Allowance For Loan Losses (Schedule Of Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 3,074,173	$ 3,046,226
Commercial Industrial Loans And Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,455,117	1,415,183
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	205,011	185,667
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,250,106	1,229,516
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,395,400	1,355,111
Pass [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	195,748	176,823
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,199,652	1,178,288
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	17,364	18,458
Special Mention [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,472	2,427
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	14,892	16,031
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	42,353	41,614
Substandard [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,791	6,417
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	35,562	35,197
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Doubtful [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0