LOANS AND ALLOWANCE FOR CREDIT LOSSES - Risk Grading of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	$ 2,236,647	$ 2,870,871
Current fiscal year, charge-offs	1,308	14,338
Fiscal year before current fiscal year	1,944,861	2,546,512
Fiscal year before current fiscal year, charge-offs	38,737	4,012
Two years before current fiscal year	2,049,586	2,063,941
Two years before current fiscal year, charge-offs	1,330	1,350
Three years before current fiscal year	1,676,529	1,410,944
Three years before current fiscal year, charge-offs	8,872	5,894
Four years before current fiscal year	1,206,739	529,690
Four years before current fiscal year, charge-offs	572	338
Prior	1,206,911	892,018
Prior, charge-offs	838	2,107
Revolving loans amortized cost basis	2,316,471	2,164,828
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	9,064	7,223
Revolving loans converted to term, charge-offs	0	0
Total	12,646,808	12,486,027
Total, charge-offs	51,657	28,039
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,153,289	1,223,491
Current fiscal year, charge-offs	1,178	13,973
Fiscal year before current fiscal year	668,386	498,757
Fiscal year before current fiscal year, charge-offs	37,655	2,711
Two years before current fiscal year	292,762	272,427
Two years before current fiscal year, charge-offs	242	576
Three years before current fiscal year	190,009	93,854
Three years before current fiscal year, charge-offs	8,577	5,665
Four years before current fiscal year	67,109	52,403
Four years before current fiscal year, charge-offs	498	78
Prior	55,389	46,773
Prior, charge-offs	236	261
Revolving loans amortized cost basis	1,613,582	1,483,039
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	691	204
Revolving loans converted to term, charge-offs	0	0
Total	4,041,217	3,670,948
Total, charge-offs	48,386	23,264
Commercial and industrial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,110,731	1,175,967
Fiscal year before current fiscal year	625,113	474,601
Two years before current fiscal year	259,418	253,148
Three years before current fiscal year	180,272	86,226
Four years before current fiscal year	62,723	47,910
Prior	53,350	45,020
Revolving loans amortized cost basis	1,495,641	1,393,756
Revolving loans converted to term	136	60
Total	3,787,384	3,476,688
Commercial and industrial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	14,480	34,356
Fiscal year before current fiscal year	9,872	3,911
Two years before current fiscal year	8,979	1,546
Three years before current fiscal year	2,730	5,149
Four years before current fiscal year	2,731	2,986
Prior	369	241
Revolving loans amortized cost basis	45,459	45,994
Revolving loans converted to term	0	0
Total	84,620	94,183
Commercial and industrial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	28,078	12,311
Fiscal year before current fiscal year	32,296	20,245
Two years before current fiscal year	24,365	17,733
Three years before current fiscal year	7,007	2,479
Four years before current fiscal year	1,655	1,507
Prior	1,670	1,512
Revolving loans amortized cost basis	72,482	40,449
Revolving loans converted to term	555	144
Total	168,108	96,380
Commercial and industrial loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	857
Fiscal year before current fiscal year	1,105	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	2,840
Revolving loans converted to term	0	0
Total	1,105	3,697
Agricultural land, production and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	24,308	35,691
Current fiscal year, charge-offs		0
Fiscal year before current fiscal year	24,089	38,561
Fiscal year before current fiscal year, charge-offs		0
Two years before current fiscal year	35,090	31,511
Two years before current fiscal year, charge-offs		0
Three years before current fiscal year	28,568	31,502
Three years before current fiscal year, charge-offs		0
Four years before current fiscal year	28,766	12,995
Four years before current fiscal year, charge-offs		0
Prior	32,975	25,620
Prior, charge-offs		0
Revolving loans amortized cost basis	64,947	87,534
Revolving loans amortized cost basis, charge-offs		0
Revolving loans converted to term	0	0
Revolving loans converted to term, charge-offs		0
Total	238,743	263,414
Total, charge-offs		0
Agricultural land, production and other loans to farmers | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	23,646	35,633
Fiscal year before current fiscal year	24,039	38,145
Two years before current fiscal year	33,909	31,511
Three years before current fiscal year	27,872	31,048
Four years before current fiscal year	28,250	12,995
Prior	32,445	25,462
Revolving loans amortized cost basis	63,526	87,534
Revolving loans converted to term	0	0
Total	233,687	262,328
Agricultural land, production and other loans to farmers | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	171	0
Fiscal year before current fiscal year	0	266
Two years before current fiscal year	245	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	444	122
Revolving loans amortized cost basis	548	0
Revolving loans converted to term	0	0
Total	1,408	388
Agricultural land, production and other loans to farmers | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	491	58
Fiscal year before current fiscal year	50	150
Two years before current fiscal year	936	0
Three years before current fiscal year	696	454
Four years before current fiscal year	516	0
Prior	86	36
Revolving loans amortized cost basis	873	0
Revolving loans converted to term	0	0
Total	3,648	698
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	244,050	430,923
Current fiscal year, charge-offs		0
Fiscal year before current fiscal year	254,267	271,917
Fiscal year before current fiscal year, charge-offs		0
Two years before current fiscal year	201,097	203,672
Two years before current fiscal year, charge-offs		0
Three years before current fiscal year	87,087	29,218
Three years before current fiscal year, charge-offs		0
Four years before current fiscal year	6,518	7,723
Four years before current fiscal year, charge-offs		0
Prior	8,857	2,357
Prior, charge-offs		0
Revolving loans amortized cost basis	12,828	11,735
Revolving loans amortized cost basis, charge-offs		0
Revolving loans converted to term	0	0
Revolving loans converted to term, charge-offs		0
Total	814,704	957,545
Total, charge-offs		0
Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	186,900	403,578
Fiscal year before current fiscal year	227,462	267,587
Two years before current fiscal year	174,201	198,350
Three years before current fiscal year	73,746	8,372
Four years before current fiscal year	6,518	7,723
Prior	8,851	2,357
Revolving loans amortized cost basis	12,828	11,735
Revolving loans converted to term	0	0
Total	690,506	899,702
Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	35,150	25,894
Fiscal year before current fiscal year	26,805	0
Two years before current fiscal year	18,197	0
Three years before current fiscal year	13,341	20,846
Four years before current fiscal year	0	0
Prior	6	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	93,499	46,740
Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	22,000	1,451
Fiscal year before current fiscal year	0	4,330
Two years before current fiscal year	8,699	5,322
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	30,699	11,103
Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	403,251	470,118
Current fiscal year, charge-offs	0	0
Fiscal year before current fiscal year	305,444	535,962
Fiscal year before current fiscal year, charge-offs	339	66
Two years before current fiscal year	374,640	542,551
Two years before current fiscal year, charge-offs	3	0
Three years before current fiscal year	443,864	443,320
Three years before current fiscal year, charge-offs	0	0
Four years before current fiscal year	372,634	160,799
Four years before current fiscal year, charge-offs	0	0
Prior	329,837	231,061
Prior, charge-offs	0	0
Revolving loans amortized cost basis	21,681	17,028
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	0	0
Revolving loans converted to term, charge-offs	0	0
Total	2,251,351	2,400,839
Total, charge-offs	342	66
Commercial real estate, non-owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	278,958	373,378
Fiscal year before current fiscal year	280,167	504,280
Two years before current fiscal year	346,311	535,327
Three years before current fiscal year	413,970	418,553
Four years before current fiscal year	351,260	141,320
Prior	299,771	200,821
Revolving loans amortized cost basis	21,681	16,744
Revolving loans converted to term	0	0
Total	1,992,118	2,190,423
Commercial real estate, non-owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	81,543	76,382
Fiscal year before current fiscal year	19,499	21,145
Two years before current fiscal year	19,347	7,005
Three years before current fiscal year	23,624	4,531
Four years before current fiscal year	1,768	19,479
Prior	28,452	27,941
Revolving loans amortized cost basis	0	37
Revolving loans converted to term	0	0
Total	174,233	156,520
Commercial real estate, non-owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	31,922	20,358
Fiscal year before current fiscal year	5,778	10,537
Two years before current fiscal year	8,982	219
Three years before current fiscal year	6,270	20,236
Four years before current fiscal year	19,606	0
Prior	1,614	2,299
Revolving loans amortized cost basis	0	247
Revolving loans converted to term	0	0
Total	74,172	53,896
Commercial real estate, non-owner occupied | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	10,828
Fiscal year before current fiscal year	0
Two years before current fiscal year	0
Three years before current fiscal year	0
Four years before current fiscal year	0
Prior	0
Revolving loans amortized cost basis	0
Revolving loans converted to term	0
Total	10,828
Commercial real estate, owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	127,141	201,554
Current fiscal year, charge-offs	0	48
Fiscal year before current fiscal year	182,523	208,567
Fiscal year before current fiscal year, charge-offs	0	0
Two years before current fiscal year	187,332	269,848
Two years before current fiscal year, charge-offs	0	0
Three years before current fiscal year	246,262	270,527
Three years before current fiscal year, charge-offs	0	0
Four years before current fiscal year	222,657	100,388
Four years before current fiscal year, charge-offs	9	2
Prior	152,608	83,316
Prior, charge-offs	0	0
Revolving loans amortized cost basis	34,228	27,883
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	0	0
Revolving loans converted to term, charge-offs	0	0
Total	1,152,751	1,162,083
Total, charge-offs	9	50
Commercial real estate, owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	118,117	176,750
Fiscal year before current fiscal year	167,922	199,821
Two years before current fiscal year	173,512	256,346
Three years before current fiscal year	230,821	263,522
Four years before current fiscal year	214,975	99,180
Prior	144,123	77,485
Revolving loans amortized cost basis	33,613	27,369
Revolving loans converted to term	0	0
Total	1,083,083	1,100,473
Commercial real estate, owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	2,220	6,712
Fiscal year before current fiscal year	2,385	5,034
Two years before current fiscal year	8,616	9,319
Three years before current fiscal year	6,545	2,460
Four years before current fiscal year	4,935	919
Prior	1,402	2,902
Revolving loans amortized cost basis	460	514
Revolving loans converted to term	0	0
Total	26,563	27,860
Commercial real estate, owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	6,804	18,092
Fiscal year before current fiscal year	12,216	3,712
Two years before current fiscal year	5,204	4,183
Three years before current fiscal year	8,896	4,545
Four years before current fiscal year	2,747	289
Prior	7,083	2,929
Revolving loans amortized cost basis	155	0
Revolving loans converted to term	0	0
Total	43,105	33,750
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	168,430	398,334
Current fiscal year, charge-offs	0	101
Fiscal year before current fiscal year	424,733	704,355
Fiscal year before current fiscal year, charge-offs	124	252
Two years before current fiscal year	692,860	448,226
Two years before current fiscal year, charge-offs	653	208
Three years before current fiscal year	415,668	368,420
Three years before current fiscal year, charge-offs	123	3
Four years before current fiscal year	342,646	100,585
Four years before current fiscal year, charge-offs	21	3
Prior	316,151	263,618
Prior, charge-offs	288	94
Revolving loans amortized cost basis	6,442	5,219
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	13	164
Revolving loans converted to term, charge-offs	0	0
Total	2,366,943	2,288,921
Total, charge-offs	1,209	661
Residential | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	166,807	395,363
Fiscal year before current fiscal year	421,280	695,056
Two years before current fiscal year	680,588	442,495
Three years before current fiscal year	408,017	365,297
Four years before current fiscal year	339,835	98,654
Prior	308,575	254,718
Revolving loans amortized cost basis	6,117	4,988
Revolving loans converted to term	13	83
Total	2,331,232	2,256,654
Residential | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,095	2,167
Fiscal year before current fiscal year	1,975	5,591
Two years before current fiscal year	5,436	3,202
Three years before current fiscal year	3,425	1,924
Four years before current fiscal year	1,745	1,065
Prior	3,585	4,837
Revolving loans amortized cost basis	0	200
Revolving loans converted to term	0	81
Total	17,261	19,067
Residential | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	528	804
Fiscal year before current fiscal year	1,478	3,708
Two years before current fiscal year	6,836	2,529
Three years before current fiscal year	4,226	1,199
Four years before current fiscal year	1,066	866
Prior	3,991	4,063
Revolving loans amortized cost basis	325	31
Revolving loans converted to term	0	0
Total	18,450	13,200
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	6,301	9,438
Current fiscal year, charge-offs	0	69
Fiscal year before current fiscal year	6,674	30,499
Fiscal year before current fiscal year, charge-offs	10	213
Two years before current fiscal year	26,315	62,318
Two years before current fiscal year, charge-offs	35	224
Three years before current fiscal year	55,167	12,176
Three years before current fiscal year, charge-offs	23	149
Four years before current fiscal year	11,864	1,107
Four years before current fiscal year, charge-offs	0	193
Prior	4,585	4,000
Prior, charge-offs	264	1,596
Revolving loans amortized cost basis	522,291	491,950
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	7,991	6,083
Revolving loans converted to term, charge-offs	0	0
Total	641,188	617,571
Total, charge-offs	332	2,444
Home equity | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	6,239	9,375
Fiscal year before current fiscal year	6,674	29,784
Two years before current fiscal year	25,743	61,591
Three years before current fiscal year	54,185	11,084
Four years before current fiscal year	11,864	1,092
Prior	4,346	3,875
Revolving loans amortized cost basis	516,564	484,330
Revolving loans converted to term	6,766	5,837
Total	632,381	606,968
Home equity | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	715
Two years before current fiscal year	0	0
Three years before current fiscal year	421	1,092
Four years before current fiscal year	0	15
Prior	33	2
Revolving loans amortized cost basis	3,772	5,031
Revolving loans converted to term	593	149
Total	4,819	7,004
Home equity | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	62	63
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	572	727
Three years before current fiscal year	561	0
Four years before current fiscal year	0	0
Prior	206	123
Revolving loans amortized cost basis	1,955	2,589
Revolving loans converted to term	632	97
Total	3,988	3,599
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	37,648	35,965
Current fiscal year, charge-offs	130	147
Fiscal year before current fiscal year	24,957	49,547
Fiscal year before current fiscal year, charge-offs	609	770
Two years before current fiscal year	34,620	28,525
Two years before current fiscal year, charge-offs	397	342
Three years before current fiscal year	12,585	6,795
Three years before current fiscal year, charge-offs	149	77
Four years before current fiscal year	3,177	2,071
Four years before current fiscal year, charge-offs	44	62
Prior	5,225	5,918
Prior, charge-offs	50	156
Revolving loans amortized cost basis	39,899	38,795
Revolving loans amortized cost basis, charge-offs	0	0
Revolving loans converted to term	369	772
Revolving loans converted to term, charge-offs	0	0
Total	158,480	168,388
Total, charge-offs	1,379	1,554
Individuals' loans for household and other personal expenditures | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	37,606	35,781
Fiscal year before current fiscal year	24,496	49,295
Two years before current fiscal year	34,052	28,387
Three years before current fiscal year	11,078	6,726
Four years before current fiscal year	3,097	2,070
Prior	5,215	5,904
Revolving loans amortized cost basis	39,613	38,619
Revolving loans converted to term	369	772
Total	155,526	167,554
Individuals' loans for household and other personal expenditures | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	42	184
Fiscal year before current fiscal year	461	246
Two years before current fiscal year	568	138
Three years before current fiscal year	1,507	69
Four years before current fiscal year	80	0
Prior	8	14
Revolving loans amortized cost basis	286	176
Revolving loans converted to term	0	0
Total	2,952	827
Individuals' loans for household and other personal expenditures | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	6
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	1
Prior	2	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	2	7
Public finance and other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	72,229	65,357
Fiscal year before current fiscal year	53,788	208,347
Two years before current fiscal year	204,870	204,863
Three years before current fiscal year	197,319	155,132
Four years before current fiscal year	151,368	91,619
Prior	301,284	229,355
Revolving loans amortized cost basis	573	1,645
Revolving loans converted to term	0	0
Total	981,431	956,318
Public finance and other commercial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	72,229	65,357
Fiscal year before current fiscal year	53,788	208,347
Two years before current fiscal year	204,870	204,863
Three years before current fiscal year	197,319	155,132
Four years before current fiscal year	151,368	91,619
Prior	301,284	229,355
Revolving loans amortized cost basis	573	1,645
Revolving loans converted to term	0	0
Total	$ 981,431	$ 956,318