Loans And Allowance For Loan Losses (Additional Information About Impaired Loans Held) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 6,520,000	$ 7,434,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,303,000	11,120,000
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	97,007,000	107,361,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	100,582,000	111,309,000
Impaired Financing Receivable, Related Allowance	3,498,000	4,243,000
Impaired Financing Receivable, Recorded Investment	103,527,000	114,795,000
Impaired Financing Receivable, Unpaid Principal Balance	110,885,000	122,429,000
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	5,221,000	5,356,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,000,000	9,000,000
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	64,228,000	72,589,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	64,448,000	73,168,000
Impaired Financing Receivable, Related Allowance	1,905,000	2,455,000
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	1,458,000	837,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,462,000	841,000
Impaired Financing Receivable, Related Allowance	42,000	27,000
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,299,000	1,299,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,303,000	1,303,000
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	10,493,000	12,532,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	11,021,000	13,071,000
Impaired Financing Receivable, Related Allowance	444,000	585,000
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	8,589,000	9,126,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	11,412,000	11,914,000
Impaired Financing Receivable, Related Allowance	415,000	532,000
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	779,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	817,000
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,415,000	5,388,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,415,000	5,426,000
Impaired Financing Receivable, Related Allowance	52,000	67,000
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	153,000	204,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	153,000	204,000
Impaired Financing Receivable, Related Allowance	17,000	11,000
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,671,000	6,685,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,671,000	6,685,000
Impaired Financing Receivable, Related Allowance	$ 623,000	$ 566,000