INVESTMENT SECURITIES - Amortized Cost and Fair Value of Available for Sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less	$ 540,310
Due from one year to five years	259,375
Due from five to ten years	71,452
Due after ten years	11,797
Mortgage-backed securities	695,603
Amortized Cost	1,578,537	$ 1,447,637
Estimated Fair Value
Due in one year or less	534,603
Due from one year to five years	253,938
Due from five to ten years	70,068
Due after ten years	10,410
Mortgage-backed securities	662,028
Estimated Fair Value	1,531,047	1,402,944
Amortized Cost
Due in one year or less	0
Due from one year to five years	0
Due from five to ten years	0
Due after ten years	33,664
Mortgage-backed securities	114,874
Amortized Cost	148,538	141,512
Estimated Fair Value
Due in one year or less	0
Due from one year to five years	0
Due from five to ten years	0
Due after ten years	27,880
Mortgage-backed securities	100,418
Estimated Fair Value	$ 128,298	$ 122,731