CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
BALANCE at Dec. 31, 2022	$ 10,096.6	$ 8.1	$ 0.0	$ 10,581.7	$ (493.2)
Net earnings attributable to Laboratory Corporation of America Holdings	212.9	0.0	0.0	212.9	0.0
Other comprehensive earnings, net of tax	49.0	0.0	0.0	0.0	49.0
Dividends	64.7	0.0	0.0	64.7	0.0
Issuance of common stock under employee stock plans	(27.6)	0.0	(27.6)	0.0	0.0
Surrender of restricted stock and performance share awards	(20.5)	0.0	(20.5)	0.0	0.0
Stock compensation	40.6	0.0	40.6	0.0	0.0
BALANCE at Mar. 31, 2023	10,341.5	8.1	47.7	10,729.9	(444.2)
Retained Earnings (Accumulated Deficit)	7,888.2
BALANCE at Dec. 31, 2023	7,875.0	7.7	38.4	7,888.2	(59.3)
Net earnings attributable to Laboratory Corporation of America Holdings	228.0	0.0	0.0	228.0	0.0
Other comprehensive earnings, net of tax	(126.1)	0.0	0.0	0.0	(126.1)
Dividends	60.9	0.0	0.0	60.9	0.0
Issuance of common stock under employee stock plans	(26.7)	0.0	(26.7)	0.0	0.0
Surrender of restricted stock and performance share awards	(14.7)	0.0	(14.7)	0.0	0.0
Stock compensation	31.6	0.0	31.6	0.0	0.0
BALANCE at Mar. 31, 2024	7,959.6	$ 7.7	$ 82.0	$ 8,055.3	$ (185.4)
Retained Earnings (Accumulated Deficit)	$ 8,055.3