Allowance For Loan Losses (Schedule Of Aging Analysis Of Accruing And Non-Accruing Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Current	$ 3,498,023	$ 3,559,926
Non-accrual	11,868	14,551
Gross loans	3,519,367	3,587,608
Residential real estate
Financing Receivable, Past Due [Line Items]
Current	1,634,837	1,621,073
Non-accrual	2,354	4,275
Gross loans	1,644,494	1,635,338
Home equity
Financing Receivable, Past Due [Line Items]
Current	150,193	152,083
Non-accrual	161	138
Gross loans	150,676	153,496
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Current	286,488	284,140
Non-accrual	2,149	1,676
Gross loans	288,803	286,314
Commercial real estate
Financing Receivable, Past Due [Line Items]
Current	1,369,886	1,445,896
Non-accrual	7,204	8,461
Gross loans	1,378,116	1,454,942
Consumer
Financing Receivable, Past Due [Line Items]
Current	53,184	50,894
Non-accrual	0	1
Gross loans	53,356	51,190
DDA overdrafts
Financing Receivable, Past Due [Line Items]
Current	3,435	5,840
Non-accrual	0	0
Gross loans	3,922	6,328
30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	8,318	11,451
30-59 days | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	6,262	8,607
30-59 days | Home equity
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	283	1,240
30-59 days | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	161	397
30-59 days | Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	972	487
30-59 days | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	162	253
30-59 days | DDA overdrafts
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	478	467
60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	1,064	1,423
60-89 days | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	964	1,213
60-89 days | Home equity
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	23	11
60-89 days | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	5	49
60-89 days | Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	54	94
60-89 days | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	10	41
60-89 days | DDA overdrafts
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	8	15
Over 90 days
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	94	257
Over 90 days | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	77	170
Over 90 days | Home equity
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	16	24
Over 90 days | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	52
Over 90 days | Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	4
Over 90 days | Consumer
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	1
Over 90 days | DDA overdrafts
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	$ 1	$ 6