Equity Incentive Plans and Employee Stock Purchase Plan - Restricted Stock Units, Additional Information (Details) - Restricted Stock Units (RSUs) |
3 Months Ended |
|---|---|
Apr. 30, 2019 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Award vesting period | 4 years |
| One Year Anniversary | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Award vesting period | 4 years |
| Vesting rights percentage | 25.00% |
| 13 to 36 Months | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Vesting rights percentage | 75.00% |