Risk Management and Use of Derivative Financial Instruments (Details 4) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	$ (141)	$ 60
Swaption | Not designated | Other income and (expense)
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	(161)	(92)
Embedded credit derivatives | Not designated | Other income and (expense)
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	0	237
Stock warrants | Not designated | Other income and (expense)
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	0	(165)
Foreign currency forward contracts | Not designated | Other income and (expense)
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	0	(4)
Interest rate swaps | Designated as hedging | Interest expense
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	24	84
Foreign currency collars | Designated as hedging | Interest expense
Amount of Gain (Loss) on Derivatives Recognized in Income
Amount of gain (loss) recognized income on derivatives	$ (4)	$ 0