Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation and Employee Benefit Plans - Fair Value of Stock Options (Detail)

v2.4.0.8
Stock-Based Compensation and Employee Benefit Plans - Fair Value of Stock Options (Detail) (Stock Options [Member], USD $)
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Stock Options [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Weighted-average grant date fair value per share (usd per share) $ 3.24 $ 2.37
Risk-free interest rate 0.71% 0.88%
Dividend yield 0.00% 0.00%
Expected life (years) 4 years 9 months 4 years 10 months 3 days
Volatility 56.00% 55.91%