Related-Party Transactions - Fees Incurred and Income Received (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Net total	$ 5,474	$ 10,979	$ 23,081	$ 37,858
AHMC
Related Party Transaction [Line Items]
AHMC – Risk pool, capitation, claims payment, net	5,683	11,215	23,739	39,165
Net total	10,500	31,500	11,000	31,900
HSMSO
Related Party Transaction [Line Items]
Management fees	(109)	(160)	(430)	(1,075)
Aurion
Related Party Transaction [Line Items]
Management fees	$ (100)	$ (76)	$ (228)	$ (232)