Basis of Presentation and Summary of Significant Accounting Policies - Contributions to Revenue and Receivables by Payor (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net revenue | Payor A
Concentration Risk [Line Items]
Concentration risk	12.50%	13.60%	14.60%
Net revenue | Payor B
Concentration Risk [Line Items]
Concentration risk	10.90%	13.40%	18.70%
Net revenue | Payor C
Concentration Risk [Line Items]
Concentration risk			14.10%
Net revenue | Payor D
Concentration Risk [Line Items]
Concentration risk	13.10%	11.70%	14.10%
Net revenue | Payor E
Concentration Risk [Line Items]
Concentration risk	16.90%	12.90%
Gross receivables | Payor F
Concentration Risk [Line Items]
Concentration risk	43.90%	30.40%
Gross receivables | Payor G
Concentration Risk [Line Items]
Concentration risk	36.50%	36.00%