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FAIR VALUE MEASUREMENTS (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jul. 01, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt	$ 5,100	$ 4,000
UMass Joint Venture
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Ownership percentage by noncontrolling owners			18.90%
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration, liability	7
Level 3 \| Contingent Consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total (gains)/losses included in earnings - realized/unrealized	12	11
Level 3 \| Contingent Consideration \| Other Operating Income (Expense)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total (gains)/losses included in earnings - realized/unrealized	$ 12	$ 11