Annual report pursuant to Section 13 and 15(d)

Stock Options - Summary of Weighted Average Assumptions Used Principally in Determining Fair Value of Options Granted (Detail)

v3.3.1.900
Stock Options - Summary of Weighted Average Assumptions Used Principally in Determining Fair Value of Options Granted (Detail) - Stock Options [Member]
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk free interest rate 1.85% 1.88%
Expected dividend yield 0.00% 0.00%
Expected term in years 6 years 8 months 23 days 6 years 2 months 12 days
Expected volatility 90.68% 89.75%
Estimated forfeiture rate 4.83% 19.20%