Annual report pursuant to Section 13 and 15(d)

Compensation (Stock Option Valuation Assumptions) (Detail)

v3.3.1.900
Compensation (Stock Option Valuation Assumptions) (Detail) - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Valuation of the options granted      
Weighted average exercise price - ($/share) $ 4.41 $ 7.05 $ 7.55
Expected life in years 2 years 6 months 2 years 6 months 2 years 6 months
Average expected volatility 61.00% 58.00% 51.00%
Risk-free interest rate 0.88% 0.52% 0.31%
Weighted average grant date fair value - ($/share) $ 1.65 $ 2.43 $ 2.45