Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Schedule of Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)

v3.7.0.1
Summary of Significant Accounting Policies - Schedule of Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]    
Risk free interest rate 1.13% 1.47%
Risk free interest rate 2.08% 1.89%
Dividend yield 0.00% 0.00%
Expected volatility 74.90% 72.65%
Expected volatility 76.00% 75.07%
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]    
Expected term 5 years 5 years
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]    
Expected term 5 years 8 months 12 days 6 years 1 month 6 days