Annual report pursuant to Section 13 and 15(d)

Derivative Contracts - Losses and Gains on Derivative Instruments (Details)

v3.10.0.1
Derivative Contracts - Losses and Gains on Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (loss) on derivative instruments $ 3,043 $ 52 $ 2,778
Common stock options/warrants      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (loss) on derivative instruments 2,643 (2,533) (4,262)
2033 Senior Notes      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (loss) on derivative instruments 0 3,185 7,001
Forward contracts      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (loss) on derivative instruments $ 400 $ (600) $ 39