v2.4.0.8
Share-Based Compensation - Additional Information (Detail) (USD $)
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Percentage of restricted shares that will be awarded if target achieved 25.00%  
Percentage of restricted shares that will be awarded if maximum target achieved 33.00%  
Fair market value of shares on grant date $ 4,500,000  
Service period 4 years  
Stockholder return, performance period 3 years  
Share-based compensation expense 5,389,000 4,993,000
Restricted Stock [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Restricted stock granted to executive officers 183,672  
Share-based compensation expense $ 1,100,000