Derivatives Schedule of Pre-tax Effect of Hedging Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Interest expense	$ 1,627	$ 1,465
Reclassifications Out of Accumulated Other Comprehensive (Loss) Income | Gains on derivative instruments: | Interest Rate Contract
Derivative [Line Items]
Interest expense	(40)	0
Designated as Hedging Instrument | Reclassifications Out of Accumulated Other Comprehensive (Loss) Income | Gains on derivative instruments: | Interest Rate Contract
Derivative [Line Items]
Interest expense	40	0
Cash Flow Hedging | Interest rate swaps
Derivative [Line Items]
Amount of Gain Recognized in OCI on Derivative (Effective Portion)	$ 309	$ 13