Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Fair value of options (Detail)

v3.7.0.1
Stockholders' Equity - Fair value of options (Detail)
6 Months Ended
Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Risk-free interest rate, Minimum 1.14%
Risk-free interest rate, Maximum 2.25%
Expected dividend yield 0.00%
Expected volatility, Minimum 95.25%
Expected volatility, Maximum 105.95%
Minimum [Member]  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Expected term in years 5 years
Maximum [Member]  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Expected term in years 6 years 11 months 23 days