INVESTMENT SECURITIES - Amortized Cost and Estimated Fair Value of Debt Securities, Available for Sale, by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Amortized Cost
Due in one year or less	$ 51,085
Due from one year to five years	756,739
Due from five to ten years	25,450
Due after ten years	24,723
Mortgage-backed securities	701,008
Debt securities, available-for-sale, amortized cost, total	1,559,005	$ 572,887
Estimated Fair Value
Due in one year or less	51,049
Due from one year to five years	739,514
Due from five to ten years	24,679
Due after ten years	22,790
Mortgage-backed securities	662,028
Debt securities, available-for-sale, estimated fair value, total	1,500,060	592,621
Amortized Cost
Due in one year or less	0
Due from one year to five years	0
Due from five to ten years	0
Due after ten years	31,905
Mortgage-backed securities	102,959
Amortized Cost	134,864	79,850
Estimated Fair Value
Due in one year or less	0
Due from one year to five years	0
Due from five to ten years	0
Due after ten years	26,525
Due after ten years	88,013
Estimated Fair Value	$ 114,538	$ 78,206