LOANS AND ALLOWANCE FOR CREDIT LOSSES - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Loans	$ 13,004,905	$ 12,854,359
Loans > 90 Days or More Past Due And Accruing	4,280	5,902
Current
Financing Receivable, Past Due [Line Items]
Loans	12,864,875	12,738,196
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	37,640	35,773
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	53,214	32,581
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	49,176	47,809
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Loans	4,306,597	4,114,292
Loans > 90 Days or More Past Due And Accruing	3,905	2,010
Commercial and industrial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	4,260,713	4,096,605
Commercial and industrial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	13,082	7,428
Commercial and industrial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	25,602	473
Commercial and industrial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,200	9,786
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Loans	243,864	256,312
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	243,504	256,148
Agricultural land, production and other loans to farmers | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	119	164
Agricultural land, production and other loans to farmers | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	241	0
Agricultural land, production and other loans to farmers | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Construction
Financing Receivable, Past Due [Line Items]
Loans	793,175	792,144
Loans > 90 Days or More Past Due And Accruing	0	3,683
Construction | Current
Financing Receivable, Past Due [Line Items]
Loans	777,629	761,819
Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	35	4,332
Construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	15,226	22,005
Construction | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	285	3,988
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,177,869	2,274,016
Loans > 90 Days or More Past Due And Accruing	0	0
Commercial real estate, non-owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	2,159,499	2,259,549
Commercial real estate, non-owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	4,878	2,407
Commercial real estate, non-owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,869	1,718
Commercial real estate, non-owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	11,623	10,342
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,214,739	1,157,944
Loans > 90 Days or More Past Due And Accruing	183	0
Commercial real estate, owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	1,202,715	1,153,861
Commercial real estate, owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,020	3,783
Commercial real estate, owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	4,496	0
Commercial real estate, owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,508	300
Residential
Financing Receivable, Past Due [Line Items]
Loans	2,389,852	2,374,729
Loans > 90 Days or More Past Due And Accruing	192	208
Residential | Current
Financing Receivable, Past Due [Line Items]
Loans	2,352,273	2,337,002
Residential | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	12,758	12,302
Residential | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,027	6,606
Residential | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	19,794	18,819
Home equity
Financing Receivable, Past Due [Line Items]
Loans	650,499	659,811
Loans > 90 Days or More Past Due And Accruing	0	0
Home equity | Current
Financing Receivable, Past Due [Line Items]
Loans	641,332	649,238
Home equity | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,840	4,431
Home equity | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	561	1,569
Home equity | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	4,766	4,573
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Loans	140,954	166,028
Loans > 90 Days or More Past Due And Accruing	0	1
Individuals' loans for household and other personal expenditures | Current
Financing Receivable, Past Due [Line Items]
Loans	139,854	164,891
Individuals' loans for household and other personal expenditures | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	908	926
Individuals' loans for household and other personal expenditures | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	192	210
Individuals' loans for household and other personal expenditures | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	1
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Loans	1,087,356	1,059,083
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	1,087,356	1,059,083
Public finance and other commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
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