Restructuring and Related Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring and Related Activities [Abstract]
Number of years restructuring liabilities expected to be paid out over	9 years 8 months 12 days
Net restructuring charges	$ 49.1	$ 54.0	$ 24.0
Restructuring charges related to severance and other employee costs	33.4	24.8	12.4
Restructuring Costs and Asset Impairment Charges	22.3
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment	1.7	1.4	0.3
Facility Related Restructuring Reserve Accrual Adjustment	4.9	0.5	0.2
Restructuring charges related to contractual obligations associated with leased facilities and other facility related costs		31.1	12.0
Restructuring Reserve	20.6	11.5	5.3
Restructuring Reserve, Current	9.5
Restructuring Reserve, Noncurrent	11.1
Restructuring Charges	55.7	55.9
Restructuring Reserve, Accrual Adjustment	(6.6)	(1.9)
Payments for Restructuring	(40.0)	(47.8)
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	20.6	11.5	5.3
Net restructuring charges	49.1	54.0	24.0
Restructuring charges related to severance and other employee costs	33.4	24.8	12.4
Restructuring Costs and Asset Impairment Charges	22.3
Restructuring Reserve, Accrual Adjustment	(6.6)	(1.9)
Payments for Restructuring	40.0	47.8
Restructuring Charges	55.7	55.9
Employee Severance [Member] | LabCorp Diagnostics [Member]
Restructuring and Related Activities [Abstract]
Restructuring Reserve	7.6	2.1	3.7
Restructuring Charges	33.4	24.8
Restructuring Reserve, Accrual Adjustment	(1.7)	(1.4)
Payments for Restructuring	26.2	25.0
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	7.6	2.1	3.7
Restructuring Reserve, Accrual Adjustment	(1.7)	(1.4)
Payments for Restructuring	(26.2)	(25.0)
Restructuring Charges	33.4	24.8
Facility Closing [Member] | LabCorp Diagnostics [Member]
Restructuring and Related Activities [Abstract]
Restructuring Reserve	13.0	9.4	1.6
Restructuring Charges	22.3	31.1
Restructuring Reserve, Accrual Adjustment	(4.9)	(0.5)
Payments for Restructuring	13.8	22.8
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	13.0	9.4	$ 1.6
Restructuring Reserve, Accrual Adjustment	(4.9)	(0.5)
Payments for Restructuring	(13.8)	(22.8)
Restructuring Charges	$ 22.3	$ 31.1