LOANS AND LEASES - Schedule of Loan and Lease Portfolio by Category (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 187,515	$ 195,281	$ 192,629	$ 186,126
Net loans and leases	12,922,842	12,996,218
Reverse mortgage, fair value	4,100	3,600	2,500
Financing Receivable Portfolio Segment, Including Reverse Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	13,110,357	13,191,499
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,665,400	2,656,174
Allowance for credit losses	50,736	57,131	55,902	49,394
Commercial | Owner-occupied commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,954,528	1,973,645
Allowance for credit losses	8,410	9,139	10,569	10,719
Commercial | Commercial mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,982,073	4,030,627
Allowance for credit losses	49,792	48,962	36,797	36,055
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	868,668	832,093
Allowance for credit losses	9,691	9,185	10,959	10,762
Commercial | Commercial Small Business Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	636,460	647,516
Allowance for credit losses	17,109	15,965	15,459	15,170
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	970,687	965,051
Allowance for credit losses	5,697	5,566	5,407	5,483
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,032,541	2,086,393
Allowance for credit losses	$ 46,080	$ 49,333	$ 57,536	$ 58,543