INVESTMENTS - Summary of Held-To-Maturity and Available-For-Sale Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Investment Holdings [Line Items]
Total	$ 77,985	$ 80,321
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	110	130
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(6,969)	(8,763)
Held-to-Maturity Market Value	71,126	71,688
Total	3,418,334	3,382,604
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	14,525	3,842
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(275,594)	(365,320)
Investment securities available-for-sale	3,157,265	3,021,126
U.S. Treasuries
Investment Holdings [Line Items]
Total	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held-to-Maturity Market Value	0	0
Total	100	34,904
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(7)	(3,661)
Investment securities available-for-sale	93	31,243
Securities of U.S. government agencies and corporations
Investment Holdings [Line Items]
Total	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held-to-Maturity Market Value	0	0
Total	82,861	81,790
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(8,952)	(12,010)
Investment securities available-for-sale	73,909	69,780
Residential Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held-to-Maturity Market Value	0	0
Total	978,973	744,546
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	8,430	2,034
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(73,462)	(85,532)
Investment securities available-for-sale	913,941	661,048
Commercial Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	31,242	32,926
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(3,778)	(4,628)
Held-to-Maturity Market Value	27,464	28,298
Total	415,811	543,134
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	384	7
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(23,626)	(35,911)
Investment securities available-for-sale	392,569	507,230
Collateralized Mortgage Backed Securities [Member]
Investment Holdings [Line Items]
Total	7,231	7,970
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(539)	(539)
Held-to-Maturity Market Value	6,692	7,431
Total	605,547	478,744
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	3,272	181
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(44,485)	(60,277)
Investment securities available-for-sale	564,334	418,648
Obligations of state and other political subdivisions
Investment Holdings [Line Items]
Total	8,262	8,175
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	110	130
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(237)	(215)
Held-to-Maturity Market Value	8,135	8,090
Total	640,066	765,223
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	593	1,614
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(98,608)	(114,320)
Investment securities available-for-sale	542,051	652,517
Asset-backed Securities [Member]
Investment Holdings [Line Items]
Total	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held-to-Maturity Market Value	0	0
Total	557,239	600,055
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	1,733	6
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(19,253)	(39,813)
Investment securities available-for-sale	539,719	560,248
Other securities
Investment Holdings [Line Items]
Total	31,250	31,250
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(2,415)	(3,381)
Held-to-Maturity Market Value	28,835	27,869
Total	137,737	134,208
Available for Sale Securities Gross Unrealized Gain Accumulated In Investments	113	0
Available for Sale Securities Gross Unrealized Loss Accumulated In Investments	(7,201)	(13,796)
Investment securities available-for-sale	$ 130,649	$ 120,412