Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Deficit) - Schedule of Fair Value Assumptions (Detail)

v3.8.0.1
Stockholders' Equity (Deficit) - Schedule of Fair Value Assumptions (Detail)
9 Months Ended
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected volatility 65.00%
Risk-free interest rate, minimum 1.89%
Risk-free interest rate, maximum 2.20%
Expected dividend yield 0.00%
Minimum [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected terms (in years) 5 years 9 months 29 days
Maximum [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected terms (in years) 6 years 29 days