Annual report pursuant to Section 13 and 15(d)

Debt - Notes (Details)

v3.10.0.1
Debt - Notes (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Debt Instrument [Roll Forward]      
Amortization of debt discount, debt issuance cost $ 187 $ 224 $ 237
Change in fair value of equity securities and derivative instruments (3,043) (52) (2,778)
Senior Notes      
Debt Instrument [Roll Forward]      
Embedded conversion option, beginning balance 0 16,736  
Convertible notes, beginning balance 31,850 31,850  
Discount, beginning balance (2,565) (4,612)  
Debt issuance costs, net beginning balance (125) (273)  
Total, beginning balance 29,160 43,701  
Amortization of debt discount, discount 2,277 2,047  
Amortization of debt discount, debt issuance cost 125 148  
Amortization of debt discount and debt issuance costs 2,402 2,195  
Change in fair value of equity securities and derivative instruments   (3,185)  
Reclassification of embedded derivatives to equity   (13,551)  
Embedded conversion option, ending balance   0 16,736
Convertible notes, ending balance 31,850 31,850 31,850
Discount, ending balance (288) (2,565) (4,612)
Debt issuance costs, net ending balance 0 (125) (273)
Total, ending balance $ 31,562 $ 29,160 $ 43,701