NET OPERATING REVENUES - Net Operating Revenue Composition, Ambulatory Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Net operating revenues	$ 20,548	$ 19,174	$ 19,485
Ambulatory Care
Disaggregation of Revenue [Line Items]
Net operating revenues	3,865	3,248	2,718
Net patient service revenues | Ambulatory Care
Disaggregation of Revenue [Line Items]
Net operating revenues	3,713	3,115	2,604
Management fees | Ambulatory Care
Disaggregation of Revenue [Line Items]
Net operating revenues	123	110	86
Revenue from other sources | Ambulatory Care
Disaggregation of Revenue [Line Items]
Net operating revenues	$ 29	$ 23	$ 28