Fair Value Measurements Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Equity Securities, Value Test Coverage, Percent	75.00%
Fair Value, Equity Securities, Fair Value Price Difference Threshold, Percent	5.00%
Corporate debt securities	$ 2,455,464,000
Significant Input, Assumed Market Return to Liquidity, Years	5 years
Other real estate owned (OREO)	15,300,000	15,052,000
Short Term Borrowings, Reprice Period, In Days	90
Minimum [Member]
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed	11.20%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate	9.10%
Equity Securities Financial Institution [Member]
Available-for-sale Securities, Equity Securities	39,800,000	40,600,000
Other Equity Securities [Member]
Available-for-sale Securities, Equity Securities	5,900,000	5,600,000
Corporate Debt Securities [Member]
Corporate debt securities	100,552,000	98,749,000
Single-issuer Trust Preferred Securities [Member]
Corporate debt securities	41,879,000	40,531,000
Pooled Trust Preferred Securities [Member]
Corporate debt securities	5,659,000	5,306,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities Financial Institution [Member]
Available-for-sale Securities, Equity Securities	39,800,000	40,600,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Equity Securities [Member]
Available-for-sale Securities, Equity Securities	5,900,000	5,600,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Financial Institutions Subordinated Debt [Member]
Corporate debt securities	50,400,000	50,300,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Single-issuer Trust Preferred Securities [Member]
Corporate debt securities	38,100,000	36,700,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Corporate Debt [Member]
Corporate debt securities	2,600,000	2,600,000
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Single-issuer Trust Preferred Securities [Member]
Corporate debt securities	41,900,000	40,500,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Single-issuer Trust Preferred Securities [Member]
Corporate debt securities	3,800,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Pooled Trust Preferred Securities [Member]
Corporate debt securities	5,700,000	5,300,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Other real estate owned (OREO)	15,300,000	15,100,000
Servicing Asset at Amortized Value, Fair Value	41,700,000	42,500,000
Trust for Benefit of Employees [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Other financial assets	15,700,000	15,300,000
Foreign Exchange Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Other financial assets	300,000	500,000
Forward Contracts [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Other financial assets	1,200,000	2,100,000
Other financial liabilities	200,000	100,000
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Other financial assets	6,600,000	5,100,000
Other financial liabilities	6,600,000	5,100,000
Foreign Exchange Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Other financial liabilities	199,000	400,000
Trust for Benefit of Employees [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Other financial liabilities	$ 15,700,000	$ 15,300,000