Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Fair Value of Employee Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Weighted Average Assumptions (Details)

v3.10.0.1
Stock-Based Compensation - Fair Value of Employee Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Weighted Average Assumptions (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term (years)   6 years 1 month 6 days   6 years 1 month 6 days
Expected volatility 82.80% 82.50%   82.50%
Expected volatility, Minimum     82.00%  
Expected volatility, Maximum     82.80%  
Risk-free interest rate 2.80% 2.10%   2.10%
Risk-free interest rate, Minimum     2.60%  
Risk-free interest rate, Maximum     2.80%  
Minimum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term (years) 5 years 6 months   5 years 6 months  
Maximum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term (years) 6 years 1 month 6 days   6 years 1 month 6 days