Eli Lilly and (LLY) 10-K 19 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 13, 2019	Jun. 30, 2018
Document & Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Entity Registrant Name	Lilly Eli & Co
Entity Central Index Key	59,478
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Public Float			$ 78,196,000,000
Entity Common Stock, Shares Outstanding		1,035,418,562

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 24,555.7	$ 22,871.3	$ 21,222.1
Costs, expenses, and other:
Cost of sales	6,430	6,150.8	5,710.1
Research and development	5,307.1	5,357.3	5,310.3
Marketing, selling, and administrative	6,631.8	6,680.1	6,528
Acquired in-process research and development (Notes 3)	1,983.9	1,112.6	30
Asset impairment, restructuring, and other special charges (Note 5)	482	1,673.6	382.5
Other—net, (income) expense (Note 17)	(74.8)	(300.5)	(112.8)
Cost of sales, operating expenses, and other-net	20,760	20,673.9	17,848.1
Income before income taxes	3,795.7	2,197.4	3,374
Income taxes (Note 13)	563.7	2,401.5	636.4
Net income (loss)	$ 3,232	$ (204.1)	$ 2,737.6
Earnings (loss) per share:
Basic (usd per share)	$ 3.14	$ (0.19)	$ 2.59
Diluted (usd per share)	$ 3.13	$ (0.19)	$ 2.58
Shares used in calculation of earnings (loss) per share:
Basic (shares)	1,027,721	1,052,023	1,058,324
Diluted (shares)	1,033,667	1,052,023	1,061,825

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 3,232	$ (204.1)	$ 2,737.6
Other comprehensive income (loss):
Change in foreign currency translation gains (losses)		(440.7)	501.9	(436.4)
Change in net unrealized gains (losses) on securities		(8.8)	(181.3)	303
Change in defined benefit pension and retiree health benefit plans (Note 14)		569.4	(576.6)	(512.8)
Change in effective portion of cash flow hedges		(6)	27.8	11.7
Other comprehensive income (loss) before income taxes		113.9	(228.2)	(634.5)
Benefit (provision) for income taxes related to other comprehensive income (loss) items		(30.3)	402.7	(10.6)
Net other comprehensive income (loss)	[1]	83.6	174.5	(645.1)
Comprehensive income (loss)		$ 3,315.6	$ (29.6)	$ 2,092.5
[1]	Other comprehensive income in 2018 consists of $72.6 million of other comprehensive income attributable to controlling interest and $11.0 million of other comprehensive income attributable to noncontrolling interest. Other comprehensive income in 2017 consists of $199.0 million of other comprehensive income attributable to controlling interest and $24.5 million of other comprehensive loss attributable to noncontrolling interest. Other comprehensive loss in 2016 consists of $693.3 million of other comprehensive loss attributable to controlling interest and $48.2 million of other comprehensive income attributable to noncontrolling interest.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Other Comprehensive Income [Abstract]
Other comprehensive income (loss), attributed to parent	$ 72.6	$ 199	$ (693.3)
Other comprehensive income (loss), non-controlling interest	$ 11	$ (24.5)	$ 48.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents (Note 7)	$ 7,998.2	$ 6,536.2
Short-term investments (Note 7)	88.2	1,497.9
Accounts receivable, net of allowances of $32.5 (2018) and $38.7 (2017)	5,246.5	4,546.3
Other receivables	958.4	715.9
Inventories (Note 6)	4,111.8	4,458.3
Prepaid expenses and other	2,146.5	1,447.5
Total current assets	20,549.6	19,202.1
Other Assets
Investments (Note 7)	2,020.7	5,678.8
Goodwill (Note 8)	4,347.5	4,370.1
Other intangibles, net (Note 8)	3,521	4,029.2
Deferred tax assets (Note 13)	2,657.7	1,166.4
Sundry	1,892.4	1,707.9
Total other assets	14,439.3	16,952.4
Property and equipment, net (Note 9)	8,919.5	8,826.5
Total assets	43,908.4	44,981
Current Liabilities
Short-term borrowings and current maturities of long-term debt (Note 10)	1,131.2	3,706.6
Accounts payable	1,412.3	1,410.7
Employee compensation	1,054.5	997.9
Sales rebates and discounts	5,021.9	4,465.1
Dividends payable	650.8	590.6
Income taxes payable (Note 13)	404	532.9
Other current liabilities	2,213.4	2,832.1
Total current liabilities	11,888.1	14,535.9
Other Liabilities
Long-term debt (Note 10)	11,639.7	9,940.5
Accrued retirement benefits (Note 14)	2,911.3	3,513.9
Long-term income taxes payable (Note 13)	3,724.6	3,776.5
Other noncurrent liabilities	2,835.6	1,546.3
Total other liabilities	21,111.2	18,777.2
Commitments and Contingencies (Note 15)
Eli Lilly and Company Shareholders' Equity (Notes 11 and 12)
Common stock—no par value Authorized shares: 3,200,000 Issued shares: 1,057,639 (2018) and 1,100,672 (2017)	661	687.9
Additional paid-in capital	6,583.6	5,817.8
Retained earnings	11,395.9	13,894.1
Employee benefit trust	(3,013.2)	(3,013.2)
Accumulated other comprehensive loss (Note 16)	(5,729.2)	(5,718.6)
Cost of common stock in treasury	(69.4)	(75.8)
Total Eli Lilly and Company shareholders' equity	9,828.7	11,592.2
Noncontrolling interests	1,080.4	75.7
Total equity	10,909.1	11,667.9
Total liabilities and equity	$ 43,908.4	$ 44,981

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 32.5	$ 38.7
Issued shares	1,057,639,000	1,100,672,000
Authorized shares, shares	3,200,000,000	3,200,000,000

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity Statement - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Employee Benefit Trust	Accumulated Other Comprehensive Loss	Common Stock in Treasury	Noncontrolling Interest
Beginning balance at Dec. 31, 2015		$ 691.3	$ 5,552.1	$ 16,011.8	$ (3,013.2)	$ (4,580.7)	$ (90)	$ 19
Shares, Beginning Balance at Dec. 31, 2015		1,106,063					796
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)				2,737.6				16.3
Other comprehensive income (loss), net of tax	$ (693.3)					(693.3)		48.2
Cash dividends declared				(2,167.6)
Retirement of treasury shares, shares		(7,306)					(7,306)
Retirement of treasury shares		$ (4.6)		(535.5)			$ 540.1
Purchase of treasury shares, shares							7,306
Purchase of treasury shares	(540.1)		(60)				$ (540.1)
Issuance of stock under employee stock plans, net, shares		2,829					(85)
Issuance of stock under employee stock plans, net		$ 1.8	(106.8)				$ 9.5
Stock-based compensation			255.3
Other	(10.7)
Shares, Ending Balance at Dec. 31, 2016		1,101,586					711
Ending balance at Dec. 31, 2016		$ 688.5	5,640.6	16,046.3	(3,013.2)	(5,274)	$ (80.5)	72.8
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)				(204.1)				30.5
Other comprehensive income (loss), net of tax	199					199		(24.5)
Cash dividends declared				(2,234.6)
Retirement of treasury shares, shares		(4,390)					(4,390)
Retirement of treasury shares		$ (2.7)		(357.1)			$ 359.8
Purchase of treasury shares, shares							4,390
Purchase of treasury shares	(359.8)		60				$ (359.8)
Issuance of stock under employee stock plans, net, shares		3,476					(47)
Issuance of stock under employee stock plans, net		$ 2.1	(164.1)				$ 4.7
Stock-based compensation			281.3
Other	(3.1)
Shares, Ending Balance at Dec. 31, 2017		1,100,672					664
Ending balance at Dec. 31, 2017	11,667.9	$ 687.9	5,817.8	13,894.1	(3,013.2)	(5,718.6)	$ (75.8)	75.7
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)				3,232				3.7
Other comprehensive income (loss), net of tax	72.6					85.6		(2)
Cash dividends declared				(2,372)
Retirement of treasury shares, shares		(45,882)					(45,882)
Retirement of treasury shares		$ (28.7)		(4,122)			$ 4,150.7
Purchase of treasury shares, shares							45,882
Purchase of treasury shares	(4,150)						$ (4,150.7)
Issuance of stock under employee stock plans, net, shares		2,849					(60)
Issuance of stock under employee stock plans, net		$ 1.8	(139)				$ 6.4
Stock-based compensation			279.5
Sale of Elanco Stock (Note 3)			629.2			9		1,017.2
Other				(3.9)				(14.2)
Shares, Ending Balance at Dec. 31, 2018		1,057,639					604
Ending balance at Dec. 31, 2018	$ 10,909.1	$ 661	$ 6,583.6	$ 11,395.9	$ (3,013.2)	(5,729.2)	$ (69.4)	$ 1,080.4
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Reclassification of stranded tax effects and Adoption of new accounting standards (Note 2)						$ (105.2)

Consolidated Statements of Sh_2

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Cash dividend declared per share (usd per share)	$ 2.33	$ 2.12	$ 2.05

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ 3,232	$ (204.1)	$ 2,737.6
Adjustments to Reconcile Net Income (Loss) to Cash Flows from Operating Activities:
Depreciation and amortization	1,609	1,567.3	1,496.6
Change in deferred income taxes	326.8	(787.9)	439.5
Stock-based compensation expense	279.5	281.3	255.3
Acquired in-process research and development	1,983.9	1,112.6	30
Other non-cash operating activities, net	472	441.5	376.1
Other changes in operating assets and liabilities, net of acquisitions and divestitures:
Receivables—(increase) decrease	(996.7)	(357)	(709.4)
Inventories—(increase) decrease	7.8	(253.9)	(328.2)
Other assets—(increase) decrease	(980)	(590.1)	(265.5)
Income taxes payable—increase (decrease)	(125.3)	3,489.6	(304.8)
Accounts payable and other liabilities—increase (decrease)	(284.5)	916.3	1,123.8
Net Cash Provided by Operating Activities	5,524.5	5,615.6	4,851
Cash Flows from Investing Activities
Purchases of property and equipment	(1,210.6)	(1,076.8)	(1,037)
Proceeds from disposals of property and equipment	3.6	40.7	73.4
Proceeds from sales and maturities of short-term investments	2,552.5	4,852.5	1,642
Purchases of short-term investments	(112.2)	(3,389.7)	(1,327.4)
Proceeds from sales of noncurrent investments	3,509.5	2,586	2,086
Purchases of noncurrent investments	(837.9)	(4,611.6)	(4,346)
Purchases of in-process research and development	(1,807.6)	(1,086.8)	(55)
Cash paid for acquisitions, net of cash acquired (Note 3)	0	(882.1)	(45)
Other investing activities, net	(191.3)	(215.8)	(130.1)
Net Cash Provided by (Used for) Investing Activities	1,906	(3,783.6)	(3,139.1)
Cash Flows from Financing Activities
Dividends paid	(2,311.8)	(2,192.1)	(2,158.5)
Net change in short-term borrowings	(2,197.9)	1,397.5	1,293.2
Proceeds from issuance of long-term debt	2,477.7	2,232	1,206.6
Repayments of long-term debt	(1,009.1)	(630.6)	(0.2)
Purchases of common stock	(4,150.7)	(299.8)	(600.1)
Net proceeds from Elanco initial public offering (Note 3)	1,659.7	0	0
Other financing activities, net	(372.8)	(364.4)	(300.8)
Net Cash Provided by (Used for) Financing Activities	(5,904.9)	142.6	(559.8)
Effect of exchange rate changes on cash and cash equivalents	(63.6)	(20.5)	(236.4)
Net increase in cash and cash equivalents	1,462	1,954.1	915.7
Cash and cash equivalents at beginning of year	6,536.2	4,582.1	3,666.4
Cash and Cash Equivalents at End of Year	$ 7,998.2	$ 6,536.2	$ 4,582.1

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP). The accounts of all wholly-owned and majority-owned subsidiaries are included in the consolidated financial statements. Where our ownership of consolidated subsidiaries is less than 100 percent, the noncontrolling shareholders’ interests are reflected as a separate component of equity. All intercompany balances and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses, and related disclosures at the date of the financial statements and during the reporting period. Actual results could differ from those estimates. We issued our financial statements by filing with the Securities and Exchange Commission (SEC) and have evaluated subsequent events up to the time of the filing. On September 24, 2018, Elanco Animal Health Incorporated (Elanco), one of our subsidiaries, completed its initial public offering (IPO) of 72.3 million shares of its common stock, which represents 19.8 percent of Elanco's outstanding shares, at $24 per share. In addition, Elanco completed a debt offering and entered into a term loan facility during the third quarter of 2018. See Notes 3 and 10 to the consolidated financial statements for additional information. Certain reclassifications have been made to prior periods in the consolidated financial statements and accompanying notes to conform with the current presentation. All per-share amounts, unless otherwise noted in the footnotes, are presented on a diluted basis. Adoption of Revenue Accounting Standard Effective January 1, 2018, we adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers and other related updates (see Note 2 for additional discussion). The new standard has been applied to contracts for which performance was not substantially complete as of the date of adoption. For those contracts that were modified prior to the date of adoption, we reflected the aggregate effect of those modifications when determining the appropriate accounting under the new standard. We don’t believe the effect of applying this practical expedient resulted in material differences. Revenue presented for periods prior to 2018 was accounted for under previous standards and has not been adjusted. Revenue and net income for 2018 do not differ materially from amounts that would have resulted from application of the previous standards. The following table summarizes our revenue recognized in our consolidated statements of operations: 2018 2017 2016 Net product revenue $ 22,928.8 $ 21,671.4 $ 20,388.4 Collaboration and other revenue (1) 1,626.9 1,199.9 833.7 Revenue $ 24,555.7 $ 22,871.3 $ 21,222.1 (1) Collaboration and other revenue associated with prior year transfers of intellectual property was $303.2 million , $145.8 million , and $146.1 million during the years ended 2018 , 2017 , and 2016 , respectively. We recognize revenue primarily from two different types of contracts, product sales to customers (net product revenue) and collaborations and other arrangements. Revenue recognized from collaborations and other arrangements will include our share of profits from the collaboration, as well as royalties, upfront and milestone payments we receive under these types of contracts. See Note 4 for additional information related to our collaborations and other arrangements. Collaboration and other revenue disclosed above includes the revenue from the Trajenta ® and Jardiance ® families of products resulting from our collaboration with Boehringer Ingelheim discussed in Note 4. Substantially all of the remainder of collaboration and other revenue is related to contracts accounted for as contracts with customers. Net Product Revenue Revenue from sales of products is recognized at the point where the customer obtains control of the goods and we satisfy our performance obligation, which generally is at the time we ship the product to the customer. Payment terms differ by jurisdiction and customer, but payment terms in most of our major jurisdictions typically range from 30 to 75 days from date of shipment. Revenue for our product sales has not been adjusted for the effects of a financing component as we expect, at contract inception, that the period between when we transfer control of the product and when we receive payment will be one year or less. Any exceptions are either not material or we collect interest for payments made after the due date. Provisions for rebates and discounts, and returns are established in the same period the related sales are recognized. We generally ship product shortly after orders are received; therefore, we generally only have a few days of orders received but not yet shipped at the end of any reporting period. Shipping and handling activities are considered to be fulfillment activities and are not considered to be a separate performance obligation. We exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are imposed on our sales of product and collected from a customer. Significant judgments must be made in determining the transaction price for our sales of products related to anticipated rebates and discounts and returns. The following describe the most significant of these judgments: Sales Rebates and Discounts - Background and Uncertainties • Most of our pharmaceutical products are sold to wholesalers that serve pharmacies, physicians and other health care professionals, and hospitals. Most of our animal health products are sold to wholesale distributors. We initially invoice our customers at contractual list prices. Contracts with direct and indirect customers may provide for various rebates and discounts that may differ in each contract. As a consequence, to determine the appropriate transaction price for our product sales at the time we recognize a sale to a direct customer, we must estimate any rebates or discounts that ultimately will be due to the direct customer and other customers in the distribution chain under the terms of our contracts. Significant judgments are required in making these estimates. • The rebate and discount amounts are recorded as a deduction to arrive at our net product revenue. Sales rebates and discounts that require the use of judgment in the establishment of the accrual include managed care, Medicare, Medicaid, chargebacks, long-term care, hospital, patient assistance programs, and various other programs. We estimate these accruals using an expected value approach. • The largest of our sales rebate and discount amounts are rebates associated with sales covered by managed care, Medicare, Medicaid, and chargeback contracts in the United States (U.S.) In determining the appropriate accrual amount, we consider our historical rebate payments for these programs by product as a percentage of our historical sales as well as any significant changes in sales trends (e.g., patent expiries and product launches), an evaluation of the current contracts for these programs, the percentage of our products that are sold via these programs, and our product pricing. Although we accrue a liability for rebates related to these programs at the time we record the sale, the rebate related to that sale is typically paid up to six months later. Because of this time lag, in any particular period our rebate adjustments may incorporate revisions of accruals for several periods. • Most of our rebates outside the U.S. are contractual or legislatively mandated and are estimated and recognized in the same period as the related sales. In some large European countries, government rebates are based on the anticipated budget for pharmaceutical payments in the country. An estimate of these rebates, updated as governmental authorities revise budgeted deficits, is recognized in the same period as the related sale. Sales Returns - Background and Uncertainties • When product sales occur, to determine the appropriate transaction price for our sales, we estimate a reserve for future product returns related to those sales using an expected value approach. This estimate is based on several factors, including: historical return rates, expiration date by product (on average, approximately 24 months after the initial sale of a product to our customer), and estimated levels of inventory in the wholesale and retail channels, as well as any other specifically-identified anticipated returns due to known factors such as the loss of patent exclusivity, product recalls and discontinuances, or a changing competitive environment. We maintain a returns policy that allows U.S. pharmaceutical customers to return product for dating issues within a specified period prior to and subsequent to the product's expiration date. Following the loss of exclusivity for a patent-dependent product, we expect to experience an elevated level of product returns as product inventory remaining in the wholesale and retail channels expires. Adjustments to the returns reserve have been and may in the future be required based on revised estimates to our assumptions. We record the return amounts as a deduction to arrive at our net product revenue. Once the product is returned, it is destroyed; we do not record a right of return asset. Our returns policies outside the U.S. are generally more restrictive than in the U.S. as returns are not allowed for reasons other than failure to meet product specifications in many countries. Our reserve for future product returns for product sales outside the U.S. is not material. • As a part of our process to estimate a reserve for product returns, we regularly review the supply levels of our significant products sold to major wholesalers in the U.S. and in major markets outside the U.S., primarily by reviewing periodic inventory reports supplied by our major wholesalers and available prescription volume information for our products, or alternative approaches. We attempt to maintain U.S. wholesaler inventory levels at an average of approximately one month or less on a consistent basis across our product portfolio. Causes of unusual wholesaler buying patterns include actual or anticipated product-supply issues, weather patterns, anticipated changes in the transportation network, redundant holiday stocking, and changes in wholesaler business operations. In the U.S., the current structure of our arrangements provides us with data on inventory levels at our wholesalers; however, our data on inventory levels in the retail channel is more limited. Wholesaler stocking and destocking activity historically has not caused any material changes in the rate of actual product returns. • Actual product returns have been less than 2 percent of our net revenue over each of the past three years and have not fluctuated significantly as a percentage of revenue, although fluctuations are more likely in periods following loss of patent exclusivity for major products in the U.S. market. Adjustments to Revenue Adjustments to revenue recognized as a result of changes in estimates for the judgments described above during 2018 for product shipped in previous years were approximately 1 percent of revenue. Disaggregation of Revenue Our disaggregated revenue is disclosed in Note 18. Collaborations and Other Arrangements We recognize several types of revenue from our collaborations and other arrangements, which we discuss in general terms immediately below and more specifically in Note 4 for each of our material collaborations and other arrangements. Our collaborations and other arrangements are not contracts with customers but are evaluated to determine whether any aspects of the arrangements are contracts with customers. • Revenue related to products we sell pursuant to these arrangements is included in net product revenue, while other sources of revenue (e.g., royalties and profit sharing from our partner) are included in collaboration and other revenue. • Initial fees and developmental milestones we receive in collaborative and other similar arrangements from the partnering of our compounds under development are generally deferred and amortized into income through the expected product approval date. • Profit-sharing due from our collaboration partners, which is based upon gross margins reported to us by our partners, is recognized as collaboration and other revenue as earned. • Royalty revenue from licensees, which is based on sales to third-parties of licensed products and technology, is recorded when the third-party sale occurs and the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). This royalty revenue is included in collaboration and other revenue. • For arrangements involving multiple goods or services (e.g., research and development, marketing and selling, manufacturing, and distribution), each required good or service is evaluated to determine whether it is distinct. If a good or service does not qualify as distinct, it is combined with the other non-distinct goods or services within the arrangement and these combined goods or services are treated as a single performance obligation for accounting purposes. The arrangement's transaction price is then allocated to each performance obligation based on the relative standalone selling price of each performance obligation. For arrangements that involve variable consideration where we have sold intellectual property, we recognize revenue based on estimates of the amount of consideration we believe we will be entitled to receive from the other party, subject to a constraint. These estimates are adjusted to reflect the actual amounts to be collected when those facts and circumstances become known. • Significant judgments must be made in determining the transaction price for our sales of intellectual property. Because of the risk that products in development will not receive regulatory approval, we generally do not recognize any contingent payments that would be due to us upon or after regulatory approval. • We have entered into arrangements whereby we transferred rights to products and committed to supply for a period of time. For those arrangements for which we concluded that the obligations were not distinct, any amounts received upfront are being amortized to revenue as net product revenue over the period of the supply arrangement as the performance obligation is satisfied. Contract Liabilities Our contract liabilities result from arrangements where we have received payment in advance of performance under the contract and do not include sales rebates, discounts, and returns. Changes in contract liabilities are generally due to either receipt of additional advance payments or our performance under the contract. We have the following amounts recorded for contract liabilities: 2018 2017 Contract liabilities $ 299.3 $ 335.2 The contract liabilities amount disclosed above as of December 31, 2018 and 2017, are primarily related to: • The remaining license period of symbolic intellectual property, and • Obligations to supply product for a defined period of time. Revenue recognized from contract liabilities as of January 1, 2018 , during the year ended December 31, 2018 was not material. Revenue expected to be recognized in the future from contract liabilities as the related performance obligations are satisfied is not expected to be material in any one year. Research and development expenses and acquired in-process research and development Research and development expenses include the following: • Research and development costs, which are expensed as incurred. • Milestone payment obligations incurred prior to regulatory approval of the product, which are accrued when the event requiring payment of the milestone occurs. Acquired in-process research and development (IPR&D) expense includes the initial costs of IPR&D projects, acquired directly in a transaction other than a business combination, that do not have an alternative future use. Earnings per share We calculate basic earnings per share (EPS) based on the weighted-average number of common shares outstanding and incremental shares from potential participating securities. We calculate diluted EPS based on the weighted-average number of common shares outstanding, including incremental shares from our stock-based compensation programs. Foreign Currency Translation Operations in our subsidiaries outside the U.S. are recorded in the functional currency of each subsidiary which is determined by a review of the environment where each subsidiary primarily generates and expends cash. The results of operations for our subsidiaries outside the U.S. are translated from functional currencies into U.S. dollars using the weighted average currency rate for the period. Assets and liabilities are translated using the period end exchange rates. The U.S. dollar effects that arise from translating the net assets of these subsidiaries are recorded in other comprehensive income (loss). Other significant accounting policies Our other significant accounting policies are described in the remaining appropriate notes to the consolidated financial statements.

Implementation of New Financial

Implementation of New Financial Accounting Pronouncements	12 Months Ended
	Dec. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Implementation of New Financial Accounting Pronouncements	Implementation of New Financial Accounting Pronouncements The following table provides a brief description of accounting standards that were effective January 1, 2018 and were adopted on that date: Standard Description Effect on the financial statements or other significant matters Accounting Standards Update 2014-09 and various other related updates, Revenue from Contracts with Customers This standard replaced existing revenue recognition standards and requires entities to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. An entity can apply the new revenue standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We applied the latter approach. Application of the new standard to applicable contracts resulted in an increase of approximately $5 million to retained earnings as of January 1, 2018. Disclosures required by the new standard are included in Note 1, Note 4, and Note 18. Accounting Standards Update 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities This standard requires entities to recognize changes in the fair value of equity investments with readily determinable fair values in net income (except for investments accounted for under the equity method of accounting or those that result in consolidation of the investee). An entity should apply the new standard through a cumulative effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Upon adoption, we reclassified from accumulated other comprehensive loss the after-tax amount of net unrealized gains resulting in an increase to retained earnings of approximately $105 million. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory This standard requires entities to recognize the income tax consequences of intra-entity transfers of assets other than inventory at the time of transfer. This standard requires a modified Upon adoption, the cumulative effect of applying the standard resulted in an increase of approximately $700 million to retained earnings, $2.5 billion to deferred tax assets, and $1.8 billion to deferred tax liabilities. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost This standard was issued to improve the transparency and comparability among organizations by requiring entities to separate their net periodic pension cost and net periodic postretirement benefit cost into a service cost component and other components. Previously, the costs of the other components along with the service cost component were classified based upon the function of the employee. This standard requires entities to classify the service cost component in the same financial statement line item or items as other compensation costs arising from services rendered by pertinent employees. The other components of net benefit cost are now presented separately from the line items that include the service cost component. When applicable, the service cost component is now the only component eligible for capitalization. An entity should apply the new standard retrospectively for the classification of the service cost and other components and prospectively for the capitalization of the service cost component. Upon adoption of this standard, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. The application of the new standard resulted in reclassification to other income of $248.1 million for the year ended December 31, 2017, while increasing cost of sales by $80.6 million, research and development expenses by $75.5 million, and marketing, selling, and administrative expenses by $92.0 million for the same period. The application of the new standard resulted in reclassification to other income of $197.6 million for the year ended December 31, 2016, while increasing cost of sales by $55.2 million, research and development expenses by $66.4 million, and marketing, selling, and administrative expenses by $76.0 million for the same period. We do not expect application of the new standard to have a material impact on an ongoing basis. We elected to early adopt Accounting Standards Update 2018-02, Income Statement-Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income as of December 31, 2017, which allowed a reclassification from accumulated other comprehensive loss to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (2017 Tax Act - see Note 13). This standard allowed us to reclassify the effect of remeasuring deferred tax liabilities and assets related to items within accumulated other comprehensive loss using the then newly enacted 21 percent federal corporate income tax rate. The provisional effect of this early adoption was a reclassification from accumulated other comprehensive loss, which resulted in an increase to retained earnings of $643.6 million as of December 31, 2017. The following table provides a brief description of the accounting standard that had not yet been adopted as of December 31, 2018: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-02, Leases This standard was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities, including leases classified as operating leases under current GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. An entity can apply the new leases standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We plan to use the latter approach. This standard was effective January 1, 2019, and we adopted on that date. We expect to record a right-of-use asset and lease liability for operating leases of approximately $650 million on our consolidated balance sheet as of January 1, 2019. Our accounting for capital leases will remain substantially unchanged. This standard will not have a material impact on our consolidated statement of operations.

Divestiture and Acquisitions

Divestiture and Acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Divestiture and Acquisitions	Divestiture and Acquisitions Divestiture Formation of Elanco and Initial Public Offering On September 24, 2018, Elanco completed the IPO resulting in the issuance of 72.3 million shares of its common stock, which represents 19.8 percent of Elanco's outstanding shares, at $24 per share. Elanco shares began trading on the New York Stock Exchange under the symbol "ELAN" in September 2018. In connection with the completion of the IPO, through a series of equity and other transactions, we transferred to Elanco the animal health businesses that form its business going forward. In exchange, Elanco transferred to us, or will transfer to us, consideration of approximately $4.2 billion , which consists primarily of the net proceeds from the IPO, the net proceeds from the debt offering completed by Elanco in August 2018, and the term loan facility entered into by Elanco during the period (see Note 10). The consideration that we receive is intended to be used for debt repayment, dividends, and/or share repurchases. The excess of the net proceeds from the IPO over the net book value of our divested interest was $629.2 million and was recorded in additional paid-in capital. Of our consolidated cash and cash equivalents as of December 31, 2018 , approximately $475 million is retained by Elanco for working capital purposes. We continue to consolidate Elanco, as we retain control over Elanco. The earnings attributable to the divested, noncontrolling interest for the period from the IPO until December 31, 2018 were not material. As of December 31, 2018 , the noncontrolling interest of $1.02 billion associated with Elanco is reflected in noncontrolling interests in the consolidated balance sheet. We have announced our intent to divest our remaining 293,290,000 shares of Elanco common stock through an exchange offer and on February 8, 2019, Elanco filed a registration statement on Form S-4 with the SEC. In the exchange offer, our shareholders can exchange all, some, or none of their shares of our common stock for shares of Elanco common stock owned by us, subject to the specific terms and conditions of the offer described in Elanco's registration statement. The completion of the exchange offer is subject to certain conditions, including at least 146,645,000 shares of Elanco common stock being distributed in exchange for shares of our common stock validly tendered in the exchange offer, and the receipt of an opinion of counsel that the exchange offer will qualify for tax-free treatment to us and our participating shareholders. However, the conditions of the exchange offer may not be satisfied; we may exchange less than our entire interest in Elanco; or we may decide to waive one or more of these conditions, to the extent legally permissible, and consummate the exchange offer even if all of the conditions are not satisfied. If the exchange offer is not fully subscribed, we intend, from time to time, to complete subsequent exchange offers and/or pro rata spin-off of our remaining interest in Elanco. Acquisitions During 2017, we completed the acquisition of Boehringer Ingelheim Vetmedica, Inc.'s U.S. feline, canine, and rabies vaccine portfolio and other related assets (BIVIVP). This transaction, as further discussed in this note below in Acquisitions of Businesses was accounted for as a business combination under the acquisition method of accounting. We also had an immaterial acquisition of a business in 2016. Under this method, the assets acquired and liabilities assumed were recorded at their respective fair values as of the acquisition date in our consolidated financial statements. The determination of estimated fair value required management to make significant estimates and assumptions. The excess of the purchase price over the fair value of the acquired net assets, where applicable, has been recorded as goodwill. The results of operations of this acquisition have been included in our consolidated financial statements from the date of acquisition. In addition to the acquisition of BIVIVP, we acquired assets in development in 2018 , 2017 , and 2016 which are further discussed in this note below in Asset Acquisitions. Upon acquisition, the acquired IPR&D charges related to these products were immediately expensed because the products had no alternative future use. For the years ended December 31, 2018 , 2017 , and 2016 , we recorded acquired IPR&D charges of $1.98 billion , $1.11 billion , and $30.0 million , respectively. The acquired IPR&D charges in 2018 were primarily related to the acquisition of ARMO Biosciences, Inc. (ARMO). Substantially all of the value of ARMO was related to pegilodecakin, its only significant asset. Acquisitions of Businesses Boehringer Ingelheim Vetmedica, Inc. Vaccine Portfolio Acquisition Overview of Transaction On January 3, 2017, we acquired BIVIVP in an all-cash transaction for $882.1 million . Under the terms of the agreement, we acquired a manufacturing and research and development site and a U.S. vaccine portfolio including vaccines used for the treatment of bordetella, Lyme disease, rabies, and parvovirus, among others. Assets Acquired and Liabilities Assumed The following table summarizes the amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at January 3, 2017 Inventories $ 108.6 Marketed products (1) 297.0 Property and equipment 148.2 Other assets and liabilities - net 8.2 Total identifiable net assets 562.0 Goodwill (2) 320.1 Total consideration transferred - net of cash acquired $ 882.1 (1) These intangible assets, which are being amortized to cost of sales on a straight-line basis over their estimated useful lives, were expected to have a weighted average useful life of 10 years . (2) The goodwill recognized from this acquisition is attributable primarily to expected synergies from combining the operations of BIVIVP with our legacy animal health business, future unidentified projects and products, and the assembled workforce of BIVIVP. The goodwill associated with this acquisition is deductible for tax purposes. Subsequent Event - Loxo Oncology, Inc. (Loxo) Acquisition Overview of transaction On February 15, 2019, we acquired Loxo for a purchase price of $235 per share, or approximately $8 billion . Under the terms of the agreement, we acquired a pipeline of highly selective potential medicines for patients with genomically defined cancers. Loxo's pipeline includes LOXO-292, an oral RET inhibitor being studied across multiple tumor types, which recently was granted Breakthrough Therapy designation by the U.S. Food and Drug Administration. The accounting impact of this acquisition and the results of the operations for Loxo will be included in our consolidated financial statements beginning in the first quarter of 2019. Assets Acquired and Liabilities Assumed The initial accounting for this acquisition is incomplete. Significant, relevant information needed to complete the initial accounting is not available because the valuation of assets acquired and liabilities assumed is not complete. As a result, determining these values is not practicable and we are unable to disclose these values or provide other related disclosures at this time. Asset Acquisitions The following table and narrative summarize our asset acquisitions during 2018 , 2017 , and 2016 . Counterparty Compound(s),Therapy, or Asset Acquisition Month Phase of Development (1) Acquired IPR&D Expense Sigilon Therapeutics Encapsulated cell therapies for the potential treatment of type 1 diabetes April 2018 Pre-clinical $ 66.9 AurKa Pharma, Inc. AK-01, an Aurora kinase A inhibitor June 2018 Phase I 81.8 ARMO Cancer therapy - pegilodecakin June 2018 Phase III 1,475.8 Anima Biotech Translation inhibitors for selected neuroscience targets July 2018 Pre-clinical 30.0 SIGA Technologies, Inc. Priority Review Voucher October 2018 Not applicable 80.0 Chugai Pharmaceutical Company OWL833, an oral non-peptidic GLP-1 receptor agonist October 2018 Pre-clinical 50.0 NextCure, Inc. Immuno-oncology cancer therapies November 2018 Pre-clinical 28.1 Dicerna Pharmaceuticals Cardio-metabolic disease, neurodegeneration, and pain December 2018 Pre-clinical 148.7 Hydra Biosciences TRPA1 antagonists program for the potential treatment of chronic pain syndromes December 2018 Pre-clinical 22.6 CoLucid Pharmaceuticals, Inc. (CoLucid) Oral therapy for the acute treatment of migraine - lasmiditan March 2017 Phase III 857.6 KeyBioscience AG Multiple molecules for treatment of metabolic disorders July 2017 Phase II 55.0 Nektar Therapeutics Immunological therapy - NKTR-358 August 2017 Phase I 150.0 CureVac AG Cancer vaccines November 2017 Pre-clinical 50.0 AstraZeneca Antibody selective for amyloid-beta 42 (Aβ42) - MEDI1814 December 2016 Phase I 30.0 (1) The phase of development presented is as of the date of the arrangement and represents the phase of development of the most advanced asset acquired, where applicable. In connection with these arrangements, our partners may be entitled to future royalties and/or commercial milestones based on sales should products be approved for commercialization and/or milestones based on the successful progress of compounds through the development process. Subsequent Event - AC Immune SA In January 2019, we entered into a license and collaboration agreement with AC Immune SA for the discovery and development of tau aggregation inhibitor small molecules for the potential treatment of Alzheimer's disease and other neurodegenerative diseases. Under terms of the agreement, we paid an upfront fee of CHF 80.0 million and we will pay $50.0 million in exchange for a note, convertible to equity at a premium. As a result of this transaction, we will record an acquired IPR&D expense of $96.9 million in the first quarter of 2019.

Collaborations and Other Arrang

Collaborations and Other Arrangements	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborations and Other Arrangements	Collaborations and Other Arrangements We often enter into collaborative and other similar arrangements to develop and commercialize drug candidates. Collaborative activities may include research and development, marketing and selling (including promotional activities and physician detailing), manufacturing, and distribution. These arrangements often require milestone and royalty or profit-share payments, contingent upon the occurrence of certain future events linked to the success of the asset in development, as well as expense reimbursements or payments to the collaboration partner. See Note 1 for amounts of collaboration and other revenue recognized from these types of arrangements. Operating expenses for costs incurred pursuant to these arrangements are reported in their respective expense line item, net of any payments due to or reimbursements due from our collaboration partners, with such reimbursements being recognized at the time the party becomes obligated to pay. Each collaboration is unique in nature, and our more significant arrangements are discussed below. Boehringer Ingelheim Diabetes Collaboration We and Boehringer Ingelheim have a global agreement to jointly develop and commercialize a portfolio of diabetes compounds. Currently, included in the collaboration are Boehringer Ingelheim’s oral diabetes products: Trajenta, Jentadueto ® , Jardiance, Glyxambi ® , and Synjardy ® , as well as our basal insulin: Basaglar ® . The table below summarizes significant milestones (deferred) capitalized for the compounds included in this collaboration: Product Family Milestones (Deferred) Capitalized (1) Year Amount Trajenta (2) Cumulative (4) $ 446.4 Jardiance (3) Cumulative (4) 289.0 Basaglar 2018 — 2017 — 2016 (187.5 ) Cumulative (4) (250.0 ) (1) In connection with the regulatory approvals of Basaglar in the U.S., Europe, and Japan, milestone payments received were recorded as contract liabilities and are being amortized through the term of the collaboration (2029) to collaboration and other revenue. In connection with the regulatory approvals of Trajenta and Jardiance, milestone payments made were capitalized as intangible assets and are being amortized to cost of sales through the term of the collaboration. (2) Jentadueto is included in the Trajenta product family. The collaboration agreement with Boehringer Ingelheim for Trajenta ends upon expiration of the compound patent and any supplementary protection certificates or extensions thereto. (3) Glyxambi and Synjardy are included in the Jardiance product family. The collaboration agreement with Boehringer Ingelheim for Jardiance ends upon expiration of the compound patent and any supplementary protection certificates or extensions thereto. (4) The cumulative amount represents the total amounts that have been (deferred) or capitalized from the start of this collaboration through the end of the reporting period. In the most significant markets, we and Boehringer Ingelheim share equally the ongoing development costs, commercialization costs, and agreed upon gross margin for any product resulting from the collaboration. We record our portion of the gross margin associated with Boehringer Ingelheim's products as collaboration and other revenue. We record our sales of Basaglar to third parties as net product revenue with the payments made to Boehringer Ingelheim for their portion of the gross margin recorded as cost of sales. For all compounds under this collaboration, we record our portion of the development and commercialization costs as research and development expense and marketing, selling, and administrative expense, respectively. Each company is entitled to potential performance payments depending on the sales of the molecules it contributes to the collaboration. These performance payments result in the owner of the molecule retaining a greater share of the agreed upon gross margin of that product. Subject to achieving these thresholds, in a given period, our reported revenue for Trajenta and Jardiance may be reduced by any performance payments we make related to these products. Similarly, performance payments we may receive related to Basaglar effectively reduce Boehringer Ingelheim's share of the gross margin, which reduces our cost of sales. The following table summarizes our collaboration and other revenue recognized with respect to the Trajenta and Jardiance families of products and net product revenue recognized with respect to Basaglar: 2018 2017 2016 Basaglar $ 801.2 $ 432.1 $ 86.1 Jardiance 658.3 447.5 201.9 Trajenta 574.7 537.9 436.6 Erbitux ® We have several collaborations with respect to Erbitux. The most significant collaborations are or, where applicable, were in Japan, and prior to the transfer of commercialization rights in the fourth quarter of 2015, the U.S. and Canada (Bristol-Myers Squibb Company); and worldwide except the U.S. and Canada (Merck KGaA). Certain rights to Erbitux outside the U.S. and Canada (North America) will remain with Merck KGaA (Merck) upon expiration of that agreement. The following table summarizes our revenue recognized with respect to Erbitux: 2018 2017 2016 Net product revenue $ 536.1 $ 548.2 $ 587.0 Collaboration and other revenue 99.2 97.7 100.0 Revenue $ 635.3 $ 645.9 $ 687.0 Bristol-Myers Squibb Company Pursuant to commercial agreements with Bristol-Myers Squibb Company and E.R. Squibb (collectively, BMS), we had been co-developing Erbitux in North America exclusively with BMS. On October 1, 2015, BMS transferred their commercialization rights to us with respect to Erbitux in North America pursuant to a modification of our existing arrangement, and we began selling Erbitux at that time. This modification did not affect our rights with respect to Erbitux in other jurisdictions. In connection with the modification of terms, we provided consideration to BMS based upon a tiered percentage of net sales of Erbitux in North America estimated to average 38 percent through September 2018. The transfer of the commercialization rights was accounted for as an acquisition of a business. The consideration to be paid to BMS was accounted for as contingent consideration liability. Merck KGaA A development and license agreement granted Merck exclusive rights to market Erbitux outside of North America until December 2018. A separate agreement grants co-exclusive rights among Merck, BMS, and us in Japan and expires in 2032. This agreement was amended in 2015 to grant Merck exclusive commercialization rights in Japan but did not result in any other changes to our rights. Merck manufactures Erbitux for supply in its territory, including Japan. We receive a royalty on the sales of Erbitux outside of North America, which is included in collaboration and other revenue as the underlying sales occur. Royalties due to third parties are recorded as a reduction of collaboration and other revenue, net of any royalty reimbursements due from third parties. Olumiant ® We have a worldwide license and collaboration agreement with Incyte Corporation (Incyte) which provides us the development and commercialization rights to its Janus tyrosine kinase (JAK) inhibitor compound, now known as Olumiant, and certain follow-on compounds, for the treatment of inflammatory and autoimmune diseases. Incyte has the right to receive tiered, double-digit royalty payments on future global sales with rates ranging up to 20 percent if the product is successfully commercialized. The agreement provides Incyte with options to co-develop these compounds on an indication-by-indication basis by funding 30 percent of the associated development costs from the initiation of a Phase IIb trial through regulatory approval in exchange for increased tiered royalties ranging up to percentages in the high twenties. Incyte exercised its option to co-develop Olumiant in rheumatoid arthritis in 2010 and psoriatic arthritis, atopic dermatitis, alopecia areata, and systemic lupus erythematosus (SLE) in 2017. The agreement calls for payments by us to Incyte associated with certain development, success-based regulatory, and sales-based milestones. The following table summarizes our milestones achieved: Year Event Classification Amount 2018 Regulatory approval in the U.S. Intangible asset $ 100.0 Began Phase III testing for SLE R&D Expense 20.0 2017 Regulatory approval in Europe Intangible asset 65.0 Regulatory approval in Japan Intangible asset 15.0 Began Phase III testing for atopic dermatitis R&D expense 30.0 2016 Regulatory submissions in the U.S. and Europe R&D expense 55.0 As of December 31, 2018, Incyte is eligible to receive up to $130.0 million of additional payments from us contingent upon certain development and success-based regulatory milestones. Incyte is also eligible to receive up to $150.0 million of potential sales-based milestones. Effient ® We are in a collaborative arrangement with Daiichi Sankyo Co., Ltd. (Daiichi Sankyo) to develop, market, and promote Effient. Marketing rights for major territories are shown below. We and Daiichi Sankyo each have exclusive marketing rights in certain other territories. Territory Marketing Rights Selling Party U.S. Co-promotion Lilly Major European markets Co-promotion Daiichi Sankyo Japan Exclusive Daiichi Sankyo The parties share approximately 50 /50 in the profits, as well as in the costs of development and marketing in the co-promotion territories. A third party manufactures bulk product, and we produce the finished product for our exclusive and co-promotion territories, including the major European markets. We record net product revenue in our exclusive and co-promotion territories where we are the selling party. Profit-share payments due to Daiichi Sankyo for co-promotion countries where we are the selling party are recorded as marketing, selling, and administrative expenses. Any profit-share payments due to us from Daiichi Sankyo for the major European markets are recorded as collaboration and other revenue. We also record our share of the expenses in these co-promotion territories as marketing, selling, and administrative expenses. In our exclusive territories, we pay Daiichi Sankyo a royalty specific to these territories. All royalties due to Daiichi Sankyo and the third-party manufacturer are recorded in cost of sales. Generic versions of Effient launched in the U.S. in the third quarter of 2017. The following table summarizes our revenue recognized with respect to Effient: 2018 2017 2016 Revenue $ 122.2 $ 388.9 $ 535.2 Tanezumab We have a collaboration agreement with Pfizer Inc. (Pfizer) to jointly develop and globally commercialize tanezumab for the treatment of osteoarthritis pain, chronic low back pain and cancer pain. Under the agreement, the companies share equally the ongoing development costs and, if successful, in gross margins and certain commercialization expenses. As of December 31, 2018 , Pfizer is eligible to receive up to $350.0 million in success-based regulatory milestones and up to $1.23 billion in a series of sales-based milestones, contingent upon the commercial success of tanezumab.

Asset Impairment, Restructuring

Asset Impairment, Restructuring, and Other Special Charges	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Asset Impairment, Restructuring, And Other Special Charges	Asset Impairment, Restructuring, and Other Special Charges The components of the charges included in asset impairment, restructuring, and other special charges in our consolidated statements of operations are described below: 2018 2017 2016 Severance: Human pharmaceutical products $ 127.8 $ 601.0 $ 85.9 Animal health products 14.8 96.4 40.8 Total severance 142.6 697.4 126.7 Pension and post-retirement medical charges associated with U.S. voluntary early retirement program (see Note 14): Human pharmaceutical products — 446.7 — Animal health products — 67.0 — Total pension and post-retirement medical charges associated with U.S. voluntary early retirement program — 513.7 — Asset impairment (gains from facility sales) and other special charges: Human pharmaceutical products 46.0 81.7 (13.0 ) Animal health products 293.4 380.8 268.8 Total asset impairment and other special charges 339.4 462.5 255.8 Total asset impairment, restructuring, and other special charges $ 482.0 $ 1,673.6 $ 382.5 Severance costs recognized during the years ended December 31, 2018 , 2017 and 2016 were incurred as a result of actions taken to reduce our cost structure. Severance costs recognized in 2017 were associated with the U.S. voluntary early retirement program. During 2017, severance costs recognized in the U.S. and outside the U.S. were $412.5 million and $284.9 million , respectively. Substantially all of the severance costs incurred in 2016 and 2017 have been paid. Of the severance costs incurred during the year ended December 31, 2018, approximately half will be paid in 2019 and half will be paid in 2020 . Asset impairment and other special charges recognized during the year ended December 31, 2018 resulted primarily from asset impairment and other special charges related to the sale of the Posilac ® (rbST) brand and the associated Augusta, Georgia manufacturing site, as well as the decision to suspend commercialization of Imrestor ® , an animal health product. We also incurred expenses associated with the IPO and separation of Elanco. Asset impairment and other special charges related to animal health products recognized during the year ended December 31, 2017 resulted primarily from asset impairments related to lower projected revenue for Posilac (rbST). The assets associated with Posilac (rbST) were written down to their fair values, which were determined based upon a discounted cash flow valuation. Impairment charges were recorded for the associated fixed assets and intangible asset of $151.5 million and $50.0 million , respectively. In addition, we incurred approximately $43.4 million of costs associated with the temporary shut down of our Puerto Rico facility following Hurricane Maria. The remaining asset impairment and other special charges recognized in 2017 and 2016 were primarily related to integration costs and asset impairments due to product rationalizations and site closures resulting from our acquisition and integration of Novartis Animal Health, including the closure of a manufacturing facility in Ireland in 2016 (refer to Note 8 for further detail relating to intangible asset impairments).

Inventories

Inventories	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories We use the last-in, first-out (LIFO) method for the majority of our inventories located in the continental U.S. Other inventories are valued by the first-in, first-out (FIFO) method. FIFO cost approximates current replacement cost. Inventories measured using LIFO must be valued at the lower of cost or market. Inventories measured using FIFO must be valued at the lower of cost or net realizable value. Inventories at December 31 consisted of the following: 2018 2017 Finished products $ 988.1 $ 1,211.4 Work in process 2,628.2 2,697.7 Raw materials and supplies 506.5 488.8 Total (approximates replacement cost) 4,122.8 4,397.9 Increase (reduction) to LIFO cost (11.0 ) 60.4 Inventories $ 4,111.8 $ 4,458.3 Inventories valued under the LIFO method comprised $1.57 billion and $1.56 billion of total inventories at December 31, 2018 and 2017 , respectively.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial Instruments Financial instruments that potentially subject us to credit risk consist principally of trade receivables and interest-bearing investments. Wholesale distributors of life-science products account for a substantial portion of our trade receivables; collateral is generally not required. We seek to mitigate the risk associated with this concentration through our ongoing credit-review procedures and insurance. A large portion of our cash is held by a few major financial institutions. We monitor our exposures with these institutions and do not expect any of these institutions to fail to meet their obligations. Major financial institutions represent the largest component of our investments in corporate debt securities. In accordance with documented corporate risk-management policies, we monitor the amount of credit exposure to any one financial institution or corporate issuer. We are exposed to credit-related losses in the event of nonperformance by counterparties to risk-management instruments but do not expect any counterparties to fail to meet their obligations given their high credit ratings. We consider all highly liquid investments with a maturity of three months or less from the date of purchase to be cash equivalents. The cost of these investments approximates fair value. Our equity investments are accounted for using three different methods depending on the type of equity investment: • Investments in companies over which we have significant influence but not a controlling interest are accounted for using the equity method, with our share of earnings or losses reported in other-net, (income) expense. • For equity investments that do not have readily determinable fair values, we measure these investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. Any change in recorded value is recorded in other-net, (income) expense. • Our public equity investments are measured and carried at fair value. Any change in fair value is recognized in other-net, (income) expense. We review equity investments other than public equity investments for indications of impairment on a regular basis. Our derivative activities are initiated within the guidelines of documented corporate risk-management policies and are intended to offset losses and gains on the assets, liabilities, and transactions being hedged. Management reviews the correlation and effectiveness of our derivatives on a quarterly basis. For derivative instruments that are designated and qualify as fair value hedges, the derivative instrument is marked to market with gains and losses recognized currently in income to offset the respective losses and gains recognized on the underlying exposure. For derivative instruments that are designated and qualify as cash flow hedges, gains and losses are reported as a component of accumulated other comprehensive loss and reclassified into earnings in the same period the hedged transaction affects earnings. For derivative and non-derivative instruments that are designated and qualify as net investment hedges, the foreign currency translation gains or losses due to spot rate fluctuations are reported as a component of accumulated other comprehensive loss. Derivative contracts that are not designated as hedging instruments are recorded at fair value with the gain or loss recognized in earnings during the period of change. We may enter into foreign currency forward or option contracts to reduce the effect of fluctuating currency exchange rates (principally the euro, British pound, and the Japanese yen). Foreign currency derivatives used for hedging are put in place using the same or like currencies and duration as the underlying exposures. Forward and option contracts are principally used to manage exposures arising from subsidiary trade and loan payables and receivables denominated in foreign currencies. These contracts are recorded at fair value with the gain or loss recognized in other–net, (income) expense. We may enter into foreign currency forward and option contracts and currency swaps as fair value hedges of firm commitments. Forward contracts generally have maturities not exceeding 12 months. At December 31, 2018 , we had outstanding foreign currency forward commitments to purchase 785.5 million U.S. dollars and sell 685.3 million euro; commitments to purchase 2.05 billion euro and sell 2.35 billion U.S. dollars; commitments to purchase 435.1 million U.S. dollars and sell 48.85 billion Japanese yen, commitments to purchase 255.6 million Swiss francs and sell 259.7 million U.S. dollars, commitments to purchase 388.3 million U.S. dollars and sell 306.7 million British pounds, and commitments to purchase 354.0 million British pounds and sell 448.1 million U.S. dollars which will all settle within 30 days . Foreign currency exchange risk is also managed through the use of foreign currency debt and cross-currency interest rate swaps. Our foreign currency-denominated notes had carrying amounts of $3.40 billion and $3.70 billion as of December 31, 2018 and 2017 , respectively, of which $ 2.65 billion and $3.70 billion have been designated as, and are effective as, economic hedges of net investments in certain of our euro-denominated and Swiss franc-denominated foreign operations as of December 31, 2018 and 2017 , respectively. Our cross-currency interest rate swaps, for which a majority convert a portion of our U.S. dollar-denominated floating rate debt to foreign-denominated floating rate debt, have also been designated as, and are effective as, economic hedges of net investments. At December 31, 2018 , we had outstanding cross currency swaps with notional amounts of $2.46 billion swapping U.S. dollars to euro and $350.0 million swapping U.S. dollars to British pounds, which all will settle within 12 months. In the normal course of business, our operations are exposed to fluctuations in interest rates which can vary the costs of financing, investing, and operating. We seek to address a portion of these risks through a controlled program of risk management that includes the use of derivative financial instruments. The objective of controlling these risks is to limit the impact of fluctuations in interest rates on earnings. Our primary interest-rate risk exposure results from changes in short-term U.S. dollar interest rates. In an effort to manage interest-rate exposures, we strive to achieve an acceptable balance between fixed- and floating-rate debt and investment positions and may enter into interest rate swaps or collars to help maintain that balance. Interest rate swaps or collars that convert our fixed-rate debt to a floating rate are designated as fair value hedges of the underlying instruments. Interest rate swaps or collars that convert floating-rate debt to a fixed rate are designated as cash flow hedges. Interest expense on the debt is adjusted to include the payments made or received under the swap agreements. Cash proceeds from or payments to counterparties resulting from the termination of interest rate swaps are classified as operating activities in our consolidated statements of cash flows. At December 31, 2018 , substantially all of our total long-term debt is at a fixed rate. We have converted approximately 20 percent of our long-term fixed-rate notes to floating rates through the use of interest rate swaps. We may enter into forward contracts and designate them as cash flow hedges to limit the potential volatility of earnings and cash flow associated with forecasted sales of available-for-sale securities. We also may enter into forward-starting interest rate swaps, which we designate as cash flow hedges, as part of any anticipated future debt issuances in order to reduce the risk of cash flow volatility from future changes in interest rates. Upon completion of a debt issuance and termination of the swap, the change in fair value of these instruments is recorded as part of other comprehensive income (loss) and is amortized to interest expense over the life of the underlying debt. The Effect of Risk Management Instruments on the Consolidated Statements of Operations The following effects of risk-management instruments were recognized in other–net, (income) expense: 2018 2017 2016 Fair value hedges: Effect from hedged fixed-rate debt $ (40.9 ) $ (14.1 ) $ (30.8 ) Effect from interest rate contracts 40.9 14.1 30.8 Cash flow hedges: Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss 14.8 14.8 15.0 Net losses on foreign currency exchange contracts not designated as hedging instruments 100.0 97.9 78.8 Total $ 114.8 $ 112.7 $ 93.8 During the years ended December 31, 2018 , the amortization of losses related to the portion of our risk management hedging instruments, fair value hedges, and cash flow hedges that were excluded from the assessment of effectiveness were not material. During the years ended December 31, 2017 , and 2016 , net losses related to ineffectiveness, as well as net losses related to the portion of our risk-management hedging instruments, fair value hedges, and cash flow hedges that were excluded from the assessment of effectiveness, were not material. The Effect of Risk-Management Instruments on Other Comprehensive Income (Loss) The effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is as follows: 2018 2017 2016 Net investment hedges: Foreign currency-denominated notes $ 110.4 $ (361.5 ) $ 137.5 Cross-currency interest rate swaps 96.8 (126.6 ) 32.5 Foreign currency exchange contracts 5.7 — 31.9 Cash flow hedges: Forward-starting interest rate swaps — 13.0 (3.4 ) During the next 12 months, we expect to reclassify $15.0 million of pretax net losses on cash flow hedges from accumulated other comprehensive loss to other–net, (income) expense. During the year ended December 31, 2018 , the amounts excluded from the assessment of hedge effectiveness recognized in other comprehensive income (loss) was not material. Fair Value of Financial Instruments The following tables summarize certain fair value information at December 31 for assets and liabilities measured at fair value on a recurring basis, as well as the carrying amount and amortized cost of certain other investments: Fair Value Measurements Using Description Carrying Amount Cost (1) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Cash equivalents $ 5,752.2 $ 5,752.2 $ 5,752.2 $ — $ — $ 5,752.2 Short-term investments: U.S. government and agency securities $ 16.9 $ 17.1 $ 16.9 $ — $ — $ 16.9 Corporate debt securities 62.2 62.6 — 62.2 — 62.2 Asset-backed securities 7.6 7.7 — 7.6 — 7.6 Other securities 1.5 1.5 — 1.5 — 1.5 Short-term investments $ 88.2 Noncurrent investments: U.S. government and agency securities $ 149.1 $ 153.6 $ 149.1 $ — $ — $ 149.1 Corporate debt securities 568.0 587.8 — 568.0 — 568.0 Mortgage-backed securities 111.4 114.5 — 111.4 — 111.4 Asset-backed securities 27.7 27.9 — 27.7 — 27.7 Other securities 87.8 29.7 — — 87.8 87.8 Marketable equity securities 357.5 238.3 357.5 — — 357.5 Equity investments without readily determinable fair values (2) 414.7 Equity method investments (2) 304.5 Noncurrent investments $ 2,020.7 December 31, 2017 Cash equivalents $ 4,763.9 $ 4,763.9 $ 4,712.4 $ 51.5 $ — $ 4,763.9 Short-term investments: U.S. government and agency securities $ 217.8 $ 218.2 $ 217.8 $ — $ — $ 217.8 Corporate debt securities 1,182.3 1,183.2 — 1,182.3 — 1,182.3 Asset-backed securities 94.2 94.3 — 94.2 — 94.2 Other securities 3.6 3.6 — 3.6 — 3.6 Short-term investments $ 1,497.9 Noncurrent investments: U.S. government and agency securities $ 360.0 $ 365.0 $ 360.0 $ — $ — $ 360.0 Corporate debt securities 3,464.3 3,473.5 — 3,464.3 — 3,464.3 Mortgage-backed securities 202.4 204.2 — 202.4 — 202.4 Asset-backed securities 653.9 656.0 — 653.9 — 653.9 Other securities 132.1 66.4 — — 132.1 132.1 Marketable equity securities 281.3 131.0 281.3 — — 281.3 Cost and equity method investments (2) 584.8 Noncurrent investments $ 5,678.8 (1) For available-for-sale debt securities, amounts disclosed represent the securities' amortized cost. (2) Fair value disclosures are not applicable for equity method investments, investments accounted for under the measurement alternative for equity investments, and cost method investments that do not have readily determinable fair values. Fair Value Measurements Using Description Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value Short-term commercial paper borrowings December 31, 2018 $ (498.9 ) $ — $ (497.6 ) $ — $ (497.6 ) December 31, 2017 (2,696.8 ) — (2,690.6 ) — (2,690.6 ) Long-term debt, including current portion December 31, 2018 $ (12,272.0 ) $ — $ (12,461.7 ) $ — $ (12,461.7 ) December 31, 2017 (10,950.3 ) — (11,529.9 ) — (11,529.9 ) Fair Value Measurements Using Description Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Risk-management instruments Interest rate contracts designated as fair value hedges: Sundry $ 4.5 $ — $ 4.5 $ — $ 4.5 Other current liabilities (22.3 ) — (22.3 ) — (22.3 ) Other noncurrent liabilities (19.0 ) — (19.0 ) — (19.0 ) Cross-currency interest rate contracts designated as net investment hedges: Other receivables 69.2 — 69.2 — 69.2 Sundry 8.2 — 8.2 — 8.2 Other current liabilities (9.2 ) — (9.2 ) — (9.2 ) Other noncurrent liabilities (25.8 ) — (25.8 ) — (25.8 ) Foreign exchange contracts not designated as hedging instruments: Other receivables 11.3 — 11.3 — 11.3 Other current liabilities (16.3 ) — (16.3 ) — (16.3 ) Contingent consideration liabilities: Other current liabilities (5.1 ) — — (5.1 ) (5.1 ) Other noncurrent liabilities (69.0 ) — — (69.0 ) (69.0 ) December 31, 2017 Risk-management instruments Interest rate contracts designated as fair value hedges: Other receivables $ 0.8 $ — $ 0.8 $ — $ 0.8 Sundry 35.1 — 35.1 — 35.1 Other current liabilities (0.2 ) — (0.2 ) — (0.2 ) Other noncurrent liabilities (10.5 ) — (10.5 ) — (10.5 ) Cross-currency interest rate contracts designated as net investment hedges: Other current liabilities (33.4 ) — (33.4 ) — (33.4 ) Other noncurrent liabilities (26.0 ) — (26.0 ) — (26.0 ) Foreign exchange contracts not designated as hedging instruments: Other receivables 26.8 — 26.8 — 26.8 Other current liabilities (36.0 ) — (36.0 ) — (36.0 ) Contingent consideration liabilities: Other current liabilities (208.0 ) — — (208.0 ) (208.0 ) Other noncurrent liabilities (45.2 ) — — (45.2 ) (45.2 ) Risk-management instruments above are disclosed on a gross basis. There are various rights of setoff associated with certain of the risk-management instruments above that are subject to an enforceable master netting arrangement or similar agreements. Although various rights of setoff and master netting arrangements or similar agreements may exist with the individual counterparties to the risk-management instruments above, individually, these financial rights are not material. We determine our Level 1 and Level 2 fair value measurements based on a market approach using quoted market values, significant other observable inputs for identical or comparable assets or liabilities, or discounted cash flow analyses. Level 3 fair value measurements for other investment securities are determined using unobservable inputs, including the investments' cost adjusted for impairments and price changes from orderly transactions. The fair values of equity method investments and investments measured under the measurement alternative for equity investments that do not have readily determinable fair values are not readily available. Contingent consideration liabilities were recorded at fair value and were estimated using a discounted cash flow analysis and Level 3 inputs, including projections representative of a market participant view for net sales and an estimated discount rate. The decrease in the fair value of the contingent consideration liabilities during the years ended December 31, 2018 and 2017 was due primarily to cash payments of $215.9 million and $203.9 million , which primarily related to Erbitux (see Note 4). The change in the fair value of the contingent consideration liabilities recognized in earnings during the years ended December 31, 2018 , 2017 , and 2016 due to changes in time value of money was not material. The table below summarizes the contractual maturities of our investments in debt securities measured at fair value as of December 31, 2018 : Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 943.0 $ 86.8 $ 604.8 $ 97.0 $ 154.4 A summary of the fair value of available-for-sale securities in an unrealized gain or loss position and the amount of unrealized gains and losses (pretax) in accumulated other comprehensive loss follows: 2018 2017 Unrealized gross gains $ 0.8 $ 184.7 Unrealized gross losses 29.0 47.5 Fair value of securities in an unrealized gain position 84.3 1,434.2 Fair value of securities in an unrealized loss position 858.6 4,692.8 The unrealized losses (pretax) recognized in our consolidated statement of operations for equity securities held as of December 31, 2018 was $20.1 million . We periodically assess our investment in available-for-sale securities for other-than-temporary impairment losses. There were no other-than-temporary impairment losses recognized in 2018 or 2017 . Other-than-temporary impairment losses recognized during the year ended December 31, 2016 totaled $53.0 million . Other-than-temporary impairment losses recognized during 2016 related primarily to our cost and equity method investments. We periodically assess our investments in equity securities other than public equity securities for impairment losses. Impairment losses recognized on these equity securities in 2018 were immaterial. For fixed-income securities, the amount of credit losses are determined by comparing the difference between the present value of future cash flows expected to be collected on these securities and the amortized cost. Factors considered in assessing credit losses include the position in the capital structure, vintage and amount of collateral, delinquency rates, current credit support, and geographic concentration. For equity securities, factors considered in assessing impairment losses include the financial condition and near term prospects of the issuer and general market conditions and industry specific factors. As of December 31, 2018 , the available-for-sale securities in an unrealized loss position include primarily fixed-rate debt securities of varying maturities, which are sensitive to changes in the yield curve and other market conditions. Approximately 55 percent of the fixed-rate debt securities in a loss position are investment-grade debt securities. As of December 31, 2018 , we do not intend to sell, and it is not more likely than not that we will be required to sell, the securities in a loss position before the market values recover or the underlying cash flows have been received, and there is no indication of default on interest or principal payments for any of our debt securities. Activity related to our investment portfolio, substantially all of which related to equity and available-for-sale securities, was as follows: 2018 2017 2016 Proceeds from sales $ 5,668.0 $ 5,769.3 $ 3,240.5 Realized gross gains on sales 11.8 176.0 30.7 Realized gross losses on sales 51.3 5.8 14.6 Realized gains and losses on sales of available-for-sale investments are computed based upon specific identification of the initial cost adjusted for any other-than-temporary declines in fair value that were recorded in earnings. Adjustments recorded to our equity investments without readily determinable fair values are based upon changes in the equity instrument's value resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. Downward adjustments resulting from an impairment are recorded based upon the impairment considerations mentioned above. Adjustments recorded during 2018 were not material. Accounts Receivable Factoring Arrangements We have entered into accounts receivable factoring agreements with financial institutions to sell certain of our non-U.S. accounts receivable. These transactions are accounted for as sales and result in a reduction in accounts receivable because the agreements transfer effective control over and risk related to the receivables to the buyers. Our factoring agreements do not allow for recourse in the event of uncollectibility, and we do not retain any interest in the underlying accounts receivable once sold. We derecognized $696.2 million and $723.2 million of accounts receivable as of December 31, 2018 and 2017 , respectively, under these factoring arrangements. The costs of factoring such accounts receivable on our consolidated results of operations for the years ended December 31, 2018 , 2017 , and 2016 were not material.

Goodwill and Other Intangibles

Goodwill and Other Intangibles	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure	Goodwill and Other Intangibles Goodwill Goodwill by segment at December 31 was as follows: 2018 2017 Human pharmaceutical products $ 1,366.6 $ 1,366.8 Animal health 2,980.9 3,003.3 Total goodwill $ 4,347.5 $ 4,370.1 Goodwill results from excess consideration in a business combination over the fair value of identifiable net assets acquired. Goodwill is not amortized but is reviewed for impairment at least annually and when impairment indicators are present. When required, a comparison of the fair value of the reporting unit to its carrying amount including goodwill is used to determine the amount of any impairment. The change in goodwill is the result of disposal of businesses and foreign exchange translation adjustments. No impairments occurred with respect to the carrying value of goodwill for the years ended December 31, 2018 , 2017 , and 2016 . Other Intangibles The components of intangible assets other than goodwill at December 31 were as follows: 2018 2017 Description Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Finite-lived intangible assets: Marketed products $ 5,270.7 $ (1,848.2 ) $ 3,422.5 $ 7,682.0 $ (3,851.1 ) $ 3,830.9 Other 142.6 (63.7 ) 78.9 171.2 (70.1 ) 101.1 Total finite-lived intangible assets 5,413.3 (1,911.9 ) 3,501.4 7,853.2 (3,921.2 ) 3,932.0 Indefinite-lived intangible assets: Acquired in-process research and development 19.6 — 19.6 97.2 — 97.2 Other intangibles $ 5,432.9 $ (1,911.9 ) $ 3,521.0 $ 7,950.4 $ (3,921.2 ) $ 4,029.2 Marketed products consist of the amortized cost of the rights to assets acquired in business combinations and approved for marketing in a significant global jurisdiction (U.S., Europe, and Japan) and capitalized milestone payments. For transactions other than a business combination, we capitalize milestone payments incurred at or after the product has obtained regulatory approval for marketing. Other finite-lived intangibles consist primarily of the amortized cost of licensed platform technologies that have alternative future uses in research and development, manufacturing technologies, and customer relationships from business combinations. Acquired IPR&D consists of the related costs capitalized, adjusted for subsequent impairments, if any. The costs of acquired IPR&D projects acquired directly in a transaction other than a business combination are capitalized if the projects have an alternative future use; otherwise, they are expensed immediately. The fair values of acquired IPR&D projects acquired in business combinations are capitalized as other intangible assets. Several methods may be used to determine the estimated fair value of other intangibles acquired in a business combination. We utilize the “income method,” which is a Level 3 fair value measurement and applies a probability weighting that considers the risk of development and commercialization to the estimated future net cash flows that are derived from projected revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, historical pricing of similar products, and expected industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. This analysis is performed for each asset independently. The acquired IPR&D assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are tested for impairment and amortized over the remaining useful life or written off, as appropriate. See Note 4 for additional discussion of recent capitalized milestone payments. Other indefinite-lived intangible assets are reviewed for impairment at least annually and when impairment indicators are present. Finite-lived intangible assets are reviewed for impairment when an indicator of impairment is present. When required, a comparison of fair value to the carrying amount of assets is performed to determine the amount of any impairment. When determining the fair value of indefinite-lived acquired IPR&D as well as the fair value of finite-lived intangible assets for impairment testing purposes, we utilize the "income method" discussed above. During 2018, we had animal health intangible impairment charges of $68.9 million (comprised of a $55.9 million impairment of finite-lived intangible assets and a $13.0 million impairment of indefinite-lived intangible assets) which were recorded in asset impairment, restructuring and other special charges on the consolidated statements of operations. These impairments were primarily related to the sale of the Posilac (rbST) brand and competitive pressures for certain companion animal products resulting in a reduction of revenue. During 2017 , we had animal health intangible impairment charges of $135.5 million (comprised of a $97.5 million impairment of finite-lived intangible assets and a $38.0 million impairment of indefinite-lived intangible assets) which were recorded in asset impairment, restructuring and other special charges on the consolidated statements of operations. These impairments were related to competitive pressures for certain companion animal products resulting in a reduction of revenue, as well as lower projected revenue for Posilac (rbST). No material impairments occurred with respect to the carrying value of other intangible assets for the year ended December 31, 2016 . Intangible assets with finite lives are capitalized and are amortized over their estimated useful lives, ranging from three to 20 years. As of December 31, 2018 , the remaining weighted-average amortization period for finite-lived intangible assets was approximately 12 years . Amortization expense related to finite-lived intangible assets was as follows: 2018 2017 2016 Amortization expense $ 558.7 $ 683.4 $ 687.9 The estimated amortization expense for each of the next five years associated with our finite-lived intangible assets as of December 31, 2018 is as follows: 2019 2020 2021 2022 2023 Estimated amortization expense $ 343.3 $ 342.3 $ 339.6 $ 329.8 $ 318.4 Amortization expense is included in either cost of sales, marketing, selling, and administrative or research and development depending on the nature of the intangible asset being amortized.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment is stated on the basis of cost. Provisions for depreciation of buildings and equipment are computed generally by the straight-line method at rates based on their estimated useful lives ( 12 to 50 years for buildings and three to 25 years for equipment). We review the carrying value of long-lived assets for potential impairment on a periodic basis and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Impairment is determined by comparing projected undiscounted cash flows to be generated by the asset to its carrying value. If an impairment is identified, a loss is recorded equal to the excess of the asset’s net book value over its fair value, and the cost basis is adjusted. At December 31, property and equipment consisted of the following: 2018 2017 Land $ 193.1 $ 192.7 Buildings 7,683.8 7,425.6 Equipment 8,817.4 8,689.0 Construction in progress 1,769.7 1,783.8 18,464.0 18,091.1 Less accumulated depreciation (9,544.5 ) (9,264.6 ) Property and equipment, net $ 8,919.5 $ 8,826.5 Depreciation expense related to property and equipment and rental expense for all leases, including contingent rentals (not material), was as follows: 2018 2017 2016 Depreciation expense $ 879.6 $ 763.1 $ 716.2 Rental expense 223.2 224.5 221.0 The future minimum rental commitments under non-cancelable operating leases are as follows: 2019 2020 2021 2022 2023 After 2023 Lease commitments $ 155.8 $ 128.0 $ 89.0 $ 74.7 $ 58.2 $ 299.5 Capitalized interest costs were not material for the years ended December 31, 2018 , 2017 , and 2016 . Assets under capital leases included in property and equipment, net on the consolidated balance sheets, capital lease obligations entered into, and future minimum rental commitments are not material.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2018
Long-term Debt, Current and Noncurrent [Abstract]
Borrowings	Borrowings Debt at December 31 consisted of the following: 2018 2017 Short-term commercial paper borrowings $ 498.9 $ 2,696.8 0.15 to 7.13 percent long-term notes (due 2019-2047) 11,640.8 10,756.7 Other long-term debt 503.1 13.6 Unamortized debt issuance costs (49.1 ) (49.0 ) Fair value adjustment on hedged long-term notes 177.2 229.0 Total debt 12,770.9 13,647.1 Less current portion (1,131.2 ) (3,706.6 ) Long-term debt $ 11,639.7 $ 9,940.5 The weighted-average effective borrowing rate on outstanding commercial paper at December 31, 2018 was 2.36 percent . At December 31, 2018 , we had a total of $6.17 billion of unused committed bank credit facilities, which consisted primarily of a $3.00 billion credit facility that expires in December 2023 and a $2.00 billion 364-day facility that expires in December 2019, both of which are available to support our commercial paper program. We have not drawn against the $3.00 billion and $2.00 billion facilities. Of the remaining facilities, there was $25.9 million outstanding under the revolving credit facilities as of December 31, 2018 , and $6.0 million was outstanding under these facilities as of December 31, 2017 . Compensating balances and commitment fees are not material, and there are no conditions that are probable of occurring under which the lines may be withdrawn. In August 2018, our subsidiary, Elanco, issued $2.00 billion of senior notes in a private placement. The senior notes are comprised of $500.0 million of 3.91 percent senior notes due in August 2021, $750.0 million of 4.27 percent senior notes due in August 2023, and $750.0 million of 4.90 percent senior notes due in August 2028. Interest is to be paid semi-annually and the interest rate payable on each series of senior notes is subject to adjustment if certain bond rating agencies downgrade, or subsequently upgrade, their ratings on the respective series of senior notes. The indenture that governs the Elanco senior notes contains covenants, including limitations on the ability of Elanco and certain Elanco subsidiaries to incur liens or engage in sale-leaseback transactions. The indenture also contains restrictions on Elanco's ability to consolidate, merge or sell substantially all of their assets, in addition to other customary terms. Elanco was in compliance with all such covenants under the indentures governing the senior notes as of December 31, 2018 . Elanco has entered into an agreement that requires it to use commercially reasonable efforts to cause a registration statement to become effective with the SEC by August 28, 2019, relating to an offer to exchange the senior notes for registered senior notes having substantially identical terms, or in certain cases, to register the senior notes for resale. If they do not register or exchange the senior notes pursuant to the terms of the registration rights agreement, they will be required to pay additional interest to the holders of the senior notes under certain circumstances. In September 2018, Elanco entered into a revolving credit agreement with a syndicate of banks providing for a five -year $750.0 million senior revolving credit facility (Revolving Facility). The Revolving Facility bears interest at a variable rate plus specified margin as defined in the agreement and is payable quarterly. There were no borrowings outstanding under the Revolving Facility at December 31, 2018 . The Revolving Facility is payable in full at the end of the term. In September 2018, Elanco also entered into a $500.0 million three -year term loan under a term credit facility with a syndicate of banks (the Term Facility and collectively with the Revolving Facility, the Credit Facilities). The Term Facility bears interest at a variable rate plus margin as defined in the Term Facility and is payable quarterly. The Term Facility is payable in full at the end of the term. The Credit Facilities are subject to various financial and other covenants including restrictions on Elanco's level of borrowings based on their consolidated leverage ratio and their consolidated interest coverage ratio. Elanco was in compliance with all such covenants as of December 31, 2018 . The aggregate net proceeds of the senior notes and Term Facility were $ 2.48 billion . See Note 3 for a discussion of the use of the proceeds of the debt offerings as part of the formation of Elanco and its IPO. In May 2017, we issued $750.0 million of 2.35 percent fixed-rate notes due in May 2022, $750.0 million of 3.10 percent fixed-rate notes due in May 2027, and $750.0 million of 3.95 percent fixed-rate notes due in May 2047, with interest to be paid semi-annually. We are using the net proceeds of $2.23 billion from the sale of these notes for general corporate purposes, which included the repayment of notes due in 2018 and may include the repayment of notes due in 2019. Prior to such uses, we may temporarily invest the net proceeds in investment securities. The aggregate amounts of maturities on long-term debt for the next five years are as follows: 2019 2020 2021 2022 2023 Maturities on long-term debt $ 634.5 $ 33.5 $ 942.3 $ 1,439.0 $ 750.3 We have converted approximately 20 percent of our long-term fixed-rate notes to floating rates through the use of interest rate swaps. The weighted-average effective borrowing rates based on long-term debt obligations and interest rates at December 31, 2018 and 2017 , including the effects of interest rate swaps for hedged debt obligations, were 3.36 percent and 2.65 percent , respectively. The aggregate amount of cash payments for interest on borrowings, net of capitalized interest, are as follows: 2018 2017 2016 Cash payments for interest on borrowings $ 223.8 $ 192.7 $ 146.4 In accordance with the requirements of derivatives and hedging guidance, the portion of our fixed-rate debt obligations that is hedged as a fair value hedge is reflected in the consolidated balance sheets as an amount equal to the sum of the debt’s carrying value plus the fair value adjustment representing changes in fair value of the hedged debt attributable to movements in market interest rates subsequent to the inception of the hedge.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Our stock-based compensation expense consists of performance awards (PAs), shareholder value awards (SVAs), and restricted stock units (RSUs). We recognize the fair value of stock-based compensation as expense over the requisite service period of the individual grantees, which generally equals the vesting period. We provide newly issued shares of our common stock and treasury stock to satisfy the issuance of PA, SVA, and RSU shares. Stock-based compensation expense and the related tax benefits were as follows: 2018 2017 2016 Stock-based compensation expense $ 279.5 $ 281.3 $ 255.3 Tax benefit 58.7 70.5 89.4 At December 31, 2018 , stock-based compensation awards may be granted under the 2002 Lilly Stock Plan for not more than 53.3 million additional shares. Performance Award Program PAs are granted to officers and management and are payable in shares of our common stock. The number of PA shares actually issued, if any, varies depending on the achievement of certain pre-established earnings-per-share targets over a two -year period. PA shares are accounted for at fair value based upon the closing stock price on the date of grant and fully vest at the end of the measurement period. The fair values of PAs granted for the years ended December 31, 2018 , 2017 , and 2016 were $71.63 , $73.54 , and $72.00 , respectively. The number of shares ultimately issued for the PA program is dependent upon the EPS achieved during the vesting period. Pursuant to this program, approximately 0.9 million shares, 1.3 million shares, and 0.5 million shares were issued during the years ended December 31, 2018 , 2017 , and 2016 , respectively. Approximately 1.2 million shares are expected to be issued in 2019 . As of December 31, 2018 , the total remaining unrecognized compensation cost related to nonvested PAs was $63.7 million , which will be amortized over the weighted-average remaining requisite service period of 12 months. Shareholder Value Award Program SVAs are granted to officers and management and are payable in shares of our common stock. The number of shares actually issued, if any, varies depending on our stock price at the end of the three -year vesting period compared to pre-established target stock prices. We measure the fair value of the SVA unit on the grant date using a Monte Carlo simulation model. The model utilizes multiple input variables that determine the probability of satisfying the market condition stipulated in the award grant and calculates the fair value of the award. Expected volatilities utilized in the model are based on implied volatilities from traded options on our stock, historical volatility of our stock price, and other factors. Similarly, the dividend yield is based on historical experience and our estimate of future dividend yields. The risk-free interest rate is derived from the U.S. Treasury yield curve in effect at the time of grant. The weighted-average fair values of the SVA units granted during the years ended December 31, 2018 , 2017 , and 2016 were $48.51 , $66.25 , and $48.68 , respectively, determined using the following assumptions: (Percents) 2018 2017 2016 Expected dividend yield 2.50 % 2.50 % 2.00 % Risk-free interest rate 2.31 1.38 0.92 Volatility 22.26 22.91 21.68 Pursuant to this program, approximately 0.7 million shares, 1.1 million shares, and 1.0 million shares were issued during the years ended December 31, 2018 , 2017 , and 2016 , respectively. Approximately 1.0 million shares are expected to be issued in 2019 . As of December 31, 2018 , the total remaining unrecognized compensation cost related to nonvested SVAs was $55.7 million , which will be amortized over the weighted-average remaining requisite service period of 20 months. Restricted Stock Units RSUs are granted to certain employees and are payable in shares of our common stock. RSU shares are accounted for at fair value based upon the closing stock price on the date of grant. The corresponding expense is amortized over the vesting period, typically three years. The fair values of RSU awards granted during the years ended December 31, 2018 , 2017 , and 2016 were $70.95 , $72.47 , and $71.46 , respectively. The number of shares ultimately issued for the RSU program remains constant with the exception of forfeitures. Pursuant to this program, 1.3 million , 1.4 million , and 1.3 million shares were granted and approximately 1.0 million , 0.9 million , and 0.6 million shares were issued during the years ended December 31, 2018 , 2017 , and 2016 , respectively. Approximately 0.8 million shares are expected to be issued in 2019 . As of December 31, 2018 , the total remaining unrecognized compensation cost related to nonvested RSUs was $112.2 million , which will be amortized over the weighted-average remaining requisite service period of 21 months.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders' Equity During 2018 , 2017 , and 2016 , we repurchased $4.15 billion , $359.8 million and $540.1 million , respectively, of shares associated with our share repurchase programs. A payment of $60.0 million was made in 2016 for shares repurchased in 2017. During 2018, we repurchased $2.05 billion of shares, which completed the $5.00 billion share repurchase program announced in October 2013 and our board authorized an $8.00 billion share repurchase program. There were $2.10 billion repurchased under the $8.00 billion program in 2018. As of December 31, 2018, there were $5.90 billion of shares remaining under the 2018 program. We have 5.0 million authorized shares of preferred stock. As of December 31, 2018 and 2017 , no preferred stock was issued. We have an employee benefit trust that held 50.0 million shares of our common stock at both December 31, 2018 and 2017 , to provide a source of funds to assist us in meeting our obligations under various employee benefit plans. The cost basis of the shares held in the trust was $3.01 billion at both December 31, 2018 and 2017 , and is shown as a reduction of shareholders’ equity. Any dividend transactions between us and the trust are eliminated. Stock held by the trust is not considered outstanding in the computation of EPS. The assets of the trust were not used to fund any of our obligations under these employee benefit plans during the years ended December 31, 2018 , 2017 , and 2016 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes 2017 Tax Act In December 2017, the President of the U.S. signed into law the 2017 Tax Act. The 2017 Tax Act included significant changes to the U.S. corporate income tax system, such as the reduction in the corporate income tax rate from 35 percent to 21 percent, transition to a territorial tax system, changes to business related exclusions, deductions and credits, and modifications to international tax provisions, including a one-time repatriation transition tax (also known as the ‘Toll Tax’) on unremitted foreign earnings. GAAP requires that the income tax accounting effects from a change in tax laws or tax rates be recognized in continuing operations in the reporting period that includes the enactment date of the change. These effects include, among other things, re-measuring deferred tax assets and liabilities, evaluating deferred tax assets for valuation allowances, and assessing the impact of the Toll Tax and certain other provisions of the 2017 Tax Act. Our accounting for the tax effects of the enactment of the 2017 Tax Act was not complete as of December 31, 2017; however, in certain cases we made a reasonable estimate. In other cases, we were not able to make a reasonable estimate and continued to account for those items based on our existing accounting model under ASC 740, Income Taxes , and the provisions of the tax laws that were in effect immediately prior to enactment. For the items for which we were able to determine a reasonable estimate, we recognized a provisional amount of $1.91 billion , which was included as a component of income tax expense from continuing operations. Our accounting for the effects of the 2017 Tax Act was completed in the current period, and we recorded $313.3 million of income tax benefit in 2018, mainly attributable to measurement period adjustments to the Toll Tax and the global intangible low-taxed income (GILTI) provision, the new U.S. minimum tax on the earnings of our foreign subsidiaries. Related to GILTI, we elected to establish deferred taxes in the amount of $1.68 billion for the reversal of temporary items in future years. Subsequent to the enactment of the 2017 Tax Act, additional guidance was issued, including Notices, Proposed Regulations, and Final Regulations. We expect that further guidance will continue to be issued in 2019 which may impact our interpretations of the 2017 Tax Act and could materially affect the estimates used. Deferred taxes are recognized for the future tax effects of temporary differences between financial and income tax reporting based on enacted tax laws and rates. We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate resolution. Following is the composition of income tax expense: 2018 2017 2016 Current: Federal $ (54.3 ) $ (100.6 ) $ (57.0 ) Foreign 80.0 38.5 378.9 State 9.7 4.0 (125.0 ) 2017 Tax Act 201.5 3,247.5 — Total current tax expense 236.9 3,189.4 196.9 Deferred: Federal 64.0 801.5 517.0 Foreign 285.6 (256.3 ) (83.3 ) State 3.4 0.4 5.8 2017 Tax Act (26.2 ) (1,333.5 ) — Total deferred tax (benefit) expense 326.8 (787.9 ) 439.5 Income taxes $ 563.7 $ 2,401.5 $ 636.4 Significant components of our deferred tax assets and liabilities as of December 31 are as follows: 2018 2017 Deferred tax assets: Purchases of intangible assets $ 2,655.9 $ 443.1 Compensation and benefits 814.2 1,021.7 Tax credit carryforwards and carrybacks 365.2 473.0 Tax loss carryforwards and carrybacks 271.7 501.4 Product return reserves 100.5 88.4 Other comprehensive loss on hedging transactions 68.9 68.9 Debt 40.3 53.5 Contingent consideration 17.7 41.8 Other 714.7 555.8 Total gross deferred tax assets 5,049.1 3,247.6 Valuation allowances (596.3 ) (709.1 ) Total deferred tax assets 4,452.8 2,538.5 Deferred tax liabilities: Earnings of foreign subsidiaries (1,692.3 ) (16.6 ) Inventories (658.4 ) (654.8 ) Property and equipment (311.7 ) (282.1 ) Prepaid employee benefits (240.1 ) (231.5 ) Intangibles (250.5 ) (314.6 ) Financial instruments (22.7 ) (41.5 ) Total deferred tax liabilities (3,175.7 ) (1,541.1 ) Deferred tax assets - net $ 1,277.1 $ 997.4 Our accounting for the effects of the 2017 Tax Act was completed in the current period; therefore, deferred tax assets and liabilities reflect re-measurement resulting from the 2017 Tax Act. The deferred tax asset and related valuation allowance amounts for U.S. federal and state net operating losses and tax credits shown above have been reduced for differences between financial reporting and tax return filings. At December 31, 2018 , based on filed tax returns we have tax credit carryforwards and carrybacks of $735.4 million available to reduce future income taxes; $150.5 million , if unused, will expire by 2027 . The remaining portion of the tax credit carryforwards is related to federal tax credits of $122.9 million , international tax credits of $122.7 million , and state tax credits of $339.4 million , all of which are substantially reserved. At December 31, 2018 , based on filed tax returns we had net operating losses and other carryforwards for international and U.S. federal income tax purposes of $922.8 million : $102.4 million will expire by 2023 ; $521.5 million will expire between 2024 and 2038 ; and $298.9 million of the carryforwards will never expire. Net operating losses and other carryforwards for international and U.S. federal income tax purposes are partially reserved. Deferred tax assets related to state net operating losses of $106.1 million and other state carryforwards of $2.6 million are fully reserved. Domestic and Puerto Rican companies contributed approximately 16 percent , 15 percent , and 70 percent for the years ended December 31, 2018 , 2017 , and 2016 , respectively, to consolidated income before income taxes. We have a subsidiary operating in Puerto Rico under a tax incentive grant effective through the end of 2031 . The 2017 Tax Act introduced international tax provisions that fundamentally change the U.S. taxation of foreign earnings. As a result, substantially all of the unremitted earnings of our foreign subsidiaries are considered to not be indefinitely reinvested for continued use in our foreign operations. At December 31, 2018, we have accrued an immaterial amount of foreign withholding taxes and state income taxes that would be owed upon future distributions of unremitted earnings of our foreign subsidiaries that are not indefinitely reinvested. For the amount considered to be indefinitely reinvested, it is not practicable to determine the amount of the related deferred income tax liability due to the complexities in the tax laws and assumptions we would have to make. Cash payments of income taxes were as follows: 2018 2017 2016 Cash payments of income taxes $ 1,101.5 $ 246.5 $ 700.6 The 2017 Tax Act provided an election to taxpayers subject to the Toll Tax to make payments over an eight-year period. We made this election; therefore, we have included Toll Tax payments accordingly. Following is a reconciliation of the income tax expense applying the U.S. federal statutory rate to income before income taxes to reported income tax expense: 2018 2017 2016 Income tax at the U.S. federal statutory tax rate $ 797.1 $ 769.1 $ 1,180.9 Add (deduct): International operations, including Puerto Rico (629.7 ) (428.9 ) (313.7 ) General business credits (87.4 ) (66.8 ) (58.3 ) Non-deductible acquired IPR&D (1) 309.9 300.1 — 2017 Tax Act 175.3 1,914.0 — Other (1.5 ) (86.0 ) (172.5 ) Income taxes $ 563.7 $ 2,401.5 $ 636.4 (1) Non-deductible acquired IPR&D was related to ARMO in 2018 and CoLucid in 2017. See Note 3 for additional information related to acquisitions. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2018 2017 2016 Beginning balance at January 1 $ 1,014.5 $ 853.4 $ 1,066.6 Additions based on tax positions related to the current year 798.2 133.8 73.4 Additions for tax positions of prior years 414.9 97.5 14.8 Reductions for tax positions of prior years (117.1 ) (59.3 ) (15.2 ) Settlements (33.2 ) (2.4 ) (171.9 ) Lapses of statutes of limitation (23.5 ) (19.3 ) (110.0 ) Changes related to the impact of foreign currency translation (6.8 ) 10.8 (4.3 ) Ending balance at December 31 $ 2,047.0 $ 1,014.5 $ 853.4 The total amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate was $1.49 billion and $670.9 million at December 31, 2018 and 2017 , respectively. We file income tax returns in the U.S. federal jurisdiction and various state, local, and non-U.S. jurisdictions. We are no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations in most major taxing jurisdictions for years before 2010. The U.S. examination of tax years 2010 - 2012 commenced during the fourth quarter of 2013. In December 2015, we executed a closing agreement with the Internal Revenue Service which effectively settled certain matters for tax years 2010 - 2012 . Accordingly, we reduced our gross uncertain tax positions by approximately $320 million in 2015. During 2016, we effectively settled the remaining matters related to tax years 2010 - 2012 . As a result of this resolution, our gross uncertain tax positions were further reduced by approximately $140 million , and our consolidated results of operations benefited from an immaterial reduction in income tax expense. During 2016, we made cash payments of approximately $150 million related to tax years 2010 - 2012 after application of available tax credit carryforwards and carrybacks. The U.S. examination of tax years 2013 - 2015 began in 2016, and we believe it is reasonably possible that this examination could reach resolution within the next 12 months for tax years 2013 - 2014 and certain matters under examination for tax year 2015 , for which the audit remains ongoing. As a result, we currently estimate that gross uncertain tax positions may be reduced by approximately $450 million within the next 12 months. Additionally, we anticipate up to $150 million of cash payments will be due upon resolution. We recognize both accrued interest and penalties related to unrecognized tax benefits in income tax expense. We recognized income tax (benefit) expense related to interest and penalties as follows: 2018 2017 2016 Income tax (benefit) expense $ 24.4 $ 27.4 $ (52.5 ) At December 31, 2018 and 2017 , our accruals for the payment of interest and penalties totaled $197.2 million and $170.7 million , respectively.

Retirement Benefits

Retirement Benefits	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Retirement Benefits	Retirement Benefits We use a measurement date of December 31 to develop the change in benefit obligation, change in plan assets, funded status, and amounts recognized in the consolidated balance sheets at December 31 for our defined benefit pension and retiree health benefit plans, which were as follows: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at beginning of year $ 15,098.4 $ 12,455.9 $ 1,728.5 $ 1,494.6 Service cost 304.0 331.3 41.5 46.4 Interest cost 461.0 413.4 57.3 52.9 Actuarial (gain) loss (1,431.2 ) 1,580.5 (182.8 ) 40.0 Benefits paid (582.1 ) (486.3 ) (82.8 ) (60.1 ) Plan amendments 17.6 — (14.1 ) — Curtailment (gain) loss (43.9 ) 90.4 2.5 105.2 Special termination benefit — 317.2 — 37.5 Foreign currency exchange rate changes and other adjustments (161.9 ) 396.0 (6.2 ) 12.0 Benefit obligation at end of year 13,661.9 15,098.4 1,543.9 1,728.5 Change in plan assets: Fair value of plan assets at beginning of year 11,844.5 10,179.7 2,372.4 1,961.2 Actual return on plan assets (370.3 ) 1,447.6 32.6 462.0 Employer contribution 324.7 414.3 75.9 9.1 Benefits paid (582.1 ) (486.3 ) (82.8 ) (60.1 ) Foreign currency exchange rate changes and other adjustments (152.6 ) 289.2 — 0.2 Fair value of plan assets at end of year 11,064.2 11,844.5 2,398.1 2,372.4 Funded status (2,597.7 ) (3,253.9 ) 854.2 643.9 Unrecognized net actuarial loss 5,011.8 5,645.5 140.6 182.0 Unrecognized prior service (benefit) cost 25.8 15.2 (299.9 ) (395.0 ) Net amount recognized $ 2,439.9 $ 2,406.8 $ 694.9 $ 430.9 Amounts recognized in the consolidated balance sheet consisted of: Sundry $ 196.0 $ 106.8 $ 1,043.6 $ 869.0 Other current liabilities (64.5 ) (64.8 ) (7.3 ) (7.1 ) Accrued retirement benefits (2,729.2 ) (3,295.9 ) (182.1 ) (218.0 ) Accumulated other comprehensive (income) loss before income taxes 5,037.6 5,660.7 (159.3 ) (213.0 ) Net amount recognized $ 2,439.9 $ 2,406.8 $ 694.9 $ 430.9 The unrecognized net actuarial loss and unrecognized prior service cost (benefit) have not yet been recognized in net periodic pension costs and are included in accumulated other comprehensive loss at December 31, 2018 . In July 2018, we announced that we would amend our defined benefit pension and retiree health benefit plans to freeze or reduce benefits for certain Elanco employees effective January 1, 2019. We remeasured the impacted pension and retiree health plans’ benefit obligations as of July 31, 2018, which resulted in a net curtailment gain of $28.0 million , which was recorded in asset impairment, restructuring, and other special charges. Market variables associated with this remeasurement, specifically an increase in the discount rate, were the primary driver for the $1.62 billion decrease in the benefit obligations in 2018. The workforce reduction plan initiated in 2017 included a curtailment loss of $159.0 million and a special termination benefit of $354.7 million , which was recorded in asset impairment, restructuring, and other special charges, as a result of a remeasurement as of October 31, 2017. The special termination benefits related to early retirement incentives offered as part of a voluntary early retirement program for the U.S. plan in the fou rth quarter of 2017. This program allowed certain employees the opportunity to voluntarily leave the Company. Market variables associated with this remeasurement, specifically a decrease in the discount rate, were the primary driver for the $2.88 billion increase in the benefit obligations in 2017. The following represents our weighted-average assumptions as of December 31: Defined Benefit Pension Plans Retiree Health Benefit Plans (Percents) 2018 2017 2016 2018 2017 2016 Discount rate for benefit obligation 3.9 % 3.4 % 3.9 % 4.4 % 3.7 % 4.3 % Discount rate for net benefit costs 3.4 3.9 4.3 3.7 4.3 4.5 Rate of compensation increase for benefit obligation 3.4 3.4 3.4 Rate of compensation increase for net benefit costs 3.4 3.4 3.4 Expected return on plan assets for net benefit costs 7.3 7.4 7.4 8.0 8.0 8.0 We annually evaluate the expected return on plan assets in our defined benefit pension and retiree health benefit plans. In evaluating the expected rate of return, we consider many factors, with a primary analysis of current and projected market conditions; asset returns and asset allocations; and the views of leading financial advisers and economists. We may also review our historical assumptions compared with actual results, as well as the assumptions and trend rates utilized by similar plans, where applicable. Given the design of our retiree health benefit plans, healthcare-cost trend rates do not have a material impact on our financial condition or results of operations. The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: 2019 2020 2021 2022 2023 2024-2028 Defined benefit pension plans $ 609.9 $ 613.6 $ 623.6 $ 638.2 $ 647.9 $ 3,560.6 Retiree health benefit plans 98.0 99.1 100.7 99.9 98.5 505.3 Amounts relating to defined benefit pension plans with projected benefit obligations in excess of plan assets were as follows at December 31: 2018 2017 Projected benefit obligation $ 11,813.4 $ 13,025.0 Fair value of plan assets 9,019.7 9,664.3 Amounts relating to defined benefit pension plans and retiree health benefit plans with accumulated benefit obligations in excess of plan assets were as follows at December 31: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2018 2017 Accumulated benefit obligation $ 11,032.1 $ 11,956.7 $ 189.4 $ 225.1 Fair value of plan assets 9,019.7 9,639.4 — — The total accumulated benefit obligation for our defined benefit pension plans was $12.76 billion and $13.90 billion at December 31, 2018 and 2017 , respectively. Net pension and retiree health benefit expense included the following components: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2016 2018 2017 2016 Components of net periodic (benefit) cost: Service cost $ 304.0 $ 331.3 $ 277.7 $ 41.5 $ 46.4 $ 39.1 Interest cost 461.0 413.4 420.8 57.3 52.9 53.2 Expected return on plan assets (848.3 ) (776.0 ) (752.1 ) (177.9 ) (160.7 ) (150.2 ) Amortization of prior service (benefit) cost 4.8 5.7 11.8 (79.5 ) (90.0 ) (85.8 ) Recognized actuarial loss 334.4 288.2 285.6 6.1 18.4 19.1 Curtailment (gain) loss 1.3 93.5 — (29.3 ) 65.5 — Special termination benefit — 317.2 — — 37.5 — Net periodic (benefit) cost $ 257.2 $ 673.3 $ 243.8 $ (181.8 ) $ (30.0 ) $ (124.6 ) The following represents the amounts recognized in other comprehensive income (loss) for the years ended December 31, 2018 , 2017 , and 2016 : Defined Benefit Retiree Health 2018 2017 2016 2018 2017 2016 Actuarial gain (loss) arising during period $ 211.1 $ (915.1 ) $ (725.2 ) $ 37.5 $ 261.3 $ (132.2 ) Plan amendments during period (17.6 ) — — 14.1 — 35.8 Curtailment gain (loss) 45.2 3.2 — (31.8 ) (39.7 ) — Amortization of prior service (benefit) cost included in net income 4.8 5.7 11.8 (79.5 ) (90.0 ) (85.8 ) Amortization of net actuarial loss included in net income 334.4 288.2 285.6 6.1 18.4 19.1 Foreign currency exchange rate changes and other 45.2 (105.3 ) 75.6 (0.1 ) (3.3 ) 2.5 Total other comprehensive income (loss) during period $ 623.1 $ (723.3 ) $ (352.2 ) $ (53.7 ) $ 146.7 $ (160.6 ) We have defined contribution savings plans that cover our eligible employees worldwide. The purpose of these plans is generally to provide additional financial security during retirement by providing employees with an incentive to save. Our contributions to the plans are based on employee contributions and the level of our match. Expenses under the plans totaled $153.5 million , $169.1 million , and $175.0 million for the years ended December 31, 2018 , 2017 , and 2016 , respectively. We provide certain other postemployment benefits primarily related to disability benefits and accrue for the related cost over the service lives of employees. Expenses associated with these benefit plans for the years ended December 31, 2018 , 2017 , and 2016 were not material. Benefit Plan Investments Our benefit plan investment policies are set with specific consideration of return and risk requirements in relationship to the respective liabilities. U.S. and Puerto Rico plans represent approximately 80 percent of our global investments. Given the long-term nature of our liabilities, these plans have the flexibility to manage an above-average degree of risk in the asset portfolios. At the investment-policy level, there are no specifically prohibited investments. However, within individual investment manager mandates, restrictions and limitations are contractually set to align with our investment objectives, ensure risk control, and limit concentrations. We manage our portfolio to minimize concentration of risk by allocating funds within asset categories. In addition, within a category we use different managers with various management objectives to eliminate any significant concentration of risk. Our global benefit plans may enter into contractual arrangements (derivatives) to implement the local investment policy or manage particular portfolio risks. Derivatives are principally used to increase or decrease exposure to a particular public equity, fixed income, commodity, or currency market more rapidly or less expensively than could be accomplished through the use of the cash markets. The plans utilize both exchange-traded and over-the-counter instruments. The maximum exposure to either a market or counterparty credit loss is limited to the carrying value of the receivable, and is managed within contractual limits. We expect all of our counterparties to meet their obligations. The gross values of these derivative receivables and payables are not material to the global asset portfolio, and their values are reflected within the tables below. The defined benefit pension and retiree health benefit plan allocation for the U.S. and Puerto Rico currently comprises approximately 70 percent growth investments and 30 percent fixed-income investments. The growth investment allocation encompasses U.S. and international public equity securities, hedge funds, private equity-like investments, and real estate. These portfolio allocations are intended to reduce overall risk by providing diversification, while seeking moderate to high returns over the long term. Public equity securities are well diversified and invested in U.S. and international small-to-large companies across various asset managers and styles. The remaining portion of the growth portfolio is invested in private alternative investments. Fixed-income investments primarily consist of fixed-income securities in U.S. treasuries and agencies, emerging market debt obligations, corporate bonds, mortgage-backed securities, commercial mortgage-backed obligations, and any related repurchase agreements. Hedge funds are privately owned institutional investment funds that generally have moderate liquidity. Hedge funds seek specified levels of absolute return regardless of overall market conditions, and generally have low correlations to public equity and debt markets. Hedge funds often invest substantially in financial market instruments (stocks, bonds, commodities, currencies, derivatives, etc.) using a very broad range of trading activities to manage portfolio risks. Hedge fund strategies focus primarily on security selection and seek to be neutral with respect to market moves. Common groupings of hedge fund strategies include relative value, tactical, and event driven. Relative value strategies include arbitrage, when the same asset can simultaneously be bought and sold at different prices, achieving an immediate profit. Tactical strategies often take long and short positions to reduce or eliminate overall market risks while seeking a particular investment opportunity. Event strategy opportunities can evolve from specific company announcements such as mergers and acquisitions, and typically have little correlation to overall market directional movements. Our hedge fund investments are made through limited partnership interests primarily in fund-of-funds structures to ensure diversification across many strategies and many individual managers. Plan holdings in hedge funds are valued based on net asset values (NAVs) calculated by each fund or general partner, as applicable, and we have the ability to redeem these investments at NAV. Private equity-like investment funds typically have low liquidity and are made through long-term partnerships or joint ventures that invest in pools of capital invested in primarily non-publicly traded entities. Underlying investments include venture capital (early stage investing), buyout, and special situation investing. Private equity management firms typically acquire and then reorganize private companies to create increased long term value. Private equity-like funds usually have a limited life of approximately 10-15 years, and require a minimum investment commitment from their limited partners. Our private investments are made both directly into funds and through fund-of-funds structures to ensure broad diversification of management styles and assets across the portfolio. Plan holdings in private equity-like investments are valued using the value reported by the partnership, adjusted for known cash flows and significant events through our reporting date. Values provided by the partnerships are primarily based on analysis of and judgments about the underlying investments. Inputs to these valuations include underlying NAVs, discounted cash flow valuations, comparable market valuations, and may also include adjustments for currency, credit, liquidity and other risks as applicable. The vast majority of these private partnerships provide us with annual audited financial statements including their compliance with fair valuation procedures consistent with applicable accounting standards. Real estate is composed of both public and private holdings. Real estate investments in registered investment companies that trade on an exchange are classified as Level 1 on the fair value hierarchy. Real estate investments in funds measured at fair value on the basis of NAV provided by the fund manager are classified as such. These NAVs are developed with inputs including discounted cash flow, independent appraisal, and market comparable analyses. Other assets include cash and cash equivalents and mark-to-market value of derivatives. The cash value of the trust-owned insurance contract is primarily invested in investment-grade publicly traded equity and fixed-income securities. Other than hedge funds, private equity-like investments, and real estate, which are discussed above, we determine fair values based on a market approach using quoted market values, significant other observable inputs for identical or comparable assets or liabilities, or discounted cash flow analyses. The fair values of our defined benefit pension plan and retiree health plan assets as of December 31, 2018 by asset category were as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Significant Inputs Significant Investments Valued at Net Asset Value (1) Defined Benefit Pension Plans Public equity securities: U.S. $ 619.9 $ 410.1 $ — $ — $ 209.8 International 2,117.8 828.8 — 1.8 1,287.2 Fixed income: Developed markets 2,963.2 25.0 2,173.3 — 764.9 Developed markets - repurchase agreements (1,225.5 ) — (1,225.5 ) — — Emerging markets 571.6 4.1 256.2 6.1 305.2 Private alternative investments: Hedge funds 2,801.9 — — — 2,801.9 Equity-like funds 1,942.5 — — 16.8 1,925.7 Real estate 525.8 147.2 — — 378.6 Other 747.0 213.3 86.1 — 447.6 Total $ 11,064.2 $ 1,628.5 $ 1,290.1 $ 24.7 $ 8,120.9 Retiree Health Benefit Plans Public equity securities: U.S. $ 59.9 $ 41.0 $ — $ — $ 18.9 International 127.0 50.5 — 0.2 76.3 Fixed income: Developed markets 69.1 — 61.5 — 7.6 Emerging markets 53.5 — 25.5 0.6 27.4 Private alternative investments: Hedge funds 245.8 — — — 245.8 Equity-like funds 169.2 — — 1.7 167.5 Cash value of trust owned insurance contract 1,574.7 — 1,574.7 — — Real estate 27.7 14.7 — — 13.0 Other 71.2 38.1 (3.8 ) — 36.9 Total $ 2,398.1 $ 144.3 $ 1,657.9 $ 2.5 $ 593.4 (1) Certain investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy. No material transfers between Level 1, Level 2, or Level 3 occurred during the year ended December 31, 2018 . The activity in the Level 3 investments during the year ended December 31, 2018 was not material. The fair values of our defined benefit pension plan and retiree health plan assets as of December 31, 2017 by asset category were as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Investments Valued at Net Asset Value (1) Defined Benefit Pension Plans Public equity securities: U.S. $ 466.2 $ 199.6 $ — $ — $ 266.6 International 2,934.2 955.1 — — 1,979.1 Fixed income: Developed markets 3,182.9 28.7 2,468.2 — 686.0 Developed markets - repurchase agreements (1,372.9 ) — (1,372.9 ) — — Emerging markets 584.7 4.2 252.0 3.1 325.4 Private alternative investments: Hedge funds 2,984.6 — — — 2,984.6 Equity-like funds 1,639.6 — — 16.8 1,622.8 Real estate 563.9 338.6 — — 225.3 Other 861.3 119.2 602.8 2.2 137.1 Total $ 11,844.5 $ 1,645.4 $ 1,950.1 $ 22.1 $ 8,226.9 Retiree Health Benefit Plans Public equity securities: U.S. $ 43.0 $ 19.4 $ — $ — $ 23.6 International 182.5 61.3 — — 121.2 Fixed income: Developed markets 71.2 — 63.5 — 7.7 Emerging markets 53.1 — 24.4 0.3 28.4 Private alternative investments: Hedge funds 256.0 — — — 256.0 Equity-like funds 137.0 — — 1.6 135.4 Cash value of trust owned insurance contract 1,524.6 — 1,524.6 — — Real estate 33.0 33.0 — — — Other 72.0 15.0 50.5 0.2 6.3 Total $ 2,372.4 $ 128.7 $ 1,663.0 $ 2.1 $ 578.6 (1) Certain investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy. No material transfers between Level 1, Level 2, or Level 3 occurred during the year ended December 31, 2017 . The activity in the Level 3 investments during the year ended December 31, 2017 was not material. In 2019, we expect to contribute approximately $45 million to our defined benefit pension plans to satisfy minimum funding requirements for the year. Additional discretionary contributions are not expected to be significant.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies We are a party to various legal actions and government investigations. The most significant of these are described below. It is not possible to determine the outcome of these matters, and we cannot reasonably estimate the maximum potential exposure or the range of possible loss in excess of amounts accrued for any of these matters; however, we believe that, except as noted below with respect to the Alimta ® patent litigation and administrative proceedings, the resolution of all such matters will not have a material adverse effect on our consolidated financial position or liquidity, but could possibly be material to our consolidated results of operations in any one accounting period. Litigation accruals, environmental liabilities, and the related estimated insurance recoverables are reflected on a gross basis as liabilities and assets, respectively, on our consolidated balance sheets. With respect to the product liability claims currently asserted against us, we have accrued for our estimated exposures to the extent they are both probable and reasonably estimable based on the information available to us. We accrue for certain product liability claims incurred but not filed to the extent we can formulate a reasonable estimate of their costs. We estimate these expenses based primarily on historical claims experience and data regarding product usage. Legal defense costs expected to be incurred in connection with significant product liability loss contingencies are accrued when both probable and reasonably estimable. Alimta Patent Litigation and Administrative Proceedings A number of generic manufacturers are seeking approvals in the U.S., Japan, and a number of countries in Europe to market generic forms of Alimta prior to the expiration of our vitamin regimen patents, alleging that those patents are invalid, not infringed, or both. We believe our Alimta vitamin regimen patents are valid and enforceable against these generic manufacturers. However, it is not possible to determine the ultimate outcome of the proceedings, and accordingly, we can provide no assurance that we will prevail. An unfavorable outcome could have a material adverse impact on our future consolidated results of operations, liquidity, and financial position. We expect that a loss of exclusivity for Alimta in one or more of the below jurisdictions would result in a rapid and severe decline in future revenue for the product in the relevant market. U.S. Patent Litigation and Administrative Proceedings In the U.S., more than 10 Abbreviated New Drug Applications (ANDAs) seeking approval to market generic versions of Alimta prior to the expiration of our vitamin regimen patent (expiring in 2021 plus pediatric exclusivity expiring in 2022) have been filed by a number of companies, including Teva Parenteral Medicines, Inc. (Teva) and APP Pharmaceuticals, LLC (APP) pursuant to procedures set out in the Drug Price Competition and Patent Term Restoration Act of 1984 (the Hatch-Waxman Act). We have received favorable decisions from the U.S. Court of Appeals for the Federal Circuit (affirming the U.S. District Court for the Southern District of Indiana's decisions finding our U.S. vitamin regimen patent valid and infringed) against Teva, APP, and two other defendants' proposed products, and similar favorable judgments have been entered by the U.S. District Court for the Southern District of Indiana against five other companies. The remaining ANDA applicants have agreed to a preliminary injunction or stay pending the appeal of the inter partes review (IPR) described in the following sentence. In October 2017, the U.S. Patent and Trademark Office issued written decisions in our favor following IPR of our vitamin regimen patent, finding that the generic company petitioners failed to show that the claims in our patent are unpatentable. A number of these challengers have appealed. A hearing on the appeal was held in the first quarter of 2019, and we expect a decision in the second quarter of 2019. We also currently have pending lawsuits in the U.S. District Court for the Southern District of Indiana alleging infringement against Actavis LLC (Actavis) and Apotex Inc. in response to their applications to market alternative forms of pemetrexed (the active ingredient in Alimta) products, and we filed a similar lawsuit in the U.S. District Court for the District of Delaware against Eagle Pharmaceuticals, Inc. In June 2018, the U.S. District Court for the Southern District of Indiana ruled in our favor in two similar cases, finding Dr. Reddy's Laboratories' (Dr. Reddy) and Hospira, Inc.'s (Hospira) proposed products would infringe our patent. Dr. Reddy and Hospira have appealed those rulings. The lawsuit against Actavis has been stayed, pending a decision in Dr. Reddy’s appeal. European Patent Litigation and Administrative Proceedings In July 2017, the United Kingdom (U.K.) Supreme Court ruled that commercialization of certain salt forms of pemetrexed by Actavis Group ehf and other Actavis companies directly infringes our vitamin regimen patents in the U.K., Italy, France, and Spain. This litigation in the U.K. is now concluded. Hexal AG, Stada Arzneimittel AG (Stada), and Fresenius Kabi Deutschland GmbH have each challenged the validity of our vitamin regimen patent before the German Federal Patent Court. At a hearing in July 2018, the German Federal Patent Court held that our vitamin regimen patent is invalid. We have appealed this decision. Under German law, the patent remains in force pending appeal. A number of generic competitors have received approval to market generic versions of pemetrexed in Germany. Injunctions are in place against four of these companies, but in two cases the injunctions have been temporarily suspended pending the validity appeal at the German Supreme Court. Stada has recently launched at risk in Germany and we are seeking an injunction. We are pursuing injunctions against others who have launched or are preparing to launch at risk. Whether the existing injunctions remain in effect, the suspended injunctions are reinstated pending the appeal or further injunctions are granted, or whether additional generic competitors choose to launch at risk, makes the timing of further generic entry and market erosion in Germany unpredictable. Additional legal proceedings are ongoing in various national courts throughout Europe. We are aware that several companies have received approval to market generic versions of pemetrexed in major European markets and that additional generic competitors may choose to launch at risk (including one generic product currently on the market in France). We will continue to seek to remove any generic pemetrexed products launched at risk in European markets, including Germany, seek damages in respect of such launches, and defend our patents against validity challenges. Japanese Administrative Proceedings Three separate sets of demands for invalidation of our two vitamin regimen patents, involving several companies, have been filed with the Japanese Patent Office (JPO). The JPO rejected a demand for invalidation by Sawai Pharmaceutical Co., Ltd., which was affirmed on appeal in 2017. In July 2018, the JPO issued written decisions dismissing demands brought by Nipro Corporation (Nipro) for invalidation of our two Japanese vitamin regimen patents. Nipro filed an appeal, and we anticipate decisions by the Japan Intellectual Property High Court in the third quarter of 2019. We anticipate decisions by the JPO with respect to another set of demands, brought by Hospira, in the third quarter of 2019. If upheld through all challenges, these patents would provide intellectual property protection for Alimta until June 2021. Notwithstanding our patents, generic versions of Alimta received regulatory approval in Japan starting in February 2016. We do not currently anticipate that generic versions of Alimta will proceed to pricing approval. Cymbalta ® Product Liability Litigation We were named as a defendant in a purported class-action lawsuit in the U.S. District Court for the Central District of California (now called Strafford et al. v. Eli Lilly and Com pany) involving Cymbalta. The plaintiffs, purporting to represent a class of all persons within the U.S. who purchased and/or paid for Cymbalta, asserted claims under the consumer protection statutes of four states, California, Massachusetts, Missouri, and New York, and sought declaratory, injunctive, and monetary relief for various alleged economic injuries arising from discontinuing treatment with Cymbalta. The district court denied the plaintiffs' motions for class certification. The district court dismissed the suits and plaintiffs appealed to the U.S. Court of Appeals for the Ninth Circuit. In November 2017, the U.S. Court of Appeals for the Ninth Circuit dismissed the suit. In July 2018, the U.S. District Court for the District of California denied plaintiffs’ motion to reopen the case. Plaintiffs’ appeal of this denial is currently pending before the U.S. Court of Appeals for the Ninth Circuit. Brazil–Employee Litigation Our subsidiary in Brazil, Eli Lilly do Brasil Limitada (Lilly Brasil), is named in a lawsuit brought by the Labor Attorney for the 15th Region in the Labor Court of Paulinia, State of Sao Paulo, Brazil, alleging possible harm to employees and former employees caused by exposure to heavy metals at a former Lilly Brasil manufacturing facility in Cosmopolis, Brazil, operated by the company between 1977 and 2003. In May 2014, the labor court judge ruled against Lilly Brasil, ordering it to undertake several actions of unspecified financial impact, including paying lifetime medical insurance for the employees and contractors who worked at the Cosmopolis facility more than six months during the affected years and their children born during and after this period. We appealed this decision. In July 2018, the appeals court affirmed the labor court's ruling with the total financial impact of the ruling estimated to be approximately 500.0 million Brazilian real (approximately $130.0 million as of December 31, 2018). The appeals court restricted the broad health coverage awarded by the labor court to health problems that claimants could show arose from exposure to the alleged contamination. We strongly disagree with the appeals court's decision. Lilly Brasil has taken an initial step in the appeal process by filing a Motion for Clarification; a decision on that motion is expected in the first quarter of 2019. We are also named in approximately 30 lawsuits filed in the same labor court by individual former employees making similar claims. These lawsuits are each at various stages in the litigation process, with judgments being handed down in approximately half of the lawsuits, nearly all of which are on appeal in the labor courts. Lilly Brasil and Elanco Quimica Ltda. have also been named in two similar lawsuits in the same labor court involving approximately 410 individual plaintiffs. The plaintiffs’ claims in these lawsuits relate only to mental anguish attributable to the possibility of illness due to alleged exposure to heavy metals or other contaminants. In 2017, the labor court dismissed the claims brought by all but the first named plaintiff in each of the lawsuits. The plaintiffs in both lawsuits are appealing. We believe all of these lawsuits are without merit and are defending against them vigorously. Adocia, S.A. We have been named as a respondent in an arbitration filed by Adocia, S.A. (Adocia), with which we entered into agreements for the co-development of an ultra-rapid insulin product. Adocia alleges that we misappropriated and misused Adocia's confidential information and intellectual property and is seeking approximately $1.30 billion in damages and other specific relief. We have asserted several counterclaims relating to fraudulent misrepresentation and are seeking approximately $188.0 million in damages. An arbitration hearing was held on Adocia’s claims and our counterclaims in December 2018, and we expect a decision in the third quarter of 2019. We believe Adocia's claims are without merit and have defended against them vigorously. Throughout the arbitrations described above, Adocia has made statements alleging that Adocia employees should be listed as inventors on two of our patents related to our ultra-rapid insulin product currently in development. We strongly contest this allegation. While inventorship of these two patents is not at issue in the arbitrations, in October 2018 we filed a declaratory judgment action against Adocia in the U.S. District Court for the Southern District of Indiana to confirm our inventorship. Insulin and Glucagon Pricing Litigation and Proceedings We, along with Sanofi and Novo Nordisk, are named as defendants in a consolidated purported class action lawsuit, In re. Insulin Pricing Litigation , in the U.S. District Court of New Jersey relating to insulin pricing. Plaintiffs seek damages under various state consumer protection laws and the Federal Racketeer Influenced and Corrupt Organization Act (Federal RICO Act). In February 2019, the court dismissed without prejudice the federal RICO Act claim as well as certain state consumer protection claims. Separately, we, along with Sanofi and Novo Nordisk, are named as defendants in a purported class action lawsuit, MSP Recovery Claims, Series, LLC et al. v. Sanofi Aventis U.S. LLC et al. , in the same court, seeking damages under various state consumer protection laws, common law fraud, unjust enrichment, and the federal RICO Act. Finally, the Minnesota Attorney General’s Office filed a complaint against us, Sanofi, and Novo Nordisk, State of Minnesota v. Sanofi-Aventis U.S. LLC et al., in the U.S. District Court of New Jersey, alleging unjust enrichment, and violations of various Minnesota state consumer protection laws and the Federal RICO Act. We believe these claims are without merit and are defending against them vigorously. We have received civil investigative demands from the Offices of the Attorney General from Washington and New Mexico relating to the pricing and sale of our insulin products. We are cooperating with these investigations. The Offices of the Attorney General in Mississippi, Washington D.C., California, Florida, Hawaii, and Nevada have requested information relating to the pricing and sale of our insulin products. We are cooperating with these requests. We received interrogatories from the California Attorney General's Office regarding our competition in the long-acting insulin market. We are cooperating with this investigation. Finally, we received a request from the House of Representatives’ Committee on Oversight and Reform; two requests from its Committee on Energy and Commerce; as well as a request from the Senate Committee on Health, Education, Labor, and Pensions, seeking certain information related to the pricing of insulin products, among other issues . We are cooperating with these investigations. We, along with Novo Nordisk and various pharmacy benefit managers, are named as defendants in a lawsuit seeking class action status in the U.S. District Court of New Jersey relating to glucagon pricing. The plaintiffs are seeking damages under various state consumer protection laws, the Federal RICO Act, the Sherman Act, and other state and federal laws. We believe this lawsuit is without merit and are defending against it vigorously. Product Liability Insurance Because of the nature of pharmaceutical products, it is possible that we could become subject to large numbers of additional product liability and related claims in the future. Due to a very restrictive market for product liability insurance, we are self-insured for product liability losses for all our currently marketed products.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The following table summarizes the activity related to each component of other comprehensive income (loss): (Amounts presented net of taxes) Foreign Currency Translation Gains (Losses) Unrealized Net Gains (Losses) on Securities Defined Benefit Pension and Retiree Health Benefit Plans Effective Portion of Cash Flow Hedges Accumulated Other Comprehensive Loss Beginning balance at January 1, 2016 $ (1,360.2 ) $ 10.1 $ (3,012.1 ) $ (218.5 ) $ (4,580.7 ) Other comprehensive income (loss) before reclassifications (581.6 ) 206.7 (518.7 ) (2.2 ) (895.8 ) Net amount reclassified from accumulated other comprehensive loss 74.5 7.2 159.2 9.8 250.7 Net other comprehensive income (loss) (507.1 ) 213.9 (359.5 ) 7.6 (645.1 ) Balance at December 31, 2016 (1) (1,867.3 ) 224.0 (3,371.6 ) (210.9 ) (5,225.8 ) Other comprehensive income (loss) before reclassifications 664.6 (15.7 ) (543.4 ) 8.5 114.0 Net amount reclassified from accumulated other comprehensive loss 8.1 (110.6 ) 153.4 9.6 60.5 Net other comprehensive income (loss) 672.7 (126.3 ) (390.0 ) 18.1 174.5 Reclassifications of stranded tax effects (Note 2) (38.8 ) 15.8 (579.1 ) (41.5 ) (643.6 ) Balance at December 31, 2017 (2) (1,233.4 ) 113.5 (4,340.7 ) (234.3 ) (5,694.9 ) Reclassification due to adoption of new accounting standard (3) — (128.9 ) — — (128.9 ) Other comprehensive income (loss) before reclassifications (389.1 ) 24.5 274.0 (16.3 ) (106.9 ) Net amount reclassified from accumulated other comprehensive loss — (31.2 ) 210.0 11.7 190.5 Net other comprehensive income (loss) (389.1 ) (6.7 ) 484.0 (4.6 ) 83.6 Ending balance at December 31, 2018 (4) $ (1,622.5 ) $ (22.1 ) $ (3,856.7 ) $ (238.9 ) $ (5,740.2 ) (1) Accumulated other comprehensive loss as of December 31, 2016 consists of $5.27 billion of accumulated other comprehensive loss attributable to controlling interest and $48.2 million of accumulated other comprehensive income attributable to noncontrolling interest. (2) Accumulated other comprehensive loss as of December 31, 2017 consists of $5.72 billion of accumulated other comprehensive loss attributable to controlling interest and $23.7 million of accumulated other comprehensive income attributable to noncontrolling interest. (3) This reclassification consists of $105.2 million of accumulated other comprehensive loss attributable to controlling interest and $23.7 million of accumulated other comprehensive loss attributable to noncontrolling interest. Refer to Note 2 for further details regarding the reclassification due to the adoption of Accounting Standards Update 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. (4) Accumulated other comprehensive loss as of December 31, 2018 consists of $5.73 billion of accumulated other comprehensive loss attributable to controlling interest and $11.0 million of accumulated other comprehensive loss attributable to noncontrolling interest. The tax effects on the net activity related to each component of other comprehensive income (loss) for the years ended December 31, were as follows: Tax benefit (expense) 2018 2017 2016 Foreign currency translation gains/losses $ 51.6 $ 170.8 $ (70.6 ) Unrealized net gains/losses on securities 2.1 55.0 (89.2 ) Defined benefit pension and retiree health benefit plans (85.3 ) 186.6 153.3 Effective portion of cash flow hedges 1.3 (9.7 ) (4.1 ) Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items $ (30.3 ) $ 402.7 $ (10.6 ) Except for the tax effects of foreign currency translation gains and losses related to our foreign currency-denominated notes, cross-currency interest rate swaps, and other foreign currency exchange contracts designated as net investment hedges (see Note 7), income taxes were not provided for foreign currency translation. Generally, the assets and liabilities of foreign operations are translated into U.S. dollars using the current exchange rate. For those operations, changes in exchange rates generally do not affect cash flows; therefore, resulting translation adjustments are made in shareholders' equity rather than in the consolidated statements of operations. Reclassifications out of accumulated other comprehensive loss were as follows: Details about Accumulated Other Comprehensive Loss Components Year Ended December 31, Affected Line Item in the Consolidated Statements of Operations 2018 2017 2016 Amortization of retirement benefit items: Prior service benefits, net $ (74.7 ) $ (84.3 ) $ (74.0 ) Other—net, (income) expense Actuarial losses 340.5 306.6 304.7 Other—net, (income) expense Total before tax 265.8 222.3 230.7 Tax benefit (55.8 ) (68.9 ) (71.5 ) Income taxes Net of tax 210.0 153.4 159.2 Unrealized gains/losses on available-for-sale securities: Realized gains, net (39.5 ) (170.2 ) (16.1 ) Other—net, (income) expense Impairment losses — — 27.3 Other—net, (income) expense Total before tax (39.5 ) (170.2 ) 11.2 Tax (benefit) expense 8.3 59.6 (4.0 ) Income taxes Net of tax (31.2 ) (110.6 ) 7.2 Other, net of tax (1) 11.7 17.7 84.3 Other—net, (income) expense Total reclassifications for the period, net of tax $ 190.5 $ 60.5 $ 250.7 (1) Amount for year ended December 31, 2016 included primarily $74.5 million of foreign currency translation losses.

Other-Net, (Income) Expense

Other-Net, (Income) Expense	12 Months Ended
	Dec. 31, 2018
Nonoperating Income (Expense) [Abstract]
Other - Net, (Income) Expense	Other–Net, (Income) Expense Other–net, (income) expense consisted of the following: 2018 2017 2016 Interest expense $ 272.1 $ 225.0 $ 185.2 Interest income (161.3 ) (167.3 ) (108.7 ) Venezuela charge — — 203.9 Retirement benefit (242.1 ) (248.1 ) (197.6 ) Other (income) expense 56.5 (110.1 ) (195.6 ) Other–net, (income) expense $ (74.8 ) $ (300.5 ) $ (112.8 ) Due to the financial crisis in Venezuela and the significant deterioration of the bolívar, we changed the exchange rate used to translate the assets and liabilities of our subsidiaries in Venezuela in 2016, which resulted in a charge of $203.9 million for the year ended December 31, 2016. Prior to this change, we used the Supplementary Foreign Currency Administration System (SICAD) rate; however, this official rate was discontinued in the first quarter of 2016. After considering several factors, including the future uncertainty of the Venezuelan economy, published exchange rates, and the limited amount of foreign currency exchanged, we changed to the Divisa Complementaria (DICOM) rate. As discussed in Note 2, upon adoption of Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. Results for the years ended December 31, 2017 and 2016 have been reclassified to reflect the adoption of this standard. For the year ended December 31, 2018 , other expense was primarily driven by net foreign exchange losses. For the years ended December 31, 2017 , and 2016 , other income is primarily related to net gains on investments (Note 7).

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information We have two operating segments—human pharmaceutical products and animal health products. Our operating segments are distinguished by the ultimate end user of the product—humans or animals. Performance is evaluated based on profit or loss from operations before income taxes. The accounting policies of the individual segments are the same as those described throughout the notes to the consolidated financial statements. Our human pharmaceutical products segment includes the discovery, development, manufacturing, marketing, and sale of human pharmaceutical products worldwide in the following therapeutic areas: endocrinology, oncology, cardiovascular, neuroscience, immunology, and other. We lost our compound patent protection for Cialis ® (tadalafil) and Adcirca ® (tadalafil) in major European markets in November 2017, and in the U.S., pediatric exclusivity expired in May 2018. Pursuant to a settlement agreement related to our unit dose patent in the U.S., generic tadalafil entered the U.S. market in September 2018. Entry of generic competition into these markets following the loss of exclusivity will continue to cause a rapid and severe decline in revenue. Our formulation patents for Forteo ® expired in December 2018 and use patents will expire in August 2019 in major European markets and the U.S. Both the formulation patent and the use patent expire in 2019 in Japan. Our animal health segment, operating through our Elanco animal health division, includes the development, manufacturing, marketing, and sales of animal health products worldwide for both food and companion animals. Animal health products include Rumensin ® , Maxiban ® , Denagard ® , Tylan ® , and other products for livestock and poultry, as well as Trifexis ® , Interceptor ® , Comfortis ® , and other products for companion animals. The animal health segment for the years ended December 31, 2018 and 2017 , included the results of operations from BIVIVP, which was acquired on January 3, 2017 (Note 3). Most of our pharmaceutical products are distributed through wholesalers that serve pharmacies, physicians and other health care professionals, and hospitals. For the years ended December 31, 2018 , 2017 , and 2016 , our three largest wholesalers each accounted for between 11 percent and 18 percent of consolidated total revenue. Further, they each accounted for between 14 percent and 22 percent of accounts receivable as of December 31, 2018 and 2017 . Animal health products are sold primarily to wholesale distributors. Our chief operating decision maker does not review any asset information by operating segment and, accordingly, we do not report asset information by operating segment. We are exposed to the risk of changes in social, political, and economic conditions inherent in foreign operations, and our results of operations and the value of our foreign assets are affected by fluctuations in foreign currency exchange rates. The following table summarizes our revenue activity: U.S. (1) Outside U.S. 2018 2017 2016 2018 2017 2016 Segment revenue—to unaffiliated customers: Human pharmaceutical products: Endocrinology: Trulicity ® $ 2,515.8 $ 1,609.8 $ 737.6 $ 683.3 $ 419.9 $ 187.9 Humalog ® 1,787.8 1,717.8 1,685.2 1,208.7 1,147.4 1,083.6 Humulin ® 910.2 884.6 861.8 421.2 450.7 504.1 Forteo 757.9 965.2 770.5 817.7 783.8 729.4 Basaglar 622.8 311.1 15.8 178.5 121.0 70.3 Jardiance 400.2 290.4 144.5 258.1 157.0 57.4 Trajenta 224.2 213.2 165.9 350.5 324.7 270.7 Other Endocrinology 292.7 380.9 450.6 272.5 307.7 347.5 Total Endocrinology 7,511.6 6,373.0 4,831.9 4,190.5 3,712.2 3,250.9 Oncology: Alimta 1,131.0 1,034.3 1,101.0 1,001.9 1,028.2 1,182.3 Erbitux 531.6 541.7 581.1 103.8 104.2 105.9 Cyramza ® 291.5 278.8 270.1 529.9 479.6 344.0 Other Oncology 449.1 195.6 22.9 221.7 149.6 114.6 Total Oncology 2,403.2 2,050.4 1,975.1 1,857.3 1,761.6 1,746.8 Cardiovascular: Cialis 1,129.2 1,358.6 1,469.5 722.7 964.5 1,002.1 Effient 68.1 340.1 465.6 54.1 48.8 69.6 Other Cardiovascular 158.4 24.0 56.3 121.8 135.2 162.3 Total Cardiovascular 1,355.7 1,722.7 1,991.4 898.6 1,148.5 1,234.0 Neuroscience: Strattera ® 89.7 284.9 534.9 361.1 333.3 319.8 Cymbalta (2) 54.3 114.9 269.3 653.7 642.2 661.2 Zyprexa ® 36.2 75.5 69.8 435.1 505.7 655.5 Other Neuroscience 97.2 115.7 115.9 93.4 98.9 93.9 Total Neuroscience 277.4 591.0 989.9 1,543.3 1,580.1 1,730.4 Immunology: Taltz ® 738.7 486.0 110.8 198.7 73.2 2.3 Other Immunology 6.7 — — 195.9 45.8 — Total Immunology 745.4 486.0 110.8 394.6 119.0 2.3 Other human pharmaceutical products 58.7 50.9 42.6 176.6 190.3 157.8 Total human pharmaceutical products 12,352.2 11,274.0 9,941.7 9,061.0 8,511.7 8,122.2 Animal health products 1,523.0 1,511.1 1,564.5 1,619.5 1,574.5 1,593.7 Revenue $ 13,875.2 $ 12,785.1 $ 11,506.2 $ 10,680.5 $ 10,086.3 $ 9,715.9 Numbers may not add due to rounding. (1) U.S. revenue includes revenue in Puerto Rico. (2) Cymbalta revenues benefited from reductions to the reserve for expected product returns of approximately $175 million during the year ended December 31, 2016. 2018 2017 2016 Segment profits: Human pharmaceutical products $ 6,217.8 $ 5,139.7 $ 4,010.0 Animal health products 607.3 561.3 663.7 Total segment profits $ 6,825.1 $ 5,701.0 $ 4,673.7 Reconciliation of total segment profits to consolidated income before taxes: Segment profits $ 6,825.1 $ 5,701.0 $ 4,673.7 Other profits (losses): Amortization of intangible assets (Note 8) (546.0 ) (674.8 ) (683.3 ) Asset impairment, restructuring, and other special charges (Note 5) (482.0 ) (1,673.6 ) (382.5 ) Venezuela charge (Note 17) — — (203.9 ) Acquired in-process research and development (Note 3) (1,983.9 ) (1,112.6 ) (30.0 ) Inventory fair value adjustment related to acquisition of BIVIVP (Note 3) — (42.7 ) — Other, net (17.5 ) — — Consolidated income before taxes $ 3,795.7 $ 2,197.4 $ 3,374.0 Numbers may not add due to rounding. Depreciation and software amortization expense included in our segment profits was as follows: 2018 2017 2016 Human pharmaceutical products $ 934.0 $ 789.8 $ 723.4 Animal health products 111.3 102.7 89.9 Total depreciation expense and software amortization included in segment profits $ 1,045.3 $ 892.5 $ 813.3 For internal management reporting presented to the chief operating decision maker, certain costs are fully allocated to our human pharmaceutical products segment and therefore are not reflected in the animal health segment's profit. Such items include costs associated with treasury-related financing and global administrative services. 2018 2017 2016 Geographic Information Revenue—to unaffiliated customers (1) : United States $ 13,875.2 $ 12,785.1 $ 11,506.2 Europe 4,231.1 3,943.2 3,768.1 Japan 2,493.7 2,419.7 2,330.9 Other foreign countries 3,955.7 3,723.3 3,616.9 Revenue $ 24,555.7 $ 22,871.3 $ 21,222.1 Long-lived assets (2) : United States $ 4,946.6 $ 5,013.4 $ 4,984.6 Europe 2,708.1 2,550.1 2,140.7 Japan 181.9 155.1 92.4 Other foreign countries 1,695.5 1,761.7 1,776.8 Long-lived assets $ 9,532.1 $ 9,480.3 $ 8,994.5 Numbers may not add due to rounding. (1) Revenue is attributed to the countries based on the location of the customer. (2) Long-lived assets consist of property and equipment, net, and certain sundry assets.

Selected Quarterly Data (Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Data (Unaudited)	Selected Quarterly Data (unaudited) 2018 Fourth Third Second First Revenue $ 6,438.6 $ 6,061.9 $ 6,355.2 $ 5,700.0 Cost of sales 1,593.7 1,562.3 1,702.7 1,571.3 Operating expenses (1) 3,315.3 2,959.9 2,986.8 2,676.9 Acquired in-process research and development (2) 329.4 30.0 1,624.5 — Asset impairment, restructuring, and other special charges 246.0 83.3 74.4 78.3 Income before income taxes 938.9 1,411.0 4.8 1,441.0 Income taxes (3) (186.2 ) 261.5 264.7 223.6 Net income (loss) 1,125.1 1,149.5 (259.9 ) 1,217.4 Earnings (loss) per share—basic 1.11 1.13 (0.25 ) 1.16 Earnings (loss) per share—diluted 1.10 1.12 (0.25 ) 1.16 Dividends paid per share 0.5625 0.5625 0.5625 0.5625 2017 Fourth Third Second First Revenue $ 6,160.7 $ 5,658.0 $ 5,824.3 $ 5,228.3 Cost of sales (4) 1,644.9 1,586.3 1,571.7 1,347.9 Operating expenses (1)(4) 3,290.4 2,918.5 3,002.5 2,826.0 Acquired in-process research and development (2) 50.0 205.0 — 857.6 Asset impairment, restructuring, and other special charges (5) 1,003.2 406.5 50.0 213.9 Income before income taxes 284.1 591.6 1,260.5 61.2 Income taxes (3) 1,941.0 36.0 252.5 172.0 Net income (loss) (1,656.9 ) 555.6 1,008.0 (110.8 ) Earnings (loss) per share—basic (1.58 ) 0.53 0.96 (0.10 ) Earnings (loss) per share—diluted (1.58 ) 0.53 0.95 (0.10 ) Dividends paid per share 0.52 0.52 0.52 0.52 (1) Includes research and development and marketing, selling, and administrative expenses. (2) Acquired IPR&D charges in the second quarter of 2018 were primarily due to the ARMO acquisition. Acquired IPR&D charges in the first quarter of 2017 were due to the CoLucid acquisition. See Note 3 for further discussion. (3) Income taxes in the fourth quarter of 2018 were a tax benefit primarily due to adjustments associated with U.S. tax reform. Income taxes in the fourth quarter of 2017 were due to the provisional charge resulting from the 2017 Tax Act. See Note 13 for further discussion. (4) As discussed in Note 2, upon adoption of Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. Results for the quarters in 2017 have been reclassified to reflect the adoption of this standard. (5) Asset impairment, restructuring, and other special charges in the third quarter 2017 were primarily from asset impairments related to lower projected revenue for Posilac (rbST). In the fourth quarter of 2017, restructuring charges were primarily due to severance costs resulting from the U.S. voluntary early retirement program. See Note 5 for further discussion. Our common stock is listed under the ticker symbol LLY on the New York Stock Exchange (NYSE) and the NYSE Euronext.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Inventory	We use the last-in, first-out (LIFO) method for the majority of our inventories located in the continental U.S. Other inventories are valued by the first-in, first-out (FIFO) method. FIFO cost approximates current replacement cost.
Investment	We consider all highly liquid investments with a maturity of three months or less from the date of purchase to be cash equivalents. The cost of these investments approximates fair value. Our equity investments are accounted for using three different methods depending on the type of equity investment: • Investments in companies over which we have significant influence but not a controlling interest are accounted for using the equity method, with our share of earnings or losses reported in other-net, (income) expense. • For equity investments that do not have readily determinable fair values, we measure these investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. Any change in recorded value is recorded in other-net, (income) expense. • Our public equity investments are measured and carried at fair value. Any change in fair value is recognized in other-net, (income) expense. We review equity investments other than public equity investments for indications of impairment on a regular basis.
Derivatives	Our derivative activities are initiated within the guidelines of documented corporate risk-management policies and are intended to offset losses and gains on the assets, liabilities, and transactions being hedged. Management reviews the correlation and effectiveness of our derivatives on a quarterly basis. For derivative instruments that are designated and qualify as fair value hedges, the derivative instrument is marked to market with gains and losses recognized currently in income to offset the respective losses and gains recognized on the underlying exposure. For derivative instruments that are designated and qualify as cash flow hedges, gains and losses are reported as a component of accumulated other comprehensive loss and reclassified into earnings in the same period the hedged transaction affects earnings. For derivative and non-derivative instruments that are designated and qualify as net investment hedges, the foreign currency translation gains or losses due to spot rate fluctuations are reported as a component of accumulated other comprehensive loss. Derivative contracts that are not designated as hedging instruments are recorded at fair value with the gain or loss recognized in earnings during the period of change. We may enter into foreign currency forward or option contracts to reduce the effect of fluctuating currency exchange rates (principally the euro, British pound, and the Japanese yen). Foreign currency derivatives used for hedging are put in place using the same or like currencies and duration as the underlying exposures. Forward and option contracts are principally used to manage exposures arising from subsidiary trade and loan payables and receivables denominated in foreign currencies. These contracts are recorded at fair value with the gain or loss recognized in other–net, (income) expense. We may enter into foreign currency forward and option contracts and currency swaps as fair value hedges of firm commitments. We may enter into forward contracts and designate them as cash flow hedges to limit the potential volatility of earnings and cash flow associated with forecasted sales of available-for-sale securities. We also may enter into forward-starting interest rate swaps, which we designate as cash flow hedges, as part of any anticipated future debt issuances in order to reduce the risk of cash flow volatility from future changes in interest rates. Upon completion of a debt issuance and termination of the swap, the change in fair value of these instruments is recorded as part of other comprehensive income (loss) and is amortized to interest expense over the life of the underlying debt. In the normal course of business, our operations are exposed to fluctuations in interest rates which can vary the costs of financing, investing, and operating. We seek to address a portion of these risks through a controlled program of risk management that includes the use of derivative financial instruments. The objective of controlling these risks is to limit the impact of fluctuations in interest rates on earnings. Our primary interest-rate risk exposure results from changes in short-term U.S. dollar interest rates. In an effort to manage interest-rate exposures, we strive to achieve an acceptable balance between fixed- and floating-rate debt and investment positions and may enter into interest rate swaps or collars to help maintain that balance. Interest rate swaps or collars that convert our fixed-rate debt to a floating rate are designated as fair value hedges of the underlying instruments. Interest rate swaps or collars that convert floating-rate debt to a fixed rate are designated as cash flow hedges. Interest expense on the debt is adjusted to include the payments made or received under the swap agreements. Cash proceeds from or payments to counterparties resulting from the termination of interest rate swaps are classified as operating activities in our consolidated statements of cash flows.
Goodwill and Intangible Assets	Other indefinite-lived intangible assets are reviewed for impairment at least annually and when impairment indicators are present. Finite-lived intangible assets are reviewed for impairment when an indicator of impairment is present. When required, a comparison of fair value to the carrying amount of assets is performed to determine the amount of any impairment. When determining the fair value of indefinite-lived acquired IPR&D as well as the fair value of finite-lived intangible assets for impairment testing purposes, we utilize the "income method" discussed above. Goodwill results from excess consideration in a business combination over the fair value of identifiable net assets acquired. Goodwill is not amortized but is reviewed for impairment at least annually and when impairment indicators are present. When required, a comparison of the fair value of the reporting unit to its carrying amount including goodwill is used to determine the amount of any impairment. The costs of acquired IPR&D projects acquired directly in a transaction other than a business combination are capitalized if the projects have an alternative future use; otherwise, they are expensed immediately. The fair values of acquired IPR&D projects acquired in business combinations are capitalized as other intangible assets. Several methods may be used to determine the estimated fair value of other intangibles acquired in a business combination. We utilize the “income method,” which is a Level 3 fair value measurement and applies a probability weighting that considers the risk of development and commercialization to the estimated future net cash flows that are derived from projected revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, historical pricing of similar products, and expected industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. This analysis is performed for each asset independently. The acquired IPR&D assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are tested for impairment and amortized over the remaining useful life or written off, as appropriate. For transactions other than a business combination, we capitalize milestone payments incurred at or after the product has obtained regulatory approval for marketing.
Property, Plant and Equipment	Property and equipment is stated on the basis of cost. Provisions for depreciation of buildings and equipment are computed generally by the straight-line method at rates based on their estimated useful lives ( 12 to 50 years for buildings and three to 25 years for equipment). We review the carrying value of long-lived assets for potential impairment on a periodic basis and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Impairment is determined by comparing projected undiscounted cash flows to be generated by the asset to its carrying value. If an impairment is identified, a loss is recorded equal to the excess of the asset’s net book value over its fair value, and the cost basis is adjusted.
Commitments and Contingencies	Litigation accruals, environmental liabilities, and the related estimated insurance recoverables are reflected on a gross basis as liabilities and assets, respectively, on our consolidated balance sheets. With respect to the product liability claims currently asserted against us, we have accrued for our estimated exposures to the extent they are both probable and reasonably estimable based on the information available to us. We accrue for certain product liability claims incurred but not filed to the extent we can formulate a reasonable estimate of their costs. We estimate these expenses based primarily on historical claims experience and data regarding product usage. Legal defense costs expected to be incurred in connection with significant product liability loss contingencies are accrued when both probable and reasonably estimable.
Revenue Recognition	Adoption of Revenue Accounting Standard Effective January 1, 2018, we adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers and other related updates (see Note 2 for additional discussion). The new standard has been applied to contracts for which performance was not substantially complete as of the date of adoption. For those contracts that were modified prior to the date of adoption, we reflected the aggregate effect of those modifications when determining the appropriate accounting under the new standard. We don’t believe the effect of applying this practical expedient resulted in material differences. Revenue presented for periods prior to 2018 was accounted for under previous standards and has not been adjusted. Revenue and net income for 2018 do not differ materially from amounts that would have resulted from application of the previous standards. The following table summarizes our revenue recognized in our consolidated statements of operations: 2018 2017 2016 Net product revenue $ 22,928.8 $ 21,671.4 $ 20,388.4 Collaboration and other revenue (1) 1,626.9 1,199.9 833.7 Revenue $ 24,555.7 $ 22,871.3 $ 21,222.1 (1) Collaboration and other revenue associated with prior year transfers of intellectual property was $303.2 million , $145.8 million , and $146.1 million during the years ended 2018 , 2017 , and 2016 , respectively. We recognize revenue primarily from two different types of contracts, product sales to customers (net product revenue) and collaborations and other arrangements. Revenue recognized from collaborations and other arrangements will include our share of profits from the collaboration, as well as royalties, upfront and milestone payments we receive under these types of contracts. See Note 4 for additional information related to our collaborations and other arrangements. Collaboration and other revenue disclosed above includes the revenue from the Trajenta ® and Jardiance ® families of products resulting from our collaboration with Boehringer Ingelheim discussed in Note 4. Substantially all of the remainder of collaboration and other revenue is related to contracts accounted for as contracts with customers. Net Product Revenue Revenue from sales of products is recognized at the point where the customer obtains control of the goods and we satisfy our performance obligation, which generally is at the time we ship the product to the customer. Payment terms differ by jurisdiction and customer, but payment terms in most of our major jurisdictions typically range from 30 to 75 days from date of shipment. Revenue for our product sales has not been adjusted for the effects of a financing component as we expect, at contract inception, that the period between when we transfer control of the product and when we receive payment will be one year or less. Any exceptions are either not material or we collect interest for payments made after the due date. Provisions for rebates and discounts, and returns are established in the same period the related sales are recognized. We generally ship product shortly after orders are received; therefore, we generally only have a few days of orders received but not yet shipped at the end of any reporting period. Shipping and handling activities are considered to be fulfillment activities and are not considered to be a separate performance obligation. We exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are imposed on our sales of product and collected from a customer. Significant judgments must be made in determining the transaction price for our sales of products related to anticipated rebates and discounts and returns. The following describe the most significant of these judgments: Sales Rebates and Discounts - Background and Uncertainties • Most of our pharmaceutical products are sold to wholesalers that serve pharmacies, physicians and other health care professionals, and hospitals. Most of our animal health products are sold to wholesale distributors. We initially invoice our customers at contractual list prices. Contracts with direct and indirect customers may provide for various rebates and discounts that may differ in each contract. As a consequence, to determine the appropriate transaction price for our product sales at the time we recognize a sale to a direct customer, we must estimate any rebates or discounts that ultimately will be due to the direct customer and other customers in the distribution chain under the terms of our contracts. Significant judgments are required in making these estimates. • The rebate and discount amounts are recorded as a deduction to arrive at our net product revenue. Sales rebates and discounts that require the use of judgment in the establishment of the accrual include managed care, Medicare, Medicaid, chargebacks, long-term care, hospital, patient assistance programs, and various other programs. We estimate these accruals using an expected value approach. • The largest of our sales rebate and discount amounts are rebates associated with sales covered by managed care, Medicare, Medicaid, and chargeback contracts in the United States (U.S.) In determining the appropriate accrual amount, we consider our historical rebate payments for these programs by product as a percentage of our historical sales as well as any significant changes in sales trends (e.g., patent expiries and product launches), an evaluation of the current contracts for these programs, the percentage of our products that are sold via these programs, and our product pricing. Although we accrue a liability for rebates related to these programs at the time we record the sale, the rebate related to that sale is typically paid up to six months later. Because of this time lag, in any particular period our rebate adjustments may incorporate revisions of accruals for several periods. • Most of our rebates outside the U.S. are contractual or legislatively mandated and are estimated and recognized in the same period as the related sales. In some large European countries, government rebates are based on the anticipated budget for pharmaceutical payments in the country. An estimate of these rebates, updated as governmental authorities revise budgeted deficits, is recognized in the same period as the related sale. Sales Returns - Background and Uncertainties • When product sales occur, to determine the appropriate transaction price for our sales, we estimate a reserve for future product returns related to those sales using an expected value approach. This estimate is based on several factors, including: historical return rates, expiration date by product (on average, approximately 24 months after the initial sale of a product to our customer), and estimated levels of inventory in the wholesale and retail channels, as well as any other specifically-identified anticipated returns due to known factors such as the loss of patent exclusivity, product recalls and discontinuances, or a changing competitive environment. We maintain a returns policy that allows U.S. pharmaceutical customers to return product for dating issues within a specified period prior to and subsequent to the product's expiration date. Following the loss of exclusivity for a patent-dependent product, we expect to experience an elevated level of product returns as product inventory remaining in the wholesale and retail channels expires. Adjustments to the returns reserve have been and may in the future be required based on revised estimates to our assumptions. We record the return amounts as a deduction to arrive at our net product revenue. Once the product is returned, it is destroyed; we do not record a right of return asset. Our returns policies outside the U.S. are generally more restrictive than in the U.S. as returns are not allowed for reasons other than failure to meet product specifications in many countries. Our reserve for future product returns for product sales outside the U.S. is not material. • As a part of our process to estimate a reserve for product returns, we regularly review the supply levels of our significant products sold to major wholesalers in the U.S. and in major markets outside the U.S., primarily by reviewing periodic inventory reports supplied by our major wholesalers and available prescription volume information for our products, or alternative approaches. We attempt to maintain U.S. wholesaler inventory levels at an average of approximately one month or less on a consistent basis across our product portfolio. Causes of unusual wholesaler buying patterns include actual or anticipated product-supply issues, weather patterns, anticipated changes in the transportation network, redundant holiday stocking, and changes in wholesaler business operations. In the U.S., the current structure of our arrangements provides us with data on inventory levels at our wholesalers; however, our data on inventory levels in the retail channel is more limited. Wholesaler stocking and destocking activity historically has not caused any material changes in the rate of actual product returns. • Actual product returns have been less than 2 percent of our net revenue over each of the past three years and have not fluctuated significantly as a percentage of revenue, although fluctuations are more likely in periods following loss of patent exclusivity for major products in the U.S. market. Adjustments to Revenue Adjustments to revenue recognized as a result of changes in estimates for the judgments described above during 2018 for product shipped in previous years were approximately 1 percent of revenue. Disaggregation of Revenue Our disaggregated revenue is disclosed in Note 18. Collaborations and Other Arrangements We recognize several types of revenue from our collaborations and other arrangements, which we discuss in general terms immediately below and more specifically in Note 4 for each of our material collaborations and other arrangements. Our collaborations and other arrangements are not contracts with customers but are evaluated to determine whether any aspects of the arrangements are contracts with customers. • Revenue related to products we sell pursuant to these arrangements is included in net product revenue, while other sources of revenue (e.g., royalties and profit sharing from our partner) are included in collaboration and other revenue. • Initial fees and developmental milestones we receive in collaborative and other similar arrangements from the partnering of our compounds under development are generally deferred and amortized into income through the expected product approval date. • Profit-sharing due from our collaboration partners, which is based upon gross margins reported to us by our partners, is recognized as collaboration and other revenue as earned. • Royalty revenue from licensees, which is based on sales to third-parties of licensed products and technology, is recorded when the third-party sale occurs and the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). This royalty revenue is included in collaboration and other revenue. • For arrangements involving multiple goods or services (e.g., research and development, marketing and selling, manufacturing, and distribution), each required good or service is evaluated to determine whether it is distinct. If a good or service does not qualify as distinct, it is combined with the other non-distinct goods or services within the arrangement and these combined goods or services are treated as a single performance obligation for accounting purposes. The arrangement's transaction price is then allocated to each performance obligation based on the relative standalone selling price of each performance obligation. For arrangements that involve variable consideration where we have sold intellectual property, we recognize revenue based on estimates of the amount of consideration we believe we will be entitled to receive from the other party, subject to a constraint. These estimates are adjusted to reflect the actual amounts to be collected when those facts and circumstances become known. • Significant judgments must be made in determining the transaction price for our sales of intellectual property. Because of the risk that products in development will not receive regulatory approval, we generally do not recognize any contingent payments that would be due to us upon or after regulatory approval. • We have entered into arrangements whereby we transferred rights to products and committed to supply for a period of time. For those arrangements for which we concluded that the obligations were not distinct, any amounts received upfront are being amortized to revenue as net product revenue over the period of the supply arrangement as the performance obligation is satisfied. Contract Liabilities Our contract liabilities result from arrangements where we have received payment in advance of performance under the contract and do not include sales rebates, discounts, and returns. Changes in contract liabilities are generally due to either receipt of additional advance payments or our performance under the contract. We have the following amounts recorded for contract liabilities: 2018 2017 Contract liabilities $ 299.3 $ 335.2 The contract liabilities amount disclosed above as of December 31, 2018 and 2017, are primarily related to: • The remaining license period of symbolic intellectual property, and • Obligations to supply product for a defined period of time. Revenue recognized from contract liabilities as of January 1, 2018 , during the year ended December 31, 2018 was not material. Revenue expected to be recognized in the future from contract liabilities as the related performance obligations are satisfied is not expected to be material in any one year.
Research and Development Expense	Research and development expenses and acquired in-process research and development Research and development expenses include the following: • Research and development costs, which are expensed as incurred. • Milestone payment obligations incurred prior to regulatory approval of the product, which are accrued when the event requiring payment of the milestone occurs. Acquired in-process research and development (IPR&D) expense includes the initial costs of IPR&D projects, acquired directly in a transaction other than a business combination, that do not have an alternative future use.
Income Tax	Deferred taxes are recognized for the future tax effects of temporary differences between financial and income tax reporting based on enacted tax laws and rates. We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate resolution.
Earnings Per Share	Earnings per share We calculate basic earnings per share (EPS) based on the weighted-average number of common shares outstanding and incremental shares from potential participating securities. We calculate diluted EPS based on the weighted-average number of common shares outstanding, including incremental shares from our stock-based compensation programs.
Share-based Compensation, Option and Incentive Plans	We recognize the fair value of stock-based compensation as expense over the requisite service period of the individual grantees, which generally equals the vesting period. We provide newly issued shares of our common stock and treasury stock to satisfy the issuance of PA, SVA, and RSU shares.
Foreign Currency Translation	Foreign Currency Translation Operations in our subsidiaries outside the U.S. are recorded in the functional currency of each subsidiary which is determined by a review of the environment where each subsidiary primarily generates and expends cash. The results of operations for our subsidiaries outside the U.S. are translated from functional currencies into U.S. dollars using the weighted average currency rate for the period. Assets and liabilities are translated using the period end exchange rates. The U.S. dollar effects that arise from translating the net assets of these subsidiaries are recorded in other comprehensive income (loss).
New Accounting Pronouncements, Policy	The following table provides a brief description of accounting standards that were effective January 1, 2018 and were adopted on that date: Standard Description Effect on the financial statements or other significant matters Accounting Standards Update 2014-09 and various other related updates, Revenue from Contracts with Customers This standard replaced existing revenue recognition standards and requires entities to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. An entity can apply the new revenue standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We applied the latter approach. Application of the new standard to applicable contracts resulted in an increase of approximately $5 million to retained earnings as of January 1, 2018. Disclosures required by the new standard are included in Note 1, Note 4, and Note 18. Accounting Standards Update 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities This standard requires entities to recognize changes in the fair value of equity investments with readily determinable fair values in net income (except for investments accounted for under the equity method of accounting or those that result in consolidation of the investee). An entity should apply the new standard through a cumulative effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Upon adoption, we reclassified from accumulated other comprehensive loss the after-tax amount of net unrealized gains resulting in an increase to retained earnings of approximately $105 million. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory This standard requires entities to recognize the income tax consequences of intra-entity transfers of assets other than inventory at the time of transfer. This standard requires a modified Upon adoption, the cumulative effect of applying the standard resulted in an increase of approximately $700 million to retained earnings, $2.5 billion to deferred tax assets, and $1.8 billion to deferred tax liabilities. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost This standard was issued to improve the transparency and comparability among organizations by requiring entities to separate their net periodic pension cost and net periodic postretirement benefit cost into a service cost component and other components. Previously, the costs of the other components along with the service cost component were classified based upon the function of the employee. This standard requires entities to classify the service cost component in the same financial statement line item or items as other compensation costs arising from services rendered by pertinent employees. The other components of net benefit cost are now presented separately from the line items that include the service cost component. When applicable, the service cost component is now the only component eligible for capitalization. An entity should apply the new standard retrospectively for the classification of the service cost and other components and prospectively for the capitalization of the service cost component. Upon adoption of this standard, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. The application of the new standard resulted in reclassification to other income of $248.1 million for the year ended December 31, 2017, while increasing cost of sales by $80.6 million, research and development expenses by $75.5 million, and marketing, selling, and administrative expenses by $92.0 million for the same period. The application of the new standard resulted in reclassification to other income of $197.6 million for the year ended December 31, 2016, while increasing cost of sales by $55.2 million, research and development expenses by $66.4 million, and marketing, selling, and administrative expenses by $76.0 million for the same period. We do not expect application of the new standard to have a material impact on an ongoing basis. We elected to early adopt Accounting Standards Update 2018-02, Income Statement-Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income as of December 31, 2017, which allowed a reclassification from accumulated other comprehensive loss to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (2017 Tax Act - see Note 13). This standard allowed us to reclassify the effect of remeasuring deferred tax liabilities and assets related to items within accumulated other comprehensive loss using the then newly enacted 21 percent federal corporate income tax rate. The provisional effect of this early adoption was a reclassification from accumulated other comprehensive loss, which resulted in an increase to retained earnings of $643.6 million as of December 31, 2017. The following table provides a brief description of the accounting standard that had not yet been adopted as of December 31, 2018: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-02, Leases This standard was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities, including leases classified as operating leases under current GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. An entity can apply the new leases standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We plan to use the latter approach. This standard was effective January 1, 2019, and we adopted on that date. We expect to record a right-of-use asset and lease liability for operating leases of approximately $650 million on our consolidated balance sheet as of January 1, 2019. Our accounting for capital leases will remain substantially unchanged. This standard will not have a material impact on our consolidated statement of operations.

Inventories (Policies)

Inventories (Policies)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventory	We use the last-in, first-out (LIFO) method for the majority of our inventories located in the continental U.S. Other inventories are valued by the first-in, first-out (FIFO) method. FIFO cost approximates current replacement cost.

Financial Instruments (Policies

Financial Instruments (Policies)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Concentration Risk, Credit Risk	Financial instruments that potentially subject us to credit risk consist principally of trade receivables and interest-bearing investments. Wholesale distributors of life-science products account for a substantial portion of our trade receivables; collateral is generally not required. We seek to mitigate the risk associated with this concentration through our ongoing credit-review procedures and insurance. A large portion of our cash is held by a few major financial institutions. We monitor our exposures with these institutions and do not expect any of these institutions to fail to meet their obligations. Major financial institutions represent the largest component of our investments in corporate debt securities. In accordance with documented corporate risk-management policies, we monitor the amount of credit exposure to any one financial institution or corporate issuer. We are exposed to credit-related losses in the event of nonperformance by counterparties to risk-management instruments but do not expect any counterparties to fail to meet their obligations given their high credit ratings.
Investment	We consider all highly liquid investments with a maturity of three months or less from the date of purchase to be cash equivalents. The cost of these investments approximates fair value. Our equity investments are accounted for using three different methods depending on the type of equity investment: • Investments in companies over which we have significant influence but not a controlling interest are accounted for using the equity method, with our share of earnings or losses reported in other-net, (income) expense. • For equity investments that do not have readily determinable fair values, we measure these investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. Any change in recorded value is recorded in other-net, (income) expense. • Our public equity investments are measured and carried at fair value. Any change in fair value is recognized in other-net, (income) expense. We review equity investments other than public equity investments for indications of impairment on a regular basis.
Derivatives	Our derivative activities are initiated within the guidelines of documented corporate risk-management policies and are intended to offset losses and gains on the assets, liabilities, and transactions being hedged. Management reviews the correlation and effectiveness of our derivatives on a quarterly basis. For derivative instruments that are designated and qualify as fair value hedges, the derivative instrument is marked to market with gains and losses recognized currently in income to offset the respective losses and gains recognized on the underlying exposure. For derivative instruments that are designated and qualify as cash flow hedges, gains and losses are reported as a component of accumulated other comprehensive loss and reclassified into earnings in the same period the hedged transaction affects earnings. For derivative and non-derivative instruments that are designated and qualify as net investment hedges, the foreign currency translation gains or losses due to spot rate fluctuations are reported as a component of accumulated other comprehensive loss. Derivative contracts that are not designated as hedging instruments are recorded at fair value with the gain or loss recognized in earnings during the period of change. We may enter into foreign currency forward or option contracts to reduce the effect of fluctuating currency exchange rates (principally the euro, British pound, and the Japanese yen). Foreign currency derivatives used for hedging are put in place using the same or like currencies and duration as the underlying exposures. Forward and option contracts are principally used to manage exposures arising from subsidiary trade and loan payables and receivables denominated in foreign currencies. These contracts are recorded at fair value with the gain or loss recognized in other–net, (income) expense. We may enter into foreign currency forward and option contracts and currency swaps as fair value hedges of firm commitments. We may enter into forward contracts and designate them as cash flow hedges to limit the potential volatility of earnings and cash flow associated with forecasted sales of available-for-sale securities. We also may enter into forward-starting interest rate swaps, which we designate as cash flow hedges, as part of any anticipated future debt issuances in order to reduce the risk of cash flow volatility from future changes in interest rates. Upon completion of a debt issuance and termination of the swap, the change in fair value of these instruments is recorded as part of other comprehensive income (loss) and is amortized to interest expense over the life of the underlying debt. In the normal course of business, our operations are exposed to fluctuations in interest rates which can vary the costs of financing, investing, and operating. We seek to address a portion of these risks through a controlled program of risk management that includes the use of derivative financial instruments. The objective of controlling these risks is to limit the impact of fluctuations in interest rates on earnings. Our primary interest-rate risk exposure results from changes in short-term U.S. dollar interest rates. In an effort to manage interest-rate exposures, we strive to achieve an acceptable balance between fixed- and floating-rate debt and investment positions and may enter into interest rate swaps or collars to help maintain that balance. Interest rate swaps or collars that convert our fixed-rate debt to a floating rate are designated as fair value hedges of the underlying instruments. Interest rate swaps or collars that convert floating-rate debt to a fixed rate are designated as cash flow hedges. Interest expense on the debt is adjusted to include the payments made or received under the swap agreements. Cash proceeds from or payments to counterparties resulting from the termination of interest rate swaps are classified as operating activities in our consolidated statements of cash flows.

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Policies)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Other indefinite-lived intangible assets are reviewed for impairment at least annually and when impairment indicators are present. Finite-lived intangible assets are reviewed for impairment when an indicator of impairment is present. When required, a comparison of fair value to the carrying amount of assets is performed to determine the amount of any impairment. When determining the fair value of indefinite-lived acquired IPR&D as well as the fair value of finite-lived intangible assets for impairment testing purposes, we utilize the "income method" discussed above. Goodwill results from excess consideration in a business combination over the fair value of identifiable net assets acquired. Goodwill is not amortized but is reviewed for impairment at least annually and when impairment indicators are present. When required, a comparison of the fair value of the reporting unit to its carrying amount including goodwill is used to determine the amount of any impairment. The costs of acquired IPR&D projects acquired directly in a transaction other than a business combination are capitalized if the projects have an alternative future use; otherwise, they are expensed immediately. The fair values of acquired IPR&D projects acquired in business combinations are capitalized as other intangible assets. Several methods may be used to determine the estimated fair value of other intangibles acquired in a business combination. We utilize the “income method,” which is a Level 3 fair value measurement and applies a probability weighting that considers the risk of development and commercialization to the estimated future net cash flows that are derived from projected revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, historical pricing of similar products, and expected industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. This analysis is performed for each asset independently. The acquired IPR&D assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are tested for impairment and amortized over the remaining useful life or written off, as appropriate. For transactions other than a business combination, we capitalize milestone payments incurred at or after the product has obtained regulatory approval for marketing.

Property and Equipment (Policie

Property and Equipment (Policies)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment is stated on the basis of cost. Provisions for depreciation of buildings and equipment are computed generally by the straight-line method at rates based on their estimated useful lives ( 12 to 50 years for buildings and three to 25 years for equipment). We review the carrying value of long-lived assets for potential impairment on a periodic basis and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Impairment is determined by comparing projected undiscounted cash flows to be generated by the asset to its carrying value. If an impairment is identified, a loss is recorded equal to the excess of the asset’s net book value over its fair value, and the cost basis is adjusted.

Stock-Based Compensation (Polic

Stock-Based Compensation (Policies)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation, Option and Incentive Plans	We recognize the fair value of stock-based compensation as expense over the requisite service period of the individual grantees, which generally equals the vesting period. We provide newly issued shares of our common stock and treasury stock to satisfy the issuance of PA, SVA, and RSU shares.

Income Taxes (Policies)

Income Taxes (Policies)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Tax	Deferred taxes are recognized for the future tax effects of temporary differences between financial and income tax reporting based on enacted tax laws and rates. We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate resolution.

Contingencies (Policies)

Contingencies (Policies)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Litigation accruals, environmental liabilities, and the related estimated insurance recoverables are reflected on a gross basis as liabilities and assets, respectively, on our consolidated balance sheets. With respect to the product liability claims currently asserted against us, we have accrued for our estimated exposures to the extent they are both probable and reasonably estimable based on the information available to us. We accrue for certain product liability claims incurred but not filed to the extent we can formulate a reasonable estimate of their costs. We estimate these expenses based primarily on historical claims experience and data regarding product usage. Legal defense costs expected to be incurred in connection with significant product liability loss contingencies are accrued when both probable and reasonably estimable.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Revenue Recognized	The following table summarizes our revenue recognized in our consolidated statements of operations: 2018 2017 2016 Net product revenue $ 22,928.8 $ 21,671.4 $ 20,388.4 Collaboration and other revenue (1) 1,626.9 1,199.9 833.7 Revenue $ 24,555.7 $ 22,871.3 $ 21,222.1 (1) Collaboration and other revenue associated with prior year transfers of intellectual property was $303.2 million , $145.8 million , and $146.1 million during the years ended 2018 , 2017 , and 2016 , respectively.
Schedule of Contract Liabilities	We have the following amounts recorded for contract liabilities: 2018 2017 Contract liabilities $ 299.3 $ 335.2

Implementation of New Financi_2

Implementation of New Financial Accounting Pronouncements (Tables)	12 Months Ended
	Dec. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table provides a brief description of accounting standards that were effective January 1, 2018 and were adopted on that date: Standard Description Effect on the financial statements or other significant matters Accounting Standards Update 2014-09 and various other related updates, Revenue from Contracts with Customers This standard replaced existing revenue recognition standards and requires entities to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. An entity can apply the new revenue standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We applied the latter approach. Application of the new standard to applicable contracts resulted in an increase of approximately $5 million to retained earnings as of January 1, 2018. Disclosures required by the new standard are included in Note 1, Note 4, and Note 18. Accounting Standards Update 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities This standard requires entities to recognize changes in the fair value of equity investments with readily determinable fair values in net income (except for investments accounted for under the equity method of accounting or those that result in consolidation of the investee). An entity should apply the new standard through a cumulative effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Upon adoption, we reclassified from accumulated other comprehensive loss the after-tax amount of net unrealized gains resulting in an increase to retained earnings of approximately $105 million. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory This standard requires entities to recognize the income tax consequences of intra-entity transfers of assets other than inventory at the time of transfer. This standard requires a modified Upon adoption, the cumulative effect of applying the standard resulted in an increase of approximately $700 million to retained earnings, $2.5 billion to deferred tax assets, and $1.8 billion to deferred tax liabilities. Adoption of this standard did not result in a material change in net income in 2018. Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost This standard was issued to improve the transparency and comparability among organizations by requiring entities to separate their net periodic pension cost and net periodic postretirement benefit cost into a service cost component and other components. Previously, the costs of the other components along with the service cost component were classified based upon the function of the employee. This standard requires entities to classify the service cost component in the same financial statement line item or items as other compensation costs arising from services rendered by pertinent employees. The other components of net benefit cost are now presented separately from the line items that include the service cost component. When applicable, the service cost component is now the only component eligible for capitalization. An entity should apply the new standard retrospectively for the classification of the service cost and other components and prospectively for the capitalization of the service cost component. Upon adoption of this standard, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. The application of the new standard resulted in reclassification to other income of $248.1 million for the year ended December 31, 2017, while increasing cost of sales by $80.6 million, research and development expenses by $75.5 million, and marketing, selling, and administrative expenses by $92.0 million for the same period. The application of the new standard resulted in reclassification to other income of $197.6 million for the year ended December 31, 2016, while increasing cost of sales by $55.2 million, research and development expenses by $66.4 million, and marketing, selling, and administrative expenses by $76.0 million for the same period. We do not expect application of the new standard to have a material impact on an ongoing basis. We elected to early adopt Accounting Standards Update 2018-02, Income Statement-Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income as of December 31, 2017, which allowed a reclassification from accumulated other comprehensive loss to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (2017 Tax Act - see Note 13). This standard allowed us to reclassify the effect of remeasuring deferred tax liabilities and assets related to items within accumulated other comprehensive loss using the then newly enacted 21 percent federal corporate income tax rate. The provisional effect of this early adoption was a reclassification from accumulated other comprehensive loss, which resulted in an increase to retained earnings of $643.6 million as of December 31, 2017. The following table provides a brief description of the accounting standard that had not yet been adopted as of December 31, 2018: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-02, Leases This standard was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities, including leases classified as operating leases under current GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. An entity can apply the new leases standard retrospectively to each prior reporting period presented or with the cumulative effect of initially applying the standard recognized at the date of initial application in retained earnings. We plan to use the latter approach. This standard was effective January 1, 2019, and we adopted on that date. We expect to record a right-of-use asset and lease liability for operating leases of approximately $650 million on our consolidated balance sheet as of January 1, 2019. Our accounting for capital leases will remain substantially unchanged. This standard will not have a material impact on our consolidated statement of operations.

Divestiture and Acquisitions (T

Divestiture and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at January 3, 2017 Inventories $ 108.6 Marketed products (1) 297.0 Property and equipment 148.2 Other assets and liabilities - net 8.2 Total identifiable net assets 562.0 Goodwill (2) 320.1 Total consideration transferred - net of cash acquired $ 882.1 (1) These intangible assets, which are being amortized to cost of sales on a straight-line basis over their estimated useful lives, were expected to have a weighted average useful life of 10 years . (2) The goodwill recognized from this acquisition is attributable primarily to expected synergies from combining the operations of BIVIVP with our legacy animal health business, future unidentified projects and products, and the assembled workforce of BIVIVP. The goodwill associated with this acquisition is deductible for tax purposes.
Schedule of Research and Development Assets Acquired Other than Through Business Combination	The following table and narrative summarize our asset acquisitions during 2018 , 2017 , and 2016 . Counterparty Compound(s),Therapy, or Asset Acquisition Month Phase of Development (1) Acquired IPR&D Expense Sigilon Therapeutics Encapsulated cell therapies for the potential treatment of type 1 diabetes April 2018 Pre-clinical $ 66.9 AurKa Pharma, Inc. AK-01, an Aurora kinase A inhibitor June 2018 Phase I 81.8 ARMO Cancer therapy - pegilodecakin June 2018 Phase III 1,475.8 Anima Biotech Translation inhibitors for selected neuroscience targets July 2018 Pre-clinical 30.0 SIGA Technologies, Inc. Priority Review Voucher October 2018 Not applicable 80.0 Chugai Pharmaceutical Company OWL833, an oral non-peptidic GLP-1 receptor agonist October 2018 Pre-clinical 50.0 NextCure, Inc. Immuno-oncology cancer therapies November 2018 Pre-clinical 28.1 Dicerna Pharmaceuticals Cardio-metabolic disease, neurodegeneration, and pain December 2018 Pre-clinical 148.7 Hydra Biosciences TRPA1 antagonists program for the potential treatment of chronic pain syndromes December 2018 Pre-clinical 22.6 CoLucid Pharmaceuticals, Inc. (CoLucid) Oral therapy for the acute treatment of migraine - lasmiditan March 2017 Phase III 857.6 KeyBioscience AG Multiple molecules for treatment of metabolic disorders July 2017 Phase II 55.0 Nektar Therapeutics Immunological therapy - NKTR-358 August 2017 Phase I 150.0 CureVac AG Cancer vaccines November 2017 Pre-clinical 50.0 AstraZeneca Antibody selective for amyloid-beta 42 (Aβ42) - MEDI1814 December 2016 Phase I 30.0 (1) The phase of development presented is as of the date of the arrangement and represents the phase of development of the most advanced asset acquired, where applicable.

Collaborations and Other Arra_2

Collaborations and Other Arrangements (Tables)	12 Months Ended
	Dec. 31, 2018
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions	The following table summarizes our milestones achieved: Year Event Classification Amount 2018 Regulatory approval in the U.S. Intangible asset $ 100.0 Began Phase III testing for SLE R&D Expense 20.0 2017 Regulatory approval in Europe Intangible asset 65.0 Regulatory approval in Japan Intangible asset 15.0 Began Phase III testing for atopic dermatitis R&D expense 30.0 2016 Regulatory submissions in the U.S. and Europe R&D expense 55.0
Diabetes Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions	The following table summarizes our collaboration and other revenue recognized with respect to the Trajenta and Jardiance families of products and net product revenue recognized with respect to Basaglar: 2018 2017 2016 Basaglar $ 801.2 $ 432.1 $ 86.1 Jardiance 658.3 447.5 201.9 Trajenta 574.7 537.9 436.6 The table below summarizes significant milestones (deferred) capitalized for the compounds included in this collaboration: Product Family Milestones (Deferred) Capitalized (1) Year Amount Trajenta (2) Cumulative (4) $ 446.4 Jardiance (3) Cumulative (4) 289.0 Basaglar 2018 — 2017 — 2016 (187.5 ) Cumulative (4) (250.0 ) (1) In connection with the regulatory approvals of Basaglar in the U.S., Europe, and Japan, milestone payments received were recorded as contract liabilities and are being amortized through the term of the collaboration (2029) to collaboration and other revenue. In connection with the regulatory approvals of Trajenta and Jardiance, milestone payments made were capitalized as intangible assets and are being amortized to cost of sales through the term of the collaboration. (2) Jentadueto is included in the Trajenta product family. The collaboration agreement with Boehringer Ingelheim for Trajenta ends upon expiration of the compound patent and any supplementary protection certificates or extensions thereto. (3) Glyxambi and Synjardy are included in the Jardiance product family. The collaboration agreement with Boehringer Ingelheim for Jardiance ends upon expiration of the compound patent and any supplementary protection certificates or extensions thereto. (4) The cumulative amount represents the total amounts that have been (deferred) or capitalized from the start of this collaboration through the end of the reporting period.
Erbitux
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions	The following table summarizes our revenue recognized with respect to Erbitux: 2018 2017 2016 Net product revenue $ 536.1 $ 548.2 $ 587.0 Collaboration and other revenue 99.2 97.7 100.0 Revenue $ 635.3 $ 645.9 $ 687.0
Effient
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions	The following table summarizes our revenue recognized with respect to Effient: 2018 2017 2016 Revenue $ 122.2 $ 388.9 $ 535.2 We are in a collaborative arrangement with Daiichi Sankyo Co., Ltd. (Daiichi Sankyo) to develop, market, and promote Effient. Marketing rights for major territories are shown below. We and Daiichi Sankyo each have exclusive marketing rights in certain other territories. Territory Marketing Rights Selling Party U.S. Co-promotion Lilly Major European markets Co-promotion Daiichi Sankyo Japan Exclusive Daiichi Sankyo

Asset Impairment, Restructuri_2

Asset Impairment, Restructuring, and Other Special Charges (Tables)	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Schedule of Other Operating Cost and Expense, by Component	The components of the charges included in asset impairment, restructuring, and other special charges in our consolidated statements of operations are described below: 2018 2017 2016 Severance: Human pharmaceutical products $ 127.8 $ 601.0 $ 85.9 Animal health products 14.8 96.4 40.8 Total severance 142.6 697.4 126.7 Pension and post-retirement medical charges associated with U.S. voluntary early retirement program (see Note 14): Human pharmaceutical products — 446.7 — Animal health products — 67.0 — Total pension and post-retirement medical charges associated with U.S. voluntary early retirement program — 513.7 — Asset impairment (gains from facility sales) and other special charges: Human pharmaceutical products 46.0 81.7 (13.0 ) Animal health products 293.4 380.8 268.8 Total asset impairment and other special charges 339.4 462.5 255.8 Total asset impairment, restructuring, and other special charges $ 482.0 $ 1,673.6 $ 382.5

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories at December 31 consisted of the following: 2018 2017 Finished products $ 988.1 $ 1,211.4 Work in process 2,628.2 2,697.7 Raw materials and supplies 506.5 488.8 Total (approximates replacement cost) 4,122.8 4,397.9 Increase (reduction) to LIFO cost (11.0 ) 60.4 Inventories $ 4,111.8 $ 4,458.3

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)	The effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is as follows: 2018 2017 2016 Net investment hedges: Foreign currency-denominated notes $ 110.4 $ (361.5 ) $ 137.5 Cross-currency interest rate swaps 96.8 (126.6 ) 32.5 Foreign currency exchange contracts 5.7 — 31.9 Cash flow hedges: Forward-starting interest rate swaps — 13.0 (3.4 )
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis	The table below summarizes the contractual maturities of our investments in debt securities measured at fair value as of December 31, 2018 : Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 943.0 $ 86.8 $ 604.8 $ 97.0 $ 154.4
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location	The following effects of risk-management instruments were recognized in other–net, (income) expense: 2018 2017 2016 Fair value hedges: Effect from hedged fixed-rate debt $ (40.9 ) $ (14.1 ) $ (30.8 ) Effect from interest rate contracts 40.9 14.1 30.8 Cash flow hedges: Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss 14.8 14.8 15.0 Net losses on foreign currency exchange contracts not designated as hedging instruments 100.0 97.9 78.8 Total $ 114.8 $ 112.7 $ 93.8
Fair Value, Assets Measured on Recurring Basis	The following tables summarize certain fair value information at December 31 for assets and liabilities measured at fair value on a recurring basis, as well as the carrying amount and amortized cost of certain other investments: Fair Value Measurements Using Description Carrying Amount Cost (1) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Cash equivalents $ 5,752.2 $ 5,752.2 $ 5,752.2 $ — $ — $ 5,752.2 Short-term investments: U.S. government and agency securities $ 16.9 $ 17.1 $ 16.9 $ — $ — $ 16.9 Corporate debt securities 62.2 62.6 — 62.2 — 62.2 Asset-backed securities 7.6 7.7 — 7.6 — 7.6 Other securities 1.5 1.5 — 1.5 — 1.5 Short-term investments $ 88.2 Noncurrent investments: U.S. government and agency securities $ 149.1 $ 153.6 $ 149.1 $ — $ — $ 149.1 Corporate debt securities 568.0 587.8 — 568.0 — 568.0 Mortgage-backed securities 111.4 114.5 — 111.4 — 111.4 Asset-backed securities 27.7 27.9 — 27.7 — 27.7 Other securities 87.8 29.7 — — 87.8 87.8 Marketable equity securities 357.5 238.3 357.5 — — 357.5 Equity investments without readily determinable fair values (2) 414.7 Equity method investments (2) 304.5 Noncurrent investments $ 2,020.7 December 31, 2017 Cash equivalents $ 4,763.9 $ 4,763.9 $ 4,712.4 $ 51.5 $ — $ 4,763.9 Short-term investments: U.S. government and agency securities $ 217.8 $ 218.2 $ 217.8 $ — $ — $ 217.8 Corporate debt securities 1,182.3 1,183.2 — 1,182.3 — 1,182.3 Asset-backed securities 94.2 94.3 — 94.2 — 94.2 Other securities 3.6 3.6 — 3.6 — 3.6 Short-term investments $ 1,497.9 Noncurrent investments: U.S. government and agency securities $ 360.0 $ 365.0 $ 360.0 $ — $ — $ 360.0 Corporate debt securities 3,464.3 3,473.5 — 3,464.3 — 3,464.3 Mortgage-backed securities 202.4 204.2 — 202.4 — 202.4 Asset-backed securities 653.9 656.0 — 653.9 — 653.9 Other securities 132.1 66.4 — — 132.1 132.1 Marketable equity securities 281.3 131.0 281.3 — — 281.3 Cost and equity method investments (2) 584.8 Noncurrent investments $ 5,678.8 (1) For available-for-sale debt securities, amounts disclosed represent the securities' amortized cost. (2) Fair value disclosures are not applicable for equity method investments, investments accounted for under the measurement alternative for equity investments, and cost method investments that do not have readily determinable fair values.
Fair Value, Liabilities Measured on Recurring Basis	Fair Value Measurements Using Description Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value Short-term commercial paper borrowings December 31, 2018 $ (498.9 ) $ — $ (497.6 ) $ — $ (497.6 ) December 31, 2017 (2,696.8 ) — (2,690.6 ) — (2,690.6 ) Long-term debt, including current portion December 31, 2018 $ (12,272.0 ) $ — $ (12,461.7 ) $ — $ (12,461.7 ) December 31, 2017 (10,950.3 ) — (11,529.9 ) — (11,529.9 )
Fair Value, by Balance Sheet Grouping	Fair Value Measurements Using Description Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Risk-management instruments Interest rate contracts designated as fair value hedges: Sundry $ 4.5 $ — $ 4.5 $ — $ 4.5 Other current liabilities (22.3 ) — (22.3 ) — (22.3 ) Other noncurrent liabilities (19.0 ) — (19.0 ) — (19.0 ) Cross-currency interest rate contracts designated as net investment hedges: Other receivables 69.2 — 69.2 — 69.2 Sundry 8.2 — 8.2 — 8.2 Other current liabilities (9.2 ) — (9.2 ) — (9.2 ) Other noncurrent liabilities (25.8 ) — (25.8 ) — (25.8 ) Foreign exchange contracts not designated as hedging instruments: Other receivables 11.3 — 11.3 — 11.3 Other current liabilities (16.3 ) — (16.3 ) — (16.3 ) Contingent consideration liabilities: Other current liabilities (5.1 ) — — (5.1 ) (5.1 ) Other noncurrent liabilities (69.0 ) — — (69.0 ) (69.0 ) December 31, 2017 Risk-management instruments Interest rate contracts designated as fair value hedges: Other receivables $ 0.8 $ — $ 0.8 $ — $ 0.8 Sundry 35.1 — 35.1 — 35.1 Other current liabilities (0.2 ) — (0.2 ) — (0.2 ) Other noncurrent liabilities (10.5 ) — (10.5 ) — (10.5 ) Cross-currency interest rate contracts designated as net investment hedges: Other current liabilities (33.4 ) — (33.4 ) — (33.4 ) Other noncurrent liabilities (26.0 ) — (26.0 ) — (26.0 ) Foreign exchange contracts not designated as hedging instruments: Other receivables 26.8 — 26.8 — 26.8 Other current liabilities (36.0 ) — (36.0 ) — (36.0 ) Contingent consideration liabilities: Other current liabilities (208.0 ) — — (208.0 ) (208.0 ) Other noncurrent liabilities (45.2 ) — — (45.2 ) (45.2 )
Available-for-sale Securities	A summary of the fair value of available-for-sale securities in an unrealized gain or loss position and the amount of unrealized gains and losses (pretax) in accumulated other comprehensive loss follows: 2018 2017 Unrealized gross gains $ 0.8 $ 184.7 Unrealized gross losses 29.0 47.5 Fair value of securities in an unrealized gain position 84.3 1,434.2 Fair value of securities in an unrealized loss position 858.6 4,692.8
Gain (Loss) on Investments	Activity related to our investment portfolio, substantially all of which related to equity and available-for-sale securities, was as follows: 2018 2017 2016 Proceeds from sales $ 5,668.0 $ 5,769.3 $ 3,240.5 Realized gross gains on sales 11.8 176.0 30.7 Realized gross losses on sales 51.3 5.8 14.6

Goodwill and Other Intangible_2

Goodwill and Other Intangibles (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Indefinite-Lived Intangible Assets	Goodwill by segment at December 31 was as follows: 2018 2017 Human pharmaceutical products $ 1,366.6 $ 1,366.8 Animal health 2,980.9 3,003.3 Total goodwill $ 4,347.5 $ 4,370.1
Schedule of Intangible Assets and Goodwill	The components of intangible assets other than goodwill at December 31 were as follows: 2018 2017 Description Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Finite-lived intangible assets: Marketed products $ 5,270.7 $ (1,848.2 ) $ 3,422.5 $ 7,682.0 $ (3,851.1 ) $ 3,830.9 Other 142.6 (63.7 ) 78.9 171.2 (70.1 ) 101.1 Total finite-lived intangible assets 5,413.3 (1,911.9 ) 3,501.4 7,853.2 (3,921.2 ) 3,932.0 Indefinite-lived intangible assets: Acquired in-process research and development 19.6 — 19.6 97.2 — 97.2 Other intangibles $ 5,432.9 $ (1,911.9 ) $ 3,521.0 $ 7,950.4 $ (3,921.2 ) $ 4,029.2
Finite-lived Intangible Assets Amortization Expense	Amortization expense related to finite-lived intangible assets was as follows: 2018 2017 2016 Amortization expense $ 558.7 $ 683.4 $ 687.9
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated amortization expense for each of the next five years associated with our finite-lived intangible assets as of December 31, 2018 is as follows: 2019 2020 2021 2022 2023 Estimated amortization expense $ 343.3 $ 342.3 $ 339.6 $ 329.8 $ 318.4

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	At December 31, property and equipment consisted of the following: 2018 2017 Land $ 193.1 $ 192.7 Buildings 7,683.8 7,425.6 Equipment 8,817.4 8,689.0 Construction in progress 1,769.7 1,783.8 18,464.0 18,091.1 Less accumulated depreciation (9,544.5 ) (9,264.6 ) Property and equipment, net $ 8,919.5 $ 8,826.5
Schedule of Rent Expense	Depreciation expense related to property and equipment and rental expense for all leases, including contingent rentals (not material), was as follows: 2018 2017 2016 Depreciation expense $ 879.6 $ 763.1 $ 716.2 Rental expense 223.2 224.5 221.0
Schedule of Future Minimum Rental Payments for Operating Leases	The future minimum rental commitments under non-cancelable operating leases are as follows: 2019 2020 2021 2022 2023 After 2023 Lease commitments $ 155.8 $ 128.0 $ 89.0 $ 74.7 $ 58.2 $ 299.5

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Long-term Debt, Current and Noncurrent [Abstract]
Schedule of Additional Borrowings Disclosures	The aggregate amount of cash payments for interest on borrowings, net of capitalized interest, are as follows: 2018 2017 2016 Cash payments for interest on borrowings $ 223.8 $ 192.7 $ 146.4
Schedule of Maturities of Long-term Debt	The aggregate amounts of maturities on long-term debt for the next five years are as follows: 2019 2020 2021 2022 2023 Maturities on long-term debt $ 634.5 $ 33.5 $ 942.3 $ 1,439.0 $ 750.3
Schedule of Debt	Debt at December 31 consisted of the following: 2018 2017 Short-term commercial paper borrowings $ 498.9 $ 2,696.8 0.15 to 7.13 percent long-term notes (due 2019-2047) 11,640.8 10,756.7 Other long-term debt 503.1 13.6 Unamortized debt issuance costs (49.1 ) (49.0 ) Fair value adjustment on hedged long-term notes 177.2 229.0 Total debt 12,770.9 13,647.1 Less current portion (1,131.2 ) (3,706.6 ) Long-term debt $ 11,639.7 $ 9,940.5

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Additional Stock-Based Compensation Disclosures	Stock-based compensation expense and the related tax benefits were as follows: 2018 2017 2016 Stock-based compensation expense $ 279.5 $ 281.3 $ 255.3 Tax benefit 58.7 70.5 89.4
Share-based Compensation Awards, Fair Value Assumptions Used	The weighted-average fair values of the SVA units granted during the years ended December 31, 2018 , 2017 , and 2016 were $48.51 , $66.25 , and $48.68 , respectively, determined using the following assumptions: (Percents) 2018 2017 2016 Expected dividend yield 2.50 % 2.50 % 2.00 % Risk-free interest rate 2.31 1.38 0.92 Volatility 22.26 22.91 21.68

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Following is the composition of income tax expense: 2018 2017 2016 Current: Federal $ (54.3 ) $ (100.6 ) $ (57.0 ) Foreign 80.0 38.5 378.9 State 9.7 4.0 (125.0 ) 2017 Tax Act 201.5 3,247.5 — Total current tax expense 236.9 3,189.4 196.9 Deferred: Federal 64.0 801.5 517.0 Foreign 285.6 (256.3 ) (83.3 ) State 3.4 0.4 5.8 2017 Tax Act (26.2 ) (1,333.5 ) — Total deferred tax (benefit) expense 326.8 (787.9 ) 439.5 Income taxes $ 563.7 $ 2,401.5 $ 636.4
Schedule of Deferred Tax Assets and Liabilities	Significant components of our deferred tax assets and liabilities as of December 31 are as follows: 2018 2017 Deferred tax assets: Purchases of intangible assets $ 2,655.9 $ 443.1 Compensation and benefits 814.2 1,021.7 Tax credit carryforwards and carrybacks 365.2 473.0 Tax loss carryforwards and carrybacks 271.7 501.4 Product return reserves 100.5 88.4 Other comprehensive loss on hedging transactions 68.9 68.9 Debt 40.3 53.5 Contingent consideration 17.7 41.8 Other 714.7 555.8 Total gross deferred tax assets 5,049.1 3,247.6 Valuation allowances (596.3 ) (709.1 ) Total deferred tax assets 4,452.8 2,538.5 Deferred tax liabilities: Earnings of foreign subsidiaries (1,692.3 ) (16.6 ) Inventories (658.4 ) (654.8 ) Property and equipment (311.7 ) (282.1 ) Prepaid employee benefits (240.1 ) (231.5 ) Intangibles (250.5 ) (314.6 ) Financial instruments (22.7 ) (41.5 ) Total deferred tax liabilities (3,175.7 ) (1,541.1 ) Deferred tax assets - net $ 1,277.1 $ 997.4
Schedule of Additional Income Tax Disclosures	Cash payments of income taxes were as follows: 2018 2017 2016 Cash payments of income taxes $ 1,101.5 $ 246.5 $ 700.6
Schedule of Effective Income Tax Rate Reconciliation	Following is a reconciliation of the income tax expense applying the U.S. federal statutory rate to income before income taxes to reported income tax expense: 2018 2017 2016 Income tax at the U.S. federal statutory tax rate $ 797.1 $ 769.1 $ 1,180.9 Add (deduct): International operations, including Puerto Rico (629.7 ) (428.9 ) (313.7 ) General business credits (87.4 ) (66.8 ) (58.3 ) Non-deductible acquired IPR&D (1) 309.9 300.1 — 2017 Tax Act 175.3 1,914.0 — Other (1.5 ) (86.0 ) (172.5 ) Income taxes $ 563.7 $ 2,401.5 $ 636.4 (1) Non-deductible acquired IPR&D was related to ARMO in 2018 and CoLucid in 2017. See Note 3 for additional information related to acquisitions.
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2018 2017 2016 Beginning balance at January 1 $ 1,014.5 $ 853.4 $ 1,066.6 Additions based on tax positions related to the current year 798.2 133.8 73.4 Additions for tax positions of prior years 414.9 97.5 14.8 Reductions for tax positions of prior years (117.1 ) (59.3 ) (15.2 ) Settlements (33.2 ) (2.4 ) (171.9 ) Lapses of statutes of limitation (23.5 ) (19.3 ) (110.0 ) Changes related to the impact of foreign currency translation (6.8 ) 10.8 (4.3 ) Ending balance at December 31 $ 2,047.0 $ 1,014.5 $ 853.4 We recognize both accrued interest and penalties related to unrecognized tax benefits in income tax expense. We recognized income tax (benefit) expense related to interest and penalties as follows: 2018 2017 2016 Income tax (benefit) expense $ 24.4 $ 27.4 $ (52.5 )

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Schedule of Changes in Accumulated Postemployment Benefit Obligations	We use a measurement date of December 31 to develop the change in benefit obligation, change in plan assets, funded status, and amounts recognized in the consolidated balance sheets at December 31 for our defined benefit pension and retiree health benefit plans, which were as follows: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at beginning of year $ 15,098.4 $ 12,455.9 $ 1,728.5 $ 1,494.6 Service cost 304.0 331.3 41.5 46.4 Interest cost 461.0 413.4 57.3 52.9 Actuarial (gain) loss (1,431.2 ) 1,580.5 (182.8 ) 40.0 Benefits paid (582.1 ) (486.3 ) (82.8 ) (60.1 ) Plan amendments 17.6 — (14.1 ) — Curtailment (gain) loss (43.9 ) 90.4 2.5 105.2 Special termination benefit — 317.2 — 37.5 Foreign currency exchange rate changes and other adjustments (161.9 ) 396.0 (6.2 ) 12.0 Benefit obligation at end of year 13,661.9 15,098.4 1,543.9 1,728.5
Schedule of Changes in Fair Value of Plan Assets	Change in plan assets: Fair value of plan assets at beginning of year 11,844.5 10,179.7 2,372.4 1,961.2 Actual return on plan assets (370.3 ) 1,447.6 32.6 462.0 Employer contribution 324.7 414.3 75.9 9.1 Benefits paid (582.1 ) (486.3 ) (82.8 ) (60.1 ) Foreign currency exchange rate changes and other adjustments (152.6 ) 289.2 — 0.2 Fair value of plan assets at end of year 11,064.2 11,844.5 2,398.1 2,372.4
Schedule of Net Funded Status	Funded status (2,597.7 ) (3,253.9 ) 854.2 643.9 Unrecognized net actuarial loss 5,011.8 5,645.5 140.6 182.0 Unrecognized prior service (benefit) cost 25.8 15.2 (299.9 ) (395.0 ) Net amount recognized $ 2,439.9 $ 2,406.8 $ 694.9 $ 430.9
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the consolidated balance sheet consisted of: Sundry $ 196.0 $ 106.8 $ 1,043.6 $ 869.0 Other current liabilities (64.5 ) (64.8 ) (7.3 ) (7.1 ) Accrued retirement benefits (2,729.2 ) (3,295.9 ) (182.1 ) (218.0 ) Accumulated other comprehensive (income) loss before income taxes 5,037.6 5,660.7 (159.3 ) (213.0 ) Net amount recognized $ 2,439.9 $ 2,406.8 $ 694.9 $ 430.9
Schedule of Assumptions Used	The following represents our weighted-average assumptions as of December 31: Defined Benefit Pension Plans Retiree Health Benefit Plans (Percents) 2018 2017 2016 2018 2017 2016 Discount rate for benefit obligation 3.9 % 3.4 % 3.9 % 4.4 % 3.7 % 4.3 % Discount rate for net benefit costs 3.4 3.9 4.3 3.7 4.3 4.5 Rate of compensation increase for benefit obligation 3.4 3.4 3.4 Rate of compensation increase for net benefit costs 3.4 3.4 3.4 Expected return on plan assets for net benefit costs 7.3 7.4 7.4 8.0 8.0 8.0
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: 2019 2020 2021 2022 2023 2024-2028 Defined benefit pension plans $ 609.9 $ 613.6 $ 623.6 $ 638.2 $ 647.9 $ 3,560.6 Retiree health benefit plans 98.0 99.1 100.7 99.9 98.5 505.3
Schedule of Net Benefit Costs	Net pension and retiree health benefit expense included the following components: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2016 2018 2017 2016 Components of net periodic (benefit) cost: Service cost $ 304.0 $ 331.3 $ 277.7 $ 41.5 $ 46.4 $ 39.1 Interest cost 461.0 413.4 420.8 57.3 52.9 53.2 Expected return on plan assets (848.3 ) (776.0 ) (752.1 ) (177.9 ) (160.7 ) (150.2 ) Amortization of prior service (benefit) cost 4.8 5.7 11.8 (79.5 ) (90.0 ) (85.8 ) Recognized actuarial loss 334.4 288.2 285.6 6.1 18.4 19.1 Curtailment (gain) loss 1.3 93.5 — (29.3 ) 65.5 — Special termination benefit — 317.2 — — 37.5 — Net periodic (benefit) cost $ 257.2 $ 673.3 $ 243.8 $ (181.8 ) $ (30.0 ) $ (124.6 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The following represents the amounts recognized in other comprehensive income (loss) for the years ended December 31, 2018 , 2017 , and 2016 : Defined Benefit Retiree Health 2018 2017 2016 2018 2017 2016 Actuarial gain (loss) arising during period $ 211.1 $ (915.1 ) $ (725.2 ) $ 37.5 $ 261.3 $ (132.2 ) Plan amendments during period (17.6 ) — — 14.1 — 35.8 Curtailment gain (loss) 45.2 3.2 — (31.8 ) (39.7 ) — Amortization of prior service (benefit) cost included in net income 4.8 5.7 11.8 (79.5 ) (90.0 ) (85.8 ) Amortization of net actuarial loss included in net income 334.4 288.2 285.6 6.1 18.4 19.1 Foreign currency exchange rate changes and other 45.2 (105.3 ) 75.6 (0.1 ) (3.3 ) 2.5 Total other comprehensive income (loss) during period $ 623.1 $ (723.3 ) $ (352.2 ) $ (53.7 ) $ 146.7 $ (160.6 )
Schedule of Allocation of Plan Assets	The fair values of our defined benefit pension plan and retiree health plan assets as of December 31, 2017 by asset category were as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Investments Valued at Net Asset Value (1) Defined Benefit Pension Plans Public equity securities: U.S. $ 466.2 $ 199.6 $ — $ — $ 266.6 International 2,934.2 955.1 — — 1,979.1 Fixed income: Developed markets 3,182.9 28.7 2,468.2 — 686.0 Developed markets - repurchase agreements (1,372.9 ) — (1,372.9 ) — — Emerging markets 584.7 4.2 252.0 3.1 325.4 Private alternative investments: Hedge funds 2,984.6 — — — 2,984.6 Equity-like funds 1,639.6 — — 16.8 1,622.8 Real estate 563.9 338.6 — — 225.3 Other 861.3 119.2 602.8 2.2 137.1 Total $ 11,844.5 $ 1,645.4 $ 1,950.1 $ 22.1 $ 8,226.9 Retiree Health Benefit Plans Public equity securities: U.S. $ 43.0 $ 19.4 $ — $ — $ 23.6 International 182.5 61.3 — — 121.2 Fixed income: Developed markets 71.2 — 63.5 — 7.7 Emerging markets 53.1 — 24.4 0.3 28.4 Private alternative investments: Hedge funds 256.0 — — — 256.0 Equity-like funds 137.0 — — 1.6 135.4 Cash value of trust owned insurance contract 1,524.6 — 1,524.6 — — Real estate 33.0 33.0 — — — Other 72.0 15.0 50.5 0.2 6.3 Total $ 2,372.4 $ 128.7 $ 1,663.0 $ 2.1 $ 578.6 (1) Certain investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy. The fair values of our defined benefit pension plan and retiree health plan assets as of December 31, 2018 by asset category were as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Significant Inputs Significant Investments Valued at Net Asset Value (1) Defined Benefit Pension Plans Public equity securities: U.S. $ 619.9 $ 410.1 $ — $ — $ 209.8 International 2,117.8 828.8 — 1.8 1,287.2 Fixed income: Developed markets 2,963.2 25.0 2,173.3 — 764.9 Developed markets - repurchase agreements (1,225.5 ) — (1,225.5 ) — — Emerging markets 571.6 4.1 256.2 6.1 305.2 Private alternative investments: Hedge funds 2,801.9 — — — 2,801.9 Equity-like funds 1,942.5 — — 16.8 1,925.7 Real estate 525.8 147.2 — — 378.6 Other 747.0 213.3 86.1 — 447.6 Total $ 11,064.2 $ 1,628.5 $ 1,290.1 $ 24.7 $ 8,120.9 Retiree Health Benefit Plans Public equity securities: U.S. $ 59.9 $ 41.0 $ — $ — $ 18.9 International 127.0 50.5 — 0.2 76.3 Fixed income: Developed markets 69.1 — 61.5 — 7.6 Emerging markets 53.5 — 25.5 0.6 27.4 Private alternative investments: Hedge funds 245.8 — — — 245.8 Equity-like funds 169.2 — — 1.7 167.5 Cash value of trust owned insurance contract 1,574.7 — 1,574.7 — — Real estate 27.7 14.7 — — 13.0 Other 71.2 38.1 (3.8 ) — 36.9 Total $ 2,398.1 $ 144.3 $ 1,657.9 $ 2.5 $ 593.4 (1) Certain investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy.
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	Amounts relating to defined benefit pension plans with projected benefit obligations in excess of plan assets were as follows at December 31: 2018 2017 Projected benefit obligation $ 11,813.4 $ 13,025.0 Fair value of plan assets 9,019.7 9,664.3
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Amounts relating to defined benefit pension plans and retiree health benefit plans with accumulated benefit obligations in excess of plan assets were as follows at December 31: Defined Benefit Pension Plans Retiree Health Benefit Plans 2018 2017 2018 2017 Accumulated benefit obligation $ 11,032.1 $ 11,956.7 $ 189.4 $ 225.1 Fair value of plan assets 9,019.7 9,639.4 — —

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	Details about Accumulated Other Comprehensive Loss Components Year Ended December 31, Affected Line Item in the Consolidated Statements of Operations 2018 2017 2016 Amortization of retirement benefit items: Prior service benefits, net $ (74.7 ) $ (84.3 ) $ (74.0 ) Other—net, (income) expense Actuarial losses 340.5 306.6 304.7 Other—net, (income) expense Total before tax 265.8 222.3 230.7 Tax benefit (55.8 ) (68.9 ) (71.5 ) Income taxes Net of tax 210.0 153.4 159.2 Unrealized gains/losses on available-for-sale securities: Realized gains, net (39.5 ) (170.2 ) (16.1 ) Other—net, (income) expense Impairment losses — — 27.3 Other—net, (income) expense Total before tax (39.5 ) (170.2 ) 11.2 Tax (benefit) expense 8.3 59.6 (4.0 ) Income taxes Net of tax (31.2 ) (110.6 ) 7.2 Other, net of tax (1) 11.7 17.7 84.3 Other—net, (income) expense Total reclassifications for the period, net of tax $ 190.5 $ 60.5 $ 250.7 (1) Amount for year ended December 31, 2016 included primarily $74.5 million of foreign currency translation losses.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the activity related to each component of other comprehensive income (loss): (Amounts presented net of taxes) Foreign Currency Translation Gains (Losses) Unrealized Net Gains (Losses) on Securities Defined Benefit Pension and Retiree Health Benefit Plans Effective Portion of Cash Flow Hedges Accumulated Other Comprehensive Loss Beginning balance at January 1, 2016 $ (1,360.2 ) $ 10.1 $ (3,012.1 ) $ (218.5 ) $ (4,580.7 ) Other comprehensive income (loss) before reclassifications (581.6 ) 206.7 (518.7 ) (2.2 ) (895.8 ) Net amount reclassified from accumulated other comprehensive loss 74.5 7.2 159.2 9.8 250.7 Net other comprehensive income (loss) (507.1 ) 213.9 (359.5 ) 7.6 (645.1 ) Balance at December 31, 2016 (1) (1,867.3 ) 224.0 (3,371.6 ) (210.9 ) (5,225.8 ) Other comprehensive income (loss) before reclassifications 664.6 (15.7 ) (543.4 ) 8.5 114.0 Net amount reclassified from accumulated other comprehensive loss 8.1 (110.6 ) 153.4 9.6 60.5 Net other comprehensive income (loss) 672.7 (126.3 ) (390.0 ) 18.1 174.5 Reclassifications of stranded tax effects (Note 2) (38.8 ) 15.8 (579.1 ) (41.5 ) (643.6 ) Balance at December 31, 2017 (2) (1,233.4 ) 113.5 (4,340.7 ) (234.3 ) (5,694.9 ) Reclassification due to adoption of new accounting standard (3) — (128.9 ) — — (128.9 ) Other comprehensive income (loss) before reclassifications (389.1 ) 24.5 274.0 (16.3 ) (106.9 ) Net amount reclassified from accumulated other comprehensive loss — (31.2 ) 210.0 11.7 190.5 Net other comprehensive income (loss) (389.1 ) (6.7 ) 484.0 (4.6 ) 83.6 Ending balance at December 31, 2018 (4) $ (1,622.5 ) $ (22.1 ) $ (3,856.7 ) $ (238.9 ) $ (5,740.2 ) (1) Accumulated other comprehensive loss as of December 31, 2016 consists of $5.27 billion of accumulated other comprehensive loss attributable to controlling interest and $48.2 million of accumulated other comprehensive income attributable to noncontrolling interest. (2) Accumulated other comprehensive loss as of December 31, 2017 consists of $5.72 billion of accumulated other comprehensive loss attributable to controlling interest and $23.7 million of accumulated other comprehensive income attributable to noncontrolling interest. (3) This reclassification consists of $105.2 million of accumulated other comprehensive loss attributable to controlling interest and $23.7 million of accumulated other comprehensive loss attributable to noncontrolling interest. Refer to Note 2 for further details regarding the reclassification due to the adoption of Accounting Standards Update 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. (4) Accumulated other comprehensive loss as of December 31, 2018 consists of $5.73 billion of accumulated other comprehensive loss attributable to controlling interest and $11.0 million of accumulated other comprehensive loss attributable to noncontrolling interest. The tax effects on the net activity related to each component of other comprehensive income (loss) for the years ended December 31, were as follows: Tax benefit (expense) 2018 2017 2016 Foreign currency translation gains/losses $ 51.6 $ 170.8 $ (70.6 ) Unrealized net gains/losses on securities 2.1 55.0 (89.2 ) Defined benefit pension and retiree health benefit plans (85.3 ) 186.6 153.3 Effective portion of cash flow hedges 1.3 (9.7 ) (4.1 ) Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items $ (30.3 ) $ 402.7 $ (10.6 )

Other - Net, (Income) Expense (

Other - Net, (Income) Expense (Tables)	12 Months Ended
	Dec. 31, 2018
Nonoperating Income (Expense) [Abstract]
Schedule of Other Nonoperating Income (Expense)	Other–net, (income) expense consisted of the following: 2018 2017 2016 Interest expense $ 272.1 $ 225.0 $ 185.2 Interest income (161.3 ) (167.3 ) (108.7 ) Venezuela charge — — 203.9 Retirement benefit (242.1 ) (248.1 ) (197.6 ) Other (income) expense 56.5 (110.1 ) (195.6 ) Other–net, (income) expense $ (74.8 ) $ (300.5 ) $ (112.8 )

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of Additional Segment Information Disclosures	Depreciation and software amortization expense included in our segment profits was as follows: 2018 2017 2016 Human pharmaceutical products $ 934.0 $ 789.8 $ 723.4 Animal health products 111.3 102.7 89.9 Total depreciation expense and software amortization included in segment profits $ 1,045.3 $ 892.5 $ 813.3
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	The following table summarizes our revenue activity: U.S. (1) Outside U.S. 2018 2017 2016 2018 2017 2016 Segment revenue—to unaffiliated customers: Human pharmaceutical products: Endocrinology: Trulicity ® $ 2,515.8 $ 1,609.8 $ 737.6 $ 683.3 $ 419.9 $ 187.9 Humalog ® 1,787.8 1,717.8 1,685.2 1,208.7 1,147.4 1,083.6 Humulin ® 910.2 884.6 861.8 421.2 450.7 504.1 Forteo 757.9 965.2 770.5 817.7 783.8 729.4 Basaglar 622.8 311.1 15.8 178.5 121.0 70.3 Jardiance 400.2 290.4 144.5 258.1 157.0 57.4 Trajenta 224.2 213.2 165.9 350.5 324.7 270.7 Other Endocrinology 292.7 380.9 450.6 272.5 307.7 347.5 Total Endocrinology 7,511.6 6,373.0 4,831.9 4,190.5 3,712.2 3,250.9 Oncology: Alimta 1,131.0 1,034.3 1,101.0 1,001.9 1,028.2 1,182.3 Erbitux 531.6 541.7 581.1 103.8 104.2 105.9 Cyramza ® 291.5 278.8 270.1 529.9 479.6 344.0 Other Oncology 449.1 195.6 22.9 221.7 149.6 114.6 Total Oncology 2,403.2 2,050.4 1,975.1 1,857.3 1,761.6 1,746.8 Cardiovascular: Cialis 1,129.2 1,358.6 1,469.5 722.7 964.5 1,002.1 Effient 68.1 340.1 465.6 54.1 48.8 69.6 Other Cardiovascular 158.4 24.0 56.3 121.8 135.2 162.3 Total Cardiovascular 1,355.7 1,722.7 1,991.4 898.6 1,148.5 1,234.0 Neuroscience: Strattera ® 89.7 284.9 534.9 361.1 333.3 319.8 Cymbalta (2) 54.3 114.9 269.3 653.7 642.2 661.2 Zyprexa ® 36.2 75.5 69.8 435.1 505.7 655.5 Other Neuroscience 97.2 115.7 115.9 93.4 98.9 93.9 Total Neuroscience 277.4 591.0 989.9 1,543.3 1,580.1 1,730.4 Immunology: Taltz ® 738.7 486.0 110.8 198.7 73.2 2.3 Other Immunology 6.7 — — 195.9 45.8 — Total Immunology 745.4 486.0 110.8 394.6 119.0 2.3 Other human pharmaceutical products 58.7 50.9 42.6 176.6 190.3 157.8 Total human pharmaceutical products 12,352.2 11,274.0 9,941.7 9,061.0 8,511.7 8,122.2 Animal health products 1,523.0 1,511.1 1,564.5 1,619.5 1,574.5 1,593.7 Revenue $ 13,875.2 $ 12,785.1 $ 11,506.2 $ 10,680.5 $ 10,086.3 $ 9,715.9 Numbers may not add due to rounding. (1) U.S. revenue includes revenue in Puerto Rico. (2) Cymbalta revenues benefited from reductions to the reserve for expected product returns of approximately $175 million during the year ended December 31, 2016. 2018 2017 2016 Segment profits: Human pharmaceutical products $ 6,217.8 $ 5,139.7 $ 4,010.0 Animal health products 607.3 561.3 663.7 Total segment profits $ 6,825.1 $ 5,701.0 $ 4,673.7 Reconciliation of total segment profits to consolidated income before taxes: Segment profits $ 6,825.1 $ 5,701.0 $ 4,673.7 Other profits (losses): Amortization of intangible assets (Note 8) (546.0 ) (674.8 ) (683.3 ) Asset impairment, restructuring, and other special charges (Note 5) (482.0 ) (1,673.6 ) (382.5 ) Venezuela charge (Note 17) — — (203.9 ) Acquired in-process research and development (Note 3) (1,983.9 ) (1,112.6 ) (30.0 ) Inventory fair value adjustment related to acquisition of BIVIVP (Note 3) — (42.7 ) — Other, net (17.5 ) — — Consolidated income before taxes $ 3,795.7 $ 2,197.4 $ 3,374.0 Numbers may not add due to rounding.
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	2018 2017 2016 Geographic Information Revenue—to unaffiliated customers (1) : United States $ 13,875.2 $ 12,785.1 $ 11,506.2 Europe 4,231.1 3,943.2 3,768.1 Japan 2,493.7 2,419.7 2,330.9 Other foreign countries 3,955.7 3,723.3 3,616.9 Revenue $ 24,555.7 $ 22,871.3 $ 21,222.1 Long-lived assets (2) : United States $ 4,946.6 $ 5,013.4 $ 4,984.6 Europe 2,708.1 2,550.1 2,140.7 Japan 181.9 155.1 92.4 Other foreign countries 1,695.5 1,761.7 1,776.8 Long-lived assets $ 9,532.1 $ 9,480.3 $ 8,994.5 Numbers may not add due to rounding. (1) Revenue is attributed to the countries based on the location of the customer. (2) Long-lived assets consist of property and equipment, net, and certain sundry assets.

Selected Quarterly Data (Unau_2

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	2018 Fourth Third Second First Revenue $ 6,438.6 $ 6,061.9 $ 6,355.2 $ 5,700.0 Cost of sales 1,593.7 1,562.3 1,702.7 1,571.3 Operating expenses (1) 3,315.3 2,959.9 2,986.8 2,676.9 Acquired in-process research and development (2) 329.4 30.0 1,624.5 — Asset impairment, restructuring, and other special charges 246.0 83.3 74.4 78.3 Income before income taxes 938.9 1,411.0 4.8 1,441.0 Income taxes (3) (186.2 ) 261.5 264.7 223.6 Net income (loss) 1,125.1 1,149.5 (259.9 ) 1,217.4 Earnings (loss) per share—basic 1.11 1.13 (0.25 ) 1.16 Earnings (loss) per share—diluted 1.10 1.12 (0.25 ) 1.16 Dividends paid per share 0.5625 0.5625 0.5625 0.5625 2017 Fourth Third Second First Revenue $ 6,160.7 $ 5,658.0 $ 5,824.3 $ 5,228.3 Cost of sales (4) 1,644.9 1,586.3 1,571.7 1,347.9 Operating expenses (1)(4) 3,290.4 2,918.5 3,002.5 2,826.0 Acquired in-process research and development (2) 50.0 205.0 — 857.6 Asset impairment, restructuring, and other special charges (5) 1,003.2 406.5 50.0 213.9 Income before income taxes 284.1 591.6 1,260.5 61.2 Income taxes (3) 1,941.0 36.0 252.5 172.0 Net income (loss) (1,656.9 ) 555.6 1,008.0 (110.8 ) Earnings (loss) per share—basic (1.58 ) 0.53 0.96 (0.10 ) Earnings (loss) per share—diluted (1.58 ) 0.53 0.95 (0.10 ) Dividends paid per share 0.52 0.52 0.52 0.52 (1) Includes research and development and marketing, selling, and administrative expenses. (2) Acquired IPR&D charges in the second quarter of 2018 were primarily due to the ARMO acquisition. Acquired IPR&D charges in the first quarter of 2017 were due to the CoLucid acquisition. See Note 3 for further discussion. (3) Income taxes in the fourth quarter of 2018 were a tax benefit primarily due to adjustments associated with U.S. tax reform. Income taxes in the fourth quarter of 2017 were due to the provisional charge resulting from the 2017 Tax Act. See Note 13 for further discussion. (4) As discussed in Note 2, upon adoption of Accounting Standards Update 2017-07, Compensation-Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, pension and postretirement benefit cost components other than service costs are presented in other–net, (income) expense. Results for the quarters in 2017 have been reclassified to reflect the adoption of this standard. (5) Asset impairment, restructuring, and other special charges in the third quarter 2017 were primarily from asset impairments related to lower projected revenue for Posilac (rbST). In the fourth quarter of 2017, restructuring charges were primarily due to severance costs resulting from the U.S. voluntary early retirement program. See Note 5 for further discussion.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Acquisitions) (Details) - Elanco Animal Health Incorporated shares in Millions	Sep. 24, 2018$ / sharesshares
Business Acquisition [Line Items]
Percentage of stock sold (in percentage)	19.80%
IPO
Business Acquisition [Line Items]
Initial public offering (in shares) | shares	72.3
Sale of stock, price per share (usd per share) | $ / shares	$ 24

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue from contract, payment term, minimum (in days)									30 days
Revenue from contract, payment term, maximum (in days)									75 days
Revenue	$ 6,438.6	$ 6,061.9	$ 6,355.2	$ 5,700	$ 6,160.7	$ 5,658	$ 5,824.3	$ 5,228.3	$ 24,555.7	$ 22,871.3	$ 21,222.1
Net product revenue
Disaggregation of Revenue [Line Items]
Revenue									22,928.8	21,671.4	20,388.4
Collaboration and other revenue
Disaggregation of Revenue [Line Items]
Revenue									1,626.9	1,199.9	833.7
Royalty
Disaggregation of Revenue [Line Items]
Revenue									$ 303.2	$ 145.8	$ 146.1

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Contract Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Contract liabilities	$ 299.3	$ 335.2

Implementation of New Financi_3

Implementation of New Financial Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings	$ 11,395.9				$ 13,894.1				$ 11,395.9	$ 13,894.1
Deferred tax assets	1,277.1				997.4				1,277.1	997.4
Accumulated other comprehensive income (loss)	5,729.2				5,718.6				5,729.2	5,718.6
Other income									74.8	300.5	$ 112.8
Cost of sales	$ 1,593.7	$ 1,562.3	$ 1,702.7	$ 1,571.3	1,644.9	$ 1,586.3	$ 1,571.7	$ 1,347.9	6,430	6,150.8	5,710.1
Research and development									5,307.1	5,357.3	5,310.3
Marketing, selling, and administrative									$ 6,631.8	6,680.1	6,528
Accounting Standards Update 2016-01
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings													$ 105
Accumulated other comprehensive income (loss)													105
Accounting Standards Update 2016-16
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings													700
Deferred tax assets													2,500
Deferred tax liabilities													1,800
Accounting Standards Update 2017-07
New Accounting Pronouncement, Early Adoption [Line Items]
Other income										248.1	197.6
Cost of sales										80.6	55.2
Research and development										75.5	66.4
Marketing, selling, and administrative										92	$ 76
Accounting Standards Update 2018-02
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings					643.6					643.6
Accumulated other comprehensive income (loss)					$ 643.6					$ 643.6
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncement, Early Adoption [Line Items]
Retained earnings													$ 5
Scenario, Forecast [Member] | Accounting Standards Update 2016-02
New Accounting Pronouncement, Early Adoption [Line Items]
Effect of adopting new accounting standard												$ 650
Operating lease, liability												$ 650

Divestiture and Acquisitions (D

Divestiture and Acquisitions (Divestitures) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	Feb. 08, 2019	Sep. 24, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents			$ 7,998.2	$ 6,536.2	$ 4,582.1	$ 3,666.4
Noncontrolling interests			1,080.4	$ 75.7
Elanco Animal Health Incorporated
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of stock sold (in percentage)		19.80%
Cash and cash equivalents			475
Noncontrolling interests			$ 1,020
IPO | Elanco Animal Health Incorporated
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Initial public offering (in shares)		72,300
Sale of stock, price per share (usd per share)		$ 24
Elanco Animal Health Incorporated | Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash transfered from subsidiary to parent		$ 4,200
Sale of Elanco Stock (Note 3)		$ 629.2
Subsequent Event | Elanco Animal Health Incorporated | Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Shares, Expected to Divest	293,290
Minimum Number of Shares to Divest for Exchange Offer	146,645

(Narrative) (Details)

(Narrative) (Details) $ / shares in Units, SFr in Millions, $ in Millions

Feb. 15, 2019USD ($)$ / shares

Jan. 03, 2017USD ($)

Jan. 31, 2019CHF (SFr)

Jan. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Nov. 30, 2018USD ($)

Oct. 31, 2018USD ($)

Jul. 31, 2018USD ($)

Jun. 30, 2018USD ($)

Apr. 30, 2018USD ($)

Nov. 30, 2017USD ($)

Aug. 31, 2017USD ($)

Jul. 31, 2017USD ($)

Mar. 31, 2017USD ($)

Jan. 31, 2017

Dec. 31, 2016USD ($)

Dec. 31, 2018USD ($)

Sep. 30, 2018USD ($)

Jun. 30, 2018USD ($)

Mar. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Sep. 30, 2017USD ($)

Jun. 30, 2017USD ($)

Mar. 31, 2017USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Business Acquisition [Line Items]

Acquired in-process research and development

$ 329.4

$ 30

$ 1,624.5

$ 0

$ 50

$ 205

$ 0

$ 857.6

$ 1,983.9

$ 1,112.6

$ 30

Boehringer

Business Acquisition [Line Items]

Consideration transferred

$ 882.1

Intangibles acquired, weighted average useful life (in years)

10 years

Sigilon Therapeutics

Business Acquisition [Line Items]

Acquired in-process research and development

$ 66.9

AurKa Pharma, Inc.

Business Acquisition [Line Items]

Acquired in-process research and development

$ 81.8

ARMO

Business Acquisition [Line Items]

Acquired in-process research and development

$ 1,475.8

Anima Biotech

Business Acquisition [Line Items]

Acquired in-process research and development

$ 30

SIGA Technologies, Inc.

Business Acquisition [Line Items]

Acquired in-process research and development

$ 80

Chugai Pharmaceutical Company

Business Acquisition [Line Items]

Acquired in-process research and development

$ 50

NextCure, Inc.

Business Acquisition [Line Items]

Acquired in-process research and development

$ 28.1

Dicerna Pharmaceuticals

Business Acquisition [Line Items]

Acquired in-process research and development

$ 148.7

Hydra Biosciences

Business Acquisition [Line Items]

Acquired in-process research and development

$ 22.6

CoLucid Pharmaceuticals, Inc. (CoLucid)

Business Acquisition [Line Items]

Acquired in-process research and development

$ 857.6

KeyBioscience AG

Business Acquisition [Line Items]

Acquired in-process research and development

$ 55

Nektar Therapeutics

Business Acquisition [Line Items]

Acquired in-process research and development

$ 150

CureVac AG

Business Acquisition [Line Items]

Acquired in-process research and development

$ 50

AstraZeneca

Business Acquisition [Line Items]

Acquired in-process research and development

$ 30

Subsequent Event | Loxo Oncology, Inc.

Business Acquisition [Line Items]

Share price (usd per share) | $ / shares

$ 235

Consideration transferred

$ 8,000

Subsequent Event | AC Immune SA

Business Acquisition [Line Items]

Acquired in-process research and development

$ 96.9

Purchased in-process research and development

SFr 80

$ 50

Divestiture and Acquisitions (P

Divestiture and Acquisitions (Purchase Price Allocation) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Jan. 03, 2017
Business Acquisition [Line Items]
Goodwill	$ 4,347.5	$ 4,370.1
Boehringer
Business Acquisition [Line Items]
Inventories			$ 108.6
Marketed products			297
Property and equipment			148.2
Other assets and liabilities - net			8.2
Total identifiable net assets			562
Goodwill			320.1
Total consideration transferred - net of cash acquired			$ 882.1

Collaborations and Other Arra_3

Collaborations and Other Arrangements (Details) - USD ($) $ in Millions	Oct. 01, 2015	Dec. 31, 2009	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue			$ 6,438.6	$ 6,061.9	$ 6,355.2	$ 5,700	$ 6,160.7	$ 5,658	$ 5,824.3	$ 5,228.3	$ 24,555.7	$ 22,871.3	$ 21,222.1
Research and development											5,307.1	5,357.3	5,310.3
Europe
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											4,231.1	3,943.2	3,768.1
JAPAN
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											2,493.7	2,419.7	2,330.9
United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											13,875.2	12,785.1	11,506.2
United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											12,352.2	11,274	9,941.7
Trajenta
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											574.7	537.9	436.6
Trajenta | United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											224.2	213.2	165.9
Trajenta | Milestone Payments, Development and Regulatory, Capitalized, Cumulative [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											446.4
Jardiance
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											658.3	447.5	201.9
Jardiance | United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											400.2	290.4	144.5
Jardiance | Milestone Payments, Development and Regulatory, Capitalized, Cumulative [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											289
Basaglar
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											801.2	432.1	86.1
Basaglar | United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											622.8	311.1	15.8
Basaglar | Milestone Payments, Development and Regulatory, Capitalized, Cumulative [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms														$ (250)
Basaglar | Milestone Payments, Development and Regulatory, Capitalized
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											0	0	(187.5)
Erbitux
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											635.3	645.9	687
Erbitux | United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											531.6	541.7	581.1
Erbitux | Sales Reported
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations percent (in percentage)	38.00%
Erbitux, Product
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											536.1	548.2	587
Erbitux, Collaboration and Other Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											99.2	97.7	100
Effient | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											122.2	388.9	535.2
Effient | United States | Human pharmaceutical products
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											$ 68.1	340.1	465.6
Effient | Profit And Development And Marketing Share
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations percent (in percentage)											50.00%
Olumiant | Research And Development Exp
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations percent (in percentage)		30.00%
Olumiant | Milestone Payments, Development and Regulatory, Expensed
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development											$ 20	30
Olumiant | Milestone Payments, Development and Regulatory, Expensed | United States and Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development													$ 55
Olumiant | Milestone Payments, Development and Regulatory, Capitalized (Deferred) | Europe
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms												65
Olumiant | Milestone Payments, Development and Regulatory, Capitalized (Deferred) | JAPAN
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms												$ 15
Olumiant | Milestone Payments, Development and Regulatory, Capitalized (Deferred) | United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											100
Olumiant | Milestone Payments, Development and Regulatory
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											130
Olumiant | Royalty Payments Received
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations percent (in percentage)		20.00%
Olumiant | Milestone Payments, Sales-based
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											150
Tanezumab | Milestone Payments, Development and Regulatory
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											350
Tanezumab | Milestone Payments, Sales-based
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations, terms											$ 1,230

Asset Impairment, Restructuri_3

Asset Impairment, Restructuring, and Other Special Charges (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unusual or Infrequent Item [Line Items]
Severance									$ 142.6	$ 697.4	$ 126.7
Asset impairment (gains from facility sales) and other special charges:									339.4	462.5	255.8
Asset impairment, restructuring, and other special charges	$ 246	$ 83.3	$ 74.4	$ 78.3	$ 1,003.2	$ 406.5	$ 50	$ 213.9	482	1,673.6	382.5
Human pharmaceutical products
Unusual or Infrequent Item [Line Items]
Severance									127.8	601	85.9
Asset impairment (gains from facility sales) and other special charges:									46	81.7	(13)
Animal health products
Unusual or Infrequent Item [Line Items]
Severance									14.8	96.4	40.8
Asset impairment (gains from facility sales) and other special charges:									293.4	380.8	268.8
United States
Unusual or Infrequent Item [Line Items]
Total pension and post-retirement medical charges associated with U.S. voluntary early retirement program									0	513.7	0
United States | Human pharmaceutical products
Unusual or Infrequent Item [Line Items]
Total pension and post-retirement medical charges associated with U.S. voluntary early retirement program									0	446.7	0
United States | Animal health products
Unusual or Infrequent Item [Line Items]
Total pension and post-retirement medical charges associated with U.S. voluntary early retirement program									$ 0	$ 67	$ 0

Asset Impairment, Restructuri_4

Asset Impairment, Restructuring, and Other Special Charges (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Severance costs	$ 142.6	$ 697.4	$ 126.7
Asset impairment charges		151.5
Impairment of intangibles		50
Asset impairment (gains from facility sales) and other special charges:	$ 339.4	462.5	$ 255.8
United States
Restructuring Cost and Reserve [Line Items]
Severance costs		412.5
Outside US
Restructuring Cost and Reserve [Line Items]
Severance costs		284.9
PUERTO RICO
Restructuring Cost and Reserve [Line Items]
Asset impairment (gains from facility sales) and other special charges:		$ 43.4

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Finished products	$ 988.1	$ 1,211.4
Work in process	2,628.2	2,697.7
Raw materials and supplies	506.5	488.8
Total (approximates replacement cost)	4,122.8	4,397.9
Increase (reduction) to LIFO cost	(11)	60.4
Inventories	4,111.8	4,458.3
LIFO Inventory Amount	$ 1,570	$ 1,560

Financial Instruments (Effect o

Financial Instruments (Effect of Risk Management) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow Hedge [Abstract]
Total	$ 114.8	$ 112.7	$ 93.8
Cash flow hedges: | Interest rate swap
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	0	13	(3.4)
Net investment hedges:
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	110.4	(361.5)	137.5
Net investment hedges: | Foreign Exchange Contract
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	5.7	0	31.9
Net investment hedges: | Cross-currency interest rate swaps
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	96.8	(126.6)	32.5
Designated as Hedging Instrument | Hedged Fixed Rate Debt
Fair Value Hedge [Abstract]
Effect from hedged fixed-rate debt	(40.9)	(14.1)	(30.8)
Designated as Hedging Instrument | Interest Rate Contract
Fair Value Hedge [Abstract]
Effect from interest rate contracts	40.9	14.1	30.8
Cash Flow Hedge [Abstract]
Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss	14.8	14.8	15
Not Designated as Hedging Instrument | Foreign Exchange Contract
Cash Flow Hedge [Abstract]
Net losses on foreign currency exchange contracts not designated as hedging instruments	$ 100	$ 97.9	$ 78.8

Financial Instruments (Fair Val

Financial Instruments (Fair Value Measurement) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Noncurrent investments:
Equity investments without readily determinable fair values	$ 414.7
Investments (Note 7)	2,020.7	$ 5,678.8
Contingent consideration liabilities:
Change on the fair value of contingent consideration	215.9	203.9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other current liabilities		0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other receivables	0
Sundry	0
Significant Other Observable Inputs (Level 2) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other current liabilities		(0.2)
Significant Other Observable Inputs (Level 2) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other receivables	69.2
Sundry	8.2
Significant Unobservable Inputs (Level 3) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other current liabilities		0
Significant Unobservable Inputs (Level 3) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other receivables	0
Sundry	0
Portion at Other than Fair Value Measurement
Statement [Line Items]
Cash equivalents	5,752.2	4,763.9
Carrying Amount
Statement [Line Items]
Cash equivalents	5,752.2	4,763.9
Short-term investments:
Short-term investments	88.2	1,497.9
Noncurrent investments:
Investments (Note 7)	2,020.7
Available-for-sale Securities, Noncurrent, Total		5,678.8
Contingent consideration liabilities:
Other current liabilities	(5.1)	(208)
Other noncurrent liabilities	(69)	(45.2)
Carrying Amount | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other receivables		0.8
Sundry	4.5	35.1
Other current liabilities	(22.3)	(0.2)
Other noncurrent liabilities	(19)	(10.5)
Carrying Amount | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other receivables	69.2
Sundry	8.2
Other current liabilities	(9.2)	(33.4)
Other noncurrent liabilities	(25.8)	(26)
Carrying Amount | Not Designated as Hedging Instrument | Foreign Exchange Contract
Risk-management instruments
Other receivables	11.3	26.8
Other current liabilities	(16.3)	(36)
Fair Value
Statement [Line Items]
Cash equivalents	5,752.2	4,763.9
Contingent consideration liabilities:
Other current liabilities	(5.1)	(208)
Other noncurrent liabilities	(69)	(45.2)
Fair Value | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other receivables		0.8
Sundry	4.5	35.1
Other current liabilities	(22.3)	(0.2)
Other noncurrent liabilities	(19)	(10.5)
Fair Value | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other receivables	69.2
Sundry	8.2
Other current liabilities	(9.2)	(33.4)
Other noncurrent liabilities	(25.8)	(26)
Fair Value | Not Designated as Hedging Instrument | Foreign Exchange Contract
Risk-management instruments
Other receivables	11.3	26.8
Other current liabilities	(16.3)	(36)
Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Statement [Line Items]
Cash equivalents	5,752.2	4,712.4
Contingent consideration liabilities:
Other current liabilities	0	0
Other noncurrent liabilities	0	0
Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other receivables		0
Sundry	0	0
Other current liabilities	0
Other noncurrent liabilities	0	0
Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other current liabilities	0	0
Other noncurrent liabilities	0	0
Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1) | Not Designated as Hedging Instrument | Foreign Exchange Contract
Risk-management instruments
Other receivables	0	0
Other current liabilities	0	0
Fair Value | Significant Other Observable Inputs (Level 2)
Statement [Line Items]
Cash equivalents	0	51.5
Contingent consideration liabilities:
Other current liabilities	0	0
Other noncurrent liabilities	0	0
Fair Value | Significant Other Observable Inputs (Level 2) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other receivables		0.8
Sundry	4.5	35.1
Other current liabilities	(22.3)
Other noncurrent liabilities	(19)	(10.5)
Fair Value | Significant Other Observable Inputs (Level 2) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other current liabilities	(9.2)	(33.4)
Other noncurrent liabilities	(25.8)	(26)
Fair Value | Significant Other Observable Inputs (Level 2) | Not Designated as Hedging Instrument | Foreign Exchange Contract
Risk-management instruments
Other receivables	11.3	26.8
Other current liabilities	(16.3)	(36)
Fair Value | Significant Unobservable Inputs (Level 3)
Statement [Line Items]
Cash equivalents	0	0
Contingent consideration liabilities:
Other current liabilities	(5.1)	(208)
Other noncurrent liabilities	(69)	(45.2)
Fair Value | Significant Unobservable Inputs (Level 3) | Designated as Hedging Instrument | Interest Rate Contract
Risk-management instruments
Other receivables		0
Sundry	0	0
Other current liabilities	0
Other noncurrent liabilities	0	0
Fair Value | Significant Unobservable Inputs (Level 3) | Designated as Hedging Instrument | Cross-currency interest rate swaps
Risk-management instruments
Other current liabilities	0	0
Other noncurrent liabilities	0	0
Fair Value | Significant Unobservable Inputs (Level 3) | Not Designated as Hedging Instrument | Foreign Exchange Contract
Risk-management instruments
Other receivables	0	0
Other current liabilities	0	0
U.S. government and agency securities | Portion at Other than Fair Value Measurement
Short-term investments:
Short-term investments, debt securities	17.1	218.2
Noncurrent investments:
Noncurrent investments, debt securities	153.6	365
U.S. government and agency securities | Carrying Amount
Short-term investments:
Short-term investments, debt securities	16.9	217.8
Noncurrent investments:
Noncurrent investments, debt securities	149.1	360
U.S. government and agency securities | Fair Value
Short-term investments:
Short-term investments, debt securities	16.9	217.8
Noncurrent investments:
Noncurrent investments, debt securities	149.1	360
U.S. government and agency securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term investments:
Short-term investments, debt securities	16.9	217.8
Noncurrent investments:
Noncurrent investments, debt securities	149.1	360
U.S. government and agency securities | Fair Value | Significant Other Observable Inputs (Level 2)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
U.S. government and agency securities | Fair Value | Significant Unobservable Inputs (Level 3)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Corporate debt securities | Portion at Other than Fair Value Measurement
Short-term investments:
Short-term investments, debt securities	62.6	1,183.2
Noncurrent investments:
Noncurrent investments, debt securities	587.8	3,473.5
Corporate debt securities | Carrying Amount
Short-term investments:
Short-term investments, debt securities	62.2	1,182.3
Noncurrent investments:
Noncurrent investments, debt securities	568	3,464.3
Corporate debt securities | Fair Value
Short-term investments:
Short-term investments, debt securities	62.2	1,182.3
Noncurrent investments:
Noncurrent investments, debt securities	568	3,464.3
Corporate debt securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Corporate debt securities | Fair Value | Significant Other Observable Inputs (Level 2)
Short-term investments:
Short-term investments, debt securities	62.2	1,182.3
Noncurrent investments:
Noncurrent investments, debt securities	568	3,464.3
Corporate debt securities | Fair Value | Significant Unobservable Inputs (Level 3)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Mortgage-backed securities | Portion at Other than Fair Value Measurement
Noncurrent investments:
Noncurrent investments, debt securities	114.5	204.2
Mortgage-backed securities | Carrying Amount
Noncurrent investments:
Noncurrent investments, debt securities	111.4	202.4
Mortgage-backed securities | Fair Value
Noncurrent investments:
Noncurrent investments, debt securities	111.4	202.4
Mortgage-backed securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Mortgage-backed securities | Fair Value | Significant Other Observable Inputs (Level 2)
Noncurrent investments:
Noncurrent investments, debt securities	111.4	202.4
Mortgage-backed securities | Fair Value | Significant Unobservable Inputs (Level 3)
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Asset-backed securities | Portion at Other than Fair Value Measurement
Short-term investments:
Short-term investments, debt securities	7.7	94.3
Noncurrent investments:
Noncurrent investments, debt securities	27.9	656
Asset-backed securities | Carrying Amount
Short-term investments:
Short-term investments, debt securities	7.6	94.2
Noncurrent investments:
Noncurrent investments, debt securities	27.7	653.9
Asset-backed securities | Fair Value
Short-term investments:
Short-term investments, debt securities	7.6	94.2
Noncurrent investments:
Noncurrent investments, debt securities	27.7	653.9
Asset-backed securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Asset-backed securities | Fair Value | Significant Other Observable Inputs (Level 2)
Short-term investments:
Short-term investments, debt securities	7.6	94.2
Noncurrent investments:
Noncurrent investments, debt securities	27.7	653.9
Asset-backed securities | Fair Value | Significant Unobservable Inputs (Level 3)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities	0	0
Other securities | Portion at Other than Fair Value Measurement
Noncurrent investments:
Equity Securities, FV-NI	29.7
Other securities | Carrying Amount
Noncurrent investments:
Equity Securities, FV-NI	87.8
Other securities | Fair Value
Noncurrent investments:
Equity Securities, FV-NI	87.8
Other securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Noncurrent investments:
Equity Securities, FV-NI	0
Other securities | Fair Value | Significant Other Observable Inputs (Level 2)
Noncurrent investments:
Equity Securities, FV-NI	0
Other securities | Fair Value | Significant Unobservable Inputs (Level 3)
Noncurrent investments:
Equity Securities, FV-NI	87.8
Marketable equity securities | Portion at Other than Fair Value Measurement
Noncurrent investments:
Equity Securities, FV-NI	238.3
Marketable equity securities | Carrying Amount
Noncurrent investments:
Equity Securities, FV-NI	357.5
Marketable equity securities | Fair Value
Noncurrent investments:
Equity Securities, FV-NI	357.5
Marketable equity securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Noncurrent investments:
Equity Securities, FV-NI	357.5
Marketable equity securities | Fair Value | Significant Other Observable Inputs (Level 2)
Noncurrent investments:
Equity Securities, FV-NI	0
Marketable equity securities | Fair Value | Significant Unobservable Inputs (Level 3)
Noncurrent investments:
Equity Securities, FV-NI	0
Other securities | Portion at Other than Fair Value Measurement
Short-term investments:
Short-term investments, debt securities	1.5	3.6
Noncurrent investments:
Noncurrent investments, debt securities		66.4
Other securities | Carrying Amount
Short-term investments:
Short-term investments, debt securities	1.5	3.6
Noncurrent investments:
Noncurrent investments, debt securities		132.1
Other securities | Fair Value
Short-term investments:
Short-term investments, debt securities	1.5	3.6
Noncurrent investments:
Noncurrent investments, debt securities		132.1
Other securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities		0
Other securities | Fair Value | Significant Other Observable Inputs (Level 2)
Short-term investments:
Short-term investments, debt securities	1.5	3.6
Noncurrent investments:
Noncurrent investments, debt securities		0
Other securities | Fair Value | Significant Unobservable Inputs (Level 3)
Short-term investments:
Short-term investments, debt securities	0	0
Noncurrent investments:
Noncurrent investments, debt securities		132.1
Marketable equity securities | Portion at Other than Fair Value Measurement
Noncurrent investments:
Marketable equity securities		131
Marketable equity securities | Carrying Amount
Noncurrent investments:
Marketable equity securities		281.3
Marketable equity securities | Fair Value
Noncurrent investments:
Marketable equity securities		281.3
Marketable equity securities | Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Noncurrent investments:
Marketable equity securities		281.3
Marketable equity securities | Fair Value | Significant Other Observable Inputs (Level 2)
Noncurrent investments:
Marketable equity securities		0
Marketable equity securities | Fair Value | Significant Unobservable Inputs (Level 3)
Noncurrent investments:
Marketable equity securities		0
Cost and equity method investments | Carrying Amount
Noncurrent investments:
Cost and equity method investments	$ 304.5	$ 584.8

Financial Instruments (Short-te

Financial Instruments (Short-term and Long-term Classification) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	$ (498.9)	$ (2,696.8)
Carrying Amount
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, including current portion	(12,272)	(10,950.3)
Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, including current portion	(12,461.7)	(11,529.9)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, including current portion	0	0
Significant Other Observable Inputs (Level 2) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, including current portion	(12,461.7)	(11,529.9)
Significant Unobservable Inputs (Level 3) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Long-term debt, including current portion	0	0
Commercial Paper | Carrying Amount
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	(498.9)	(2,696.8)
Commercial Paper | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	(497.6)	(2,690.6)
Commercial Paper | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	0	0
Commercial Paper | Significant Other Observable Inputs (Level 2) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	(497.6)	(2,690.6)
Commercial Paper | Significant Unobservable Inputs (Level 3) | Fair Value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Short-term commercial paper borrowings	$ 0	$ 0

Financial Instruments (Contract

Financial Instruments (Contractual Maturities) (Details) $ in Millions	Dec. 31, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Total	$ 943
Less Than 1 Year	86.8
1-5 Years	604.8
6-10 Years	97
More Than 10 Years	$ 154.4

Financial Instruments (Summary

Financial Instruments (Summary of AFS Unrealized Gain(Loss)) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Unrealized gross gains	$ 0.8	$ 184.7
Unrealized gross losses	29	47.5
Fair value of securities in an unrealized gain position	84.3	1,434.2
Fair value of securities in an unrealized loss position	$ 858.6	$ 4,692.8

Financial Instruments (Investme

Financial Instruments (Investment Portfolio Activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Proceeds from sales	$ 5,668	$ 5,769.3	$ 3,240.5
Realized gross gains on sales	11.8	176	30.7
Realized gross losses on sales	$ 51.3	$ 5.8	$ 14.6

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details) € in Millions, ¥ in Millions, £ in Millions, SFr in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2018EUR (€)	Dec. 31, 2018CHF (SFr)	Dec. 31, 2018GBP (£)	Dec. 31, 2018USD ($)	Dec. 31, 2018JPY (¥)	Aug. 31, 2018USD ($)
Derivative [Line Items]
Average remaining maturity of foreign currency derivatives		12 months
Maximum remaining maturity of foreign currency derivatives (in days)		30 days
Foreign currency-denominated notes, designated as hedge			$ 3,700,000,000					$ 2,650,000,000
Variable rate (in percentage)					20.00%	20.00%	20.00%	20.00%	20.00%
Losses expected to be reclassified in the next 12 months								$ 15,000,000
Change on the fair value of contingent consideration		$ 215,900,000	203,900,000
Unrealized losses from equity securities		20,100,000
Other-than-temporary impairment losses recognized during the year		$ 0	0	$ 53,000,000
Percentage of nonperforming assets (in percentage)		55.00%
Amount derecognized			723,200,000					696,200,000
Buy USD Sell Euro
Derivative [Line Items]
Derivative liability, notional amount								785,500,000
Derivative asset, notional amount | €					€ 685.3
Buy euro Sell US dollar
Derivative [Line Items]
Derivative liability, notional amount | €					€ 2,050
Derivative asset, notional amount								2,350,000,000
Buy USD Sell Japanese Yen
Derivative [Line Items]
Derivative liability, notional amount								435,100,000
Derivative asset, notional amount | ¥									¥ 48,850
Buy Swiss francs Sell US dollar
Derivative [Line Items]
Derivative liability, notional amount | SFr						SFr 255.6
Derivative asset, notional amount								259,700,000
Buy US dollar Sell British pound
Derivative [Line Items]
Derivative liability, notional amount								388,300,000
Derivative asset, notional amount | £							£ 306.7
Buy GBP Sell USD
Derivative [Line Items]
Derivative liability, notional amount | £							£ 354
Derivative asset, notional amount								448,100,000
Currency Swap
Derivative [Line Items]
Derivative liability, notional amount								2,460,000,000
Interest rate swap
Derivative [Line Items]
Derivative asset, notional amount								350,000,000
Maximum remaining maturity of foreign currency derivatives (in days)		12 months
Foreign Currency Denominated Debt
Derivative [Line Items]
Long-term debt			3,700,000,000					3,400,000,000
Senior Notes
Derivative [Line Items]
Debt instrument, face amount										$ 2,000,000,000
Carrying Amount
Derivative [Line Items]
Long-term debt			$ 10,950,300,000					$ 12,272,000,000
Senior Notes Due August 27, 2021 | Senior Notes
Derivative [Line Items]
Debt instrument, face amount										$ 500,000,000
Stated interest rate (in percentage)										3.91%
Senior Notes Due August 28, 2023 | Senior Notes
Derivative [Line Items]
Debt instrument, face amount										$ 750,000,000
Stated interest rate (in percentage)										4.27%
Senior Notes Due August 28, 2028 | Senior Notes
Derivative [Line Items]
Debt instrument, face amount										$ 750,000,000
Stated interest rate (in percentage)										4.90%
Term Facility | Secured Debt
Derivative [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt instrument, term (in years)	3 years

Goodwill and Other Intangible_3

Goodwill and Other Intangibles (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Finite-lived intangible assets:
Total goodwill	$ 4,347.5	$ 4,370.1
Human pharmaceutical products
Finite-lived intangible assets:
Total goodwill	1,366.6	1,366.8
Animal health products
Finite-lived intangible assets:
Total goodwill	$ 2,980.9	$ 3,003.3

Goodwill and Other Intangible_4

Goodwill and Other Intangibles (Intangibles) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-lived intangible assets:
Carrying Amount, Gross	$ 5,413.3	$ 7,853.2
Accumulated Amortization	(1,911.9)	(3,921.2)
Carrying Amount, Net	3,501.4	3,932
Indefinite-lived intangible assets:	19.6	97.2
Other Intangibles, gross	5,432.9	7,950.4
Other intangibles, net	3,521	4,029.2
Amortization expense	558.7	683.4	$ 687.9
Marketed products
Finite-lived intangible assets:
Carrying Amount, Gross	5,270.7	7,682
Accumulated Amortization	(1,848.2)	(3,851.1)
Carrying Amount, Net	3,422.5	3,830.9
Other
Finite-lived intangible assets:
Carrying Amount, Gross	142.6	171.2
Accumulated Amortization	(63.7)	(70.1)
Carrying Amount, Net	$ 78.9	$ 101.1

Goodwill and Other Intangible_5

Goodwill and Other Intangibles (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-lived intangible assets:
Goodwill, impairment loss	$ 0	$ 0	$ 0
Impairment of intangibles		50
Remaining amortization period (in years)	12 years
Animal health products
Finite-lived intangible assets:
Impairment of intangibles	$ 68.9	135.5
Impairment of finite-lived intangible	55.9	97.5
Impairment of indefinite-lived intangibles	$ 13	$ 38
Minimum
Finite-lived intangible assets:
Finite-lived intangible asset, useful life (in years)	3 years
Maximum
Finite-lived intangible assets:
Finite-lived intangible asset, useful life (in years)	20 years

Goodwill and Other Intangible_6

Goodwill and Other Intangibles (Amortization Expense) (Details) $ in Millions	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 343.3
2,020	342.3
2,021	339.6
2,022	329.8
2,023	$ 318.4

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Land	$ 193.1	$ 192.7
Buildings	7,683.8	7,425.6
Equipment	8,817.4	8,689
Construction in progress	1,769.7	1,783.8
Property and equipment, gross	18,464	18,091.1
Less accumulated depreciation	(9,544.5)	(9,264.6)
Property and equipment, net	8,919.5	8,826.5
Depreciation expense	879.6	763.1	$ 716.2
Rental expense	223.2	$ 224.5	$ 221
Property, Plant and Equipment [Line Items]
2,019	155.8
2,020	128
2,021	89
2,022	74.7
2,023	58.2
After 2,023	$ 299.5
Building | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	12 years
Building | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	50 years
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years

Borrowings (Long-term Debt) (De

Borrowings (Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Short-term commercial paper borrowings	$ 498.9	$ 2,696.8
0.15 to 7.13 percent long-term notes (due 2019-2047)	11,640.8	10,756.7
Other long-term debt	503.1	13.6
Unamortized debt issuance costs	(49.1)	(49)
Fair value adjustment on hedged long-term notes	177.2	229
Total debt	12,770.9	13,647.1
Less current portion	(1,131.2)	(3,706.6)
Long-term debt	$ 11,639.7	$ 9,940.5

Borrowings (narrative) (Details

Borrowings (narrative) (Details) - USD ($)	1 Months Ended		12 Months Ended
	Sep. 30, 2018	May 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 31, 2018
Debt Instrument [Line Items]
Weighted average interest rate (in percentage)			2.36%
Line of credit facility, remaining borrowing capacity			$ 6,170,000,000
Line of credit facility, outstanding			25,900,000	$ 6,000,000
Proceeds from issuance of long-term debt			$ 2,477,700,000	$ 2,232,000,000	$ 1,206,600,000
Proceeds from issuance of secured debt		$ 2,230,000,000
Description of derivative activity volume percent			20.00%
Debt instrument, interest rate, effective percentage (in percentage)			3.36%	2.65%
Cash payments for interest on borrowings			$ 223,800,000	$ 192,700,000	$ 146,400,000
Notes Due in May 2022
Debt Instrument [Line Items]
Debt instrument, face amount		$ 750,000,000
Stated interest rate (in percentage)		2.35%
Notes Due in May 2027
Debt Instrument [Line Items]
Debt instrument, face amount		$ 750,000,000
Stated interest rate (in percentage)		3.10%
Notes Due in 2047
Debt Instrument [Line Items]
Debt instrument, face amount		$ 750,000,000
Stated interest rate (in percentage)		3.95%
Minimum
Debt Instrument [Line Items]
Stated interest rate (in percentage)			0.15%
Maximum
Debt Instrument [Line Items]
Stated interest rate (in percentage)			7.13%
Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount						$ 2,000,000,000
Senior Notes | Senior Notes Due August 27, 2021
Debt Instrument [Line Items]
Debt instrument, face amount						$ 500,000,000
Stated interest rate (in percentage)						3.91%
Senior Notes | Senior Notes Due August 28, 2023
Debt Instrument [Line Items]
Debt instrument, face amount						$ 750,000,000
Stated interest rate (in percentage)						4.27%
Senior Notes | Senior Notes Due August 28, 2028
Debt Instrument [Line Items]
Debt instrument, face amount						$ 750,000,000
Stated interest rate (in percentage)						4.90%
Secured Debt | Term Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt instrument, term (in years)	3 years
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 750,000,000
Debt instrument, term (in years)	5 years
Borrowings outstanding			$ 0
Maturity Date, 2023
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			3,000,000,000
Maturity Date, 2019
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 2,000,000,000

Borrowings (Debt maturities) (D

Borrowings (Debt maturities) (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 634.5
2,020	33.5
2,021	942.3
2,022	1,439
2,023	$ 750.3

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 279.5	$ 281.3	$ 255.3
Tax benefit	$ 58.7	$ 70.5	$ 89.4
Number of shares available for grant (in shares)	53.3
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	2 years
Weighted average grant date fair value (in usd per share)	$ 71.63	$ 73.54	$ 72
Shares issued in period (in shares)	0.9	1.3	0.5
Shares expected to be issued (in shares)	1.2
Total compensation cost not yet recognized	$ 63.7
Period for recognition of the compensation cost not yet recognized (in months)	12 months
Shareholder Value Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Weighted average grant date fair value (in usd per share)	$ 48.51	$ 66.25	$ 48.68
Shares issued in period (in shares)	0.7	1.1	1
Shares expected to be issued (in shares)	1
Total compensation cost not yet recognized	$ 55.7
Period for recognition of the compensation cost not yet recognized (in months)	20 months
Expected dividend yield (in percentage)	2.50%	2.50%	2.00%
Risk-free interest rate (in percentage)	2.31%	1.38%	0.92%
Volatility (in percentage)	22.26%	22.91%	21.68%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Weighted average grant date fair value (in usd per share)	$ 70.95	$ 72.47	$ 71.46
Shares issued in period (in shares)	1	0.9	0.6
Shares expected to be issued (in shares)	0.8
Total compensation cost not yet recognized	$ 112.2
Period for recognition of the compensation cost not yet recognized (in months)	21 months
Grants in period (in shares)	1.3	1.4	1.3

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2013
Statement [Line Items]
Purchase for treasury	$ 4,150	$ 359.8	$ 540.1
Purchases of common stock			$ 60
Preferred stock, shares authorized (in shares)	5,000,000
Shares issued (in shares)	0	0
Shares held in employee trust (in shares)	50,000,000	50,000,000
Employee benefit trust	$ 3,013.2	$ 3,013.2
2013 Share Repurchase Program
Statement [Line Items]
Purchase for treasury	2,050
Stock repurchase program, authorized amount				$ 5,000
2018 Repurchase Program
Statement [Line Items]
Purchase for treasury	2,100
Stock repurchase program, authorized amount	8,000
Remaining authorized repurchase amount	$ 5,900

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Operating Loss Carryforwards [Line Items]
2017 Tax Act provision		$ 1,914	$ 0
2017 Tax Act benefit	$ 313.3
2017 Tax Act, deferred taxes related to GILTI	$ 1,680
Domestic and Puerto Rican companies contribution	16.00%	15.00%	70.00%
Unrecognized tax benefits that would impact effective tax rate	$ 1,490	$ 670.9
Year under examination				2,015	2,014	2,013	2,012	2,010
Settlements	33.2	2.4	$ 171.9
Cash payments of income taxes	1,101.5	246.5	700.6
Decrease in unrecognized tax benefits is reasonably possible	450
Income tax payment, anticipated	150
Income tax (benefit) expense	24.4	27.4	(52.5)
Accruals for the payment of interest and penalties	197.2	$ 170.7
Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	735.4
Operating loss carryforwards	922.8
Expiration in 9 Years
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	150.5
Designated Unusable | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	122.9
Designated Unusable | Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	122.7
Designated Unusable | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	339.4
Deferred tax assets related to state net operating losses	106.1
Other state carryforwards	2.6
Expiration within 5 years
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	102.4
Expiration 5 to 20 Years
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	521.5
No Expiration
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 298.9
Tax Years 2010-2012
Operating Loss Carryforwards [Line Items]
Settlements				$ 320
Cash payments of income taxes			150
Maximum
Operating Loss Carryforwards [Line Items]
Decrease in unrecognized tax benefits is reasonably possible			$ 140

Income Taxes (Current and Defer

Income Taxes (Current and Deferred) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal									$ (54.3)	$ (100.6)	$ (57)
Foreign									80	38.5	378.9
State									9.7	4	(125)
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)									201.5
2017 Tax Act										3,247.5	0
Total current tax expense									236.9	3,189.4	196.9
Deferred:
Federal									64	801.5	517
Foreign									285.6	(256.3)	(83.3)
State									3.4	0.4	5.8
Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit), Total									(26.2)
2017 Tax Act										(1,333.5)	0
Total deferred tax (benefit) expense									326.8	(787.9)	439.5
Income taxes	$ (186.2)	$ 261.5	$ 264.7	$ 223.6	$ 1,941	$ 36	$ 252.5	$ 172	$ 563.7	$ 2,401.5	$ 636.4

Income Taxes (Deferred tax asse

Income Taxes (Deferred tax asset and liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Purchases of intangible assets	$ 2,655.9	$ 443.1
Compensation and benefits	814.2	1,021.7
Tax credit carryforwards and carrybacks	365.2	473
Tax loss carryforwards and carrybacks	271.7	501.4
Product return reserves	100.5	88.4
Other comprehensive loss on hedging transactions	68.9	68.9
Debt	40.3	53.5
Contingent consideration	17.7	41.8
Other	714.7	555.8
Total gross deferred tax assets	5,049.1	3,247.6
Valuation allowances	(596.3)	(709.1)
Total deferred tax assets	4,452.8	2,538.5
Deferred tax liabilities:
Earnings of foreign subsidiaries	(1,692.3)	(16.6)
Inventories	(658.4)	(654.8)
Property and equipment	(311.7)	(282.1)
Prepaid employee benefits	(240.1)	(231.5)
Intangibles	(250.5)	(314.6)
Financial instruments	(22.7)	(41.5)
Total deferred tax liabilities	(3,175.7)	(1,541.1)
Deferred tax assets, net	$ 1,277.1	$ 997.4

Income Taxes (Unrecognized bene

Income Taxes (Unrecognized benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits	$ 1,014.5	$ 853.4	$ 1,066.6
Additions based on tax positions related to the current year	798.2	133.8	73.4
Additions for tax positions of prior years	414.9	97.5	14.8
Reductions for tax positions of prior years	(117.1)	(59.3)	(15.2)
Settlements	(33.2)	(2.4)	(171.9)
Lapses of statutes of limitation	(23.5)	(19.3)	(110)
Changes related to the impact of foreign currency translation, increase		10.8
Changes related to the impact of foreign currency translation, decrease	(6.8)		(4.3)
Unrecognized Tax Benefits	$ 2,047	$ 1,014.5	$ 853.4

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax at the U.S. federal statutory tax rate									$ 797.1	$ 769.1	$ 1,180.9
Add (deduct):
International operations, including Puerto Rico									(629.7)	(428.9)	(313.7)
General business credits									(87.4)	(66.8)	(58.3)
Non-deductible acquired IPR&D									309.9	300.1	0
2017 Tax Act										1,914	0
2017 Tax Act									175.3
Other									(1.5)	(86)	(172.5)
Income taxes	$ (186.2)	$ 261.5	$ 264.7	$ 223.6	$ 1,941	$ 36	$ 252.5	$ 172	$ 563.7	$ 2,401.5	$ 636.4

Retirement Benefits (Schedule o

Retirement Benefits (Schedule of Benefit Obligations and Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in benefit obligation:
Curtailment (gain) loss		$ 159
Special termination benefit		354.7
Defined Benefit Pension Plans
Change in benefit obligation:
Benefit obligation at beginning of year	$ 15,098.4	12,455.9
Service cost	304	331.3	$ 277.7
Interest cost	461	413.4	420.8
Actuarial (gain) loss	(1,431.2)	1,580.5
Benefits paid	(582.1)	(486.3)
Plan amendments	17.6	0
Curtailment (gain) loss	(43.9)	90.4
Special termination benefit	0	317.2
Foreign currency exchange rate changes and other adjustments	(161.9)	396
Benefit obligation at end of year	13,661.9	15,098.4	12,455.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	11,844.5	10,179.7
Actual return on plan assets	(370.3)	1,447.6
Employer contribution	324.7	414.3
Benefits paid	(582.1)	(486.3)
Foreign currency exchange rate changes and other adjustments	(152.6)	289.2
Fair value of plan assets at end of year	11,064.2	11,844.5	10,179.7
Funded status	(2,597.7)	(3,253.9)
Unrecognized net actuarial loss	5,011.8	5,645.5
Unrecognized prior service (benefit) cost	25.8	15.2
Net amount recognized	2,439.9	2,406.8
Retiree Health Benefit Plans
Change in benefit obligation:
Benefit obligation at beginning of year	1,728.5	1,494.6
Service cost	41.5	46.4	39.1
Interest cost	57.3	52.9	53.2
Actuarial (gain) loss	(182.8)	40
Benefits paid	(82.8)	(60.1)
Plan amendments	(14.1)	0
Curtailment (gain) loss	2.5	105.2
Special termination benefit	0	37.5
Foreign currency exchange rate changes and other adjustments	(6.2)	12
Benefit obligation at end of year	1,543.9	1,728.5	1,494.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	2,372.4	1,961.2
Actual return on plan assets	32.6	462
Employer contribution	75.9	9.1
Benefits paid	(82.8)	(60.1)
Foreign currency exchange rate changes and other adjustments	0	0.2
Fair value of plan assets at end of year	2,398.1	2,372.4	$ 1,961.2
Funded status	854.2	643.9
Unrecognized net actuarial loss	140.6	182
Unrecognized prior service (benefit) cost	(299.9)	(395)
Net amount recognized	$ 694.9	$ 430.9

Retirement Benefits (Schedule_2

Retirement Benefits (Schedule of Components in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Accrued retirement benefits	$ (2,911.3)	$ (3,513.9)
Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Sundry	196	106.8
Other current liabilities	(64.5)	(64.8)
Accrued retirement benefits	(2,729.2)	(3,295.9)
Accumulated other comprehensive (income) loss before income taxes	5,037.6	5,660.7
Net amount recognized	2,439.9	2,406.8
Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Sundry	1,043.6	869
Other current liabilities	(7.3)	(7.1)
Accrued retirement benefits	(182.1)	(218)
Accumulated other comprehensive (income) loss before income taxes	(159.3)	(213)
Net amount recognized	$ 694.9	$ 430.9

Retirement Benefits (Schedule_3

Retirement Benefits (Schedule of Weighted Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Discount rate for benefit obligation (in percentage)	3.90%	3.40%	3.90%
Discount rate for net benefit costs (in percentage)	3.40%	3.90%	4.30%
Rate of compensation increase for benefit obligation (in percentage)	3.40%	3.40%	3.40%
Rate of compensation increase for net benefit costs (in percentage)	3.40%	3.40%	3.40%
Expected return on plan assets for net benefit costs (in percentage)	7.30%	7.40%	7.40%
Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Discount rate for benefit obligation (in percentage)	4.40%	3.70%	4.30%
Discount rate for net benefit costs (in percentage)	3.70%	4.30%	4.50%
Expected return on plan assets for net benefit costs (in percentage)	8.00%	8.00%	8.00%

Retirement Benefits (Schedule_4

Retirement Benefits (Schedule of Expected Benefit Payments, Contributions and Expense) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation		$ 11,813.4	$ 13,025
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Fair value of plan assets		9,019.7	9,664.3
Components of net periodic (benefit) cost:
Curtailment (gain) loss	$ (28)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]
Total other comprehensive income (loss) during period		569.4	(576.6)	$ (512.8)
Defined Benefit Pension Plans
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,019		609.9
2,020		613.6
2,021		623.6
2,022		638.2
2,023		647.9
2024-2028		3,560.6
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation		11,032.1	11,956.7
Fair value of plan assets		9,019.7	9,639.4
Components of net periodic (benefit) cost:
Service cost		304	331.3	277.7
Interest cost		461	413.4	420.8
Expected return on plan assets		(848.3)	(776)	(752.1)
Amortization of prior service (benefit) cost		4.8	5.7	11.8
Recognized actuarial loss		334.4	288.2	285.6
Curtailment (gain) loss		1.3	93.5	0
Special termination benefit		0	317.2	0
Net periodic (benefit) cost		257.2	673.3	243.8
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]
Actuarial gain (loss) arising during period		211.1	(915.1)	(725.2)
Plan amendments during period		(17.6)	0	0
Curtailment gain (loss)		45.2	3.2	0
Amortization of prior service (benefit) cost included in net income		4.8	5.7	11.8
Amortization of net actuarial loss included in net income		334.4	288.2	285.6
Foreign currency exchange rate changes and other		45.2	(105.3)	75.6
Total other comprehensive income (loss) during period		623.1	(723.3)	(352.2)
Retiree Health Benefit Plans
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,019		98
2,020		99.1
2,021		100.7
2,022		99.9
2,023		98.5
2024-2028		505.3
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation		189.4	225.1
Fair value of plan assets		0	0
Components of net periodic (benefit) cost:
Service cost		41.5	46.4	39.1
Interest cost		57.3	52.9	53.2
Expected return on plan assets		(177.9)	(160.7)	(150.2)
Amortization of prior service (benefit) cost		(79.5)	(90)	(85.8)
Recognized actuarial loss		6.1	18.4	19.1
Curtailment (gain) loss		(29.3)	65.5	0
Special termination benefit		0	37.5	0
Net periodic (benefit) cost		(181.8)	(30)	(124.6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]
Actuarial gain (loss) arising during period		37.5	261.3	(132.2)
Plan amendments during period		14.1	0	35.8
Curtailment gain (loss)		(31.8)	(39.7)	0
Amortization of prior service (benefit) cost included in net income		(79.5)	(90)	(85.8)
Amortization of net actuarial loss included in net income		6.1	18.4	19.1
Foreign currency exchange rate changes and other		(0.1)	(3.3)	2.5
Total other comprehensive income (loss) during period		$ (53.7)	$ 146.7	$ (160.6)

Retirement Benefits (Fair Value

Retirement Benefits (Fair Value Disclosures) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	$ 11,064.2	$ 11,844.5	$ 10,179.7
Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,398.1	2,372.4	$ 1,961.2
U.S. | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	619.9	466.2
U.S. | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	59.9	43
International | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,117.8	2,934.2
International | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	127	182.5
Developed markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,963.2	3,182.9
Developed markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	69.1	71.2
Developed markets - repurchase agreements | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	(1,225.5)	(1,372.9)
Emerging markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	571.6	584.7
Emerging markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	53.5	53.1
Hedge funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,801.9	2,984.6
Hedge funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	245.8	256
Equity-like funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,942.5	1,639.6
Equity-like funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	169.2	137
Cash value of trust owned insurance contract | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,574.7	1,524.6
Real estate | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	525.8	563.9
Real estate | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	27.7	33
Other | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	747	861.3
Other | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	71.2	72
Significant Unobservable Inputs (Level 3) | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	24.7	22.1
Significant Unobservable Inputs (Level 3) | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2.5	2.1
Significant Unobservable Inputs (Level 3) | U.S. | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | U.S. | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | International | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1.8	0
Significant Unobservable Inputs (Level 3) | International | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0.2	0
Significant Unobservable Inputs (Level 3) | Developed markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Developed markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Developed markets - repurchase agreements | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Emerging markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	6.1	3.1
Significant Unobservable Inputs (Level 3) | Emerging markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0.6	0.3
Significant Unobservable Inputs (Level 3) | Hedge funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Hedge funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Equity-like funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	16.8	16.8
Significant Unobservable Inputs (Level 3) | Equity-like funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1.7	1.6
Significant Unobservable Inputs (Level 3) | Cash value of trust owned insurance contract | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Real estate | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Real estate | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Other | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	2.2
Significant Unobservable Inputs (Level 3) | Other | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0.2
Significant Other Observable Inputs (Level 2) | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,290.1	1,950.1
Significant Other Observable Inputs (Level 2) | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,657.9	1,663
Significant Other Observable Inputs (Level 2) | U.S. | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | U.S. | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | International | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | International | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Developed markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,173.3	2,468.2
Significant Other Observable Inputs (Level 2) | Developed markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	61.5	63.5
Significant Other Observable Inputs (Level 2) | Developed markets - repurchase agreements | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	(1,225.5)	(1,372.9)
Significant Other Observable Inputs (Level 2) | Emerging markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	256.2	252
Significant Other Observable Inputs (Level 2) | Emerging markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	25.5	24.4
Significant Other Observable Inputs (Level 2) | Hedge funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Hedge funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Equity-like funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Equity-like funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Cash value of trust owned insurance contract | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,574.7	1,524.6
Significant Other Observable Inputs (Level 2) | Real estate | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Real estate | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Significant Other Observable Inputs (Level 2) | Other | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	86.1	602.8
Significant Other Observable Inputs (Level 2) | Other | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	(3.8)	50.5
Quoted Prices in Active Markets for Identical Assets (Level 1) | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,628.5	1,645.4
Quoted Prices in Active Markets for Identical Assets (Level 1) | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	144.3	128.7
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	410.1	199.6
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	41	19.4
Quoted Prices in Active Markets for Identical Assets (Level 1) | International | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	828.8	955.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | International | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	50.5	61.3
Quoted Prices in Active Markets for Identical Assets (Level 1) | Developed markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	25	28.7
Quoted Prices in Active Markets for Identical Assets (Level 1) | Developed markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Developed markets - repurchase agreements | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Emerging markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	4.1	4.2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Emerging markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Hedge funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Hedge funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity-like funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity-like funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash value of trust owned insurance contract | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Real estate | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	147.2	338.6
Quoted Prices in Active Markets for Identical Assets (Level 1) | Real estate | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	14.7	33
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	213.3	119.2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	38.1	15
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	8,120.9	8,226.9
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	593.4	578.6
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | U.S. | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	209.8	266.6
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | U.S. | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	18.9	23.6
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | International | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,287.2	1,979.1
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | International | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	76.3	121.2
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Developed markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	764.9	686
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Developed markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	7.6	7.7
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Developed markets - repurchase agreements | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Emerging markets | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	305.2	325.4
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Emerging markets | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	27.4	28.4
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Hedge funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	2,801.9	2,984.6
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Hedge funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	245.8	256
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Equity-like funds | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	1,925.7	1,622.8
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Equity-like funds | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	167.5	135.4
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Cash value of trust owned insurance contract | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	0	0
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Real estate | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	378.6	225.3
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Real estate | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	13	0
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Other | Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	447.6	137.1
Fair Value, Retirement Benefits, Investments Valued at Net Asset Value | Other | Retiree Health Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Line Items] [Line Items]
Fair value of plan assets	$ 36.9	$ 6.3

Retirement Benefits (Narrative)

Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Curtailment (gain) loss	$ (28)
Defined benefit obligation, increase (decrease)		$ (1,620)	$ 2,880
Curtailment (gain) loss			159
Special termination benefit			354.7
Total accumulated benefit obligation for our defined benefit pension plans		12,760	13,900
Expense under the plans		$ 153.5	$ 169.1	$ 175
Percentage of global investments in plan assets (in percentage)		80.00%
Expected contribution		$ 45
Marketable equity securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (in percentage)		70.00%
Developed markets
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation (in percentage)		30.00%

Contingencies (Details)

Contingencies (Details) R$ in Millions, $ in Millions	1 Months Ended		12 Months Ended
	Jul. 31, 2018companyproduct	Jun. 30, 2018case	Dec. 31, 2018USD ($)individualapplicationcompanypatentlawsuitdemanddefendant	Dec. 31, 2018BRL (R$)individuallawsuitdefendant
Loss Contingencies [Line Items]
Number of companies | company	4
Number of generic products | product	1
Dr Reddy's Lab
Loss Contingencies [Line Items]
Claims settled and dismissed | case		2
Adocia S.A
Loss Contingencies [Line Items]
Number of patents | patent			2
Amount of claim | $			$ 1,300
Gain contingency, unrecorded amount | $			$ 188
Japanese Administrative Proceedings
Loss Contingencies [Line Items]
Number of demands | demand			3
Number of patents | patent			2
United States | Alimta
Loss Contingencies [Line Items]
Number of new application | application			10
Number of defendants | defendant			2	2
Number of companies | company			5
Brazil | Employee Litigation
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit			30	30
Damages awarded, value			$ 130	R$ 500.0
Plaintiff Appealing Decision of Court | Brazil | Employee Litigation
Loss Contingencies [Line Items]
Number of individuals | individual			410	410

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Roll-forward) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ 11,667.9
Other comprehensive income (loss) before reclassifications		(106.9)	$ 114	$ (895.8)
Net amount reclassified from accumulated other comprehensive loss		190.5	60.5	250.7
Net other comprehensive income (loss)	[1]	83.6	174.5	(645.1)
Reclassifications of stranded tax effects (Note 2)			(643.6)
Ending balance		10,909.1	11,667.9
Accumulated other comprehensive loss		5,729.2	5,718.6
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(5,694.9)	(5,225.8)	(4,580.7)
Reclassification due to adoption of new accounting standard(3)		(128.9)
Ending balance		(5,740.2)	(5,694.9)	(5,225.8)
Foreign Currency Translation Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(1,233.4)	(1,867.3)	(1,360.2)
Reclassification due to adoption of new accounting standard(3)		0
Other comprehensive income (loss) before reclassifications		(389.1)	664.6	(581.6)
Net amount reclassified from accumulated other comprehensive loss		0	8.1	74.5
Net other comprehensive income (loss)		(389.1)	672.7	(507.1)
Reclassifications of stranded tax effects (Note 2)			(38.8)
Ending balance		(1,622.5)	(1,233.4)	(1,867.3)
Unrealized Net Gains (Losses) on Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		113.5	224	10.1
Reclassification due to adoption of new accounting standard(3)		(128.9)
Other comprehensive income (loss) before reclassifications		24.5	(15.7)	206.7
Net amount reclassified from accumulated other comprehensive loss		(31.2)	(110.6)	7.2
Net other comprehensive income (loss)		(6.7)	(126.3)	213.9
Reclassifications of stranded tax effects (Note 2)			15.8
Ending balance		(22.1)	113.5	224
Defined Benefit Pension and Retiree Health Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(4,340.7)	(3,371.6)	(3,012.1)
Reclassification due to adoption of new accounting standard(3)		0
Other comprehensive income (loss) before reclassifications		274	(543.4)	(518.7)
Net amount reclassified from accumulated other comprehensive loss		210	153.4	159.2
Net other comprehensive income (loss)		484	(390)	(359.5)
Reclassifications of stranded tax effects (Note 2)			(579.1)
Ending balance		(3,856.7)	(4,340.7)	(3,371.6)
Effective Portion of Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(234.3)	(210.9)	(218.5)
Reclassification due to adoption of new accounting standard(3)		0
Other comprehensive income (loss) before reclassifications		(16.3)	8.5	(2.2)
Net amount reclassified from accumulated other comprehensive loss		11.7	9.6	9.8
Net other comprehensive income (loss)		(4.6)	18.1	7.6
Reclassifications of stranded tax effects (Note 2)			(41.5)
Ending balance		(238.9)	(234.3)	(210.9)
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(5,718.6)	(5,274)	(4,580.7)
Reclassification due to adoption of new accounting standard(3)		(105.2)			$ (105.2)	$ (643.6)
Ending balance		(5,729.2)	(5,718.6)	(5,274)
Accumulated other comprehensive loss		(5,730)	5,720	5,270
AOCI Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Reclassification due to adoption of new accounting standard(3)		(23.7)
Accumulated other comprehensive loss		$ 11	$ (23.7)	$ (48.2)
[1]	Other comprehensive income in 2018 consists of $72.6 million of other comprehensive income attributable to controlling interest and $11.0 million of other comprehensive income attributable to noncontrolling interest. Other comprehensive income in 2017 consists of $199.0 million of other comprehensive income attributable to controlling interest and $24.5 million of other comprehensive loss attributable to noncontrolling interest. Other comprehensive loss in 2016 consists of $693.3 million of other comprehensive loss attributable to controlling interest and $48.2 million of other comprehensive income attributable to noncontrolling interest.

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) (Tax effect) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items	$ (30.3)	$ 402.7	$ (10.6)
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items	51.6	170.8	(70.6)
Unrealized Net Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items	2.1	55	(89.2)
Defined Benefit Pension and Retiree Health Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items	(85.3)	186.6	153.3
Effective Portion of Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit/(provision) for income taxes allocated to other comprehensive income (loss) items	$ 1.3	$ (9.7)	$ (4.1)

Other Comprehensive Income (L_5

Other Comprehensive Income (Loss) (Reclassification) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									$ 56.5	$ (110.1)	$ (195.6)
Total before tax									(3,795.7)	(2,197.4)	(3,374)
Tax (benefit) expense	$ 186.2	$ (261.5)	$ (264.7)	$ (223.6)	$ (1,941)	$ (36)	$ (252.5)	$ (172)	(563.7)	(2,401.5)	(636.4)
Net of tax	$ (1,125.1)	$ (1,149.5)	$ 259.9	$ (1,217.4)	$ 1,656.9	$ (555.6)	$ (1,008)	$ 110.8
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax									190.5	60.5	250.7
Prior service benefits, net | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									(74.7)	(84.3)	(74)
Amortization of retirement benefit items: | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									340.5	306.6	304.7
Defined Benefit Pension and Retiree Health Benefit Plans | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax									265.8	222.3	230.7
Tax (benefit) expense									55.8	68.9	71.5
Net of tax									210	153.4	159.2
Unrealized Net Gains (Losses) on Securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									(39.5)	(170.2)	(16.1)
Total before tax									(39.5)	(170.2)	11.2
Tax (benefit) expense									(8.3)	(59.6)	4
Net of tax									(31.2)	(110.6)	7.2
Impairment losses | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									0	0	27.3
Other, net of tax | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense									$ 11.7	$ 17.7	84.3
Foreign Currency Translation Gains (Losses) | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net (income) expense											$ (74.5)

Other - Net, (Income) Expense_2

Other - Net, (Income) Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Nonoperating Income (Expense) [Abstract]
Interest expense	$ 272.1	$ 225	$ 185.2
Interest income	(161.3)	(167.3)	(108.7)
Venezuela charge	0	0	203.9
Retirement benefit	(242.1)	(248.1)	(197.6)
Other (income) expense	56.5	(110.1)	(195.6)
Other–net, (income) expense	$ (74.8)	$ (300.5)	$ (112.8)

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)wholesalersegment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment									2
Number of wholesalers | wholesaler									3
Revenue	$ 6,438.6	$ 6,061.9	$ 6,355.2	$ 5,700	$ 6,160.7	$ 5,658	$ 5,824.3	$ 5,228.3	$ 24,555.7	$ 22,871.3	$ 21,222.1
Total segment profits									3,795.7	2,197.4	3,374
Amortization of intangible assets (Note 8)									(558.7)	(683.4)	(687.9)
Asset impairment, restructuring, and other special charges (Note 5)	(246)	(83.3)	(74.4)	(78.3)	(1,003.2)	(406.5)	(50)	(213.9)	(482)	(1,673.6)	(382.5)
Venezuela charge (Note 17)									0	0	203.9
Acquired in-process research and development (Note 3)	(329.4)	(30)	(1,624.5)	0	(50)	(205)	0	(857.6)	(1,983.9)	(1,112.6)	(30)
Inventory fair value adjustment related to acquisition of BIVIVP (Note 3)	(1,593.7)	$ (1,562.3)	$ (1,702.7)	$ (1,571.3)	(1,644.9)	$ (1,586.3)	$ (1,571.7)	$ (1,347.9)	(6,430)	(6,150.8)	(5,710.1)
Other—net, (income) expense (Note 17)									(74.8)	(300.5)	(112.8)
Consolidated income before taxes									3,795.7	2,197.4	3,374
Long-lived assets	9,532.1				9,480.3				9,532.1	9,480.3	8,994.5
United States
Segment Reporting Information [Line Items]
Revenue									13,875.2	12,785.1	11,506.2
Long-lived assets	4,946.6				5,013.4				4,946.6	5,013.4	4,984.6
Outside U.S.
Segment Reporting Information [Line Items]
Revenue									10,680.5	10,086.3	9,715.9
Europe
Segment Reporting Information [Line Items]
Revenue									4,231.1	3,943.2	3,768.1
Long-lived assets	2,708.1				2,550.1				2,708.1	2,550.1	2,140.7
JAPAN
Segment Reporting Information [Line Items]
Revenue									2,493.7	2,419.7	2,330.9
Long-lived assets	181.9				155.1				181.9	155.1	92.4
Other foreign countries
Segment Reporting Information [Line Items]
Revenue									3,955.7	3,723.3	3,616.9
Long-lived assets	$ 1,695.5				$ 1,761.7				1,695.5	1,761.7	1,776.8
Human pharmaceutical products
Segment Reporting Information [Line Items]
Total depreciation expense and software amortization included in segment profits									934	789.8	723.4
Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									12,352.2	11,274	9,941.7
Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									9,061	8,511.7	8,122.2
Animal health products
Segment Reporting Information [Line Items]
Total depreciation expense and software amortization included in segment profits									111.3	102.7	89.9
Animal health products | United States
Segment Reporting Information [Line Items]
Revenue									1,523	1,511.1	1,564.5
Animal health products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									1,619.5	1,574.5	1,593.7
Endocrinology | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									7,511.6	6,373	4,831.9
Endocrinology | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									4,190.5	3,712.2	3,250.9
Trulicity | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									2,515.8	1,609.8	737.6
Trulicity | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									683.3	419.9	187.9
Humalog | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									1,787.8	1,717.8	1,685.2
Humalog | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									1,208.7	1,147.4	1,083.6
Humulin | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									910.2	884.6	861.8
Humulin | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									421.2	450.7	504.1
Forteo | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									757.9	965.2	770.5
Forteo | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									817.7	783.8	729.4
Basaglar
Segment Reporting Information [Line Items]
Revenue									801.2	432.1	86.1
Basaglar | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									622.8	311.1	15.8
Basaglar | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									178.5	121	70.3
Jardiance
Segment Reporting Information [Line Items]
Revenue									658.3	447.5	201.9
Jardiance | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									400.2	290.4	144.5
Jardiance | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									258.1	157	57.4
Trajenta
Segment Reporting Information [Line Items]
Revenue									574.7	537.9	436.6
Trajenta | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									224.2	213.2	165.9
Trajenta | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									350.5	324.7	270.7
Other Endocrinology | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									292.7	380.9	450.6
Other Endocrinology | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									272.5	307.7	347.5
Oncology: | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									2,403.2	2,050.4	1,975.1
Oncology: | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									1,857.3	1,761.6	1,746.8
Alimta | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									1,131	1,034.3	1,101
Alimta | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									1,001.9	1,028.2	1,182.3
Erbitux
Segment Reporting Information [Line Items]
Revenue									635.3	645.9	687
Erbitux | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									531.6	541.7	581.1
Erbitux | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									103.8	104.2	105.9
Cyramza® | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									291.5	278.8	270.1
Cyramza® | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									529.9	479.6	344
Other Oncology | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									449.1	195.6	22.9
Other Oncology | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									221.7	149.6	114.6
Cardiovascular: | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									1,355.7	1,722.7	1,991.4
Cardiovascular: | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									898.6	1,148.5	1,234
Cialis | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									1,129.2	1,358.6	1,469.5
Cialis | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									722.7	964.5	1,002.1
Effient | Human pharmaceutical products
Segment Reporting Information [Line Items]
Revenue									122.2	388.9	535.2
Effient | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									68.1	340.1	465.6
Effient | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									54.1	48.8	69.6
Other Cardiovascular | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									158.4	24	56.3
Other Cardiovascular | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									121.8	135.2	162.3
Neuroscience: | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									277.4	591	989.9
Neuroscience: | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									1,543.3	1,580.1	1,730.4
Strattera® | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									89.7	284.9	534.9
Strattera® | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									361.1	333.3	319.8
Cymbalta | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									54.3	114.9	269.3
Cymbalta | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									653.7	642.2	661.2
Zyprexa® | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									36.2	75.5	69.8
Zyprexa® | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									435.1	505.7	655.5
Other Neuroscience | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									97.2	115.7	115.9
Other Neuroscience | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									93.4	98.9	93.9
Immunology: | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									745.4	486	110.8
Immunology: | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									394.6	119	2.3
Taltz | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									738.7	486	110.8
Taltz | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									198.7	73.2	2.3
Other Immunology | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									6.7	0	0
Other Immunology | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									195.9	45.8	0
Other human pharmaceutical products | Human pharmaceutical products | United States
Segment Reporting Information [Line Items]
Revenue									58.7	50.9	42.6
Other human pharmaceutical products | Human pharmaceutical products | Outside U.S.
Segment Reporting Information [Line Items]
Revenue									$ 176.6	$ 190.3	$ 157.8
Minimum | Sales Revenue, Goods, Net
Segment Reporting Information [Line Items]
Concentration risk, percentage									11.00%	12.00%	11.00%
Minimum | Accounts Receivable
Segment Reporting Information [Line Items]
Concentration risk, percentage									14.00%	14.00%
Maximum | Sales Revenue, Goods, Net
Segment Reporting Information [Line Items]
Concentration risk, percentage									18.00%	18.00%	17.00%
Maximum | Accounts Receivable
Segment Reporting Information [Line Items]
Concentration risk, percentage									22.00%	22.00%
Adjustment to Return Reserve | Cymbalta | Human pharmaceutical products
Segment Reporting Information [Line Items]
Revenue											$ 175
Operating Segments
Segment Reporting Information [Line Items]
Total segment profits									$ 6,825.1	$ 5,701	4,673.7
Consolidated income before taxes									6,825.1	5,701	4,673.7
Total depreciation expense and software amortization included in segment profits									1,045.3	892.5	813.3
Operating Segments | Human pharmaceutical products
Segment Reporting Information [Line Items]
Total segment profits									6,217.8	5,139.7	4,010
Consolidated income before taxes									6,217.8	5,139.7	4,010
Operating Segments | Animal health products
Segment Reporting Information [Line Items]
Total segment profits									607.3	561.3	663.7
Consolidated income before taxes									607.3	561.3	663.7
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total segment profits									3,795.7	2,197.4	3,374
Amortization of intangible assets (Note 8)									(546)	(674.8)	(683.3)
Asset impairment, restructuring, and other special charges (Note 5)									(482)	(1,673.6)	(382.5)
Venezuela charge (Note 17)									0	0	(203.9)
Acquired in-process research and development (Note 3)									(1,983.9)	(1,112.6)	(30)
Inventory fair value adjustment related to acquisition of BIVIVP (Note 3)									0	(42.7)	0
Other—net, (income) expense (Note 17)									(17.5)	0	0
Consolidated income before taxes									$ 3,795.7	$ 2,197.4	$ 3,374

Selected Quarterly Data (Unau_3

Selected Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 6,438.6	$ 6,061.9	$ 6,355.2	$ 5,700	$ 6,160.7	$ 5,658	$ 5,824.3	$ 5,228.3	$ 24,555.7	$ 22,871.3	$ 21,222.1
Cost of sales	1,593.7	1,562.3	1,702.7	1,571.3	1,644.9	1,586.3	1,571.7	1,347.9	6,430	6,150.8	5,710.1
Operating expenses	3,315.3	2,959.9	2,986.8	2,676.9	3,290.4	2,918.5	3,002.5	2,826
Acquired in-process research and development	329.4	30	1,624.5	0	50	205	0	857.6	1,983.9	1,112.6	30
Asset impairment, restructuring, and other special charges (Note 5)	246	83.3	74.4	78.3	1,003.2	406.5	50	213.9	482	1,673.6	382.5
Income before income taxes	938.9	1,411	4.8	1,441	284.1	591.6	1,260.5	61.2
Income taxes (Note 13)	(186.2)	261.5	264.7	223.6	1,941	36	252.5	172	$ 563.7	$ 2,401.5	$ 636.4
Net income (loss)	$ 1,125.1	$ 1,149.5	$ (259.9)	$ 1,217.4	$ (1,656.9)	$ 555.6	$ 1,008	$ (110.8)
Basic (usd per share)	$ 1.11	$ 1.13	$ (0.25)	$ 1.16	$ (1.58)	$ 0.53	$ 0.96	$ (0.10)	$ 3.14	$ (0.19)	$ 2.59
Diluted (usd per share)	1.10	1.12	(0.25)	1.16	(1.58)	0.53	0.95	(0.10)	$ 3.13	$ (0.19)	$ 2.58
Dividends paid per share (usd per share)	$ 0.5625	$ 0.5625	$ 0.5625	$ 0.5625	$ 0.52	$ 0.52	$ 0.52	$ 0.52

Uncategorized Items - lly-20181

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 643,600,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 763,800,000