Derivative Instruments - Cash flow hedges (Details) - Cash Flow Hedging - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Effects of derivative instruments
Amount of (Loss) Gain Recognized in OCI on Derivatives (Effective Portion)	$ (769)	$ (454)	$ 5,727	$ (3,772)
Interest rate contracts
Effects of derivative instruments
Amount of (Loss) Gain Recognized in OCI on Derivatives (Effective Portion)	$ (769)	$ (454)	$ 5,727	$ (3,772)