Laboratory Corporation of America (LH) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares shares in Millions	6 Months Ended
	Jun. 30, 2021	Aug. 04, 2021
Document Information [Table]
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		96.4
Document Fiscal Period Focus	Q2
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	1-11353
Entity Registrant Name	LABORATORY CORPORATION OF AMERICA HOLDINGS
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3757370
Entity Address, Address Line One	358 South Main Street
Entity Address, City or Town	Burlington,
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27215
City Area Code	336
Local Phone Number	229-1127
Title of 12(b) Security	Common Stock, $0.10 par value
Trading Symbol	LH
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000920148

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)	3 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Current assets:
Cash and cash equivalents	$ 1,963,200,000	$ 1,963,200,000	$ 1,320,800,000
Accounts Receivable, after Allowance for Credit Loss, Current	2,210,100,000	2,210,100,000	2,479,800,000
Unbilled Contracts Receivable	637,000,000	637,000,000	536,800,000
Supplies inventories	421,300,000	421,300,000	423,200,000
Prepaid expenses and other	461,900,000	461,900,000	364,800,000
Total current assets	5,693,500,000	5,693,500,000	5,125,400,000
Property, plant and equipment, net	2,701,800,000	2,701,800,000	2,729,600,000
Goodwill, net	7,744,500,000	7,744,500,000	7,751,500,000
Intangible Assets, Net (Excluding Goodwill)	3,753,800,000	3,753,800,000	3,961,100,000
Joint venture partnerships and equity method investments	82,100,000	82,100,000	73,500,000
Deferred Income Taxes and Other Assets, Current	23,700,000	23,700,000	20,600,000
Other assets, net	417,700,000	417,700,000	410,000,000
Total assets	20,417,100,000	20,417,100,000	20,071,700,000
Liabilities, Current [Abstract]
Accounts Payable, Current	599,900,000	599,900,000	638,900,000
Accrued Liabilities, Current	1,317,900,000	1,317,900,000	1,357,700,000
Deferred Revenue, Current	546,700,000	546,700,000	506,500,000
Operating Lease, Liability, Current	190,000,000	190,000,000	192,000,000
Finance Lease, Liability, Current	10,800,000	10,800,000	6,700,000
Current debt excluding finance lease liability	1,800,000	1,800,000	376,700,000
Long-term debt, less current portion	2,667,100,000	2,667,100,000	3,078,500,000
Long-term Debt, Excluding Current Maturities	5,422,600,000	5,422,600,000	5,419,000,000
Commitments and contingent liabilities	502,900,000	502,900,000	526,400,000
Operating Lease, Liability, Noncurrent	645,200,000	645,200,000	677,600,000
Finance Lease, Liability, Noncurrent	87,200,000	87,200,000	84,400,000
Deferred income taxes and other tax liabilities	826,000,000	826,000,000	905,400,000
Noncontrolling interest	10,151,000,000	10,151,000,000	10,691,300,000
Shareholders' equity:
Common stock, 92.8 and 93.5 shares outstanding at March 31, 2013 and December 31, 2012, respectively	21,000,000	21,000,000	20,700,000
Additional paid-in capital	0	0	110,300,000
Retained earnings	8,900,000	8,900,000	9,000,000
Accumulated other comprehensive income	(10,417,400,000)	(10,417,400,000)	(9,402,300,000)
Total liabilities and shareholders' equity	(181,200,000)	(181,200,000)	(161,900,000)
Stockholders' Equity Attributable to Parent	10,245,100,000	10,245,100,000	9,359,700,000
Liabilities and Equity	20,417,100,000	20,417,100,000	$ 20,071,700,000
Repayments of Senior Debt		1,000,000,000
Net earnings	$ 468,000,000	$ 1,238,100,000

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - USD ($) shares in Millions, $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss	$ 20.9	$ 22.1
Shareholders' Equity:
Common stock, shares outstanding (in shares)	96.7	97.5

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net restructuring and other special charges	$ 9,600,000	$ 6,400,000	$ 28,800,000	$ 31,800,000
Revenues	3,840,700,000	2,768,800,000	8,002,200,000	5,592,600,000
Cost of Revenue	2,575,900,000	2,008,300,000	5,138,400,000	4,104,100,000
Gross Profit	1,264,800,000	760,500,000	2,863,800,000	1,488,500,000
Selling, general and administrative expenses	458,700,000	396,300,000	888,500,000	791,800,000
Amortization of intangibles and other assets	92,400,000	60,100,000	184,500,000	122,400,000
Asset Impairment Charges	0	0	0	437,400,000
Net restructuring and other special charges	9,600,000	6,400,000	28,800,000	31,800,000
Operating Income (Loss)	704,100,000	297,700,000	1,762,000,000	105,100,000
Other income (expenses):
Interest expense	(78,300,000)	(52,700,000)	(126,800,000)	(107,700,000)
Equity method income, net	8,000,000	1,800,000	12,500,000	(4,800,000)
Investment income	2,700,000	2,500,000	5,100,000	5,100,000
Other, net	14,100,000	47,700,000	19,600,000	31,600,000
Earnings before income taxes	650,600,000	297,000,000	1,672,400,000	29,300,000
Provision for income taxes	182,600,000	65,400,000	434,300,000	114,600,000
Net earnings	468,000,000	231,600,000	1,238,100,000	(85,300,000)
Less: Net earnings attributable to the noncontrolling interest	(600,000)	0	(1,100,000)	(300,000)
Net earnings attributable to Laboratory Corporation of America Holdings	$ 467,400,000	$ 231,600,000	$ 1,237,000,000	$ (85,600,000)
Basic earnings per common share (in dollars per share)	$ 4.80	$ 2.38	$ 12.69	$ (0.88)
Diluted earnings per common share (in dollars per share)	$ 4.76	$ 2.37	$ 12.58	$ (0.88)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Provision for income taxes	$ 182,600,000	$ 65,400,000	$ 434,300,000	$ 114,600,000
Net earnings	468,000,000	231,600,000	1,238,100,000	(85,300,000)
Other Comprehensive Earnings, Net of Tax
Foreign currency translation adjustments	43,800,000	66,900,000	(23,000,000)	(80,500,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	2,100,000	2,700,000	5,100,000	5,400,000
Other comprehensive earnings (loss) before tax	45,900,000	69,600,000	(17,900,000)	(75,100,000)
Tax effect of adjustments	(600,000)	(700,000)	(1,400,000)	(1,500,000)
Other comprehensive earnings (loss), net of tax	45,300,000	68,900,000	(19,300,000)	(76,600,000)
Comprehensive earnings	513,300,000	300,500,000	1,218,800,000	(161,900,000)
Less: Net earnings attributable to the noncontrolling interest	(600,000)	0	(1,100,000)	(300,000)
Comprehensive earnings attributable to Laboratory Corporation of America Holdings	$ 512,700,000	$ 300,500,000	$ 1,217,700,000	$ (162,200,000)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
BALANCE at Dec. 31, 2019	$ 7,567,000,000	$ 9,000,000	$ 26,800,000	$ 7,903,600,000	$ (372,400,000)
Net earnings attributable to Laboratory Corporation of America Holdings	(317,200,000)	0	0	(317,200,000)	0
Other comprehensive earnings, net of tax	(145,500,000)	0	0	0	(145,500,000)
Issuance of common stock under employee stock plans	(26,900,000)	0	(26,900,000)	0	0
Surrender of restricted stock and performance share awards	(22,000,000)	0	(22,000,000)	0	0
Stock compensation	17,900,000	0	17,900,000	0	0
Purchase of common stock	(100,000,000)	0	49,600,000	50,400,000	0
BALANCE at Mar. 31, 2020	7,020,100,000	9,000,000	0	7,529,000,000	(517,900,000)
BALANCE at Dec. 31, 2019	7,567,000,000	9,000,000	26,800,000	7,903,600,000	(372,400,000)
Net earnings attributable to Laboratory Corporation of America Holdings	(85,600,000)
Other comprehensive earnings, net of tax	(76,600,000)
BALANCE at Jun. 30, 2020	7,352,700,000	9,000,000	32,100,000	7,760,600,000	(449,000,000)
BALANCE at Mar. 31, 2020	7,020,100,000	9,000,000	0	7,529,000,000	(517,900,000)
Net earnings attributable to Laboratory Corporation of America Holdings	231,600,000	0	0	231,600,000	0
Other comprehensive earnings, net of tax	68,900,000	0	0	0	68,900,000
Issuance of common stock under employee stock plans	(1,800,000)	0	(1,800,000)	0	0
Surrender of restricted stock and performance share awards	(9,500,000)	0	(9,500,000)	0	0
Stock compensation	39,800,000	0	39,800,000	0	0
BALANCE at Jun. 30, 2020	7,352,700,000	9,000,000	32,100,000	7,760,600,000	(449,000,000)
Retained Earnings (Accumulated Deficit)	9,402,300,000
BALANCE at Dec. 31, 2020	9,359,700,000	9,000,000	110,300,000	9,402,300,000	(161,900,000)
Net earnings attributable to Laboratory Corporation of America Holdings	769,600,000	0	0	769,600,000	0
Other comprehensive earnings, net of tax	(64,600,000)	0	0	0	(64,600,000)
Issuance of common stock under employee stock plans	(24,700,000)	0	(24,700,000)	0	0
Surrender of restricted stock and performance share awards	(28,100,000)	0	(28,100,000)	0	0
Stock compensation	28,700,000	0	28,700,000	0	0
Purchase of common stock	(68,500,000)	0	68,500,000	0	0
BALANCE at Mar. 31, 2021	10,021,500,000	9,000,000	67,100,000	10,171,900,000	(226,500,000)
BALANCE at Dec. 31, 2020	9,359,700,000	9,000,000	110,300,000	9,402,300,000	(161,900,000)
Net earnings attributable to Laboratory Corporation of America Holdings	1,237,000,000
Other comprehensive earnings, net of tax	(19,300,000)
BALANCE at Jun. 30, 2021	10,245,100,000	8,900,000	0	10,417,400,000	(181,200,000)
BALANCE at Mar. 31, 2021	10,021,500,000	9,000,000	67,100,000	10,171,900,000	(226,500,000)
Net earnings attributable to Laboratory Corporation of America Holdings	467,400,000	0	0	467,400,000	0
Other comprehensive earnings, net of tax	45,300,000	0	0	0	45,300,000
Issuance of common stock under employee stock plans	(1,900,000)	0	(1,900,000)	0	0
Surrender of restricted stock and performance share awards	(14,900,000)	0	(14,900,000)	0	0
Stock compensation	23,900,000	0	23,900,000	0	0
Purchase of common stock	(300,000,000)	100,000	78,000,000	221,900,000	0
BALANCE at Jun. 30, 2021	10,245,100,000	$ 8,900,000	$ 0	$ 10,417,400,000	$ (181,200,000)
Retained Earnings (Accumulated Deficit)	$ 10,417,400,000

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 1,238,100,000	$ (85,300,000)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation And Amortization Of Leased Assets	96,300,000	103,900,000
Depreciation and amortization	371,000,000	288,500,000
Stock compensation	52,600,000	57,700,000
Asset Impairment Charges	0	437,400,000
Deferred income taxes	(85,500,000)	(29,400,000)
Other Operating Activities, Cash Flow Statement	2,300,000	55,400,000
Change in assets and liabilities (net of effects of acquisitions):
Increase in accounts receivable (net)	(265,000,000)	124,200,000
Increase (Decrease) in Unbilled Contract Receivable	100,300,000	58,900,000
Increase in inventories	17,500,000	98,400,000
Decrease in accounts payable	(44,300,000)	(88,900,000)
Increase (Decrease) in Deferred Revenue	37,700,000	28,900,000
Increase (Decrease) in Prepaid Expense and Other Assets	31,000,000	(33,100,000)
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities	(139,600,000)	54,700,000
Net cash provided by operating activities	1,644,800,000	574,500,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash payments for laboratory-related assets	192,600,000	205,100,000
Proceeds from sale of assets	2,700,000	7,200,000
Proceeds from Sales of Business, Affiliate and Productive Assets	13,100,000	0
Proceeds from Sale of Equity Method Investments	0	1,000,000
Payments to Acquire Equity Method Investments	11,900,000	21,800,000
Net Cash Provided by (Used in) Investing Activities	(222,800,000)	(230,000,000)
Payments to Acquire Businesses, Net of Cash Acquired	34,100,000	11,300,000
Net cash used for investing activities	(222,800,000)	(230,000,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Issuance of Senior Long-term Debt	1,000,000,000	0
Repayments of Senior Debt	1,000,000,000	0
Repayments of Other Long-term Debt	375,000,000	0
Proceeds from revolving credit facilities	0	151,700,000
Repayments of Lines of Credit	0	151,700,000
Payment, Tax Withholding, Share-based Payment Arrangement	43,000,000	31,500,000
Net proceeds from issuance of stock to employees	26,600,000	28,800,000
Payments for Repurchase of Common Stock	368,500,000	100,000,000
Other Financing Cash Flows	15,600,000	17,000,000
Net cash provided by (used for) financing activities	(775,500,000)	(119,700,000)
Effect of exchange rate changes on cash and cash equivalents	(4,100,000)	(5,300,000)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	642,400,000	219,500,000
Cash and cash equivalents at beginning of period	1,320,800,000	337,500,000
Cash and cash equivalents at end of period	$ 1,963,200,000	$ 557,000,000

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, 2021 2020 Cash paid during period for: Interest $ 109.3 $ 111.5 Income taxes, net of refunds 591.6 15.1 Disclosure of non-cash financing and investing activities: Change in accrued property, plant and equipment 4.8 (17.1)
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2021 2020 Cash paid during period for: Interest $ 109.3 $ 111.5 Income taxes, net of refunds 591.6 15.1 Disclosure of non-cash financing and investing activities: Change in accrued property, plant and equipment 4.8 (17.1)

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION Tabular Information	3 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, 2021 2020 Cash paid during period for: Interest $ 109.3 $ 111.5 Income taxes, net of refunds 591.6 15.1 Disclosure of non-cash financing and investing activities: Change in accrued property, plant and equipment 4.8 (17.1)
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2021 2020 Cash paid during period for: Interest $ 109.3 $ 111.5 Income taxes, net of refunds 591.6 15.1 Disclosure of non-cash financing and investing activities: Change in accrued property, plant and equipment 4.8 (17.1)

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION Description Information - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Debt Conversion [Line Items]
Capital Expenditures Incurred but Not yet Paid		$ (17.1)
Decrease in Capital Expenditures Incurred but not yet Paid	$ 4.8
Cash paid during period for:
Interest	109.3	111.5
Income taxes, net of refunds	$ 591.6	$ 15.1

BASIS OF FINANCIAL STATEMENT PR

BASIS OF FINANCIAL STATEMENT PRESENTATION	3 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	BASIS OF FINANCIAL STATEMENT PRESENTATION Laboratory Corporation of America ® Holdings (Labcorp ® or the Company) is a leading global life sciences company that provides vital information to help doctors, hospitals, pharmaceutical companies, researchers, and patients make clear and confident decisions. By leveraging its strong diagnostics and drug development capabilities, the Company provides insights and accelerates innovations to improve health and improve lives. The Company reports its business in two segments, Labcorp Diagnostics (Dx) and Labcorp Drug Development (DD). For further financial information about these segments, see Note 14 Business Segment Information to the Condensed Consolidated Financial Statements. During the three months ended June 30, 2021, Dx and DD contributed approximately 61% and 39% respectively, of revenues to the Company. During the six months ended June 30, 2021, Dx and DD contributed approximately 63% and 37% respectively of revenues to the Company. The condensed consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries for which it exercises control. Long-term investments in affiliated companies in which the Company exercises significant influence, but which it does not control, are accounted for using the equity method. Investments in which the Company does not exercise significant influence (generally, when the Company has an investment of less than 20.0% and no representation on the investee's board of directors) are accounted for at fair value or at cost minus impairment adjusted for observable price changes in orderly transactions for an identical or similar investment of the same issuer for those investments that do not have readily determinable fair values. All significant inter-company transactions and accounts have been eliminated. The Company does not have any significant variable interest entities or special purpose entities whose financial results are not included in the condensed consolidated financial statements. The financial statements of the Company's operating foreign subsidiaries are measured using the local currency as the functional currency. Assets and liabilities are translated at exchange rates as of the balance sheet date. Revenues and expenses are translated at average monthly exchange rates prevailing during the period. Resulting translation adjustments are included in “Accumulated other comprehensive income (loss).” The accompanying condensed consolidated financial statements of the Company are unaudited. In the opinion of management, all adjustments necessary for a fair statement of results of operations, cash flows, and financial position have been made. Except as otherwise disclosed, all such adjustments are of a normal recurring nature. Interim results are not necessarily indicative of results for a full year. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles. The condensed consolidated financial statements and notes are presented in accordance with the rules and regulations of the United States (U.S.) Securities and Exchange Commission (SEC) and do not contain certain information included in the Company’s fiscal year 2020 Annual Report on Form 10-K (Annual Report). Therefore, these interim statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report. Recently Adopted Guidance In August 2018, the Financial Accounting Standards Board (FASB) issued a new accounting standard to reduce, modify, and add to the disclosure requirements on defined benefit pension and other postretirement plans. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements. In December 2019, the FASB issued a new accounting standard to simplify accounting for income taxes and remove, modify, and add to the disclosure requirements of income taxes. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements. In January 2020, the FASB issued a new accounting standard to clarify the interaction of the accounting for equity securities and investments accounted for under the equity method of accounting and the accounting for certain forward contracts and purchased options. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements. New Accounting Pronouncements In January 2021, the FASB issued a new accounting standard to clarify that certain optional expedients and exceptions relative to reference rate reform for contract modification and hedge accounting apply to derivatives that are affected by the discounting transition. An entity may elect to apply the amendment on a full retrospective basis as of any date from the
Basis of Presentation and Significant Accounting Policies [Text Block]	BASIS OF FINANCIAL STATEMENT PRESENTATION Laboratory Corporation of America ® Holdings (Labcorp ® or the Company) is a leading global life sciences company that provides vital information to help doctors, hospitals, pharmaceutical companies, researchers, and patients make clear and confident decisions. By leveraging its strong diagnostics and drug development capabilities, the Company provides insights and accelerates innovations to improve health and improve lives. The Company reports its business in two segments, Labcorp Diagnostics (Dx) and Labcorp Drug Development (DD). For further financial information about these segments, see Note 14 Business Segment Information to the Condensed Consolidated Financial Statements. During the three months ended June 30, 2021, Dx and DD contributed approximately 61% and 39% respectively, of revenues to the Company. During the six months ended June 30, 2021, Dx and DD contributed approximately 63% and 37% respectively of revenues to the Company. The condensed consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries for which it exercises control. Long-term investments in affiliated companies in which the Company exercises significant influence, but which it does not control, are accounted for using the equity method. Investments in which the Company does not exercise significant influence (generally, when the Company has an investment of less than 20.0% and no representation on the investee's board of directors) are accounted for at fair value or at cost minus impairment adjusted for observable price changes in orderly transactions for an identical or similar investment of the same issuer for those investments that do not have readily determinable fair values. All significant inter-company transactions and accounts have been eliminated. The Company does not have any significant variable interest entities or special purpose entities whose financial results are not included in the condensed consolidated financial statements. The financial statements of the Company's operating foreign subsidiaries are measured using the local currency as the functional currency. Assets and liabilities are translated at exchange rates as of the balance sheet date. Revenues and expenses are translated at average monthly exchange rates prevailing during the period. Resulting translation adjustments are included in “Accumulated other comprehensive income (loss).” The accompanying condensed consolidated financial statements of the Company are unaudited. In the opinion of management, all adjustments necessary for a fair statement of results of operations, cash flows, and financial position have been made. Except as otherwise disclosed, all such adjustments are of a normal recurring nature. Interim results are not necessarily indicative of results for a full year. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by generally accepted accounting principles. The condensed consolidated financial statements and notes are presented in accordance with the rules and regulations of the United States (U.S.) Securities and Exchange Commission (SEC) and do not contain certain information included in the Company’s fiscal year 2020 Annual Report on Form 10-K (Annual Report). Therefore, these interim statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report.

EARNINGS PER SHARE

EARNINGS PER SHARE	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS (LOSS) PER SHARE Basic earnings (loss) per share is computed by dividing net earnings (loss) attributable to Laboratory Corporation of America Holdings by the weighted average number of common shares outstanding. Diluted earnings (loss) per share is computed by dividing net earnings (loss) including the impact of dilutive adjustments by the weighted average number of common shares outstanding plus potentially dilutive shares, as if they had been issued at the earlier of the date of issuance or the beginning of the period presented. Potentially dilutive common shares result primarily from the Company’s outstanding stock options, restricted stock awards, restricted stock units, and performance share awards. The following represents a reconciliation of basic earnings (loss) per share to diluted earnings (loss) per share: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Earnings Shares Per Share Amount Earnings (Loss) Shares Per Share Amount Earning Shares Per Share Amount Earnings Shares Per Share Amount Basic earnings (loss) per share: Net earnings (loss) $ 467.4 97.4 $ 4.80 $ 231.6 97.3 $ 2.38 $ 1,237.0 97.5 $ 12.69 $ (85.6) 97.2 $ (0.88) Dilutive effect of employee stock options and awards — 0.8 — 0.4 — 0.8 — — Net earnings (loss) including impact of dilutive adjustments $ 467.4 98.2 $ 4.76 $ 231.6 97.7 $ 2.37 $ 1,237.0 98.4 $ 12.58 $ (85.6) 97.2 $ (0.88) Diluted earnings per share represent the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. These potential shares include dilutive stock options and unissued restricted stock awards. The following table summarizes the potential common shares not included in the computation of diluted earnings per share because their impact would have been antidilutive: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Employee stock options and awards 0.1 0.8 0.1 1.3

RESTRUCTURING AND OTHER SPECIAL

RESTRUCTURING AND OTHER SPECIAL CHARGES	3 Months Ended
	Jun. 30, 2021
Restructuring and Related Activities [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	RESTRUCTURING AND OTHER CHARGES During the three months ended June 30, 2021, the Company recorded net restructuring and other charges of $9.6: $6.0 within Dx and $3.6 within DD. The charges were comprised of $6.1 related to severance and other personnel costs and $3.5 in facility closures, lease terminations, and general integration activities. The charges were adjusted by an increase of $0.1 of previously established severance liabilities and the reversal of previously established liability of $0.1 in unused facility-related costs. During the six months ended June 30, 2021, the Company recorded net restructuring and other charges of $28.8: $13.5 within Dx and $15.3 within DD. The charges were comprised of $10.2 related to severance and other personnel costs and $18.7 in facility closures, lease terminations, and general integration activities. The charges were adjusted by an increase of $0.1 of previously established severance liabilities and the reversal of previously established liability of $0.2 in unused facility-related costs. During the three months ended June 30, 2020, the Company recorded net restructuring and other special charges of $6.4: $3.7 within Dx and $2.7 within DD. The charges were comprised of $5.4 related to severance and other personnel costs, $3.3 for a DD lab facility and equipment impairment, and $4.2 in facility closures, impairment of operating lease right-of-use assets, and general integration initiatives. The charges were offset by the reversal of previously established reserves of $1.1 and $5.5 in unused severance and facility-related costs, respectively. During the six months ended June 30, 2020, the Company recorded net restructuring and other charges of $31.8: $11.8 within Dx and $20.0 within DD. The charges were comprised of $10.5 related to severance and other personnel costs, $8.0 for a DD lab facility impairment and equipment impairments, and $20.0 in costs associated with facility closures, impairment of operating lease right-of-use assets, and general integration initiatives. The charges were offset by the reversal of previously established liability of $1.0 and $5.7 in unused severance costs and facility-related costs, respectively. The following represents the Company’s restructuring reserve activities for the period indicated: Dx DD Severance and Other Employee Costs Facility Costs Severance and Other Employee Costs Facility Costs Total Balance as of December 31, 2020 $ 0.3 $ 0.4 $ 2.4 $ 4.7 $ 7.8 Restructuring charges 5.2 8.4 5.0 10.3 28.9 Adjustments to prior restructuring accruals 0.1 (0.2) — — (0.1) Cash payments and other adjustments (4.8) (8.2) (3.1) (9.1) (25.2) Balance as of June 30, 2021 $ 0.8 $ 0.4 $ 4.3 $ 5.9 $ 11.4 Current $ 8.9 Non-current 2.5 $ 11.4

DEBT

DEBT	3 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	DEBT Short-term borrowings and the current portion of long-term debt at June 30, 2021, and December 31, 2020, consisted of the following: June 30, December 31, 2020 2019 Term Loan $ — $ 375.0 Debt issuance costs — (0.4) Current portion of note payable 1.8 2.1 Total short-term borrowings and current portion of long-term debt $ 1.8 $ 376.7 Long-term debt at June 30, 2021, and December 31, 2020, consisted of the following: June 30, December 31, 2020 3.20% senior notes due 2022 $ — $ 500.0 3.75% senior notes due 2022 — 500.0 4.00% senior notes due 2023 300.0 300.0 3.25% senior notes due 2024 600.0 600.0 2.30% senior notes due 2024 400.0 400.0 3.60% senior notes due 2025 1,000.0 1,000.0 1.55% senior notes due 2026 500.0 — 3.60% senior notes due 2027 600.0 600.0 2.95% senior notes due 2029 650.0 650.0 2.70% senior notes due 2031 509.5 — 4.70% senior notes due 2045 900.0 900.0 Debt issuance costs (42.4) (37.1) Note payable 5.5 6.1 Total long-term debt $ 5,422.6 $ 5,419.0 Senior Notes On May 26, 2021, the Company issued new senior notes representing $1,000.0 in debt securities and consisting of $500.0 aggregate principal amount of 1.55% senior notes due 2026 and $500.0 aggregate principal amount of 2.70% senior notes due 2031. Interest on these notes is payable semi-annually in arrears on June 1 and December 1 of each year, commencing on December 1, 2021. Net proceeds from the offering of these notes were $989.4 after deducting underwriting discounts and other expenses of the offering. The net proceeds were used, along with cash on hand, to redeem, prior to maturity, the Company's outstanding 3.20% senior notes due February 1, 2022 and 3.75% senior notes due August 23, 2022. During the second quarter of 2021, the Company entered into fixed-to-variable interest rate swap agreements for its 2.70% senior notes due 2031 with an aggregate notional amount of $500.0 and variable interest rates based on three-month LIBOR plus 1.0706% to hedge against changes in the fair value of a portion of the Company's long-term debt. These interest rate swaps are included in other long-term assets and added to the value of the senior notes with an aggregate fair value of $9.5 at June 30, 2021. Credit Facilities On June 3, 2019, the Company entered into an $850.0 term loan (the 2019 Term Loan) with a scheduled maturity date of June 3, 2021. The Company paid off the 2019 Term Loan balance during the first quarter of 2021. The Company also maintains a senior revolving credit facility, which was amended and restated on April 30, 2021. It consists of a five-year facility in the principal amount of up to $1,000.0, with the option of increasing the facility by up to an additional $500.0, subject to the agreement of one or more new or existing lenders to provide such additional amounts and certain other customary conditions. The revolving credit facility also provides for a subfacility of up to $100.0 for swing line borrowings and a subfacility of up to $150.0 for issuances of letters of credit. The Company is required to pay a facility fee on the aggregate commitments under the revolving credit facility, at a per annum rate ranging from 0.100% to 0.225%, depending on the Company's debt ratings. The revolving credit facility is permitted to be used for general corporate purposes, including working capital, capital expenditures, funding of share repurchases and certain other payments, acquisitions, and other investments. There were no balances outstanding on the Company's current revolving credit facility as of June 30, 2021 and December 31, 2020. As of June 30, 2021, the effective interest rate on the revolving credit facility was 1.10%. The credit facility expires on April 30, 2026. Under the revolving credit facility, the Company is subject to negative covenants limiting subsidiary indebtedness and certain other covenants typical for investment grade-rated borrowers, and the Company is required to maintain certain leverage ratios. The Company was in compliance with all covenants in the revolving credit facility at June 30, 2021, and expects that it will remain in compliance with its existing debt covenants for the next twelve months.
Short-term borrowings and current portion of long-term debt	Short-term borrowings and the current portion of long-term debt at June 30, 2021, and December 31, 2020, consisted of the following: June 30, December 31, 2020 2019 Term Loan $ — $ 375.0 Debt issuance costs — (0.4) Current portion of note payable 1.8 2.1 Total short-term borrowings and current portion of long-term debt $ 1.8 $ 376.7

PREFERRED STOCK AND COMMON SHAR

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY	3 Months Ended
	Jun. 30, 2021
Stockholders' Equity Note [Abstract]
Changes in common shares issued and held in treasury	The changes in common shares issued are summarized below: Issued and Outstanding Common shares at December 31, 2020 97.5 Shares issued under employee stock plans 0.6 Shares repurchased (1.4) Common shares at June 30, 2021 96.7
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The components of accumulated other comprehensive earnings (loss) are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance as of December 31, 2020 $ (21.3) $ (140.6) $ (161.9) Current year adjustments (23.0) 10.2 (12.8) Amounts reclassified from accumulated other comprehensive income — (5.1) (5.1) Tax effect of adjustments — (1.4) (1.4) Balance as of June 30, 2021 $ (44.3) $ (136.9) $ (181.2)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Preferred Stock and Common Shareholders' Equity	PREFERRED STOCK AND COMMON SHAREHOLDERS’ EQUITY The Company is authorized to issue up to 265.0 shares of common stock, par value $0.10 per share. The Company is authorized to issue up to 30.0 shares of preferred stock, par value $0.10 per share. There were no preferred shares outstanding as of June 30, 2021 and December 31, 2020. The changes in common shares issued are summarized below: Issued and Outstanding Common shares at December 31, 2020 97.5 Shares issued under employee stock plans 0.6 Shares repurchased (1.4) Common shares at June 30, 2021 96.7 Share Repurchase Program During the six months ended June 30, 2021, the Company purchased 1.4 shares of its common stock at an average price of $257.38. When the Company repurchases shares, the amount paid to repurchase the shares in excess of the par or stated value is allocated to additional paid-in-capital unless subject to limitation or the balance in additional paid-in-capital is exhausted. Remaining amounts are recognized as a reduction in retained earnings. As of June 30, 2021, the Company had outstanding authorization from the board of directors to purchase up to $431.5 of the Company's common stock. The repurchase authorization has no expiration date. Accumulated Other Comprehensive Earnings (Loss) The components of accumulated other comprehensive earnings (loss) are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance as of December 31, 2020 $ (21.3) $ (140.6) $ (161.9) Current year adjustments (23.0) 10.2 (12.8) Amounts reclassified from accumulated other comprehensive income — (5.1) (5.1) Tax effect of adjustments — (1.4) (1.4) Balance as of June 30, 2021 $ (44.3) $ (136.9) $ (181.2)

INCOME TAXES

INCOME TAXES	3 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company does not recognize a tax benefit unless it concludes that it is more likely than not that the benefit will be sustained on audit by the taxing authority based solely on the technical merits of the associated tax position. If the recognition threshold is met, the Company recognizes a tax benefit measured at the largest amount of the tax benefit that it believes is greater than 50% likely to be realized. The year to date 2021 tax rate was favorable to the corresponding year to date 2020 tax rate due primarily to the 2020 impairment charges for which either no tax benefit was recorded (as they were not deductible) or the associated tax assets required a full valuation allowance partially offset by the 2021 revaluation of the United Kingdom net deferred tax liabilities reflecting a 25% effective tax rate as of 2023. The gross unrecognized income tax benefits were $48.8 and $48.8 at June 30, 2021, and December 31, 2020, respectively. It is anticipated that the amount of the unrecognized income tax benefits will change within the next 12 months; however, these changes are not expected to have a significant impact on the results of operations, cash flows or the financial position of the Company. As of June 30, 2021, and December 31, 2020, $46.7 and $46.7, respectively, are the approximate amounts of gross unrecognized income tax benefits that, if recognized, would favorably affect the effective income tax rate in future periods. The Company recognizes interest and penalties related to unrecognized income tax benefits in income tax expense. Accrued interest and penalties related to uncertain tax positions totaled $9.1 and $8.3 as of June 30, 2021, and December 31, 2020, respectively. The Company has substantially concluded all U.S. federal income tax matters for years through 2016. Substantially all material state and local and foreign income tax matters have been concluded through 2015 and 2011, respectively. The Company has various state and foreign income tax examinations ongoing throughout the year. The Company believes adequate provisions have been recorded related to all open tax years.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company’s population of financial assets and liabilities subject to fair value measurements as of June 30, 2021, and December 31, 2020, is as follows: Fair Value Measurements as of June 30, 2021 Balance Sheet Fair Value as of Using Fair Value Hierarchy Classification June 30, 2021 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 16.6 $ — $ 16.6 $ — Cross currency swaps Other liabilities 16.6 — 16.6 — Interest rate swaps Other assets, net 9.5 — 9.5 — Cash surrender value of life insurance policies Other assets, net 101.1 — 101.1 — Deferred compensation liability Other liabilities 99.2 — 99.2 — Investment in equity securities Other current assets 0.8 0.8 — — Contingent consideration Other liabilities 12.8 — — 12.8 Fair Value Measurements as of December 31, 2020 Balance Sheet Fair Value as of Using Fair Value Hierarchy Classification December 31, 2020 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 16.2 $ — $ 16.2 $ — Cross currency swaps Other liabilities 40.4 — 40.4 — Cash surrender value of life insurance policies Other assets, net 90.6 — 90.6 — Deferred compensation liability Other liabilities 89.2 — 89.2 — Contingent consideration Other liabilities 13.9 — — 13.9 Fair Value Measurement of Level 3 Liabilities Contingent Consideration Balance at December 31, 2020 $ 13.9 Adjustments (1.1) Balance at June 30, 2021 $ 12.8 The Company has a noncontrolling interest put related to its Ontario subsidiary that has been classified as mezzanine equity in the Company’s condensed consolidated balance sheets. The noncontrolling interest put is valued at its contractually determined value, which approximates fair value. The Company offers certain employees the opportunity to participate in an employee-funded deferred compensation plan (DCP). A participant's deferrals are allocated by the participant to one or more of 16 measurement funds, which are indexed to externally managed funds. From time to time, to offset the cost of the growth in the participant's investment accounts, the Company purchases life insurance policies, with the Company named as beneficiary of the policies. Changes in the cash surrender value of the life insurance policies are based upon earnings and changes in the value of the underlying investments, which are typically invested in a similar manner to the participant's allocations. Changes in the fair value of the DCP obligation are derived using quoted prices in active markets based on the market price per unit multiplied by the number of units. The cash surrender value and the DCP obligations are classified within Level 2 because their inputs are derived principally from observable market data by correlation to the hypothetical investments. Contingent acquisition consideration liabilities are measured at fair value using Level 3 valuations. These contingent consideration liabilities were recorded at fair value on the acquisition date and are remeasured quarterly based on the then assessed fair value and adjusted if necessary. The increases or decreases in the fair value of contingent consideration payable can result from changes in anticipated revenue levels and changes in assumed discount periods and rates. As the fair value measure is based on significant inputs that are not observable in the market, they are categorized as Level 3.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	3 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain (Loss) [Table Text Block]	The table below provides information regarding the location and amount of pretax (gains) losses of derivatives designated in fair value hedging: Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Three Months Ended June 30, Three Months Ended June 30, Six Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 2021 2020 2021 2020 Interest rate swap contracts $ — $ (0.9) $ — $ — $ — $ 0.9 $ — $ — Cross currency swaps $ (13.6) $ (8.8) $ — $ — $ 23.7 $ 11.1 $ — $ —
Derivative Instruments And Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company addresses its exposure to market risks, principally the market risk associated with changes in interest rates and foreign currency exchange rates, through a controlled program of risk management that includes, from time to time, the use of derivative financial instruments. The Company does not hold or issue derivative financial instruments for trading purposes. The Company does not believe that its exposure to market risk is material to the Company’s financial position or results of operations. Interest Rate Swaps During the second quarter of 2021, the Company entered into fixed-to-variable interest rate swap agreements for its 2.70% senior notes due 2031 with an aggregate notional amount of $500.0 and variable interest rates based on three-month LIBOR plus 1.0706%. These agreements were designated as hedges against changes in the fair value of a portion of the Company's long-term debt. The aggregate fair value of $9.5 at June 30, 2021 was included as a component of other long-term assets and added to the reported value of the senior notes. Cross Currency Swaps During the fourth quarter of 2018, the Company entered into U.S. Dollar to Swiss Franc cross-currency swap agreements with an aggregate notional value of $600.0. These instruments are designated as a hedge against the impact of foreign exchange movements on its net investment in a Swiss subsidiary. Of the notional value, $300.0 matures in 2022 and $300.0 matures in 2025. The cross currency swaps maturing in 2022 and 2025 with an aggregate fair value of $(13.2) and $(3.5) as of June 30, 2021, respectively, are included in other long-term liabilities. The cross currency swaps maturing in 2022 and 2025 with an aggregate fair value of $(26.0) and $(14.4) as of December 31, 2020, respectively, are included in other long-term liabilities. Changes in the fair value of the cross-currency swaps are recorded as a component of the foreign currency translation adjustment in accumulated other comprehensive income in the Condensed Consolidated Balance Sheet until the hedged item is recognized in earnings. The cumulative change in the fair value of these instruments of $(13.6) and $23.7 for the three and six months ended June 30, 2021, respectively, was recognized as currency translation within the Condensed Consolidated Statement of Comprehensive Earnings. There were no amounts reclassified from the Condensed Consolidated Statement of Comprehensive Earnings to the Condensed Consolidated Statement of Operations during the three or six months ended June 30, 2021. The table below presents the fair value of derivatives on a gross basis and the balance sheet classification of those instruments: June 30, 2021 December 31, 2020 Fair Value of Derivative Fair Value of Derivative Balance Sheet Caption Asset Liability U.S. Dollar Notional Asset Liability U.S. Dollar Notional Derivatives Designated as Hedging Instruments Interest rate swap Other assets, net $ 9.5 — $ 500.0 — — — Cross currency swaps Other assets, net or Other liabilities $ — $ 16.6 $ 600.0 $ — $ 40.4 $ 600.0 The table below provides information regarding the location and amount of pretax (gains) losses of derivatives designated in fair value hedging: Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Three Months Ended June 30, Three Months Ended June 30, Six Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 2021 2020 2021 2020 Interest rate swap contracts $ — $ (0.9) $ — $ — $ — $ 0.9 $ — $ — Cross currency swaps $ (13.6) $ (8.8) $ — $ — $ 23.7 $ 11.1 $ — $ — No gains or losses from derivative instruments have been recognized into income for the three and six months ended June 30, 2021, and 2020.
Schedule of Derivative Instruments [Table Text Block]	The table below presents the fair value of derivatives on a gross basis and the balance sheet classification of those instruments: June 30, 2021 December 31, 2020 Fair Value of Derivative Fair Value of Derivative Balance Sheet Caption Asset Liability U.S. Dollar Notional Asset Liability U.S. Dollar Notional Derivatives Designated as Hedging Instruments Interest rate swap Other assets, net $ 9.5 — $ 500.0 — — — Cross currency swaps Other assets, net or Other liabilities $ — $ 16.6 $ 600.0 $ — $ 40.4 $ 600.0

BUSINESS ACQUISITIONS

BUSINESS ACQUISITIONS	6 Months Ended
	Jun. 30, 2021
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	BUSINESS ACQUISITIONS AND DISPOSITIONS During the six months ended June 30, 2021, the Company acquired a business and related assets for approximately $34.1 in cash within Dx. The purchase consideration for the acquisition in the six months ended June 30, 2021, has been allocated under the acquisition method of accounting to the estimated fair market value of the net assets acquired, including approximately $17.6 in identifiable intangible assets and a residual amount of non-tax deductible goodwill of approximately $15.6. The amortization periods for intangible assets acquired from the business range from 5 to 15 years for customer relationships and non-compete agreements. The acquisition was made primarily to expand the Company's services for hospitals and health system laboratories. The excess of the fair value of the consideration conveyed over the fair value of the net assets acquired was recorded as goodwill. The goodwill reflects the Company's expectations to utilize the acquired business' workforce and established relationships and the benefits of being able to leverage operational efficiencies with favorable growth opportunities in these markets.

BUSINESS SEGMENT INFORMATION Bu

BUSINESS SEGMENT INFORMATION Business Segment information (Notes)	3 Months Ended
	Jun. 30, 2021
Segment Reporting Information [Line Items]
Segment Reporting Disclosure [Text Block]	BUSINESS SEGMENT INFORMATIONThe following table is a summary of segment information for the three and six months ended June 30, 2021, and 2020. The management approach has been used to present the following segment information. This approach is based upon the way the management of the Company organizes segments within an enterprise for making operating decisions and assessing performance. Financial information is reported on the basis that it is used internally by the chief operating decision maker (CODM) for evaluating segment performance and deciding how to allocate resources to segments. The Company’s chief executive officer has been identified as the CODM. Segment asset information is not presented because it is not used by the CODM at the segment level. Operating earnings of each segment represent revenues less directly identifiable expenses to arrive at operating income for the segment. General management and administrative corporate expenses are included in general corporate expenses below. Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Revenues: Dx $ 2,365.5 $ 1,692.7 $ 5,123.3 $ 3,394.7 DD 1,495.2 1,093.7 2,933.4 2,237.5 Intercompany eliminations and other (20.0) (17.6) (54.5) (39.6) Revenues 3,840.7 2,768.8 8,002.2 5,592.6 Operating earnings (loss): Dx 603.6 281.3 1,552.7 486.7 DD 147.3 65.5 303.7 (273.2) General corporate expenses (46.8) (49.1) (94.4) (108.4) Total operating income 704.1 297.7 1,762.0 105.1 Non-operating expenses, net (53.5) (0.7) (89.6) (75.8) Earnings before income taxes 650.6 297.0 1,672.4 29.3 Provision for income taxes 182.6 65.4 434.3 114.6 Net earnings (loss) 468.0 231.6 1,238.1 (85.3) Less: Net earnings attributable to the noncontrolling interest (0.6) — (1.1) (0.3) Net earnings (loss) attributable to Laboratory Corporation of America Holdings $ 467.4 $ 231.6 $ 1,237.0 $ (85.6)

BASIS OF FINANCIAL STATEMENT _2

BASIS OF FINANCIAL STATEMENT PRESENTATION Use of Estimates (Policies)	3 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In January 2021, the FASB issued a new accounting standard to clarify that certain optional expedients and exceptions relative to reference rate reform for contract modification and hedge accounting apply to derivatives that are affected by the discounting transition. An entity may elect to apply the amendment on a full retrospective basis as of any date from the
Recently Adopted Accounting Guidance [Policy Text Block]	Recently Adopted Guidance In August 2018, the Financial Accounting Standards Board (FASB) issued a new accounting standard to reduce, modify, and add to the disclosure requirements on defined benefit pension and other postretirement plans. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements. In December 2019, the FASB issued a new accounting standard to simplify accounting for income taxes and remove, modify, and add to the disclosure requirements of income taxes. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements. In January 2020, the FASB issued a new accounting standard to clarify the interaction of the accounting for equity securities and investments accounted for under the equity method of accounting and the accounting for certain forward contracts and purchased options. The Company adopted this standard effective January 1, 2021. The adoption of this standard did not have a material impact on the consolidated financial statements.

Intangible Assets, Goodwill and

Intangible Assets, Goodwill and Other (Policies)	3 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Goodwill, Policy	GOODWILL AND INTANGIBLE ASSETS The changes in the carrying amount of goodwill for the six months ended June 30, 2021, are as follows: Dx DD Total Balance as of December 31, 2020 $ 3,800.2 $ 3,951.3 $ 7,751.5 Goodwill acquired during the period 15.6 — 15.6 Foreign currency impact and other adjustments to goodwill 5.8 (28.4) (22.6) Balance as of June 30, 2021 $ 3,821.6 $ 3,922.9 $ 7,744.5 The Company assesses goodwill and indefinite-lived intangibles for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. The Company recognizes an impairment charge for the amount by which the reporting unit's carrying amount exceeds its fair value. Based upon the revised forecasted revenues and operating income following the declaration of the COVID-19 global pandemic, management concluded there was a triggering event and updated its annual 2019 goodwill impairment testing as of March 31, 2020, for certain of its DD reporting units and Dx reporting units. Based on the quantitative impairment assessment, performed in the same manner as the annual quantitative assessment, the Company concluded that the fair value was less than carrying value for two of its reporting units and recorded a goodwill impairment of $418.7 for DD and $3.7 for Dx. The components of identifiable intangible assets are as follows: June 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Customer relationships $ 4,553.6 $ (1,605.6) $ 2,948.0 $ 4,643.3 $ (1,534.9) $ 3,108.4 Patents, licenses and technology 456.7 (263.6) 193.1 434.7 (252.6) 182.1 Non-compete agreements 114.4 (76.4) 38.0 109.6 (70.7) 38.9 Trade name 399.9 (331.4) 68.5 401.8 (263.9) 137.9 Land use right 10.8 (7.5) 3.3 10.9 (6.9) 4.0 Canadian licenses 502.9 — 502.9 489.8 — 489.8 $ 6,038.3 $ (2,284.5) $ 3,753.8 $ 6,090.1 $ (2,129.0) $ 3,961.1 Amortization of intangible assets for the three and six months ended June 30, 2021, and 2020, was $92.4 and $60.1 and $184.5 and $122.4, respectively. During the fourth quarter of 2020, as part of a rebranding initiative, the Company reduced the estimated useful life of its trade name assets to reflect their anticipated use through December 2021. This change in estimated useful life resulted in accelerated amortization of $28.0 and $57.2, respectively, during the three and six months ended June 30,

Revenue from Contract with Cust

Revenue from Contract with Customer (Policies)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue	REVENUES The Company's revenues by segment and by payers/customer groups for the three and six months ended June 30, 2021, and 2020, were as follows: For the Three Months Ended June 30, 2021 For the Three Months Ended June 30, 2020 North America Europe Other Total North America Europe Other Total Payer/Customer Dx Clients 17 % — % — % 17 % 21 % — % — % 21 % Patients 7 % — % — % 7 % 7 % — % — % 7 % Medicare and Medicaid 6 % — % — % 6 % 7 % — % — % 7 % Third-party 31 % — % — % 31 % 26 % — % — % 26 % Total Dx revenues by payer 61 % — % — % 61 % 61 % — % — % 61 % DD Biopharmaceutical and medical device companies 23 % 12 % 4 % 39 % 18 % 12 % 9 % 39 % Total revenues 84 % 12 % 4 % 100 % 79 % 12 % 9 % 100 % For the Six Months Ended June 30, 2021 For the Six Months Ended June 30, 2020 North America Europe Other Total North America Europe Other Total Payer/Customer Dx Clients 18 % — % — % 18 % 19 % — % — % 19 % Patients 6 % — % — % 6 % 7 % — % — % 7 % Medicare and Medicaid 6 % — % — % 6 % 7 % — % — % 7 % Third-party 33 % — % — % 33 % 27 % — % — % 27 % Total Dx revenues by payer 63 % — % — % 63 % 60 % — % — % 60 % DD Biopharmaceutical and medical device companies 22 % 11 % 4 % 37 % 19 % 13 % 8 % 40 % Total revenues 85 % 11 % 4 % 100 % 79 % 13 % 8 % 100 % Revenues in the U.S. were $3,091.3 (80.5%) and $2,129.0 (76.9%) for the three months ended June 30, 2021, and 2020, respectively and for the six months ended June 30, 2021, and 2020, were $6,537.4 (81.7%) and $4,294.2 (76.8%), respectively. Contract costs DD incurs sales commissions in the process of obtaining contracts with customers. Sales commissions that are payable upon contract award are recognized as assets and amortized over the expected contract term, along with related payroll tax expense. The amortization of commission expense is based on the weighted average contract duration for all commissionable awards in the respective business in which the commission expense is paid, which approximates the period over which goods and services are transferred to the customer. The amortization period of sales commissions ranges from approximately 1 to 5 years, depending on the business. For businesses that enter into primarily short-term contracts, the Company applies the practical expedient, which allows costs to obtain a contract to be expensed when incurred if the amortization period of the assets that would otherwise have been recognized is one year or less. Amortization of assets from sales commissions is included in selling, general, and administrative expense. DD incurs costs to fulfill contracts with customers. Contract fulfillment costs include software implementation costs and setup costs for certain market access solutions. These costs are recognized as assets and amortized over the expected term of the contract to which the implementation relates, which is the period over which services are expected to be provided to the customer. This period typically ranges from 2 to 5 years. Amortization of deferred contract fulfillment costs is included in cost of goods sold. June 30, 2021 December 31, 2020 Sales commission assets $ 36.4 $ 32.6 Deferred contract fulfillment costs 14.9 12.6 Total $ 51.3 $ 45.2 Amortization related to sales commission assets and associated payroll taxes for the three months ended June 30, 2021, and 2020, was $6.4 and $5.5, respectively and for the six month periods ended June 30, 2021, and 2020, was $13.3 and $10.8 respectively. Amortization related to deferred contract fulfillment costs for the three months ended June 30, 2021, and 2020, was $3.0 and $2.3, respectively, and was $6.5 and $5.3, respectively, for the six month periods ended June 30, 2021, and 2020. Receivables, Unbilled Services and Unearned Revenue Unbilled services are comprised primarily of unbilled receivables, but also include contract assets. A contract asset is recorded when a right to payment has been earned for work performed, but billing and payment for that work is determined by certain contractual milestones, whereas unbilled receivables are billable upon the passage of time. While the Company attempts to negotiate terms that provide for billing and payment of services prior or in close proximity to the provision of services, this is not always possible and there are fluctuations in the level of unbilled services and unearned revenue from period to period. The following table provides information about receivables, unbilled services, and unearned revenue (contract liabilities) from contracts with customers which primarily exist within DD. June 30, 2021 December 31, 2020 Receivables, which are included in accounts receivable $ 1,086.2 $ 1,001.5 Unbilled services 648.4 548.1 Unearned revenue 529.6 492.2 Revenues recognized during the period, that were included in the unearned revenue balance at the beginning of the period were $233.0 and $102.2 for the six months ended June 30, 2021, and 2020, respectively. Credit Loss Rollforward The Company estimates future expected losses on accounts receivable, unbilled services and notes receivable over the remaining collection period of the instrument. The rollforward for the allowance for credit losses for the six months ended June 30, 2021 is as follows: For the Six Months Ended June 30, 2021 Accounts Receivable Unbilled Services Note and Other Receivables Total Balance as of December 31, 2020 $ 22.1 $ 11.3 $ 5.7 $ 39.1 Plus, credit loss expense (credit) (0.4) — — (0.4) Less, write offs 0.8 (0.1) — 0.7 Balance as of June 30, 2021 $ 20.9 $ 11.4 $ 5.7 $ 38.0 Performance Obligations Under Long-Term Contracts Long-term contracts at the Company consist primarily of fully managed clinical studies within DD. The amount of existing performance obligations under such long-term contracts unsatisfied as of June 30, 2021, was $5,616.6. The Company expects to recognize revenue over the remaining contract term of the individual projects, with contract terms generally ranging from 1 to 8 years. Within DD, revenues of $12.2 and $4.0 were recognized during the three months ended June 30, 2021 and 2020, respectively and revenues of $28.7 and $13.7 were recognized during the six months ended June 30, 2021 and 2020, respectively, from performance obligations that were satisfied in previous periods. This revenue primarily relates to adjustments related to changes in scope in full service clinical studies, and to a lesser extent, changes in estimates.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Reconciliation of Basic earnings per Share to Diluted Earnings per Share	The following represents a reconciliation of basic earnings (loss) per share to diluted earnings (loss) per share: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Earnings Shares Per Share Amount Earnings (Loss) Shares Per Share Amount Earning Shares Per Share Amount Earnings Shares Per Share Amount Basic earnings (loss) per share: Net earnings (loss) $ 467.4 97.4 $ 4.80 $ 231.6 97.3 $ 2.38 $ 1,237.0 97.5 $ 12.69 $ (85.6) 97.2 $ (0.88) Dilutive effect of employee stock options and awards — 0.8 — 0.4 — 0.8 — — Net earnings (loss) including impact of dilutive adjustments $ 467.4 98.2 $ 4.76 $ 231.6 97.7 $ 2.37 $ 1,237.0 98.4 $ 12.58 $ (85.6) 97.2 $ (0.88)
Potential common shares not included in computation of diluted earnings per share	The following table summarizes the potential common shares not included in the computation of diluted earnings per share because their impact would have been antidilutive: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Employee stock options and awards 0.1 0.8 0.1 1.3

RESTRUCTURING AND OTHER SPECI_2

RESTRUCTURING AND OTHER SPECIAL CHARGES Restructuring and Other Special Charges Detail (Tables)	6 Months Ended
	Jun. 30, 2021
Restructuring Cost and Reserve [Line Items]
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	The following represents the Company’s restructuring reserve activities for the period indicated: Dx DD Severance and Other Employee Costs Facility Costs Severance and Other Employee Costs Facility Costs Total Balance as of December 31, 2020 $ 0.3 $ 0.4 $ 2.4 $ 4.7 $ 7.8 Restructuring charges 5.2 8.4 5.0 10.3 28.9 Adjustments to prior restructuring accruals 0.1 (0.2) — — (0.1) Cash payments and other adjustments (4.8) (8.2) (3.1) (9.1) (25.2) Balance as of June 30, 2021 $ 0.8 $ 0.4 $ 4.3 $ 5.9 $ 11.4 Current $ 8.9 Non-current 2.5 $ 11.4

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill		The changes in the carrying amount of goodwill for the six months ended June 30, 2021, are as follows: Dx DD Total Balance as of December 31, 2020 $ 3,800.2 $ 3,951.3 $ 7,751.5 Goodwill acquired during the period 15.6 — 15.6 Foreign currency impact and other adjustments to goodwill 5.8 (28.4) (22.6) Balance as of June 30, 2021 $ 3,821.6 $ 3,922.9 $ 7,744.5
Schedule of Intangible Assets and Goodwill [Table Text Block]	The components of identifiable intangible assets are as follows: June 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Customer relationships $ 4,553.6 $ (1,605.6) $ 2,948.0 $ 4,643.3 $ (1,534.9) $ 3,108.4 Patents, licenses and technology 456.7 (263.6) 193.1 434.7 (252.6) 182.1 Non-compete agreements 114.4 (76.4) 38.0 109.6 (70.7) 38.9 Trade name 399.9 (331.4) 68.5 401.8 (263.9) 137.9 Land use right 10.8 (7.5) 3.3 10.9 (6.9) 4.0 Canadian licenses 502.9 — 502.9 489.8 — 489.8 $ 6,038.3 $ (2,284.5) $ 3,753.8 $ 6,090.1 $ (2,129.0) $ 3,961.1

Debt (Tables)

Debt (Tables)	3 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Short-term borrowings and current portion of long-term debt	Short-term borrowings and the current portion of long-term debt at June 30, 2021, and December 31, 2020, consisted of the following: June 30, December 31, 2020 2019 Term Loan $ — $ 375.0 Debt issuance costs — (0.4) Current portion of note payable 1.8 2.1 Total short-term borrowings and current portion of long-term debt $ 1.8 $ 376.7

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Company's population of financial assets and liabilities subject to fair value measurements	The Company’s population of financial assets and liabilities subject to fair value measurements as of June 30, 2021, and December 31, 2020, is as follows: Fair Value Measurements as of June 30, 2021 Balance Sheet Fair Value as of Using Fair Value Hierarchy Classification June 30, 2021 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 16.6 $ — $ 16.6 $ — Cross currency swaps Other liabilities 16.6 — 16.6 — Interest rate swaps Other assets, net 9.5 — 9.5 — Cash surrender value of life insurance policies Other assets, net 101.1 — 101.1 — Deferred compensation liability Other liabilities 99.2 — 99.2 — Investment in equity securities Other current assets 0.8 0.8 — — Contingent consideration Other liabilities 12.8 — — 12.8 Fair Value Measurements as of December 31, 2020 Balance Sheet Fair Value as of Using Fair Value Hierarchy Classification December 31, 2020 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 16.2 $ — $ 16.2 $ — Cross currency swaps Other liabilities 40.4 — 40.4 — Cash surrender value of life insurance policies Other assets, net 90.6 — 90.6 — Deferred compensation liability Other liabilities 89.2 — 89.2 — Contingent consideration Other liabilities 13.9 — — 13.9
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Fair Value Measurement of Level 3 Liabilities Contingent Consideration Balance at December 31, 2020 $ 13.9 Adjustments (1.1) Balance at June 30, 2021 $ 12.8

BUSINESS SEGMENT INFORMATION (T

BUSINESS SEGMENT INFORMATION (Tables)	3 Months Ended
	Jun. 30, 2021
Segment Reconciliation of Operating Income to Consolidated [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Revenues: Dx $ 2,365.5 $ 1,692.7 $ 5,123.3 $ 3,394.7 DD 1,495.2 1,093.7 2,933.4 2,237.5 Intercompany eliminations and other (20.0) (17.6) (54.5) (39.6) Revenues 3,840.7 2,768.8 8,002.2 5,592.6 Operating earnings (loss): Dx 603.6 281.3 1,552.7 486.7 DD 147.3 65.5 303.7 (273.2) General corporate expenses (46.8) (49.1) (94.4) (108.4) Total operating income 704.1 297.7 1,762.0 105.1 Non-operating expenses, net (53.5) (0.7) (89.6) (75.8) Earnings before income taxes 650.6 297.0 1,672.4 29.3 Provision for income taxes 182.6 65.4 434.3 114.6 Net earnings (loss) 468.0 231.6 1,238.1 (85.3) Less: Net earnings attributable to the noncontrolling interest (0.6) — (1.1) (0.3) Net earnings (loss) attributable to Laboratory Corporation of America Holdings $ 467.4 $ 231.6 $ 1,237.0 $ (85.6)

REVENUE (Tables)

REVENUE (Tables)	3 Months Ended
	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Financing Receivable, Allowance for Credit Loss [Table Text Block]	The rollforward for the allowance for credit losses for the six months ended June 30, 2021 is as follows: For the Six Months Ended June 30, 2021 Accounts Receivable Unbilled Services Note and Other Receivables Total Balance as of December 31, 2020 $ 22.1 $ 11.3 $ 5.7 $ 39.1 Plus, credit loss expense (credit) (0.4) — — (0.4) Less, write offs 0.8 (0.1) — 0.7 Balance as of June 30, 2021 $ 20.9 $ 11.4 $ 5.7 $ 38.0
Contract with Customer, Asset and Liability [Table Text Block]	June 30, 2021 December 31, 2020 Receivables, which are included in accounts receivable $ 1,086.2 $ 1,001.5 Unbilled services 648.4 548.1 Unearned revenue 529.6 492.2
Disaggregation of Revenue [Table Text Block]	The Company's revenues by segment and by payers/customer groups for the three and six months ended June 30, 2021, and 2020, were as follows: For the Three Months Ended June 30, 2021 For the Three Months Ended June 30, 2020 North America Europe Other Total North America Europe Other Total Payer/Customer Dx Clients 17 % — % — % 17 % 21 % — % — % 21 % Patients 7 % — % — % 7 % 7 % — % — % 7 % Medicare and Medicaid 6 % — % — % 6 % 7 % — % — % 7 % Third-party 31 % — % — % 31 % 26 % — % — % 26 % Total Dx revenues by payer 61 % — % — % 61 % 61 % — % — % 61 % DD Biopharmaceutical and medical device companies 23 % 12 % 4 % 39 % 18 % 12 % 9 % 39 % Total revenues 84 % 12 % 4 % 100 % 79 % 12 % 9 % 100 % For the Six Months Ended June 30, 2021 For the Six Months Ended June 30, 2020 North America Europe Other Total North America Europe Other Total Payer/Customer Dx Clients 18 % — % — % 18 % 19 % — % — % 19 % Patients 6 % — % — % 6 % 7 % — % — % 7 % Medicare and Medicaid 6 % — % — % 6 % 7 % — % — % 7 % Third-party 33 % — % — % 33 % 27 % — % — % 27 % Total Dx revenues by payer 63 % — % — % 63 % 60 % — % — % 60 % DD Biopharmaceutical and medical device companies 22 % 11 % 4 % 37 % 19 % 13 % 8 % 40 % Total revenues 85 % 11 % 4 % 100 % 79 % 13 % 8 % 100 % Revenues in the U.S. were $3,091.3 (80.5%) and $2,129.0 (76.9%) for the three months ended June 30, 2021, and 2020, respectively and for the six months ended June 30, 2021, and 2020, were $6,537.4 (81.7%) and $4,294.2 (76.8%), respectively.
Capitalized Contract Cost [Table Text Block]	June 30, 2021 December 31, 2020 Sales commission assets $ 36.4 $ 32.6 Deferred contract fulfillment costs 14.9 12.6 Total $ 51.3 $ 45.2

Leases (Tables)

Leases (Tables)	3 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2021 2020 Cash paid during period for: Interest $ 109.3 $ 111.5 Income taxes, net of refunds 591.6 15.1 Disclosure of non-cash financing and investing activities: Change in accrued property, plant and equipment 4.8 (17.1)

BASIS OF FINANCIAL STATEMENT _3

BASIS OF FINANCIAL STATEMENT PRESENTATION (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Asset Impairment Charges	$ 0		$ 0		$ 0	$ 437,400,000
Revenues	3,840,700,000		2,768,800,000		8,002,200,000	5,592,600,000
Contract with Customer, Liability	529,600,000				529,600,000		$ 492,200,000
Amortization of Deferred Sales Commissions	$ 6,400,000		$ 5,500,000		$ 13,300,000	$ 10,800,000
Percent of Revenue Contributed	100.00%		100.00%		100.00%	100.00%
Nonoperating Income (Expense)	$ (53,500,000)		$ (700,000)		$ (89,600,000)	$ (75,800,000)
Provision for income taxes	182,600,000		65,400,000		434,300,000	114,600,000
Net earnings	468,000,000		231,600,000		1,238,100,000	(85,300,000)
Net Income (Loss) Attributable to Parent	467,400,000	$ 769,600,000	231,600,000	$ (317,200,000)	1,237,000,000	(85,600,000)
Stockholders' Equity Attributable to Parent	10,245,100,000	10,021,500,000	7,352,700,000	7,020,100,000	10,245,100,000	7,352,700,000	9,359,700,000	$ 7,567,000,000
Capitalized Contract Cost, Amortization	3,000,000		2,300,000		6,500,000	5,300,000
Deferred Revenue, Revenue Recognized					233,000,000	102,200,000
Revenue, Remaining Performance Obligation, Amount	5,616,600,000				5,616,600,000
Contract with Customer, Performance Obligation Satisfied in Previous Period	12,200,000		4,000,000		$ 28,700,000	13,700,000
Ownership percentage below which investments are generally accounted for on the cost method (in thousandths)					20.00%
LabCorp Diagnostics [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenues	$ 2,365,500,000		$ 1,692,700,000		$ 5,123,300,000	$ 3,394,700,000
Percent of Revenue Contributed	61.00%		61.00%		63.00%	60.00%
Goodwill, Impairment Loss					$ 3,700,000
Covance Drug Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenues	$ 1,495,200,000		$ 1,093,700,000		$ 2,933,400,000	$ 2,237,500,000
Percent of Revenue Contributed					37.00%
Goodwill, Impairment Loss					$ 418,700,000
Retained Earnings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Income (Loss) Attributable to Parent	467,400,000	769,600,000	231,600,000	(317,200,000)
Stockholders' Equity Attributable to Parent	$ 10,417,400,000	$ 10,171,900,000	$ 7,760,600,000	$ 7,529,000,000	$ 10,417,400,000	$ 7,760,600,000	$ 9,402,300,000	$ 7,903,600,000

EARNINGS PER SHARE (Reconciliat

EARNINGS PER SHARE (Reconciliation of Basic Earnings Per Share to Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Income [Abstract]
Net earnings attributable to Laboratory Corporation of America Holdings	$ 467,400,000	$ 769,600,000	$ 231,600,000	$ (317,200,000)	$ 1,237,000,000	$ (85,600,000)
Shares [Abstract]
Net earnings, basic (in shares)	97.4		97.3		97.5	97.2
Dilutive effect of employee stock options and awards, (in shares)	0.8		0.4		0.8	0
Per Share Amount [Abstract]
Basic earnings per common share (in dollars per share)	$ 4.80		$ 2.38		$ 12.69	$ (0.88)
Diluted earnings per common share (in dollars per share)	$ 4.76		$ 2.37		$ 12.58	$ (0.88)
Net Income (Loss) Available to Common Stockholders, Diluted	$ 467,400,000		$ 231,600,000		$ 1,237,000,000	$ (85,600,000)
Weighted Average Number of Shares Outstanding, Diluted	98.2		97.7		98.4	97.2

EARNINGS PER SHARE (Potential c

EARNINGS PER SHARE (Potential common shares not included in computation of diluted earnings per share) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Stock options (in shares)	0.1	0.8	0.1	1.3

RESTRUCTURING AND OTHER SPECI_3

RESTRUCTURING AND OTHER SPECIAL CHARGES (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 11,400,000		$ 11,400,000		$ 7,800,000
Restructuring Charges			28,900,000
Restructuring Reserve, Accrual Adjustment			100,000
Restructuring Reserve Settled With Cash And Other Adjustment			(25,200,000)
Restructuring charges related to severance and other employee costs	6,100,000	$ 5,400,000	10,200,000	$ 10,500,000
Restructuring charges related to contractual obligations associated with leased facilities and other facility related costs	3,500,000	4,200,000	18,700,000	20,000,000
Unused facility restructuring reserves	(100,000)	(5,500,000)	(200,000)	(5,700,000)
Restructuring Reserve, Current	8,900,000		8,900,000
Restructuring Reserve, Noncurrent	2,500,000		2,500,000
Asset Impairment Charges	0	0	0	437,400,000
Severance reserve adjustments	100,000	1,100,000	100,000	1,000,000
Leaseholds and Leasehold Improvements
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges		3,300,000		8,000,000
Covance Drug Development [Member]
Restructuring Cost and Reserve [Line Items]
Net restructuring charges	3,600,000	2,700,000	15,300,000	20,000,000
Covance Drug Development [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	4,300,000		4,300,000		2,400,000
Restructuring Charges			5,000,000
Restructuring Reserve, Accrual Adjustment			0
Restructuring Reserve Settled With Cash And Other Adjustment			(3,100,000)
Covance Drug Development [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	5,900,000		5,900,000		4,700,000
Restructuring Charges			10,300,000
Restructuring Reserve, Accrual Adjustment			0
Restructuring Reserve Settled With Cash And Other Adjustment			(9,100,000)
LabCorp Diagnostics [Member]
Restructuring Cost and Reserve [Line Items]
Net restructuring charges	6,000,000	$ 3,700,000	13,500,000	$ 11,800,000
LabCorp Diagnostics [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	800,000		800,000		300,000
Restructuring Charges			5,200,000
Restructuring Reserve, Accrual Adjustment			(100,000)
Restructuring Reserve Settled With Cash And Other Adjustment			(4,800,000)
LabCorp Diagnostics [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 400,000		400,000		$ 400,000
Restructuring Charges			8,400,000
Restructuring Reserve, Accrual Adjustment			200,000
Restructuring Reserve Settled With Cash And Other Adjustment			$ (8,200,000)

RESTRUCTURING RESERVES (Details

RESTRUCTURING RESERVES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Unused facility restructuring reserves	$ 0.1	$ 5.5	$ 0.2	$ 5.7
Balance, beginning of period			7.8
Restructuring charges			28.9
Cash payments and other adjustments			(25.2)
Balance, end of period	11.4		11.4
Current	8.9		8.9
Non-current	2.5		2.5
Total Restructuring Reserve	11.4		11.4
LabCorp Diagnostics [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period			0.3
Restructuring charges			5.2
Cash payments and other adjustments			(4.8)
Balance, end of period	0.8		0.8
Total Restructuring Reserve	0.8		0.8
LabCorp Diagnostics [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period			0.4
Restructuring charges			8.4
Cash payments and other adjustments			(8.2)
Balance, end of period	0.4		0.4
Total Restructuring Reserve	0.4		0.4
Covance Drug Development [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period			2.4
Restructuring charges			5
Cash payments and other adjustments			(3.1)
Balance, end of period	4.3		4.3
Total Restructuring Reserve	4.3		4.3
Covance Drug Development [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period			4.7
Restructuring charges			10.3
Cash payments and other adjustments			(9.1)
Balance, end of period	5.9		5.9
Total Restructuring Reserve	$ 5.9		$ 5.9

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS (Changes in Carrying Amount of Goodwill) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Goodwill [Line Items]
Amortization of intangibles and other assets	$ 92,400,000	$ 60,100,000	$ 184,500,000	$ 122,400,000
Severance Costs	6,100,000	$ 5,400,000	10,200,000	$ 10,500,000
Intangible Assets, Gross (Excluding Goodwill)	6,038,300,000		6,038,300,000		$ 6,090,100,000
Balance as of January 1			7,751,500,000
Adjustments to goodwill			(22,600,000)
Balance at end of period	7,744,500,000		7,744,500,000
Finite-Lived Intangible Assets, Accumulated Amortization	2,284,500,000		2,284,500,000		2,129,000,000
Intangible Assets, Net (Excluding Goodwill)	3,753,800,000		3,753,800,000		3,961,100,000
Goodwill, Acquired During Period			15,600,000
LabCorp Diagnostics [Member]
Goodwill [Line Items]
Balance as of January 1			3,800,200,000
Adjustments to goodwill			5,800,000
Balance at end of period	3,821,600,000		3,821,600,000
Goodwill, Impairment Loss			3,700,000
Goodwill, Acquired During Period			15,600,000
Covance Drug Development [Member]
Goodwill [Line Items]
Balance as of January 1			3,951,300,000
Adjustments to goodwill			(28,400,000)
Balance at end of period	3,922,900,000		3,922,900,000
Goodwill, Impairment Loss			418,700,000
Goodwill, Acquired During Period			0
Customer Relationships [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	4,553,600,000		4,553,600,000		4,643,300,000
Finite-Lived Intangible Assets, Accumulated Amortization	1,605,600,000		1,605,600,000		1,534,900,000
Intangible Assets, Net (Excluding Goodwill)	2,948,000,000		2,948,000,000		3,108,400,000
Patents, Licenses And Technology [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	456,700,000		456,700,000		434,700,000
Finite-Lived Intangible Assets, Accumulated Amortization	263,600,000		263,600,000		252,600,000
Intangible Assets, Net (Excluding Goodwill)	193,100,000		193,100,000		182,100,000
Noncompete Agreements [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	114,400,000		114,400,000		109,600,000
Finite-Lived Intangible Assets, Accumulated Amortization	76,400,000		76,400,000		70,700,000
Intangible Assets, Net (Excluding Goodwill)	38,000,000		38,000,000		38,900,000
Trade Names [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	399,900,000		399,900,000		401,800,000
Finite-Lived Intangible Assets, Accumulated Amortization	331,400,000		331,400,000		263,900,000
Intangible Assets, Net (Excluding Goodwill)	68,500,000		68,500,000		137,900,000
Use Rights [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	10,800,000		10,800,000		10,900,000
Finite-Lived Intangible Assets, Accumulated Amortization	7,500,000		7,500,000		6,900,000
Intangible Assets, Net (Excluding Goodwill)	3,300,000		3,300,000		4,000,000
Canadian licenses [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	502,900,000		502,900,000		489,800,000
Finite-Lived Intangible Assets, Accumulated Amortization	0		0		0
Intangible Assets, Net (Excluding Goodwill)	$ 502,900,000		$ 502,900,000		$ 489,800,000

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS (Components of identifiable intangible assets) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 6,038.3	$ 6,090.1
Accumulated Amortization	(2,284.5)	(2,129)
Intangible Assets, Net (Excluding Goodwill)	3,753.8	3,961.1
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	4,553.6	4,643.3
Accumulated Amortization	(1,605.6)	(1,534.9)
Intangible Assets, Net (Excluding Goodwill)	2,948	3,108.4
Patents, Licenses And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	456.7	434.7
Accumulated Amortization	(263.6)	(252.6)
Intangible Assets, Net (Excluding Goodwill)	193.1	182.1
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	114.4	109.6
Accumulated Amortization	(76.4)	(70.7)
Intangible Assets, Net (Excluding Goodwill)	38	38.9
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	399.9	401.8
Accumulated Amortization	(331.4)	(263.9)
Intangible Assets, Net (Excluding Goodwill)	68.5	137.9
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	10.8	10.9
Accumulated Amortization	(7.5)	(6.9)
Intangible Assets, Net (Excluding Goodwill)	3.3	4
Canadian licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	502.9	489.8
Accumulated Amortization	0	0
Intangible Assets, Net (Excluding Goodwill)	$ 502.9	$ 489.8

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 6,038,300,000		$ 6,038,300,000		$ 6,090,100,000
Goodwill	7,744,500,000		7,744,500,000		7,751,500,000
Amortization of intangibles and other assets	92,400,000	$ 60,100,000	184,500,000	$ 122,400,000
Amortization of intangible assets	92,400,000	$ 60,100,000	184,500,000	$ 122,400,000
Finite-Lived Intangible Assets, Future Amortization Expense
Estimated amortization expense, 2012	177,300,000		177,300,000
Estimated amortization expense, 2013	220,200,000		220,200,000
Estimated amortization expense, 2014	217,100,000		217,100,000
Estimated amortization expense, 2015	212,500,000		212,500,000
Estimated amortization expense, 2016	200,400,000		200,400,000
Estimated amortization expense, Thereafter	2,135,900,000		2,135,900,000
LabCorp Diagnostics [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	3,821,600,000		3,821,600,000		3,800,200,000
Goodwill, Impairment Loss			3,700,000
Covance Drug Development [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	3,922,900,000		3,922,900,000		$ 3,951,300,000
Goodwill, Impairment Loss			418,700,000
Covance [Member] | Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization	$ 28,000,000		$ 57,200,000

DEBT (Short-term borrowings and

DEBT (Short-term borrowings and current portion of long-term debt) (Table) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Current debt excluding finance lease liability	$ 1.8	$ 376.7

DEBT (Long-term debt) (Details)

DEBT (Long-term debt) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2021	May 26, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term Debt [Text Block]	Long-term debt at June 30, 2021, and December 31, 2020, consisted of the following: June 30, December 31, 2020 3.20% senior notes due 2022 $ — $ 500.0 3.75% senior notes due 2022 — 500.0 4.00% senior notes due 2023 300.0 300.0 3.25% senior notes due 2024 600.0 600.0 2.30% senior notes due 2024 400.0 400.0 3.60% senior notes due 2025 1,000.0 1,000.0 1.55% senior notes due 2026 500.0 — 3.60% senior notes due 2027 600.0 600.0 2.95% senior notes due 2029 650.0 650.0 2.70% senior notes due 2031 509.5 — 4.70% senior notes due 2045 900.0 900.0 Debt issuance costs (42.4) (37.1) Note payable 5.5 6.1 Total long-term debt $ 5,422.6 $ 5,419.0
Long-term Debt, Excluding Current Maturities	$ 5,422.6		$ 5,419
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Credit Facility, Maximum Swing Line Borrowings	100
Notes Payable	$ 5.5		6.1
Three month LIBOR	1.0706%
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 0		500
Senior Notes, Noncurrent	0		500
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	300		300
Senior notes due 2025 [Member] [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	1,000		1,000
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	900		900
Senior notes due 2026
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	500	$ 500	0
Senior notes due 2031
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	509.5		0
3.25% Senior notes due 2024
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	600		$ 600
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility, Maximum Letters of Credit	$ 150

DEBT (Senior Notes) (Details)

DEBT (Senior Notes) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2021	May 26, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Short term debt issuance costs	$ 0		$ 0.4
Long-term Debt, Excluding Current Maturities	5,422.6		5,419
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Credit Facility, Maximum Swing Line Borrowings	100
Long term debt issuance costs	42.4		37.1
Notes Payable	1.8		2.1
Foreign Currency Contract, Asset, Fair Value Disclosure			40.4
2.30% senior notes due 2024	400		400
2.95% senior notes due 2029	650		650
2021 Senior Notes		$ 1,000
Proceeds from Debt, Net of Issuance Costs	989.4
Fair Value Hedge Liabilities	9.5
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	300		300
Senior notes due 2027 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	600		600
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	900		900
Senior notes due 2031
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 509.5		0
Subordinated Borrowing, Interest Rate	2.70%
Debt Instrument, Face Amount		500
Senior notes due 2026
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 500	$ 500	0
Subordinated Borrowing, Interest Rate	1.55%
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 0		500
Senior Notes, Noncurrent	$ 0		500
Senior notes due August 2022 [Member]
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate	3.75%
Senior notes due February 2022
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate	3.20%
3.25% Senior notes due 2024
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 600		$ 600

DEBT (Credit Facilities) (Detai

DEBT (Credit Facilities) (Details) - USD ($)	3 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 03, 2019
Line of Credit Facility [Line Items]
2019 Term Loan	$ 0	$ 375,000,000			$ 850,000,000
Cash and cash equivalents	1,963,200,000	1,320,800,000	$ 557,000,000	$ 337,500,000
Revolving Credit Facility, maximum borrowing capacity	1,000,000,000
Notes Payable	1,800,000	2,100,000
Credit Facility, Maximum Swing Line Borrowings	100,000,000
Notes Payable	5,500,000	6,100,000
Senior notes due 2022 [Member]
Line of Credit Facility [Line Items]
Senior Notes, Noncurrent	0	$ 500,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	1,000,000,000
Credit Facility, Maximum Letters of Credit	$ 150,000,000
Line of Credit Facility, Interest Rate at Period End	1.10%
Third Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Credit Facility Option to Increase	$ 500,000,000
Prime Rate [Member] | Third Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.100% to 0.225%

PREFERRED STOCK AND COMMON SH_2

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Class of Stock [Line Items]
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	431,500,000			431,500,000
Rollforward of common shares issued
Stock Repurchased During Period, Shares				1,400,000
Payments for Repurchase of Common Stock				$ 368.5	$ 100
Rollforward of Share Repurchase Program
Purchase of common stock	$ (300)	$ (68.5)	$ (100)
Common Shares Outstanding Rollforward [Abstract]
Common shares outstanding, beginning balance (in shares)		97,500,000		97,500,000
Common shares outstanding, ending balance (in shares)	96,700,000			96,700,000
Rollforward of common shares held in treasury
Common Stock, Shares Authorized	265,000,000			265,000,000
Common Stock, Par or Stated Value Per Share	$ 0.10			$ 0.10
Preferred Stock, Shares Authorized	30,000,000			30,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.10			$ 0.10
Preferred Stock, Shares Outstanding	0			0
Treasury Stock Acquired, Average Cost Per Share				$ 257.38
Common Stock [Member]
Rollforward of common shares issued
Common shares issued, beginning balance (in shares)		97,500,000		97,500,000
Commons Stock Issued During Period Shares Employee Stock Plans				600,000
Stock Repurchased and Retired During Period, Shares				(1,400,000)
Common shares issued, ending balance (in shares)	96,700,000			96,700,000
Common Stock, Shares, Issued	96,700,000			96,700,000
Common Shares Outstanding Rollforward [Abstract]
Commons Stock Issued During Period Shares Employee Stock Plans				600,000
Stock Repurchased and Retired During Period, Shares				(1,400,000)
Commons Stock Issued During Period Shares Employee Stock Plans				600,000
Rollforward of common shares held in treasury
Stock Repurchased and Retired During Period, Shares				(1,400,000)

PREFERRED STOCK AND COMMON SH_3

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY - Accumulated Other Comprehensive Earnings (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The components of accumulated other comprehensive earnings (loss) are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance as of December 31, 2020 $ (21.3) $ (140.6) $ (161.9) Current year adjustments (23.0) 10.2 (12.8) Amounts reclassified from accumulated other comprehensive income — (5.1) (5.1) Tax effect of adjustments — (1.4) (1.4) Balance as of June 30, 2021 $ (44.3) $ (136.9) $ (181.2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax			$ 10,200,000
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(12,800,000)
Accumulated Other Comprehensive Earnings [Roll Forward]
Foreign Currency Translation Adjustments, Beginning balance			(21,300,000)
Other comprehensive income before reclassifications			(23,000,000)
Tax effect of adjustments			0
Foreign Currency Translation Adjustments, Ending balance	$ (44,300,000)		(44,300,000)
Net Benefit Plan Adjustments, Beginning balance			(140,600,000)
Tax effect of adjustments			(1,400,000)
Net Benefit Plan Adjustments, Ending balance	(136,900,000)		(136,900,000)
Accumulated Other Comprehensive Earnings, Beginning balance			(161,900,000)
Other comprehensive income before reclassifications			(23,000,000)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax			0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax			(5,100,000)
Tax effect of adjustments	(600,000)	$ (700,000)	(1,400,000)	$ (1,500,000)
Accumulated Other Comprehensive Earnings, Ending balance	$ (181,200,000)		$ (181,200,000)

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Tax Contingency, Percent	50.00%
Gross unrecognized income tax benefits	$ 48.8	$ 48.8
Accrued interest and penalties related to unrecognized income tax benefits	9.1	8.3
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 46.7	$ 46.7

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Number of Measurement Funds Available For Participant Election	16
Noncontrolling interest puts	$ 16.6	$ 16.2
Foreign Currency Contracts, Liability, Fair Value Disclosure	16.6
Fair market value of senior notes	5,892.8	6,121.8
Cash Surrender Value, Fair Value Disclosure	101.1	90.6
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	99.2	89.2
Available-for-sale Securities, Equity Securities, Current	0.8
Contingent Consideration Classified as Equity, Fair Value Disclosure	12.8	13.9
Foreign Currency Contract, Asset, Fair Value Disclosure		40.4
Fair Value Hedges, Net	9.5
Contingent consideration adjustment	(1.1)
Level 1 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	0	0
Cash Surrender Value, Fair Value Disclosure	0	0
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	0	0
Available-for-sale Securities, Equity Securities, Current	0.8
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value Hedges, Net	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	16.6	16.2
Foreign Currency Contracts, Liability, Fair Value Disclosure	16.6
Cash Surrender Value, Fair Value Disclosure	101.1	90.6
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	99.2	89.2
Available-for-sale Securities, Equity Securities, Current	0
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure		40.4
Fair Value Hedges, Net	9.5
Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	0	0
Cash Surrender Value, Fair Value Disclosure	0	0
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	0	0
Available-for-sale Securities, Equity Securities, Current	0
Contingent Consideration Classified as Equity, Fair Value Disclosure	12.8	13.9
Foreign Currency Contract, Asset, Fair Value Disclosure	0	$ 0
Fair Value Hedges, Net	$ 0

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	May 26, 2021	Dec. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Fair Value Hedge Liabilities	$ 9.5		$ 9.5
Long-term Debt, Excluding Current Maturities	5,422.6		5,422.6			$ 5,419
Senior notes due 2025 [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign Currency Fair Value Hedge Derivative at Fair Value, Net	(3.5)		(3.5)			(14.4)
Cross currency swap maturing 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign Currency Fair Value Hedge Derivative at Fair Value, Net	(13.2)		(13.2)			(26)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	(13.6)	$ (8.8)	23.7	$ 11.1
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	0
Fair Value Hedge Assets	0		0			0
Fair Value Hedge Liabilities	16.6		16.6			40.4
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	(0.9)	0	0.9
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	$ 0	0	$ 0
Fair Value Hedge Assets	9.5		9.5			0
Fair Value Hedge Liabilities	0		0			0
Senior notes due 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	0		0			500
Cross currency swap maturing 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	300		300
Senior notes due 2025 [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	300		300
Senior notes due 2025 [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	1,000		1,000			1,000
Senior notes due 2027 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	600		600			600
Senior notes due 2031
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	$ 509.5		$ 509.5			$ 0
Debt Instrument, Face Amount					$ 500

BUSINESS ACQUISITIONS (Details)

BUSINESS ACQUISITIONS (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Business Combinations [Abstract]
Finite-lived Intangible Assets Acquired	$ 17.6
Payments to Acquire Businesses, Net of Cash Acquired	34.1	$ 11.3
Business Acquisition [Line Items]
Goodwill, Acquired During Period	15.6
Finite-lived Intangible Assets Acquired	17.6
Gain (Loss) on Disposition of Business	$ 5
Customer Relationships [Member] | Maximum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Noncompete Agreements [Member] | Minimum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years

BUSINESS SEGMENT INFORMATION _2

BUSINESS SEGMENT INFORMATION Business Segment Information (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Percent of Revenue Contributed	100.00%		100.00%		100.00%	100.00%
Intercompany revenue elimination	$ (20,000,000)		$ (17,600,000)		$ (54,500,000)	$ (39,600,000)
Revenues	3,840,700,000		2,768,800,000		8,002,200,000	5,592,600,000
Operating Income (Loss)	704,100,000		297,700,000		1,762,000,000	105,100,000
Earnings before income taxes	650,600,000		297,000,000		1,672,400,000	29,300,000
Provision for income taxes	182,600,000		65,400,000		434,300,000	114,600,000
Net earnings	468,000,000		231,600,000		1,238,100,000	(85,300,000)
Net income attributable to Laboratory Corporation of America Holdings	(600,000)		0		(1,100,000)	(300,000)
Nonoperating Income (Expense)	(53,500,000)		(700,000)		(89,600,000)	(75,800,000)
Net Income (Loss) Attributable to Parent	467,400,000	$ 769,600,000	231,600,000	$ (317,200,000)	1,237,000,000	(85,600,000)
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (46,800,000)		$ (49,100,000)		$ (94,400,000)	$ (108,400,000)
LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Percent of Revenue Contributed	61.00%		61.00%		63.00%	60.00%
Revenues	$ 2,365,500,000		$ 1,692,700,000		$ 5,123,300,000	$ 3,394,700,000
Operating Income (Loss)	603,600,000		281,300,000		$ 1,552,700,000	486,700,000
Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Percent of Revenue Contributed					37.00%
Revenues	1,495,200,000		1,093,700,000		$ 2,933,400,000	2,237,500,000
Operating Income (Loss)	$ 147,300,000		$ 65,500,000		$ 303,700,000	$ (273,200,000)

REVENUE (Details)

REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Amortization of Deferred Sales Commissions	$ 6.4	$ 5.5	$ 13.3	$ 10.8
Capitalized Contract Cost, Amortization	3	2.3	6.5	5.3
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 12.2	$ 4	28.7	13.7
Deferred Revenue, Revenue Recognized			$ 233	$ 102.2

REVENUE Disaggregated Revenue T

REVENUE Disaggregated Revenue Table (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 20,900,000		$ 20,900,000		$ 22,100,000
Unbilled Services, Allowance for Credit Loss	11,400,000		11,400,000		11,300,000
Note Receivable, Allowance for Credit Loss	5,700,000		5,700,000		5,700,000
Allowance for Credit Loss	$ 38,000,000		38,000,000		39,100,000
Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings			(400,000)
Allowance for Credit Loss, Write Off			700,000
Sales Commission Amortization Period Minimum	1 year
Deferred Revenue, Revenue Recognized			233,000,000	$ 102,200,000
Contract with Customer, Asset, before Allowance for Credit Loss	$ 648,400,000		648,400,000		548,100,000
Revenue, Remaining Performance Obligation, Amount	$ 5,616,600,000		5,616,600,000
Long Term Contracts Duration Minimum	1 year
Long Term Contracts Duration Maximum	8 years
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 12,200,000	$ 4,000,000	28,700,000	13,700,000
Contract with Customer, Liability	529,600,000		529,600,000		492,200,000
Capitalized Contract Cost, Amortization	3,000,000	2,300,000	6,500,000	5,300,000
Accrued Sales Commission	36,400,000		36,400,000		32,600,000
Capitalized Contract Cost, Net	14,900,000		14,900,000		12,600,000
Amount of Deferred Costs Related to Long-term Contracts	51,300,000		51,300,000		45,200,000
Amortization of Deferred Sales Commissions	6,400,000	$ 5,500,000	13,300,000	$ 10,800,000
Unbilled Contracts Receivable	$ 637,000,000		$ 637,000,000		536,800,000
Percent of Revenue Contributed	100.00%	100.00%	100.00%	100.00%
Sales Commission Amortization Period Maximum	5 years
Revenues	$ 3,840,700,000	$ 2,768,800,000	$ 8,002,200,000	$ 5,592,600,000
Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	12.00%	12.00%	11.00%	13.00%
North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	84.00%	79.00%	85.00%	79.00%
Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	4.00%	9.00%	4.00%	8.00%
UNITED STATES
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	80.50%	76.90%	81.70%	76.80%
Revenues	$ 3,091,300,000	$ 2,129,000,000	$ 6,537,400,000	$ 4,294,200,000
Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	6.00%	7.00%	6.00%	7.00%
LabCorp Diagnostics [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	61.00%	61.00%	63.00%	60.00%
Revenues	$ 2,365,500,000	$ 1,692,700,000	$ 5,123,300,000	$ 3,394,700,000
LabCorp Diagnostics [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	61.00%	61.00%	63.00%	60.00%
LabCorp Diagnostics [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	17.00%	21.00%	18.00%	19.00%
LabCorp Diagnostics [Member] | Client [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Client [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	17.00%	21.00%	18.00%	19.00%
LabCorp Diagnostics [Member] | Client [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	7.00%	7.00%	6.00%	7.00%
LabCorp Diagnostics [Member] | Self-Pay [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Self-Pay [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	7.00%	7.00%	6.00%	7.00%
LabCorp Diagnostics [Member] | Self-Pay [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Medicare and Medicaid [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Medicare and Medicaid [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	6.00%	7.00%	6.00%	7.00%
LabCorp Diagnostics [Member] | Medicare and Medicaid [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	31.00%	26.00%	33.00%	27.00%
LabCorp Diagnostics [Member] | Third party [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Third party [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	31.00%	26.00%	33.00%	27.00%
LabCorp Diagnostics [Member] | Third party [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
Covance Drug Development [Member]
Disaggregation of Revenue [Line Items]
Unbilled Contracts Receivable	$ 1,086,200,000		$ 1,086,200,000		$ 1,001,500,000
Percent of Revenue Contributed			37.00%
Revenues	$ 1,495,200,000	$ 1,093,700,000	$ 2,933,400,000	$ 2,237,500,000
Covance Drug Development [Member] | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	39.00%	39.00%	37.00%	40.00%
Covance Drug Development [Member] | Biopharmaceutical and medical device companies [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	12.00%	12.00%	11.00%	13.00%
Covance Drug Development [Member] | Biopharmaceutical and medical device companies [Member] | North America
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	23.00%	18.00%	22.00%	19.00%
Covance Drug Development [Member] | Biopharmaceutical and medical device companies [Member] | Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	4.00%	9.00%	4.00%	8.00%
Minimum [Member]
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost, Amortization Period	2 years		2 years
Maximum [Member]
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost, Amortization Period	5 years		5 years
Notes Receivable [Member]
Disaggregation of Revenue [Line Items]
Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings			$ 0
Allowance for Credit Loss, Write Off			0
Unbilled Contracts Receivable [Member]
Disaggregation of Revenue [Line Items]
Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings			0
Allowance for Credit Loss, Write Off			(100,000)
Accounts Receivable [Member]
Disaggregation of Revenue [Line Items]
Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings			(400,000)
Allowance for Credit Loss, Write Off			$ 800,000

Leases (Details)

Leases (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Operating Lease, Liability, Current	$ 190	$ 192
Operating Lease, Liability, Noncurrent	645.2	677.6
Finance Lease, Liability, Current	10.8	6.7
Finance Lease, Liability, Noncurrent	$ 87.2	$ 84.4

Uncategorized Items - lh-202106

Label	Element	Value
Common Stock [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Retained Earnings (Accumulated Deficit)	us-gaap_RetainedEarningsAccumulatedDeficit	$ 0
Additional Paid-in Capital [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Retained Earnings (Accumulated Deficit)	us-gaap_RetainedEarningsAccumulatedDeficit	0
Retained Earnings [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Retained Earnings (Accumulated Deficit)	us-gaap_RetainedEarningsAccumulatedDeficit	(7,000,000)
AOCI Attributable to Parent [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Retained Earnings (Accumulated Deficit)	us-gaap_RetainedEarningsAccumulatedDeficit	$ 0