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Stockholders' Equity - Additional Information (Detail) (USD $)
 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Sep. 23, 2013
Common Stock [Member]
Sep. 23, 2013
Common Stock [Member]
Underwriters [Member]
Dec. 31, 2013
2013 Stock Incentive Plan [Member]
Dec. 31, 2013
2010 Employee Stock Purchase Plan [Member]
Dec. 31, 2013
Stock Option Activity [Member]
Dec. 31, 2013
Stock Option Activity [Member]
2013 Stock Incentive Plan [Member]
Dec. 31, 2013
Restricted Stock Units (RSUs) [Member]
Installment
Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Dec. 31, 2011
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Preferred shares authorized 5,000,000                      
Public offering, common stock shares issued       7,015,000                
Public offering price of common stock issued       $ 10.58                
Net proceeds from issuance under public offering       $ 69,500,000                
Sale of stock, number of shares issued in transaction         915,000              
Percent of fair value per share of common stock on option grant date           100.00% 85.00%          
Stock option maximum term           10 years            
Specified stockholder ownership percentage 10.00%                      
Purchase price of common stock percent under stock incentive plans for specified stockholder 110.00%                      
Stock option maximum term for specified stockholder 5 years                      
Share based vesting rights The RSUs will vest as follows: One-third on second anniversary and two-thirds will vest on the third anniversary of the award date.               Options granted under the 2013 Plan generally vest over four years at a rate of 25 percent one year from the grant date and one thirty-sixth per month thereafter and expire ten years after the grant, or earlier upon employment termination. These awards will vest as follows: one-third of the award will vest in a series of three successive equal annual installments.    
Stock options vesting period 2 years         4 years            
Stock options granted vesting percentage                 25.00%      
Stock options expiration term           10 years            
Stock reserved for issuance under plan           14,100,000 2,100,000          
Annual increase in number of shares authorized           9,700,000            
Additional shares authorized under 2004 plan 4,400,000                      
Share of common stock subject to a stock option or stock appreciation right 1                      
Fixed ratio shares of common stock 1.33 shares                      
Purchase plan offering period             2 years          
Purchase plan purchase period             6 months          
Shares subject to repurchase rights               0        
Intrinsic value of options exercised 8,900,000 600,000 1,000,000                  
Aggregate intrinsic values outstanding options 56,425,000                      
Aggregate intrinsic values exercisable options 41,073,000                      
Options vested and expected to vest, aggregate intrinsic value 54,900,000 8,500,000 100,000                  
Restricted stock units issued                   392,500 486,750 550,000
Grant date fair value of restricted stock units issued                   $ 12.12 $ 5.41 $ 2.55
Share-based compensation arrangement by share-based payment award, number of vesting installment                   3    
Share-based compensation arrangement by share-based payment award, vesting portion                   0.33    
Share-based compensation arrangement by share-based payment award, vesting portion on second anniversary 0.33                      
Share-based compensation arrangement by share-based payment award, vesting portion on third anniversary 0.67                      
Aggregate value of shares vested in period                   4,100,000 100,000 200,000
Shares withheld from issuance in order to pay employee taxes 167,138 0 8,937                  
Total payments for the employees' tax obligations to taxing authorities $ 2,000,000   $ 100,000                  
Shares reserved for issuance of future awards           2,929,590 1,527,763