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Loans (Loan Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	$ 2,694,922	$ 2,305,071
Net Deferred Loan Costs (Fees)	40,095	35,090
Loans, Net	2,735,017	2,340,161
Allowance for loan losses	(34,672)	(30,934)
Total loans, net	2,700,345	2,309,227
Commercial Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	449,763	349,079
Net Deferred Loan Costs (Fees)	563	468
Loans, Net	450,326	349,547
Commercial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	810,851	671,552
Net Deferred Loan Costs (Fees)	(1,943)	(1,494)
Loans, Net	808,908	670,058
Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	457,761	421,476
Net Deferred Loan Costs (Fees)	7,522	6,461
Loans, Net	465,283	427,937
Residential Real Estate Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	113,422	119,745
Net Deferred Loan Costs (Fees)	2,887	2,810
Loans, Net	116,309	122,555
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	845,682	725,754
Net Deferred Loan Costs (Fees)	30,888	26,667
Loans, Net	876,570	752,421
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Gross	17,443	17,465
Net Deferred Loan Costs (Fees)	178	178
Loans, Net	$ 17,621	$ 17,643

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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