Loans (Commercial Loan Portfolio Categorized By Internally Assigned Asset Classification) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 2,694,922	$ 2,305,071
Commercial Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	449,763	349,079
Commercial Business [Member] | Uncriticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	429,692	326,254
Commercial Business [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,120	10,377
Commercial Business [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	12,951	12,448
Commercial Business [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans
Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	810,851	671,552
Commercial Mortgage [Member] | Uncriticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	791,127	652,550
Commercial Mortgage [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	12,185	12,690
Commercial Mortgage [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,539	6,312
Commercial Mortgage [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans