v3.21.1

Background and liquidity (Detail) - USD ($) $ / shares in Units, $ in Thousands |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Oct. 23, 2020 | Dec. 17, 2019 | Jul. 22, 2019 | Oct. 31, 2020 | Jan. 31, 2021 | Jan. 31, 2020 | Jan. 31, 2019
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of issuance costs (in shares) | 5,750,000 |  |  | 5,750,000 |  |  |
Issue price per share (in USD per share) | $ 32.00 |  |  | $ 32.00 |  |  |
Payment of offering costs |  |  |  |  | $ 290 | $ 6,217 | $ 195
Dividend paid |  |  |  |  | 0 | 14,955 | 0
Net proceeds after discounts and offering expenses | $ 174,510 |  |  | $ 174,800 | $ 174,800 | $ 130,781 | $ 0
Number of months with sufficient funds to operate |  |  |  |  | 12 months |  |
Common stock |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of issuance costs (in shares) |  | 7,762,500 |  |  | 5,750,000 | 7,812,500 |
Payment of offering costs |  | $ 1,047 |  |  |  |  |
Conversion of preferred stock into common stock and cancellation of redeemable preferred stock (in shares) |  |  |  |  |  | 25,311,535 |
IPO |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Conversion of preferred stock into common stock and cancellation of redeemable preferred stock (in shares) |  |  | 588,763 |  |  |  |
Dividend paid |  |  | $ 14,955 |  |  |  |
IPO | Common stock |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of issuance costs (in shares) |  |  | 7,812,500 |  |  |  |
Issue price per share (in USD per share) |  |  | $ 18.00 |  |  |  |
Proceeds from issuance of common stock in equity offerings, net of underwriters' discounts and commissions |  |  | $ 130,781 |  |  |  |
Underwriting discounts and commission |  |  | 9,844 |  |  |  |
Payment of offering costs |  |  | $ 6,412 |  |  |  |
IPO | Common stock | Certain Selling Stockholders |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of issuance costs (in shares) |  |  | 2,868,923 |  |  |  |

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