SECURITIES (Securities available for sale debt maturities) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Amortized Cost
Due in 1 year or less	$ 25,192
Due in 1 to 5 years	62,702
Due in 5 to 10 years	21,452
Due after 10 years	895,157
Total debt securities	1,004,503
Mortgage and asset-backed securities	3,860,500
Equity securities with a readily determinable fair value	21,301
Total investment securities	4,886,304
Estimated Fair Value
Due in 1 year or less	25,066
Due in 1 to 5 years	61,628
Due in 5 to 10 years	19,054
Due after 10 years	786,558
Estimated Fair Value	892,306
Mortgage and asset-backed securities	3,504,615
Equity securities with a readily determinable fair value	21,301	$ 21,056
Total investment securities	$ 4,418,222