Net loss per share - Antidilutive (Details) - shares	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022
Net loss per share
Total shares excluded from calculation (in shares)	15,291,430	14,330,779
Employee Stock Option [Member]
Net loss per share
Total shares excluded from calculation (in shares)	11,674,491	11,815,952
Restricted stock awards and units
Net loss per share
Total shares excluded from calculation (in shares)	3,616,939	2,514,827

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

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