Elanco Animal Health (ELAN) 10-K 28 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 25, 2020	Jun. 30, 2019
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Elanco Animal Health Inc.
Entity Central Index Key	0001739104
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 12.4
Entity Common Stock, Shares Outstanding		398,532,256

Consolidated and Combined State

Consolidated and Combined Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 3,071	$ 3,066.8	$ 2,889
Costs, expenses and other:
Cost of sales	1,470.3	1,573.8	1,493.9
Research and development	270.1	246.6	251.7
Marketing, selling and administrative	760.2	735.2	779.8
Amortization of intangible assets	200.4	197.4	221.2
Asset impairment, restructuring and other special charges (Note 7)	185.5	128.8	375.1
Interest expense, net of capitalized interest	78.9	29.6	0
Other-net, expense (income)	27.4	41.3	(0.1)
Costs, expenses and other	2,992.8	2,952.7	3,121.6
Income (loss) before income taxes	78.2	114.1	(232.6)
Income tax expense	10.3	27.6	78.1
Net income (loss)	$ 67.9	$ 86.5	$ (310.7)
Earnings (loss) per share
Basic (usd per share)	$ 0.18	$ 0.28	$ (1.06)
Diluted (usd per share)	$ 0.18	$ 0.28	$ (1.06)
Weighted average shares outstanding
Basic (in shares)	369	313.7	293.3
Diluted (in shares)	370.3	313.7	293.3

Consolidated and Combined Sta_2

Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 67.9	$ 86.5	$ (310.7)
Other comprehensive income (loss)
Foreign currency translation	19.8	(47.1)	210.1
Defined benefit pension and retiree health benefit plans, net of taxes	28.7	25.4	(9.8)
Other comprehensive income (loss), net of taxes	48.5	(21.7)	200.3
Comprehensive income (loss)	$ 116.4	$ 64.8	$ (110.4)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 334	$ 474.8
Accounts receivable, net of allowances of $6.2 (2019) and $8.4 (2018)	816.9	651.8
Other receivables	73	57.6
Inventories (Note 8)	1,050.7	1,004.1
Prepaid expenses and other	87.4	113.9
Restricted cash (Note 20)	11.1	202.7
Total current assets	2,373.1	2,504.9
Noncurrent Assets
Goodwill (Note 11)	2,989.6	2,958
Other intangibles, net (Note 11)	2,482.8	2,504.8
Other noncurrent assets	185	66.6
Property and equipment, net (Note 12)	955.3	922.4
Total assets	8,985.8	8,956.7
Current Liabilities
Accounts payable	222.6	205.2
Employee compensation	99.6	98.9
Sales rebates and discounts	211	169.9
Current portion of long term debt (Note 9)	24.5	29
Other current liabilities	244.4	199
Payable to Lilly (Note 20)	16.4	268.7
Total current liabilities	818.5	970.7
Noncurrent Liabilities
Long-term debt (Note 9)	2,330.5	2,443.3
Accrued retirement benefits (Note 18)	82.5	109.1
Deferred taxes (Note 15)	100.8	114.6
Other noncurrent liabilities	106.6	121.5
Total liabilities	3,438.9	3,759.2
Commitments and Contingencies (Note 16)
Equity
Preferred stock, 1,000,000,000 shares authorized, no par value; none issued	0	0
Common stock, 5,000,000,000 shares authorized, no par value; 373,011,513 and 365,643,911 shares issued and outstanding as of December 31, 2019 and 2018, respectively	0	0
Additional paid-in capital	5,636.3	5,403.3
Retained earnings	84.3	16.4
Accumulated other comprehensive loss	(173.7)	(222.2)
Total equity	5,546.9	5,197.5
Total liabilities and equity	$ 8,985.8	$ 8,956.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, net of allowances	$ 6.2	$ 8.4
Preferred stock authorized (in shares)	1,000,000,000	1,000,000,000
Preferred stock issued (in shares)	0	0
Common stock authorized (in shares)	5,000,000,000	5,000,000,000
Common stock issued (in shares)	373,011,513	365,643,911
Common stock outstanding (in shares)	373,011,513	365,643,911

Consolidated and Combined Sta_3

Consolidated and Combined Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities
Net income (loss)	$ 67.9	$ 86.5	$ (310.7)
Adjustments to reconcile net income (loss) to cash flows from operating activities:
Depreciation and amortization	314.5	296	318.4
Change in deferred income taxes	0.1	(60.7)	(13.4)
Stock-based compensation expense	49.4	26	25
Asset impairment charges	32.6	120.5	110.6
Gain on sale of assets	0	(0.8)	(19.6)
Other non-cash operating activities, net	(12.7)	49	10
Other changes in operating assets and liabilities, net of acquisitions and divestitures:
Receivables	(172.4)	(122)	48.4
Inventories	(33.1)	(20.1)	(39)
Other assets	7	(3.2)	52.5
Accounts payable and other liabilities	(29.2)	116.1	(8.4)
Net Cash Provided by Operating Activities	224.1	487.3	173.8
Cash Flows from Investing Activities
Purchases of property and equipment	(140.4)	(134.5)	(98.6)
Disposals of property and equipment	0.3	9.4	37.6
Purchases of software	(57)	(2)	(18.5)
Cash paid for acquisitions, net of cash acquired	(32.8)	0	(882.1)
Other investing activities, net	(4.9)	0.1	(3)
Net Cash Used for Investing Activities	(234.8)	(127)	(964.6)
Cash Flows from Financing Activities
Proceeds from issuance of long-term debt (Note 9)	0	2,500	0
Repayments of borrowings (Note 9)	(121.1)	(7.5)	0
Proceeds from issuance of common stock (Note 1)	0	1,659.7	0
Debt issuance costs	0	(24.5)	0
Consideration paid to Lilly in connection with the Separation (Note 1)	(191.6)	(3,991.3)	0
Other financing activities, net	1.6	(17.2)	(0.8)
Other net transactions with Lilly	6.3	(154.4)	848.3
Net Cash Provided by (Used for) Financing Activities	(304.8)	(35.2)	847.5
Effect of exchange rate changes on cash and cash equivalents	(16.9)	29	7.9
Net (decrease) increase in cash, cash equivalents and restricted cash	(332.4)	354.1	64.6
Cash, cash equivalents and restricted cash at beginning of period	677.5	323.4	258.8
Cash, cash equivalents and restricted cash at end of period	345.1	677.5	323.4
Cash, cash equivalents and restricted cash at end of period	$ 677.5	$ 323.4	$ 323.4

Consolidated and Combined Sta_4

Consolidated and Combined Statements of Equity - USD ($) shares in Millions, $ in Millions		Total	Aratana Therapeutics, Inc.	Common Stock	Common StockAratana Therapeutics, Inc.		Additional Paid-in Capital	Additional Paid-in CapitalAratana Therapeutics, Inc.	Net Parent Company Investment	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Foreign Currency Translation	Defined Benefit Pension and Retiree Health Benefit Plans
Balance at beginning of period (in shares) at Dec. 31, 2016				293.3
Balance at beginning of period at Dec. 31, 2016		$ 7,017.4		$ 0			$ 0		$ 7,474.3	$ 0	$ (456.9)	$ (437.3)	$ (19.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(310.7)							(310.7)
Other comprehensive income (loss), net of tax		200.3									200.3	210.1	(9.8)
Transfers (to)/from Lilly, net		873.3							873.3
Balance at end of period (in shares) at Dec. 31, 2017				293.3
Balance at end of period at Dec. 31, 2017		7,780.3		$ 0			0		8,036.9	0	(256.6)	(227.2)	(29.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		86.5							70.1	16.4
Other comprehensive income (loss), net of tax		(21.7)									(21.7)	(47.1)	25.4
Transfers (to)/from Lilly, net		(226.3)							(226.3)
Separation adjustments	[1]	99.6							43.5		56.1	56.1
Issuance of common stock (in shares)				72.3
Issuance of common stock		1,659.7					1,659.7
Consideration to Lilly in connection with Separation		(4,194.9)					(4,194.9)
Reclassification of net parent company investment		0					7,923.9		(7,923.9)
Stock compensation		1.8					1.8
Capital contribution from Lilly		12.8					12.8
Balance at end of period (in shares) at Dec. 31, 2018				365.6
Balance at end of period at Dec. 31, 2018		5,197.5		$ 0			5,403.3		0	16.4	(222.2)	(218.2)	(4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		67.9								67.9
Other comprehensive income (loss), net of tax		48.5									48.5	19.8	28.7
Separation adjustments	[2]	(51.2)					(51.2)
Stock compensation		40.7					40.7
Issuance of stock under employee stock plans, net (in shares)				0.1
Issuance to Aratana shareholders for acquisition (in shares)	[3]				7.2
Issuance to Aratana shareholders for acquisition	[3]		$ 238					$ 238
Accelerated vesting of equity awards (in shares)			0.1		0.1	[3]
Accelerated vesting of equity awards	[3]		$ 3.6					3.6
Other	[3]		1.9					$ 1.9
Balance at end of period (in shares) at Dec. 31, 2019				373
Balance at end of period at Dec. 31, 2019		$ 5,546.9	$ 5,546.9	$ 0			$ 5,636.3		$ 0	$ 84.3	$ (173.7)	$ (198.4)	$ 24.7
[1]	See Note 3: Impact of Separation for further discussion.
[2]	See Note 20: Related Party Agreements and Transactions for further discussion.
[3]	See Note 6: Acquisitions for further discussion.

Nature of Business and Organiza

Nature of Business and Organization	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Organization	Nature of Business and Organization Nature of Business Elanco was formed as a wholly-owned subsidiary of Lilly, and is a global animal health company that innovates, develops, manufactures and markets products for companion and food animals. We offer a diverse portfolio of more than 125 brands to veterinarians and food animal producers in more than 90 countries. Organization Elanco Parent was formed in 2018, as a wholly-owned subsidiary of Lilly, to serve as the ultimate parent company of substantially all of the animal health businesses of Lilly. On September 24, 2018, Elanco Parent completed an IPO resulting in the issuance of 72.3 million shares of its common stock (including shares issued pursuant to the underwriters’ option to purchase additional shares), which represented 19.8% of the outstanding shares, at $24 per share resulting in total net proceeds, after underwriting discounts and commissions, of $1.7 billion. In connection with the completion of the IPO, through a series of equity and other transactions, Lilly transferred to Elanco Parent the animal health businesses that form its business. In exchange, Elanco Parent has paid to Lilly approximately $4.2 billion, which included the net proceeds from the IPO, the net proceeds from the debt offering completed by Elanco Parent in August 2018 and the term loan facility entered into by Elanco Parent in September 2018 (see Note 9: Debt). These transactions are collectively referred to herein as the Separation. On February 8, 2019, Lilly announced an exchange offer whereby Lilly shareholders could exchange all or a portion of Lilly common stock for shares of Elanco common stock owned by Lilly. The disposition of Elanco shares was completed on March 11, 2019 and resulted in the full separation of Elanco along with the disposal of Lilly's entire ownership and voting interest in Elanco.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation We have prepared the accompanying consolidated and combined financial statements in accordance with accounting principles generally accepted in the United States (GAAP). In our opinion, the financial statements reflect all adjustments (including those that are normal and recurring) that are necessary for fair presentation of the results of operations for the periods shown. The accounts of all wholly-owned and majority-owned subsidiaries are included in the consolidated financial statements, and all intercompany balances and transactions have been eliminated. Certain reclassifications have been made to prior periods in the unaudited condensed consolidated and combined financial statements and accompanying notes to conform with current presentation. In preparing financial statements in conformity with GAAP, we must make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, 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 and have evaluated subsequent events up to the time of the filing. For the periods after Separation, the financial statements are prepared on a consolidated basis and reflect the results of operations, comprehensive income, financial position, equity and cash flows resulting from our operations as an independent company. For periods prior to Separation, our financial statements are combined, have been prepared on a standalone basis, and are derived from Lilly's consolidated financial statements and accounting records. The consolidated and combined financial statements reflect the financial position, results of operations and cash flows related to the animal health businesses that were transferred to Elanco Parent and are prepared in conformity with GAAP. The combined financial statements include the attribution of certain assets and liabilities that historically have been held at the Lilly corporate level but which are specifically identifiable or attributable to the businesses that have been transferred to Elanco Parent. All intercompany transactions and accounts within Elanco have been eliminated. All transactions between us and Lilly are considered to be effectively settled in the combined financial statements at the time the intercompany transaction is recorded. The total net effect of the settlement of these intercompany transactions is reflected in the combined statements of cash flows as a financing activity and in the consolidated and combined statement of equity as net parent company investment. Prior to Separation, these combined financial statements include an allocation of expenses related to certain Lilly corporate functions, including executive oversight, treasury, legal, finance, human resources, tax, internal audit, financial reporting, information technology and investor relations, prior to IPO. These expenses were allocated to us based on direct usage or benefit where specifically identifiable, with the remainder allocated primarily on a pro rata basis of revenue, headcount and other measures. We consider the expenses methodology and results to be reasonable for all periods presented. However, the allocations may not be indicative of the actual expense that would have been incurred had we operated as an independent, publicly traded company for the periods presented. It is impractical to estimate what the standalone costs of Elanco would have been in the historical periods. After the Separation, a TSA between Lilly and Elanco went into effect. Under the terms of the TSA, we will be able to use these Lilly services for a fixed term established on a service-by-service basis. We are paying Lilly mutually agreed upon fees for the Lilly services provided under the TSA. Our consolidated and combined financial statements reflect the charges for Lilly services after the IPO. See Note 20: Related Party Agreements and Transactions for additional details. The income tax amounts in the combined financial statements have been calculated based on a separate return methodology and presented as if our operations were separate taxpayers in the respective jurisdictions. We file income tax returns in the U.S. federal jurisdiction and various state, local and non-U.S. jurisdictions. Prior to full separation, certain of these income tax returns were filed on a consolidated or combined basis with Eli Lilly and Company and/or its subsidiaries. Prior to Separation, Lilly maintained various benefit and combined stock-based compensation plans at a corporate level and other benefit plans at a country level. Our employees participated in such programs and the portion of the cost of those plans related to our employees is included in our financial statements. However, the consolidated balance sheets do not include any equity issued related to stock-based compensation plans or any net benefit plan obligations unless the benefit plan covers only our dedicated employees or where the legal obligation associated with the benefit plan transferred to Elanco. Upon Lilly's full divestiture of Elanco in March 2019, all Lilly share-based awards held by our employees were converted into awards that will be settled in Elanco shares. Prior to Separation, the equity balance in the combined financial statements represents the excess of total assets over liabilities, including intercompany balances between Elanco and Lilly (net parent company investment) and accumulated other comprehensive income (loss). Net parent company investment is primarily impacted by contributions from Lilly which are the result of treasury activities and net funding provided by or distributed to Lilly. See Note 20: Related Party Agreements and Transactions for further information.

Impact of Separation

Impact of Separation	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Impact of Separation	Impact of Separation In connection with the Separation, we issued $2.0 billion aggregate principal amount of senior notes in a private placement, and we also entered into a $750.0 million senior unsecured revolving credit facility and $500.0 million senior unsecured term credit facility. See Note 9: Debt for further information. In connection with the Separation, we entered into various agreements with Lilly, including a master separation agreement, a tax matters agreement and the TSA. In connection with the terms of the Separation, there were certain assets and liabilities included in the pre-Separation balance sheet that were retained by Lilly and there were certain assets not included in the pre-Separation balance sheet that were transferred to us. The cumulative adjustment to the historical balance sheet increased net assets and total equity by approximately $99.6 million. The impact on net assets primarily represents the elimination of certain income tax assets and liabilities and the contribution of additional assets. We will also continue to have certain ongoing relationships with Lilly as described in Note 20: Related Party Agreements and Transactions.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Revenue recognition Effective January 1, 2018, we adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers (ASU 2014-09) and other related updates. The new standard has been applied to contracts for which performance had not been completed as of the date of adoption. Revenue presented for periods prior to 2018 was accounted for under previous standards and has not been adjusted. Revenue and net income for the years ended December 31, 2019 and 2018 do not differ materially from amounts that would have resulted from application of the previous standards. Product Sales We recognize revenue primarily from product sales to customers. 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 120 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. For arrangements with contract manufacturing organizations (CMO), we recognize revenue over time or at a point in time depending on our evaluation of when the customer obtains control of the promised goods or service. Revenue is recognized over time when we are creating or enhancing an asset that the customer controls. In this instance revenue is recognized as the asset is created or enhanced or our performance does not create an asset with an alternative use and we have an enforceable right to payment for performance completed. Provisions for rebates and discounts, as well as 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 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 products are sold to wholesale distributors. We initially invoice our customers 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. Judgments are required in making these estimates. • The rebate and discount amounts are recorded as a deduction to arrive at our net product sales. We estimate these accruals using an expected value approach. • In determining the appropriate accrual amount, we consider our historical experience with similar incentives programs and current sales data and estimates of inventory levels at our channel distributors to evaluate the impact of such programs on revenue and continually monitor the impact of this experience and adjust as necessary. Although we accrue a liability for rebates related to these programs at the time the sale is recorded, the rebate related to that sale is typically paid up to six months after the rebate or incentive period expires. Because of this time lag, in any particular period rebate adjustments may incorporate revisions of accruals for several periods. Sales Returns - Background and Uncertainties • We estimate a reserve for future product returns related to product sales using an expected value approach. This estimate is based on several factors, including: local returns policies and practices; returns as a percentage of revenue; an understanding of the reasons for past returns; estimated shelf life by product; and estimate of the amount of time between shipment and return. Adjustments to the returns reserve have been and may in the future be required based on revised estimates to our assumptions, which would have an impact on our consolidated results of operations. We record the return amounts as a deduction to arrive at our net product sales. 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, which 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. 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 combined financial statements. Implementation of New Financial Accounting Pronouncements The following table provides a brief description of an accounting standard that was effective January 1, 2019 and was adopted on that date: Standard Description 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 previous GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. We adopted the standard on January 1, 2019 using the modified retrospective approach, applied at the beginning of the period of adoption, and we elected the package of transition practical expedients. Upon adoption of the standard, we recorded $84.9 million of right-of-use assets and $85.3 million of operating lease liabilities on our consolidated balance sheet. Adoption of this standard did not have a material impact on our consolidated statement of operations for the year ended December 31, 2019. See Note 13: Leases for further information. The following table provides a brief description of the accounting standards applicable to us that have not yet been adopted: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard modifies the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables. This may result in the earlier recognition of allowances for losses. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. We do not expect that the adoption of this standard will have a material impact on our consolidated financial statements based on financial instruments currently held. Accounting Standards Update 2018-15, Intangibles - Goodwill and Other Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract This guidance aligns the requirements for capitalizing implementation costs incurred in a cloud-based hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. Adoption of this standard is not expected to have a significant impact on our consolidated financial statements. Accounting Standards Update 2019-12, Simplifying the Accounting for Income Taxes The amendments in this update simplify the accounting for income taxes by removing certain exceptions and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. This standard is effective January 1, 2021, with early adoption permitted. We intend to adopt this standard on that date. We are currently evaluating the impact of adoption of the new standard on our consolidated financial statements.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Our sales rebates and discounts are based on specific agreements and the majority relate to sales in the U.S. As of December 31, 2019 and 2018, the liability for sales rebates and discounts in the U.S. represents approximately 71% and 70%, respectively, of our total liability with the next largest country representing approximately 8% of our total liability for 2019 and 2018. The following table summarizes the activity in the sales rebates and discounts liability in the U.S.: Year Ended December 31, 2019 2018 Beginning balance $ 118.5 $ 114.8 Reduction of revenue 316.3 221.0 Payments (284.4) (217.3) Ending balance $ 150.4 $ 118.5 Adjustments to revenue recognized as a result of changes in estimates for the judgments described above during the years ended December 31, 2019 and 2018 for product shipped in previous periods were not material. Actual product returns were 0.2% and 0.6% of net revenue for the years ended December 31, 2019 and 2018, respectively, and have not fluctuated significantly as a percentage of revenue. Disaggregation of Revenue The following table summarizes our revenue disaggregated by product category for the years ended December 31: 2019 2018 2017 Companion Animal Disease Prevention $ 787.9 $ 804.6 $ 660.2 Companion Animal Therapeutics 348.0 283.1 260.8 Food Animal Future Protein & Health 745.1 711.2 649.2 Food Animal Ruminants Swine 1,110.3 1,174.0 1,175.0 Strategic Exits (1) 79.7 93.9 143.8 Total Revenue $ 3,071.0 $ 3,066.8 $ 2,889.0 (1) Represents revenue from business activities we have either exited or made a strategic decision to exit.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions During the year ended December 31, 2019, we completed the acquisitions of all outstanding shares of Aratana Therapeutics, Inc. (Aratana) and Prevtec Microbia Inc. (Prevtec). During 2017, we completed the acquisition of BIVIVP. These transactions were accounted for as business combinations under the acquisition method of accounting. Under this method, the assets acquired and liabilities assumed were recorded at their respective fair values as of the acquisition date in our consolidated and combined 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 these acquisitions are included in our consolidated and combined financial statements from the dates of acquisition. Aratana Therapeutics, Inc. On July 18, 2019, we acquired Aratana, a pet therapeutics company focused on innovative therapies for dogs and cats, for stock and cash-based contingent value rights. Aratana is the creator of the canine osteoarthritis medicine, Galliprant , the rights to which we acquired in 2016. The acquisition enhances our presence in the areas of appetite stimulants in dogs, pain relief in dogs and cats, and treatments of other conditions in the U.S. and internationally. In connection with the acquisition, we issued approximately 7.2 million shares with a value of $238.0 million to Aratana shareholders, based on our stock price on the last trading day immediately prior to the closing date. The purchase consideration also included up to $12 million in contingent value rights, which represent the rights of Aratana shareholders to receive a contingent payment of $0.25 per share in cash upon the achievement of a specified milestone as outlined in the merger agreement. We calculated an immaterial fair value for the contingent value rights using the Monte Carlo simulation model. Contingent consideration liabilities that we previously recorded for future royalty and milestone payments in relation to the 2016 acquisition of rights to Galliprant were settled upon the closing of our acquisition of Aratana. The liabilities were valued at $84.7 million as of the acquisition date using the Monte Carlo simulation model. The resulting $7.5 million loss upon settlement was recorded in Other - net, expense in the consolidated and combined statement of operations for the year ended December 31, 2019. The following table summarizes the preliminary amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at July 18, 2019 Cash and cash equivalents $ 26.4 Inventories 10.3 Acquired in-process research and development 31.9 Marketed products (1) 36.7 Other intangible assets (1) 13.2 Other assets and liabilities - net 24.0 Total identifiable net assets 142.5 Goodwill (2) 10.8 Settlement of existing contingent consideration liabilities 84.7 Total consideration transferred $ 238.0 (1) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, are expected to have a weighted average useful life of approximately 12.5 years. (2) The goodwill recognized from this acquisition is attributable primarily to expected synergies from combining the operations of Aratana with our legacy business. The majority of goodwill associated with this acquisition is not deductible for tax purposes. The accounting for this acquisition is substantially complete, with the exception of the finalization of the valuation of intangible assets, tax-related amounts and minor working capital adjustments. The final determination of these amounts will be completed as soon as possible but no later than one year from the acquisition date. We issued 0.1 million shares and recorded $3.6 million of stock-based compensation expense for the vesting of Aratana equity awards that was accelerated upon the closing of the acquisition during the year ended December 31, 2019. Our consolidated statement of operations for the year ended December 31, 2019 included revenues of $10.0 million from Aratana. Had Aratana been acquired on January 1, 2018, the unaudited pro forma combined revenues of Elanco and Aratana would have been $3.1 billion for both the years ending December 31, 2019 and December 31, 2018, and income before income taxes would have been $63.2 million and $117.7 million for the years ending December 31, 2019 and December 31, 2018, respectively. Prevtec Microbia Inc. On July 31, 2019, we acquired Prevtec in a cash transaction for approximately $60.3 million, inclusive of certain post-closing adjustments. Prevtec is a Canadian biotechnology company specializing in the development of vaccines intended to help prevent bacterial diseases in food animals. The acquisition allows us to expand on our previous distribution arrangement for Coliprotec and is consistent with our efforts to explore innovative antibiotic alternatives. The purchase consideration included up to $16.3 million in additional cash consideration, contingent upon the achievement of specific sales milestones by December 31, 2021. We have recorded a $4.7 million liability on the consolidated balance sheet as of the acquisition date based on the fair value of the contingent consideration as calculated using the Monte Carlo simulation model. A previously existing $0.7 million receivable owed from Prevtec to Elanco Animal Health UK Limited was settled upon the closing of our acquisition of Prevtec. The resulting immaterial gain upon settlement was recorded in Other - net, expense in the consolidated and combined statement of operations for the year ended December 31, 2019. The following table summarizes the preliminary amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at July 31, 2019 Cash and cash equivalents $ 0.9 Property and equipment 0.5 Acquired in-process research and development 2.8 Marketed products (1) 58.9 Other intangible assets 1.1 Other assets and liabilities - net (10.3) Total identifiable net assets 53.9 Goodwill (2) 11.1 Total consideration transferred $ 65.0 (1) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, are 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 Prevtec with our legacy business and future unidentified projects and products. The goodwill associated with this acquisition is not deductible for tax purposes. The accounting for this acquisition is substantially complete, with the exception of the finalization of the valuation of intangible assets, tax-related amounts and minor working capital adjustments. The final determination of these amounts will be completed as soon as possible but no later than one year from the acquisition date. Boehringer Ingelheim Vetmedica, Inc. Vaccine Portfolio Acquisition On January 3, 2017, we acquired BIVIVP in a cash transaction for $882.1 million. Under the terms of the agreement, we acquired a manufacturing and research and development site, a U.S. vaccine portfolio including vaccines used for the treatment of bordetella, Lyme disease, rabies and parvovirus, among others. 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 (1) $ 108.6 Marketed products (2) 297.0 Property and equipment 148.2 Other assets and liabilities — net 8.2 Total identifiable net assets 562.0 Goodwill (3) 320.1 Total consideration transferred — net of cash acquired $ 882.1 (1) The fair value for inventories include a purchase accounting adjustment to write up the inventory value, which resulted in incremental cost of sales of $42.7 million in 2017. The fair value was determined by estimating the expected sales price of the inventories, reduced for all costs expected to the incurred and a profit on those costs. (2) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, were expected to have a weighted average useful life of 10 years. (3) The goodwill recognized from this acquisition is attributable primarily to expected synergies from combining the operations of BIVIVP with our legacy business, future unidentified projects and products, and the assembled workforce of BIVIVP. The goodwill associated with this acquisition is deductible for tax purposes. Our combined statement of operations for the year ended December 31, 2017 included BIVIVP revenues of $216.7 million. We are unable to provide the results of operations attributable to BIVIVP as those operations were substantially integrated into our legacy business. Pending Acquisition Bayer Animal Health Business In August 2019, we entered into the Purchase Agreement with Bayer, a German corporation, to acquire Bayer's animal health business. Bayer's animal health business is a provider of products intended to improve the health and well-being of pets and farm animals. This acquisition is expected to expand our Companion Animal product category, advance our planned intentional portfolio mix transformation and create a better balance between our Food Animal and Companion Animal product categories. Pursuant to the Purchase Agreement and subject to the satisfaction of certain customary closing conditions, including the receipt of antitrust approvals and the absence of any law or order enjoining or otherwise prohibiting the transaction in specified jurisdictions, we will purchase Bayer’s animal health business for approximately $5.3 billion in cash and approximately $2.3 billion of our common stock, subject to certain customary adjustments. Unless the parties agree otherwise, the transaction will close no earlier than July 1, 2020, per the terms of the Purchase Agreement. See Note 16: Commitments and Contingencies for discussion regarding certain commitments related to this transaction.

Asset Impairment, Restructuring

Asset Impairment, Restructuring and Other Special Charges	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Asset Impairment, Restructuring and Other Special Charges	Asset Impairment, Restructuring and Other Special Charges In recent years, we have incurred substantial costs associated with restructuring programs and cost-reduction initiatives designed to achieve a flexible and competitive cost structure. Restructuring activities primarily include charges associated with facility rationalization and workforce reductions. In connection with our recent acquisitions, we have also incurred costs associated with executing transactions and integrating acquired operations, which may include expenditures for banking, legal, accounting, and other similar services. In addition, we have incurred costs to stand up our organization as an independent company. All operating functions can be impacted by these actions; therefore, non-cash expenses associated with our tangible and intangible assets can be incurred as a result of revised fair value projections and/or determinations to no longer utilize certain assets in the business on an ongoing basis. For finite-lived intangible asset and other long-lived assets, whenever impairment indicators are present, we calculate the undiscounted value of projected cash flows associated with the asset, or group of assets, and compare it to the carrying amount. If the carrying amount is greater, we record an impairment loss for the excess of book value over fair value. Determinations of fair value can result from a complex series of judgments and rely on estimates and assumptions. See Note 2: Basis of Presentation for discussion regarding estimates and assumptions. Components of asset impairment, restructuring and other special charges for the years ended December 31 are as follows: 2019 2018 2017 Restructuring charges: (1) Severance and other costs $ 8.2 $ 15.5 $ 162.0 Facility exit costs — 5.7 31.8 Acquisition related charges: Transaction and integration costs (2) 144.7 26.5 90.3 Non-cash and other items: Asset impairment (3) 15.4 81.9 110.6 Asset write-down (4) 17.2 — — Gain on sale of fixed assets (5) — (0.8) (19.6) Total expense $ 185.5 $ 128.8 $ 375.1 (1) For the year ended December 31, 2019, these charges primarily relate to a new program that will eliminate certain positions across multiple locations and functions, including exiting R&D operations in Prince Edward Island, Canada, ceasing certain manufacturing operations in Wusi, China, and streamlining operations in Speke, England. We expect to substantially complete these restructuring activities by September 2020. For the year ended December 31, 2018, these charges primarily relate to a program to streamline international operations, including shifting focus and resources to priority areas. Among other actions, amounts reflect a change from having a physical location to a distribution model in certain countries in connection with the Separation. These activities were substantially complete as of December 31, 2019. We historically participated in Lilly’s cost-reduction initiatives, which resulted in restructuring charges in the period prior to our IPO. These restructuring charges include severance and other costs associated with the reduction of our workforce, including special termination benefits recognized in 2017 associated with the U.S. voluntary early retirement program offered by Lilly, related to our employees and pension curtailment costs and facility exit costs. We also recorded certain impairment charges related to the activities as described below. (2) Transaction costs represent external costs directly related to acquiring businesses and primarily include expenditures for banking, legal, accounting and other similar services. Integration costs represent external, incremental costs directly related to integrating acquired businesses (e.g., expenditures for consulting, system and process integration, and product transfers), as well as stand-up costs related to the implementation of new systems, programs, and processes due to the Separation from Lilly . (3) Asset impairment charges are associated with the following: • For the year ended December 31, 2019, write-off certain IPR&D and manufacturing assets in the US, Canada and Speke, resulting from the adjustment to fair value of property and equipment and intangible assets that were subject to product rationalization. • For the year ended December 31, 2018, the decision to dispose of a manufacturing facility in the U.S., the suspension of commercial activities for Imrestor , the write-off of certain idle assets in a U.S. manufacturing facility and product rationalization. • For the year ended December 31, 2017, intangible asset impairments related to revised projections of fair value due to product rationalization and to a lesser extent competitive pressures. (4) Asset write-down expenses resulted from the adjustments recorded to write assets classified as held and used and held for sale down to their current fair values. These charges primarily related to fixed assets in Prince Edward Island, Canada; Wusi, China and Indianapolis, Indiana. $11.2 million of Property and equipment, net in Prince Edward Island, Canada and Indianapolis, Indiana are classified as held for sale. (5) Represents a gain on the disposal of a site that was previously closed as part of the acquisition and integration of Novartis Animal Health beginning on January 1, 2015. The following table summarizes the activity in our reserves established in connection with restructuring activities: Exit costs Severance Total Balance at December 31, 2017 $ 34.9 $ 43.1 $ 78.0 Charges 11.7 15.5 27.2 Separation adjustment (5.9) — (5.9) Reserve adjustment (6.0) — (6.0) Cash paid (25.4) (23.5) (48.9) Balance at December 31, 2018 9.3 35.1 44.4 Charges — 19.3 19.3 Reserve adjustment (1) — (11.1) (11.1) Cash paid (3.9) (27.8) (31.7) Balance at December 31, 2019 $ 5.4 $ 15.5 $ 20.9 (1) Reserve adjustment represents the reversal of reserves for severance programs that are no longer active. These reserves are included in other current liabilities in the consolidated balance sheets. Substantially all of the reserves are expected to be paid in the next twelve months. We believe that the reserves are adequate.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories We state all inventories at the lower of cost or net realizable value. We use the last-in, first-out (LIFO) method for a portion 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 at December 31 consisted of the following: 2019 2018 Finished products $ 402.9 $ 400.7 Work in process 603.2 570.4 Raw materials and supplies 83.9 80.4 Total (approximates replacement cost) 1,090.0 1,051.5 Decrease to LIFO cost (39.3) (47.4) Inventories $ 1,050.7 $ 1,004.1 Inventories valued under the LIFO method comprised $197.2 million and $194.8 million of total inventories at December 31, 2019 and 2018, respectively. During the year ended December 31, 2018, we recognized $38.6 million of inventory write-offs in cost of sales primarily related to the suspension of commercial activities for Imrestor .

Debt

Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt	Debt Long-term debt as of December 31 consisted of the following: 2019 2018 Term credit facility $ 371.4 $ 492.5 3.912% Senior Notes due 2021 500.0 500.0 4.272% Senior Notes due 2023 750.0 750.0 4.900% Senior Notes due 2028 750.0 750.0 Other obligations 0.4 0.5 Unamortized debt issuance costs (16.8) (20.7) 2,355.0 2,472.3 Less current portion of long-term debt (24.5) (29.0) Total long-term debt $ 2,330.5 $ 2,443.3 Revolving and Term Credit Facilities On September 5, 2018, we entered into a revolving credit agreement with a syndicate of banks providing for a five On September 5, 2018, we also entered into a $500.0 million three The Credit Facilities are subject to various financial and other covenants, including restrictions on the level of borrowings based on a consolidated leverage ratio and a consolidated interest coverage ratio. We were in compliance with all such covenants as of December 31, 2019. Senior Notes On August 28, 2018, we issued $2.0 billion of senior notes (Senior Notes) in a private placement. The Senior Notes comprised of $500.0 million of 3.912% Senior Notes due August 27, 2021, $750.0 million of 4.272% Senior Notes due August 28, 2023, and $750.0 million of 4.900% Senior Notes due August 28, 2028. The interest rate payable on each series of Senior Notes is subject to adjustment if Moody's Investor Services, Inc. or Standard & Poor's Financial Services LLC downgrades, or subsequently upgrades, its ratings on the respective series of Senior Notes. The indenture that governs the Senior Notes contains covenants, including limitations on our ability, and certain of our subsidiaries, to incur liens or engage in sale-leaseback transactions. The indenture also contains restrictions on our ability to consolidate, merge or sell substantially all of our assets, in addition to other customary terms. We were in compliance with all such covenants under the indenture governing the Senior Notes as of December 31, 2019. On June 26, 2019, we completed an exchange offer pursuant to which the privately issued Senior Notes were exchanged for publicly registered Senior Notes having substantially identical terms.

Financial Instruments and Fair

Financial Instruments and Fair Value	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value	Financial Instruments and Fair Value Financial instruments that are potentially subject to credit risk consist principally of trade receivables. Collateral is generally not required. The risk associated with this concentration is mitigated by our ongoing credit-review procedures. A large portion of our cash is held by a few major financial institutions. We monitor the exposure with these institutions and do not expect any of these institutions to fail to meet their obligations. All highly liquid investments with a maturity of three months or less from the date of purchase are considered to be cash equivalents. The cost of these investments approximates fair value. We also consider the carrying value of restricted cash balances to be representative of its fair value. As of December 31, 2019 and 2018, we had $18.8 million and $15.3 million , respectively, primarily related to equity method investments included in other noncurrent assets in our consolidated balance sheet. The following table summarizes the fair value information at December 31, 2019 and 2018 for contingent consideration liabilities, and net investment hedge assets/(liabilities) measured at fair value on a recurring basis in the respective balance sheet line items, as well as long-term debt for which fair value is disclosed on a recurring basis: Fair Value Measurements Using Financial statement line item Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Fair Value December 31, 2019 Other noncurrent liabilities- contingent consideration $ (4.7) $ — $ — $ (4.7) $ (4.7) Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges 2.3 — 2.3 — 2.3 Long-term debt - senior notes (2,000.0) — (2,120.6) — (2,120.6) Long-term debt - term credit facility (371.4) — (371.4) — (371.4) December 31, 2018 Other current liabilities- contingent consideration $ (5.1) $ — $ — $ (5.1) $ (5.1) Other noncurrent liabilities- contingent consideration (69.0) — — (69.0) (69.0) Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges (7.4) — (7.4) — (7.4) Long-term debt - senior notes (2,000.0) — (2,005.0) — (2,005.0) Long-term debt - term credit facility (492.5) — (492.5) — (492.5) We determine our Level 2 fair value measurements based on a market approach using quoted market values or significant other observable inputs for identical or comparable assets or liabilities. Contingent consideration liabilities as of December 31, 2019 related to contingent consideration associated with the acquisitions of Aratana and Prevtec during the period. For Aratana, we will pay up to $12 million in contingent value rights that are dependent on the achievement of a specified milestone as outlined in the merger agreement. For Prevtec, based on the terms of the purchase agreement, we will pay up to $16.3 million contingent upon the achievement of specific Coliprotec sales milestones by December 31, 2021. The fair value of both contingent consideration liabilities was estimated using the Monte Carlo simulation model and Level 3 inputs including historical revenue, discount rate, asset volatility, and revenue volatility. See Note 6: Acquisitions for further discussion. Contingent consideration liabilities as of December 31, 2018 related to Galliprant for which the fair value was estimated using a discounted cash flow analysis and Level 3 inputs, including projections representative of a market participant view for the probability of achieving potential future payments to Aratana and an estimated discount rate. The amount to be paid as of December 31, 2018 was dependent upon certain development, success-based regulatory, and sales-based milestones. These liabilities were settled upon the closing of our acquisition of Aratana on July 18, 2019. See Note 6: Acquisitions for further discussion. In October 2018, we entered into a five

Goodwill and Intangibles

Goodwill and Intangibles	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	Goodwill and Intangibles Goodwill Goodwill was $3.0 billion as of December 31, 2019 and 2018. 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. Goodwill may be impaired if the carrying amount of a reporting unit exceeds the fair value of that reporting unit, calculated as based on discounted cash flows. An impairment charge would be recorded for the excess, if any, of the reporting unit's carrying amount over its fair value, but not to exceed the total amount of goodwill allocated to the reporting unit. The estimated fair value is based on a number of assumptions, including current market capitalization as corroboration of fair value. See Note 6: Acquisitions for further discussion of goodwill resulting from recent business combinations. The remaining change in goodwill is primarily the result of foreign exchange translation adjustments. No impairments occurred with respect to the carrying value of goodwill for the years ended December 31, 2019, 2018 and 2017. Other Intangibles The components of intangible assets other than goodwill at December 31 were as follows: 2019 2018 Description Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Finite-lived intangible assets: Marketed products $ 3,302.7 $ (980.6) $ 2,322.1 $ 3,193.5 $ (779.2) $ 2,414.3 Software 159.2 (72.2) 87.0 101.3 (49.5) 51.8 Other 58.3 (34.0) 24.3 53.1 (34.0) 19.1 Total finite-lived intangible assets 3,520.2 (1,086.8) 2,433.4 3,347.9 (862.7) 2,485.2 Indefinite-lived intangible assets: Acquired in-process research and development 49.4 — 49.4 19.6 — 19.6 Other intangibles $ 3,569.6 $ (1,086.8) $ 2,482.8 $ 3,367.5 $ (862.7) $ 2,504.8 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. For transactions other than a business combination, we capitalize milestone payments incurred at or after the product has obtained regulatory approval for marketing. Software consists of certain costs incurred in connection with obtaining or developing internal-use software, including payroll and payroll-related costs for employees directly associated with the internal-use software projects and direct costs of external resources. These costs include software classified as "in process" until the project is substantially complete and the software is ready for its intended purpose, at which point the costs are amortized on a straight-line basis over the estimated useful life. Depreciation expense includes $20.4 million in 2019, $18.4 million in 2018, and $17.4 million in 2017 for amortization of software. 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" for other intangibles. This method 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 group of assets 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 6: Acquisitions for further discussion of intangible assets acquired in recent business combinations. Other indefinite-lived intangible assets are reviewed for impairment at least annually and when impairment indicators are present. The fair value of the indefinite lived intangible assets (acquired IPR&D) is estimated using the same assumptions as used for goodwill and by applying a probability weighting that reflects the risk of development and commercialization to the estimated future net cash flows that are derived from projected revenues and estimated costs. Finite-lived intangible assets are reviewed for impairment when an indicator of impairment is present. We compare the carrying amounts of the assets with the estimated undiscounted future cash flows. In the event the carrying amount exceeds the undiscounted cash flows, an impairment charge is recorded for the amount by which the carrying amount of the asset exceeds the estimated fair value, which is determined based on discounted future cash flows. During 2019, we recorded impairment charges of $11.4 million primarily related to indefinite-lived intangible assets which are included in asset impairment, restructuring and other special charges on the consolidated and combined statements of operations. The impairment of indefinite-lived intangible assets primarily related to product rationalization. During 2018, we recorded impairment charges of $22.5 million (comprised of $9.5 million impairment of finite-lived intangible assets and $13.0 million impairment of indefinite-lived intangible assets) which are included in asset impairment, restructuring and other special charges on the consolidated and combined statements of operations. The impairment of finite-lived intangible assets primarily related to competitive pressures for a certain marketed product resulting in a reduction of projected cash flows. The impairment of indefinite-lived intangible assets primarily related to revised projections of fair value due to competitive pressures and to a lesser extent product rationalization. The increase in the carrying amount of finite intangibles is primarily due to the receipt of full commercialization rights outside the U.S. for Galliprant . During 2017, we had impairment charges of $94.5 million (comprised of $56.5 million impairment of finite-lived intangible assets and $38.0 million impairment of indefinite-lived intangible assets) which are included in asset impairment, restructuring and other special charges on the consolidated and combined statements of operations. The impairment of finite-lived intangible assets primarily related to competitive pressures for a certain marketed product resulting in a reduction of projected cash flows. The impairment of indefinite-lived intangible assets primarily related to revised projections of fair value due to competitive pressures and to a lesser extent product rationalization. Intangible assets with finite lives are capitalized and are amortized over their estimated useful lives, ranging from 3 to 20 years. As of December 31, 2019, the remaining weighted-average amortization periods for finite-lived intangible assets are as follows: Weighted Average Life (Years) Marketed products 13 Software 6 Other 8 The estimated amortization expense for each of the next five years associated with our finite-lived intangible assets as of December 31, 2019 is as follows: 2020 2021 2022 2023 2024 Estimated amortization expense $ 206.2 $ 205.4 $ 203.3 $ 203.0 $ 203.0

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2019
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 3 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 utilizing a discounted cash flow analysis, and the cost basis is adjusted. At December 31, property and equipment consisted of the following: 2019 2018 Land $ 28.3 $ 27.6 Buildings 608.5 567.2 Equipment 1,109.4 1,025.1 Construction in progress 139.1 181.1 Finance lease asset 0.5 — 1,885.8 1,801.0 Less accumulated depreciation (930.5) (878.6) Property and equipment, net $ 955.3 $ 922.4 Depreciation expense related to property and equipment was as follows: 2019 2018 2017 Depreciation expense $ 93.7 $ 81.3 $ 79.8

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases We determine if an arrangement is a lease at inception. We have operating leases for corporate offices, research and development facilities, vehicles, and equipment. Our leases have remaining lease terms of one Right-of-use assets included in noncurrent assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Right-of-use assets and operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate if it is readily determinable. The right-of-use asset also includes any lease payments made and excludes lease incentives. Our lease terms may include options to extend or terminate the lease when it is reasonably certain and there is a significant economic incentive to exercise that option. Operating lease expense for right-of-use assets is recognized on a straight-line basis over the lease term. Variable lease payments, which represent lease payments that vary due to changes in facts or circumstances occurring after the commencement date other than the passage of time, are expensed in the period in which the obligation for these payments was incurred. We elected not to apply the recognition requirements of ASC 842, Leases , to short-term leases, which are deemed to be leases with a lease term of 12 months or less. Instead, we recognize lease payments in the consolidated statements of operations on a straight-line basis over the lease term and variable payments in the period in which the obligation for these payments are incurred. We elected this policy for all classes of underlying assets. We elected not to apply the practical expedient related to the separation of lease and non-lease components or the practical expedient which allows entities to use hindsight when determining lease term. The impact of operating leases to our consolidated financial statements for the year ended December 31, 2019 was as follows: 2019 Lease cost Operating lease cost $ 26.1 Short-term lease cost 0.5 Variable lease cost 2.5 Total lease cost (1) $ 29.1 Other information Operating cash outflows from operating leases $ 24.0 Right-of-use assets obtained in exchange for new operating lease liabilities 20.1 Weighted-average remaining lease term - operating leases 5.1 years Weighted-average discount rate - operating leases 3.6 % (1) Rental expense for all leases was $47.5 million and $47.1 million for the years ended December 31, 2018 and 2017, respectively. Supplemental balance sheet information related to our operating leases is as follows: Balance Sheet Classification December 31, 2019 Right-of-use assets Other noncurrent assets $ 85.0 Current operating lease liabilities Other current liabilities 23.7 Non-current operating lease liabilities Other noncurrent liabilities 61.7 As of December 31, 2019, the annual minimum lease payments of our operating lease liabilities were as follows: Year 1 $ 26.0 Year 2 20.3 Year 3 11.9 Year 4 9.7 Year 5 7.2 After Year 5 16.5 Total lease payments 91.6 Less imputed interest (6.2) Total $ 85.4

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Elanco Stock Compensation Plans The 2018 Elanco Stock Plan (Plan) provides long-term incentives to attract, motivate and retain employees and non-employee directors. The types of stock-based awards available include, but are not limited to, restricted stock units (RSUs), performance-based awards (PAs), and stock options. Our practices and policies specify that stock-based compensation awards are approved by the Compensation Committee of the Board of Directors. The Plan, initially authorized the issuance of up to 5.5 million common shares (subject to adjustments for certain events). Pursuant to the terms of the Plan, an additional 5.5 million common shares became automatically available for all awards upon completion of the Separation. The total number of shares authorized for stock-based compensation awards is 11 million as of December 31, 2019. Stock-Based Compensation Expense Components of stock-based compensation expense and related tax benefit for the years ended December 31 are as follows: 2019 2018 Stock-based compensation expense (1) $ 40.7 $ 1.8 Related tax benefit (9.8) (0.4) (1) We include the impact of estimated forfeitures when determining stock-based compensation expense. Restricted Stock Units RSUs are granted to certain employees and are settled in shares of our common stock. RSU shares are accounted for at fair value based upon the closing stock price on the date of the grant. The corresponding expense is amortized over the vesting period, typically three years. The number of shares ultimately issued for the RSU program remains constant with the exception of forfeitures. RSUs granted to employees for the years ended December 31 are as follows: (Units in millions) 2019 2018 Granted units 2.9 0.2 Weighted-average fair value $ 31.22 $ 31.09 Changes in nonvested portion of RSUs for 2019 is summarized below: (Shares in millions) Shares Weighted-Average Fair Value Nonvested units at January 1, 2019 0.2 $ 31.09 Granted 2.9 31.22 Vested (0.8) 31.33 Forfeited (0.1) 31.25 Nonvested units at December 31, 2019 2.2 30.42 As of December 31, 2019, the total remaining unrecognized stock-based compensation expense related to nonvested RSUs was $25.5 million, which will amortize over the weighted-average remaining requisite service period of 19 months. Performance-Based Awards PAs, which are granted to eligible officers and management, represent the right to receive a share of our common stock and are subject to forfeiture until restrictions lapse (including continued employment through the end of the vesting period and achievement of certain pre-established metrics). Payouts can vary depending on achievement. 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. PA activity during the year ended December 31, 2019 is summarized below: (Shares in millions) Shares Weighted-Average Fair Value Nonvested awards at January 1, 2019 — $ — Granted 0.8 25.75 Vested — — Forfeited — — Nonvested awards at December 31, 2019 0.8 25.75 As of December 31, 2019, the total remaining unrecognized stock-based compensation expense related to nonvested PAs was $11.0 million, which will amortize over the weighted-average remaining requisite service period of 13 months. Stock Option Program Stock options represent the right to purchase shares of our common stock within a specified period of time at a specified price. The exercise price for a stock option will be not less than 100% of the fair market value of the common stock on the date of the grant. Stock options are accounted for using a fair-value based method at the date of the grant in the consolidated statement of operations. The values determined through this fair-value-based method generally are amortized on a straight-line basis over the vesting term. Stock options were granted in 2018 to our officers, management and board members at exercise prices equal to the fair market value of our stock at the date of the grant. Options fully vest 3 years from the grant date and have a term of 10 years. No stock options were granted in 2019. The fair-value-based method for valuing each Elanco stock option grant on the grant date uses the Black-Scholes-Merton option-pricing model, which incorporates a number of valuation assumptions noted in the following table, shown at their weighted-average values for the year ended December 31: 2018 Expected dividend yield (1) 0.70 % Risk-free interest rate (2) 3.07 % Expected stock price volatility (3) 28.25 % Expected term (4) (years) 6.5 (1) Determined using the expected quarterly dividend divided by the available three-month average stock price as of the valuation date, annualized and continuously compounded. (2) Determined using the term-matched, zero-coupon risk-free rate from the Treasury Constant Maturity yield curve, continuously compounded (3) Determined using a leverage-adjusted historical volatility of peer companies (4) Determined using SEC safe harbor approach, based on a 3-year cliff vesting schedule and 10-year contractual term. Stock option activity during the year ended December 31, 2019 is summarized below: (Shares in millions) Shares of Common Stock Attributable to Options Weighted-Average Exercise Price of Options Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (1) Outstanding at January 1, 2019 0.4 $ 31.61 Granted — — Exercised (0.1) 31.61 Forfeited or expired — — Outstanding at December 31, 2019 0.3 $ 31.61 8.8 $ — Exercisable at December 31, 2019 — — — — (1) Market price of underlying Elanco common stock less exercise price. Options do not have an intrinsic value unless the market price exceeds the exercise price. As of December 31, 2019, there was approximately $2.2 million of unrecognized compensation costs related to nonvested stock options, which will be recognized over an expected remaining weighted-average period of 22 months. The following table summarizes data related to stock option activity: 2019 2018 Weighted-average grant date fair value per stock option $ 10.21 $ 10.21 Aggregate intrinsic value on exercise 0.10 — Cash received upon exercise 1.9 — Treatment of Lilly Equity Awards Prior to the Separation, our employees participated in Lilly stock-based compensation plans, the cost of which was allocated to us and recorded in costs of sales, research and development, and marketing, selling and administrative expense in the consolidated and combined statements of operations. The cost of such plans related to our employees was $5.1 million, $26.0 million and $25.0 million for the years ended December 31, 2019, 2018 and 2017, respectively. Following the IPO and until completion of the exchange offer, the equity awards previously granted to our employees by Lilly continued to vest with Elanco service counting toward the Lilly award's vesting provisions. On March 11, 2019, Elanco completed the exchange offer whereby Lilly disposed of all of its shares of Elanco common stock owned by Lilly. As a result, our employees' unvested Lilly equity awards were forfeited and replaced with Elanco RSUs (replacement awards), which were equivalent in value and vest on the same date as their forfeited Lilly equity awards. These replacement awards are included in the RSU activity described above.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our income taxes for the year ended December 31, 2019 reflect the results on a stand-alone basis independent of Lilly, except for the period during which we were included in a combined tax return until full separation. In the jurisdictions in which we were included in a combined tax return, our income taxes were determined based on the tax matters agreement between us and Lilly. During the periods presented in the consolidated and combined financial statements for the year ended December 31, 2018 and December 31, 2017, our operations were generally included in the tax grouping of other Lilly entities within the respective entity's tax jurisdiction; however, in certain jurisdictions, we filed separate tax returns. Prior to the Separation, the income tax expense included in these financial statements has been calculated using the separate return basis as if Elanco filed separate tax returns. 2017 Tax Act In 2017, the U.S. enacted the Tax Cuts and Jobs Act (2017 Tax Act), which significantly revised U.S. tax law. Guidance related to the 2017 Tax Act, including Notices, Proposed Regulations, and Final Regulations, has been issued, and we expect additional guidance will be issued in 2020. This additional guidance could materially impact our assumptions and estimates used to record our U.S. federal and state income tax expense resulting from the 2017 Tax Act. We are included in Lilly's U.S. tax examinations by the Internal Revenue Service through the full separation date of March 11, 2019. Pursuant to the tax matters agreement we executed with Lilly in connection with the IPO, the potential liabilities or potential refunds attributable to pre-IPO periods in which Elanco was included in a Lilly consolidated or combined tax return remain with Lilly. Certain matters of Lilly’s U.S. examination of tax years 2013 - 2015 effectively settled during the second quarter of 2019 and the resulting adjustments will not require any cash tax payments by Elanco. During the fourth quarter of 2019, certain matters for tax year 2015 were effectively settled upon conclusion of the IRS' examination and the resulting adjustments will not require any cash tax payments by Elanco. In the fourth quarter of 2019, the IRS began its examination of tax years 2016 - 2018. 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% likelihood of being realized upon ultimate resolution. Following is the composition of income (loss) before income tax expense (benefit): 2019 2018 2017 Federal $ 55.5 $ 12.2 $ (133.2) Foreign 22.7 101.9 (99.4) Income (loss) before income taxes $ 78.2 $ 114.1 $ (232.6) Following is the composition of income tax expense (benefit): 2019 2018 2017 Current: Federal $ (5.5) $ 45.1 $ — Foreign 13.4 45.5 91.6 State 2.3 (2.3) (0.1) Total current tax expense 10.2 88.3 91.5 Deferred: Federal 14.5 (56.8) 42.6 Foreign (7.5) (5.6) (16.6) State (6.9) 1.7 (6.3) 2017 Tax Act — — (33.1) Total deferred tax expense (benefit) 0.1 (60.7) (13.4) Income taxes $ 10.3 $ 27.6 $ 78.1 Significant components of our deferred tax assets and liabilities as of December 31 are as follows: 2019 2018 Deferred tax assets: Compensation and benefits $ 25.3 $ 32.2 Accruals and reserves 13.7 26.9 Tax credit carryovers 12.8 6.2 Tax loss carryovers 69.5 17.4 Inventories 20.1 18.3 Restructuring and other reserves 24.6 6.0 Operating lease liabilities 20.5 — Other 2.3 20.1 Total gross deferred tax assets 188.8 127.1 Valuation allowances (32.7) (21.4) Total deferred tax assets 156.1 105.7 Deferred tax liabilities: Right-of-use assets (20.5) — Intangibles (134.5) (130.8) Property and equipment (56.4) (50.8) Other (0.6) (2.7) Total deferred tax liabilities (212.0) (184.3) Deferred tax liabilities - net $ (55.9) $ (78.6) Deferred tax assets and liabilities reflect the impact of re-measurement resulting from the 2017 Tax Act. The deferred tax assets 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, 2019, we have tax credit carryovers of $14.0 million available to reduce future income taxes. The amount is comprised of foreign, U.S. federal and state credits. The foreign credits total $5.1 million and if unused, will begin to expire in 2030. The U.S. federal credits total $3.2 million and if unused, will begin to expire in 2030. The state credits total $5.7 million and if unused, will begin to expire in 2020. The U.S. federal and state credits are subject to a full valuation allowance. At December 31, 2019, we had net operating loss carryovers and other carryovers for foreign, U.S. federal and state income tax purposes of $348.4 million: $285.5 million will expire between 2020 and 2039; and $62.9 million of the carryovers have an indefinite carryforward period. Net operating losses and other carryovers for foreign and state income tax purposes are subject to a partial valuation allowance. The movements in the valuation allowance are as follows: 2019 2018 January 1 $ (21.4) $ (127.7) Adjustment related to Separation — 110.4 January 1 (21.4) (17.3) Increase (1) (23.2) (5.8) Release 11.9 1.7 December 31 $ (32.7) $ (21.4) (1) The increase in the valuation allowance during 2019 is primarily attributable to the acquisition of Aratana Therapeutics, Inc. and Prevtec Microbia Inc. (see Note 6: Acquisitions). Prior to the IPO, we prepared the income tax amounts and balances based upon a separate return methodology, as if we were separate taxpayers from Lilly. As a result, certain tax credits and net operating loss carryovers are not available for use in future periods as they were used in Lilly consolidated or combined tax return filings. Accordingly, as a result of the Separation, the tax credit and net operating loss carryovers and related valuation allowance have been adjusted to reflect the balance after Separation. These adjustments had no impact on income tax expense in the consolidated and combined financial statements. The separation entries related to the valuation allowance were offset by $133.7 million, prior to tax effect, of separation entries related to the removal of the net operating losses. The 2017 Tax Act introduced international tax provisions that significantly change the U.S. taxation of foreign earnings. At December 31, 2019, no U.S. taxes or foreign withholding taxes have been accrued with respect to the $496.7 million in unremitted earnings of our foreign subsidiaries as they are considered indefinitely reinvested for continued use in our foreign operations. It is not practicable to determine the unrecognized deferred tax liability related to these earnings. Cash payments of income taxes were as follows: 2019 2018 2017 Cash payments of income taxes $ 42.5 $ 26.9 $ 35.7 The following is a reconciliation of the income tax expense (benefit) applying the U.S. federal statutory rate to income before income taxes to reported income tax expense: 2019 2018 2017 Income tax at the U.S. federal statutory tax rate $ 16.4 $ 24.0 $ (81.4) Add (deduct): Taxation of international operations 20.7 20.5 59.8 State taxes 2.9 4.4 5.4 Income tax credits (9.8) (17.3) (1.8) Non-deductible employee compensation 4.2 (1.9) — IPO and separation costs — 2.3 — Other permanent adjustments (4.2) (1.0) 0.8 Change in uncertain tax positions (14.7) (1.7) 6.2 Change in valuation allowance (5.2) (1.7) 122.2 2017 Tax Act — — (33.1) Income taxes $ 10.3 $ 27.6 $ 78.1 A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2019 2018 2017 Beginning balance at January 1 $ 14.7 $ 29.6 $ 25.7 Adjustments related to Separation (2.2) (17.6) — Adjusted beginning balance at January 1 12.5 12.0 25.7 Additions based on tax positions related to the current year 1.3 2.2 7.9 Changes for tax positions of prior years (1.2) 4.0 — Settlements (4.3) (3.0) (4.0) Changes related to the impact of foreign currency translation (0.1) (0.5) — Ending balance at December 31 $ 8.2 $ 14.7 $ 29.6 The total amount of unrecognized tax benefits that, if recognized, would affect tax expense was $8.2 million and $12.8 million at December 31, 2019 and 2018, respectively. There were $1.9 million of 2018 unrecognized tax benefits which related to temporary differences which did not impact the effective tax rate. Adjustments related to the Separation represent unrecognized tax benefits assumed by Lilly in the Separation and have no impact on income tax expense in the consolidated and combined financial statements. We file income tax returns in the U.S. federal jurisdiction and various state, local and non-U.S. jurisdictions. Prior to full separation, certain of these income tax returns were filed on a consolidated or combined basis with Lilly. We recognize both accrued interest and penalties related to unrecognized tax benefits in income tax expense (benefit). We recognized income tax expense (benefit) related to interest and penalties as follows: 2019 2018 2017 Income tax expense (benefit) $ (10.6) $ (2.5) $ 2.5 At December 31, 2019 and 2018, our accruals for the payment of interest and penalties totaled $3.0 million and $13.3 million, respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal matters We are party to various legal actions in the normal course of business. In determining whether a pending matter is significant for financial reporting and disclosure purposes, we consider both quantitative and qualitative factors in order to assess materiality. We accrue for certain liability claims to the extent we can formulate a reasonable estimate of their costs and there is a reasonable probability of incurring significant costs or expenses. At December 31, 2019 and December 31, 2018, we had no liabilities established related to litigation as there were no significant claims which were probable and estimable. We have not historically had any significant litigation expense and are not currently subject to a significant claim. Bayer Animal Health acquisition financing

Geographic Information

Geographic Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Geographic Information	Geographic Information We operate as a single operating segment engaged in the development, manufacturing, marketing and sales of animal health products worldwide for both food animals and companion animals. Consistent with our operational structure, our President and Chief Executive Officer (CEO), as the chief operating decision maker, makes resource allocation and business process decisions globally across our consolidated business. Strategic decisions are managed globally with global functional leaders responsible for determining significant costs/investments and with regional leaders responsible for overseeing the execution of the global strategy. Our global research and development organization is responsible for development of new products. Our manufacturing organization is responsible for the manufacturing and supply of products and for the optimization of our supply chain. Regional leaders are responsible for the distribution and sale of our products and for local direct costs. The business is also supported by global corporate staff functions. Managing and allocating resources at the global corporate level enables our CEO to assess the overall level of resources available and how to best deploy these resources across functions, product types, regional commercial organizations and research and development projects in line with our overarching long-term corporate-wide strategic goals, rather than on a product or geographic basis. Consistent with this decision-making process, our CEO uses consolidated, single-segment financial information for purposes of evaluating performance, allocating resources, setting incentive compensation targets, as well as forecasting future period financial results. Our products include Rumensin , Optaflexx , Denagard , Tylan , Maxiban and other products for livestock and poultry, as well as Trifexis , Intercepto r, Comfortis , Galliprant and other products for companion animals. We have a single customer that accounted for 12.9%, 11.9% and 12.9% of revenue for the years ended December 31, 2019, 2018 and 2017, respectively. The product sales resulted in accounts receivable with this customer of $90.5 million and $96.4 million as of December 31, 2019 and 2018, respectively. 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. Selected geographic area information was as follows: 2019 2018 2017 Revenue — to unaffiliated customers (1) : United States $ 1,524.7 $ 1,483.2 $ 1,373.0 International 1,546.3 1,583.6 1,516.0 Revenue $ 3,071.0 $ 3,066.8 $ 2,889.0 Long-lived assets (2) : United States $ 709.8 $ 602.6 $ 604.7 United Kingdom 192.6 187.5 204.4 Other foreign countries 244.7 195.8 190.2 Long-lived assets $ 1,147.1 $ 985.9 $ 999.3 (1) Revenue is attributed to the countries based on the location of the customer.

Retirement Benefits

Retirement Benefits	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Retirement Benefits	Retirement Benefits Pension Plans There are certain defined benefit pension plans that our employees participate in that are either dedicated to our employees or where the plan assets and liabilities that relate to our employees were legally required to transfer to Elanco at the time of our separation from Lilly. The plans in Switzerland represent approximately 80% of our global benefit obligation. 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 plans, which were as follows: 2019 2018 Change in benefit obligation: Benefit obligation at beginning of year $ 234.8 $ 258.6 Service cost 9.3 11.3 Interest cost 2.2 2.5 Actuarial loss (gain) 56.4 (44.7) Benefits paid (5.5) (2.7) Plan amendments (74.7) — Foreign currency exchange rate changes and other adjustments 1.9 9.8 Benefit obligation at end of year 224.4 234.8 Change in plan assets: Fair value of plan assets at beginning of year 131.6 131.5 Actual return on plan assets 15.3 (10.2) Employer contribution 5.3 5.7 Benefits paid (5.5) (2.7) Foreign currency exchange rate changes and other adjustments 2.0 7.3 Fair value of plan assets at end of year 148.7 131.6 Funded status (75.7) (103.2) Unrecognized net actuarial loss 45.9 0.5 Unrecognized prior service cost (74.1) 0.8 Net amount recognized $ (103.9) $ (101.9) Amounts recognized in the consolidated balance sheet consisted of: Noncurrent assets $ 2.1 $ 2.3 Other current liabilities (0.3) (0.3) Accrued retirement benefits (77.5) (105.2) Accumulated other comprehensive (income) loss before income taxes (28.2) 1.3 Net amount recognized $ (103.9) $ (101.9) The unrecognized net actuarial loss and unrecognized prior service cost for these pension plans have not yet been recognized in net periodic pension costs and are included in accumulated other comprehensive loss at December 31, 2019. Pension plan amendment In September 2019, we signed agreements under which certain defined pension benefits in Switzerland transferred from the previous Lilly pension fund as of December 31, 2019 to a new Elanco pension fund effective January 1, 2020. This resulted in a plan amendment during the period. The plan amendment decreased our pension benefit obligation by approximately $21 million, consisting primarily of a decrease in prior service costs of approximately $75 million, partially offset by a loss of approximately $54 million driven by changes in certain assumptions. The net impact to accumulated other comprehensive income was a gain of approximately $21 million, which will be amortized over the average remaining service period of employees expected to receive benefits under the plans. We do not expect any plan assets to be returned to us in 2020. The following represents our weighted-average assumptions related to these pension plans as of December 31: (Percents) 2019 2018 2017 Discount rate for benefit obligation 0.6% 1.5% 1.1% Discount rate for net benefit costs 1.4 1.1 1.0 Rate of compensation increase for benefit obligation 2.3 2.2 2.1 Rate of compensation increase for net benefit costs 2.2 2.1 3.1 Expected return on plan assets for net benefit costs 4.0 4.0 4.4 We annually evaluate the expected return on the plan assets in these pension 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. The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: 2020 2021 2022 2023 2024 2025-2029 Benefit payments $ 7.9 $ 8.6 $ 8.4 $ 8.0 $ 8.1 $ 48.4 Amounts relating to these pension plans with projected benefit obligations in excess of plan assets were as follows at December 31: 2019 2018 Projected benefit obligation $ 218.2 $ 229.2 Fair value of plan assets 140.3 124.1 Amounts relating to these defined benefit pension plans with accumulated benefit obligations in excess of plan assets were as follows at December 31: 2019 2018 Accumulated benefit obligation $ 203.9 $ 194.3 Fair value of plan assets 140.3 124.1 The total accumulated benefit obligation for these defined benefit pension plans was $210.1 million and $199.9 million at December 31, 2019 and 2018, respectively. Net pension expense related to these plans included the following components: 2019 2018 2017 Service cost $ 9.3 $ 11.3 $ 10.5 Interest cost 2.2 2.5 1.8 Expected return on plan assets (4.2) (6.2) (2.4) Amortization of prior service cost (1.7) 0.2 0.1 Amortization of net actuarial loss 1.1 1.9 1.4 Other — 0.5 — Net pension expense $ 6.7 $ 10.2 $ 11.4 The following represents the amounts recognized for these plans in other comprehensive loss: 2019 2018 2017 Actuarial gain (loss) arising during period $ (45.6) $ 28.3 $ (17.0) Prior year service cost during the year 74.7 — — Amortization of prior service cost included in net loss (1.7) 0.2 0.1 Amortization of net actuarial loss included in net loss 1.1 1.9 1.4 Foreign currency exchange rate changes and other 1.0 (1.9) 3.5 Total other comprehensive income (loss) during period $ 29.5 $ 28.5 $ (12.0) Benefit Plan Investments Our benefit plan investment policies are set with specific consideration of return and risk requirements in relationship to the respective liabilities. Our plan assets in our Switzerland pension plans represent approximately 87% of our plan assets for these pension plans. 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. The investment strategy is to diversify in five major categories with a designated percentage invested in each including 5% liquidity, 36% fixed income securities, 32% equity securities, a share of 21% in real estate and 6% in other alternative investments. Each category is diversified and comprised of the following: • Liquidity - cash and cash equivalents • Fixed-income securities - Swiss bonds, global aggregates, global aggregate corporates, emerging market local currencies and emerging markets hard currencies. • Equity investments - Swiss equities, global equities, low volatility equities (to reduce risk), and emerging market equities. • Real estate - Swiss real estate and global real estate funds. • Other investments - represents primarily investments in senior secured loans. We determine the fair value of the investments based on a market approach using quoted market values, significant other observable inputs for identical or comparable assets or liabilities, or discounted cash flow analysis for all investments except hedge funds, private equity-like investments and real estate. We determine the fair value of investments 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 financial statements including their compliance with fair valuation procedures consistent with applicable accounting standards. We determine the fair value of real estate investments based on the NAV provided by the fund manager. These NAVs are developed with inputs including discounted cash flow, independent appraisal and market comparable analyses. The fair values of these pension plan assets as of December 31, 2019 by asset category are as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Identical Assets Significant Observable Significant Unobservable Inputs Investments Valued at Net Asset Value (1) Cash and cash equivalents (2) $ 129.0 $ 129.0 $ — $ — $ — Public equity securities 3.8 1.9 — — 1.9 Fixed income: Developed markets 2.5 2.1 — — 0.4 Emerging markets 9.1 8.8 0.3 — — Other 4.3 0.9 3.4 — — Total $ 148.7 $ 142.7 $ 3.7 $ — $ 2.3 (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. (2) Switzerland plan assets were exiting the Lilly pension plan as of December 31, 2019. As a result, assets were converted to cash and transferred to the new Elanco pension fund effective January 1, 2020. No material transfers between Level 1, Level 2, or Level 3 occurred during the year ended December 31, 2019. The activity in the Level 3 investments during the year ended December 31, 2019 was not material. The fair values of these pension plan assets as of December 31, 2018 by asset category are 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) Public equity securities $ 2.2 $ 1.0 $ — $ — $ 1.2 Fixed income: Developed markets 29.9 7.8 0.1 — 22.0 Emerging markets 6.4 0.7 0.4 — 5.3 Private alternative investments: Hedge funds 6.6 — — — 6.6 Equity-like funds 49.0 — — — 49.0 Real estate 20.1 0.1 — — 20.0 Other 17.4 0.3 2.3 — 14.8 Total $ 131.6 $ 9.9 $ 2.8 $ — $ 118.9 (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. Contributions of $6.5 million to these pension plans are expected in 2020. Retiree Health Benefit Plan There are two retiree health benefit plan where the plan liabilities that relate to our employees were legally required to transfer to Elanco at the time of separation from Lilly. The accrued retirement benefits for these plans were $4.7 million and $3.9 million as of December 31, 2019 and 2018, respectively. Defined Contribution Plans Elanco has defined contribution savings plans that include certain 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 our employee contributions and the level of our match. Expenses related to our employees under the plans totaled $32.2 million, $20.9 million and $22.1 million for the years ended December 31, 2019, 2018, and 2017, respectively. The expense for our 401(k) plan increased in 2019 primarily due to an increase our match and participant headcount. Treatment of Lilly Plans Prior to the Separation, our employees participated in defined benefit pension and other postretirement plans sponsored by Lilly, which include participants of Lilly's other business. Such plans were accounted for as multiemployer plans in the combined financial statements and as a result, no asset or liability was recorded by us to recognize the funded status of these plans.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic Earnings Per Share As discussed in Note 1, Elanco Parent was formed for the purpose of facilitating the IPO. Lilly held all shares of Elanco Parent from the time of formation until the IPO. Prior to IPO, there were an aggregate of 293,290,000 shares of our common stock held by Lilly (which represents the 100 shares held by Lilly prior to giving effect to the 2,932,900-for-1 stock split that occurred on September 19, 2018). In connection with the completion of the IPO, an additional 72,335,000 shares of our common stock were issued. Earnings per share was calculated based on the assumptions that the shares held by Lilly were outstanding for all periods prior to IPO. We compute basic earnings per share by dividing net earnings available to common shareholders by the actual weighted average number of common shares outstanding for the reporting period. For the year ended December 31, 2019, weighted average number of common shares outstanding used to calculate basic earnings per share includes the impact of approximately 7.3 million shares that were issued during the period in connection with the acquisition of Aratana. See Note 6: Acquisitions for further discussion. Diluted Earnings Per Share Elanco has common stock equivalents related to certain equity awards in stock-based compensation arrangements. Diluted earnings per share reflects the potential dilution that could occur if holders of unvested RSUs, PAs and stock options converted their holdings into common stock. The weighted average number of potentially dilutive shares outstanding is calculated using the treasury stock method. Weighted average diluted shares outstanding included common stock equivalents of 1.3 million for 2019. The dilutive impact for 2018 was immaterial. Potential common shares that would have the effect of increasing diluted earnings per share are considered to be anti-dilutive and as such, these shares are not included in the calculation of diluted earnings per share. For the year ended December 31, 2019, approximately 0.1 million shares of potential common shares were excluded from the calculation of diluted earnings per share because their effect was anti-dilutive.

Related Party Agreements and Tr

Related Party Agreements and Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party Agreements and Transactions	Related Party Agreements and Transactions Transactions with Lilly Subsequent to Separation and Related to the Separation Amounts due from/(due to) Lilly in connection with the Separation and agreed upon services as of December 31 were as follows: 2019 2018 TSA $ 10.5 $ (28.0) Other activities (15.8) (38.0) Local country asset purchases (11.1) (202.7) Total receivable from/(payable to) Lilly $ (16.4) $ (268.7) As described in Note 1, we completed an IPO in September 2018 and Lilly fully divested all ownership of Elanco in March 2019. In connection with the Separation, we entered into various agreements with Lilly related to the form of our separation and certain ongoing activities that will continue for a period of time. These included, among others, a master separation agreement (MSA), a TSA and a tax matters agreement. In addition, there was a portion of our operations for which the legal transfer of our net assets did not occur prior to the Separation due to certain regulatory requirements in each of these countries. Transitional Services Agreement (TSA) Historically, Lilly has provided us significant shared services and resources related to corporate functions such as executive oversight, treasury, legal, finance, human resources, tax, internal audit, financial reporting, information technology and investor relations, which we refer to collectively as the "Lilly Services." Under the terms of the TSA, we will be able to use Lilly Services for a fixed term established on a service-by-service basis. We will pay Lilly mutually agreed-upon fees for the Lilly Services provided under the TSA, which will be based on Lilly's cost (including third-party costs) of providing the Lilly Services through March 31, 2021, and subject to a mark-up of 7% thereafter, with additional inflation-based escalation beginning January 1, 2022. The fees under the TSA became payable for all periods beginning after October 1, 2018. Separation Activities Subsequent to our IPO, there continue to be transactions between us and Lilly related primarily to the completion of the local country asset purchases and finalization of assets and liabilities associated with the legal separation from Lilly, combined income tax returns and the impact of the tax matters agreement, historical Lilly retirement benefits, and centralized cash management. The net impact of these activities of $51.2 million for the year ended December 31, 2019 has been reflected as Separation Activities within shareholders' equity. The most significant of these activities includes the finalization of the local country valuation of business and the resulting impact on deferred tax assets and the impact of combined tax returns. Other Activities We continue to share certain services and back office functions with Lilly, which in certain instances result in Lilly paying costs for Elanco (e.g., utilities, local country operating costs, etc.) that are then passed through to Elanco for reimbursement. These amounts are included in cash flows from operating activities in our consolidated and combined statements of cash flows. In addition, we operate through a single treasury settlement process and prior to the local country asset purchases (as described below) continued to transact through Lilly's processes in certain instances. As a result of these activities, there were certain amounts of financing that occurred between Lilly and Elanco during the year ended December 31, 2019. These amounts are included in cash flows from financing activities in our consolidated and combined statements of cash flows. Local Country Asset Purchases The legal transfer of certain of our net assets did not occur prior to the Separation due to certain regulatory requirements in each of these countries. The related assets, liabilities, and results of operations have been reported in our consolidated and combined financial statements, as we are responsible for the business activities conducted by Lilly on our behalf and are subject to the risks and entitled to the benefits generated by these operations and assets under the terms of the MSA. We held restricted cash, and the associated payable to Lilly, at the date of Separation to fund the acquisition of these assets. As of December 31, 2019, the majority of these assets have been legally acquired and the remainder are expected to be purchased during 2020. Restricted cash and Payable to Lilly of $11.1 million are recorded in the consolidated balance sheet for the remainder of the assets expected to be purchased by the end of 2020. Intellectual Property and Technology License Agreement. We entered into an intellectual property and technology license agreement with Lilly immediately prior to the completion of the IPO. Under the intellectual property and technology license agreement, Lilly granted Elanco an exclusive, perpetual license to exploit products in the animal health field that utilize or use certain of Lilly's intellectual property (excluding trademarks). In addition, Lilly granted Elanco non-exclusive, non-sublicensable license to screen certain compounds in Lilly's compound libraries to exploit products in the animal use certain of Lilly's intellectual property. This screening license has an initial term of two years, subject to three one We also entered into a tax matters agreement (TMA), an employee matters agreement, a toll manufacturing and supply agreement and a registration rights agreement with Lilly in connection with the Separation. Our consolidated and combined financial statement of operations includes revenue related to a toll manufacturing agreement of $17.8 million and $7.0 million for the years ended December 31, 2019 and 2018, respectively. Also included are approximately $93.7 million and $28.1 million related to TSA charges for 2019 and 2018, respectively. Transactions with Lilly Prior to Separation Prior to the IPO, we did not operate as a standalone business and had various relationships with Lilly whereby Lilly provided services to us. The impact on our historical combined financial statements includes the following: Transfers to/from Lilly, net As discussed in Note 2: Basis of Presentation, net parent company investment is primarily impacted by contributions from Lilly, which are the result of treasury activity and net funding provided by or distributed to Lilly. For the years ended December 31, 2018 and 2017, net transfers (to)/from Lilly were $(226.3) million and $873.3 million, respectively. The most significant activity impacting the 2017 transfer was the financing by Lilly of our acquisition in the amount of $882.1 million for the acquisition of BIVIVP as described in Note 6: Acquisitions. Other activities that impacted the net transfers (to)/from Lilly include corporate overhead and other allocations, income taxes, retirement benefits, and centralized cash management. Corporate Overhead and Other Allocations Prior to full separation, Lilly provided us certain services, including executive oversight, treasury, legal, finance, human resources, tax, internal audit, financial reporting, information technology and investor relations. We provide Lilly certain services related to manufacturing support. Our financial statements reflect an allocation of these costs. When specific identification is not practicable, the remainder have been allocated primarily on a proportional cost method on a basis of revenue or headcount. The allocations of services from Lilly, prior to IPO, to us were reflected as follows in the combined statements of operations: 2018 (1) 2017 Cost of sales $ 21.8 $ 31.8 Research and development 2.2 2.8 Marketing, selling and administrative 81.2 117.1 Total $ 105.2 $ 151.7 (1) Through September 30, 2018 There were no allocations from Lilly to us reflected in the consolidated and combined statement of operations for the year ended December 31, 2019. We provided Lilly certain services related to manufacturing support. Allocations of manufacturing support from us to Lilly were $3.7 million and $6.2 million for the years ended December 31, 2018 and 2017, respectively, which reduced the cost of sales in the consolidated and combined statements of operations. The financial information herein may not necessarily reflect our consolidated financial position, results of operations and cash flows in the future or what they would have been if we had been a separate, standalone entity during the periods presented. Management believes that the methods used to allocate expenses are reasonable. Stock-based Compensation As discussed in Note 14: Stock-based Compensation, prior to full separation, our employees participated in Lilly stock-based compensation plans, the costs of which were allocated to us and recorded in cost of sales, research and development, and marketing, selling and administrative expenses in the consolidated and combined statements of operations. The costs of such plans related to our employees were $5.1 million, $26.0 million and $25.0 million for the years ended December 31, 2019, 2018 and 2017, respectively. Retirement Benefits As discussed in Note 18: Retirement Benefits, prior to full separation, our employees participated in defined benefit pension and other post retirement plans sponsored by Lilly, the costs and benefits of which were recorded in the consolidated and combined statement of operations in cost of sales, research and development, and marketing, selling and administrative expenses. The costs/(benefits) of such plans related to our employees were $(6.3) million and $73.7 million for the years ended December 31, 2018 and 2017, respectively. Centralized Cash Management Lilly uses a centralized approach to cash management and financing of operations. Until Separation, the majority of our business was party to Lilly’s cash pooling arrangements to maximize Lilly's availability of cash for general operating and investing purposes. Under these cash pooling arrangements, cash balances were swept regularly from our accounts. Cash transfers to and from Lilly’s cash concentration accounts and the resulting balances at the end of each reporting period were reflected in net parent company investment in the consolidated balance sheets. Debt Lilly’s third-party debt and the related interest expense were not allocated to us for any of the periods presented as we were not the legal obligor of the debt and Lilly borrowings were not directly attributable to our business.

Selected Quarterly Data (unaudi

Selected Quarterly Data (unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Data (unaudited)	Selected Quarterly Data (unaudited) 2019 Fourth Third Second First Revenue $ 787.0 $ 771.3 $ 781.6 $ 731.1 Cost of sales 410.1 360.4 356.0 343.8 Operating expenses (1) 253.2 262.2 269.7 245.2 Asset impairment, restructuring, and other special charges 51.6 77.2 31.8 24.9 Interest expense, net of capitalized interest 18.7 18.7 20.7 20.8 Income (loss) before income taxes (4.3) (12.5) 50.2 44.8 Income tax (benefit) expense 5.2 (22.5) 14.3 13.3 Net income (loss) (9.5) 10.0 35.9 31.5 Earnings (loss) per share—basic and diluted (0.03) 0.03 0.10 0.09 2018 Fourth Third Second First Revenue $ 799.3 $ 761.1 $ 770.2 $ 736.2 Cost of sales 412.5 369.8 431.5 360.0 Operating expenses (1) 246.2 237.9 252.5 245.2 Asset impairment, restructuring, and other special charges 46.0 12.4 68.0 2.4 Interest expense, net of capitalized interest 21.0 8.6 — — Income (loss) before income taxes (2.2) 78.8 (40.0) 77.5 Income tax (benefit) expense (18.6) 18.6 22.8 4.8 Net income (loss) 16.4 60.2 (62.8) 72.7 Earnings (loss) per share—basic and diluted 0.04 0.20 (0.21) 0.25 (1) Includes research and development and marketing, selling, and administrative expenses. Numbers may not add up to totals for each year due to rounding.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Bayer Animal Health acquisition financing Equity offerings On January 22, 2020, we entered into an underwriting agreement in which we agreed to sell approximately 22.7 million shares of our common stock at a public offering price of $32.00 per share. In connection with the offering, we granted the underwriters an option to purchase up to an additional 2.3 million shares, which was exercised in full on January 23, 2020. As a result, we issued and sold a total of approximately 25.0 million shares of our common stock. Total cash of $769.9 million was received upon closing on January 27, 2020. In addition, on January 22, 2020, we issued $550 million in tangible equity units (TEUs). We offered 11 million 5.00% TEUs at the stated amount of $50 per unit, composed of a prepaid stock purchase contract and a senior amortizing note due February 1, 2023 (the mandatory settlement date). Total cash of $530.1 million was received upon closing on January 27, 2020, which was comprised of $453.8 million of prepaid stock purchase contracts and $76.3 million of senior amortizing notes, net of debt issuance costs. Unless the stock purchase contracts are redeemed by us or settled earlier at the unit holder’s option, they are mandatorily convertible into shares of our common stock at a minimum of 1.3021 shares per purchase contract or a maximum of 1.5625 shares per purchase contract on the mandatory settlement date. This corresponds to a minimum of 14.3 million shares and a maximum of 17.2 million shares. Debt activity On January 31, 2020, we used a portion of the proceeds from the common stock and TEU issuances to repay indebtedness outstanding under our existing term loan facility. We paid $372.4 million in cash, composed of $371.4 million of principal and $1.0 million of accrued interest, resulting in a debt extinguishment loss of $0.8 million, primarily related to the write-off of deferred debt issuance costs. On February 4, 2020, we successfully priced our senior secured credit facilities, consisting of the following: • Term loan B facility with an aggregate principal amount of $4,275.0 million and a maturity of seven years. • Revolving loan facility providing up to $750.0 million and a maturity of five years. The term loan B facility was priced at par at LIBOR plus 175 basis points, and the revolving loan facility is expected to bear interest at LIBOR plus an applicable margin ranging between 1.50% and 2.25% per annum based on our corporate family rating or corporate credit rating. We intend to use the proceeds from the equity and debt activities to finance the cash portion of the pending acquisition of Bayer's animal health business and to pay related fees and expenses. As a result, we have obtained substantially all of the financing necessary to consummate the acquisition and do not currently intend to pursue any additional financing previously provided under the commitment letter obtained in August 2019 (see Note 16: Commitments and Contingencies). Divestitures Osurnia and Capstar In January 2020, we signed agreements to divest the worldwide rights to Osurnia and the U.S. rights to Capstar for an aggregate of $230 million in all cash deals, with the intent to advance our efforts to secure the necessary regulatory clearances for the pending acquisition of the Bayer animal health business. The closing of these transactions is contingent on us entering into consent decrees with certain agencies in connection with the pending acquisition as well as customary closing conditions. Both divestitures are expected to close by the end of 2020. The related assets met the assets held for sale criteria as of December 31, 2019. No adjustment was required to record the assets at the lower of their carrying amounts or fair values less costs to sell on the consolidated balance sheet. Assets and liabilities considered held for sale in connection with the divestitures as of December 31, 2019 were included in the respective line items in the consolidated balance sheet as follows: Inventories $ 10.6 Other intangibles, net 61.2 Property and equipment, net 0.2 Total assets held for sale 72.0 Deferred taxes (1.4) Total liabilities held for sale $ (1.4) Other intangibles, net classified as held for sale primarily consist of marketed products. We determined that the disposal of these net assets does not qualify for reporting as a discontinued operation because it does not represent a strategic shift that has or will have a major effect on our operations and financial results. Vecoxan In February 2020, we signed an agreement to divest the worldwide rights to Vecoxan for $55 million in an all cash deal, with the intent to advance our efforts to secure the necessary regulatory clearances for the pending acquisition of the Bayer animal health business. The closing of this transaction is contingent on us entering into consent decrees with certain agencies in connection with the pending acquisition as well as customary closing conditions. This divestiture is expected to close by the end of 2020.

Basis of Presentation (Policies

Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	We have prepared the accompanying consolidated and combined financial statements in accordance with accounting principles generally accepted in the United States (GAAP). In our opinion, the financial statements reflect all adjustments (including those that are normal and recurring) that are necessary for fair presentation of the results of operations for the periods shown. The accounts of all wholly-owned and majority-owned subsidiaries are included in the consolidated financial statements, and all intercompany balances and transactions have been eliminated. Certain reclassifications have been made to prior periods in the unaudited condensed consolidated and combined financial statements and accompanying notes to conform with current presentation.
Consolidation	For the periods after Separation, the financial statements are prepared on a consolidated basis and reflect the results of operations, comprehensive income, financial position, equity and cash flows resulting from our operations as an independent company. For periods prior to Separation, our financial statements are combined, have been prepared on a standalone basis, and are derived from Lilly's consolidated financial statements and accounting records. The consolidated and combined financial statements reflect the financial position, results of operations and cash flows related to the animal health businesses that were transferred to Elanco Parent and are prepared in conformity with GAAP. The combined financial statements include the attribution of certain assets and liabilities that historically have been held at the Lilly corporate level but which are specifically identifiable or attributable to the businesses that have been transferred to Elanco Parent. All intercompany transactions and accounts within Elanco have been eliminated. All transactions between us and Lilly are considered to be effectively settled in the combined financial statements at the time the intercompany transaction is recorded. The total net effect of the settlement of these intercompany transactions is reflected in the combined statements of cash flows as a financing activity and in the consolidated and combined statement of equity as net parent company investment.
Expenses Related to Certain Corporate Functions	Prior to Separation, these combined financial statements include an allocation of expenses related to certain Lilly corporate functions, including executive oversight, treasury, legal, finance, human resources, tax, internal audit, financial reporting, information technology and investor relations, prior to IPO. These expenses were allocated to us based on direct usage or benefit where specifically identifiable, with the remainder allocated primarily on a pro rata basis of revenue, headcount and other measures. We consider the expenses methodology and results to be reasonable for all periods presented. However, the allocations may not be indicative of the actual expense that would have been incurred had we operated as an independent, publicly traded company for the periods presented. It is impractical to estimate what the standalone costs of Elanco would have been in the historical periods. After the Separation, a TSA between Lilly and Elanco went into effect. Under the terms of the TSA, we will be able to use these Lilly services for a fixed term established on a service-by-service basis. We are paying Lilly mutually agreed upon fees for the Lilly services provided under the TSA. Our consolidated and combined financial statements reflect the charges for Lilly services after the IPO. See Note 20: Related Party Agreements and Transactions for additional details.
Income Tax	The income tax amounts in the combined financial statements have been calculated based on a separate return methodology and presented as if our operations were separate taxpayers in the respective jurisdictions. We file income tax returns in the U.S. federal jurisdiction and various state, local and non-U.S. jurisdictions. Prior to full separation, certain of these income tax returns were filed on a consolidated or combined basis with Eli Lilly and Company and/or its subsidiaries.
Benefit and Combined Stock-Based Compensation Plans	Prior to Separation, Lilly maintained various benefit and combined stock-based compensation plans at a corporate level and other benefit plans at a country level. Our employees participated in such programs and the portion of the cost of those plans related to our employees is included in our financial statements. However, the consolidated balance sheets do not include any equity issued related to stock-based compensation plans or any net benefit plan obligations unless the benefit plan covers only our dedicated employees or where the legal obligation associated with the benefit plan transferred to Elanco. Upon Lilly's full divestiture of Elanco in March 2019, all Lilly share-based awards held by our employees were converted into awards that will be settled in Elanco shares.
Equity Balance	Prior to Separation, the equity balance in the combined financial statements represents the excess of total assets over liabilities, including intercompany balances between Elanco and Lilly (net parent company investment) and accumulated other comprehensive income (loss). Net parent company investment is primarily impacted by contributions from Lilly which are the result of treasury activities and net funding provided by or distributed to Lilly.
Revenue recognition	Revenue recognition Effective January 1, 2018, we adopted Accounting Standards Update 2014-09, Revenue from Contracts with Customers (ASU 2014-09) and other related updates. The new standard has been applied to contracts for which performance had not been completed as of the date of adoption. Revenue presented for periods prior to 2018 was accounted for under previous standards and has not been adjusted. Revenue and net income for the years ended December 31, 2019 and 2018 do not differ materially from amounts that would have resulted from application of the previous standards. Product Sales We recognize revenue primarily from product sales to customers. 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 120 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. For arrangements with contract manufacturing organizations (CMO), we recognize revenue over time or at a point in time depending on our evaluation of when the customer obtains control of the promised goods or service. Revenue is recognized over time when we are creating or enhancing an asset that the customer controls. In this instance revenue is recognized as the asset is created or enhanced or our performance does not create an asset with an alternative use and we have an enforceable right to payment for performance completed. Provisions for rebates and discounts, as well as 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 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 products are sold to wholesale distributors. We initially invoice our customers 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. Judgments are required in making these estimates. • The rebate and discount amounts are recorded as a deduction to arrive at our net product sales. We estimate these accruals using an expected value approach. • In determining the appropriate accrual amount, we consider our historical experience with similar incentives programs and current sales data and estimates of inventory levels at our channel distributors to evaluate the impact of such programs on revenue and continually monitor the impact of this experience and adjust as necessary. Although we accrue a liability for rebates related to these programs at the time the sale is recorded, the rebate related to that sale is typically paid up to six months after the rebate or incentive period expires. Because of this time lag, in any particular period rebate adjustments may incorporate revisions of accruals for several periods. Sales Returns - Background and Uncertainties • We estimate a reserve for future product returns related to product sales using an expected value approach. This estimate is based on several factors, including: local returns policies and practices; returns as a
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, which 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.
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).
Implementation of New Financial Accounting Pronouncements	The following table provides a brief description of an accounting standard that was effective January 1, 2019 and was adopted on that date: Standard Description 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 previous GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. We adopted the standard on January 1, 2019 using the modified retrospective approach, applied at the beginning of the period of adoption, and we elected the package of transition practical expedients. Upon adoption of the standard, we recorded $84.9 million of right-of-use assets and $85.3 million of operating lease liabilities on our consolidated balance sheet. Adoption of this standard did not have a material impact on our consolidated statement of operations for the year ended December 31, 2019. See Note 13: Leases for further information. The following table provides a brief description of the accounting standards applicable to us that have not yet been adopted: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard modifies the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables. This may result in the earlier recognition of allowances for losses. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. We do not expect that the adoption of this standard will have a material impact on our consolidated financial statements based on financial instruments currently held. Accounting Standards Update 2018-15, Intangibles - Goodwill and Other Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract This guidance aligns the requirements for capitalizing implementation costs incurred in a cloud-based hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. Adoption of this standard is not expected to have a significant impact on our consolidated financial statements. Accounting Standards Update 2019-12, Simplifying the Accounting for Income Taxes The amendments in this update simplify the accounting for income taxes by removing certain exceptions and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. This standard is effective January 1, 2021, with early adoption permitted. We intend to adopt this standard on that date. We are currently evaluating the impact of adoption of the new standard on our consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Description of Accounting Standards Adopted and Not Yet Adopted	The following table provides a brief description of an accounting standard that was effective January 1, 2019 and was adopted on that date: Standard Description 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 previous GAAP, on the balance sheet and requiring additional disclosures about leasing arrangements. We adopted the standard on January 1, 2019 using the modified retrospective approach, applied at the beginning of the period of adoption, and we elected the package of transition practical expedients. Upon adoption of the standard, we recorded $84.9 million of right-of-use assets and $85.3 million of operating lease liabilities on our consolidated balance sheet. Adoption of this standard did not have a material impact on our consolidated statement of operations for the year ended December 31, 2019. See Note 13: Leases for further information. The following table provides a brief description of the accounting standards applicable to us that have not yet been adopted: Standard Description Effective Date Effect on the financial statements or other significant matters Accounting Standards Update 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard modifies the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables. This may result in the earlier recognition of allowances for losses. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. We do not expect that the adoption of this standard will have a material impact on our consolidated financial statements based on financial instruments currently held. Accounting Standards Update 2018-15, Intangibles - Goodwill and Other Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract This guidance aligns the requirements for capitalizing implementation costs incurred in a cloud-based hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This standard is effective January 1, 2020, with early adoption permitted. We intend to adopt this standard on that date. Adoption of this standard is not expected to have a significant impact on our consolidated financial statements. Accounting Standards Update 2019-12, Simplifying the Accounting for Income Taxes The amendments in this update simplify the accounting for income taxes by removing certain exceptions and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. This standard is effective January 1, 2021, with early adoption permitted. We intend to adopt this standard on that date. We are currently evaluating the impact of adoption of the new standard on our consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Summary of Activity in Sales Rebates and Discounts Liability	The following table summarizes the activity in the sales rebates and discounts liability in the U.S.: Year Ended December 31, 2019 2018 Beginning balance $ 118.5 $ 114.8 Reduction of revenue 316.3 221.0 Payments (284.4) (217.3) Ending balance $ 150.4 $ 118.5
Disaggregation of Revenue	The following table summarizes our revenue disaggregated by product category for the years ended December 31: 2019 2018 2017 Companion Animal Disease Prevention $ 787.9 $ 804.6 $ 660.2 Companion Animal Therapeutics 348.0 283.1 260.8 Food Animal Future Protein & Health 745.1 711.2 649.2 Food Animal Ruminants Swine 1,110.3 1,174.0 1,175.0 Strategic Exits (1) 79.7 93.9 143.8 Total Revenue $ 3,071.0 $ 3,066.8 $ 2,889.0 (1) Represents revenue from business activities we have either exited or made a strategic decision to exit.

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Summary of Amounts Recognized for Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at July 18, 2019 Cash and cash equivalents $ 26.4 Inventories 10.3 Acquired in-process research and development 31.9 Marketed products (1) 36.7 Other intangible assets (1) 13.2 Other assets and liabilities - net 24.0 Total identifiable net assets 142.5 Goodwill (2) 10.8 Settlement of existing contingent consideration liabilities 84.7 Total consideration transferred $ 238.0 (1) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, are expected to have a weighted average useful life of approximately 12.5 years. (2) The goodwill recognized from this acquisition is attributable primarily to expected synergies from combining the operations of Aratana with our legacy business. The majority of goodwill associated with this acquisition is not deductible for tax purposes. The following table summarizes the preliminary amounts recognized for assets acquired and liabilities assumed as of the acquisition date: Estimated Fair Value at July 31, 2019 Cash and cash equivalents $ 0.9 Property and equipment 0.5 Acquired in-process research and development 2.8 Marketed products (1) 58.9 Other intangible assets 1.1 Other assets and liabilities - net (10.3) Total identifiable net assets 53.9 Goodwill (2) 11.1 Total consideration transferred $ 65.0 (1) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, are 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 Prevtec with our legacy business and future unidentified projects and products. The goodwill associated with this acquisition is not deductible for tax purposes. 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 (1) $ 108.6 Marketed products (2) 297.0 Property and equipment 148.2 Other assets and liabilities — net 8.2 Total identifiable net assets 562.0 Goodwill (3) 320.1 Total consideration transferred — net of cash acquired $ 882.1 (1) The fair value for inventories include a purchase accounting adjustment to write up the inventory value, which resulted in incremental cost of sales of $42.7 million in 2017. The fair value was determined by estimating the expected sales price of the inventories, reduced for all costs expected to the incurred and a profit on those costs. (2) These intangible assets, which are being amortized on a straight-line basis over their estimated useful lives, were expected to have a weighted average useful life of 10 years.

Asset Impairment, Restructuri_2

Asset Impairment, Restructuring and Other Special Charges (Tables)	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Total Charges Related to Asset Impairment, Restructuring and Other Special Charges	Components of asset impairment, restructuring and other special charges for the years ended December 31 are as follows: 2019 2018 2017 Restructuring charges: (1) Severance and other costs $ 8.2 $ 15.5 $ 162.0 Facility exit costs — 5.7 31.8 Acquisition related charges: Transaction and integration costs (2) 144.7 26.5 90.3 Non-cash and other items: Asset impairment (3) 15.4 81.9 110.6 Asset write-down (4) 17.2 — — Gain on sale of fixed assets (5) — (0.8) (19.6) Total expense $ 185.5 $ 128.8 $ 375.1 (1) For the year ended December 31, 2019, these charges primarily relate to a new program that will eliminate certain positions across multiple locations and functions, including exiting R&D operations in Prince Edward Island, Canada, ceasing certain manufacturing operations in Wusi, China, and streamlining operations in Speke, England. We expect to substantially complete these restructuring activities by September 2020. For the year ended December 31, 2018, these charges primarily relate to a program to streamline international operations, including shifting focus and resources to priority areas. Among other actions, amounts reflect a change from having a physical location to a distribution model in certain countries in connection with the Separation. These activities were substantially complete as of December 31, 2019. We historically participated in Lilly’s cost-reduction initiatives, which resulted in restructuring charges in the period prior to our IPO. These restructuring charges include severance and other costs associated with the reduction of our workforce, including special termination benefits recognized in 2017 associated with the U.S. voluntary early retirement program offered by Lilly, related to our employees and pension curtailment costs and facility exit costs. We also recorded certain impairment charges related to the activities as described below. (2) Transaction costs represent external costs directly related to acquiring businesses and primarily include expenditures for banking, legal, accounting and other similar services. Integration costs represent external, incremental costs directly related to integrating acquired businesses (e.g., expenditures for consulting, system and process integration, and product transfers), as well as stand-up costs related to the implementation of new systems, programs, and processes due to the Separation from Lilly . (3) Asset impairment charges are associated with the following: • For the year ended December 31, 2019, write-off certain IPR&D and manufacturing assets in the US, Canada and Speke, resulting from the adjustment to fair value of property and equipment and intangible assets that were subject to product rationalization. • For the year ended December 31, 2018, the decision to dispose of a manufacturing facility in the U.S., the suspension of commercial activities for Imrestor , the write-off of certain idle assets in a U.S. manufacturing facility and product rationalization. • For the year ended December 31, 2017, intangible asset impairments related to revised projections of fair value due to product rationalization and to a lesser extent competitive pressures. (4) Asset write-down expenses resulted from the adjustments recorded to write assets classified as held and used and held for sale down to their current fair values. These charges primarily related to fixed assets in Prince Edward Island, Canada; Wusi, China and Indianapolis, Indiana. $11.2 million of Property and equipment, net in Prince Edward Island, Canada and Indianapolis, Indiana are classified as held for sale. (5) Represents a gain on the disposal of a site that was previously closed as part of the acquisition and integration of Novartis Animal Health beginning on January 1, 2015.
Summary of Activity in Reserves	The following table summarizes the activity in our reserves established in connection with restructuring activities: Exit costs Severance Total Balance at December 31, 2017 $ 34.9 $ 43.1 $ 78.0 Charges 11.7 15.5 27.2 Separation adjustment (5.9) — (5.9) Reserve adjustment (6.0) — (6.0) Cash paid (25.4) (23.5) (48.9) Balance at December 31, 2018 9.3 35.1 44.4 Charges — 19.3 19.3 Reserve adjustment (1) — (11.1) (11.1) Cash paid (3.9) (27.8) (31.7) Balance at December 31, 2019 $ 5.4 $ 15.5 $ 20.9 (1) Reserve adjustment represents the reversal of reserves for severance programs that are no longer active.

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories at December 31 consisted of the following: 2019 2018 Finished products $ 402.9 $ 400.7 Work in process 603.2 570.4 Raw materials and supplies 83.9 80.4 Total (approximates replacement cost) 1,090.0 1,051.5 Decrease to LIFO cost (39.3) (47.4) Inventories $ 1,050.7 $ 1,004.1

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt as of December 31 consisted of the following: 2019 2018 Term credit facility $ 371.4 $ 492.5 3.912% Senior Notes due 2021 500.0 500.0 4.272% Senior Notes due 2023 750.0 750.0 4.900% Senior Notes due 2028 750.0 750.0 Other obligations 0.4 0.5 Unamortized debt issuance costs (16.8) (20.7) 2,355.0 2,472.3 Less current portion of long-term debt (24.5) (29.0) Total long-term debt $ 2,330.5 $ 2,443.3

Financial Instruments and Fai_2

Financial Instruments and Fair Value (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Summary of Fair Value Information	The following table summarizes the fair value information at December 31, 2019 and 2018 for contingent consideration liabilities, and net investment hedge assets/(liabilities) measured at fair value on a recurring basis in the respective balance sheet line items, as well as long-term debt for which fair value is disclosed on a recurring basis: Fair Value Measurements Using Financial statement line item Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Fair Value December 31, 2019 Other noncurrent liabilities- contingent consideration $ (4.7) $ — $ — $ (4.7) $ (4.7) Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges 2.3 — 2.3 — 2.3 Long-term debt - senior notes (2,000.0) — (2,120.6) — (2,120.6) Long-term debt - term credit facility (371.4) — (371.4) — (371.4) December 31, 2018 Other current liabilities- contingent consideration $ (5.1) $ — $ — $ (5.1) $ (5.1) Other noncurrent liabilities- contingent consideration (69.0) — — (69.0) (69.0) Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges (7.4) — (7.4) — (7.4) Long-term debt - senior notes (2,000.0) — (2,005.0) — (2,005.0) Long-term debt - term credit facility (492.5) — (492.5) — (492.5)

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Components of Finite-Lived Intangible Assets	The components of intangible assets other than goodwill at December 31 were as follows: 2019 2018 Description Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Finite-lived intangible assets: Marketed products $ 3,302.7 $ (980.6) $ 2,322.1 $ 3,193.5 $ (779.2) $ 2,414.3 Software 159.2 (72.2) 87.0 101.3 (49.5) 51.8 Other 58.3 (34.0) 24.3 53.1 (34.0) 19.1 Total finite-lived intangible assets 3,520.2 (1,086.8) 2,433.4 3,347.9 (862.7) 2,485.2 Indefinite-lived intangible assets: Acquired in-process research and development 49.4 — 49.4 19.6 — 19.6 Other intangibles $ 3,569.6 $ (1,086.8) $ 2,482.8 $ 3,367.5 $ (862.7) $ 2,504.8
Components of Indefinite-Lived Intangible Assets	The components of intangible assets other than goodwill at December 31 were as follows: 2019 2018 Description Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Carrying Amount, Gross Accumulated Amortization Carrying Amount, Net Finite-lived intangible assets: Marketed products $ 3,302.7 $ (980.6) $ 2,322.1 $ 3,193.5 $ (779.2) $ 2,414.3 Software 159.2 (72.2) 87.0 101.3 (49.5) 51.8 Other 58.3 (34.0) 24.3 53.1 (34.0) 19.1 Total finite-lived intangible assets 3,520.2 (1,086.8) 2,433.4 3,347.9 (862.7) 2,485.2 Indefinite-lived intangible assets: Acquired in-process research and development 49.4 — 49.4 19.6 — 19.6 Other intangibles $ 3,569.6 $ (1,086.8) $ 2,482.8 $ 3,367.5 $ (862.7) $ 2,504.8
Schedule of Weighted-Average Amortization Periods For Finite-Lived Intangible Assets	As of December 31, 2019, the remaining weighted-average amortization periods for finite-lived intangible assets are as follows: Weighted Average Life (Years) Marketed products 13 Software 6 Other 8
Estimated Amortization Expense	The estimated amortization expense for each of the next five years associated with our finite-lived intangible assets as of December 31, 2019 is as follows: 2020 2021 2022 2023 2024 Estimated amortization expense $ 206.2 $ 205.4 $ 203.3 $ 203.0 $ 203.0

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment and Depreciation Expense	At December 31, property and equipment consisted of the following: 2019 2018 Land $ 28.3 $ 27.6 Buildings 608.5 567.2 Equipment 1,109.4 1,025.1 Construction in progress 139.1 181.1 Finance lease asset 0.5 — 1,885.8 1,801.0 Less accumulated depreciation (930.5) (878.6) Property and equipment, net $ 955.3 $ 922.4
Rental Expense for All Leases	Depreciation expense related to property and equipment was as follows: 2019 2018 2017 Depreciation expense $ 93.7 $ 81.3 $ 79.8

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Impact of Operating Leases to Condensed Consolidated Financial Statements	The impact of operating leases to our consolidated financial statements for the year ended December 31, 2019 was as follows: 2019 Lease cost Operating lease cost $ 26.1 Short-term lease cost 0.5 Variable lease cost 2.5 Total lease cost (1) $ 29.1 Other information Operating cash outflows from operating leases $ 24.0 Right-of-use assets obtained in exchange for new operating lease liabilities 20.1 Weighted-average remaining lease term - operating leases 5.1 years Weighted-average discount rate - operating leases 3.6 % (1) Rental expense for all leases was $47.5 million and $47.1 million for the years ended December 31, 2018 and 2017, respectively.
Supplemental Balance Sheet Information Related to Operating Leases	Supplemental balance sheet information related to our operating leases is as follows: Balance Sheet Classification December 31, 2019 Right-of-use assets Other noncurrent assets $ 85.0 Current operating lease liabilities Other current liabilities 23.7 Non-current operating lease liabilities Other noncurrent liabilities 61.7
Annual Minimum Lease Payments of Operating Lease Liabilities	As of December 31, 2019, the annual minimum lease payments of our operating lease liabilities were as follows: Year 1 $ 26.0 Year 2 20.3 Year 3 11.9 Year 4 9.7 Year 5 7.2 After Year 5 16.5 Total lease payments 91.6 Less imputed interest (6.2) Total $ 85.4

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Stock-Based Compensation Expenses	Components of stock-based compensation expense and related tax benefit for the years ended December 31 are as follows: 2019 2018 Stock-based compensation expense (1) $ 40.7 $ 1.8 Related tax benefit (9.8) (0.4) (1) We include the impact of estimated forfeitures when determining stock-based compensation expense.
Schedule of Restricted Stock Unit Activity	RSUs granted to employees for the years ended December 31 are as follows: (Units in millions) 2019 2018 Granted units 2.9 0.2 Weighted-average fair value $ 31.22 $ 31.09 Changes in nonvested portion of RSUs for 2019 is summarized below: (Shares in millions) Shares Weighted-Average Fair Value Nonvested units at January 1, 2019 0.2 $ 31.09 Granted 2.9 31.22 Vested (0.8) 31.33 Forfeited (0.1) 31.25 Nonvested units at December 31, 2019 2.2 30.42
Schedule of Performance Awards Activity	PA activity during the year ended December 31, 2019 is summarized below: (Shares in millions) Shares Weighted-Average Fair Value Nonvested awards at January 1, 2019 — $ — Granted 0.8 25.75 Vested — — Forfeited — — Nonvested awards at December 31, 2019 0.8 25.75
Schedule of Assumptions Used	The fair-value-based method for valuing each Elanco stock option grant on the grant date uses the Black-Scholes-Merton option-pricing model, which incorporates a number of valuation assumptions noted in the following table, shown at their weighted-average values for the year ended December 31: 2018 Expected dividend yield (1) 0.70 % Risk-free interest rate (2) 3.07 % Expected stock price volatility (3) 28.25 % Expected term (4) (years) 6.5 (1) Determined using the expected quarterly dividend divided by the available three-month average stock price as of the valuation date, annualized and continuously compounded. (2) Determined using the term-matched, zero-coupon risk-free rate from the Treasury Constant Maturity yield curve, continuously compounded (3) Determined using a leverage-adjusted historical volatility of peer companies (4) Determined using SEC safe harbor approach, based on a 3-year cliff vesting schedule and 10-year contractual term.
Schedule of Stock Option Activity	Stock option activity during the year ended December 31, 2019 is summarized below: (Shares in millions) Shares of Common Stock Attributable to Options Weighted-Average Exercise Price of Options Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (1) Outstanding at January 1, 2019 0.4 $ 31.61 Granted — — Exercised (0.1) 31.61 Forfeited or expired — — Outstanding at December 31, 2019 0.3 $ 31.61 8.8 $ — Exercisable at December 31, 2019 — — — — (1) Market price of underlying Elanco common stock less exercise price. Options do not have an intrinsic value unless the market price exceeds the exercise price. The following table summarizes data related to stock option activity: 2019 2018 Weighted-average grant date fair value per stock option $ 10.21 $ 10.21 Aggregate intrinsic value on exercise 0.10 — Cash received upon exercise 1.9 —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Composition of Income (Loss) Before Income Tax Expense (Benefit)	Following is the composition of income (loss) before income tax expense (benefit): 2019 2018 2017 Federal $ 55.5 $ 12.2 $ (133.2) Foreign 22.7 101.9 (99.4) Income (loss) before income taxes $ 78.2 $ 114.1 $ (232.6)
Composition of Income Tax Expense (Benefit)	Following is the composition of income tax expense (benefit): 2019 2018 2017 Current: Federal $ (5.5) $ 45.1 $ — Foreign 13.4 45.5 91.6 State 2.3 (2.3) (0.1) Total current tax expense 10.2 88.3 91.5 Deferred: Federal 14.5 (56.8) 42.6 Foreign (7.5) (5.6) (16.6) State (6.9) 1.7 (6.3) 2017 Tax Act — — (33.1) Total deferred tax expense (benefit) 0.1 (60.7) (13.4) Income taxes $ 10.3 $ 27.6 $ 78.1
Significant Components of Deferred Tax Assets and Liabilities	Significant components of our deferred tax assets and liabilities as of December 31 are as follows: 2019 2018 Deferred tax assets: Compensation and benefits $ 25.3 $ 32.2 Accruals and reserves 13.7 26.9 Tax credit carryovers 12.8 6.2 Tax loss carryovers 69.5 17.4 Inventories 20.1 18.3 Restructuring and other reserves 24.6 6.0 Operating lease liabilities 20.5 — Other 2.3 20.1 Total gross deferred tax assets 188.8 127.1 Valuation allowances (32.7) (21.4) Total deferred tax assets 156.1 105.7 Deferred tax liabilities: Right-of-use assets (20.5) — Intangibles (134.5) (130.8) Property and equipment (56.4) (50.8) Other (0.6) (2.7) Total deferred tax liabilities (212.0) (184.3) Deferred tax liabilities - net $ (55.9) $ (78.6)
Movements in the Valuation Allowance	The movements in the valuation allowance are as follows: 2019 2018 January 1 $ (21.4) $ (127.7) Adjustment related to Separation — 110.4 January 1 (21.4) (17.3) Increase (1) (23.2) (5.8) Release 11.9 1.7 December 31 $ (32.7) $ (21.4) (1) The increase in the valuation allowance during 2019 is primarily attributable to the acquisition of Aratana Therapeutics, Inc. and Prevtec Microbia Inc. (see Note 6: Acquisitions).
Cash Payments of Income Taxes	Cash payments of income taxes were as follows: 2019 2018 2017 Cash payments of income taxes $ 42.5 $ 26.9 $ 35.7
Reconciliation of Income Tax Expense (Benefit)	The following is a reconciliation of the income tax expense (benefit) applying the U.S. federal statutory rate to income before income taxes to reported income tax expense: 2019 2018 2017 Income tax at the U.S. federal statutory tax rate $ 16.4 $ 24.0 $ (81.4) Add (deduct): Taxation of international operations 20.7 20.5 59.8 State taxes 2.9 4.4 5.4 Income tax credits (9.8) (17.3) (1.8) Non-deductible employee compensation 4.2 (1.9) — IPO and separation costs — 2.3 — Other permanent adjustments (4.2) (1.0) 0.8 Change in uncertain tax positions (14.7) (1.7) 6.2 Change in valuation allowance (5.2) (1.7) 122.2 2017 Tax Act — — (33.1) Income taxes $ 10.3 $ 27.6 $ 78.1
Reconciliation of Gross Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2019 2018 2017 Beginning balance at January 1 $ 14.7 $ 29.6 $ 25.7 Adjustments related to Separation (2.2) (17.6) — Adjusted beginning balance at January 1 12.5 12.0 25.7 Additions based on tax positions related to the current year 1.3 2.2 7.9 Changes for tax positions of prior years (1.2) 4.0 — Settlements (4.3) (3.0) (4.0) Changes related to the impact of foreign currency translation (0.1) (0.5) — Ending balance at December 31 $ 8.2 $ 14.7 $ 29.6
Income Tax Expense (Benefit) Related to Interest and Penalties	We recognized income tax expense (benefit) related to interest and penalties as follows: 2019 2018 2017 Income tax expense (benefit) $ (10.6) $ (2.5) $ 2.5

Geographic Information (Tables)

Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Revenue by Selected Geographic Area Information	Selected geographic area information was as follows: 2019 2018 2017 Revenue — to unaffiliated customers (1) : United States $ 1,524.7 $ 1,483.2 $ 1,373.0 International 1,546.3 1,583.6 1,516.0 Revenue $ 3,071.0 $ 3,066.8 $ 2,889.0 Long-lived assets (2) : United States $ 709.8 $ 602.6 $ 604.7 United Kingdom 192.6 187.5 204.4 Other foreign countries 244.7 195.8 190.2 Long-lived assets $ 1,147.1 $ 985.9 $ 999.3 (1) Revenue is attributed to the countries based on the location of the customer.
Long-lived Assets by Selected Geographic Area Information	Selected geographic area information was as follows: 2019 2018 2017 Revenue — to unaffiliated customers (1) : United States $ 1,524.7 $ 1,483.2 $ 1,373.0 International 1,546.3 1,583.6 1,516.0 Revenue $ 3,071.0 $ 3,066.8 $ 2,889.0 Long-lived assets (2) : United States $ 709.8 $ 602.6 $ 604.7 United Kingdom 192.6 187.5 204.4 Other foreign countries 244.7 195.8 190.2 Long-lived assets $ 1,147.1 $ 985.9 $ 999.3 (1) Revenue is attributed to the countries based on the location of the customer.

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Change in Benefit Obligation, Change in Plan Assets, and Funded Status	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 plans, which were as follows: 2019 2018 Change in benefit obligation: Benefit obligation at beginning of year $ 234.8 $ 258.6 Service cost 9.3 11.3 Interest cost 2.2 2.5 Actuarial loss (gain) 56.4 (44.7) Benefits paid (5.5) (2.7) Plan amendments (74.7) — Foreign currency exchange rate changes and other adjustments 1.9 9.8 Benefit obligation at end of year 224.4 234.8 Change in plan assets: Fair value of plan assets at beginning of year 131.6 131.5 Actual return on plan assets 15.3 (10.2) Employer contribution 5.3 5.7 Benefits paid (5.5) (2.7) Foreign currency exchange rate changes and other adjustments 2.0 7.3 Fair value of plan assets at end of year 148.7 131.6 Funded status (75.7) (103.2) Unrecognized net actuarial loss 45.9 0.5 Unrecognized prior service cost (74.1) 0.8 Net amount recognized $ (103.9) $ (101.9)
Amounts Recognized in Combined Balance Sheet	Amounts recognized in the consolidated balance sheet consisted of: Noncurrent assets $ 2.1 $ 2.3 Other current liabilities (0.3) (0.3) Accrued retirement benefits (77.5) (105.2) Accumulated other comprehensive (income) loss before income taxes (28.2) 1.3 Net amount recognized $ (103.9) $ (101.9)
Weighted-Average Assumptions Related to Pension Plans	The following represents our weighted-average assumptions related to these pension plans as of December 31: (Percents) 2019 2018 2017 Discount rate for benefit obligation 0.6% 1.5% 1.1% Discount rate for net benefit costs 1.4 1.1 1.0 Rate of compensation increase for benefit obligation 2.3 2.2 2.1 Rate of compensation increase for net benefit costs 2.2 2.1 3.1 Expected return on plan assets for net benefit costs 4.0 4.0 4.4
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid as follows: 2020 2021 2022 2023 2024 2025-2029 Benefit payments $ 7.9 $ 8.6 $ 8.4 $ 8.0 $ 8.1 $ 48.4
Projected Benefit Obligations in Excess of Plan Assets	Amounts relating to these pension plans with projected benefit obligations in excess of plan assets were as follows at December 31: 2019 2018 Projected benefit obligation $ 218.2 $ 229.2 Fair value of plan assets 140.3 124.1
Accumulated Benefit Obligations in Excess of Plan Assets	Amounts relating to these defined benefit pension plans with accumulated benefit obligations in excess of plan assets were as follows at December 31: 2019 2018 Accumulated benefit obligation $ 203.9 $ 194.3 Fair value of plan assets 140.3 124.1
Net Pension Expense	Net pension expense related to these plans included the following components: 2019 2018 2017 Service cost $ 9.3 $ 11.3 $ 10.5 Interest cost 2.2 2.5 1.8 Expected return on plan assets (4.2) (6.2) (2.4) Amortization of prior service cost (1.7) 0.2 0.1 Amortization of net actuarial loss 1.1 1.9 1.4 Other — 0.5 — Net pension expense $ 6.7 $ 10.2 $ 11.4
Amounts Recognized in Other Comprehensive Loss	The following represents the amounts recognized for these plans in other comprehensive loss: 2019 2018 2017 Actuarial gain (loss) arising during period $ (45.6) $ 28.3 $ (17.0) Prior year service cost during the year 74.7 — — Amortization of prior service cost included in net loss (1.7) 0.2 0.1 Amortization of net actuarial loss included in net loss 1.1 1.9 1.4 Foreign currency exchange rate changes and other 1.0 (1.9) 3.5 Total other comprehensive income (loss) during period $ 29.5 $ 28.5 $ (12.0)
Fair Value of Pension Plan Assets	The fair values of these pension plan assets as of December 31, 2019 by asset category are as follows: Fair Value Measurements Using Asset Class Total Quoted Prices in Active Markets for Identical Assets Significant Observable Significant Unobservable Inputs Investments Valued at Net Asset Value (1) Cash and cash equivalents (2) $ 129.0 $ 129.0 $ — $ — $ — Public equity securities 3.8 1.9 — — 1.9 Fixed income: Developed markets 2.5 2.1 — — 0.4 Emerging markets 9.1 8.8 0.3 — — Other 4.3 0.9 3.4 — — Total $ 148.7 $ 142.7 $ 3.7 $ — $ 2.3 (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. (2) Switzerland plan assets were exiting the Lilly pension plan as of December 31, 2019. As a result, assets were converted to cash and transferred to the new Elanco pension fund effective January 1, 2020. The fair values of these pension plan assets as of December 31, 2018 by asset category are 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) Public equity securities $ 2.2 $ 1.0 $ — $ — $ 1.2 Fixed income: Developed markets 29.9 7.8 0.1 — 22.0 Emerging markets 6.4 0.7 0.4 — 5.3 Private alternative investments: Hedge funds 6.6 — — — 6.6 Equity-like funds 49.0 — — — 49.0 Real estate 20.1 0.1 — — 20.0 Other 17.4 0.3 2.3 — 14.8 Total $ 131.6 $ 9.9 $ 2.8 $ — $ 118.9 (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.

Related Party Agreements and _2

Related Party Agreements and Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Amounts Due From/(Due To) Lilly and Allocations of Services	Amounts due from/(due to) Lilly in connection with the Separation and agreed upon services as of December 31 were as follows: 2019 2018 TSA $ 10.5 $ (28.0) Other activities (15.8) (38.0) Local country asset purchases (11.1) (202.7) Total receivable from/(payable to) Lilly $ (16.4) $ (268.7) The allocations of services from Lilly, prior to IPO, to us were reflected as follows in the combined statements of operations: 2018 (1) 2017 Cost of sales $ 21.8 $ 31.8 Research and development 2.2 2.8 Marketing, selling and administrative 81.2 117.1 Total $ 105.2 $ 151.7 (1) Through September 30, 2018

Selected Quarterly Data (unau_2

Selected Quarterly Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Selected Quarterly Data	2019 Fourth Third Second First Revenue $ 787.0 $ 771.3 $ 781.6 $ 731.1 Cost of sales 410.1 360.4 356.0 343.8 Operating expenses (1) 253.2 262.2 269.7 245.2 Asset impairment, restructuring, and other special charges 51.6 77.2 31.8 24.9 Interest expense, net of capitalized interest 18.7 18.7 20.7 20.8 Income (loss) before income taxes (4.3) (12.5) 50.2 44.8 Income tax (benefit) expense 5.2 (22.5) 14.3 13.3 Net income (loss) (9.5) 10.0 35.9 31.5 Earnings (loss) per share—basic and diluted (0.03) 0.03 0.10 0.09 2018 Fourth Third Second First Revenue $ 799.3 $ 761.1 $ 770.2 $ 736.2 Cost of sales 412.5 369.8 431.5 360.0 Operating expenses (1) 246.2 237.9 252.5 245.2 Asset impairment, restructuring, and other special charges 46.0 12.4 68.0 2.4 Interest expense, net of capitalized interest 21.0 8.6 — — Income (loss) before income taxes (2.2) 78.8 (40.0) 77.5 Income tax (benefit) expense (18.6) 18.6 22.8 4.8 Net income (loss) 16.4 60.2 (62.8) 72.7 Earnings (loss) per share—basic and diluted 0.04 0.20 (0.21) 0.25 (1) Includes research and development and marketing, selling, and administrative expenses. Numbers may not add up to totals for each year due to rounding.

Subsequent Events (Tables)

Subsequent Events (Tables)	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Disclosure of Long Lived Assets Held-for-sale	Assets and liabilities considered held for sale in connection with the divestitures as of December 31, 2019 were included in the respective line items in the consolidated balance sheet as follows: Inventories $ 10.6 Other intangibles, net 61.2 Property and equipment, net 0.2 Total assets held for sale 72.0 Deferred taxes (1.4) Total liabilities held for sale $ (1.4)

Nature of Business and Organi_2

Nature of Business and Organization (Details) $ / shares in Units, $ in Billions	Sep. 24, 2018USD ($)$ / sharesshares	Dec. 31, 2019USD ($)countrybrand
Subsidiary, Sale of Stock [Line Items]
Number of brands in diverse portfolio (more than) | brand		125
Number of countries in which entity operates (more than) | country		90
IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued (in shares) | shares	72,335,000
Percentage of total outstanding shares	19.80%
Price per share (usd per share) | $ / shares	$ 24
Total net proceeds, after underwriting discounts and commissions	$ 1.7
Payments made to date		$ 4.2

Impact of Separation (Details)

Impact of Separation (Details) - USD ($)	Sep. 24, 2018	Dec. 31, 2019	[1]	Dec. 31, 2018	[2]	Sep. 05, 2018	Aug. 28, 2018
Debt Instrument [Line Items]
Separation adjustments	$ 99,600,000	$ (51,200,000)		$ 99,600,000
Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount							$ 2,000,000,000
Credit Facility | Revolving credit facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	750,000,000					$ 750,000,000
Credit Facility | Term credit facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 500,000,000					$ 500,000,000
[1]	See Note 20: Related Party Agreements and Transactions for further discussion.
[2]	See Note 3: Impact of Separation for further discussion.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 85
Operating lease liabilities	$ 85.4
Payment terms	Payment terms differ by jurisdiction and customer, but payment terms in most of our major jurisdictions typically range from 30 to 120 days from date of shipment.
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets		$ 84.9
Operating lease liabilities		$ 85.3

Revenue - Narrative (Details)

Revenue - Narrative (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Rebate period	6 months
Geographic Concentration Risk | Sales rebates and discounts, liability | United States
Concentration Risk [Line Items]
Concentration risk	71.00%	70.00%
Geographic Concentration Risk | Sales rebates and discounts, liability | Next Largest Country
Concentration Risk [Line Items]
Concentration risk	8.00%	8.00%
Product Return Concentration Risk | Net Revenue
Concentration Risk [Line Items]
Concentration risk	0.20%	0.60%

Revenue - Summary of Activity i

Revenue - Summary of Activity in Sales Rebates and Discounts Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 118.5	$ 114.8
Reduction of revenue	316.3	221
Payments	(284.4)	(217.3)
Ending balance	$ 150.4	$ 118.5

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total Revenue	$ 3,071	$ 3,066.8	$ 2,889
Companion Animal Disease Prevention
Disaggregation of Revenue [Line Items]
Total Revenue	787.9	804.6	660.2
Companion Animal Therapeutics
Disaggregation of Revenue [Line Items]
Total Revenue	348	283.1	260.8
Food Animal Future Protein & Health
Disaggregation of Revenue [Line Items]
Total Revenue	745.1	711.2	649.2
Food Animal Ruminants Swine
Disaggregation of Revenue [Line Items]
Total Revenue	1,110.3	1,174	1,175
Strategic Exits
Disaggregation of Revenue [Line Items]
Total Revenue	$ 79.7	$ 93.9	$ 143.8

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Aug. 19, 2019	Jul. 31, 2019	Jul. 18, 2019	Jan. 03, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Aratana Therapeutics, Inc.
Business Acquisition [Line Items]
Number of shares issued to previous shareholders upon closing (in shares)			7.2
Value of shares issued as consideration			$ 238
Maximum aggregate contingent payment			$ 12
Business acquisition (usd per share)			$ 0.25
Accelerated vesting of equity awards (in shares)					0.1
Accelerated stock based compensation					$ 3.6
Revenues					10
Unaudited pro forma combined revenues					3,100	$ 3,100
Pro forma combined income before income taxes					63.2	$ 117.7
Weighted average useful life			12 years 6 months
Galliprant
Business Acquisition [Line Items]
Contingent consideration liability			$ 84.7
Loss upon settlement of contingent consideration liability					$ 7.5
Prevtec
Business Acquisition [Line Items]
Maximum aggregate contingent payment		$ 16.3
Contingent consideration liability		4.7
Settlement of accounts receivable		0.7
Total consideration transferred		$ 60.3
Weighted average useful life		10 years
BIVIVP
Business Acquisition [Line Items]
Revenues							$ 216.7
Total consideration transferred				$ 882.1
Weighted average useful life				10 years
Bayer Animal Business
Business Acquisition [Line Items]
Value of shares issued as consideration	$ 2,300
Amount paid at closing	$ 5,300

Acquisitions - Summary of Amoun

Acquisitions - Summary of Amounts Recognized for Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Jul. 31, 2019	Jul. 18, 2019	Jan. 03, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Estimated Fair Value
Goodwill					$ 2,989.6	$ 2,958
Aratana Therapeutics, Inc.
Estimated Fair Value
Cash and cash equivalents		$ 26.4
Inventories		10.3
Other assets and liabilities - net		24
Total identifiable net assets		142.5
Goodwill		10.8
Settlement of existing contingent consideration liabilities		84.7
Total consideration transferred		$ 238
Weighted average useful life		12 years 6 months
Aratana Therapeutics, Inc. | Acquired in-process research and development
Estimated Fair Value
Acquired in-process research and development		$ 31.9
Aratana Therapeutics, Inc. | Marketed products
Estimated Fair Value
Marketed products		36.7
Aratana Therapeutics, Inc. | Other
Estimated Fair Value
Marketed products		$ 13.2
Prevtec
Estimated Fair Value
Cash and cash equivalents	$ 0.9
Property and equipment	0.5
Other assets and liabilities - net	(10.3)
Total identifiable net assets	53.9
Goodwill	11.1
Total consideration transferred	$ 65
Weighted average useful life	10 years
Prevtec | Acquired in-process research and development
Estimated Fair Value
Acquired in-process research and development	$ 2.8
Prevtec | Marketed products
Estimated Fair Value
Marketed products	58.9
Prevtec | Other
Estimated Fair Value
Marketed products	$ 1.1
BIVIVP
Estimated Fair Value
Inventories			$ 108.6
Property and equipment			148.2
Marketed products			297
Other assets and liabilities - net			8.2
Total identifiable net assets			562
Goodwill			320.1
Total consideration transferred			$ 882.1
Weighted average useful life			10 years
BIVIVP | Marketed products
Estimated Fair Value
Purchase accounting adjustment				$ 42.7

Asset Impairment, Restructuri_3

Asset Impairment, Restructuring and Other Special Charges - Total Charges Related to Asset Impairment, Restructuring and Other Special Charges (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring charges
Severance and other costs									$ 8.2	$ 15.5	$ 162
Facility exit costs									0	5.7	31.8
Transaction and integration costs									144.7	26.5	90.3
Non-cash and other items
Asset impairment									15.4	81.9	110.6
Asset write-down									17.2	0	0
Gain on sale of fixed assets									0	(0.8)	(19.6)
Total expense	$ 51.6	$ 77.2	$ 31.8	$ 24.9	$ 46	$ 12.4	$ 68	$ 2.4	185.5	$ 128.8	$ 375.1
Property, plant and equipment classified as held for sale	$ 11.2								$ 11.2

Asset Impairment, Restructuri_4

Asset Impairment, Restructuring and Other Special Charges - Summary of Activity in Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 44.4	$ 78
Charges	19.3	27.2
Separation adjustment		(5.9)
Reserve adjustment	(11.1)	(6)
Cash paid	(31.7)	(48.9)
Balance at end of period	20.9	44.4
Exit costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	9.3	34.9
Charges	0	11.7
Separation adjustment		(5.9)
Reserve adjustment	0	(6)
Cash paid	(3.9)	(25.4)
Balance at end of period	5.4	9.3
Severance
Restructuring Reserve [Roll Forward]
Balance at beginning of period	35.1	43.1
Charges	19.3	15.5
Separation adjustment		0
Reserve adjustment	(11.1)	0
Cash paid	(27.8)	(23.5)
Balance at end of period	$ 15.5	$ 35.1

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Finished products	$ 402.9	$ 400.7
Work in process	603.2	570.4
Raw materials and supplies	83.9	80.4
Total (approximates replacement cost)	1,090	1,051.5
Decrease to LIFO cost	(39.3)	(47.4)
Inventories	$ 1,050.7	$ 1,004.1

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories valued under the LIFO method	$ 194.8	$ 197.2
Inventory write-offs	$ 38.6

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Aug. 28, 2018
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (16.8)	$ (20.7)
Long-term debt	2,355	2,472.3
Less current portion of long-term debt	(24.5)	(29)
Total long-term debt	2,330.5	2,443.3
Credit Facility | Term credit facility
Debt Instrument [Line Items]
Long-term debt, gross	371.4	492.5
Senior Notes | 3.912% Senior Notes due 2021
Debt Instrument [Line Items]
Interest rate			3.912%
Long-term debt, gross	500	500
Senior Notes | 4.272% Senior Notes due 2023
Debt Instrument [Line Items]
Interest rate			4.272%
Long-term debt, gross	750	750
Senior Notes | 4.900% Senior Notes due 2028
Debt Instrument [Line Items]
Interest rate			4.90%
Long-term debt, gross	750	750
Other obligations
Debt Instrument [Line Items]
Long-term debt, gross	$ 0.4	$ 0.5

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	Sep. 05, 2018	Dec. 31, 2019	Dec. 31, 2018	Sep. 24, 2018	Aug. 28, 2018
Credit Facility | Revolving credit facility
Debt Instrument [Line Items]
Debt maturity term	5 years
Credit facility, maximum borrowing capacity	$ 750,000,000			$ 750,000,000
Borrowings outstanding		$ 0	$ 0
Credit Facility | Term credit facility
Debt Instrument [Line Items]
Debt maturity term	3 years
Credit facility, maximum borrowing capacity	$ 500,000,000			$ 500,000,000
Borrowings outstanding		$ 371,400,000	$ 492,500,000
Interest rate at period end		3.01%	3.77%
Quarterly principal payments percentage	1.50%
Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount					$ 2,000,000,000
Senior Notes | 3.912% Senior Notes due 2021
Debt Instrument [Line Items]
Borrowings outstanding		$ 500,000,000	$ 500,000,000
Aggregate principal amount					$ 500,000,000
Interest rate					3.912%
Senior Notes | 4.272% Senior Notes due 2023
Debt Instrument [Line Items]
Borrowings outstanding		750,000,000	750,000,000
Aggregate principal amount					$ 750,000,000
Interest rate					4.272%
Senior Notes | 4.900% Senior Notes due 2028
Debt Instrument [Line Items]
Borrowings outstanding		$ 750,000,000	$ 750,000,000
Aggregate principal amount					$ 750,000,000
Interest rate					4.90%

Financial Instruments and Fai_3

Financial Instruments and Fair Value - Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Jul. 31, 2019USD ($)	Jul. 18, 2019USD ($)	Oct. 31, 2018CHF (SFr)
Business Acquisition, Contingent Consideration [Line Items]
Equity method investments		$ 18.8	$ 15.3
Aratana Therapeutics, Inc.
Business Acquisition, Contingent Consideration [Line Items]
Maximum aggregate contingent payment					$ 12
Prevtec
Business Acquisition, Contingent Consideration [Line Items]
Maximum aggregate contingent payment				$ 16.3
Net Investment Hedging | Designated as Hedging Instrument | Foreign Exchange Contract
Business Acquisition, Contingent Consideration [Line Items]
Derivative, term of contract	5 years
Notional amount | SFr						SFr 750,000,000
Expected cash and contra interest per year	$ 25
Gain (Loss) to AOCI, net of tax		7.7	5.9
Net Investment Hedging | Designated as Hedging Instrument | Foreign Exchange Contract | Interest Expense
Business Acquisition, Contingent Consideration [Line Items]
Contra interest expense		$ 25.1	$ 5.6

Financial Instruments and Fai_4

Financial Instruments and Fair Value - Summary of Fair Value Information (Details) - Recurring - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges	$ 0	$ 0
Long-term debt - senior notes	0	0
Long-term debt - term credit facility	0	0
Significant Observable  Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges	2.3	(7.4)
Long-term debt - senior notes	(2,120.6)	(2,005)
Long-term debt - term credit facility	(371.4)	(492.5)
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges	0	0
Long-term debt - senior notes	0	0
Long-term debt - term credit facility	0	0
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges	2.3	(7.4)
Long-term debt - senior notes	(2,000)	(2,000)
Long-term debt - term credit facility	(371.4)	(492.5)
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other noncurrent assets/(liabilities) - cross currency interest rate contracts designated as net investment hedges	2.3	(7.4)
Long-term debt - senior notes	(2,120.6)	(2,005)
Long-term debt - term credit facility	(371.4)	(492.5)
Other current liabilities- contingent consideration | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		0
Other current liabilities- contingent consideration | Significant Observable  Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		0
Other current liabilities- contingent consideration | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		(5.1)
Other current liabilities- contingent consideration | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		(5.1)
Other current liabilities- contingent consideration | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		(5.1)
Other noncurrent liabilities- contingent consideration | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0	0
Other noncurrent liabilities- contingent consideration | Significant Observable  Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0	0
Other noncurrent liabilities- contingent consideration | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	(4.7)	(69)
Other noncurrent liabilities- contingent consideration | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	(4.7)	(69)
Other noncurrent liabilities- contingent consideration | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ (4.7)	$ (69)

Goodwill and Intangibles - Narr

Goodwill and Intangibles - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,989,600,000	$ 2,958,000,000
Impairments with respect to the carrying value of goodwill	0	0	$ 0
Impairment charges	11,400,000	22,500,000	94,500,000
Impairment of finite-lived intangible assets		9,500,000	56,500,000
Impairment of indefinite-lived intangible assets		13,000,000	38,000,000
Software
Finite-Lived Intangible Assets [Line Items]
Amortization	$ 20,400,000	$ 18,400,000	$ 17,400,000
Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	20 years

Goodwill and Intangibles - Comp

Goodwill and Intangibles - Components of Intangible Assets Other Than Goodwill (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Carrying Amount, Gross	$ 3,520.2	$ 3,347.9
Accumulated Amortization	(1,086.8)	(862.7)
Carrying Amount, Net	2,433.4	2,485.2
Other intangibles
Carrying Amount, Gross	3,569.6	3,367.5
Accumulated Amortization	(1,086.8)	(862.7)
Carrying Amount, Net	2,482.8	2,504.8
Acquired in-process research and development
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	49.4	19.6
Marketed products
Finite-Lived Intangible Assets [Line Items]
Carrying Amount, Gross	3,302.7	3,193.5
Accumulated Amortization	(980.6)	(779.2)
Carrying Amount, Net	2,322.1	2,414.3
Other intangibles
Accumulated Amortization	(980.6)	(779.2)
Software
Finite-Lived Intangible Assets [Line Items]
Carrying Amount, Gross	159.2	101.3
Accumulated Amortization	(72.2)	(49.5)
Carrying Amount, Net	87	51.8
Other intangibles
Accumulated Amortization	(72.2)	(49.5)
Other
Finite-Lived Intangible Assets [Line Items]
Carrying Amount, Gross	58.3	53.1
Accumulated Amortization	(34)	(34)
Carrying Amount, Net	24.3	19.1
Other intangibles
Accumulated Amortization	$ (34)	$ (34)

Goodwill and Intangibles - Rema

Goodwill and Intangibles - Remaining Weighted Average Amortization Periods (Details)	12 Months Ended
	Dec. 31, 2019
Marketed products
Finite-Lived Intangible Assets [Line Items]
Remaining amortization period	13 years
Software
Finite-Lived Intangible Assets [Line Items]
Remaining amortization period	6 years
Other
Finite-Lived Intangible Assets [Line Items]
Remaining amortization period	8 years

Goodwill and Intangibles - Esti

Goodwill and Intangibles - Estimated Amortization Expense (Details) $ in Millions	Dec. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 206.2
2021	205.4
2022	203.3
2023	203
2024	$ 203

Property and Equipment - Narrat

Property and Equipment - Narrative (Details)	12 Months Ended
	Dec. 31, 2019
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	12 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	50 years
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 1,801
Finance lease asset	$ 0.5
Property and equipment gross	1,885.8
Less accumulated depreciation	(930.5)
Less accumulated depreciation		(878.6)
Property and equipment, net	955.3
Property and equipment, net	955.3	922.4
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	28.3	27.6
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	608.5	567.2
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,109.4	1,025.1
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 139.1	$ 181.1

Property and Equipment - Deprec

Property and Equipment - Depreciation Expense and Rental Expense for All Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 93.7	$ 81.3	$ 79.8

Leases - Narrative (Details)

Leases - Narrative (Details)	12 Months Ended
	Dec. 31, 2019
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	12 years

Leases - Impact of Operating Le

Leases - Impact of Operating Leases to Condensed Consolidated Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lease cost
Operating lease cost	$ 26.1
Short-term lease cost	0.5
Variable lease cost	2.5
Total lease cost	29.1
Other information
Operating cash outflows from operating leases	24
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 20.1
Weighted-average remaining lease term - operating leases	5 years 1 month 6 days
Weighted-average discount rate - operating leases	3.60%
Rent expense		$ 47.5	$ 47.1

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Operating Leases (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
Right-of-use assets	$ 85
Current operating lease liabilities	23.7
Non-current operating lease liabilities	$ 61.7

Leases - Annual Minimum Lease P

Leases - Annual Minimum Lease Payments of Operating Lease Liabilities (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
Year 1	$ 26
Year 2	20.3
Year 3	11.9
Year 4	9.7
Year 5	7.2
After Year 5	16.5
Total lease payments	91.6
Less imputed interest	(6.2)
Total	$ 85.4

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Feb. 28, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	0
PAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 11
Weighted-average remaining requisite service period	13 months
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Unrecognized compensation cost	$ 25.5
Weighted-average remaining requisite service period	19 months
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Unrecognized compensation cost	$ 2.2
Weighted-average remaining requisite service period	22 months
Expiration period	10 years
Elanco Stock Compensation Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock to be reserved for future issuance (in shares)	11,000,000	5,500,000		5,500,000
Stock-based compensation	$ 40.7	$ 1.8
Lilly's Stock-Based Compensation Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 5.1	$ 26	$ 25

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expenses (Details) - Elanco Stock Compensation Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 40.7	$ 1.8
Related tax benefit	$ (9.8)	$ (0.4)

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Restricted Stock Unit and Performance Award Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
RSUs
Outstanding Restricted Stock Units
Beginning nonvested balance (in shares)	200,000
Granted (in shares)	2,900,000	200,000
Vested (in shares)	(800,000)
Forfeited (in shares)	(100,000)
Ending nonvested balance (in shares)	2,200,000	200,000
Weighted-Average Restricted Stock Unit Fair Value
Beginning nonvested balance (in dollars per share)	$ 31.09
Granted (in dollars per share)	31.22	$ 31.09
Vested (in dollars per share)	31.33
Forfeited (in dollars per share)	31.25
Ending nonvested balance (in dollars per share)	$ 30.42	$ 31.09
PAs
Outstanding Restricted Stock Units
Beginning nonvested balance (in shares)	0
Granted (in shares)	800,000
Vested (in shares)	0
Forfeited (in shares)	0
Ending nonvested balance (in shares)	800,000	0
Weighted-Average Restricted Stock Unit Fair Value
Beginning nonvested balance (in dollars per share)	$ 0
Granted (in dollars per share)	25.75
Vested (in dollars per share)	0
Forfeited (in dollars per share)	0
Ending nonvested balance (in dollars per share)	$ 25.75	$ 0

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Assumptions Used (Details) - Stock options	12 Months Ended
	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.70%
Risk-free interest rate	3.07%
Expected stock price volatility	28.25%
Expected term (years)	6 years 6 months

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Shares of Common Stock Attributable to Options
Outstanding at beginning of period (in shares)	400,000
Granted (in shares)	0
Exercised (in shares)	(100,000)
Forfeited or expired (in shares)	0
Outstanding at end of period (in shares)	300,000	400,000
Exercisable (in shares)	0
Weighted-Average Exercise Price of Options
Outstanding at beginning of period (usd per share)	$ 31.61
Granted (usd per share)	0
Exercised (usd per share)	31.61
Forfeited or expired (usd per share)	0
Outstanding at end of period (usd per share)	31.61	$ 31.61
Exercisable (usd per share)	$ 0
Stock Option Activity, Additional Disclosures
Weighted-average remaining contractual term of the outstanding options	8 years 9 months 18 days
Weighted-average remaining contractual term of the exercisable options	0 years
Aggregate intrinsic value of outstanding options	$ 0
Aggregate intrinsic value of exercisable options	$ 0
Weighted-average grant date fair value per stock option (usd per share)	$ 10.21	10.21
Aggregate intrinsic value on exercise (usd per share)	$ 0.10	$ 0
Cash received upon exercise	$ 1,900,000	$ 0

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	Sep. 24, 2018	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Tax credit carryovers		$ 14,000,000
Net operating losses and other carryovers		69,500,000	$ 17,400,000
Separation entries related to the removal of the net operating losses	$ 133,700,000
Taxes accrued with respect to unremitted earnings of foreign subsidiaries		0
Unremitted earnings of foreign subsidiaries		496,700,000
Unrecognized tax benefits that, if recognized, would affect effective tax rate		8,200,000	12,800,000
Unrecognized tax benefits that, if recognized, would not affect effective tax rate			1,900,000
Accruals for payment of interest and penalties		3,000,000	$ 13,300,000
Foreign
Operating Loss Carryforwards [Line Items]
Tax credit carryovers		5,100,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Tax credit carryovers		3,200,000
State
Operating Loss Carryforwards [Line Items]
Tax credit carryovers		5,700,000
International, State and Federal
Operating Loss Carryforwards [Line Items]
Net operating losses and other carryovers		348,400,000
Net operating loss carryforwards with indefinite carryforward period		62,900,000
International, State and Federal | 2020 To 2039
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that expire		$ 285,500,000

Income Taxes - Composition of I

Income Taxes - Composition of Income (Loss) Before Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal									$ 55.5	$ 12.2	$ (133.2)
Foreign									22.7	101.9	(99.4)
Income (loss) before income taxes	$ (4.3)	$ (12.5)	$ 50.2	$ 44.8	$ (2.2)	$ 78.8	$ (40)	$ 77.5	$ 78.2	$ 114.1	$ (232.6)

Income Taxes - Composition of_2

Income Taxes - Composition of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal									$ (5.5)	$ 45.1	$ 0
Foreign									13.4	45.5	91.6
State									2.3	(2.3)	(0.1)
Total current tax expense									10.2	88.3	91.5
Deferred:
Federal									14.5	(56.8)	42.6
Foreign									(7.5)	(5.6)	(16.6)
State									(6.9)	1.7	(6.3)
2017 Tax Act									0	0	(33.1)
Total deferred tax expense (benefit)									0.1	(60.7)	(13.4)
Income taxes	$ 5.2	$ (22.5)	$ 14.3	$ 13.3	$ (18.6)	$ 18.6	$ 22.8	$ 4.8	$ 10.3	$ 27.6	$ 78.1

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Compensation and benefits	$ 25.3	$ 32.2
Accruals and reserves	13.7	26.9
Tax credit carryovers	12.8	6.2
Tax loss carryovers	69.5	17.4
Inventories	20.1	18.3
Restructuring and other reserves	24.6	6
Operating lease liabilities	20.5
Other	2.3	20.1
Total gross deferred tax assets	188.8	127.1
Valuation allowances	(32.7)	(21.4)
Total deferred tax assets	156.1	105.7
Deferred tax liabilities:
Right-of-use assets	(20.5)
Intangibles	(134.5)	(130.8)
Property and equipment	(56.4)	(50.8)
Other	(0.6)	(2.7)
Total deferred tax liabilities	(212)	(184.3)
Deferred tax liabilities - net	$ (55.9)	$ (78.6)

Income Taxes - Movements in the

Income Taxes - Movements in the Valuation Allowance (Details) - Valuation Allowance, Deferred Tax Asset - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ (21.4)	$ (17.3)
Increase (1)	(23.2)	(5.8)
Release	11.9	1.7
Ending balance	(32.7)	(21.4)
Previously Reported
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	(21.4)	(127.7)
Ending balance		(21.4)
Adjustment related to Separation
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 0	110.4
Ending balance		$ 0

Income Taxes - Cash Payments of

Income Taxes - Cash Payments of Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Cash payments of income taxes	$ 42.5	$ 26.9	$ 35.7

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax at the U.S. federal statutory tax rate									$ 16.4	$ 24	$ (81.4)
Add (deduct):
Taxation of international operations									20.7	20.5	59.8
State taxes									2.9	4.4	5.4
Income tax credits									(9.8)	(17.3)	(1.8)
Non-deductible employee compensation									4.2	(1.9)	0
IPO and separation costs									0	2.3	0
Other permanent adjustments									(4.2)	(1)	0.8
Change in uncertain tax positions									(14.7)	(1.7)	6.2
Change in valuation allowance									(5.2)	(1.7)	122.2
2017 Tax Act									0	0	(33.1)
Income taxes	$ 5.2	$ (22.5)	$ 14.3	$ 13.3	$ (18.6)	$ 18.6	$ 22.8	$ 4.8	$ 10.3	$ 27.6	$ 78.1

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 12.5	$ 12	$ 25.7
Additions based on tax positions related to the current year	1.3	2.2	7.9
Changes for tax positions of prior years	(1.2)
Changes for tax positions of prior years		4	0
Settlements	(4.3)	(3)	(4)
Changes related to the impact of foreign currency translation	(0.1)	(0.5)	0
Ending balance	8.2	12.5	12
Previously Reported
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	14.7	29.6	25.7
Ending balance		14.7	29.6
Adjustment related to Separation
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ (2.2)	(17.6)	0
Ending balance		$ (2.2)	$ (17.6)

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Benefit) Related to Interest and Penalties (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (10.6)	$ (2.5)	$ 2.5

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	Aug. 19, 2019	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Liabilities related to litigation		$ 0	$ 0
Bayer Animal Business
Business Acquisition [Line Items]
Line of credit facility, commitment fee amount	$ 40,400,000
Bayer Animal Business | Revolving credit facility
Business Acquisition [Line Items]
Credit facility, maximum borrowing capacity	750,000,000
Bayer Animal Business | Term Facility
Business Acquisition [Line Items]
Credit facility, maximum borrowing capacity	3,000,000,000
Bayer Animal Business | Bridge Facility
Business Acquisition [Line Items]
Credit facility, maximum borrowing capacity	$ 2,750,000,000

Geographic Information - Narrat

Geographic Information - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)segment	Dec. 31, 2018USD ($)	Dec. 31, 2017
Segment Reporting [Abstract]
Number of operating segments | segment	1
Concentration Risk [Line Items]
Accounts receivable	$ 816.9	$ 651.8
Product Sales
Concentration Risk [Line Items]
Accounts receivable	$ 90.5	$ 96.4
Customer Concentration Risk | Revenue | Single Customer
Concentration Risk [Line Items]
Concentration risk	12.90%	11.90%	12.90%

Geographic Information - Revenu

Geographic Information - Revenue and Long-lived Assets by Selected Geographic Area Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 787	$ 771.3	$ 781.6	$ 731.1	$ 799.3	$ 761.1	$ 770.2	$ 736.2	$ 3,071	$ 3,066.8	$ 2,889
Long-lived assets	1,147.1				985.9				1,147.1	985.9	999.3
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,524.7	1,483.2	1,373
Long-lived assets	709.8				602.6				709.8	602.6	604.7
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,546.3	1,583.6	1,516
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	192.6				187.5				192.6	187.5	204.4
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 244.7				$ 195.8				$ 244.7	$ 195.8	$ 190.2

Retirement Benefits - Narrative

Retirement Benefits - Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)plan	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Decrease in pension benefit obligation	$ 21
Decreased in prior service costs	75
Decrease for plan amendment related to other costs and losses	54
Accumulated other comprehensive income net impact	$ 21
Contributions expected in 2020		$ 6.5
Accrued retirement benefits		82.5	$ 109.1
Expenses related to employees under Defined Contribution Plans		32.2	20.9	$ 22.1
Multiemployer plans expense			4	73.7
Multiemployer plans, curtailment loss and special termination benefits				$ 67
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Decrease in pension benefit obligation		(74.7)	0
Total accumulated benefit obligation		210.1	199.9
Accrued retirement benefits		$ 77.5	105.2
Pension Plans | Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Designated percentage invested		32.00%
Pension Plans | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Designated percentage invested		5.00%
Pension Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Designated percentage invested		21.00%
Pension Plans | Other Alternative Investments
Defined Benefit Plan Disclosure [Line Items]
Designated percentage invested		6.00%
Pension Plans | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Designated percentage invested		36.00%
Pension Plans | Switzerland
Defined Benefit Plan Disclosure [Line Items]
Percentage of benefit obligation in Switzerland pension plans		80.00%
Percentage of plan assets in Switzerland pension plans		87.00%
Retiree Health Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Number of plans | plan		2
Accrued retirement benefits		$ 4.7	$ 3.9

Retirement Benefits - Change in

Retirement Benefits - Change in Benefit Obligation, Change in Plan Assets, and Funded Status (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in benefit obligation:
Plan amendments	$ (21)
Pension Plans
Change in benefit obligation:
Benefit obligation at beginning of year		$ 234.8	$ 258.6
Service cost		9.3	11.3	$ 10.5
Interest cost		2.2	2.5	1.8
Actuarial loss (gain)		56.4	(44.7)
Benefits paid		(5.5)	(2.7)
Plan amendments		74.7	0
Foreign currency exchange rate changes and other adjustments		1.9	9.8
Benefit obligation at end of year		224.4	234.8	258.6
Change in plan assets:
Fair value of plan assets at beginning of year		131.6	131.5
Actual return on plan assets		15.3	(10.2)
Employer contribution		5.3	5.7
Benefits paid		(5.5)	(2.7)
Foreign currency exchange rate changes and other adjustments		2	7.3
Fair value of plan assets at end of year		148.7	131.6	$ 131.5
Funded status		(75.7)	(103.2)
Unrecognized net actuarial loss		45.9	0.5
Unrecognized prior service cost		(74.1)	0.8
Net amount recognized		$ (103.9)	$ (101.9)

Retirement Benefits - Amounts R

Retirement Benefits - Amounts Recognized in Combined Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in the consolidated balance sheet consisted of:
Accrued retirement benefits	$ (82.5)	$ (109.1)
Pension Plans
Amounts recognized in the consolidated balance sheet consisted of:
Noncurrent assets	2.1	2.3
Other current liabilities	(0.3)	(0.3)
Accrued retirement benefits	(77.5)	(105.2)
Accumulated other comprehensive (income) loss before income taxes	(28.2)	1.3
Net amount recognized	$ (103.9)	$ (101.9)

Retirement Benefits - Weighted-

Retirement Benefits - Weighted-Average Assumptions Related to Pension Plans (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase for benefit obligation	2.30%	2.20%	2.10%
Rate of compensation increase for net benefit costs	2.20%	2.10%	3.10%
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate for benefit obligation	0.60%	1.50%	1.10%
Discount rate for net benefit costs	1.40%	1.10%	1.00%
Expected return on plan assets for net benefit costs	4.00%	4.00%	4.40%

Retirement Benefits - Schedule

Retirement Benefits - Schedule of Expected Benefit Payments (Details) - Pension Plans $ in Millions	Dec. 31, 2019USD ($)
Benefit payments
2020	$ 7.9
2021	8.6
2022	8.4
2023	8
2024	8.1
2025-2029	$ 48.4

Retirement Benefits - Projected

Retirement Benefits - Projected Benefit Obligations in Excess of Plan Assets (Details) - Pension Plans - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 218.2	$ 229.2
Fair value of plan assets	$ 140.3	$ 124.1

Retirement Benefits - Accumulat

Retirement Benefits - Accumulated Benefit Obligations in Excess of Plan Assets (Details) - Pension Plans - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 203.9	$ 194.3
Fair value of plan assets	$ 140.3	$ 124.1

Retirement Benefits - Net Pensi

Retirement Benefits - Net Pension Expense (Details) - Pension Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9.3	$ 11.3	$ 10.5
Interest cost	2.2	2.5	1.8
Expected return on plan assets	(4.2)	(6.2)	(2.4)
Amortization of prior service cost	(1.7)	0.2	0.1
Amortization of net actuarial loss	1.1	1.9	1.4
Other	0	0.5	0
Net pension expense	$ 6.7	$ 10.2	$ 11.4

Retirement Benefits - Amounts_2

Retirement Benefits - Amounts Recognized in Other Comprehensive Loss (Details) - Pension Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Actuarial gain (loss) arising during period	$ (45.6)	$ 28.3	$ (17)
Prior year service cost during the year	74.7	0	0
Amortization of prior service cost included in net loss	(1.7)	0.2	0.1
Amortization of net actuarial loss included in net loss	1.1	1.9	1.4
Foreign currency exchange rate changes and other	1	(1.9)	3.5
Total other comprehensive income (loss) during period	$ 29.5	$ 28.5	$ (12)

Retirement Benefits - Fair Valu

Retirement Benefits - Fair Value of Pension Plan Assets (Details) - Pension Plans - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 148.7	$ 131.6	$ 131.5
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129
Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.8	2.2
Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.5	29.9
Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.1	6.4
Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		6.6
Equity-like funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		49
Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		20.1
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.3	17.4
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	142.7	9.9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129
Quoted Prices in Active Markets for Identical Assets (Level 1) | Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.9	1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.1	7.8
Quoted Prices in Active Markets for Identical Assets (Level 1) | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.8	0.7
Quoted Prices in Active Markets for Identical Assets (Level 1) | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity-like funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.9	0.3
Significant Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.7	2.8
Significant Observable  Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Significant Observable  Inputs (Level 2) | Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Significant Observable  Inputs (Level 2) | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0.1
Significant Observable  Inputs (Level 2) | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.4
Significant Observable  Inputs (Level 2) | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Observable  Inputs (Level 2) | Equity-like funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Observable  Inputs (Level 2) | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Observable  Inputs (Level 2) | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.4	2.3
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Significant Unobservable Inputs (Level 3) | Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Significant Unobservable Inputs (Level 3) | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Unobservable Inputs (Level 3) | Equity-like funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Unobservable Inputs (Level 3) | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Significant Unobservable Inputs (Level 3) | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investments Valued at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.3	118.9
Investments Valued at Net Asset Value | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Investments Valued at Net Asset Value | Public equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.9	1.2
Investments Valued at Net Asset Value | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.4	22
Investments Valued at Net Asset Value | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	5.3
Investments Valued at Net Asset Value | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		6.6
Investments Valued at Net Asset Value | Equity-like funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		49
Investments Valued at Net Asset Value | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		20
Investments Valued at Net Asset Value | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 14.8

Earnings Per Share (Details)

Earnings Per Share (Details)	Sep. 24, 2018shares	Sep. 19, 2018	Dec. 31, 2019shares	Dec. 31, 2018shares	Sep. 18, 2018shares
Subsidiary, Sale of Stock [Line Items]
Stock split ratio		2,932,900
Weighted average number of shares issued basic (in shares)			7,300,000
Weighted average number diluted shares outstanding adjustment (in shares)			1,300,000
Antidilutive shares not included in calculation diluted earnings per share (in shares)			100,000
IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued (in shares)	72,335,000
Elanco | Lilly
Subsidiary, Sale of Stock [Line Items]
Common shares outstanding				293,290,000	100

Related Party Agreements and _3

Related Party Agreements and Transactions - Amounts Due From/(Due To) Lilly (Details) - Lilly - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Total receivable from/(payable to) Lilly	$ (16.4)	$ (268.7)
TSA
Related Party Transaction [Line Items]
Total receivable from/(payable to) Lilly	10.5	(28)
Other Related Party Activities
Related Party Transaction [Line Items]
Total receivable from/(payable to) Lilly	(15.8)	(38)
Local Country Asset Purchases
Related Party Transaction [Line Items]
Total receivable from/(payable to) Lilly	$ (11.1)	$ (202.7)

Related Party Agreements and _4

Related Party Agreements and Transactions - Narrative (Details) $ in Millions		Sep. 24, 2018USD ($)	Dec. 31, 2019USD ($)renewal_term		Dec. 31, 2018USD ($)		Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Separation adjustments		$ 99.6	$ (51.2)	[1]	$ 99.6	[2]
Restricted cash			11.1		202.7		$ 0
Net transfers (to)/from Lilly					(226.3)		873.3
Acquisition amount			32.8		0		882.1
Additional Paid-in Capital
Related Party Transaction [Line Items]
Separation adjustments	[1]		(51.2)
Boehringer Ingelheim Vetmedica, Inc.
Related Party Transaction [Line Items]
Acquisition amount							882.1
Lilly
Related Party Transaction [Line Items]
Stock-based compensation			5.1		26		25
Costs/(benefits) of defined benefit pension plan					(6.3)		73.7
Lilly | TSA
Related Party Transaction [Line Items]
Revenue from related parties			$ 93.7		28.1
Lilly | Intellectual Property and Technology License Agreement
Related Party Transaction [Line Items]
Initial term			2 years
Number of renewal terms | renewal_term			3
Extension term			1 year
Lilly | Toll Manufacturing Arrangement
Related Party Transaction [Line Items]
Revenue from related parties			$ 17.8		7
Lilly | Manufacturing Support
Related Party Transaction [Line Items]
Revenue from related parties					$ 3.7		$ 6.2
[1]	See Note 20: Related Party Agreements and Transactions for further discussion.
[2]	See Note 3: Impact of Separation for further discussion.

Related Party Agreements and _5

Related Party Agreements and Transactions - Allocation of Services (Details) - Lilly - Transitional Services Agreement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Allocation of services	$ 105.2	$ 151.7
Cost of sales
Related Party Transaction [Line Items]
Allocation of services	21.8	31.8
Research and development
Related Party Transaction [Line Items]
Allocation of services	2.2	2.8
Marketing, selling and administrative
Related Party Transaction [Line Items]
Allocation of services	$ 81.2	$ 117.1

Selected Quarterly Data (unau_3

Selected Quarterly Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 787	$ 771.3	$ 781.6	$ 731.1	$ 799.3	$ 761.1	$ 770.2	$ 736.2	$ 3,071	$ 3,066.8	$ 2,889
Cost of sales	410.1	360.4	356	343.8	412.5	369.8	431.5	360	1,470.3	1,573.8	1,493.9
Operating expenses	253.2	262.2	269.7	245.2	246.2	237.9	252.5	245.2
Asset impairment, restructuring, and other special charges	51.6	77.2	31.8	24.9	46	12.4	68	2.4	185.5	128.8	375.1
Interest expense, net of capitalized interest	18.7	18.7	20.7	20.8	21	8.6	0	0	78.9	29.6	0
Income (loss) before income taxes	(4.3)	(12.5)	50.2	44.8	(2.2)	78.8	(40)	77.5	78.2	114.1	(232.6)
Income tax (benefit) expense	5.2	(22.5)	14.3	13.3	(18.6)	18.6	22.8	4.8	10.3	27.6	78.1
Net income (loss)	$ (9.5)	$ 10	$ 35.9	$ 31.5	$ 16.4	$ 60.2	$ (62.8)	$ 72.7	$ 67.9	$ 86.5	$ (310.7)
Earnings (loss) per share—basic and diluted (usd per share)	$ (0.03)	$ 0.03	$ 0.10	$ 0.09	$ 0.04	$ 0.20	$ (0.21)	$ 0.25

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) $ / shares in Units, shares in Thousands	Feb. 04, 2020USD ($)	Jan. 31, 2020USD ($)	Jan. 27, 2020USD ($)	Jan. 23, 2020shares	Jan. 23, 2020shares	Jan. 22, 2020USD ($)$ / sharesshares	Sep. 05, 2018USD ($)	Feb. 28, 2020USD ($)	Jan. 31, 2020USD ($)	Dec. 31, 2018USD ($)	Sep. 24, 2018USD ($)
Subsequent Event [Line Items]
Issuance of stock										$ 1,659,700,000
Credit Facility | Term credit facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity							$ 500,000,000				$ 500,000,000
Debt maturity term							3 years
Credit Facility | Revolving credit facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity							$ 750,000,000				$ 750,000,000
Debt maturity term							5 years
Subsequent Event | Disposal group | Osurnia and Capstar
Subsequent Event [Line Items]
Proceeds from divestiture									$ 230,000,000
Subsequent Event | Disposal group | Veocoxan
Subsequent Event [Line Items]
Proceeds from divestiture								$ 55,000,000
Subsequent Event | Credit Facility | Term credit facility
Subsequent Event [Line Items]
Repayments of debt		$ 372,400,000
Repayments of debt, principal		371,400,000
Repayments of debt, interest		1,000,000
Debt extinguishment loss		$ 800,000
Subsequent Event | Credit Facility | Term loan B credit facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity	$ 4,275
Debt maturity term	7 years
Subsequent Event | Credit Facility | Revolving credit facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity	$ 750,000,000
Debt maturity term	5 years
Subsequent Event | LIBOR | Credit Facility | Term loan B credit facility
Subsequent Event [Line Items]
Basis points	1.75%
Subsequent Event | Minimum | LIBOR | Credit Facility | Revolving credit facility
Subsequent Event [Line Items]
Basis points	1.50%
Subsequent Event | Maximum | LIBOR | Credit Facility | Revolving credit facility
Subsequent Event [Line Items]
Basis points	2.25%
Subsequent Event | Common Stock
Subsequent Event [Line Items]
Number of shares issued (in shares) | shares					25,000
Total cash received upon sale closing			$ 769,900,000
Subsequent Event | Tangible Equity Unit
Subsequent Event [Line Items]
Number of shares issued (in shares) | shares						11,000
Price per share (usd per share) | $ / shares						$ 50
Total cash received upon sale closing			530,100,000
Issuance of stock						$ 550,000,000
Interest rate						5.00%
Consideration received for prepaid stock purchase contracts			453,800,000
Subsequent Event | Tangible Equity Unit | 5.00% Senior Amortizing Notes
Subsequent Event [Line Items]
Net proceeds from senior amortizing notes			$ 76,300,000
Subsequent Event | Tangible Equity Unit | Minimum
Subsequent Event [Line Items]
Purchase contract conversion of stock ratio						1.3021
Purchase contract, shares issued upon conversion | shares						14,300
Subsequent Event | Tangible Equity Unit | Maximum
Subsequent Event [Line Items]
Purchase contract conversion of stock ratio						1.5625
Purchase contract, shares issued upon conversion | shares						17,200
Subsequent Event | Underwriting Agreement | Common Stock
Subsequent Event [Line Items]
Number of shares issued (in shares) | shares						22,700
Price per share (usd per share) | $ / shares						$ 32
Subsequent Event | Over-Allotment Option | Common Stock
Subsequent Event [Line Items]
Number of shares issued (in shares) | shares				2,300

Subsequent Events - Divestiture

Subsequent Events - Divestitures (Details) $ in Millions	Dec. 31, 2019USD ($)
Noncash or Part Noncash Divestitures [Line Items]
Property and equipment, net	$ 11.2
Disposal group | Osurnia and Capstar
Noncash or Part Noncash Divestitures [Line Items]
Inventories	10.6
Other intangibles, net	61.2
Property and equipment, net	0.2
Total assets held for sale	72
Deferred taxes	1.4
Total liabilities held for sale	$ 1.4

Uncategorized Items - elan-2019

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (300,000)
Net Parent Company Investment [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (300,000)