Loans and Allowance for Loan Losses (Aging Information on Past Due and Accruing Loans) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current or Less Than 30 Days Past Due	$ 9,068,607	$ 9,223,775
30-89 Days Past Due	65,156	81,466
90 Days Past Due and Still Accruing	23,598	20,466
Non-accrual	79,717	85,275
Total	9,237,078	9,410,982
Business [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	2,884,367	2,927,403
30-89 Days Past Due	10,404	19,853
90 Days Past Due and Still Accruing	755	854
Non-accrual	26,030	8,933
Total	2,921,556	2,957,043
Real Estate - Construction and Land [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	399,555	400,420
30-89 Days Past Due	4,329	7,464
90 Days Past Due and Still Accruing	871	217
Non-accrual	28,709	52,752
Total	433,464	460,853
Real Estate - Business [Member] | Commercial [Member]
Current or Less Than 30 Days Past Due	2,058,387	2,040,794
30-89 Days Past Due	15,960	8,801
90 Days Past Due and Still Accruing	6,564
Non-accrual	16,780	16,242
Total	2,097,691	2,065,837
Real Estate - Personal [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	1,414,558	1,413,905
30-89 Days Past Due	10,713	15,579
90 Days Past Due and Still Accruing	4,561	3,554
Non-accrual	8,198	7,348
Total	1,438,030	1,440,386
Consumer [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	1,094,631	1,145,561
30-89 Days Past Due	12,790	15,899
90 Days Past Due and Still Accruing	1,488	2,867
Non-accrual
Total	1,108,909	1,164,327
Revolving Home Equity [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	465,795	475,764
30-89 Days Past Due	836	929
90 Days Past Due and Still Accruing	760	825
Non-accrual
Total	467,391	477,518
Consumer Credit Card [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	746,505	806,373
30-89 Days Past Due	9,740	12,513
90 Days Past Due and Still Accruing	8,599	12,149
Non-accrual
Total	764,844	831,035
Overdrafts [Member] | Personal Banking [Member]
Current or Less Than 30 Days Past Due	4,809	13,555
30-89 Days Past Due	384	428
90 Days Past Due and Still Accruing
Non-accrual
Total	$ 5,193	$ 13,983