Description of Business and Summary of Significant Accounting Policies - Summary of Revenue from Services (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenues	$ 9,193	$ 3,942	$ 18,528	$ 16,281
Diagnostic Tests
Disaggregation Of Revenue [Line Items]
Revenues	8,552	3,770	15,798	12,716
Services
Disaggregation Of Revenue [Line Items]
Revenues	$ 641	$ 172	$ 2,730	$ 3,565