FAIR VALUE - Summary of assets measured at level 3 fair value on recurring basis (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Summary of assets measured on a recurring and nonrecurring basis
Other real estate owned, gross	$ 0		$ 0			$ 0
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net income available for common shareholders	Net income available for common shareholders	Net income available for common shareholders	Net income available for common shareholders
Corporate bonds
Summary of assets measured on a recurring and nonrecurring basis
Transfer to held-to-maturity				$ (6,215,000)
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | Corporate bonds
Summary of assets measured on a recurring and nonrecurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 0	$ 0	$ 0	0	$ 0	0	$ 0	$ 2,113,000
Loans acquired				4,000,000
Unrealized gains, net				102,000
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | Loans Held at Fair Value
Summary of assets measured on a recurring and nonrecurring basis
Settlements	(2,169,000)	(6,339,000)	(8,472,000)	(9,439,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	15,464,000	22,871,000	15,464,000	22,871,000	17,523,000	23,321,000	21,477,000
Loans acquired		7,867,000	1,162,000	32,599,000
Gains/(losses) in net income, net	110,000	(134,000)	(547,000)	(289,000)
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | Forward commitments and FSC
Summary of assets measured on a recurring and nonrecurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	0	(11,000)	0	(11,000)		0		(9,000)
Loans acquired		(11,000)	0	(2,000)
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | Guarantee Asset
Summary of assets measured on a recurring and nonrecurring basis
Settlements	(6,000)		(16,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	158,000	159,000	158,000	159,000	166,000	143,000	174,000	237,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances	(6,000)		(20,000)
Gains/(losses) in net income, net	(8,000)	(15,000)	11,000	(78,000)
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | IRLC, net
Summary of assets measured on a recurring and nonrecurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	319,000	138,000	319,000	138,000	453,000	229,000	990,000	1,473,000
Loans acquired	312,000	170,000	1,652,000	1,253,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances	(606,000)	(720,000)	(2,784,000)	(2,783,000)
Gains/(losses) in net income, net	160,000	(302,000)	1,222,000	195,000
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring | Equity Warrants
Summary of assets measured on a recurring and nonrecurring basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	825,000	827,000	825,000	827,000	$ 825,000	$ 825,000	$ 725,000	$ 160,000
Loans acquired		102,000		344,000
Gains/(losses) in net income, net		$ 0		$ 323,000
Commercial | Fair Value, Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Net recorded investment	4,575,000		4,575,000
Commercial | Significant Unobservable Inputs (Level 3) | Fair Value, Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Net recorded investment	4,575,000		4,575,000
Commercial | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Net recorded investment	0		0
Commercial | Significant Other Observable Inputs (Level 2) | Fair Value, Nonrecurring
Summary of assets measured on a recurring and nonrecurring basis
Net recorded investment	$ 0		$ 0