Summary of significant accounting policies - Summary of Property and Equipment Estimated Useful Lives (Details)	12 Months Ended
Dec. 31, 2020
Property Plant And Equipment [Line Items]
Leasehold improvements	Shorter of useful life or term of lease
Maximum
Property Plant And Equipment [Line Items]
Useful life (in years)	6 years
Computer equipment and software
Property Plant And Equipment [Line Items]
Useful life (in years)	3 years
Furniture, fixtures and other
Property Plant And Equipment [Line Items]
Useful life (in years)	5 years
Scientific equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful life (in years)	5 years

Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68071081&loc=d3e1205-110223

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration