CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Consolidated Statements of Operations [Abstract]
Revenues	$ 12,161.6	$ 11,863.9	$ 13,136.1
Cost of Revenue	8,796.7	8,155.0	8,143.7
Gross profit	3,364.9	3,708.9	4,992.4
Selling, general and administrative expenses	2,021.4	1,763.1	1,690.3
Amortization of intangibles and other assets	219.8	193.6	229.5
Goodwill and Intangible Asset Impairment	349.0	261.7	0.0
Restructuring and other special charges	49.1	54.0	24.0
Operating income	725.6	1,436.5	3,048.6
Interest expense	(199.6)	(179.8)	(211.8)
Equity method income, net	(1.4)	5.4	26.5
Investment income	28.8	7.5	8.8
Other, net	15.5	(32.2)	15.5
Provision for income taxes	188.5	233.9	690.0
Net earnings	419.2	1,280.6	2,379.5
Less: Net earnings attributable to the noncontrolling interest	(1.2)	(1.5)	(2.2)
Net earnings attributable to Laboratory Corporation of America Holdings	$ 418.0	$ 1,279.1	$ 2,377.3
Income (Loss) from Continuing Operations, Per Basic Share	$ 4.35	$ 11.00	$ 22.71
Earnings Per Share, Basic	$ 4.80	$ 14.05	$ 24.60
Income (Loss) from Continuing Operations Before Income Taxes and Noncontrolling Interest	$ 568.9	$ 1,237.4	$ 2,887.6
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	380.4	1,003.5	2,197.6
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 38.8	$ 277.1	$ 181.9
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	$ 0.45	$ 3.04	$ 1.88
Income (Loss) from Continuing Operations, Per Diluted Share	4.33	10.94	22.52
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	0.44	3.03	1.87
Earnings Per Share, Diluted	$ 4.77	$ 13.97	$ 24.39