Revenue Recognition - Disaggregation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 625,486	$ 391,005	$ 302,328
United States
Disaggregation of Revenue [Line Items]
Total revenues	590,872	365,660	260,846
Americas, excluding U.S.
Disaggregation of Revenue [Line Items]
Total revenues	4,047	3,469	3,218
Europe, Middle East, India, and Africa
Disaggregation of Revenue [Line Items]
Total revenues	20,429	14,332	15,434
Asia Pacific and Other
Disaggregation of Revenue [Line Items]
Total revenues	10,138	7,544	22,830
Insurance carriers
Disaggregation of Revenue [Line Items]
Total revenues	492,563	300,220	210,919
Laboratory partners
Disaggregation of Revenue [Line Items]
Total revenues	100,019	58,196	59,876
Patients
Disaggregation of Revenue [Line Items]
Total revenues	32,904	32,589	31,533
Licensing and other
Disaggregation of Revenue [Line Items]
Total revenues	$ 58,337	$ 23,794	$ 32,447