ACQUISITIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Apr. 01, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 712,002	$ 712,002		$ 545,385
Level One
Business Acquisition [Line Items]
Cash and due from banks			$ 217,104
Investment securities available for sale			370,071
Investment securities held to maturity			587
Loans held for sale			7,951
Loans			1,627,423
Allowance for credit losses - loans			(16,599)
Premises and equipment			11,848
Federal Home Loan Bank stock			11,688
Interest receivable			7,188
Cash surrender value of life insurance			30,143
Tax asset, deferred and receivable			16,223
Other assets			41,690
Deposits			(1,930,790)
Securities sold under repurchase agreements			(1,521)
Federal Home Loan Bank advances			(160,043)
Subordinated debentures			(32,631)
Interest payable			(1,065)
Other liabilities			(42,813)
Net tangible assets acquired			156,454
Other intangibles			18,642
Goodwill			166,617
Purchase price			$ 341,713