GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 5,891.8		$ 5,851.4
Goodwill	8,116.0		8,121.0
Amortization of intangibles and other assets	69.3	$ 67.1
Adjustments to goodwill	(5.0)
Estimated amortization expense, 2012	206.2
Estimated amortization expense, 2013	267.5
Estimated amortization expense, 2014	255.3
Estimated amortization expense, 2015	245.5
Estimated amortization expense, 2016	233.9
Estimated amortization expense, Thereafter	2,141.3
Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings	11.1
Amortization of intangible assets	69.3	$ 67.1
LabCorp Diagnostics [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	4,514.3		4,533.5
Adjustments to goodwill	(19.2)
Covance Drug Development [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	3,601.7		$ 3,587.5
Adjustments to goodwill	$ 14.2