v2.4.0.8
Stock-Based Compensation (Details 2) (USD $)
 9 Months Ended 12 Months Ended
Sep. 30, 2014
Dec. 31, 2013
Stock options
    
Number of Options    
Outstanding balance at the beginning of the period (in shares) 5,883,885  
Granted (in shares) 1,314,970  
Exercised (in shares) (552,137)  
Forfeited (in shares) (364,061)  
Outstanding balance at the end of the period (in shares) 6,282,657 5,883,885
Exercisable at the end of the period (in shares) 3,212,353  
Vested and expected to vest at the end of the period (in shares) 6,030,608  
Weighted Average Exercise Price per Share    
Outstanding balance at the beginning of the period (in dollars per share) $ 3.53  
Granted (in dollars per share) $ 11.22  
Exercised (in dollars per share) $ 2.21  
Forfeited (in dollars per share) $ 3.53  
Outstanding balance at the end of the period (in dollars per share) $ 5.23 $ 3.53
Exercisable at the end of the period (in dollars per share) $ 2.65  
Vested and expected to vest at the end of the period (in dollars per share) $ 5.12  
Weighted Average Remaining Contractual Term    
Outstanding balance at the beginning of the period 7 years 5 months 23 days 7 years 5 months 12 days
Granted 9 years 22 days  
Exercised 5 years 5 months 12 days  
Outstanding balance at the end of the period 7 years 5 months 23 days 7 years 5 months 12 days
Exercisable at the end of the period 6 years 3 months 11 days  
Vested and expected to vest at the end of the period 7 years 5 months 5 days  
Aggregate Intrinsic Value    
Outstanding balance at the end of the period $ 64,938,000 $ 36,884,000
Exercisable at the end of the period 41,563,000  
Vested and expected to vest at the end of the period 63,172,000  
Additional disclosures    
Compensation cost related to the nonvested awards not yet recognized 10,800,000  
Weighted average period for recognition of compensation cost 2 years 7 months 6 days  
Aggregate intrinsic value of employee options exercised $ 7,400,000  
2014 Equity Incentive Plan
    
Stock-Based Compensation    
Common stock reserved for issuance (in shares) 2,800,000  
Period of annual automatic increase in the number of shares authorized 10 years  
2014 Equity Incentive Plan | Maximum
    
Stock-Based Compensation    
Number of shares that may be added to the 2014 Plan 5,943,348  
Percentage applied on total number of shares of common stock outstanding on previous calendar year for automatic inclusion in the plan 5.00%