Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	$ 9,850,961	$ 9,696,644
30 - 89 Days Past Due	71,971	67,983
90 Days Past Due and Still Accruing	15,015	15,347
Non-accrual	44,739	51,410
Total	9,982,686	9,831,384
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	3,178,043	3,110,403
30 - 89 Days Past Due	15,387	10,054
90 Days Past Due and Still Accruing	1,085	1,288
Non-accrual	12,079	13,056
Total	3,206,594	3,134,801
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	328,115	325,541
30 - 89 Days Past Due	12,570	16,721
90 Days Past Due and Still Accruing	0	56
Non-accrual	12,974	13,678
Total	353,659	355,996
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,194,179	2,194,395
30 - 89 Days Past Due	4,709	3,276
90 Days Past Due and Still Accruing	176	0
Non-accrual	14,289	17,304
Total	2,213,353	2,214,975
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,608,631	1,564,281
30 - 89 Days Past Due	9,721	10,862
90 Days Past Due and Still Accruing	2,368	2,854
Non-accrual	5,386	6,862
Total	1,626,106	1,584,859
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,392,285	1,273,581
30 - 89 Days Past Due	13,838	13,926
90 Days Past Due and Still Accruing	2,112	2,143
Non-accrual	11	0
Total	1,408,246	1,289,650
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	413,731	433,437
30 - 89 Days Past Due	5,551	2,121
90 Days Past Due and Still Accruing	937	1,499
Non-accrual	0	510
Total	420,219	437,567
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	733,293	786,081
30 - 89 Days Past Due	9,041	10,657
90 Days Past Due and Still Accruing	8,337	7,507
Non-accrual	0	0
Total	750,671	804,245
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,684	8,925
30 - 89 Days Past Due	1,154	366
90 Days Past Due and Still Accruing	0	0
Non-accrual	0	0
Total	$ 3,838	$ 9,291