Basis of presentation and summary of significant accounting policies - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Deferred offering costs	$ 7,233	$ 0

Specific incremental costs directly attributable to a proposed or actual offering of securities which are deferred at the end of the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.A)
-URI http://asc.fasb.org/extlink&oid=122040515&loc=d3e105025-122735

Name:	us-gaap_DeferredOfferingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant