Laboratory Corporation of America (LH) 10-K 27 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) shares in Millions, $ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Feb. 22, 2018

Entity Information [Line Items]

Net sales

$ 2,701.5

$ 2,597.9

$ 2,498.4

$ 2,408.1

$ 2,387.3

$ 2,372.7

$ 2,382

$ 2,295.2

$ 10,205.9

$ 9,437.2

$ 8,505.7

Entity Registrant Name

LABORATORY CORP OF AMERICA HOLDINGS

Entity Central Index Key

920,148

Current Fiscal Year End Date

--12-31

Entity Filer Category

Large Accelerated Filer

Document Type

10-K

Document Period End Date

Dec. 31, 2017

Document Fiscal Year Focus

2,017

Document Fiscal Period Focus

FY

Amendment Flag

false

Entity Common Stock, Shares Outstanding

101.9

Entity Well-known Seasoned Issuer

Yes

Entity Voluntary Filers

No

Entity Current Reporting Status

Yes

Entity Public Float

$ 14,900

Genomic and Esoteric Testing [Member]

Entity Information [Line Items]

Net sales

$ 2,844.1

$ 2,306.4

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 316.7	$ 433.6
Accounts receivable, net of allowance for doubtful accounts of $260.9 and $235.6 at December 31, 2017 and 2016, respectively	1,481.3	1,328.7
Unbilled Contracts Receivable	235.6	190
Supplies inventories	227.6	205.2
Prepaid expenses and other	421.4	321.2
Total current assets	2,682.6	2,478.7
Property, plant and equipment, net	1,748.9	1,718.6
Goodwill, net	7,530	6,424.4
Intangible assets, net	4,340.8	3,400.5
Joint venture partnerships and equity method investments	58.4	57.6
Deferred Income Tax Assets, Net	1.9	2.1
Other assets, net	205.4	165.1
Total assets	16,568	14,247
Current liabilities:
Accounts payable	663	508.4
Accrued expenses and other	632.9	593.7
Deferred Revenue, Current	332.7	176
Short-term borrowings and current portion of long-term debt	417.5	549.5
Total current liabilities	2,046.1	1,827.6
Long-term debt, less current portion	6,344.6	5,300
Deferred income taxes and other tax liabilities	948.3	1,206.4
Other liabilities	378.2	392
Total liabilities	9,717.2	8,726
Commitments and contingent liabilities
Noncontrolling interest	20.8	15.2
Shareholders’ equity
Common stock, 101.9 and 102.7 shares outstanding at December 31, 2017 and 2016, respectively	12	12.1
Additional paid-in capital	1,989.8	2,131.7
Retained earnings	6,224	4,955.8
Less common stock held in treasury	(1,060.1)	(1,012.7)
Accumulated other comprehensive loss	(335.7)	(581.1)
Total shareholders’ equity	6,830	5,505.8
Total liabilities and shareholders’ equity	$ 16,568	$ 14,247

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parentheticals) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Allowance for Doubtful Accounts	$ 260.9	$ 235.6
Shareholders’ equity
Common Stock, Shares, Outstanding (in shares)	101.9	102.7

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest expense	$ (235.1)	$ (219.1)	$ (274.9)
Operating income	1,364.2	1,312.4	996.8
Net sales	10,205.9	9,437.2	8,505.7
Reimbursement Revenue	235.5	204.6	174.4
Revenues	10,441.4	9,641.8	8,680.1
Cost of sales	6,741.9	6,256.7	5,602.4
Cost of Reimbursable Expense	235.5	204.6	174.4
Cost of Revenue	6,977.4	6,461.3	5,776.8
Gross profit	3,464	3,180.5	2,903.3
Selling, general and administrative expenses	1,812.4	1,630.2	1,628.1
Amortization of intangibles and other assets	216.5	179.5	164.5
Restructuring and other special charges	70.9	58.4	113.9
Equity method income, net	11.3	7.9	10
Investment income	2.1	1.7	1.9
Other, net	(7.6)	2.6	(7.8)
Earnings before income taxes	1,134.9	1,105.5	726
Net earnings	1,274	733.2	438.7
Less: Net earnings attributable to the noncontrolling interest	5.8	1.1	1.1
Net earnings attributable to Laboratory Corporation of America Holdings	1,268.2	732.1	437.6
Income Tax Expense (Benefit)	$ (139.1)	$ 372.3	$ 287.3

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net earnings	$ 1,274	$ 733.2	$ 438.7
Foreign currency translation adjustments	262.3	(250)	(370.7)
Net benefit plan adjustments	20.9	(40.3)	7.7
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	0	0	(0.1)
Other comprehensive loss before tax	283.2	(290.3)	(363.1)
Provision for income tax related to items of comprehensive earnings	(37.8)	(3.8)	86.6
Other comprehensive loss, net of tax	245.4	(294.1)	(276.5)
Comprehensive earnings	1,519.4	439.1	162.2
Less: Net earnings attributable to the noncontrolling interest	(5.8)	(1.1)	(1.1)
Net comprehensive earnings attributable to Laboratory Corporation of America Holdings	$ 1,513.6	$ 438	$ 161.1

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (10.5)
Net earnings attributable to Laboratory Corporation of America Holdings	437.6	$ 0	$ 0	$ 437.6	$ 0	$ 0
Other comprehensive earnings, net of tax	(276.5)	0	0	0	0	(276.5)
Issuance of common stock for acquisition consideration	1,762.5	1.5	1,761	0	0	0
Issuance of common stock under employee stock plans	98.9	0.1	98.8	0	0	0
Surrender of restricted stock and performance share awards	(12.6)	0	0	0	(12.6)	0
Conversion of zero-coupon convertible debt	0.4	0	0.4	0	0	0
Stock compensation	102.1	0	102.1	0	0	0
Income tax benefit from stock options exercised	12.2	0	12.2	0	0	0
BALANCE at Dec. 31, 2015	4,945.1
Common Stock, Value, Outstanding		12
Additional Paid in Capital			1,974.5
Retained Earnings (Accumulated Deficit)				4,223.7
Treasury Stock, Value					(978.1)
Accumulated Other Comprehensive Income (Loss), Net of Tax						(287)
Net earnings attributable to Laboratory Corporation of America Holdings	732.1	0	0	732.1	0	0
Other comprehensive earnings, net of tax	(294.1)	0	0	0	0	(294.1)
Issuance of common stock under employee stock plans	70.6	0.1	70.5	0	0	0
Surrender of restricted stock and performance share awards	(34.6)	0	0	0	(34.6)	0
Conversion of zero-coupon convertible debt	21	0	21	0	0	0
Stock compensation	109.6	0	109.6	0	0	0
Purchase of common stock	(43.9)	0	(43.9)	0	0	0
BALANCE at Dec. 31, 2016	5,505.8
Common Stock, Value, Outstanding	12.1	12.1
Additional Paid in Capital	2,131.7		2,131.7
Retained Earnings (Accumulated Deficit)	4,955.8			4,955.8
Treasury Stock, Value	(1,012.7)				(1,012.7)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(581.1)					(581.1)
Net earnings attributable to Laboratory Corporation of America Holdings	1,268.2	0	0	1,268.2	0	0
Other comprehensive earnings, net of tax	245.4	0	0	0	0	245.4
Issuance of common stock under employee stock plans	73.6	0.1	73.5	0	0	0
Surrender of restricted stock and performance share awards	(47.4)	0	0	0	(47.4)	0
Conversion of zero-coupon convertible debt	12.8	0	12.8	0	0	0
Stock compensation	109.7	0	109.7	0	0	0
Purchase of common stock	(338.1)	(0.2)	(337.9)	0	0	0
BALANCE at Dec. 31, 2017	6,830
Common Stock, Value, Outstanding	12	$ 12
Additional Paid in Capital	1,989.8		$ 1,989.8
Retained Earnings (Accumulated Deficit)	6,224			$ 6,224
Treasury Stock, Value	(1,060.1)				$ (1,060.1)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (335.7)					$ (335.7)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Proceeds from bridge loan	$ 0	$ 0	$ 400
Repayments of Senior Debt	(500.1)	(454.7)	(500)
Payments on bridge loan	0	0	(400)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	1,274	733.2	438.7
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	533.2	499.2	457.8
Stock compensation	109.7	109.6	102.1
(Gain) loss on sale of assets	1.5	(9.2)	4.6
Accrued interest on zero-coupon subordinated notes	0.3	1.6	2
Cumulative earnings less than distributions from equity method investments	0.5	1.2	0.1
Asset Impairment Charges	23.5	0	39.7
Deferred Income Tax Expense (Benefit)	(525.8)	54.7	(34.1)
Change in assets and liabilities (net of effects of acquisitions):
Increase in accounts receivable, net	(2.1)	(85.5)	(71.8)
Increase (Decrease) in Unbilled Receivables	(8.3)	(33.4)	(16.9)
Increase in inventories	(16.4)	(9.6)	(0.2)
(Increase) decrease in prepaid expenses and other	(20.3)	(20.5)	62.3
(Decrease) increase in accounts payable	85.6	(8.7)	30.7
Increase (Decrease) in Deferred Revenue	19	29.9	5.4
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities	(15)	(86.6)	(38)
Net cash provided by operating activities	1,459.4	1,175.9	982.4
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(312.9)	(278.9)	(255.8)
Proceeds from sale of assets	5.5	30.8	0.6
Proceeds from Sale of Equity Method Investments	0	13.5	8
Acquisition of licensing technology	2.5	0	0
Investments in equity affiliates	(36.2)	(12.5)	(11.7)
Acquisition of businesses, net of cash acquired	(1,882.6)	(548.6)	(3,736)
Net cash used for investing activities	(2,228.7)	(795.7)	(3,994.9)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from senior notes offerings	1,200	0	2,900
Proceeds from Issuance of Other Long-term Debt	750	0	1,000
Line of Credit Facility Payment	(493)	(150)	(285)
Proceeds from revolving credit facilities	1,392.2	139.5	60
Payments on revolving credit facilities	(1,392.2)	(139.5)	(60)
Payments on zero-coupon subordinated notes	(33.9)	(53.7)	(1.3)
Payment of debt issuance costs	(15.3)	0	(36.7)
Repayments of Long-term Capital Lease Obligations	(7.7)	(8.4)	(4.3)
Noncontrolling interest distributions	(1)	(2.1)	0
Excess tax benefits from stock based compensation	0	0	13.1
Net proceeds from issuance of stock to employees	73.6	70.6	98.9
Purchase of common stock	(338.1)	(43.9)	0
Net cash (used for) provided by financing activities	631.9	(649.8)	3,184.6
Deferred payments on acquisitions	(2.6)	(7.6)	(0.1)
Effect of exchange rate changes on cash and cash equivalents	20.5	(13.2)	(35.7)
Net (decrease) increase in cash and cash equivalents	(116.9)	(282.8)	136.4
Cash and cash equivalents at beginning of year	433.6	716.4	580
Cash and cash equivalents at end of year	$ 316.7	$ 433.6	$ 716.4

BUSINESS ACQUISITIONS

BUSINESS ACQUISITIONS	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
BUSINESS ACQUISITIONS	BUSINESS ACQUISITIONS On September 1, 2017, the Company completed the acquisition of Chiltern International Group Limited (Chiltern), a specialty contract research organization, pursuant to a definitive agreement to acquire all of the share capital of Chiltern, in an all-cash transaction valued at approximately $1,224.5 . The Company funded the acquisition through a combination of bank financing and the issuance of bonds. Chiltern is part of the Company's CDD segment. The valuation of acquired assets and assumed liabilities as of September 1, 2017, include the following: Consideration Transferred Cash consideration $ 1,224.5 Initial Measurement Period Adjustments Preliminary as of December 31, 2017 Net Assets Acquired Cash and cash equivalents $ 30.7 $ — $ 30.7 Accounts receivable 116.9 (11.3 ) 105.6 Unbilled services 32.6 — 32.6 Prepaid expenses and other 57.9 — 57.9 Property, plant and equipment 12.1 — 12.1 Goodwill 676.6 83.9 760.5 Customer relationships 629.0 (27.0 ) 602.0 Trade names and trademarks 24.1 (13.5 ) 10.6 Technology 47.0 (21.0 ) 26.0 Favorable leases — 0.9 0.9 Total assets acquired 1,626.9 12.0 1,638.9 Accounts payable 18.1 27.0 45.1 Accrued expenses and other 51.0 (27.6 ) 23.4 Unearned revenue 124.2 — 124.2 Deferred income taxes 208.0 12.6 220.6 Other liabilities 1.1 — 1.1 Total liabilities acquired 402.4 12.0 414.4 Net assets acquired $ 1,224.5 $ — $ 1,224.5 The amortization periods for intangible assets acquired are 21 years for customer relationships, 4 years for trade names and trademarks, and 6 years for technology. During the fourth quarter, the Company recorded certain measurement period adjustments to appropriately state the fair value of the net assets acquired from Chiltern. Given the September 1, 2017 closing date of the Chiltern acquisition, these adjustments would have had no material income statement impact had they been recorded as part of the initial purchase price allocation. The acquisition contributed $188.4 and $11.6 of net revenue and operating income, respectively, during the year ended December 31, 2017. Unaudited Pro Forma Information The Company completed the Chiltern acquisition on September 1, 2017. Had the Chiltern acquisition been completed as of January 1, 2016, the Company's pro forma results for 2017 would have been as follows: Year Ended December 31, 2017 December 31, 2016 Total net revenues $ 10,576.3 $ 9,937.4 Operating income 1,377.0 1,327.2 Net income 1,258.3 714.3 Earnings per share: Basic $ 12.29 $ 6.97 Diluted $ 12.11 $ 6.85 During the year ended December 31, 2017 , the Company also acquired various laboratories and related assets, including Pathology Associates Medical Laboratories (PAML), for approximately $688.8 in cash (net of cash acquired). These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. The purchase consideration for these acquisitions, including Chiltern, has been allocated to the estimated fair market value of the net assets acquired, including approximately $1,053.0 in identifiable intangible assets (primarily customer relationships and non-compete agreements) and a residual amount of goodwill of approximately $1,009.8 . As a result of the acquisition of PAML, the Company acquired PAML’s ownership interests in six joint ventures. During 2017, the Company further acquired the ownership interests of the other members of two of the six joint ventures, and the Company’s ownership interest in one of the six joint ventures was acquired by the other member. During 2018, the Company intends to acquire the membership interests of the other members of an additional two of these six joint ventures and will continue to evaluate future options for the membership interests in the sixth joint venture. The Company will continue to record minority interests in the consolidated joint ventures for which final transactions have not yet been completed. The purchase consideration for the transaction has been preliminarily allocated to the estimated fair market value of the net assets acquired. The amounts paid in advance for the ownership interest in the three joint ventures are included in other assets on the condensed consolidated balance sheet. The total purchase consideration for the transaction is classified as cash paid for acquisition of a business on the condensed consolidated statement of cash flows. The purchase price allocation for the Chiltern and PAML acquisitions are still preliminary and subject to change. The areas of the purchase price allocation that are not yet finalized relate primarily to intangible assets, goodwill, investment in joint ventures 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 within a year from each acquisition date. Any adjustments will be recorded in the period in which they are identified. During the year ended December 31, 2016 , the Company acquired various laboratories and related assets for approximately $548.6 in cash (net of cash acquired). The Company completed the acquisition of Sequenom, Inc., a market leader in non-invasive prenatal testing, women's health and reproductive genetics on September 7, 2016, through a cash tender offer for $2.40 per share, or a transaction price of $249.1 , net of cash received, and acquired $130.0 of debt. The Sequenom purchase consideration has been allocated to the estimated fair market value of the net assets acquired, including approximately $146.6 in identifiable intangible assets (primarily customer relationships, technology, and trade names) with weighted-average useful lives of approximately 14.6 years; $45.1 in deferred tax liabilities (relating to identifiable intangible assets); and a residual amount of non-tax deductible goodwill of approximately $206.0 . The Company also acquired various other laboratories and related assets for approximately $299.5 in cash (net of cash acquired). The purchase consideration for these acquisitions has been allocated to the estimated fair market value of the net assets acquired, including approximately $126.2 in identifiable intangible assets (primarily customer relationships) and a residual amount of goodwill of approximately $192.3 . These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. On February 19, 2015, the Company completed its acquisition of Covance Inc. (Covance), a leading drug development services company and a leader in nutritional analysis, for $6,150.7 . The Company issued debt and common stock to fund the acquisition of Covance. Covance stockholders received $75.76 in cash and 0.2686 shares of the Company's common stock for each share of Covance common stock they owned. The Company financed the Covance acquisition with $3,900.0 of debt, 15.3 shares of its common stock and $488.2 of available cash, $400.0 of which was derived from a bridge term loan credit facility. On January 30, 2015, the Company issued $2,900.0 in debt securities, consisting of $500.0 aggregate principal amount of 2.625% Senior Notes due 2020, $500.0 aggregate principal amount of 3.20% Senior Notes due 2022, $1,000.0 aggregate principal amount of 3.60% Senior Notes due 2025 and $900.0 aggregate principal amount of 4.70% Senior Notes due 2045. The Company also entered into a $1,000.0 term loan facility which was advanced in full on the February 19, 2015. The term loan credit facility will mature five years after the closing date of the Covance acquisition and may be prepaid without penalty. Unaudited Pro Forma Information The Company completed the acquisition of Covance on February 19, 2015. Had the acquisition been completed as of the beginning of 2014, the Company's pro forma results for 2015 would have been as follows: Year Ended December 31, 2015 Total revenues $ 9,033.3 Operating income 1,117.2 Net income 547.5 Earnings per share: Basic $ 5.05 Diluted $ 5.03 During the year ended December 31, 2015 , the Company also acquired various other laboratories and related assets for approximately $128.4 in cash (net of cash acquired). These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. The purchase consideration for these acquisitions has been allocated to the estimated fair market value of the net assets acquired, including approximately $17.4 in identifiable intangible assets (primarily customer relationships and non-compete agreements) and a residual amount of goodwill of approximately $68.4 .

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES 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, 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, food and nutritional companies and independent clinical laboratories. The Company believes that it generated more revenue from laboratory testing than any other company in the world in 2017. The Company reports its business in two segments, LabCorp Diagnostics (LCD) and Covance Drug Development (CDD). For further financial information about these segments, including information for each of the last three fiscal years regarding revenue, operating income, and other important information, see Note 20 to the Consolidated Financial Statements. In 2017, LCD and CDD contributed 70.3% and 29.7% , respectively, of net revenues to the Company, and in 2016 contributed 69.9% and 30.1% , respectively. The 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% and no representation on the investee's board of directors) are accounted for using the cost method. All significant inter-company transactions and accounts have been eliminated. The Company does not have any variable interest entities or special purpose entities whose financial results are not included in the 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 year. Resulting translation adjustments are included in “Accumulated other comprehensive income.” Revenue Recognition LCD recognizes revenue on the accrual basis at the time test results are reported, which approximates when services are provided. Services are provided to certain patients covered by various third-party payer programs including various MCOs, as well as the Medicare and Medicaid programs. Billings for services under third-party payer programs are included in sales net of allowances for contractual discounts and allowances for differences between the amounts billed and estimated program payment amounts. Adjustments to the estimated payment amounts based on final settlement with the programs are recorded upon settlement as an adjustment to revenue. In 2017 , 2016 and 2015 , approximately 15.1% , 15.5% and 16.0% , respectively, of LCD's revenues were derived directly from the Medicare and Medicaid programs. LCD has capitated agreements with certain MCO customers and recognizes related revenue based on a predetermined monthly contractual rate for each member of the managed care plan regardless of the number of tests performed. In 2017 , 2016 and 2015 , approximately 3.6% , 3.4% and 3.5% , respectively, of LCD's revenues were derived from such capitated agreements. CDD recognizes revenue either as services are performed or products are delivered, depending on the nature of the work contracted. Historically, a majority of CDD’s net revenues have been earned under contracts that range in duration from a few months to a few years, but can extend in duration up to five years or longer. Occasionally, CDD also has committed minimum volume arrangements with certain customers. Underlying these arrangements are individual project contracts for the specific services to be provided. These arrangements enable CDD's customers to secure its services in exchange for which they commit to purchase an annual minimum dollar value of services. Under these types of arrangements, if the annual minimum dollar value of service commitment is not reached, the customer is required to pay CDD for the shortfall. Progress towards the achievement of annual minimum dollar value of service commitments is monitored throughout the year. Annual minimum commitment shortfalls are not included in net revenues until the amount has been determined and agreed to by the customer. Service contracts generally take the form of fee-for-service or fixed-price arrangements subject to pricing adjustments based on changes in scope. In cases where performance spans multiple accounting periods, revenue is recognized as services are performed, measured on a proportional-performance basis, generally using output measures that are specific to the service provided. Examples of output measures in preclinical services, include among others, the number of slides read, or specimens prepared. Examples of output measures in the clinical trials services, include among others, number of investigators enrolled, number of sites initiated, number of trial subjects enrolled and number of monitoring visits completed, or number of dosings for clinical pharmacology. Revenue is determined by dividing the actual units of work completed by the total units of work required under the contract and multiplying that percentage by the total contract value. The total contract value, or total contractual payments, represents the aggregate contracted price for each of the agreed upon services to be provided. CDD does not have any contractual arrangements spanning multiple accounting periods where revenue is recognized on a proportional-performance basis under which the Company has earned more than an immaterial amount of performance-based revenue (i.e., potential additional revenue tied to specific deliverables or performance). Changes in the scope of work are common, especially under long-term contracts, and generally result in a change in contract value. Once the customer has agreed to the changes in scope and renegotiated pricing terms, the contract value is amended with revenue recognized as described above. Estimates of costs to complete are made to provide, where appropriate, for losses expected on contracts. Costs are not deferred in anticipation of contracts being awarded, but instead are expensed as incurred. Billing schedules and payment terms are generally negotiated on a contract-by-contract basis. In some cases, CDD bills the customer for the total contract value in progress-based installments as certain non-contingent billing milestones are reached over the contract duration, such as, but not limited to, contract signing, initial dosing, investigator site initiation, patient enrollment or database lock. The term “billing milestone” relates only to a billing trigger in a contract whereby amounts become billable and payable in accordance with a negotiated predetermined billing schedule throughout the term of a project. These billing milestones are generally not performance-based (i.e., there is no potential additional consideration tied to specific deliverables or performance). In other cases, billing and payment terms are tied to the passage of time (e.g., monthly billings). In either case, the total contract value and aggregate amounts billed to the customer would be the same at the end of the project. While CDD attempts to negotiate terms that provide for billing and payment of services prior or within close proximity to the provision of services, this is not always possible, and there are fluctuations in the levels of unbilled services and unearned revenue from period to period. While a project is ongoing, cash payments are not necessarily representative of aggregate revenue earned at any particular point in time, as revenues are recognized when services are provided, while amounts billed and paid are in accordance with the negotiated billing and payment terms. In some cases, payments received are in excess of revenue recognized. For example, a contract invoicing schedule may provide for an upfront payment of 10% of the full contract value upon contract signing, but at the time of signing performance of services has not yet begun. Payments received in advance of services being provided are deferred as unearned revenue on the balance sheet. As the contracted services are subsequently performed and the associated revenue is recognized, the unearned revenue balance is reduced by the amount of revenue recognized during the period. In other cases, services may be provided and revenue recognized before the customer is invoiced. In these cases, revenue recognized will exceed amounts billed, and the difference, representing an unbilled receivable, is recorded for the amount that is currently unbillable to the customer pursuant to contractual terms. Once the customer is invoiced, the unbilled services are reduced for the amount billed, and a corresponding account receivable is recorded. All unbilled services are billable to customers within one year from the respective balance sheet date. Most contracts are terminable with or without cause by the customer, either immediately or upon notice. These contracts often require payment to CDD of expenses to wind down the study or project, fees earned to date and, in some cases, a termination fee or a payment to CDD of some portion of the fees or profits that could have been earned by CDD under the contract if it had not been terminated early. Termination fees are included in net revenues when services are performed and realization is assured. In connection with the management of multi-site clinical trials, CDD pays on behalf of its customers fees to investigators, clinical trial subjects and certain out-of-pocket costs, for which it is reimbursed at cost, without markup or profit. Investigator fees are not reflected in net revenues or expenses where CDD acts in the capacity of an agent on behalf of the biopharmaceutical company sponsor, passing through these costs without markup or profit. All other out-of-pocket costs are included in total revenues and expenses. The Company's total revenues are comprised of the following: Years Ended December 31, Total revenues 2017 2016 2015 LCD - net revenue $ 7,170.5 $ 6,593.9 $ 6,199.3 CDD - net revenue 3,037.2 2,844.1 2,306.4 CDD - reimbursable out-of-pocket expenses 235.5 204.6 174.4 Intercompany eliminations (1.8 ) (0.8 ) — Total revenues $ 10,441.4 $ 9,641.8 $ 8,680.1 Reimbursable Out-of-Pocket Expenses CDD pays on behalf of its customers certain out-of-pocket costs for which the Company is reimbursed at cost, without mark-up or profit. Out-of-pocket costs paid by CDD are reflected in operating expenses, while the reimbursements received are reflected in revenues in the consolidated statements of operations. CDD excludes from revenue and expense in the consolidated statements of operations fees paid to investigators and the associated reimbursement because CDD acts as an agent on behalf of the biopharmaceutical company sponsors with regard to investigator payments. Cost of Revenue Cost of revenue includes direct labor and related benefit charges, other direct costs, shipping and handling fees, and an allocation of facility charges and information technology costs. Selling, general and administrative expenses consist primarily of administrative payroll and related benefit charges, advertising and promotional expenses, administrative travel and an allocation of facility charges and information technology costs. Cost of advertising is expensed as incurred. Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Significant estimates include the allowances for doubtful accounts, deferred tax assets, fair values and amortization lives for intangible assets, and accruals for self-insurance reserves and pensions. The allowance for doubtful accounts is determined based on historical collections trends, the aging of accounts, current economic conditions and regulatory changes. Actual results could differ from those estimates. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The Company maintains cash and cash equivalents with various major financial institutions. The total cash and cash equivalent balances that exceeded the balances insured by the Federal Deposit Insurance Commission, were approximately $315.5 at December 31, 2017 . Substantially all of the Company’s accounts receivable are with companies in the healthcare or biopharmaceutical industry and individuals. However, concentrations of credit risk are limited due to the number of the Company’s customers as well as their dispersion across many different geographic regions. Although LCD has receivables due from U.S. and state governmental agencies, the Company does not believe that such receivables represent a credit risk since the related healthcare programs are funded by U.S. and state governments, and payment is primarily dependent upon submitting appropriate documentation. Accounts receivable balances (gross) from Medicare and Medicaid were $109.8 and $113.0 at December 31, 2017 , and 2016 , respectively. For the Company's operations in Ontario, Canada, the Ontario Ministry of Health and Long-Term Care (Ministry) determines who can establish a licensed community medical laboratory and caps the amount that each of these licensed laboratories can bill the government sponsored healthcare plan. The Ontario government-sponsored healthcare plan covers the cost of commercial laboratory testing performed by the licensed laboratories. The provincial government discounts the annual testing volumes based on certain utilization discounts and establishes an annual maximum it will pay for all community laboratory tests. The agreed-upon reimbursement rates are subject to Ministry review at the end of year and can be adjusted (at the government's discretion) based upon the actual volume and mix of test work performed by the licensed healthcare providers in the province during the year. The capitated accounts receivable balances from the Ontario government sponsored healthcare plan were CAD $12.9 and CAD $15.8 at December 31, 2017 , and 2016 , respectively. The portion of the Company's accounts receivable due from patients comprises the largest portion of credit risk. At December 31, 2017 , and 2016 , receivables due from patients represented approximately 20.9% and 20.0% of the Company's consolidated gross accounts receivable. The Company applies assumptions and judgments including historical collection experience for assessing collectability and determining allowances for doubtful accounts for accounts receivable from patients. 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, 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: 2017 2016 2015 Income Shares Per Share Amount Income Shares Per Share Amount Income Shares Per Share Amount Basic earnings per share $ 1,268.2 102.4 $ 12.39 $ 732.1 102.5 $ 7.14 $ 437.6 98.8 $ 4.43 Stock options — 1.4 — 1.5 — 1.2 Restricted stock awards and other — — — — — — Effect of convertible debt, net of tax — 0.1 — 0.3 — 0.6 Diluted earnings per share $ 1,268.2 103.9 $ 12.21 $ 732.1 104.3 $ 7.02 $ 437.6 100.6 $ 4.35 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: Years Ended December 31, 2017 2016 2015 Stock options 0.1 — — Stock Compensation Plans The Company measures stock compensation cost for all equity awards at fair value on the date of grant and recognizes compensation expense over the service period for awards expected to vest. The fair value of restricted stock units and performance share awards is determined based on the number of shares granted and the quoted price of the Company’s common stock on the grant date. Such value is recognized as expense over the service period, net of estimated forfeitures. The estimation of equity awards that will ultimately vest requires judgment and the Company considers many factors when estimating expected forfeitures, including types of awards, employee class, and historical experience. The cumulative effect on current and prior periods of a change in the estimated forfeiture rate is recognized as compensation expense in earnings in the period of the revision. Actual results and future estimates may differ substantially from the Company’s current estimates. See Note 14 for assumptions used in calculating compensation expense for the Company’s stock compensation plans. Cash Equivalents Cash and cash equivalents consist of highly liquid instruments, such as commercial paper, time deposits, and other money market instruments, substantially all of which have maturities when purchased of three months or less. Inventories Inventories, consisting primarily of purchased laboratory and customer supplies and finished goods, are stated at the lower of cost (first-in, first-out) or market. Supplies accounted for $ 195.2 and $ 171.7 and finished goods accounted for $ 32.4 and $ 33.5 of total inventory at December 31, 2017 , and 2016 , respectively. Prepaid Expenses and Other In connection with the management of multi-site clinical trials, CDD pays on behalf of its customers certain out-of-pocket costs, for which the Company is reimbursed at cost, without markup or profit. Amounts receivable from customers in connection with such out-of-pocket pass-through costs are included in prepaid expenses and other in the accompanying consolidated balance sheets and totaled $138.2 at December 31, 2017 , and $97.1 at December 31, 2016 . Also included in prepaid expenses and other current assets are assets held for sale. The Company records long-lived assets as held for sale when a plan to sell the asset has been initiated and all other held for sale criteria have been satisfied. Assets classified as held for sale of $55.2 and $51.2 as of December 31, 2017 , and 2016, respectively, are recorded in other current assets on the consolidated balance sheet at the lower of their carrying value or fair value less cost to sell. Property, Plant and Equipment Property, plant and equipment are recorded at cost. The cost of properties held under capital leases is equal to the lower of the net present value of the minimum lease payments or the fair value of the leased property at the inception of the lease. Depreciation and amortization expense is computed on all classes of assets based on their estimated useful lives, as indicated below, using the straight-line method. Years Buildings and building improvements 10 - 40 Machinery and equipment 3 - 10 Furniture and fixtures 5 - 10 Software 3 - 10 Leasehold improvements and assets held under capital leases are amortized over the shorter of their estimated useful lives or the term of the related leases. Expenditures for repairs and maintenance are charged to operations as incurred. Retirements, sales and other disposals of assets are recorded by removing the cost and accumulated depreciation from the related accounts with any resulting gain or loss reflected in the consolidated statements of operations. Capitalized Software Costs The Company capitalizes purchased software which is ready for service and capitalizes software development costs incurred on significant projects starting from the time that the preliminary project stage is completed and the Company commits to funding a project until the project is substantially complete and the software is ready for its intended use. Capitalized costs include direct material and service costs and payroll and payroll-related costs. Research and development (R&D) costs and other computer software maintenance costs related to software development are expensed as incurred. Capitalized software costs are amortized using the straight-line method over the estimated useful life of the underlying system, generally five years. Long-Lived Assets The Company assesses goodwill and indefinite-lived intangibles for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. In accordance with the FASB updates to their authoritative guidance regarding goodwill and indefinite-lived intangible asset impairment testing, an entity is allowed to first assess qualitative factors as a basis for determining whether it is necessary to perform quantitative impairment testing. If an entity determines that it is not more likely than not that the estimated fair value of an asset is less than its carrying value, then no further testing is required. Otherwise, impairment testing must be performed in accordance with the original accounting standards. The updated FASB guidance also allows an entity to bypass the qualitative assessment for any reporting unit in its goodwill assessment and proceed directly to performing the quantitative assessment. Similarly, a company can proceed directly to a quantitative assessment in the case of impairment testing for indefinite-lived intangible assets as well. The quantitative goodwill impairment test includes the estimation of the fair value of each reporting unit as compared to the carrying value of the reporting unit. Reporting units are businesses with discrete financial information that is available and reviewed by management. The Company estimates the fair value of a reporting unit using both income-based and market-based valuation methods. The income-based approach is based on the reporting unit's forecasted future cash flows that are discounted to the present value using the reporting unit's weighted average cost of capital. For the market-based approach, the Company utilizes a number of factors such as publicly available information regarding the market capitalization of the Company as well as operating results, business plans, market multiples, and present value techniques. Based upon the range of estimated values developed from the income and market-based methods, the Company determines the estimated fair value for the reporting unit. If the estimated fair value of the reporting unit exceeds the carrying value, the goodwill is not impaired and no further review is required. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Management performed its annual goodwill and intangible asset impairment testing as of the beginning of the fourth quarter of 2017. The Company elected to perform the qualitative assessment for goodwill and intangible assets for all reporting units except the Canadian reporting unit and its indefinite-lived assets consisting of acquired Canadian licenses for which a quantitative assessment was performed. In this qualitative assessment, the Company considered relevant events and circumstances for each reporting unit, including (i) current year results, (ii) financial performance versus management’s annual and five-year strategic plans, iii) changes in the reporting unit carrying value since prior year, (iv) industry and market conditions in which the reporting unit operates, (v) macroeconomic conditions, including discount rate changes, and (vi) changes in products or services offered by the reporting unit. If applicable, performance in recent years was compared to forecasts included in prior valuations. Based on the results of the qualitative assessment, the Company concluded that it was not more likely than not that the carrying values of the goodwill and intangible assets were greater than their fair values, and that further quantitative testing was not necessary. In 2017, the Company utilized an income approach to determine the fair value of its Canadian reporting unit and its indefinite-lived assets consisting of acquired Canadian licenses. Based upon the results of the quantitative assessment, the Company concluded that the fair value of the indefinite-lived Canadian licenses was greater than the carrying value. It is possible that the Company's conclusions regarding impairment or recoverability of goodwill or intangible assets in any reporting unit could change in future periods. There can be no assurance that the estimates and assumptions used in the Company's goodwill and intangible asset impairment testing performed as of the beginning of the fourth quarter of 2017 will prove to be accurate predictions of the future, if, for example, (i) the businesses do not perform as projected, (ii) overall economic conditions in 2018 or future years vary from current assumptions (including changes in discount rates), (iii) business conditions or strategies for a specific reporting unit change from current assumptions, including loss of major customers, (iv) investors require higher rates of return on equity investments in the marketplace or (v) enterprise values of comparable publicly traded companies, or actual sales transactions of comparable companies, were to decline, resulting in lower multiples of revenues and earnings before interest, tax, depreciation and amortization (EBITDA). A future impairment charge for goodwill or intangible assets could have a material effect on the Company's consolidated financial position and results of operations. Long-lived assets, other than goodwill and indefinite-lived assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Recoverability of assets to be held and used is determined by the Company at the level for which there are identifiable cash flows by comparison of the carrying amount of the assets to future undiscounted net cash flows before interest expense and income taxes expected to be generated by the assets. Impairment, if any, is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets (based on market prices in an active market or on discounted cash flows). Assets to be disposed of are reported at the lower of the carrying amount or fair value. Intangible Assets Intangible assets are amortized on a straight-line basis over the expected periods to be benefited, as set forth in the table below, such as legal life for patents and technology and contractual lives for non-compete agreements. Years Customer relationships 10 - 36 Patents, licenses and technology 3 - 15 Non-compete agreements 5 - 10 Trade names 5 - 15 Debt Issuance Costs The costs related to the issuance of debt are capitalized, netted against the related debt for presentation purposes and amortized to interest expense over the terms of the related debt. Professional Liability The Company is self-insured (up to certain limits) for professional liability claims arising in the normal course of business, generally related to the testing and reporting of laboratory test results. The Company estimates a liability that represents the ultimate exposure for aggregate losses below those limits. The liability is based on assumptions and factors for known and incurred but not reported claims, including the frequency and payment trends of historical claims. Income Taxes The Company accounts for income taxes utilizing the asset and liability method. Under this method deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and for tax loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. 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 Company records interest and penalties in income tax expense. Derivative Financial Instruments Interest rate swap agreements, which have been used by the Company from time to time in the management of interest rate exposure, are accounted for at fair value. The Company’s zero-coupon subordinated notes contain two features that are considered to be embedded derivative instruments under authoritative guidance in connection with accounting for derivative instruments and hedging activities. The Company believes these embedded derivatives had no fair value at December 31, 2017 , and 2016 . See Note 18 for the Company’s objectives in using derivative instruments and the effect of derivative instruments and related hedged items on the Company’s financial position, financial performance and cash flows. Fair Value of Financial Instruments Fair value measurements for financial assets and liabilities are determined based on the assumptions that a market participant would use in pricing an asset or liability. A three-tiered fair value hierarchy draws distinctions between market participant assumptions based on (i) observable inputs such as quoted prices in active markets (Level 1), (ii) inputs other than quoted prices in active markets that are observable either directly or indirectly (Level 2) and (iii) unobservable inputs that require the Company to use present value and other valuation techniques in the determination of fair value (Level 3). Research and Development The Company expenses R&D costs as incurred. Foreign Currencies For subsidiaries outside of the U.S. that operate in a local currency environment, income and expense items are translated to U.S. dollars at the monthly average rates of exchange prevailing during the period, assets and liabilities are translated at period-end exchange rates and equity accounts are translated at historical exchange rates. Translation adjustments are accumulated in a separate component of shareholders’ equity in the consolidated balance sheets and are included in the determination of comprehensive income in the consolidated statements of comprehensive earnings and consolidated statements of changes in shareholders’ equity. Transaction gains and losses are included in the determination of net income in the consolidated statements of operations. New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued the converged standard on revenue recognit

RESTRUCTURING AND OTHER SPECIAL

RESTRUCTURING AND OTHER SPECIAL CHARGES	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND OTHER SPECIAL CHARGES	RESTRUCTURING AND OTHER SPECIAL CHARGES During 2017 , the Company recorded net restructuring charges of $70.9 ; $16.8 within LCD and $54.1 within CDD. The charges were comprised of $36.1 in severance and other personnel costs and $39.9 in facility-related costs primarily associated with general integration activities. The charges were offset by the reversal of previously established reserves of $0.5 in unused severance and $4.6 in unused facility-related costs. The Company also incurred legal and other costs of $43.9 relating to acquisition initiatives, including Chiltern. The Company recorded $25.4 in consulting and other expenses relating to the Covance and Chiltern integration and compensation analysis, along with $0.9 in short-term equity retention arrangements relating to the Covance acquisition. In addition, the Company incurred $1.3 in consulting expenses relating to fees incurred as part of its integration and management transition costs as well as $8.2 of non-capitalized costs associated with the implementation of a major system as part of its LaunchPad business process improvement initiative (all recorded in selling, general and administrative expenses). The Company also recognized asset impairment losses of $23.5 related to the termination of software development projects within the CDD segment and the forgiveness of certain indebtedness for LCD customers in areas heavily impacted by hurricanes during the third quarter. On April 25, 2017, the Company announced that it was expanding LaunchPad to include its CDD segment. The Company generated $20.0 in savings in 2017, and expects to achieve additional net savings of $130.0 through the three-year period ending 2020. This initiative is expected to align people and capabilities with client and business demand, utilize automation and new information technology platforms to create efficiencies, and enhance customers' experience with CDD through investments in commercial and operational processes. During 2016 , the Company recorded net restructuring charges of $58.4 ; $15.8 within LCD and $42.6 within CDD. The charges were comprised of $30.9 in severance and other personnel costs and $33.8 in facility-related costs primarily associated with general integration activities. The Company incurred additional legal and other costs of $4.6 relating to the wind down of its minimum volume service contract operations and incurred $8.0 in acquisition fees and expenses. The Company also recorded $6.9 in consulting expenses relating to fees incurred as part of its Covance acquisition integration costs and compensation analysis, along with $2.5 in short-term equity retention arrangements relating to the Covance acquisition and $8.9 of accelerated equity compensation and other final compensation relating to executive transition, along with $9.0 of non-capitalized costs associated with the implementation of a major system as part of LaunchPad, LCD's comprehensive, enterprise-wide business process improvement initiative (all recorded in selling, general and administrative expenses). The Company also recorded a $3.6 gain on sale for certain assets held for sale. The Company incurred $5.6 of interest expense relating to the early retirement of subsidiary indebtedness assumed as part of its recent acquisition of Sequenom. During 2015 , the Company recorded net restructuring charges of $113.9 ; $39.2 within LCD and $74.7 within CDD. The charges were comprised of $59.2 in severance and other personnel costs and $55.8 in facility-related costs primarily associated with the ongoing integration of Orchid Cellmark, Inc. and the Integrated Genetics business (formerly Genzyme Genetics) and costs associated with the previously announced termination of an executive vice president. These charges were offset by the reversal of previously established reserves of $1.1 in unused facility-related costs. A substantial portion of these costs relate to the planned closure of two CDD operations that serviced a minimum volume contract that expired on October 31, 2015. These charges were offset by the reversal of previously established reserves of $3.5 in unused facility related costs. Included within the facility-related charges noted above is a $26.7 asset impairment charge relating to CDD lab and customer service applications that will no longer be used. In addition, during 2015, the Company recorded $25.6 in consulting expenses (recorded in selling, general and administrative expenses) relating to fees incurred as part of LaunchPad as well as Covance integration costs and employee compensation studies, along with $5.4 in short-term equity retention arrangements relating to the acquisition of Covance and $0.3 of accelerated equity compensation relating to the retirement of a Company executive (all recorded in selling, general and administrative expenses). The Company also incurred $5.7 relating to the wind down of the minimum volume contract operations referred to in the previous paragraph. Additionally, the Company recorded $166.0 of deal costs related to the Covance acquisition, of which $113.4 is included in selling, general and administrative expenses and $52.6 is included in interest expense. During 2015, the Company also recorded a non-cash loss of $2.3 , upon the dissolution of one of its equity investments, which is included in other, net expenses. During the fourth quarter, the Company paid $12.2 in settlement costs and litigation expenses related to the resolution of a U.S. court putative class action lawsuit. In addition, the Company incurred $3.0 of non-capitalized costs associated with the implementation of a major system as part of LaunchPad.

RESTRUCTURING RESERVES

RESTRUCTURING RESERVES	12 Months Ended
	Dec. 31, 2017
Restructuring Reserve [Abstract]
RESTRUCTURING RESERVES	The following represents the Company’s restructuring activities for the period indicated: LCD CDD Total Severance and Other Employee Costs Lease and Other Facility Costs Severance and Other Employee Costs Lease and Other Facility Costs Balance as of December 31, 2016 $ 7.5 $ 14.1 $ 28.2 $ 32.5 $ 82.3 Restructuring charges 11.4 6.6 24.7 33.3 76.0 Reduction of prior restructuring accruals (1.1 ) (0.1 ) (3.5 ) (0.4 ) (5.1 ) Cash payments and other adjustments (16.1 ) (10.5 ) (41.1 ) (30.8 ) (98.5 ) Balance as of December 31, 2017 $ 1.7 $ 10.1 $ 8.3 $ 34.6 $ 54.7 Current $ 22.2 Non-current 32.5 $ 54.7 The non-current portion of the restructuring liabilities is expected to be paid out over 6.4 years. Cash payments and other adjustments include the reclassification of profit sharing, pension, and holiday accrual.

JOINT VENTURE PARTNERSHIPS AND

JOINT VENTURE PARTNERSHIPS AND EQUITY METHOD INVESTMENTS	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
JOINT VENTURE PARTNERSHIPS AND EQUITY METHOD INVESTMENTS	JOINT VENTURE PARTNERSHIPS AND EQUITY METHOD INVESTMENTS At December 31, 2017 , the Company had investments in the following unconsolidated joint venture partnerships and equity method investments: Locations Net Investment Interest Owned Joint Venture Partnerships : Alberta, Canada (2) $ 45.5 43.37 % Florence, South Carolina 10.1 49.00 % PAML joint ventures $ (0.1 ) various Equity Method Investments : Various 3.7 various The joint venture agreements that govern the conduct of business of these partnerships mandate unanimous agreement between partners on all major business decisions as well as providing other participating rights to each partner. The equity method investments represent the Company’s purchase of ownership interests in clinical diagnostic companies. The investments are accounted for under the equity method of accounting as the Company does not have control of these investments. The Company has no material obligations or guarantees to, or in support of, these unconsolidated investments and their operations. As a result of the acquisition of PAML, the Company acquired PAML’s ownership interests in six joint ventures. During 2017, the Company further acquired the ownership interests of the other members of two of the six joint ventures, and the Company’s ownership interest in one of the six joint ventures was acquired by the other member. During 2018, the Company intends to acquire the membership interests of the other members of an additional two of these six joint ventures and will continue to evaluate future options for the membership interests in the sixth joint venture. The Company will continue to record minority interests in the consolidated joint ventures for which final transactions have not yet been completed. Condensed unconsolidated financial information for joint venture partnerships and equity method investments is shown in the following table. As of December 31: 2017 2016 Current assets $ 45.7 $ 24.3 Other assets 14.4 16.9 Total assets $ 60.1 $ 41.2 Current liabilities $ 31.6 $ 15.5 Other liabilities 1.0 0.3 Total liabilities 32.6 15.8 Partners' equity 27.5 25.4 Total liabilities and partners’ equity $ 60.1 $ 41.2 For the period January 1 - December 31: 2017 2016 2015 Net revenues $ 212.5 $ 156.7 $ 213.7 Gross profit 62.6 45.7 54.3 Net earnings 25.7 20.3 20.1 The Company’s recorded investment in one of its Alberta joint venture partnerships at December 31, 2017, includes $34.6 of value assigned to that partnership’s Canadian license to conduct diagnostic testing services in the province. Substantially all of the joint venture's revenue is received as reimbursement from the Alberta government's healthcare programs. While the Canadian license provides the joint venture the ability to conduct diagnostic testing in Alberta, it does not guarantee that the provincial government will continue to reimburse diagnostic laboratory testing in future years at current levels. A decision by the provincial government to limit or reduce its reimbursement of laboratory diagnostic services would have a negative impact on the profits and cash flows the Company derives from the joint venture. In August 2016, AHS and the Canadian partnership reached an agreement to extend the contract for five additional years through March 2022, with the intent to have the services provided pursuant to the contract transferred to AHS at the end of the five-year period. In consideration of AHS acquiring the assets and assuming liabilities in accordance with the parties’ agreement, AHS will pay CAD $50.0 to the partnership when the transfer is effective, subject to a working capital adjustment. The Company will amortize the value of the partnership's Canadian license to its residual over the remaining term of the agreement.

ACCOUNTS RECEIVABLE, NET

ACCOUNTS RECEIVABLE, NET	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
ACCOUNTS RECEIVABLE, NET	ACCOUNTS RECEIVABLE, NET December 31, 2017 December 31, Gross accounts receivable $ 1,742.2 $ 1,564.3 Less allowance for doubtful accounts (260.9 ) (235.6 ) $ 1,481.3 $ 1,328.7 Bad debt expense was $314.7 , $287.3 and $265.4 in 2017 , 2016 and 2015 respectively.

PROPERTY, PLANT AND EQUIPMENT,

PROPERTY, PLANT AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT, NET	PROPERTY, PLANT AND EQUIPMENT, NET December 31, 2017 December 31, 2016 Land $ 78.4 $ 78.4 Buildings and building improvements 708.6 692.8 Machinery and equipment 1,181.0 1,060.1 Software 672.2 626.2 Leasehold improvements 333.5 302.0 Furniture and fixtures 90.6 76.9 Construction in progress 185.1 193.0 Equipment and real estate under capital leases 79.2 81.3 3,328.6 3,110.7 Less accumulated depreciation and amortization of capital lease assets (1,579.7 ) (1,392.1 ) $ 1,748.9 $ 1,718.6 Depreciation expense and amortization of property, plant and equipment was $306.8 , $311.1 and $269.9 for 2017 , 2016 and 2015 , respectively, including software depreciation of $85.6 , $79.2 , and $66.1 for 2017 , 2016 and 2015 , respectively.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS The changes in the carrying amount of goodwill (net of accumulated amortization) for the years ended December 31, 2017 and 2016 are as follows: LCD CDD Total December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Balance as of January 1 $ 3,644.8 $ 3,137.7 $ 2,779.6 $ 3,064.4 $ 6,424.4 $ 6,202.1 Goodwill acquired during the year 198.5 398.3 811.3 — 1,009.8 398.3 Foreign currency impact and other adjustments to goodwill 1.1 108.8 94.7 (284.8 ) 95.8 (176.0 ) Balance at end of year $ 3,844.4 $ 3,644.8 $ 3,685.6 $ 2,779.6 $ 7,530.0 $ 6,424.4 The components of identifiable intangible assets are as follows: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 4,297.9 $ (1,014.9 ) $ 3,283.0 $ 3,275.3 $ (855.2 ) $ 2,420.1 Patents, licenses and technology 457.9 (188.6 ) 269.3 395.3 (163.3 ) 232.0 Non-compete agreements 79.0 (49.4 ) 29.6 53.0 (42.1 ) 10.9 Trade names 426.3 (171.4 ) 254.9 406.3 (141.6 ) 264.7 Land use rights 10.9 (2.6 ) 8.3 10.0 (1.4 ) 8.6 Canadian licenses 495.7 — 495.7 464.2 — 464.2 $ 5,767.7 $ (1,426.9 ) $ 4,340.8 $ 4,604.1 $ (1,203.6 ) $ 3,400.5 A summary of amortizable intangible assets acquired during 2017 , and their respective weighted average amortization periods are as follows: Amount Weighted Average Amortization Period Customer relationships $ 955.7 20.7 Patents, licenses and technology 52.9 6.7 Non-compete agreements 27.8 6.6 Trade names 15.7 5.7 Favorable leases 0.9 3.0 $ 1,053.0 19.3 Amortization of intangible assets, including amortization of the Canadian license recorded in other assets, was $216.5 , $179.5 and $164.5 in 2017 , 2016 and 2015 , respectively. The Company recorded earn-out and purchase accounting adjustments through amortization expense of $3.0 , $4.9 , and $1.7 in 2017 , 2016 and 2015 , respectively. Amortization expense of intangible assets is estimated to be $195.0 in fiscal 2018 , $187.2 in fiscal 2019 , $179.8 in fiscal 2020 , $176.8 in fiscal 2021 , $175.0 in fiscal 2022 , and $2,899.7 thereafter.

ACCRUED EXPENSES AND OTHER

ACCRUED EXPENSES AND OTHER	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND OTHER	ACCRUED EXPENSES AND OTHER December 31, 2017 December 31, 2016 Employee compensation and benefits $ 324.6 $ 288.2 Self-insurance reserves 45.7 48.2 Accrued taxes payable 64.5 61.2 Royalty and license fees payable 6.2 9.5 Restructuring reserves 22.2 47.7 Acquisition related reserves 21.3 10.3 Interest payable 71.7 58.6 Rebates 24.6 19.5 Other 52.1 50.5 $ 632.9 $ 593.7

OTHER LIABILITIES

OTHER LIABILITIES	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
OTHER LIABILITIES	OTHER LIABILITIES December 31, 2017 December 31, 2016 Post-retirement benefit obligation $ 7.4 $ 5.8 Defined-benefit plan obligation 163.4 195.4 Restructuring reserves 32.5 34.6 Self-insurance reserves 28.9 17.1 Acquisition related reserves 3.1 15.7 Deferred compensation plan obligation 64.5 54.2 Worker's compensation and auto 39.0 33.1 Straight-line rent 12.7 13.3 Escheat liability 10.9 8.3 Other 15.8 14.5 $ 378.2 $ 392.0

DEBT

DEBT	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
DEBT	DEBT Short-term borrowings and current portion of long-term debt at December 31, 2017 , and 2016 consisted of the following: December 31, 2017 December 31, 2016 Zero-coupon convertible subordinated notes $ 8.8 $ 42.4 2.20% Senior Notes due 2017 — 500.0 2.50% Senior Notes due 2018 400.0 — Debt issuance costs (1.4 ) (1.3 ) Capital lease obligation 8.3 8.4 Current portion of note payable 1.8 — Total short-term borrowings and current portion of long-term debt $ 417.5 $ 549.5 Long-term debt at December 31, 2017 , and 2016 consisted of the following: December 31, 2017 December 31, 2016 2.50% Senior Notes due 2018 — 400.0 4.625% Senior Notes due 2020 604.1 614.6 2.625% Senior Notes due 2020 500.0 500.0 3.75% Senior Notes due 2022 500.0 500.0 3.20% 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 — 3.60% Senior Notes due 2025 1,000.0 1,000.0 3.60% Senior Notes due 2027 600.0 — 4.70% Senior Notes due 2045 900.0 900.0 2014 Term loan 72.0 565.0 2017 Term loan 750.0 — Debt issuance costs (48.2 ) (43.0 ) Capital leases 57.8 56.2 Note payable 8.9 7.2 Total long-term debt $ 6,344.6 $ 5,300.0 Credit Facilities On September 15, 2017, the Company entered into a new $750.0 term loan. The 2017 term loan facility will mature on September 15, 2022. The 2014 term loan balance was $72.0 and $565.0 at December 31, 2017 , and 2016, respectively. The 2017 term loan balance at December 31, 2017 , was $750.0 . On December 19, 2014, the Company entered into a five-year term loan credit facility in the principal amount of $1,000.0 for the purpose of financing a portion of the cash consideration and the fees and expenses in connection with the transactions contemplated by the November 2, 2014 Merger Agreement to acquire Covance. The term loan credit facility was advanced in full on the Covance acquisition date and was amended on July 13, 2016 and further amended on September 15, 2017. The term loan credit facility will mature five years after the Covance acquisition date and may be prepaid without penalty. The term loan balance at December 31, 2017 , was $72.0 . On September 15, 2017, the Company also entered into an amendment and restatement of its existing senior revolving credit facility, which was originally entered into on December 21, 2011, was amended and restated on December 15, 2015 and was further amended on July 13, 2016. The senior 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. There were no balances outstanding on the Company's current revolving credit facility at December 31, 2017 , or December 31, 2016 . On January 30, 2015, the Company issued the Covance acquisition notes, which represent $ 2,900.0 in debt securities consisting of $500.0 aggregate principal amount of 2.625% Senior Notes due 2020, $500.0 aggregate principal amount of 3.20% Senior Notes due 2022, $1,000.0 aggregate principal amount of 3.60% Senior Notes due 2025 and $900.0 aggregate principal amount of 4.70% Senior Notes due 2045. Net proceeds from the offering of the Covance acquisition notes were $ 2,870.2 after deducting underwriting discounts and other estimated expenses of the offering. Net proceeds were used to pay a portion of the cash consideration and the fees and expenses in connection with the Covance acquisition. On February 13, 2015, the Company entered into a 60 -day cash bridge term loan credit facility in the principal amount of $400.0 for the purpose of financing a portion of the cash consideration and the fees and expenses in connection with the transactions contemplated by the Merger Agreement. The 60 -day cash bridge term loan credit facility was entered into on the terms set forth in the bridge facility commitment letter for the $400.0 60 -day cash bridge tranche. The 60 -day cash bridge term loan credit facility was advanced in full on the Covance acquisition date. On March 16, 2015, the Company elected to prepay the bridge facility without penalty. Under the Company's 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 facility and the revolving credit facility at December 31, 2017 , and 2016. As of December 31, 2017 , the ratio of total debt to consolidated EBITDA was 3.2 to 1.0. The 2014 term loan credit facility accrues interest at a per annum rate equal to, at the Company’s election, either an Intercontinental Exchange London Inter-bank Offered Rate (LIBOR) rate plus a margin ranging from 1.125% to 2.00% , or a base rate determined according to a prime rate or federal funds rate plus a margin ranging from 0.125% to 1.00% . The 2017 term loan credit 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% . Advances under the revolving credit facility 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 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 S&P and Moody’s. As of December 31, 2017 , the effective interest rate on the revolving credit facility was 2.7% , and the effective interest rate on the 2014 term loan was 2.8% and on the 2017 term loan was 2.6% . Zero-Coupon Convertible Subordinated Notes The Company had $9.0 and $46.0 aggregate principal amount at maturity of zero-coupon convertible subordinated notes (the Notes) due 2021 outstanding at December 31, 2017 , and 2016 , respectively. The Notes, which are subordinate to the Company’s bank debt, were sold at an issue price of $671.65 per $1,000.0 principal amount at maturity (representing a yield to maturity of 2.0% per year). Each one thousand dollar principal amount at maturity of the Notes is convertible into 13.4108 shares of the Company’s common stock, subject to adjustment in certain circumstances, if one of the following conditions occurs: 1) The sales price of the Company’s common stock for at least 20 trading days in a period of 30 consecutive trading days ending on the last trading day of the preceding quarter reaches specified thresholds (beginning at 120% and declining 0.1282% per quarter until it reaches approximately 110% for the quarter beginning July 1, 2021 of the accreted conversion price per share of common stock on the last day of the preceding quarter). The accreted conversion price per share will equal the issue price of a note plus the accrued original issue discount and any accrued contingent additional principal, divided by the number of shares of common stock issuable upon conversion of a note on that day. The conversion trigger price for the fourth quarter of 2017 was $77.45 . 2) The credit rating assigned to the notes by S&P Ratings Services is at or below BB-. 3) The Notes are called for redemption. 4) Specified corporate transactions have occurred (such as if the Company is party to a consolidation, merger or binding share exchange or a transfer of all or substantially all of its assets). The Company may redeem for cash all or a portion of the Notes at any time at specified redemption prices per one thousand dollar principal amount at maturity of the Notes. The Company has registered the notes and the shares of common stock issuable upon conversion of the Notes with the Securities and Exchange Commission. During 2017 and 2016 , the Company settled notices to convert $ 37.1 and $ 59.4 aggregate principal amount at maturity of its zero-coupon subordinated notes with a conversion value of $ 33.9 and $ 53.7 , respectively. The total cash used for these settlements was $ 33.9 and $ 53.7 and the Company also issued 0.3 and 0.4 additional shares of common stock, respectively. As a result of these conversions, in 2017 and 2016 the Company also reversed approximately $ 0.0 and $ 4.9 , respectively, of deferred tax liability to reflect the tax benefit realized upon issuance of the shares. On September 12, 2017 , the Company announced that for the period of September 12, 2017, to March 10, 2018, 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 September 8, 2017, in addition to the continued accrual of the original issue discount . On January 3, 2018 , 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 January 1, 2018 , 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 Friday, March 31, 2018 . 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. Senior Notes On August 22, 2017, the Company issued new Senior Notes representing $1,200.0 in debt securities and consisting of a $ 600.0 aggregate principal amount of 3.25% Senior Notes due 2024 and a $ 600.0 aggregate principal amount of 3.60% Senior Notes due 2027. Interest on these notes is payable semi-annually on March 1 and September 1 of each year, commencing on March 1, 2018. Net proceeds from the offering of these notes were $ 1,190.1 after deducting underwriting discounts and other expenses of the offering. Net proceeds were used to pay off the 2.20% Senior Notes due August 23, 2017, as well as a portion of the cash consideration and the fees and expenses in connection with the Chiltern acquisition. On September 30, 2016, the Company announced the successful completion of consent solicitations for the 5.00% convertible Senior Notes due 2017 and 2018, totaling $130.0 , assumed as part of the acquisition of Sequenom. On October 20, 2016, the Company retired $129.9 of these outstanding notes, and paid an additional $5.6 relating to the early retirement of the subsidiary indebtedness (recorded as interest expense in the Consolidated Statement of Operations). On January 30, 2015, the Company issued the Covance acquisition notes, which represent $2,900.0 in debt securities consisting of $500.0 aggregate principal amount of 2.625% Senior Notes due 2020, $500.0 aggregate principal amount of 3.20% Senior Notes due 2022, $1,000.0 aggregate principal amount of 3.60% Senior Notes due 2025 and $900.0 aggregate principal amount of 4.70% Senior Notes due 2045. Interest on these notes is payable semi-annually on February 1 and August 1 of each year, commencing on August 1, 2015 . Net proceeds from the offering of the Covance acquisition notes were $2,870.2 after deducting underwriting discounts and other estimated expenses of the offering. Net proceeds were used to pay a portion of the cash consideration and the fees and expenses in connection with the Covance acquisition. On November 1, 2013 , the Company issued $700.0 in new Senior Notes pursuant to the Company’s effective shelf registration on Form S-3. The Senior Notes consisted of $400.0 aggregate principal amount of 2.50% Senior Notes due 2018 and $300.0 aggregate principal amount of 4.00% Senior Notes due 2023. Interest on these notes is payable semi-annually on November 1 and May 1 of each year, commencing on May 1, 2014 . The net proceeds were used to repay all of the outstanding borrowings under the Company’s former revolving credit facility and for general corporate purposes. During the third quarter of 2013, the Company entered into two fixed-to-variable interest rate swap agreements for the 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 outstanding at that time. These interest rate swaps are included in other long-term assets or liabilities, as applicable, and added to the value of the Senior Notes, with an aggregate fair value of $4.1 at December 31, 2017 . The Senior Notes due 2022 bear interest at the rate of 3.75% per annum, payable semi-annually on February 23 and August 23 of each year, commencing February 23, 2013 . The Senior Notes due 2017 bore interest at the rate 2.20% of per annum from November 19, 2010, which was payable semi-annually on February 23 and August 23 . The scheduled payments of long-term debt and future minimum lease payments for capital leases at the end of 2017 are summarized as follows: Notes and Other Capital Leases Total 2018 $ 409.2 $ 15.6 $ 424.8 2019 35.9 14.4 50.3 2020 1,226.9 13.1 1,240.0 2021 71.0 11.7 82.7 2022 1,601.3 10.6 1,611.9 Thereafter 3,351.7 45.1 3,396.8 6,696.0 110.5 6,806.5 Less amounts representing interest — (44.4 ) (44.4 ) Total long-term debt 6,696.0 66.1 6,762.1 Less current portion (409.2 ) (8.3 ) (417.5 ) Long-term debt, due beyond one year $ 6,286.8 $ 57.8 $ 6,344.6

PREFERRED STOCK AND COMMON SHAR

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
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 are recorded at aggregate cost. Common shares issued and outstanding are summarized in the following table: 2017 2016 Issued 125.1 125.6 In treasury (23.2 ) (22.9 ) Outstanding 101.9 102.7 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 December 31, 2017 and 2016 . The changes in common shares issued and held in treasury are summarized below: Common Shares Issued 2017 2016 2015 Common stock issued at January 1 125.6 123.9 107.1 Common stock issued under employee stock plans 1.7 1.6 1.5 Common stock issued upon conversion of zero-coupon subordinated notes 0.3 0.4 — Common stock issued in conjunction with the Covance acquisition — — 15.3 Retirement of common stock (2.5 ) (0.3 ) — Common stock issued at December 31 125.1 125.6 123.9 Common Shares Held in Treasury 2017 2016 2015 Common shares held in treasury at January 1 22.9 22.6 22.5 Surrender of restricted stock and performance share awards 0.3 0.3 0.1 Common shares held in treasury at December 31 23.2 22.9 22.6 Share Repurchase Program During 2017, the Company purchased 2.5 shares of its common stock at a total cost of $338.1 . At the end of 2017, the Company had outstanding authorization from its board of directors to purchase $401.4 of Company common stock. The repurchase authorization has no expiration date. Accumulated Other Comprehensive Earnings The components of accumulated other comprehensive earnings are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Unrealized Gains and Losses on Available for Sale Securities Accumulated Other Comprehensive Earnings Balance at December 31, 2014 $ 68.0 $ (78.6 ) $ 0.1 $ (10.5 ) Current year adjustments (370.7 ) 19.0 (0.1 ) (351.8 ) Amounts reclassified from accumulated other comprehensive income (a) (b) — (11.3 ) — (11.3 ) Tax effect of adjustments 90.1 (3.5 ) — 86.6 Balance at December 31, 2015 (212.6 ) (74.4 ) — (287.0 ) Current year adjustments (250.0 ) (3.3 ) — (253.3 ) Amounts reclassified from accumulated other comprehensive income (a) — (37.0 ) — (37.0 ) Tax effect of adjustments (8.1 ) 4.3 — (3.8 ) Balance at December 31, 2016 (470.7 ) (110.4 ) — (581.1 ) Current year adjustments 262.3 2.4 — 264.7 Amounts reclassified from accumulated other comprehensive income (a) — 18.5 — 18.5 Tax effect of adjustments (34.3 ) (3.5 ) — (37.8 ) Balance at December 31, 2017 $ (242.7 ) $ (93.0 ) $ — $ (335.7 ) (a) The amortization of prior service cost is included in the computation of net periodic benefit cost. Refer to Note 16 Pension and Postretirement Plans for additional information regarding the Company's net periodic benefit cost. (b) The realized gain from the sale of an available for sale investment and the other-than-temporary impairment on an available for sale investment are included in Other, net on the Consolidated Statement of Operations.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The sources of income before taxes, classified between domestic and foreign entities are as follows: Pre-tax income 2017 2016 2015 Domestic $ 891.8 $ 914.0 $ 593.5 Foreign 243.1 191.5 132.5 Total pre-tax income $ 1,134.9 $ 1,105.5 $ 726.0 The provisions (benefits) for income taxes in the accompanying consolidated statements of operations consist of the following: Years Ended December 31, 2017 2016 2015 Current: Federal $ 300.8 $ 235.1 $ 218.3 State 32.9 38.6 33.7 Foreign 53.0 43.9 69.4 $ 386.7 $ 317.6 $ 321.4 Deferred: Federal $ (534.3 ) $ 64.4 $ (14.1 ) State 12.9 6.0 (4.2 ) Foreign (4.4 ) (15.7 ) (15.8 ) (525.8 ) 54.7 (34.1 ) $ (139.1 ) $ 372.3 $ 287.3 In 2017, a benefit of $18.9 in excess stock-based compensation was recorded directly to income tax expense. In 2016, as a result of the early adoption of the accounting standard associated with simplifying several aspects of share-based compensation, a benefit of $14.0 in excess stock-based compensation was recorded directly to income tax expense. For 2015, a portion of the tax benefit associated with option exercises from stock plans, which reduces taxes payable, was recorded through additional paid-in capital. The 2015 benefits recorded through additional paid-in capital were approximately $13.1 . The effective tax rates on earnings before income taxes are reconciled to statutory U.S. income tax rates as follows: Years Ended December 31, 2017 2016 2015 Statutory U.S. rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of U.S. Federal income tax effect 2.5 2.6 3.2 Foreign earnings taxed at lower rates than the statutory U.S. rate (3.5 ) (3.1 ) (1.8 ) Restructuring and acquisition items 0.6 — 2.7 Share-based compensation (1.7 ) (1.2 ) — Re-measurement of deferred taxes (35.0 ) — — Deferred taxes on unremitted foreign earnings (15.8 ) — — Repatriation tax 5.0 — — Other 0.6 0.4 1.1 Effective rate (12.3 )% 33.7 % 40.2 % In December 2017, the U.S. enacted the Tax Cuts and Jobs Act (TCJA) which makes widespread changes to the Internal Revenue Code. The TCJA, among other things, reduces the U.S. federal corporate tax rate from 35% to 21% beginning January 1, 2018, requires companies to pay a repatriation tax on earnings of certain foreign subsidiaries that were previously not subject to U.S. tax, and creates new income taxes on certain foreign sourced earnings. Also on December 22, 2017, the SEC issued Staff Accounting Bulletin No. 118 (SAB 118), which provides companies with additional guidance on how to account for the TCJA in its financial statements, allowing companies to use a measurement period. At December 31, 2017, the Company had not completed the accounting for the tax effects of enactment of the TCJA; however, as described below, a reasonable estimate on the re-measurement of the Company's existing deferred tax balances, the deferred tax revaluation for unremitted foreign earnings, and the one-time repatriation tax has been made. For these items, in accordance with SAB 118, a provisional net benefit has been recognized, totaling $519.0 , which is included as a component of income tax expense from continuing operations. The Company expects to finalize this provisional estimate before the end of 2018 after completing its reviews and analysis, and after incorporating further anticipated guidance from the U.S. Treasury issued during this measurement period. As a result, the reported net benefit could change during 2018. The effective rate for 2017 was favorably impacted by the re-measurement of the Company's net deferred tax liabilities using the rates enacted in the TCJA and the deferred tax revaluation for unremitted foreign earnings, partially offset by the deemed repatriation tax enacted in this legislation. The 2017 rate was also favorably impacted by foreign earnings taxed at rates lower than the U.S. and by share-based compensation. The effective rate for 2016 was favorably impacted by foreign earnings taxed at rates lower than the U.S. statutory rate and the early adoption of the share-based compensation standard. The effective rate for 2015 was favorably impacted by foreign earnings taxed at rates lower than the U.S. statutory rate and unfavorably impacted by restructuring and acquisition items, the recording of additional uncertain tax reserves, and a decrease in the benefit recorded from releasing uncertain tax reserves. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows: December 31, 2017 December 31, 2016 Deferred tax assets: Accounts receivable $ 14.7 $ 13.5 Employee compensation and benefits 113.6 160.8 Acquisition and restructuring reserves 16.8 38.5 Tax loss carryforwards 107.0 167.7 Other 26.0 44.8 278.1 425.3 Less: valuation allowance (42.8 ) (31.3 ) Deferred tax assets, net of valuation allowance $ 235.3 $ 394.0 Deferred tax liabilities: Deferred earnings $ (5.1 ) $ (193.2 ) Intangible assets (913.2 ) (1,047.4 ) Property, plant and equipment (156.9 ) (208.8 ) Zero-coupon subordinated notes (10.1 ) (48.5 ) Currency translation adjustment (0.1 ) (47.0 ) Other (27.2 ) (27.9 ) Total gross deferred tax liabilities (1,112.6 ) (1,572.8 ) Net deferred tax liabilities $ (877.3 ) $ (1,178.8 ) The TCJA includes provisions relating to global low-taxed intangible income (GILTI). Relevant to the current consolidated financial statements is the Company's selection of an accounting policy with respect to the new GILTI tax rules, and whether to account for GILTI as a periodic charge in the period it arises, or to record deferred taxes associated with the basis in the Company’s foreign subsidiaries. Due to the intricacy of this topic, the Company is still in the process of investigating the implications of accounting for the GILTI tax and intends to make an accounting policy decision once additional guidance is available for assessment. The Company has U.S. federal tax loss carryforwards of approximately $294.3 , which expire periodically through 2035 . The utilization of tax loss carryforwards is limited due to change of ownership rules; however, at this time, the Company expects to fully utilize substantially all U.S. federal tax loss carryforwards with the exception of approximately $ 3.9 for which a full valuation allowance has been provided. The Company has U.S. state tax loss carryforwards of $602.2 , which also expire periodically through 2036, and on which a valuation allowance of $485.5 has been provided. The Company has foreign tax loss carryforwards of $ 37.4 of which $27.1 has a full valuation allowance. Most of the foreign losses have an indefinite carryover. In addition to the foreign net operating losses, the Company has a foreign capital loss carryforward of $6.9 . The capital loss has an indefinite life and has a full valuation allowance. The valuation allowance increased from $31.3 in 2016 to $42.8 in 2017 primarily due to additional state losses for which no benefit is anticipated. Unrecognized income tax benefits were $19.5 and $18.4 at December 31, 2017 , and 2016 , 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. 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 $7.9 and $9.9 as of December 31, 2017 , and 2016 , respectively. During the years ended December 31, 2017 , 2016 and 2015 , the Company recognized $2.3 , $1.2 and $1.8 , respectively, in interest and penalties expense, which was offset by a benefit from reversing previous accruals for interest and penalties of $4.3 , $4.0 and $2.2 , respectively. The following table shows a reconciliation of the unrecognized income tax benefits, excluding interest and penalties, from uncertain tax positions for the years ended December 31, 2017 , 2016 and 2015 : 2017 2016 2015 Balance as of January 1 $ 18.4 $ 24.2 $ 16.7 Increase in reserve for tax positions taken in the current year 7.3 2.3 4.1 Increase in reserve as a result of acquisition — — 8.5 Decrease in reserve as a result of lapses in the statute of limitations (6.2 ) (8.1 ) (5.1 ) Balance as of December 31 $ 19.5 $ 18.4 $ 24.2 As of December 31, 2017 , and 2016 , $19.5 and $18.4 , respectively, are the approximate amounts of unrecognized income tax benefits that, if recognized, would favorably affect the effective income tax rate in any future periods. The Company has substantially concluded all U.S. federal income tax matters for years through 2012. Substantially all material state and local and foreign income tax matters have been concluded through 2012 and 2008, respectively. The Internal Revenue Service concluded the examination of the Company's 2014 federal consolidated income tax return, which did not include Covance Inc., in the third quarter of 2016. Covance Inc.'s 2013 federal consolidated income tax return is under examination. The Canada Revenue Agency is currently examining the Company's 2013 and 2014 Canadian subsidiaries' 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. As a result of the TCJA, the Company was effectively taxed on all of its previously unremitted foreign earnings. The TCJA also enacts a territorial tax system that allows, for the most part, tax-free repatriation of foreign earnings. The Company still considers the earnings of its foreign subsidiaries to be permanently reinvested, but if repatriation were to occur we would be required to accrue U.S. taxes, if any, and applicable withholding taxes as appropriate. Along with the provisions of the TCJA, the Company will continue to review its repatriation policy.

STOCK COMPENSATION PLANS

STOCK COMPENSATION PLANS	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The Company uses the Black-Scholes model to calculate the fair value of the employee’s purchase right. The fair value of the employee’s purchase right and the assumptions used in its calculation are as follows: 2017 2016 2015 Fair value of the employee’s purchase right $ 31.54 $ 23.32 $ 21.95 Valuation assumptions Risk free interest rate 1.3 % 0.5 % 0.3 % Expected volatility 0.2 0.2 0.2 Expected dividend yield — — —
STOCK COMPENSATION PLANS	STOCK COMPENSATION PLANS Stock Incentive Plans There are currently 10.7 shares authorized for issuance under the Laboratory Corporation of America Holdings 2016 Omnibus Incentive Plan (the Plan) and at December 31, 2017 there were 8.3 additional shares available for grant under the Plan. The Plan was approved by shareholders at the 2016 annual meeting. Stock Options The following table summarizes grants of non-qualified options made by the Company to officers, key employees, and non-employee directors under all plans. Stock options are generally granted at an exercise price equal to or greater than the fair market price per share on the date of grant. Also, for each grant, options vest ratably over a period of three years on the anniversaries of the grant date, subject to their earlier expiration or termination. Changes in options outstanding under the plans for the period indicated were as follows: Number of Options Weighted-Average Exercise Price per Option Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at December 31, 2016 1.6 $ 82.43 Granted 0.1 130.60 Exercised (0.5 ) 83.85 Cancelled — 80.37 Outstanding at December 31, 2017 1.2 $ 86.55 3.9 $ 85.4 Vested and expected to vest at December 31, 2017 1.1 $ 81.73 3.3 $ 82.1 Exercisable at December 31, 2017 1.1 $ 81.73 3.3 $ 82.1 The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the Company’s closing stock price on the last trading day of 2017 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2017 . The amount of intrinsic value will change based on the fair market value of the Company’s stock. Cash received by the Company from option exercises, the actual tax benefit realized for the tax deductions and the aggregate intrinsic value of options exercised from option exercises under all share-based payment arrangements during the years ended December 31, 2017 , 2016 , and 2015 were as follows: 2017 2016 2015 Cash received by the Company $ 43.9 $ 52.6 $ 82.6 Tax benefits realized $ 13.4 $ 13.6 $ 16.2 Aggregate intrinsic value $ 34.8 $ 35.5 $ 42.2 The following table summarizes information concerning currently outstanding and exercisable options. Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Number Exercisable Weighted Average Exercise Price Remaining Contractual Life Average Exercise Price $59.38 - 67.60 0.1 1.1 $60.64 0.1 $60.64 $67.61 - 75.63 0.2 1.8 $72.06 0.2 $72.06 $75.64 - 84.86 0.6 4.2 $84.73 0.6 $84.73 $84.87 - 130.60 0.3 5.2 $105.29 0.3 $91.13 1.2 3.9 $86.55 1.2 $81.73 The following table shows the weighted average grant-date fair values of options issued during the respective year and the weighted average assumptions that the Company used to develop the fair value estimates: 2017 2016 2015 Fair value per option $ 32.75 N/A N/A Valuation assumptions Weighted average expected life (in years) 6.0 N/A N/A Risk free interest rate 2.1 % N/A N/A Expected volatility 0.2 N/A N/A Expected dividend yield N/A N/A N/A The Black Scholes model incorporates assumptions to value stock-based awards. The risk-free interest rate for periods within the contractual life of the option is based on a zero-coupon U.S. government instrument over the contractual term of the equity instrument. Expected volatility of the Company’s stock is based on historical volatility of the Company’s stock. The Company uses historical data to calculate the expected life of the option. Groups of employees and non-employee directors that have similar exercise behavior with regard to option exercise timing and forfeiture rates are considered separately for valuation purposes. For 2017 , 2016 and 2015 , expense related to the Company’s stock option plan totaled $0.9 , $0.0 and $2.2 , respectively. The Company did not grant any options to employees during 2016 or 2015 . Restricted Stock, Restricted Stock Units and Performance Shares The Company grants restricted stock, restricted stock units and performance shares (non-vested shares) to officers and key employees and grants restricted stock and restricted stock units to non-employee directors. Restricted stock and units typically vest annually in equal one third increments beginning on the first anniversary of the grant . A performance share grant in 2015 represents a three-year award opportunity for the period 2015-2017, and if earned, vests fully (to the extent earned) in the first quarter of 2018. A performance share grant in 2016 represents a three-year award opportunity for the period of 2016-2018 and, if earned, vests fully (to the extent earned) in the first quarter of 2019. A performance share grant in 2017 represents a three-year award opportunity for the period of 2017-2019 and, if earned, vests fully (to the extent earned) in the first quarter of 2020. Performance share awards are subject to certain earnings per share, revenue, operating income, earnings before income taxes and total shareholder return targets , the achievement of which may increase or decrease the number of shares which the grantee earns and therefore receives upon vesting. Unearned restricted stock and performance share compensation is amortized to expense over the applicable vesting periods. For 2017 , 2016 and 2015 , total restricted stock, restricted stock unit and performance share compensation expense was $100.8 , $104.1 and $83.8 , respectively. The following table shows a summary of non-vested shares for the year ended December 31, 2017 : Number of Shares Weighted-Average Grant Date Fair Value Non-vested at January 1, 2017 1.6 $ 108.23 Granted 0.9 132.48 Vested (0.9 ) 100.86 Canceled (0.1 ) 118.74 Non-vested at December 31, 2017 1.5 $ 121.36 As of December 31, 2017 , there was $104.0 of total unrecognized compensation cost related to non-vested restricted stock, restricted stock unit and performance share-based compensation arrangements granted under the Company's stock incentive plans. That cost is expected to be recognized over a weighted average period of 1.8 years. Employee Stock Purchase Plan Under the 2016 Employee Stock Purchase Plan, the Company is authorized to issue 2.4 shares of common stock. The plan permits substantially all employees to purchase a limited number of shares of Company stock at 85% of market value. The Company issues shares to participating employees semi-annually in January and July of each year. Approximately 0.3 shares were purchased by eligible employees in each of 2017 , 2016 and 2015 , respectively, under either the 2016 Employee Stock Purchase Plan or the prior plan, which began in 1997 and was amended in 1999, 2004, 2008 and 2012. For 2017 , 2016 and 2015 , expense related to the Company’s employee stock purchase plan was $8.0 , $5.5 and $4.1 , respectively. The Company uses the Black-Scholes model to calculate the fair value of the employee’s purchase right. The fair value of the employee’s purchase right and the assumptions used in its calculation are as follows: 2017 2016 2015 Fair value of the employee’s purchase right $ 31.54 $ 23.32 $ 21.95 Valuation assumptions Risk free interest rate 1.3 % 0.5 % 0.3 % Expected volatility 0.2 0.2 0.2 Expected dividend yield — — —

COMMITMENTS AND CONTINGENT LIAB

COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENT LIABILITIES	COMMITMENTS AND CONTINGENT LIABILITIES 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; 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 healthcare providers (e.g., physician assistants and nurse practitioners, generally referred to herein as physicians). 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. The amount of ultimate loss may also differ from the Company’s estimates. It is possible that an unfavorable outcome that exceeds the Company’s current accrued estimate, if any, for one or more of the matters below could have a material adverse effect on the Company’s financial condition. As previously reported, the Company reached a settlement in the previously disclosed lawsuit, California ex rel. Hunter Laboratories, LLC et al. v. Quest Diagnostics Incorporated, et al. (Hunter Labs Settlement Agreement), to avoid the uncertainty and costs associated with prolonged litigation. Pursuant to the executed Hunter Labs Settlement Agreement, the Company recorded a litigation settlement expense of $34.5 in the second quarter of 2011 (net of a previously recorded reserve of $15.0 ) and paid the settlement amount of $49.5 in the third quarter of 2011. The Company also agreed to certain reporting obligations regarding its pricing for a limited time period and, at the option of the Company in lieu of such reporting obligations, to provide Medi-Cal with a discount from Medi-Cal's otherwise applicable maximum reimbursement rate from November 1, 2011, through October 31, 2012. In 2011, the California legislature enacted Assembly Bill No. 97, which imposed a 10.0% Medi-Cal payment cut on most providers of healthcare services, including clinical laboratories. In 2012, the California legislature enacted Assembly Bill No. 1494, which directed the Department of Healthcare Services (DHCS) to establish new reimbursement rates for Medi-Cal commercial laboratory services based on payments made to California clinical laboratories for similar services by other third-party payers, and provided that until the new rates are set through this process, Medi-Cal payments for commercial laboratory services will be reduced (in addition to a 10.0% payment reduction imposed by Assembly Bill No. 97 in 2011) by “up to 10 percent” for tests with dates of service on or after July 1, 2012, with a cap on payments set at 80.0% of the lowest maximum allowance established under the Medicare program. Under the terms of the Hunter Labs Settlement Agreement, the enactment of this California legislation terminated the Company's reporting obligations (or obligation to provide a discount in lieu of reporting) under that agreement. In April 2015, CMS approved a 10.0% payment reduction under Assembly Bill No. 1494. The new rate methodology established new rates that were effective July 1, 2015, but these new rates were not entered into the state computer system until February 2016. The 2016 rates have been implemented and recoupments began in 2017. Taken together, these changes are not expected to have a material impact on the Company's consolidated revenues or results of operations. 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 United States 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 an 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 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 United States District Court for the Northern District of Georgia. 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. 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. The Company will vigorously defend the lawsuit. On August 24, 2012, the Company was served with a putative class action lawsuit, Sandusky Wellness Center, LLC, et al. v. MEDTOX Scientific, Inc., et al. , filed in the United States District Court for the District of Minnesota. The lawsuit alleges that on or about February 21, 2012, the defendants violated the U.S. Telephone Consumer Protection Act (TCPA) by sending unsolicited facsimiles to Plaintiff and more than 39 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. In September of 2014, Plaintiff’s Motion for Class Certification was denied. In January of 2015, the Company’s Motion for Summary Judgment on the remaining individual claim was granted. Plaintiff filed a notice of appeal. On May 3, 2016, the United States Court of Appeals for the Eighth Circuit issued its decision and order reversing the District Court’s denial of class certification. The Eighth Circuit remanded the matter for further proceedings. On December 7, 2016, the District Court granted the Plaintiff’s renewed Motion for Class Certification. The Company will vigorously defend 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 requests information regarding remuneration and services provided by the Company to physicians who also received draw and processing/handling fees from competitor laboratories Health Diagnostic Laboratory, Inc. and Singulex, Inc. The Company is cooperating with the request. On August 3, 2016, Covance Inc. 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 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, Inc. 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 United States District Court for the Southern District of California. The Company will vigorously defend the lawsuit. Prior to the Company’s acquisition of 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 United States 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. In connection with the settlement, Sequenom agreed to make certain additional disclosures to its stockholders. 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 Company is awaiting the Court’s appointment of a permanent lead plaintiff. The Company is awaiting the Court's appointment of a permanent lead plaintiff. 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. The Company will vigorously defend the lawsuit. On February 7, 2017, Sequenom received a subpoena from the U.S. Securities and Exchange Commission (SEC) relating to an SEC investigation into the trading activity of Sequenom shares in connection with the Company’s July 2016 announcement regarding the Sequenom merger. On March 7, 2017, the Company received a similar subpoena. The Company is cooperating with these requests. 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 United States 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; this motion is currently pending. On October 10, 2017, a second putative class action lawsuit, Sheryl Anderson, et al. v. Laboratory Corporation of America Holdings , was filed in the United States District Court for the Middle District of North Carolina. The complaint contains similar allegations and seeks similar relief to the Bouffard complaint, and adds additional counts regarding state consumer protection laws. The Company will vigorously defend the lawsuits. On May 24, 2017, a putative class action lawsuit, Maria T. Gonzalez, et al. v. Examination Management Services, Inc. and Laboratory Corporation of America Holdings , was filed against the Company in the United States District Court for the Southern District of California. The complaint alleges that the Company misclassified phlebotomists as independent contractors through an arrangement with the co-Defendant temporary staffing agency. The complaint further alleges that the Company violated the California Labor Code and California Business and Professions Code by failing to pay minimum wage, failing to pay for all hours worked, failing to pay for all wages owed upon termination, and failing to provide accurate itemized wage statements. The lawsuit seeks monetary damages, civil penalties, injunctive relief, and recovery of attorney's fees and costs. The Company will vigorously defend the lawsuit. On August 3, 2017, a putative class action lawsuit, John Sealock, et al. v. Covance Market Access Services, Inc. , was filed in the United States District Court for the Southern District of New York. The complaint alleges 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 seeks 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. In December 2017, the Plaintiff filed a Motion for Conditional Certification of a Collective Action. The parties’ motions remain pending. The Company will vigorously defend the lawsuit. On November 6, 2017, Covance was served with two False Claims Act lawsuits, Health Choice Alliance, LLC on behalf of the United States of America, et al. v. Eli Lilly and Company, Inc. et al. , and Health Choice Advocates, LLC, on behalf of the United States of America v. Gilead Sciences, Inc., et al. , both filed in the United States District Court for the Eastern District of Texas. The complaints allege under the Federal False Claims Act and various state analogues that Covance and the co-defendants unlawfully provided in-kind remuneration to medical providers in the form of reimbursement support services in order to induce providers to prescribe certain drugs. Neither the U.S. government nor any state government intervened in the lawsuits. The lawsuit seeks actual and treble damages and civil penalties for each alleged false claim, as well as recovery of costs. The Company will vigorously defend the lawsuits. 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. At December 31, 2017 , the Company had provided letters of credit aggregating approximately $72.2 , primarily in connection with certain insurance programs. The Company’s availability under its Revolving Credit Facility is reduced by the amount of these letters of credit. 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, 2017 are as follows: Operating 2018 $ 196.1 2019 149.0 2020 109.7 2021 83.5 2022 64.2 Thereafter 160.9 Total minimum lease payments 763.4 Less: Amounts included in restructuring and acquisition related accruals (17.6 ) Non-cancelable sub-lease income — Total minimum operating lease payments $ 745.8 Rental expense, which includes rent for real estate, equipment and automobiles under operating leases, amounted to $313.8 , $291.2 and $287.1 for the years ended December 31, 2017 , 2016 and 2015 , respectively.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2017
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 December 31, 2017 , and 2016 were as follows: Fair Value Measurements as of December 31, 2017 Fair Value as of December 31, 2017 Using Fair Value Hierarchy Level 1 Level 2 Level 3 Noncontrolling interest put $ 16.7 $ — $ 16.7 $ — Interest rate swap 4.1 — 4.1 — Cash surrender value of life insurance policies 64.0 — 64.0 — Deferred compensation liability 64.5 — 64.5 — Contingent consideration 16.5 — — 16.5 Fair Value Measurements as of December 31, 2016 Fair Value as of December 31, 2016 Using Fair Value Hierarchy Level 1 Level 2 Level 3 Noncontrolling interest put $ 15.2 $ — $ 15.2 $ — Interest rate swap 14.6 — 14.6 — Cash surrender value of life insurance policies 53.6 — 53.6 — Deferred compensation liability 54.2 — 54.2 — Contingent consideration 16.8 — — 16.8 The noncontrolling interest put is valued at its contractually determined value, which approximates fair value. During the year ended December 31, 2017 , the carrying value of the noncontrolling interest put increased by $1.0 consisting of a $0.7 increase in the contractually determined value and a $0.3 increase for foreign currency translation. The Company offers certain employees the opportunity to participate in a DCP. A participant's deferrals are allocated by the participant to one or more of 16 measurement funds, which are indexed to externally managed funds. From time to time, to offset the cost of the growth in the participant's investment accounts, the Company purchases life insurance policies, with the Company named as beneficiary of the policies. Changes in the cash surrender value of the life insurance policies are based upon earnings and changes in the value of the underlying investments, which are typically invested in a similar manner to the 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. Contingent accrued earn-out business acquisition consideration liabilities for which fair values are measured as Level 3 instruments. These contingent consideration liabilities were recorded at fair value on the acquisition date and are remeasured quarterly based on the then assessed fair value and adjusted if necessary. The increases or decreases in the fair value of contingent consideration payable can result from changes in anticipated revenue levels and changes in assumed discount periods and rates. As the fair value measure is based on significant inputs that are not observable in the market, they are categorized as Level 3. 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 $18.8 and $79.3 as of December 31, 2017 , and 2016 , respectively. The fair market value of the Senior Notes, based on market pricing, was approximately $6,078.9 and $5,254.5 as of December 31, 2017 , and 2016 , respectively. The Company's note and debt instruments are considered Level 2 instruments, as the fair market values of these instruments are determined using other observable inputs.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
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, through a controlled program of risk management that includes, from time to time, the use of derivative financial instruments such as interest rate swap agreements (see Interest Rate Swap section below). Although the Company’s zero-coupon subordinated notes contain features that are considered to be embedded derivative instruments (see Embedded Derivative section below), the Company does not hold or issue derivative financial instruments for trading purposes. The Company does not believe that its exposure to market risk is material to the Company’s financial position or results of operations. Interest Rate Swap During the third quarter of 2013, the Company entered into two fixed-to-variable interest rate swap agreements for the 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 liabilities, as applicable, and added to the value of the Senior Notes, with an aggregate fair value of $4.1 at December 31, 2017 . 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 consolidated statements of operations. Cash flows from the interest rate swaps are including in operating activities. 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 S&P’s Ratings Services is BB- or lower. The Company believes these embedded derivatives had no fair value at December 31, 2017 , and 2016 . These embedded derivatives also had no impact on the consolidated statements of operations for the years ended December 31, 2017 , 2016 and 2015 . Derivatives 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 December 31, 2017 .

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION Years Ended December 31, 2017 2016 2015 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 239.1 $ 210.7 $ 166.1 Income taxes, net of refunds 348.0 345.7 237.6 Disclosure of non-cash financing and investing activities: Surrender of restricted stock awards and performance shares 47.4 34.6 12.6 Conversion of zero-coupon convertible debt 35.0 39.1 1.1 Assets acquired under capital leases 7.3 16.0 22.6 Accrued property, plant and equipment 1.6 4.4 4.3

QUARTERLY DATA (UNAUDITED)

QUARTERLY DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY DATA (UNAUDITED)	QUARTERLY DATA (UNAUDITED) The following is a summary of unaudited quarterly data: Year Ended December 31, 2017 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (a) Full Year Net revenues $ 2,408.1 $ 2,498.4 $ 2,597.9 $ 2,701.5 $ 10,205.9 Gross profit 803.6 861.8 882.8 915.8 3,464.0 Net earnings attributable to Laboratory Corporation of America Holdings 192.2 188.6 180.6 706.8 1,268.2 Basic earnings per common share 1.87 1.84 1.77 6.91 12.39 Diluted earnings per common share 1.84 1.82 1.74 6.81 12.21 (a) Net earnings attributable to Laboratory Corporation of America Holdings in the fourth quarter of 2017 includes amounts recorded due to TCJA. Year Ended December 31, 2016 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Full Year Net revenues $ 2,295.2 $ 2,382.0 $ 2,372.7 $ 2,387.3 $ 9,437.2 Gross profit 777.3 826.8 788.4 788.0 3,180.5 Net earnings attributable to Laboratory Corporation of America Holdings 164.1 204.1 179.5 184.4 732.1 Basic earnings per common share 1.61 2.00 1.74 1.79 7.14 Diluted earnings per common share 1.58 1.96 1.71 1.75 7.02

Schedule II - Valuation And Qua

Schedule II - Valuation And Qualifying Accounts And Reserves	12 Months Ended
	Dec. 31, 2017
Schedule to Financial Statments [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II LABORATORY CORPORATION OF AMERICA HOLDINGS AND SUBSIDIARIES VALUATION AND QUALIFYING ACCOUNTS AND RESERVES Years Ended December 31, 2017 , 2016 and 2015 (Dollars in millions) Balance at beginning of year Additions Charged to Costs and Expense (1) Balance at end of year Year ended December 31, 2017: Applied against asset accounts: Allowance for doubtful accounts $ 235.6 $ 314.7 $ (289.4 ) $ 260.9 Valuation allowance-deferred tax assets $ 31.3 $ 11.5 $ — $ 42.8 Year ended December 31, 2016: Applied against asset accounts: Allowance for doubtful accounts $ 217.0 $ 287.3 $ (268.7 ) $ 235.6 Valuation allowance-deferred tax assets $ 15.1 $ 16.2 $ — $ 31.3 Year ended December 31, 2015: Applied against asset accounts: Allowance for doubtful accounts $ 211.6 $ 265.4 $ (260.0 ) $ 217.0 Valuation allowance-deferred tax assets $ 17.1 $ — $ (2.0 ) $ 15.1 (1) Other (Deductions) Additions consists primarily of write-offs of accounts receivable amounts.

Business Segments _Disclosure_

Business Segments [Disclosure] Business Segment (Notes)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	20. BUSINESS SEGMENT INFORMATION The following table is a summary of segment information for the years ended December 31, 2017 , 2016 , and 2015 . The “management approach” has been used to present the following segment information. This approach is based upon the way the management of the Company organizes segments within an enterprise for making operating decisions and assessing performance. Financial information is reported on the basis that it is used internally by the chief operating decision maker (CODM) for evaluating segment performance and deciding how to allocate resources to segments. The Company’s chief executive officer has been identified as the CODM. Segment asset information is not presented because it is not used by the CODM at the segment level. Operating earnings (loss) 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. 2017 2016 2015 Net Revenues: LCD $ 7,170.5 $ 6,593.9 $ 6,199.3 CDD 3,037.2 2,844.1 2,306.4 Intercompany eliminations (1.8 ) (0.8 ) — Total net revenues $ 10,205.9 $ 9,437.2 $ 8,505.7 Operating Earnings (Loss): LCD $ 1,298.6 $ 1,187.6 $ 1,053.7 CDD 206.2 272.7 73.5 General corporate expenses (140.6 ) (147.9 ) (130.4 ) Total operating income 1,364.2 1,312.4 996.8 Non-operating expenses, net (229.3 ) (206.9 ) (270.8 ) Earnings before income taxes 1,134.9 1,105.5 726.0 Provision for income taxes (139.1 ) 372.3 287.3 Net earnings 1,274.0 733.2 438.7 Less: Net income attributable to noncontrolling interests (5.8 ) (1.1 ) (1.1 ) Net income attributable to Laboratory Corporation of America Holdings $ 1,268.2 $ 732.1 $ 437.6 2017 2016 2015 Depreciation and Amortization LCD $ 304.7 $ 270.9 $ 245.8 CDD 217.4 219.5 184.4 General corporate 1.2 0.1 4.1 Total depreciation and amortization $ 523.3 $ 490.5 $ 434.3 LCD CDD Intercompany Eliminations Total Geographic distribution of net revenues US $ 6,808.6 $ 1,427.2 $ (1.8 ) $ 8,234.0 Canada 327.8 — — 327.8 United Kingdom 29.6 272.4 — 302.0 Switzerland — 484.4 — 484.4 Other 4.5 853.2 — 857.7 Total net revenues $ 7,170.5 $ 3,037.2 $ (1.8 ) $ 10,205.9 LCD CDD Total Geographic distribution of property, plant and equipment, net U.S. $ 826.2 $ 590.6 $ 1,416.8 Canada 54.6 — 54.6 U.K. 2.1 120.7 122.8 Switzerland — 81.4 81.4 Other 3.0 70.3 73.3 Total property, plant and equipment, net $ 885.9 $ 863.0 $ 1,748.9

SUMMARY OF SIGNIFICANT ACCOUN29

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Reimbursable Out of Pocket Expenses Policy [Policy Text Block]	Reimbursable Out-of-Pocket Expenses CDD pays on behalf of its customers certain out-of-pocket costs for which the Company is reimbursed at cost, without mark-up or profit. Out-of-pocket costs paid by CDD are reflected in operating expenses, while the reimbursements received are reflected in revenues in the consolidated statements of operations. CDD excludes from revenue and expense in the consolidated statements of operations fees paid to investigators and the associated reimbursement because CDD acts as an agent on behalf of the biopharmaceutical company sponsors with regard to investigator payments.
Cost of Sales, Policy [Policy Text Block]	Cost of Revenue Cost of revenue includes direct labor and related benefit charges, other direct costs, shipping and handling fees, and an allocation of facility charges and information technology costs. Selling, general and administrative expenses consist primarily of administrative payroll and related benefit charges, advertising and promotional expenses, administrative travel and an allocation of facility charges and information technology costs. Cost of advertising is expensed as incurred.
Basis of Financial Statement Presentation	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, 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, food and nutritional companies and independent clinical laboratories. The Company believes that it generated more revenue from laboratory testing than any other company in the world in 2017. The Company reports its business in two segments, LabCorp Diagnostics (LCD) and Covance Drug Development (CDD). For further financial information about these segments, including information for each of the last three fiscal years regarding revenue, operating income, and other important information, see Note 20 to the Consolidated Financial Statements. In 2017, LCD and CDD contributed 70.3% and 29.7% , respectively, of net revenues to the Company, and in 2016 contributed 69.9% and 30.1% , respectively. The 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% and no representation on the investee's board of directors) are accounted for using the cost method. All significant inter-company transactions and accounts have been eliminated. The Company does not have any variable interest entities or special purpose entities whose financial results are not included in the 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 year. Resulting translation adjustments are included in “Accumulated other comprehensive income.”
Revenue Recognition	Revenue Recognition LCD recognizes revenue on the accrual basis at the time test results are reported, which approximates when services are provided. Services are provided to certain patients covered by various third-party payer programs including various MCOs, as well as the Medicare and Medicaid programs. Billings for services under third-party payer programs are included in sales net of allowances for contractual discounts and allowances for differences between the amounts billed and estimated program payment amounts. Adjustments to the estimated payment amounts based on final settlement with the programs are recorded upon settlement as an adjustment to revenue. In 2017 , 2016 and 2015 , approximately 15.1% , 15.5% and 16.0% , respectively, of LCD's revenues were derived directly from the Medicare and Medicaid programs. LCD has capitated agreements with certain MCO customers and recognizes related revenue based on a predetermined monthly contractual rate for each member of the managed care plan regardless of the number of tests performed. In 2017 , 2016 and 2015 , approximately 3.6% , 3.4% and 3.5% , respectively, of LCD's revenues were derived from such capitated agreements. CDD recognizes revenue either as services are performed or products are delivered, depending on the nature of the work contracted. Historically, a majority of CDD’s net revenues have been earned under contracts that range in duration from a few months to a few years, but can extend in duration up to five years or longer. Occasionally, CDD also has committed minimum volume arrangements with certain customers. Underlying these arrangements are individual project contracts for the specific services to be provided. These arrangements enable CDD's customers to secure its services in exchange for which they commit to purchase an annual minimum dollar value of services. Under these types of arrangements, if the annual minimum dollar value of service commitment is not reached, the customer is required to pay CDD for the shortfall. Progress towards the achievement of annual minimum dollar value of service commitments is monitored throughout the year. Annual minimum commitment shortfalls are not included in net revenues until the amount has been determined and agreed to by the customer. Service contracts generally take the form of fee-for-service or fixed-price arrangements subject to pricing adjustments based on changes in scope. In cases where performance spans multiple accounting periods, revenue is recognized as services are performed, measured on a proportional-performance basis, generally using output measures that are specific to the service provided. Examples of output measures in preclinical services, include among others, the number of slides read, or specimens prepared. Examples of output measures in the clinical trials services, include among others, number of investigators enrolled, number of sites initiated, number of trial subjects enrolled and number of monitoring visits completed, or number of dosings for clinical pharmacology. Revenue is determined by dividing the actual units of work completed by the total units of work required under the contract and multiplying that percentage by the total contract value. The total contract value, or total contractual payments, represents the aggregate contracted price for each of the agreed upon services to be provided. CDD does not have any contractual arrangements spanning multiple accounting periods where revenue is recognized on a proportional-performance basis under which the Company has earned more than an immaterial amount of performance-based revenue (i.e., potential additional revenue tied to specific deliverables or performance). Changes in the scope of work are common, especially under long-term contracts, and generally result in a change in contract value. Once the customer has agreed to the changes in scope and renegotiated pricing terms, the contract value is amended with revenue recognized as described above. Estimates of costs to complete are made to provide, where appropriate, for losses expected on contracts. Costs are not deferred in anticipation of contracts being awarded, but instead are expensed as incurred. Billing schedules and payment terms are generally negotiated on a contract-by-contract basis. In some cases, CDD bills the customer for the total contract value in progress-based installments as certain non-contingent billing milestones are reached over the contract duration, such as, but not limited to, contract signing, initial dosing, investigator site initiation, patient enrollment or database lock. The term “billing milestone” relates only to a billing trigger in a contract whereby amounts become billable and payable in accordance with a negotiated predetermined billing schedule throughout the term of a project. These billing milestones are generally not performance-based (i.e., there is no potential additional consideration tied to specific deliverables or performance). In other cases, billing and payment terms are tied to the passage of time (e.g., monthly billings). In either case, the total contract value and aggregate amounts billed to the customer would be the same at the end of the project. While CDD attempts to negotiate terms that provide for billing and payment of services prior or within close proximity to the provision of services, this is not always possible, and there are fluctuations in the levels of unbilled services and unearned revenue from period to period. While a project is ongoing, cash payments are not necessarily representative of aggregate revenue earned at any particular point in time, as revenues are recognized when services are provided, while amounts billed and paid are in accordance with the negotiated billing and payment terms. In some cases, payments received are in excess of revenue recognized. For example, a contract invoicing schedule may provide for an upfront payment of 10% of the full contract value upon contract signing, but at the time of signing performance of services has not yet begun. Payments received in advance of services being provided are deferred as unearned revenue on the balance sheet. As the contracted services are subsequently performed and the associated revenue is recognized, the unearned revenue balance is reduced by the amount of revenue recognized during the period. In other cases, services may be provided and revenue recognized before the customer is invoiced. In these cases, revenue recognized will exceed amounts billed, and the difference, representing an unbilled receivable, is recorded for the amount that is currently unbillable to the customer pursuant to contractual terms. Once the customer is invoiced, the unbilled services are reduced for the amount billed, and a corresponding account receivable is recorded. All unbilled services are billable to customers within one year from the respective balance sheet date. Most contracts are terminable with or without cause by the customer, either immediately or upon notice. These contracts often require payment to CDD of expenses to wind down the study or project, fees earned to date and, in some cases, a termination fee or a payment to CDD of some portion of the fees or profits that could have been earned by CDD under the contract if it had not been terminated early. Termination fees are included in net revenues when services are performed and realization is assured. In connection with the management of multi-site clinical trials, CDD pays on behalf of its customers fees to investigators, clinical trial subjects and certain out-of-pocket costs, for which it is reimbursed at cost, without markup or profit. Investigator fees are not reflected in net revenues or expenses where CDD acts in the capacity of an agent on behalf of the biopharmaceutical company sponsor, passing through these costs without markup or profit. All other out-of-pocket costs are included in total revenues and expenses. The Company's total revenues are comprised of the following: Years Ended December 31, Total revenues 2017 2016 2015 LCD - net revenue $ 7,170.5 $ 6,593.9 $ 6,199.3 CDD - net revenue 3,037.2 2,844.1 2,306.4 CDD - reimbursable out-of-pocket expenses 235.5 204.6 174.4 Intercompany eliminations (1.8 ) (0.8 ) — Total revenues $ 10,441.4 $ 9,641.8 $ 8,680.1
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported periods. Significant estimates include the allowances for doubtful accounts, deferred tax assets, fair values and amortization lives for intangible assets, and accruals for self-insurance reserves and pensions. The allowance for doubtful accounts is determined based on historical collections trends, the aging of accounts, current economic conditions and regulatory changes. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The Company maintains cash and cash equivalents with various major financial institutions. The total cash and cash equivalent balances that exceeded the balances insured by the Federal Deposit Insurance Commission, were approximately $315.5 at December 31, 2017 . Substantially all of the Company’s accounts receivable are with companies in the healthcare or biopharmaceutical industry and individuals. However, concentrations of credit risk are limited due to the number of the Company’s customers as well as their dispersion across many different geographic regions. Although LCD has receivables due from U.S. and state governmental agencies, the Company does not believe that such receivables represent a credit risk since the related healthcare programs are funded by U.S. and state governments, and payment is primarily dependent upon submitting appropriate documentation. Accounts receivable balances (gross) from Medicare and Medicaid were $109.8 and $113.0 at December 31, 2017 , and 2016 , respectively. For the Company's operations in Ontario, Canada, the Ontario Ministry of Health and Long-Term Care (Ministry) determines who can establish a licensed community medical laboratory and caps the amount that each of these licensed laboratories can bill the government sponsored healthcare plan. The Ontario government-sponsored healthcare plan covers the cost of commercial laboratory testing performed by the licensed laboratories. The provincial government discounts the annual testing volumes based on certain utilization discounts and establishes an annual maximum it will pay for all community laboratory tests. The agreed-upon reimbursement rates are subject to Ministry review at the end of year and can be adjusted (at the government's discretion) based upon the actual volume and mix of test work performed by the licensed healthcare providers in the province during the year. The capitated accounts receivable balances from the Ontario government sponsored healthcare plan were CAD $12.9 and CAD $15.8 at December 31, 2017 , and 2016 , respectively. The portion of the Company's accounts receivable due from patients comprises the largest portion of credit risk. At December 31, 2017 , and 2016 , receivables due from patients represented approximately 20.9% and 20.0% of the Company's consolidated gross accounts receivable. The Company applies assumptions and judgments including historical collection experience for assessing collectability and determining allowances for doubtful accounts for accounts receivable from patients.
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, 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: 2017 2016 2015 Income Shares Per Share Amount Income Shares Per Share Amount Income Shares Per Share Amount Basic earnings per share $ 1,268.2 102.4 $ 12.39 $ 732.1 102.5 $ 7.14 $ 437.6 98.8 $ 4.43 Stock options — 1.4 — 1.5 — 1.2 Restricted stock awards and other — — — — — — Effect of convertible debt, net of tax — 0.1 — 0.3 — 0.6 Diluted earnings per share $ 1,268.2 103.9 $ 12.21 $ 732.1 104.3 $ 7.02 $ 437.6 100.6 $ 4.35 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: Years Ended December 31, 2017 2016 2015 Stock options 0.1 — —
Stock Compensation Plans	Stock Compensation Plans The Company measures stock compensation cost for all equity awards at fair value on the date of grant and recognizes compensation expense over the service period for awards expected to vest. The fair value of restricted stock units and performance share awards is determined based on the number of shares granted and the quoted price of the Company’s common stock on the grant date. Such value is recognized as expense over the service period, net of estimated forfeitures. The estimation of equity awards that will ultimately vest requires judgment and the Company considers many factors when estimating expected forfeitures, including types of awards, employee class, and historical experience. The cumulative effect on current and prior periods of a change in the estimated forfeiture rate is recognized as compensation expense in earnings in the period of the revision. Actual results and future estimates may differ substantially from the Company’s current estimates. See Note 14 for assumptions used in calculating compensation expense for the Company’s stock compensation plans.
Cash Equivalents	Cash Equivalents Cash and cash equivalents consist of highly liquid instruments, such as commercial paper, time deposits, and other money market instruments, substantially all of which have maturities when purchased of three months or less.
Inventories	Inventories Inventories, consisting primarily of purchased laboratory and customer supplies and finished goods, are stated at the lower of cost (first-in, first-out) or market. Supplies accounted for $ 195.2 and $ 171.7 and finished goods accounted for $ 32.4 and $ 33.5 of total inventory at December 31, 2017 , and 2016 , respectively.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are recorded at cost. The cost of properties held under capital leases is equal to the lower of the net present value of the minimum lease payments or the fair value of the leased property at the inception of the lease. Depreciation and amortization expense is computed on all classes of assets based on their estimated useful lives, as indicated below, using the straight-line method. Years Buildings and building improvements 10 - 40 Machinery and equipment 3 - 10 Furniture and fixtures 5 - 10 Software 3 - 10 Leasehold improvements and assets held under capital leases are amortized over the shorter of their estimated useful lives or the term of the related leases. Expenditures for repairs and maintenance are charged to operations as incurred. Retirements, sales and other disposals of assets are recorded by removing the cost and accumulated depreciation from the related accounts with any resulting gain or loss reflected in the consolidated statements of operations.
Capitalized Software Costs	Capitalized Software Costs The Company capitalizes purchased software which is ready for service and capitalizes software development costs incurred on significant projects starting from the time that the preliminary project stage is completed and the Company commits to funding a project until the project is substantially complete and the software is ready for its intended use. Capitalized costs include direct material and service costs and payroll and payroll-related costs. Research and development (R&D) costs and other computer software maintenance costs related to software development are expensed as incurred. Capitalized software costs are amortized using the straight-line method over the estimated useful life of the underlying system, generally five years.
Long-Lived Assets	Long-Lived Assets The Company assesses goodwill and indefinite-lived intangibles for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. In accordance with the FASB updates to their authoritative guidance regarding goodwill and indefinite-lived intangible asset impairment testing, an entity is allowed to first assess qualitative factors as a basis for determining whether it is necessary to perform quantitative impairment testing. If an entity determines that it is not more likely than not that the estimated fair value of an asset is less than its carrying value, then no further testing is required. Otherwise, impairment testing must be performed in accordance with the original accounting standards. The updated FASB guidance also allows an entity to bypass the qualitative assessment for any reporting unit in its goodwill assessment and proceed directly to performing the quantitative assessment. Similarly, a company can proceed directly to a quantitative assessment in the case of impairment testing for indefinite-lived intangible assets as well. The quantitative goodwill impairment test includes the estimation of the fair value of each reporting unit as compared to the carrying value of the reporting unit. Reporting units are businesses with discrete financial information that is available and reviewed by management. The Company estimates the fair value of a reporting unit using both income-based and market-based valuation methods. The income-based approach is based on the reporting unit's forecasted future cash flows that are discounted to the present value using the reporting unit's weighted average cost of capital. For the market-based approach, the Company utilizes a number of factors such as publicly available information regarding the market capitalization of the Company as well as operating results, business plans, market multiples, and present value techniques. Based upon the range of estimated values developed from the income and market-based methods, the Company determines the estimated fair value for the reporting unit. If the estimated fair value of the reporting unit exceeds the carrying value, the goodwill is not impaired and no further review is required. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Management performed its annual goodwill and intangible asset impairment testing as of the beginning of the fourth quarter of 2017. The Company elected to perform the qualitative assessment for goodwill and intangible assets for all reporting units except the Canadian reporting unit and its indefinite-lived assets consisting of acquired Canadian licenses for which a quantitative assessment was performed. In this qualitative assessment, the Company considered relevant events and circumstances for each reporting unit, including (i) current year results, (ii) financial performance versus management’s annual and five-year strategic plans, iii) changes in the reporting unit carrying value since prior year, (iv) industry and market conditions in which the reporting unit operates, (v) macroeconomic conditions, including discount rate changes, and (vi) changes in products or services offered by the reporting unit. If applicable, performance in recent years was compared to forecasts included in prior valuations. Based on the results of the qualitative assessment, the Company concluded that it was not more likely than not that the carrying values of the goodwill and intangible assets were greater than their fair values, and that further quantitative testing was not necessary. In 2017, the Company utilized an income approach to determine the fair value of its Canadian reporting unit and its indefinite-lived assets consisting of acquired Canadian licenses. Based upon the results of the quantitative assessment, the Company concluded that the fair value of the indefinite-lived Canadian licenses was greater than the carrying value. It is possible that the Company's conclusions regarding impairment or recoverability of goodwill or intangible assets in any reporting unit could change in future periods. There can be no assurance that the estimates and assumptions used in the Company's goodwill and intangible asset impairment testing performed as of the beginning of the fourth quarter of 2017 will prove to be accurate predictions of the future, if, for example, (i) the businesses do not perform as projected, (ii) overall economic conditions in 2018 or future years vary from current assumptions (including changes in discount rates), (iii) business conditions or strategies for a specific reporting unit change from current assumptions, including loss of major customers, (iv) investors require higher rates of return on equity investments in the marketplace or (v) enterprise values of comparable publicly traded companies, or actual sales transactions of comparable companies, were to decline, resulting in lower multiples of revenues and earnings before interest, tax, depreciation and amortization (EBITDA). A future impairment charge for goodwill or intangible assets could have a material effect on the Company's consolidated financial position and results of operations. Long-lived assets, other than goodwill and indefinite-lived assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. Recoverability of assets to be held and used is determined by the Company at the level for which there are identifiable cash flows by comparison of the carrying amount of the assets to future undiscounted net cash flows before interest expense and income taxes expected to be generated by the assets. Impairment, if any, is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets (based on market prices in an active market or on discounted cash flows). Assets to be disposed of are reported at the lower of the carrying amount or fair value.
Intangible Assets	Intangible Assets Intangible assets are amortized on a straight-line basis over the expected periods to be benefited, as set forth in the table below, such as legal life for patents and technology and contractual lives for non-compete agreements. Years Customer relationships 10 - 36 Patents, licenses and technology 3 - 15 Non-compete agreements 5 - 10 Trade names 5 - 15
Debt Issuance Costs	Debt Issuance Costs The costs related to the issuance of debt are capitalized, netted against the related debt for presentation purposes and amortized to interest expense over the terms of the related debt.
Professional Liability	Professional Liability The Company is self-insured (up to certain limits) for professional liability claims arising in the normal course of business, generally related to the testing and reporting of laboratory test results. The Company estimates a liability that represents the ultimate exposure for aggregate losses below those limits. The liability is based on assumptions and factors for known and incurred but not reported claims, including the frequency and payment trends of historical claims.
Income Taxes	Income Taxes The Company accounts for income taxes utilizing the asset and liability method. Under this method deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and for tax loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. 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 Company records interest and penalties in income tax expense.
Derivative Financial Instruments	Derivative Financial Instruments Interest rate swap agreements, which have been used by the Company from time to time in the management of interest rate exposure, are accounted for at fair value. The Company’s zero-coupon subordinated notes contain two features that are considered to be embedded derivative instruments under authoritative guidance in connection with accounting for derivative instruments and hedging activities. The Company believes these embedded derivatives had no fair value at December 31, 2017 , and 2016 . See Note 18 for the Company’s objectives in using derivative instruments and the effect of derivative instruments and related hedged items on the Company’s financial position, financial performance and cash flows.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value measurements for financial assets and liabilities are determined based on the assumptions that a market participant would use in pricing an asset or liability. A three-tiered fair value hierarchy draws distinctions between market participant assumptions based on (i) observable inputs such as quoted prices in active markets (Level 1), (ii) inputs other than quoted prices in active markets that are observable either directly or indirectly (Level 2) and (iii) unobservable inputs that require the Company to use present value and other valuation techniques in the determination of fair value (Level 3).
Research and Development	Research and Development The Company expenses R&D costs as incurred.
Foreign Currency Disclosure [Text Block]	Foreign Currencies For subsidiaries outside of the U.S. that operate in a local currency environment, income and expense items are translated to U.S. dollars at the monthly average rates of exchange prevailing during the period, assets and liabilities are translated at period-end exchange rates and equity accounts are translated at historical exchange rates. Translation adjustments are accumulated in a separate component of shareholders’ equity in the consolidated balance sheets and are included in the determination of comprehensive income in the consolidated statements of comprehensive earnings and consolidated statements of changes in shareholders’ equity. Transaction gains and losses are included in the determination of net income in the consolidated statements of operations.

BUSINESS ACQUISITIONS Business

BUSINESS ACQUISITIONS Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information [Table Text Block]	Had the Chiltern acquisition been completed as of January 1, 2016, the Company's pro forma results for 2017 would have been as follows: Year Ended December 31, 2017 December 31, 2016 Total net revenues $ 10,576.3 $ 9,937.4 Operating income 1,377.0 1,327.2 Net income 1,258.3 714.3 Earnings per share: Basic $ 12.29 $ 6.97 Diluted $ 12.11 $ 6.85
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	BUSINESS ACQUISITIONS On September 1, 2017, the Company completed the acquisition of Chiltern International Group Limited (Chiltern), a specialty contract research organization, pursuant to a definitive agreement to acquire all of the share capital of Chiltern, in an all-cash transaction valued at approximately $1,224.5 . The Company funded the acquisition through a combination of bank financing and the issuance of bonds. Chiltern is part of the Company's CDD segment. The valuation of acquired assets and assumed liabilities as of September 1, 2017, include the following: Consideration Transferred Cash consideration $ 1,224.5 Initial Measurement Period Adjustments Preliminary as of December 31, 2017 Net Assets Acquired Cash and cash equivalents $ 30.7 $ — $ 30.7 Accounts receivable 116.9 (11.3 ) 105.6 Unbilled services 32.6 — 32.6 Prepaid expenses and other 57.9 — 57.9 Property, plant and equipment 12.1 — 12.1 Goodwill 676.6 83.9 760.5 Customer relationships 629.0 (27.0 ) 602.0 Trade names and trademarks 24.1 (13.5 ) 10.6 Technology 47.0 (21.0 ) 26.0 Favorable leases — 0.9 0.9 Total assets acquired 1,626.9 12.0 1,638.9 Accounts payable 18.1 27.0 45.1 Accrued expenses and other 51.0 (27.6 ) 23.4 Unearned revenue 124.2 — 124.2 Deferred income taxes 208.0 12.6 220.6 Other liabilities 1.1 — 1.1 Total liabilities acquired 402.4 12.0 414.4 Net assets acquired $ 1,224.5 $ — $ 1,224.5 The amortization periods for intangible assets acquired are 21 years for customer relationships, 4 years for trade names and trademarks, and 6 years for technology. During the fourth quarter, the Company recorded certain measurement period adjustments to appropriately state the fair value of the net assets acquired from Chiltern. Given the September 1, 2017 closing date of the Chiltern acquisition, these adjustments would have had no material income statement impact had they been recorded as part of the initial purchase price allocation. The acquisition contributed $188.4 and $11.6 of net revenue and operating income, respectively, during the year ended December 31, 2017. Unaudited Pro Forma Information The Company completed the Chiltern acquisition on September 1, 2017. Had the Chiltern acquisition been completed as of January 1, 2016, the Company's pro forma results for 2017 would have been as follows: Year Ended December 31, 2017 December 31, 2016 Total net revenues $ 10,576.3 $ 9,937.4 Operating income 1,377.0 1,327.2 Net income 1,258.3 714.3 Earnings per share: Basic $ 12.29 $ 6.97 Diluted $ 12.11 $ 6.85 During the year ended December 31, 2017 , the Company also acquired various laboratories and related assets, including Pathology Associates Medical Laboratories (PAML), for approximately $688.8 in cash (net of cash acquired). These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. The purchase consideration for these acquisitions, including Chiltern, has been allocated to the estimated fair market value of the net assets acquired, including approximately $1,053.0 in identifiable intangible assets (primarily customer relationships and non-compete agreements) and a residual amount of goodwill of approximately $1,009.8 . As a result of the acquisition of PAML, the Company acquired PAML’s ownership interests in six joint ventures. During 2017, the Company further acquired the ownership interests of the other members of two of the six joint ventures, and the Company’s ownership interest in one of the six joint ventures was acquired by the other member. During 2018, the Company intends to acquire the membership interests of the other members of an additional two of these six joint ventures and will continue to evaluate future options for the membership interests in the sixth joint venture. The Company will continue to record minority interests in the consolidated joint ventures for which final transactions have not yet been completed. The purchase consideration for the transaction has been preliminarily allocated to the estimated fair market value of the net assets acquired. The amounts paid in advance for the ownership interest in the three joint ventures are included in other assets on the condensed consolidated balance sheet. The total purchase consideration for the transaction is classified as cash paid for acquisition of a business on the condensed consolidated statement of cash flows. The purchase price allocation for the Chiltern and PAML acquisitions are still preliminary and subject to change. The areas of the purchase price allocation that are not yet finalized relate primarily to intangible assets, goodwill, investment in joint ventures 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 within a year from each acquisition date. Any adjustments will be recorded in the period in which they are identified. During the year ended December 31, 2016 , the Company acquired various laboratories and related assets for approximately $548.6 in cash (net of cash acquired). The Company completed the acquisition of Sequenom, Inc., a market leader in non-invasive prenatal testing, women's health and reproductive genetics on September 7, 2016, through a cash tender offer for $2.40 per share, or a transaction price of $249.1 , net of cash received, and acquired $130.0 of debt. The Sequenom purchase consideration has been allocated to the estimated fair market value of the net assets acquired, including approximately $146.6 in identifiable intangible assets (primarily customer relationships, technology, and trade names) with weighted-average useful lives of approximately 14.6 years; $45.1 in deferred tax liabilities (relating to identifiable intangible assets); and a residual amount of non-tax deductible goodwill of approximately $206.0 . The Company also acquired various other laboratories and related assets for approximately $299.5 in cash (net of cash acquired). The purchase consideration for these acquisitions has been allocated to the estimated fair market value of the net assets acquired, including approximately $126.2 in identifiable intangible assets (primarily customer relationships) and a residual amount of goodwill of approximately $192.3 . These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. On February 19, 2015, the Company completed its acquisition of Covance Inc. (Covance), a leading drug development services company and a leader in nutritional analysis, for $6,150.7 . The Company issued debt and common stock to fund the acquisition of Covance. Covance stockholders received $75.76 in cash and 0.2686 shares of the Company's common stock for each share of Covance common stock they owned. The Company financed the Covance acquisition with $3,900.0 of debt, 15.3 shares of its common stock and $488.2 of available cash, $400.0 of which was derived from a bridge term loan credit facility. On January 30, 2015, the Company issued $2,900.0 in debt securities, consisting of $500.0 aggregate principal amount of 2.625% Senior Notes due 2020, $500.0 aggregate principal amount of 3.20% Senior Notes due 2022, $1,000.0 aggregate principal amount of 3.60% Senior Notes due 2025 and $900.0 aggregate principal amount of 4.70% Senior Notes due 2045. The Company also entered into a $1,000.0 term loan facility which was advanced in full on the February 19, 2015. The term loan credit facility will mature five years after the closing date of the Covance acquisition and may be prepaid without penalty. Unaudited Pro Forma Information The Company completed the acquisition of Covance on February 19, 2015. Had the acquisition been completed as of the beginning of 2014, the Company's pro forma results for 2015 would have been as follows: Year Ended December 31, 2015 Total revenues $ 9,033.3 Operating income 1,117.2 Net income 547.5 Earnings per share: Basic $ 5.05 Diluted $ 5.03 During the year ended December 31, 2015 , the Company also acquired various other laboratories and related assets for approximately $128.4 in cash (net of cash acquired). These acquisitions were made primarily to extend the Company's geographic reach in important market areas and/or enhance the Company's scientific differentiation and esoteric testing capabilities. The purchase consideration for these acquisitions has been allocated to the estimated fair market value of the net assets acquired, including approximately $17.4 in identifiable intangible assets (primarily customer relationships and non-compete agreements) and a residual amount of goodwill of approximately $68.4 .

SUMMARY OF SIGNIFICANT ACCOUN31

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Net Sales	The Company's total revenues are comprised of the following: Years Ended December 31, Total revenues 2017 2016 2015 LCD - net revenue $ 7,170.5 $ 6,593.9 $ 6,199.3 CDD - net revenue 3,037.2 2,844.1 2,306.4 CDD - reimbursable out-of-pocket expenses 235.5 204.6 174.4 Intercompany eliminations (1.8 ) (0.8 ) — Total revenues $ 10,441.4 $ 9,641.8 $ 8,680.1
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: 2017 2016 2015 Income Shares Per Share Amount Income Shares Per Share Amount Income Shares Per Share Amount Basic earnings per share $ 1,268.2 102.4 $ 12.39 $ 732.1 102.5 $ 7.14 $ 437.6 98.8 $ 4.43 Stock options — 1.4 — 1.5 — 1.2 Restricted stock awards and other — — — — — — Effect of convertible debt, net of tax — 0.1 — 0.3 — 0.6 Diluted earnings per share $ 1,268.2 103.9 $ 12.21 $ 732.1 104.3 $ 7.02 $ 437.6 100.6 $ 4.35
Potential common shares not included in computation of diluted earnings per share	Years Ended December 31, 2017 2016 2015 Stock options 0.1 — —
Property, Plant and Equipment	P
Finite-Lived Intangible Assets	Intangible assets are amortized on a straight-line basis over the expected periods to be benefited, as set forth in the table below, such as legal life for patents and technology and contractual lives for non-compete agreements. Years Customer relationships 10 - 36 Patents, licenses and technology 3 - 15 Non-compete agreements 5 - 10 Trade names 5 - 15

RESTRUCTURING RESERVES (Tables)

RESTRUCTURING RESERVES (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring Reserve [Abstract]
Schedule of Restructuring Reserves	RESTRUCTURING RESERVES The following represents the Company’s restructuring activities for the period indicated: LCD CDD Total Severance and Other Employee Costs Lease and Other Facility Costs Severance and Other Employee Costs Lease and Other Facility Costs Balance as of December 31, 2016 $ 7.5 $ 14.1 $ 28.2 $ 32.5 $ 82.3 Restructuring charges 11.4 6.6 24.7 33.3 76.0 Reduction of prior restructuring accruals (1.1 ) (0.1 ) (3.5 ) (0.4 ) (5.1 ) Cash payments and other adjustments (16.1 ) (10.5 ) (41.1 ) (30.8 ) (98.5 ) Balance as of December 31, 2017 $ 1.7 $ 10.1 $ 8.3 $ 34.6 $ 54.7 Current $ 22.2 Non-current 32.5 $ 54.7 The non-current portion of the restructuring liabilities is expected to be paid out over 6.4 years. Cash payments and other adjustments include the reclassification of profit sharing, pension, and holiday accrual.

JOINT VENTURE PARTNERSHIPS AN33

JOINT VENTURE PARTNERSHIPS AND EQUITY METHOD INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments in unconsolidated joint venture partnerships and equity method investment	Condensed unconsolidated financial information for joint venture partnerships and equity method investments is shown in the following table. As of December 31: 2017 2016 Current assets $ 45.7 $ 24.3 Other assets 14.4 16.9 Total assets $ 60.1 $ 41.2 Current liabilities $ 31.6 $ 15.5 Other liabilities 1.0 0.3 Total liabilities 32.6 15.8 Partners' equity 27.5 25.4 Total liabilities and partners’ equity $ 60.1 $ 41.2 For the period January 1 - December 31: 2017 2016 2015 Net revenues $ 212.5 $ 156.7 $ 213.7 Gross profit 62.6 45.7 54.3 Net earnings 25.7 20.3 20.1 At December 31, 2017 , the Company had investments in the following unconsolidated joint venture partnerships and equity method investments: Locations Net Investment Interest Owned Joint Venture Partnerships : Alberta, Canada (2) $ 45.5 43.37 % Florence, South Carolina 10.1 49.00 % PAML joint ventures $ (0.1 ) various Equity Method Investments : Various 3.7 various

ACCOUNTS RECEIVABLE, NET (Table

ACCOUNTS RECEIVABLE, NET (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Accounts receivable	December 31, 2017 December 31, Gross accounts receivable $ 1,742.2 $ 1,564.3 Less allowance for doubtful accounts (260.9 ) (235.6 ) $ 1,481.3 $ 1,328.7

PROPERTY, PLANT AND EQUIPMENT35

PROPERTY, PLANT AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	December 31, 2017 December 31, 2016 Land $ 78.4 $ 78.4 Buildings and building improvements 708.6 692.8 Machinery and equipment 1,181.0 1,060.1 Software 672.2 626.2 Leasehold improvements 333.5 302.0 Furniture and fixtures 90.6 76.9 Construction in progress 185.1 193.0 Equipment and real estate under capital leases 79.2 81.3 3,328.6 3,110.7 Less accumulated depreciation and amortization of capital lease assets (1,579.7 ) (1,392.1 ) $ 1,748.9 $ 1,718.6

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill (net of accumulated amortization) for the years ended December 31, 2017 and 2016 are as follows: LCD CDD Total December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Balance as of January 1 $ 3,644.8 $ 3,137.7 $ 2,779.6 $ 3,064.4 $ 6,424.4 $ 6,202.1 Goodwill acquired during the year 198.5 398.3 811.3 — 1,009.8 398.3 Foreign currency impact and other adjustments to goodwill 1.1 108.8 94.7 (284.8 ) 95.8 (176.0 ) Balance at end of year $ 3,844.4 $ 3,644.8 $ 3,685.6 $ 2,779.6 $ 7,530.0 $ 6,424.4
Components of identifiable intangible assets	The components of identifiable intangible assets are as follows: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 4,297.9 $ (1,014.9 ) $ 3,283.0 $ 3,275.3 $ (855.2 ) $ 2,420.1 Patents, licenses and technology 457.9 (188.6 ) 269.3 395.3 (163.3 ) 232.0 Non-compete agreements 79.0 (49.4 ) 29.6 53.0 (42.1 ) 10.9 Trade names 426.3 (171.4 ) 254.9 406.3 (141.6 ) 264.7 Land use rights 10.9 (2.6 ) 8.3 10.0 (1.4 ) 8.6 Canadian licenses 495.7 — 495.7 464.2 — 464.2 $ 5,767.7 $ (1,426.9 ) $ 4,340.8 $ 4,604.1 $ (1,203.6 ) $ 3,400.5
Acquired amortizable intangible assets and their respective weighted average amortization periods	A summary of amortizable intangible assets acquired during 2017 , and their respective weighted average amortization periods are as follows: Amount Weighted Average Amortization Period Customer relationships $ 955.7 20.7 Patents, licenses and technology 52.9 6.7 Non-compete agreements 27.8 6.6 Trade names 15.7 5.7 Favorable leases 0.9 3.0 $ 1,053.0 19.3

ACCRUED EXPENSES AND OTHER (Tab

ACCRUED EXPENSES AND OTHER (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued expenses and other	December 31, 2017 December 31, 2016 Employee compensation and benefits $ 324.6 $ 288.2 Self-insurance reserves 45.7 48.2 Accrued taxes payable 64.5 61.2 Royalty and license fees payable 6.2 9.5 Restructuring reserves 22.2 47.7 Acquisition related reserves 21.3 10.3 Interest payable 71.7 58.6 Rebates 24.6 19.5 Other 52.1 50.5 $ 632.9 $ 593.7

OTHER LIABILITIES (Tables)

OTHER LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Other liabilities	December 31, 2017 December 31, 2016 Post-retirement benefit obligation $ 7.4 $ 5.8 Defined-benefit plan obligation 163.4 195.4 Restructuring reserves 32.5 34.6 Self-insurance reserves 28.9 17.1 Acquisition related reserves 3.1 15.7 Deferred compensation plan obligation 64.5 54.2 Worker's compensation and auto 39.0 33.1 Straight-line rent 12.7 13.3 Escheat liability 10.9 8.3 Other 15.8 14.5 $ 378.2 $ 392.0

DEBT (Tables)

DEBT (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt [Table Text Block]	The scheduled payments of long-term debt and future minimum lease payments for capital leases at the end of 2017 are summarized as follows: Notes and Other Capital Leases Total 2018 $ 409.2 $ 15.6 $ 424.8 2019 35.9 14.4 50.3 2020 1,226.9 13.1 1,240.0 2021 71.0 11.7 82.7 2022 1,601.3 10.6 1,611.9 Thereafter 3,351.7 45.1 3,396.8 6,696.0 110.5 6,806.5 Less amounts representing interest — (44.4 ) (44.4 ) Total long-term debt 6,696.0 66.1 6,762.1 Less current portion (409.2 ) (8.3 ) (417.5 ) Long-term debt, due beyond one year $ 6,286.8 $ 57.8 $ 6,344.6
Short-term borrowings and current portion of long-term debt	Short-term borrowings and current portion of long-term debt at December 31, 2017 , and 2016 consisted of the following: December 31, 2017 December 31, 2016 Zero-coupon convertible subordinated notes $ 8.8 $ 42.4 2.20% Senior Notes due 2017 — 500.0 2.50% Senior Notes due 2018 400.0 — Debt issuance costs (1.4 ) (1.3 ) Capital lease obligation 8.3 8.4 Current portion of note payable 1.8 — Total short-term borrowings and current portion of long-term debt $ 417.5 $ 549.5
Long-term debt	Long-term debt at December 31, 2017 , and 2016 consisted of the following: December 31, 2017 December 31, 2016 2.50% Senior Notes due 2018 — 400.0 4.625% Senior Notes due 2020 604.1 614.6 2.625% Senior Notes due 2020 500.0 500.0 3.75% Senior Notes due 2022 500.0 500.0 3.20% 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 — 3.60% Senior Notes due 2025 1,000.0 1,000.0 3.60% Senior Notes due 2027 600.0 — 4.70% Senior Notes due 2045 900.0 900.0 2014 Term loan 72.0 565.0 2017 Term loan 750.0 — Debt issuance costs (48.2 ) (43.0 ) Capital leases 57.8 56.2 Note payable 8.9 7.2 Total long-term debt $ 6,344.6 $ 5,300.0

PREFERRED STOCK AND COMMON SH40

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Common shares issued and outstanding [Text Block]	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 are recorded at aggregate cost. Common shares issued and outstanding are summarized in the following table: 2017 2016 Issued 125.1 125.6 In treasury (23.2 ) (22.9 ) Outstanding 101.9 102.7
Changes in common shares issued and held in treasury [Text Block]	The changes in common shares issued and held in treasury are summarized below: Common Shares Issued 2017 2016 2015 Common stock issued at January 1 125.6 123.9 107.1 Common stock issued under employee stock plans 1.7 1.6 1.5 Common stock issued upon conversion of zero-coupon subordinated notes 0.3 0.4 — Common stock issued in conjunction with the Covance acquisition — — 15.3 Retirement of common stock (2.5 ) (0.3 ) — Common stock issued at December 31 125.1 125.6 123.9 Common Shares Held in Treasury 2017 2016 2015 Common shares held in treasury at January 1 22.9 22.6 22.5 Surrender of restricted stock and performance share awards 0.3 0.3 0.1 Common shares held in treasury at December 31 23.2 22.9 22.6
Accumulated Other Comprehensive Earnings Components [Text Block]	The components of accumulated other comprehensive earnings are as follows: Foreign Currency Translation Adjustments Net Benefit Plan Adjustments Unrealized Gains and Losses on Available for Sale Securities Accumulated Other Comprehensive Earnings Balance at December 31, 2014 $ 68.0 $ (78.6 ) $ 0.1 $ (10.5 ) Current year adjustments (370.7 ) 19.0 (0.1 ) (351.8 ) Amounts reclassified from accumulated other comprehensive income (a) (b) — (11.3 ) — (11.3 ) Tax effect of adjustments 90.1 (3.5 ) — 86.6 Balance at December 31, 2015 (212.6 ) (74.4 ) — (287.0 ) Current year adjustments (250.0 ) (3.3 ) — (253.3 ) Amounts reclassified from accumulated other comprehensive income (a) — (37.0 ) — (37.0 ) Tax effect of adjustments (8.1 ) 4.3 — (3.8 ) Balance at December 31, 2016 (470.7 ) (110.4 ) — (581.1 ) Current year adjustments 262.3 2.4 — 264.7 Amounts reclassified from accumulated other comprehensive income (a) — 18.5 — 18.5 Tax effect of adjustments (34.3 ) (3.5 ) — (37.8 ) Balance at December 31, 2017 $ (242.7 ) $ (93.0 ) $ — $ (335.7 )

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The sources of income before taxes, classified between domestic and foreign entities are as follows: Pre-tax income 2017 2016 2015 Domestic $ 891.8 $ 914.0 $ 593.5 Foreign 243.1 191.5 132.5 Total pre-tax income $ 1,134.9 $ 1,105.5 $ 726.0
Provision for Income Tax Expense (Benefit)	The provisions (benefits) for income taxes in the accompanying consolidated statements of operations consist of the following: Years Ended December 31, 2017 2016 2015 Current: Federal $ 300.8 $ 235.1 $ 218.3 State 32.9 38.6 33.7 Foreign 53.0 43.9 69.4 $ 386.7 $ 317.6 $ 321.4 Deferred: Federal $ (534.3 ) $ 64.4 $ (14.1 ) State 12.9 6.0 (4.2 ) Foreign (4.4 ) (15.7 ) (15.8 ) (525.8 ) 54.7 (34.1 ) $ (139.1 ) $ 372.3 $ 287.3
Schedule of Effective Income Tax Rate Reconciliation	The effective tax rates on earnings before income taxes are reconciled to statutory U.S. income tax rates as follows: Years Ended December 31, 2017 2016 2015 Statutory U.S. rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of U.S. Federal income tax effect 2.5 2.6 3.2 Foreign earnings taxed at lower rates than the statutory U.S. rate (3.5 ) (3.1 ) (1.8 ) Restructuring and acquisition items 0.6 — 2.7 Share-based compensation (1.7 ) (1.2 ) — Re-measurement of deferred taxes (35.0 ) — — Deferred taxes on unremitted foreign earnings (15.8 ) — — Repatriation tax 5.0 — — Other 0.6 0.4 1.1 Effective rate (12.3 )% 33.7 % 40.2 %
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows: December 31, 2017 December 31, 2016 Deferred tax assets: Accounts receivable $ 14.7 $ 13.5 Employee compensation and benefits 113.6 160.8 Acquisition and restructuring reserves 16.8 38.5 Tax loss carryforwards 107.0 167.7 Other 26.0 44.8 278.1 425.3 Less: valuation allowance (42.8 ) (31.3 ) Deferred tax assets, net of valuation allowance $ 235.3 $ 394.0 Deferred tax liabilities: Deferred earnings $ (5.1 ) $ (193.2 ) Intangible assets (913.2 ) (1,047.4 ) Property, plant and equipment (156.9 ) (208.8 ) Zero-coupon subordinated notes (10.1 ) (48.5 ) Currency translation adjustment (0.1 ) (47.0 ) Other (27.2 ) (27.9 ) Total gross deferred tax liabilities (1,112.6 ) (1,572.8 ) Net deferred tax liabilities $ (877.3 ) $ (1,178.8 )
Reconciliation of Unrecognized Tax Benefits from Uncertain Tax Positions	The following table shows a reconciliation of the unrecognized income tax benefits, excluding interest and penalties, from uncertain tax positions for the years ended December 31, 2017 , 2016 and 2015 : 2017 2016 2015 Balance as of January 1 $ 18.4 $ 24.2 $ 16.7 Increase in reserve for tax positions taken in the current year 7.3 2.3 4.1 Increase in reserve as a result of acquisition — — 8.5 Decrease in reserve as a result of lapses in the statute of limitations (6.2 ) (8.1 ) (5.1 ) Balance as of December 31 $ 19.5 $ 18.4 $ 24.2

STOCK COMPENSATION PLANS (Table

STOCK COMPENSATION PLANS (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Share Based Compensation Arrangements by Share Based Payment Awards	Changes in options outstanding under the plans for the period indicated were as follows: Number of Options Weighted-Average Exercise Price per Option Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at December 31, 2016 1.6 $ 82.43 Granted 0.1 130.60 Exercised (0.5 ) 83.85 Cancelled — 80.37 Outstanding at December 31, 2017 1.2 $ 86.55 3.9 $ 85.4 Vested and expected to vest at December 31, 2017 1.1 $ 81.73 3.3 $ 82.1 Exercisable at December 31, 2017 1.1 $ 81.73 3.3 $ 82.1
Disclosure of the Impact of Stock Options Exercised	Cash received by the Company from option exercises, the actual tax benefit realized for the tax deductions and the aggregate intrinsic value of options exercised from option exercises under all share-based payment arrangements during the years ended December 31, 2017 , 2016 , and 2015 were as follows: 2017 2016 2015 Cash received by the Company $ 43.9 $ 52.6 $ 82.6 Tax benefits realized $ 13.4 $ 13.6 $ 16.2 Aggregate intrinsic value $ 34.8 $ 35.5 $ 42.2
Schedule of Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices	The following table summarizes information concerning currently outstanding and exercisable options. Options Outstanding Options Exercisable Range of Exercise Prices Number Outstanding Weighted Average Number Exercisable Weighted Average Exercise Price Remaining Contractual Life Average Exercise Price $59.38 - 67.60 0.1 1.1 $60.64 0.1 $60.64 $67.61 - 75.63 0.2 1.8 $72.06 0.2 $72.06 $75.64 - 84.86 0.6 4.2 $84.73 0.6 $84.73 $84.87 - 130.60 0.3 5.2 $105.29 0.3 $91.13 1.2 3.9 $86.55 1.2 $81.73
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The Company uses the Black-Scholes model to calculate the fair value of the employee’s purchase right. The fair value of the employee’s purchase right and the assumptions used in its calculation are as follows: 2017 2016 2015 Fair value of the employee’s purchase right $ 31.54 $ 23.32 $ 21.95 Valuation assumptions Risk free interest rate 1.3 % 0.5 % 0.3 % Expected volatility 0.2 0.2 0.2 Expected dividend yield — — —
Schedule of Nonvested Share Activity	The following table shows a summary of non-vested shares for the year ended December 31, 2017 : Number of Shares Weighted-Average Grant Date Fair Value Non-vested at January 1, 2017 1.6 $ 108.23 Granted 0.9 132.48 Vested (0.9 ) 100.86 Canceled (0.1 ) 118.74 Non-vested at December 31, 2017 1.5 $ 121.36

COMMITMENTS AND CONTINGENT LI43

COMMITMENTS AND CONTINGENT LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Future minimum rental commitments	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, 2017 are as follows: Operating 2018 $ 196.1 2019 149.0 2020 109.7 2021 83.5 2022 64.2 Thereafter 160.9 Total minimum lease payments 763.4 Less: Amounts included in restructuring and acquisition related accruals (17.6 ) Non-cancelable sub-lease income — Total minimum operating lease payments $ 745.8

PENSION AND POSTRETIREMENT PLAN

PENSION AND POSTRETIREMENT PLANS Pension and Postretirement Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Postemployment Benefits [Abstract]
Assumed Benefit Payments By Year [Text Block]	The following assumed benefit payments under the Company's post-retirement benefit plan, which reflect expected future service, as appropriate, and which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 1.3 2019 1.1 2020 1.0 2021 1.0 2022 0.9 Years 2023 and thereafter 2.8
Defined Benefit Plan Fair Value Of Plan Assets By Category [Table Text Block]	The weighted average expected long-term rate of return for the Company Plan’s assets is as follows: Target Weighted Average Expected Long-Term Rate of Return Equity securities 50.0 % 5.6 % Fixed income securities 45.0 % 1.1 % Other assets 5.0 % 0.1 % The fair values of the Company Plan’s assets at December 31, 2017 , and 2016 , by asset category are as follows: Fair Value Measurements as of December 31, 2017 Fair Value as of December 31, 2017 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 7.4 $ 7.4 $ — $ — Equity securities: U.S. large cap - blend (a) 59.9 — 59.9 — U.S. mid cap - blend (b) 23.6 — 23.6 — U.S. small cap - blend (c) 7.7 — 7.7 — International equity - blend (d) 39.1 — 39.1 — Real estate (e) 12.8 — 12.8 — Fixed income securities: U.S. fixed income (f) 107.0 — 107.0 — U.S inflation protection income (g) 6.2 — 6.2 — Total fair value of the Company Plan’s assets $ 263.7 $ 7.4 $ 256.3 $ — Fair Value Measurements as of December 31, 2016 Fair Value as of December 31, 2016 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 6.8 $ 6.8 $ — $ — Equity securities: U.S. large cap - blend (a) 55.3 — 55.3 — U.S. mid cap - blend (b) 21.2 — 21.2 — U.S. small cap - blend (c) 7.4 — 7.4 — International equity - blend (d) 36.1 — 36.1 — Commodities index (h) 12.9 — 12.9 — Fixed income securities: U.S. fixed income (f) 101.8 — 101.8 — U.S inflation protection income (g) 6.0 — 6.0 — Total fair value of the Company Plan’s assets $ 247.5 $ 6.8 $ 240.7 $ — a) This category represents an equity index fund not actively managed that tracks the S&P 500 Index. b) This category represents an equity index fund not actively managed that tracks the S&P mid-cap 400 Index. c) This category represents an equity index fund not actively managed that tracks the Russell 2000 Index. d) This category represents an equity index fund not actively managed that tracks the MSCI ACWI ex USA Index. e) This category represents a real estate index fund not actively managed that tracks the MSCI US REIT Index. f) This category primarily represents bond index funds not actively managed that track the Barclays Capital U.S. Aggregate Index as well as an actively managed strategy which utilizes the Barclays Capital U.S. Aggregate Bond Index as its primary prospectus benchmark. g) This category primarily represents a bond index fund not actively managed that tracks the Barclays Capital U.S. TIPS Index. h) This category represents a commodities index fund not actively managed that tracks the Dow Jones - UBS Commodity Index.
Schedule of Changes in Fair Value of Plan Assets [Table Text Block]	A summary of the changes in the fair value of plan assets follows: 2017 2016 Fair value of plan assets at beginning of year $ 247.5 $ 250.6 Actual return on plan assets 29.2 13.6 Employer contributions 17.6 12.4 Benefits and administrative expenses paid (30.6 ) (29.1 ) Fair value of plan assets at end of year $ 263.7 $ 247.5
Schedule of Defined Benefit Plans Disclosures [Table Text Block]	Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ — $ — $ 0.1 Interest cost on benefit obligation 0.3 0.3 1.0 Net amortization and deferral (6.7 ) (15.9 ) (10.4 ) Post-retirement medical plan costs $ (6.4 ) $ (15.6 ) $ (9.3 ) A summary of the changes in the accumulated post-retirement benefit obligation follows: 2017 2016 Balance at January 1 $ 6.8 $ 21.4 Service cost for benefits earned — — Interest cost on benefit obligation 0.3 0.3 Actuarial loss 2.5 (0.2 ) Benefits paid (1.0 ) (1.3 ) Plan amendment — (13.4 ) Balance at December 31 $ 8.6 $ 6.8 Recorded as: Accrued expenses and other $ 1.2 $ 1.0 Other liabilities 7.4 5.8 $ 8.6 $ 6.8 The effect on operations for both the Company Plan and the PEP are summarized as follows: Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ 5.5 $ 4.9 $ 3.9 Interest cost on benefit obligation 14.4 15.5 15.1 Expected return on plan assets (16.3 ) (16.7 ) (18.3 ) Net amortization and deferral 11.0 11.2 11.3 Defined-benefit plan costs $ 14.6 $ 14.9 $ 12.0 A summary of the changes in the projected benefit obligations of the Company Plan and the PEP are summarized as follows: 2017 2016 Balance at January 1 $ 366.5 $ 363.1 Service cost 5.5 4.9 Interest cost 14.4 15.5 Actuarial loss 12.2 12.1 Benefits and administrative expenses paid (30.6 ) (29.1 ) Balance at December 31 $ 368.0 $ 366.5
Schedule of Net Funded Status [Table Text Block]	he net funded status of the Company Plan and the PEP at December 31: 2017 2016 Funded status $ 104.3 $ 119.0 Recorded as: Accrued expenses and other $ 2.2 $ 2.0 Other liabilities 102.1 117.0 $ 104.3 $ 119.0
Schedule of Assumptions Used [Table Text Block]	Weighted average assumptions used in the accounting for the Company Plan and the PEP are summarized as follows: 2017 2016 2015 Discount rate 3.7 % 4.2 % 4.0 % Expected long term rate of return 6.8 % 6.8 % 7.0 %
Schedule of Expected Benefit Payments [Table Text Block]	2018 $ 0.1 2019 0.1 2020 0.1 2021 0.1 2022 0.1 2023 and thereafter 0.2 The following assumed benefit payments under the Company Plan and PEP, which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 27.2 2019 26.6 2020 26.2 2021 25.5 2022 25.4 Years 2023 and thereafter 118.2 U.K. Plans German Plan 2018 $ 4.4 $ 0.3 2019 5.3 0.4 2020 5.5 0.6 2021 6.0 0.6 2022 7.4 0.7 Years 2023 and thereafter 43.0 3.7

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
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 December 31, 2017 , and 2016 were as follows: Fair Value Measurements as of December 31, 2017 Fair Value as of December 31, 2017 Using Fair Value Hierarchy Level 1 Level 2 Level 3 Noncontrolling interest put $ 16.7 $ — $ 16.7 $ — Interest rate swap 4.1 — 4.1 — Cash surrender value of life insurance policies 64.0 — 64.0 — Deferred compensation liability 64.5 — 64.5 — Contingent consideration 16.5 — — 16.5 Fair Value Measurements as of December 31, 2016 Fair Value as of December 31, 2016 Using Fair Value Hierarchy Level 1 Level 2 Level 3 Noncontrolling interest put $ 15.2 $ — $ 15.2 $ — Interest rate swap 14.6 — 14.6 — Cash surrender value of life insurance policies 53.6 — 53.6 — Deferred compensation liability 54.2 — 54.2 — Contingent consideration 16.8 — — 16.8

SUPPLEMENTAL CASH FLOW INFORM46

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	Years Ended December 31, 2017 2016 2015 Supplemental schedule of cash flow information: Cash paid during period for: Interest $ 239.1 $ 210.7 $ 166.1 Income taxes, net of refunds 348.0 345.7 237.6 Disclosure of non-cash financing and investing activities: Surrender of restricted stock awards and performance shares 47.4 34.6 12.6 Conversion of zero-coupon convertible debt 35.0 39.1 1.1 Assets acquired under capital leases 7.3 16.0 22.6 Accrued property, plant and equipment 1.6 4.4 4.3

QUARTERLY DATA (UNAUDITED) (Tab

QUARTERLY DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly data summary:	The following is a summary of unaudited quarterly data: Year Ended December 31, 2017 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (a) Full Year Net revenues $ 2,408.1 $ 2,498.4 $ 2,597.9 $ 2,701.5 $ 10,205.9 Gross profit 803.6 861.8 882.8 915.8 3,464.0 Net earnings attributable to Laboratory Corporation of America Holdings 192.2 188.6 180.6 706.8 1,268.2 Basic earnings per common share 1.87 1.84 1.77 6.91 12.39 Diluted earnings per common share 1.84 1.82 1.74 6.81 12.21 (a) Net earnings attributable to Laboratory Corporation of America Holdings in the fourth quarter of 2017 includes amounts recorded due to TCJA. Year Ended December 31, 2016 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Full Year Net revenues $ 2,295.2 $ 2,382.0 $ 2,372.7 $ 2,387.3 $ 9,437.2 Gross profit 777.3 826.8 788.4 788.0 3,180.5 Net earnings attributable to Laboratory Corporation of America Holdings 164.1 204.1 179.5 184.4 732.1 Basic earnings per common share 1.61 2.00 1.74 1.79 7.14 Diluted earnings per common share 1.58 1.96 1.71 1.75 7.02

Schedule II - Valuation And Q48

Schedule II - Valuation And Qualifying Accounts And Reserves (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule to Financial Statments [Abstract]
Valuation and Qualifying Accounts	Balance at beginning of year Additions Charged to Costs and Expense (1) Balance at end of year Year ended December 31, 2017: Applied against asset accounts: Allowance for doubtful accounts $ 235.6 $ 314.7 $ (289.4 ) $ 260.9 Valuation allowance-deferred tax assets $ 31.3 $ 11.5 $ — $ 42.8 Year ended December 31, 2016: Applied against asset accounts: Allowance for doubtful accounts $ 217.0 $ 287.3 $ (268.7 ) $ 235.6 Valuation allowance-deferred tax assets $ 15.1 $ 16.2 $ — $ 31.3 Year ended December 31, 2015: Applied against asset accounts: Allowance for doubtful accounts $ 211.6 $ 265.4 $ (260.0 ) $ 217.0 Valuation allowance-deferred tax assets $ 17.1 $ — $ (2.0 ) $ 15.1 (1) Other (Deductions) Additions consists primarily of write-offs of accounts receivable amounts.

Business Segments _Disclosure49

Business Segments [Disclosure] Schedule of Segment Reporting Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	2017 2016 2015 Net Revenues: LCD $ 7,170.5 $ 6,593.9 $ 6,199.3 CDD 3,037.2 2,844.1 2,306.4 Intercompany eliminations (1.8 ) (0.8 ) — Total net revenues $ 10,205.9 $ 9,437.2 $ 8,505.7 Operating Earnings (Loss): LCD $ 1,298.6 $ 1,187.6 $ 1,053.7 CDD 206.2 272.7 73.5 General corporate expenses (140.6 ) (147.9 ) (130.4 ) Total operating income 1,364.2 1,312.4 996.8 Non-operating expenses, net (229.3 ) (206.9 ) (270.8 ) Earnings before income taxes 1,134.9 1,105.5 726.0 Provision for income taxes (139.1 ) 372.3 287.3 Net earnings 1,274.0 733.2 438.7 Less: Net income attributable to noncontrolling interests (5.8 ) (1.1 ) (1.1 ) Net income attributable to Laboratory Corporation of America Holdings $ 1,268.2 $ 732.1 $ 437.6 2017 2016 2015 Depreciation and Amortization LCD $ 304.7 $ 270.9 $ 245.8 CDD 217.4 219.5 184.4 General corporate 1.2 0.1 4.1 Total depreciation and amortization $ 523.3 $ 490.5 $ 434.3 LCD CDD Intercompany Eliminations Total Geographic distribution of net revenues US $ 6,808.6 $ 1,427.2 $ (1.8 ) $ 8,234.0 Canada 327.8 — — 327.8 United Kingdom 29.6 272.4 — 302.0 Switzerland — 484.4 — 484.4 Other 4.5 853.2 — 857.7 Total net revenues $ 7,170.5 $ 3,037.2 $ (1.8 ) $ 10,205.9 LCD CDD Total Geographic distribution of property, plant and equipment, net U.S. $ 826.2 $ 590.6 $ 1,416.8 Canada 54.6 — 54.6 U.K. 2.1 120.7 122.8 Switzerland — 81.4 81.4 Other 3.0 70.3 73.3 Total property, plant and equipment, net $ 885.9 $ 863.0 $ 1,748.9

Debt - Convertible Subordinated

Debt - Convertible Subordinated Notes (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)Rate	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jan. 30, 2015USD ($)	Nov. 01, 2013USD ($)
Debt Instrument [Line Items]
Notes Payable, Noncurrent		$ 8.9		$ 7.2
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months		409.2
Convertible Subordinated Debt, Current		8.8		42.4
Short term debt issuance costs		(1.4)		(1.3)
Capital Lease Obligations, Current		8.3		8.4
Notes Payable, Current		1.8		0
Debt, Current		417.5		549.5
Senior notes current 2016		0		500
Senior notes current 2017		400
Long-term debt, less current portion		6,344.6		5,300
Senior notes due 2024		600		0
Senior Notes, Noncurrent		$ 2,900				$ 2,900	$ 700
Senior notes due 2017 [Member]
Debt Instrument [Line Items]
Senior notes current 2017				$ 0
Zero-coupon convertible subordinated notes [Member]
Debt Instrument [Line Items]
Contingent cash interest accrual rate	0.125%
Number of days used to establish average market price of zero coupon subordinated notes	5
Debt Instrument, Interest Rate, Effective Percentage				2.00%
Senior notes due 2018 [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion					$ 130
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt to EBITDA (leverage) ratio				3,200,000
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent						$ 900
Senior notes due 2024 and 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion			$ 1,200
Net Proceeds from Debt			1,190.1
Senior notes due 2018 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent							$ 400
Senior notes due 2024 [Member] [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion			$ 600
Debt Instrument, Interest Rate, Effective Percentage | Rate			3.25%
Senior notes due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion			$ 600
Debt Instrument, Interest Rate, Effective Percentage | Rate			3.60%
Senior notes due 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage | Rate			2.20%

Note 11 - Debt Debt - Credit Fa

Note 11 - Debt Debt - Credit Facilities(Details) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2017USD ($)	Mar. 31, 2016Quarters	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
2017 Term loan			$ 750	$ 0
Notes Payable, Current			1.8	0
2014 Term Loan			72	565
Long-term debt, less current portion			6,344.6	5,300
Long term debt issuance costs			48.2	43
Debt covenant, requirement for number of consecutive fiscal quarters | Quarters		4
Amortization of Debt Discount (Premium)			$ 5.6	$ 5.6
Debt Covenant Requirement [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt to EBITDA (leverage) ratio				3
Debt Covenant Actual [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt to EBITDA (leverage) ratio				2.5
Senior notes due 2018 [Member]
Schedule of Available-for-sale Securities [Line Items]
Long-term debt, less current portion					$ 130
Sequenom notes retired	$ 129.9
Revolving Credit Facility [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate at Period End			2.70%
Debt to EBITDA (leverage) ratio				3,200,000
Term Loan [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate at Period End			2.80%
2017 Term Loan [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate at Period End			2.60%
Prime Rate [Member] | Revolving Credit Facility [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate Description		0.00% to 0.25%
Prime Rate [Member] | Term Loan [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate Description		0.125% to 1.00%	0.0% to 0.50%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate Description		0.775% to 1.25%
London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member]
Schedule of Available-for-sale Securities [Line Items]
Line of Credit Facility, Interest Rate Description		1.125% to 2.00%	0.875% to 1.50%

Note 14 - Stock Comp Plan (Deta

Note 14 - Stock Comp Plan (Details)	12 Months Ended
	Dec. 31, 2017$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range01 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower range limit	$ 60.04
Exercise price range, upper range limit	64.42
Exercise Price Range 2 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower range limit	64.43
Exercise price range, upper range limit	75.63
Exercise Price Range 3 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower range limit	75.64
Exercise price range, upper range limit	84.86
Exercise Price Range 4 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price range, lower range limit	84.87
Exercise price range, upper range limit	$ 130.60

BUSINESS ACQUISITIONS (Details)

BUSINESS ACQUISITIONS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 31, 2017	Jul. 27, 2016	Feb. 19, 2015	Jan. 30, 2015	Dec. 19, 2014	Nov. 01, 2013
Business Acquisition [Line Items]
Stock Issued During Period, Shares, Acquisitions										15.3
Total acquisition consideration (cash and non-cash)														$ 1,224.5	$ 249.1	$ 6,150.7
Long-term debt, less current portion	$ 6,344.6				$ 5,300					$ 6,344.6	$ 5,300
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability								$ 4.9	$ 1.7	3
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment										0.5
Facility Related Restructuring Reserve Accrual Adjustment								3.5		4.6			$ 1.1
Business Acquisition, Share Price															$ 2.40
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														0.9
Goodwill, net	7,530				6,424.4					7,530	6,424.4	$ 6,202.1
Payments to Acquire Businesses, Net of Cash Acquired										1,882.6	548.6	3,736
Finite-lived Intangible Assets Acquired										1,053
Goodwill, Acquired During Period								398.3		$ 1,009.8
Line of Credit Facility, Maximum Borrowing Capacity																		$ 1,000
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets										19 years 3 months
Cash payments to acquire laboratory-related assets										$ 312.9	278.9	255.8
Senior Notes, Noncurrent	2,900									2,900							$ 2,900		$ 700
Noncontrolling Interest Put [Abstract]
Net sales	2,701.5	$ 2,597.9	$ 2,498.4	$ 2,408.1	2,387.3	$ 2,372.7	$ 2,382	2,295.2		10,205.9	9,437.2	8,505.7
Proforma consolidated net revenue								188.4		10,576.3	9,937.4
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax										1,377	1,327.2
Business Acquisition, Pro Forma Net Income (Loss)										$ 1,258.3	$ 714.3
Proforma consolidated net income								11.6
Business Acquisition, Pro Forma Earnings Per Share, Basic										$ 12,290,000	$ 6,970,000
Unbilled Receivables, Current	138.2				97.1					$ 138.2	$ 97.1
Revenues								9,641.8		10,441.4	9,641.8	8,680.1
Operating Income (Loss)										1,364.2	1,312.4	996.8
Net earnings attributable to Laboratory Corporation of America Holdings	706.8	$ 180.6	$ 188.6	$ 192.2	184.4	179.5	$ 204.1	164.1		1,268.2	$ 732.1	437.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents														30.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables														105.6
Purchase price adjustment										$ 0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets														57.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment														12.1
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net														(760.5)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable														45.1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities														23.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue														124.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other														1.1
Business Combination, Separately Recognized Transactions, Liabilities Recognized														414.4
Proforma consolidated diluted earnings per share										$ 12,110,000	$ 6,850,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets														32.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets														1,638.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent														220.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net														1,224.5
Senior notes due 2025 [Member]
Purchase Price Allocation [Abstract]
Debt Instrument, Interest Rate, Stated Percentage																	3.60%
Senior Notes, Noncurrent																	$ 1,000
Senior notes due 2020 [Member]
Business Acquisition [Line Items]
Long-term debt, less current portion	600									$ 600
Covance, Inc. [Member]
Noncontrolling Interest Put [Abstract]
Proforma consolidated net revenue												9,033.3
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax												1,117.2
Business Acquisition, Pro Forma Net Income (Loss)												$ 547.5
Business Acquisition, Pro Forma Earnings Per Share, Basic												$ 5,050,000
Proforma consolidated diluted earnings per share												$ 5,030,000
Chiltern [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														0
Noncontrolling Interest Put [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents														30.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables														116.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets														57.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment														12.1
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net														(676.6)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable														18.1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities														51
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue														124.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other														1.1
Business Combination, Separately Recognized Transactions, Liabilities Recognized														402.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets														32.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets														1,626.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent														208
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net														1,224.5
Sequenom acquisition [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable deferred tax liabilities assumed					45.1						$ 45.1
Finite-lived Intangible Assets Acquired											146.6
Goodwill, Acquired During Period											$ 206
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets											14 years 7 months
Excluding Covance [Member]
Cost of Acquired Entity [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired										688.8	$ 299.5
Finite-lived Intangible Assets Acquired										1,053	126.2
Goodwill, Acquired During Period										1,009.8	192.3
Acquisitions excluding LipoScience [Member]
Cost of Acquired Entity [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired												$ 128.4
Finite-lived Intangible Assets Acquired												17.4
Goodwill, Acquired During Period												68.4
Covance [Member]
Business Acquisition [Line Items]
Cash on Hand Used for Acquisition																$ 488.2
Business Acquisition, Share Price																$ 75.76
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Rate				26.86%
Acquisition Financing																$ 3,900,000
Business Acquisition, Transaction Costs	$ 25.4				6.9					25.4	6.9	$ 166
Purchase Price Allocation [Abstract]
Net Proceeds from Debt																	$ 2,870.2
Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Other Special Charges								$ 25.6		1.3	9
Selling, General and Administrative Expenses [Member] | Covance [Member]
Business Acquisition [Line Items]
Business Acquisition, Transaction Costs					113.4						113.4
Interest Expense [Member] | Covance [Member]
Business Acquisition [Line Items]
Business Acquisition, Transaction Costs					$ 52.6						$ 52.6
60-Day Debt Bridge Traunche [Domain]
Cost of Acquired Entity [Abstract]
Bridge Term Credit Facility Agreement, Maximum Borrowing Amount																		$ 400
Short-term Debt, Terms								P60D
Cash and Cash Equivalents [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										0
Accrued Liabilities [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										(27.6)
Deferred Revenue [Domain]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										0
Deferred tax liability [Domain]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										12.6
Other Liabilities [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										0
Accounts Receivable [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										(11.3)
Prepaid Expenses and Other Current Assets [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										0
Property, Plant and Equipment [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										0
Goodwill [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										83.9
Assets [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										12
Accounts Payable [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										27
Liability [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										12
Other Current Assets [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										$ 0
Software and Software Development Costs [Member] | Chiltern [Member]
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets										6 years
Use Rights [Member]
Cost of Acquired Entity [Abstract]
Finite-lived Intangible Assets Acquired										$ 0.9
Technology-Based Intangible Assets [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														26
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										(21)
Technology-Based Intangible Assets [Member] | Chiltern [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														47
Trademarks and Trade Names [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														10.6
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										$ (13.5)
Trademarks and Trade Names [Member] | Chiltern [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														24.1
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets										4 years
Trade Names [Member]
Cost of Acquired Entity [Abstract]
Finite-lived Intangible Assets Acquired										$ 15.7
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets										5 years 8 months
Customer Relationships [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														602
Finite-lived Intangible Assets Acquired										$ 955.7
Acquired Finite-lived Intangible Assets, Useful Life										21 years
Purchase Price Allocation [Abstract]
Weighted-average useful lives of identifiable intangible assets										20 years 8 months
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										$ (27)
Customer Relationships [Member] | Chiltern [Member]
Cost of Acquired Entity [Abstract]
Business combination, recognized identifiable intangible assets acquired														$ 629
Off-Market Favorable Lease [Member]
Noncontrolling Interest Put [Abstract]
Purchase price adjustment										$ 0.9
Senior notes due 2018 [Member]
Business Acquisition [Line Items]
Long-term debt, less current portion						$ 130

SUMMARY OF SIGNIFICANT ACCOUN54

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017USD ($)yr	Dec. 31, 2016USD ($)	Dec. 31, 2014	Dec. 31, 2015USD ($)
Goodwill [Line Items]
Cash, Uninsured Amount			$ 315.5
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			18.9	$ 14
Goodwill			7,530	6,424.4		$ 6,202.1
Derivative, Fair Value, Net			0
Other Inventory, Supplies, Gross			195.2	171.7
Inventory, Finished Goods, Gross			32.4	33.5
Unbilled Receivables, Current			138.2	97.1
Ownership percentage below which investments are generally accounted for on the cost method (in hundredths)	20.00%
Revenue from Medicare and Medicaid programs, percentage (in hundredths)	15.10%	15.50%			16.00%
Revenue from capitated agreements with certain managed care customers, percentage (in hundredths)	3.60%	3.40%			3.50%
Accounts receivable balances (gross) from Medicare and Medicaid			$ 109.8	113
Estimated useful life of capitalized software costs (in years) | yr			5
Minimum threshold percentage required to recognize income tax benefit (in hundredths)			50.00%
Accounts receivable from Ontario government sponsored healthcare plan			$ 12.9	$ 15.8
Percent of gross accounts receivable due from patients			20.90%	20.00%
Assets Held-for-sale, Not Part of Disposal Group, Current, Other			$ 55.2	$ 51.2
Gain (Loss) on Disposition of Assets				3.6
Minimum [Member] | Customer Relationships [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Minimum [Member] | Patents, Licenses And Technology [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			3 years
Minimum [Member] | Non-compete agreements [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			5 years
Minimum [Member] | Trade Names [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			5 years
Maximum [Member] | Customer Relationships [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			36 years
Maximum [Member] | Patents, Licenses And Technology [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			15 years
Maximum [Member] | Non-compete agreements [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Maximum [Member] | Trade Names [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life			15 years
LabCorp Diagnostics [Member]
Goodwill [Line Items]
Goodwill			$ 3,844.4	3,644.8		3,137.7
Covance Drug Development [Member]
Goodwill [Line Items]
Goodwill			$ 3,685.6	$ 2,779.6		$ 3,064.4

SUMMARY OF SIGNIFICANT ACCOUN55

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NET SALES (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net sales	$ 2,701.5	$ 2,597.9	$ 2,498.4	$ 2,408.1	$ 2,387.3	$ 2,372.7	$ 2,382	$ 2,295.2	$ 10,205.9	$ 9,437.2	$ 8,505.7
Intercompany revenue elimination									(1.8)	(0.8)	0
Revenues								9,641.8	10,441.4	9,641.8	8,680.1
Reimbursement Revenue								$ 204.6	$ 235.5	204.6	174.4
LabCorp Diagnostics [Member]
Percent of Revenue Contributed								69.90%	70.30%
Net sales									$ 7,170.5	6,593.9	6,199.3
Clinical diagnostics laboratory [Member]
Net sales									$ 7,170.5
Routine Testing [Member]
Net sales								$ 6,593.9			6,199.3
Genomic and Esoteric Testing [Member]
Net sales								$ 2,844.1			2,306.4
Covance Drug Development [Member]
Percent of Revenue Contributed								30.10%	29.70%
Net sales									$ 3,037.2	$ 2,844.1	2,306.4
Intercompany revenue elimination								$ (0.8)	(1.8)		$ 0
Other Segments [Member]
Net sales									$ 3,037.2

SUMMARY OF SIGNIFICANT ACCOUN56

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income [Abstract]
Net earnings, basic	$ 706.8	$ 180.6	$ 188.6	$ 192.2	$ 184.4	$ 179.5	$ 204.1	$ 164.1	$ 1,268.2	$ 732.1	$ 437.6
Net earnings, diluted									$ 1,268.2	$ 732.1	$ 437.6
Shares [Abstract]
Outstanding shares, basic (in shares)									102.4	102.5	98.8
Dilutive effect of stock options (in shares)									1.4	1.5	1.2
Dilutive effect of restricted stock awards and other (in shares)									0	0	0
Dilutive effect of convertible debt, net of tax (in shares)									0.1	0.3	0.6
Outstanding shares, diluted (in shares)									103.9	104.3	100.6
Per Share Amount [Abstract]
Basic earnings per common share	$ 6.91	$ 1.77	$ 1.84	$ 1.87	$ 1.79	$ 1.74	$ 2	$ 1.61	$ 12.39	$ 7.14	$ 4.43
Diluted earnings per share (in dollars per share)	$ 6.81	$ 1.74	$ 1.82	$ 1.84	$ 1.75	$ 1.71	$ 1.96	$ 1.58	$ 12.21	$ 7.02	$ 4.35

SUMMARY OF SIGNIFICANT ACCOUN57

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - ANTIDILUTIVE SECURITIES EXCLUDED FROM EARNINGS PER SHARE (Details) - shares shares in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017
Accounting Policies [Abstract]
Stock Options (in shares)	0	0	0.1

SUMMARY OF SIGNIFICANT ACCOUN58

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PROPERTY, PLANT AND EQUIPMENT (Details)	12 Months Ended
	Dec. 31, 2017
Minimum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	3 years
Minimum [Member] | Buildings and building improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	10 years
Minimum [Member] | Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	3 years
Minimum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	5 years
Maximum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	10 years
Maximum [Member] | Buildings and building improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	40 years
Maximum [Member] | Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	10 years
Maximum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum (years)	10 years

SUMMARY OF SIGNIFICANT ACCOUN59

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 7,530	$ 6,424.4	$ 6,202.1
Minimum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	10 years
Minimum [Member] | Patents, Licenses And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	3 years
Minimum [Member] | Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	5 years
Minimum [Member] | Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	5 years
Maximum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	36 years
Maximum [Member] | Patents, Licenses And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	15 years
Maximum [Member] | Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	10 years
Maximum [Member] | Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets, minimum (years)	15 years

RESTRUCTURING AND OTHER SPECI60

RESTRUCTURING AND OTHER SPECIAL CHARGES (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Sep. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Net restructuring charges			$ 70.9	$ 58.4		$ 113.9
Restructuring charges related to severance and other employee costs	$ 36.1			30.9		59.2
Restructuring charges related to contractual obligations associated with leased facilities and other facility related costs	39.9			33.8		55.8
Reduction in prior employee severance benefits related restructuring accruals			0.5
Reduction in prior facility related restructuring accruals	3.5		4.6			$ 1.1
Asset Impairment Charges			23.5	0	$ 39.7
Launchpad Phase 2 pretax savings			20
Launchpad net estimated cost savings			130
Reduction in total prior restructuring accruals			5.1
Gain (Loss) on Disposition of Assets				3.6
Amortization of Debt Discount (Premium)			5.6	5.6
Special charge, ST equity retention arrangement	5.4		0.9	2.5
Special charge, accelerated equity compensation	0.3			8.9
Special charge, wind-down of min volume contract	$ 5.7			4.6
Business Combination, Acquisition Related Costs			43.9	8
Other special charge, dissolution of equity investment			2.3
Payment of legal settlement		$ 49.5	12.2
Other special charges, non-capitalized costs			8.2		3
Covance [Member]
Restructuring Cost and Reserve [Line Items]
Business Acquisition, Transaction Costs			25.4	6.9	166
Covance [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Business Acquisition, Transaction Costs				113.4
Covance [Member] | Interest Expense [Member]
Restructuring Cost and Reserve [Line Items]
Business Acquisition, Transaction Costs				52.6
Covance Drug Development [Member]
Restructuring Cost and Reserve [Line Items]
Net restructuring charges			54.1	42.6	74.7
Asset Impairment Charges			23.5		26.7
LabCorp Diagnostics [Member]
Restructuring Cost and Reserve [Line Items]
Net restructuring charges			$ 16.8	$ 15.8	$ 39.2

RESTRUCTURING RESERVES (Details

RESTRUCTURING RESERVES (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Employee Severance Benefits Related Restructuring Reserve Accrual Adjustment		$ 0.5
Number of years restructuring liabilities expected to be paid out over		6 years 5 months
Balance, beginning of period	$ 82.3		$ 82.3
Restructuring charges		$ 76
Reduction of prior restructuring accruals		(5.1)
Cash payments and other adjustments		(98.5)
Balance, end of period		54.7		$ 82.3
Current		22.2	47.7
Non-current		32.5	34.6
Facility Related Restructuring Reserve Accrual Adjustment	$ 3.5	4.6			$ 1.1
Asset Impairment Charges		23.5	0	39.7
LabCorp Diagnostics [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		7.5
Restructuring charges		11.4
Reduction of prior restructuring accruals		(1.1)
Cash payments and other adjustments		(16.1)
Balance, end of period		1.7	7.5
LabCorp Diagnostics [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		14.1
Restructuring charges		6.6
Reduction of prior restructuring accruals		(0.1)
Cash payments and other adjustments		(10.5)
Balance, end of period		10.1	14.1
Covance Drug Development [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges		23.5		$ 26.7
Covance Drug Development [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		28.2
Restructuring charges		24.7
Reduction of prior restructuring accruals		3.5
Cash payments and other adjustments		(41.1)
Balance, end of period		8.3	28.2
Covance Drug Development [Member] | Lease and Other Facility Costs [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		32.5
Restructuring charges		33.3
Reduction of prior restructuring accruals		0.4
Cash payments and other adjustments		30.8
Balance, end of period		$ 34.6	$ 32.5

JOINT VENTURE PARTNERSHIPS AN62

JOINT VENTURE PARTNERSHIPS AND EQUITY METHOD INVESTMENTS (Details) CAD in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017CAD	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Investments in unconsolidated joint venture partnerships and equity method investments Financial Statement, Reported Amounts
Net Investment					$ (0.1)
Joint venture partnerships and equity method investments, condensed unconsolidated financial information
Current assets					45.7	$ 24.3
Other assets					14.4	16.9
Total assets					60.1	41.2
Current liabilities					31.6	15.5
Other liabilities					1	0.3
Total liabilities					32.6	15.8
Partners' equity					27.5	25.4
Total liabilities and partners’ equity					60.1	$ 41.2
Joint venture partnerships and equity method investments, condensed unconsolidated financial information, Income Statement
Net revenues	$ 156.7	$ 213.7	$ 212.5
Gross profit	45.7	54.3	62.6
Net earnings	$ 20.3	$ 20.1	$ 25.7
The value of the Company's recorded investment in the Alberta partnership assigned to Canadian licenses					34.6
AHS transfer to Canadian JV | CAD				CAD 50
Alberta, Canada [Member]
Investments in unconsolidated joint venture partnerships and equity method investments Financial Statement, Reported Amounts
Net Investment					$ (45.5)
Interest Owned				43.37%	43.37%
Charlotte, North Carolina [Member]
Investments in unconsolidated joint venture partnerships and equity method investments Financial Statement, Reported Amounts
Net Investment					$ (3.7)
Florence, South Carolina [Member]
Investments in unconsolidated joint venture partnerships and equity method investments Financial Statement, Reported Amounts
Net Investment					$ (10.1)
Interest Owned				49.00%	49.00%

ACCOUNTS RECEIVABLE, NET (Detai

ACCOUNTS RECEIVABLE, NET (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, net [Abstract]
Gross accounts receivable			$ 1,742.2	$ 1,564.3
Less allowance for doubtful accounts			(260.9)	(235.6)
Accounts receivable, net			1,481.3	$ 1,328.7
Provision for doubtful accounts	$ 287.3	$ 265.4	$ 314.7

PROPERTY, PLANT AND EQUIPMENT64

PROPERTY, PLANT AND EQUIPMENT, NET (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Property, plant and equipment, net
Gross property, plant and equipment			$ 3,328.6	$ 3,110.7
Less accumulated depreciation and amortization of capital lease assets			(1,579.7)	(1,392.1)
Property, plant and equipment, net			1,748.9	1,718.6
Depreciation expense and amortization of capital lease assets	$ 311.1	$ 269.9	306.8
Software depreciation	$ 79.2	$ 66.1	85.6
Land [Member]
Property, plant and equipment, net
Gross property, plant and equipment			78.4	78.4
Buildings and building improvements [Member]
Property, plant and equipment, net
Gross property, plant and equipment			708.6	692.8
Machinery and equipment [Member]
Property, plant and equipment, net
Gross property, plant and equipment			1,181	1,060.1
Software and Software Development Costs [Member]
Property, plant and equipment, net
Gross property, plant and equipment			672.2	626.2
Leasehold improvements [Member]
Property, plant and equipment, net
Gross property, plant and equipment			333.5	302
Furniture and Fixtures [Member]
Property, plant and equipment, net
Gross property, plant and equipment			90.6	76.9
Construction in progress [Member]
Property, plant and equipment, net
Gross property, plant and equipment			185.1	193
Equipment under capital leases [Member]
Property, plant and equipment, net
Gross property, plant and equipment			$ 79.2	$ 81.3

GOODWILL AND INTANGIBLE ASSET65

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 179.5	$ 164.5	$ 216.5	$ 179.5	$ 164.5
Finite-Lived Intangible Assets, Future Amortization Expense
Estimated amortization expense, 2013			195
Estimated amortization expense, 2014			187.2
Estimated amortization expense, 2015			179.8
Estimated amortization expense, 2016			176.8
Estimated amortization expense, 2017			175
Estimated amortization expense, Thereafter			$ 2,899.7

GOODWILL AND INTANGIBLE ASSET66

GOODWILL AND INTANGIBLE ASSETS - SCHEDULE OF GOODWILL (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill	$ 6,202.1	$ 6,424.4	$ 6,202.1
Adjustments to goodwill	(176)	95.8
Goodwill, Acquired During Period	398.3	1,009.8
Goodwill [Roll Forward]
Balance as of January 1	6,202.1	6,424.4	6,202.1
Adjustments to goodwill	(176)	95.8
Goodwill, net		7,530	6,424.4
LabCorp Diagnostics [Member]
Goodwill [Line Items]
Goodwill	3,137.7	3,644.8	3,137.7
Adjustments to goodwill	108.8	1.1
Goodwill, Acquired During Period	398.3	198.5
Goodwill [Roll Forward]
Balance as of January 1	3,137.7	3,644.8	3,137.7
Adjustments to goodwill	108.8	1.1
Goodwill, net		3,844.4	3,644.8
Covance Drug Development [Member]
Goodwill [Line Items]
Goodwill	3,064.4	2,779.6	3,064.4
Adjustments to goodwill	(284.8)	94.7
Goodwill, Acquired During Period	0	811.3
Goodwill [Roll Forward]
Balance as of January 1	3,064.4	2,779.6	3,064.4
Adjustments to goodwill	$ (284.8)	94.7
Goodwill, net		$ 3,685.6	$ 2,779.6

GOODWILL AND INTANGIBLE ASSET67

GOODWILL AND INTANGIBLE ASSETS - COMPONENTS OF IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	$ 5,767.7	$ 4,604.1
Accumulated Amortization	(1,426.9)	(1,203.6)
Net Carrying Amount	4,340.8	3,400.5
Customer Relationships [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount		3,275.3
Accumulated Amortization		(855.2)
Net Carrying Amount		2,420.1
Patents, licenses and technology [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount		395.3
Accumulated Amortization		(163.3)
Net Carrying Amount		232
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount		53
Accumulated Amortization		(42.1)
Net Carrying Amount		10.9
Trade names [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount		406.3
Accumulated Amortization		(141.6)
Net Carrying Amount		264.7
Canadian licenses [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount		464.2
Accumulated Amortization		0
Net Carrying Amount		464.2
Patents, licenses and technology [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	457.9
Accumulated Amortization	(188.6)
Net Carrying Amount	269.3
Customer Relationships [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	4,297.9
Accumulated Amortization	(1,014.9)
Net Carrying Amount	3,283
Use Rights [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	10.9	10
Accumulated Amortization	(2.6)	(1.4)
Net Carrying Amount	8.3	$ 8.6
Trade names [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	426.3
Accumulated Amortization	(171.4)
Net Carrying Amount	254.9
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	79
Accumulated Amortization	(49.4)
Net Carrying Amount	29.6
Canadian licenses [Member]
Finite-Lived Intangible Assets [Abstract]
Gross Carrying Amount	495.7
Accumulated Amortization	0
Net Carrying Amount	$ 495.7

GOODWILL AND INTANGIBLE ASSET68

GOODWILL AND INTANGIBLE ASSETS - SUMMARY OF ACQUIRED AMORTIZABLE INTANGIBLE ASSETS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,053
Weighted average amortization period (in years)	19 years 3 months
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 955.7
Weighted average amortization period (in years)	20 years 8 months
Patents, licenses and technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 52.9
Weighted average amortization period (in years)	6 years 8 months
Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 27.8
Weighted average amortization period (in years)	6 years 7 months
Trade names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 15.7
Weighted average amortization period (in years)	5 years 8 months
Use Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 0.9

ACCRUED EXPENSES AND OTHER (Det

ACCRUED EXPENSES AND OTHER (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accrued expenses and other [Abstract]
Employee compensation and benefits	$ 324.6	$ 288.2
Self-insurance reserves	45.7	48.2
Accrued taxes payable	64.5	61.2
Royalty and license fees payable	6.2	9.5
Restructuring reserves	22.2	47.7
Acquisition related reserves	21.3	10.3
Interest payable	71.7	58.6
Other Accrued Liabilities	24.6	19.5
Other	52.1	50.5
Total accrued expenses and other	$ 632.9	$ 593.7

OTHER LIABILITIES (Details)

OTHER LIABILITIES (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Post-retirement benefit obligation	$ 7.4	$ 5.8
Defined-benefit plan obligation	163.4	195.4
Restructuring reserves	32.5	34.6
Self-insurance reserves	28.9	17.1
Acquisition related reserves	3.1	15.7
Deferred Compensation Liability, Classified, Noncurrent	64.5	54.2
Workers' Compensation Liability, Noncurrent	39	33.1
Accrued Rent	12.7	13.3
Escheat liability	10.9	8.3
Other	15.8	14.5
Total other liabilities	$ 378.2	$ 392

DEBT - SCHEDULE OF SHORT-TERM D

DEBT - SCHEDULE OF SHORT-TERM DEBT (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Debt, Current	$ 417.5	$ 549.5
Convertible Subordinated Debt, Current	8.8	42.4
Short term debt issuance costs	(1.4)	(1.3)
Capital Lease Obligations, Current	8.3	8.4
Notes Payable, Current	1.8	0
Senior notes current 2016	$ 0	$ 500

DEBT - SCHEDULE OF LONG-TERM DE

DEBT - SCHEDULE OF LONG-TERM DEBT (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Jan. 30, 2015	Dec. 19, 2014	Nov. 01, 2013
Debt Instrument [Line Items]
Other Long-term Debt	$ 72
Long-term Debt and Capital Lease Obligations, Current	424.8
Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months	409.2
Credit Facility Option to Increase					$ 350
Long-term debt, less current portion	6,344.6		$ 5,300
2.50% Senior notes due 2018	0		400
2014 Term Loan	72		565
4.625% Senior notes due 2020	604.1		614.6
Senior notes due 2027	600		0
4.70 % Senior notes due 2045	900		900
Senior notes due 2024	600		0
3.60% Senior notes due 2025	1,000		1,000
2017 Term loan	750		0
Long term debt issuance costs	(48.2)		(43)
Notes Payable, Noncurrent	8.9		7.2
Senior Notes, Noncurrent	2,900			$ 2,900		$ 700
3.20% Senior notes due 2022	500		500
4.00% Senior notes due 2023	300		300
3.75% Senior notes due 2022	500		500
2.625% Senior Notes due 2020	500		500
Long-term Debt, Current Maturities	(409.2)
Capital lease obligations, net of interest, current	(8.3)
Long term and capital lease obligations, net of interest, current	(417.5)
Capital Lease Obligations, Current	15.6
Long-term Debt, Maturities, Repayments of Principal in Year Two	35.9
Total long-term debt	6,286.8
Capital Lease Obligations, Noncurrent	57.8		$ 56.2
Capital Leases, Future Minimum Payments Due in Two Years	14.4
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	50.3
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,226.9
Capital Leases, Future Minimum Payments Due in Three Years	13.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	1,240
Long-term Debt, Maturities, Repayments of Principal in Year Four	71
Capital Leases, Future Minimum Payments Due in Four Years	11.7
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	82.7
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,601.3
Capital Leases, Future Minimum Payments Due in Five Years	10.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	1,611.9
Long-term Debt, Maturities, Repayments of Principal after Year Five	3,351.7
Capital Leases, Future Minimum Payments Due Thereafter	45.1
Long-term Debt	6,696
Capital lease obligations, net of interest	66.1
Long term and capital lease obligations, net of interest	6,762.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	3,396.8
Capital Lease Obligations	110.5
Long-term Debt and Capital Lease Obligations	6,806.5
Long term debt, future minimum payments, interest included in payments	0
Capital Leases, Future Minimum Payments, Interest Included in Payments	(44.4)
Long term and capital lease future minimum payments, interest included in payments	(44.4)
Long term and capital lease obligations, net of interest, noncurrent	$ 6,344.6
Debt Instrument, Basis Spread on Variable Rate	2.298%
Senior notes due 2018 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent						400
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				500
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				500
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent						$ 300
Senior notes due 2024 [Member] [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion		$ 600
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 900

DEBT - CREDIT FACILITIES (Detai

DEBT - CREDIT FACILITIES (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016Quarters	Dec. 31, 2017USD ($)$ / shares	Dec. 31, 2016USD ($)	Dec. 19, 2014USD ($)
Line of Credit Facility [Line Items]
Long-term debt, less current portion		$ 6,344.6	$ 5,300
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,000
Debt covenant, requirement for number of consecutive fiscal quarters | Quarters	4
Credit Facility Option to Increase				350
Credit Facility, Maximum Swing Line Borrowings				100
Long-term Debt, Maturities, Repayment Terms		P5Y
Debt Covenant Requirement [Member]
Line of Credit Facility [Line Items]
Debt to EBITDA (leverage) ratio			3
Debt Covenant Actual [Member]
Line of Credit Facility [Line Items]
Debt to EBITDA (leverage) ratio			2.5
60-Day Debt Bridge Traunche [Domain]
Line of Credit Facility [Line Items]
Bridge Term Credit Facility Agreement, Maximum Borrowing Amount				400
Short-term Debt, Terms	P60D
Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End		2.80%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Facility, Maximum Letters of Credit				$ 150
Debt to EBITDA (leverage) ratio			3,200,000
Line of Credit Facility, Interest Rate at Period End		2.70%
Prime Rate [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.125% to 1.00%	0.0% to 0.50%
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%
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] | Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	1.125% to 2.00%	0.875% to 1.50%
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%
Zero-coupon convertible subordinated notes [Member]
Line of Credit Facility [Line Items]
Zero Coupon Convertible Subordinated Notes Conversion Trigger Price | $ / shares		$ 77.45

DEBT - COVERTIBLE SUBORDINATED

DEBT - COVERTIBLE SUBORDINATED NOTES (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016USD ($)shares	Mar. 31, 2015shares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Debt, Current			$ 417,500,000	$ 549,500,000
Payments On Zero Coupon Subordinated Notes			$ 33,900,000	$ 53,700,000	$ 1,300,000
Common stock issued upon conversion of zero-coupon subordinated notes (in shares) | shares	400,000	0	300,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt to EBITDA (leverage) ratio				3,200,000
Zero-coupon convertible subordinated notes [Member]
Debt Instrument [Line Items]
Principal amount at maturity of zero-coupon subordinated notes outstanding			$ 9,000,000	$ 46,000,000
Issued price per principal amount at maturity			$ 671.65
Principal amount of zero-coupon subordinated notes				$ 1,000
Debt Instrument, Interest Rate, Effective Percentage				2.00%
Stock conversion rate for zero-coupon subordinated notes (per thousand) | shares				13.4108
Minimum number of trading days in a period the common stock sale price must meet a specified threshold to trigger conversion price (in days)	20
Number of consecutive trading days ending on the last trading day of the preceding quarter for the common stock sale price to reach a specified threshold to trigger conversion price (in days)	30
Common stock sales price threshold, beginning	120.00%
Common stock sales price threshold, declining per quarter	0.1282%
Common stock sales price threshold, ending	110.00%
Zero Coupon Convertible Subordinated Notes Conversion Trigger Price | $ / shares			$ 77.45
Principal Amount At Maturity Of Zero Coupon Subordinated Notes Converted	$ 59,400,000		$ 37,100,000
Value Of Cash And Common Stock In Connection With Conversions Of Zero Coupon Subordinated Notes Settled In Current Period	53,700,000		33,900,000
Payments On Zero Coupon Subordinated Notes	$ 53,700,000		$ 33,900,000
Common stock issued upon conversion of zero-coupon subordinated notes (in shares) | shares	400,000		300,000
Tax Benefit Realized Upon Conversion Of Zero Coupon Convertible Debt	$ 4,900,000		$ 0
Contingent cash interest accrual rate description	no less than 0.125% of the average market price of a zero-coupon subordinated note for the five trading days ended September 8, 2017, in addition to the continued accrual of the original issue discount
Contingent cash interest accrual rate	0.125%
Number of days used to establish average market price of zero coupon subordinated notes	5
Debt Conversion Date Of Subordinated Notes And Indenture			Oct. 24, 2006

DEBT - SENIOR NOTES (Details)

DEBT - SENIOR NOTES (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jan. 30, 2015	Dec. 19, 2014	Nov. 01, 2013	Aug. 23, 2012
Debt Instrument [Line Items]
Credit Facility, Maximum Swing Line Borrowings					$ 100
Senior Notes, Noncurrent		$ 2,900		$ 2,900		$ 700
Long-term debt, less current portion		$ 6,344.6	$ 5,300
Debt Instrument, Basis Spread on Variable Rate		2.298%
Fair Value Hedges, Net		$ 14.6
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 900
Interest rate (in hundredths)				4.70%
Senior notes due 2018 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent						$ 400
Interest rate (in hundredths)						2.50%
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent						$ 300
Interest rate (in hundredths)						4.00%
Covance senior notes due 2020 [Domain]
Debt Instrument [Line Items]
Interest rate (in hundredths)				2.625%
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 500
Interest rate (in hundredths)		4.625%		2.625%
Senior notes due 2017 [Member]
Debt Instrument [Line Items]
Interest rate (in hundredths)							2.20%
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 500
Interest rate (in hundredths)				3.20%			3.75%
Senior notes due 2025 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 1,000
Interest rate (in hundredths)				3.60%
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion		$ 600
Senior notes due 2015 [Member]
Debt Instrument [Line Items]
Periodic payments, frequency	semi-annually
Excluding Underwriting Discounts & Other Fees [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent				$ 2,870.2
Fair Value, Inputs, Level 2 [Member]
Debt Instrument [Line Items]
Fair Value Hedges, Net		$ 4.1

PREFERRED STOCK AND COMMON SH76

PREFERRED STOCK AND COMMON SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012
Stockholders' Equity Note [Abstract]
Stock Repurchased During Period, Shares			2.5
Treasury Stock, Carrying Basis						$ 338.1
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax						$ 0	$ 0	$ 0	$ 0.1
Common shares issued and outstanding [Abstract]
Common shares issued	123.9		125.6	123.9	123.9	125.1	125.6	123.9		107.1
In treasury	(22.6)		(22.9)	(22.6)	(22.6)	(23.2)	(22.9)	(22.6)		(22.5)
Outstanding						101.9	102.7
Common stock, shares authorized (in shares)						265
Common stock, par value per share (in dollars per share)						$ 0.10
Preferred stock, shares authorized (in shares)						30
Preferred stock, par value per share (in dollars per share)						$ 0.10
Rollforward of common shares issued [Abstract]
Common shares issued, beginning balance (in shares)	123.9		125.6	123.9
Common stock issued under employee stock plans (in shares)	1.6	1.5	1.7
Common stock issued upon conversion of zero-coupon subordinated notes (in shares)	0.4	0	0.3
Common stock shares issued for Acquisition	0	15.3	0
Common shares repurchased (in shares)	(0.3)	0	(2.5)
Common shares issued, ending balance (in shares)			125.1	125.6	123.9
Rollforward of common shares held in treasury [Abstract]
Common shares held in treasury, beginning balance	22.6		22.9	22.6
Surrender of restricted stock and performance share awards	0.3	0.1	0.3
Common shares held in treasury, ending balance			23.2	22.9	22.6
Share repurchase program [Abstract]
Purchase of common stock			$ (338.1)	$ (43.9)
Outstanding common stock repurchase authorization						$ 401.4
Foreign Currency Translation Adjustments
Foreign Currency Translation Adjustments, balance	$ (212.6)	$ 68	(470.7)	(212.6)	$ 68
Current year adjustments, Foreign Currency Translation Adjustments	(250)	(370.7)	262.3	(250)	(370.7)
Tax effect of adjustments, Foreign Currency Translation Adjustments	(8.1)	90.1	(34.3)
Foreign Currency Translation Adjustments, balance			(242.7)	(470.7)	(212.6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax	(3.3)	19	2.4
Net Benefit Plan Adjustments
Net Benefit Plan Adjustments, balance	(74.4)	(78.6)	(110.4)	(74.4)	(78.6)
Tax effect of adjustments, Net Benefit Plan Adjustments	4.3	(3.5)	(3.5)
Net Benefit Plan Adjustments, balance			(93)	(110.4)	(74.4)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax			0	0	(0.1)
Interest Rate Swap Adjustments
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(253.3)	(351.8)	264.7
Accumulated Other Comprehensive Earnings
Accumulated Other Comprehensive Earnings, balance						335.7	$ 581.1		$ 10.5	$ 10.5
Tax effect of adjustments, Accumulated Other Comprehensive Earnings	(3.8)	86.6	(37.8)	(3.8)	$ 86.6
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	(37)	(11.3)	18.5
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(37)	$ (11.3)	18.5
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments and Tax	$ 0		0
AOCI Attributable to Parent [Member]
Share repurchase program [Abstract]
Purchase of common stock			$ 0	$ 0
Accumulated Other Comprehensive Earnings
Accumulated Other Comprehensive Earnings, balance						$ 335.7	$ 581.1	$ 287

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2012
Valuation Allowance [Line Items]
Effective Income Tax Rate Reconciliation, Repatriation Foreign Earnings, Jobs Creation Act of 2004, Percent			$ 519
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			18.9	$ 14
Pre-tax income [Abstract]
Domestic	$ 914	$ 593.5	891.8
Foreign	191.5	132.5	243.1
Total pre-tax income	1,105.5	726	1,134.9	1,105.5	$ 726
Current:
Federal	235.1	218.3	300.8
State	38.6	33.7	32.9
Foreign	43.9	69.4	53
Total current income taxes	317.6	321.4	386.7
Deferred Federal Income Tax Expense (Benefit)	64.4	(14.1)	(534.3)
Deferred:
Federal			3.9
State	6	(4.2)	12.9
Foreign	(15.7)	(15.8)	(4.4)
Total deferred income taxes	54.7	(34.1)	(525.8)	54.7	(34.1)
Total income tax provision	$ 372.3	$ 287.3	$ (139.1)	$ 372.3	287.3
Deferred Tax Assets, Operating Loss Carryforwards, State and Local						$ 602.2
Operating Loss Carryforwards, Valuation Allowance						485.5
Tax benefit associated with option exercises from stock plans					$ 13.1
Federal statutory tax rate reconciliation [Abstract]
Statutory U.S. rate	35.00%	35.00%	35.00%
State and local income taxes, net of U.S. Federal income tax effect	2.60%	3.20%	2.50%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(3.10%)	(1.80%)	(3.50%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Restructuring Charges, Percent	0.00%	2.70%	0.60%
Effective Income Tax Rate Reconciliation, Deduction, Percent	(1.20%)	(0.00%)	(1.70%)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount			(35.00%)	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Repatriation Foreign Earnings, Jobs Creation Act of 2004, Percent			(15.80%)	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent			5.00%	0.00%	0.00%
Other	0.40%	1.10%	0.60%
Effective rate	33.70%	40.20%	(12.30%)
Deferred tax assets:
Accounts receivable						14.7	$ 13.5
Employee compensation and benefits						113.6	160.8
Acquisition and restructuring reserves						16.8	38.5
Tax loss carryforwards						107	167.7
Other						26	44.8
Total deferred tax assets						278.1	425.3
Less: valuation allowance						(42.8)	(31.3)
Deferred tax assets, net of valuation allowance						235.3	394
Deferred tax liabilities:
Deferred earnings						(5.1)	(193.2)
Intangible assets						(913.2)	(1,047.4)
Property, plant and equipment						(156.9)	(208.8)
Zero-coupon subordinated notes						(10.1)	(48.5)
Currency translation adjustment						(0.1)	(47)
Deferred Tax Liabilities, Other						27.2	(27.9)
Total gross deferred tax liabilities						(877.3)	(1,178.8)
Deferred Tax Liabilities, Gross						1,112.6	1,572.8
Foreign tax loss carryovers						37.4
Foreign Tax Loss Carryover with Valuation Allowance			$ 27.1
Federal tax loss carryovers						294.3
Federal tax loss carryovers, expiration dates			Dec. 31, 2035
Capital loss carryover						6.9
Gross unrecognized income tax benefits	$ 24.2		$ 18.4	$ 24.2	$ 24.2	19.5	18.4	$ 16.7
Accrued interest and penalties related to unrecognized income tax benefits						7.9	9.9
Interest and penalties expense related to unrecognized income tax benefits	1.2	$ 1.8	2.3
Interest and penalties benefit related to unrecognized income tax benefits	4	2.2	4.3
Reconciliation of unrecognized tax benefits [Roll Forward]
Balance as of January 1	24.2		18.4	24.2
Increase in reserve for tax positions taken in the current year	2.3	4.1	7.3
Increase in reserve as a result of acquisition	0	8.5	0
Decrease in reserve as a result of lapses in the statute of limitations	$ (8.1)	$ (5.1)	(6.2)
Balance as of December 31			$ 19.5	$ 18.4	$ 24.2
Unrecognized income tax benefits that would impact effective tax rate						$ 19.5	$ 18.4

STOCK COMPENSATION PLANS (Detai

STOCK COMPENSATION PLANS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017
Summary of Changes in Options Outstanding Under the Stock Incentive Plans [Rollforward]
Shares authorized for issuance under the 2008 and 2000 Stock Incentive Plans			10.7
Shares available for grant under the Company's stock option plans			8.3
Award vesting period (in years)			3 years
Stock Options Vested and Expected to Vest at December 31, 2011
Aggregate intrinsic value, vested and expected to vest options			$ 82.1
Stock Options Exercised, Impact Disclosures
Cash received by the Company	$ 52.6	$ 82.6	43.9
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	13.6	16.2	13.4
Aggregate intrinsic value	$ 35.5	$ 42.2	$ 34.8
Assumptions the Company Used to Develop Fair Value Estimates
Fair value of the employee's purchase right	$ 23.32	$ 21.95	$ 31.54
Fair Values of Options Granted and the Employee's Purchase Right in the Stock Purchase Plan
Stock option plan expense	$ 0	$ 2.2	$ 0.9
Restricted Stock and Performance Shares
Restricted stock, vesting increment			one third increments beginning on the first anniversary of the grant
Performance share awards, vesting conditions			Performance share awards are subject to certain earnings per share, revenue, operating income, earnings before income taxes and total shareholder return targets
Restricted stock and performance share compensation expense	104.1	83.8	$ 100.8
Unrecognized compensation cost related to nonvested restricted stock and performance share-based compensation arrangements			$ 104
Unrecognized compensation cost weighted average expected future recognition period (in years)			1 year 10 months
Employee Stock Purchase Plan Disclosure
Shares of common stock authorized for issuance under the employee stock purchase plan			2.4
The employee stock purchase plan permits employees to purchase shares of common stock at a certain percentage of the market price (in hundredths)			85.00%
Number of shares purchased by eligible employees			0.3
Expense related to the Company's employee stock purchase plan	$ 5.5	$ 4.1	$ 8
Employee Stock Purchase Plan [Member]
Assumptions the Company Used to Develop Fair Value Estimates
Risk free interest rate	0.50%	0.30%	1.30%
Expected volatility	20.00%	20.00%	20.00%
Expected dividend yield	0.00%	0.00%	0.00%
Restricted Stock and Performance Shares [Member]
Summary of Nonvested Shares
Nonvested, beginning of period			1.6
Number of options granted			0.9
Number of options vested			(0.9)
Nonvested, end of period			1.5
Weighted-average grant date fair value, nonvested, beginning of period			$ 108.23
Weighted-average grant date fair value, granted			132.48
Weighted-average grant date fair value, vested			$ 100.86
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period			0.1
Weighted-average grant date fair value, nonvested, end of period			$ 121.36
Employee Stock Purchase Plan Disclosure
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 118.74
Stock Options [Member]
Changes in Options Outstanding Under the Stock Incentive Plans, Additional Disclosures
Number of options outstanding, beginning balance			1.6
Number of options granted			0.1
Number of options exercised			(0.5)
Number of options cancelled			0
Number of options outstanding, ending balance			1.2
Weighted-average exercise price per option, outstanding, beginning balance			$ 82.43
Weighted-average exercise price per option granted			130.60
Weighted-average exercise price per option exercised			83.85
Weighted-average exercise price per option cancelled			80.37
Weighted-average exercise price per option, outstanding, ending balance			$ 86.55
Weighted-average remaining contractual term of options outstanding (in years)			3 years 11 months
Aggregate intrinsic value of options outstanding			$ 85.4
Stock Options Vested and Expected to Vest at December 31, 2011
Number of options vested and expected to vest			1.1
Weighted-average exercise price per option, vested and expected to vest options			$ 81.73
Weighted-average exercise price per exercisable option			$ 81.73
Weighted-average remaining contractual term, vested and expected to vest options (in years)			3 years 4 months
Number of options exercisable			1.1
Weighted-average remaining contractual term, exercisable options (in years)			3 years 4 months
Aggregate intrinsic value, exercisable options			$ 82.1

STOCK COMPENSATION PLANS (Sched

STOCK COMPENSATION PLANS (Schedule of Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices) (Details) shares in Millions	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices
Number Outstanding | shares	1.2
Options outstanding, weighted-average remaining contractual life (in years)	3 years 11 months
Options outstanding, weighted-average exercise price	$ 86.55
Options exercisable | shares	1.2
Options exercisable, weighted-average exercise price	$ 81.73
Exercise Price Range 2 [Member]
Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices
Exercise price range, lower range limit	64.43
Exercise price range, upper range limit	$ 75.63
Number Outstanding | shares	0.1
Options outstanding, weighted-average remaining contractual life (in years)	1 year 1 month
Options outstanding, weighted-average exercise price	$ 60.64
Options exercisable | shares	0.1
Options exercisable, weighted-average exercise price	$ 60.64
Exercise Price Range 3 [Member]
Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices
Exercise price range, lower range limit	75.64
Exercise price range, upper range limit	$ 84.86
Number Outstanding | shares	0.2
Options outstanding, weighted-average remaining contractual life (in years)	1 year 9 months
Options outstanding, weighted-average exercise price	$ 72.06
Options exercisable | shares	0.2
Options exercisable, weighted-average exercise price	$ 72.06
Exercise Price Range 4 [Member]
Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices
Exercise price range, lower range limit	84.87
Exercise price range, upper range limit	$ 130.60
Number Outstanding | shares	0.6
Options outstanding, weighted-average remaining contractual life (in years)	4 years 2 months
Options outstanding, weighted-average exercise price	$ 84.73
Options exercisable | shares	0.6
Options exercisable, weighted-average exercise price	$ 84.73
Exercise Price Range 5 [Member]
Options Outstanding and Exercisable at December 31, 2013, by Range of Exercise Prices
Number Outstanding | shares	0.3
Options outstanding, weighted-average remaining contractual life (in years)	5 years 2 months
Options outstanding, weighted-average exercise price	$ 105.29
Options exercisable | shares	0.3
Options exercisable, weighted-average exercise price	$ 91.13

(Details)

(Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2011	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Loss related to litigation settlement	$ 34.5		$ 34.5
Previously recorded litigation reserve in connection with false claims act lawsuit			$ 15		$ 15
Payment of legal settlement		$ 49.5		$ 12.2

COMMITMENTS AND CONTINGENT LI81

COMMITMENTS AND CONTINGENT LIABILITIES (Details) CAD in Millions, $ in Millions	3 Months Ended					12 Months Ended
	Mar. 31, 2016USD ($)	Sep. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Sep. 30, 2011USD ($)	Jun. 30, 2011USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017CAD	Dec. 31, 2017USD ($)	Jul. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jul. 27, 2016USD ($)	Feb. 19, 2015USD ($)	Aug. 24, 2012Recipients$ / Violation
Loss Contingencies [Line Items]
Percent of lowest maximum (cap on payments)						80.00%
Payment reduction by Assembly Bill No. 97						10.00%
Other Inventory, Supplies, Gross								$ 195.2		$ 171.7
Loss related to litigation settlement	$ 34.5				$ 34.5
Previously recorded litigation reserve in connection with false claims act lawsuit					$ 15					$ 15
Payment of legal settlement		$ 49.5				$ 12.2
AHS transfer to Canadian JV | CAD							CAD 50
Total acquisition consideration (cash and non-cash)									$ 1,224.5		$ 249.1	$ 6,150.7
Number of recipients | Recipients													39
Proposed damages per violation | $ / Violation													0.0005
Letters of credit								72.2
Future minimum rental commitments [Abstract]
2,013								196.1
2,014								149
2,015								109.7
2,016								83.5
2,017								64.2
Thereafter								160.9
Total minimum lease payments								763.4
Less: amounts included in restructuring and acquisition related accruals								(17.6)
Less: non-cancelable sub-lease income								0
Total minimum operating lease payments								$ 745.8
Rental expense	$ 291.2		$ 287.1			$ 313.8
Litigation Settlement, Amount (Deprecated 2017-01-31)				$ 49.5

PENSION AND POSTRETIREMENT PL82

PENSION AND POSTRETIREMENT PLANS (Details) - USD ($) $ in Millions		3 Months Ended		10 Months Ended	12 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018	Dec. 31, 2014	Dec. 31, 2012
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits					$ 0	$ 1.6
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate						6.70%
Maximum deferral percentage of annual base salary					50.00%
Defined Benefit Plan, Funded (Unfunded) Status of Plan					$ 104.3	$ 119
Minimum non-elective contribution (NEC) % for the 401(K) plan (in hundredths)					3.00%
Discretionary contribution % for the 401(K) plan, range minimum (in hundredths)					1.00%
Discretionary contribution % for the 401(K) plan, range maximum (in hundredths)					3.00%
Defined contribution retirement plan cost		$ 56	$ 43.3		$ 58.1
Postemployment Benefits, Period Expense					$ 37.8
Defined Contribution Plan, Employer Matching Contribution, Percent of Match					4.50%
Company contributions to the defined benefit retirement plan		10.8	9.5		$ 16
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year					247.5
Fair value of plan assets at end of year					263.7	247.5
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Tax effect of adjustments, Net Benefit Plan Adjustments		4.3	$ (3.5)		(3.5)
Accumulated Other Comprehensive Income (Loss), Net of Tax					$ (335.7)	(581.1)			$ (10.5)	$ (10.5)
Pension and Other Postretirement Benefits Disclosure [Text Block]					PENSION AND POSTRETIREMENT PLANS Pension Plans The Company has a defined-benefit retirement plan (Company Plan) and a nonqualified supplemental retirement plan (PEP). Both plans have been closed to new participants since December 31, 2009. Employees participating in the Company Plan and the PEP no longer earn service-based credits, but continue to earn interest credits. In addition, effective January 1, 2010, all employees eligible for the defined-contribution retirement plan (401K Plan) receive a minimum 3% non-elective contribution (NEC) concurrent with each payroll period. Employees are not required to make a contribution to the 401K Plan to receive the NEC. The NEC is non-forfeitable and vests immediately. 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 service. The Company’s 401K Plan covers substantially all pre-Covance acquisition employees. Prior to 2010, Company contributions to the plan were based on a percentage of employee contributions. From 2011, the Company made non-elective and discretionary contributions to the plan. In 2017, 2016, and 2015, non-elective and discretionary contributions were $58.1 , $56.0 and $43.3 , respectively. As a result of the Covance acquisition, the Company also incurred expense of $37.8 for the Covance 401K Plan during the year ended December 31, 2015. Under the Covance 401K Plan, which is available on a voluntary basis to substantially all U.S. Covance employees, the Company matches employee contributions up to a maximum Company contribution of 4.5% . The Company Plan covers substantially all employees employed prior to December 31, 2009. The benefits to be paid under the Company Plan are based on years of credited service through December 31, 2009, interest credits and average compensation. The Company’s policy is to fund the Company Plan with at least the minimum amount required by applicable regulations. The Company made contributions to the Company Plan of $16.0 , $10.8 and $9.5 in 2017 , 2016 and 2015 , respectively. The PEP covers a portion of the Company’s senior management group. Prior to 2010, the PEP provided for the payment of the difference, if any, between the amount of any maximum limitation on annual benefit payments under the Employee Retirement Income Security Act of 1974 and the annual benefit that would be payable under the Company Plan but for such limitation. Effective January 1, 2010, employees participating in the PEP no longer earn service-based credits. The PEP is an unfunded plan. Projected pension expense for the Company Plan and the PEP is expected to increase to $13.3 in 2018 . This amount excludes any accelerated recognition of pension cost due to the total lump-sum payouts exceeding certain components of net periodic pension cost in a fiscal year. If such levels were to be met in 2018 , the Company projects that it would result in additional pension expense of several million dollars. The actual amount would be determined in the fiscal quarter when the lump-sum payments cross the threshold and would be based upon the plan's funded status and actuarial assumptions in effect at that time. The Company plans to make contributions of $ 7.6 to the Company Plan and the PEP during 2018 . The effect on operations for both the Company Plan and the PEP are summarized as follows: Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ 5.5 $ 4.9 $ 3.9 Interest cost on benefit obligation 14.4 15.5 15.1 Expected return on plan assets (16.3 ) (16.7 ) (18.3 ) Net amortization and deferral 11.0 11.2 11.3 Defined-benefit plan costs $ 14.6 $ 14.9 $ 12.0 Amounts included in accumulated other comprehensive earnings consist of unamortized net loss of $127.4 . The accumulated other comprehensive earnings that are expected to be recognized as components of the defined-benefit plan costs during 2018 are $10.9 related to amortization of the net loss. A summary of the changes in the projected benefit obligations of the Company Plan and the PEP are summarized as follows: 2017 2016 Balance at January 1 $ 366.5 $ 363.1 Service cost 5.5 4.9 Interest cost 14.4 15.5 Actuarial loss 12.2 12.1 Benefits and administrative expenses paid (30.6 ) (29.1 ) Balance at December 31 $ 368.0 $ 366.5 The Accumulated Benefit Obligation was $368.0 and $366.5 at December 31, 2017 and 2016 , respectively. A summary of the changes in the fair value of plan assets follows: 2017 2016 Fair value of plan assets at beginning of year $ 247.5 $ 250.6 Actual return on plan assets 29.2 13.6 Employer contributions 17.6 12.4 Benefits and administrative expenses paid (30.6 ) (29.1 ) Fair value of plan assets at end of year $ 263.7 $ 247.5 The net funded status of the Company Plan and the PEP at December 31: 2017 2016 Funded status $ 104.3 $ 119.0 Recorded as: Accrued expenses and other $ 2.2 $ 2.0 Other liabilities 102.1 117.0 $ 104.3 $ 119.0 Weighted average assumptions used in the accounting for the Company Plan and the PEP are summarized as follows: 2017 2016 2015 Discount rate 3.7 % 4.2 % 4.0 % Expected long term rate of return 6.8 % 6.8 % 7.0 % The Company also updated the mortality assumption to the RP-2014 Mortality Tables in 2016 and again in 2017 which decreased the Company's total projected obligation. The Company maintains an investment policy for the management of the Company Plan’s assets. The objective of this policy is to build a portfolio designed to achieve a balance between investment return and asset protection by investing in indexed funds that are comprised of equities of high quality companies and in high quality fixed income securities which are broadly balanced and represent all market sectors. The target allocations for plan assets are 50% equity securities, 45% fixed income securities and 5% in other assets. Equity securities primarily include investments in large-cap, mid-cap and small-cap companies located in the U.S. and to a lesser extent international equities in developed and emerging countries. Fixed income securities primarily include U.S. Treasury securities, mortgage-backed bonds and corporate bonds of companies from diversified industries. Other assets include investments in commodities. The weighted average expected long-term rate of return for the Company Plan’s assets is as follows: Target Weighted Average Expected Long-Term Rate of Return Equity securities 50.0 % 5.6 % Fixed income securities 45.0 % 1.1 % Other assets 5.0 % 0.1 % The fair values of the Company Plan’s assets at December 31, 2017 , and 2016 , by asset category are as follows: Fair Value Measurements as of December 31, 2017 Fair Value as of December 31, 2017 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 7.4 $ 7.4 $ — $ — Equity securities: U.S. large cap - blend (a) 59.9 — 59.9 — U.S. mid cap - blend (b) 23.6 — 23.6 — U.S. small cap - blend (c) 7.7 — 7.7 — International equity - blend (d) 39.1 — 39.1 — Real estate (e) 12.8 — 12.8 — Fixed income securities: U.S. fixed income (f) 107.0 — 107.0 — U.S inflation protection income (g) 6.2 — 6.2 — Total fair value of the Company Plan’s assets $ 263.7 $ 7.4 $ 256.3 $ — Fair Value Measurements as of December 31, 2016 Fair Value as of December 31, 2016 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 6.8 $ 6.8 $ — $ — Equity securities: U.S. large cap - blend (a) 55.3 — 55.3 — U.S. mid cap - blend (b) 21.2 — 21.2 — U.S. small cap - blend (c) 7.4 — 7.4 — International equity - blend (d) 36.1 — 36.1 — Commodities index (h) 12.9 — 12.9 — Fixed income securities: U.S. fixed income (f) 101.8 — 101.8 — U.S inflation protection income (g) 6.0 — 6.0 — Total fair value of the Company Plan’s assets $ 247.5 $ 6.8 $ 240.7 $ — a) This category represents an equity index fund not actively managed that tracks the S&P 500 Index. b) This category represents an equity index fund not actively managed that tracks the S&P mid-cap 400 Index. c) This category represents an equity index fund not actively managed that tracks the Russell 2000 Index. d) This category represents an equity index fund not actively managed that tracks the MSCI ACWI ex USA Index. e) This category represents a real estate index fund not actively managed that tracks the MSCI US REIT Index. f) This category primarily represents bond index funds not actively managed that track the Barclays Capital U.S. Aggregate Index as well as an actively managed strategy which utilizes the Barclays Capital U.S. Aggregate Bond Index as its primary prospectus benchmark. g) This category primarily represents a bond index fund not actively managed that tracks the Barclays Capital U.S. TIPS Index. h) This category represents a commodities index fund not actively managed that tracks the Dow Jones - UBS Commodity Index. The following assumed benefit payments under the Company Plan and PEP, which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 27.2 2019 26.6 2020 26.2 2021 25.5 2022 25.4 Years 2023 and thereafter 118.2 In addition to the PEP, as a result of the Covance acquisition, the Company also has a frozen non-qualified Supplemental Executive Retirement Plan (SERP). The SERP, which is not funded, is intended to provide retirement benefits for certain employees who were executive officers of Covance prior to the acquisition. Benefit amounts are based upon years of service and compensation of the participating employees. The pension benefit obligation as of the Covance acquisition date was $32.8 . The components of the net periodic pension cost for the years ended December 31, 2017 , and December 31, 2016 , are as follows: Year Ended December 31, 2017 Year Ended December 31, 2016 Service cost $ — $ — Interest cost 0.2 0.8 Settlement gain (0.3 ) — Net periodic pension cost $ (0.1 ) $ 0.8 Assumptions used to determine defined-benefit plan cost Discount rate 4.2 % 3.8 % Expected return on assets N/A N/A The change in the projected benefit obligation, the funded status of the plan and a reconciliation of such funded status to the amounts reported in the consolidated balance sheet as of December 31, 2017 , and December 31, 2016 , is as follows: 2017 2016 Balance at beginning of year $ 7.5 $ 30.9 Service cost — — Interest cost 0.2 0.8 Actuarial loss/(gain) 0.3 (0.8 ) Gross benefits paid (3.7 ) (25.0 ) Termination benefits — 1.6 Balance at end of year $ 4.3 $ 7.5 2017 2016 Funded status $ 4.3 $ 7.5 Recorded as: Accrued expenses and other $ 0.9 $ 3.7 Other liabilities 3.4 3.8 $ 4.3 $ 7.5 The accumulated benefit obligation was $4.3 and $7.5 as of December 31, 2017 , and December 31, 2016 , respectively. The following assumed benefit payments under the SERP, which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 0.9 2019 0.1 2020 0.1 2021 0.1 2022 0.1 Year 2023 and thereafter 0.9 As a result of the Covance acquisiton, 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. 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 Year Ended December 31, 2017 Year Ended December 31, 2016 Service cost $ 5.1 $ 4.4 Interest cost 7.6 8.4 Expected return on plan assets (11.5 ) (11.6 ) Net amortization and deferral 0.7 — Expected participant contributions (1.3 ) (1.5 ) Defined-benefit plan costs $ 0.6 $ (0.3 ) Assumptions used to determine defined-benefit plan cost: Discount rate 2.7 % 3.8 % Expected return on assets 4.7 % 5.6 % Salary increases 3.8 % 3.6 % German Plan Year Ended December 31, 2017 Year Ended December 31, 2016 Service cost $ 1.2 $ 0.9 Interest cost 0.5 0.6 Net amortization and deferral — (0.2 ) Defined-benefit plan costs $ 1.7 $ 1.3 Assumptions used to determine defined-benefit plan cost: Discount rate 1.7 % 2.5 % Expected return on assets N/A N/A Salary increases 2.0 % 2.0 % The weighted average expected long-term rate of return on assets of the U.K Plans is based on the target asset allocation and the average rate of growth expected for the asset classes invested. The rate of expected growth is derived from a combination of historic returns, current market indicators, the expected risk premium for each asset class over the risk-free rate, and the opinion of professional advisors. The change in the projected benefit obligation and plan assets, the funded status of the plan and a reconciliation of such funded status to the amounts reported in the consolidated balance sheet as of December 31, 2017 , and December 31, 2016 , is as follows: Change in Projected Benefit Obligation: U.K. Plans 2017 2016 Balance at beginning of year $ 278.1 $ 246.5 Service cost 5.1 4.4 Interest cost 7.6 8.4 Actuarial (gain) loss (7.7 ) 72.6 Benefits paid (6.1 ) (4.2 ) Foreign currency exchange rate changes 26.4 (49.6 ) Balance at end of year $ 303.4 $ 278.1 Change in Projected Benefit Obligation: German Plan 2017 2016 Balance at beginning of year $ 29.0 $ 23.6 Service cost 1.2 0.9 Interest cost 0.5 0.6 Actuarial (gain) loss 1.0 5.3 Benefits paid (0.2 ) (0.2 ) Foreign currency exchange rate changes 4.2 (1.2 ) Balance at end of year $ 35.7 $ 29.0 Change in Fair Value of Assets: U.K. Plans 2017 2016 Balance at beginning of year $ 233.2 $ 226.2 Company contributions 6.3 6.8 Participant contributions 1.3 1.5 Actual return on assets 23.6 46.2 Benefits paid (6.1 ) (4.2 ) Foreign currency exchange rate changes 23.6 (43.3 ) Fair value of plan assets at end of year $ 281.9 $ 233.2 U.K. Plans 2017 2016 Funded status $ 21.5 $ 44.9 Recorded as: Other liabilities 21.5 44.9 $ 21.5 $ 44.9 German Plan 2017 2016 Funded status $ 35.7 $ 29.0 Recorded as: Accrued expenses and other $ 0.3 $ 0.2 Other liabilities 35.4 28.8 $ 35.7 $ 29.0 The Company contributed $6.3 in 2017 to the U.K. Plans and expects to contribute $6.6 in 2018 . No contributions were made to the German plan during 2017 , nor are any contributions expected to be made in 2018 , as the plan is unfunded. The accumulated benefit obligation for the U.K. Plans and the German Plan was $261.2 and $31.5 at December 31, 2017 , respectively. The accumulated benefit obligation for the U.K. Plans and the German Plan was $235.8 and $25.4 at December 31, 2016 , respectively. The amounts recognized in accumulated other comprehensive income for the year ended December 31, 2017 , and December 31, 2016 , is as follows: U.K. Plans 2017 2016 Net actuarial loss $ 17.2 $ 39.2 Less: Tax benefit (deferred tax asset) (2.9 ) (6.7 ) Accumulated other comprehensive income impact $ 14.3 $ 32.5 Assumptions used to determine benefit obligations: Discount rate 2.5 % 2.7 % Salary increases 3.6 % 3.8 % German Plan 2017 2016 Net actuarial loss/(gain) $ 0.7 $ (0.4 ) Less: Tax expense (deferred tax liability) (0.2 ) 0.1 Accumulated other comprehensive income impact $ 0.5 $ (0.3 ) Assumptions used to determine benefit obligations: Discount rate 1.7 % 1.7 % Salary increases 2.0 % 2.0 % There is no net actuarial loss for the U.K. Plans and German Plan, respectively required to be amortized from accumulated other comprehensive income into net periodic pension cost in 2018 . The investment policies for the U.K. Plans are set by the plan trustees, based upon the guidance of professional advisors and after consultation with the Company, taking into consideration the plans’ liabilities and future funding levels. The trustees have set the long-term investment policy largely in accordance with the asset allocation of a broadly diversified investment portfolio. Assets are generally invested within the target ranges as follows: Equity securities 60.0% to 70.0% Debt securities 10.0% to 15.0% Annuities 10.0% to 20.0% Real estate —% to 10.0% Other —% to 5.0% The weighted average asset allocation of the U.K. Plans as of December 31, 2017 , by asset category is as follows: December 31, 2017 Equity securities 66.0% Debt securities 19.0% Annuities 11.0% Real estate 4.0% Investments are made in pooled investment funds. Pooled investment fund managers are regulated by the Financial Conduct Authority in the U.K. and operate under terms which contain restrictions on the way in which the portfolios are managed and require the managers to ensure that suitable internal operating procedures are in place. The trustees have set performance objectives for each fund manager and routinely monitor and assess the managers’ performance against such objectives. Annuities represent annuity buy-in insurance policies purchased by the plan trustees from large, financially sound insurers. The cash flows from the annuities are intended to match the plan’s obligations to specific groups of participants, typically those participants currently receiving benefits. The fair value of the Company’s U.K. Plans' assets as of December 31, 2017 , and December 31, 2016 , by asset category, are as follows: Fair Value Measurements as of December 31, 2017 December 31, Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 0.8 $ 0.8 $ — $ — Mutual funds (a) 249.6 — 249.6 — Annuities (b) 31.5 — — 31.5 Total fair value of the Company Plan’s assets $ 281.9 $ 0.8 $ 249.6 $ 31.5 Fair Value Measurements as of December 31, 2016 December 31, Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 0.9 $ 0.9 $ — $ — Mutual funds (a) 202.5 — 202.5 — Annuities (b) 29.8 — — 29.8 Total fair value of the Company Plan’s assets $ 233.2 $ 0.9 $ 202.5 $ 29.8 a) Mutual funds represent pooled investment vehicles offered by investment managers, which are generally comprised of investments in equities, bonds, property and cash. The plans’ trustees hold units in these funds, the value of which is determined by the number of units held multiplied by the unit price calculated by the investment managers. That unit price is derived based on the market value of the securities that comprise the fund, which are determined by quoted prices in active markets. No element of the valuation is based on inputs made by the plans’ trustees. b) Annuities represent annuity buy-in insurance policies, whereby the insurer pays the pension payments for the lifetime of the members covered. The annuities are assets of the plan and payments from the insurer are made to the plans’ trustees, who then use those proceeds to pay the pensioners. The cash flows from the annuities are intended to effectively match the payments to the pensioners covered by the policy. As such, these assets are valued actuarially based upon the value of the liabilities with which they are associated. As the valuation of these assets is judgmental, and there are no observable inputs associated with the valuation, these assets are classified as Level 3 in the fair value hierarchy. Expected future benefit payments are as follows: U.K. Plans German Plan 2018 $ 4.4 $ 0.3 2019 5.3 0.4 2020 5.5 0.6 2021 6.0 0.6 2022 7.4 0.7 Years 2023 and thereafter 43.0 3.7 Post-employment Retiree Health and Welfare Plan As a result of the Covance acquisition, the Company sponsors a post-employment retiree health and welfare plan for the benefit of eligible employees at certain U.S. subsidiaries who retire after satisfying service and age requirements. This plan is funded on a pay-as-you-go basis and the cost of providing these benefits is shared with the retirees. The net periodic post-retirement benefit cost for the year ended December 31, 2017 , and December 31, 2016 , was $(2.0) and ($2.0) , respectively, and the pension benefit obligation as of the Covance acquisition date was $6.3 . The components of net periodic post-retirement benefit cost for 2017 are as follows: Year Ended December 31, 2017 Year Ended December 31, 2016 Interest cost $ — $ — Actuarial gain (0.1 ) (0.1 ) Prior service credit (1.9 ) (1.9 ) Net periodic post-retirement benefit cost $ (2.0 ) $ (2.0 ) Assumptions used to determine net periodic post-retirement benefit cost: Discount rate 4.1 % 4.2 % Healthcare cost trend rate N/A 7.0 % The change in the projected post-retirement benefit obligation, the funded status of the plan and the reconciliation of such funded status to the amounts reported in the consolidated balance sheets as of December 31, 2017 , and December 31, 2016 , is as follows: 2017 2016 Balance at beginning of year $ 0.8 $ 5.2 Interest cost — — Participant contributions — 0.7 Actuarial (gain) loss (0.1 ) 0.1 Benefits paid — (1.3 ) Plan amendments — (3.9 ) Balance at end of year $ 0.7 $ 0.8 2017 2016 Funded status $ 0.7 $ 0.8 Recorded as: Accrued expenses and other $ 0.1 $ 0.1 Other liabilities 0.6 0.7 $ 0.7 $ 0.8 The amounts recognized in accumulated other comprehensive income as of December 31, 2017 , are as follows: Year Ended December 31, 2017 Year Ended December 31, 2016 Net actuarial gain $ (0.7 ) $ (2.6 ) Less: Deferred tax benefit 0.3 0.9 Accumulated other comprehensive income impact $ (0.4 ) $ (1.7 ) Assumptions used to determine benefit obligation: Discount rate 3.6 % 4.1 % Healthcare cost trend rate N/A 6.7 % A one percentage point (1.0%) increase or decrease in the assumed healthcare cost trend rate would not impact the net service and interest cost components of the net periodic post-retirement benefit cost or the post-retirement benefit obligation since future increases in plan costs are paid by participant contributions. The Company expects to contribute $1.3 to the post-employment retiree health and welfare plan in 2018 . Expected future gross benefit payments are as follows: 2018 $ 0.1 2019 0.1 2020 0.1 2021 0.1 2022 0.1 2023 and thereafter 0.2 Post-retirement Medical Plan The Company assumed obligations under a subsidiary's post-retirement medical plan. Coverage under this plan is restricted to a limited number of existing employees of the subsidiary. This plan is unfunded and the Company’s policy is to fund benefits as claims are incurred. The effect on operations of the post-retirement medical plan is shown in the following table: Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ — $ — $ 0.1 Interest cost on benefit obligation 0.3 0.3 1.0 Net amortization and deferral (6.7 ) (15.9 ) (10.4 ) Post-retirement medical plan costs $ (6.4 ) $ (15.6 ) $ (9.3 ) Amounts included in accumulated other comprehensive earnings consist of unamortized net loss of $2.3 . The accumulated other comprehensive earnings that are expected to be recognized as components of the post-retirement medical plan costs during 2018 are $0.7 related to amortization of the net gain resulting from the shift of Medicare-eligible participants to private exchanges. A summary of the changes in the accumulated post-retirement benefit obligation follows: 2017 2016 Balance at January 1 $ 6.8 $ 21.4 Service cost for benefits earned — — Interest cost on benefit obligation 0.3 0.3 Actuarial loss 2.5 (0.2 ) Benefits paid (1.0 ) (1.3 ) Plan amendment — (13.4 ) Balance at December 31 $ 8.6 $ 6.8 Recorded as: Accrued expenses and other $ 1.2 $ 1.0 Other liabilities 7.4 5.8 $ 8.6 $ 6.8 The weighted-average discount rates used in the calculation of the accumulated post-retirement benefit obligation were 3.4% and 3.8% as of December 31, 2017 , and 2016 , respectively. The healthcare cost trend rate was removed due to the expectation of future funding to be at the same level as the previous year's funding. The following assumed benefit payments under the Company's post-retirement benefit plan, which reflect expected future service, as appropriate, and which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 1.3 2019 1.1 2020 1.0 2021 1.0 2022 0.9 Years 2023 and thereafter 2.8 Deferred Compensation Plan The Company has a Deferred Compensation Plan (DCP) under which certain of its executives may elect to defer up to 100.0% of their annual cash incentive pay and/or up to 50.0% of their annual base salary and/or eligible commissions subject to annual limits established by the U.S. government. The DCP provides executives a tax efficient strategy for retirement savings and capital accumulation without significant cost to the Company. The Company makes no contributions to the DCP. Amounts deferred by a participant are credited to a bookkeeping account maintained on behalf of each participant, which is used for measurement and determination of amounts to be paid to a participant, or his or her designated beneficiary, pursuant to the terms of the DCP. The amounts accrued under this plan were $64.5 and $54.2 at December 31, 2017 , and 2016 , respectively. Deferred amounts are the Company's general unsecured obligations and are subject to claims by the Company's creditors. The Company's general assets may be used to fund obligations and pay DCP benefits.
Schedule of Defined Benefit Plans Disclosures [Table Text Block]					Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ — $ — $ 0.1 Interest cost on benefit obligation 0.3 0.3 1.0 Net amortization and deferral (6.7 ) (15.9 ) (10.4 ) Post-retirement medical plan costs $ (6.4 ) $ (15.6 ) $ (9.3 ) A summary of the changes in the accumulated post-retirement benefit obligation follows: 2017 2016 Balance at January 1 $ 6.8 $ 21.4 Service cost for benefits earned — — Interest cost on benefit obligation 0.3 0.3 Actuarial loss 2.5 (0.2 ) Benefits paid (1.0 ) (1.3 ) Plan amendment — (13.4 ) Balance at December 31 $ 8.6 $ 6.8 Recorded as: Accrued expenses and other $ 1.2 $ 1.0 Other liabilities 7.4 5.8 $ 8.6 $ 6.8 The effect on operations for both the Company Plan and the PEP are summarized as follows: Year ended December 31, 2017 2016 2015 Service cost for benefits earned $ 5.5 $ 4.9 $ 3.9 Interest cost on benefit obligation 14.4 15.5 15.1 Expected return on plan assets (16.3 ) (16.7 ) (18.3 ) Net amortization and deferral 11.0 11.2 11.3 Defined-benefit plan costs $ 14.6 $ 14.9 $ 12.0 A summary of the changes in the projected benefit obligations of the Company Plan and the PEP are summarized as follows: 2017 2016 Balance at January 1 $ 366.5 $ 363.1 Service cost 5.5 4.9 Interest cost 14.4 15.5 Actuarial loss 12.2 12.1 Benefits and administrative expenses paid (30.6 ) (29.1 ) Balance at December 31 $ 368.0 $ 366.5
Schedule of Changes in Fair Value of Plan Assets [Table Text Block]					A summary of the changes in the fair value of plan assets follows: 2017 2016 Fair value of plan assets at beginning of year $ 247.5 $ 250.6 Actual return on plan assets 29.2 13.6 Employer contributions 17.6 12.4 Benefits and administrative expenses paid (30.6 ) (29.1 ) Fair value of plan assets at end of year $ 263.7 $ 247.5
Schedule of Net Funded Status [Table Text Block]					he net funded status of the Company Plan and the PEP at December 31: 2017 2016 Funded status $ 104.3 $ 119.0 Recorded as: Accrued expenses and other $ 2.2 $ 2.0 Other liabilities 102.1 117.0 $ 104.3 $ 119.0
Schedule of Assumptions Used [Table Text Block]					Weighted average assumptions used in the accounting for the Company Plan and the PEP are summarized as follows: 2017 2016 2015 Discount rate 3.7 % 4.2 % 4.0 % Expected long term rate of return 6.8 % 6.8 % 7.0 %
Defined Benefit Plan Fair Value Of Plan Assets By Category [Table Text Block]					The weighted average expected long-term rate of return for the Company Plan’s assets is as follows: Target Weighted Average Expected Long-Term Rate of Return Equity securities 50.0 % 5.6 % Fixed income securities 45.0 % 1.1 % Other assets 5.0 % 0.1 % The fair values of the Company Plan’s assets at December 31, 2017 , and 2016 , by asset category are as follows: Fair Value Measurements as of December 31, 2017 Fair Value as of December 31, 2017 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 7.4 $ 7.4 $ — $ — Equity securities: U.S. large cap - blend (a) 59.9 — 59.9 — U.S. mid cap - blend (b) 23.6 — 23.6 — U.S. small cap - blend (c) 7.7 — 7.7 — International equity - blend (d) 39.1 — 39.1 — Real estate (e) 12.8 — 12.8 — Fixed income securities: U.S. fixed income (f) 107.0 — 107.0 — U.S inflation protection income (g) 6.2 — 6.2 — Total fair value of the Company Plan’s assets $ 263.7 $ 7.4 $ 256.3 $ — Fair Value Measurements as of December 31, 2016 Fair Value as of December 31, 2016 Using Fair Value Hierarchy Asset Category Level 1 Level 2 Level 3 Cash $ 6.8 $ 6.8 $ — $ — Equity securities: U.S. large cap - blend (a) 55.3 — 55.3 — U.S. mid cap - blend (b) 21.2 — 21.2 — U.S. small cap - blend (c) 7.4 — 7.4 — International equity - blend (d) 36.1 — 36.1 — Commodities index (h) 12.9 — 12.9 — Fixed income securities: U.S. fixed income (f) 101.8 — 101.8 — U.S inflation protection income (g) 6.0 — 6.0 — Total fair value of the Company Plan’s assets $ 247.5 $ 6.8 $ 240.7 $ — a) This category represents an equity index fund not actively managed that tracks the S&P 500 Index. b) This category represents an equity index fund not actively managed that tracks the S&P mid-cap 400 Index. c) This category represents an equity index fund not actively managed that tracks the Russell 2000 Index. d) This category represents an equity index fund not actively managed that tracks the MSCI ACWI ex USA Index. e) This category represents a real estate index fund not actively managed that tracks the MSCI US REIT Index. f) This category primarily represents bond index funds not actively managed that track the Barclays Capital U.S. Aggregate Index as well as an actively managed strategy which utilizes the Barclays Capital U.S. Aggregate Bond Index as its primary prospectus benchmark. g) This category primarily represents a bond index fund not actively managed that tracks the Barclays Capital U.S. TIPS Index. h) This category represents a commodities index fund not actively managed that tracks the Dow Jones - UBS Commodity Index.
Schedule of Expected Benefit Payments [Table Text Block]					2018 $ 0.1 2019 0.1 2020 0.1 2021 0.1 2022 0.1 2023 and thereafter 0.2 The following assumed benefit payments under the Company Plan and PEP, which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 27.2 2019 26.6 2020 26.2 2021 25.5 2022 25.4 Years 2023 and thereafter 118.2 U.K. Plans German Plan 2018 $ 4.4 $ 0.3 2019 5.3 0.4 2020 5.5 0.6 2021 6.0 0.6 2022 7.4 0.7 Years 2023 and thereafter 43.0 3.7
Assumed Benefit Payments By Year [Text Block]					The following assumed benefit payments under the Company's post-retirement benefit plan, which reflect expected future service, as appropriate, and which were used in the calculation of projected benefit obligations, are expected to be paid as follows: 2018 $ 1.3 2019 1.1 2020 1.0 2021 1.0 2022 0.9 Years 2023 and thereafter 2.8
Maximum deferral percentage of annual cash incentive pay					100.00%
Deferred Compensation Liability, Classified, Noncurrent					$ 64.5	54.2
Equity Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					50.00%
Fixed Income Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					45.00%
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]				$ 6
Fair value of plan assets at end of year	[1]				6.2	6
Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan						(117)
Accrued Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan						2
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three					0.1
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter					0.9
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months					0.9
Defined Benefit Plan, Expected Future Benefit Payment, Year Two					0.1
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(4.3)	(7.5)
Effect on operations for both the Company Plan and the PEP [Abstract]
Service cost					0	0
Interest cost					(0.2)	(0.8)
Defined-benefit plan costs					0.1	(0.8)
Net Defined Benefit Plan Amortization And Deferral		0			(0.3)
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		$ 30.9		$ 32.8	7.5	30.9
Service cost					0	0
Interest cost					(0.2)	(0.8)
Actuarial loss					0.3	(0.8)
Ending balance				30.9	4.3	7.5	$ 30.9
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Benefits and administrative expenses paid					$ (3.7)	$ (25)
Defined Benefit Plans, Weighted Average Assumptions Used in Calculating Benefit Obligations [Abstract]
Discount rate					4.20%	3.80%
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four					$ 0.1
Defined Benefit Plan, Expected Future Benefit Payment, Year Five					0.1
Supplemental Employee Retirement Plan [Member] | Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(3.4)	$ (3.8)
Supplemental Employee Retirement Plan [Member] | Accrued Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(0.9)	(3.7)
Foreign Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Participants contributions					$ (1.3)	(1.5)
Defined Benefit Plan, Assumptions Used in Calculation, Description		0.0265			0.025
Defined Benefit Plan, Funded (Unfunded) Status of Plan					$ 21.5	44.9
Effect on operations for both the Company Plan and the PEP [Abstract]
Service cost				4.4	5.1	4.4
Interest cost				(8.4)	(7.6)	(8.4)
Expected return on plan assets					(11.5)	(11.6)
Defined-benefit plan costs					(0.6)	0.3
Net Defined Benefit Plan Amortization And Deferral					$ 0.7	0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		3.80%			2.70%
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		$ 246.5			$ 278.1	246.5
Service cost				4.4	5.1	4.4
Interest cost				(8.4)	(7.6)	(8.4)
Participants contributions					1.3	1.5
Actuarial loss				72.6	(7.7)
Ending balance				246.5	303.4	278.1	246.5
Defined Benefit Plan, Accumulated Benefit Obligation					261.2	235.8
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax		39.2			17.2
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		$ 226.2			233.2	226.2
Actual return on plan assets					23.6	46.2
Employer contributions					6.3	6.8
Benefits and administrative expenses paid				(4.2)	(6.1)	(4.2)
Fair value of plan assets at end of year				226.2	$ 281.9	233.2	226.2
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Weighted average expected long-term rate of return for other assets (in hundredths)		5.60%			4.70%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase		3.60%			3.80%
Defined Benefit Plan Expected Salary Increase		3.80%			3.60%
Tax effect of adjustments, Net Benefit Plan Adjustments		$ (6.7)			$ (2.9)
Accumulated Other Comprehensive Income (Loss), Net of Tax					14.3	32.5
Foreign Plan [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year					29.8
Fair value of plan assets at end of year					31.5	29.8
Foreign Plan [Member] | Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					21.5	44.9
Postretirement Health Coverage [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit					0.1	0.1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)					$ (1.9)	(1.9)
Defined Benefit Plan, Assumptions Used in Calculation, Description		0.041			0.036
Defined Benefit Plan, Accumulated Benefit Obligation, Increase (Decrease) for Plan Amendment					$ 0	$ (3.9)
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate						7.00%
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(0.7)	$ (0.8)
Effect on operations for both the Company Plan and the PEP [Abstract]
Interest cost		$ 0			0	0
Defined-benefit plan costs				2	$ 2	2
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		4.20%			4.10%
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		$ 5.2		6.3	$ 0.8	5.2
Interest cost		0			0	0
Participants contributions		0.7			0
Actuarial loss		0.1			(0.1)
Ending balance				5.2	0.7	0.8	5.2
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax		(2.6)			(0.7)
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Benefits and administrative expenses paid		(1.3)			0
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Tax effect of adjustments, Net Benefit Plan Adjustments		0.9			0.3
Accumulated Other Comprehensive Income (Loss), Net of Tax					(0.4)	(1.7)
Postretirement Health Coverage [Member] | Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(0.6)	(0.7)
Postretirement Health Coverage [Member] | Accrued Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(0.1)	(0.1)
Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment					0	(13.4)
Effect on operations for both the Company Plan and the PEP [Abstract]
Service cost					0	0	0.1
Interest cost					(0.3)	(0.3)	(1)
Net amortization and deferral					(6.7)	(15.9)	(10.4)
Defined-benefit plan costs					6.4	15.6	9.3
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		$ 21.4			6.8	21.4
Service cost					0	0	0.1
Interest cost					(0.3)	(0.3)	(1)
Actuarial loss					2.5	(0.2)
Ending balance				21.4	8.6	6.8	21.4
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Benefits and administrative expenses paid					$ (1)	$ (1.3)
Defined Benefit Plans, Weighted Average Assumptions Used in Calculating Benefit Obligations [Abstract]
Discount rate					3.40%	3.80%
Other Pension, Postretirement and Supplemental Plans [Member] | Other Liabilities [Member]
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance					$ 5.8
Ending balance					7.4	$ 5.8
Other Pension, Postretirement and Supplemental Plans [Member] | Accrued Liabilities [Member]
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance					1
Ending balance					$ 1.2	1
Other Pension Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Assumptions Used in Calculation, Description		0.017			0.017
Defined Benefit Plan, Funded (Unfunded) Status of Plan					$ (35.7)	(29)
Effect on operations for both the Company Plan and the PEP [Abstract]
Service cost					1.2	0.9
Interest cost					(0.5)	(0.6)
Defined-benefit plan costs					(1.7)	(1.3)
Net Defined Benefit Plan Amortization And Deferral					$ 0	(0.2)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		2.50%			1.70%
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		$ 23.6			$ 29	23.6
Service cost					1.2	0.9
Interest cost					(0.5)	(0.6)
Actuarial loss					1	5.3
Ending balance				23.6	35.7	29	23.6
Defined Benefit Plan, Accumulated Benefit Obligation					31.5	25.4
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax		$ (0.4)			0.7
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Employer contributions				0
Benefits and administrative expenses paid					$ (0.2)	(0.2)
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase		2.00%			2.00%
Defined Benefit Plan Expected Salary Increase		2.00%			2.00%
Tax effect of adjustments, Net Benefit Plan Adjustments		$ 0.1			$ (0.2)
Accumulated Other Comprehensive Income (Loss), Net of Tax					0.5	(0.3)
Other Pension Plan [Member] | Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(35.4)	(28.8)
Other Pension Plan [Member] | Accrued Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(0.3)	(0.2)
Pension Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three					26.2
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter					118.2
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months					27.2
Defined Benefit Plan, Expected Future Benefit Payment, Year Two					26.6
Defined Benefit Plan, Funded (Unfunded) Status of Plan					$ 104.3
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					5.00%
Projected defined benefit plan costs in fiscal 2012					$ 13.3
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year					7.6
Effect on operations for both the Company Plan and the PEP [Abstract]
Service cost					5.5	4.9	3.9
Interest cost					(14.4)	(15.5)	(15.1)
Expected return on plan assets					(16.3)	(16.7)	(18.3)
Net amortization and deferral					11	11.2	11.3
Defined-benefit plan costs					(14.6)	(14.9)	(12)
Unamortized net gain included in accumulated other comprehensive earnings					127.4
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year					10.9
Defined Benefit Plans, Changes in Benefit Obligations [Roll Forward]
Beginning balance		363.1			366.5	363.1
Service cost					5.5	4.9	3.9
Interest cost					(14.4)	(15.5)	(15.1)
Actuarial loss					12.2	12.1
Ending balance				363.1	368	366.5	363.1
Defined Benefit Plan, Accumulated Benefit Obligation					368	366.5
Defined Benefit Plans, Changes in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		$ 250.6			247.5	250.6
Actual return on plan assets					29.2	13.6
Employer contributions					17.6	12.4
Benefits and administrative expenses paid					(30.6)	(29.1)
Fair value of plan assets at end of year				$ 250.6	$ 263.7	$ 247.5	$ 250.6
Defined Benefit Plans, Weighted Average Assumptions Used in Calculating Benefit Obligations [Abstract]
Discount rate				4.00%	3.70%	4.20%	4.00%
Expected long term rate of return				7.00%	6.80%	6.80%	7.00%
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Weighted average expected long-term rate of return for equity securities (in hundredths)					5.60%
Weighted average expected long-term rate of return for fixed income securities (in hundredths)					1.10%
Weighted average expected long-term rate of return for other assets (in hundredths)					0.10%
Defined Benefit Plan, Expected Future Benefit Payment, Year Four					$ 25.5
Defined Benefit Plan, Expected Future Benefit Payment, Year Five					25.4
Pension Plan [Member] | Other Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					(102.1)
Pension Plan [Member] | Accrued Liabilities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan					$ 2.2
Maximum [Member] | Foreign Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					5.00%
Maximum [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					70.00%
Maximum [Member] | Foreign Plan [Member] | Debt Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					15.00%
Maximum [Member] | Foreign Plan [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					20.00%
Maximum [Member] | Foreign Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					10.00%
Minimum [Member] | Foreign Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					0.00%
Minimum [Member] | Foreign Plan [Member] | Equity Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					60.00%
Minimum [Member] | Foreign Plan [Member] | Debt Securities [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					10.00%
Minimum [Member] | Foreign Plan [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					10.00%
Minimum [Member] | Foreign Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage					0.00%
Subsequent Event [Member] | Foreign Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three								$ 5.5
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter								43
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months								4.4
Defined Benefit Plan, Expected Future Benefit Payment, Year Two								5.3
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year								6.6
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four								6
Defined Benefit Plan, Expected Future Benefit Payment, Year Five								7.4
Subsequent Event [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three								0.1
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter								0.2
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months								0.1
Defined Benefit Plan, Expected Future Benefit Payment, Year Two								0.1
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year								1.3
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four								0.1
Defined Benefit Plan, Expected Future Benefit Payment, Year Five								0.1
Subsequent Event [Member] | Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three								1
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter								2.8
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months								1.3
Defined Benefit Plan, Expected Future Benefit Payment, Year Two								1.1
Effect on operations for both the Company Plan and the PEP [Abstract]
Unamortized net gain included in accumulated other comprehensive earnings								2.3
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four								1
Defined Benefit Plan, Expected Future Benefit Payment, Year Five								0.9
Subsequent Event [Member] | Other Pension Plan [Member]
Defined Benefit Plans Disclosures [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Year Three								0.6
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter								3.7
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months								0.3
Defined Benefit Plan, Expected Future Benefit Payment, Year Two								0.4
Defined Benefit Plans, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four								0.6
Defined Benefit Plan, Expected Future Benefit Payment, Year Five								$ 0.7
[1]	This category primarily represents bond index funds not actively managed that track the Barclays Capital U.S. Aggregate Index a

DEFINED BENEFIT PLANS, FAIR VAL

DEFINED BENEFIT PLANS, FAIR VALUE OF PLAN ASSETS (Details) - USD ($)		3 Months Ended	10 Months Ended	12 Months Ended
		Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015	Feb. 19, 2015
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 263,700,000	$ 247,500,000
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits				0	1,600,000
Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				7,400,000	6,800,000
U.S. large cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]			59,900,000	55,300,000
U.S. mid cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]			23,600,000	21,200,000
U.S. small cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]			7,700,000	7,400,000
International - developed [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				39,100,000	36,100,000	[4]
Commodities index [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			12,800,000	12,900,000
U.S. fixed income [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			107,000,000	101,800,000
Fixed Income Securities [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			6,200,000	6,000,000
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				7,400,000	6,800,000
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				7,400,000	6,800,000
Fair Value, Inputs, Level 1 [Member] | U.S. large cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]			0	0
Fair Value, Inputs, Level 1 [Member] | U.S. mid cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]			0	0
Fair Value, Inputs, Level 1 [Member] | U.S. small cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]			0	0
Fair Value, Inputs, Level 1 [Member] | International - developed [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0	[4]
Fair Value, Inputs, Level 1 [Member] | Commodities index [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			0	0
Fair Value, Inputs, Level 1 [Member] | U.S. fixed income [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			0	0
Fair Value, Inputs, Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				256,300,000	240,700,000
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 2 [Member] | U.S. large cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]			59,900,000	55,300,000
Fair Value, Inputs, Level 2 [Member] | U.S. mid cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]			23,600,000	21,200,000
Fair Value, Inputs, Level 2 [Member] | U.S. small cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]			7,700,000	7,400,000
Fair Value, Inputs, Level 2 [Member] | International - developed [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				39,100,000	36,100,000	[4]
Fair Value, Inputs, Level 2 [Member] | Commodities index [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			12,800,000	12,900,000
Fair Value, Inputs, Level 2 [Member] | U.S. fixed income [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			107,000,000	101,800,000
Fair Value, Inputs, Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			6,200,000	6,000,000
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | U.S. large cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]			0	0
Fair Value, Inputs, Level 3 [Member] | U.S. mid cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]			0	0
Fair Value, Inputs, Level 3 [Member] | U.S. small cap - blend [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]			0	0
Fair Value, Inputs, Level 3 [Member] | International - developed [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0	[4]
Fair Value, Inputs, Level 3 [Member] | Commodities index [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			0	0
Fair Value, Inputs, Level 3 [Member] | U.S. fixed income [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			0	0
Fair Value, Inputs, Level 3 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]			0
Foreign Plan [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Benefit Obligation			$ 246,500,000	303,400,000	278,100,000		$ 246,500,000
Service cost			4,400,000	5,100,000	4,400,000
Defined Benefit Plan, Fair Value of Plan Assets			226,200,000	281,900,000	233,200,000		226,200,000
Employer contributions				6,300,000	6,800,000
Defined Benefit Plan, Benefit Obligation, Benefits Paid			4,200,000	6,100,000	4,200,000
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)			(49,600,000)	26,400,000
Defined Benefit Plan, Interest Cost			8,400,000	7,600,000	8,400,000
Actuarial loss			72,600,000	(7,700,000)
Defined Benefit Plan, Expected Return (Loss) on Plan Assets				(11,500,000)	(11,600,000)
Net Defined Benefit Plan Amortization And Deferral				700,000	0
Actual return on plan assets				23,600,000	46,200,000
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)				$ 23,600,000	(43,300,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		3.80%		2.70%
Weighted average expected long-term rate of return for other assets (in hundredths)		5.60%		4.70%
Participants contributions				$ (1,300,000)	(1,500,000)
Defined-benefit plan costs				(600,000)	300,000
Foreign Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				800,000	900,000
Foreign Plan [Member] | Mutual Funds [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				249,600,000	202,500,000
Foreign Plan [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				31,500,000	29,800,000
Foreign Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				800,000	900,000
Foreign Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				800,000	900,000
Foreign Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Mutual Funds [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				249,600,000	202,500,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Mutual Funds [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				249,600,000	202,500,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				31,500,000	29,800,000
Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Mutual Funds [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Life and Annuity Insurance Product Line [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				31,500,000	29,800,000
Other Pension Plan [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Benefit Obligation			23,600,000	35,700,000	29,000,000		23,600,000
Service cost				1,200,000	900,000
Employer contributions			0
Defined Benefit Plan, Benefit Obligation, Benefits Paid				200,000	200,000
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)				4,200,000	(1,200,000)
Defined Benefit Plan, Interest Cost				500,000	600,000
Actuarial loss				1,000,000	5,300,000
Net Defined Benefit Plan Amortization And Deferral				$ 0	(200,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		2.50%		1.70%
Defined-benefit plan costs				$ (1,700,000)	(1,300,000)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Benefit Obligation			30,900,000	4,300,000	7,500,000		30,900,000	$ 32,800,000
Service cost				0	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid				3,700,000	25,000,000
Defined Benefit Plan, Interest Cost				200,000	800,000
Actuarial loss				300,000	(800,000)
Net Defined Benefit Plan Amortization And Deferral		$ 0		(300,000)
Defined-benefit plan costs				100,000	(800,000)
Pension Plan [Member]
Defined Benefit Plans, Fair Value of Plan Assets by Category [Line Items]
Defined Benefit Plan, Benefit Obligation			363,100,000	368,000,000	366,500,000		363,100,000
Service cost				5,500,000	4,900,000		3,900,000
Defined Benefit Plan, Fair Value of Plan Assets			$ 250,600,000	263,700,000	247,500,000		250,600,000
Employer contributions				17,600,000	12,400,000
Defined Benefit Plan, Benefit Obligation, Benefits Paid				30,600,000	29,100,000
Defined Benefit Plan, Interest Cost				14,400,000	15,500,000		15,100,000
Actuarial loss				12,200,000	12,100,000
Defined Benefit Plan, Expected Return (Loss) on Plan Assets				(16,300,000)	(16,700,000)		(18,300,000)
Actual return on plan assets				$ 29,200,000	13,600,000
Weighted average expected long-term rate of return for other assets (in hundredths)				0.10%
Defined-benefit plan costs				$ (14,600,000)	$ (14,900,000)		$ (12,000,000)
[1]	This category represents an equity index fund not actively managed that tracks the S&P 500 Index.
[2]	This category represents an equity index fund not actively managed that tracks the S&P mid-cap 400 Index.
[3]	This category represents an equity index fund not actively managed that tracks the Russell 2000 Index.
[4]	This category represents an equity index fund not actively managed that tracks the MSCI ACWI ex USA Index.
[5]	This category represents a real estate index fund not actively managed that tracks the MSCI US REIT Index.
[6]	This category primarily represents bond index funds not actively managed that track the Barclays Capital U.S. Aggregate Index a

PENSION AND POSTRETIREMENT PL84

PENSION AND POSTRETIREMENT PLANS, OTHER DISCLOSURES (Details) - USD ($)	3 Months Ended		10 Months Ended	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018	Feb. 19, 2015	Dec. 31, 2014	Dec. 31, 2012
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 263,700,000	$ 247,500,000
Tax effect of adjustments, Net Benefit Plan Adjustments	$ 4,300,000	$ (3,500,000)		(3,500,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax				(335,700,000)	$ (581,100,000)				$ (10,500,000)	$ (10,500,000)
Ultimate health care cost trend rate					6.70%
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits				0	$ 1,600,000
Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	$ 39,200,000			$ 17,200,000
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.60%			3.80%
Defined benefit plan costs				$ 600,000	(300,000)
Participants contributions				(1,300,000)	(1,500,000)
Defined Benefit Plan, Fair Value of Plan Assets			$ 226,200,000	281,900,000	233,200,000	$ 226,200,000
Actual return on plan assets				23,600,000	46,200,000
Tax effect of adjustments, Net Benefit Plan Adjustments	$ (6,700,000)			(2,900,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax				$ 14,300,000	32,500,000
Defined Benefit Plan, Assumptions Used in Calculation, Description	0.0265			0.025
Employer contributions				$ 6,300,000	6,800,000
Defined Benefit Plan, Benefit Obligation			246,500,000	303,400,000	278,100,000	246,500,000
Service cost			4,400,000	5,100,000	4,400,000
Defined Benefit Plan, Expected Return (Loss) on Plan Assets				(11,500,000)	(11,600,000)
Defined Benefit Plan, Interest Cost			8,400,000	7,600,000	8,400,000
Net Defined Benefit Plan Amortization And Deferral				700,000	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)			(4,200,000)	(6,100,000)	(4,200,000)
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)				$ 23,600,000	(43,300,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.80%			2.70%
Weighted average expected long-term rate of return for other assets (in hundredths)	5.60%			4.70%
Defined Benefit Plan, Accumulated Benefit Obligation				$ 261,200,000	235,800,000
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)			(49,600,000)	$ 26,400,000
Defined Benefit Plan Expected Salary Increase	3.80%			3.60%
Other Pension Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	$ (400,000)			$ 700,000
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.00%			2.00%
Defined benefit plan costs				$ 1,700,000	1,300,000
Tax effect of adjustments, Net Benefit Plan Adjustments	$ 100,000			(200,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax				$ 500,000	(300,000)
Defined Benefit Plan, Assumptions Used in Calculation, Description	0.017			0.017
Employer contributions			0
Defined Benefit Plan, Benefit Obligation			23,600,000	$ 35,700,000	29,000,000	23,600,000
Service cost				1,200,000	900,000
Defined Benefit Plan, Interest Cost				500,000	600,000
Net Defined Benefit Plan Amortization And Deferral				0	(200,000)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)				$ (200,000)	(200,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.50%			1.70%
Defined Benefit Plan, Accumulated Benefit Obligation				$ 31,500,000	25,400,000
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)				$ 4,200,000	(1,200,000)
Defined Benefit Plan Expected Salary Increase	2.00%			2.00%
Pension Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax				$ 127,400,000
Defined Benefit Plan Amortization And Deferral				11,000,000	11,200,000	11,300,000
Defined benefit plan costs				$ 14,600,000	14,900,000	12,000,000
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				5.00%
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year				$ 10,900,000
Defined Benefit Plan, Fair Value of Plan Assets			250,600,000	263,700,000	247,500,000	250,600,000
Actual return on plan assets				29,200,000	13,600,000
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year				7,600,000
Employer contributions				17,600,000	12,400,000
Defined Benefit Plan, Benefit Obligation			$ 363,100,000	368,000,000	366,500,000	363,100,000
Service cost				5,500,000	4,900,000	3,900,000
Defined Benefit Plan, Expected Return (Loss) on Plan Assets				(16,300,000)	$ (16,700,000)	$ (18,300,000)
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months				27,200,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two				26,600,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three				26,200,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four				25,500,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five				25,400,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter				$ 118,200,000
Discount rate			4.00%	3.70%	4.20%	4.00%
Defined Benefit Plan, Interest Cost				$ 14,400,000	$ 15,500,000	$ 15,100,000
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)				$ (30,600,000)	$ (29,100,000)
Weighted average expected long-term rate of return for other assets (in hundredths)				0.10%
Expected long term rate of return			7.00%	6.80%	6.80%	7.00%
Defined Benefit Plan, Accumulated Benefit Obligation				$ 368,000,000	$ 366,500,000
Postretirement Health Coverage [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	$ (2,600,000)			(700,000)
Defined benefit plan costs			$ (2,000,000)	(2,000,000)	(2,000,000)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax				(100,000)	(100,000)
Tax effect of adjustments, Net Benefit Plan Adjustments	$ 900,000			300,000
Accumulated Other Comprehensive Income (Loss), Net of Tax				$ (400,000)	(1,700,000)
Defined Benefit Plan, Assumptions Used in Calculation, Description	0.041			0.036
Defined Benefit Plan, Benefit Obligation			5,200,000	$ 700,000	$ 800,000	$ 5,200,000		$ 6,300,000
Ultimate health care cost trend rate					7.00%
Defined Benefit Plan, Interest Cost	$ 0			0	$ 0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)				(1,900,000)	(1,900,000)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	$ (1,300,000)			0
Defined Benefit Plan, Accumulated Benefit Obligation, Increase (Decrease) for Plan Amendment				$ 0	(3,900,000)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.20%			4.10%
Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan Amortization And Deferral				$ (6,700,000)	(15,900,000)	(10,400,000)
Defined benefit plan costs				(6,400,000)	(15,600,000)	(9,300,000)
Defined Benefit Plan, Benefit Obligation			21,400,000	8,600,000	6,800,000	21,400,000
Service cost				$ 0	$ 0	100,000
Discount rate				3.40%	3.80%
Defined Benefit Plan, Interest Cost				$ 300,000	$ 300,000	1,000,000
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)				(1,000,000)	(1,300,000)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment				0	(13,400,000)
Other Pension, Postretirement and Supplemental Plans [Member] | Accrued Liabilities [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Benefit Obligation				1,200,000	1,000,000
Other Pension, Postretirement and Supplemental Plans [Member] | Other Liabilities [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Benefit Obligation				7,400,000	5,800,000
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined benefit plan costs				(100,000)	800,000
Defined Benefit Plan, Benefit Obligation			$ 30,900,000	4,300,000	7,500,000	$ 30,900,000		$ 32,800,000
Service cost				0	$ 0
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months				900,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two				100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three				100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four				100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five				100,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter				$ 900,000
Discount rate				4.20%	3.80%
Defined Benefit Plan, Interest Cost				$ 200,000	$ 800,000
Net Defined Benefit Plan Amortization And Deferral	$ 0			(300,000)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)				$ (3,700,000)	(25,000,000)
Equity Securities [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				50.00%
Equity Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Actual Asset Allocation				66.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 7,400,000	6,800,000
Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 800,000	900,000
Debt Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Actual Asset Allocation				19.00%
Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 249,600,000	202,500,000
Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 31,500,000	29,800,000
Variable Annuity [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Actual Asset Allocation				11.00%
Real Estate Properties [Domain] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Actual Asset Allocation				4.00%
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 7,400,000	6,800,000
Fair Value, Inputs, Level 1 [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				800,000	900,000
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				7,400,000	6,800,000
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				800,000	900,000
Fair Value, Inputs, Level 1 [Member] | Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 1 [Member] | Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				256,300,000	240,700,000
Fair Value, Inputs, Level 2 [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				249,600,000	202,500,000
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				249,600,000	202,500,000
Fair Value, Inputs, Level 2 [Member] | Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				31,500,000	29,800,000
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | Mutual Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				0	0
Fair Value, Inputs, Level 3 [Member] | Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Fair Value of Plan Assets				$ 31,500,000	$ 29,800,000
Minimum [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				0.00%
Minimum [Member] | Equity Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				60.00%
Minimum [Member] | Debt Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				10.00%
Minimum [Member] | Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				10.00%
Minimum [Member] | Real Estate Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				0.00%
Maximum [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				5.00%
Maximum [Member] | Equity Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				70.00%
Maximum [Member] | Debt Securities [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				15.00%
Maximum [Member] | Life and Annuity Insurance Product Line [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				20.00%
Maximum [Member] | Real Estate Funds [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage				10.00%
Subsequent Event [Member] | Foreign Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year							$ 6,600,000
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months							4,400,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two							5,300,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three							5,500,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four							6,000,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five							7,400,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter							43,000,000
Subsequent Event [Member] | Other Pension Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months							300,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two							400,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three							600,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four							600,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five							700,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter							3,700,000
Subsequent Event [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year							1,300,000
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months							100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two							100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three							100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four							100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five							100,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter							200,000
Subsequent Event [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year							700,000
Subsequent Event [Member] | Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans, Estimated Future Benefit Payments [Line items]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax							2,300,000
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months							1,300,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Two							1,100,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Three							1,000,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four							1,000,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five							900,000
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter							$ 2,800,000

PENSION AND POSTRETIREMENT PL85

PENSION AND POSTRETIREMENT PLANS PENSION AND POSTRETIREMENT PLANS, FUNDED STATUS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 19, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	$ 104.3	$ 119
Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	303.4	278.1	$ 246.5
Funded status of plan	21.5	44.9
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	4.3	7.5	30.9	$ 32.8
Funded status of plan	(4.3)	(7.5)
Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	0.7	0.8	5.2	$ 6.3
Funded status of plan	(0.7)	(0.8)
Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	35.7	29	23.6
Funded status of plan	(35.7)	(29)
Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	8.6	6.8	$ 21.4
Other Liabilities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan		(117)
Other Liabilities [Member] | Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	21.5	44.9
Other Liabilities [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(3.4)	(3.8)
Other Liabilities [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(0.6)	(0.7)
Other Liabilities [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(35.4)	(28.8)
Other Liabilities [Member] | Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	7.4	5.8
Accrued Liabilities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan		2
Accrued Liabilities [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(0.9)	(3.7)
Accrued Liabilities [Member] | Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(0.1)	(0.1)
Accrued Liabilities [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Funded status of plan	(0.3)	(0.2)
Accrued Liabilities [Member] | Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	$ 1.2	$ 1

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Long-term debt, less current portion	$ 6,344.6	$ 5,300
Increase (Decrease) in Noncontrolling Interest Put	1
Noncontrolling interest puts	16.7	15.2
Fair market value of zero-coupon subordinated notes	18.8	79.3
Fair market value of senior notes	6,078.9	5,254.5
Fair Value Hedges, Net	14.6
Cash Surrender Value, Fair Value Disclosure	64	53.6
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	64.5	54.2
Contingent Consideration Classified as Equity, Fair Value Disclosure	16.5	16.8
Fair Value, Inputs, Level 1 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	0	0
Fair Value Hedges, Net	0
Interest Rate Fair Value Hedge Asset at Fair Value	0
Cash Surrender Value, Fair Value Disclosure	0	0
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability	0
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	16.7	15.2
Fair Value Hedges, Net	4.1
Interest Rate Fair Value Hedge Derivative at Fair Value, Net		14.6
Cash Surrender Value, Fair Value Disclosure	64	53.6
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability		0
Contingent Consideration Classified as Equity, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Noncontrolling interest puts	0	0
Fair Value Hedges, Net	0
Interest Rate Fair Value Hedge Derivative at Fair Value, Net	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	16.5	$ 16.8
Contractually Determined Value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Increase (Decrease) in Noncontrolling Interest Put	0.7
Foreign Currency Translation [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Increase (Decrease) in Noncontrolling Interest Put	$ 0.3

DERIVATIVE INSTRUMENTS AND HE87

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Schedule of Derivative Instruments in Statement of Financial Position at Fair Value) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jan. 30, 2015
Derivative [Line Items]
Long-term debt, less current portion	$ 6,344.6	$ 5,300
Debt Instrument, Basis Spread on Variable Rate	2.298%
Fair Value Hedges, Net	$ 14.6
Derivative Instruments in Statement of Financial Position at Fair Value
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%
Senior notes due 2020 [Member]
Derivative [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	(4.625%)		(2.625%)
Senior notes due 2020 [Member]
Derivative [Line Items]
Long-term debt, less current portion	$ 600

SUPPLEMENTAL CASH FLOW INFORM88

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash paid during period for:
Interest	$ 239.1	$ 210.7	$ 166.1
Income taxes, net of refunds	348	345.7	237.6
Disclosure of non-cash financing and investing activities
Surrender of restricted stock awards and performance shares	47.4	34.6	12.6
Noncash conversion of zero-coupon convertible debt	35	39.1	1.1
Fair Value of Assets Acquired	7.3	16	22.6
Capital Expenditures Incurred but Not yet Paid	$ 1.6	$ 4.4	$ 4.3

QUARTERLY DATA (UNAUDITED) (Det

QUARTERLY DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of unaudited quarterly data
Net sales	$ 2,701.5	$ 2,597.9	$ 2,498.4	$ 2,408.1	$ 2,387.3	$ 2,372.7	$ 2,382	$ 2,295.2	$ 10,205.9	$ 9,437.2	$ 8,505.7
Cost of Goods and Services Sold									6,741.9	6,256.7	5,602.4
Gross profit	915.8	882.8	861.8	803.6	788	788.4	826.8	777.3	3,464	3,180.5	2,903.3
Net earnings attributable to Laboratory Corporation of America Holdings	$ 706.8	$ 180.6	$ 188.6	$ 192.2	$ 184.4	$ 179.5	$ 204.1	$ 164.1	$ 1,268.2	$ 732.1	$ 437.6
Earnings Per Share
Basic earnings per share (in dollars per share)	$ 6.91	$ 1.77	$ 1.84	$ 1.87	$ 1.79	$ 1.74	$ 2	$ 1.61	$ 12.39	$ 7.14	$ 4.43
Diluted earnings per common share (in dollars per share)	$ 6.81	$ 1.74	$ 1.82	$ 1.84	$ 1.75	$ 1.71	$ 1.96	$ 1.58	$ 12.21	$ 7.02	$ 4.35

Schedule II - Valuation And Q90

Schedule II - Valuation And Qualifying Accounts And Reserves (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2015
Allowance for doubtful accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		$ 217	$ 235.6	$ 211.6
Additions Charged to Costs and Expense		287.3	314.7	265.4
Other (Deductions) Additions	[1]	(268.7)	(289.4)	(260)
Balance at end of year			260.9	217
Valuation allowance-deferred tax assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		15.1	31.3	17.1
Additions Charged to Costs and Expense		16.2	11.5	0
Other (Deductions) Additions	[1]	$ 0	0	(2)
Balance at end of year			$ 42.8	$ 15.1
[1]	Other (Deductions) Additions consists primarily of write-offs of accounts receivable amounts.

Business Segments _Disclosure91

Business Segments [Disclosure] (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 1,748.9				$ 1,718.6					$ 1,748.9	$ 1,718.6
Depreciation and amortization:
Depreciation and amortization										533.2	499.2	$ 457.8
Depreciation and Amortization of Intangible Assets								$ 490.5	$ 434.3	523.3
Net revenues:
Net sales	2,701.5	$ 2,597.9	$ 2,498.4	$ 2,408.1	2,387.3	$ 2,372.7	$ 2,382	2,295.2		10,205.9	9,437.2	8,505.7
Intercompany revenue elimination										(1.8)	(0.8)	0
Reimbursement Revenue								204.6		235.5	204.6	174.4
Revenues								9,641.8		10,441.4	9,641.8	8,680.1
Operating Income (Loss)										1,364.2	1,312.4	996.8
Nonoperating Income (Expense)										(229.3)	(206.9)	(270.8)
Total pre-tax income								1,105.5	726	1,134.9	1,105.5	726
Income Tax Expense (Benefit)								372.3	287.3	(139.1)	372.3	287.3
Net earnings										1,274	733.2	438.7
Net Income (Loss) Attributable to Noncontrolling Interest										(5.8)	(1.1)	(1.1)
Net earnings attributable to Laboratory Corporation of America Holdings	706.8	$ 180.6	$ 188.6	$ 192.2	$ 184.4	$ 179.5	$ 204.1	164.1		1,268.2	732.1	437.6
LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	885.9									885.9
Depreciation and amortization:
Depreciation and amortization								270.9	245.8	304.7
Net revenues:
Net sales										7,170.5	6,593.9	6,199.3
Operating Income (Loss)										1,298.6	1,187.6	1,053.7
Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	863									863
Depreciation and amortization:
Depreciation and amortization								219.5	184.4	217.4
Net revenues:
Net sales										3,037.2	2,844.1	2,306.4
Intercompany revenue elimination								(0.8)		(1.8)		0
Operating Income (Loss)										206.2	272.7	73.5
Corporate Segment [Member]
Depreciation and amortization:
Depreciation and amortization								$ 0.1	$ 4.1	1.2
Net revenues:
Operating Income (Loss)										(140.6)	$ (147.9)	$ (130.4)
UNITED STATES
Segment Reporting Information [Line Items]
Property, plant and equipment, net	1,416.8									1,416.8
Net revenues:
Net sales										8,234
UNITED STATES | LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	826.2									826.2
Net revenues:
Net sales										6,808.6
UNITED STATES | Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	590.6									590.6
Net revenues:
Net sales										1,427.2
CANADA
Segment Reporting Information [Line Items]
Property, plant and equipment, net	54.6									54.6
Net revenues:
Net sales										327.8
Intercompany revenue elimination										0
CANADA | LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	54.6									54.6
Net revenues:
Net sales										327.8
CANADA | Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	0									0
Net revenues:
Net sales										0
UNITED KINGDOM
Segment Reporting Information [Line Items]
Property, plant and equipment, net	122.8									122.8
Net revenues:
Net sales										302
Intercompany revenue elimination										0
UNITED KINGDOM | LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	2.1									2.1
Net revenues:
Net sales										29.6
UNITED KINGDOM | Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	120.7									120.7
Net revenues:
Net sales										272.4
SWITZERLAND
Segment Reporting Information [Line Items]
Property, plant and equipment, net	81.4									81.4
Net revenues:
Net sales										484.4
Intercompany revenue elimination										0
SWITZERLAND | LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	0									0
Net revenues:
Net sales										0
SWITZERLAND | Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	81.4									81.4
Net revenues:
Net sales										484.4
Other countries [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	73.3									73.3
Net revenues:
Net sales										857.7
Intercompany revenue elimination										0
Other countries [Member] | LabCorp Diagnostics [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	3									3
Net revenues:
Net sales										4.5
Other countries [Member] | Covance Drug Development [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 70.3									70.3
Net revenues:
Net sales										$ 853.2