Risk Management and Use of Derivative Financial Instruments - Information Regarding Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value
Derivative asset fair value	$ 4,081	$ 3,231
Derivative liability, fair value	(1,576)	(4,330)
Designated as Hedging Instrument | Accounts receivable and other assets, net | Foreign currency forward contracts
Derivatives, Fair Value
Derivative asset fair value	2,004	2,419
Designated as Hedging Instrument | Accounts receivable and other assets, net | Interest rate swaps
Derivatives, Fair Value
Derivative asset fair value	1,907	553
Designated as Hedging Instrument | Accounts receivable and other assets, net | Foreign currency collars
Derivatives, Fair Value
Derivative asset fair value	169	258
Designated as Hedging Instrument | Accounts receivable and other assets, net | Interest rate caps
Derivatives, Fair Value
Derivative asset fair value	1	1
Designated as Hedging Instrument | Accounts payable, accrued expenses and other liabilities | Interest rate swaps
Derivatives, Fair Value
Derivative liability, fair value	(18)	(698)
Designated as Hedging Instrument | Accounts payable, accrued expenses and other liabilities | Foreign currency collars
Derivatives, Fair Value
Derivative liability, fair value	(1,558)	(3,266)
Derivatives Not Designated as Hedging Instruments | Accounts payable, accrued expenses and other liabilities | Foreign currency collars
Derivatives, Fair Value
Derivative liability, fair value	$ 0	$ (366)