Revenue Recognition - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenues	$ 224,344	$ 228,772	$ 226,368	$ 222,451	$ 221,852	$ 249,815	$ 263,685	$ 254,914	$ 901,935	$ 990,266	$ 966,006
Healthcare insurers
Disaggregation of Revenue [Line Items]
Total revenues									419,101	492,995	495,209
Government payors
Disaggregation of Revenue [Line Items]
Total revenues									116,662	150,851	140,195
Client payors
Disaggregation of Revenue [Line Items]
Total revenues									159,972	148,070	126,264
Patients
Disaggregation of Revenue [Line Items]
Total revenues									20,699	21,332	21,042
Total
Disaggregation of Revenue [Line Items]
Total revenues									$ 716,434	$ 813,248	$ 782,710