LOANS AND LEASES - Collateral (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 9,241,617	$ 9,288,299
Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	11,399	13,171
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	13,885	13,050
Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	7,512	6,973
Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	78	38
Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	10,986	11,729
Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,594	3,431
Total Collateral
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	45,454	48,392
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	14,390	17,362
Commercial | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	11,399	13,171
Commercial | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	15
Commercial | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,560	833
Commercial | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,431	3,343
Commercial real estate - investor
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	6,509	6,784
Commercial real estate - investor | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial real estate - investor | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	6,362	6,362
Commercial real estate - investor | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial real estate - investor | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	41	0
Commercial real estate - investor | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	106	422
Commercial real estate - investor | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial Real Estate-Owner
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	13,334	12,728
Commercial Real Estate-Owner | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial Real Estate-Owner | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	7,523	6,673
Commercial Real Estate-Owner | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	5,703	5,937
Commercial Real Estate-Owner | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	37	38
Commercial Real Estate-Owner | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	71	80
Commercial Real Estate-Owner | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	7,432	8,305
Residential real estate | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	7,432	8,305
Residential real estate | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Home Equity Loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,377	2,922
Home Equity Loan | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Home Equity Loan | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Home Equity Loan | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Home Equity Loan | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Home Equity Loan | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,377	2,922
Home Equity Loan | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	163	88
Installment | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Installment | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	163	88
Lease financing
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	249	203
Lease financing | Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Lease financing | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Lease financing | Equipment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	249	203
Lease financing | Land
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Lease financing | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Lease financing | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 0	$ 0