Share-based compensation - Underwriters Warrants (Details) - USD ($) |
Sep. 30, 2021 |
Dec. 16, 2020 |
|---|---|---|
| Share-based compensation | ||
| Warrants to purchase shares | 172,500 | 172,500 |
| Warrants exercise price | $ 12.50 | $ 12.50 |
| Remaining contractual term | 4 years 2 months 15 days | |
| Aggregate intrinsic value of the warrants outstanding | $ 0 |
| X | ||||||||||
- Definition Exercise price per share or per unit of warrants or rights outstanding. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Aggregate intrinsic value of warrants. No definition available.
|