Revenue Recognition - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 152,316	$ 94,012
United States
Disaggregation of Revenue [Line Items]
Total revenues	144,957	86,731
Americas, excluding U.S.
Disaggregation of Revenue [Line Items]
Total revenues	813	782
Europe, Middle East, India, Africa
Disaggregation of Revenue [Line Items]
Total revenues	4,459	3,476
Asia Pacific and Other
Disaggregation of Revenue [Line Items]
Total revenues	2,087	3,023
Insurance carriers
Disaggregation of Revenue [Line Items]
Total revenues	100,399	70,672
Laboratory partners
Disaggregation of Revenue [Line Items]
Total revenues	44,535	15,683
Patients
Disaggregation of Revenue [Line Items]
Total revenues	7,382	7,657
Product
Disaggregation of Revenue [Line Items]
Total revenues	118,382	87,046
Licensing and other
Disaggregation of Revenue [Line Items]
Total revenues	$ 33,934	$ 6,966