Allowance For Loan Losses (Schedule Of Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Total	$ 3,559,322	$ 3,587,608
Commercial Industrial Loans And Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,725,517	1,741,256
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	289,327	286,314
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,436,190	1,454,942
Pass
Financing Receivable, Recorded Investment [Line Items]
Total	1,638,840	1,653,677
Pass | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	258,096	250,856
Pass | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	1,380,744	1,402,821
Special mention
Financing Receivable, Recorded Investment [Line Items]
Total	35,699	33,582
Special mention | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	25,457	27,886
Special mention | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	10,242	5,696
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total	50,978	53,997
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	5,774	7,572
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total	45,204	46,425
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