Loans And Allowance For Loan Losses (Summary Classification Of Held To Maturity Loan Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 14,140,298	$ 13,983,674
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	5,106,427	4,958,554
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	869,659	968,820
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,875,788	2,697,452
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,127,083	2,062,787
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	1,955,572	2,104,487
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	376,399	400,587
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	814,134	783,864
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 15,236	$ 7,123