Allowance For Loan Losses (Schedule Of Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total	$ 3,155,468	$ 3,127,410
Commercial Industrial Loans And Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,508,176	1,486,060
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	213,687	208,484
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,294,489	1,277,576
Pass
Financing Receivable, Recorded Investment [Line Items]
Total	1,435,888	1,407,207
Pass | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	180,720	175,951
Pass | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,255,168	1,231,256
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	33,243	33,940
Special mention | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	26,614	25,872
Special mention | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	6,629	8,068
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	39,045	44,913
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	6,353	6,661
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	32,692	38,252
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Doubtful | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Doubtful | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0