Summary of significant accounting policies - Summary of Estimated Useful Life of Asset (Detail)	3 Months Ended
	Mar. 31, 2021
Lab Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Furniture and Office Equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Furniture and Office Equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	8 years
Vehicles [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	4 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	Shorter of the useful life or remaining lease term