BUSINESS ACQUISITIONS (Narrative) (Details) - USD ($) $ in Millions							3 Months Ended								12 Months Ended
	Nov. 16, 2015	Aug. 03, 2015	Apr. 18, 2014	Apr. 16, 2014	Mar. 07, 2014	Jan. 02, 2013	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Business acquisitions, net of cash acquired															$ 67	$ 728	$ 213
Net revenues							$ 1,849	$ 1,880	$ 1,925	$ 1,839	$ 1,883	$ 1,904	$ 1,902	$ 1,746	7,493	7,435	7,146
Total consideration																	$ 264
Estimated fair value of contingent consideration			$ 26
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]
Cash					$ 572
Business acquisitions, net of cash acquired					563
Net revenues																300
Operating costs and expenses																294
Integration and transaction related costs																17
Total consideration					572
Transaction related costs due to sellers					0
Estimated fair value of contingent consideration					$ 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
Summit Health, Inc. [Member]
Business Acquisition [Line Items]
Cash			125
Business acquisitions, net of cash acquired			124
Total consideration			152
Working capital adjustments			10
Transaction related costs due to sellers			5
Estimated fair value of contingent consideration			22
Contingent consideration arrangements, range of outcomes, value, high			$ 25
Summit Health, Inc. [Member] | To be Paid in 2016 Based on Revenue Targets [Member]
Business Acquisition [Line Items]
Estimated fair value of contingent consideration							0				$ 13				0	$ 13
Steward Health Care Systems, LLC [Member] [Member]
Business Acquisition [Line Items]
Cash				$ 30
Total consideration				34
Estimated fair value of contingent consideration				4
Contingent consideration arrangements, range of outcomes, value, high							$ 4								$ 4
Steward Health Care Systems, LLC [Member] [Member] | Non-compete Agreements [Member]
Business Acquisition [Line Items]
Contingent consideration arrangements, range of outcomes, value, high				$ 5
UMass [Member]
Business Acquisition [Line Items]
Deferred liability						$ 50
Percentage of equity interest expected to be divested						18.90%