Net loss per share - Antidilutive (Details) - shares	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022
Net loss per share
Total shares excluded from calculation (in shares)	14,850,885	13,967,365
Employee Stock Option
Net loss per share
Total shares excluded from calculation (in shares)	11,436,783	11,478,421
Restricted stock awards and units
Net loss per share
Total shares excluded from calculation (in shares)	3,414,102	2,488,944

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration