BUSINESS ACQUISITIONS (Narrative) (Details) - USD ($) $ in Millions							3 Months Ended								12 Months Ended
	Feb. 29, 2016	Nov. 16, 2015	Aug. 03, 2015	Apr. 18, 2014	Apr. 16, 2014	Mar. 07, 2014	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Total consideration															$ 139	$ 63	$ 768
Goodwill acquired during the year															95	33	383
Goodwill deductible for tax purposes							$ 95				$ 32				95	32	90
Finite-lived intangibles							44				26				44	26	270
Business acquisitions, net of cash acquired															139	67	728
Net revenues							1,861	$ 1,885	$ 1,906	$ 1,863	1,849	$ 1,880	$ 1,925	$ 1,839	$ 7,515	7,493	7,435
Estimated fair value of contingent consideration				$ 26
Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life															18 years
Non-compete Agreements [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life															6 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
Solstas Lab Parnters Group [Member]
Business Acquisition [Line Items]
Total consideration						$ 572
Cash						572
Finite-lived intangibles						210
Business acquisitions, net of cash acquired						563
Net revenues																	300
Operating costs and expenses																	294
Integration and transaction related costs																	17
Estimated fair value of contingent consideration						0
Transaction related costs due to sellers						0
Solstas Lab Parnters Group [Member] | Cost of Services [Member]
Business Acquisition [Line Items]
Integration and transaction related costs																	4
Solstas Lab Parnters Group [Member] | Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Integration and transaction related costs																	13
Solstas Lab Parnters Group [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles						$ 203
Summit Health, Inc. [Member]
Business Acquisition [Line Items]
Total consideration				152
Cash				125
Finite-lived intangibles				38
Business acquisitions, net of cash acquired				124
Working capital adjustments				10
Estimated fair value of contingent consideration				22							$ 0					$ 0	$ 13
Transaction related costs due to sellers				5
Contingent consideration arrangements, range of outcomes, value, high				25
Summit Health, Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles				$ 33
Steward Health Care Systems, LLC [Member]
Business Acquisition [Line Items]
Total consideration					$ 34
Cash					30
Estimated fair value of contingent consideration					4
Contingent consideration arrangements, range of outcomes, value, high							$ 4								$ 4
Steward Health Care Systems, LLC [Member] | Non-compete Agreements [Member]
Business Acquisition [Line Items]
Contingent consideration arrangements, range of outcomes, value, high					$ 5