Revenue Recognition - Revenues Disaggregated by Revenue Source and Market (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 171,412	$ 147,953
Commercial
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	88,750	76,259
State
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	68,669	61,742
Federal
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13,993	9,952
Coordination of Benefits
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	118,056	105,851
Payment Integrity
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	39,308	27,726
Population Health Management
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 14,048	$ 14,376