Allowance For Loan Losses (Schedule Of Aging Analysis Of Accruing And Non-Accruing Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 2,934,352	$ 2,836,419
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	526	506
Non-accrual	14,591	16,948
Gross loans	2,957,912	2,862,534
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,435,610	1,373,604
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	0	0
Non-accrual	3,919	2,918
Gross loans	1,445,242	1,383,133
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	140,537	146,493
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	0	0
Non-accrual	154	136
Gross loans	141,616	147,036
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	173,547	162,435
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	0	0
Non-accrual	2,441	2,745
Gross loans	176,387	165,340
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,148,737	1,114,953
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	526	506
Non-accrual	8,077	11,149
Gross loans	1,158,088	1,127,581
Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	33,510	35,886
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	0	0
Non-accrual	0	0
Gross loans	33,614	36,083
Demand Deposit Account Overdrafts [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,411	3,048
Financing Receivable, Acquired with Deteriorated Credit Quality, Recorded Investment, Past Due	0	0
Non-accrual	0	0
Gross loans	2,965	3,361
Commercial Industrial Loans And Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross loans	1,334,475	1,292,921
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	6,827	6,946
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,612	5,261
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	889	318
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	291	141
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	668	762
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	91	154
Financing Receivables, 30 to 59 Days Past Due [Member] | Demand Deposit Account Overdrafts [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	276	310
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,047	1,220
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	886	932
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	36	65
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	108	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	211
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	13	9
Financing Receivables, 60 to 89 Days Past Due [Member] | Demand Deposit Account Overdrafts [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4	3
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	569	495
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	215	418
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	24
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	19
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	80	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	34
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Demand Deposit Account Overdrafts [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 274	$ 0