BORROWED FUNDS - Short-term borrowings - Additional information (Details) - USD ($)	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
BORROWED FUNDS AND SUBORDINATED DEBT
Short-term Debt, Weighted Average Interest Rate, at Point in Time	4.28%	0.10%
Letter of credit	$ 0	$ 0
Short-term borrowings	80,062,000	1,803,000
Line of Credit Facility, Maximum Month-end Outstanding Amount	90,042,000	17,353,000	$ 56,647,000
Other Correspondent Banks
BORROWED FUNDS AND SUBORDINATED DEBT
Line of Credit Facility, Maximum Borrowing Capacity	95,000,000	45,000,000
Long-term Line of Credit, Total	0	0
Federal Reserve Bank of Philadelphia \| Collateral Pledged
BORROWED FUNDS AND SUBORDINATED DEBT
Investment pledged as collateral	$ 24,113,000	$ 14,034,000
Customer repurchase agreements
BORROWED FUNDS AND SUBORDINATED DEBT
Debt, Weighted Average Interest Rate	0.10%	0.10%
Carrying Value of Securities Sold under Repurchase Agreements and Deposits Received for Securities Loaned, Total	$ 3,080,000	$ 1,820,000
Short-term borrowings	3,062,000	1,803,000
FHLB-Pittsburgh borrowings
BORROWED FUNDS AND SUBORDINATED DEBT
Short-term borrowings	77,000,000	0
Federal Home Loan Bank of Pittsburgh
BORROWED FUNDS AND SUBORDINATED DEBT
Line of Credit Facility, Maximum Borrowing Capacity	839,378,000	756,868,000
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	1,209,179,000	1,046,242,000
Line of Credit Facility, Remaining Borrowing Capacity	689,279,000	723,557,000
Federal Home Loan Bank of Pittsburgh \| Other assets
BORROWED FUNDS AND SUBORDINATED DEBT
Federal Home Loan Bank Stock	14,168,000	9,313,000
Federal Home Loan Bank of Pittsburgh \| Federal Reserve Bank of Philadelphia
BORROWED FUNDS AND SUBORDINATED DEBT
Line of Credit Facility, Maximum Borrowing Capacity	23,107,000	13,642,000
Long-term Line of Credit, Total	$ 0	$ 0
Federal Home Loan Bank of Pittsburgh \| Overnight Borrowing
BORROWED FUNDS AND SUBORDINATED DEBT
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	4.45%
Short-term borrowings	$ 77,000,000

Carrying value of securities sold under agreements to repurchase and deposits received for securities loaned.

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