Guarantees (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Derivative Liabilities	$ 31,772	$ 12,729
Notional amount of underlying interest rate swaps associated with risk participation agreements	1,498,856	$ 1,184,666
Financial Standby Letter Of Credit [Member]
Guarantor Obligations [Line Items]
Standby letters of credit, net liability	2,400
Contractual amount of letters of credit, guaranteed maximum potential future payments	352,100
Risk Participation Agreement [Member] | Indirect Guarantee Of Indebtedness [Member]
Guarantor Obligations [Line Items]
Derivative Liabilities	272
Notional amount of underlying interest rate swaps associated with risk participation agreements	$ 60,200
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