Derivatives and Hedging Activity - Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	$ 71,040	$ 89,361
Fair Value of Derivatives in a Liability Position	1,567	3,904
Derivatives designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	62	30
Fair Value of Derivatives in a Liability Position	14	56
Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	70,978	89,331
Fair Value of Derivatives in a Liability Position	1,553	3,848
Interest rate swaps | Derivatives designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	62	30
Fair Value of Derivatives in a Liability Position	14	56
Interest rate swaps | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	27,487	26,591
Fair Value of Derivatives in a Liability Position	338	3,484
Foreign exchange contracts | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	42,461	62,295
Fair Value of Derivatives in a Liability Position	1,215	364
Credit index instruments | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	$ 1,030	$ 445