Loans and Allowance for Loan Losses (Aging Information on Past Due and Accruing Loans) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current or Less Than 30 Days Past Due	$ 8,871,391	$ 9,223,775
30-89 Days Past Due	105,716	81,466
90 Days Past Due and Still Accruing	20,104	20,466
Non-accrual	75,912	85,275
Total	9,073,123	9,410,982
Business [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	2,738,215	2,927,403
30-89 Days Past Due	4,030	19,853
90 Days Past Due and Still Accruing	676	854
Non-accrual	26,334	8,933
Total	2,769,255	2,957,043
Real Estate - Construction and Land [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	364,757	400,420
30-89 Days Past Due	5,837	7,464
90 Days Past Due and Still Accruing	697	217
Non-accrual	26,307	52,752
Total	397,598	460,853
Real Estate - Business [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	2,060,992	2,040,794
30-89 Days Past Due	56,611	8,801
90 Days Past Due and Still Accruing	5,262
Non-accrual	15,948	16,242
Total	2,138,813	2,065,837
Real Estate - Personal [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	1,403,167	1,413,905
30-89 Days Past Due	15,422	15,579
90 Days Past Due and Still Accruing	2,580	3,554
Non-accrual	7,323	7,348
Total	1,428,492	1,440,386
Consumer [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	1,091,709	1,145,561
30-89 Days Past Due	12,011	15,899
90 Days Past Due and Still Accruing	2,065	2,867
Total	1,105,785	1,164,327
Revolving Home Equity [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	464,739	475,764
30-89 Days Past Due	1,382	929
90 Days Past Due and Still Accruing	825	825
Total	466,946	477,518
Consumer Credit Card [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	734,431	806,373
30-89 Days Past Due	10,028	12,513
90 Days Past Due and Still Accruing	7,999	12,149
Total	752,458	831,035
Overdrafts [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	13,381	13,555
30-89 Days Past Due	395	428
Total	$ 13,776	$ 13,983