|
Share-Based Compensation - Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)
|
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
|
| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
| Dividend yield | 0.00% | 0.00% |
| Expected volatility | 80.00% | 79.70% |
| Weighted-average risk-free interest rate | 2.20% | 1.20% |
| Expected term | 6 years 2 months 12 days | 6 years 3 months 18 days |