BASIS OF FINANCIAL STATEMENT PRESENTATION (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Asset Impairment Charges	$ 2.8		$ 0.0		$ 5.0	$ 1.2
Revenues	3,033.7		$ 2,923.0		6,071.5	$ 6,067.5
Contract with Customer, Liability	$ 349.7				$ 349.7		$ 310.6
Percent of Revenue Contributed	100.00%		100.00%		100.00%	100.00%
Provision for income taxes	$ 49.8		$ 92.1		$ 113.7	$ 222.6
Net Income (Loss) Attributable to Parent	188.9	$ 212.9	358.6	$ 491.6	401.8	850.2
Stockholders' Equity Attributable to Parent	8,785.0	$ 10,341.5	10,400.7	$ 10,721.1	8,785.0	10,400.7	10,096.6	$ 10,273.4
Deferred Revenue, Revenue Recognized					72.8	56.6
Cash and cash equivalents	1,930.6				1,930.6		$ 320.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,930.6		$ 978.3		$ 1,930.6	$ 978.3		$ 1,472.7
Ownership percentage below which investments are generally accounted for on the cost method (in thousandths)					20.00%
LabCorp Diagnostics [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percent of Revenue Contributed	77.00%		77.00%		78.00%	77.00%