FAIR VALUE DISCLOSURES AND REPORTING, THE FAIR VALUE OPTION AND FAIR VALUE MEASUREMENTS - Quantitative Information About Recurring Level 3 Fair Value Measurements (Details) $ in Thousands	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Securities available-for-sale	$ 1,141,971	$ 1,257,101
Trust Preferred Securities | Valuation Technique, Discounted Cash Flow
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Securities available-for-sale	$ 31	$ 31
Trust Preferred Securities | Measurement Input, Default Rate | Valuation Technique, Discounted Cash Flow | Minimum
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Range of Inputs	0.0791	0.0698
Trust Preferred Securities | Measurement Input, Default Rate | Valuation Technique, Discounted Cash Flow | Maximum
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Range of Inputs	0.0793	0.0719
Municipal securities | Valuation Technique, Discounted Cash Flow
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Securities available-for-sale	$ 19,493	$ 15,117
Municipal securities | Measurement Input, Discount Rate | Valuation Technique, Discounted Cash Flow | Minimum
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Range of Inputs	0.0450	0.0300
Municipal securities | Measurement Input, Discount Rate | Valuation Technique, Discounted Cash Flow | Maximum
Quantitative Information About Recurring Fair Value Measurements [Line Items]
Range of Inputs	0.0677	0.0400