loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable loan	$ 2,649,484,000	$ 2,425,565,000
Loans, net	$ 2,628,982,000	$ 2,407,235,000
Number of loans modified | loan	0	1
Number of loans experiencing default | loan	0	0
Interest income on nonaccrual loans	$ 0	$ 0
Reversal of interest income on nonaccrual loans	100,000	700,000
OREO carrying amount		37,000,000.0
OREO provision amount	$ 1,300,000	1,100,000
Number of OREO loans sold | loan	2
Net gain on sale of other real estate owned	$ 500,000
Other real estate owned, gross	$ 3,000,000.0	$ 35,900,000
Loans secured by real estate | loan	0	0
Accrued interest receivable	$ 10,400,000	$ 9,800,000
MSLP loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of loans | loan		1
Loans, net		$ 1,700,000
Percent of loans on total loan segment (as a percent)		0.80%
Simmons Bank
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable loan	$ 121,300,000	$ 164,300,000