Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 8) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Past Due Loans and Leases
30-59 Days Past Due	$ 8,191	$ 29,273
60-89 Days Past Due	2,925	10,813
Greater Than 90 Days and Accruing	453	981
Nonaccrual	68,651	99,787
Total Past Due and Nonaccrual Loans	80,220	140,854
Current	17,090,218	14,677,441
Total Loans and Leases	17,170,438	14,818,295
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	6,013	8,549	15,465
Less: Interest income recognized on nonaccrual loans on a cash basis	(1,219)	(1,446)	(1,494)
Interest income foregone on nonaccrual loans	4,794	7,103	13,971
Commercial
Past Due Loans and Leases
30-59 Days Past Due	4,450	6,207
60-89 Days Past Due	362	4,219
Greater Than 90 Days and Accruing		602
Nonaccrual	14,248	9,087
Total Past Due and Nonaccrual Loans	19,060	20,115
Current	7,385,056	6,191,238
Total Loans and Leases	7,404,116	6,211,353
Commercial real estate mortgages
Past Due Loans and Leases
30-59 Days Past Due	1,197	16,968
60-89 Days Past Due	1,633	3,249
Nonaccrual	18,449	33,198
Total Past Due and Nonaccrual Loans	21,279	53,415
Current	3,201,722	2,685,869
Total Loans and Leases	3,223,001	2,739,284
Residential mortgage
Past Due Loans and Leases
60-89 Days Past Due		1,969
Greater Than 90 Days and Accruing	379	379
Nonaccrual	11,661	9,603
Total Past Due and Nonaccrual Loans	12,040	11,951
Current	4,542,271	3,950,254
Total Loans and Leases	4,554,311	3,962,205
Fixed
Past Due Loans and Leases
60-89 Days Past Due		1,969
Greater Than 90 Days and Accruing	379	379
Nonaccrual	3,789	4,902
Total Past Due and Nonaccrual Loans	4,168	7,250
Current	1,436,283	1,458,224
Total Loans and Leases	1,440,451	1,465,474
Variable
Past Due Loans and Leases
Nonaccrual	7,872	4,701
Total Past Due and Nonaccrual Loans	7,872	4,701
Current	3,105,988	2,492,030
Total Loans and Leases	3,113,860	2,496,731
Real estate construction
Past Due Loans and Leases
60-89 Days Past Due	797	859
Nonaccrual	19,067	40,882
Total Past Due and Nonaccrual Loans	19,864	41,741
Current	347,140	271,449
Total Loans and Leases	367,004	313,190
Construction
Past Due Loans and Leases
Nonaccrual	5,467	15,067
Total Past Due and Nonaccrual Loans	5,467	15,067
Current	332,131	239,740
Total Loans and Leases	337,598	254,807
Land
Past Due Loans and Leases
60-89 Days Past Due	797	859
Nonaccrual	13,600	25,815
Total Past Due and Nonaccrual Loans	14,397	26,674
Current	15,009	31,709
Total Loans and Leases	29,406	58,383
Home equity loans and 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	5,144	6,424
Total Past Due and Nonaccrual Loans	5,218	10,311
Current	704,126	701,439
Total Loans and Leases	709,344	711,750
Installment
Past Due Loans and Leases
30-59 Days Past Due	11	58
60-89 Days Past Due	7	35
Nonaccrual	32	473
Total Past Due and Nonaccrual Loans	50	566
Current	151,905	142,227
Total Loans and Leases	151,955	142,793
Commercial Installment loan
Past Due Loans and Leases
30-59 Days Past Due	1
Total Past Due and Nonaccrual Loans	1
Current	361	437
Total Loans and Leases	362	437
Consumer Installment loan
Past Due Loans and Leases
30-59 Days Past Due	10	58
60-89 Days Past Due	7	35
Nonaccrual	32	473
Total Past Due and Nonaccrual Loans	49	566
Current	151,544	141,790
Total Loans and Leases	151,593	142,356
Lease financing
Past Due Loans and Leases
30-59 Days Past Due	2,533	2,633
60-89 Days Past Due	126	2
Nonaccrual	50	120
Total Past Due and Nonaccrual Loans	2,709	2,755
Current	757,998	734,965
Total Loans and Leases	$ 760,707	$ 737,720