Derivative Instruments - Realized and Unrealized Gain (Loss) on Derivatives Not Designated as Hedging Instruments (Details) - Derivatives not designated as hedging instruments: - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative [Line Items]
Unrealized Gain (Loss)	$ 12,267	$ (9,999)
Realized Loss	(120)	(751)
Total Gain (Loss)	12,147	(10,750)
Contingent redemption features - Series A Preferred Stock
Derivative [Line Items]
Unrealized Gain (Loss)	12,223	0
Total Gain (Loss)	12,223	0
Cross currency and interest rate swaps
Derivative [Line Items]
Unrealized Gain (Loss)	18	(9,998)
Realized Loss	(120)	(703)
Total Gain (Loss)	(102)	(10,701)
Interest rate swaps
Derivative [Line Items]
Unrealized Gain (Loss)	26	(1)
Realized Loss	0	(48)
Total Gain (Loss)	$ 26	$ (49)