INVESTMENT SECURITIES - Maturities of Investment Securities Available-for-Sale and Held-to-Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Available for Sale Amortized Cost
Within one year	$ 16,833	$ 0
After one year but within five years	147,157	86,224
After five years but within ten years	487,921	569,956
After ten years	3,566,355	3,848,162
Amortized Cost	4,218,266	4,504,342
Available for Sale Fair Value
Within one year	16,698	0
After one year but within five years	138,870	82,387
After five years but within ten years	409,908	485,593
After ten years	2,945,172	3,278,557
Fair Value	3,510,648	3,846,537
Held to Maturity, Amortized Cost
Within one year	0	0
After one year but within five years	16,727	10,932
After five years but within ten years	51,671	46,489
After ten years	946,770	1,001,144
Past due held-to-maturity debt securities	1,015,168	1,058,565
Held to Maturity, Fair Value
Within one year	0	0
After one year but within five years	16,444	10,856
After five years but within ten years	50,451	46,246
After ten years	828,616	928,829
Fair Value	$ 895,511	$ 985,931