LOAN CREDIT QUALITY AND RELATED ALLOWANCE FOR CREDIT LOSSES - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) category	Dec. 31, 2022 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-mixed use non-owner occupied office building exposure (less than)	$ 20,000,000
Interest income, non-accrual loans	117,000,000
Impaired financing receivable commitment to lend	$ 2,000
Period to classify TDR non performing loans to performing (in months)	6 months
Number of TDRs granted | loan		1
TDRs that subsequently defaulted	$ 0	$ 0
Loans considered modifications	$ 5,019,000	7,468,000
Number of categories, internal risk rating to monitor credit quality (in categories) | category	10
Number of categories considered not criticized and rated as Pass | category	6
Minimum period after which loans are considered as substandard (in days)	90 days
Average outstanding commercial portfolio percentage	59.00%
Total		1,639,083,000
Amount of foreclosed residential real estate held	$ 700,000	950,000
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process	$ 601,000	$ 890,000
Rate Concession
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDRs granted | loan		1
Amount of TDRs granted		$ 220,000
Other consumer installment loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		$ 10,361,000
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of categories in which real estate loans are segmented | category	3