Annual report pursuant to Section 13 and 15(d)

Share-based Compensation - Schedule of Share-Based Compensation Expense Based on Fair Value of Options (Detail)

v3.3.1.900
Share-based Compensation - Schedule of Share-Based Compensation Expense Based on Fair Value of Options (Detail) - Stock Options [Member] - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk free interest rate   0.25%
Expected lives at date of grant (in years) 4 years 5 months 5 days 2 years 4 months 21 days
Weighted average fair value of options granted $ 2.90 $ 2.83
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 50.00% 48.00%
Risk free interest rate 0.25%  
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 54.00% 54.00%
Risk free interest rate 0.66%