Share-Based Compensation - 2018 Plan and 2018 Employee Stock Purchase Plan (Details) shares in Thousands |
3 Months Ended |
|---|---|
|
Apr. 30, 2019
shares
| |
| 2018 Plan | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Balance at January 31, 2019 | 8,458,343 |
| Authorized | 5,248,572 |
| Granted | (2,125,418) |
| Forfeited | 135,065 |
| Balance at April 30, 2019 | 11,716,562 |
| 2018 ESPP | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Balance at January 31, 2019 | 1,719,782 |
| Authorized | 1,049,714 |
| Granted | (172,521) |
| Forfeited | 0 |
| Balance at April 30, 2019 | 2,596,975 |