GOODWILL AND INTANGIBLE ASSETS - SCHEDULE OF GOODWILL (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 8,121,000,000	$ 7,958,900,000	$ 7,751,500,000
Adjustments to goodwill	(176,400,000)	(91,000,000.0)
Goodwill, Acquired During Period	598,500,000	298,400,000
Goodwill, Impairment Loss	(260,000,000.0)	0
Goodwill [Roll Forward]
Balance as of January 1	7,958,900,000	7,751,500,000
Adjustments to goodwill	(176,400,000)	(91,000,000.0)
Goodwill, net	8,121,000,000	7,958,900,000	7,751,500,000
LabCorp Diagnostics [Member]
Goodwill [Line Items]
Goodwill	4,533,500,000	4,046,200,000	3,800,200,000
Adjustments to goodwill	(70,600,000)	900,000
Goodwill, Acquired During Period	557,900,000	245,100,000
Goodwill, Impairment Loss	0	0	(3,700,000)
Goodwill [Roll Forward]
Balance as of January 1	4,046,200,000	3,800,200,000
Adjustments to goodwill	(70,600,000)	900,000
Goodwill, net	4,533,500,000	4,046,200,000	3,800,200,000
Covance Drug Development [Member]
Goodwill [Line Items]
Goodwill	3,587,500,000	3,912,700,000	3,951,300,000
Adjustments to goodwill	(105,800,000)	(91,900,000)
Goodwill, Acquired During Period	40,600,000	53,300,000
Goodwill, Impairment Loss	(260,000,000.0)	0	(418,700,000)
Goodwill [Roll Forward]
Balance as of January 1	3,912,700,000	3,951,300,000
Adjustments to goodwill	(105,800,000)	(91,900,000)
Goodwill, net	$ 3,587,500,000	$ 3,912,700,000	$ 3,951,300,000