BASIS OF PRESENTATION AND SIGNIFICANT EVENTS - Equity Method Investment in Kindred at Home (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Total cash consideration for equity method investment		$ 0	$ 1,095
Allocated to investment		$ 1,061		$ 1,047
Kindred at Home
Schedule of Equity Method Investments [Line Items]
Ownership percentage (percent)	40.00%	40.00%	40.00%
Total cash consideration for equity method investment	$ 1,100
Allocated to investment	1,000		$ 1,000
Equity Option | Put Option
Schedule of Equity Method Investments [Line Items]
Purchase price allocation, financial liability	236		236
Equity Option | Put Option | Other long-term liabilities
Schedule of Equity Method Investments [Line Items]
Financial liability, fair value		$ 90
Equity Option | Call Option
Schedule of Equity Method Investments [Line Items]
Purchase price allocation, financial asset	$ 291		$ 291
Equity Option | Call Option | Other long-term assets
Schedule of Equity Method Investments [Line Items]
Financial asset, fair value		$ 327