Risk Management and Use of Derivative Financial Instruments (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	$ 21,153	$ 29,389	$ 831
Foreign currency forward contracts | Cash Flow Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	18,126	29,313	(6,168)
Foreign currency forward contracts | Net Investment Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	417	484	0
Foreign currency forward contracts | Derivatives Formerly in Net Investment Hedging Relationships
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	0	4,511	(2,237)
Interest rate swap | Cash Flow Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	2,715	(5,542)	10,107
Foreign currency collars | Cash Flow Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	(107)	(290)	(2,059)
Foreign currency collars | Net Investment Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	2	0	0
Interest rate cap | Cash Flow Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net	$ 0	913	1,188
Noncontrolling interest | Interest rate cap | Cash Flow Hedging
Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive (Loss) Income (Effective Portion)
Derivatives, gain (loss) recognized in OCI, effective portion, net		$ 400	$ 500