XML 54 R41.htm IDEA: XBRL DOCUMENT v3.10.0.1
Equity-based Compensation - Summary of Stock Option Activity for Employees and Non-employees (Detail) - Employees and Non-employees [Member] - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock Options, Outstanding, Beginning Balance 6,262,339  
Stock Options, Granted 2,029,497  
Stock Options, Exercised (870,213)  
Stock Options, Cancelled or forfeited (723,044)  
Stock Options, Outstanding, Ending Balance 6,698,579 6,262,339
Stock Options, Exercisable 2,104,857  
Stock Options, Vested or expected to vest 6,698,579  
Weighted-Average Exercise Price, Outstanding, Beginning Balance $ 13.24  
Weighted-Average Exercise Price, Granted 52.86  
Weighted-Average Exercise Price, Exercised 11.07  
Weighted-Average Exercise Price, Cancelled or forfeited 19.10  
Weighted-Average Exercise Price, Outstanding, Ending Balance 24.89 $ 13.24
Weighted-Average Exercise Price, Exercisable 14.28  
Weighted-Average Exercise Price, Vested or expected to vest $ 24.89  
Weighted-Average Remaining Contractual Term 8 years 7 months 6 days 8 years 9 months 18 days
Weighted-Average Remaining Contractual Term, Exercisable 8 years  
Weighted-Average Remaining Contractual Term, Vested or expected to vest 8 years 7 months 6 days  
Aggregate Intrinsic Value, Outstanding Balance $ 147,659 $ 64,120
Aggregate Intrinsic Value, Exercisable 64,661  
Aggregate Intrinsic Value, Vested or expected to vest $ 147,659