Summary of significant accounting policies - Leases (Details) - USD ($)	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Operating lease, impairment loss	$ 0	$ 0

Amount of loss from impairment of right-of-use asset from operating lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479365/842-20-25-6

Name:	us-gaap_OperatingLeaseImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration