LOANS AND ALLOWANCE FOR CREDIT LOSSES - Summary of Non-Accrual Loans by Loan Class (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	$ 117,415	$ 71,773
Nonaccrual Loans with no Allowance for Credit Losses	16,060	27,844
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	44,727	10,548
Nonaccrual Loans with no Allowance for Credit Losses	1,935	2,174
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	182	250
Nonaccrual Loans with no Allowance for Credit Losses	0	0
Construction
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	9,718	22,481
Nonaccrual Loans with no Allowance for Credit Losses	9,674	22,482
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	9,619	837
Nonaccrual Loans with no Allowance for Credit Losses	0	0
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	11,031	3,705
Nonaccrual Loans with no Allowance for Credit Losses	4,310	3,188
Residential
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	35,142	29,774
Nonaccrual Loans with no Allowance for Credit Losses	141	0
Home equity
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	6,865	4,158
Nonaccrual Loans with no Allowance for Credit Losses	0	0
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	41	20
Nonaccrual Loans with no Allowance for Credit Losses	0	0
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	90	0
Nonaccrual Loans with no Allowance for Credit Losses	$ 0	$ 0