Derivatives and Hedging Activity - Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	$ 53,676	$ 52,691
Fair Value of Derivatives in a Liability Position	8,891	15,415
Interest rate swaps | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	22,851	30,791
Fair Value of Derivatives in a Liability Position	7,796	14,457
Interest Rate Swap Guarantees | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in a Liability Position	435	396
Foreign exchange contracts | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	30,801	21,346
Fair Value of Derivatives in a Liability Position	511	562
Credit spread instrument | Derivatives not designated as hedging instruments
Fair value of derivative instruments
Fair Value of Derivatives in an Asset Position	24	$ 554
Fair Value of Derivatives in a Liability Position	$ 149