LOANS AND ALLOWANCE - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Loans	$ 12,270,233	$ 12,003,894
Loans > 90 Days or More Past Due And Accruing	428	1,737
Current
Financing Receivable, Past Due [Line Items]
Loans	12,199,643	11,952,887
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	35,860	29,051
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,660	5,935
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	29,070	16,021
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Loans	3,531,395	3,437,126
Loans > 90 Days or More Past Due And Accruing	278	1,147
Commercial and industrial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	3,515,917	3,429,314
Commercial and industrial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,165	4,904
Commercial and industrial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	492	434
Commercial and industrial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	9,821	2,474
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Loans	230,003	241,793
Loans > 90 Days or More Past Due And Accruing	0	0
Agricultural land, production and other loans to farmers | Current
Financing Receivable, Past Due [Line Items]
Loans	229,976	241,739
Agricultural land, production and other loans to farmers | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Agricultural land, production and other loans to farmers | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Agricultural land, production and other loans to farmers | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	27	54
Construction
Financing Receivable, Past Due [Line Items]
Loans	949,918	835,582
Loans > 90 Days or More Past Due And Accruing	0	0
Construction | Current
Financing Receivable, Past Due [Line Items]
Loans	947,715	832,716
Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,898	2,436
Construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	418
Construction | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	305	12
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,379,819	2,407,475
Loans > 90 Days or More Past Due And Accruing	0	264
Commercial real estate, non-owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	2,362,561	2,395,495
Commercial real estate, non-owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	6,475	5,946
Commercial real estate, non-owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	881
Commercial real estate, non-owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	10,783	5,153
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,179,739	1,246,528
Loans > 90 Days or More Past Due And Accruing	0	0
Commercial real estate, owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	1,171,933	1,241,714
Commercial real estate, owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,793	4,495
Commercial real estate, owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	13	0
Commercial real estate, owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	319
Residential
Financing Receivable, Past Due [Line Items]
Loans	2,248,473	2,096,655
Loans > 90 Days or More Past Due And Accruing	0	0
Residential | Current
Financing Receivable, Past Due [Line Items]
Loans	2,228,923	2,079,959
Residential | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	10,033	8,607
Residential | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,657	2,278
Residential | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,860	5,811
Home equity
Financing Receivable, Past Due [Line Items]
Loans	614,366	630,632
Loans > 90 Days or More Past Due And Accruing	150	326
Home equity | Current
Financing Receivable, Past Due [Line Items]
Loans	607,419	624,543
Home equity | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,618	2,206
Home equity | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,055	1,782
Home equity | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,274	2,101
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Loans	172,896	175,211
Loans > 90 Days or More Past Due And Accruing	0	0
Individuals' loans for household and other personal expenditures | Current
Financing Receivable, Past Due [Line Items]
Loans	171,575	174,629
Individuals' loans for household and other personal expenditures | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	878	343
Individuals' loans for household and other personal expenditures | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	443	142
Individuals' loans for household and other personal expenditures | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	97
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Loans	963,624	932,892
Loans > 90 Days or More Past Due And Accruing	0	0
Public finance and other commercial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	963,624	932,778
Public finance and other commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	114
Public finance and other commercial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Public finance and other commercial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	$ 0	$ 0