Risk Management and Use of Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amount of Gain (Loss) Reclassified from Other Comprehensive (Loss) Income into Income (Effective Portion)
Derivatives, gain (loss) reclassified from AOCI to Income, effective portion, net	$ 246	$ (6,074)	$ (6,333)
Foreign currency forward contracts | Other income and (expense)
Amount of Gain (Loss) Reclassified from Other Comprehensive (Loss) Income into Income (Effective Portion)
Derivatives, gain (loss) reclassified from AOCI to Income, effective portion, net	8,083	1,145	909
Interest rate swap | Interest expense
Amount of Gain (Loss) Reclassified from Other Comprehensive (Loss) Income into Income (Effective Portion)
Derivatives, gain (loss) reclassified from AOCI to Income, effective portion, net	(7,837)	(7,057)	(7,268)
Interest rate cap | Interest expense
Amount of Gain (Loss) Reclassified from Other Comprehensive (Loss) Income into Income (Effective Portion)
Derivatives, gain (loss) reclassified from AOCI to Income, effective portion, net	0	(913)	(1,189)
Foreign currency collars | Other income and (expense)
Amount of Gain (Loss) Reclassified from Other Comprehensive (Loss) Income into Income (Effective Portion)
Derivatives, gain (loss) reclassified from AOCI to Income, effective portion, net	$ 0	$ 751	$ 1,215