ACQUISITIONS AND DIVESTITURES - Narrative (Details) $ in Millions			3 Months Ended
	Feb. 01, 2020 USD ($) primary_care_center	Jan. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)
Business Acquisition [Line Items]
Goodwill, acquired during period			$ 515
WCAS
Business Acquisition [Line Items]
Expected number of payor-agnostic, senior-focused primary care centers to be opened by strategic partnership | primary_care_center	50
Expected time frame for opening primary care centers	3 years
Value of partnership entity	$ 600
Time frame for put and call option activity per partnership agreement, minimum	5 years
Time frame for put and call option activity per partnership agreement, maximum	10 years
Enclara
Business Acquisition [Line Items]
Cash consideration for acquisition		$ 709
Goodwill, acquired during period		515
Other intangible assets acquired		240
Net tangible liabilities assumed		$ 11
Other intangible assets, weighted average useful life		11 years 4 months 24 days