INVESTMENTS (Schedule of Amortized Cost and Estimated Fair Values of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Available-for-sale, Amortized Cost
Due in one year or less	$ 1,002
Due after one year through five years	13,835
Due after five years through ten years	59,950
Due after ten years	0
Subtotal	74,787
Mortgage-related securities	683,172
Available-for-sale securities, book value	757,959	$ 796,960
Available-for-sale, Fair Value
Due in one year or less	998
Due after one year through five years	12,483
Due after five years through ten years	57,243
Due after ten years	0
Subtotal	70,724
Mortgage-related securities	587,481
Fair value, total	$ 658,205	$ 695,875