Derivatives and Hedging Activities Derivatives not designated as hedges, effect on statement of operations (Details) - Derivatives not designated as hedging instruments: - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), Net, Recognized in Income on Derivatives for Years Ended December 31,	$ 40	$ (497)	$ 600
Derivatives - interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), Net, Recognized in Income on Derivatives for Years Ended December 31,	(118)	(851)	596
Risk participation agreements
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), Net, Recognized in Income on Derivatives for Years Ended December 31,	$ 158	$ 354	$ 4