INVESTMENT SECURITIES - Schedule of Maturities of Investment Securities Available-for-Sale and Held-to-Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Available for Sale, Amortized Cost
Within one year	$ 17,032	$ 0
After one year but within five years	118,845	86,224
After five years but within ten years	520,143	569,956
After ten years	3,718,313	3,848,162
Amortized Cost	4,374,333	4,504,342
Available for Sale, Fair Value
Within one year	16,616	0
After one year but within five years	111,923	82,387
After five years but within ten years	435,930	485,593
After ten years	3,087,444	3,278,557
Available-for-sale, fair value total	3,651,913	3,846,537
Held to Maturity, Amortized Cost
Within one year	0	0
After one year but within five years	13,255	10,932
After five years but within ten years	47,748	46,489
After ten years	977,858	1,001,144
Investment securities held-to-maturity, net	1,038,861	1,058,565
Held to Maturity, Fair Value
Within one year	0	0
After one year but within five years	12,876	10,856
After five years but within ten years	46,336	46,246
After ten years	870,456	928,829
Held-to-maturity, fair value total	$ 929,668	$ 985,931