INVESTMENT SECURITIES - Debt Maturities (Details) - Investment securities - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized Cost
Due within one year	$ 346,788
Due after one year through five years	2,372,245
Due after five years through ten years	2,474,834
Due after ten years	747,454
Available-for-sale, amortized cost	5,941,321	$ 5,060,135
Fair Value
Due within one year	347,433
Due after one year through five years	2,377,160
Due after five years through ten years	2,414,718
Due after ten years	738,625
Total fair value	$ 5,877,936	$ 4,918,931
Weighted- Average Yield
Due within one year	3.09%
Due after one year through five years	4.33%
Due after five years through ten years	4.27%
Due after ten years	5.56%
Weighted-average yield	4.39%