NET OPERATING REVENUES - Conifer (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net operating revenues	$ 3,648	$ 4,560	$ 8,168	$ 9,105
Conifer
Disaggregation of Revenue [Line Items]
Net operating revenues	305	355	637	704
Conifer | Revenue cycle services | Tenet
Disaggregation of Revenue [Line Items]
Net operating revenues	109	142	243	284
Conifer | Revenue cycle services | Non-Tenet
Disaggregation of Revenue [Line Items]
Net operating revenues	172	187	348	367
Conifer | Other services | Tenet
Disaggregation of Revenue [Line Items]
Net operating revenues	4	4	6	8
Conifer | Other services | Non-Tenet
Disaggregation of Revenue [Line Items]
Net operating revenues	$ 20	$ 22	$ 40	$ 45
Conifer | Revenue from other sources
Disaggregation of Revenue [Line Items]
Net operating revenues, percentage of total			7.00%