DEPOSITS (Deposit Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Deposits:
Non-interest-bearing accounts	$ 5,197,854	$ 6,176,998
Interest-bearing checking	2,006,866	1,811,153
Regular savings accounts	2,751,453	2,710,090
Money market accounts	1,760,066	2,198,288
Total interest-bearing transaction and savings accounts	6,518,385	6,719,531
Certificates of Deposit Greater Than or Equal to $250,000	448,843	178,324
Certificates of Deposit Less Than $250,000	1,009,470	545,206
Total certificates of deposit	1,458,313	723,530
Total deposits	13,174,552	13,620,059
Included in total deposits:
Public fund transaction and savings accounts	357,889	392,859
Public fund interest-bearing certificates	46,349	26,810
Total public deposits	404,238	419,669
Total brokered certificates of deposit	$ 162,856	$ 0