IMPAIRMENT AND RESTRUCTURING CHARGES, AND ACQUISITION-RELATED COSTS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Number of continuing operating segments | segment	3
Impairment and restructuring charges, and acquisition-related costs	$ 85	$ 290	$ 185
Restructuring charges	57	184	137
Impairment charges	8	92	42
Acquisition costs	20	14	6
Acquisition-related transaction costs		14	6
Other impairment charges		16	16
Memphis Area
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges			26
Buildings Subject To Impairment Charges
Impaired Long-Lived Assets Held and Used [Line Items]
Assets for which impairment charges have been recorded		483
Series of Individual Business Acquisitions
Impaired Long-Lived Assets Held and Used [Line Items]
Acquisition-related transaction costs	20	14	6
Employee Severance
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring charges	14	65	57
Global Business Center in Republic of Philippines
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring charges	19	50	28
Other Restructuring
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring charges	24	32	46
USPI Management Equity Plan
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring charges		23
Contract and Lease Termination Fees
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring charges		14	6
Ambulatory Care
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	5	12	6
Hospital Operations
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges		79	31
Conifer Segment
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	$ 3	$ 1	$ 5