SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) yr Employee countries	Dec. 31, 2023 USD ($)	Dec. 31, 2022	Dec. 31, 2024 CAD ($) Employee countries	Dec. 31, 2023 CAD ($)
Accounting Policies [Abstract]
Entity Number of Employees | Employee	70,000			70,000
Number of Countries in which Entity Operates | countries	100			100
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	100.00%	100.00%	100.00%
Ownership percentage below which investments are generally accounted for on the cost method (in hundredths)	20.00%
Cash, Uninsured Amount	$ 1,516.0	$ 534.7
Accounts receivable balances (gross) from Medicare and Medicaid	$ 97.4	$ 86.5
Accounts receivable from Ontario government sponsored healthcare plan				$ 6.4	$ 5.5
Percent of gross accounts receivable due from patients	24.50%	20.40%		24.50%	20.40%
Inventory, Supplies, Net of Reserves	$ 384.2	$ 385.1
Inventory, Finished Goods, Net of Reserves	109.0	89.5
Inventory Valuation Reserves	$ 43.8	$ 66.1
Estimated useful life of capitalized software minimum (in years) | yr	3
Estimated useful life of capitalized software maximum (in years) | yr	15
Estimated useful life of capitalized software costs (in years) | yr	5
Minimum threshold percentage required to recognize income tax benefit (in hundredths)	50.00%			50.00%
LabCorp Diagnostics [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	78.00%	77.00%	77.00%
Biopharma Laboratory Services
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	22.00%	23.00%	23.00%