Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares |
Apr. 30, 2019 |
Jan. 31, 2019 |
|---|---|---|
| Statement Of Financial Position [Abstract] | ||
| Preference shares, par value | $ 0.00045 | $ 0.00045 |
| Preference shares, shares authorized | 20,000,000 | 20,000,000 |
| Preference shares, shares issued | 0 | 0 |
| Preference shares, shares outstanding | 0 | 0 |
| Ordinary shares, par value | $ 0.00045 | $ 0.00045 |
| Ordinary shares, shares authorized | 200,000,000 | 200,000,000 |
| Ordinary shares, shares issued | 32,738,600 | 32,303,540 |
| Ordinary shares, shares outstanding | 32,738,600 | 32,303,540 |