BUSINESS ACQUISITIONS (Details) - USD ($)								12 Months Ended
	Dec. 13, 2021	Jun. 01, 2021	Aug. 01, 2020	Jul. 31, 2020	Apr. 06, 2020	Jan. 21, 2020	Feb. 11, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Total consideration								$ 336,000,000	$ 330,000,000	$ 63,000,000
Cash consideration								331,000,000	351,000,000	58,000,000
Goodwill acquired during the year								228,000,000	247,000,000	43,000,000
Goodwill deductible for tax purposes								223,000,000	210,000,000	36,000,000
Finite-lived intangibles								104,000,000	146,000,000	21,000,000
Revenues									127,000,000
Goodwill								$ 7,095,000,000	6,873,000,000	6,619,000,000
Cash acquired from acquisition									$ 21,000,000
Technology-Based Intangible Assets
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life								14 years
Customer - related
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life								17 years
Mercy Health
Business Acquisition [Line Items]
Cash consideration		$ 225,000,000
Goodwill deductible for tax purposes		171,000,000
Goodwill		171,000,000
Mercy Health | Customer - related
Business Acquisition [Line Items]
Finite-lived intangibles		$ 54,000,000
Finite-lived intangible asset, useful life		15 years
Labtech Diagnostics, LLC
Business Acquisition [Line Items]
Total consideration	$ 85,000,000
Cash consideration	80,000,000
Goodwill deductible for tax purposes	35,000,000
Property, plant and equipment, net	11,000,000
Finance lease liabilities	9,000,000
Operating lease right-of-use assets	6,000,000
Operating lease liabilities	6,000,000
Inventories	2,000,000
Finite-lived intangibles	41,000,000
Goodwill	40,000,000
Labtech Diagnostics, LLC | Level 3
Business Acquisition [Line Items]
Contingent consideration	$ 5,000,000
Labtech Diagnostics, LLC | Customer - related
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life	15 years
Blueprint Genetics Oy
Business Acquisition [Line Items]
Cash consideration						$ 108,000,000
Goodwill deductible for tax purposes						66,000,000
Finite-lived intangibles						43,000,000
Goodwill						66,000,000
Cash acquired from acquisition						3,000,000
Property, plant, and equipment and working capital						$ 2,000,000
Blueprint Genetics Oy | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life						10 years
Blueprint Genetics Oy | Customer - related
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life						15 years
Memorial Hermann
Business Acquisition [Line Items]
Cash consideration					$ 120,000,000
Goodwill deductible for tax purposes					93,000,000
Goodwill					93,000,000
Memorial Hermann | Customer - related
Business Acquisition [Line Items]
Finite-lived intangibles					$ 27,000,000
Finite-lived intangible asset, useful life					15 years
Mid America Clinical Laboratories, LLC (MACL)
Business Acquisition [Line Items]
Cash consideration			$ 93,000,000
Goodwill deductible for tax purposes			47,000,000
Property, plant and equipment, net			11,000,000
Goodwill			84,000,000
Cash acquired from acquisition			$ 18,000,000
Percentage of voting interests acquired			56.00%
Equity interest in acquiree, percentage				44.00%
Equity interest in acquiree, fair value				$ 87,000,000
Equity interest in acquiree, long-term growth rate used to determine fair value			1.50%
Equity interest in acquiree, discount rate used to determine fair value			7.50%
Working capital			$ 11,000,000
Mid America Clinical Laboratories, LLC (MACL) | Other Income (Expense)
Business Acquisition [Line Items]
Equity interest in acquiree, remeasurement gain			70,000,000
Mid America Clinical Laboratories, LLC (MACL) | Customer - related
Business Acquisition [Line Items]
Finite-lived intangibles			$ 74,000,000
Finite-lived intangible asset, useful life			15 years
Boyce & Bynum Pathology Laboratories, P.C. (Boyce & Bynum)
Business Acquisition [Line Items]
Total consideration							$ 61,000,000
Cash consideration							55,000,000
Goodwill deductible for tax purposes							35,000,000
Goodwill							41,000,000
Boyce & Bynum Pathology Laboratories, P.C. (Boyce & Bynum) | Level 3
Business Acquisition [Line Items]
Contingent consideration							6,000,000			0
Boyce & Bynum Pathology Laboratories, P.C. (Boyce & Bynum) | Other Operating Income (Expense)
Business Acquisition [Line Items]
Contingent consideration arrangements										$ 6,000,000
Boyce & Bynum Pathology Laboratories, P.C. (Boyce & Bynum) | Customer - related
Business Acquisition [Line Items]
Finite-lived intangibles							$ 20,000,000
Finite-lived intangible asset, useful life							15 years