SECURITIES (Schedule of Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule of Securities [Line Items]
Debt Securities, Trading, Amortized Cost	$ 27,203	$ 27,203
Securities—trading	25,268	28,694
Debt Securities, Available-for-sale, Amortized Cost, Total	2,774,972	3,218,777
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	207	1,463
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	486,436	431,209
Debt Securities, Available-for-sale, Allowance for Credit Loss	(750)	0
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	2,287,993	2,789,031
Held-to-maturity Securities, Amortized Cost	1,082,505	1,117,967
Held-to-maturity Securities, Gross Unrealized Gains	12	109
Held-to-maturity Securities, Gross Unrealized Losses	228,515	175,896
Securities—held-to-maturity	853,653	942,180
Allowance for Credit Losses	(349)	(379)
debt securities, held-to-maturity, accrued interest receivable	4,200	4,800
Debt Securities, Available-for-Sale, Accrued Interest Receivable	11,000	12,400
U.S. Government and agency obligations
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	35,342	56,344
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	8
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,015	1,244
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	34,327	55,108
Held-to-maturity Securities, Amortized Cost	308	312
Held-to-maturity Securities, Gross Unrealized Gains	0	0
Held-to-maturity Securities, Gross Unrealized Losses	8	7
Securities—held-to-maturity	300	305
Allowance for Credit Losses	0	0
Municipal bonds
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	166,902	301,449
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	530
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	43,304	40,770
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	123,598	261,209
Held-to-maturity Securities, Amortized Cost	491,152	503,117
Held-to-maturity Securities, Gross Unrealized Gains	12	109
Held-to-maturity Securities, Gross Unrealized Losses	95,444	70,907
Securities—held-to-maturity	395,551	432,319
Allowance for Credit Losses	(169)	183
Corporate bonds
Schedule of Securities [Line Items]
Debt Securities, Trading, Amortized Cost	27,203	27,203
Securities—trading	25,268	28,694
Debt Securities, Available-for-sale, Amortized Cost, Total	106,015	133,334
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	14,247	11,481
Debt Securities, Available-for-sale, Allowance for Credit Loss	(750)
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	91,018	121,853
Held-to-maturity Securities, Amortized Cost	2,813	2,961
Held-to-maturity Securities, Gross Unrealized Gains	0	0
Held-to-maturity Securities, Gross Unrealized Losses	27	16
Securities—held-to-maturity	2,606	2,945
Allowance for Credit Losses	(180)	196
Mortgage-backed or related securities
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	2,244,179	2,505,172
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	885
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	424,727	366,721
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	1,819,452	2,139,336
Held-to-maturity Securities, Amortized Cost	588,232	611,577
Held-to-maturity Securities, Gross Unrealized Gains	0	0
Held-to-maturity Securities, Gross Unrealized Losses	133,036	104,966
Securities—held-to-maturity	455,196	506,611
Allowance for Credit Losses	0	0
Asset-backed securities
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	222,534	222,478
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	207	40
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	3,143	10,993
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	$ 219,598	$ 211,525