Derivative Contracts - Derivative Gains (Losses) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gain (loss)	$ 1,235	$ (16,556)	$ (188)	$ (66,344)
Common Stock options/warrants
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gain (loss)	(3,730)	(2,446)	(4,716)	1,425
Notes
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gain (loss)	4,872	(14,220)	4,734	(67,950)
Forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gain (loss)	$ 93	$ 110	$ (206)	$ 181