Fair value measurements - Reconciliation of change in Fair value of warrant liability (Details) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Change in fair value of warrant liability	$ 5,538
Common stock warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Issuance of warrants on June 2, 2020	1,522
Change in fair value of warrant liability	5,538
Reclass of warrant liability to additional paid-in capital upon IPO	$ (7,060)

The amount of reclassification of additional paid in capital.

No definition available.

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- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 25
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=109262497&loc=d3e20148-110875

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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