Allowance For Loan Losses (Schedule Of Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total	$ 3,137,681	$ 3,127,410
Commercial Industrial Loans And Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,500,896	1,486,060
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	204,592	208,484
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,296,304	1,277,576
Pass
Financing Receivable, Recorded Investment [Line Items]
Total	1,424,752	1,407,207
Pass | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	171,815	175,951
Pass | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,252,937	1,231,256
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	32,602	33,940
Special mention | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	25,524	25,872
Special mention | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	7,078	8,068
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	43,542	44,913
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	7,253	6,661
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	36,289	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