Loans And Allowance For Loan Losses (Summary Classification Of Held To Maturity Loan Portfolio) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 14,260,248	$ 14,140,298
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	5,257,682	5,106,427
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	909,784	869,659
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,867,831	2,875,788
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,160,515	2,127,083
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	1,927,623	1,955,572
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	357,406	376,399
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	776,333	814,134
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 3,074	$ 15,236