FAIR VALUE MEASUREMENT AND DISCLOSURE (Schedule of Carrying Amounts and Estimated Fair Value for Financial Instrument Assets and Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial assets:
Cash and due from banks	$ 89,435	$ 87,707
Available-for-sale Securities	797,251	779,867
Held-to-maturity securities, at amortized cost	94,207	94,609
Held-to-maturity Securities, Fair Value	95,094	94,596
Loans held for sale	12,997	14,836
Mortgage servicing rights	1,740	1,701
Interest receivable	9,415	8,654
Customer loan swaps	3,482	1,945
Derivative Asset	495
Financial liabilities:
Deposits	2,953,386	2,826,484
Short-term Debt, Fair Value	538,861	530,435
Long-term Debt, Fair Value	10,816	10,836
Subordinated debentures	42,090	41,660
Interest payable	574	534
Customer loan swaps		1,945
Residential Real Estate
Financial assets:
Loans receivable, net of allowance	854,198	800,122
Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,082,977	1,006,249
Commercial
Financial assets:
Loans receivable, net of allowance	409,833	391,493
Home Equity
Financial assets:
Loans receivable, net of allowance	323,943	327,292
Consumer
Financial assets:
Loans receivable, net of allowance	17,465	16,845
Readily Available Market Prices (Level 1)
Financial assets:
Cash and due from banks	89,435	87,707
Available-for-sale Securities	0	0
Held-to-maturity Securities, Fair Value	0	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Interest receivable	0	0
Customer loan swaps	0	0
Derivative Asset	0
Financial liabilities:
Deposits	0	0
Short-term Debt, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Subordinated debentures	0	0
Interest payable	0	0
Customer loan swaps		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) | 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) | 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:
Cash and due from banks	0	0
Available-for-sale Securities	797,251	779,867
Held-to-maturity Securities, Fair Value	95,094	94,596
Loans held for sale	12,997	14,836
Mortgage servicing rights	0	0
Interest receivable	9,415	8,654
Customer loan swaps	3,482	1,945
Derivative Asset	495
Financial liabilities:
Deposits	2,953,386	2,826,484
Short-term Debt, Fair Value	538,861	530,435
Long-term Debt, Fair Value	10,816	10,836
Subordinated debentures	42,090	41,660
Interest payable	574	534
Customer loan swaps		1,945
Observable Market Data (Level 2) | Residential Real Estate
Financial assets:
Loans receivable, net of allowance	0	0
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) | 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:
Cash and due from banks	0	0
Available-for-sale Securities	0	0
Held-to-maturity Securities, Fair Value	0	0
Loans held for sale	0	0
Mortgage servicing rights	1,740	1,701
Interest receivable	0	0
Customer loan swaps	0	0
Derivative Asset	0
Financial liabilities:
Deposits	0	0
Short-term Debt, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Subordinated debentures	0	0
Interest payable	0	0
Customer loan swaps		0
Company Determined Fair Value (Level 3) | Residential Real Estate
Financial assets:
Loans receivable, net of allowance	854,198	800,122
Company Determined Fair Value (Level 3) | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,082,977	1,006,249
Company Determined Fair Value (Level 3) | Commercial
Financial assets:
Loans receivable, net of allowance	409,833	391,493
Company Determined Fair Value (Level 3) | Home Equity
Financial assets:
Loans receivable, net of allowance	323,943	327,292
Company Determined Fair Value (Level 3) | Consumer
Financial assets:
Loans receivable, net of allowance	17,465	16,845
Carrying Amount
Financial assets:
Cash and due from banks	89,435	87,707
Available-for-sale Securities	797,251	779,867
Held-to-maturity securities, at amortized cost	94,207	94,609
Loans held for sale	12,997	14,836
Mortgage servicing rights	1,109	1,210
Interest receivable	9,415	8,654
Customer loan swaps	3,482	1,945
Derivative Asset	495
Financial liabilities:
Deposits	2,956,413	2,828,529
Short-term Debt, Fair Value	538,997	530,129
Long-term Debt, Fair Value	10,738	10,791
Subordinated debentures	58,872	58,755
Interest payable	574	534
Customer loan swaps		1,945
Carrying Amount | Residential Real Estate
Financial assets:
Loans receivable, net of allowance	848,309	798,334
Carrying Amount | Commercial Real Estate
Financial assets:
Loans receivable, net of allowance	1,119,087	1,038,626
Carrying Amount | Commercial
Financial assets:
Loans receivable, net of allowance	412,402	389,624
Carrying Amount | Home Equity
Financial assets:
Loans receivable, net of allowance	326,151	327,713
Carrying Amount | Consumer
Financial assets:
Loans receivable, net of allowance	17,928	17,151
Interest Rate Lock Commitments [Member]
Financial assets:
Customer loan swaps		202
Financial liabilities:
Customer loan swaps	25	15
Interest Rate Lock Commitments [Member] | Readily Available Market Prices (Level 1)
Financial assets:
Customer loan swaps		0
Financial liabilities:
Customer loan swaps	0	0
Interest Rate Lock Commitments [Member] | Observable Market Data (Level 2)
Financial assets:
Customer loan swaps		202
Financial liabilities:
Customer loan swaps	25	15
Interest Rate Lock Commitments [Member] | Company Determined Fair Value (Level 3)
Financial assets:
Customer loan swaps		0
Financial liabilities:
Customer loan swaps	0	0
Interest Rate Lock Commitments [Member] | Carrying Amount
Financial assets:
Customer loan swaps		202
Financial liabilities:
Customer loan swaps	25	15
Forward Contracts [Member]
Financial assets:
Customer loan swaps	332	587
Financial liabilities:
Customer loan swaps	19	309
Forward Contracts [Member] | Readily Available Market Prices (Level 1)
Financial assets:
Customer loan swaps	0	0
Financial liabilities:
Customer loan swaps	0	0
Forward Contracts [Member] | Observable Market Data (Level 2)
Financial assets:
Customer loan swaps	332	587
Financial liabilities:
Customer loan swaps	19	309
Forward Contracts [Member] | Company Determined Fair Value (Level 3)
Financial assets:
Customer loan swaps	0	0
Financial liabilities:
Customer loan swaps	0	0
Forward Contracts [Member] | Carrying Amount
Financial assets:
Customer loan swaps	332	587
Financial liabilities:
Customer loan swaps	19	309
Interest rate swaps
Financial liabilities:
Junior subordinated debt interest rate swaps	8,123	8,372
Interest rate swaps | Readily Available Market Prices (Level 1)
Financial liabilities:
Junior subordinated debt interest rate swaps	0	0
Interest rate swaps | Observable Market Data (Level 2)
Financial liabilities:
Junior subordinated debt interest rate swaps	8,123	8,372
Interest rate swaps | Company Determined Fair Value (Level 3)
Financial liabilities:
Junior subordinated debt interest rate swaps	0	0
Interest rate swaps | Carrying Amount
Financial liabilities:
Junior subordinated debt interest rate swaps	8,123	8,372
Forward-Starting Interest Rate Swap
Financial liabilities:
Junior subordinated debt interest rate swaps	98	389
Forward-Starting Interest Rate Swap | Readily Available Market Prices (Level 1)
Financial liabilities:
Junior subordinated debt interest rate swaps	0	0
Forward-Starting Interest Rate Swap | Observable Market Data (Level 2)
Financial liabilities:
Junior subordinated debt interest rate swaps	98	389
Forward-Starting Interest Rate Swap | Company Determined Fair Value (Level 3)
Financial liabilities:
Junior subordinated debt interest rate swaps	0	0
Forward-Starting Interest Rate Swap | Carrying Amount
Financial liabilities:
Junior subordinated debt interest rate swaps	98	$ 389
Customer Loan Swaps
Financial liabilities:
Customer loan swaps	3,482
Customer Loan Swaps | Readily Available Market Prices (Level 1)
Financial liabilities:
Customer loan swaps	0
Customer Loan Swaps | Observable Market Data (Level 2)
Financial liabilities:
Customer loan swaps	3,482
Customer Loan Swaps | Company Determined Fair Value (Level 3)
Financial liabilities:
Customer loan swaps	0
Customer Loan Swaps | Carrying Amount
Financial liabilities:
Customer loan swaps	$ 3,482