Basis of Presentation and Summary of Significant Accounting Policies - Contributions to Revenue and Receivables by Payor (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net revenue | Payor A
Concentration Risk [Line Items]
Concentration risk	13.60%	14.60%	14.10%
Net revenue | Payor B
Concentration Risk [Line Items]
Concentration risk	13.40%	18.70%	18.10%
Net revenue | Payor C
Concentration Risk [Line Items]
Concentration risk			11.10%
Net revenue | Payor D
Concentration Risk [Line Items]
Concentration risk		14.10%	11.30%
Net revenue | Payor E
Concentration Risk [Line Items]
Concentration risk	11.70%	14.10%
Net revenue | Payor F
Concentration Risk [Line Items]
Concentration risk	12.90%
Gross receivables | Payor G
Concentration Risk [Line Items]
Concentration risk	30.40%	34.10%
Gross receivables | Payor H
Concentration Risk [Line Items]
Concentration risk	36.00%	42.20%