Loans And Allowance For Loan Losses (Credit Quality Of Commercial Loan Portfolio) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	$ 6,993,115	$ 6,661,674
Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	6,828,866	6,441,941
Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	63,274	107,437
Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	79,876	77,713
Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	21,099	34,583
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	4,267,997	3,969,952
Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	4,179,038	3,871,569
Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	46,321	62,904
Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	30,782	23,919
Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	11,856	11,560
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	448,887	403,507
Real Estate - Construction And Land [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	439,769	385,831
Real Estate - Construction And Land [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	1,111	3,865
Real Estate - Construction And Land [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	4,407	8,654
Real Estate - Construction And Land [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	3,600	5,157
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	2,276,231	2,288,215
Real Estate - Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	2,210,059	2,184,541
Real Estate - Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	15,842	40,668
Real Estate - Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	44,687	45,140
Real Estate - Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Commercial	$ 5,643	$ 17,866