Share-based compensation - Summary of stock option activity under the Plans (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
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| Options Outstanding | |||
| Beginning balance | 43,996 | 47,332 | |
| Granted | 103,711 | 13,638 | |
| Exercised | (16,974) | ||
| Ending balance | 147,707 | 43,996 | 47,332 |
| Options exercisable | 43,996 | ||
| Weighted Average Exercise Price | |||
| Beginning balance | $ 20.46 | $ 8.03 | |
| Granted | 8.22 | 44 | |
| Exercised | 4.71 | ||
| Ending balance | 11.87 | $ 20.46 | $ 8.03 |
| Options exercisable | $ 20.46 | ||
| Weighted Average Remaining Contractual Term in Years | |||
| Weighted average remaining contractual term | 9 years 3 months 25 days | 8 years 6 months | 8 years 9 months 18 days |
| Granted | 9 years 8 months 1 day | ||
| Options exercisable | 7 years 2 months 23 days | ||
| Aggregate intrinsic value | |||
| Beginning balance | $ 510 | $ 1,326 | |
| Ending balance | $ 510 | $ 1,326 | |
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- Definition Weighted average remaining contractual term for option awards granted during the period, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. No definition available.
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- References No definition available.
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- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Gross number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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