Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	$ 9,098,846	$ 9,033,219
30 - 89 Days Past Due	63,822	53,819
90 Days Past Due and Still Accruing	16,428	14,958
Non-accrual	68,875	75,482
Total	9,247,971	9,177,478
Business [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,893,883	2,777,578
30 - 89 Days Past Due	5,430	4,368
90 Days Past Due and Still Accruing	782	595
Non-accrual	20,142	25,724
Total	2,920,237	2,808,265
Real Estate - Construction And Land [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	341,369	362,592
30 - 89 Days Past Due	14,068	1,113
90 Days Past Due and Still Accruing	150	121
Non-accrual	21,055	22,772
Total	376,642	386,598
Real Estate - Business [Member] | Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,168,501	2,151,822
30 - 89 Days Past Due	12,892	8,875
90 Days Past Due and Still Accruing	1,638	29
Non-accrual	20,655	19,374
Total	2,203,686	2,180,100
Real Estate - Personal [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,437,273	1,406,449
30 - 89 Days Past Due	11,020	11,671
90 Days Past Due and Still Accruing	3,151	3,045
Non-accrual	7,023	7,612
Total	1,458,467	1,428,777
Consumer [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,101,279	1,096,742
30 - 89 Days Past Due	10,511	15,917
90 Days Past Due and Still Accruing	1,691	2,230
Non-accrual
Total	1,113,481	1,114,889
Revolving Home Equity [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	445,990	461,941
30 - 89 Days Past Due	911	1,003
90 Days Past Due and Still Accruing	1,268	643
Non-accrual
Total	448,169	463,587
Consumer Credit Card [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	707,328	769,922
30 - 89 Days Past Due	8,683	10,484
90 Days Past Due and Still Accruing	7,748	8,295
Non-accrual
Total	723,759	788,701
Overdrafts [Member] | Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	3,223	6,173
30 - 89 Days Past Due	307	388
90 Days Past Due and Still Accruing
Non-accrual
Total	$ 3,530	$ 6,561