Revenue Recognition and Contractual Adjustments - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 86,977	$ 101,713	$ 193,007	$ 197,290
Clinical Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	73,884	88,982	166,866	175,192
Clinical Services | Client direct billing
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	45,244	54,008	99,535	103,243
Clinical Services | Commercial Insurance
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	15,148	20,894	37,142	41,802
Clinical Services | Medicare and Medicaid
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	13,541	13,719	30,024	29,581
Clinical Services | Self-Pay
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	(49)	361	165	566
Pharma Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenue	$ 13,093	$ 12,731	$ 26,141	$ 22,098