BUSINESS ACQUISITIONS (Details) - USD ($) $ in Millions									12 Months Ended
	Dec. 07, 2017	Dec. 01, 2017	Sep. 28, 2017	Jul. 14, 2017	May 01, 2017	Feb. 29, 2016	Nov. 16, 2015	Aug. 03, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total consideration									$ 587	$ 139	$ 63
Goodwill acquired during the year									335	95	33
Goodwill deductible for tax purposes									273	95	32
Finite-lived intangibles									242	44	26
Revenues									75
Cash acquired from acquisition									12	0
Goodwill									$ 6,335	$ 6,000	$ 5,905
Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life									18 years
PeaceHealth (PHL) [Member]
Business Acquisition [Line Items]
Goodwill deductible for tax purposes					$ 71
Cash					101
PeaceHealth (PHL) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles					$ 30
Finite-lived intangible asset, useful life					15 years
Med Fusion and Clear Point [Member]
Business Acquisition [Line Items]
Goodwill deductible for tax purposes				$ 60
Cash				150
Property, plant and equipment, net				31
Goodwill				62
Med Fusion and Clear Point [Member] | Capital Lease Obligations [Member]
Business Acquisition [Line Items]
Capital lease obligation				28
Med Fusion and Clear Point [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles				$ 84
Finite-lived intangible asset, useful life				15 years
The William W. Backus Hospital and The Hospital of Central Connecticut [Member]
Business Acquisition [Line Items]
Cash			$ 30
Cleveland HeartLab, Inc. (CHL) [Member]
Business Acquisition [Line Items]
Goodwill deductible for tax purposes		$ 1
Cash		94
Property, plant and equipment, net		3
Cash acquired from acquisition		12
Goodwill		55
Deferred tax assets		11
Deferred tax liabilities		11
Working capital		4
Cleveland HeartLab, Inc. (CHL) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles		$ 32
Finite-lived intangible asset, useful life		15 years
Shiel Holdings LLC (Shiel) [Member]
Business Acquisition [Line Items]
Total consideration	$ 176
Goodwill deductible for tax purposes	100
Cash	170
Goodwill	106
Estimated contingent consideration	6
Shiel Holdings LLC (Shiel) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles	$ 70
Finite-lived intangible asset, useful life	15 years
Clinical Laboratory Partners, LLC (CLP) [Member]
Business Acquisition [Line Items]
Goodwill deductible for tax purposes						$ 91
Cash						135
Clinical Laboratory Partners, LLC (CLP) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles						$ 43
Finite-lived intangible asset, useful life						15 years
MemorialCare [Member]
Business Acquisition [Line Items]
Cash								$ 35
Superior Mobile Medics, Inc. [Member]
Business Acquisition [Line Items]
Cash							$ 27