Risk Management and Use of Derivative Financial Instruments (Details 1) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value
Derivative assets, fair value, net	$ 52,855	$ 32,094
Derivative liability, fair value, net	(19,105)	(17,458)
Foreign currency forward | Designated as hedging | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	40,650	24,051
Foreign currency forward | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	9,525	5,120
Foreign currency forward | Not designated | Accounts payable, accrued expenses and other liabilities
Derivatives, Fair Value
Derivative liability, fair value, net	(7,325)	(2,904)
Interest rate swap | Designated as hedging | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	141	71
Interest rate swap | Designated as hedging | Accounts payable, accrued expenses and other liabilities
Derivatives, Fair Value
Derivative liability, fair value, net	(11,780)	(14,554)
Embedded derivatives | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	85	499
Stock warrants | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	1,914	1,848
Swaption | Not designated | Other assets
Derivatives, Fair Value
Derivative assets, fair value, net	$ 540	$ 505