Basic and Diluted Net Loss per Share - Antidilutive Securities (Details) - shares
|
12 Months Ended |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
| Preferred shares - weighted average |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
86,731,855
|
167,855,481
|
141,543,341
|
| Share options - weighted average |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
39,846,432
|
26,923,735
|
17,280,175
|
| Restricted share - weighted average |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
479,275
|
5,154,272
|
11,358,874
|
| Restricted share units - weighted average |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
32,870
|
0
|
0
|
| VPP shares – weighted average |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Antidilutive securities excluded from computation of earnings per share (in shares) |
39,311
|
0
|
0
|