Guarantees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Derivative Liabilities	$ (27,195)	$ (12,729)
Notional amount of underlying interest rate swaps associated with risk participation agreements	1,340,347	$ 1,184,666
Financial Standby Letter Of Credit [Member]
Guarantor Obligations [Line Items]
Standby letters of credit, net liability	2,700
Contractual amount of letters of credit, guaranteed maximum potential future payments	346,600
Risk Participation Agreement [Member] | Indirect Guarantee Of Indebtedness [Member]
Guarantor Obligations [Line Items]
Derivative Liabilities	(267)
Notional amount of underlying interest rate swaps associated with risk participation agreements	$ 58,600
Minimum [Member] | Risk Participation Agreement [Member]
Guarantor Obligations [Line Items]
Term, in years	3 years
Maximum [Member] | Risk Participation Agreement [Member]
Guarantor Obligations [Line Items]
Term, in years	11 years