BORROWINGS (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Jan. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Repurchase Agreements	$ 201,499		$ 200,657
Total short-term borrowings	601,499		485,607
Subordinated Debt	44,331		44,331
Short-term Debt [Member]
Debt Instrument [Line Items]
Repurchase Agreements	201,499		200,657
Short-Term Bank Loans and Notes Payable	225,000		135,000
FHLBB and Correspondent Bank Overnight Borrowings	0		24,950
Federal Home Loan Bank, Advance, Maturity, Year One	175,000		$ 125,000
Short-term Debt [Member] \| Bank Term Funding Program
Debt Instrument [Line Items]
Face amount	$ 225,000	$ 135,000
Interest rate	4.76%

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