Income taxes - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Tax Credit Carryforward [Line Items]
Net operating loss (NOL) carryforwards	$ 5,036	$ 7,017
Foreign
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$ 4,600

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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