LOANS AND ALLOWANCE FOR CREDIT LOSSES - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) loan_segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	$ 40,652,000		$ 40,652,000		$ 18,934,000
Loans	12,646,808,000		12,646,808,000		12,486,027,000
Interest income recognized on non-accrual loans	0	$ 0	0	$ 0
Payment default	1,700,000	0	$ 2,900,000	0
Number of loan segments | loan_segment			10
Allowance for credit losses increase (decrease)	(1,700,000)		$ (17,100,000)
Net charge-offs	6,700,000		48,600,000
Provision for credit losses	$ 5,000,000	5,000,000	$ 31,500,000	5,000,000
Standby letters of credit usual term	2 years		2 years
Increase (decrease) in provision	$ 0	$ (3,000,000)	$ 0	$ (3,000,000)
Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,251,351,000		2,251,351,000		2,400,839,000
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,041,217,000		4,041,217,000		3,670,948,000
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	814,704,000		814,704,000		957,545,000
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	158,480,000		158,480,000		168,388,000
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,366,943,000		2,366,943,000		2,288,921,000
Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	95,000,000		95,000,000		79,200,000
Increase (decrease) in past due loans			15,800,000
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	30,287,000		30,287,000		34,075,000
Increase (decrease) in past due loans			(3,800,000)
30-59 Days Past Due | Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	8,680,000		8,680,000		12,995,000
Increase (decrease) in past due loans			(4,300,000)
30-59 Days Past Due | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,906,000		1,906,000		5,021,000
Increase (decrease) in past due loans			(3,100,000)
30-59 Days Past Due | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,522,000		2,522,000		0
Increase (decrease) in past due loans			2,500,000
30-59 Days Past Due | Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,567,000		2,567,000		635,000
Increase (decrease) in past due loans			1,900,000
30-59 Days Past Due | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,377,000		10,377,000		11,810,000
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	18,773,000		18,773,000		11,189,000
Increase (decrease) in past due loans			7,600,000
60-89 Days Past Due | Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	485,000		485,000		195,000
60-89 Days Past Due | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	7,805,000		7,805,000		1,622,000
60-89 Days Past Due | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,646,000		1,646,000		1,957,000
Increase (decrease) in past due loans			6,200,000
60-89 Days Past Due | Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	385,000		385,000		192,000
60-89 Days Past Due | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,029,000		6,029,000		5,472,000
90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	45,944,000		45,944,000		33,980,000
Increase (decrease) in past due loans			12,000,000
90 Days or More Past Due | Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	16,404,000		16,404,000		11,465,000
Increase (decrease) in past due loans			4,900,000
90 Days or More Past Due | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	8,490,000		8,490,000		6,858,000
Increase (decrease) in past due loans			1,600,000
90 Days or More Past Due | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0		0		0
90 Days or More Past Due | Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,000		2,000		8,000
90 Days or More Past Due | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 16,225,000		16,225,000		$ 12,143,000
Increase (decrease) in past due loans			$ 4,100,000