Revenue Recognition - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 401,332	$ 385,813	$ 442,408	$ 545,165	$ 494,676	$ 428,064	$ 301,207	$ 211,466	$ 1,774,718	$ 1,435,413	$ 901,935
Healthcare insurers
Disaggregation of Revenue [Line Items]
Total revenues									520,244	483,643	421,386
Government payors
Disaggregation of Revenue [Line Items]
Total revenues									222,242	90,288	115,711
Client payors
Disaggregation of Revenue [Line Items]
Total revenues									843,405	637,645	158,527
Patients
Disaggregation of Revenue [Line Items]
Total revenues									21,215	50,666	20,810
Total
Disaggregation of Revenue [Line Items]
Total revenues									$ 1,607,106	$ 1,262,242	$ 716,434