v3.20.4
Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Payment Arrangement [Abstract]    
Beginning Balance of Options Outstanding 497,441,159  
Options granted 397,885,337  
Options exercised (120,617,527)  
Options canceled and forfeited (238,942,466)  
Ending Balance of Options Outstanding 535,766,503 497,441,159
Options vested and exercisable as of December 31, 2020 304,428,660  
Beginning Balance of Weighted-Average Exercise Price Per Share $ 4.10  
Options granted 7.43  
Options exercised 2.48  
Options canceled and forfeited 5.95  
Ending Balance of Weighted-Average Exercise Price Per Share 6.12 $ 4.10
Options vested and exercisable as of December 31, 2020 $ 3.67  
Weighted- Average Remaining Contractual Life (years) 7 years 11 months 26 days 5 years 9 months 21 days
Options vested and exercisable as of December 31, 2020 5 years 10 months 2 days  
Beginning Balance of Aggregate Intrinsic Value   $ 975,798
Ending Balance of Aggregate Intrinsic Value $ 9,340,245  
Options vested and exercisable as of December 31, 2020 $ 6,051,074