Allowance For Loan Losses (Schedule of Non-Commercial Loans By Payment Performance) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	$ 3,622,119	$ 3,616,099
Residential Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	1,587,694	1,640,396
Financing Receivable, before Allowance for Credit Loss	1,587,694	1,640,396
Home Equity Line of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	136,469	148,928
Financing Receivable, before Allowance for Credit Loss		148,928
Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	47,688	54,263
Financing Receivable, before Allowance for Credit Loss	47,688	54,263
DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	$ 2,497	4,760
Financing Receivable, before Allowance for Credit Loss		4,760
Non-commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,848,347
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,844,340
Performing | Residential Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,636,920
Performing | Home Equity Line of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		148,397
Performing | Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		54,263
Performing | DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,760
Non-Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,007
Non-Performing | Residential Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		3,476
Non-Performing | Home Equity Line of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		531
Non-Performing | Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		0
Non-Performing | DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 0