Restructuring and Related Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Number of years restructuring liabilities expected to be paid out over	4 years 9 months 18 days
Net restructuring charges	$ 43.1	$ 40.6	$ 54.6
Restructuring charges related to severance and other employee costs	16.3	14.1	32.9
Restructuring Costs and Asset Impairment Charges	28.0	17.4	24.9
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment	0.4	0.6	1.7
Facility Related Restructuring Reserve Accrual Adjustment	0.8	9.2	1.5
Restructuring charges related to contractual obligations associated with leased facilities and other facility related costs		18.9
Restructuring Reserve	8.4	7.8	13.4
Restructuring Reserve, Current	6.8
Restructuring Reserve, Noncurrent	1.6
Restructuring Charges	44.3	33.0
Restructuring Reserve, Accrual Adjustment	(1.2)	(9.8)
Payments for Restructuring	(42.5)	(46.2)
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	8.4	7.8	13.4
Net restructuring charges	43.1	40.6	54.6
Restructuring charges related to severance and other employee costs	16.3	14.1	32.9
Restructuring Costs and Asset Impairment Charges	28.0	17.4	24.9
Restructuring Reserve, Accrual Adjustment	(1.2)	(9.8)
Payments for Restructuring	42.5	46.2
Restructuring Charges	44.3	33.0
LabCorp Diagnostics [Member]
Restructuring and Related Activities [Abstract]
Net restructuring charges	18.6	15.3	26.7
Restructuring Cost and Reserve [Line Items]
Net restructuring charges	18.6	15.3	26.7
Covance Drug Development [Member]
Restructuring and Related Activities [Abstract]
Net restructuring charges	24.5	25.3	27.9
Restructuring Cost and Reserve [Line Items]
Net restructuring charges	24.5	25.3	27.9
Employee Severance [Member] | LabCorp Diagnostics [Member]
Restructuring and Related Activities [Abstract]
Restructuring Costs and Asset Impairment Charges		0.0
Restructuring Reserve	1.0	0.3	0.5
Restructuring Charges	7.8	5.2
Restructuring Reserve, Accrual Adjustment	0.0	(0.1)
Payments for Restructuring	7.1	5.3
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1.0	0.3	0.5
Restructuring Costs and Asset Impairment Charges		0.0
Restructuring Reserve, Accrual Adjustment	0.0	(0.1)
Payments for Restructuring	(7.1)	(5.3)
Restructuring Charges	7.8	5.2
Employee Severance [Member] | Covance Drug Development [Member]
Restructuring and Related Activities [Abstract]
Restructuring Costs and Asset Impairment Charges		0.0
Restructuring Reserve	3.3	2.4	5.5
Restructuring Charges	8.5	8.9
Restructuring Reserve, Accrual Adjustment	(0.4)	(0.5)
Payments for Restructuring	7.2	11.5
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3.3	2.4	5.5
Restructuring Costs and Asset Impairment Charges		0.0
Restructuring Reserve, Accrual Adjustment	(0.4)	(0.5)
Payments for Restructuring	(7.2)	(11.5)
Restructuring Charges	8.5	8.9
Facility Closing [Member] | LabCorp Diagnostics [Member]
Restructuring and Related Activities [Abstract]
Restructuring Costs and Asset Impairment Charges		7.5
Restructuring Reserve	0.3	0.4	2.7
Restructuring Charges	11.0	5.5
Restructuring Reserve, Accrual Adjustment	(0.2)	(2.8)
Payments for Restructuring	10.9	12.5
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.3	0.4	2.7
Restructuring Costs and Asset Impairment Charges		7.5
Restructuring Reserve, Accrual Adjustment	(0.2)	(2.8)
Payments for Restructuring	(10.9)	(12.5)
Restructuring Charges	11.0	5.5
Facility Closing [Member] | Covance Drug Development [Member]
Restructuring and Related Activities [Abstract]
Restructuring Costs and Asset Impairment Charges		9.9
Restructuring Reserve	3.8	4.7	4.7
Restructuring Charges	17.0	13.4
Restructuring Reserve, Accrual Adjustment	(0.6)	(6.4)
Payments for Restructuring	17.3	16.9
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3.8	4.7	$ 4.7
Restructuring Costs and Asset Impairment Charges		9.9
Restructuring Reserve, Accrual Adjustment	(0.6)	(6.4)
Payments for Restructuring	(17.3)	(16.9)
Restructuring Charges	$ 17.0	$ 13.4