LOANS AND ALLOWANCE - Risk Grading of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	$ 1,732,491	$ 3,483,295
Fiscal year before current fiscal year	2,821,004	2,680,834
Two years before current fiscal year	2,321,967	1,843,080
Three years before current fiscal year	1,585,360	686,065
Four years before current fiscal year	624,792	385,461
Prior	1,025,749	828,159
Revolving loans amortized cost basis	2,155,805	2,084,096
Revolving loans converted to term	3,065	12,904
Total	12,270,233	12,003,894
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	741,552	1,094,363
Current fiscal year, writeoff	196
Fiscal year before current fiscal year	661,810	576,080
Fiscal year before current fiscal year, writeoff	85
Two years before current fiscal year	357,706	159,416
Two years before current fiscal year, writeoff	340
Three years before current fiscal year	120,512	131,332
Three years before current fiscal year, writeoff	109
Four years before current fiscal year	106,247	48,822
Four years before current fiscal year, writeoff	57
Prior	65,018	48,058
Prior, writeoff	92
Revolving loans amortized cost basis	1,478,520	1,373,714
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	30	5,341
Revolving loans converted to term, writeoff	0
Total	3,531,395	3,437,126
Total, writeoff	879
Commercial and industrial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	729,958	1,064,687
Fiscal year before current fiscal year	621,373	531,504
Two years before current fiscal year	324,532	141,985
Three years before current fiscal year	104,165	114,999
Four years before current fiscal year	97,712	43,136
Prior	62,081	45,310
Revolving loans amortized cost basis	1,370,356	1,302,562
Revolving loans converted to term	30	5,048
Total	3,310,207	3,249,231
Commercial and industrial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	10,124	2,164
Fiscal year before current fiscal year	5,537	18,005
Two years before current fiscal year	19,973	11,900
Three years before current fiscal year	5,729	5,727
Four years before current fiscal year	4,188	1,012
Prior	924	2,181
Revolving loans amortized cost basis	54,818	27,702
Revolving loans converted to term	0	150
Total	101,293	68,841
Commercial and industrial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,470	27,512
Fiscal year before current fiscal year	34,900	26,571
Two years before current fiscal year	11,649	5,531
Three years before current fiscal year	10,618	10,606
Four years before current fiscal year	4,347	4,674
Prior	2,013	567
Revolving loans amortized cost basis	52,518	43,450
Revolving loans converted to term	0	143
Total	117,515	119,054
Commercial and industrial loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0
Fiscal year before current fiscal year	0
Two years before current fiscal year	1,552
Three years before current fiscal year	0
Four years before current fiscal year	0
Prior	0
Revolving loans amortized cost basis	828
Revolving loans converted to term	0
Total	2,380
Agricultural land, production and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	19,861	44,910
Fiscal year before current fiscal year	40,901	37,083
Two years before current fiscal year	34,883	36,281
Three years before current fiscal year	33,168	15,296
Four years before current fiscal year	14,360	4,127
Prior	29,377	30,694
Revolving loans amortized cost basis	57,453	73,402
Revolving loans converted to term	0	0
Total	230,003	241,793
Agricultural land, production and other loans to farmers | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	19,826	44,446
Fiscal year before current fiscal year	40,472	36,299
Two years before current fiscal year	34,147	35,791
Three years before current fiscal year	32,710	15,296
Four years before current fiscal year	14,360	3,752
Prior	29,187	28,910
Revolving loans amortized cost basis	57,453	73,402
Revolving loans converted to term	0	0
Total	228,155	237,896
Agricultural land, production and other loans to farmers | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	286
Fiscal year before current fiscal year	266	784
Two years before current fiscal year	736	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	281
Prior	125	632
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	1,127	1,983
Agricultural land, production and other loans to farmers | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	35	178
Fiscal year before current fiscal year	163	0
Two years before current fiscal year	0	490
Three years before current fiscal year	458	0
Four years before current fiscal year	0	94
Prior	65	1,152
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	721	1,914
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	304,386	383,367
Fiscal year before current fiscal year	291,573	301,986
Two years before current fiscal year	272,758	117,541
Three years before current fiscal year	56,696	11,428
Four years before current fiscal year	3,184	857
Prior	2,586	3,236
Revolving loans amortized cost basis	18,735	17,167
Revolving loans converted to term	0	0
Total	949,918	835,582
Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	261,410	366,414
Fiscal year before current fiscal year	287,961	301,986
Two years before current fiscal year	267,572	117,541
Three years before current fiscal year	56,696	11,428
Four years before current fiscal year	3,184	857
Prior	2,586	3,224
Revolving loans amortized cost basis	18,735	17,167
Revolving loans converted to term	0	0
Total	898,144	818,617
Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	42,961	16,922
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	42,961	16,922
Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	15	31
Fiscal year before current fiscal year	3,612	0
Two years before current fiscal year	5,186	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	0	12
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	8,813	43
Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	241,517	630,708
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	555,310	615,408
Fiscal year before current fiscal year, writeoff	2
Two years before current fiscal year	577,479	596,899
Two years before current fiscal year, writeoff	0
Three years before current fiscal year	516,832	187,486
Three years before current fiscal year, writeoff	0
Four years before current fiscal year	177,728	132,847
Four years before current fiscal year, writeoff	0
Prior	281,375	209,128
Prior, writeoff	0
Revolving loans amortized cost basis	29,578	31,196
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	0	3,803
Revolving loans converted to term, writeoff	0
Total	2,379,819	2,407,475
Total, writeoff	2
Commercial real estate, non-owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	186,868	560,146
Fiscal year before current fiscal year	520,251	603,254
Two years before current fiscal year	571,103	550,605
Three years before current fiscal year	473,530	168,701
Four years before current fiscal year	159,184	116,859
Prior	236,905	190,264
Revolving loans amortized cost basis	28,807	31,196
Revolving loans converted to term	0	3,803
Total	2,176,648	2,224,828
Commercial real estate, non-owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	35,854	49,439
Fiscal year before current fiscal year	23,713	4,026
Two years before current fiscal year	6,185	38,268
Three years before current fiscal year	20,666	18,785
Four years before current fiscal year	18,544	11,546
Prior	28,369	17,992
Revolving loans amortized cost basis	49	0
Revolving loans converted to term	0	0
Total	133,380	140,056
Commercial real estate, non-owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	18,795	21,123
Fiscal year before current fiscal year	11,346	8,128
Two years before current fiscal year	191	8,026
Three years before current fiscal year	22,636	0
Four years before current fiscal year	0	4,442
Prior	16,101	872
Revolving loans amortized cost basis	722	0
Revolving loans converted to term	0	0
Total	69,791	42,591
Commercial real estate, owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	94,523	271,593
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	240,101	324,004
Fiscal year before current fiscal year, writeoff	0
Two years before current fiscal year	297,710	335,062
Two years before current fiscal year, writeoff	0
Three years before current fiscal year	295,146	119,104
Three years before current fiscal year, writeoff	0
Four years before current fiscal year	110,170	67,946
Four years before current fiscal year, writeoff	2
Prior	110,963	90,990
Prior, writeoff	0
Revolving loans amortized cost basis	31,126	34,451
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	0	3,378
Revolving loans converted to term, writeoff	0
Total	1,179,739	1,246,528
Total, writeoff	2
Commercial real estate, owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	78,115	260,725
Fiscal year before current fiscal year	219,693	316,665
Two years before current fiscal year	291,902	330,441
Three years before current fiscal year	285,053	114,015
Four years before current fiscal year	104,801	63,816
Prior	101,825	81,286
Revolving loans amortized cost basis	26,379	33,123
Revolving loans converted to term	0	3,378
Total	1,107,768	1,203,449
Commercial real estate, owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	7,061	7,744
Fiscal year before current fiscal year	17,962	6,125
Two years before current fiscal year	5,484	2,245
Three years before current fiscal year	3,946	3,481
Four years before current fiscal year	3,767	1,210
Prior	4,714	2,984
Revolving loans amortized cost basis	4,085	1,328
Revolving loans converted to term	0	0
Total	47,019	25,117
Commercial real estate, owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	9,347	3,124
Fiscal year before current fiscal year	2,446	1,214
Two years before current fiscal year	324	2,376
Three years before current fiscal year	6,147	1,608
Four years before current fiscal year	1,602	2,920
Prior	4,424	6,720
Revolving loans amortized cost basis	662	0
Revolving loans converted to term	0	0
Total	24,952	17,962
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	266,163	762,399
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	726,091	494,049
Fiscal year before current fiscal year, writeoff	42
Two years before current fiscal year	469,342	405,136
Two years before current fiscal year, writeoff	135
Three years before current fiscal year	382,007	115,738
Three years before current fiscal year, writeoff	3
Four years before current fiscal year	111,538	79,632
Four years before current fiscal year, writeoff	0
Prior	284,972	234,141
Prior, writeoff	53
Revolving loans amortized cost basis	8,293	5,459
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	67	101
Revolving loans converted to term, writeoff	0
Total	2,248,473	2,096,655
Total, writeoff	233
Residential | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	265,212	758,161
Fiscal year before current fiscal year	719,278	489,301
Two years before current fiscal year	464,773	401,353
Three years before current fiscal year	379,390	114,420
Four years before current fiscal year	110,163	77,768
Prior	279,528	229,812
Revolving loans amortized cost basis	8,262	5,365
Revolving loans converted to term	67	46
Total	2,226,673	2,076,226
Residential | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	937	2,839
Fiscal year before current fiscal year	5,008	2,924
Two years before current fiscal year	3,064	1,972
Three years before current fiscal year	1,062	513
Four years before current fiscal year	941	396
Prior	3,522	2,588
Revolving loans amortized cost basis	0	34
Revolving loans converted to term	0	0
Total	14,534	11,266
Residential | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	14	1,399
Fiscal year before current fiscal year	1,805	1,824
Two years before current fiscal year	1,505	1,811
Three years before current fiscal year	1,555	805
Four years before current fiscal year	434	1,468
Prior	1,922	1,741
Revolving loans amortized cost basis	31	60
Revolving loans converted to term	0	55
Total	7,266	9,163
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	8,228	40,768
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	37,720	75,749
Fiscal year before current fiscal year, writeoff	161
Two years before current fiscal year	68,450	14,621
Two years before current fiscal year, writeoff	182
Three years before current fiscal year	13,007	1,572
Three years before current fiscal year, writeoff	67
Four years before current fiscal year	1,159	1,528
Four years before current fiscal year, writeoff	79
Prior	5,838	3,393
Prior, writeoff	993
Revolving loans amortized cost basis	477,580	492,720
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	2,384	281
Revolving loans converted to term, writeoff	0
Total	614,366	630,632
Total, writeoff	1,482
Home equity | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	8,165	40,768
Fiscal year before current fiscal year	36,789	75,670
Two years before current fiscal year	67,851	14,621
Three years before current fiscal year	11,793	1,572
Four years before current fiscal year	1,159	1,348
Prior	5,619	3,325
Revolving loans amortized cost basis	471,557	486,924
Revolving loans converted to term	1,952	281
Total	604,885	624,509
Home equity | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	931	0
Two years before current fiscal year	0	0
Three years before current fiscal year	1,214	0
Four years before current fiscal year	0	115
Prior	43	8
Revolving loans amortized cost basis	4,625	3,698
Revolving loans converted to term	200	0
Total	7,013	3,821
Home equity | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	63	0
Fiscal year before current fiscal year	0	79
Two years before current fiscal year	599	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	65
Prior	176	60
Revolving loans amortized cost basis	1,398	2,098
Revolving loans converted to term	232	0
Total	2,468	2,302
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	23,193	68,062
Current fiscal year, writeoff	3
Fiscal year before current fiscal year	57,001	43,773
Fiscal year before current fiscal year, writeoff	428
Two years before current fiscal year	34,451	13,105
Two years before current fiscal year, writeoff	183
Three years before current fiscal year	9,592	5,422
Three years before current fiscal year, writeoff	48
Four years before current fiscal year	3,488	5,942
Four years before current fiscal year, writeoff	22
Prior	7,297	3,800
Prior, writeoff	137
Revolving loans amortized cost basis	37,290	35,107
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	584	0
Revolving loans converted to term, writeoff	0
Total	172,896	175,211
Total, writeoff	821
Individuals' loans for household and other personal expenditures | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	23,136	67,883
Fiscal year before current fiscal year	56,812	43,639
Two years before current fiscal year	34,167	13,025
Three years before current fiscal year	9,527	5,389
Four years before current fiscal year	3,468	5,830
Prior	7,294	3,775
Revolving loans amortized cost basis	36,866	35,091
Revolving loans converted to term	306	0
Total	171,576	174,632
Individuals' loans for household and other personal expenditures | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	57	178
Fiscal year before current fiscal year	189	134
Two years before current fiscal year	284	77
Three years before current fiscal year	65	33
Four years before current fiscal year	20	28
Prior	3	17
Revolving loans amortized cost basis	424	16
Revolving loans converted to term	278	0
Total	1,320	483
Individuals' loans for household and other personal expenditures | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	1
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	3
Three years before current fiscal year	0	0
Four years before current fiscal year	0	84
Prior	0	8
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	0	96
Public finance and other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	33,068	187,125
Current fiscal year, writeoff	199
Fiscal year before current fiscal year	210,497	212,702
Fiscal year before current fiscal year, writeoff	718
Two years before current fiscal year	209,188	165,019
Two years before current fiscal year, writeoff	840
Three years before current fiscal year	158,400	98,687
Three years before current fiscal year, writeoff	227
Four years before current fiscal year	96,918	43,760
Four years before current fiscal year, writeoff	160
Prior	238,323	204,719
Prior, writeoff	1,275
Revolving loans amortized cost basis	17,230	20,880
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	0	0
Revolving loans converted to term, writeoff	0
Total	963,624	932,892
Total, writeoff	3,419
Public finance and other commercial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	33,068	187,125
Fiscal year before current fiscal year	210,497	212,702
Two years before current fiscal year	209,188	165,019
Three years before current fiscal year	158,400	98,687
Four years before current fiscal year	96,918	43,760
Prior	238,323	204,719
Revolving loans amortized cost basis	17,230	20,880
Revolving loans converted to term	0	0
Total	$ 963,624	$ 932,892