License and Collaboration Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Oct. 31, 2018	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020
License And Collaboration Agreements [Line Items]
Contract with customer liability revenue recognized		$ 2,869,000	$ 5,454,000
Contract with customer liability		18,334,000	39,747,000				$ 21,203,000	$ 45,201,000
2017 License and Collaboration Agreement With Roche [Member] | Roche [Member]
License And Collaboration Agreements [Line Items]
Estimated costs to be incurred to satisfy performance obligation			300,000
Contract with customer liability revenue recognized		0	600,000
2018 License and Collaboration Agreement With Roche [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable on exercise of option rights		100,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member]
License And Collaboration Agreements [Line Items]
Upfront payment received towards technology access fee	$ 45,000,000.0
Estimated costs to be incurred to satisfy performance obligation		0	0
Contract with customer liability current		9,100,000					12,000,000.0
Milestone payment receivable based on product		1,600,000
Milestone payment received		3,000.0
Performance obligation revenue recognized		2,900,000	$ 4,900,000
Contract with customer liability		18,300,000					$ 21,200,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Development Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		217,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Development Milestone [Member] | First Patient Doosing Phase One Clinical Trial [Member]
License And Collaboration Agreements [Line Items]
Milestone payment received				$ 20,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Regulatory Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		240,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Regulatory Milestone [Member] | Preclinical Data Submitted To FDA For Approval [Member]
License And Collaboration Agreements [Line Items]
Milestone payment received						$ 10,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Sales Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		1,200,000,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | APC [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		15,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Contract liabilities current reclassified to non current					$ 9,200,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Maximum [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		100,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Minimum [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		$ 50,000,000.0