Revenue - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	May 31, 2023	Feb. 28, 2019	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenue from collaboration agreement			$ 170,276,000	$ 185,308,000	$ 154,344,000
Medicare Reimbursements
Disaggregation Of Revenue [Line Items]
Revenue from collaboration agreement			5,600,000	5,200,000	5,800,000
Medicare Reimbursements | Immune Medicine Service Revenue
Disaggregation Of Revenue [Line Items]
Revenue from collaboration agreement			600,000	700,000
MRD Development Agreements | Maximum
Disaggregation Of Revenue [Line Items]
Additional milestone payment receivable			440,000,000
Genentech Collaboration Agreement
Disaggregation Of Revenue [Line Items]
Revenue from collaboration agreement	$ 7,700,000		42,600,000	$ 62,800,000	$ 62,000,000
Non-refundable upfront payments received		$ 300,000,000	300,000,000
Additional transaction price of regulatory milestone	$ 10,000,000
Genentech Collaboration Agreement | Regulatory Milestones
Disaggregation Of Revenue [Line Items]
Additional transaction price of regulatory milestone			$ 10,000,000
Genentech Collaboration Agreement | Maximum
Disaggregation Of Revenue [Line Items]
Revenue recognition expected period			9 years
Genentech Collaboration Agreement | Maximum | Regulatory Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments			$ 75,000,000
Genentech Collaboration Agreement | Maximum | Development Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments			300,000,000
Genentech Collaboration Agreement | Maximum | Commercial Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments			1,430,000,000
Genentech Collaboration Agreement | Minimum
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments			$ 1,800,000,000