SECURITIES - Additional Information (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017 security	Dec. 31, 2024 USD ($) item security	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral		$ 929,800	$ 992,100
Gain on sale of investments		133	1	$ 6
Loss on sale of investments		$ 30	2	3
Number of CDO other-than-temporary impaired | security		3
Number of CDO called | security	1
Cumulative credit loss charges recorded through earnings to date		$ 2,974	2,974	$ 2,974	$ 2,974	$ 2,974
Number of Investment securities with an amortized cost greater than fair value | item		962
Unrealized losses		$ 168,934	$ 157,845
Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Contractual balance		3,700
Reduced balance		3,000
Interest payment received		750
Other comprehensive income net		2,900
Cumulative credit loss charges recorded through earnings to date		$ 3,000