Loans And Allowance For Credit Losses (Schedule Of Investment Of Accruing And Nonaccruing Loans Modified As Troubled Debt Restructurings) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	$ 2,336	$ 10,460	$ 22,559
Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	35
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	2,336	10,460	22,524
Commercial [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	107	6,846	2,176
Commercial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	35
Commercial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	107	6,846	2,141
Commercial [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	107	1,441	1,735
Commercial [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	35
Commercial [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	107	1,441	1,700
Commercial [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	5,405	441
Commercial [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Commercial [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	5,405	441
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	2,229	2,525	17,638
Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	2,229	2,525	17,638
Commercial Real Estate [Member] | Construction And Land Development [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	2,229	2,525	11,667
Commercial Real Estate [Member] | Construction And Land Development [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Commercial Real Estate [Member] | Construction And Land Development [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	2,229	2,525	11,667
Commercial Real Estate [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	5,971
Commercial Real Estate [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Commercial Real Estate [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	5,971
Consumer [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	1,089	2,745
Consumer [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Consumer [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	1,089	2,745
Consumer [Member] | 1-4 Family Residential [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	1,089	2,745
Consumer [Member] | 1-4 Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	0	0	0
Consumer [Member] | 1-4 Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
TDR defaults during the period, recorded investment	$ 0	$ 1,089	$ 2,745