LOANS AND LEASES - Schedule of Loan and Lease Portfolio by Category (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 175,988	$ 171,869	$ 151,861	$ 146,195	$ 141,970	$ 94,507
Net loans and leases	12,502,404		11,759,992
Reverse mortgage, fair value	2,800		2,400	3,000
Financing Receivable Portfolio Segment, Including Reverse Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	12,678,392		11,911,853
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	858,111		761,882
Allowance for credit losses	5,351	5,043	4,668	4,818	4,988	3,352
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,957,082		1,810,930
Allowance for credit losses	56,613	56,543	53,320	47,457	41,830	23,088
Commercial and industrial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,644,039		2,575,345
Allowance for credit losses	61,670	62,783	59,394	59,884	60,921	49,967
Owner-occupied commercial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,924,171		1,809,582
Allowance for credit losses	7,850	6,335	6,019	6,003	5,510	4,574
Commercial mortgages | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,645,723		3,351,084
Allowance for credit losses	33,187	31,937	21,473	21,534	23,663	11,623
Construction | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,043,568		1,044,049
Allowance for credit losses	11,317	$ 9,228	6,987	$ 6,499	$ 5,058	$ 1,903
Commercial small business leases | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 605,698		$ 558,981