Allowance For Loan Losses (Schedule of Non-Commercial Loans By Payment Performance) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	$ 3,616,099	$ 3,587,608
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	1,640,396	1,635,338
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	148,928	153,496
Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	54,263	51,190
DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	4,760	6,328
Non-commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	1,848,347	1,846,352
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	1,844,340	1,841,736
Performing | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	1,636,920	1,630,892
Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	148,397	153,334
Performing | Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	54,263	51,188
Performing | DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	4,760	6,322
Non-Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	4,007	4,616
Non-Performing | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	3,476	4,446
Non-Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	531	162
Non-Performing | Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	0	2
Non-Performing | DDA Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, Total	$ 0	$ 6