Basis of Presentation and Summary of Significant Accounting Policies - Contributions to Revenue and Receivables by Payor (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Net Revenue | Payor A
Accounts Receivable And Net Revenue [Line Items]
Concentration risk	12.70%	12.00%	12.10%	14.30%
Net Revenue | Payor B
Accounts Receivable And Net Revenue [Line Items]
Concentration risk		11.70%	10.10%	13.30%
Net Revenue | Payor C
Accounts Receivable And Net Revenue [Line Items]
Concentration risk				10.00%
Net Revenue | Payor D
Accounts Receivable And Net Revenue [Line Items]
Concentration risk	16.20%	12.00%	17.00%
Net Revenue | Payor E
Accounts Receivable And Net Revenue [Line Items]
Concentration risk	16.70%	19.90%	14.20%	11.00%
Receivables and Receivables-Related Parties | Payor D
Accounts Receivable And Net Revenue [Line Items]
Concentration risk			16.70%
Receivables and Receivables-Related Parties | Payor F
Accounts Receivable And Net Revenue [Line Items]
Concentration risk			32.50%		30.40%
Receivables and Receivables-Related Parties | Payor G
Accounts Receivable And Net Revenue [Line Items]
Concentration risk			29.20%		36.00%