Revenue - Revenues Disaggregated by Market (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]
Revenue	$ 163,445	$ 146,815	$ 168,182	$ 147,953	$ 155,828	$ 154,246	$ 146,791	$ 141,425	$ 626,395	$ 598,290	$ 521,212
Commercial
Disaggregation of Revenue [Line Items]
Revenue									302,489	323,150
State
Disaggregation of Revenue [Line Items]
Revenue									257,685	233,921
Federal
Disaggregation of Revenue [Line Items]
Revenue									66,221	41,219
Coordination of Benefits
Disaggregation of Revenue [Line Items]
Revenue									404,123	397,095
Payment Integrity
Disaggregation of Revenue [Line Items]
Revenue									162,194	144,063
Population Health Management
Disaggregation of Revenue [Line Items]
Revenue									$ 60,078	$ 57,132