Medical Expenses Payable - Components of Change in Medical Expenses Payable (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Insurance [Abstract]
Claims incurred but not paid - beginning balance	$ 82,391	$ 83,939
Incurred related to:
Current year	164,620	136,119
Prior years	(3,016)	(13,244)
Total incurred, net of reinsurance	161,604	122,875
Payments related to:
Current year	100,606	83,536
Prior years	66,015	54,199
Total payments, net of reinsurance	166,621	137,735
Claims incurred but not paid - ending balance	77,374	69,079
Other medical expenses payable	59,104	35,957
Total medical expenses payable	$ 136,478	$ 105,036	$ 112,605