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)
6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Risk-free interest rates 1.81% 1.16%
Expected dividend yield 0.00% 0.00%
Expected life 5 years 10 months 24 days 5 years 9 months 18 days
Expected volatility 81.61% 87.17%