Risk Management and Use of Derivative Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value
Derivative assets, fair value, net	$ 8,683	$ 11,148
Derivative liability, fair value, net	(27,704)	(27,003)
Foreign currency forward | Designated as hedging | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	1,801	2,002
Foreign currency forward | Designated as hedging | Accounts payable, accrued expenses and other liabilities
Derivatives, Fair Value
Derivative liability, fair value, net	(11,818)	(11,928)
Foreign currency forward | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	1,402	1,521
Foreign currency collars | Designated as hedging | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	145	429
Interest rate swap | Designated as hedging | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	549	1,895
Interest rate swap | Designated as hedging | Accounts payable, accrued expenses and other liabilities
Derivatives, Fair Value
Derivative liability, fair value, net	(15,287)	(12,911)
Embedded derivatives | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	2,295	2,314
Embedded derivatives | Not designated | Accounts payable, accrued expenses and other liabilities
Derivatives, Fair Value
Derivative liability, fair value, net	(599)	(2,164)
Stock warrants | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	1,716	1,782
Swaption | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	$ 775	$ 1,205