LOANS AND ALLOWANCE - Risk Grading of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	$ 913,813	$ 3,483,295
Fiscal year before current fiscal year	3,163,594	2,680,834
Two years before current fiscal year	2,541,697	1,843,080
Three years before current fiscal year	1,723,708	686,065
Four years before current fiscal year	657,568	385,461
Prior	1,125,881	828,159
Revolving loans amortized cost basis	2,112,773	2,084,096
Revolving loans converted to term	2,427	12,904
Total	12,241,461	12,003,894
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	345,300	1,094,363
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	874,832	576,080
Fiscal year before current fiscal year, writeoff	57
Two years before current fiscal year	496,521	159,416
Two years before current fiscal year, writeoff	37
Three years before current fiscal year	133,501	131,332
Three years before current fiscal year, writeoff	88
Four years before current fiscal year	123,839	48,822
Four years before current fiscal year, writeoff	31
Prior	87,070	48,058
Prior, writeoff	30
Revolving loans amortized cost basis	1,441,141	1,373,714
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	0	5,341
Revolving loans converted to term, writeoff	0
Total	3,502,204	3,437,126
Total, writeoff	243
Commercial and industrial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	344,116	1,064,687
Fiscal year before current fiscal year	833,832	531,504
Two years before current fiscal year	459,180	141,985
Three years before current fiscal year	118,142	114,999
Four years before current fiscal year	110,854	43,136
Prior	80,036	45,310
Revolving loans amortized cost basis	1,351,418	1,302,562
Revolving loans converted to term	0	5,048
Total	3,297,578	3,249,231
Commercial and industrial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,184	2,164
Fiscal year before current fiscal year	5,100	18,005
Two years before current fiscal year	22,970	11,900
Three years before current fiscal year	12,611	5,727
Four years before current fiscal year	2,594	1,012
Prior	2,022	2,181
Revolving loans amortized cost basis	53,264	27,702
Revolving loans converted to term	0	150
Total	99,745	68,841
Commercial and industrial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	27,512
Fiscal year before current fiscal year	35,900	26,571
Two years before current fiscal year	13,576	5,531
Three years before current fiscal year	2,748	10,606
Four years before current fiscal year	10,391	4,674
Prior	5,012	567
Revolving loans amortized cost basis	36,459	43,450
Revolving loans converted to term	0	143
Total	104,086	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	795
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	795
Agricultural land, production and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	12,605	44,910
Fiscal year before current fiscal year	42,609	37,083
Two years before current fiscal year	36,225	36,281
Three years before current fiscal year	34,706	15,296
Four years before current fiscal year	14,954	4,127
Prior	31,198	30,694
Revolving loans amortized cost basis	47,301	73,402
Revolving loans converted to term	0	0
Total	219,598	241,793
Agricultural land, production and other loans to farmers | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	12,568	44,446
Fiscal year before current fiscal year	42,153	36,299
Two years before current fiscal year	35,465	35,791
Three years before current fiscal year	34,244	15,296
Four years before current fiscal year	14,954	3,752
Prior	30,246	28,910
Revolving loans amortized cost basis	47,301	73,402
Revolving loans converted to term	0	0
Total	216,931	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	286	784
Two years before current fiscal year	760	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	281
Prior	885	632
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	1,931	1,983
Agricultural land, production and other loans to farmers | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	37	178
Fiscal year before current fiscal year	170	0
Two years before current fiscal year	0	490
Three years before current fiscal year	462	0
Four years before current fiscal year	0	94
Prior	67	1,152
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	736	1,914
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	193,441	383,367
Fiscal year before current fiscal year	334,070	301,986
Two years before current fiscal year	300,258	117,541
Three years before current fiscal year	111,333	11,428
Four years before current fiscal year	930	857
Prior	3,162	3,236
Revolving loans amortized cost basis	17,785	17,167
Revolving loans converted to term	0	0
Total	960,979	835,582
Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	177,799	366,414
Fiscal year before current fiscal year	317,261	301,986
Two years before current fiscal year	295,533	117,541
Three years before current fiscal year	111,333	11,428
Four years before current fiscal year	930	857
Prior	3,162	3,224
Revolving loans amortized cost basis	17,785	17,167
Revolving loans converted to term	0	0
Total	923,803	818,617
Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	15,625	16,922
Fiscal year before current fiscal year	14,014	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	29,639	16,922
Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	17	31
Fiscal year before current fiscal year	2,795	0
Two years before current fiscal year	4,725	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	7,537	43
Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	113,230	630,708
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	597,010	615,408
Fiscal year before current fiscal year, writeoff	2
Two years before current fiscal year	591,861	596,899
Two years before current fiscal year, writeoff	0
Three years before current fiscal year	543,357	187,486
Three years before current fiscal year, writeoff	0
Four years before current fiscal year	184,020	132,847
Four years before current fiscal year, writeoff	0
Prior	311,401	209,128
Prior, writeoff	0
Revolving loans amortized cost basis	34,531	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	2,375,410	2,407,475
Total, writeoff	2
Commercial real estate, non-owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	82,982	560,146
Fiscal year before current fiscal year	551,019	603,254
Two years before current fiscal year	572,828	550,605
Three years before current fiscal year	496,049	168,701
Four years before current fiscal year	165,356	116,859
Prior	259,267	190,264
Revolving loans amortized cost basis	34,481	31,196
Revolving loans converted to term	0	3,803
Total	2,161,982	2,224,828
Commercial real estate, non-owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	23,243	49,439
Fiscal year before current fiscal year	29,870	4,026
Two years before current fiscal year	6,510	38,268
Three years before current fiscal year	23,885	18,785
Four years before current fiscal year	18,664	11,546
Prior	35,865	17,992
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	138,037	140,056
Commercial real estate, non-owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	7,005	21,123
Fiscal year before current fiscal year	16,121	8,128
Two years before current fiscal year	12,523	8,026
Three years before current fiscal year	23,423	0
Four years before current fiscal year	0	4,442
Prior	16,269	872
Revolving loans amortized cost basis	50	0
Revolving loans converted to term	0	0
Total	75,391	42,591
Commercial real estate, owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	65,131	271,593
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	262,142	324,004
Fiscal year before current fiscal year, writeoff	0
Two years before current fiscal year	309,584	335,062
Two years before current fiscal year, writeoff	0
Three years before current fiscal year	320,750	119,104
Three years before current fiscal year, writeoff	0
Four years before current fiscal year	116,690	67,946
Four years before current fiscal year, writeoff	2
Prior	134,116	90,990
Prior, writeoff	0
Revolving loans amortized cost basis	35,704	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	1,244,117	1,246,528
Total, writeoff	2
Commercial real estate, owner occupied | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	53,588	260,725
Fiscal year before current fiscal year	240,722	316,665
Two years before current fiscal year	306,558	330,441
Three years before current fiscal year	309,989	114,015
Four years before current fiscal year	114,099	63,816
Prior	122,322	81,286
Revolving loans amortized cost basis	31,628	33,123
Revolving loans converted to term	0	3,378
Total	1,178,906	1,203,449
Commercial real estate, owner occupied | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	63	7,744
Fiscal year before current fiscal year	17,766	6,125
Two years before current fiscal year	2,692	2,245
Three years before current fiscal year	5,623	3,481
Four years before current fiscal year	732	1,210
Prior	3,502	2,984
Revolving loans amortized cost basis	4,076	1,328
Revolving loans converted to term	0	0
Total	34,454	25,117
Commercial real estate, owner occupied | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	11,480	3,124
Fiscal year before current fiscal year	3,654	1,214
Two years before current fiscal year	334	2,376
Three years before current fiscal year	5,138	1,608
Four years before current fiscal year	1,859	2,920
Prior	8,292	6,720
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	30,757	17,962
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	148,541	762,399
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	735,432	494,049
Fiscal year before current fiscal year, writeoff	7
Two years before current fiscal year	485,417	405,136
Two years before current fiscal year, writeoff	13
Three years before current fiscal year	394,797	115,738
Three years before current fiscal year, writeoff	1
Four years before current fiscal year	113,935	79,632
Four years before current fiscal year, writeoff	0
Prior	301,763	234,141
Prior, writeoff	110
Revolving loans amortized cost basis	6,033	5,459
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	25	101
Revolving loans converted to term, writeoff	0
Total	2,185,943	2,096,655
Total, writeoff	131
Residential | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	148,051	758,161
Fiscal year before current fiscal year	730,773	489,301
Two years before current fiscal year	481,262	401,353
Three years before current fiscal year	392,890	114,420
Four years before current fiscal year	113,139	77,768
Prior	296,233	229,812
Revolving loans amortized cost basis	5,875	5,365
Revolving loans converted to term	25	46
Total	2,168,248	2,076,226
Residential | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	490	2,839
Fiscal year before current fiscal year	3,491	2,924
Two years before current fiscal year	2,056	1,972
Three years before current fiscal year	1,190	513
Four years before current fiscal year	316	396
Prior	2,456	2,588
Revolving loans amortized cost basis	158	34
Revolving loans converted to term	0	0
Total	10,157	11,266
Residential | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	1,399
Fiscal year before current fiscal year	1,168	1,824
Two years before current fiscal year	2,099	1,811
Three years before current fiscal year	717	805
Four years before current fiscal year	480	1,468
Prior	3,074	1,741
Revolving loans amortized cost basis	0	60
Revolving loans converted to term	0	55
Total	7,538	9,163
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	6,244	40,768
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	41,548	75,749
Fiscal year before current fiscal year, writeoff	18
Two years before current fiscal year	72,051	14,621
Two years before current fiscal year, writeoff	25
Three years before current fiscal year	14,226	1,572
Three years before current fiscal year, writeoff	2
Four years before current fiscal year	1,529	1,528
Four years before current fiscal year, writeoff	20
Prior	6,417	3,393
Prior, writeoff	169
Revolving loans amortized cost basis	477,065	492,720
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	2,274	281
Revolving loans converted to term, writeoff	0
Total	621,354	630,632
Total, writeoff	234
Home equity | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	6,244	40,768
Fiscal year before current fiscal year	41,482	75,670
Two years before current fiscal year	71,558	14,621
Three years before current fiscal year	14,219	1,572
Four years before current fiscal year	1,529	1,348
Prior	6,052	3,325
Revolving loans amortized cost basis	471,404	486,924
Revolving loans converted to term	2,006	281
Total	614,494	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	66	0
Two years before current fiscal year	415	0
Three years before current fiscal year	7	0
Four years before current fiscal year	0	115
Prior	11	8
Revolving loans amortized cost basis	4,611	3,698
Revolving loans converted to term	227	0
Total	5,337	3,821
Home equity | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	79
Two years before current fiscal year	78	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	65
Prior	354	60
Revolving loans amortized cost basis	1,050	2,098
Revolving loans converted to term	41	0
Total	1,523	2,302
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	16,207	68,062
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	61,224	43,773
Fiscal year before current fiscal year, writeoff	191
Two years before current fiscal year	39,180	13,105
Two years before current fiscal year, writeoff	114
Three years before current fiscal year	11,360	5,422
Three years before current fiscal year, writeoff	37
Four years before current fiscal year	4,417	5,942
Four years before current fiscal year, writeoff	13
Prior	8,432	3,800
Prior, writeoff	102
Revolving loans amortized cost basis	31,441	35,107
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	128	0
Revolving loans converted to term, writeoff	0
Total	172,389	175,211
Total, writeoff	457
Individuals' loans for household and other personal expenditures | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	16,204	67,883
Fiscal year before current fiscal year	60,965	43,639
Two years before current fiscal year	39,063	13,025
Three years before current fiscal year	11,318	5,389
Four years before current fiscal year	4,409	5,830
Prior	8,397	3,775
Revolving loans amortized cost basis	30,980	35,091
Revolving loans converted to term	0	0
Total	171,336	174,632
Individuals' loans for household and other personal expenditures | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	3	178
Fiscal year before current fiscal year	259	134
Two years before current fiscal year	117	77
Three years before current fiscal year	42	33
Four years before current fiscal year	8	28
Prior	23	17
Revolving loans amortized cost basis	461	16
Revolving loans converted to term	128	0
Total	1,041	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	12	8
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Total	12	96
Public finance and other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	13,114	187,125
Current fiscal year, writeoff	0
Fiscal year before current fiscal year	214,727	212,702
Fiscal year before current fiscal year, writeoff	275
Two years before current fiscal year	210,600	165,019
Two years before current fiscal year, writeoff	189
Three years before current fiscal year	159,678	98,687
Three years before current fiscal year, writeoff	128
Four years before current fiscal year	97,254	43,760
Four years before current fiscal year, writeoff	66
Prior	242,322	204,719
Prior, writeoff	411
Revolving loans amortized cost basis	21,772	20,880
Revolving loans amortized cost basis, writeoff	0
Revolving loans converted to term	0	0
Revolving loans converted to term, writeoff	0
Total	959,467	932,892
Total, writeoff	1,069
Public finance and other commercial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	13,114	187,125
Fiscal year before current fiscal year	214,727	212,702
Two years before current fiscal year	210,600	165,019
Three years before current fiscal year	159,678	98,687
Four years before current fiscal year	97,254	43,760
Prior	242,322	204,719
Revolving loans amortized cost basis	21,772	20,880
Revolving loans converted to term	0	0
Total	$ 959,467	$ 932,892