Balance Sheet Components - Intangible Assets, Net - Licenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
The University of Chicago Agreement
Intangible Assets, net
Maximum contingent milestone payments	$ 1,600,000
Milestone payments accrued		$ 100,000	$ 0
The Brigham and Women's Hospital, Inc
Intangible Assets, net
Maximum contingent milestone payments	860,000
Milestone payments accrued		0
The University of Iowa Research Foundation
Intangible Assets, net
Maximum contingent milestone payments	712,500
Milestone payments accrued	75,000	0
Brigham Young University
Intangible Assets, net
Maximum contingent milestone payments	$ 400,000
Milestone payments accrued		$ 0
Reimbursement of 3rd party costs (in percent)	33.00%
Kenta Biotech Ltd
Intangible Assets, net
Accrued royalty obligation	$ 0
Maximum royalty base for royalty payments	50,000,000
Emergent Product Development Gaithersburg Inc
Intangible Assets, net
Milestone payments under the agreement	$ 2,800,000