Allowance For Loan Losses (Schedule Of Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
SharedNationalCreditMinimumBalanceforRegulatoryReview	$ 20,000
Total	3,105,912	$ 3,046,226
Commercial Industrial Loans And Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,465,628	1,415,183
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	204,722	185,667
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,260,906	1,229,516
Pass
Financing Receivable, Recorded Investment [Line Items]
Total	1,380,934	1,355,111
Pass | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	166,408	176,823
Pass | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,214,526	1,178,288
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	38,908	18,458
Special mention | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
SharedNationalCreditBalance	25,800
Total	26,228	2,427
Special mention | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	12,680	16,031
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	45,786	41,614
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	12,086	6,417
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	33,700	35,197
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