Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	$ 9,512,353	$ 9,033,219
30 - 89 Days Past Due	58,859	53,819
90 Days Past Due and Still Accruing	12,232	14,958
Non-accrual	55,201	75,482
Total	9,638,645	9,177,478
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	3,081,649	2,777,578
30 - 89 Days Past Due	2,598	4,368
90 Days Past Due and Still Accruing	595	595
Non-accrual	14,066	25,724
Total	3,098,908	2,808,265
Business [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	3,098,908	2,808,265
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	318,841	362,592
30 - 89 Days Past Due	549	1,113
90 Days Past Due and Still Accruing	300	121
Non-accrual	15,423	22,772
Total	335,113	386,598
Real Estate - Construction And Land [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	335,113	386,598
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,158,019	2,151,822
30 - 89 Days Past Due	16,668	8,875
90 Days Past Due and Still Accruing	90	29
Non-accrual	18,429	19,374
Total	2,193,206	2,180,100
Real Estate - Business [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,193,206	2,180,100
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,535,326	1,406,449
30 - 89 Days Past Due	12,988	11,671
90 Days Past Due and Still Accruing	1,798	3,045
Non-accrual	6,642	7,612
Total	1,556,754	1,428,777
Real Estate - Personal [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	1,556,754	1,428,777
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,226,713	1,096,742
30 - 89 Days Past Due	15,350	15,917
90 Days Past Due and Still Accruing	1,206	2,230
Non-accrual	131	0
Total	1,243,400	1,114,889
Consumer [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	1,243,400	1,114,889
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	450,540	461,941
30 - 89 Days Past Due	1,494	1,003
90 Days Past Due and Still Accruing	983	643
Non-accrual	510	0
Total	453,527	463,587
Revolving Home Equity [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	453,527	463,587
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	732,749	769,922
30 - 89 Days Past Due	8,876	10,484
90 Days Past Due and Still Accruing	7,260	8,295
Non-accrual	0	0
Total	748,885	788,701
Consumer Credit Card [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	748,885	788,701
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	8,516	6,173
30 - 89 Days Past Due	336	388
90 Days Past Due and Still Accruing	0	0
Non-accrual	0	0
Total	8,852	6,561
Overdrafts [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	$ 8,852	$ 6,561