Stock Incentive Plan - Summary of Assumptions Used in the Monte Carlo Simulation Model (Detail)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Volatility 55.00% 60.00%
Market-based Restricted Stock Units [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 0.62%  
Volatility 54.00%