Quarterly report pursuant to Section 13 or 15(d)

Derivative Contracts - Balance Sheet Component (Details)

v3.8.0.1
Derivative Contracts - Balance Sheet Component (Details) - Not Designated as Hedging Instrument - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Common Stock options/warrants | Investments, net    
Derivatives, Fair Value [Line Items]    
Derivative asset, fair value $ 2,020 $ 4,017
Embedded conversion option | 2033 Senior Notes, net of discount and estimated fair value of embedded derivatives    
Derivatives, Fair Value [Line Items]    
Derivative liability, fair value 0 (16,736)
Forward contracts | Unrealized gains on forward contracts are recorded in Other current assets and prepaid expenses. Unrealized (losses) on forward contracts are recorded in Accrued expenses.    
Derivatives, Fair Value [Line Items]    
Derivative liability, fair value $ 264 $ (39)