LOANS AND LEASES - Additional Information (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) loans	Jun. 30, 2021 USD ($) loans	Jun. 30, 2022 USD ($) loans	Jun. 30, 2021 USD ($) loans	Dec. 31, 2021 USD ($) loans	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	6	5	14	27
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts | loans	0	0	0	0
Restructured Loans, Portion Determined to be Uncollectible	$ 800,000	$ 0	$ 3,200,000	$ 30,000
Restructured Loans, Nonaccrual Status	9,500,000		9,500,000		$ 16,000,000
Real Estate Acquired Through Foreclosure	22,000	$ 340,000	22,000	$ 340,000	98,000	$ 72,000	$ 854,000	$ 1,287,000
Troubled Debt Restructuring	20,700,000		20,700,000		27,600,000
Financing Receivable, Non-Troubled Debt Restructuring Modifications, Amount	0		0		16,500,000
Loans and Leases Receivable, Net of Deferred Income	$ 9,420,417,000		$ 9,420,417,000		9,288,299,000
Total consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	0	0	0	0
Commercial segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	3	1	6	5
Loans and Leases Receivable, Net of Deferred Income	$ 11,675,000		$ 11,675,000		17,362,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum			$ 250,000
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	3	3	6	13
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum			$ 250,000
Loans and Leases Receivable, Net of Deferred Income	$ 8,879,000		8,879,000		8,305,000
Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	217,000		217,000		203,000
Lease financing | Summit Funding Group, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income					41,800,000
Commercial segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned fees	400,000		400,000		2,600,000
Paycheck Protection Program Amount of Funding	8,500,000		8,500,000		55,600,000
Loans and Leases Receivable, Net of Deferred Income	$ 2,927,175,000		$ 2,927,175,000		$ 2,720,028,000
Payment Deferral [Member] | Commercial segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans					2