Risk Management and Use of Derivative Financial Instruments - Derivative Gain Loss Recognized in OCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	$ (2,302)	$ (9,397)	$ 17,280	$ 3,900
Derivatives in Cash Flow Hedging Relationships  | Foreign currency collars
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	(2,539)	(6,311)	13,628	11,505
Derivatives in Cash Flow Hedging Relationships  | Interest rate swaps
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	235	(122)	3,648	(2,359)
Derivatives in Cash Flow Hedging Relationships  | Interest rate caps
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	2	(1)	4	1
Derivatives in Cash Flow Hedging Relationships  | Foreign currency forward contracts
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	0	(2,943)	0	(5,272)
Derivatives in Net Investment Hedging Relationships | Foreign currency collars
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized on derivatives in other comprehensive income (loss)	$ 0	$ (20)	$ 0	$ 25