Commitments and contingencies - Additional Information (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Contingent liabilities	$ 0	$ 0
STOPS
Loss Contingencies [Line Items]
Non-cancellable purchase commitments	$ 1,900,000

Amount of loss contingency liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant