FAIR VALUE MEASUREMENT AND DISCLOSURE (Schedule of Carrying Amounts and Estimated Fair Value for Financial Instrument Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial assets:
Held-to-maturity securities, at amortized cost	$ 540,074	$ 546,583
Held-to-maturity securities, fair value	510,999	506,193
Mortgage servicing rights	4,187	4,412
Financial liabilities:
Time deposits	351,795	291,568
Short-term Debt, Fair Value	485,505	264,779
Subordinated debentures	31,918	31,032
Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,586,974	1,550,379
Commercial
Financial assets:
Loans receivable, net of allowance	405,429	414,353
Residential real estate
Financial assets:
Loans receivable, net of allowance	1,509,387	1,494,707
Home equity
Financial assets:
Loans receivable, net of allowance	228,821	237,967
Consumer
Financial assets:
Loans receivable, net of allowance	16,993	17,853
Readily Available Market Prices (Level 1)
Financial assets:
Held-to-maturity securities, fair value	0	0
Mortgage servicing rights	0	0
Financial liabilities:
Time deposits	0	0
Short-term Debt, Fair Value	0	0
Subordinated debentures	0	0
Readily Available Market Prices (Level 1) | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	0	0
Readily Available Market Prices (Level 1) | Commercial
Financial assets:
Loans receivable, net of allowance	0	0
Readily Available Market Prices (Level 1) | Residential real estate
Financial assets:
Loans receivable, net of allowance	0	0
Readily Available Market Prices (Level 1) | Home equity
Financial assets:
Loans receivable, net of allowance	0	0
Readily Available Market Prices (Level 1) | Consumer
Financial assets:
Loans receivable, net of allowance	0	0
Observable Market Data (Level 2)
Financial assets:
Held-to-maturity securities, fair value	510,999	506,193
Mortgage servicing rights	0	0
Financial liabilities:
Time deposits	351,795	291,568
Short-term Debt, Fair Value	485,505	264,779
Subordinated debentures	31,918	31,032
Observable Market Data (Level 2) | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	0	0
Observable Market Data (Level 2) | Commercial
Financial assets:
Loans receivable, net of allowance	0	0
Observable Market Data (Level 2) | Residential real estate
Financial assets:
Loans receivable, net of allowance	0	0
Observable Market Data (Level 2) | Home equity
Financial assets:
Loans receivable, net of allowance	0	0
Observable Market Data (Level 2) | Consumer
Financial assets:
Loans receivable, net of allowance	0	0
Company Determined Fair Value (Level 3)
Financial assets:
Held-to-maturity securities, fair value	0	0
Mortgage servicing rights	4,187	4,412
Financial liabilities:
Time deposits	0	0
Short-term Debt, Fair Value	0	0
Subordinated debentures	0	0
Company Determined Fair Value (Level 3) | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,586,974	1,550,379
Company Determined Fair Value (Level 3) | Commercial
Financial assets:
Loans receivable, net of allowance	404,847	414,353
Company Determined Fair Value (Level 3) | Residential real estate
Financial assets:
Loans receivable, net of allowance	1,509,387	1,494,707
Company Determined Fair Value (Level 3) | Home equity
Financial assets:
Loans receivable, net of allowance	228,821	237,967
Company Determined Fair Value (Level 3) | Consumer
Financial assets:
Loans receivable, net of allowance	16,993	17,853
Carrying Amount
Financial assets:
Held-to-maturity securities, at amortized cost	540,074	546,583
Mortgage servicing rights	2,413	2,458
Financial liabilities:
Time deposits	360,103	300,451
Short-term Debt, Fair Value	486,318	265,176
Subordinated debentures	44,331	44,331
Carrying Amount | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,647,823	1,605,279
Carrying Amount | Commercial
Financial assets:
Loans receivable, net of allowance	416,518	424,685
Carrying Amount | Residential real estate
Financial assets:
Loans receivable, net of allowance	1,722,335	1,691,177
Carrying Amount | Home equity
Financial assets:
Loans receivable, net of allowance	230,072	232,203
Carrying Amount | Consumer
Financial assets:
Loans receivable, net of allowance	$ 19,226	$ 20,087