v3.20.2
Warrants - Additional Information (Detail)
$ / shares in Units, $ in Billions
 3 Months Ended 9 Months Ended
Sep. 30, 2020
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Common Class B [Member] | Series I Lead [Member]    
Class of Warrant or Right [Line Items]    
Warrants outstanding 5,211,093 5,211,093
Exercise price of each warrant | $ / shares $ 6.13 $ 6.13
Common Class B [Member] | Venture 13 Warrants [Member]    
Class of Warrant or Right [Line Items]    
Warrants outstanding 814,666 814,666
Exercise price of each warrant | $ / shares $ 3.51 $ 3.51
Common Class B [Member] | Series I Lead Or Venture Thirteen Warrants [Member] | Maximum [Member]    
Class of Warrant or Right [Line Items]    
Class of warrant or right, expiration month and year   2025-01
Common Class B [Member] | Series I Lead Or Venture Thirteen Warrants [Member] | Minimum [Member]    
Class of Warrant or Right [Line Items]    
Class of warrant or right, expiration month and year   2021-12
Common Class B [Member] | Series I IPO [Member]    
Class of Warrant or Right [Line Items]    
Warrants outstanding 13,042,415 13,042,415
Class of warrant or right, expiration month and year   2023-11
Warrants and rights outstanding exercise contingency | $ $ 12.9 $ 12.9
Common Stock [Member]    
Class of Warrant or Right [Line Items]    
Issuance of common stock upon net exercise of common stock warrants shares 7,631,329 7,631,329
Warrants issued to purchase shares 7,632,154 7,632,154
Exercise price of each warrant | $ / shares $ 0.001 $ 0.001
SeriesDConvertibleStock [Member]    
Class of Warrant or Right [Line Items]    
Warrants issued to purchase shares 2,586,208 2,586,208
Exercise price of each warrant | $ / shares $ 0.7406 $ 0.7406
Stock shares issued during the period share 2,380,034