Liability for Appeals - Activity in the Liability for Appeals (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Estimated Liability for Appeals [Roll Forward]
Beginning balance		$ 30,787	$ 21,723	$ 30,787
Provision			9,373	2,166
Appeals found in providers favor			(8,146)	(2,794)
Release of estimated liability	$ (10,500)	(8,400)	(19,380)	(8,436)
Ending balance			3,570	21,723
Original RAC contract
Increase (Decrease) in Estimated Liability for Appeals [Roll Forward]
Beginning balance		27,816	19,380	27,816
Provision			0	108
Appeals found in providers favor			0	(108)
Release of estimated liability	$ (19,400)		(19,380)	(8,436)
Ending balance			0	19,380
RAC 4 contract
Increase (Decrease) in Estimated Liability for Appeals [Roll Forward]
Beginning balance		0	20	0
Provision			2,026	20
Appeals found in providers favor			(440)	0
Release of estimated liability			0	0
Ending balance			1,606	20
Commercial contracts
Increase (Decrease) in Estimated Liability for Appeals [Roll Forward]
Beginning balance		$ 2,971	2,323	2,971
Provision			7,347	2,038
Appeals found in providers favor			(7,706)	(2,686)
Release of estimated liability			0	0
Ending balance			$ 1,964	$ 2,323