Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation and Employee Benefit Plans - Additional Information (Detail)

v2.4.0.8
Stock-Based Compensation and Employee Benefit Plans - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 9 Months Ended 9 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Dec. 31, 2013
Sep. 30, 2014
Class A Common Stock [Member]
vote
Dec. 31, 2013
Class A Common Stock [Member]
Sep. 30, 2014
Class B Common Stock [Member]
vote
Dec. 31, 2013
Class B Common Stock [Member]
Jan. 02, 2014
Equity Incentive Plan [Member]
Sep. 30, 2014
Employee Stock Purchase Plan [Member]
Jan. 02, 2014
Employee Stock Purchase Plan [Member]
Sep. 30, 2014
RSU and RSA [Member]
Sep. 30, 2013
RSU and RSA [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 700,000 1,100,000                    
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Unit, Grant Date Fair Value $ 6.4 $ 7.1                    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value                     $ 9.04 $ 6.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures 400,000 600,000                    
Share-based Compensation Arrangement by Share-based Payments Awards, Options, Grant Date Fair Value $ 1.7 $ 2.0                    
Percentage of fair value market of common stock 100.00%                      
Vesting period for new restricted stock units 4 years                      
Term of option granted, minimum 7 years                      
Term of option granted, maximum 10 years                      
Shares authorized for issuance               1,400,000   400,000    
Shares Issued upon Settlement of Executive Bonus Plan 600,000   800,000                  
Contribution of earnings by employees                 15.00%      
Percentage of purchase of common stock                 85.00%      
Percentage of common stock on the date of purchase                 85.00%      
Common stock, shares authorized (shares) 550,000,000   550,000,000 500,000,000 500,000,000 500,000,000 500,000,000          
Voting rights per share       1   10            
Number of convertible common stock       1