Leases - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2021 ft²	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) ft²
Lessee Lease Description [Line Items]
Operating lease, option to extend				the lease amendment and replaced by two options to extend the lease term for the entire 150,753 square feet then under lease in the Hayward premises for a period of eight years each.
Operating lease, existence of option to extend	true
Operating lease, option to extend lease term	8 years
Weighted average remaining term		10 years 3 months 18 days		10 years 3 months 18 days
Weighted average discount rate		5.20%		5.20%
Lease expense		$ 1,500,000	$ 700,000	$ 4,100,000	$ 1,800,000
Short-term lease costs		0	$ 0	300,000	$ 100,000
Right-of-use assets		35,553,000		35,553,000		$ 12,781,000
Operating lease, liabilities		51,700,000		51,700,000
Incentives receivable		10,785,000		10,785,000
Short-term portion of operating lease liability		$ 2,800,000		$ 2,800,000
Operating lease, liability, current, statement of financial position [extensible list]		us-gaap:OtherCurrentLiabilitiesMember		us-gaap:OtherCurrentLiabilitiesMember
Operating lease liabilities, noncurrent		$ 48,943,000		$ 48,943,000		$ 15,243,000
Incentives receivable, expected period				1 year
Operating lease Undiscounted amount		67,681,000		$ 67,681,000
Operating lease, lease not yet commenced, description				Total undiscounted future minimum lease payments do not include approximately $90.3 million and $5.3 million, respectively, related to the Company’s Brisbane lease and its additional space in Hayward, neither of which have yet commenced.
Deposits for letters of credit		3,000,000.0		$ 3,000,000.0
Hayward, California
Lessee Lease Description [Line Items]
Square feet of space leased | ft²	150,753
Operating lease commencement year				2022
Operating lease expiration date				Dec. 31, 2031
Operating lease Undiscounted amount		5,300,000		$ 5,300,000
Hayward, California | Executive Offices Research and Development and Business Operations
Lessee Lease Description [Line Items]
Square feet of space leased | ft²	14,460					136,293
Operating lease commencement year	2022
Operating lease expiration date	Dec. 31, 2031
Brisbane, California
Lessee Lease Description [Line Items]
Operating lease commencement period, description				fourth quarter of 2021
Operating lease expiration date				Dec. 31, 2031
Operating lease Undiscounted amount		$ 90,300,000		$ 90,300,000