Revenue and Accounts Receivable Credit Concentration - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Primary sources of revenue, description	We derive our revenue from two primary sources: (i) providing diagnostic testing in the clinical setting (Diagnostic Tests); and (ii) providing biopharmaceutical companies with services that include diagnostic research, clinical research, clinical trial testing, development and testing services generally provided outside the clinical setting and governed by individual contracts with third parties as well as development and commercialization of companion diagnostics (Services).
Revenue recognized		$ 3,000,000.0
Deferred revenue	$ 1,850,000	$ 3,532,000
Revenue \| Minimum \| Customer Concentration Risk \| Medicare
Disaggregation Of Revenue [Line Items]
Concentration risk, percentage	18.00%	17.00%
Other Long-term Liabilities
Disaggregation Of Revenue [Line Items]
Non-current deferred revenue	$ 800	$ 1,400,000
Up Front Cash Payments
Disaggregation Of Revenue [Line Items]
Deferred revenue	$ 1,400,000

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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