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Loans (Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	$ 2,946,668	$ 2,694,922
Net Deferred Loan (Fees) Costs	41,663	40,095
Loans, Net	2,988,331	2,735,017
Allowance for loan losses	(33,955)	(34,672)
Total loans, net	2,954,376	2,700,345
Commercial Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	537,160	449,763
Net Deferred Loan (Fees) Costs	782	563
Loans, Net	537,942	450,326
Commercial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	907,107	810,851
Net Deferred Loan (Fees) Costs	(2,096)	(1,943)
Loans, Net	905,011	808,908
Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	498,883	457,761
Net Deferred Loan (Fees) Costs	8,715	7,522
Loans, Net	507,598	465,283
Residential Real Estate Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	108,227	113,422
Net Deferred Loan (Fees) Costs	2,977	2,887
Loans, Net	111,204	116,309
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	878,316	845,682
Net Deferred Loan (Fees) Costs	31,118	30,888
Loans, Net	909,434	876,570
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Amount Outstanding	16,975	17,443
Net Deferred Loan (Fees) Costs	167	178
Loans, Net	$ 17,142	$ 17,621

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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 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 before allowance and after 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.

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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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