Stockholders’ equity - Pricing model (Details)	Dec. 31, 2020
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0013
Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)	1 year
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.65
Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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