Derivatives and Hedging Activities - Gain/Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivatives and Hedging Activities
Other comprehensive gain - change in fair value of interest rate swaps	$ 67	$ 35	$ 80
Interest rate swaps
Derivatives and Hedging Activities
Other comprehensive gain - change in fair value of interest rate swaps	67	35
Interest rate swaps | Interest expense
Derivatives and Hedging Activities
Amount of (Gain)/Loss Reclassified from AOCI into income	$ 28	$ 30