INVESTMENT SECURITIES - Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Amortized Cost
Due in one year or less	$ 1,317	$ 1,800
Due after one through five years	12,995	12,189
Due after five through ten years	178,514	168,338
Due after ten years	908,593	922,636
Total debt securities with a single maturity date	1,101,419	1,104,963
Total investment securities	1,618,983	1,624,906
Fair Value
Due in one year or less	1,316	1,795
Due after one through five years	12,608	11,857
Due after five through ten years	159,809	151,467
Due after ten years	763,810	789,734
Total debt securities with a single maturity date	937,543	954,853
Total investment securities	1,378,489	1,386,475
Amortized Cost
Due in one year or less	5,268	5,268
Due after one through five years	119,035	124,004
Due after five through ten years	187,050	174,533
Due after ten years	1,111,080	1,129,147
Total debt securities with a single maturity date	1,422,433	1,432,952
Total investment securities	2,048,877	2,074,465
Fair Value
Due in one year or less	5,264	5,254
Due after one through five years	114,249	117,999
Due after five through ten years	165,301	154,533
Due after ten years	882,453	906,564
Total debt securities with a single maturity date	1,167,267	1,184,350
Total investment securities	1,705,006	1,723,520
U.S. Government-sponsored mortgage-backed securities
Amortized Cost
U.S. Government-sponsored mortgage-backed securities	517,564	519,943
Fair Value
U.S. Government-sponsored mortgage-backed securities	440,946	431,622
Total investment securities	440,946	431,622
Amortized Cost
U.S. Government-sponsored mortgage-backed securities	626,444	641,513
Total investment securities	626,444	641,513
Fair Value
U.S. Government-sponsored mortgage-backed securities	537,739	539,170
Total investment securities	$ 537,739	$ 539,170