Share-based compensation - Company's stock options (Details)	3 Months Ended
Mar. 31, 2023 $ / shares shares
Stock options
Stock options outstanding, at beginning of period \| shares	870,567
Forfeited, Stock options \| shares	(85,555)
Stock options outstanding, at end of period \| shares	785,012
Stock options exercisable \| shares	197,912
Weighted-Average Per share Exercise Price
Exercise price, at beginning of period	$ 2.81
Granted, exercise price	2.81
Forfeited, exercise price	2.81
Exercise price, at end of period	2.81
Exercisable, exercise price	$ 2.81

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.

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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.

+ References

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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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.

+ References

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.

+ References

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- References

No definition available.

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- Definition

Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

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