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 9 Months Ended
Sep. 30, 2013
May 03, 2013
Dec. 31, 2012
Sep. 30, 2013
Class A Common Stock [Member]
vote
Dec. 31, 2012
Class A Common Stock [Member]
Sep. 30, 2013
Class B Common Stock [Member]
vote
Dec. 31, 2012
Class B Common Stock [Member]
Sep. 30, 2013
Equity Incentive Plan-Annual Equity Compensation Review Program [Member]
Dec. 31, 2012
Equity Incentive Plan [Member]
Sep. 30, 2013
Employee Stock Purchase Plan [Member]
Jan. 02, 2013
Employee Stock Purchase Plan [Member]
Sep. 30, 2013
RSU and RSA
Sep. 30, 2012
RSU and RSA
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, Weighted Average Grant Date Fair Value                       $ 6.39 $ 5.87
Restricted stock units granted related to the Company's annual compensation review program               1,100,000          
Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Unit, Grant Date Fair Value               $ 7.1          
Stock options granted (shares)               600,000          
Share-based Compensation Arrangement by Share-based Payments Awards, Options, Grant Date Fair Value               $ 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                 1,300,000   400,000    
Shares Issed upon Settlement of Executive Bonus Plan   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