Annual report pursuant to Section 13 and 15(d)

Stock Option Plan - Additional Information (Detail)

v2.4.0.6
Stock Option Plan - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended 3 Months Ended 12 Months Ended
Nov. 29, 2012
Aug. 30, 2012
May 31, 2012
Mar. 31, 2012
Mar. 07, 2012
Dec. 31, 2012
EquityPlan
Dec. 31, 2012
Employee
OptionPlan
EquityPlan
Dec. 31, 2011
Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Number of stock option plans             1    
Awards issued to number of employees             2    
Number of outstanding accelerated vesting stock awards           2 2    
Accelerated additional compensation cost           $ 0.1      
Class A and Class B common stock, dividend declared per share $ 0.035 $ 0.035 $ 0.035 $ 0.035 $ 0.035        
Closing stock price           $ 5.46 $ 5.46    
Total fair value of options vested             1.2 1.0 1.1
Total unrecognized compensation cost related to non-vested awards of stock options and restricted shares           $ 1.2 $ 1.2    
Total unrecognized compensation cost related to non-vested awards of stock options and restricted shares, weighted average recognition period             2 years 1 month 6 days    
Minimum
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Stock option, historical volatility term             6 years    
Maximum
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Stock option, historical volatility term             10 years    
Stock Option
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Shares authorized under plan           5,000,000 5,000,000    
Additional shares authorized under plan             1,900,000    
Stock Option | Minimum
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share based compensation, vesting period             4 years    
Stock Option | Maximum
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Stock options, term             5 years    
Restricted stock
                 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                  
Share based compensation, vesting period             1 year