Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Fair Value of Option Awards (Detail)

v2.4.0.8
Common Stock - Summary of Fair Value of Option Awards (Detail)
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Risk-free interest rates 1.15% 0.96%
Expected dividend yield 0.00% 0.00%
Expected life 5 years 9 months 18 days 6 years
Expected volatility 87.02% 95.47%