Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 7) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Past Due Loans and Leases
30-59 Days Past Due	$ 29,273	$ 13,467
60-89 Days Past Due	10,813	4,511
Greater Than 90 Days and Accruing	981	453
Nonaccrual	99,787	112,026
Total Past Due and Nonaccrual Loans	140,854	130,457
Current	14,677,441	12,178,928
Total Loans and Leases	14,818,295	12,309,385
Contractual interest foregone on nonaccrual loans, excluding covered loans
Interest income that would have been recognized had nonaccrual loans performed in accordance with their original terms	8,549	15,465	17,869
Less: Interest income recognized on nonaccrual loans on a cash basis	(1,446)	(1,494)	(1,689)
Interest income foregone on nonaccrual loans	7,103	13,971	16,180
Commercial
Past Due Loans and Leases
30-59 Days Past Due	6,207	6,817
60-89 Days Past Due	4,219	1,003
Greater Than 90 Days and Accruing	602
Nonaccrual	9,087	19,888
Total Past Due and Nonaccrual Loans	20,115	27,708
Current	6,191,238	4,818,886
Total Loans and Leases	6,211,353	4,846,594
Commercial real estate mortgages
Past Due Loans and Leases
30-59 Days Past Due	16,968	5,838
60-89 Days Past Due	3,249
Nonaccrual	33,198	21,948
Total Past Due and Nonaccrual Loans	53,415	27,786
Current	2,776,279	2,082,963
Total Loans and Leases	2,829,694	2,110,749
Residential mortgage
Past Due Loans and Leases
30-59 Days Past Due		662
60-89 Days Past Due	1,969	3,508
Greater Than 90 Days and Accruing	379	379
Nonaccrual	9,603	9,771
Total Past Due and Nonaccrual Loans	11,951	14,320
Current	3,950,254	3,748,898
Total Loans and Leases	3,962,205	3,763,218
Fixed
Past Due Loans and Leases
30-59 Days Past Due		662
60-89 Days Past Due	1,969	525
Greater Than 90 Days and Accruing	379	379
Nonaccrual	4,902	5,572
Total Past Due and Nonaccrual Loans	7,250	7,138
Current	1,458,224	1,574,658
Total Loans and Leases	1,465,474	1,581,796
Variable
Past Due Loans and Leases
60-89 Days Past Due		2,983
Nonaccrual	4,701	4,199
Total Past Due and Nonaccrual Loans	4,701	7,182
Current	2,492,030	2,174,240
Total Loans and Leases	2,496,731	2,181,422
Real estate construction
Past Due Loans and Leases
60-89 Days Past Due	859
Nonaccrual	40,882	50,876
Total Past Due and Nonaccrual Loans	41,741	50,876
Current	181,039	264,733
Total Loans and Leases	222,780	315,609
Construction
Past Due Loans and Leases
Nonaccrual	15,067	15,582
Total Past Due and Nonaccrual Loans	15,067	15,582
Current	150,548	202,279
Total Loans and Leases	165,615	217,861
Land
Past Due Loans and Leases
60-89 Days Past Due	859
Nonaccrual	25,815	35,294
Total Past Due and Nonaccrual Loans	26,674	35,294
Current	30,491	62,454
Total Loans and Leases	57,165	97,748
Equity lines of credit
Past Due Loans and Leases
30-59 Days Past Due	3,407
60-89 Days Past Due	480
Greater Than 90 Days and Accruing		74
Nonaccrual	6,424	8,669
Total Past Due and Nonaccrual Loans	10,311	8,743
Current	701,439	732,338
Total Loans and Leases	711,750	741,081
Installment loan
Past Due Loans and Leases
30-59 Days Past Due	58	150
60-89 Days Past Due	35
Nonaccrual	473	874
Total Past Due and Nonaccrual Loans	566	1,024
Current	142,227	131,623
Total Loans and Leases	142,793	132,647
Commercial Installment loan
Past Due Loans and Leases
Nonaccrual		4
Total Past Due and Nonaccrual Loans		4
Current	437	601
Total Loans and Leases	437	605
Consumer Installment loan
Past Due Loans and Leases
30-59 Days Past Due	58	150
60-89 Days Past Due	35
Nonaccrual	473	870
Total Past Due and Nonaccrual Loans	566	1,020
Current	141,790	131,022
Total Loans and Leases	142,356	132,042
Lease financing
Past Due Loans and Leases
30-59 Days Past Due	2,633
60-89 Days Past Due	2
Nonaccrual	120
Total Past Due and Nonaccrual Loans	2,755
Current	734,965	399,487
Total Loans and Leases	$ 737,720	$ 399,487