Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	$ 11,840,177	$ 11,365,009
30 - 89 Days Past Due	47,441	49,796
90 Days Past Due and Still Accruing	14,218	13,658
Non-accrual	26,645	40,775
Total	11,928,481	11,469,238
Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	4,252,087	3,946,144
30 - 89 Days Past Due	3,643	11,152
90 Days Past Due and Still Accruing	411	1,096
Non-accrual	11,856	11,560
Total	4,267,997	3,969,952
Real Estate - Construction And Land [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	438,905	397,488
30 - 89 Days Past Due	4,903	827
90 Days Past Due and Still Accruing	1,479	35
Non-accrual	3,600	5,157
Total	448,887	403,507
Real Estate - Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	2,264,297	2,266,688
30 - 89 Days Past Due	6,291	3,661
90 Days Past Due and Still Accruing	0	0
Non-accrual	5,643	17,866
Total	2,276,231	2,288,215
Real Estate - Personal [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	1,885,544	1,868,606
30 - 89 Days Past Due	8,480	6,618
90 Days Past Due and Still Accruing	2,201	1,676
Non-accrual	5,446	6,192
Total	1,901,671	1,883,092
Consumer [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	1,832,142	1,687,285
30 - 89 Days Past Due	14,179	16,053
90 Days Past Due and Still Accruing	2,036	1,796
Non-accrual	100	0
Total	1,848,457	1,705,134
Revolving Home Equity [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	427,644	428,478
30 - 89 Days Past Due	1,912	1,552
90 Days Past Due and Still Accruing	1,324	843
Non-accrual	0	0
Total	430,880	430,873
Consumer Credit Card [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	736,213	764,599
30 - 89 Days Past Due	7,751	9,559
90 Days Past Due and Still Accruing	6,767	8,212
Non-accrual	0	0
Total	750,731	782,370
Overdrafts [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Recorded Investment, 1 to 29 Days Past Due	3,345	5,721
30 - 89 Days Past Due	282	374
90 Days Past Due and Still Accruing	0	0
Non-accrual	0	0
Total	$ 3,627	$ 6,095