Loans Schedule of Accounts, Notes, Loans and Financing Receivables (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 5,888,337	$ 5,866,489	$ 5,220,051
Loans and Leases Receivable, Gross, Consumer, Mortgage	451,522	445,211	428,950
Loans and Leases Receivable, Gross, Consumer, Installment, Other	1,322,795	1,328,258	1,259,930
Loans and Leases Receivable, Gross, Consumer, Home Equity	812,458	806,078	739,548
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	140,721	146,387	140,618
Loans and Leases Receivable, Gross, Consumer, Lease Financing	164,137	139,236	74,112
Loans and Leases Receivable, Gross	8,779,970	8,731,659	7,863,209
Allowance for noncovered loan losses	(98,843)	(98,942)	(103,849)
Net non-covered loans	8,681,127	8,632,717	7,759,360
Loans and Leases Receivable, Gross, Carrying Amount, Covered	896,832	1,019,125	1,378,150
Covered Certain Loans Acquired in Transfer not Accounted for as Debt Securities Allowance for Loan Losses	(47,945)	(43,255)	(41,070)
Covered Loans and Leases Receivable Gross Carrying Amount	848,887	975,870	1,337,080
Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered	$ 9,530,014	$ 9,608,587	$ 9,096,440