Risk Management and Use of Derivative Financial Instruments - Derivative Gain Loss Reclassified From OCI (Details) - Designated as Cash Flow Hedging Instruments - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)	$ 1,116	$ 3,080	$ 9,027	$ 8,393
Foreign currency collars | Other gains and (losses)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)	1,664	1,241	4,565	3,614
Interest rate swaps and caps | Interest expense
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)	(548)	(432)	(1,254)	(2,046)
Foreign currency forward contracts | Other gains and (losses)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)
Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income (Loss)	$ 0	$ 2,271	$ 5,716	$ 6,825