LOANS AND ALLOWANCE - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Loans	$ 12,241,461	$ 12,003,894
Loans > 90 Days or More Past Due And Accruing	7,032	1,737
Current
Financing Receivable, Past Due [Line Items]
Loans	12,158,608	11,952,887
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	28,871	29,051
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	26,936	5,935
Increase (decrease) in past due loans	21,000
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	27,046	16,021
Increase (decrease) in past due loans	(11,000)
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Loans	3,502,204	3,437,126
Loans > 90 Days or More Past Due And Accruing	4,631	1,147
Commercial and industrial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	3,480,761	3,429,314
Commercial and industrial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	4,438	4,904
Commercial and industrial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	9,995	434
Increase (decrease) in past due loans	9,600
Commercial and industrial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,010	2,474
Increase (decrease) in past due loans	4,500
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Loans	219,598	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	219,571	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	960,979	835,582
Loans > 90 Days or More Past Due And Accruing	0	0
Construction | Current
Financing Receivable, Past Due [Line Items]
Loans	957,367	832,716
Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,612	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	0	12
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,375,410	2,407,475
Loans > 90 Days or More Past Due And Accruing	797	264
Commercial real estate, non-owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	2,353,426	2,395,495
Commercial real estate, non-owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,154	5,946
Commercial real estate, non-owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,891	881
Increase (decrease) in past due loans	3,000
Commercial real estate, non-owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	10,939	5,153
Increase (decrease) in past due loans	5,800
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,244,117	1,246,528
Loans > 90 Days or More Past Due And Accruing	1,588	0
Commercial real estate, owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	1,231,113	1,241,714
Commercial real estate, owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,757	4,495
Commercial real estate, owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,444	0
Increase (decrease) in past due loans	7,400
Commercial real estate, owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,803	319
Residential
Financing Receivable, Past Due [Line Items]
Loans	2,185,943	2,096,655
Loans > 90 Days or More Past Due And Accruing	0	0
Residential | Current
Financing Receivable, Past Due [Line Items]
Loans	2,170,577	2,079,959
Residential | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	6,667	8,607
Residential | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,759	2,278
Residential | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,940	5,811
Home equity
Financing Receivable, Past Due [Line Items]
Loans	621,354	630,632
Loans > 90 Days or More Past Due And Accruing	16	326
Home equity | Current
Financing Receivable, Past Due [Line Items]
Loans	615,199	624,543
Home equity | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,626	2,206
Home equity | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,214	1,782
Home equity | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,315	2,101
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Loans	172,389	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	171,336	174,629
Individuals' loans for household and other personal expenditures | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	408	343
Individuals' loans for household and other personal expenditures | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	633	142
Individuals' loans for household and other personal expenditures | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	12	97
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Loans	959,467	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	959,258	932,778
Public finance and other commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	209	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