Annual report pursuant to Section 13 and 15(d)

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

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Stock-Based Compensation and Employee Benefit Plans - Additional Information (Detail) (USD $)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
May 03, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Intrinsic value of restricted stock units, vested $ 14,900,000 $ 3,200,000 $ 700,000  
Intrinsic value of options exercised 300,000 2,100,000 6,700,000  
Restricted stock units issued in the period 2,755,000 1,000,000    
Shares issed upon settlement of executive bonus plan       800,000
Common stock, shares authorized (shares) 550,000,000 550,000,000    
Stock repurchased and retired during the period, shares 0      
Share based compensation expense exchange offer   7,300,000    
Incremental value attributable to modification of options   1,800,000    
Stock repurchased and retired during the period, value   (12,076,000)    
Share-based compensation expense related to non-employee 200,000 800,000 200,000  
Intrinsic value of restricted stock units, outstanding 46,700,000      
Accrual of bonus awards recorded for employees 5,100,000      
Class A Common Stock
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Common stock, shares authorized (shares) 500,000,000 500,000,000    
Voting rights per share 1      
Stock repurchased and retired during the period, shares   1,200,000    
Eligible options to purchase shares   1,300,000    
Class B Common Stock
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Common stock, shares authorized (shares) 500,000,000 500,000,000    
Voting rights per share 10      
Right to appoint directors number of directors 2      
Stock repurchased and retired during the period, shares   1,000,000    
Eligible options to purchase shares   600,000    
2010 Equity Incentive Plan [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period for new restricted stock units 4 years 0 months 0 days      
Term of option granted, minimum 7 years 0 months 0 days      
Term of option granted, maximum 10 years 0 months 0 days      
2010 Equity Incentive Plan [Member] | Class A Common Stock
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Increase in common stock reserved for issuance 2,600,000      
Percentage of outstanding shares of common stock 4.00%      
2010 Employee Stock Purchase Plan [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Contribution of earnings by employees 15.00%      
Percentage of purchase of common stock 85.00%      
Increase in common stock reserved for issuance 1,000,000      
Percentage of outstanding shares of common stock 1.25%      
Maximum duration of employee stock purchase plan 27 months      
Percentage of common stock at the date of purchase 85.00%      
Unvested Stock Options [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total unrecognized compensation cost 3,800,000      
Weighted average period over equity awards expected to vest 2 years 7 months 13 days      
RSU and RSA
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total unrecognized compensation cost $ 21,400,000      
Weighted average period over equity awards expected to vest 2 years 5 months 26 days