Loans (Retail Loan Portfolio Categorized By Payment Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 2,694,922	$ 2,305,071
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	457,761	421,476
Residential Real Estate Loans [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	455,509	420,240
Residential Real Estate Loans [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,252	1,236
Residential Real Estate Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	113,422	119,745
Residential Real Estate Lines [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	113,018	119,373
Residential Real Estate Lines [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	404	372
Consumer Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	845,682	725,754
Consumer Indirect [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	843,787	724,228
Consumer Indirect [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,895	1,526
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,443	17,465
Other Consumer [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,430	17,449
Other Consumer [Member] | Non-Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 13	$ 16