INVESTMENT SECURITIES - Amortized cost and estimated fair value of held-to-maturity and available-for-sale securities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Amortized Cost
Due within one year	$ 0
Due between one year and five years	0
Due between five years and ten years	0
Due after ten years	0
CMO and MBS securities	49,407
Total	49,407	$ 0
Fair Value
Due within one year	0
Due between one year and five years	0
Due between five years and ten years	0
Due after ten years	0
CMO and MBS securities	49,177
Total	49,177	0
Amortized Cost
Due within one year	0
Due between one year and five years	4,244
Due between five years and ten years	19,420
Due after ten years	1,162
CMO and MBS securities	73,450
Amortized Cost	98,276	75,795
Fair Value
Due within one year	0
Due between one year and five years	4,293
Due between five years and ten years	17,810
Due after ten years	1,158
CMO and MBS securities	70,328
Total	$ 93,589	$ 68,161