Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Common Share - Narrative (Details)

v3.8.0.1
Net Loss Per Common Share - Narrative (Details) - $ / shares
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2017
Jun. 30, 2017
Jun. 09, 2017
Dec. 09, 2015
1.75% convertible senior notes due 2020 | Convertible debt          
Debt Instrument [Line Items]          
Debt instrument, conversion price (in dollars per share)         $ 16.42
Unrealized gain 1.75% 1.75%     1.75%
Series A convertible preferred stock          
Debt Instrument [Line Items]          
Agreement to sell shares (in shares)     480,000 480,000  
Shares issued, shares 307,500 480,000      
Conversion price (in dollars per share)     $ 10.50 $ 10.50  
Series A convertible preferred stock | Initial closing          
Debt Instrument [Line Items]          
Agreement to sell shares (in shares)       172,500