SECURITIES - Summary of Available-For-Sale Securities With Unrealized and Unrecognized Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	$ 71,558	$ 475,479
Fair value, 12 months or longer	1,099,835	752,306
Fair value, total	1,171,393	1,227,785
Unrealized losses, less than 12 months	4,026	43,854
Unrealized losses, 12 months or longer	154,052	118,054
Unrealized losses, total	158,078	161,908
Fair value, held-to-maturity, less than 12 months	70,504	530,503
Fair value, held-to-maturity, 12 months or longer	418,128	15,303
Fair value, held-to-maturity, total	488,632	545,806
Unrealized losses, held-to-maturity, less than 12 months	6,105	53,803
Unrealized losses, held-to-maturity, 12 months or longer	49,867	116
Unrealized losses, held-to-maturity, total	55,972	53,919
U.S. Treasury
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	0	4,563
Fair value, 12 months or longer	124,616	119,292
Fair value, total	124,616	123,855
Unrealized losses, less than 12 months	0	419
Unrealized losses, 12 months or longer	11,067	11,479
Unrealized losses, total	11,067	11,898
Fair value, held-to-maturity, less than 12 months	0	104,457
Fair value, held-to-maturity, 12 months or longer	85,039	0
Fair value, held-to-maturity, total	85,039	104,457
Unrealized losses, held-to-maturity, less than 12 months	0	5,175
Unrealized losses, held-to-maturity, 12 months or longer	4,648	0
Unrealized losses, held-to-maturity, total	4,648	5,175
Obligations of U.S. government agencies and sponsored entities
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	1,031	34,254
Fair value, 12 months or longer	131,338	109,431
Fair value, total	132,369	143,685
Unrealized losses, less than 12 months	38	2,293
Unrealized losses, 12 months or longer	19,745	16,395
Unrealized losses, total	19,783	18,688
Fair value, held-to-maturity, less than 12 months	736	31,636
Fair value, held-to-maturity, 12 months or longer	30,561	0
Fair value, held-to-maturity, total	31,297	31,636
Unrealized losses, held-to-maturity, less than 12 months	0	2,153
Unrealized losses, held-to-maturity, 12 months or longer	2,383	0
Unrealized losses, held-to-maturity, total	2,383	2,153
Tax-exempt and taxable obligations of states and municipal subdivisions
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	47,332	275,202
Fair value, 12 months or longer	378,121	159,508
Fair value, total	425,453	434,710
Unrealized losses, less than 12 months	2,055	31,152
Unrealized losses, 12 months or longer	55,705	30,779
Unrealized losses, total	57,760	61,931
Fair value, held-to-maturity, less than 12 months	44,551	127,628
Fair value, held-to-maturity, 12 months or longer	67,739	15,303
Fair value, held-to-maturity, total	112,290	142,931
Unrealized losses, held-to-maturity, less than 12 months	4,276	13,583
Unrealized losses, held-to-maturity, 12 months or longer	11,692	116
Unrealized losses, held-to-maturity, total	15,968	13,699
Mortgage-backed securities - residential
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	9,805	76,125
Fair value, 12 months or longer	268,497	222,274
Fair value, total	278,302	298,399
Unrealized losses, less than 12 months	423	4,970
Unrealized losses, 12 months or longer	40,199	37,071
Unrealized losses, total	40,622	42,041
Fair value, held-to-maturity, less than 12 months	0	138,639
Fair value, held-to-maturity, 12 months or longer	131,957	0
Fair value, held-to-maturity, total	131,957	138,639
Unrealized losses, held-to-maturity, less than 12 months	0	17,479
Unrealized losses, held-to-maturity, 12 months or longer	16,902	0
Unrealized losses, held-to-maturity, total	16,902	17,479
Mortgage-backed securities - commercial
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	5,067	50,193
Fair value, 12 months or longer	167,716	136,062
Fair value, total	172,783	186,255
Unrealized losses, less than 12 months	333	3,025
Unrealized losses, 12 months or longer	24,138	21,338
Unrealized losses, total	24,471	24,363
Fair value, held-to-maturity, less than 12 months	25,217	119,758
Fair value, held-to-maturity, 12 months or longer	94,887	0
Fair value, held-to-maturity, total	120,104	119,758
Unrealized losses, held-to-maturity, less than 12 months	1,829	13,798
Unrealized losses, held-to-maturity, 12 months or longer	12,187	0
Unrealized losses, held-to-maturity, total	14,016	13,798
Corporate obligations
Debt and Equity Securities, FV-NI [Line Items]
Fair value, less than 12 months	8,323	35,142
Fair value, 12 months or longer	29,547	5,739
Fair value, total	37,870	40,881
Unrealized losses, less than 12 months	1,177	1,995
Unrealized losses, 12 months or longer	3,198	992
Unrealized losses, total	4,375	2,987
Fair value, held-to-maturity, less than 12 months	0	8,385
Fair value, held-to-maturity, 12 months or longer	7,945	0
Fair value, held-to-maturity, total	7,945	8,385
Unrealized losses, held-to-maturity, less than 12 months	0	1,615
Unrealized losses, held-to-maturity, 12 months or longer	2,055	0
Unrealized losses, held-to-maturity, total	$ 2,055	$ 1,615