v3.10.0.1
Stockholders' Equity - Summary of Stock Option Award Activity (Details) - Stock Options - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Weighted-Average Exercise Price    
Weighted-Average Exercise Price, Beginning balance $ 4.10  
Weighted-Average Exercise Price, Granted 13.55  
Weighted-Average Exercise Price, Exercised 2.49  
Weighted-Average Exercise Price, Forfeited 14.57  
Weighted-Average Exercise Price, Ending balance 7.83 $ 4.10
Weighted-Average Exercise Price, Exercisable 6.76  
Weighted-Average Exercise Price, Vested and expected to vest $ 7.52  
Weighted-Average Remaining Contractual Term    
Weighted-Average Remaining Contractual Term (in years) 6 years 4 months 28 days 4 years 11 months 26 days
Weighted-Average Remaining Contractual Term (in years), Exercisable 5 years 1 month 13 days  
Weighted-Average Remaining Contractual Term (in years), Vested and expected to vest 6 years 3 months 10 days  
Aggregate Intrinsic Value    
Aggregate Intrinsic Value, Outstanding $ 343,110  
Aggregate Intrinsic Value, Outstanding 34,567 $ 343,110
Aggregate Intrinsic Value, Exercisable 27,356  
Aggregate Intrinsic Value, Vested and expected to vest $ 34,560  
Class A Common Stock    
Number of Shares    
Number of Shares, Beginning balance 20,807  
Number of Shares, Granted 4,987  
Number of Shares, Exercised (10,688)  
Number of Shares, Forfeited (1,784)  
Number of Shares, Ending balance 13,322 20,807
Number of Shares, Exercisable 7,853  
Number of Shares, Vested and expected to vest 12,605  
Class B Common Stock    
Number of Shares    
Number of Shares, Beginning balance 11,790  
Number of Shares, Exercised (8,582)  
Number of Shares, Forfeited (239)  
Number of Shares, Ending balance 2,969 11,790
Number of Shares, Exercisable 2,969  
Number of Shares, Vested and expected to vest 2,969