Derivatives - Effect on Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, (Gain) Loss [Line Items]
Interest expense presented in the Statements of Operations in which the effects of cash flow hedges are recorded	$ 21,941	$ 25,084	$ 58,347	$ 59,877
Interest rate swaps | Cash flow hedges
Derivative Instruments, (Gain) Loss [Line Items]
Amount of loss recognized in other comprehensive income on derivative	492	7,159	31,446	16,760
Amount of loss (gain) reclassified from AOCI into income	3,616	7	7,682	(213)
Interest expense presented in the Statements of Operations in which the effects of cash flow hedges are recorded	$ 21,941	$ 25,084	$ 58,347	$ 59,877