Convertible Preferred Stock - Summary of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands |
Dec. 31, 2019 |
Jan. 31, 2019 |
Dec. 31, 2018 |
Jun. 30, 2018 |
Dec. 31, 2017 |
Aug. 31, 2017 |
---|---|---|---|---|---|---|
Temporary Equity [Line Items] | ||||||
Shares Authorized | 0 | 421,450,000 | ||||
Shares Issued and Outstanding | 69,910,520 | |||||
Carrying Value | $ 309,137 | $ 292,525 | ||||
Liquidation Preference | $ 0 | $ 333,058 | ||||
Series A-1 Convertible Preferred Stock | ||||||
Temporary Equity [Line Items] | ||||||
Shares Authorized | 310,350,000 | |||||
Shares Issued and Outstanding | 67,611,100 | |||||
Issuance Price per Share | $ 4.50 | $ 4.50 | $ 4.50 | |||
Carrying Value | $ 303,224 | |||||
Liquidation Preference | $ 322,100 | |||||
Series A-2 Convertible Preferred Stock | ||||||
Temporary Equity [Line Items] | ||||||
Shares Authorized | 11,100,000 | |||||
Shares Issued and Outstanding | 2,299,420 | |||||
Issuance Price per Share | $ 2.57 | |||||
Carrying Value | $ 5,913 | |||||
Liquidation Preference | $ 10,958 | |||||
Series B | ||||||
Temporary Equity [Line Items] | ||||||
Shares Authorized | 100,000,000 | |||||
Issuance Price per Share | $ 18.00 | $ 18.00 |