BUSINESS ACQUISITIONS (Details) - USD ($) $ in Millions		3 Months Ended
	Feb. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Cash acquired from acquisition		$ 5	$ 0
Goodwill		$ 6,392		$ 6,335	$ 6,000
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
Cash acquired from acquisition	5
Cash paid for acquisition	130
Contingent consideration, liability	12
Intangible assets	77
Goodwill	57
Goodwill, expected tax deductible amount	45
Working capital	7
Property, plant and equipment	$ 1
Mobile Medical Examination Services, Inc. (MedXM) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	15 years