Laboratory Corporation of America (LH) 10-Q 8 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares shares in Millions	6 Months Ended
	Jun. 30, 2019	Aug. 06, 2019
Cover page.
Entity Central Index Key	0000920148
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	1-11353
Entity Registrant Name	LABORATORY CORP 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
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		97.7

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts Payable, Current	$ 531.6	$ 634.6
Current assets:
Cash and cash equivalents	265.4	426.8
Accounts Receivable, after Allowance for Credit Loss, Current	1,576.1	1,467.9
Unbilled Contracts Receivable	488.8	394.4
Supplies inventories	219.7	237.3
Prepaid expenses and other	298.6	309
Total current assets	2,848.6	2,835.4
Property, plant and equipment, net	2,544.2	1,740.3
Goodwill, net	7,843.7	7,360.3
Intangible Assets, Net (Excluding Goodwill)	4,015.9	3,911.1
Joint venture partnerships and equity method investments	86.7	60.5
Deferred Income Taxes and Other Assets, Current	1.7	1.7
Other assets, net	403.6	276
Total assets	17,744.4	16,185.3
Liabilities, Current [Abstract]
Accrued Liabilities, Current	820.3	870
Deferred Revenue, Current	404.2	356.4
Operating Lease, Liability, Current	229.2	0
Finance Lease, Liability, Current	8.2	7.9
Debt, Current	502.3	10
Long-term debt, less current portion	2,495.8	1,878.9
Long-term Debt, Excluding Current Maturities	6,135	5,990.9
Commitments and contingent liabilities	368.6	334
Operating Lease, Liability, Noncurrent	586.1	0
Finance Lease, Liability, Noncurrent	46.2	51
Deferred income taxes and other tax liabilities	948.3	940
Noncontrolling interest	10,580	9,194.8
Shareholders' equity:
Common stock, 92.8 and 93.5 shares outstanding at March 31, 2013 and December 31, 2012, respectively	20	19.1
Additional paid-in capital	91.4	1,451.1
Retained earnings	9.1	11.7
Accumulated other comprehensive income	(7,455.8)	(7,079.8)
Total shareholders' equity	0	(1,108.1)
Total liabilities and shareholders' equity	(411.9)	(463.1)
Stockholders' Equity Attributable to Parent	7,144.4	6,971.4
Liabilities and Equity	$ 17,744.4	$ 16,185.3

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - shares shares in Millions	Jun. 30, 2019	Dec. 31, 2018
Shareholders' Equity:
Common stock, shares outstanding (in shares)	97.8	98.9

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues	$ 2,881.7	$ 2,866.3	$ 5,672.9	$ 5,714.6
Cost of Revenue	2,056.9	2,031.2	4,058.4	4,100.5
Gross Profit	824.8	835.1	1,614.5	1,614.1
Selling, general and administrative expenses	415.3	395.2	809.1	792.2
Amortization of intangibles and other assets	60.2	58.5	117.3	120.8
Net restructuring and other special charges	13.6	12.2	34.2	26.5
Operating Income (Loss)	335.7	369.2	653.9	674.6
Other income (expenses):
Interest expense	(59.1)	(63.1)	(115.8)	(126.6)
Equity method income, net	2.5	3	5.5	5.5
Investment income	1.4	0.8	2	1.4
Other, net	(10.5)	2.8	(20.9)	(0.7)
Earnings before income taxes	270	312.7	524.7	554.2
Provision for income taxes	79.3	78.6	148.1	147.6
Net earnings	190.7	234.1	376.6	406.6
Less: Net earnings attributable to the noncontrolling interest	(0.3)	(0.3)	(0.6)	0.4
Net earnings attributable to Laboratory Corporation of America Holdings	$ 190.4	$ 233.8	$ 376	$ 407
Basic earnings per common share (in dollars per share)	$ 1.94	$ 2.29	$ 3.82	$ 3.99
Diluted earnings per common share (in dollars per share)	$ 1.93	$ 2.27	$ 3.79	$ 3.94

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net restructuring and other special charges	$ 13.6	$ 12.2	$ 34.2	$ 26.5
Provision for income taxes	79.3	78.6	148.1	147.6
Net earnings	190.7	234.1	376.6	406.6
Other Comprehensive Earnings, Net of Tax
Foreign currency translation adjustments	25.6	(121.9)	47.2	(82.6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	2.8	3.3	5.5	6.2
Other comprehensive earnings (loss) before tax	28.4	(118.6)	52.7	(76.4)
Tax effect of adjustments	(0.8)	(7.2)	(1.5)	3.1
Other comprehensive earnings (loss), net of tax	27.6	(125.8)	51.2	(73.3)
Comprehensive earnings	218.3	108.3	427.8	333.3
Less: Net earnings attributable to the noncontrolling interest	(0.3)	(0.3)	(0.6)	0.4
Comprehensive earnings attributable to Laboratory Corporation of America Holdings	$ 218	$ 108	$ 427.2	$ 333.7

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]
BALANCE at Dec. 31, 2017	$ 6,804.1	$ 12	$ 1,989.8	$ 6,196.1	$ (1,060.1)	$ (333.7)
Net earnings attributable to Laboratory Corporation of America Holdings	173.2			173.2
Other comprehensive earnings, net of tax	52.5					52.5
Issuance of common stock under employee stock plans	(28.4)	0	(28.4)
Surrender of restricted stock and performance share awards	(25)				(25)
Stock compensation	25.8		25.8
Purchase of common stock	(75)	0	75
BALANCE at Mar. 31, 2018	6,984	12	1,969	6,369.3	(1,085.1)	(281.2)
BALANCE at Dec. 31, 2017	6,804.1	12	1,989.8	6,196.1	(1,060.1)	(333.7)
Net earnings attributable to Laboratory Corporation of America Holdings	407
Other comprehensive earnings, net of tax	(73.3)
BALANCE at Jun. 30, 2018	7,037.7	12	1,934.8	6,603.1	(1,105.2)	(407)
BALANCE at Mar. 31, 2018	6,984	12	1,969	6,369.3	(1,085.1)	(281.2)
Net earnings attributable to Laboratory Corporation of America Holdings	233.8			233.8
Other comprehensive earnings, net of tax	(125.8)					(125.8)
Issuance of common stock under employee stock plans	20.1		(14.6)
Issuance of common stock for acquisition consideration	14.6
Surrender of restricted stock and performance share awards					(20.1)
Conversion of zero-coupon convertible debt	26.2
Stock compensation	(75)		26.2
BALANCE at Jun. 30, 2018	7,037.7	12	1,934.8	6,603.1	(1,105.2)	(407)
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			(75)
BALANCE at Dec. 31, 2018	6,971.4	11.7	1,451.1	7,079.8	(1,108.1)	(463.1)
Net earnings attributable to Laboratory Corporation of America Holdings	185.6			185.6
Other comprehensive earnings, net of tax	23.6			0		23.6
Other Significant Noncash Transaction, Value of Consideration Given	24.7
Issuance of common stock under employee stock plans	(19.4)	0	(24.7)
Surrender of restricted stock and performance share awards					(19.4)
Stock compensation	25.5		25.5
Purchase of common stock	(100.1)	0.1	100
BALANCE at Mar. 31, 2019	7,111.3	11.6	1,401.3	7,265.4	(1,127.5)	(439.5)
BALANCE at Dec. 31, 2018	6,971.4	11.7	1,451.1	7,079.8	(1,108.1)	(463.1)
Net earnings attributable to Laboratory Corporation of America Holdings	376
Other comprehensive earnings, net of tax	51.2
BALANCE at Jun. 30, 2019	7,144.4	9.1	91.4	7,455.8	0	(411.9)
BALANCE at Mar. 31, 2019	7,111.3	11.6	1,401.3	7,265.4	(1,127.5)	(439.5)
Net earnings attributable to Laboratory Corporation of America Holdings	190.4			190.4
Other comprehensive earnings, net of tax	27.6			0		27.6
Other Significant Noncash Transaction, Value of Consideration Given	9.2
Issuance of common stock under employee stock plans	(20.7)	0	(9.2)
Surrender of restricted stock and performance share awards					(20.7)
Conversion of zero-coupon convertible debt	26.5
Treasury Stock, Retired, Cost Method, Amount	0	(2.4)	(1,145.8)		(1,148.2)
Stock compensation	(199.9)		26.5
Purchase of common stock		0.1
BALANCE at Jun. 30, 2019	$ 7,144.4	$ 9.1	91.4	$ 7,455.8	$ 0	$ (411.9)
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			$ (199.8)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 376.6	$ 406.6
Adjustments to reconcile net earnings to net cash provided by operating activities:
Gain (Loss) on Disposition of Assets	(8.8)	0
Depreciation And Amortization Of Leased Assets	94	0
Accreted interest on zero-coupon subordinated notes	0	0.1
Depreciation and amortization	277.1	281.3
Stock compensation	52	52
Loss on sale of assets	4.5	(0.3)
Cumulative earnings in excess of distributions from equity method investments	8	(1.3)
Asset Impairment Charges	0	2.3
Deferred income taxes	15.2	36
Change in assets and liabilities (net of effects of acquisitions):
Increase in accounts receivable (net)	(91.1)	13.2
Increase (Decrease) in Unbilled Receivables	(67.4)	(36.5)
Increase in inventories	(1.7)	(4.7)
Decrease in prepaid expenses and other	16.1	(27.2)
Decrease in accounts payable	(109)	(91.3)
Increase (Decrease) in Deferred Revenue	(5)	8.3
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities	(158.8)	(71.4)
Net cash provided by operating activities	419.3	567.1
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(179.4)	(159.7)
Increase (Decrease) in Assets Held-for-sale	0	(49.1)
Proceeds from sale of assets	4.2	0.7
Proceeds from Sale of Equity Method Investments	3.4	0
Investments in equity affiliates	(15.8)	(7.3)
Acquisition of businesses, net of cash acquired	(703.7)	(79.1)
Net cash used for investing activities	(891.3)	(196.3)
CASH FLOWS FROM FINANCING ACTIVITIES:
Deferred payments on acquisitions	4.7	0
Repayments of Other Long-term Debt	(250)	(295)
Proceeds from Issuance of Other Long-term Debt	850	0
tax benefit realized upon conversion of zero coupon convertible debt	1.7
Proceeds from revolving credit facilities	419.5	394.7
Noncontrolling interest distributions	(0.5)	(5.9)
Repayments of Long-term Capital Lease Obligations	(6.7)	(5.1)
Payment, Tax Withholding, Share-based Payment Arrangement	(40.1)	(45.1)
Net proceeds from issuance of stock to employees	33.9	43
Payments for Repurchase of Common Stock	(300)	(150)
Payments On Zero Coupon Subordinated Notes	(5.2)	0
Repayments of Lines of Credit	(384.5)	(394.7)
Net cash provided by (used for) financing activities	311.7	(458.1)
Effect of exchange rate changes on cash and cash equivalents	(1.1)	(7.9)
Net increase (decrease) in cash and cash equivalents	(161.4)	(95.2)
Cash and cash equivalents at beginning of period	426.8
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Disposal Group, Including Discontinued Operations		$ 221.4
Cash and cash equivalents at end of period	$ 265.4

BASIS OF FINANCIAL STATEMENT PR

BASIS OF FINANCIAL STATEMENT PRESENTATION	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	BASIS OF FINANCIAL STATEMENT PRESENTATION Laboratory Corporation of America ® Holdings together with its subsidiaries (the Company) is a leading global life sciences company that is deeply integrated in guiding patient care, providing comprehensive clinical laboratory and end-to-end drug development services. The Company’s mission is to improve health and improve lives by delivering world-class diagnostic solutions, bringing innovative medicines to patients faster and using technology to provide better care. The Company serves a broad range of customers, including managed care organizations (MCOs), biopharmaceutical companies, medical device companies, governmental agencies, physicians and other healthcare providers (e.g., physician assistants and nurse practitioners, generally referred to herein as physicians), hospitals and health systems, employers, patients and consumers, contract research organizations (CROs) and independent clinical laboratories. The Company believes that it generated more revenue from laboratory testing than any other company in the world in 2018. The Company reports its business in two segments, LabCorp Diagnostics (LCD) and Covance Drug Development (CDD). For further financial information about these segments, see Note 16 (Business Segment Information). During the three months ended June 30, 2019 , LCD and CDD contributed approximately 61% and 39% , respectively, of revenues to the Company. During the six months ended June 30, 2019 , LCD and CDD contributed approximately 61% and 39% , 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% ) are accounted for at fair value or at cost minus impairment 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.” 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 2018 Annual Report on Form 10-K. 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 Leases In February 2016, the Financial Accounting Standards Board (FASB) issued a new accounting standard that sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. The Company has elected to utilize the short-term lease exemption and not record leases with initial terms of 12 months or less on the balance sheet. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases and direct financing leases. The Company adopted the standard on January 1, 2019, using the modified retrospective method. Comparative periods were not adjusted and are presented in accordance with lease guidance in effect for that period. The Company elected the package of practical expedients, which includes not reassessing whether existing contracts contain leases under the new definition of a lease, reassessing the classification of existing leases, and reassessing whether previously capitalized initial direct costs qualify for capitalization under the new standard. Leases with an initial term of 12 months or less are not recorded on the Condensed Consolidated Balance Sheets. Operating lease expense is recognized on a straight-line basis over the lease term. Operating lease assets and liabilities are recognized at the commencement date, based on the present value of the future minimum lease payments over the lease term. A certain number of these leases contain rent escalation clauses either fixed or adjusted periodically for inflation or market rates that are factored into the Company's determination of lease payments. The Company also has variable lease payments that do not depend on a rate or index, for items such as volume purchase commitments, which are recorded as variable cost when incurred. As most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date to discount payments to the present value. Some operating leases contain renewal options, some of which also include options to early terminate the leases. The exercise of these options is at the Company's discretion. The Company determined that all renewal options within leases for main laboratories, STAT laboratories, branches or combination sites were reasonably possible to be exercised and therefore are included in the accounting lease term. The standard had a material impact in the consolidated balance sheets, but no material impact in the consolidated income statements. The most significant impact was the recognition of right-of-use (ROU) assets and lease liabilities for operating leases, while the accounting for finance leases remained unchanged. New Accounting Pronouncements In June 2016, the FASB issued a new accounting standard intended to provide financial statement users with more decision-useful information about expected credit losses and other commitments to extend credit held by the reporting entity. The standard replaces the incurred loss impairment methodology in current GAAP with one that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The update is effective on January 1, 2020, with early adoption permitted. The Company is currently evaluating the impact this new standard will have on the consolidated financial statements. In August 2018, the FASB issued a new accounting standard to reduce, modify, and add to the disclosure requirements on fair value measurements. The standard is effective on January 1, 2020, with early adoption permitted. The Company is currently evaluating the impact this new standard will have on the consolidated financial statements. In August 2018, the FASB issued a new accounting standard to reduce, modify, and add to the disclosure requirements on defined benefit pension and other postretirement plans. The standard is effective on January 1, 2021, with early adoption permitted. The Company is currently evaluating the impact this new standard will have on the consolidated financial statements. In August 2018, the FASB issued a new accounting standard to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The standard is effective on January 1, 2020, with early adoption permitted. The Company is currently evaluating the impact this new standard will have on the consolidated financial statements. Reclassifications and Revisions The Company adopted Accounting Standard Update 2016-09 Compensation - Stock Compensation (Topic 718) during 2016 and incorrectly classified payments made to tax authorities for withheld shares from an employee’s equity award as cash flows from operating activities versus cash flows from financing activities. As a result, the Company has revised the consolidated statement of cash flows for these tax payments of $ 45.1 for the six months ended June 30, 2018, from operating activities to financing activities. The Company concluded that these errors were not material individually or in the aggregate to any of the periods impacted. In conjunction with the adoption of the new lease standard, the Company reclassified the capital lease asset balance of $44.4 at December 31, 2018, from Property, plant and equipment, net to Other assets.

EARNINGS PER SHARE

EARNINGS PER SHARE	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is computed by dividing net earnings attributable to Laboratory Corporation of America Holdings by the weighted average number of common shares outstanding. Diluted earnings per share is computed by dividing net earnings 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, performance share awards, and shares issuable upon conversion of zero-coupon subordinated notes. The following represents a reconciliation of basic earnings per share to diluted earnings per share: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Earnings Shares Per Share Amount Earnings Shares Per Share Amount Earnings Shares Per Share Amount Earnings Shares Per Share Amount Basic earnings per share: Net earnings $ 190.4 98.1 $ 1.94 $ 233.8 101.9 $ 2.29 $ 376.0 98.4 $ 3.82 $ 407.0 101.9 $ 3.99 Dilutive effect of employee stock options and awards — 0.7 — 1.0 — 0.7 — 1.3 Net earnings including impact of dilutive adjustments $ 190.4 98.8 $ 1.93 $ 233.8 103.0 $ 2.27 $ 376.0 99.1 $ 3.79 $ 407.0 103.3 $ 3.94 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, 2019 2018 2019 2018 Stock options 0.2 0.1 0.2 0.1

RESTRUCTURING AND OTHER SPECIAL

RESTRUCTURING AND OTHER SPECIAL CHARGES	6 Months Ended
	Jun. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	RESTRUCTURING AND OTHER SPECIAL CHARGES During the six months ended June 30, 2019 , the Company recorded net restructuring and other special charges of $34.2 : $16.1 within LCD and $18.1 within CDD. The charges were comprised of $20.3 related to severance and other personnel costs and $13.5 in costs associated with facility closures, impairment of operating lease right-of-use assets and general integration initiatives. The charges were increased by the adjustment of previously established reserves of $0.4 in severance reserves. During the six months ended June 30, 2018 , the Company recorded net restructuring and other special charges of $26.5 : $9.1 within LCD and $17.4 within CDD. The charges were comprised of $23.1 related to severance and other personnel costs, $2.5 in costs associated with facility closures and general integration initiatives, and $2.3 in impairment to land held for sale. The Company reversed previously established reserves of $0.9 and $0.5 in unused facility reserves and unused severance reserves, respectively. The following represents the Company’s restructuring reserve activities for the period indicated: LCD CDD Severance and Other Employee Costs Facility Costs Severance and Other Employee Costs Facility Costs Total Balance as of December 31, 2018 $ 2.1 $ 7.4 $ 6.5 $ 27.6 $ 43.6 Reclassification for ASC 842 adoption — (5.7 ) — (27.1 ) (32.8 ) Restructuring charges 11.9 1.0 8.4 1.7 23.0 Adjustments to prior restructuring accruals (0.1 ) — 0.5 — 0.4 Impairment of operating lease right-of-use asset — 3.3 — 7.5 10.8 Cash payments and other adjustments (13.6 ) (3.1 ) (8.5 ) (7.2 ) (32.4 ) Balance as of June 30, 2019 $ 0.3 $ 2.9 $ 6.9 $ 2.5 $ 12.6 Current $ 10.4 Non-current 2.2 $ 12.6

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS The changes in the carrying amount of goodwill for the three-month period ended June 30, 2019 , are as follows: LCD CDD Total Balance as of January 1, 2019 $ 3,638.8 $ 3,721.5 $ 7,360.3 Goodwill acquired during the period 22.3 468.2 490.5 Dispositions — (12.6 ) (12.6 ) Adjustments to goodwill 1.9 3.6 5.5 Balance at June 30, 2019 $ 3,663.0 $ 4,180.7 $ 7,843.7 The components of identifiable intangible assets are as follows: June 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Customer relationships $ 4,307.9 $ (1,233.0 ) $ 3,074.9 $ 4,119.4 $ (1,146.7 ) $ 2,972.7 Patents, licenses and technology 452.3 (224.1 ) 228.2 447.3 (211.2 ) 236.1 Non-compete agreements 82.5 (57.2 ) 25.3 76.8 (53.7 ) 23.1 Trade names 407.7 (202.9 ) 204.8 404.0 (189.1 ) 214.9 Land use right 11.1 (4.9 ) 6.2 10.8 (4.1 ) 6.7 Canadian licenses 476.5 — 476.5 457.6 — 457.6 $ 5,738.0 $ (1,722.1 ) $ 4,015.9 $ 5,515.9 $ (1,604.8 ) $ 3,911.1 Amortization of intangible assets for the three-month periods ended June 30, 2019 , and 2018 , was $60.2 and $58.5 , respectively and for the six-month periods ended June 30, 2019 , and 2018 , was $117.3 and $120.8 , respectively. Amortization expense for the net carrying amount of intangible assets is estimated to be $119.1 for the remainder of fiscal 2019 , $ 232.0 in fiscal 2020 , $225.2 in fiscal 2021 , $219.3 in fiscal 2022 , $215.6 in fiscal 2023 and $2,528.2

DEBT

DEBT	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt	DEBT Short-term borrowings and the current portion of long-term debt at June 30, 2019 , and December 31, 2018 , consisted of the following: June 30, December 31, 2018 Zero-coupon convertible subordinated notes $ 1.4 $ 8.7 2.625% senior notes due 2020 500.0 — Debt issuance costs (1.0 ) (0.5 ) Current portion of note payable 1.9 1.8 Total short-term borrowings and current portion of long-term debt $ 502.3 $ 10.0 Long-term debt at June 30, 2019 , and December 31, 2018 , consisted of the following: June 30, December 31, 2018 2.625% senior notes due 2020 $ — $ 500.0 4.625% senior notes due 2020 603.7 596.9 3.20% senior notes due 2022 500.0 500.0 3.75% senior notes due 2022 500.0 500.0 4.00% senior notes due 2023 300.0 300.0 3.25% senior notes due 2024 600.0 600.0 3.60% senior notes due 2025 1,000.0 1,000.0 3.60% senior notes due 2027 600.0 600.0 4.70% senior notes due 2045 900.0 900.0 Revolving credit facility 35.0 — 2019 Term loan 850.0 — 2017 Term loan 277.0 527.0 Debt issuance costs (37.1 ) (40.2 ) Note payable 6.4 7.2 Total long-term debt $ 6,135.0 $ 5,990.9 Senior Notes During the third quarter of 2013, the Company entered into two fixed-to-variable interest rate swap agreements for its 4.625% senior notes due 2020 with an aggregate notional amount of $600.0 and variable interest rates based on one-month LIBOR plus 2.298% to hedge against changes in the fair value of a portion of the Company's long-term debt. These derivative financial instruments are accounted for as fair value hedges of the senior notes due 2020. These interest rate swaps are included in other long-term assets or other long-term liabilities, as applicable, and added to or subtracted from the value of the senior notes, with an aggregate fair value asset of $ 3.7 at June 30, 2019 , and an aggregate fair value liability of $3.1 at December 31, 2018 . Zero-Coupon Subordinated Notes On March 11, 2019, the Company announced that for the period from March 11, 2019, to September 10, 2019, the zero-coupon subordinated notes will accrue contingent cash interest at a rate of no less than 0.125% of the average market price of a zero-coupon subordinated note for the five trading days ended August 27, 2019, in addition to the continued accrual of the original issue discount. During the six months ended June 30, 2019 , the Company settled notices to convert $7.7 aggregate principal amount of its zero-coupon subordinated notes with a conversion value of $14.5 . The total cash used for these settlements was $7.3 . As a result of these conversions, the Company also reversed deferred tax liabilities of $1.7 . On July 1, 2019, the Company announced that its zero-coupon subordinated notes may be converted into cash and common stock at the conversion rate of 13.4108 per $1,000.0 principal amount at maturity of the notes, subject to the terms of the zero-coupon subordinated notes and the Indenture, dated as of October 24, 2006 , between the Company and The Bank of New York Mellon, as trustee and the conversion agent. In order to exercise the option to convert all or a portion of the zero-coupon subordinated notes, holders are required to validly surrender their zero-coupon subordinated notes at any time during the calendar quarter beginning July 1, 2019, through the close of business on the last business day of the calendar quarter, which is 5:00 p.m., New York City time, on Monday, September 30, 2019. If notices of conversion are received, the Company plans to settle the cash portion of the conversion obligation with cash on hand and/or borrowings under its revolving credit facility. Credit Facilities On June 3, 2019, the Company entered into a new $850.0 term loan facility in addition to its $750.0 2017 term loan facility. The 2019 term loan facility will mature on June 3, 2021. Proceeds of the 2019 term loan facility were used for general corporate purposes, including to repay approximately $250.0 of the 2017 term loan facility and in connection with the acquisition of Envigo's nonclinical research services business. This net change of $600.0 represents the only contractual obligation as of June 30, 2019, that materially changed from December 31, 2018. The 2019 term loan facility accrues interest at a per annum rate equal to at the Company's election, either a LIBOR rate plus a margin ranging from 0.55% to 1.175% , or a base rate determined according to a prime rate or federal funds rate plus a margin ranging from 0.0% to 0.175% . The 2019 term loan balance at June 30, 2019, was $850.0 . As of June 30, 2019, the effective interest rate on the 2019 term loan was 3.24% . On September 15, 2017, the Company entered into a $750.0 term loan facility in addition to its then existing $1,000.0 term loan entered into in December 2014. The 2017 term loan facility will mature on September 15, 2022. The Company paid off the 2014 term loan during the second quarter of 2018. The 2017 term loan facility accrues interest at a per annum rate equal to, at the Company's election, either a LIBOR rate plus a margin ranging from 0.875% to 1.50% , or a base rate determined according to a prime rate or federal funds rate plus a margin ranging from 0.0% to 0.50% . The 2017 term loan balance at June 30, 2019 , was $277.0 and at December 31, 2018 , was $527.0 . As of June 30, 2019 , the effective interest rate on the 2017 term loan was 3.56% . The Company entered into a senior unsecured revolving credit facility on December 21, 2011, which was amended and restated on December 19, 2014, further amended on July 13, 2016, and further amended and restated on September 15, 2017. The revolving credit facility consists of a five-year revolving facility in the principal amount of up to $1,000.0 , with the option of increasing the facility by up to an additional $350.0 , 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 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, and acquisitions and other investments. The Company had $35.0 outstanding on its revolving credit facility at June 30, 2019 , and no outstanding balance on December 31, 2018 . Advances under the revolving credit facility will accrue interest at a per annum rate equal to, at the Company’s election, either a LIBOR rate plus a margin ranging from 0.775% to 1.25% , or a base rate determined according to a prime rate or federal funds rate plus a margin ranging from 0.00% to 0.25% . Fees are payable on outstanding letters of credit under the revolving credit facility at a per annum rate equal to the applicable margin for LIBOR loans, and 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 0.10% to 0.25% . The interest margin applicable to the term loan and credit facilities, and the facility fee and letter of credit fees payable under the revolving credit facility, are based on the Company’s senior credit ratings as determined by Standard & Poor’s and Moody’s. Under the term loan facilities and 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 term loan facilities and the revolving credit facility at June 30, 2019 . As of June 30, 2019 , the ratio of total debt to consolidated proforma trailing 12 month EBITDA was 3.4 to 1.0. As of June 30, 2019 , the Company had provided letters of credit aggregating approximately $72.2 , primarily in connection with certain insurance programs. The Company's availability of $892.8 at June 30, 2019, under its revolving credit facility is reduced by the amount of these letters of credit.

PREFERRED STOCK AND COMMON SHAR

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY	6 Months Ended
	Jun. 30, 2019
Stockholders' Equity Note [Abstract]
Changes in common shares issued and held in treasury	The changes in common shares issued and held in treasury are summarized below: Issued Held in Treasury Outstanding Common shares at December 31, 2018 122.4 (23.5 ) 98.9 Common stock issued under employee stock plans 1.0 — 1.0 Surrender of restricted stock and performance share awards — (0.1 ) (0.1 ) Retirement of common stock (2.0 ) — (2.0 ) Retirement of treasury stock (23.6 ) 23.6 — Common shares at June 30, 2019 97.8 — 97.8
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The components of accumulated other comprehensive earnings are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance at December 31, 2018 $ (389.8 ) $ (73.3 ) $ (463.1 ) Other comprehensive earnings before reclassifications 47.2 5.5 52.7 Tax effect of adjustments — (1.5 ) (1.5 ) Balance at June 30, 2019 $ (342.6 ) $ (69.3 ) $ (411.9 )
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’s treasury shares were recorded at aggregate cost and were retired during the second quarter of 2019. 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, 2019 , and December 31, 2018. The changes in common shares issued and held in treasury are summarized below: Issued Held in Treasury Outstanding Common shares at December 31, 2018 122.4 (23.5 ) 98.9 Common stock issued under employee stock plans 1.0 — 1.0 Surrender of restricted stock and performance share awards — (0.1 ) (0.1 ) Retirement of common stock (2.0 ) — (2.0 ) Retirement of treasury stock (23.6 ) 23.6 — Common shares at June 30, 2019 97.8 — 97.8 Share Repurchase Program At the end of 2018, the Company had outstanding authorization from the board of directors to purchase up to $443.5 of Company common stock. During January 2019, the Company purchased 0.8 shares of its common stock at an average price of $131.71 for a total cost of $100.1 under this plan. On February 6, 2019, the board of directors replaced the Company's existing share repurchase plan with a new plan authorizing repurchase of up to $1.25 billion of the Company's common stock. The repurchase authorization has no expiration. During the three months ended June 30, 2019, the Company purchased 1.3 shares of its common stock at an average price of $159.13 for a total cost of $199.9 . As of June 30, 2019, the Company had outstanding authorization from the board of directors to purchase up to $1.05 billion of the Company's common stock. Accumulated Other Comprehensive Earnings The components of accumulated other comprehensive earnings are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance at December 31, 2018 $ (389.8 ) $ (73.3 ) $ (463.1 ) Other comprehensive earnings before reclassifications 47.2 5.5 52.7 Tax effect of adjustments — (1.5 ) (1.5 ) Balance at June 30, 2019 $ (342.6 ) $ (69.3 ) $ (411.9 )

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company does not recognize a tax benefit unless the Company 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 the Company believes is greater than 50% likely to be realized. The gross unrecognized income tax benefits were $25.6 and $18.0 at June 30, 2019 , and December 31, 2018 , 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, 2019 , and December 31, 2018 , $25.6 and $18.0 , 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 $10.3 and $8.7 as of June 30, 2019 , and December 31, 2018 , respectively. The Company has substantially concluded all U.S. federal income tax matters for years through 2014. Substantially all material state and local, and foreign income tax matters have been concluded through 2013 and 2014, respectively. The IRS has not initiated a new examination of any of the Company's federal income tax returns. 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	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company is involved from time to time in various claims and legal actions, including arbitrations, class actions, and other litigation (including those described in more detail below), arising in the ordinary course of business. Some of these actions involve claims that are substantial in amount. These matters include, but are not limited to, intellectual property disputes; commercial and contract disputes; professional liability claims; employee-related matters; and inquiries, including subpoenas and other civil investigative demands, from governmental agencies, Medicare or Medicaid payers and MCOs reviewing billing practices or requesting comment on allegations of billing irregularities that are brought to their attention through billing audits or third parties. The Company receives civil investigative demands or other inquiries from various governmental bodies in the ordinary course of its business. Such inquiries can relate to the Company or other parties, including physicians and other health care providers. The Company works cooperatively to respond to appropriate requests for information. The Company also is named from time to time in suits brought under the qui tam provisions of the False Claims Act and comparable state laws. These suits typically allege that the Company has made false statements and/or certifications in connection with claims for payment from U.S. federal or state healthcare programs. The suits may remain under seal (hence, unknown to the Company) for some time while the government decides whether to intervene on behalf of the qui tam plaintiff. Such claims are an inevitable part of doing business in the healthcare field today. The Company believes that it is in compliance in all material respects with all statutes, regulations and other requirements applicable to its commercial laboratory operations and drug development support services. The healthcare diagnostics and drug development industries are, however, subject to extensive regulation, and the courts have not interpreted many of the applicable statutes and regulations. Therefore, the applicable statutes and regulations could be interpreted or applied by a prosecutorial, regulatory or judicial authority in a manner that would adversely affect the Company. Potential sanctions for violation of these statutes and regulations include significant civil and criminal penalties, fines, the loss of various licenses, certificates and authorizations, additional liabilities from third-party claims, and/or exclusion from participation in government programs. Many of the current claims and legal actions against the Company are in preliminary stages, and many of these cases seek an indeterminate amount of damages. The Company records an aggregate legal reserve, which is determined using calculations based on historical loss rates and assessment of trends experienced in settlements and defense costs. In accordance with FASB Accounting Standards Codification Topic 450 “Contingencies,” the Company establishes reserves for judicial, regulatory, and arbitration matters outside the aggregate legal reserve if and when those matters present loss contingencies that are both probable and estimable and would exceed the aggregate legal reserve. When loss contingencies are not both probable and estimable, the Company does not establish separate reserves. The Company is unable to estimate a range of reasonably probable loss for the proceedings described in more detail below in which damages either have not been specified or, in the Company's judgment, are unsupported and/or exaggerated and (i) the proceedings are in early stages; (ii) there is uncertainty as to the outcome of pending appeals or motions; (iii) there are significant factual issues to be resolved; and/or (iv) there are novel legal issues to be presented. For these proceedings, however, the Company does not believe, based on currently available information, that the outcomes will have a material adverse effect on the Company's financial condition, though the outcomes could be material to the Company's operating results for any particular period, depending, in part, upon the operating results for such period. As previously reported, the Company responded to an October 2007 subpoena from the U.S. Department of Health & Human Services Office of Inspector General's regional office in New York. On August 17, 2011, the U.S. District Court for the Southern District of New York unsealed a False Claims Act lawsuit, United States of America ex rel. NPT Associates v. Laboratory Corporation of America Holdings , which alleges that the Company offered UnitedHealthcare kickbacks in the form of discounts in return for Medicare business. The Plaintiff's Third Amended Complaint further alleges that the Company's billing practices violated the False Claims Acts of 14 states and the District of Columbia. The lawsuit seeks actual and treble damages and civil penalties for each alleged false claim, as well as recovery of costs, attorney's fees, and legal expenses. Neither the U.S. government nor any state government has intervened in the lawsuit. The Company's Motion to Dismiss was granted in October 2014 and Plaintiff was granted the right to replead. On January 11, 2016, Plaintiff filed a motion requesting leave to file an amended complaint under seal and to vacate the briefing schedule for the Company's Motion to Dismiss, while the government reviews the amended complaint. The Court granted the motion and vacated the briefing dates. Plaintiff then filed the Amended Complaint under seal. The Company will vigorously defend the lawsuit. In addition, the Company has received various other subpoenas since 2007 related to Medicaid billing. In October 2009, the Company received a subpoena from the State of Michigan Department of Attorney General seeking documents related to its billing to Michigan Medicaid. The Company cooperated with this request. In October 2013, the Company received a Civil Investigative Demand from the State of Texas Office of the Attorney General requesting documents related to its billing to Texas Medicaid. The Company cooperated with this request. On October 5, 2018, the Company received a second Civil Investigative Demand from the State of Texas Office of the Attorney General requesting documents related to its billing to Texas Medicaid. The Company is cooperating with this request. On May 2, 2013, the Company was served with a False Claims Act lawsuit, State of Georgia ex rel. Hunter Laboratories, LLC and Chris Riedel v. Quest Diagnostics Incorporated, et al. , filed in the State Court of Fulton County, Georgia. The lawsuit, filed by a competitor laboratory, alleges that the Company overcharged Georgia's Medicaid program. The State of Georgia filed a Notice of Declination on August 13, 2012, before the Company was served with the complaint. The case was removed to the U.S. District Court for the Northern District of Georgia. The lawsuit sought actual and treble damages and civil penalties for each alleged false claim, as well as recovery of costs, attorney's fees, and legal expenses. On March 14, 2014, the Company's Motion to Dismiss was granted. The Plaintiffs repled their complaint, and the Company filed a Motion to Dismiss the First Amended Complaint. In May 2015, the Court dismissed the Plaintiffs' anti-kickback claim and remanded the remaining state law claims to the State Court of Fulton County. In July 2015, the Company filed a Motion to Dismiss these remaining claims. The Plaintiffs filed an opposition to the Company's Motion to Dismiss in August 2015. Also, the State of Georgia filed a brief as amicus curiae. In May, 2019, the parties settled the lawsuit. On August 31, 2015, the Company was served with a putative class action lawsuit, Patty Davis v. Laboratory Corporation of America, et al., filed in the Circuit Court of the Thirteenth Judicial Circuit for Hillsborough County, Florida. The complaint alleges that the Company violated the Florida Consumer Collection Practices Act by billing patients who were collecting benefits under the Workers' Compensation Statutes. The lawsuit seeks injunctive relief and actual and statutory damages, as well as recovery of attorney's fees and legal expenses. In April 2017, the Circuit Court granted the Company’s Motion for Judgment on the Pleadings. The Plaintiff has appealed the Circuit Court’s ruling to the Florida Second District Court of Appeal. The Company will vigorously defend the lawsuit. In December 2014, the Company received a Civil Investigative Demand issued pursuant to the U.S. False Claims Act from the U.S. Attorney's Office for South Carolina, which requested information regarding alleged remuneration and services provided by the Company to physicians who also received draw and processing/handling fees from competitor laboratories Health Diagnostic Laboratory, Inc. (HDL) and Singulex, Inc. (Singulex). The Company cooperated with the request. On April 4, 2018, the U.S. District Court for the District of South Carolina, Beaufort Division, unsealed a False Claims Act lawsuit, United States of America ex rel. Scarlett Lutz, et al. v. Laboratory Corporation of America Holdings , which alleges that the Company's financial relationships with referring physicians violate federal and state anti-kickback statutes. The Plaintiffs' Fourth Amended Complaint further alleges that the Company conspired with HDL and Singulex in violation of the Federal False Claims Act and the California and Illinois insurance fraud prevention acts by facilitating HDL's and Singulex's offers of illegal inducements to physicians and the referral of patients to HDL and Singulex for laboratory testing. The lawsuit seeks actual and treble damages and civil penalties for each alleged false claim, as well as recovery of costs, attorney's fees, and legal expenses. Neither the U.S. government nor any state government has intervened in the lawsuit. The Company filed a Motion to Dismiss seeking the dismissal of the claims asserted under the California and Illinois insurance fraud prevention statutes, the conspiracy claim, the reverse False Claims Act claim, and all claims based on the theory that the Company performed medically unnecessary testing. On January 16, 2019, the Court entered an order granting in part and denying in part the Motion to Dismiss. The Court dismissed the Plaintiffs' claims based on the theory that the Company performed medically unnecessary testing, the claims asserted under the California and Illinois insurance fraud prevention statutes, and the reverse False Claims Act claim. The Court denied the Motion to Dismiss as to the conspiracy claim. The Company will vigorously defend the lawsuit. On August 3, 2016, the Company was served with a putative class action lawsuit, Daniel L. Bloomquist v. Covance Inc., et al. , filed in the Superior Court of California, County of San Diego. The Complaint alleges that Covance Inc. violated the California Labor Code and California Business & Professions Code by failing to provide overtime wages, failing to provide meal and rest periods, failing to pay for all hours worked, failing to pay for all wages owed upon termination, and failing to provide accurate itemized wage statements to Clinical Research Associates and Senior Clinical Research Associates employed by Covance in California. The lawsuit seeks monetary damages, civil penalties, injunctive relief, and recovery of attorney's fees and costs. On October 13, 2016, the case was removed to the U.S. District Court for the Southern District of California. On May 3, 2017, the U.S. District Court for the Southern District of California remanded the case to the Superior Court. The Company will vigorously defend the lawsuit. Prior to the Company's acquisition of Sequenom, Inc. (Sequenom) between August 15, 2016, and August 24, 2016, six putative class-action lawsuits were filed on behalf of purported Sequenom stockholders (captioned Malkoff v. Sequenom, Inc., et al., No. 16-cv-02054- JAH-BLM , Gupta v. Sequenom, Inc., et al ., No. 16-cv-02084-JAH-KSC, Fruchter v. Sequenom, Inc., et al ., No. 16-cv-02101- WQH-KSC, Asiatrade Development Ltd. v. Sequenom, Inc., et al. , No. 16-cv-02113-AJB-JMA, Nunes v. Sequenom, Inc., et al. , No. 16-cv-02128-AJB-MDD, and Cusumano v. Sequenom, Inc., et al. , No. 16-cv-02134-LAB-JMA) in the U.S. District Court for the Southern District of California challenging the acquisition transaction. The complaints asserted claims against Sequenom and members of its board of directors (the Individual Defendants). The Nunes action also named the Company and Savoy Acquisition Corp. (Savoy), a wholly owned subsidiary of the Company, as defendants. The complaints alleged that the defendants violated Sections 14(e), 14(d)(4) and 20 of the Securities Exchange Act of 1934 by failing to disclose certain allegedly material information. In addition, the complaints in the Malkoff action, Asiatrade action, and the Cusumano action alleged that the Individual Defendants breached their fiduciary duties to Sequenom shareholders. The actions sought, among other things, injunctive relief enjoining the merger. On August 30, 2016, the parties entered into a Memorandum of Understanding (MOU) in each of the above-referenced actions. On September 6, 2016, the Court entered an order consolidating for all pre-trial purposes the six individual actions described above under the caption In re Sequenom, Inc. Shareholder Litig. , Lead Case No. 16-cv-02054-JAH-BLM, and designating the complaint from the Malkoff action as the operative complaint for the consolidated action. On November 11, 2016, two competing motions were filed by two separate stockholders (James Reilly and Shikha Gupta) seeking appointment as lead plaintiff under the terms of the Private Securities Litigation Reform Act of 1995. On June 7, 2017, the Court entered an order declaring Mr. Reilly as the lead plaintiff and approving Mr. Reilly's selection of lead counsel. The parties agree that the MOU has been terminated. The Plaintiffs filed a Consolidated Amended Class Action Complaint on July 24, 2017, and the Defendants filed a Motion to Dismiss, which remains pending. On March 13, 2019, the Court stayed the action in its entirety pending the U.S. Supreme Court's anticipated decision in Emulex Corp. v. Varjabedian . On April 23, 2019, however, the U.S. Supreme Court dismissed the writ of certiorari in Emulex as improvidently granted. The Company will vigorously defend the lawsuit. On March 10, 2017, the Company was served with a putative class action lawsuit, Victoria Bouffard, et al. v. Laboratory Corporation of America Holdings , filed in the U.S. District Court for the Middle District of North Carolina. The complaint alleges that the Company's patient list prices unlawfully exceed the rates negotiated for the same services with private and public health insurers in violation of various state consumer protection laws. The lawsuit also alleges breach of implied contract or quasi-contract, unjust enrichment, and fraud. The lawsuit seeks statutory, exemplary, and punitive damages, injunctive relief, and recovery of attorney's fees and costs. In May 2017, the Company filed a Motion to Dismiss Plaintiffs' Complaint and Strike Class Allegations; the Motion to Dismiss was granted in March 2018 without prejudice. On October 10, 2017, a second putative class action lawsuit, Sheryl Anderson, et al. v. Laboratory Corporation of America Holdings , was filed in the U.S. District Court for the Middle District of North Carolina. The complaint contained similar allegations and sought similar relief to the Bouffard complaint, and added additional counts regarding state consumer protection laws. On August 10, 2018, the Plaintiffs filed an Amended Complaint, which consolidated the Bouffard and Anderson actions. On September 10, 2018, the Company filed a Motion to Dismiss Plaintiffs' Amended Complaint and Strike Class Allegations, which remains pending. The Company will vigorously defend the lawsuit. On September 7, 2017, the Company was served with a putative class action lawsuit, John Sealock, et al. v. Covance Market Access Services, Inc ., filed in the U.S. District Court for the Southern District of New York. The complaint alleged that Covance Market Access Services, Inc. violated the Fair Labor Standards Act and New York labor laws by failing to provide overtime wages, failing to pay for all hours worked, and failing to provide accurate wage statements. The lawsuit sought monetary damages, civil penalties, injunctive relief, and recovery of attorney's fees and costs. In November 2017, the Company filed a Motion to Strike Class Allegations, which was denied. In December 2017, the Plaintiff filed a Motion for Conditional Certification of a Collective Action, which was granted in May 2018. In December 2018, Plaintiff filed, and the Court granted, a second motion to conditionally certify an expanded class to a nationwide class action. This matter has been settled in principle and the settlement is subject to judicial review and approval. On July 16, 2018, the Company reported that it had detected suspicious activity on its information technology network and was taking steps to respond to and contain the activity. The activity was subsequently determined to be a new variant of ransomware affecting certain LCD information technology systems. As part of its response, the Company took certain systems offline, which temporarily affected test processing and customer access to test results, and also affected certain other information technology systems involved in conducting Company-wide operations. Operations were returned to normal within a few days of the incident. As part of its in-depth investigation into this incident, the Company engaged outside security experts and worked with authorities, including law enforcement. The investigation determined that the ransomware did not and could not transfer patient or client data outside of Company systems and that there was no theft or misuse of patient or client data. The Company cooperated with law enforcement and regulatory authorities with respect to the incident. The Company has insurance coverage for costs resulting from cyber-attacks and has filed a claim for recovery of its losses resulting from this incident. However, disputes over the extent of insurance coverage for claims are not uncommon and the Company has not recognized any estimated proceeds resulting from this claim. Furthermore, while the Company has not been the subject of any legal proceedings involving this incident, it is possible that the Company could be the subject of claims from persons alleging they suffered damages from the incident, or actions by governmental authorities. On September 10, 2018, the Company was served with a Labor Code Private Attorneys General Act (LCPAGA) lawsuit, Terri Wilson v. Laboratory Corporation of America Holdings , which was filed in the U.S. District Court for the Northern District of California. Plaintiff alleged claims for failure to pay meal and rest break premiums, failure to provide compliant wage statements, failure to compensate employees for all hours worked, and failure to pay wages upon termination of employment. Plaintiff asserted these actions violated various California Labor Code provisions and constituted an unfair competition practice under California law. The lawsuit sought monetary damages, civil penalties, injunctive relief, and recovery of attorney's fees and costs. In June, 2019, the parties settled the lawsuit. On September 21, 2018, the Company was served with a putative class action lawsuit, Alma Haro v. Laboratory Corporation of America, et al. , which was filed in the Superior Court of California, County of Los Angeles. Plaintiff alleges that employees were not properly paid overtime compensation, minimum wages, meal and rest break premiums, did not receive compliant wage statements, and were not properly paid wages upon termination of employment. Plaintiff asserts these actions violate various California Labor Code provisions and constitute an unfair competition practice under California law. The lawsuit seeks monetary damages, civil penalties, and recovery of attorney's fees and costs. The Company will vigorously defend the lawsuit. On December 20, 2018, the Company was served with a putative class action lawsuit, Feckley v. Covance Inc., et al ., filed in the Superior Court of California, County of Orange. The complaint alleges that Covance Inc. violated the California Labor Code and California Business & Professions Code by failing to properly pay commissions to employees under a sales incentive compensation plan upon their termination of employment. The lawsuit seeks monetary damages, civil penalties, punitive damages, and recovery of attorney’s fees and costs. On January 22, 2018, the case was removed to the U.S. District Court for the Central District of California. The Company will vigorously defend the lawsuit. On April 1, 2019, Covance Research Products was served with a Grand Jury Subpoena issued by the Department of Justice (DOJ) in Miami, Florida requiring the production of documents related to the importation into the United States of live non-human primate shipments originating from or transiting through China, Cambodia, and/or Vietnam from April 1, 2014 through March 28, 2019. The Company is cooperating with the DOJ. On April 4, 2019, Tri-Cities Laboratory (a joint venture that was acquired as part of the Pathology Associates Medical Laboratories transaction in May 2017) was served with a subpoena issued by the DOJ in Newark, New Jersey requiring the production of documents related to test orders and payments to various third party companies and individuals. The Company cooperated with the DOJ. On April 22, 2019, the Company was served with a putative class action lawsuit, Kawa Orthodontics LLP, et al. v. Laboratory Corporation of America Holdings, et al. , filed in the U.S. District Court for the Middle District of Florida. The lawsuit alleges that on or about February 6, 2019, the defendants violated the U.S. Telephone Consumer Protection Act (TCPA) by sending unsolicited facsimiles to Plaintiff and at least 40 other recipients without the recipients' prior express invitation or permission. The lawsuit seeks the greater of actual damages or the sum of $0.0005 for each violation, subject to trebling under the TCPA, and injunctive relief. The Company filed a motion to dismiss the case on May 28, 2019. In response to the Motion to Dismiss, the Plaintiff filed an amended complaint, which contains additional allegations, including allegations related to another facsimile. The Company filed a Motion to Dismiss the amended complaint. The Company will vigorously defend the lawsuit. On May 14, 2019, Retrieval-Masters Creditors Bureau, Inc. d/b/a American Medical Collection Agency (AMCA), an external collection agency, notified the Company about a security incident AMCA experienced that may have involved certain personal information about some of the Company’s patients (the AMCA Incident). The Company referred patient balances to AMCA only when direct collection efforts were unsuccessful. The Company’s systems were not impacted by the AMCA Incident. Upon learning of the AMCA Incident, the Company promptly stopped sending new collection requests to AMCA and stopped AMCA from continuing to work on any pending collection requests from the Company. AMCA informed the Company that it appeared that an unauthorized user had access to AMCA’s system between August 1, 2018 and March 30, 2019, and that AMCA could not rule out the possibility that personal information on AMCA’s system was at risk during that time period. Information on AMCA’s affected system from the Company may have included name, address, and balance information for the patient and person responsible for payment, along with the patient’s phone number, date of birth, referring physician, and date of service. The Company was later informed by AMCA that health insurance information may have been included for some individuals, and because some insurance carriers utilize the Social Security Number as a subscriber identification number, the Social Security Number for some individuals may also have been affected. No ordered tests, laboratory test results, or diagnostic information from the Company were in the AMCA affected system. The Company notified individuals for whom it had a valid mailing address. For the individuals whose Social Security Number was affected, the notice included an offer to enroll in credit monitoring and identity protection services that will be provided free of charge for 24 months. Eighteen putative class action lawsuits were filed against the Company related to the AMCA Incident. Numerous similar lawsuits have been filed against other health care providers who used AMCA. The lawsuits against the Company were filed in various United States District Courts. The lawsuits generally allege that the Company did not adequately protect its patients’ data, and assert various causes of action, including but not limited to negligence, breach of implied contract, unjust enrichment, and the violation of state data protection statutes. The lawsuits seek damages on behalf of a class of all affected Company consumers. The attorneys for certain of the Plaintiffs filed a motion with the Judicial Panel on Multi-District Litigation (JPML) seeking to have all cases related to the AMCA Incident consolidated for pre-trial proceedings in a multi-district litigation. The JPML ordered the transfer of the cases to the District of New Jersey. The Company will vigorously defend the multi-district litigation. Certain governmental entities and individuals have requested information from the Company related to the AMCA Incident. The Company has received requests for information from United States Senators Robert Menendez and Cory A. Booker and from the Attorneys General of Colorado, Connecticut, Illinois, Florida, New York, and Indiana. The request from Indiana includes a Civil Investigative Demand, which requests certain documents from the Company. The Company also provided notice of the AMCA Incident to state and federal regulators where appropriate. The Company is cooperating with these requests. On June 10, 2019, the Company was served with a class action lawsuit, Ignacio v. Laboratory Corporation of America , filed in Superior Court of the State of California for the County of Los Angeles. Plaintiff alleges that non-exempt employees based in California were not properly paid overtime compensation, minimum wages, meal and rest break premiums, were not indemnified for business expenses, did not receive compliant wage statements, and were not properly paid wages upon termination of employment. Plaintiff asserts these actions violate various California Labor Code provisions and constitute an unfair competition practice under California law. The lawsuit seeks monetary damages, liquidated damages, injunctive relief, and recovery of attorney's fees and costs. The Company will vigorously defend the lawsuit. On June 26, 2019, a class action lawsuit, Jan v. Laboratory Corporation of America , was filed in the Superior Court for the State of California for the County of Sacramento. Plaintiff alleges that non-exempt employees based in California were not properly paid meal and rest break premiums, did not receive compliant wage statements, and were not properly paid wages upon termination of employment. Plaintiff asserts these actions violate various California Labor Code provisions and constitute an unfair competition practice under California law. The lawsuit seeks monetary damages, liquidated damages, injunctive relief, and recovery of attorney's fees and costs. The Company will vigorously defend the lawsuit. On July 1, 2019, a class action lawsuit, Mitchell v. Covance, Inc. et al. , was filed in the United States District Court for the Eastern District of Pennsylvania. Plaintiff alleges that certain individuals employed by Covance Inc. and Chiltern International Inc. were misclassified as exempt employees under the Fair Labor Standards Act and the Pennsylvania Minimum Wage Act and were thereby not properly paid overtime compensation. The lawsuit seeks monetary damages, liquidated damages, and recovery of attorneys’ fees and costs. The Company will vigorously defend the lawsuit. Under the Company's present insurance programs, coverage is obtained for catastrophic exposure as well as those risks required to be insured by law or contract. The Company is responsible for the uninsured portion of losses related primarily to general, professional and vehicle liability, certain medical costs and workers' compensation. The self-insured retentions are on a per-occurrence basis without any aggregate annual limit. Provisions for losses expected under these programs are recorded based upon the Company's estimates of the aggregated liability of claims incurred.

PENSION AND POSTRETIREMENT PLAN

PENSION AND POSTRETIREMENT PLANS	6 Months Ended
	Jun. 30, 2019
Postemployment Benefits [Abstract]
Pension And Postretirement Plans	PENSION AND POST-RETIREMENT PLANS The Company has two defined contribution retirement plans (401K Plans) which cover substantially all U.S. employees. All employees eligible for the LabCorp 401K Plan receive a minimum 3% non-elective contribution concurrent with each payroll period. The 401K Plan also permits discretionary contributions by the Company of up to 1% and up to 3% of pay for eligible employees based on years of service with the Company. The cost of this plan was $12.9 and $15.8 for the three months ended June 30, 2019 , and 2018 , respectively, and was $37.1 and $31.8 for the six months ended June 30, 2019 , and 2018 , respectively. All of the Covance U.S. employees, including legacy Chiltern employees, are eligible to participate in the Covance 401K plan, which features a maximum 4.5% Company match, based upon a percentage of the employee’s contributions. Chiltern employees were previously eligible to participate in the Chiltern 401K plan, which featured a maximum 3.0% Company match, based upon a percentage of the employee's contributions. The Chiltern 401K plan merged into the Covance Plan effective January, 7, 2019. The Company incurred expense of $17.9 and $16.5 for the Covance 401K plan during the three months ended June 30, 2019 , and 2018 , respectively, and $37.8 and $35.3 during the six months ended June 30, 2019 , and 2018 , respectively. The Company also maintains several other immaterial 401K plans associated with companies acquired over the last several years. The Company also maintains a frozen defined benefit retirement plan (Company Plan), which as of December 31, 2009, covered substantially all employees. The benefits to be paid under the Company Plan are based on years of credited service through December 31, 2009, and ongoing interest credits. Effective January 1, 2010, the Company Plan was closed to new participants. The Company’s policy is to fund the Company Plan with at least the minimum amount required by applicable regulations. The Company maintains a second, unfunded, non-contributory, non-qualified defined benefit retirement plan (PEP), which as of December 31, 2009, covered substantially all of its senior management group. The PEP supplements the Company Plan and was closed to new participants effective January 1, 2010. The effect on operations for the Company Plan and the PEP is summarized as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 1.0 $ 1.2 $ 2.0 $ 2.6 Interest cost on benefit obligation 3.5 3.2 7.0 6.5 Expected return on plan assets (3.8 ) (4.1 ) (7.6 ) (8.2 ) Net amortization and deferral 2.6 3.1 5.2 5.9 Defined benefit plan costs $ 3.3 $ 3.4 $ 6.6 $ 6.8 During the six months ended June 30, 2019 , the Company made no contributions to the Company Plan. As a result of the Covance acquisition, the Company sponsors two defined benefit pension plans for the benefit of its employees at two U.K. subsidiaries (U.K. Plans) and one defined benefit pension plan for the benefit of its employees at a German subsidiary (German Plan), all of which are legacy plans of previously acquired companies. Benefit amounts for all three plans are based upon years of service and compensation. The German plan is unfunded while the U.K. pension plans are funded. The Company’s funding policy has been to contribute annually amounts at least equal to the local statutory funding requirements. U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.8 $ 0.9 $ 1.6 $ 1.8 Interest cost on benefit obligation 1.9 1.9 3.8 3.8 Expected return on plan assets (2.8 ) (3.2 ) (5.7 ) (6.5 ) Defined benefit plan costs $ (0.1 ) $ (0.4 ) $ (0.3 ) $ (0.9 ) U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Assumptions used to determine defined benefit plan cost Discount rate 2.9 % 2.5 % 2.9 % 2.5 % Expected return on assets 4.5 % 4.5 % 4.5 % 4.5 % Salary increases 3.6 % 3.6 % 3.6 % 3.6 % German Plan Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.3 $ 0.3 $ 0.6 $ 0.6 Interest cost on benefit obligation 0.2 0.2 0.3 0.3 Defined benefit plan costs $ 0.5 $ 0.5 $ 0.9 $ 0.9 Assumptions used to determine defined benefit plan cost Discount rate 1.9 % 1.7 % 1.9 % 1.7 % Expected return on assets N/A N/A N/A N/A Salary increases 2.0 % 2.0 % 2.0 % 2.0 % As a result of the Envigo acquisition, the Company assumed a defined benefit pension plan for the benefit of Envigo's U.K. employees (the Envigo plan), which is a legacy plan of a company previously acquired by Envigo. The Envigo plan is a funded plan that is closed to future accrual. The related net pension obligation of $56.8

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2019
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, 2019 , and December 31, 2018 , is as follows: Fair Value Measurements as of Fair Value as of June 30, 2019 Balance Sheet Using Fair Value Hierarchy Classification June 30, 2019 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 15.7 $ — $ 15.7 $ — Cross currency swap asset Other assets, net 1.2 — 1.2 — Interest rate swap Other assets, net 3.7 — 3.7 — Cash surrender value of life insurance policies Other assets, net 75.3 — 75.3 — Deferred compensation liability Other liabilities 74.3 — 74.3 — Contingent consideration Other liabilities 20.1 — — 20.1 Investment in equity securities Prepaid expenses and other 29.8 29.8 — — Fair Value Measurements as of Fair Value as of December 31, 2018 Balance Sheet Using Fair Value Hierarchy Classification December 31, 2018 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 15.0 $ — $ 15.0 $ — Cross currency swap liability Other liabilities 2.8 — 2.8 — Interest rate swap Other liabilities 3.1 — 3.1 — Cash surrender value of life insurance policies Other assets, net 63.5 — 63.5 — Deferred compensation liability Other liabilities 64.2 — 64.2 — Contingent consideration Other liabilities 18.6 — — 18.6 Fair Value Measurement of Level 3 Assets Contingent Consideration Balance at December 31, 2018 18.6 Addition 1.5 Balance at June 30, 2019 $ 20.1 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 22 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 these policies are based upon earnings and changes in the value of the underlying investments, which are typically invested in a manner similar to the participants' 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. The Company has contingent accrued earn-out business acquisition consideration liabilities which 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. The carrying amounts of cash and cash equivalents, accounts receivable, income taxes receivable, and accounts payable are considered to be representative of their respective fair values due to their short-term nature. The fair market value of the zero-coupon subordinated notes, based on market pricing, was approximately $1.8 and $16.9 as of June 30, 2019 , and December 31, 2018 , respectively. The fair market value of all of the senior notes, based on market pricing, was approximately $5,658.5 and $5,318.0 as of June 30, 2019 , and December 31, 2018 , respectively. The fair market value of the floating rate secured note due 2022 received for the sale of CRP was $110.0 as of June 30, 2019. The effective interest rate on the floating rate secured note receivable was 7.79%

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	6 Months Ended
	Jun. 30, 2019
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 relationships: Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Statement of Operations 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, 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swap contracts $ 4.3 $ (10.0 ) $ — $ — $ 6.8 $ (9.7 ) $ — $ — Cross currency swaps $ (7.8 ) $ (24.3 ) $ — $ — $ 4.0 $ (24.2 ) $ — $ —
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 such as interest rate and cross currency swap agreements (see Interest Rate Swap and Cross Currency Swap sections below). Although the Company’s zero-coupon subordinated notes contain features that are considered to be embedded derivative instruments (see Embedded Derivatives Related to the Zero-Coupon Subordinated Notes section below), the Company does not hold or issue derivative financial instruments for trading purposes. The derivative financial instrument contracts are with major investment grade financial institutions and the Company does not anticipate any material non-performance by any of the counterparties. 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 Swap The Company is party to two fixed-to-variable interest rate swap agreements for its 4.625% senior notes due 2020 with an aggregate notional amount of $600.0 and variable interest rates based on one-month LIBOR plus 2.298% to hedge against changes in the fair value of a portion of the Company's long term debt. These derivative financial instruments are accounted for as fair value hedges of the senior notes due 2020. These interest rate swaps are included in other long-term assets or other long-term liabilities, as applicable, and added to or subtracted from the value of the senior notes, with an aggregate fair value of $3.7 (asset) and $3.1 (liability) at June 30, 2019 , and December 31, 2018 , respectively. As the specific terms and notional amounts of the derivative financial instruments match those of the fixed-rate debt being hedged, the derivative instruments are assumed to be perfectly effective hedges and accordingly, there is no impact to the Company's Condensed Consolidated Statements of Operations. Carrying amount of hedged liabilities as of Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Liabilities as of June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Balance Sheet Line Item in which Hedged Items are Included Long-term debt, less current portion $ 603.7 $ 597.0 $ 3.7 $ (3.1 ) Cross Currency Swap During the fourth quarter of 2018, the Company entered into six U.S. Dollar to Swiss Franc cross-currency swap agreements with an aggregate notional value of $600.0 and which are accounted for as a hedge against its net investment in a Swiss subsidiary. Of the notional value, $300.0 matures in 2022 and $300.0 matures in 2025. These cross currency swaps maturing in 2022 and 2025 are included in other long-term assets with an aggregate fair value of $0.3 and $0.9 , respectively, as of June 30, 2019 and are included in other long-term liabilities with an aggregate fair value of $1.0 and $1.8 , respectively, as of December 31, 2018 . Changes in the fair value of the cross-currency swaps are charged or credited through accumulated other comprehensive income in the Condensed Consolidated Balance Sheet until the hedged item is recognized in earnings. The cumulative amount of the fair value hedging adjustment included in the current value of the cross currency swaps is $(7.8) and $4.0 , respectively, for the three and six months ended June 30, 2019 , and 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 months ended June 30, 2019. The table below presents the fair value of derivatives on a gross basis and the balance sheet classification of those instruments: June 30, 2019 December 31, 2018 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 or Other liabilities $ 3.7 $ — $ 600.0 $ — $ (3.1 ) $ 600.0 Cross currency swaps Other assets, net or Other liabilities $ 1.2 $ — $ 600.0 $ — $ (2.8 ) $ 600.0 The table below provides information regarding the location and amount of pretax (gains) losses of derivatives designated in fair value hedging relationships: Amount of pre-tax gain/(loss) included in other comprehensive income Amounts reclassified to the Statement of Operations 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, 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swap contracts $ 4.3 $ (10.0 ) $ — $ — $ 6.8 $ (9.7 ) $ — $ — Cross currency swaps $ (7.8 ) $ (24.3 ) $ — $ — $ 4.0 $ (24.2 ) $ — $ — No gains or losses from derivative instruments classified as hedging instruments have been recognized into income for the three and six months ended June 30, 2019 and 2018. Embedded Derivatives Related to the Zero-Coupon Subordinated Notes The Company’s zero-coupon subordinated notes contain the following two features that are considered to be embedded derivative instruments under authoritative guidance in connection with accounting for derivative instruments and hedging activities: 1) The Company will pay contingent cash interest on the zero-coupon subordinated notes after September 11, 2006, if the average market price of the notes equals 120% or more of the sum of the issue price, accrued original issue discount and contingent additional principal, if any, for a specified measurement period. 2) Holders may surrender zero-coupon subordinated notes for conversion during any period in which the rating assigned to the zero-coupon subordinated notes by Standard & Poor’s Ratings Services is BB- or lower. The Company believes these embedded derivatives had no fair value at June 30, 2019 , and December 31, 2018 . These embedded derivatives also had no impact on the Condensed Consolidated Statements of Operations for the six months ended June 30, 2019 , and 2018 . Other Derivative Instruments The Company periodically enters into foreign currency forward contracts, which are recognized as assets or liabilities at their fair value. These contracts do not qualify for hedge accounting and the changes in fair value are recorded directly to earnings. The contracts are short-term in nature and the fair value of these contracts is based on market prices for comparable contracts. The fair value of these contracts is not significant as of June 30, 2019 , and December 31, 2018
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, 2019 December 31, 2018 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 or Other liabilities $ 3.7 $ — $ 600.0 $ — $ (3.1 ) $ 600.0 Cross currency swaps Other assets, net or Other liabilities $ 1.2 $ — $ 600.0 $ — $ (2.8 ) $ 600.0

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	6 Months Ended
	Jun. 30, 2019
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, 2019 2018 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 123.8 $ 188.2 Income taxes, net of refunds 119.6 148.6 Disclosure of non-cash financing and investing activities: Conversion of zero-coupon convertible debt 7.2 — Change in accrued property, plant and equipment (12.5 ) 4.8 Floating rate secured note receivable due 2022 from the sale of CRP 110.0 —
Supplemental Cash Flow Information	Supplemental cash flow information related to leases was as follows: Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (115.2 ) Operating cash flows from finance leases (0.9 ) Financing cash flows from finance leases (4.8 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 43.7 Finance leases 0.2 SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2019 2018 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 123.8 $ 188.2 Income taxes, net of refunds 119.6 148.6 Disclosure of non-cash financing and investing activities: Conversion of zero-coupon convertible debt 7.2 — Change in accrued property, plant and equipment (12.5 ) 4.8 Floating rate secured note receivable due 2022 from the sale of CRP 110.0 —

BUSINESS ACQUISITIONS

BUSINESS ACQUISITIONS	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	BUSINESS ACQUISITIONS AND DISPOSITIONS On June 3, 2019, the Company's CDD segment completed the acquisition of Envigo's nonclinical contract research services business, expanding CDD's global nonclinical drug development capabilities with additional locations and resources. Envigo also completed the acquisition of the Covance Research Products (CRP) business, which was part of the CDD segment. The two companies will continue to collaborate through a multi-year, renewable supply agreement. The Company paid cash consideration of $601.0 , received a floating rate secured note of $110.0 , and recorded a loss on sale of CRP of $8.8 . The Company funded the transaction through a new term loan facility. The preliminary valuation of acquired assets and assumed liabilities as of June 3, 2019, include the following: Consideration Transferred Cash consideration $ 601.0 Fair value of CRP 110.0 Total $ 711.0 Preliminary Net Assets Acquired Cash and cash equivalents $ 15.1 Accounts receivable 16.5 Unbilled services 26.5 Inventories 4.5 Prepaid expenses and other 3.5 Property, plant and equipment (including ROU operating lease assets) 99.1 Deferred tax asset 25.5 Goodwill 432.2 Customer relationships 125.8 Trade name and trademarks 0.6 Other assets 9.9 Total assets acquired 759.2 Accounts payable 15.4 Accrued expenses and other 11.6 Unearned revenue 49.9 Operating lease liabilities 15.0 Other liabilities 66.3 Total liabilities acquired 158.2 Net Envigo assets acquired 601.0 Floating rate secured note receivable due 2022 110.0 Total $ 711.0 The amortization periods for intangible assets acquired are 11 years for customer relationships. The Envigo transaction contributed $16.5 and $0.7 of revenues and operating income, respectively, during the three and six months ended June 30, 2019. The purchase price allocation for the Envigo transaction is still preliminary and subject to change. The areas of the purchase price allocation that are not yet finalized relate primarily to intangible assets, goodwill, fixed assets and the impact of finalizing deferred taxes. Accordingly, adjustments may be made as additional information is obtained about the facts and circumstances that existed as of the valuation date. The Company expects these purchase price allocations to be finalized by the second quarter of 2020. Any adjustments will be recorded in the period in which they are identified. During the six months ended June 30, 2019, the Company also acquired various businesses and related assets for approximately $117.7 in cash (net of cash acquired). The purchase consideration for all acquisitions year to date has been allocated to the estimated fair market value of the net assets acquired, including approximately $90.7 in identifiable intangible assets and a residual amount of non-tax deductible goodwill of approximately $53.8 . The amortization periods for intangible assets acquired from these businesses range from 11 to 15 years for customer relationships. These acquisitions were made primarily to extend the Company's geographic reach in important market areas, enhance the Company's scientific differentiation and to expand the breadth and scope of the Company's CRO services. 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 businesses’ workforce and established relationships and the benefits of being able to leverage operational efficiencies with favorable growth opportunities in these markets. Additionally, the Company divested its food solutions and forensic testing services business in the United Kingdom (U.K) and the U.S. in 2018. Total operating income for the three divested businesses was $3.4 and $5.4 for the three and six months ended June 30, 2018, respectively.

BUSINESS SEGMENT INFORMATION Bu

BUSINESS SEGMENT INFORMATION Business Segment information (Notes)	6 Months Ended
	Jun. 30, 2019
Segment Reporting Information [Line Items]
Segment Reporting Disclosure [Text Block]	BUSINESS SEGMENT INFORMATION The following table is a summary of segment information for the three and six months ended June 30, 2019 , and 2018 . 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 its business unit operations 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 represents net 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. The table below represents information about the Company’s reporting segments for the three and six months ended June 30, 2019 , and 2018 : Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Revenues: LCD $ 1,760.9 $ 1,814.0 $ 3,482.9 $ 3,584.2 CDD 1,126.3 1,054.2 2,201.0 2,132.6 Intercompany eliminations (5.5 ) (1.9 ) (11.0 ) (2.2 ) Revenues 2,881.7 2,866.3 5,672.9 5,714.6 Operating earnings: LCD 312.5 336.3 580.8 639.8 CDD 65.8 68.8 153.8 107.3 Unallocated corporate expenses (42.6 ) (35.9 ) (80.7 ) (72.5 ) Total operating income 335.7 369.2 653.9 674.6 Other income (expense), net (65.7 ) (56.5 ) (129.2 ) (120.4 ) Earnings before income taxes 270.0 312.7 524.7 554.2 Provision for income taxes 79.3 78.6 148.1 147.6 Net earnings 190.7 234.1 376.6 406.6 Less (earnings) loss attributable to noncontrolling interests (0.3 ) (0.3 ) (0.6 ) 0.4 Net income attributable to Laboratory Corporation of America Holdings $ 190.4 $ 233.8 $ 376.0 $ 407.0

Leases (Notes)

Leases (Notes)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	LEASES The Company has operating and finance leases for patient service centers, laboratories and testing facilities, general office spaces, vehicles, and certain equipment. Leases have remaining lease terms of less than a year to 15 years, some of which include options to extend the leases for up to 15 years. The components of lease expense were as follows: Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease cost $ 59.9 $ 110.8 Finance lease cost: Amortization of ROU assets $ 1.5 $ 2.9 Interest on lease liabilities 0.4 1.2 Total finance lease cost $ 1.9 $ 4.1 Supplemental cash flow information related to leases was as follows: Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (115.2 ) Operating cash flows from finance leases (0.9 ) Financing cash flows from finance leases (4.8 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 43.7 Finance leases 0.2 Supplemental balance sheet information related to leases was as follows: June 30, 2019 Operating Leases Operating lease ROU assets (included in Property, plant and equipment, net) $ 770.3 Short-term operating lease liabilities 229.2 Operating lease liabilities 586.1 Total operating lease liabilities $ 815.3 June 30, 2019 Finance Leases Finance lease ROU assets (included in Other assets) $ 85.4 Short-term finance lease liabilities $ 8.2 Finance lease liabilities 46.2 Total finance lease liabilities $ 54.4 Weighted Average Remaining Lease Term Operating leases 5.8 Finance leases 6.5 Weighted Average Discount Rate Operating leases 4.2 % Finance leases 4.8 % Maturities of lease liabilities are as follows: Six Months Ended June 30, 2019 Operating Leases Finance Leases 2019 $ 254.1 $ 7.1 2020 274.7 13.8 2021 174.6 12.0 2022 69.3 10.8 2023 45.1 10.7 Thereafter 153.1 34.5 Total lease payments 970.9 88.9 Less imputed interest (155.6 ) (34.5 ) Total $ 815.3 $ 54.4 Rental expense for short term leases with a term less than one year for the three and six months ended June 30, 2019 , amounted to $2.6 and $5.9 , respectively. The Company has variable lease payments that do not depend on a rate or index, primarily for purchase volume commitments, which are recorded as variable cost when incurred. Total variable payments for the three and six months ended June 30, 2019 , were $4.7 and $9.2 , respectively. As of June 30, 2019 , the Company has entered into approximately 50 additional operating leases, primarily for patient service centers, that have not yet commenced and are not significant to the overall lease portfolio. These operating leases will commence later in 2019 with lease terms ranging from less than a year to 11 years. The Company leases various facilities and equipment under non-cancelable lease arrangements. Future minimum rental commitments for leases with non-cancelable terms of one year or more at December 31, 2018, under Accounting Standards Codification 840 are as follows: Year Ended December 31, Operating Leases Finance Leases 2019 $ 191.1 $ 8.6 2020 145.4 8.0 2021 107.0 6.7 2022 80.9 6.0 2023 61.5 6.5 Thereafter 155.6 23.1 Rental expense, which includes rent for real estate, equipment and automobiles under operating leases, amounted to $85.1 and $167.5 , respectively, for the three and six months ended June 30, 2019 .

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Reconciliation of Basic earnings per Share to Diluted Earnings per Share	The following represents a reconciliation of basic earnings per share to diluted earnings per share: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Earnings Shares Per Share Amount Earnings Shares Per Share Amount Earnings Shares Per Share Amount Earnings Shares Per Share Amount Basic earnings per share: Net earnings $ 190.4 98.1 $ 1.94 $ 233.8 101.9 $ 2.29 $ 376.0 98.4 $ 3.82 $ 407.0 101.9 $ 3.99 Dilutive effect of employee stock options and awards — 0.7 — 1.0 — 0.7 — 1.3 Net earnings including impact of dilutive adjustments $ 190.4 98.8 $ 1.93 $ 233.8 103.0 $ 2.27 $ 376.0 99.1 $ 3.79 $ 407.0 103.3 $ 3.94
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, 2019 2018 2019 2018 Stock options 0.2 0.1 0.2 0.1

RESTRUCTURING AND OTHER SPECI_2

RESTRUCTURING AND OTHER SPECIAL CHARGES Restructuring and Other Special Charges Detail (Tables)	6 Months Ended
	Jun. 30, 2019
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: LCD CDD Severance and Other Employee Costs Facility Costs Severance and Other Employee Costs Facility Costs Total Balance as of December 31, 2018 $ 2.1 $ 7.4 $ 6.5 $ 27.6 $ 43.6 Reclassification for ASC 842 adoption — (5.7 ) — (27.1 ) (32.8 ) Restructuring charges 11.9 1.0 8.4 1.7 23.0 Adjustments to prior restructuring accruals (0.1 ) — 0.5 — 0.4 Impairment of operating lease right-of-use asset — 3.3 — 7.5 10.8 Cash payments and other adjustments (13.6 ) (3.1 ) (8.5 ) (7.2 ) (32.4 ) Balance as of June 30, 2019 $ 0.3 $ 2.9 $ 6.9 $ 2.5 $ 12.6 Current $ 10.4 Non-current 2.2 $ 12.6

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the three-month period ended June 30, 2019 , are as follows: LCD CDD Total Balance as of January 1, 2019 $ 3,638.8 $ 3,721.5 $ 7,360.3 Goodwill acquired during the period 22.3 468.2 490.5 Dispositions — (12.6 ) (12.6 ) Adjustments to goodwill 1.9 3.6 5.5 Balance at June 30, 2019 $ 3,663.0 $ 4,180.7 $ 7,843.7
Schedule of Intangible Assets and Goodwill [Table Text Block]	The components of identifiable intangible assets are as follows: June 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Customer relationships $ 4,307.9 $ (1,233.0 ) $ 3,074.9 $ 4,119.4 $ (1,146.7 ) $ 2,972.7 Patents, licenses and technology 452.3 (224.1 ) 228.2 447.3 (211.2 ) 236.1 Non-compete agreements 82.5 (57.2 ) 25.3 76.8 (53.7 ) 23.1 Trade names 407.7 (202.9 ) 204.8 404.0 (189.1 ) 214.9 Land use right 11.1 (4.9 ) 6.2 10.8 (4.1 ) 6.7 Canadian licenses 476.5 — 476.5 457.6 — 457.6 $ 5,738.0 $ (1,722.1 ) $ 4,015.9 $ 5,515.9 $ (1,604.8 ) $ 3,911.1

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2019
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, 2019 , and December 31, 2018 , is as follows: Fair Value Measurements as of Fair Value as of June 30, 2019 Balance Sheet Using Fair Value Hierarchy Classification June 30, 2019 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 15.7 $ — $ 15.7 $ — Cross currency swap asset Other assets, net 1.2 — 1.2 — Interest rate swap Other assets, net 3.7 — 3.7 — Cash surrender value of life insurance policies Other assets, net 75.3 — 75.3 — Deferred compensation liability Other liabilities 74.3 — 74.3 — Contingent consideration Other liabilities 20.1 — — 20.1 Investment in equity securities Prepaid expenses and other 29.8 29.8 — — Fair Value Measurements as of Fair Value as of December 31, 2018 Balance Sheet Using Fair Value Hierarchy Classification December 31, 2018 Level 1 Level 2 Level 3 Noncontrolling interest put Noncontrolling interest $ 15.0 $ — $ 15.0 $ — Cross currency swap liability Other liabilities 2.8 — 2.8 — Interest rate swap Other liabilities 3.1 — 3.1 — Cash surrender value of life insurance policies Other assets, net 63.5 — 63.5 — Deferred compensation liability Other liabilities 64.2 — 64.2 — Contingent consideration Other liabilities 18.6 — — 18.6
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Fair Value Measurement of Level 3 Assets Contingent Consideration Balance at December 31, 2018 18.6 Addition 1.5 Balance at June 30, 2019 $ 20.1

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2019
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Six Months Ended June 30, 2019 2018 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 123.8 $ 188.2 Income taxes, net of refunds 119.6 148.6 Disclosure of non-cash financing and investing activities: Conversion of zero-coupon convertible debt 7.2 — Change in accrued property, plant and equipment (12.5 ) 4.8 Floating rate secured note receivable due 2022 from the sale of CRP 110.0 —
Supplemental Cash Flow Information	Supplemental cash flow information related to leases was as follows: Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (115.2 ) Operating cash flows from finance leases (0.9 ) Financing cash flows from finance leases (4.8 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 43.7 Finance leases 0.2 SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2019 2018 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 123.8 $ 188.2 Income taxes, net of refunds 119.6 148.6 Disclosure of non-cash financing and investing activities: Conversion of zero-coupon convertible debt 7.2 — Change in accrued property, plant and equipment (12.5 ) 4.8 Floating rate secured note receivable due 2022 from the sale of CRP 110.0 —

BUSINESS ACQUISITIONS Business

BUSINESS ACQUISITIONS Business Acquisitions Tables (Tables)	6 Months Ended
	Jun. 30, 2019
Business Acquisition [Line Items]
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]	Carrying amount of hedged liabilities as of Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Liabilities as of June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Balance Sheet Line Item in which Hedged Items are Included Long-term debt, less current portion $ 603.7 $ 597.0 $ 3.7 $ (3.1 )

BUSINESS SEGMENT INFORMATION (T

BUSINESS SEGMENT INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reconciliation of Operating Income to Consolidated [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]	The table below represents information about the Company’s reporting segments for the three and six months ended June 30, 2019 , and 2018 : Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Revenues: LCD $ 1,760.9 $ 1,814.0 $ 3,482.9 $ 3,584.2 CDD 1,126.3 1,054.2 2,201.0 2,132.6 Intercompany eliminations (5.5 ) (1.9 ) (11.0 ) (2.2 ) Revenues 2,881.7 2,866.3 5,672.9 5,714.6 Operating earnings: LCD 312.5 336.3 580.8 639.8 CDD 65.8 68.8 153.8 107.3 Unallocated corporate expenses (42.6 ) (35.9 ) (80.7 ) (72.5 ) Total operating income 335.7 369.2 653.9 674.6 Other income (expense), net (65.7 ) (56.5 ) (129.2 ) (120.4 ) Earnings before income taxes 270.0 312.7 524.7 554.2 Provision for income taxes 79.3 78.6 148.1 147.6 Net earnings 190.7 234.1 376.6 406.6 Less (earnings) loss attributable to noncontrolling interests (0.3 ) (0.3 ) (0.6 ) 0.4 Net income attributable to Laboratory Corporation of America Holdings $ 190.4 $ 233.8 $ 376.0 $ 407.0

REVENUE (Tables)

REVENUE (Tables)	6 Months Ended
	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset and Liability [Table Text Block]	June 30, 2019 December 31, 2018 Receivables, which are included in Accounts Receivable, net $ 735.4 $ 693.6 Unbilled services 491.5 396.9 Unearned revenue 402.2 354.1
Revenue from Contract with Customer [Text Block]	REVENUES The Company's revenues by segment payers/customer groups for the three and six months ended June 30, 2019 , and 2018 , is as follows: For the Three Months Ended June 30, 2019 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 16 % 1 % — % — % — % — % 17 % Patients 8 % — % — % — % — % — % 8 % Medicare and Medicaid 8 % — % — % — % — % — % 8 % Third-party 26 % 2 % — % — % — % — % 28 % Total LCD revenues by payer 58 % 3 % — % — % — % — % 61 % CDD Biopharmaceutical and medical 20 % — % 4 % 5 % 3 % 7 % 39 % Total revenues 78 % 3 % 4 % 5 % 3 % 7 % 100 % For the Three Months Ended June 30, 2018 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 18 % 1 % — % — % — % — % 19 % Patients 7 % — % — % — % — % — % 7 % Medicare and Medicaid 10 % — % — % — % — % — % 10 % Third-party 25 % 2 % — % — % — % — % 27 % Total LCD revenues by payer 60 % 3 % — % — % — % — % 63 % CDD Biopharmaceutical and medical 20 % — % 2 % 5 % 3 % 7 % 37 % Total revenues 80 % 3 % 2 % 5 % 3 % 7 % 100 % For the Six Months Ended June 30, 2019 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 16 % 1 % — % — % — % — % 17 % Patients 8 % — % — % — % — % — % 8 % Medicare and Medicaid 8 % — % — % — % — % — % 8 % Third-party 26 % 2 % — % — % — % — % 28 % Total LCD revenues by payer 58 % 3 % — % — % — % — % 61 % CDD Biopharmaceutical and medical 20 % — % 4 % 5 % 3 % 7 % 39 % Total revenues 78 % 3 % 4 % 5 % 3 % 7 % 100 % For the Six Months Ended June 30, 2018 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 18 % 1 % — % — % — % — % 19 % Patients 7 % — % — % — % — % — % 7 % Medicare and Medicaid 9 % — % — % — % — % — % 9 % Third-party 25 % 2 % — % — % — % — % 27 % Total LCD revenues by payer 59 % 3 % — % — % — % — % 62 % CDD Biopharmaceutical and medical 20 % — % 2 % 5 % 4 % 7 % 38 % Total revenues 79 % 3 % 2 % 5 % 4 % 7 % 100 % Contract costs CDD incurs sales commissions in the process of obtaining contracts with customers, which are recoverable through the service fees in the contract. 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 12 months to 57 months, 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. CDD incurs costs to fulfill contracts with customers, which are recoverable through the service fees in the contract. Contract fulfillment costs include software implementation costs and setup costs for certain endpoint and 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 24-60 months. Amortization of deferred contract fulfillment costs is included in cost of goods sold. June 30, 2019 December 31, 2018 Sales commission assets $ 27.4 $ 24.2 Deferred contract fulfillment costs 14.2 12.9 Total $ 41.6 $ 37.1 Amortization related to sales commission assets and associated payroll taxes for the three-month periods ended June 30, 2019 , and 2018 , was $5.1 and $4.4 , respectively, and for the six-month periods ended June 30, 2019 , and 2018 , was $9.5 and $8.6 , respectively. Amortization related to deferred contract fulfillment costs for the three-month periods ended June 30, 2019 , and 2018 , was $1.9 and $1.9 , respectively, and was $3.8 and $2.5 , respectively, for the six-month periods ended June 30, 2019 , and 2018 . Impairment expense related to contract costs was immaterial to the Company’s consolidated statement of operations. Receivables, Unbilled Services and Unearned Revenue The following table provides information about receivables, unbilled services, and unearned revenue (contract liabilities) from contracts with customers for the CDD segment. 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 CDD 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. June 30, 2019 December 31, 2018 Receivables, which are included in Accounts Receivable, net $ 735.4 $ 693.6 Unbilled services 491.5 396.9 Unearned revenue 402.2 354.1 Revenues recognized during the period, which was included in the unearned revenue balance at the beginning of the period for the six-month periods ended June 30, 2019 , and June 30, 2018, was $161.6 and $135.6 , respectively. Bad debt expense on receivables for the six-month periods ended June 30, 2019 , and 2018 , was immaterial to the Company’s consolidated statement of operations. Performance Obligations Under Long-Term Contracts Long-term contracts at the Company consist primarily of fully managed clinical studies within the CDD segment. The amount of existing performance obligations under such long-term contracts unsatisfied as of June 30, 2019 , was $4,138.0 . The Company expects to recognize approximately 34% of the remaining performance obligations as revenues over the next 12 months, and the balance thereafter. The Company's long-term contracts generally range from 1 to 8 years. Within CDD, revenue of $48.4 and $(12.5) was recognized during the six months ended June 30, 2019 , and 2018, respectively, from performance obligations that were satisfied in previous periods. This revenue comes from adjustments related to changes in scope and estimates in full service clinical studies.
Disaggregation of Revenue [Table Text Block]	The Company's revenues by segment payers/customer groups for the three and six months ended June 30, 2019 , and 2018 , is as follows: For the Three Months Ended June 30, 2019 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 16 % 1 % — % — % — % — % 17 % Patients 8 % — % — % — % — % — % 8 % Medicare and Medicaid 8 % — % — % — % — % — % 8 % Third-party 26 % 2 % — % — % — % — % 28 % Total LCD revenues by payer 58 % 3 % — % — % — % — % 61 % CDD Biopharmaceutical and medical 20 % — % 4 % 5 % 3 % 7 % 39 % Total revenues 78 % 3 % 4 % 5 % 3 % 7 % 100 % For the Three Months Ended June 30, 2018 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 18 % 1 % — % — % — % — % 19 % Patients 7 % — % — % — % — % — % 7 % Medicare and Medicaid 10 % — % — % — % — % — % 10 % Third-party 25 % 2 % — % — % — % — % 27 % Total LCD revenues by payer 60 % 3 % — % — % — % — % 63 % CDD Biopharmaceutical and medical 20 % — % 2 % 5 % 3 % 7 % 37 % Total revenues 80 % 3 % 2 % 5 % 3 % 7 % 100 % For the Six Months Ended June 30, 2019 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 16 % 1 % — % — % — % — % 17 % Patients 8 % — % — % — % — % — % 8 % Medicare and Medicaid 8 % — % — % — % — % — % 8 % Third-party 26 % 2 % — % — % — % — % 28 % Total LCD revenues by payer 58 % 3 % — % — % — % — % 61 % CDD Biopharmaceutical and medical 20 % — % 4 % 5 % 3 % 7 % 39 % Total revenues 78 % 3 % 4 % 5 % 3 % 7 % 100 % For the Six Months Ended June 30, 2018 U.S. Canada U.K. Switzerland Other Europe Other Total Payer/Customer LCD Clients 18 % 1 % — % — % — % — % 19 % Patients 7 % — % — % — % — % — % 7 % Medicare and Medicaid 9 % — % — % — % — % — % 9 % Third-party 25 % 2 % — % — % — % — % 27 % Total LCD revenues by payer 59 % 3 % — % — % — % — % 62 % CDD Biopharmaceutical and medical 20 % — % 2 % 5 % 4 % 7 % 38 % Total revenues 79 % 3 % 2 % 5 % 4 % 7 % 100 %
Capitalized Contract Cost [Table Text Block]	June 30, 2019 December 31, 2018 Sales commission assets $ 27.4 $ 24.2 Deferred contract fulfillment costs 14.2 12.9 Total $ 41.6 $ 37.1

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Future minimum rental commitments for leases with non-cancelable terms of one year or more at December 31, 2018, under Accounting Standards Codification 840 are as follows: Year Ended December 31, Operating Leases Finance Leases 2019 $ 191.1 $ 8.6 2020 145.4 8.0 2021 107.0 6.7 2022 80.9 6.0 2023 61.5 6.5 Thereafter 155.6 23.1
Operating Lease, Lease Income [Table Text Block]	The components of lease expense were as follows: Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease cost $ 59.9 $ 110.8 Finance lease cost: Amortization of ROU assets $ 1.5 $ 2.9 Interest on lease liabilities 0.4 1.2 Total finance lease cost $ 1.9 $ 4.1
Supplemental Cash Flow Information	Supplemental cash flow information related to leases was as follows: Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (115.2 ) Operating cash flows from finance leases (0.9 ) Financing cash flows from finance leases (4.8 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 43.7 Finance leases 0.2 SUPPLEMENTAL CASH FLOW INFORMATION Six Months Ended June 30, 2019 2018 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 123.8 $ 188.2 Income taxes, net of refunds 119.6 148.6 Disclosure of non-cash financing and investing activities: Conversion of zero-coupon convertible debt 7.2 — Change in accrued property, plant and equipment (12.5 ) 4.8 Floating rate secured note receivable due 2022 from the sale of CRP 110.0 —
Lessee, Operating Lease, Disclosure [Table Text Block]	Supplemental balance sheet information related to leases was as follows: June 30, 2019 Operating Leases Operating lease ROU assets (included in Property, plant and equipment, net) $ 770.3 Short-term operating lease liabilities 229.2 Operating lease liabilities 586.1 Total operating lease liabilities $ 815.3 June 30, 2019 Finance Leases Finance lease ROU assets (included in Other assets) $ 85.4 Short-term finance lease liabilities $ 8.2 Finance lease liabilities 46.2 Total finance lease liabilities $ 54.4 Weighted Average Remaining Lease Term Operating leases 5.8 Finance leases 6.5 Weighted Average Discount Rate Operating leases 4.2 % Finance leases 4.8 %
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Six Months Ended June 30, 2019 Operating Leases Finance Leases 2019 $ 254.1 $ 7.1 2020 274.7 13.8 2021 174.6 12.0 2022 69.3 10.8 2023 45.1 10.7 Thereafter 153.1 34.5 Total lease payments 970.9 88.9 Less imputed interest (155.6 ) (34.5 ) Total $ 815.3 $ 54.4

BASIS OF FINANCIAL STATEMENT _2

BASIS OF FINANCIAL STATEMENT PRESENTATION (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenues	$ 2,881.7		$ 2,866.3		$ 5,672.9	$ 5,714.6
Cost of Revenue	2,056.9		2,031.2		4,058.4	4,100.5
Contract with Customer, Liability	402.2				402.2		$ 354.1
Amortization of Deferred Sales Commissions	5.1		$ 4.4		9.5	8.6
Assets, Current	$ 2,848.6				2,848.6		2,835.4
Net Cash Provided by (Used in) Operating Activities					$ 419.3	$ 567.1
Percent of Revenue Contributed	100.00%		100.00%		100.00%	100.00%
Selling, general and administrative expenses	$ 415.3		$ 395.2		$ 809.1	$ 792.2
Nonoperating Income (Expense)	(65.7)		(56.5)		(129.2)	(120.4)
Provision for income taxes	79.3		78.6		148.1	147.6
Net earnings	190.7		234.1		376.6	406.6
Net Income (Loss) Attributable to Parent	$ 190.4	$ 185.6	$ 233.8	$ 173.2	$ 376	$ 407
Basic earnings per common share (in dollars per share)	$ 1.94		$ 2.29		$ 3.82	$ 3.99
Diluted earnings per common share (in dollars per share)	$ 1.93		$ 2.27		$ 3.79	$ 3.94
Net Cash Provided by (Used in) Investing Activities					$ (891.3)	$ (196.3)
Net Cash Provided by (Used in) Financing Activities					311.7	(458.1)
Effect of exchange rate changes on cash and cash equivalents					(1.1)	(7.9)
Cash and Cash Equivalents, Period Increase (Decrease)					(161.4)	(95.2)
Assets	$ 17,744.4				17,744.4		16,185.3
Long-term debt, less current portion	2,495.8				2,495.8		1,878.9
Common stock, 92.8 and 93.5 shares outstanding at March 31, 2013 and December 31, 2012, respectively	20				20		19.1
Stockholders' Equity Attributable to Parent	7,144.4	$ 7,111.3	$ 7,037.7	$ 6,984	7,144.4	7,037.7	6,971.4	$ 6,804.1
Liabilities and Equity	17,744.4				17,744.4		16,185.3
Capitalized Contract Cost, Amortization	1.9		1.9		3.8	2.5
Deferred Revenue, Revenue Recognized					161.6	135.6
Revenue, Remaining Performance Obligation, Amount	4,138				$ 4,138
Contract with Customer, Performance Obligation Satisfied in Previous Period	48.4		(12.5)
Prior Period Reclassification Adjustment						45.1	$ 44.4
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	$ 1,760.9		$ 1,814		$ 3,482.9	$ 3,584.2
Percent of Revenue Contributed	61.00%		63.00%		61.00%	62.00%
Covance Drug Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenues	$ 1,126.3		$ 1,054.2		$ 2,201	$ 2,132.6
Percent of Revenue Contributed	39.00%				39.00%

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, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Income [Abstract]
Net earnings attributable to Laboratory Corporation of America Holdings	$ 190.4	$ 185.6	$ 233.8	$ 173.2	$ 376	$ 407
Shares [Abstract]
Net earnings, basic (in shares)	98.1		101.9		98.4	101.9
Dilutive effect of employee stock options and awards, (in shares)	0.7		1		0.7	1.3
Per Share Amount [Abstract]
Basic earnings per common share (in dollars per share)	$ 1.94		$ 2.29		$ 3.82	$ 3.99
Diluted earnings per common share (in dollars per share)	$ 1.93		$ 2.27		$ 3.79	$ 3.94
Net Income (Loss) Available to Common Stockholders, Diluted	$ 190.4		$ 233.8		$ 376	$ 407
Weighted Average Number of Shares Outstanding, Diluted	98.8		103		99.1	103.3

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, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Stock options (in shares)	0.2	0.1	0.2	0.1

RESTRUCTURING AND OTHER SPECI_3

RESTRUCTURING AND OTHER SPECIAL CHARGES (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Goodwill, Acquired During Period	$ 490.5
Restructuring Reserve	12.6		$ 43.6
ASC 842 Lease Adoption Implementation Impact	(32.8)
Restructuring Charges	23
Restructuring Reserve Settled With Cash And Other Adjustment	32.4
Net restructuring charges	34.2	$ 26.5
Restructuring charges related to severance and other employee costs	20.3	23.1
Restructuring charges related to contractual obligations associated with leased facilities and other facility related costs	13.5	2.5
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment	0.4	0.5
Asset Impairment Charges	0	2.3
Unused facility restructuring reserves		0.9
Reduction in total prior restructuring accruals	0.4
Operating Lease, Impairment Loss	10.8
Restructuring Reserve, Current	10.4
Restructuring Reserve, Noncurrent	2.2
Covance Drug Development [Member]
Restructuring Cost and Reserve [Line Items]
Goodwill, Acquired During Period	468.2
Net restructuring charges	18.1	17.4
Asset Impairment Charges	2.3
Covance Drug Development [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	6.9		6.5
ASC 842 Lease Adoption Implementation Impact	0
Restructuring Charges	8.4
Restructuring Reserve Settled With Cash And Other Adjustment	8.5
Reduction in total prior restructuring accruals	(0.5)
Operating Lease, Impairment Loss	0
Covance Drug Development [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	2.5		27.6
ASC 842 Lease Adoption Implementation Impact	(27.1)
Restructuring Charges	1.7
Restructuring Reserve Settled With Cash And Other Adjustment	(7.2)
Reduction in total prior restructuring accruals	0
Operating Lease, Impairment Loss	7.5
LabCorp Diagnostics [Member]
Restructuring Cost and Reserve [Line Items]
Goodwill, Acquired During Period	22.3
Net restructuring charges	16.1	$ 9.1
LabCorp Diagnostics [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.3		2.1
ASC 842 Lease Adoption Implementation Impact	0
Restructuring Charges	11.9
Restructuring Reserve Settled With Cash And Other Adjustment	13.6
Reduction in total prior restructuring accruals	(0.1)
Operating Lease, Impairment Loss	0
LabCorp Diagnostics [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	2.9		$ 7.4
ASC 842 Lease Adoption Implementation Impact	(5.7)
Restructuring Charges	1
Restructuring Reserve Settled With Cash And Other Adjustment	3.1
Reduction in total prior restructuring accruals	0
Operating Lease, Impairment Loss	$ 3.3

RESTRUCTURING RESERVES (Details

RESTRUCTURING RESERVES (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Unused facility restructuring reserves		$ 0.9
Balance, beginning of period	$ 43.6
Restructuring charges	23
Reduction of prior restructuring accruals	0.4
Cash payments and other adjustments	(32.4)
Balance, end of period	12.6
Current			$ 10.4
Non-current			2.2
Total Restructuring Reserve	43.6		12.6
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment	0.4	$ 0.5
LabCorp Diagnostics [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	2.1
Restructuring charges	11.9
Reduction of prior restructuring accruals	(0.1)
Cash payments and other adjustments	(13.6)
Balance, end of period	0.3
Total Restructuring Reserve	2.1		0.3
LabCorp Diagnostics [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	7.4
Restructuring charges	1
Reduction of prior restructuring accruals	0
Cash payments and other adjustments	(3.1)
Balance, end of period	2.9
Total Restructuring Reserve	7.4		2.9
Covance Drug Development [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	6.5
Restructuring charges	8.4
Reduction of prior restructuring accruals	(0.5)
Cash payments and other adjustments	(8.5)
Balance, end of period	6.9
Total Restructuring Reserve	6.5		6.9
Covance Drug Development [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	27.6
Restructuring charges	1.7
Reduction of prior restructuring accruals	0
Cash payments and other adjustments	7.2
Balance, end of period	2.5
Total Restructuring Reserve	$ 27.6		$ 2.5

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS (Changes in Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Written off Related to Sale of Business Unit			$ 12.6
Amortization of intangibles and other assets	$ 60.2	$ 58.5	117.3	$ 120.8
Severance Costs			20.3	$ 23.1
Intangible Assets, Gross (Excluding Goodwill)	5,738		5,738		$ 5,515.9
Balance as of January 1			7,360.3
Goodwill, Acquired During Period			490.5
Adjustments to goodwill			5.5
Balance at end of period	7,843.7		7,843.7
Finite-Lived Intangible Assets, Accumulated Amortization	1,722.1		1,722.1		1,604.8
Intangible Assets, Net (Excluding Goodwill)	4,015.9		4,015.9		3,911.1
LabCorp Diagnostics [Member]
Goodwill [Line Items]
Goodwill, Written off Related to Sale of Business Unit			0
Balance as of January 1			3,638.8
Goodwill, Acquired During Period			22.3
Adjustments to goodwill			1.9
Balance at end of period	3,663		3,663
Covance Drug Development [Member]
Goodwill [Line Items]
Goodwill, Written off Related to Sale of Business Unit			12.6
Balance as of January 1			3,721.5
Goodwill, Acquired During Period			468.2
Adjustments to goodwill			3.6
Balance at end of period	4,180.7		4,180.7
Customer Relationships [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	4,307.9		4,307.9		4,119.4
Finite-Lived Intangible Assets, Accumulated Amortization	1,233		1,233		1,146.7
Intangible Assets, Net (Excluding Goodwill)	3,074.9		3,074.9		2,972.7
Patents, Licenses And Technology [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	452.3		452.3		447.3
Finite-Lived Intangible Assets, Accumulated Amortization	224.1		224.1		211.2
Intangible Assets, Net (Excluding Goodwill)	228.2		228.2		236.1
Noncompete Agreements [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	82.5		82.5		76.8
Finite-Lived Intangible Assets, Accumulated Amortization	57.2		57.2		53.7
Intangible Assets, Net (Excluding Goodwill)	25.3		25.3		23.1
Trade Names [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	407.7		407.7		404
Finite-Lived Intangible Assets, Accumulated Amortization	202.9		202.9		189.1
Intangible Assets, Net (Excluding Goodwill)	204.8		204.8		214.9
Use Rights [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	11.1		11.1		10.8
Finite-Lived Intangible Assets, Accumulated Amortization	4.9		4.9		4.1
Intangible Assets, Net (Excluding Goodwill)	6.2		6.2		6.7
Canadian licenses [Member]
Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	476.5		476.5		457.6
Finite-Lived Intangible Assets, Accumulated Amortization	0		0		0
Intangible Assets, Net (Excluding Goodwill)	$ 476.5		$ 476.5		$ 457.6

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS (Components of identifiable intangible assets) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 5,738	$ 5,515.9
Accumulated Amortization	(1,722.1)	(1,604.8)
Intangible Assets, Net (Excluding Goodwill)	4,015.9	3,911.1
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	4,307.9	4,119.4
Accumulated Amortization	(1,233)	(1,146.7)
Intangible Assets, Net (Excluding Goodwill)	3,074.9	2,972.7
Patents, Licenses And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	452.3	447.3
Accumulated Amortization	(224.1)	(211.2)
Intangible Assets, Net (Excluding Goodwill)	228.2	236.1
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	82.5	76.8
Accumulated Amortization	(57.2)	(53.7)
Intangible Assets, Net (Excluding Goodwill)	25.3	23.1
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	407.7	404
Accumulated Amortization	(202.9)	(189.1)
Intangible Assets, Net (Excluding Goodwill)	204.8	214.9
Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	11.1	10.8
Accumulated Amortization	(4.9)	(4.1)
Intangible Assets, Net (Excluding Goodwill)	6.2	6.7
Canadian licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	476.5	457.6
Accumulated Amortization	0	0
Intangible Assets, Net (Excluding Goodwill)	$ 476.5	$ 457.6

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 7,843.7		$ 7,843.7		$ 7,360.3
Amortization of intangible assets	60.2	$ 58.5	117.3	$ 120.8
Finite-Lived Intangible Assets, Future Amortization Expense
Estimated amortization expense, 2012	119.1		119.1
Estimated amortization expense, 2013	232		232
Estimated amortization expense, 2014	225.2		225.2
Estimated amortization expense, 2015	219.3		219.3
Estimated amortization expense, 2016	215.6		215.6
Estimated amortization expense, Thereafter	2,528.2		2,528.2
LabCorp Diagnostics [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	3,663		3,663		3,638.8
Covance Drug Development [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 4,180.7		$ 4,180.7		$ 3,721.5

DEBT (Short-term borrowings and

DEBT (Short-term borrowings and current portion of long-term debt) (Table) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Amount Outstanding Letters Of Credit	$ 72.2
Line of Credit Facility, Fair Value of Amount Outstanding		$ 0
Total short-term borrowings and current portion of long-term debt	$ 502.3	10
Short-term borrowings and current portion of long-term debt	Short-term borrowings and the current portion of long-term debt at June 30, 2019 , and December 31, 2018 , consisted of the following: June 30, December 31, 2018 Zero-coupon convertible subordinated notes $ 1.4 $ 8.7 2.625% senior notes due 2020 500.0 — Debt issuance costs (1.0 ) (0.5 ) Current portion of note payable 1.9 1.8 Total short-term borrowings and current portion of long-term debt $ 502.3 $ 10.0
Senior notes due 2020 [Member]
Short-term Debt [Line Items]
Senior Notes, Noncurrent	$ 0	500
Debt Instrument, Interest Rate, Stated Percentage	4.625%
Senior notes due 2022 [Member]
Short-term Debt [Line Items]
Senior Notes, Noncurrent	$ 500	$ 500

DEBT (Long-term debt) (Details)

DEBT (Long-term debt) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 19, 2014
Debt Instrument [Line Items]
Long-term Debt [Text Block]		Long-term debt at June 30, 2019 , and December 31, 2018 , consisted of the following: June 30, December 31, 2018 2.625% senior notes due 2020 $ — $ 500.0 4.625% senior notes due 2020 603.7 596.9 3.20% senior notes due 2022 500.0 500.0 3.75% senior notes due 2022 500.0 500.0 4.00% senior notes due 2023 300.0 300.0 3.25% senior notes due 2024 600.0 600.0 3.60% senior notes due 2025 1,000.0 1,000.0 3.60% senior notes due 2027 600.0 600.0 4.70% senior notes due 2045 900.0 900.0 Revolving credit facility 35.0 — 2019 Term loan 850.0 — 2017 Term loan 277.0 527.0 Debt issuance costs (37.1 ) (40.2 ) Note payable 6.4 7.2 Total long-term debt $ 6,135.0 $ 5,990.9
Long-term Debt, Excluding Current Maturities	$ 6,135	$ 6,135		$ 5,990.9
Line of Credit Facility, Fair Value of Amount Outstanding				0
Repayments of Other Long-term Debt		250	$ 295
Line of Credit Facility, Maximum Borrowing Capacity					$ 1,000
Credit Facility Option to Increase					350
Credit Facility, Maximum Swing Line Borrowings					100
Long-term Line of Credit	35	35		0
2019 Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	850	850
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	603.7	603.7		596.9
Senior Notes, Noncurrent	$ 0	$ 0		500
Stated interest rate percentage	4.625%	4.625%
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 500	$ 500		500
Senior Notes, Noncurrent	500	500		500
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	300	300		300
Senior notes due 2025 [Member] [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	1,000	1,000		1,000
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$ 900	$ 900		$ 900
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt to EBITDA (Leverage) Ratio	3.4	3.4
Credit Facility, Maximum Letters of Credit					$ 150
Prime Rate [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate Description	0.00% to 0.25%
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Description	0.10% to 0.25%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate Description	0.775% to 1.25%
2019 Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	3.24%	3.24%

DEBT (Senior Notes) (Details)

DEBT (Senior Notes) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 19, 2014
Debt Instrument [Line Items]
Senior notes due 2018	$ 500	$ 0
Convertible Subordinated Debt, Current	1.4	8.7
Short term debt issuance costs	1	0.5
Long-term Debt, Excluding Current Maturities	6,135	5,990.9
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,000
Credit Facility Option to Increase				350
Credit Facility, Maximum Swing Line Borrowings				$ 100
Fair Value Hedges, Net	$ 3.7	3.1
Debt Instrument, Basis Spread on Variable Rate	2.298%
Line of Credit Facility, Fair Value of Amount Outstanding		0
Long term debt issuance costs	$ 37.1	40.2
Notes Payable	1.9	1.8
Debt, Current	502.3	10
Foreign Currency Contract, Asset, Fair Value Disclosure	1.2	2.8
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	300	300
Senior notes due 2024 [Member] [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	600	600
Senior notes due 2025 [Member] [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount	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
2019 Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	850
Cross currency swap maturing 2022 [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount	300
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	603.7	596.9
Senior Notes, Noncurrent	$ 0	500
Stated interest rate percentage	4.625%
2017 Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	$ 277	$ 527	$ 750

DEBT (Convertible Subordinated

DEBT (Convertible Subordinated Notes) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)shares	Jun. 30, 2019USD ($)shares
Zero Coupon Convertible Subordinated Notes [Line Items]
Number of trading days used to establish contingent cash interest rate on zero-coupon subordinated notes (in days)	five
Principal Amount At Maturity Of Zero Coupon Subordinated Notes Converted		$ 7,700,000
Value Of Cash And Common Stock In Connection With Conversions Of Zero Coupon Subordinated Notes Settled In Current Period		14,500,000
Payments On Zero Coupon Subordinated Notes		7,300,000
tax benefit realized upon conversion of zero coupon convertible debt		$ 1,700,000
Zero-coupon convertible subordinated notes [Member]
Zero Coupon Convertible Subordinated Notes [Line Items]
Minimum contingent cash interest rate on zero-coupon subordinated notes (in hundredths)	0.125%
Stock conversion rate for zero-coupon subordinated notes (per thousand) | shares	13.4108	13.4108
Principal amount of zero-coupon subordinated notes	$ 1,000,000,000	$ 1,000,000,000

DEBT (Credit Facilities) (Detai

DEBT (Credit Facilities) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 19, 2014
Line of Credit Facility [Line Items]
Line of Credit Facility, Increase (Decrease), Other, Net		$ 600
Line of Credit Facility, Remaining Borrowing Capacity	$ 892.8	892.8
Long-term Debt, Excluding Current Maturities	6,135	6,135	$ 5,990.9
Convertible Subordinated Debt, Current	1.4	1.4	8.7
Line of Credit Facility, Fair Value of Amount Outstanding			0
Revolving Credit Facility, maximum borrowing capacity					$ 1,000
Notes Payable	1.9	1.9	1.8
Debt, Current	502.3	502.3	10
Credit Facility Option to Increase					350
Credit Facility, Maximum Swing Line Borrowings					100
Notes Payable	$ 6.4	$ 6.4	7.2
2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	3.56%	3.56%
Senior notes due 2027 [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Excluding Current Maturities	$ 600	$ 600	600
Senior notes due 2024 [Member] [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Excluding Current Maturities	600	600	600
Senior notes due 2020 [Member]
Line of Credit Facility [Line Items]
Senior Notes, Noncurrent	0	0	500
Long-term Debt, Excluding Current Maturities	$ 603.7	$ 603.7	596.9
Debt Instrument, Interest Rate, Stated Percentage	4.625%	4.625%
Senior notes due 2045 [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Excluding Current Maturities	$ 900	$ 900	900
Senior notes due 2022 [Member]
Line of Credit Facility [Line Items]
Senior Notes, Noncurrent	500	500	500
Long-term Debt, Excluding Current Maturities	500	500	500
2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	$ 277	$ 277	$ 527	$ 750
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Facility, Maximum Letters of Credit					$ 150
Debt to EBITDA (leverage) ratio	3.4	3.4
Prime Rate [Member] | 2019 Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.0% to 0.175%
Prime Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.00% to 0.25%
Prime Rate [Member] | 2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.0% to 0.50%
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Description	0.10% to 0.25%
London Interbank Offered Rate (LIBOR) [Member] | 2019 Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.55% to 1.175%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.775% to 1.25%
London Interbank Offered Rate (LIBOR) [Member] | 2017 Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.875% to 1.50%

PREFERRED STOCK AND COMMON SH_2

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019
Class of Stock [Line Items]
Treasury Stock, Shares, Retired				0
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased						1,050
Stock Repurchase Program, Authorized Amount						$ 1,250
Rollforward of common shares issued
Commons Stock Issued During Period Shares Employee Stock Plans				1
Stock Repurchased and Retired During Period, Shares				(2)
Stock Repurchased During Period, Shares	0.8	1.3
Treasury Stock Acquired, Average Cost Per Share				$ 131.71
Payments for Repurchase of Common Stock	$ 199.9			$ 300	$ 150
Rollforward of Share Repurchase Program
Outstanding common stock repurchase authorization, beginning balance		$ 443.5		$ 443.5
Purchase of common stock		$ (100.1)	$ (75)
Common Shares Outstanding Rollforward [Abstract]
Common shares outstanding, beginning balance (in shares)		98.9		98.9
Commons Stock Issued During Period Shares Employee Stock Plans				1
Stock Repurchased and Retired During Period, Shares				(2)
Common shares outstanding, ending balance (in shares)	97.8			97.8
Commons Stock Issued During Period Shares Employee Stock Plans				1
Rollforward of common shares held in treasury
Treasury Stock, Carrying Basis						$ 100.1
Common Stock, Shares Authorized						265
Common Stock, Par or Stated Value Per Share						$ 0.10
Preferred Stock, Shares Authorized						30
Preferred Stock, Par or Stated Value Per Share						$ 0.10
Stock Repurchased and Retired During Period, Shares				(2)
Preferred Stock, Shares Outstanding						0
Restricted Stock Awards And Performance Shares Surrendered, share amount				(0.1)
Common Stock [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Retired				(23.6)
Rollforward of common shares issued
Common shares issued, beginning balance (in shares)		122.4		122.4
Commons Stock Issued During Period Shares Employee Stock Plans				1
Stock Repurchased and Retired During Period, Shares				(2)
Common shares issued, ending balance (in shares)	97.8			97.8
Common Stock, Shares, Issued	97.8	122.4		122.4		97.8
Common Shares Outstanding Rollforward [Abstract]
Commons Stock Issued During Period Shares Employee Stock Plans				1
Stock Repurchased and Retired During Period, Shares				(2)
Commons Stock Issued During Period Shares Employee Stock Plans				1
Rollforward of common shares held in treasury
Stock Repurchased and Retired During Period, Shares				(2)
Restricted Stock Awards And Performance Shares Surrendered, share amount				0
Treasury Stock, Common [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Retired				(23.6)
Rollforward of common shares issued
Commons Stock Issued During Period Shares Employee Stock Plans				0
Stock Repurchased and Retired During Period, Shares				0
Common Shares Outstanding Rollforward [Abstract]
Commons Stock Issued During Period Shares Employee Stock Plans				0
Stock Repurchased and Retired During Period, Shares				0
Commons Stock Issued During Period Shares Employee Stock Plans				0
Rollforward of common shares held in treasury
Common shares held in Treasury, beginning balance (in shares)		(23.5)		(23.5)
Common shares held in Treasury, ending balance (in shares)	0			0
Treasury Stock, Shares	0	23.5		23.5		0
Stock Repurchased and Retired During Period, Shares				0
Restricted Stock Awards And Performance Shares Surrendered, share amount				(0.1)

PREFERRED STOCK AND COMMON SH_3

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY - Accumulated Other Comprehensive Earnings (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]			The components of accumulated other comprehensive earnings are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Accumulated Other Comprehensive Earnings (Loss) Balance at December 31, 2018 $ (389.8 ) $ (73.3 ) $ (463.1 ) Other comprehensive earnings before reclassifications 47.2 5.5 52.7 Tax effect of adjustments — (1.5 ) (1.5 ) Balance at June 30, 2019 $ (342.6 ) $ (69.3 ) $ (411.9 )
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax			$ 5.5
Other Comprehensive Income (Loss), before Reclassifications, before Tax			52.7
Accumulated Other Comprehensive Earnings [Roll Forward]
Foreign Currency Translation Adjustments, Beginning balance			(389.8)
Other comprehensive income before reclassifications			47.2
Tax effect of adjustments			0
Foreign Currency Translation Adjustments, Ending balance	$ (342.6)		(342.6)
Net Benefit Plan Adjustments, Beginning balance			(73.3)
Tax effect of adjustments			(1.5)
Net Benefit Plan Adjustments, Ending balance	(69.3)		(69.3)
Accumulated Other Comprehensive Earnings, Beginning balance			(463.1)
Other comprehensive income before reclassifications			47.2
Tax effect of adjustments	(0.8)	$ (7.2)	(1.5)	$ 3.1
Accumulated Other Comprehensive Earnings, Ending balance	$ (411.9)		$ (411.9)

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Tax Contingency, Percent	50.00%
Gross unrecognized income tax benefits	$ 25.6	$ 18
Accrued interest and penalties related to unrecognized income tax benefits	$ 10.3	$ 8.7

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	Jun. 30, 2019USD ($)
Loss Contingencies [Line Items]
Amount Outstanding Letters Of Credit	$ 72.2

PENSION AND POSTRETIREMENT PL_2

PENSION AND POSTRETIREMENT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosures [Line Items]
Minimum non-elective contribution (NEC) % for the 401(K) plan (in hundredths)	3.00%
Discretionary Contribution Percentage Mininum	1.00%
Discretionary Contribution Percentage Maximum	3.00%
Defined contribution retirement plan cost	$ (12.9)	$ (15.8)	$ (37.1)	$ (31.8)
Defined Benefit Plan and Postretirement Plan Disclosure
Schedule of Pensions and Postretirement Plans			As a result of the Covance acquisition, the Company sponsors two defined benefit pension plans for the benefit of its employees at two U.K. subsidiaries (U.K. Plans) and one defined benefit pension plan for the benefit of its employees at a German subsidiary (German Plan), all of which are legacy plans of previously acquired companies. Benefit amounts for all three plans are based upon years of service and compensation. The German plan is unfunded while the U.K. pension plans are funded. The Company’s funding policy has been to contribute annually amounts at least equal to the local statutory funding requirements. U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.8 $ 0.9 $ 1.6 $ 1.8 Interest cost on benefit obligation 1.9 1.9 3.8 3.8 Expected return on plan assets (2.8 ) (3.2 ) (5.7 ) (6.5 ) Defined benefit plan costs $ (0.1 ) $ (0.4 ) $ (0.3 ) $ (0.9 ) U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Assumptions used to determine defined benefit plan cost Discount rate 2.9 % 2.5 % 2.9 % 2.5 % Expected return on assets 4.5 % 4.5 % 4.5 % 4.5 % Salary increases 3.6 % 3.6 % 3.6 % 3.6 % German Plan Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.3 $ 0.3 $ 0.6 $ 0.6 Interest cost on benefit obligation 0.2 0.2 0.3 0.3 Defined benefit plan costs $ 0.5 $ 0.5 $ 0.9 $ 0.9 Assumptions used to determine defined benefit plan cost Discount rate 1.9 % 1.7 % 1.9 % 1.7 % Expected return on assets N/A N/A N/A N/A Salary increases 2.0 % 2.0 % 2.0 % 2.0 % The effect on operations for the Company Plan and the PEP is summarized as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 1.0 $ 1.2 $ 2.0 $ 2.6 Interest cost on benefit obligation 3.5 3.2 7.0 6.5 Expected return on plan assets (3.8 ) (4.1 ) (7.6 ) (8.2 ) Net amortization and deferral 2.6 3.1 5.2 5.9 Defined benefit plan costs $ 3.3 $ 3.4 $ 6.6 $ 6.8
Pension And Postretirement Plans			PENSION AND POST-RETIREMENT PLANS The Company has two defined contribution retirement plans (401K Plans) which cover substantially all U.S. employees. All employees eligible for the LabCorp 401K Plan receive a minimum 3% non-elective contribution concurrent with each payroll period. The 401K Plan also permits discretionary contributions by the Company of up to 1% and up to 3% of pay for eligible employees based on years of service with the Company. The cost of this plan was $12.9 and $15.8 for the three months ended June 30, 2019 , and 2018 , respectively, and was $37.1 and $31.8 for the six months ended June 30, 2019 , and 2018 , respectively. All of the Covance U.S. employees, including legacy Chiltern employees, are eligible to participate in the Covance 401K plan, which features a maximum 4.5% Company match, based upon a percentage of the employee’s contributions. Chiltern employees were previously eligible to participate in the Chiltern 401K plan, which featured a maximum 3.0% Company match, based upon a percentage of the employee's contributions. The Chiltern 401K plan merged into the Covance Plan effective January, 7, 2019. The Company incurred expense of $17.9 and $16.5 for the Covance 401K plan during the three months ended June 30, 2019 , and 2018 , respectively, and $37.8 and $35.3 during the six months ended June 30, 2019 , and 2018 , respectively. The Company also maintains several other immaterial 401K plans associated with companies acquired over the last several years. The Company also maintains a frozen defined benefit retirement plan (Company Plan), which as of December 31, 2009, covered substantially all employees. The benefits to be paid under the Company Plan are based on years of credited service through December 31, 2009, and ongoing interest credits. Effective January 1, 2010, the Company Plan was closed to new participants. The Company’s policy is to fund the Company Plan with at least the minimum amount required by applicable regulations. The Company maintains a second, unfunded, non-contributory, non-qualified defined benefit retirement plan (PEP), which as of December 31, 2009, covered substantially all of its senior management group. The PEP supplements the Company Plan and was closed to new participants effective January 1, 2010. The effect on operations for the Company Plan and the PEP is summarized as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 1.0 $ 1.2 $ 2.0 $ 2.6 Interest cost on benefit obligation 3.5 3.2 7.0 6.5 Expected return on plan assets (3.8 ) (4.1 ) (7.6 ) (8.2 ) Net amortization and deferral 2.6 3.1 5.2 5.9 Defined benefit plan costs $ 3.3 $ 3.4 $ 6.6 $ 6.8 During the six months ended June 30, 2019 , the Company made no contributions to the Company Plan. As a result of the Covance acquisition, the Company sponsors two defined benefit pension plans for the benefit of its employees at two U.K. subsidiaries (U.K. Plans) and one defined benefit pension plan for the benefit of its employees at a German subsidiary (German Plan), all of which are legacy plans of previously acquired companies. Benefit amounts for all three plans are based upon years of service and compensation. The German plan is unfunded while the U.K. pension plans are funded. The Company’s funding policy has been to contribute annually amounts at least equal to the local statutory funding requirements. U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.8 $ 0.9 $ 1.6 $ 1.8 Interest cost on benefit obligation 1.9 1.9 3.8 3.8 Expected return on plan assets (2.8 ) (3.2 ) (5.7 ) (6.5 ) Defined benefit plan costs $ (0.1 ) $ (0.4 ) $ (0.3 ) $ (0.9 ) U.K. Plans Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Assumptions used to determine defined benefit plan cost Discount rate 2.9 % 2.5 % 2.9 % 2.5 % Expected return on assets 4.5 % 4.5 % 4.5 % 4.5 % Salary increases 3.6 % 3.6 % 3.6 % 3.6 % German Plan Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Service cost for administrative expenses $ 0.3 $ 0.3 $ 0.6 $ 0.6 Interest cost on benefit obligation 0.2 0.2 0.3 0.3 Defined benefit plan costs $ 0.5 $ 0.5 $ 0.9 $ 0.9 Assumptions used to determine defined benefit plan cost Discount rate 1.9 % 1.7 % 1.9 % 1.7 % Expected return on assets N/A N/A N/A N/A Salary increases 2.0 % 2.0 % 2.0 % 2.0 % As a result of the Envigo acquisition, the Company assumed a defined benefit pension plan for the benefit of Envigo's U.K. employees (the Envigo plan), which is a legacy plan of a company previously acquired by Envigo. The Envigo plan is a funded plan that is closed to future accrual. The related net pension obligation of $56.8
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	56.8		$ 56.8
Pension Plan [Member]
Defined Benefit Plan and Postretirement Plan Disclosure
Service cost for benefits earned	1	1.2	2	2.6
Interest cost on benefit obligation	3.5	3.2	7	6.5
Expected return on plan assets	(3.8)	(4.1)	(7.6)	(8.2)
Net amortization and deferral	2.6	3.1	5.2	5.9
Defined benefit/postretirement plan costs	3.3	3.4	$ 6.6	6.8
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan and Postretirement Plan Disclosure
Schedule of Costs of Retirement Plans [Table Text Block]
Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plan Disclosures [Line Items]
Defined contribution retirement plan cost	(0.1)	(0.4)		(0.9)
Defined Benefit Plan and Postretirement Plan Disclosure
Service cost for benefits earned	0.8	0.9	$ 1.6	1.8
Interest cost on benefit obligation	1.9	1.9	3.8	3.8
Expected return on plan assets	$ (2.8)	$ (3.2)	(5.7)	$ (6.5)
Defined benefit/postretirement plan costs			$ (0.3)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.90%	2.50%	2.90%	2.50%
Defined Benefit Plan Expected Rate Of Return On Assets Other Assets	4.50%	4.50%	4.50%	4.50%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.60%	3.60%	3.60%	3.60%
Other Pension Plan [Member]
Defined Benefit Plan and Postretirement Plan Disclosure
Service cost for benefits earned	$ 0.3	$ 0.3	$ 0.6	$ 0.6
Interest cost on benefit obligation	0.2	0.2	0.3	0.3
Defined benefit/postretirement plan costs	$ 0.5	$ 0.5	$ 0.9	$ 0.9
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	1.90%	1.70%	1.90%	1.70%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.00%	2.00%	2.00%	2.00%
Covance [Member]
Defined Benefit Plan Disclosures [Line Items]
Defined contribution retirement plan cost	$ (17.9)	$ (16.5)	$ (37.8)	$ (35.3)

PENSION AND POSTRETIREMENT PL_3

PENSION AND POSTRETIREMENT PLANS Defined Contribution Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Non Elective Contribution	3.00%
Defined Contribution Plan, Cost	$ 12.9	$ 15.8	$ 37.1	$ 31.8
Discretionary Contribution Percentage Mininum	1.00%
Discretionary Contribution Percentage Maximum	3.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	4.50%
chiltern [Member]
Defined Benefit Plan Disclosure [Line Items]
Discretionary Contribution Percentage Maximum	3.00%
Covance [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 17.9	$ 16.5	$ 37.8	$ 35.3

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	$ 15.7	$ 15
Fair market value of zero-coupon subordinated notes	1.8	16.9
Fair market value of senior notes	5,658.5	5,318
Notes Receivable, Fair Value Disclosure	110	0
Cash Surrender Value, Fair Value Disclosure	75.3	63.5
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	74.3	64.2
Contingent Consideration Classified as Equity, Fair Value Disclosure	20.1	18.6
Fair Value Hedges, Net	3.7	3.1
Foreign Currency Contract, Asset, Fair Value Disclosure	1.2	2.8
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	1.5
Equity Securities, FV-NI	29.8
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
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Fair Value Hedges, Net	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Equity Securities, FV-NI	29.8
Fair Value, Inputs, Level 2 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	15.7	15
Cash Surrender Value, Fair Value Disclosure	75.3	63.5
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	0	0
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Fair Value Hedges, Net	3.7	3.1
Foreign Currency Contract, Asset, Fair Value Disclosure	1.2	2.8
Equity Securities, FV-NI	0
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
Contingent Consideration Classified as Equity, Fair Value Disclosure	20.1	18.6
Fair Value Hedges, Net	0	0
Foreign Currency Contract, Asset, Fair Value Disclosure	0	$ 0
Equity Securities, FV-NI	$ 0
Notes Receivable [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	7.79%

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
4.625% Senior notes due 2020					$ 597,000,000
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	$ (7,800,000)		$ 4,000,000
Long-term Debt, Excluding Current Maturities	$ 6,135,000,000		6,135,000,000		5,990,900,000
Debt Instrument, Basis Spread on Variable Rate	2.298%
Fair Value Hedges, Net	$ 3,700,000		3,700,000		3,100,000
Foreign Currency Contract, Asset, Fair Value Disclosure	$ 1,200,000		1,200,000		2,800,000
Minimum percentage of market price to calculated value of zero-coupon subordinated debt at which the entity is subject to contingent cash interest	120.00%
Embedded derivative, fair value	$ 0		0
Embedded derivative, impact on condensed consolidated statements of operations	0
Fair Value Hedge Liabilities					3,100,000
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)	4,300,000	$ (10,000,000)	6,800,000	$ (9,700,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	0
Fair Value Hedge Assets	3,700,000		3,700,000
Fair Value Hedge Liabilities					3,100,000
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)	(7,800,000)	(24,300,000)	4,000,000	(24,200,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	$ 0	0	$ 0
Fair Value Hedge Assets	1,200,000		1,200,000
Fair Value Hedge Liabilities					2,800,000
Senior notes due 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	500,000,000		500,000,000		500,000,000
Foreign Currency Contract, Asset, Fair Value Disclosure	300,000		300,000
Foreign Currency Contracts, Liability, Fair Value Disclosure					1,000,000
Cross currency swap maturing 2022 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 300,000,000		$ 300,000,000
Senior notes due 2020 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.625%		4.625%
Long-term Debt, Excluding Current Maturities	$ 603,700,000		$ 603,700,000		596,900,000
Senior Long Term Notes Due2020 Member
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	600,000,000		600,000,000		600,000,000
Senior notes due 2025 [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	1,000,000,000		1,000,000,000		1,000,000,000
Foreign Currency Contract, Asset, Fair Value Disclosure	900,000		900,000
Foreign Currency Contracts, Liability, Fair Value Disclosure					1,800,000
Senior notes due 2027 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Long-term Debt, Excluding Current Maturities	600,000,000		600,000,000		600,000,000
Fair Value, Inputs, Level 2 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Fair Value Hedges, Net	3,700,000		3,700,000		3,100,000
Foreign Currency Contract, Asset, Fair Value Disclosure	$ 1,200,000		$ 1,200,000		$ 2,800,000

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Debt Conversion [Line Items]
Decrease in Capital Expenditures Incurred but not yet Paid			$ (12.5)
Capital Expenditures Incurred but Not yet Paid				$ 4.8
Notes Receivable, Fair Value Disclosure	$ 110		110		$ 0
Cash paid during period for:
Interest			123.8	188.2
Income taxes, net of refunds			119.6	148.6
Disclosure of non-cash financing and investing activities:
Conversion of zero-coupon convertible debt			$ 7.2	$ 0
Other Significant Noncash Transaction, Value of Consideration Given	$ 9.2	$ 24.7

BUSINESS ACQUISITIONS (Details)

BUSINESS ACQUISITIONS (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 03, 2019	Dec. 31, 2018
Business Combination Purchase Price Allocation [Line Items]
Disposal Group, Including Discontinued Operation, Operating Income (Loss)			$ 3.4			$ 5.4
Revenues	$ 2,881.7		2,866.3		$ 5,672.9	5,714.6
Operating Income (Loss)	335.7		369.2		653.9	674.6
Other Significant Noncash Transaction, Value of Consideration Given	9.2	$ 24.7
Net Income (Loss) Attributable to Parent	190.4	$ 185.6	$ 233.8	$ 173.2	376	407
Goodwill, Acquired During Period					490.5
Goodwill	7,843.7				7,843.7			$ 7,360.3
Cash payments for laboratory-related assets					179.4	159.7
Payments to Acquire Businesses, Net of Cash Acquired					703.7	79.1
Notes Receivable, Fair Value Disclosure	110				110			$ 0
Total acquisition consideration (cash, stock, notes, etc.)							$ 711
Gain (Loss) on Disposition of Assets					(8.8)	$ 0
Envigo [Member]
Business Combination Purchase Price Allocation [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents							15.1
Revenues					16.5
Operating Income (Loss)					0.7
Payments to Acquire Businesses, Net of Cash Acquired					601
Notes Receivable, Fair Value Disclosure	$ 110				$ 110
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					11 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables							16.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other							26.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory							4.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets							3.5
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets							25.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment							99.1
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net							432.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles							125.8
Indefinite-Lived Trade Names							0.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets							9.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets							759.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable							15.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other							11.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue							49.9
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Lease Obligation							15
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities							66.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities							158.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net							$ 601

BUSINESS ACQUISITIONS Busines_2

BUSINESS ACQUISITIONS Business Acquisitions in the Aggregate (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			15 years
Revenues	$ 2,881.7	$ 2,866.3	$ 5,672.9	$ 5,714.6
Payments to Acquire Businesses, Net of Cash Acquired			703.7	$ 79.1
Goodwill, Acquired During Period			490.5
Goodwill	$ 7,843.7		7,843.7		$ 7,360.3
Other acquirees [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired			117.7
Goodwill, Acquired During Period			53.8
Finite-lived Intangible Assets Acquired			$ 90.7

BUSINESS ACQUISITIONS DISPOSITI

BUSINESS ACQUISITIONS DISPOSITIONS (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	$ 3.4	$ 5.4
Cash and cash equivalents			$ (265.4)	$ (426.8)	$ (316.6)
Accounts Receivable, after Allowance for Credit Loss, Current			1,576.1	1,467.9
Unbilled Contracts Receivable			488.8	394.4
Supplies inventories			219.7	237.3
Prepaid expenses and other			298.6	309
Property, plant and equipment, net			2,544.2	1,740.3
Goodwill			7,843.7	7,360.3
Intangible Assets, Net (Excluding Goodwill)			4,015.9	3,911.1
Other assets, net			403.6	276
Accounts Payable, Current			531.6	634.6
Accrued Liabilities, Current			820.3	870
Deferred Revenue, Current			404.2	356.4
Deferred income taxes and other tax liabilities			948.3	940
Commitments and contingent liabilities			$ 368.6	$ 334

BUSINESS SEGMENT INFORMATION _2

BUSINESS SEGMENT INFORMATION Business Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Percent of Revenue Contributed	100.00%		100.00%		100.00%	100.00%
Intercompany revenue elimination	$ (5.5)		$ (1.9)		$ (11)	$ (2.2)
Revenues	2,881.7		2,866.3		5,672.9	5,714.6
Operating Income (Loss)	335.7		369.2		653.9	674.6
Earnings before income taxes	270		312.7		524.7	554.2
Provision for income taxes	270		312.7		524.7	554.2
Provision for income taxes	79.3		78.6		148.1	147.6
Net earnings	190.7		234.1		376.6	406.6
Net income attributable to Laboratory Corporation of America Holdings	(0.3)		(0.3)		(0.6)	0.4
Nonoperating Income (Expense)	(65.7)		(56.5)		(129.2)	(120.4)
Net Income (Loss) Attributable to Parent	190.4	$ 185.6	233.8	$ 173.2	376	407
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (42.6)		$ (35.9)		$ (80.7)	$ (72.5)
LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Percent of Revenue Contributed	61.00%		63.00%		61.00%	62.00%
Revenues	$ 1,760.9		$ 1,814		$ 3,482.9	$ 3,584.2
Operating Income (Loss)	$ 312.5		336.3		$ 580.8	639.8
Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Percent of Revenue Contributed	39.00%				39.00%
Revenues	$ 1,126.3		1,054.2		$ 2,201	2,132.6
Operating Income (Loss)	$ 65.8		$ 68.8		$ 153.8	$ 107.3

REVENUE Disaggregated Revenue T

REVENUE Disaggregated Revenue Table (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Deferred Revenue, Revenue Recognized			$ 161.6	$ 135.6
Contract with Customer, Asset, before Allowance for Credit Loss	$ 491.5		491.5		$ 396.9
Revenue, Remaining Performance Obligation, Amount	$ 4,138		$ 4,138
Percent of remaining performance obligations recognized as revenue in next year	34.00%		34.00%
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 48.4	$ (12.5)
Contract with Customer, Liability	402.2		$ 402.2		354.1
Capitalized Contract Cost, Amortization	1.9	1.9	3.8	2.5
Accrued Sales Commission	27.4		27.4		24.2
Deferred Sales Commission	41.6		41.6		37.1
Capitalized Contract Cost, Net	14.2		14.2		12.9
Amortization of Deferred Sales Commissions	5.1	$ 4.4	9.5	$ 8.6
Unbilled Contracts Receivable	$ 488.8		$ 488.8		394.4
Percent of Revenue Contributed	100.00%	100.00%	100.00%	100.00%
Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	8.00%	10.00%	8.00%	9.00%
UNITED STATES
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	78.00%	80.00%	78.00%	79.00%
CANADA
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	3.00%	3.00%	3.00%	3.00%
UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	4.00%	2.00%	4.00%	2.00%
SWITZERLAND
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	5.00%	5.00%	5.00%	5.00%
Europe [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	3.00%	3.00%	3.00%	4.00%
Other countries [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	7.00%	7.00%	7.00%	7.00%
LabCorp Diagnostics [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	61.00%	63.00%	61.00%	62.00%
LabCorp Diagnostics [Member] | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	17.00%	19.00%	17.00%	19.00%
LabCorp Diagnostics [Member] | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	8.00%	7.00%	8.00%	7.00%
LabCorp Diagnostics [Member] | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	28.00%	27.00%	28.00%	27.00%
LabCorp Diagnostics [Member] | UNITED STATES
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	58.00%	60.00%	58.00%	59.00%
LabCorp Diagnostics [Member] | UNITED STATES | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	16.00%	18.00%	16.00%	18.00%
LabCorp Diagnostics [Member] | UNITED STATES | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	8.00%	7.00%	8.00%	7.00%
LabCorp Diagnostics [Member] | UNITED STATES | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	8.00%	10.00%	8.00%	9.00%
LabCorp Diagnostics [Member] | UNITED STATES | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	26.00%	25.00%	26.00%	25.00%
LabCorp Diagnostics [Member] | CANADA
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	3.00%	3.00%	3.00%	3.00%
LabCorp Diagnostics [Member] | CANADA | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	1.00%	1.00%	1.00%	1.00%
LabCorp Diagnostics [Member] | CANADA | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | CANADA | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | CANADA | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	2.00%	2.00%	2.00%	2.00%
LabCorp Diagnostics [Member] | UNITED KINGDOM
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | UNITED KINGDOM | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | UNITED KINGDOM | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | UNITED KINGDOM | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | UNITED KINGDOM | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | SWITZERLAND
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | SWITZERLAND | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | SWITZERLAND | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | SWITZERLAND | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | SWITZERLAND | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
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] | Europe [Member] | Client [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Europe [Member] | Self-Pay [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Europe [Member] | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Europe [Member] | Third party [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
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] | Other countries [Member] | Medicare and Medicaid [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
LabCorp Diagnostics [Member] | Other countries [Member] | Third party [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	$ 735.4		$ 735.4		$ 693.6
Percent of Revenue Contributed	39.00%		39.00%
Covance Drug Development [Member] | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	39.00%	37.00%	39.00%	38.00%
Covance Drug Development [Member] | UNITED STATES | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	20.00%	20.00%	20.00%	20.00%
Covance Drug Development [Member] | CANADA | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	0.00%	0.00%	0.00%	0.00%
Covance Drug Development [Member] | UNITED KINGDOM | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	4.00%	2.00%	4.00%	2.00%
Covance Drug Development [Member] | SWITZERLAND | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	5.00%	5.00%	5.00%	5.00%
Covance Drug Development [Member] | Europe [Member] | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	3.00%	3.00%	3.00%	4.00%
Covance Drug Development [Member] | Other countries [Member] | Biopharmaceutical and medical device companies [Member]
Disaggregation of Revenue [Line Items]
Percent of Revenue Contributed	7.00%	7.00%	7.00%	7.00%

Leases (Details)

Leases (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Leases [Abstract]
Lessee, Operating Lease, Term of Contract	15 years	15 years
Operating Lease, Payments		$ (115.2)
Short-term Lease, Cost	$ 2.6	5.9
Variable Lease, Cost	$ 4.7	$ 9.2
leases not yet commenced	50	50
Operating Leases, Rent Expense		$ 167.5	$ 85.1
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 254.1	254.1		$ 191.1
Finance Lease, Liability, Payments, Due Next Twelve Months	7.1	7.1		8.6
Finance Lease, Liability, Payment, Due	88.9	88.9
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(155.6)	(155.6)
Finance Lease, Liability, Undiscounted Excess Amount	(34.5)	(34.5)
Operating Lease, Right-of-Use Asset	770.3	770.3
Operating Lease, Liability, Current	229.2	229.2		0
Operating Lease, Liability, Noncurrent	586.1	586.1		0
Operating Lease, Liability	815.3	815.3
Finance Lease, Right-of-Use Asset	85.4	85.4
Finance Lease, Liability, Current	8.2	8.2		7.9
Finance Lease, Liability, Noncurrent	46.2	46.2		51
Finance Lease, Liability	$ 54.4	$ 54.4
Operating Lease, Weighted Average Remaining Lease Term	5 years 9 months 18 days	5 years 9 months 18 days
Operating Lease, Cost	$ 59.9	$ 110.8
Finance Lease, Right-of-Use Asset, Amortization	1.5	2.9
Finance Lease, Interest Expense	$ 0.4	$ 1.2
Finance Lease, Weighted Average Remaining Lease Term	6 years 6 months	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	4.20%	4.20%
Finance Lease, Weighted Average Discount Rate, Percent	4.80%	4.80%
Operating Leases, Future Minimum Payments, Due in Two Years	$ 274.7	$ 274.7		145.4
Finance Lease, Liability, Payments, Due Year Two	13.8	13.8		8
Operating Leases, Future Minimum Payments, Due in Three Years	174.6	174.6		107
Finance Lease, Liability, Payments, Due Year Three	12	12		6.7
Operating Leases, Future Minimum Payments, Due in Four Years	69.3	69.3		80.9
Finance Lease, Liability, Payments, Due Year Four	10.8	10.8		6
Operating Leases, Future Minimum Payments, Due in Five Years	45.1	45.1		61.5
Finance Lease, Liability, Payments, Due Year Five	10.7	10.7		6.5
Operating Leases, Future Minimum Payments, Due Thereafter	153.1	153.1		155.6
Finance Lease, Liability, Payments, Due after Year Five	34.5	34.5		$ 23.1
Lessee, Operating Lease, Liability, Payments, Due	970.9	970.9
Lease, Cost	$ 1.9	4.1
Finance Lease, Interest Payment on Liability		(0.9)
Finance Lease, Principal Payments		(4.8)
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		43.7
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability		$ 0.2
Lessee, Operating Lease, Renewal Term	15 years	15 years