Employee Benefits and Stock-based Compensation - Weighted-Average Assumptions Used to Estimate Fair Value (Detail) |
12 Months Ended | ||
|---|---|---|---|
Jan. 31, 2022 |
Jan. 31, 2021 |
Jan. 31, 2020 |
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Dividend yield | 0.00% | 0.00% | 0.00% |
| Stock options [Member] | |||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Volatility | 51.00% | 52.00% | 52.00% |
| Risk-free interest rate | 1.04% | 0.52% | 1.82% |
| Expected term (years) | 5 years 21 days | 5 years 9 months 10 days | 6 years 3 days |
| Dividend yield | 0.00% | 0.00% | 0.00% |
| Employee stock purchase plan awards [Member] | |||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Volatility | 57.00% | 59.00% | 47.00% |
| Risk-free interest rate | 0.06% | 0.21% | 2.23% |
| Expected term (years) | 6 months | 6 months | 6 months |
| Dividend yield | 0.00% | 0.00% | 0.00% |