BUSINESS ACQUISITIONS (Details) - USD ($)				3 Months Ended			9 Months Ended
	Sep. 19, 2018	Jun. 18, 2018	Feb. 01, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Cash acquired from acquisition				$ 0		$ 0	$ 5,000,000	$ 0
Goodwill				6,447,000,000			$ 6,447,000,000		$ 6,335,000,000	$ 6,000,000,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life							18 years
Mobile Medical Examination Services, Inc. (MedXM) [Member]
Business Acquisition [Line Items]
Consideration			$ 142,000,000
Cash acquired from acquisition			5,000,000
Cash paid for acquisition			130,000,000
Intangible assets			77,000,000
Goodwill			57,000,000
Goodwill, expected tax deductible amount			45,000,000
Working capital			7,000,000
Property, plant and equipment			1,000,000
Mobile Medical Examination Services, Inc. (MedXM) [Member] | Other Operating Income [Member]
Business Acquisition [Line Items]
Gain due to remeasure				13,000,000	$ (1,000,000)
Mobile Medical Examination Services, Inc. (MedXM) [Member] | Fair Value, Inputs, Level 3 [Member]
Business Acquisition [Line Items]
Contingent consideration, liability			$ 12,000,000	$ 0	$ 13,000,000		$ 0
Mobile Medical Examination Services, Inc. (MedXM) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life			15 years
Cape Cod Healthcare, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 35,000,000
ReproSource, Inc. [Member]
Business Acquisition [Line Items]
Consideration	$ 35,000,000
Cash paid for acquisition	30,000,000
ReproSource, Inc. [Member] | Fair Value, Inputs, Level 3 [Member]
Business Acquisition [Line Items]
Contingent consideration, liability	$ 5,000,000