LOANS AND ALLOWANCE FOR CREDIT LOSSES - Narrative (Details) $ in Thousands			3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 01, 2023 USD ($)	Aug. 01, 2022 USD ($)	Sep. 30, 2024 USD ($) categoryOfLoan	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) categoryOfLoan	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jan. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Categories of loans | categoryOfLoan			4		4
Financing receivable, accrued interest, before allowance for credit loss			$ 26,000		$ 26,000		$ 24,700
Amortized cost, PCD loans			50,800		50,800		57,800
PCD loans, estimated ACL			2,700		2,700		3,700
Total loans, other financial institutions			325,500		325,500		304,000
Loans sold to other financial institutions			181,500		181,500		165,900
Loans purchased			144,000		$ 144,000		138,100
LGD Rate					15.00%
Threshold default percentage					1.00%
Provision for credit losses, LHFI			$ 1,000	$ 1,000	$ 2,650	$ 12,500
Initial allowance on PCD loans										$ 3,176
Provision for credit loss					$ 2,650	13,250
Beach Bancorp
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business combination, acquired receivable, fair value		$ 460,000
Discount (premium) on loans acquired		8,800
Gross contractual amounts receivable		468,800
Contractual cash flows not expected to be collected		6,400
Business combination, loans		482,903		$ 485,171		$ 485,171
Provision for credit loss		$ 1,300
Heritage Southeast Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business combination, acquired receivable, fair value	$ 1,091,000
Discount (premium) on loans acquired	33,700
Gross contractual amounts receivable	1,125,000
Contractual cash flows not expected to be collected	16,500
Business combination, loans	1,155,712						1,155,712		$ 1,159,000
Initial allowance on PCD loans								$ 3,200
Provision for credit loss	$ 3,200						$ 10,700