Southern Copper (SCCO) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 27, 2019	Jun. 30, 2018
Document and Entity Information
Entity Registrant Name	SOUTHERN COPPER CORP/
Entity Central Index Key	1,001,838
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 2,639.1
Entity Common Stock, Shares Outstanding		773,044,469
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY

CONSOLIDATED STATEMENTS OF EARN

CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF EARNINGS
Net sales (including sales to related parties, see note 16)	$ 7,096.7	$ 6,654.5	$ 5,379.8
Operating cost and expenses:
Cost of sales (exclusive of depreciation, amortization and depletion shown separately below)	3,409	3,252.8	3,034.1
Selling, general and administrative	102.6	93.1	94.3
Depreciation, amortization and depletion	674.3	671.1	647.1
Exploration	29.6	28.8	40.1
Environmental remediation		(10.2)
Total operating costs and expenses	4,215.5	4,035.6	3,815.6
Operating income	2,881.2	2,618.9	1,564.2
Interest expense	(360.9)	(357.4)	(360.3)
Capitalized interest	83.8	51.4	69.6
Other expense	(30.7)	(15.7)	(24.6)
Interest income	16	5.5	7.1
Income before income taxes	2,589.4	2,302.7	1,256
Current income taxes and royalty taxes	1,105	951.7	623.6
Deferred income taxes	(51.5)	641.7	(122.5)
Net income before equity earnings of affiliate	1,535.9	709.3	754.9
Equity earnings of affiliate, net of income tax	12.3	23.1	23.9
Net income	1,548.2	732.4	778.8
Less: Net income attributable to the non-controlling interest	5.2	3.9	2.3
Net income attributable to SCC	$ 1,543	$ 728.5	$ 776.5
Per common share amounts attributable to SCC:
Net earnings - basic and diluted	$ 2	$ 0.94	$ 1
Dividends declared and paid	$ 1.40	$ 0.59	$ 0.18
Weighted average shares outstanding - basic and diluted	773	773	773.6

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
COMPREHENSIVE INCOME:
Net income	$ 1,548.2	$ 732.4	$ 778.8
Other comprehensive income (loss) net of tax:
Decrease (increase) in pension and other post-retirement benefits (net of income tax of $2.1, $(1.6) and $2.6, respectively)	(2.9)	2.6	(3.5)
Foreign currency translation adjustments		0.3
Total other comprehensive income (loss)	(2.9)	2.9	(3.5)
Total comprehensive income	1,545.3	735.3	775.3
Comprehensive income attributable to the non-controlling interest	5.2	3.9	2.3
Comprehensive income attributable to SCC	$ 1,540.1	$ 731.4	$ 773

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Decrease (increase) in pension and other post-retirement benefits, income tax	$ 2.1	$ (1.6)	$ 2.6

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 844.6	$ 1,004.8
Short-term investments	213.8	50.5
Accounts receivable trade	822.4	890.6
Accounts receivable other (including related parties 2018- $101.5 and 2017- $26.1)	150.2	85.8
Inventories	1,032.7	1,041.9
Prepaid taxes	87	85.5
Other current assets	29.3	11
Total current assets	3,180	3,170.1
Property and mine development, net	9,403.8	9,099.6
Ore stockpiles on leach pads	1,177.4	977.4
Intangible assets, net	147.7	152.5
Deferred income tax	400.9	164.9
Equity method investment	103.6	99.7
Other non-current assets	71.4	115.9
Total assets	14,484.8	13,780.1
Current liabilities:
Accounts payable (including related parties 2018- $75.3 and 2017- $90.1)	673.4	659.8
Accrued income taxes	232.8	226.4
Accrued workers' participation	206.7	176.9
Accrued interest	83.9	83.9
Other accrued liabilities	19.5	21.3
Total current liabilities	1,216.3	1,168.3
Long-term debt	5,960.1	5,957.1
Deferred income taxes	202.6	38.5
Non-current taxes payable	207.1	207.1
Other liabilities and reserves	68.2	37.2
Asset retirement obligation	217.7	222.5
Total non-current liabilities	6,655.7	6,462.4
Commitments and contingencies (Note 12)
STOCKHOLDERS' EQUITY (NOTE 13)
Common stock par value $0.01; shares authorized, 2018 and 2017 - 2,000; shares issued, 2018 and 2017 - 884.6	8.8	8.8
Additional paid-in capital	3,393.7	3,373.3
Retained earnings	6,186.9	5,726.2
Accumulated other comprehensive income	(2.4)	0.5
Treasury stock, at cost, common shares	(3,019.6)	(3,001.1)
Total Southern Copper Corporation stockholders' equity	6,567.4	6,107.7
Non-controlling interest	45.4	41.7
Total equity	6,612.8	6,149.4
Total liabilities and equity	$ 14,484.8	$ 13,780.1

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED BALANCE SHEETS
Accounts receivable other, related parties	$ 101.5	$ 26.1
Accounts payable, related parties	$ 75.3	$ 90.1
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000	2,000
Common stock, shares issued	884.6	884.6

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES
Net income	$ 1,548.2	$ 732.4	$ 778.8
Adjustments to reconcile net earnings to net cash provided from operating activities:
Depreciation, amortization and depletion	674.3	671.1	647.1
Equity earnings of affiliate, net of dividends received	(3.9)	(12.3)	(11.3)
Loss (gain) on foreign currency transaction effect	17.3	24.9	(8.9)
Provision (benefit) for deferred income taxes	(51.5)	641.5	(117)
Other, net	27	8.9	28.2
Change in operating assets and liabilities:
(Increase) decrease in accounts receivable	68.3	(298.7)	(143.3)
(Increase) decrease in inventories	(190.8)	(201.9)	(207.9)
Increase (decrease) in accounts payable and accrued liabilities	117.8	139.5	30.5
(Increase) decrease in other operating assets and liabilities	28.4	271.2	(73.1)
Net cash provided by operating activities	2,235.1	1,976.6	923.1
INVESTING ACTIVITIES
Capital expenditures	(1,121.4)	(1,023.5)	(1,118.5)
Purchase of short-term investments	(310.6)	(61.3)	(129.8)
Proceeds on sale of short-term investment	147.3	62.3	681.9
Loan repaid by related parties			111.2
Other, net	(11.5)	3.5	3.2
Net cash used in investing activities	(1,296.2)	(1,019)	(452)
FINANCING ACTIVITIES
Repurchase of common shares			(71.7)
Cash dividends paid to common stockholders	(1,082.3)	(456.1)	(139.3)
Distributions to non-controlling interest	(1.5)	(0.3)
Other, net	0.4	0.3	0.3
Net cash used in financing activities	(1,083.4)	(456.1)	(210.7)
Effect of exchange rate changes on cash and cash equivalents	(15.7)	(42.7)	11.1
Increase (decrease) in cash and cash equivalents	(160.2)	458.8	271.5
Cash and cash equivalents, at beginning of year	1,004.8	546	274.5
Cash and cash equivalents, at end of year	844.6	1,004.8	546
Cash paid during the year for:
Interest	356.7	356.7	356.7
Income taxes	1,155.3	889.8	571.8
Workers' participation	194	136	121.6
Supplemental schedule of non-cash operating, investing and financing activities:
Decrease (increase) in pension and other post-retirement benefits	(2.9)	2.9	(3.5)
Capital expenditures incurred but not yet paid	$ 37.7	$ 137.7	$ 99.4

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	CAPITAL STOCK:	ADDITIONAL PAID-IN CAPITAL:	TREASURY STOCK:Southern copper common shares	TREASURY STOCK:Parent Company (Grupo Mexico) common shares	TREASURY STOCK:	RETAINED EARNINGS:	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS):	STOCKHOLDERS' EQUITY	NON-CONTROLLING INTEREST	Parent Company (Grupo Mexico) common shares	Total
Balance at Dec. 31, 2015	$ 8.8	$ 3,349.8	$ (2,697.6)	$ (211.3)		$ 4,812.1	$ 1.1	$ 5,262.9	$ 36.3		$ 5,299.2
Increase (Decrease) in Stockholders' Equity
Share repurchase program			(71.7)
Used for corporate purposes			0.3
Other activity, including dividend, interest and foreign currency transaction effect				(7.3)
Other comprehensive income (loss)							(3.5)				775.3
Net earnings						776.5			2.3		776.5
Dividends/distributions declared and paid						(139.3)
Other activity of the period		8.4				6
Balance at Dec. 31, 2016	8.8	3,358.2	(2,769)	(218.6)	$ (2,987.6)	5,455.3	(2.4)	5,832.3	38.6		5,870.9
Increase (Decrease) in Stockholders' Equity
Used for corporate purposes			0.3
Other activity, including dividend, interest and foreign currency transaction effect				(13.8)
Other comprehensive income (loss)							2.9				735.3
Net earnings						728.5			3.9		728.5
Dividends/distributions declared and paid						(456.1)			(0.8)
Other activity of the period		15.1				(1.5)
Balance at Dec. 31, 2017	$ 8.8	3,373.3	(2,768.7)	(232.4)	(3,001.1)	5,726.2	0.5	6,107.7	41.7		6,149.4
Increase (Decrease) in Stockholders' Equity
Share repurchase program										$ (2,900)
Used for corporate purposes			0.4
Other activity, including dividend, interest and foreign currency transaction effect				(18.9)
Other comprehensive income (loss)							(2.9)				1,545.3
Net earnings						1,543			5.2		1,543
Dividends/distributions declared and paid						(1,082.3)			(1.5)
Other activity of the period		20.4
Balance at Dec. 31, 2018		$ 3,393.7	$ (2,768.3)	$ (251.3)	$ (3,019.6)	$ 6,186.9	$ (2.4)	$ 6,567.4	$ 45.4		$ 6,612.8

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends paid as cash dividend (in dollars per share)	$ 1.40	$ 0.59	$ 0.18
RETAINED EARNINGS:
Dividends paid as cash dividend (in dollars per share)	$ 1.40	$ 0.59	$ 0.18

DESCRIPTION OF THE BUSINESS_

DESCRIPTION OF THE BUSINESS:	12 Months Ended
	Dec. 31, 2018
DESCRIPTION OF THE BUSINESS:
DESCRIPTION OF THE BUSINESS:	NOTE 1-DESCRIPTION OF THE BUSINESS: The Company is a majority-owned, indirect subsidiary of Grupo Mexico S.A.B. de C.V. (“Grupo Mexico”). At December 31, 2018, Grupo Mexico through its wholly-owned subsidiary Americas Mining Corporation (“AMC”) owned 88.9% of the Company’s capital stock. The consolidated financial statements presented herein consist of the accounts of Southern Copper Corporation ("SCC", "Southern Copper" or the “Company”), a Delaware corporation, and its subsidiaries. The Company is an integrated producer of copper and other minerals, and operates mining, smelting and refining facilities in Peru and Mexico. The Company conducts its primary operations in Peru through a registered branch (the "Peruvian Branch" or “Branch” or “SPCC Peru Branch”). The Peruvian Branch is not a corporation separate from the Company. The Company's Mexican operations are conducted through subsidiaries. The Company also conducts exploration activities in Argentina, Chile, Ecuador, Mexico and Peru.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:	12 Months Ended
	Dec. 31, 2018
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:	NOTE 2-SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES: Principles of consolidation— The consolidated financial statements include the accounts of subsidiaries of which the Company has voting control, in accordance with Accounting Standards Codification (“ASC”) 810 Consolidation . Such financial statements are prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP"). Use of estimates— The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include the carrying value of ore reserves that are the basis for future cash flow estimates and amortization calculations; environmental reclamation, closure and retirement obligations; estimates of recoverable copper in mill and leach stockpiles; asset impairments (including estimates of future cash flows); unrecognized tax benefits; valuation allowances for deferred tax assets; and fair value of financial instruments. Management bases its estimates on the Company's historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates. Revenue recognition— The Company adopted ASC 606, Revenue from Contracts with Customers, effective January 1, 2018, on a modified retrospective basis, applying the standard to all contracts that are not completed as such date. The Company’s revenue consists of product revenue resulting from the sale of copper and non-copper products, such as molybdenum, silver, zinc, lead and gold. Other than increased disclosures, the adoption of the new guidance did not have an impact on the Company's revenue recognition. The Company accounts for a contract with a customer when there is a legally enforceable contract between the Company and the customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. The Company's revenues are measured based on consideration specified in the contract with each customer. Disclosures regarding disaggregation of revenues and contract balances are disclosed within Note 17 "Segment and related information". The Company’s marketing strategy and annual sales planning emphasize developing and maintaining long-term customer relationships. Generally, 80% to 90% of the Company’s metal production is sold under annual or longer-term contracts, which specify a volume of mineral to be sold over a stated period and delivery schedule; the price at which mineral will be sold at each delivery date is generally determined by the weekly or monthly average rate of the commodity published by major metal exchanges at specific dates stipulated within each contract. The Company considers each contract to be a single performance obligation, represented by the delivery of a series of distinct goods that are substantially the same, with the same pattern of transfer to the Company’s customers. The Company concluded this as, based on the nature of its contracts, customers receive the benefit of mineral sold as it is shipped per the terms of the contracts at each contractual delivery date. Likewise, each shipment of product represents the same measure of progress as other shipments within the contract. Accordingly, the Company recognizes revenues for each contract over the period of time in which the specified quantity of mineral is delivered. In doing so, the Company considers that it has a right to consideration from its customers in an amount that corresponds directly to the value transferred to those customers that being the quantity of mineral delivered at the price per unit delivered. Accordingly, the Company recognizes revenue at the amount to which it has the right to invoice (the invoice practical expedient), as it believes that this method is a faithful depiction of the transfer of goods to its customers. For contracts with a term greater than one year, the Company is unable to disclose an allocation of the transaction price to the remaining unsatisfied performance obligation, given that unit prices of mineral sold are determined by published commodity prices at specified dates within the contract. The volume of mineral to be delivered after the first year of the contract is subject to annual volume negotiations in accordance with the terms of the contract. As of December 31, 2018, the Company has long-term contracts with promises to deliver a total of 1,724,840 metric tons of mineral in 2019. This is an estimate that will vary in 2020 and 2021 based on the negotiations with the customers as mentioned above. The remainder of the Company’s revenues, including its by-product revenues, are generated by spot sales that are recognized at a point in time. Under both sales models, revenue is recognized when or as the performance obligations are satisfied, when the Company transfers control of the goods and title passes to the customer. Considering the International Commercial Terms (Incoterms) utilized by the Company, control is transferred generally upon the completion of loading the material at the point of origin. This is the point at which the customer obtains legal title to the product as well as the ability to direct the use of and obtain substantially all of the remaining benefits of ownership of the asset. Additionally, payment is generally due upon the delivery of the shipping and title documents at the point of origin, customers typically have 30 days to remit payment. Copper and non-copper revenues are measured based on the monthly average of prevailing commodity prices according to the terms of the contracts. The Company provides allowances for doubtful accounts based upon historical bad debt and claims experience and periodic evaluation of specific customer accounts. Substantially all of the Company’s sales are made under carriage and insurance paid to, or cost, insurance and freight Incoterms, whereby the Company is responsible for providing shipping and insurance after control of the inventory has been transferred to the customer. According to the terms of the Company’s contracts, these services are not distinct within the context of the contract, and they are not separately identifiable from the other promises within the contract. Additionally, it is the Company policy and it has a long-standing history of providing shipping and insurance services to its customers. Accordingly, shipping and insurance are not considered separate performance obligations. The related costs of shipping and insurance are presented within the cost of sales line in the accompanying consolidated statements of income. Furthermore, the Company considered the impact of the shipping and insurance services on the determination of when control is transferred to its customers. It has concluded that the terms of these services do not impact its customers’ ability to sell, pledge, or otherwise use the products in shipment. Also, there is a small likelihood and minimal history of lost or damaged goods during shipment. Considering these factors, combined with the other indicators of control previously mentioned, the Company has concluded that these services do not impact the determination that control is transferred at the point of origin. For certain of the Company’s sales of copper and molybdenum products, customer contracts allow for pricing based on a month subsequent to shipping, in most cases within the following three months and occasionally in some cases a few additional months. In such cases, revenue is recorded at a provisional price at the time of shipment. The provisionally priced copper sales are adjusted to reflect forward LME or COMEX copper prices at the end of each month until a final adjustment is made to the price of the shipments upon settlement with customers pursuant to the terms of the contract. In the case of molybdenum sales, for which there are no published forward prices, the provisionally priced sales are adjusted to reflect the market prices at the end of each month until a final adjustment is made to the price of the shipments upon settlement with customers pursuant to the terms of the contract. These provisional pricing arrangements are accounted for separately from the contract as an embedded derivative instrument under ASC 815-30 “Derivatives and Hedging—Cash Flow Hedges.” The Company sells copper in concentrate, anode, blister and refined form at industry standard commercial terms. Net sales include the invoiced value of copper, zinc, silver, molybdenum, sulfuric acid and other metals and the corresponding fair value adjustment of the related forward contract of copper and molybdenum. Disclosure regarding adjustments to sales for provisionally priced contracts is disclosed within Note 17 “Segment and related information”. Cash and cash equivalents— Cash and cash equivalents include bank deposits, certificates of deposit and short-term investment funds with original maturities of three months or less at the date of purchase. The carrying value of cash and cash equivalents approximates fair value. Short-term investments— The Company accounts for short-term investments in accordance with ASC 320-10 “Investments Debt and Equity Securities-Recognition.” The Company determines the appropriate classification of all short-term investments as held-to-maturity, available-for-sale or trading at the time of purchase and re-evaluates such classifications as of each balance sheet date. Unrealized gains and losses on available-for-sale investments, net of taxes, are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity, unless such loss is deemed to be other than temporary. Inventories— The Company principally produces copper and, in the production process, obtains several by-products, including molybdenum, silver, zinc, sulfuric acid and other metals. Metal inventories, consisting of work-in-process and finished goods, are carried at the lower of average cost or market. Costs of work-in-process inventories and finished goods mainly include power, labor, fuel, operating and repair materials, depreciation, amortization, depletion, and other necessary costs related to the extraction and processing of ore, including mining, milling, concentrating, smelting, refining, leaching and chemical processing. Costs incurred in the production of metal inventories exclude general and administrative costs. Once molybdenum, silver, zinc and other by-products are identified, they are transferred to their respective production facilities and the incremental cost required to complete production is assigned to their inventory value. Work-in-process inventories represent materials that are in the process of being converted into a saleable product. Conversion processes vary depending on the nature of the copper ore and the specific mining operation. For sulfide ores, processing includes milling and concentrating and results in the production of copper and molybdenum concentrates. Finished goods include saleable products (e.g., copper concentrates, copper anodes, copper cathodes, copper rod, molybdenum concentrate and other metallurgical products). Supplies inventories are carried at the lower of average cost or market. Long-term inventory-Ore stockpiles on leach pads. The leaching process is an integral part of the mining operations carried out at the Company’s open-pit mines. The Company capitalizes the production cost of leachable material at its Toquepala, La Caridad and Buenavista mines recognizing it as inventory. This cost includes mining and haulage costs incurred to deliver ore to leach pads, depreciation, amortization, depletion and site overhead costs. The estimates of recoverable mineral content contained in the leaching dumps are supported by engineering studies. As the production cycle of the leaching process is significantly longer than the conventional process of concentrating, smelting and electrolytic refining, the Company includes on its balance sheet current leach inventory (included in work-in-process inventories) and long-term leach inventory. Amortization of leachable material is recorded by the units of production method. Property— Property is recorded at acquisition cost, net of accumulated depreciation and amortization. Cost includes major expenditures for improvements and replacements, which extend useful lives or increase capacity and interest costs associated with significant capital additions. Maintenance, repairs, normal development costs at existing mines and gains or losses on assets retired or sold are reflected in earnings as incurred. Buildings and equipment are depreciated on the straight-line method over estimated lives from five to 40 years or the estimated life of the mine if shorter. Mine development - Mine development includes primarily the cost of acquiring land rights to an exploitable ore body, pre-production stripping costs at new mines that are commercially exploitable, costs associated with bringing new mineral properties into production, and removal of overburden to prepare unique and identifiable areas outside the current mining area for such future production. Mine development costs are amortized on a unit of production basis over the remaining life of the mines. There is a diversity of practices in the mining industry in the treatment of drilling and other related costs to delineate new ore reserves. The Company follows the practices outlined in the next two paragraphs in its treatment of drilling and related costs. Drilling and other associated costs incurred in the Company's efforts to delineate new resources, whether near-mine or Greenfield are expensed as incurred. These costs are classified as mineral exploration costs. Once the Company determines through feasibility studies that proven and probable reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs. These mine development costs incurred prospectively to develop the property are capitalized as incurred, until the commencement of production, and are amortized using the units of production method over estimated life of the ore body. During the production stage, drilling and other related costs incurred to maintain production are included in production cost in the period in which they are incurred. Drilling and other related costs incurred in the Company’s efforts to delineate a major expansion of reserves at an existing production property are expensed as incurred. Once the Company determines through feasibility studies that proven and probable incremental reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs. These incremental mine development costs are capitalized as incurred, until the commencement of production and amortized using the units of production method over the estimated life of the ore body. A major expansion of reserves is one that increases total reserves at a property by approximately 10% or more. For the years ended December 31, 2018, 2017 and 2016, the Company did not capitalize any drilling and related costs. Asset retirement obligations (reclamation and remediation costs)— The fair value of a liability for asset retirement obligations is recognized in the period in which the liability is incurred. The liability is measured at fair value and is adjusted to its present value in subsequent periods as accretion expense is recorded. The corresponding asset retirement costs are capitalized as part of the carrying value of the related long-lived assets and depreciated over the asset's useful life. Intangible assets— Intangible assets include primarily the excess amount paid over the book value for investment shares which are presented as mining concessions, and mining and engineering development studies. Intangible assets are carried at acquisition costs, net of accumulated amortization and are amortized principally on a unit of production basis over the estimated remaining life of the mines. Intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. Debt issuance costs— Debt issuance costs related to a recognized debt liability are presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with the treatment of a debt discount. Ore reserves— The Company periodically reevaluates estimates of its ore reserves, which represent the Company’s estimate as to the amount of unmined copper remaining in its existing mine locations that can be produced and sold at a profit. Such estimates are based on engineering evaluations derived from samples of drill holes and other openings, combined with assumptions about copper market prices and production costs at each of the respective mines. The Company updates its estimate of ore reserves at the beginning of each year. In this calculation, the Company uses current metal prices which are defined as the average metal price over the preceding three years. The current price per pound of copper, as defined, was $2.64, $2.50 and $2.61 at the end of 2018, 2017 and 2016, respectively. The ore reserve estimates are used to determine the amortization of mine development and intangible assets. Once the Company determines through feasibility studies that proven and probable reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs and the Company discloses the related ore reserves. Exploration— Tangible and intangible costs incurred in the search for mineral properties are charged against earnings when incurred. Income taxes— Provisions for income taxes are based on taxes payable or refundable for the current year and deferred taxes on temporary differences between the amount of taxable income and pretax financial income and between the tax bases of assets and liabilities and their reported amounts in the financial statements. Deferred tax assets and liabilities are included in the financial statements at currently enacted income tax rates applicable to the period in which the deferred tax assets and liabilities are expected to be realized and settled as prescribed in ASC 740 “Income taxes.” As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through the provision for income taxes. Deferred income tax assets are reduced by any benefits that, in the opinion of management, are more likely not to be realized. The Company’s operations involve dealing with uncertainties and judgments in the application of complex tax regulations in multiple jurisdictions. The final taxes paid are dependent upon many factors, including negotiations with taxing authorities in various jurisdictions and resolution of disputes arising from federal, state, and international tax audits. The Company recognizes potential liabilities and records tax liabilities for anticipated tax audit issues in the U.S. and other tax jurisdictions based on its estimate of whether, and the extent to which, additional taxes will be due. The Company follows the guidance of ASC 740 “Income taxes” to record these liabilities. (See Note 7 “Income taxes” of the consolidated financial statements for additional information). The Company adjusts these reserves in light of changing facts and circumstances; however, due to the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from the Company’s current estimate of the tax liabilities. If its estimate of tax liabilities proves to be less than the ultimate assessment, an additional charge to expense would result. If payment of these amounts ultimately proves to be less than the recorded amounts, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company classifies income tax-related interest and penalties as income taxes in the financial statements, as well as interest and penalties, if any, related to unrecognized tax benefits. On December 22, 2017, the U.S. government enacted the “Tax Cuts and Jobs Act” (the “TCJA”). The TCJA contains numerous provisions, the following of which most significantly impact the Company: (i) a decrease in the corporate tax rate from 35% to 21%; (ii) a transition of the U.S. taxation of international operation from a worldwide system to a quasi-territorial system and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017, (iii) generally eliminates U.S. federal income taxes on dividends from foreign subsidiaries, requiring a current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations and (iv) limitations on the use of foreign tax credits to reduce the U.S. income tax liability. The U.S. Securities and Exchange Commission (“SEC”) issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provides guidance on accounting for the tax effects of the TCJA. The Company has adopted SAB 118. Accordingly, the provisions of the TCJA deemed most relevant to the Company were considered in preparation of its financial statements as of December 31, 2017 based on the Company’s best estimate, and the provisions of the TCJA were finalized in its financial statements as of December 31, 2018. See further disclosure regarding the impacts of the TCJA and the adoption of SAB 118 in Note 7 to the accompanying consolidated financial statements. Foreign exchange— The Company’s functional currency is the U.S. dollar. As required by local law, both the Peruvian Branch and Minera Mexico maintain their books of accounts in Peruvian soles and Mexican pesos, respectively. Foreign currency assets and liabilities are remeasured into U.S. dollars at current exchange rates, except for non-monetary items such as inventory, property, intangible assets and other assets which are remeasured at historical exchange rates. Revenues and expenses are generally translated at actual exchange rates in effect during the period, except for those items related to balance sheet amounts that are remeasured at historical exchange rates. Gains and losses from foreign currency remeasurement are included in earnings of the period. Gains and (losses) resulting from foreign currency transactions are included in "Cost of sales (exclusive of depreciation, amortization and depletion)." Asset impairments - The Company evaluates long-term assets when events or changes in economic circumstances indicate that the carrying amount of such assets may not be recoverable. These evaluations are based on business plans that are prepared using a time horizon that is reflective of the Company’s expectations of metal prices over its business cycle. The Company is currently using a long-term average copper price and an average molybdenum price for impairment tests, reflective of what the Company believes is the lower level of the current price environment. The results of its impairment tests using these long-term copper and molybdenum prices show no impairment in the carrying value of their assets. In recent years testing using assumptions for long-term average prices have resulted in stricter evaluation for impairment analysis than would the higher three year average prices for copper and molybdenum prices. Should this situation reverse in the future with three year average prices below the long-term price assumption, the Company would assess the need to use the three year average prices in its evaluations. The Company uses an estimate of the future undiscounted net cash flows of the related asset or asset group over the remaining life to measure whether the assets are recoverable and measures any impairment by reference to fair value. Other comprehensive income— Comprehensive income represents changes in equity during a period, except those resulting from investments by owners and distributions to owners. During the fiscal years ended December 31, 2018, 2017 and 2016, the components of "other comprehensive income (loss)" were, the unrecognized gain (loss) on employee benefit obligations and foreign currency translation adjustments. Business segments- Company management views Southern Copper as having three reportable segments and manages it on the basis of these segments. The segments identified by the Company are: 1) the Peruvian operations, which include the two open-pit copper mines in Peru and the plants and services supporting such mines, 2) the Mexican open-pit copper mines, which include La Caridad and Buenavista mine complexes and their supporting facilities and 3) the Mexican underground mining operations, which include five underground mines that produce zinc, lead, copper, silver and gold, a coal mine and a zinc refinery. Please see Note 17 “Segments and Related Information.” Senior management of the Company focus on operating income as measure of performance to evaluate different segments, and to make decisions to allocate resources to the reported segments. This is a common measure in the mining industry. ADOPTION OF LEASES STANDARD On February 25, 2016, the FASB issued ASU 2016-02 “Leases” (Topic 842). This update significantly modifies the accounting model of leases for lessees requiring them to recognize assets and liabilities in the balance sheet for virtually all leases. However, the classification of leases as finance leases or operating leases is maintained for lessees. In addition, for leases with a term of 12 months or less, a lessee can elect by class of underlying asset not to record assets and liabilities on the balance sheet, and recognize lease expense on a straight-line basis over the lease term. The lessor accounting model for leases remains mostly unchanged from previous guidance, except for specific profit recognition requirements which were modified in order to align them to the new revenue recognition standard issued by the FASB, and the lease classification criteria, to ensure consistency with those for a lessee. The amendments in this update were effective for the Company on January 1, 2019. During 2018, the Company developed an implementation plan with a cross-functional team, which performed a completeness assessment over the lease contracts of the Company, established new policies, procedures and internal controls related to the new standard. As result of it analysis, the Company has preliminarily concluded that substantially all of its existing lease contracts at December 31, 2018, will be classified as operating lease contracts. The Company elected the transition approach whereby it will apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, the financial statements for prior periods will not be modified. At the date of adoption, the Company preliminarily assessed that the adoption of the new leases standard will result in the recognition of right of use assets and lease obligations of approximately $1,115.9 million, which will be recorded in the Company’s balance sheet as of January 1, 2019. Additionally, the Company may elect the short-term lease recognition exemption (short-term lease practical expedient) by class of underlying asset (which results in off-balance-sheet accounting for the lease). It is expected that the Company will disclose if that it has done so and its effects in 2019.

SHORT-TERM INVESTMENTS_

SHORT-TERM INVESTMENTS:	12 Months Ended
	Dec. 31, 2018
SHORT-TERM INVESTMENTS:
SHORT-TERM INVESTMENTS:	NOTE 3- SHORT-TERM INVESTMENTS: Short-term investments were as follows ($ in millions): At December 31, 2018 2017 Trading securities $ 213.1 $ 49.5 Weighted average interest rate 2.2 % 1.8 % Available-for-sale $ 0.7 $ 1.0 Weighted average interest rate 0.7 % 0.70 % Total $ 213.8 $ 50.5 Trading securities consist of bonds issued by public companies and are publicly traded. Each financial instrument is independent of the others. The Company has the intention to sell these bonds in the short-term. Available-for-sale investments consist of securities issued by public companies. Each security is independent of the others and, as of December 31, 2018 and 2017, included corporate bonds and asset and mortgage backed obligations. As of December 31, 2018 and 2017, gross unrealized gains and losses on available-for-sale securities were not material. Related to these investments the Company earned interest, which was recorded as interest income in the consolidated statement of earnings. Also the Company redeemed some of these securities and recognized gains (losses) due to changes in fair value, which were recorded as other income (expense) in the consolidated statement of earnings. The following table summarizes the activity of these investments by category (in millions): Years ended December 31, 2018 2017 Trading: Interest earned $ 0.5 $ 0.7 Unrealized gain (loss) at December 31, $ (0.2) $ 0.1 Available-for-sale: Interest earned (*) (*) Investment redeemed $ 0.3 $ 1.1 (*) Less than $0.1 million At December 31, 2018 and 2017, contractual maturities of the available-for-sale debt securities are as follows (in millions): 2018 2017 One year or less $ — $ — Maturing after one year through five years — — Maturing after five years through ten years — — Due after 10 years 0.7 1.0 Total debt securities $ 0.7 $ 1.0

INVENTORIES_

INVENTORIES:	12 Months Ended
	Dec. 31, 2018
INVENTORIES:
INVENTORIES:	NOTE 4-INVENTORIES: At December 31, (in millions) 2018 2017 Inventory, current: Metals at average cost: Finished goods $ 69.6 $ 48.8 Work-in-process 256.8 308.0 Ore stockpiles on leach pads 328.0 320.9 Supplies at average cost 378.3 364.2 Total current inventory $ 1,032.7 $ 1,041.9 Inventory, long-term: Ore stockpiles on leach pads $ 1,177.4 $ 977.4 Total leaching costs added as long-term inventory of ore stockpiles in leach pads amounted to $506.6 million, $513.9 million and $439.0 million in 2018, 2017 and 2016, respectively. Long-term leaching inventories recognized as cost of sales amounted to $299.4 million, $333.5 million and $316.6 million in 2018, 2017 and 2016, respectively.

PROPERTY_

PROPERTY:	12 Months Ended
	Dec. 31, 2018
PROPERTY:
PROPERTY:	NOTE 5-PROPERTY: At December 31, (in millions) 2018 2017 Buildings and equipment $ 14,294.0 $ 12,552.8 Construction in progress 1,516.9 2,301.9 Mine development 267.9 267.9 Mineral assets 83.2 83.2 Land, other than mineral 164.1 218.4 Total property 16,326.1 15,424.2 Accumulated depreciation, amortization and depletion (6,922.3) (6,324.6) Total property and mine development, net $ 9,403.8 $ 9,099.6 Construction in progress decreased in 2018 as a result of the completion of some of the Company expansion projects. For more detailed information, please see Item 7 “Management Discussion and Analysis of Financial Condition and Results of Operations - Capital Investment Program.” Depreciation and depletion expense for the years ended December 31, 2018, 2017 and 2016, amounted to $668.9 million, $665.2 million and $639.1 million, respectively.

INTANGIBLE ASSETS_

INTANGIBLE ASSETS:	12 Months Ended
	Dec. 31, 2018
INTANGIBLE ASSETS:
INTANGIBLE ASSETS:	NOTE 6-INTANGIBLE ASSETS: At December 31, (in millions) 2018 2017 Mining concessions $ 121.2 $ 121.2 Mine engineering and development studies 19.8 19.8 Software 49.6 49.0 190.6 190.0 Accumulated amortization: Mining concessions (37.4) (36.6) Mine engineering and development studies (15.3) (15.3) Software (32.1) (27.5) (84.8) (79.4) Goodwill 41.9 41.9 Intangible assets, net $ 147.7 $ 152.5 Amortization of intangibles for the years ended December 31, 2018, 2017 and 2016, amounted to $5.4 million, $5.9 million and $8.0 million, respectively. Estimated amortization is as follows: Estimated amortization expense (in millions): 2019 $ 4.7 2020 5.0 2021 5.1 2022 5.0 2023 5.0 Total 2019 - 2023 $ 24.8 Average annual $ 5.0 Goodwill includes $17.0 million generated in 1997 as a result of purchasing a third party interest in the Buenavista mine. It also includes $24.9 million representing the amount of the purchase price in excess of the fair value of the net assets acquired from El Pilar mine. This goodwill is attributable to future benefits that the Company expects to realize from the mine and will not be deductible for income tax purposes.

INCOME TAXES_

INCOME TAXES:	12 Months Ended
	Dec. 31, 2018
INCOME TAXES:
INCOME TAXES:	NOTE 7-INCOME TAXES: Since March 2009, Grupo Mexico, through its wholly-owned subsidiary AMC, owns an interest in excess of 80% of SCC. Accordingly, SCC’s results are included in the consolidated results of the Grupo Mexico subsidiary for U.S. federal income tax reporting. SCC provides current and deferred income taxes, as if it were filing a separate U.S. federal income tax return. On December 22, 2017, the TCJA was signed into law, making substantial changes to the 1986 Internal Revenue Code. Changes under the TCJA include, among others, a decrease in the corporate tax rate from 35% to 21%, the transition of the U.S. taxation of international operation from a worldwide system to a quasi-territorial system, a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017, a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries, and a current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations. Although most provisions of the TCJA began on January 1, 2018, ASC 740 “Income Taxes” requires that the effects of tax law changes be recognized in the year and period of the law change and be reflected in the company’s financial results for 2017. On December 22, 2017, the SEC staff issued SAB 118 to address the application of U.S. GAAP in situations when a registrant did not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects of the TCJA. SAB 118 required a company to reflect the income tax effects of the TCJA for which the accounting under ASC 740 “Income Taxes” is complete; if it is incomplete but the Company is able to determine a reasonable estimate, a provisional estimate must be provided in the financial statements. If a provisional estimate cannot be reasonably prepared, the Company should continue to apply ASC 740 on the basis of the provision of the tax law that were in effect immediately before the enactment of the TCJA. Companies have one year from the enactment of the TCJA to finalize accounting for the impacts of the TCJA. The Company adopted SAB 118 and accordingly recorded a provisional $785.9 million non-cash tax expense for the estimated effects of the TCJA in its 2017 financial statements as a result of adjustments related to the valuation allowances for foreign tax credits and other deferred tax assets, valuation of net deferred tax assets due to the rate change from 35% to 21% and the transition tax on the repatriation of cumulative foreign earnings. In 2018, the Company determined the final impact of the TCJA to be $816.8 million, a $30.9 million change from the provisional amount estimated at December 31, 2017. For 2018, the TCJA created a new category of foreign income, the Global Intangible Low Tax Income or GILTI. The new GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. For 2018, there was no U.S. tax liability from the GILTI inclusion. The Company does not anticipate a tax on GILTI in the future because of increased fixed asset amounts and with a Mexican tax rate of 30% no U.S. deferred taxes would be recorded. Accordingly, the Company has elected that if GILTI were to apply in the future, a current period expense would be recorded when incurred. The BEAT is a 5% minimum tax for tax year 2018, 10% for the years 2019 through 2025 and 12.5% in years thereafter. It is calculated on a base equal to the Company’s income determined without the tax benefit arising from base erosion payments. The Company did not incur a BEAT liability in 2018 since it has met the safe harbor rule that provides a Company not to be subject to the BEAT if related party payments from the U.S. to foreign entities does not exceed 3% of expenses excluding cost of goods sold. The Company must continue to analyze applicability of the BEAT provisions on a quarterly basis. The components of the provision for income taxes for the three years ended December 31, 2018, are as follows: (in millions) 2018 2017 2016 U.S. federal and state: Current $ 2.6 $ — $ — Deferred (13.0) 686.2 (109.4) Uncertain tax positions — 16.2 20.3 (10.4) 702.4 (89.1) Foreign (Peru and Mexico): Current 1,102.4 951.7 625.0 Deferred (38.5) (60.7) (34.8) 1,063.9 891.0 590.2 Total provision for income taxes $ 1,053.5 $ 1,593.4 $ 501.1 The source of income is as follows: (in millions) 2018 2017 2016 Earnings by location: U.S. $ (2.3) $ (1.5) $ (1.9) Foreign Peru 441.8 284.6 (85.7) Mexico 2,149.9 2,019.6 1,343.6 2,591.7 2,304.2 1,257.9 Earnings before taxes on income $ 2,589.4 $ 2,302.7 $ 1,256.0 The reconciliation of the statutory income tax rate to the effective tax rate for the three years ended December 31, 2018, is as follows (in percentage points): 2018 2017 2016 Expected tax at U.S. statutory rate 21.0 % 35.0 % 35.0 % Foreign tax at other than statutory rate, net of foreign tax credit benefit (1) 13.9 0.6 2.0 Percentage depletion (2.1) (2.9) (2.7) Other permanent differences 0.4 5.2 — Change in 2017 valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred 7.5 26.9 — Additional valuation allowance on 2018 U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred 1.0 — — Decrease in 2017 U.S. deferred tax asset due to tax rate changes (0.2) 4.8 — U.S. one time transition tax on accumulated foreign earnings 0.4 2.4 — Increase (decrease) in unrecognized tax benefits for uncertain tax positions — 0.7 0.2 Repatriated foreign earnings — (2.0) 3.6 Amounts (over) / under provided in prior years (1.3) (0.1) (0.5) Other 0.1 (1.4) 2.3 Effective income tax rate 40.7 % 69.2 % 39.9 % (1) Foreign tax at other than statutory rates, net of foreign tax credit benefit, also includes the effects of permanent differences in Peru and Mexico, that are determined at the local statutory rate. The Company files income tax returns in three jurisdictions, Peru, Mexico and the United States. For the three years presented above, the statutory income tax rate for Mexico was 30%. The United States tax rate was 21% in 2018, and 35% for 2017 and 2016. The Peruvian tax rate was 29.5% for 2018 and 2017 and 28% for 2016. While the largest components of income taxes are the Peruvian and Mexican taxes, the Company is a domestic U.S. entity. Therefore, the rate used in the above reconciliation is the U.S. statutory rate. For all of the years presented, both the Peruvian branch and Minera Mexico filed separate tax returns in their respective tax jurisdictions. Although the tax rules and regulations imposed in the separate tax jurisdictions may vary significantly, similar permanent items exist, such as items which are nondeductible or nontaxable. Some permanent differences relate specifically to SCC such as the allowance in the United States for percentage depletion. Deferred taxes include the U.S., Peruvian and Mexican tax effects of the following types of temporary differences and carryforwards: At December 31, (in millions) 2018 2017 Assets: Inventories $ 61.5 $ 47.0 Capitalized exploration expenses 11.1 9.5 U.S. foreign tax credit carryforward, net of FIN 48 liability 483.4 280.2 U.S. tax effect of Peruvian deferred tax liability 165.1 174.1 Provisions 155.0 152.6 Mexican tax on consolidated dividends 14.8 14.5 Deferred workers participation 27.0 3.0 Accrued salaries, wages and vacations 9.1 7.2 Sales price adjustment (PUI) 2.7 — Social responsibility expenses 2.1 2.1 Deferred charges 6.1 — Valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred (819.1) (619.6) Other 10.1 1.6 Total deferred tax assets 128.9 72.2 Liabilities: Property, plant and equipment (137.3) (130.3) Deferred charges — (16.9) Unremitted foreign earnings — — Sales price adjustment (PUI) — (0.4) Other (0.4) (5.3) Total deferred tax liabilities (137.7) (152.9) Total net deferred tax (liabilities) / assets $ (8.8) $ (80.7) In 2018, several items that were previously included in the "other" category are separately stated; 2017 was adjusted to open those items for comparative purposes. The valuation allowance increased by $199.5 million in 2018, mostly due to the valuation of unutilized Foreign Tax Credits generated in 2018. The Peru branch operations are taxed in the U.S. as a flow through entity to SCC. Prior to 2017 U.S. Tax Reform, the U.S. corporate income tax rate was 35% on the Peru earnings, which enabled the company to use more currently generated foreign tax credits. Since tax reform reduced the U.S. tax rate to 21%, there is less U.S. income tax to absorb currently generated FTC’s or carryforwards. Additionally, allowable expenses in the U.S. for percentage depletion and U.S. sourced interest expense on debt reduced the branch income subject to U.S. tax, further limiting utilization of foreign tax credits. U.S. Tax Matters— As of December 31, 2018, the Company considers its ownership of the stock of Minera Mexico to be essentially permanent in duration. As of December 31, 2018, $97.6 million of the Company´s total cash, cash equivalents, restricted cash and short-term investments of $1,058.4 million was held by foreign subsidiaries. The cash, cash equivalents and short-term investments maintained in our foreign operations are generally used to cover local operating and investment expenses. At December 31, 2016, Minera Mexico determined that it had $470.5 million in earnings available for dividends to the United States. These earnings had not been remitted, but U.S. federal income tax, net of foreign tax credit was recognized in 2016 resulting in an increase in tax of $45.7 million. At December 31, 2017, Minera Mexico had determined that it had earnings available for dividends to the United States of $555.5 million. The 2017 U.S. tax reform introduced a one-time transition tax that is based upon the Company’s total accumulated post-1986 prescribed foreign earnings and profits (“E&P”) estimated to be $8.9 billion, the majority of which was previously considered to be indefinitely reinvested and accordingly, no U.S. federal and state income taxes were provided. At December 31, 2018, there were $689.1 million of foreign tax credits available for carryback or carryforward. These credits have a one year carryback and a ten year carryforward period and can only be used to reduce U.S. income tax on foreign earnings. There were no other unused U.S. tax credits at December 31, 2018. These credits will expire as follows: Year Amount 2022 51.5 2023 69.2 2024 102.0 2025 189.5 2026 104.8 2028 172.1 Total $ 689.1 These foreign tax credits are presented above on a gross basis and have not been reduced here for any unrecognized tax benefits. These foreign tax credits have been adjusted to include the 2016 Net Operating Loss carryback in the U.S. jurisdiction, increasing foreign tax credits by approximately $15.9 million. In accordance with ASU 2013-11 the Company has recorded $205.7 million of an unrecognized tax benefit as an offset to the Company’s deferred tax asset for foreign tax credits. The remaining foreign tax credits of $483.4 million are being re-valued to zero at December 31, 2018. It is the opinion of management that with the reduction in the U.S. corporate tax rate to 21% and the corporate tax rates in Mexico of 30% and in Peru at 29.5%, it is unlikely the excess foreign tax credits can be utilized. Additionally, foreign dividends will no longer be taxed in the U.S. thereby reducing the U.S. tax on the foreign source income that the credits can be used to offset. Peruvian Tax Matters- Royalty mining charge: The royalty charge is based on operating income margins with graduated rates ranging from 1% to 12% of operating profits, with a minimum royalty charge assessed at 1% of net sales. The minimum royalty charge is recorded as cost of sales and those amounts assessed at higher rates are included in the income tax provision. The Company has accrued $32.9 million, $23.4 million and $16.8 million of royalty charges in 2018, 2017 and 2016, respectively, of which $9.0 million and $2.5 million were included in income taxes in 2018 and 2017, respectively; no amounts were included in income tax in 2016. Peruvian special mining tax: This tax is based on operating income with graduated rates increasing from 2% to 8.4%. The Company recognized $30.6 million, $23.3 million and $10.8 million in 2018, 2017 and 2016, respectively, with respect to this tax. These amounts are included as “income taxes” in the consolidated statement of earnings. Mexican Tax Matters- On October 2017, the Federation’s Revenue Law for 2018 was approved by the House of Representatives and the Senate. There are certain modifications that are worth highlighting: i) The incentive of crediting of the special use and service tax to income tax. In the case of fuel, it includes purchased diesel for final consumption in certain mining equipment. The crediting of the special use and service tax was extended to the purchase of imported diesel. ii) The Federal Revenue Law allows the deduction of statutory profit sharing paid, on advance monthly payments of income tax. iii) The withholding rate applied by banks and other members of the financial system on interest will decrease from an annual rate of 0.58% to 0.46%. iv) The obligation to provide certain information regarding relevant transactions will be incorporated to the Federation’s Revenue Law for 2018 given the recent rulings issued by the Mexican Supreme Court. Taxpayers will be obligated to provide on a quarterly basis to the Mexican tax authorities information regarding financial derivative transactions, transactions with related parties, transactions related to the participation in the equity of other companies and changes of tax residence, corporate restructures and other similar transactions. It is worth noting that there are no further amendments in connection with the Base Erosion and Profit Shifting action plan. Accounting for Uncertainty in Income Taxes- The total amount of unrecognized tax benefits in 2018, 2017 and 2016, was as follows (in millions): 2018 2017 2016 Unrecognized tax benefits, opening balance $ 214.5 $ 304.0 $ 400.0 Gross increases—tax positions in prior period — (89.5) 3.9 Gross increases—current-period tax positions — — 23.3 Decreases related to settlements with taxing authorities — — (123.2) — (89.5) (96.0) Unrecognized tax benefits, ending balance $ 214.5 $ 214.5 $ 304.0 The amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate was $214.5 million at December 31, 2018 and 2017. These amounts relate entirely to U.S. income tax matters. The Company has no unrecognized Peruvian or Mexican tax benefits. The Company anticipates effective settlement and closing of the 2011-2013 IRS field audit by December 31, 2019. With the closing of the audit, unrecognized tax benefits are expected to reverse in the next twelve months and are not expected to have a material impact on the Company's financial statements. The Company also anticipates that the IRS audit of 2014 -2016 will commence in 2019. As of December 31, 2018 and December 31, 2017 the Company’s liability for uncertain tax positions included accrued interest and penalties of $1.9 million. The following tax years remain open to examination and adjustment in the Company’s three major tax jurisdictions: Peru: 2013 and all subsequent years U.S.: 2011 and all subsequent years Mexico: 2013 and all subsequent years Management does not expect that any of the open years will result in a cash payment within the upcoming twelve months ending December 31, 2019. The Company’s reasonable expectations about future resolutions of uncertain items did not materially change during the year ended December 31, 2018.

WORKERS' PARTICIPATION_

WORKERS' PARTICIPATION:	12 Months Ended
	Dec. 31, 2018
WORKERS' PARTICIPATION:
WORKERS' PARTICIPATION:	NOTE 8-WORKERS’ PARTICIPATION: The Company's operations in Peru and Mexico are subject to statutory workers' participation. In Peru, the provision for workers' participation is calculated at 8% of pre-tax earnings. The current portion of this participation, which is accrued during the year, is based on the Peruvian Branch's taxable income and is distributed to workers following determination of final results for the year. The annual amount payable to an individual worker is capped at the worker’s salary for an 18 month period. Amounts determined in excess of the 18 months of worker’s salary is no longer made as a payment to the worker and is levied first for the benefit of the “Fondo Nacional de Capacitacion Laboral y de Promocion del Empleo” (National Workers’ Training and Employment Promotion Fund) until this entity receives from all employers in its region an amount equivalent to 2,200 Peruvian taxable units (approximately $2.7 million in 2018). Any remaining excess is levied as payment for the benefit of the regional governments. These levies fund worker training, employment promotion, entrepreneurship and various other programs. In Mexico, workers' participation is determined using the guidelines established in the Mexican income tax law at a rate of 10% of pre-tax earnings as adjusted by the tax law. The provision for workers’ participation is allocated to “Cost of sales (exclusive of depreciation, amortization and depletion)” and to “selling, general and administrative” in the consolidated statement of earnings, proportional to the number of workers in the production and administrative areas, respectively. Workers’ participation expense for the three years ended December 31, 2018 was as follows (in millions): 2018 2017 2016 Current $ 219.9 $ 192.7 $ 131.8 Deferred 9.8 6.6 (13.4) $ 229.7 $ 199.3 $ 118.4

ASSET RETIREMENT OBLIGATION_

ASSET RETIREMENT OBLIGATION:	12 Months Ended
	Dec. 31, 2018
ASSET RETIREMENT OBLIGATION:
ASSET RETIREMENT OBLIGATION:	NOTE 9 -ASSET RETIREMENT OBLIGATION: The Company maintains an asset retirement obligation for its mining properties in Peru, as required by the Peruvian Mine Closure Law. In accordance with the requirements of this law the Company’s closure plans were approved by the Peruvian Ministry of Energy and Mines (“MINEM”). As part of the closure plans, the Company is required to provide annual guarantees over the estimated life of the mines, based on a present value approach, and to furnish the funds for the asset retirement obligation. This law requires a review of closing plans every five years. Currently and for the near-term future, the Company has pledged the value of its Lima office complex and a warehouse in Lima as support for this obligation. The accepted values of these facilities, for this purpose, are of $45.3 million. Through January 2019, the Company has provided guarantees of $37.8 million. The closure cost recognized for this liability includes the cost, as outlined in its closure plans, of dismantling the Toquepala and Cuajone concentrators, the Ilo smelter and refinery, and the shops and auxiliary facilities at the three units. In March 2016, MINEM approved the Mining Closure Plan for the Toquepala expansion project. The closure plan for the Tia Maria project was approved in February 2017. The Company, however, has not recorded a retirement obligation for the project as the construction permit has not been received, and work on the project is on hold. The Company believes that under these circumstances the recording of a retirement obligation is not appropriate. In accordance with requirements of Peruvian law, the Company in December 2017 and February 2018, submitted to MINEM revised closure plans for the Cuajone mine and the Ilo facilities respectively, which at September 30, 2018 are pending approval. As a result of these new estimates, the Company has reduced the asset retirement obligation by $11.6 million in December 2017 and $5.2 million in the first quarter of 2018. In 2010, the Company announced to the Mexican federal environmental authorities its closure plans for the copper smelter plant at San Luis Potosi. The Company developed a program for plant demolition and soil remediation with a cost of $66.2 million. In 2016, the environmental authorities approved the conclusion of the remediation effort. The Company continues studying the possibilities for this property in order to decide whether to sell or develop the property. The Company has recognized an estimated asset retirement obligation for its mining properties in Mexico as part of its environmental commitment. Even though there is currently no enacted law, statute, ordinance, written or oral contract requiring the Company to carry out mine closure and environmental remediation activities, the Company believes that a constructive obligation presently exists based on the remediation requirements caused by the closure of any facility. The overall cost recognized for mining closure in Mexico includes the estimated costs of dismantling concentrators, smelter and refinery plants, shops and other facilities. During 2018, the Company made a change in the estimate for the asset retirement obligation in its Mexican operations, mainly due to a change in the discount rate used to determine such obligation. The effect of this change was a reduction in the asset retirement obligation of $10.4 million, which was recorded in the second quarter of 2018. The following table summarizes the asset retirement obligation activity for years ended December 31, 2018 and 2017 (in millions): 2018 2017 Balance as of January 1 $ 222.5 $ 216.5 Changes in estimates (15.6) (11.6) Additions — — Closure payments (0.6) (0.3) Accretion expense 11.4 17.9 Balance as of December 31, $ 217.7 $ 222.5

FINANCING_

FINANCING:	12 Months Ended
	Dec. 31, 2018
FINANCING:
FINANCING:	NOTE 10-FINANCING: Long-term debt (in millions): Carrying value as of Face Issuance Issuance December 31, amount discount costs 2018 5.375% Senior unsecured notes due 2020 $ 400 $ (0.3) $ (0.4) $ 399.3 3.500% Senior unsecured notes due 2022 300 (0.5) (0.6) 298.9 3.875% Senior unsecured notes due 2025 500 (1.8) (1.8) 496.4 9.250% Yankee bonds due 2028 125 — — 51.2 7.500% Senior unsecured notes due 2035 1,000 (12.9) (8.4) 978.7 6.750% Senior unsecured notes due 2040 1,100 (7.3) (5.8) 1,086.9 5.250% Senior unsecured notes due 2042 1,200 (19.4) (6.5) 1,174.1 5.875% Senior unsecured notes due 2045 1,500 (16.6) (8.8) 1,474.6 Total $ 6,125 $ (58.8) $ (32.3) 5,960.1 Less, current portion — Total long-term debt $ 5,960.1 Carrying value as of Face Issuance Issuance December 31, amount discount costs 2017 5.375% Senior unsecured notes due 2020 $ 400 $ (0.6) $ (0.6) $ 398.8 3.500% Senior unsecured notes due 2022 300 (0.5) (0.8) 298.7 3.875% Senior unsecured notes due 2025 500 (2.1) (2.0) 495.9 9.250% Yankee bonds due 2028 125 — — 51.2 7.500% Senior unsecured notes due 2035 1,000 (13.2) (8.8) 978.0 6.750% Senior unsecured notes due 2040 1,100 (7.4) (5.9) 1,086.7 5.250% Senior unsecured notes due 2042 1,200 (19.8) (6.6) 1,173.6 5.875% Senior unsecured notes due 2045 1,500 (16.9) (8.9) 1,474.2 Total $ 6,125 $ (60.5) $ (33.6) 5,957.1 Less, current portion — Total long-term debt $ 5,957.1 The bonds, referred above as “Yankee bonds”, contain a covenant requiring Minera Mexico to maintain a ratio of EBITDA to interest expense of not less than 2.5 to 1.0 as such terms are defined in the debt instrument. At December 31, 2018, Minera Mexico was in compliance with this covenant. Between July 2005 and November 2012 the Company issued senior unsecured notes six times totaling $4.2 billion, as listed above. Interest on the notes is paid semi-annually in arrears. The notes rank pari passu with each other and rank pari passu in right of payment with all of the Company’s other existing and future unsecured and unsubordinated indebtedness. On April 20, 2015, the Company issued $2.0 billion of fixed-rate senior unsecured notes. This debt was issued in two tranches, $500 million due 2025 at an annual interest rate of 3.875% and $1.5 billion due 2045 at an annual interest rate of 5.875%. These notes are general unsecured obligations of the Company and rank equally with all of its existing and future unsecured and unsubordinated debt. Net proceeds are being used for general corporate purposes, including the financing of the Company´s capital investment program. The notes were issued with an underwriters’ discount of $20.2 million. Additionally, issuance costs of $11.8 million associated with these notes were paid and deferred. The unamortized balance of the discount and the costs are presented net of the carrying value of the debt issued and are amortized as interest expense over the life of the loan. The indentures relating to the notes contain certain restrictive covenants, including limitations on liens, limitations on sale and leaseback transactions, rights of the holders of the notes upon the occurrence of a change of control triggering event, limitations on subsidiary indebtedness and limitations on consolidations, mergers, sales or conveyances. Certain of these covenants cease to be applicable before the notes mature if the Company obtains an investment grade rating. The Company obtained investment grade rating in 2005. The Company has registered these notes under the Securities Act of 1933, as amended. The Company may issue additional debt from time to time pursuant to certain of the indentures. If the Company experiences a “Change of Control Triggering Event”, the Company must offer to repurchase the notes at a purchase price equal to 101% of the principal amount thereof, plus accrued and unpaid interest, if any. A Change of Control Trigger Event means a Change of Control (as defined) and a rating decline (as defined), that is, if the rating of the notes, by at least one of the rating agencies shall be decreased by one or more gradations. At December 31, 2018, the Company was in compliance with the covenants of the notes. Aggregate maturities of the outstanding borrowings at December 31, 2018, are as follows: Principal Years Due(*) (in millions) 2019 $ — 2020 400.0 2021 — 2022 300.0 2023 — Thereafter 5,351.2 Total $ 6,051.2 (*) Total debt maturities do not include the debt discount valuation account of $91.1 million.

BENEFIT PLANS_

BENEFIT PLANS:	12 Months Ended
	Dec. 31, 2018
BENEFIT PLANS:
BENEFIT PLANS:	NOTE 11-BENEFIT PLANS: Post retirement defined benefit plans and defined contribution plan The Company has two noncontributory defined benefit pension plans covering former salaried employees in the United States and certain former expatriate employees in Peru (the “Expatriate Plan”). Effective October 31, 2000, the Board of Directors amended the qualified pension plan to suspend the accrual of benefits.In addition, the Company’s Mexican subsidiaries have a defined contribution pension plan for salaried employees and a non-contributory defined benefit pension plan for union employees (the “Mexican Plan”). The components of net periodic benefit costs calculated in accordance with ASC 715 “Compensation retirement benefits,” using December 31 as a measurement date, consist of the following: Years ended December 31, (in millions) 2018 2017 2016 Service cost $ 1.0 $ 0.8 $ 0.7 Interest cost 1.6 1.4 1.0 Expected return on plan assets (3.4) (2.9) (2.2) Amortization of prior service cost / (credit) 0.2 0.1 0.1 Settlement / Curtailment (0.2) 0.1 (0.2) Amortization of net loss/(gain) 0.2 0.2 0.2 Net periodic benefit cost $ (0.6) $ (0.3) $ (0.4) The change in benefit obligation and plan assets and a reconciliation of funded status are as follows: As of December 31, (in millions) 2018 2017 Change in benefit obligation: Projected benefit obligation at beginning of year $ 27.5 $ 25.6 Service cost 1.0 0.8 Interest cost 1.6 1.4 Settlement — 0.9 Benefits paid (1.6) (1.9) Actuarial (gain)/loss (0.2) (0.3) Actuarial gain assumption changes (0.8) 0.3 Inflation adjustment (0.1) 0.7 Projected benefit obligation at end of year $ 27.4 $ 27.5 Change in plan assets: Fair value of plan assets at beginning of year $ 51.6 $ 44.6 Actual return on plan assets (3.5) 6.9 Employer contributions (0.4) (0.4) Benefits paid (1.0) (0.9) Currency exchange rate adjustment — 1.4 Fair value of plan assets at end of year $ 46.7 $ 51.6 Funded status at end of year: $ 19.3 $ 24.1 ASC-715 amounts recognized in statement of financial position consists of: Non-current assets $ 19.4 $ 24.2 Total $ 19.4 $ 24.2 ASC-715 amounts recognized in accumulated other comprehensive income (net of income taxes of $(4.3) million and $(2.0) million in 2018 and 2017, respectively) consists of: Net loss (gain) $ 5.8 $ 2.3 Prior service cost 1.4 1.5 Total $ 7.2 $ 3.8 The following table summarizes the changes in accumulated other comprehensive income for the years ended December 31, related to the defined benefit pension plan, net of income tax: (in millions) 2018 2017 Reconciliation of accumulated other comprehensive income: Accumulated other comprehensive income at beginning of plan year $ 3.8 $ 5.8 Net loss/(gain) amortized during the year 3.6 (0.1) Net loss/(gain) occurring during the year (0.1) (2.4) Prior service cost (credit) — 0.4 Currency exchange rate adjustment (0.1) 0.1 Net adjustment to accumulated other comprehensive income (net of income taxes of $(2.2) million and $1.3 million in 2018 and 2017, respectively) 3.4 (2.0) Accumulated other comprehensive income at end of plan year $ 7.2 $ 3.8 The following table summarizes the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost in 2018 and 2017, net of income tax: (in millions) 2018 2017 Net loss / (gain) $ 3.6 $ (2.4) Amortization of net (loss) gain (0.1) (0.1) Amortization of prior services cost (credit) — 0.4 Total amortization expenses $ 3.5 $ (2.1) The assumptions used to determine the pension obligations are: Expatriate Plan 2018 2017 2016 Discount rate 3.90 % 3.25 % 3.65 % Expected long-term rate of return on plan asset 4.00 % 4.00 % 4.00 % Rate of increase in future compensation level N/A N/A N/A Mexican Plan(*) 2018 2017 2016 Discount rate 8.45 % 7.80 % 7.55 % Expected long-term rate of return on plan asset 8.45 % 7.55 % 7.55 % Rate of increase in future compensation level 4.50 % 4.50 % 4.50 % (*) These rates are based on Mexican pesos as pension obligations are denominated in pesos. The scheduled maturities of the benefits expected to be paid in each of the next five years, and thereafter, are as follows: Expected Years Benefit Payments (in millions) 2019 $ 2.6 2020 1.7 2021 1.8 2022 1.9 2023 2.0 2024 to 2026 13.4 Total $ 23.4 Expatriate Plan The Company’s funding policy is to contribute amounts to the qualified plan sufficient to meet the minimum funding requirements set forth in the Employee Retirement Income Security Act of 1974 plus such additional amounts as the Company may determine to be appropriate. Plan assets are invested in a group annuity contract with Metropolitan Life Insurance Company (“MetLife”). The Contract invests in the MetLife General Account Payment Fund (the "Money Fund") and the MetLife Broad Market Core Bond Fund (the “Bond Fund”) managed by BlackRock, Inc. The Money Fund seeks to earn interest and maintain a $1.00 per share net asset value, by investing in U.S. Dollar-denominated money market securities. The Bond Fund seeks to outperform the Bloomberg Barclays ® U.S. Aggregate Bond Index, net of fees, over a full market cycle. The Bond Fund invests in publicly traded, investment grade securities. These may include corporate securities, mortgage securities, treasuries and cash, agency securities, commercial mortgage backed securities and other investment vehicles adhering to the fund’s investment objectives. These investments are classified as Level 1 because they are valued using quoted prices of the same securities as they consist of instruments which are publicly traded. Plan assets are invested with the objective of maximizing returns with an acceptable level of risk and maintaining adequate liquidity to fund expected benefit payments. The Company's policy for determining asset mix-targets to meet investment objectives includes periodic consultation with recognized third party investment consultants. The expected long-term rate of return on plan assets is reviewed annually, taking into consideration asset allocations, historical returns and the current economic environment. Based on these factors the Company expects its assets will earn an average of 4.00% per annum assuming its long-term mix will be consistent with its current mix. Mexican Plan Minera Mexico’s policy for determining asset mix targets includes periodic consultation with recognized third party investment consultants. The expected long-term rate of return on plan assets is updated periodically, taking into consideration assets allocations, historical returns and the current economic environment. The fair value of plan assets is impacted by general market conditions. If actual returns on plan assets vary from the expected returns, actual results could differ. The plan assets are managed by three financial institutions, Scotiabank Inverlat S.A., Banco Santander and GBM Grupo Bursatil Mexicano, S.A. 78% of the funds are invested in Mexican government securities, including treasury certificates and development bonds of the Mexican government. The remaining 22% is invested in common shares of Grupo Mexico.The plan assets are invested without restriction in active markets that are accessible when required and are therefore considered as level 1, in accordance with ASC 820 “Fair Value Measurement.” These plans accounted for approximately 30% of benefit obligations. The following table represents the asset mix of the investment portfolio as of December 31: 2018 2017 Asset category: Treasury bills 78 % 70 % Equity securities 22 % 30 % 100 % 100 % The amount of contributions that the Company expects to pay to the plan during 2019 is $1.7 million, which excludes $2.7 million of pending payments to former Buenavista workers. Post-retirement Health Care Plan: United States: The Company adopted a post-retirement health care plan for retired salaried employees eligible for Medicare in 1996. The Company manages the plan and is currently providing health benefits to retirees. The plan is accounted for in accordance with ASC 715 “Compensation retirement benefits.” In Mexico, health services are provided by the Mexican Social Security Institute. The components of net period benefit costs for the three years ended December 31, 2017 are as follows: Years ended December 31, (in millions) 2018 2017 2016 Interest cost $ 0.9 $ 0.9 $ 0.6 Amortization of prior service cost/ (credit) (0.2) (0.2) (0.5) Net periodic benefit cost $ 0.7 $ 0.7 $ 0.1 The change in benefit obligation and a reconciliation of funded status are as follows: As of December 31, (in millions) 2018 2017 Change in benefit obligation: Projected benefit obligation at beginning of year $ 12.5 $ 12.9 Interest cost 0.9 0.9 Actuarial loss/ (gain)-claims cost 0.2 (0.4) Benefits paid (0.9) (0.9) Actuarial (gain)/loss (0.9) (0.6) Inflation adjustment 0.1 0.6 Projected benefit obligation at end of year $ 11.9 $ 12.5 Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Employer contributions 0.1 0.1 Benefits paid (0.1) (0.1) Fair value of plan assets at end of year $ — $ — Funded status at end of year: $ 11.9 $ 12.5 ASC-715 amounts recognized in statement of financial position consists of: Current liabilities $ (0.1) $ (0.1) Non-current liabilities (11.8) (12.5) Total $ (11.9) $ (12.6) ASC-715 amounts recognized in accumulated other comprehensive income consists of: Net loss (gain) $ (4.4) $ (3.9) Total (net of income taxes of $1.9 million and $1.7 million in 2018 and 2017, respectively) $ (4.4) $ (3.9) The following table summarizes the changes in accumulated other comprehensive income for the years ended December 31, related to the post-retirement health care plan, net of income tax: As of December 31, (in millions) 2018 2017 Reconciliation of accumulated other comprehensive income: Accumulated other comprehensive income at beginning of plan year $ (3.9) $ (2.8) Net loss/(gain) occurring during the year (0.6) (0.6) Net loss/(gain) amortized during the year 0.1 0.1 Currency exchange rate adjustment — (0.6) Net adjustment to accumulated other comprehensive income (net of income taxes of $0.2 million and $0.3 million in 2018 and 2017, respectively) (0.5) (1.1) Accumulated other comprehensive income at end of plan year $ (4.4) $ (3.9) The following table summarizes the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost in 2018 and 2017, net of income tax: At December 31, (in millions) 2018 2017 Net loss / (gain) $ (0.6) $ (0.6) Amortization of net (loss) gain 0.2 0.1 Total amortization expenses $ (0.4) $ (0.5) The discount rates used in the calculation of other post-retirement benefits and cost as of December 31 were: 2018 2017 2016 Expatriate health plan Discount rate 3.90 % 3.25 % 3.65 % Mexican health plan Weighted average discount rate 8.45 % 7.80 % 7.55 % The benefits expected to be paid in each of the next five years, and thereafter, are as follows: Expected Year Benefit Payments (in millions) 2019 $ 0.9 2020 0.9 2021 0.9 2022 0.9 2023 0.9 2024 to 2028 2.9 Total $ 7.4 Expatriate Health Plan For measurement purposes for pre 65 year old participants, a 5.8% annual rate of increase in the per capita cost of covered health care benefits was assumed for 2018 which gradually decrease to 4.2%. For post 65 year old the annual rate of increase in the per capita cost for 2018 is 5.2% which is assumed to decrease gradually to 4.0%. Assumed health care cost trend rates can have a significant effect on amounts reported for health care plans. However, because of the size of the Company’s plan, a one percentage-point change in assumed health care trend rate would not have a significant effect. Mexican Health Plan For measurement purposes, a 4.5% annual rate of increase in the per capita cost of covered health care benefits was assumed for 2018 and remains at that level thereafter. An increase in other benefit cost trend rates have a significant effect on the amount of the reported obligations, as well as component cost of the other benefit plan. One percentage-point change in assumed other benefits cost trend rates would have the following effects: One Percentage Point (in millions) Increase Decrease Effect on total service and interest cost components $ 1.0 $ 0.8 Effect on the post-retirement benefit obligation $ 11.7 $ 10.5

COMMITMENTS AND CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES:	12 Months Ended
	Dec. 31, 2018
COMMITMENTS AND CONTINGENCIES:
COMMITMENTS AND CONTINGENCIES:	NOTE 12-COMMITMENTS AND CONTINGENCIES: Environmental matters: The Company has instituted extensive environmental conservation programs at its mining facilities in Peru and Mexico. The Company’s environmental programs include, among others, water recovery systems to conserve water and minimize the impact on nearby streams, reforestation programs to stabilize the surface of the tailings dams and the implementation of scrubbing technology in the mines to reduce dust emissions. Environmental capital investments in years 2018, 2017 and 2016, were as follows (in millions): 2018 2017 2016 Peruvian operations $ 59.3 $ 93.7 $ 110.3 Mexican operations 43.5 128.9 140.1 Total $ 102.8 $ 222.6 $ 250.4 Peruvian operations : The Company’s operations are subject to applicable Peruvian environmental laws and regulations. The Peruvian government, through the Ministry of Environment (“MINAM”) conducts annual audits of the Company’s Peruvian mining and metallurgical operations. Through these environmental audits, matters related to environmental obligation, compliance with legal requirements, atmospheric emissions, effluent monitoring and waste management are reviewed. The Company believes that it is in material compliance with applicable Peruvian environmental laws and regulations. Peruvian law requires that companies in the mining industry provide assurances for future mine closure and remediation. In accordance with the requirements of this law, the Company’s closure plans were approved by MINEM. See Note 6 “Asset retirement obligation,” for further discussion of this matter. Air Quality Standards (“AQS”): In June 2017, MINAM enacted a supreme decree which defines new AQS for daily sulfur dioxide in the air. The Company believes that these new AQS will allow Peruvian industry to be more competitive with other countries. As of December 31, 2018, the Company maintains a lower daily average level of µg/m3 of SO2, than those required by the new AQS. Soil Environmental Quality Standards (“SQS”): In 2013, the Peruvian government enacted SQS applicable to any existing facility or project that generates or could generate the risk of soil contamination in its area of operation or influence. In March 2014, MINAM issued a supreme decree, which established additional provisions for the gradual implementation of SQS. Pursuant to this regulation, the Company had twelve months to identify contaminated sites in and around its facilities and present a report of identified contaminated sites. These documents were submitted to MINEM for approval in April 2015, and were fully approved in July 2017. The next step is for the Company to prepare a characterization study to determine the depth, extent and physio-chemical composition of the contaminated areas and define an appropriate remediation plan with a time-frame for completion. In addition, the Company must submit a Soil Decontamination Plan ("SDP") for approval within 30 months after being notified by the authority. This SDP must include remediation actions, a schedule and compliance deadlines. Pursuant to this regulation, the Company may request a one year extension for the decontamination plan if deemed necessary with reasonable justification. Soil confirmation tests must be carried out after completion of the decontamination actions (within the approved schedule) and results must be presented to authorities within 30 days after receiving such results. Although no specific sanctions have been established yet, non-compliance with this obligation or with decontamination goals will carry penalties for companies. However, companies cannot be penalized for non-compliance with the SQS during the schedule set forth for compliance. In accordance with the regulatory requirements, the Company has been working on the characterization phase and SDPs for environmentally impacted sites in each of its operating units (Toquepala, Cuajone, and Ilo) with the assistance of consulting companies. It is estimated that the Toquepala and Cuajone SDPs will be presented to the authorities for review and approval at the end of the second quarter of 2019, and the Ilo SDP will be submitted during the third quarter of 2019. While the Company believes that there is a reasonable possibility that a potential loss contingency may exist, it cannot currently reasonably estimate the amount of the contingency. The Company believes that a reasonable determination of the loss will be possible once the characterization study and the SDP are substantially completed, which is expected for the third quarter of 2019. At that time the Company will be in a position to estimate the remediation cost. Furthermore, the Company does not believe that it can estimate a reasonable range of possible costs until the noted studies have substantially progressed and therefore is not able to disclose a range of costs that is meaningful. Water Quality Standards (“WQS”): In June 2017, MINAM enacted a supreme decree which establishes water quality standards in the Peruvian territory. The adoption of these standards have not a material impact on its financial position. Mexican operations : The Company’s operations are subject to applicable Mexican federal, state and municipal environmental laws, to Mexican official standards, and to regulations for the protection of the environment, including regulations relating to water supply, water quality, air quality, noise levels and hazardous and solid waste. The principal legislation applicable to the Company’s Mexican operations is the Federal General Law of Ecological Balance and Environmental Protection (the “General Law”), which is enforced by the Federal Bureau of Environmental Protection (“PROFEPA”). PROFEPA monitors compliance with environmental legislation and enforces Mexican environmental laws, regulations and official standards. It may also initiate administrative proceedings against companies that violate environmental laws, which in the most extreme cases may result in the temporary or permanent shutdown of non-complying facilities, the revocation of operating licenses and/or other sanctions or fines. In 2011, the General Law was amended, giving an individual or entity the ability to contest administrative acts, including environmental authorizations, permits or concessions granted, without the need to demonstrate the actual existence of harm to the environment as long as it can be argued that the harm may be caused. In addition, in 2011, amendments to the Civil Federal Procedures Code (“CFPC”) were enacted. These amendments establish three categories of collective actions by means of which 30 or more people claiming injury derived from environmental, consumer protection, financial services and economic competition issues will be considered to be sufficient in order to have a legitimate interest to seek through a civil procedure restitution or economic compensation or suspension of the activities from which the alleged injury derived. The amendments to the CFPC may result in more litigation, with plaintiffs seeking remedies, including suspension of the activities alleged to cause harm. In 2013, the Environmental Liability Federal Law was enacted. The law establishes general guidelines for actions to be considered to likely cause environmental harm. If a possible determination regarding harm occurs, environmental clean-up and remedial actions sufficient to restore environment to a pre-existing condition should be taken. Under this law, if restoration is not possible, compensation measures should be provided. Criminal penalties and monetary fines can be imposed under this law. On February 2019, the Mexican Supreme Court confirmed the constitutionality of an ecological tax to extractive activities developed in the state of Zacatecas, which taxes the environmental remediation actions, emissions of certain gases to the atmosphere, emissions of pollutant substances to the soil or water, and waste storage within the state territory. The Company is evaluating the potential impact of this new environmental regulation in its financial position. The Company believes that all of its facilities in Peru and Mexico are in material compliance with applicable environmental, mining and other laws and regulations. The Company also believes that continued compliance with environmental laws of Mexico and Peru will not have a material adverse effect on the Company’s business, properties, result of operations, financial condition or prospects and will not result in material capital investments. Litigation matters : Peruvian operations The Tia Maria Mining Project There are three lawsuits filed against the Peruvian Branch of the Company related to the Tia Maria project. The lawsuits seek (i) to declare null and void the resolution which approved the Environmental Impact Assessment of the project; (ii) the cancellation of the project and the withdrawal of mining activities in the area and (iii) to declare null and void the mining concession application of the Tia Maria project. The lawsuits were filed by Messrs. Jorge Isaac del Carpio Lazo (filed May 22, 2015), Ernesto Mendoza Padilla (filed May 26, 2015) and Juan Alberto Guillen Lopez (filed June 18, 2015). The del Carpio Lazio case was rejected by the court of first instance on November 14, 2016. The plaintiff filed an appeal before the Superior Court on January 3, 2017. On January 9, 2018, the lawyers of both parties presented their respective positions before the Appellate Court. On March 8, 2018, the Appellate Court issued its final decision, which upholds the first instance ruling. On April 27, 2018, the plaintiff filed an extraordinary appeal before the Supreme Court. As of December 31, 2018, the case remains pending resolution. The Mendoza Padilla case was initially rejected by the lower court on July 8, 2015. This ruling was confirmed by the Superior Court on June 14, 2016. On July 12, 2016, the case was appealed before the Constitutional Court. As of December 31, 2018, the case remains pending resolution without further developments. The Guillen Lopez case is currently before the lower court. As of December 31, 2018, the case remains pending resolution without further developments. The Company asserts that these lawsuits are without merit and is vigorously defending against them. The potential contingency amount for these cases cannot be reasonably estimated by management at this time. Special Regional Pasto Grande Project (“Pasto Grande Project”) In 2012, the Pasto Grande Project, an entity of the Regional Government of Moquegua, filed a lawsuit against SCC’s Peruvian Branch alleging property rights over a certain area used by the Peruvian Branch and seeking the demolition of the tailings dam where SCC’s Peruvian Branch has deposited its tailings from the Toquepala and Cuajone operations since 1995. The Peruvian Branch has had title to use the area in question since 1960 and has constructed and operated the tailings dams with proper governmental authorization, since 1995. Upon a motion filed by the Peruvian Branch, the lower court has included MINEM as a defendant in this lawsuit. MINEM has answered the complaint and denied the validity of the claim. As of December 31, 2018, the case remains pending resolution without further developments. SCC’s Peruvian Branch asserts that the lawsuit is without merit and is vigorously defending against it. The amount of this contingency cannot be reasonably estimated by management at this time. Mexican operations The 2014 Accidental Spill at Buenavista Mine In relation to the 2014 accidental spill of copper sulfate solution that occurred at a leaching pond of the Buenavista mine, the following legal procedures are pending against the Company: On August 19, 2014, PROFEPA, as part of the administrative proceeding initiated after the spill, announced the filing of a criminal complaint against Buenavista del Cobre S.A. de C.V. (“BVC”), a subsidiary of the Company, in order to determine those responsible for the environmental damages. During the second quarter of 2018, the criminal complaint was dismissed. This decision was appealed and remains pending resolution. Through the first half of 2015, six collective action lawsuits were filed in federal courts in Mexico City and Sonora against two subsidiaries of the Company seeking economic compensation, clean up and remedial activities in order to restore the environment to its pre-existing conditions. Two of the collective action lawsuits have been dismissed by the court. The plaintiffs in the four remaining lawsuits are: Acciones Colectivas de Sinaloa, A.C. which established two collective actions, Defensa Colectiva A.C.; and Ana Luisa Salazar Medina et al. which has been granted a collective action certification. The remaining plaintiffs have requested cautionary measures on the construction of facilities for the monitoring of public health services and the prohibition of the closure of the Río Sonora Trust. As of December 31, 2018, these cases remain pending resolution. Similarly, during 2015, eight civil action lawsuits were filed against BVC in the state courts of Sonora seeking damages for alleged injuries and for moral damages as a consequence of the spill. The plaintiffs in the state court lawsuits are: Jose Vicente Arriola Nunez et al; Santana Ruiz Molina et al; Andres Nogales Romero et al; Teodoro Javier Robles et al; Gildardo Vasquez Carvajal et al; Rafael Noriega Souffle et al; Grupo Banamichi Unido de Sonora El Dorado, S.C. de R.L. de C.V; and Marcelino Mercado Cruz. In 2016, three additional civil action lawsuits, claiming similar damages, were filed by Juan Melquicedec Lebaron; Blanca Lidia Valenzuela Rivera et al and Ramona Franco Quijada et al. In 2017, BVC was served with thirty-three additional civil action lawsuits, claiming similar damages. The lawsuits were filed by Francisco Javier Molina Peralta et al; Anacleto Cohen Machini et al; Francisco Rafael Alvarez Ruiz et al; Jose Alberto Martinez Bracamonte et al; Gloria del Carmen Ramirez Duarte et al; Flor Margarita Sabori et al; Blanca Esthela Ruiz Toledo et al; Julio Alfonso Corral Dominguez et al; Maria Eduwiges Bracamonte Villa et al; Francisca Marquez Dominguez et al; Jose Juan Romo Bravo et al; Jose Alfredo Garcia Leyva et al; Gloria Irma Dominguez Perez et al; Maria del Refugio Romero et al; Miguel Rivas Medina et al; Yolanda Valenzuela Garrobo et al; Maria Elena Garcia Leyva et al; Manuel Alfonso Ortiz Valenzuela et al; Francisco Alberto Arvayo Romero et al; Maria del Carmen Villanueva Lopez et al; Manuel Martin Garcia Salazar; Miguel Garcia Arguelles et al; Dora Elena Rodriguez Ochoa et al; Honora Eduwiges Ortiz Rodriguez et al; Francisco Jose Martinez Lopez et al; Maria Eduwiges Lopez Bustamante; Rodolfo Barron Villa et al, Jose Carlos Martinez Fernandez et al, Maria de los Angeles Fabela et al; Rafaela Edith Haro et al; Luz Mercedes Cruz et al; Juan Pedro Montaño et al; and Juana Irma Alday Villa. During the first quarter of 2018, BVC was served with another civil action lawsuit, claiming similar damages. The lawsuit was filed by Alma Angelina Del Cid Rivera et al. During the last quarter of 2018, BVC was served with other three civil action lawsuits, claiming similar damages, such lawsuits were filed by Los Corrales de la Estancia, S.C. de R.L.; Jose Antonio Navarro; Jesus Maria Peña Molina, et al. As of December 31, 2018, these cases remain pending resolution. During 2015, four constitutional lawsuits (juicios de amparo) were filed before Federal Courts against various authorities and against a subsidiary of the Company, arguing; (i) the alleged lack of a waste management program approved by SEMARNAT; (ii) the alleged lack of a remediation plan approved by SEMARNAT with regard to the August 2014 spill; (iii) the alleged lack of community approval regarding the environmental impact authorizations granted by SEMARNAT to one subsidiary of the Company; and (iv) the alleged inactivity of the authorities with regard of the spill in August 2014. The plaintiffs of these lawsuits are: Francisca Garcia Enriquez, et al which established two lawsuits, Francisco Ramon Miranda, et al and Jesus David Lopez Peralta et al. During the third quarter of 2016, four additional constitutional lawsuits, claiming similar damages were filed by Mario Alberto Salcido et al; Maria Elena Heredia Bustamante et al; Martin Eligio Ortiz Gamez et al; and Maria de los Angeles Enriquez Bacame et al. During the third quarter of 2017, BVC was served with another constitutional lawsuit filed by Francisca García Enriquez et al. In 2018, BVC was served with two additional constitutional lawsuits that were filed against SEMARNAT by Norberto Bustamante et al. Regarding the constitutional lawsuit filed by Maria Elena Heredia Bustamante et al; in which it was claimed the lack of community approval regarding the authorization granted by SEMARNAT to build the new BVC tailings dam, on September 5, 2018, the Supreme Court of Justice issued a resolution which established that such authorization was granted to BVC in compliance with the applicable legislation. However, SEMARNAT must carry out a public meeting to inform the community of the technical aspects required to build the dam, potential impacts and prevention measures, with no material effects to BVC’s operations. As of December 31, 2018, the remaining cases are still pending resolution. It is not currently possible to determine the extent of the damages sought in these state and federal lawsuits but the Company considers that these lawsuits are without merit. Accordingly, the Company is vigorously defending against them. Nevertheless, the Company considers that none of the legal proceedings resulting from the spill, individually or in the aggregate, would have a material effect on its financial position or results of operations. Corporate operations Carla Lacey, on behalf of herself and all other similarly situated stockholders of Southern Copper Corporation, and derivatively on behalf of Southern Copper Corporation As previously reported, a purported class action derivative lawsuit filed in the Delaware Court of Chancery was served on the Company and its Directors in February 2016 relating to the 2012 capitalization of 99.999% of MGE by Controladora de Infraestructura Energetica Mexico, S.A. de C.V., an indirect subsidiary of Grupo Mexico (the “CIEM Capitalization”), the Company’s entry into a power purchase agreement with MGE in 2012 (the “MGE Power Purchase Agreement”), and the 2012 restructuring of a loan from the Company’s Mexican Operations to MGE for the construction of two power plants to supply power to the Company’s Mexican operations (the “MGE Loan Restructuring”). The action purports to be brought on behalf of the Company and its common stockholders. The complaint alleges, among other things, that the CIEM Capitalization, the MGE Power Purchase Agreement and the MGE Loan Restructuring were the result of breaches of fiduciary duties and the Company’s charter. On March 20, 2018, the parties reached an agreement-in-principle to settle the action. On March 23, 2018, the parties informed the Court of the settlement-in-principle to resolve all claims asserted by Plaintiff against Defendants in the action and requested that the Court stay the action in its entirety pending filing by the parties of a stipulation of settlement. The Parties filed the executed stipulation on August 22, 2018. Under the proposed settlement, Grupo Mexico or Americas Mining would pay to the Company $50 million in cash less any attorneys’ fees (including costs) awarded by the Court to Plaintiff’s counsel (the “Net Settlement Amount”) in return for a release of all derivative and direct claims. A settlement hearing was held on November 27, 2018. On December 27, 2018, the Court issued its ruling approving the $50 million settlement. Pursuant to the Court’s ruling, Plaintiff’s counsel was awarded $13.5 million (for attorneys’ fees, expenses, and a $5,000 incentive fee award to plaintiff Carla Lacey). The remaining $36.5 million was distributed via a special dividend on February 21, 2019 to the Company’s public stockholders (other than the director defendants, Grupo Mexico, Americas Mining, or any entity in which Grupo Mexico or Americas Mining has or had a direct or indirect controlling interest) who held shares of common stock of the Company as of February 11, 2019. As result of the payment of the settlement, the claims against the Defendants have been dismissed with prejudice. Labor matters : Peruvian operations: 75% of the Company's 4,850 Peruvian employees were unionized at December 31, 2018. Currently, there are six separate unions, one large union and five smaller unions. In the first quarter of 2016, the Company signed three-year agreements with all the existing unions at that time. These agreements included, among other things, annual salary increases of 5% for each of the three years. In June 2018, the Company signed a three-year collective bargaining agreement with one of the smaller unions. This agreement includes, among other things, annual salary increases of 5% for each year starting September 2018, and a signing bonus of S/ 45,000 (approximately $13,600) which was recorded as labor expense. In August 2018, the Company signed a three-year collective bargaining agreement with three additional unions. This agreement includes, among other things, annual salary increases of 5% for each year starting December 2018, and a signing bonus of S/ 45,000 (approximately $13,600) which was recorded as labor expense. As of December 31, 2018, the Company continues negotiations on collective bargaining agreements with the two unsigned unions. Mexican operations: In recent years, the Mexican operations have experienced a positive improvement of their labor environment, as its workers opted to change their affiliation from the Sindicato Nacional de Trabajadores Mineros, Metalurgicos y Similares de la Republica Mexicana (the “National Mining Union”) to other less politicized unions. The workers of the San Martin mine were on strike since July 2007. On February 28, 2018, the striking workers of the San Martín mine of IMMSA held an election to vote on the union that will hold the collective bargaining agreement at the San Martín mine. The Federacion Nacional de Sindicatos Independientes (the National Federation of Independent Unions), won the vote by a majority. Nevertheless, the vote was challenged by the National Mining Union. On June 26, 2018, the Federal Mediation and Arbitration Board issued a ruling recognizing the election results. Due to the agreement between workers and the Company to end the protracted strike, on August 22, 2018, the Federal Mediation and Arbitration Board authorized the restart of operations of the San Martín mine. Such authorization was challenged by the National Mining Union. The Company is working on a rehabilitation plan to restart operations at the San Martin mine with a budget of $77 million. At December 31, 2018 the plan is in progress with a total expense of $17.7 million. The Company is restoring mining operations in the first quarter of 2019 and expects to restore copper production in the second quarter of 2019. In the case of the Taxco mine, its workers have been on strike since July 2007. After several legal procedures, in August 2015, the Supreme Court decided to assert jurisdiction over the case and to rule on it directly. As of December 31, 2018, the case remains pending resolution without further developments. It is expected that operations at the Taxco mine will remain suspended until the labor issues are resolved. In view of the lengthy strike, the Company has reviewed the carrying value of the Taxco mine to ascertain whether impairment exists. The Company concluded that there is a non-material impairment of the assets located at this mine. Other legal matters : The Company is involved in various other legal proceedings incidental to its operations, but does not believe that decisions adverse to it in any such proceedings, individually or in the aggregate, would have a material effect on its financial position or results of operations. Other commitments: Peruvian Operations Tia Maria: On August 1, 2014, the Company received the final approval of Tia Maria’s Environmental Impact Assessment (“EIA”). However, the issuance of the project’s construction permit has been delayed due to pressures from anti-mining groups. The Company continues working with community groups in order to resolve open issues concerning the project. The Company is also working jointly with the Peruvian government to obtain the construction license for this 120,000 ton (annual) SX-EW copper greenfield project. The Company expects the license to be issued in the first half of 2019. Tia Maria’s project budget is approximately $1.4 billion, of which $333.9 million has been invested through December 31, 2018. When completed, it is expected to produce 120,000 tons of copper cathodes per year. This project will use state-of-the-art SX-EW technology with the highest international environmental standards. SX-EW facilities are the most environmentally friendly in the industry as they do not require a smelting process and consequently, no emissions are released into the atmosphere. The project will only use seawater, transporting it more than 25 kilometers to 1,000 meters above sea level, and includes a desalinization plant which will be constructed at a cost of $95 million. Consequently, the Tambo river water resources will be used solely for farming and human consumption. The Company expects the project to generate 9,000 jobs (3,600 direct and 5,400 indirect) during the construction phase. When in operation, Tia Maria will directly employ 600 workers and indirectly provide jobs to another 4,200. Through its expected twenty-year life, the project related services will create significant business opportunities in the Arequipa region. In view of the delay in this project, the Company continues to review the carrying value of this asset to ascertain whether impairment exists. Should the Tia Maria project not move forward, the Company is confident that most of the project equipment will continue to be used productively, through reassignment to other mine locations operated by the Company. The Company believes that an impairment loss, if any, will not be material. Michiquillay: In June 2018, the Company signed a contract for the acquisition of the Michiquillay copper project in Cajamarca, Peru, at a purchase price of $400 million. Michiquillay is a world class mining project with estimated mineralized material of 1,150 million tons and a copper grade of 0.63%. It is expected to produce 225,000 tons of copper per year (along with by-products of molybdenum, gold and silver) for an initial mine life of more than 25 years. The Company paid $12.5 million at the signing of the contract. An additional $12.5 million has been accrued by the Company as it evaluates the project for development, over a three to five year period. This amount is classified in other non-current liabilities in the Company’s consolidated financial statements. The balance of $375 million will be paid if the Company decides to develop the project. Toquepala Concentrator Expansion: In April 2015, the construction permit for the Toquepala expansion project was approved by the MINEM. The project budget is $1.3 billion, of which $1,227 million has been invested through December 31, 2018. When completed, this project is expected to increase annual production capacity by 100,000 tons of copper and 3,100 tons of molybdenum. The construction of the project was completed and the project began production in the fourth quarter of 2018. Full production is expected to be reached by the second quarter of 2019. Corporate Social Responsibility: The Company has a corporate social responsibility policy to maintain and promote continuity of its mining operations and obtain the best results. The main objective of this policy is to integrate its operations with the local communities in the areas of influence of its operations by creating a permanent positive relationship with them, in order to develop the optimum social conditions and to promote sustainable development in the area. Accordingly, the Company has made the following commitments: Tacna Region : In connection with the Toquepala concentrator expansion, the Company has committed to fund various social and infrastructure improvement projects in Toquepala's neighboring communities. The total amount committed for these purposes is S/ 445.0 million (approximately $131.7 million). Moquegua Region : In the Moquegua region, the Company is part of a “development roundtable” in which the local municipal authorities, the community representatives and the Company discuss the social needs and the way the Company could contribute to sustainable development in the region. As part of this, the roundtable is discussing the creation of a Moquegua Region Development Fund for which the Company has offered a contribution of S/ 700 million (approximately $207.2 million). While final funding is not yet settled, the Company has committed to contribute S/ 108.5 million (approximately $32.1 million) in advance, which is being utilized in an educational project and S/ 48.4 million (approximately $14.3 million) for a residual water treatment plant in Ilo, a sea-wall embankment and a fresh water facility at El Algarrobal. In addition, the Company has committed S/ 202.0 million (approximately $59.8 million) for the construction of six infrastructure projects in the Moquegua region under the “social investment for taxes” (obras por impuestos) program which allows the Company to use these amounts as an advance payment of taxes. These commitments are subject to the continuity of the respective mine operations and, as such, are not considered to be present obligations of the Company. Therefore, the Company has not recorded a liability in its condensed consolidated financial statements. Peruvian operations Power purchase agreements: · Electroperu S.A.: In June 2014, the Company entered into a power purchase agreement for 120 megawatt (“MW”) with the state power company Electroperu S.A., under which Electroperu S.A. began supplying energy for the Peruvian operations for twenty years starting on April 17, 2017. · Kallpa Generacion S.A. (“Kallpa”): In July 2014, the Company entered into a power purchase agreement for 120MW with Kallpa, an independent Israeli owned power company, under which Kallpa will supply energy for the Peruvian operations for ten years starting on April 17, 2017 and ending on April 30, 2027. In May 2016, the Company signed an additional power purchase agreement for a maximum of 80MW with Kallpa, under which Kallpa began supplying energy for the Peruvian operations related to the Toquepala Expansion and other minor projects for ten years starting on May 1, 2017 and ending after ten years of commercial operation of the Toquepala Expansion or on April 30, 2029; whichever occurs first. Mexican operations Power purchase agreements: · MGE: In 2012, the Company signed a power purchase agreement with MGE, an indirect subsidiary of Grupo Mexico, to supply power to some of the Company’s Mexican operations through 2032. For further information, please see Note 16 “Related party transactions”. · Eolica el Retiro, S.A.P.I. de C.V.: In 2013, the Company signed a power purchase agreement with Eolica el Retiro, S.A.P.I de C.V. a windfarm energy producer that is an indirect subsidiary of Grupo Mexico, to supply power to some of the Company’s Mexican operations. For further information, please see Note 16 “Related party transactions”. For an estimate of the Company’s contractual obligations for power purchases, please see, “Contractual Obligations” under Item 7 “Management Discussion and Analysis of Financial Condition and Results of Operations.” Corporate operations Commitment for Capital projects: As of December 31, 2018, the Company has committed approximately $343.1 million for the development of its capital investment projects. Tax contingency matters: Tax contingencies are provided for under ASC 740-10-50-15 Uncertain tax position (see Note 7 “Income taxes”).

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2018
STOCKHOLDERS' EQUITY:
STOCKHOLDERS' EQUITY:	NOTE 13-STOCKHOLDERS’ EQUITY Treasury Stock: Activity in treasury stock in the years 2018 and 2017 was as follows (in millions): 2018 2017 Southern Copper common shares Balance as of January 1, $ 2,768.7 $ 2,769.0 Purchase of shares — — Used for corporate purposes (0.4) (0.3) Balance as of December 31, 2,768.3 2,768.7 Parent Company (Grupo Mexico) common shares Balance as of January 1, 232.4 218.6 Other activity, including dividend, interest and foreign currency transaction effect 18.9 13.8 Balance as of December 31, 251.3 232.4 Treasury stock balance as of December 31, $ 3,019.6 $ 3,001.1 SCC shares of common stock in treasury: At December 31, 2018 and 2017, treasury stock holds 111,551,617 shares and 111,567,617 shares of SCC’s common stock with a cost of $2,768.7 million and $2,769.0 million, respectively. The shares of SCC’s common stock held in treasury are used for Director’s stock award plans and available for general corporate purposes. SCC share repurchase program: In 2008, the Company’s Board of Directors (“BOD”) authorized a $500 million share repurchase program that has since been increased by the BOD and is currently authorized to $3 billion. Pursuant to this program, the Company has purchased 119.5 million shares of common stock at a cost of $2.9 billion. These shares are available for general corporate purposes. The Company may purchase additional shares of its common stock from time to time, based on market conditions and other factors. This repurchase program has no expiration date and may be modified or discontinued at any time. There has not been activity in the SCC share repurchase program since the third quarter of 2016. The NYSE closing price of SCC common shares at December 31, 2018 was $30.77 and the maximum number of shares that the Company could purchase at that price is 2.7 million shares. Grupo Mexico’s direct and indirect ownership remains at 88.9% as of December 31, 2018. Directors’ Stock Award Plan: The Company established a stock award compensation plan for certain directors who are not compensated as employees of the Company. Under this plan, participants received 1,200 shares of common stock upon election and 1,200 additional shares following each annual meeting of stockholders thereafter. 600,000 shares of Southern Copper common stock have been reserved for this plan. On April 26, 2018, the Company’s stockholders approved a five-year extension of the Plan until January 28, 2023 and an increase of the shares award from 1,200 to 1,600. The fair value of the award is measured each year at the date of the grant. In 2018 and 2017 the stock based compensation expense under this plan equaled $0.4 million for each of these years. The activity of this plan for the years ended December 31, 2018 and 2017 was as follows: 2018 2017 Total SCC shares reserved for the plan 600,000 600,000 Total shares granted at January 1, (346,800) (334,800) Granted in the period (16,000) (12,000) Total shares granted at December 31, (362,800) (346,800) Remaining shares reserved 237.200 253,200 Parent Company common shares: At December 31, 2018 and 2017, there were in treasury 100,188,809 and 108,450,672 of Grupo Mexico’s common shares, respectively. Employee Stock Purchase Plan: 2010 Plan: During 2010, the Company offered to eligible employees a stock purchase plan through a trust that acquires series B shares of Grupo Mexico stock for sale to its employees, employees of subsidiaries, and certain affiliated companies. The purchase price was established at 26.51 Mexican pesos (approximately $1.28) for the initial subscription. Every two years employees were able to acquire title to 50% of the shares paid in the previous two years. The employees paid for shares purchased through monthly payroll deductions over the eight year period of the plan. At the end of the eight year period, the Company granted the participant a bonus of one share for every ten shares purchased by the employee. The participants were entitled to receive dividends in cash for dividends paid by Grupo Mexico for all shares that were fully purchased and paid by the employee as of the date that the dividend is paid. If the participant had only partially paid for shares, the entitled dividends were used to reduce the remaining liability owed for purchased shares. In the case of voluntary or involuntary resignation/termination of the employee, the Company paid to the employee the fair market sales price at the date of resignation/termination of the fully paid shares, net of costs and taxes. When the fair market sales value of the shares was higher than the purchase price, the Company applied a deduction over the amount to be paid to the employee based on a decreasing schedule specified in the plan. In case of retirement or death of the employee, the Company rendered the buyer or his legal beneficiary, the fair market sales value as of the date of retirement or death of the shares effectively paid, net of costs and taxes. The stock based compensation expense for the years ended December 31, 2018, 2017 and 2016 and the remaining balance of the unrecognized compensation expense under this plan were as follows (in millions): 2018 2017 2016 Stock based compensation expense $ 0.2 $ 0.6 $ 0.6 Unrecognized compensation expense $ — $ 0.2 $ 0.8 The plan ended in January 29, 2018. The following table presents the stock award activity of the 2010 Employee Stock Purchase Plan for the years ended December 31, 2017 and 2016: Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 1,393,663 $ 2.05 Granted — — Exercised (1,275,729) 2.05 Forfeited — — Outstanding shares at December 31, 2018 117,934 $ 2.05 Outstanding shares at January 1, 2017 1,401,096 $ 2.05 Granted — — Exercised (7,433) 2.05 Forfeited — — Outstanding shares at December 31, 2017 1,393,663 $ 2.05 2015 Plan: In January 2015, the Company offered to eligible employees a new stock purchase plan through a trust that acquires series B shares of Grupo Mexico stock for sale to its employees, and employees of subsidiaries, and certain affiliated companies. The purchase price was established at 38.44 Mexican pesos (approximately $1.86) for the initial subscription, which expires in January 2023. Every two years employees will be able to acquire title to 50% of the shares paid in the previous two years. The employees will pay for shares purchased through monthly payroll deductions over the eight year period of the plan. At the end of the eight year period, the Company will grant the participant a bonus of 1 share for every 10 shares purchased by the employee. Any future subscription will be at the average market price at the date of acquisition or the grant date. If Grupo Mexico pays dividends on shares during the eight year period, the participants will be entitled to receive the dividend in cash for all shares that have been fully purchased and paid as of the date that the dividend is paid. If the participant has only partially paid for shares, the entitled dividends will be used to reduce the remaining liability owed for purchased shares. In the case of voluntary or involuntary resignation/termination of the employee, the Company will pay to the employee the fair market sales price at the date of resignation of the fully paid shares, net of costs and taxes. When the fair market sales value of the shares is higher than the purchase price, the Company will apply a deduction over the amount to be paid to the employee based on a decreasing schedule specified in the plan. In case of retirement or death of the employee, the Company will render the buyer or his legal beneficiary, the fair market sales value as of the date of retirement or death of the shares effectively paid, net of costs and taxes. The stock based compensation expense for the years ended December 31, 2018, 2017 and 2016 and the unrecognized compensation expense under this plan were as follows (in millions): 2018 2017 2016 Stock based compensation expense $ 0.6 $ 0.6 $ 0.6 Unrecognized compensation expense $ 2.6 $ 3.2 $ 3.8 The following table presents the stock award activity of this plan for the years ended December 31, 2017 and 2016: Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 2,293,120 $ 2.63 Granted — — Exercised (452,784) $ 2.63 Forfeited — — Outstanding shares at December 31, 2018 1,840,336 $ 2.63 Outstanding shares at January 1, 2017 2,540,223 $ 2.63 Granted — — Exercised (247,103) $ 2.63 Forfeited — — Outstanding shares at December 31, 2018 2,293,120 $ 2.63 2018 Plan: In November 2018, the Company offered to eligible employees a new stock purchase plan (the "New Employee Stock Purchase Plan") through a trust that acquires series B shares of Grupo Mexico stock for sale to its employees, and employees of subsidiaries, and certain affiliated companies . The purchase price was established at 37.89 Mexican pesos (approximately $1.86) for the initial subscription, which expires in October 2026. Every two years employees will be able to acquire title to 50% of the shares paid in the previous two years. The employees will pay for shares purchased through monthly payroll deductions over the eight year period of the plan. At the end of the eight year period, the Company will grant the participant a bonus of 1 share for every 10 shares purchased by the employee. Any future subscription will be at the average market price at the date of acquisition or the grant date. If Grupo Mexico pays dividends on shares during the eight year period, the participants will be entitled to receive the dividend in cash for all shares that have been fully purchased and paid as of the date that the dividend is paid. If the participant has only partially paid for shares, the entitled dividends will be used to reduce the remaining liability owed for purchased shares. In the case of voluntary resignation of the employee, the Company will pay to the employee the fair market sales price at the date of resignation of the fully paid shares, net of costs and taxes. When the fair market sales value of the shares is higher than the purchase price, the Company will apply a deduction over the amount to be paid to the employee based on the following schedule: % Deducted If the resignation occurs during: 1st year after the grant date 90 % 2nd year after the grant date 80 % 3rd year after the grant date 70 % 4th year after the grant date 60 % 5th year after the grant date 50 % 6th year after the grant date 40 % 7th year after the grant date 20 % In the case of involuntary termination of the employee, the Company will pay to the employee the fair market sales price at the date of termination of employment of the fully paid shares, net of costs and taxes. When the fair market sales value of the shares is higher than the purchase price, the Company will apply a deduction over the amount to be paid to the employee based on the following schedule: % Deducted If the resignation occurs during: 1st year after the grant date 100 % 2nd year after the grant date 95 % 3rd year after the grant date 90 % 4th year after the grant date 80 % 5th year after the grant date 70 % 6th year after the grant date 60 % 7th year after the grant date 50 % In case of retirement or death of the employee, the Company will render the buyer or his legal beneficiary, the fair market sales value as of the date of retirement or death of the shares effectively paid, net of costs and taxes. The stock based compensation expense for the year ended December 31, 2018 and the unrecognized compensation expense under this plan were as follows (in millions): 2018 Stock based compensation expense $ — Unrecognized compensation expense $ 3.6 The following table presents the stock award activity of this plan for the year ended December 31, 2018: Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 — — Granted 2,782,424 1.86 Exercised — — Forfeited — — Outstanding shares at December 31, 2018 2,782,424 1.86 Executive Stock Purchase Plan: Grupo Mexico also offers a stock purchase plan for certain members of its executive management and the executive management of its subsidiaries and certain affiliated companies. Under this plan, participants will receive incentive cash bonuses which are used to purchase shares of Grupo Mexico which are deposited in a trust. Non-controlling interest: For all the years presented, in the consolidated statement of earnings the income attributable to non-controlling interest is based on the earnings of the Company's Peruvian Branch. The non-controlling interest of the Company’s Peruvian Branch is for investment shares. These shares were generated by legislation in place in Peru from the 1970s through 1991; such legislation provided for the participation of mining workers in the profits of the enterprises for which they worked. This participation was divided between equity and cash. The investment shares included in the non-controlling interest on the consolidated balance sheets are the still outstanding equity distributions made to the Peruvian Branch’s employees. In prior years, the Company acquired some Peruvian investment shares in exchange for newly issued common shares of the Company and through purchases at market value. These acquisitions were accounted for as purchases of non-controlling interests. The excess paid over the carrying value was assigned to intangible assets and is being amortized based on production. As a result of these acquisitions, the remaining investment shareholders hold a 0.71% interest in the Peruvian Branch and are entitled to a pro rata participation in the cash distributions made by the Peruvian Branch. The shares are recorded as a non-controlling interest in the Company's financial statements.

FAIR VALUE MEASUREMENT_

FAIR VALUE MEASUREMENT:	12 Months Ended
	Dec. 31, 2018
FINANCIAL INSTRUMENTS:
FAIR VALUE MEASUREMENT:	NOTE 14- FAIR VALUE MEASUREMENT: Subtopic 820-10 of ASC “Fair value measurement and disclosures -Overall” establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under Subtopic 820-10 are described below: Level 1 -Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 -Inputs that are observable, either directly or indirectly, but do not qualify as Level 1 inputs. (i.e., quoted prices for similar assets or liabilities). Level 3 -Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). The carrying amounts of certain financial instruments, including cash and cash equivalents, accounts receivable (other than accounts receivable associated with provisionally priced sales) and accounts payable approximate fair value due to their short maturities. Consequently, such financial instruments are not included in the following table that provides information about the carrying amounts and estimated fair values of other financial instruments that are not measured at fair value in the consolidated balance sheet as of December 31, 2018 and December 31, 2017 (in millions): At December 31, 2018 At December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value Liabilities: Long-term debt level 1 5,210.7 5,540.0 5,208.4 6,488.9 Long-term debt level 2 749.4 761.7 748.7 806.1 Total long-term debt $ 5,960.1 $ 6,301.7 $ 5,957.1 $ 7,295.0 Long-term debt is carried at amortized cost and its estimated fair value is based on quoted market prices classified as Level 1 in the fair value hierarchy except for the cases of the Yankee bonds, the notes due 2020 and the notes due 2022, which qualify as Level 2 in the fair value hierarchy as they are based on quoted priced in market that are not active. Fair values of assets and liabilities measured at fair value on a recurring basis were calculated as of December 31, 2018 and 2017, as follows (in millions): Fair Value at Measurement Date Using: Significant Fair Value Quoted prices in other Significant as of active markets for observable unobservable December 31, identical assets inputs inputs Description 2018 (Level 1) (Level 2) (Level 3) Assets: Short term investment: — Trading securities $ 213.1 $ 213.1 $ — $ — — Available-for-sale debt securities: Corporate bonds — — — — Asset backed securities 0.4 — 0.4 — Mortgage backed securities 0.3 — 0.3 — Accounts receivable: — Embedded derivatives — Not classified as hedges: Provisionally priced sales: Copper 274.3 274.3 — — Molybdenum 107.4 107.4 — — Total $ 595.5 $ 594.8 $ 0.7 $ — Fair Value at Measurement Date Using: Significant Fair Value Quoted prices in other Significant as of active markets for observable unobservable December 31, identical assets inputs inputs Description 2017 (Level 1) (Level 2) (Level 3) Assets: Short term investment: — Trading securities $ 49.5 $ 49.5 $ — $ — — Available-for-sale debt securities: Corporate bonds 0.1 — 0.1 — Asset backed securities 0.5 — 0.5 — Mortgage backed securities 0.4 — 0.4 — Accounts receivable: — Embedded derivatives-Not classified as hedges: Provisionally priced sales: Copper 184.6 184.6 — — Molybdenum 102.8 102.8 — — Total $ 337.9 $ 336.9 $ 1.0 $ — The Company’s short-term trading securities investments are classified as Level 1 because they are valued using quoted prices of the same securities as they consist of bonds issued by public companies and publicly traded. The Company’s short-term available-for-sale investments are classified as Level 2 because they are valued using quoted prices for similar investments. The Company’s accounts receivables associated with provisionally priced copper sales are valued using quoted market prices based on the forward price on the LME or on the COMEX. Such value is classified within Level 1 of the fair value hierarchy. Molybdenum prices are established by reference to the publication Platt’s Metals Week and are considered Level 1 in the fair value hierarchy.

CONCENTRATION OF RISK_

CONCENTRATION OF RISK:	12 Months Ended
	Dec. 31, 2018
CONCENTRATION OF RISK:
CONCENTRATION OF RISK:	NOTE 15-CONCENTRATION OF RISK: The Company operates four open-pit copper mines, five underground poly-metallic mines, two smelters and ten refineries in Peru and Mexico and substantially all of its assets are located in these countries. There can be no assurances that the Company’s operations and assets that are subject to the jurisdiction of the governments of Peru and Mexico will not be adversely affected by future actions of such governments. Much of the Company’s products are exported from Peru and Mexico to customers principally in the United States, Europe, Asia and South America. Financial instruments, which potentially subject the Company to a concentration of credit risk, consist primarily of cash and cash equivalents, short-term investments and trade accounts receivable. The Company invests or maintains available cash with various banks, principally in the United States, Mexico, Europe and Peru, or in commercial papers of highly-rated companies. As part of its cash management process, the Company regularly monitors the relative credit standing of these institutions. At December 31, 2018, SCC had invested its cash and cash equivalents and short-term investments as follows: $ in % of total % in one institution Country million cash (1) of country of total cash United States $ 697.1 65.9 % 27.7 % 18.3 % Switzerland 315.7 29.8 % 61.2 % 18.3 % Peru 7.6 0.7 % 75.6 % 0.5 % Mexico 38.0 3.6 % 89.3 % 3.2 % Total cash and short-term investment $ 1,058.4 100.0 % (1) 95.8% of the Company’s cash is in U.S. dollars. During the normal course of business, the Company provides credit to its customers. Although the receivables resulting from these transactions are not collateralized, the Company has not experienced significant problems with the collection of receivables. The Company is exposed to credit loss in cases where the financial institutions with which it has entered into derivative transactions (commodity, foreign exchange and currency/interest rate swaps) are unable to pay when they owe funds as a result of protection agreements with them. To minimize the risk of such losses, the Company only uses highly-rated financial institutions that meet certain requirements. The Company also periodically reviews the creditworthiness of these institutions to ensure that they are maintaining their ratings. The Company does not anticipate that any of the financial institutions will default on their obligations. The Company’s largest customers as percentage of accounts receivable and total sales were as follows: 2018 2017 2016 Accounts receivable trade as of December 31, Five largest customers 34.2 % 28.4 % 31.1 % Largest customer 10.9 % 8.2 % 11.9 % Total sales in year Five largest customers 28.4 % 25.1 % 30.4 % Largest customer 9.3 % 8.8 % 8.4 %

RELATED PARTY TRANSACTIONS_

RELATED PARTY TRANSACTIONS:	12 Months Ended
	Dec. 31, 2018
RELATED PARTY TRANSACTIONS:
RELATED PARTY TRANSACTIONS:	NOTE 16-RELATED PARTY TRANSACTIONS: The Company has entered into certain transactions in the ordinary course of business with parties that are controlling shareholders or their affiliates. These transactions include the lease of office space, air transportation, construction services and products and services related to mining and refining. The Company lends and borrows funds among affiliates for acquisitions and other corporate purposes. These financial transactions bear interest and are subject to review and approval by senior management, as are all related party transactions. It is the Company’s policy that the Audit Committee of the Board of Directors shall review all related party transactions. The Company is prohibited from entering or continuing a material related party transaction that has not been reviewed and approved or ratified by the Audit Committee. Receivable and payable balances with related parties are shown below (in millions): At December 31, 2018 2017 Related parties receivable current: Grupo Mexico and affiliates: Asarco LLC $ 74.4 4.1 Americas Mining Corporation (“AMC”) 11.0 — AMMINCO Apoyo Administrativo, S.A. de C.V. (“AMMINCO”) 0.2 — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates 1.4 1.4 Ferrocarril Mexicano, S.A. de C.V. 0.1 — Grupo Mexico 2.7 2.8 Mexico Generadora de Energia S. de R.L. ("MGE") 10.3 $ 16.2 Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates 0.6 1.1 Related to the controlling group: Boutique Bowling de Mexico S.A. de C.V. 0.3 0.2 Mexico Transportes Aereos, S.A. de C.V. ("Mextransport") 0.1 — Operadora de Cinemas S.A. de C.V. 0.4 0.3 $ 101.5 $ 26.1 Related parties payable: Grupo Mexico and affiliates: Asarco LLC $ 4.1 $ 24.2 AMMINCO 8.0 — Eolica El Retiro, S.A.P.I. de C.V. 1.0 0.8 Ferrocarril Mexicano S.A. de C.V. 6.4 2.6 Grupo Mexico 0.6 0.7 MGE 40.6 38.5 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates 14.4 21.7 Related to the controlling group: Boutique Bowling de Mexico S.A. de C.V. 0.1 0.6 Mexico Transportes Aereos S.A. de C.V. (“Mextransport”) — 0.3 Operadora de Cinemas S.A. de C.V. 0.1 0.7 $ 75.3 $ 90.1 Purchase and sale activity: Grupo Mexico and affiliates: The following table summarizes the purchase and sale activities with Grupo Mexico and its affiliates in 2018, 2017 and 2016 (in millions): 2018 2017 2016 Purchase activity Asarco LLC $ 37.2 $ 37.2 $ 30.3 AMMINCO 8.0 — — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates — — 0.3 Eolica El Retiro, S.A.P.I. de C.V. 3.6 3.3 2.0 Ferrocarril Mexicano, S.A. de C.V. 41.7 43.5 42.7 Grupo Mexico 10.1 14.0 13.8 MGE 200.1 223.7 233.8 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates 79.8 152.9 76.0 Total purchases $ 380.5 $ 474.6 $ 398.9 Sales activity Asarco LLC $ 81.8 $ 96.2 $ 37.1 AMMINCO 0.3 — — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates — 0.2 0.6 Grupo Mexico — 0.2 0.6 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates — — 0.4 Operadora de Generadoras de Energia Mexico S.A. de C.V — — 0.1 MGE 68.2 101.0 95.9 Total sales $ 150.3 $ 197.6 $ 134.7 Grupo Mexico, the parent and the majority indirect stockholder of the Company, and its affiliates provide various services to the Company. These services are primarily related to accounting, legal, tax, financial, treasury, human resources, price risk assessment and hedging, purchasing, procurement and logistics, sales and administrative and other support services. In 2018, AMMINCO, a subsidiary of Grupo Mexico, began providing these services for the Company's Peruvian operations. The Company pays Grupo Mexico and AMMINCO for these services and expects to continue these services in the future. The Company sold vehicles to AMMINCO. In 2018, the Company donated $6.2 million to Fundacion Grupo Mexico,A.C., an organization dedicated to promoting the social and economic development of the communities close to the Company’s Mexican operations. In addition, in December 2018, the Company´s Peruvian operations advanced $11 million to AMC for the payment of the Company's GILTI tax which later was determined not to be due. The Company’s Mexican operations paid fees for freight services provided by Ferrocarril Mexicano, S.A de C.V., for construction services provided by Mexico Proyectos y Desarrollos, S.A. de C.V. and its affiliates, and for drilling services provided by Compañia Perforadora Mexico S.A.P.I. de C.V. All of these companies are subsidiaries of Grupo Mexico. The Company’s Mexican operations purchased scrap and other residual copper mineral from Asarco, and power from MGE. Both companies are subsidiaries of Grupo Mexico. In 2005, the Company organized MGE, as a subsidiary of Minera Mexico, for the construction of two power plants to supply power to the Company’s Mexican operations. In May 2010, the Company’s Mexican operations granted a $350 million line of credit to MGE for the construction of the power plants. That line of credit was due on December 31, 2012 and carried an interest rate of 4.4%. In the first quarter of 2012, an indirect subsidiary of Grupo Mexico, acquired 99.999% of MGE through a capital subscription of 1,928.6 million of Mexican pesos (approximately $150 million), reducing Minera Mexico’s participation to less than 0.001%. As consequence of this change in control, MGE became an indirect subsidiary of Grupo Mexico. Additionally, at the same time, MGE paid $150 million to the Company’s Mexican operations, partially reducing the total debt. The remaining balance was repaid in the third quarter of 2016. Related to this loan, the Company recorded interest income of $4.2 million in 2016. In 2012, the Company signed a power purchase agreement with MGE, whereby MGE will supply some of the Company’s Mexican operations with power through 2032. MGE has two natural gas-fired combined cycle power generating units, with a net total capacity of 516.2 megawatts and has been supplying power to the Company since December 2013. Currently, MGE is supplying 17.1% of its power output to third-party energy users; compared to 14% at December 31, 2017. In 2014, Mexico Generadora de Energia Eolica, S. de R.L. de C.V, an indirect subsidiary of Grupo Mexico, located in Oaxaca, Mexico, acquired Eolica el Retiro, a windfarm with 37 wind turbines. This company started operations in January 2014 and started to sell power to Industrial Minera Mexico, S.A. de C.V. and subsidiaries (IMMSA) and other subsidiaries of Grupo Mexico in the third quarter of 2014. Currently, Eolica el Retiro is supplying approximately 18% of its power output to IMMSA; compared to 27% at December 31, 2017. The Company sold copper cathodes, rod and anodes, as well as sulfuric acid, silver, gold and lime to Asarco. In addition, the Company received fees for building rental and maintenance services provided to Mexico Proyectos y Desarrollos, S.A. de C.V. and its affiliates and to Perforadora Mexico S.A.P.I de C.V., and for natural gas and services provided by MGE, all subsidiaries of Grupo Mexico. Companies with relationships with the controlling group: The following table summarizes the purchase and sales activities with other Larrea family companies in 2018, 2017 and 2016 (in millions): 2018 2017 2016 Purchase activity Boutique Bowling de Mexico S.A. de C.V. $ 0.3 $ 0.3 $ 0.4 Mextransport 12.4 1.3 2.0 Operadora de Cinemas S.A. de C.V. 0.2 0.1 0.5 Total purchases $ 12.9 $ 1.7 $ 2.9 Sales activity Boutique Bowling de Mexico S.A. de C.V. $ 0.2 $ 0.2 $ 0.2 Mextransport 1.2 0.3 0.2 Operadora de Cinemas S.A. de C.V. 0.1 0.2 0.1 Total sales $ 1.5 $ 0.7 $ 0.5 The Larrea family controls a majority of the capital stock of Grupo Mexico, and has extensive interests in other businesses, including transportation, real estate and entertainment. The Company engages in certain transactions in the ordinary course of business with other entities controlled by the Larrea family relating to the lease of office space, air transportation and entertainment. The Company’s Mexican operations paid fees for entertainment services provided by Boutique Bowling de Mexico S.A de C.V. and Operadora de Cinemas S.A. de C.V. Both companies are controlled by the Larrea family. MexTransport provides aviation services to the Company’s Mexican operations. In addition, the Company received fees for building rental provided to Mextransport. This is a company controlled by the Larrea family. In addition, the Company received fees for building rental and maintenance services provided to Boutique Bowling de Mexico S.A de C.V. and Operadora de Cinemas S.A. de C.V. Equity Investment in Affiliate: The Company has a 44.2% participation in Compañia Minera Coimolache S.A. (“Coimolache”), which it accounts for on the equity method. Coimolache owns Tantahuatay, a gold mine located in northern Peru. It is anticipated that in the future the Company will enter into similar transactions with these same parties. Companies with relationships with SCC executive officers: In 2018, the Company did not have purchase activities with companies having relationships with SCC executive officers. In 2017 and 2016, the Company purchased industrial material from these companies amounting to $0.2 million and $2.0 million, respectively. It is anticipated that in the future the Company will not enter into similar transactions with these same parties. Tax Agreement: On February 28, 2017, AMC and the Company entered into a tax agreement, effective as of February 20, 2017, pursuant to which AMC, as the parent of the consolidated group of which the Company is a member and joins in the filing of a U.S. federal income tax return, (a) will be responsible for and discharge, any and all liabilities and payments due to the IRS on account of any incremental tax liabilities of the Company in connection with the potential adjustments being considered by the IRS in connection with the interest of the 2012 Judgment, (b) will not seek reimbursement, contribution or collection of any amounts of money or any other asset in connection therewith from the Company, and (c) will indemnify, defend and hold harmless the Company from any such liability, including the cost of such defense.

SEGMENT AND RELATED INFORMATION

SEGMENT AND RELATED INFORMATION:	12 Months Ended
	Dec. 31, 2018
SEGMENT AND RELATED INFORMATION:
SEGMENT AND RELATED INFORMATION:	NOTE 17-SEGMENT AND RELATED INFORMATION: Company management views Southern Copper as having three reportable segments and manages it on the basis of these segments. The reportable segments identified by the Company are: the Peruvian operations, the Mexican open-pit operations and the Mexican underground mining operations segment identified as the IMMSA unit. The three reportable segments identified are groups of mines, each of which constitute an operating segment, with similar economic characteristics, type of products, processes and support facilities, similar regulatory environments, similar employee bargaining contracts and similar currency risks. In addition, each mine within the individual group earns revenues from similar type of customers for their products and services and each group incurs expenses independently, including commercial transactions between groups. Intersegment sales are based on arm’s length prices at the time of sale. These may not be reflective of actual prices realized by the Company due to various factors, including additional processing, timing of sales to outside customers and transportation cost. Added to the segment data is information regarding the Company’s sales. The segments identified by the Company are: 1. Peruvian operations, which include the Toquepala and Cuajone mine complexes and the smelting and refining plants, including a precious metals plant, industrial railroad and port facilities that service both mines. The Peruvian operations produce copper, with production of by-products of molybdenum, silver and other material. 2. Mexican open-pit operations, which include La Caridad and Buenavista mine complexes and the smelting and refining plants, including a precious metals plant and a copper rod plant and support facilities that service both mines. The Mexican open-pit operations produce copper, with production of by-products of molybdenum, silver and other material. 3. Mexican underground mining operations, which include five underground mines that produce zinc, copper, silver and gold, a coal mine which produces coal and coke, and a zinc refinery. This group is identified as the IMMSA unit. The Peruvian operations include two open-pit copper mines whose mineral output is transported by rail to Ilo, Peru where it is processed at the Company’s Ilo smelter and refinery, without distinguishing between the products of the two mines. The resulting product, anodes and refined copper, are then shipped to customers throughout the world. These shipments are recorded as revenue of the Company’s Peruvian mines. The Mexican open-pit segment includes two copper mines whose mineral output is processed in the same smelter and refinery without distinguishing between the products of the two mines. The resultant product, anodes and refined copper, are then shipped to customers throughout the world. These shipments are recorded as revenues of the Company’s Mexican open-pit mines. The Company has determined that it is necessary to classify the Peruvian open-pit operations as a separate operating segment from the Mexican open-pit operations due to the very distinct regulatory and political environments in which they operate. The Company’s senior management must consider the operations in each country separately when analyzing results of the Company and making key decisions. The open-pit mines in Peru must comply with stricter environmental rules and must continually deal with a political climate that has a very distinct vision of the mining industry as compared to Mexico. In addition, the collective bargaining agreement contracts are negotiated differently in each of the countries. These key differences result in the Company taking varying decisions with regards to open-pit operations in the two countries. The IMMSA segment includes five mines whose minerals are processed in the same refinery. This segment also includes an underground coal mine. Sales of product from this segment are recorded as revenues of the Company’s IMMSA unit. While the Mexican underground mines are subject to a very similar regulatory environment of the Mexican open-pit mines, the nature of the products and processes of two Mexican operations vary distinctly. These differences cause the Company’s senior management to take a very different approach when analyzing results and making decisions regarding the two Mexican operations. Financial information is regularly prepared for each of the three segments and the results of the Company’s operations are regularly reported to senior management on the segment basis. Senior management of the Company focus on operating income and on total assets as measures of performance to evaluate different segments and to make decisions to allocate resources to the reported segments. These are common measures in the mining industry. Financial information relating to Company’s segments is as follows: Year Ended December 31, 2018 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 4,075.9 $ 448.6 $ 2,572.2 $ — $ 7,096.7 Intersegment sales — 79.3 — (79.3) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,611.0 377.2 1,509.4 (88.6) 3,409.0 Selling, general and administrative 55.3 8.5 36.7 2.1 102.6 Depreciation, amortization and depletion 360.4 47.6 237.4 28.9 674.3 Exploration 2.0 5.3 18.5 3.8 29.6 Operating income $ 2,047.2 $ 89.3 $ 770.2 $ (25.5) 2,881.2 Less: Interest, net (261.1) Other income (expense) (30.7) Income taxes (1,053.5) Equity earnings of affiliate 12.3 Non-controlling interest (5.2) Net income attributable to SCC $ 1,543.0 Capital investment $ 266.8 $ 60.0 $ 774.0 $ 20.6 $ 1,121.4 Property and mine development, net $ 4,783.8 $ 448.3 $ 3,797.2 $ 374.5 $ 9,403.8 Total assets $ 8,165.2 $ 930.2 $ 4,813.1 $ 576.3 $ 14,484.8 Year Ended December 31, 2017 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 3,972.7 $ 437.7 $ 2,244.1 $ — $ 6,654.5 Intersegment sales — 71.0 — (71.0) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,594.3 365.3 1,362.8 (69.6) 3,252.8 Selling, general and administrative 47.9 7.9 36.2 1.1 93.1 Depreciation, amortization and depletion 401.0 56.2 203.6 10.3 671.1 Exploration 2.7 5.5 14.4 6.2 28.8 Environmental remediation (10.2) — — — (10.2) Operating income $ 1,937.0 $ 73.8 $ 627.1 $ (19.0) 2,618.9 Less: Interest, net (300.5) Other income (expense) (15.7) Income taxes (1,593.4) Equity earnings of affiliate 23.1 Non-controlling interest (3.9) Net income attributable to SCC $ 728.5 Capital investment $ 297.6 $ 36.5 $ 685.4 $ 4.0 $ 1,023.5 Property and mine development, net $ 5,004.5 $ 366.9 $ 3,389.8 $ 338.4 $ 9,099.6 Total assets $ 8,323.1 $ 889.1 $ 4,314.5 $ 253.4 $ 13,780.1 Year Ended December 31, 2016 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 3,234.3 $ 351.1 $ 1,794.4 $ — $ 5,379.8 Intersegment sales — 72.0 — (72.0) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,523.2 304.1 1,280.2 (73.4) 3,034.1 Selling, general and administrative 47.1 7.4 37.5 2.3 94.3 Depreciation, amortization and depletion 364.7 49.8 217.1 15.5 647.1 Exploration 5.2 5.0 13.0 16.9 40.1 Operating income $ 1,294.1 $ 56.8 $ 246.6 $ (33.3) 1,564.2 Less: Interest, net (283.6) Other income (expense) (24.6) Income taxes (501.1) Equity earnings of affiliate 23.9 Non-controlling interest (2.3) Net income attributable to SCC $ 776.5 Capital investment $ 537.0 $ 35.8 $ 541.0 $ 4.7 $ 1,118.5 Property and mine development, net $ 5,136.8 $ 448.7 $ 2,949.3 $ 231.7 $ 8,766.5 Total assets $ $ 825.0 $ 4,225.3 $ 9.6 $ 13,234.3 The following table presents information regarding the opening and closing balances of receivables by reporting segment of the Company for the three years ended December 31, 2018 (in millions): Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated As of December 31, 2018: Trade receivables $ 505.9 $ 50.5 $ 266.0 $ — $ 822.4 Related parties 81.6 — — 19.9 101.5 As of December 31, 2017: Trade receivables $ 556.2 $ 79.7 $ 254.7 $ — $ 890.6 Related parties 18.0 — — 8.1 26.1 As of December 31, 2016: Trade receivables $ 365.2 $ 47.1 $ 179.6 $ — $ 591.9 Related parties 12.9 — — 10.5 23.4 SALES VALUE PER SEGMENT: The following table presents information regarding the sales value by reporting segment of the Company’s significant products for the three years ended December 31, 2018 (in millions): Year Ended December 31, 2018 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 3,459.1 $ 45.6 $ 2,251.2 $ (48.1) $ 5,707.8 Molybdenum 342.5 — 167.4 — 509.9 Silver 175.3 83.5 69.5 (28.1) 300.2 Zinc — 328.7 — (0.1) 328.6 Other 99.0 70.1 84.1 (3.0) 250.2 Total $ 4,075.9 $ 527.9 $ 2,572.2 $ (79.3) $ 7,096.7 Year Ended December 31, 2017 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 3,480.2 $ 37.2 $ 1,996.4 $ (37.3) $ 5,476.5 Molybdenum 224.0 — 129.4 — 353.4 Silver 170.7 71.9 70.6 (26.9) 286.3 Zinc — 327.2 — (0.6) 326.6 Other 97.8 73.2 47.7 (7.0) 211.7 Total $ 3,972.7 $ 509.5 $ 2,244.1 $ (71.8) $ 6,654.5 Year Ended December 31, 2016 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 2,663.1 $ 32.0 $ 1,557.7 $ (32.0) $ 4,220.8 Molybdenum 144.0 — 124.0 — 268.0 Silver 182.3 82.1 61.5 (31.6) 294.3 Zinc — 234.4 — — 234.4 Other 244.9 74.6 51.2 (8.4) 362.3 Total $ 3,234.3 $ 423.1 $ 1,794.4 $ (72.0) $ 5,379.8 NET SALES AND GEOGRAPHICAL INFORMATION: The geographic breakdown of the Company’s sales for the three years ended December 31, 2018 was as follows (in millions): Year Ended December 31, 2018 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,343.0 $ 385.6 $ — $ (79.3) $ 1,649.3 United States 1,008.0 6.6 244.0 — 1,258.6 Peru — — 390.4 — 390.4 Brazil — 43.8 228.1 — 271.9 Chile — — 136.3 — 136.3 Other American countries 60.6 3.8 1.4 — 65.8 Europe: Switzerland 453.3 43.4 156.7 — 653.4 Italy 20.6 21.7 305.0 — 347.3 Spain 169.4 — — — 169.4 Other European countries 234.8 19.9 124.9 — 379.6 Asia: Singapore 528.8 2.2 538.2 — 1,069.2 Japan 71.8 — 411.6 — 483.4 Other Asian countries 185.6 0.9 35.6 — 222.1 Total $ 4,075.9 $ 527.9 $ 2,572.2 $ (79.3) $ 7,096.7 Year Ended December 31, 2017 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,240.0 $ 349.1 $ 6.6 $ (71.8) $ 1,523.9 United States 1,001.2 41.7 147.4 — 1,190.3 Peru — 0.8 373.4 — 374.2 Brazil — 48.7 191.4 — 240.1 Chile — — 103.4 — 103.4 Other American countries 68.1 4.1 19.3 — 91.5 Europe: Switzerland 473.1 14.3 114.9 — 602.3 Italy 27.7 18.6 286.1 — 332.4 Spain 142.8 — — — 142.8 Other European countries 230.3 30.3 76.6 — 337.2 Asia: Singapore 547.9 1.4 502.0 — 1,051.3 Japan 93.0 — 386.6 — 479.6 Other Asian countries 148.6 0.5 36.4 — 185.5 Total $ 3,972.7 $ 509.5 $ 2,244.1 $ (71.8) $ 6,654.5 Year Ended December 31, 2016 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,184.8 $ 296.9 $ — $ (72.0) $ 1,409.7 United States 933.6 49.5 66.9 — 1,050.0 Peru — — 294.4 — 294.4 Brazil — 26.1 170.0 — 196.1 Chile — — 92.4 — 92.4 Other American countries 52.9 2.6 18.8 — 74.3 Europe: Switzerland 245.9 9.4 182.0 — 437.3 Italy 20.9 17.2 266.4 — 304.5 Spain 71.2 — — — 71.2 Other European countries 127.0 20.8 54.0 — 201.8 Asia: Singapore 471.9 — 180.9 — 652.8 Japan 49.2 — 360.6 — 409.8 Other Asian countries 76.9 0.6 108.0 — 185.5 Total $ 3,234.3 $ 423.1 $ 1,794.4 $ (72.0) $ 5,379.8 PROVISIONAL SALES PRICE: At December 31, 2018, the Company has recorded provisionally priced sales of copper at average forward prices per pound, and molybdenum at the year-end market price per pound. These sales are subject to final pricing based on the average monthly copper prices on the London Metal Exchange (“LME”) or New York Commodities Exchange (“COMEX”) and Dealer Oxide molybdenum prices in the future month of settlement. Following are the provisionally priced copper and molybdenum sales outstanding at December 31, 2017: Sales volume Priced at (million lbs.) (per pound) Month of settlement Copper 102.4 2.68 January through March 2019 Molybdenum 9.0 11.88 January through March 2019 Provisional sales price adjustments included in accounts receivable and net sales were as follows at December, 31 (in millions): At December 31, 2018 2017 Copper $ (7.6) $ 8.3 Molybdenum (2.4) 14.6 Total $ (10.0) $ 22.9 Management believes that the final pricing of these sales will not have a material effect on the Company’s financial position or results of operations. LONG-TERM SALES CONTRACTS: The following are the significant outstanding long-term contracts: In 2013, a five year copper cathodes sales agreement was signed with Mitsui, with shipments beginning in 2015. Mitsui and the Company will negotiate market terms and conditions for annual contracts no later than November 30 of the year prior to shipment. The contract considers the following annual volumes of copper cathodes; 6,000 tons for 2015 and 48,000 tons for each of the years from 2016 through 2019. The contract volume would increase by 24,000 tons the year after Tia Maria reaches full production capacity. Failure to reach an agreement on market terms would cancel the annual contract but not the long-term agreement. Under the terms of the agreement all shipments would be to Asia and there are no exclusivity rights for Mitsui or commissions included. This contract may be renewed for additional years, upon the agreement of both parties. Under the terms of a sales contract with Molymet Group (Molibdenos y Metales, S.A. and Sadaci N.V.), SPCC Peru Branch is required to supply approximately 70% of the molybdenum concentrates production from 2019 through 2022. The roasting charge deduction is agreed based on international market terms. Under the terms of a sales contract with Molymex, S.A. de C.V., Operadora de Minas de Nacozari, S.A. de C.V. and Operadora de Minas e Instalaciones Mineras, S.A. de C. V. are required to supply at least the 80% of their molybdenum concentrates production from 2016 through 2019. The sale price of the molybdenum concentrate is based on the monthly average of the high and low Metals Week Dealer Oxide quotation. The roasting charge deduction is negotiated based on international market terms.

QUARTERLY DATA (unaudited)

QUARTERLY DATA (unaudited)	12 Months Ended
	Dec. 31, 2018
QUARTERLY DATA (unaudited)
QUARTERLY DATA (unaudited)	NOTE 18-QUARTERLY DATA (unaudited) 2018 (in millions, except per share data) 1 st 2 nd 3 rd 4 th Year Net sales $ 1,841.1 $ 1,837.2 $ 1,723.7 $ 1,694.7 $ 7,096.7 Gross profit (1) $ 802.6 $ 822.9 $ 729.1 $ 658.8 $ 3,013.4 Operating income $ 773.3 $ 787.6 $ 696.7 $ 623.6 $ 2,881.2 Net income $ 471.9 $ 411.1 $ 370.7 $ 294.5 $ 1,548.2 Net income attributable to SCC $ 470.7 $ 409.6 $ 369.4 $ 293.3 $ 1,543.0 Per share amounts attributable to SCC: Net earnings basic and diluted $ 0.61 $ 0.53 $ 0.48 $ 0.38 $ 2.00 Dividend per share $ 0.30 $ 0.30 $ 0.40 $ 0.40 $ 1.40 2017 1 st 2 nd 3 rd 4 th Year Net sales $ 1,583.9 $ 1,529.8 $ 1,676.5 $ 1,864.3 $ 6,654.5 Gross profit (1) $ 586.7 $ 553.8 $ 725.7 $ 864.4 $ 2,730.6 Operating income $ 570.4 $ 525.9 $ 692.6 $ 830.0 $ 2,618.9 Net income (loss) $ 315.3 $ 300.5 $ 402.8 $ (286.2) $ 732.4 Net income (loss) attributable to SCC $ 314.4 $ 299.7 $ 401.8 $ (287.4) $ 728.5 Per share amounts attributable to SCC: Net earnings basic and diluted $ 0.41 $ 0.39 $ 0.52 $ (0.38) $ 0.94 Dividend per share $ 0.08 $ 0.12 $ 0.14 $ 0.25 $ 0.59 Gross profit is the result of net sales less cost of sales (excluding depreciation, amortization and depletion) and less depreciation, amortization and depletion.

SUBSEQUENT EVENTS_

SUBSEQUENT EVENTS:	12 Months Ended
	Dec. 31, 2018
SUBSEQUENT EVENTS:
SUBSEQUENT EVENTS:	NOTE 19-SUBSEQUENT EVENTS: DIVIDENDS: On January 24, 2019, the Board of Directors authorized a dividend of $0.40 per share paid on February 26, 2019, to shareholders of record at the close of business on February 12, 2019. In addition, as part of the settlement of claims brought on behalf of the Company and its shareholders against Grupo Mexico, AMC and certain current and former directors (together with Grupo Mexico and AMC, the "Defendants") a dividend of $0.44428 per share was paid on February 21, 2019 to shareholders of record at the close of business on February 11, 2019, other than the Defendants. The settlement dividend, totaling $36.5 million is an obligation of Grupo Mexico and AMC and therefore, have been funded by them. In addition Grupo Mexico and AMC paid $13.5 million of legal fees. For more information, please see "Litigation matters-Corporate operations" in Note 12 "Commitments and Contingencies" of this Item. NEW MEXICAN ENVIRONMENTAL TAX: On February 2019, the Mexican Supreme Court confirmed the constitutionality of an ecological tax to extractive activities developed in the state of Zacatecas, which taxes the environmental remediation actions, emissions of certain gases to the atmosphere, emissions of pollutant substances to the soil or water, and waste storage within the state territory. The Company is evaluating the potential impact of this new environmental regulation in its financial position.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts and Reserves	12 Months Ended
	Dec. 31, 2018
Schedule II Valuation and Qualifying Accounts and Reserves
Schedule II Valuation and Qualifying Accounts and Reserves	Schedule II Valuation and Qualifying Accounts and Reserves (in millions): Additions Balance at Charged to beginning of costs and Deduction/ Balance at period expenses Additions Application end of period Reserve deducted in balance sheet to which applicable: Accounts Receivable: 2018 $ 1.1 — — (0.6) $ 0.5 2017 $ 0.7 0.6 — 0.2 $ 1.1 2016 $ 0.9 — — 0.2 $ 0.7 Notes issued under par: 2018 $ 60.5 1.7 — — $ 58.8 2017 $ 62.2 1.7 — — $ 60.5 2016 $ 63.8 1.6 — — $ 62.2 Valuation allowance: 2018 $ 619.6 199.5 — — $ 819.1 2017 $ — — — $ 2016 $ — — — — $ —

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES: (Policies)	12 Months Ended
	Dec. 31, 2018
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:
Principles of consolidation	Principles of consolidation— The consolidated financial statements include the accounts of subsidiaries of which the Company has voting control, in accordance with Accounting Standards Codification (“ASC”) 810 Consolidation . Such financial statements are prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP").
Use of estimates	Use of estimates— The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include the carrying value of ore reserves that are the basis for future cash flow estimates and amortization calculations; environmental reclamation, closure and retirement obligations; estimates of recoverable copper in mill and leach stockpiles; asset impairments (including estimates of future cash flows); unrecognized tax benefits; valuation allowances for deferred tax assets; and fair value of financial instruments. Management bases its estimates on the Company's historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates.
Revenue recognition	Revenue recognition— The Company adopted ASC 606, Revenue from Contracts with Customers, effective January 1, 2018, on a modified retrospective basis, applying the standard to all contracts that are not completed as such date. The Company’s revenue consists of product revenue resulting from the sale of copper and non-copper products, such as molybdenum, silver, zinc, lead and gold. Other than increased disclosures, the adoption of the new guidance did not have an impact on the Company's revenue recognition. The Company accounts for a contract with a customer when there is a legally enforceable contract between the Company and the customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. The Company's revenues are measured based on consideration specified in the contract with each customer. Disclosures regarding disaggregation of revenues and contract balances are disclosed within Note 17 "Segment and related information". The Company’s marketing strategy and annual sales planning emphasize developing and maintaining long-term customer relationships. Generally, 80% to 90% of the Company’s metal production is sold under annual or longer-term contracts, which specify a volume of mineral to be sold over a stated period and delivery schedule; the price at which mineral will be sold at each delivery date is generally determined by the weekly or monthly average rate of the commodity published by major metal exchanges at specific dates stipulated within each contract. The Company considers each contract to be a single performance obligation, represented by the delivery of a series of distinct goods that are substantially the same, with the same pattern of transfer to the Company’s customers. The Company concluded this as, based on the nature of its contracts, customers receive the benefit of mineral sold as it is shipped per the terms of the contracts at each contractual delivery date. Likewise, each shipment of product represents the same measure of progress as other shipments within the contract. Accordingly, the Company recognizes revenues for each contract over the period of time in which the specified quantity of mineral is delivered. In doing so, the Company considers that it has a right to consideration from its customers in an amount that corresponds directly to the value transferred to those customers that being the quantity of mineral delivered at the price per unit delivered. Accordingly, the Company recognizes revenue at the amount to which it has the right to invoice (the invoice practical expedient), as it believes that this method is a faithful depiction of the transfer of goods to its customers. For contracts with a term greater than one year, the Company is unable to disclose an allocation of the transaction price to the remaining unsatisfied performance obligation, given that unit prices of mineral sold are determined by published commodity prices at specified dates within the contract. The volume of mineral to be delivered after the first year of the contract is subject to annual volume negotiations in accordance with the terms of the contract. As of December 31, 2018, the Company has long-term contracts with promises to deliver a total of 1,724,840 metric tons of mineral in 2019. This is an estimate that will vary in 2020 and 2021 based on the negotiations with the customers as mentioned above. The remainder of the Company’s revenues, including its by-product revenues, are generated by spot sales that are recognized at a point in time. Under both sales models, revenue is recognized when or as the performance obligations are satisfied, when the Company transfers control of the goods and title passes to the customer. Considering the International Commercial Terms (Incoterms) utilized by the Company, control is transferred generally upon the completion of loading the material at the point of origin. This is the point at which the customer obtains legal title to the product as well as the ability to direct the use of and obtain substantially all of the remaining benefits of ownership of the asset. Additionally, payment is generally due upon the delivery of the shipping and title documents at the point of origin, customers typically have 30 days to remit payment. Copper and non-copper revenues are measured based on the monthly average of prevailing commodity prices according to the terms of the contracts. The Company provides allowances for doubtful accounts based upon historical bad debt and claims experience and periodic evaluation of specific customer accounts. Substantially all of the Company’s sales are made under carriage and insurance paid to, or cost, insurance and freight Incoterms, whereby the Company is responsible for providing shipping and insurance after control of the inventory has been transferred to the customer. According to the terms of the Company’s contracts, these services are not distinct within the context of the contract, and they are not separately identifiable from the other promises within the contract. Additionally, it is the Company policy and it has a long-standing history of providing shipping and insurance services to its customers. Accordingly, shipping and insurance are not considered separate performance obligations. The related costs of shipping and insurance are presented within the cost of sales line in the accompanying consolidated statements of income. Furthermore, the Company considered the impact of the shipping and insurance services on the determination of when control is transferred to its customers. It has concluded that the terms of these services do not impact its customers’ ability to sell, pledge, or otherwise use the products in shipment. Also, there is a small likelihood and minimal history of lost or damaged goods during shipment. Considering these factors, combined with the other indicators of control previously mentioned, the Company has concluded that these services do not impact the determination that control is transferred at the point of origin. For certain of the Company’s sales of copper and molybdenum products, customer contracts allow for pricing based on a month subsequent to shipping, in most cases within the following three months and occasionally in some cases a few additional months. In such cases, revenue is recorded at a provisional price at the time of shipment. The provisionally priced copper sales are adjusted to reflect forward LME or COMEX copper prices at the end of each month until a final adjustment is made to the price of the shipments upon settlement with customers pursuant to the terms of the contract. In the case of molybdenum sales, for which there are no published forward prices, the provisionally priced sales are adjusted to reflect the market prices at the end of each month until a final adjustment is made to the price of the shipments upon settlement with customers pursuant to the terms of the contract. These provisional pricing arrangements are accounted for separately from the contract as an embedded derivative instrument under ASC 815-30 “Derivatives and Hedging—Cash Flow Hedges.” The Company sells copper in concentrate, anode, blister and refined form at industry standard commercial terms. Net sales include the invoiced value of copper, zinc, silver, molybdenum, sulfuric acid and other metals and the corresponding fair value adjustment of the related forward contract of copper and molybdenum. Disclosure regarding adjustments to sales for provisionally priced contracts is disclosed within Note 17 “Segment and related information”.
Cash and cash equivalents	Cash and cash equivalents— Cash and cash equivalents include bank deposits, certificates of deposit and short-term investment funds with original maturities of three months or less at the date of purchase. The carrying value of cash and cash equivalents approximates fair value.
Short-term investments	Short-term investments— The Company accounts for short-term investments in accordance with ASC 320-10 “Investments Debt and Equity Securities-Recognition.” The Company determines the appropriate classification of all short-term investments as held-to-maturity, available-for-sale or trading at the time of purchase and re-evaluates such classifications as of each balance sheet date. Unrealized gains and losses on available-for-sale investments, net of taxes, are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity, unless such loss is deemed to be other than temporary.
Inventories	Inventories— The Company principally produces copper and, in the production process, obtains several by-products, including molybdenum, silver, zinc, sulfuric acid and other metals. Metal inventories, consisting of work-in-process and finished goods, are carried at the lower of average cost or market. Costs of work-in-process inventories and finished goods mainly include power, labor, fuel, operating and repair materials, depreciation, amortization, depletion, and other necessary costs related to the extraction and processing of ore, including mining, milling, concentrating, smelting, refining, leaching and chemical processing. Costs incurred in the production of metal inventories exclude general and administrative costs. Once molybdenum, silver, zinc and other by-products are identified, they are transferred to their respective production facilities and the incremental cost required to complete production is assigned to their inventory value. Work-in-process inventories represent materials that are in the process of being converted into a saleable product. Conversion processes vary depending on the nature of the copper ore and the specific mining operation. For sulfide ores, processing includes milling and concentrating and results in the production of copper and molybdenum concentrates. Finished goods include saleable products (e.g., copper concentrates, copper anodes, copper cathodes, copper rod, molybdenum concentrate and other metallurgical products). Supplies inventories are carried at the lower of average cost or market.
Long-term inventory - Ore stockpiles on leach pads	Long-term inventory-Ore stockpiles on leach pads. The leaching process is an integral part of the mining operations carried out at the Company’s open-pit mines. The Company capitalizes the production cost of leachable material at its Toquepala, La Caridad and Buenavista mines recognizing it as inventory. This cost includes mining and haulage costs incurred to deliver ore to leach pads, depreciation, amortization, depletion and site overhead costs. The estimates of recoverable mineral content contained in the leaching dumps are supported by engineering studies. As the production cycle of the leaching process is significantly longer than the conventional process of concentrating, smelting and electrolytic refining, the Company includes on its balance sheet current leach inventory (included in work-in-process inventories) and long-term leach inventory. Amortization of leachable material is recorded by the units of production method.
Property	Property— Property is recorded at acquisition cost, net of accumulated depreciation and amortization. Cost includes major expenditures for improvements and replacements, which extend useful lives or increase capacity and interest costs associated with significant capital additions. Maintenance, repairs, normal development costs at existing mines and gains or losses on assets retired or sold are reflected in earnings as incurred. Buildings and equipment are depreciated on the straight-line method over estimated lives from five to 40 years or the estimated life of the mine if shorter.
Mine development	Mine development - Mine development includes primarily the cost of acquiring land rights to an exploitable ore body, pre-production stripping costs at new mines that are commercially exploitable, costs associated with bringing new mineral properties into production, and removal of overburden to prepare unique and identifiable areas outside the current mining area for such future production. Mine development costs are amortized on a unit of production basis over the remaining life of the mines. There is a diversity of practices in the mining industry in the treatment of drilling and other related costs to delineate new ore reserves. The Company follows the practices outlined in the next two paragraphs in its treatment of drilling and related costs. Drilling and other associated costs incurred in the Company's efforts to delineate new resources, whether near-mine or Greenfield are expensed as incurred. These costs are classified as mineral exploration costs. Once the Company determines through feasibility studies that proven and probable reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs. These mine development costs incurred prospectively to develop the property are capitalized as incurred, until the commencement of production, and are amortized using the units of production method over estimated life of the ore body. During the production stage, drilling and other related costs incurred to maintain production are included in production cost in the period in which they are incurred. Drilling and other related costs incurred in the Company’s efforts to delineate a major expansion of reserves at an existing production property are expensed as incurred. Once the Company determines through feasibility studies that proven and probable incremental reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs. These incremental mine development costs are capitalized as incurred, until the commencement of production and amortized using the units of production method over the estimated life of the ore body. A major expansion of reserves is one that increases total reserves at a property by approximately 10% or more. For the years ended December 31, 2018, 2017 and 2016, the Company did not capitalize any drilling and related costs.
Asset retirement obligations (reclamation and remediation costs)	Asset retirement obligations (reclamation and remediation costs)— The fair value of a liability for asset retirement obligations is recognized in the period in which the liability is incurred. The liability is measured at fair value and is adjusted to its present value in subsequent periods as accretion expense is recorded. The corresponding asset retirement costs are capitalized as part of the carrying value of the related long-lived assets and depreciated over the asset's useful life.
Intangible assets	Intangible assets— Intangible assets include primarily the excess amount paid over the book value for investment shares which are presented as mining concessions, and mining and engineering development studies. Intangible assets are carried at acquisition costs, net of accumulated amortization and are amortized principally on a unit of production basis over the estimated remaining life of the mines. Intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable.
Debt issuance costs	Debt issuance costs— Debt issuance costs related to a recognized debt liability are presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with the treatment of a debt discount.
Ore reserves	Ore reserves— The Company periodically reevaluates estimates of its ore reserves, which represent the Company’s estimate as to the amount of unmined copper remaining in its existing mine locations that can be produced and sold at a profit. Such estimates are based on engineering evaluations derived from samples of drill holes and other openings, combined with assumptions about copper market prices and production costs at each of the respective mines. The Company updates its estimate of ore reserves at the beginning of each year. In this calculation, the Company uses current metal prices which are defined as the average metal price over the preceding three years. The current price per pound of copper, as defined, was $2.64, $2.50 and $2.61 at the end of 2018, 2017 and 2016, respectively. The ore reserve estimates are used to determine the amortization of mine development and intangible assets. Once the Company determines through feasibility studies that proven and probable reserves exist and that the drilling and other associated costs embody a probable future benefit that involves a capacity, singly or in combination with other assets, to contribute directly or indirectly to future net cash inflow, then the costs are classified as mine development costs and the Company discloses the related ore reserves.
Exploration	Exploration— Tangible and intangible costs incurred in the search for mineral properties are charged against earnings when incurred.
Income taxes	Income taxes— Provisions for income taxes are based on taxes payable or refundable for the current year and deferred taxes on temporary differences between the amount of taxable income and pretax financial income and between the tax bases of assets and liabilities and their reported amounts in the financial statements. Deferred tax assets and liabilities are included in the financial statements at currently enacted income tax rates applicable to the period in which the deferred tax assets and liabilities are expected to be realized and settled as prescribed in ASC 740 “Income taxes.” As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through the provision for income taxes. Deferred income tax assets are reduced by any benefits that, in the opinion of management, are more likely not to be realized. The Company’s operations involve dealing with uncertainties and judgments in the application of complex tax regulations in multiple jurisdictions. The final taxes paid are dependent upon many factors, including negotiations with taxing authorities in various jurisdictions and resolution of disputes arising from federal, state, and international tax audits. The Company recognizes potential liabilities and records tax liabilities for anticipated tax audit issues in the U.S. and other tax jurisdictions based on its estimate of whether, and the extent to which, additional taxes will be due. The Company follows the guidance of ASC 740 “Income taxes” to record these liabilities. (See Note 7 “Income taxes” of the consolidated financial statements for additional information). The Company adjusts these reserves in light of changing facts and circumstances; however, due to the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from the Company’s current estimate of the tax liabilities. If its estimate of tax liabilities proves to be less than the ultimate assessment, an additional charge to expense would result. If payment of these amounts ultimately proves to be less than the recorded amounts, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company classifies income tax-related interest and penalties as income taxes in the financial statements, as well as interest and penalties, if any, related to unrecognized tax benefits. On December 22, 2017, the U.S. government enacted the “Tax Cuts and Jobs Act” (the “TCJA”). The TCJA contains numerous provisions, the following of which most significantly impact the Company: (i) a decrease in the corporate tax rate from 35% to 21%; (ii) a transition of the U.S. taxation of international operation from a worldwide system to a quasi-territorial system and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017, (iii) generally eliminates U.S. federal income taxes on dividends from foreign subsidiaries, requiring a current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations and (iv) limitations on the use of foreign tax credits to reduce the U.S. income tax liability. The U.S. Securities and Exchange Commission (“SEC”) issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provides guidance on accounting for the tax effects of the TCJA. The Company has adopted SAB 118. Accordingly, the provisions of the TCJA deemed most relevant to the Company were considered in preparation of its financial statements as of December 31, 2017 based on the Company’s best estimate, and the provisions of the TCJA were finalized in its financial statements as of December 31, 2018. See further disclosure regarding the impacts of the TCJA and the adoption of SAB 118 in Note 7 to the accompanying consolidated financial statements.
Foreign exchange	Foreign exchange— The Company’s functional currency is the U.S. dollar. As required by local law, both the Peruvian Branch and Minera Mexico maintain their books of accounts in Peruvian soles and Mexican pesos, respectively. Foreign currency assets and liabilities are remeasured into U.S. dollars at current exchange rates, except for non-monetary items such as inventory, property, intangible assets and other assets which are remeasured at historical exchange rates. Revenues and expenses are generally translated at actual exchange rates in effect during the period, except for those items related to balance sheet amounts that are remeasured at historical exchange rates. Gains and losses from foreign currency remeasurement are included in earnings of the period. Gains and (losses) resulting from foreign currency transactions are included in "Cost of sales (exclusive of depreciation, amortization and depletion)."
Asset impairments	Asset impairments - The Company evaluates long-term assets when events or changes in economic circumstances indicate that the carrying amount of such assets may not be recoverable. These evaluations are based on business plans that are prepared using a time horizon that is reflective of the Company’s expectations of metal prices over its business cycle. The Company is currently using a long-term average copper price and an average molybdenum price for impairment tests, reflective of what the Company believes is the lower level of the current price environment. The results of its impairment tests using these long-term copper and molybdenum prices show no impairment in the carrying value of their assets. In recent years testing using assumptions for long-term average prices have resulted in stricter evaluation for impairment analysis than would the higher three year average prices for copper and molybdenum prices. Should this situation reverse in the future with three year average prices below the long-term price assumption, the Company would assess the need to use the three year average prices in its evaluations. The Company uses an estimate of the future undiscounted net cash flows of the related asset or asset group over the remaining life to measure whether the assets are recoverable and measures any impairment by reference to fair value.
Other comprehensive income	Other comprehensive income— Comprehensive income represents changes in equity during a period, except those resulting from investments by owners and distributions to owners. During the fiscal years ended December 31, 2018, 2017 and 2016, the components of "other comprehensive income (loss)" were, the unrecognized gain (loss) on employee benefit obligations and foreign currency translation adjustments.
Business segments	Business segments- Company management views Southern Copper as having three reportable segments and manages it on the basis of these segments. The segments identified by the Company are: 1) the Peruvian operations, which include the two open-pit copper mines in Peru and the plants and services supporting such mines, 2) the Mexican open-pit copper mines, which include La Caridad and Buenavista mine complexes and their supporting facilities and 3) the Mexican underground mining operations, which include five underground mines that produce zinc, lead, copper, silver and gold, a coal mine and a zinc refinery. Please see Note 17 “Segments and Related Information.” Senior management of the Company focus on operating income as measure of performance to evaluate different segments, and to make decisions to allocate resources to the reported segments. This is a common measure in the mining industry.
ADOPTION OF LEASES STANDARD	ADOPTION OF LEASES STANDARD On February 25, 2016, the FASB issued ASU 2016-02 “Leases” (Topic 842). This update significantly modifies the accounting model of leases for lessees requiring them to recognize assets and liabilities in the balance sheet for virtually all leases. However, the classification of leases as finance leases or operating leases is maintained for lessees. In addition, for leases with a term of 12 months or less, a lessee can elect by class of underlying asset not to record assets and liabilities on the balance sheet, and recognize lease expense on a straight-line basis over the lease term. The lessor accounting model for leases remains mostly unchanged from previous guidance, except for specific profit recognition requirements which were modified in order to align them to the new revenue recognition standard issued by the FASB, and the lease classification criteria, to ensure consistency with those for a lessee. The amendments in this update were effective for the Company on January 1, 2019. During 2018, the Company developed an implementation plan with a cross-functional team, which performed a completeness assessment over the lease contracts of the Company, established new policies, procedures and internal controls related to the new standard. As result of it analysis, the Company has preliminarily concluded that substantially all of its existing lease contracts at December 31, 2018, will be classified as operating lease contracts. The Company elected the transition approach whereby it will apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, the financial statements for prior periods will not be modified. At the date of adoption, the Company preliminarily assessed that the adoption of the new leases standard will result in the recognition of right of use assets and lease obligations of approximately $1,115.9 million, which will be recorded in the Company’s balance sheet as of January 1, 2019. Additionally, the Company may elect the short-term lease recognition exemption (short-term lease practical expedient) by class of underlying asset (which results in off-balance-sheet accounting for the lease). It is expected that the Company will disclose if that it has done so and its effects in 2019.

SHORT-TERM INVESTMENTS_ (Tables

SHORT-TERM INVESTMENTS: (Tables)	12 Months Ended
	Dec. 31, 2018
SHORT-TERM INVESTMENTS:
Schedule of short-term investments	Short-term investments were as follows ($ in millions): At December 31, 2018 2017 Trading securities $ 213.1 $ 49.5 Weighted average interest rate 2.2 % 1.8 % Available-for-sale $ 0.7 $ 1.0 Weighted average interest rate 0.7 % 0.70 % Total $ 213.8 $ 50.5
Summary of activity investments	The following table summarizes the activity of these investments by category (in millions): Years ended December 31, 2018 2017 Trading: Interest earned $ 0.5 $ 0.7 Unrealized gain (loss) at December 31, $ (0.2) $ 0.1 Available-for-sale: Interest earned (*) (*) Investment redeemed $ 0.3 $ 1.1 (*) Less than $0.1 million
Schedule of contractual maturities of the Company's available-for-sale debt securities	At December 31, 2018 and 2017, contractual maturities of the available-for-sale debt securities are as follows (in millions): 2018 2017 One year or less $ — $ — Maturing after one year through five years — — Maturing after five years through ten years — — Due after 10 years 0.7 1.0 Total debt securities $ 0.7 $ 1.0

INVENTORIES_ (Tables)

INVENTORIES: (Tables)	12 Months Ended
	Dec. 31, 2018
INVENTORIES:
Schedule of inventories	At December 31, (in millions) 2018 2017 Inventory, current: Metals at average cost: Finished goods $ 69.6 $ 48.8 Work-in-process 256.8 308.0 Ore stockpiles on leach pads 328.0 320.9 Supplies at average cost 378.3 364.2 Total current inventory $ 1,032.7 $ 1,041.9 Inventory, long-term: Ore stockpiles on leach pads $ 1,177.4 $ 977.4

PROPERTY_ (Tables)

PROPERTY: (Tables)	12 Months Ended
	Dec. 31, 2018
PROPERTY:
Schedule of major classes of property, plant and equipment	At December 31, (in millions) 2018 2017 Buildings and equipment $ 14,294.0 $ 12,552.8 Construction in progress 1,516.9 2,301.9 Mine development 267.9 267.9 Mineral assets 83.2 83.2 Land, other than mineral 164.1 218.4 Total property 16,326.1 15,424.2 Accumulated depreciation, amortization and depletion (6,922.3) (6,324.6) Total property and mine development, net $ 9,403.8 $ 9,099.6

INTANGIBLE ASSETS_ (Tables)

INTANGIBLE ASSETS: (Tables)	12 Months Ended
	Dec. 31, 2018
INTANGIBLE ASSETS:
Schedule of major classes of intangible assets and goodwill	At December 31, (in millions) 2018 2017 Mining concessions $ 121.2 $ 121.2 Mine engineering and development studies 19.8 19.8 Software 49.6 49.0 190.6 190.0 Accumulated amortization: Mining concessions (37.4) (36.6) Mine engineering and development studies (15.3) (15.3) Software (32.1) (27.5) (84.8) (79.4) Goodwill 41.9 41.9 Intangible assets, net $ 147.7 $ 152.5
Schedule of estimated amortization of intangible assets for future periods	Estimated amortization expense (in millions): 2019 $ 4.7 2020 5.0 2021 5.1 2022 5.0 2023 5.0 Total 2019 - 2023 $ 24.8 Average annual $ 5.0

INCOME TAXES_ (Tables)

INCOME TAXES: (Tables)	12 Months Ended
	Dec. 31, 2018
INCOME TAXES:
Components of the provision for income taxes	(in millions) 2018 2017 2016 U.S. federal and state: Current $ 2.6 $ — $ — Deferred (13.0) 686.2 (109.4) Uncertain tax positions — 16.2 20.3 (10.4) 702.4 (89.1) Foreign (Peru and Mexico): Current 1,102.4 951.7 625.0 Deferred (38.5) (60.7) (34.8) 1,063.9 891.0 590.2 Total provision for income taxes $ 1,053.5 $ 1,593.4 $ 501.1
Schedule of source of income	(in millions) 2018 2017 2016 Earnings by location: U.S. $ (2.3) $ (1.5) $ (1.9) Foreign Peru 441.8 284.6 (85.7) Mexico 2,149.9 2,019.6 1,343.6 2,591.7 2,304.2 1,257.9 Earnings before taxes on income $ 2,589.4 $ 2,302.7 $ 1,256.0
Reconciliation of the statutory income tax rate to the effective tax rate	The reconciliation of the statutory income tax rate to the effective tax rate for the three years ended December 31, 2018, is as follows (in percentage points): 2018 2017 2016 Expected tax at U.S. statutory rate 21.0 % 35.0 % 35.0 % Foreign tax at other than statutory rate, net of foreign tax credit benefit (1) 13.9 0.6 2.0 Percentage depletion (2.1) (2.9) (2.7) Other permanent differences 0.4 5.2 — Change in 2017 valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred 7.5 26.9 — Additional valuation allowance on 2018 U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred 1.0 — — Decrease in 2017 U.S. deferred tax asset due to tax rate changes (0.2) 4.8 — U.S. one time transition tax on accumulated foreign earnings 0.4 2.4 — Increase (decrease) in unrecognized tax benefits for uncertain tax positions — 0.7 0.2 Repatriated foreign earnings — (2.0) 3.6 Amounts (over) / under provided in prior years (1.3) (0.1) (0.5) Other 0.1 (1.4) 2.3 Effective income tax rate 40.7 % 69.2 % 39.9 % (1) Foreign tax at other than statutory rates, net of foreign tax credit benefit, also includes the effects of permanent differences in Peru and Mexico, that are determined at the local statutory rate.
Schedule of deferred tax assets and liabilities	At December 31, (in millions) 2018 2017 Assets: Inventories $ 61.5 $ 47.0 Capitalized exploration expenses 11.1 9.5 U.S. foreign tax credit carryforward, net of FIN 48 liability 483.4 280.2 U.S. tax effect of Peruvian deferred tax liability 165.1 174.1 Provisions 155.0 152.6 Mexican tax on consolidated dividends 14.8 14.5 Deferred workers participation 27.0 3.0 Accrued salaries, wages and vacations 9.1 7.2 Sales price adjustment (PUI) 2.7 — Social responsibility expenses 2.1 2.1 Deferred charges 6.1 — Valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred (819.1) (619.6) Other 10.1 1.6 Total deferred tax assets 128.9 72.2 Liabilities: Property, plant and equipment (137.3) (130.3) Deferred charges — (16.9) Unremitted foreign earnings — — Sales price adjustment (PUI) — (0.4) Other (0.4) (5.3) Total deferred tax liabilities (137.7) (152.9) Total net deferred tax (liabilities) / assets $ (8.8) $ (80.7)
Summary of expiry of foreign tax credits	Year Amount 2022 51.5 2023 69.2 2024 102.0 2025 189.5 2026 104.8 2028 172.1 Total $ 689.1
Schedule of reconciliation of amount of unrecognized tax benefits	The total amount of unrecognized tax benefits in 2018, 2017 and 2016, was as follows (in millions): 2018 2017 2016 Unrecognized tax benefits, opening balance $ 214.5 $ 304.0 $ 400.0 Gross increases—tax positions in prior period — (89.5) 3.9 Gross increases—current-period tax positions — — 23.3 Decreases related to settlements with taxing authorities — — (123.2) — (89.5) (96.0) Unrecognized tax benefits, ending balance $ 214.5 $ 214.5 $ 304.0
Summary of tax years remaining open to examination and adjustment in major tax jurisdictions	Peru: 2013 and all subsequent years U.S.: 2011 and all subsequent years Mexico: 2013 and all subsequent years

WORKERS' PARTICIPATION_ (Tables

WORKERS' PARTICIPATION: (Tables)	12 Months Ended
	Dec. 31, 2018
WORKERS' PARTICIPATION:
Schedule of workers' participation expense	Workers’ participation expense for the three years ended December 31, 2018 was as follows (in millions): 2018 2017 2016 Current $ 219.9 $ 192.7 $ 131.8 Deferred 9.8 6.6 (13.4) $ 229.7 $ 199.3 $ 118.4

ASSET RETIREMENT OBLIGATION_ (T

ASSET RETIREMENT OBLIGATION: (Tables)	12 Months Ended
	Dec. 31, 2018
ASSET RETIREMENT OBLIGATION:
Summary of asset retirement obligation activity	The following table summarizes the asset retirement obligation activity for years ended December 31, 2018 and 2017 (in millions): 2018 2017 Balance as of January 1 $ 222.5 $ 216.5 Changes in estimates (15.6) (11.6) Additions — — Closure payments (0.6) (0.3) Accretion expense 11.4 17.9 Balance as of December 31, $ 217.7 $ 222.5

FINANCING_ (Tables)

FINANCING: (Tables)	12 Months Ended
	Dec. 31, 2018
FINANCING:
Schedule of long-term debt	Long-term debt (in millions): Carrying value as of Face Issuance Issuance December 31, amount discount costs 2018 5.375% Senior unsecured notes due 2020 $ 400 $ (0.3) $ (0.4) $ 399.3 3.500% Senior unsecured notes due 2022 300 (0.5) (0.6) 298.9 3.875% Senior unsecured notes due 2025 500 (1.8) (1.8) 496.4 9.250% Yankee bonds due 2028 125 — — 51.2 7.500% Senior unsecured notes due 2035 1,000 (12.9) (8.4) 978.7 6.750% Senior unsecured notes due 2040 1,100 (7.3) (5.8) 1,086.9 5.250% Senior unsecured notes due 2042 1,200 (19.4) (6.5) 1,174.1 5.875% Senior unsecured notes due 2045 1,500 (16.6) (8.8) 1,474.6 Total $ 6,125 $ (58.8) $ (32.3) 5,960.1 Less, current portion — Total long-term debt $ 5,960.1 Carrying value as of Face Issuance Issuance December 31, amount discount costs 2017 5.375% Senior unsecured notes due 2020 $ 400 $ (0.6) $ (0.6) $ 398.8 3.500% Senior unsecured notes due 2022 300 (0.5) (0.8) 298.7 3.875% Senior unsecured notes due 2025 500 (2.1) (2.0) 495.9 9.250% Yankee bonds due 2028 125 — — 51.2 7.500% Senior unsecured notes due 2035 1,000 (13.2) (8.8) 978.0 6.750% Senior unsecured notes due 2040 1,100 (7.4) (5.9) 1,086.7 5.250% Senior unsecured notes due 2042 1,200 (19.8) (6.6) 1,173.6 5.875% Senior unsecured notes due 2045 1,500 (16.9) (8.9) 1,474.2 Total $ 6,125 $ (60.5) $ (33.6) 5,957.1 Less, current portion — Total long-term debt $ 5,957.1
Schedule of aggregate maturities of the outstanding borrowings	Aggregate maturities of the outstanding borrowings at December 31, 2018, are as follows: Principal Years Due(*) (in millions) 2019 $ — 2020 400.0 2021 — 2022 300.0 2023 — Thereafter 5,351.2 Total $ 6,051.2 (*) Total debt maturities do not include the debt discount valuation account of $91.1 million.

BENEFIT PLANS_ (Tables)

BENEFIT PLANS: (Tables)	12 Months Ended
	Dec. 31, 2018
Post retirement defined benefit plans and defined contribution plan
Components of net periodic benefit costs
Schedule of the components of net periodic benefit costs	Years ended December 31, (in millions) 2018 2017 2016 Service cost $ 1.0 $ 0.8 $ 0.7 Interest cost 1.6 1.4 1.0 Expected return on plan assets (3.4) (2.9) (2.2) Amortization of prior service cost / (credit) 0.2 0.1 0.1 Settlement / Curtailment (0.2) 0.1 (0.2) Amortization of net loss/(gain) 0.2 0.2 0.2 Net periodic benefit cost $ (0.6) $ (0.3) $ (0.4)
Schedule of changes in the benefit obligation and plan assets, the funded status of the plans and the amount recognized in balance sheet and accumulated other comprehensive income	As of December 31, (in millions) 2018 2017 Change in benefit obligation: Projected benefit obligation at beginning of year $ 27.5 $ 25.6 Service cost 1.0 0.8 Interest cost 1.6 1.4 Settlement — 0.9 Benefits paid (1.6) (1.9) Actuarial (gain)/loss (0.2) (0.3) Actuarial gain assumption changes (0.8) 0.3 Inflation adjustment (0.1) 0.7 Projected benefit obligation at end of year $ 27.4 $ 27.5 Change in plan assets: Fair value of plan assets at beginning of year $ 51.6 $ 44.6 Actual return on plan assets (3.5) 6.9 Employer contributions (0.4) (0.4) Benefits paid (1.0) (0.9) Currency exchange rate adjustment — 1.4 Fair value of plan assets at end of year $ 46.7 $ 51.6 Funded status at end of year: $ 19.3 $ 24.1 ASC-715 amounts recognized in statement of financial position consists of: Non-current assets $ 19.4 $ 24.2 Total $ 19.4 $ 24.2 ASC-715 amounts recognized in accumulated other comprehensive income (net of income taxes of $(4.3) million and $(2.0) million in 2018 and 2017, respectively) consists of: Net loss (gain) $ 5.8 $ 2.3 Prior service cost 1.4 1.5 Total $ 7.2 $ 3.8
Schedule of changes in accumulated other comprehensive income	(in millions) 2018 2017 Reconciliation of accumulated other comprehensive income: Accumulated other comprehensive income at beginning of plan year $ 3.8 $ 5.8 Net loss/(gain) amortized during the year 3.6 (0.1) Net loss/(gain) occurring during the year (0.1) (2.4) Prior service cost (credit) — 0.4 Currency exchange rate adjustment (0.1) 0.1 Net adjustment to accumulated other comprehensive income (net of income taxes of $(2.2) million and $1.3 million in 2018 and 2017, respectively) 3.4 (2.0) Accumulated other comprehensive income at end of plan year $ 7.2 $ 3.8
Summary of the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of tax	(in millions) 2018 2017 Net loss / (gain) $ 3.6 $ (2.4) Amortization of net (loss) gain (0.1) (0.1) Amortization of prior services cost (credit) — 0.4 Total amortization expenses $ 3.5 $ (2.1)
Scheduled maturities of the benefits expected to be paid in each of the next five years, and thereafter	Expected Years Benefit Payments (in millions) 2019 $ 2.6 2020 1.7 2021 1.8 2022 1.9 2023 2.0 2024 to 2026 13.4 Total $ 23.4
Post-retirement Health care plans
Components of net periodic benefit costs
Schedule of the components of net periodic benefit costs	Years ended December 31, (in millions) 2018 2017 2016 Interest cost $ 0.9 $ 0.9 $ 0.6 Amortization of prior service cost/ (credit) (0.2) (0.2) (0.5) Net periodic benefit cost $ 0.7 $ 0.7 $ 0.1
Schedule of changes in the benefit obligation and plan assets, the funded status of the plans and the amount recognized in balance sheet and accumulated other comprehensive income	As of December 31, (in millions) 2018 2017 Change in benefit obligation: Projected benefit obligation at beginning of year $ 12.5 $ 12.9 Interest cost 0.9 0.9 Actuarial loss/ (gain)-claims cost 0.2 (0.4) Benefits paid (0.9) (0.9) Actuarial (gain)/loss (0.9) (0.6) Inflation adjustment 0.1 0.6 Projected benefit obligation at end of year $ 11.9 $ 12.5 Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Employer contributions 0.1 0.1 Benefits paid (0.1) (0.1) Fair value of plan assets at end of year $ — $ — Funded status at end of year: $ 11.9 $ 12.5 ASC-715 amounts recognized in statement of financial position consists of: Current liabilities $ (0.1) $ (0.1) Non-current liabilities (11.8) (12.5) Total $ (11.9) $ (12.6) ASC-715 amounts recognized in accumulated other comprehensive income consists of: Net loss (gain) $ (4.4) $ (3.9) Total (net of income taxes of $1.9 million and $1.7 million in 2018 and 2017, respectively) $ (4.4) $ (3.9)
Schedule of changes in accumulated other comprehensive income	As of December 31, (in millions) 2018 2017 Reconciliation of accumulated other comprehensive income: Accumulated other comprehensive income at beginning of plan year $ (3.9) $ (2.8) Net loss/(gain) occurring during the year (0.6) (0.6) Net loss/(gain) amortized during the year 0.1 0.1 Currency exchange rate adjustment — (0.6) Net adjustment to accumulated other comprehensive income (net of income taxes of $0.2 million and $0.3 million in 2018 and 2017, respectively) (0.5) (1.1) Accumulated other comprehensive income at end of plan year $ (4.4) $ (3.9)
Summary of the amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of tax	At December 31, (in millions) 2018 2017 Net loss / (gain) $ (0.6) $ (0.6) Amortization of net (loss) gain 0.2 0.1 Total amortization expenses $ (0.4) $ (0.5)
Schedule of assumptions used to determine the pension obligations and other post-retirement benefits	2018 2017 2016 Expatriate health plan Discount rate 3.90 % 3.25 % 3.65 % Mexican health plan Weighted average discount rate 8.45 % 7.80 % 7.55 %
Scheduled maturities of the benefits expected to be paid in each of the next five years, and thereafter	Expected Year Benefit Payments (in millions) 2019 $ 0.9 2020 0.9 2021 0.9 2022 0.9 2023 0.9 2024 to 2028 2.9 Total $ 7.4
Expatriate Plan | Post retirement defined benefit plans and defined contribution plan
Components of net periodic benefit costs
Schedule of assumptions used to determine the pension obligations and other post-retirement benefits	Expatriate Plan 2018 2017 2016 Discount rate 3.90 % 3.25 % 3.65 % Expected long-term rate of return on plan asset 4.00 % 4.00 % 4.00 % Rate of increase in future compensation level N/A N/A N/A
Mexican Health Plan | Post retirement defined benefit plans and defined contribution plan
Components of net periodic benefit costs
Schedule of asset mix of the investment portfolio	2018 2017 Asset category: Treasury bills 78 % 70 % Equity securities 22 % 30 % 100 % 100 %
Mexican Health Plan | Post-retirement Health care plans
Components of net periodic benefit costs
Schedule of assumptions used to determine the pension obligations and other post-retirement benefits	Mexican Plan(*) 2018 2017 2016 Discount rate 8.45 % 7.80 % 7.55 % Expected long-term rate of return on plan asset 8.45 % 7.55 % 7.55 % Rate of increase in future compensation level 4.50 % 4.50 % 4.50 % (*) These rates are based on Mexican pesos as pension obligations are denominated in pesos.
Schedule of effects of one percentage-point change in assumed other benefits cost trend rates	One Percentage Point (in millions) Increase Decrease Effect on total service and interest cost components $ 1.0 $ 0.8 Effect on the post-retirement benefit obligation $ 11.7 $ 10.5

COMMITMENTS AND CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES: (Tables)	12 Months Ended
	Dec. 31, 2018
COMMITMENTS AND CONTINGENCIES:
Schedule of environmental capital investments	Environmental capital investments in years 2018, 2017 and 2016, were as follows (in millions): 2018 2017 2016 Peruvian operations $ 59.3 $ 93.7 $ 110.3 Mexican operations 43.5 128.9 140.1 Total $ 102.8 $ 222.6 $ 250.4

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	12 Months Ended
	Dec. 31, 2018
Share based Compensation Plan
Schedule of activity in treasury stock	Activity in treasury stock in the years 2018 and 2017 was as follows (in millions): 2018 2017 Southern Copper common shares Balance as of January 1, $ 2,768.7 $ 2,769.0 Purchase of shares — — Used for corporate purposes (0.4) (0.3) Balance as of December 31, 2,768.3 2,768.7 Parent Company (Grupo Mexico) common shares Balance as of January 1, 232.4 218.6 Other activity, including dividend, interest and foreign currency transaction effect 18.9 13.8 Balance as of December 31, 251.3 232.4 Treasury stock balance as of December 31, $ 3,019.6 $ 3,001.1
Schedule of activity in Directors' Stock Award Plan	2018 2017 Total SCC shares reserved for the plan 600,000 600,000 Total shares granted at January 1, (346,800) (334,800) Granted in the period (16,000) (12,000) Total shares granted at December 31, (362,800) (346,800) Remaining shares reserved 237.200 253,200
Employee Stock Purchase 2010 Plan
Share based Compensation Plan
Schedule of stock based compensation expense and unrecognized compensation expense	The stock based compensation expense for the years ended December 31, 2018, 2017 and 2016 and the remaining balance of the unrecognized compensation expense under this plan were as follows (in millions): 2018 2017 2016 Stock based compensation expense $ 0.2 $ 0.6 $ 0.6 Unrecognized compensation expense $ — $ 0.2 $ 0.8
Schedule of stock award activity	Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 1,393,663 $ 2.05 Granted — — Exercised (1,275,729) 2.05 Forfeited — — Outstanding shares at December 31, 2018 117,934 $ 2.05 Outstanding shares at January 1, 2017 1,401,096 $ 2.05 Granted — — Exercised (7,433) 2.05 Forfeited — — Outstanding shares at December 31, 2017 1,393,663 $ 2.05
Employee Stock Purchase 2015 Plan
Share based Compensation Plan
Schedule of stock based compensation expense and unrecognized compensation expense	The stock based compensation expense for the years ended December 31, 2018, 2017 and 2016 and the unrecognized compensation expense under this plan were as follows (in millions): 2018 2017 2016 Stock based compensation expense $ 0.6 $ 0.6 $ 0.6 Unrecognized compensation expense $ 2.6 $ 3.2 $ 3.8
Schedule of stock award activity	Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 2,293,120 $ 2.63 Granted — — Exercised (452,784) $ 2.63 Forfeited — — Outstanding shares at December 31, 2018 1,840,336 $ 2.63 Outstanding shares at January 1, 2017 2,540,223 $ 2.63 Granted — — Exercised (247,103) $ 2.63 Forfeited — — Outstanding shares at December 31, 2018 2,293,120 $ 2.63
Employee Stock Purchase 2018 Plan
Share based Compensation Plan
Schedule of stock based compensation expense and unrecognized compensation expense	The stock based compensation expense for the year ended December 31, 2018 and the unrecognized compensation expense under this plan were as follows (in millions): 2018 Stock based compensation expense $ — Unrecognized compensation expense $ 3.6
Schedule of stock award activity	Unit Weighted Average Shares Grant Date Fair Value Outstanding shares at January 1, 2018 — — Granted 2,782,424 1.86 Exercised — — Forfeited — — Outstanding shares at December 31, 2018 2,782,424 1.86
Employee Stock Purchase 2018 Plan | Voluntary Resignation
Share based Compensation Plan
Schedule of percentage deduction from the amount to be paid to the employee on termination of service	% Deducted If the resignation occurs during: 1st year after the grant date 90 % 2nd year after the grant date 80 % 3rd year after the grant date 70 % 4th year after the grant date 60 % 5th year after the grant date 50 % 6th year after the grant date 40 % 7th year after the grant date 20 %
Employee Stock Purchase 2018 Plan | Involuntary Termination
Share based Compensation Plan
Schedule of percentage deduction from the amount to be paid to the employee on termination of service	% Deducted If the resignation occurs during: 1st year after the grant date 100 % 2nd year after the grant date 95 % 3rd year after the grant date 90 % 4th year after the grant date 80 % 5th year after the grant date 70 % 6th year after the grant date 60 % 7th year after the grant date 50 %

FAIR VALUE MEASUREMENT_ (Tables

FAIR VALUE MEASUREMENT: (Tables)	12 Months Ended
	Dec. 31, 2018
FINANCIAL INSTRUMENTS:
Schedule of carrying amount and estimated fair values of the Company's financial instruments	Consequently, such financial instruments are not included in the following table that provides information about the carrying amounts and estimated fair values of other financial instruments that are not measured at fair value in the consolidated balance sheet as of December 31, 2018 and December 31, 2017 (in millions): At December 31, 2018 At December 31, 2017 Carrying Value Fair Value Carrying Value Fair Value Liabilities: Long-term debt level 1 5,210.7 5,540.0 5,208.4 6,488.9 Long-term debt level 2 749.4 761.7 748.7 806.1 Total long-term debt $ 5,960.1 $ 6,301.7 $ 5,957.1 $ 7,295.0
Schedule of fair values of assets and liabilities measured at fair value on a recurring basis	Fair values of assets and liabilities measured at fair value on a recurring basis were calculated as of December 31, 2018 and 2017, as follows (in millions): Fair Value at Measurement Date Using: Significant Fair Value Quoted prices in other Significant as of active markets for observable unobservable December 31, identical assets inputs inputs Description 2018 (Level 1) (Level 2) (Level 3) Assets: Short term investment: — Trading securities $ 213.1 $ 213.1 $ — $ — — Available-for-sale debt securities: Corporate bonds — — — — Asset backed securities 0.4 — 0.4 — Mortgage backed securities 0.3 — 0.3 — Accounts receivable: — Embedded derivatives — Not classified as hedges: Provisionally priced sales: Copper 274.3 274.3 — — Molybdenum 107.4 107.4 — — Total $ 595.5 $ 594.8 $ 0.7 $ — Fair Value at Measurement Date Using: Significant Fair Value Quoted prices in other Significant as of active markets for observable unobservable December 31, identical assets inputs inputs Description 2017 (Level 1) (Level 2) (Level 3) Assets: Short term investment: — Trading securities $ 49.5 $ 49.5 $ — $ — — Available-for-sale debt securities: Corporate bonds 0.1 — 0.1 — Asset backed securities 0.5 — 0.5 — Mortgage backed securities 0.4 — 0.4 — Accounts receivable: — Embedded derivatives-Not classified as hedges: Provisionally priced sales: Copper 184.6 184.6 — — Molybdenum 102.8 102.8 — — Total $ 337.9 $ 336.9 $ 1.0 $ —

CONCENTRATION OF RISK_ (Tables)

CONCENTRATION OF RISK: (Tables)	12 Months Ended
	Dec. 31, 2018
CONCENTRATION OF RISK:
Schedule of concentration risk for cash equivalents and short- term investments	$ in % of total % in one institution Country million cash (1) of country of total cash United States $ 697.1 65.9 % 27.7 % 18.3 % Switzerland 315.7 29.8 % 61.2 % 18.3 % Peru 7.6 0.7 % 75.6 % 0.5 % Mexico 38.0 3.6 % 89.3 % 3.2 % Total cash and short-term investment $ 1,058.4 100.0 % (1) 95.8% of the Company’s cash is in U.S. dollars.
Schedule of company's largest customers as percentage of accounts receivable and total sales	2018 2017 2016 Accounts receivable trade as of December 31, Five largest customers 34.2 % 28.4 % 31.1 % Largest customer 10.9 % 8.2 % 11.9 % Total sales in year Five largest customers 28.4 % 25.1 % 30.4 % Largest customer 9.3 % 8.8 % 8.4 %

RELATED PARTY TRANSACTIONS_ (Ta

RELATED PARTY TRANSACTIONS: (Tables)	12 Months Ended
	Dec. 31, 2018
RELATED PARTY TRANSACTIONS:
Schedule of receivable and payable balances with related parties	Receivable and payable balances with related parties are shown below (in millions): At December 31, 2018 2017 Related parties receivable current: Grupo Mexico and affiliates: Asarco LLC $ 74.4 4.1 Americas Mining Corporation (“AMC”) 11.0 — AMMINCO Apoyo Administrativo, S.A. de C.V. (“AMMINCO”) 0.2 — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates 1.4 1.4 Ferrocarril Mexicano, S.A. de C.V. 0.1 — Grupo Mexico 2.7 2.8 Mexico Generadora de Energia S. de R.L. ("MGE") 10.3 $ 16.2 Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates 0.6 1.1 Related to the controlling group: Boutique Bowling de Mexico S.A. de C.V. 0.3 0.2 Mexico Transportes Aereos, S.A. de C.V. ("Mextransport") 0.1 — Operadora de Cinemas S.A. de C.V. 0.4 0.3 $ 101.5 $ 26.1 Related parties payable: Grupo Mexico and affiliates: Asarco LLC $ 4.1 $ 24.2 AMMINCO 8.0 — Eolica El Retiro, S.A.P.I. de C.V. 1.0 0.8 Ferrocarril Mexicano S.A. de C.V. 6.4 2.6 Grupo Mexico 0.6 0.7 MGE 40.6 38.5 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates 14.4 21.7 Related to the controlling group: Boutique Bowling de Mexico S.A. de C.V. 0.1 0.6 Mexico Transportes Aereos S.A. de C.V. (“Mextransport”) — 0.3 Operadora de Cinemas S.A. de C.V. 0.1 0.7 $ 75.3 $ 90.1
Grupo Mexico and affiliates
RELATED PARTY TRANSACTIONS:
Schedule of purchase and sales activities with related parties	The following table summarizes the purchase and sale activities with Grupo Mexico and its affiliates in 2018, 2017 and 2016 (in millions): 2018 2017 2016 Purchase activity Asarco LLC $ 37.2 $ 37.2 $ 30.3 AMMINCO 8.0 — — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates — — 0.3 Eolica El Retiro, S.A.P.I. de C.V. 3.6 3.3 2.0 Ferrocarril Mexicano, S.A. de C.V. 41.7 43.5 42.7 Grupo Mexico 10.1 14.0 13.8 MGE 200.1 223.7 233.8 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates 79.8 152.9 76.0 Total purchases $ 380.5 $ 474.6 $ 398.9 Sales activity Asarco LLC $ 81.8 $ 96.2 $ 37.1 AMMINCO 0.3 — — Compania Perforadora Mexico S.A.P.I. de C.V. and affiliates — 0.2 0.6 Grupo Mexico — 0.2 0.6 Mexico Proyectos y Desarrollos S.A. de C.V. and affiliates — — 0.4 Operadora de Generadoras de Energia Mexico S.A. de C.V — — 0.1 MGE 68.2 101.0 95.9 Total sales $ 150.3 $ 197.6 $ 134.7
Related to the controlling group
RELATED PARTY TRANSACTIONS:
Schedule of purchase and sales activities with related parties	The following table summarizes the purchase and sales activities with other Larrea family companies in 2018, 2017 and 2016 (in millions): 2018 2017 2016 Purchase activity Boutique Bowling de Mexico S.A. de C.V. $ 0.3 $ 0.3 $ 0.4 Mextransport 12.4 1.3 2.0 Operadora de Cinemas S.A. de C.V. 0.2 0.1 0.5 Total purchases $ 12.9 $ 1.7 $ 2.9 Sales activity Boutique Bowling de Mexico S.A. de C.V. $ 0.2 $ 0.2 $ 0.2 Mextransport 1.2 0.3 0.2 Operadora de Cinemas S.A. de C.V. 0.1 0.2 0.1 Total sales $ 1.5 $ 0.7 $ 0.5

SEGMENT AND RELATED INFORMATI_2

SEGMENT AND RELATED INFORMATION: (Tables)	12 Months Ended
	Dec. 31, 2018
SEGMENT AND RELATED INFORMATION:
Schedule of financial information relating to Company's segments	Year Ended December 31, 2018 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 4,075.9 $ 448.6 $ 2,572.2 $ — $ 7,096.7 Intersegment sales — 79.3 — (79.3) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,611.0 377.2 1,509.4 (88.6) 3,409.0 Selling, general and administrative 55.3 8.5 36.7 2.1 102.6 Depreciation, amortization and depletion 360.4 47.6 237.4 28.9 674.3 Exploration 2.0 5.3 18.5 3.8 29.6 Operating income $ 2,047.2 $ 89.3 $ 770.2 $ (25.5) 2,881.2 Less: Interest, net (261.1) Other income (expense) (30.7) Income taxes (1,053.5) Equity earnings of affiliate 12.3 Non-controlling interest (5.2) Net income attributable to SCC $ 1,543.0 Capital investment $ 266.8 $ 60.0 $ 774.0 $ 20.6 $ 1,121.4 Property and mine development, net $ 4,783.8 $ 448.3 $ 3,797.2 $ 374.5 $ 9,403.8 Total assets $ 8,165.2 $ 930.2 $ 4,813.1 $ 576.3 $ 14,484.8 Year Ended December 31, 2017 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 3,972.7 $ 437.7 $ 2,244.1 $ — $ 6,654.5 Intersegment sales — 71.0 — (71.0) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,594.3 365.3 1,362.8 (69.6) 3,252.8 Selling, general and administrative 47.9 7.9 36.2 1.1 93.1 Depreciation, amortization and depletion 401.0 56.2 203.6 10.3 671.1 Exploration 2.7 5.5 14.4 6.2 28.8 Environmental remediation (10.2) — — — (10.2) Operating income $ 1,937.0 $ 73.8 $ 627.1 $ (19.0) 2,618.9 Less: Interest, net (300.5) Other income (expense) (15.7) Income taxes (1,593.4) Equity earnings of affiliate 23.1 Non-controlling interest (3.9) Net income attributable to SCC $ 728.5 Capital investment $ 297.6 $ 36.5 $ 685.4 $ 4.0 $ 1,023.5 Property and mine development, net $ 5,004.5 $ 366.9 $ 3,389.8 $ 338.4 $ 9,099.6 Total assets $ 8,323.1 $ 889.1 $ 4,314.5 $ 253.4 $ 13,780.1 Year Ended December 31, 2016 (in millions) Mexican Corporate, other Mexican IMMSA Peruvian and Open-pit Unit Operations eliminations Consolidated Net sales outside of segments $ 3,234.3 $ 351.1 $ 1,794.4 $ — $ 5,379.8 Intersegment sales — 72.0 — (72.0) — Cost of sales (exclusive of depreciation, amortization and depletion) 1,523.2 304.1 1,280.2 (73.4) 3,034.1 Selling, general and administrative 47.1 7.4 37.5 2.3 94.3 Depreciation, amortization and depletion 364.7 49.8 217.1 15.5 647.1 Exploration 5.2 5.0 13.0 16.9 40.1 Operating income $ 1,294.1 $ 56.8 $ 246.6 $ (33.3) 1,564.2 Less: Interest, net (283.6) Other income (expense) (24.6) Income taxes (501.1) Equity earnings of affiliate 23.9 Non-controlling interest (2.3) Net income attributable to SCC $ 776.5 Capital investment $ 537.0 $ 35.8 $ 541.0 $ 4.7 $ 1,118.5 Property and mine development, net $ 5,136.8 $ 448.7 $ 2,949.3 $ 231.7 $ 8,766.5 Total assets $ $ 825.0 $ 4,225.3 $ 9.6 $ 13,234.3
Schedule of opening and closing balances of receivables by reporting segment	The following table presents information regarding the opening and closing balances of receivables by reporting segment of the Company for the three years ended December 31, 2018 (in millions): Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated As of December 31, 2018: Trade receivables $ 505.9 $ 50.5 $ 266.0 $ — $ 822.4 Related parties 81.6 — — 19.9 101.5 As of December 31, 2017: Trade receivables $ 556.2 $ 79.7 $ 254.7 $ — $ 890.6 Related parties 18.0 — — 8.1 26.1 As of December 31, 2016: Trade receivables $ 365.2 $ 47.1 $ 179.6 $ — $ 591.9 Related parties 12.9 — — 10.5 23.4
Schedule of sales value per segment	The following table presents information regarding the sales value by reporting segment of the Company’s significant products for the three years ended December 31, 2018 (in millions): Year Ended December 31, 2018 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 3,459.1 $ 45.6 $ 2,251.2 $ (48.1) $ 5,707.8 Molybdenum 342.5 — 167.4 — 509.9 Silver 175.3 83.5 69.5 (28.1) 300.2 Zinc — 328.7 — (0.1) 328.6 Other 99.0 70.1 84.1 (3.0) 250.2 Total $ 4,075.9 $ 527.9 $ 2,572.2 $ (79.3) $ 7,096.7 Year Ended December 31, 2017 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 3,480.2 $ 37.2 $ 1,996.4 $ (37.3) $ 5,476.5 Molybdenum 224.0 — 129.4 — 353.4 Silver 170.7 71.9 70.6 (26.9) 286.3 Zinc — 327.2 — (0.6) 326.6 Other 97.8 73.2 47.7 (7.0) 211.7 Total $ 3,972.7 $ 509.5 $ 2,244.1 $ (71.8) $ 6,654.5 Year Ended December 31, 2016 Mexican Mexican IMMSA Peruvian Corporate, Other & Total (in millions) Open-pit Unit Operations Eliminations Consolidated Copper $ 2,663.1 $ 32.0 $ 1,557.7 $ (32.0) $ 4,220.8 Molybdenum 144.0 — 124.0 — 268.0 Silver 182.3 82.1 61.5 (31.6) 294.3 Zinc — 234.4 — — 234.4 Other 244.9 74.6 51.2 (8.4) 362.3 Total $ 3,234.3 $ 423.1 $ 1,794.4 $ (72.0) $ 5,379.8
Schedule of net sales by countries	The geographic breakdown of the Company’s sales for the three years ended December 31, 2018 was as follows (in millions): Year Ended December 31, 2018 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,343.0 $ 385.6 $ — $ (79.3) $ 1,649.3 United States 1,008.0 6.6 244.0 — 1,258.6 Peru — — 390.4 — 390.4 Brazil — 43.8 228.1 — 271.9 Chile — — 136.3 — 136.3 Other American countries 60.6 3.8 1.4 — 65.8 Europe: Switzerland 453.3 43.4 156.7 — 653.4 Italy 20.6 21.7 305.0 — 347.3 Spain 169.4 — — — 169.4 Other European countries 234.8 19.9 124.9 — 379.6 Asia: Singapore 528.8 2.2 538.2 — 1,069.2 Japan 71.8 — 411.6 — 483.4 Other Asian countries 185.6 0.9 35.6 — 222.1 Total $ 4,075.9 $ 527.9 $ 2,572.2 $ (79.3) $ 7,096.7 Year Ended December 31, 2017 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,240.0 $ 349.1 $ 6.6 $ (71.8) $ 1,523.9 United States 1,001.2 41.7 147.4 — 1,190.3 Peru — 0.8 373.4 — 374.2 Brazil — 48.7 191.4 — 240.1 Chile — — 103.4 — 103.4 Other American countries 68.1 4.1 19.3 — 91.5 Europe: Switzerland 473.1 14.3 114.9 — 602.3 Italy 27.7 18.6 286.1 — 332.4 Spain 142.8 — — — 142.8 Other European countries 230.3 30.3 76.6 — 337.2 Asia: Singapore 547.9 1.4 502.0 — 1,051.3 Japan 93.0 — 386.6 — 479.6 Other Asian countries 148.6 0.5 36.4 — 185.5 Total $ 3,972.7 $ 509.5 $ 2,244.1 $ (71.8) $ 6,654.5 Year Ended December 31, 2016 Mexican Mexican IMMSA Peruvian Corporate & Open-Pit Unit Operations Elimination Consolidated The Americas: Mexico $ 1,184.8 $ 296.9 $ — $ (72.0) $ 1,409.7 United States 933.6 49.5 66.9 — 1,050.0 Peru — — 294.4 — 294.4 Brazil — 26.1 170.0 — 196.1 Chile — — 92.4 — 92.4 Other American countries 52.9 2.6 18.8 — 74.3 Europe: Switzerland 245.9 9.4 182.0 — 437.3 Italy 20.9 17.2 266.4 — 304.5 Spain 71.2 — — — 71.2 Other European countries 127.0 20.8 54.0 — 201.8 Asia: Singapore 471.9 — 180.9 — 652.8 Japan 49.2 — 360.6 — 409.8 Other Asian countries 76.9 0.6 108.0 — 185.5 Total $ 3,234.3 $ 423.1 $ 1,794.4 $ (72.0) $ 5,379.8
Schedule of provisionally priced copper and molybdenum sales outstanding	Sales volume Priced at (million lbs.) (per pound) Month of settlement Copper 102.4 2.68 January through March 2019 Molybdenum 9.0 11.88 January through March 2019
Schedule of provisional sales price adjustments included in accounts receivable and net sales	Provisional sales price adjustments included in accounts receivable and net sales were as follows at December, 31 (in millions): At December 31, 2018 2017 Copper $ (7.6) $ 8.3 Molybdenum (2.4) 14.6 Total $ (10.0) $ 22.9

QUARTERLY DATA (unaudited) (Tab

QUARTERLY DATA (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
QUARTERLY DATA (unaudited)
Schedule of quarterly financial data	2018 (in millions, except per share data) 1 st 2 nd 3 rd 4 th Year Net sales $ 1,841.1 $ 1,837.2 $ 1,723.7 $ 1,694.7 $ 7,096.7 Gross profit (1) $ 802.6 $ 822.9 $ 729.1 $ 658.8 $ 3,013.4 Operating income $ 773.3 $ 787.6 $ 696.7 $ 623.6 $ 2,881.2 Net income $ 471.9 $ 411.1 $ 370.7 $ 294.5 $ 1,548.2 Net income attributable to SCC $ 470.7 $ 409.6 $ 369.4 $ 293.3 $ 1,543.0 Per share amounts attributable to SCC: Net earnings basic and diluted $ 0.61 $ 0.53 $ 0.48 $ 0.38 $ 2.00 Dividend per share $ 0.30 $ 0.30 $ 0.40 $ 0.40 $ 1.40 2017 1 st 2 nd 3 rd 4 th Year Net sales $ 1,583.9 $ 1,529.8 $ 1,676.5 $ 1,864.3 $ 6,654.5 Gross profit (1) $ 586.7 $ 553.8 $ 725.7 $ 864.4 $ 2,730.6 Operating income $ 570.4 $ 525.9 $ 692.6 $ 830.0 $ 2,618.9 Net income (loss) $ 315.3 $ 300.5 $ 402.8 $ (286.2) $ 732.4 Net income (loss) attributable to SCC $ 314.4 $ 299.7 $ 401.8 $ (287.4) $ 728.5 Per share amounts attributable to SCC: Net earnings basic and diluted $ 0.41 $ 0.39 $ 0.52 $ (0.38) $ 0.94 Dividend per share $ 0.08 $ 0.12 $ 0.14 $ 0.25 $ 0.59 (1) Gross profit is the result of net sales less cost of sales (excluding depreciation, amortization and depletion) and less depreciation, amortization and depletion.

DESCRIPTION OF THE BUSINESS_ (D

DESCRIPTION OF THE BUSINESS: (Details)	Dec. 31, 2018
DESCRIPTION OF THE BUSINESS:
Percentage of ownership interest held by the parent company	88.90%

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)segmentitem$ / lb	Dec. 31, 2017$ / lb	Dec. 31, 2016$ / lb	Jan. 01, 2019USD ($)
Significant Accounting Policies
Increase in total reserves at a property to qualify as a major expansion (as a percent)	10.00%
Period considered for calculation of average metal price	3 years
Current price of copper (in dollars per pound) | $ / lb	2.64	2.50	2.61
U.S. statutory rate (as a percent)	21.00%	35.00%	35.00%
Impairment in the carrying value of long-term assets	$ 0
Number of years of average prices for copper and molybdenum used for impairment analysis	3 years
Number of reportable segments | segment	3
Long-term contracts with promises to deliver mineral	1,724,840
ASU 2016-02 | Restatement
Significant Accounting Policies
Right of use assets				$ 1,020.4
Lease obligations				$ 1,115.9
Minimum
Financial information related to segments
Estimated useful lives of buildings and equipment	5 years
Significant Accounting Policies
Percentage Of Metal Production Sold Under Annual Or Longer Term Contracts	80.00%
Maximum
Financial information related to segments
Maximum period after shipping within which pricing is based by customer contracts in most cases	3 months
Estimated useful lives of buildings and equipment	40 years
Significant Accounting Policies
Percentage Of Metal Production Sold Under Annual Or Longer Term Contracts	90.00%
Peruvian Operations
Financial information related to segments
Number of open-pit copper mines | item	2
Mexican IMMSA Unit
Financial information related to segments
Number of underground poly metal mines | item	5

SHORT-TERM INVESTMENTS_ (Detail

SHORT-TERM INVESTMENTS: (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Short-term investment:
Trading securities	$ 213.1	$ 49.5
Weighted average interest rate (as a percent)	2.20%	1.80%
Available-for-sale	$ 0.7	$ 1
Weighted average interest rate (as a percent)	0.70%	0.70%
Total	$ 213.8	$ 50.5
Trading:
Interest earned	0.5	0.7
Unrealized gain (loss) at the end of the period	(0.2)	0.1
Available-for-sale:
Interest earned	16	5.5	$ 7.1
Investment redeemed	0.3	1.1
Contractual maturities of available-for-sale debt securities
Due after 10 years	0.7	1
Total debt securities	0.7	1
Maximum
Available-for-sale:
Interest earned	$ 0.1	$ 0.1

INVENTORIES_ (Details)

INVENTORIES: (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Metals at average cost:
Finished goods	$ 69.6	$ 48.8
Work-in-process	256.8	308
Ore stockpiles on leach pads	328	320.9
Supplies at average cost	378.3	364.2
Total current inventory	1,032.7	1,041.9
Inventory, long-term:
Ore stockpiles on leach pads	1,177.4	977.4
Total leaching costs added as long-term inventory of ore stockpiles in leach pads	506.6	513.9	$ 439
Long-term leaching inventories recognized as cost of sales	$ 299.4	$ 333.5	$ 316.6

PROPERTY_ (Details)

PROPERTY: (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property
Total property	$ 16,326.1	$ 15,424.2
Accumulated depreciation, amortization and depletion	(6,922.3)	(6,324.6)
Total property and mine development, net	9,403.8	9,099.6	$ 8,766.5
Depreciation and depletion expense	668.9	665.2	$ 639.1
Buildings and equipment
Property
Total property	14,294	12,552.8
Construction in progress
Property
Total property	1,516.9	2,301.9
Mine development
Property
Total property	267.9	267.9
Mineral assets
Property
Total property	83.2	83.2
Land, other than mineral
Property
Total property	$ 164.1	$ 218.4

INTANGIBLE ASSETS_ (Details)

INTANGIBLE ASSETS: (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible assets
Intangible assets excluding goodwill, gross	$ 190.6	$ 190
Accumulated amortization	(84.8)	(79.4)
Goodwill	41.9	41.9
Intangible assets, net	147.7	152.5
Amortization expense:
Amortization expense	5.4	5.9	$ 8
Estimated amortization expense:
2,019	4.7
2,020	5
2,021	5.1
2,022	5
2,023	5
Total 2019-2023	24.8
Average annual	5
Buenavista del Cobre, S.A. de C.V
Intangible assets
Goodwill	17
El Pilar
Intangible assets
Goodwill	24.9
Mining concessions
Intangible assets
Intangible assets excluding goodwill, gross	121.2	121.2
Accumulated amortization	(37.4)	(36.6)
Mine engineering and development studies
Intangible assets
Intangible assets excluding goodwill, gross	19.8	19.8
Accumulated amortization	(15.3)	(15.3)
Software
Intangible assets
Intangible assets excluding goodwill, gross	49.6	49
Accumulated amortization	$ (32.1)	$ (27.5)

INCOME TAXES_ - TCJA (Details)

INCOME TAXES: - TCJA (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2009
Income Taxes
Percentage of ownership by parent	88.90%
U.S. statutory rate (as a percent)	21.00%	35.00%	35.00%
Non-cash tax expense for estimated tax effect of the TCJA		$ 785.9
Amount determined for final impact of the TCJA	$ 816.8
Amount of change in income tax expense (benefit) from provisional amount	$ 30.9
Maximum percentage of expenses excluding cost of goods sold	3.00%
Minimum
Income Taxes
BEAT tax rate (as a percent)	5.00%
Minimum | Years 2019 through 2025
Income Taxes
BEAT tax rate (as a percent)	10.00%
Minimum | Years thereafter
Income Taxes
BEAT tax rate (as a percent)	12.50%
AMC | Minimum
Income Taxes
Percentage of ownership by parent				80.00%

INCOME TAXES_ - Provision (Deta

INCOME TAXES: - Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
U.S. federal and state:
Current	$ 2.6
Deferred	(13)	$ 686.2	$ (109.4)
Uncertain tax positions		16.2	20.3
Provision for income taxes	(10.4)	702.4	(89.1)
Foreign (Peru and Mexico):
Current	1,102.4	951.7	625
Deferred	(38.5)	(60.7)	(34.8)
Provision for income taxes	1,063.9	891	590.2
Total income tax provision	1,053.5	1,593.4	501.1
Earnings by location:
U.S.	(2.3)	(1.5)	(1.9)
Peru	441.8	284.6	(85.7)
Mexico	2,149.9	2,019.6	1,343.6
Foreign	2,591.7	2,304.2	1,257.9
Income before income taxes	$ 2,589.4	$ 2,302.7	$ 1,256

INCOME TAXES_ - Effective tax r

INCOME TAXES: - Effective tax rate (Details) - item	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of the statutory income tax rate to the effective tax rate
Expected tax at U.S. statutory rate (as a percent)	21.00%	35.00%	35.00%
Foreign tax at other than statutory rate, net of foreign tax credit benefit (as a percent)	13.90%	0.60%	2.00%
Percentage depletion (as a percent)	(2.10%)	(2.90%)	(2.70%)
Other permanent differences (as a percent)	0.40%	5.20%
Change in 2017 valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred	7.50%	26.90%
Additional valuation allowance on 2018 U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred	1.00%
Decrease in U.S. deferred tax asset due to tax rate changes	(0.20%)	4.80%
U.S. one time transition tax on accumulated foreign earnings	0.40%	2.40%
Increase (decrease) in unrecognized tax benefits for uncertain tax positions (as a percent)		0.70%	0.20%
Repatriated foreign earnings (as a percent)		(2.00%)	3.60%
Amounts (over) / under provided in prior years	(1.30%)	(0.10%)	(0.50%)
Other (as a percent)	0.10%	(1.40%)	2.30%
Effective income tax rate	40.70%	69.20%	39.90%
Number of jurisdictions where company files income tax returns	3
Duration for which statutory tax rates for Peru and Mexico are considered to determine effective tax rate	3 years
Mexico
Reconciliation of the statutory income tax rate to the effective tax rate
Expected tax at U.S. statutory rate (as a percent)	30.00%	30.00%	30.00%
Peru
Reconciliation of the statutory income tax rate to the effective tax rate
Expected tax at U.S. statutory rate (as a percent)	29.50%	29.50%	28.00%

INCOME TAXES_ - Tax assets and

INCOME TAXES: - Tax assets and liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets:
Inventories	$ 61.5	$ 47
Capitalized exploration expenses	11.1	9.5
U.S. foreign tax credit carryforward, net of FIN 48 liability	483.4	280.2
U.S. tax effect of Peruvian deferred tax liability	165.1	174.1
Provisions	155	152.6
Mexican tax on consolidated dividends	14.8	14.5
Deferred workers participation	27	3
Accrued salaries, wages and vacations	9.1	7.2
Sales price adjustment (PUI)	2.7
Social responsibility expenses	2.1	2.1
Deferred charges	6.1
Valuation allowance on U.S. deferred tax assets, foreign tax credits and U.S. tax effect on Peruvian deferred	(819.1)	(619.6)
Other	10.1	1.6
Total deferred tax assets	128.9	72.2
Liabilities:
Property, plant and equipment	(137.3)	(130.3)
Deferred charges		(16.9)
Sales price adjustment (PUI)		(0.4)
Other	(0.4)	(5.3)
Total deferred tax liabilities	(137.7)	(152.9)
Total net deferred tax (liabilities) / assets	(8.8)	$ (80.7)
Increase in valuation allowance	$ 199.5
U.S. statutory rate (as a percent)	21.00%	35.00%	35.00%

INCOME TAXES_ - Carryforward (D

INCOME TAXES: - Carryforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Foreign tax credits
Other U.S. tax credits	$ 0
Unrecognized Tax Benefits	$ 214.5	$ 214.5	$ 304	$ 400
Income Tax Rate (as a percent)	21.00%	35.00%	35.00%
Mexico
Foreign tax credits
Unrecognized Tax Benefits	$ 0
Income Tax Rate (as a percent)	30.00%	30.00%	30.00%
Peru
Foreign tax credits
Unrecognized Tax Benefits	$ 0
Income Tax Rate (as a percent)	29.50%	29.50%	28.00%
Foreign
Foreign tax credits
Tax credits carryback period	1 year
Tax credits carryforward period	10 years
Increase in foreign tax credits	$ 15.9
Unrecognized Tax Benefits	205.7
Foreign tax credit carryforward	689.1
Foreign tax credit carryforward net of unrecognized tax benefit	483.4
2022 | Foreign
Foreign tax credits
Foreign tax credit carryforward	51.5
2023 | Foreign
Foreign tax credits
Foreign tax credit carryforward	69.2
2024 | Foreign
Foreign tax credits
Foreign tax credit carryforward	102
2025 | Foreign
Foreign tax credits
Foreign tax credit carryforward	189.5
2026 | Foreign
Foreign tax credits
Foreign tax credit carryforward	104.8
2028 | Foreign
Foreign tax credits
Foreign tax credit carryforward	$ 172.1

INCOME TAXES_ - Other (Details)

INCOME TAXES: - Other (Details) S/ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018PEN (S/)	Dec. 31, 2018USD ($)item	Dec. 31, 2017PEN (S/)	Dec. 31, 2017USD ($)	Dec. 31, 2016PEN (S/)	Dec. 31, 2016USD ($)	Oct. 31, 2017	Sep. 30, 2017
Income Taxes
Cash, cash equivalents, restricted cash and short-term investments		$ 1,058.4
Estimated one time transition tax on foreign earnings and profits				$ 8,900
U.S. federal income tax		0
State income tax		0
Provisional tax amount				181.1
Reduced tax amount from provisional tax amount		28
Finalized transition tax liability		153.1
Deferred tax asset		128.9		72.2
State income tax liability		0
Withholding taxes due to the tax treaty between the United States and Mexico		0
Withholding tax rate on interest							0.46%	0.58%
Changes in unrecognized tax benefits
Unrecognized tax benefits, opening balance		214.5		304		$ 400
Gross increases - tax positions in prior period						3.9
Gross decreases - tax positions in prior period				(89.5)
Gross increases - current-period tax positions						23.3
Decreases related to settlements with taxing authorities						(123.2)
Increase (decrease) in unrecognized tax benefits				(89.5)		(96)
Unrecognized tax benefits, ending balance		214.5		214.5		304
Amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate		$ 214.5		214.5
Period of unrecognized tax benefits are expected to be reversed	12 months	12 months
Accrued interest and penalties included in liability for uncertain tax positions		$ 1.9		1.9
Number of major tax jurisdictions | item		3
Minera Mexico
Income Taxes
Earnings available for dividends to United States				555.5		470.5
Unremitted foreign earnings						45.7
Foreign subsidiaries
Income Taxes
Cash, cash equivalents, restricted cash and short-term investments		$ 97.6
Deferred tax asset		1,900
Foreign
Changes in unrecognized tax benefits
Unrecognized tax benefits, ending balance		$ 205.7
Peru
Income Taxes
Royalty charge assessed as a percentage of net sales	1.00%	1.00%
Royalty charges | S/	S/ 32.9		S/ 23.4		S/ 16.8
Provision for royalty tax		$ 9		2.5		0
Peruvian special mining tax		30.6		$ 23.3		$ 10.8
Changes in unrecognized tax benefits
Unrecognized tax benefits, ending balance		$ 0
Peru | Minimum
Income Taxes
Mining royalty tax (as a percent)	1.00%	1.00%
Special mine tax (as a percent)	2.00%	2.00%
Peru | Maximum
Income Taxes
Mining royalty tax (as a percent)	12.00%	12.00%
Special mine tax (as a percent)	8.40%	8.40%
Mexico
Changes in unrecognized tax benefits
Unrecognized tax benefits, ending balance		$ 0

WORKERS' PARTICIPATION_ (Detail

WORKERS' PARTICIPATION: (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Statutory workers' participation
Current	$ 219.9	$ 192.7	$ 131.8
Deferred	9.8	6.6	(13.4)
Workers' participation expense (in USD)	$ 229.7	$ 199.3	$ 118.4
Peru
Statutory workers' participation
Provision for workers' participation as a percentage of pre-tax earnings	8.00%
Number of months for which an individual worker's salary is capped for consideration of annual individual worker participation	18 months
Maximum taxable units contributed by employer to benefit fund (in Peruvian taxable units) | item	2,200
Maximum employer contribution to benefit fund (in USD)	$ 2.7
Mexico
Statutory workers' participation
Provision for workers' participation as a percentage of pre-tax earnings	10.00%

ASSET RETIREMENT OBLIGATION_ (D

ASSET RETIREMENT OBLIGATION: (Details) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2017USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)item	Dec. 31, 2017USD ($)
Asset retirement obligation activity
Balance at the beginning of the year			$ 222.5	$ 222.5	$ 216.5
Changes in estimates				(15.6)	(11.6)
Closure Payments				(0.6)	(0.3)
Accretion expense				11.4	17.9
Balance at the end of the year	$ 222.5			217.7	$ 222.5
Mexico
ASSET RETIREMENT OBLIGATION:
Plant demolition and soil remediation cost				$ 66.2
Asset retirement obligation activity
Changes in estimates		$ (10.4)
Peru
ASSET RETIREMENT OBLIGATION:
Period after which successive reviews are required by the law (in years)				5 years
Accepted value of the Lima office complex and warehouse				$ 45.3
Cumulative guarantee amount				$ 37.8
Number of units with future closure costs recognized as an asset retirement obligation | item				3
Asset retirement obligation activity
Changes in estimates	$ (11.6)		$ (5.2)

FINANCING_ - Debt instruments (

FINANCING: - Debt instruments (Details) $ in Millions	Apr. 20, 2015USD ($)tranche	Dec. 31, 2018USD ($)itemgrade	Nov. 30, 2012USD ($)item	Dec. 31, 2017USD ($)
FINANCING
Face amount		$ 6,125	$ 4,200	$ 6,125
Issuance discount		(58.8)		(60.5)
Issuance costs	$ (11.8)	(32.3)		(33.6)
Carrying value		5,960.1		5,957.1
Total long term debt		$ 5,960.1		5,957.1
Number of tranches | tranche	2
Underwriters discount	$ 20.2
Number of times for which senior unsecured notes were issued | item			6
Percentage of principal amount at which notes may be required to be repurchased in event of change of control in the entity		101.00%
Minimum
FINANCING
Number of decreased gradations that could cause a change of control triggering event | grade		1
5.375% Senior unsecured notes due 2020
FINANCING
Face amount		$ 400		400
Issuance discount		(0.3)		(0.6)
Issuance costs		(0.4)		(0.6)
Carrying value		$ 399.3		$ 398.8
Interest rate (as a percent)		5.375%		5.375%
3.500% Senior unsecured notes due 2022
FINANCING
Face amount		$ 300		$ 300
Issuance discount		(0.5)		(0.5)
Issuance costs		(0.6)		(0.8)
Carrying value		$ 298.9		$ 298.7
Interest rate (as a percent)		3.50%		3.50%
3.875% Senior unsecured notes due 2025
FINANCING
Face amount	$ 500	$ 500		$ 500
Issuance discount		(1.8)		(2.1)
Issuance costs		(1.8)		(2)
Carrying value		$ 496.4		$ 495.9
Interest rate (as a percent)	3.875%	3.875%		3.875%
9.250% Yankee Bonds due 2028
FINANCING
Face amount		$ 125		$ 125
Carrying value		$ 51.2		$ 51.2
Interest rate (as a percent)		9.25%		9.25%
9.250% Yankee Bonds due 2028 | Minera Mexico | Minimum
FINANCING
Ratio of EBITDA to interest expense | item		2.5
7.500% Senior unsecured notes due 2035
FINANCING
Face amount		$ 1,000		$ 1,000
Issuance discount		(12.9)		(13.2)
Issuance costs		(8.4)		(8.8)
Carrying value		$ 978.7		$ 978
Interest rate (as a percent)		7.50%		7.50%
6.750% Senior unsecured notes due 2040
FINANCING
Face amount		$ 1,100		$ 1,100
Issuance discount		(7.3)		(7.4)
Issuance costs		(5.8)		(5.9)
Carrying value		$ 1,086.9		$ 1,086.7
Interest rate (as a percent)		6.75%		6.75%
5.250% Senior unsecured notes due 2042
FINANCING
Face amount		$ 1,200		$ 1,200
Issuance discount		(19.4)		(19.8)
Issuance costs		(6.5)		(6.6)
Carrying value		$ 1,174.1		$ 1,173.6
Interest rate (as a percent)		5.25%		5.25%
5.875% Senior unsecured notes due 2045
FINANCING
Face amount	$ 1,500	$ 1,500		$ 1,500
Issuance discount		(16.6)		(16.9)
Issuance costs		(8.8)		(8.9)
Carrying value		$ 1,474.6		$ 1,474.2
Interest rate (as a percent)	5.875%	5.875%		5.875%
Fixed-rate senior unsecured notes issued in April 2015
FINANCING
Face amount	$ 2,000

FINANCING_ - Outstanding borrow

FINANCING: - Outstanding borrowing (Details) $ in Millions	Dec. 31, 2018USD ($)
Aggregate maturities of the outstanding borrowings
2,020	$ 400
2,022	300
Thereafter	5,351.2
Total	6,051.2
Total debt discount	$ 91.1

BENEFIT PLANS_ - Other (Details

BENEFIT PLANS: - Other (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)plan	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Benefit plans
Number of noncontributory defined benefit pension plans | plan	2
Post retirement defined benefit plans and defined contribution plan
Defined benefit plan, net periodic benefit costs
Service cost	$ 1	$ 0.8	$ 0.7
Interest cost	1.6	1.4	1
Expected return on plan assets	(3.4)	(2.9)	(2.2)
Amortization of prior service cost (credit)	0.2	0.1	0.1
Settlement / Curtailment	(0.2)	0.1	(0.2)
Amortization of net loss (gain)	0.2	0.2	0.2
Net periodic benefit cost	(0.6)	(0.3)	(0.4)
Change in benefit obligation:
Projected benefit obligation at beginning of year	27.5	25.6
Service cost	1	0.8	0.7
Interest cost	1.6	1.4	1
Settlement		0.9
Benefits paid	(1.6)	(1.9)
Actuarial (gain)/loss	(0.2)	(0.3)
Actuarial gain assumption changes	(0.8)	0.3
Inflation adjustment	(0.1)	0.7
Projected benefit obligation at end of year	27.4	27.5	25.6
Change in plan assets:
Fair value of plan assets at beginning of year	51.6	44.6
Actual return on plan assets	(3.5)	6.9
Employer contributions	(0.4)	(0.4)
Benefits paid	(1)	(0.9)
Currency exchange rate adjustment		1.4
Fair value of plan assets at end of year	46.7	51.6	44.6
Funded status at end of year				$ 19.3	$ 24.1
Amounts recognized in statement of financial position
Non-current assets				19.4	24.2
Total				19.4	24.2
Amounts recognized in accumulated other comprehensive income
Net loss (gain)				5.8	2.3
Prior service cost (credit)				1.4	1.5
Total, net of tax	3.8	5.8	5.8	7.2	3.8
Net loss (gain), income taxes				(4.3)	(2)
Reconciliation of accumulated other comprehensive income:
Accumulated other comprehensive income at beginning of plan year	3.8	5.8
Net loss/(gain) amortized during the year	3.6	(0.1)
Net loss/(gain) occurring during the year	(0.1)	(2.4)
Prior service cost (credit)		0.4
Currency exchange rate adjustment	(0.1)	0.1
Net adjustment to accumulated other comprehensive income	3.4	(2)
Accumulated other comprehensive income at end of plan year	7.2	3.8	$ 5.8
Net adjustment to accumulated other comprehensive income, income taxes	(2.2)	1.3
Amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of income tax
Net loss / (gain)	3.6	(2.4)
Amortization of net (loss) gain	(0.1)	(0.1)
Prior service cost (credit)		0.4
Total amortization expenses	$ 3.5	$ (2.1)
Expected Benefit Payments
2,019				2.6
2,020				1.7
2,021				1.8
2,022				1.9
2,023				2
2024 to 2026				13.4
Total				23.4
Post retirement defined benefit plans and defined contribution plan | Expatriate Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Discount rate (as a percent)	3.90%	3.25%	3.65%
Expected long-term rate of return on plan asset (as a percent)	4.00%	4.00%	4.00%
Post retirement defined benefit plans and defined contribution plan | Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Discount rate (as a percent)	8.45%	7.80%	7.55%
Expected long-term rate of return on plan asset (as a percent)	8.45%	7.55%	7.55%
Rate of increase in future compensation level (as a percent)	4.50%	4.50%	4.50%
Post-retirement Health care plans
Defined benefit plan, net periodic benefit costs
Interest cost	$ 0.9	$ 0.9	$ 0.6
Amortization of prior service cost (credit)	(0.2)	(0.2)	(0.5)
Net periodic benefit cost	0.7	0.7	0.1
Change in benefit obligation:
Projected benefit obligation at beginning of year	12.5	12.9
Interest cost	0.9	0.9	0.6
Actuarial loss/ (gain) - claims cost	0.2	(0.4)
Benefits paid	(0.9)	(0.9)
Actuarial (gain)/loss	(0.9)	(0.6)
Inflation adjustment	0.1	0.6
Projected benefit obligation at end of year	11.9	12.5	12.9
Change in plan assets:
Employer contributions	(0.1)	(0.1)
Benefits paid	(0.1)	(0.1)
Funded status at end of year				11.9	12.5
Amounts recognized in statement of financial position
Current liabilities				(0.1)	(0.1)
Non-current liabilities				(11.8)	(12.5)
Total				(11.9)	(12.6)
Amounts recognized in accumulated other comprehensive income
Net loss (gain)				(4.4)	(3.9)
Total, net of tax	(3.9)	(2.8)	(2.8)	(4.4)	(3.9)
Net loss (gain), income taxes				1.9	$ 1.7
Reconciliation of accumulated other comprehensive income:
Accumulated other comprehensive income at beginning of plan year	(3.9)	(2.8)
Net loss/(gain) amortized during the year	0.1	0.1
Net loss/(gain) occurring during the year	(0.6)	(0.6)
Currency exchange rate adjustment		(0.6)
Net adjustment to accumulated other comprehensive income	(0.5)	(1.1)
Accumulated other comprehensive income at end of plan year	(4.4)	(3.9)	$ (2.8)
Net adjustment to accumulated other comprehensive income, income taxes	0.2	0.3
Amounts in accumulated other comprehensive income amortized and recognized as a component of net periodic benefit cost, net of income tax
Net loss / (gain)	(0.6)	(0.6)
Amortization of net (loss) gain	0.2	0.1
Total amortization expenses	$ (0.4)	$ (0.5)
Expected Benefit Payments
2,019				0.9
2,020				0.9
2,021				0.9
2,022				0.9
2,023				0.9
2024 to 2028				2.9
Total				$ 7.4
Post-retirement Health care plans | Expatriate Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Discount rate (as a percent)	3.90%	3.25%	3.65%
Expected Benefit Payments
Assumed trend rate for covered health care benefit cost (as a percent)	5.80%
Assumed trend rate for covered health care benefit cost post-65 years of age (as a percent)	5.20%
Assumed ultimate trend rate for health care benefit cost (as a percent)				4.20%
Assumed ultimate trend rate for health care benefit cost post-65 years of age (as a percent)	4.00%
Post-retirement Health care plans | Mexican Health Plan
Expected Benefit Payments
Assumed trend rate for covered health care benefit cost (as a percent)		4.50%
Effect of one percentage-point change in assumed other benefit cost trend rates
Effect of one percentage-point increase on total service and interest cost components	$ 1
Effect of one percentage-point decrease on total service and interest cost components	0.8
Effect of one percentage-point increase on post-retirement benefit obligation	11.7
Effect of one percentage-point decrease on post-retirement benefit obligation	$ 10.5
Post-retirement Health care plans | Weighted average | Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Discount rate (as a percent)	8.45%	7.80%	7.55%

BENEFIT PLANS_ - Post retiremen

BENEFIT PLANS: - Post retirement (Details) - Post retirement defined benefit plans and defined contribution plan $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)entity$ / shares	Dec. 31, 2017
Expatriate Plan
Benefit plans
Net asset value (in dollars per share) | $ / shares	$ 1
Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Number of financial institutions managing plan assets | entity	3
Plan obligations as a percentage of benefit obligation	30.00%
Asset allocation (as a percent)	100.00%	100.00%
Expected employer contribution in next fiscal year	$ 1.7
Pending payments to former Buenavista workers	$ 2.7
Parent Company (Grupo Mexico) common shares | Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Asset allocation (as a percent)	22.00%
Treasury bills | Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Asset allocation (as a percent)	78.00%	70.00%
Equity securities | Mexican Health Plan
Assumptions used to determine the pension obligation and other post-retirement benefits and cost
Asset allocation (as a percent)	22.00%	30.00%

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES: - Environmental matters (Details) $ in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2011categoryperson
Environmental costs
Environmental capital investment		$ 102.8	$ 222.6	$ 250.4
Peru
Environmental costs
Environmental capital investment		59.3	93.7	110.3
Number of months for identification of contaminated sites and around in facilities	12 months
Period for preparation of decontamination plan	P30M
Period of extension for preparation of decontamination plan	1 year
Number of days in which results of soil confirmation tests are to be presented to authorities	30 days
Mexico
Environmental costs
Environmental capital investment		$ 43.5	$ 128.9	$ 140.1
Number of categories of collective actions | category					3
Minimum number of people claiming injury due to collective action initiative in Civil Federal Procedures Code (CFPC) | person					30

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES: - Litigation matters (Details)	Dec. 27, 2018USD ($)	Sep. 30, 2016lawsuit	Jun. 30, 2015lawsuititem	Dec. 31, 2018lawsuit	Dec. 31, 2015lawsuititem	Dec. 31, 2012item	Dec. 31, 2005item	Dec. 31, 2017lawsuit	Dec. 31, 2016lawsuit	Mar. 31, 2012
Litigation Matter
Number of collective action lawsuits			6
Number of collective action lawsuits dismissed			2
Remaining number of lawsuits			4
Number of civil actions seeking damages								33
Number Of Constitutional Action Lawsuits					4
Number of subsidiaries to which environmental impact authorizations were granted | item					1
Number of subsidiaries against which lawsuits were filed | item			2
Tia Maria
Litigation Matter
Number of lawsuits				3
Grupo Mexico and Americas Mining
Litigation Matter
Amount of litigation settlement | $	$ 50,000,000
Attorneys fees | $	13,500,000
Incentive fee | $	5,000
Special dividend | $	$ 36,500,000
Buenavista del Cobre, S.A. de C.V
Litigation Matter
Number of civil actions seeking damages					8				3
Mexico Generadora de Energia, S. de R.L. ("MGE") | Controladora de Infraestructura Energetica Mexico, S. A. de C. V.
Litigation Matter
Acquisition percentage										99.999%
Mexico | Mexico Generadora de Energia, S. de R.L. ("MGE")
Litigation Matter
Number of power plants | item						2	2
Mexico | Mexico Generadora de Energia, S. de R.L. ("MGE") | Controladora de Infraestructura Energetica Mexico, S. A. de C. V.
Litigation Matter
Acquisition percentage						99.999%
Francisca Garcia Enriquez
Litigation Matter
Number of additional constitutional lawsuits filed					2
Mario Alberto Salcido et al; Maria Elena Heredia Bustamante et al; Martin Eligio Ortiz Gamez et al and Maria de los Angeles Enriquez Bacame et al
Litigation Matter
Number of additional constitutional lawsuits filed		4
Norberto Bustamante et al
Litigation Matter
Number of additional constitutional lawsuits filed				2

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES: - Labor matters (Details)	1 Months Ended				3 Months Ended	12 Months Ended
	Aug. 31, 2018PEN (S/)item	Aug. 31, 2018USD ($)item	Jun. 30, 2018PEN (S/)	Jun. 30, 2018USD ($)	Mar. 31, 2016	Dec. 31, 2018USD ($)item	Aug. 22, 2018USD ($)
Peru | Labor Matters
Labor matters
Percentage of labor unionized						75.00%
Total number of workers						4,850
Number of labor unions						6
Number of labor unions represent majority of workers						1
Number of labor unions other than majority workers unions						5
Term of agreement	3 years	3 years	3 years	3 years	3 years
Annual salary increase (as a percent)	5.00%	5.00%	5.00%	5.00%	5.00%
Labor expense	S/ 45,000	$ 13,600	S/ 45,000	$ 13,600
Number of additional unions	3	3
Number of unsigned unions						2
Mexico | San Martin
Labor matters
Budgeted cost for rehabilitation of mine | $							$ 77,000,000
Total expense incurred on rehabilitation of mine till date | $						$ 17,700,000

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES: - Other (Details) S/ in Millions, $ in Millions	1 Months Ended				12 Months Ended
	Jun. 30, 2018USD ($)T	May 31, 2016MW	Jul. 31, 2014MW	Jun. 30, 2014MW	Dec. 31, 2018PEN (S/)itemmkmT	Dec. 31, 2018USD ($)itemmkmT	Dec. 31, 2017USD ($)
Other commitments
Amount accrued for project to evaluate the next 3 to 5 years						$ 68.2	$ 37.2
Commitment for capital projects						343.1
Tia Maria | Peru
Other commitments
Project budget						1,400
Amount spend as of the current date						$ 333.9
Annual production ( in tons) | T					120,000	120,000
Distance of sea water transportation | km					25	25
Height above sea level of the desalinization plant | m					1,000	1,000
Additional investment in desalinization plant						$ 95
Number of jobs expected to be generated | item					9,000	9,000
Number of direct jobs expected to be generated | item					3,600	3,600
Number of indirect jobs expected to be generated | item					5,400	5,400
Number of workers expected to be directly employed | item					600	600
Number of workers expected to be indirectly employed | item					4,200	4,200
Term life of environmental project (in years)					20 years	20 years
Toquepala Concentrator Expansion | Peru
Other commitments
Project budget						$ 1,300
Amount spend as of the current date						1,227
Amount committed to funding for social and infrastructure improvement projects					S/ 445.0	131.7
Development Fund Moquegua Region | Peru
Other commitments
Amount committed to funding for social and infrastructure improvement projects					S/ 700.0	$ 207.2
Copper | Michiquillay | Peru
Other commitments
Annual production ( in tons) | T	225,000
Contingent contractual obligation	$ 400
Estimated mineralized material (in tons) | T	1,150,000,000
Copper grade percentage	0.63%
Initial mine life	25 years
Contractual obligation paid on project	$ 12.5
Amount accrued for project to evaluate the next 3 to 5 years	12.5
Remaining amount to pay if project is developed	$ 375
Copper | Toquepala Concentrator Expansion | Peru
Other commitments
Estimated increase in annual production (in tons) | T					100,000	100,000
Molybdenum | Toquepala Concentrator Expansion | Peru
Other commitments
Estimated increase in annual production (in tons) | T					3,100	3,100
Power purchase agreements | Electroperu S.A | Peru
Other commitments
Purchase agreement, contracted power capacity (in megawatts) | MW				120
Term of power purchase agreement related to sale of power plant				20 years
Power purchase agreements | Kallpa | Peru
Other commitments
Purchase agreement, contracted power capacity (in megawatts) | MW			120
Term of power purchase agreement related to sale of power plant		10 years	10 years
Power purchase agreements | Kallpa | Peru | Maximum
Other commitments
Purchase agreement, contracted power capacity (in megawatts) | MW		80
Educational Project | Development Fund Moquegua Region | Peru
Other commitments
Amount committed to funding for social and infrastructure improvement projects					S/ 108.5	$ 32.1
Water Treatment | Development Fund Moquegua Region | Peru
Other commitments
Amount committed to funding for social and infrastructure improvement projects					48.4	14.3
Social Investment For Taxes | Development Fund Moquegua Region | Peru
Other commitments
Amount committed to funding for social and infrastructure improvement projects					S/ 202.0	$ 59.8
Number of infrastructure projects agreed for construction | item					6	6

STOCKHOLDERS' EQUITY - Treasury

STOCKHOLDERS' EQUITY - Treasury Stock (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Activity in treasury stock
Balance at the beginning of the period	$ 3,001.1
Balance at the end of the period	$ 3,019.6	$ 3,001.1
Southern copper common shares
Activity in treasury stock
Treasury stock balance at the end of the period (in shares)	111,551,617	111,567,617
Parent Company (Grupo Mexico) common shares
Activity in treasury stock
Purchase of shares	$ 2,900
TREASURY STOCK: | Southern copper common shares
Activity in treasury stock
Balance at the beginning of the period	2,768.7	$ 2,769
Purchase of shares			$ 71.7
Used for corporate purposes	(0.4)	(0.3)	(0.3)
Balance at the end of the period	2,768.3	2,768.7	2,769
TREASURY STOCK: | Parent Company (Grupo Mexico) common shares
Activity in treasury stock
Balance at the beginning of the period	232.4	218.6
Other activity, including dividend, interest and foreign currency transaction effect	18.9	13.8	7.3
Balance at the end of the period	$ 251.3	$ 232.4	$ 218.6

STOCKHOLDERS' EQUITY - Repurcha

STOCKHOLDERS' EQUITY - Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2008
SCC share repurchase program:
Amount authorized for share repurchase program	$ 3,000	$ 500
Closing price of NYSE (in dollars per share)	$ 30.77
Maximum Number of Shares that May Yet Be Purchased Under the Plan @ $30.77	2.7
Percentage of Ownership by Parent	88.90%
Parent Company (Grupo Mexico) common shares
SCC share repurchase program:
Total Number of Shares Purchased	119.5
Cost of purchase of shares	$ 2,900

STOCKHOLDERS' EQUITY_ - Directo

STOCKHOLDERS' EQUITY: - Directors' Stock Award Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Parent Company (Grupo Mexico) common shares
Activity in directors' stock award plan
Treasury stock balance at the end of the period (in shares)	100,188,809	108,450,672
Directors' Stock Award Plan
Share based Compensation Plan
Common shares received on election as director	1,200
Additional shares issued at each annual general meeting	1,200
Total SCC shares reserved for the plan	600,000	600,000
Period of extension of plan	5 years
Increased share awards issued to directors	1,600
Activity in directors' stock award plan
Total shares granted at the beginning of the period (in shares)	(346,800)	(334,800)
Granted in the period	(16,000)	(12,000)
Total shares granted at the end of the period (in shares)	(362,800)	(346,800)
Remaining shares reserved	237.200	253,200
Share based compensation
Stock based compensation expense	$ 0.4	$ 0.4

STOCKHOLDERS' EQUITY - Compensa

STOCKHOLDERS' EQUITY - Compensation Plan (Details) $ / shares in Units, $ in Millions	1 Months Ended				12 Months Ended
	Nov. 30, 2018$ / shares	Nov. 30, 2018$ / shares	Jan. 31, 2015$ / shares	Jan. 31, 2015$ / shares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2010$ / shares	Dec. 31, 2010$ / shares
Peruvian Operations
Non-controlling interest
Investment shareholders' interest in Peruvian Branch (as a percent)					0.71%
Employee Stock Purchase 2010 Plan
Information related to compensation cost
Purchase price for initial subscription (in dollars per share) | (per share)								$ 1.28	$ 26.51
Percentage of title acquired by employee in every two years on shares paid in previous two years					50.00%
Period of plan					8 years
Ratio of bonus shares granted to participant					0.1
Stock based compensation expense | $					$ 0.2	$ 0.6	$ 0.6
Unrecognized compensation expense | $						$ 0.2	$ 0.8
Stock award activity, Shares
Outstanding shares at the beginning of the period | shares					1,393,663	1,401,096
Exercised (in shares) | shares					(1,275,729)	(7,433)
Outstanding shares at the end of the period | shares					117,934	1,393,663	1,401,096
Unit Weighted Average Grant Date Fair Value
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares					$ 2.05	$ 2.05
Exercised (in dollars per share) | $ / shares					2.05	2.05
Outstanding shares at the end of the period (in dollars per share) | $ / shares					2.05	$ 2.05	$ 2.05
Employee Stock Purchase 2015 Plan
Information related to compensation cost
Purchase price for initial subscription (in dollars per share) | (per share)			$ 1.86	$ 38.44	$ 1.86
Percentage of title acquired by employee in every two years on shares paid in previous two years					50.00%
Period of plan					8 years
Ratio of bonus shares granted to participant					0.1
Stock based compensation expense | $					$ 0.6	$ 0.6	$ 0.6
Unrecognized compensation expense | $					$ 2.6	$ 3.2	$ 3.8
Stock award activity, Shares
Outstanding shares at the beginning of the period | shares					2,293,120	2,540,223
Exercised (in shares) | shares					(452,784)	(247,103)
Outstanding shares at the end of the period | shares					1,840,336	2,293,120	2,540,223
Unit Weighted Average Grant Date Fair Value
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares					$ 2.63	$ 2.63
Exercised (in dollars per share) | $ / shares					2.63	2.63
Outstanding shares at the end of the period (in dollars per share) | $ / shares					$ 2.63	$ 2.63	$ 2.63
Employee Stock Purchase 2018 Plan
Information related to compensation cost
Purchase price for initial subscription (in dollars per share) | (per share)	$ 1.86	$ 37.89
Percentage of title acquired by employee in every two years on shares paid in previous two years	50.00%	50.00%
Period of plan	8 years	8 years
Ratio of bonus shares granted to participant	0.1	0.1
Unrecognized compensation expense | $					$ 3.6
Stock award activity, Shares
Granted in the period | shares					2,782,424
Outstanding shares at the end of the period | shares					2,782,424
Unit Weighted Average Grant Date Fair Value
Granted (in dollars per share) | $ / shares					$ 1.86
Outstanding shares at the end of the period (in dollars per share) | $ / shares					$ 1.86
Employee Stock Purchase 2018 Plan | Resignation occurs during 1st year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					90.00%
Percentage of deduction for involuntary termination					100.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 2nd year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					80.00%
Percentage of deduction for involuntary termination					95.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 3rd year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					70.00%
Percentage of deduction for involuntary termination					90.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 4th year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					60.00%
Percentage of deduction for involuntary termination					80.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 5th year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					50.00%
Percentage of deduction for involuntary termination					70.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 6th year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					40.00%
Percentage of deduction for involuntary termination					60.00%
Employee Stock Purchase 2018 Plan | Resignation occurs during 7th year after grant date
Information related to compensation cost
Percentage of deduction for voluntary resignation					20.00%
Percentage of deduction for involuntary termination					50.00%

FAIR VALUE MEASUREMENT (Details

FAIR VALUE MEASUREMENT (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Liabilities:
Long-term debt, Carrying Value	$ 5,960.1	$ 5,957.1
Long-term debt, Fair Value	6,301.7	7,295
Short-term investment:
Trading securities	213.1	49.5
Available-for-sale:
Available-for-sale debt securities	0.7	1
Available-for-sale Securities, Current, Total	0.7	1
Quoted prices in active markets for identical assets (Level 1)
Liabilities:
Long-term debt, Carrying Value	5,210.7	5,208.4
Long-term debt, Fair Value	5,540	6,488.9
Significant other observable inputs (Level 2)
Liabilities:
Long-term debt, Carrying Value	749.4	748.7
Long-term debt, Fair Value	761.7	806.1
Fair value measurements recurring | Fair value as of the end of the period
Short-term investment:
Trading securities	213.1	49.5
Derivative:
Total assets, fair value	595.5	337.9
Fair value measurements recurring | Fair value as of the end of the period | Copper
Derivative:
Provisionally priced sales	274.3	184.6
Fair value measurements recurring | Fair value as of the end of the period | Molybdenum
Derivative:
Provisionally priced sales	107.4	102.8
Fair value measurements recurring | Corporate bonds | Fair value as of the end of the period
Available-for-sale:
Available-for-sale debt securities		0.1
Fair value measurements recurring | Asset backed securities | Fair value as of the end of the period
Available-for-sale:
Available-for-sale debt securities	0.4	0.5
Fair value measurements recurring | Mortgage backed securities | Fair value as of the end of the period
Available-for-sale:
Available-for-sale debt securities	0.3	0.4
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1)
Short-term investment:
Trading securities	213.1	49.5
Derivative:
Total assets, fair value	594.8	336.9
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1) | Copper
Derivative:
Provisionally priced sales	274.3	184.6
Fair value measurements recurring | Quoted prices in active markets for identical assets (Level 1) | Molybdenum
Derivative:
Provisionally priced sales	107.4	102.8
Fair value measurements recurring | Significant other observable inputs (Level 2)
Available-for-sale:
Available-for-sale Securities, Current, Total	0.7	1
Fair value measurements recurring | Significant other observable inputs (Level 2) | Corporate bonds
Available-for-sale:
Available-for-sale debt securities		0.1
Fair value measurements recurring | Significant other observable inputs (Level 2) | Asset backed securities
Available-for-sale:
Available-for-sale debt securities	0.4	0.5
Fair value measurements recurring | Significant other observable inputs (Level 2) | Mortgage backed securities
Available-for-sale:
Available-for-sale debt securities	$ 0.3	$ 0.4

CONCENTRATION OF RISK_ (Details

CONCENTRATION OF RISK: (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)item	Dec. 31, 2017	Dec. 31, 2016
Concentration of risk
Number of open-pit copper mines | item	4
Number of underground poly metallic mines | item	5
Number of smelters | item	2
Number of refineries | item	10
Cash equivalents
Concentration of risk
Total cash and short-term investment	$ 1,058.4
Percentage of total cash	100.00%
Percentage of cash in US dollars	95.80%
Cash equivalents | United States
Concentration of risk
Total cash and short-term investment	$ 697.1
Percentage of total cash	65.90%
Percentage invested in one institution of country	27.70%
Percentage invested in one institution of total cash	18.30%
Cash equivalents | Switzerland
Concentration of risk
Total cash and short-term investment	$ 315.7
Percentage of total cash	29.80%
Percentage invested in one institution of country	61.20%
Percentage invested in one institution of total cash	18.30%
Cash equivalents | Peru
Concentration of risk
Total cash and short-term investment	$ 7.6
Percentage of total cash	0.70%
Percentage invested in one institution of country	75.60%
Percentage invested in one institution of total cash	0.50%
Cash equivalents | Mexico
Concentration of risk
Total cash and short-term investment	$ 38
Percentage of total cash	3.60%
Percentage invested in one institution of country	89.30%
Percentage invested in one institution of total cash	3.20%
Accounts receivable trade | Five largest customers
Concentration of risk
Percentage of accounts receivable and total sales	34.20%	28.40%	31.10%
Accounts receivable trade | Largest customer
Concentration of risk
Percentage of accounts receivable and total sales	10.90%	8.20%	11.90%
Total sales | Five largest customers
Concentration of risk
Percentage of accounts receivable and total sales	28.40%	25.10%	30.40%
Total sales | Largest customer
Concentration of risk
Percentage of accounts receivable and total sales	9.30%	8.80%	8.40%

RELATED PARTY TRANSACTIONS_ (De

RELATED PARTY TRANSACTIONS: (Details) $ in Millions, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	May 31, 2010USD ($)	Mar. 31, 2012USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2012itemMW	Dec. 31, 2005item	Dec. 31, 2014item	Mar. 31, 2012MXN ($)	Mar. 31, 2012USD ($)
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			$ 101.5	$ 26.1	$ 23.4
Related parties payable:			75.3	90.1
Grupo Mexico and affiliates
RELATED PARTY TRANSACTIONS:
Total purchases			380.5	474.6	398.9
Total sales			150.3	197.6	134.7
Asarco LLC
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			74.4	4.1
Related parties payable:			4.1	24.2
Total purchases			37.2	37.2	30.3
Total sales			81.8	96.2	37.1
Americas Mining Corporation ("AMC")
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			11
AMMINCO
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			0.2
Related parties payable:			8
Total purchases			8
Total sales			0.3
Compania Perforadora Mexico, S.A.P.I. de C.V. and affiliates
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			1.4	1.4
Total purchases					0.3
Total sales				0.2	0.6
Eolica El Retiro, S.A.P.I. de C.V.
RELATED PARTY TRANSACTIONS:
Related parties payable:			1	0.8
Total purchases			$ 3.6	$ 3.3	2
Number of wind turbines | item								37
Percentage of supply to third-party energy users			18.00%	27.00%
Ferrocarril Mexicano, S.A. de C.V.
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			$ 0.1
Related parties payable:			6.4	$ 2.6
Total purchases			41.7	43.5	42.7
Grupo Mexico
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			2.7	2.8
Related parties payable:			0.6	0.7
Total purchases			10.1	14	13.8
Total sales				0.2	0.6
Donations			6.2
Mexico Generadora de Energia, S. de R.L. ("MGE")
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			10.3	16.2
Related parties payable:			40.6	38.5
Total purchases			200.1	223.7	233.8
Total sales			68.2	101	95.9
Maximum amount of line of credit granted to related party	$ 350
Interest rate (as a percent)	4.40%
Loan repaid		$ 150
Interest earned					4.2
Mexico Generadora de Energia, S. de R.L. ("MGE") | Mexico
RELATED PARTY TRANSACTIONS:
Number of power plants | item						2	2
Number of natural gas-fired combined cycle power generating units | item						2
Net total capacity (in megawatts) | MW						516.2
Percentage of supply to third-party energy users						17.10%
Mexico Generadora de Energia, S. de R.L. ("MGE") | Minera Mexico | Maximum
RELATED PARTY TRANSACTIONS:
Ownership percentage									0.001%	0.001%
Mexico Generadora de Energia, S. de R.L. ("MGE") | Controladora de Infraestructura Energetica Mexico, S. A. de C. V.
RELATED PARTY TRANSACTIONS:
Percentage of interest acquired									99.999%	99.999%
Value of interest acquired									$ 1,928.6	$ 150
Mexico Generadora de Energia, S. de R.L. ("MGE") | Controladora de Infraestructura Energetica Mexico, S. A. de C. V. | Mexico
RELATED PARTY TRANSACTIONS:
Percentage of interest acquired						99.999%
Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			0.6	1.1
Related parties payable:			14.4	21.7
Total purchases			79.8	152.9	76
Total sales					0.4
Operadora de Generadoras de Energia Mexico S.A. de C.V.
RELATED PARTY TRANSACTIONS:
Total sales					0.1
Related to the controlling group
RELATED PARTY TRANSACTIONS:
Total purchases			12.9	1.7	2.9
Total sales			1.5	0.7	0.5
Boutique Bowling de Mexico, S.A. de C.V.
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			0.3	0.2
Related parties payable:			0.1	0.6
Total purchases			0.3	0.3	0.4
Total sales			0.2	0.2	0.2
Mexico Transportes Aereos, S.A. de C.V. ("Mextransport")
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			0.1
Related parties payable:				0.3
Total purchases			12.4	1.3	2
Total sales			1.2	0.3	0.2
Operadora de Cinemas S.A. de C.V.
RELATED PARTY TRANSACTIONS:
Related parties receivable current:			0.4	0.3
Related parties payable:			0.1	0.7
Total purchases			0.2	0.1	0.5
Total sales			$ 0.1	0.2	0.1
Related to SCC executive officers
RELATED PARTY TRANSACTIONS:
Total purchases				$ 0.2	$ 2
Equity investment in affiliate
RELATED PARTY TRANSACTIONS:
Ownership percentage			44.20%

SEGMENT AND RELATED INFORMATI_3

SEGMENT AND RELATED INFORMATION: - Financial (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)segmentcountryitem	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Financial information related to segments
Number of reportable segments | segment									3
Number of countries having open-pit operations | country									2
Financial information relating to segments
Net sales (including sales to related parties, see note 16)	$ 1,694,700	$ 1,723,700	$ 1,837,200	$ 1,841,100	$ 1,864,300	$ 1,676,500	$ 1,529,800	$ 1,583,900	$ 7,096,700	$ 6,654,500	$ 5,379,800
Cost of sales (exclusive of depreciation, amortization and depletion)									3,409,000	3,252,800	3,034,100
Selling, general and administrative									102,600	93,100	94,300
Depreciation, amortization and depletion									674,300	671,100	647,100
Exploration									29,600	28,800	40,100
Environmental remediation										(10,200)
Operating income	623,600	696,700	787,600	773,300	830,000	692,600	525,900	570,400	2,881,200	2,618,900	1,564,200
Interest, net									(261,100)	(300,500)	(283,600)
Other income (expense)									(30,700)	(15,700)	(24,600)
Income taxes									(1,053,500)	(1,593,400)	(501,100)
Equity earnings of affiliate, net of income tax									12,300	23,100	23,900
Non-controlling interest									(5,200)	(3,900)	(2,300)
Net income attributable to SCC	293,300	$ 369,400	$ 409,600	$ 470,700	(287,400)	$ 401,800	$ 299,700	$ 314,400	1,543,000	728,500	776,500
Capital investment									1,121,400	1,023,500	1,118,500
Property and mine development, net	9,403,800				9,099,600				9,403,800	9,099,600	8,766,500
Total assets	14,484,800				13,780,100				14,484,800	13,780,100	13,234,300
Intersegment sales
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									(79,300)	(71,000)	(72,000)
Corporate, other and eliminations
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									(79,300)	(71,800)	(72,000)
Cost of sales (exclusive of depreciation, amortization and depletion)									(88,600)	(69,600)	(73,400)
Selling, general and administrative									2,100	1,100	2,300
Depreciation, amortization and depletion									28,900	10,300	15,500
Exploration									3,800	6,200	16,900
Operating income									(25,500)	(19,000)	(33,300)
Capital investment									20,600	4,000	4,700
Property and mine development, net	374,500				338,400				374,500	338,400	231,700
Total assets	576,300				253,400				$ 576,300	253,400	9,600
Mexican Open-pit
Financial information related to segments
Number of open-pit copper mines | item									2
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 4,075,900	3,972,700	3,234,300
Mexican Open-pit | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									4,075,900	3,972,700	3,234,300
Cost of sales (exclusive of depreciation, amortization and depletion)									1,611,000	1,594,300	1,523,200
Selling, general and administrative									55,300	47,900	47,100
Depreciation, amortization and depletion									360,400	401,000	364,700
Exploration									2,000	2,700	5,200
Environmental remediation										(10,200)
Operating income									2,047,200	1,937,000	1,294,100
Capital investment									266,800	297,600	537,000
Property and mine development, net	4,783,800				5,004,500				4,783,800	5,004,500	5,136,800
Total assets	8,165,200				8,323,100				8,165,200	8,323,100	8,174,400
Mexican Open-pit | Reportable subsegments | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 4,075,900	3,972,700	3,234,300
Mexican IMMSA Unit
Financial information related to segments
Number of underground poly metal mines | item									5
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 527,900	509,500	423,100
Mexican IMMSA Unit | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									527,900	509,500	423,100
Cost of sales (exclusive of depreciation, amortization and depletion)									377,200	365,300	304,100
Selling, general and administrative									8,500	7,900	7,400
Depreciation, amortization and depletion									47,600	56,200	49,800
Exploration									5,300	5,500	5,000
Operating income									89,300	73,800	56,800
Capital investment									60,000	36,500	35,800
Property and mine development, net	448,300				366,900				448,300	366,900	448,700
Total assets	930,200				889,100				930,200	889,100	825,000
Mexican IMMSA Unit | Reportable subsegments | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									448,600	437,700	351,100
Mexican IMMSA Unit | Intersubsegment sales | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 79,300	71,000	72,000
Peruvian Operations
Financial information related to segments
Number of open-pit copper mines | item									2
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 2,572,200	2,244,100	1,794,400
Peruvian Operations | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									2,572,200	2,244,100	1,794,400
Cost of sales (exclusive of depreciation, amortization and depletion)									1,509,400	1,362,800	1,280,200
Selling, general and administrative									36,700	36,200	37,500
Depreciation, amortization and depletion									237,400	203,600	217,100
Exploration									18,500	14,400	13,000
Operating income									770,200	627,100	246,600
Capital investment									774,000	685,400	541,000
Property and mine development, net	3,797,200				3,389,800				3,797,200	3,389,800	2,949,300
Total assets	$ 4,813,100				$ 4,314,500				4,813,100	4,314,500	4,225,300
Peruvian Operations | Reportable subsegments | Operating segment
Financial information relating to segments
Net sales (including sales to related parties, see note 16)									$ 2,572,200	$ 2,244,100	$ 1,794,400

SEGMENT AND RELATED INFORMATI_4

SEGMENT AND RELATED INFORMATION: - Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financial information related to segments
Trade receivables	$ 822.4	$ 890.6	$ 591.9
Related parties receivable current:	101.5	26.1	23.4
Corporate, other and eliminations
Financial information related to segments
Related parties receivable current:	19.9	8.1	10.5
Mexican Open-pit
Financial information related to segments
Trade receivables	505.9	556.2	365.2
Related parties receivable current:	81.6	18	12.9
Mexican IMMSA Unit
Financial information related to segments
Trade receivables	50.5	79.7	47.1
Peruvian Operations
Financial information related to segments
Trade receivables	$ 266	$ 254.7	$ 179.6

SEGMENT AND RELATED INFORMATI_5

SEGMENT AND RELATED INFORMATION: - Sales (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)	$ 1,694.7	$ 1,723.7	$ 1,837.2	$ 1,841.1	$ 1,864.3	$ 1,676.5	$ 1,529.8	$ 1,583.9	$ 7,096.7	$ 6,654.5	$ 5,379.8
Copper
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									5,707.8	5,476.5	4,220.8
Molybdenum
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									509.9	353.4	268
Silver
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									300.2	286.3	294.3
Zinc
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									328.6	326.6	234.4
Other
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									250.2	211.7	362.3
Corporate, other and eliminations
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									(79.3)	(71.8)	(72)
Corporate, other and eliminations | Copper
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									(48.1)	(37.3)	(32)
Corporate, other and eliminations | Silver
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									(28.1)	(26.9)	(31.6)
Corporate, other and eliminations | Zinc
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									(0.1)	(0.6)
Corporate, other and eliminations | Other
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									(3)	(7)	(8.4)
Mexican Open-pit
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									4,075.9	3,972.7	3,234.3
Mexican Open-pit | Operating segment
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									4,075.9	3,972.7	3,234.3
Mexican Open-pit | Operating segment | Copper
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									3,459.1	3,480.2	2,663.1
Mexican Open-pit | Operating segment | Molybdenum
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									342.5	224	144
Mexican Open-pit | Operating segment | Silver
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									175.3	170.7	182.3
Mexican Open-pit | Operating segment | Other
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									99	97.8	244.9
Mexican IMMSA Unit
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									527.9	509.5	423.1
Mexican IMMSA Unit | Operating segment
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									527.9	509.5	423.1
Mexican IMMSA Unit | Operating segment | Copper
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									45.6	37.2	32
Mexican IMMSA Unit | Operating segment | Silver
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									83.5	71.9	82.1
Mexican IMMSA Unit | Operating segment | Zinc
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									328.7	327.2	234.4
Mexican IMMSA Unit | Operating segment | Other
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									70.1	73.2	74.6
Peruvian Operations
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									2,572.2	2,244.1	1,794.4
Peruvian Operations | Operating segment
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									2,572.2	2,244.1	1,794.4
Peruvian Operations | Operating segment | Copper
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									2,251.2	1,996.4	1,557.7
Peruvian Operations | Operating segment | Molybdenum
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									167.4	129.4	124
Peruvian Operations | Operating segment | Silver
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									69.5	70.6	61.5
Peruvian Operations | Operating segment | Other
SALES VALUE PER SEGMENT:
Net sales (including sales to related parties, see note 16)									$ 84.1	$ 47.7	$ 51.2

SEGMENT AND RELATED INFORMATI_6

SEGMENT AND RELATED INFORMATION: - Geographical (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of revenue by geographical location
Net sales	$ 1,694.7	$ 1,723.7	$ 1,837.2	$ 1,841.1	$ 1,864.3	$ 1,676.5	$ 1,529.8	$ 1,583.9	$ 7,096.7	$ 6,654.5	$ 5,379.8
Mexico
Schedule of revenue by geographical location
Net sales									1,649.3	1,523.9	1,409.7
United States
Schedule of revenue by geographical location
Net sales									1,258.6	1,190.3	1,050
Peru
Schedule of revenue by geographical location
Net sales									390.4	374.2	294.4
Brazil
Schedule of revenue by geographical location
Net sales									271.9	240.1	196.1
Chile
Schedule of revenue by geographical location
Net sales									136.3	103.4	92.4
Other American countries
Schedule of revenue by geographical location
Net sales									65.8	91.5	74.3
Switzerland
Schedule of revenue by geographical location
Net sales									653.4	602.3	437.3
Italy
Schedule of revenue by geographical location
Net sales									347.3	332.4	304.5
Spain
Schedule of revenue by geographical location
Net sales									169.4	142.8	71.2
Other European Countries
Schedule of revenue by geographical location
Net sales									379.6	337.2	201.8
Singapore
Schedule of revenue by geographical location
Net sales									1,069.2	1,051.3	652.8
Japan
Schedule of revenue by geographical location
Net sales									483.4	479.6	409.8
Other Asian countries
Schedule of revenue by geographical location
Net sales									222.1	185.5	185.5
Corporate, other and eliminations
Schedule of revenue by geographical location
Net sales									(79.3)	(71.8)	(72)
Corporate, other and eliminations | Mexico
Schedule of revenue by geographical location
Net sales									(79.3)	(71.8)	(72)
Mexican Open-pit
Schedule of revenue by geographical location
Net sales									4,075.9	3,972.7	3,234.3
Mexican Open-pit | Mexico
Schedule of revenue by geographical location
Net sales									1,343	1,240	1,184.8
Mexican Open-pit | United States
Schedule of revenue by geographical location
Net sales									1,008	1,001.2	933.6
Mexican Open-pit | Other American countries
Schedule of revenue by geographical location
Net sales									60.6	68.1	52.9
Mexican Open-pit | Switzerland
Schedule of revenue by geographical location
Net sales									453.3	473.1	245.9
Mexican Open-pit | Italy
Schedule of revenue by geographical location
Net sales									20.6	27.7	20.9
Mexican Open-pit | Spain
Schedule of revenue by geographical location
Net sales									169.4	142.8	71.2
Mexican Open-pit | Other European Countries
Schedule of revenue by geographical location
Net sales									234.8	230.3	127
Mexican Open-pit | Singapore
Schedule of revenue by geographical location
Net sales									528.8	547.9	471.9
Mexican Open-pit | Japan
Schedule of revenue by geographical location
Net sales									71.8	93	49.2
Mexican Open-pit | Other Asian countries
Schedule of revenue by geographical location
Net sales									185.6	148.6	76.9
Mexican IMMSA Unit
Schedule of revenue by geographical location
Net sales									527.9	509.5	423.1
Mexican IMMSA Unit | Mexico
Schedule of revenue by geographical location
Net sales									385.6	349.1	296.9
Mexican IMMSA Unit | United States
Schedule of revenue by geographical location
Net sales									6.6	41.7	49.5
Mexican IMMSA Unit | Peru
Schedule of revenue by geographical location
Net sales										0.8
Mexican IMMSA Unit | Brazil
Schedule of revenue by geographical location
Net sales									43.8	48.7	26.1
Mexican IMMSA Unit | Other American countries
Schedule of revenue by geographical location
Net sales									3.8	4.1	2.6
Mexican IMMSA Unit | Switzerland
Schedule of revenue by geographical location
Net sales									43.4	14.3	9.4
Mexican IMMSA Unit | Italy
Schedule of revenue by geographical location
Net sales									21.7	18.6	17.2
Mexican IMMSA Unit | Other European Countries
Schedule of revenue by geographical location
Net sales									19.9	30.3	20.8
Mexican IMMSA Unit | Singapore
Schedule of revenue by geographical location
Net sales									2.2	1.4
Mexican IMMSA Unit | Other Asian countries
Schedule of revenue by geographical location
Net sales									0.9	0.5	0.6
Peruvian Operations
Schedule of revenue by geographical location
Net sales									2,572.2	2,244.1	1,794.4
Peruvian Operations | Mexico
Schedule of revenue by geographical location
Net sales										6.6
Peruvian Operations | United States
Schedule of revenue by geographical location
Net sales									244	147.4	66.9
Peruvian Operations | Peru
Schedule of revenue by geographical location
Net sales									390.4	373.4	294.4
Peruvian Operations | Brazil
Schedule of revenue by geographical location
Net sales									228.1	191.4	170
Peruvian Operations | Chile
Schedule of revenue by geographical location
Net sales									136.3	103.4	92.4
Peruvian Operations | Other American countries
Schedule of revenue by geographical location
Net sales									1.4	19.3	18.8
Peruvian Operations | Switzerland
Schedule of revenue by geographical location
Net sales									156.7	114.9	182
Peruvian Operations | Italy
Schedule of revenue by geographical location
Net sales									305	286.1	266.4
Peruvian Operations | Other European Countries
Schedule of revenue by geographical location
Net sales									124.9	76.6	54
Peruvian Operations | Singapore
Schedule of revenue by geographical location
Net sales									538.2	502	180.9
Peruvian Operations | Japan
Schedule of revenue by geographical location
Net sales									411.6	386.6	360.6
Peruvian Operations | Other Asian countries
Schedule of revenue by geographical location
Net sales									$ 35.6	$ 36.4	$ 108

SEGMENT AND RELATED INFORMATI_7

SEGMENT AND RELATED INFORMATION: - Provisional Sale (Details) lb in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)lb$ / lb
Provisionally priced sales:
Provisional price sales adjustment amounts included in net sales	$ 10	$ (22.9)
Copper
Provisionally priced sales:
Provisional price sales adjustment amounts included in accounts receivable	7.6	$ (8.3)
Copper | January through March 2019
Provisionally priced sales:
Sales volume (in million lbs.) | lb		102.4
Provisional price | $ / lb		2.68
Molybdenum
Provisionally priced sales:
Provisional price sales adjustment amounts included in accounts receivable	$ 2.4	$ (14.6)
Molybdenum | January through March 2019
Provisionally priced sales:
Sales volume (in million lbs.) | lb		9
Provisional price | $ / lb		11.88

SEGMENT AND RELATED INFORMATI_8

SEGMENT AND RELATED INFORMATION: - Long Term Sales Contract (Details)	12 Months Ended
	Dec. 31, 2018T
Copper cathodes | Mitsui
Long-term sales contract
Term of agreement	5 years
Quantity to be supplied related to additional annual contract in 2015 (in tons)	6,000
Quantity to be supplied related to additional annual contract from 2016 until 2019 (in tons)	48,000
Copper cathodes | Mitsui | Tia Maria
Long-term sales contract
Quantity to be supplied following the full startup of project (in tons)	24,000
Molybdenum concentrates | Molibdenos y Metales
Long-term sales contract
Minimum percentage of total production required to be supplied	70.00%
Molybdenum concentrates | Molymex
Long-term sales contract
Minimum percentage of total production required to be supplied	80.00%

QUARTERLY DATA (unaudited) (Det

QUARTERLY DATA (unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
QUARTERLY DATA (unaudited)
Net sales	$ 1,694.7	$ 1,723.7	$ 1,837.2	$ 1,841.1	$ 1,864.3	$ 1,676.5	$ 1,529.8	$ 1,583.9	$ 7,096.7	$ 6,654.5	$ 5,379.8
Gross profit	658.8	729.1	822.9	802.6	864.4	725.7	553.8	586.7	3,013.4	2,730.6
Operating income	623.6	696.7	787.6	773.3	830	692.6	525.9	570.4	2,881.2	2,618.9	1,564.2
Net income (loss)	294.5	370.7	411.1	471.9	(286.2)	402.8	300.5	315.3	1,548.2	732.4	778.8
Net income (loss) attributable to SCC	$ 293.3	$ 369.4	$ 409.6	$ 470.7	$ (287.4)	$ 401.8	$ 299.7	$ 314.4	$ 1,543	$ 728.5	$ 776.5
Per share amounts attributable to SCC:
Net earnings basic and diluted (in dollars per share)	$ 0.38	$ 0.48	$ 0.53	$ 0.61	$ (0.38)	$ 0.52	$ 0.39	$ 0.41	$ 2	$ 0.94	$ 1
Dividend per share	$ 0.40	$ 0.40	$ 0.30	$ 0.30	$ 0.25	$ 0.14	$ 0.12	$ 0.08	$ 1.40	$ 0.59	$ 0.18

SUBSEQUENT EVENTS_ (Details)

SUBSEQUENT EVENTS: (Details) - USD ($) $ / shares in Units, $ in Millions

Feb. 26, 2019

Feb. 21, 2019

Jan. 24, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

SUBSEQUENT EVENTS

Dividend per share

$ 0.40

$ 0.40

$ 0.30

$ 0.30

$ 0.25

$ 0.14

$ 0.12

$ 0.08

$ 1.40

$ 0.59

$ 0.18

Subsequent Events

SUBSEQUENT EVENTS

Quarterly dividend authorized (in dollars per share)

$ 0.40

Dividend per share

$ 0.40

Subsequent Events | Grupo Mexico and Americas Mining

SUBSEQUENT EVENTS

Dividend per share

$ 0.44428

Settlement dividend paid

$ 36.5

Legal fees paid

$ 13.5

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable
Valuation and Qualifying Accounts and Reserves
Balance at beginning of period	$ 1.1	$ 0.7	$ 0.9
Charged to costs and expenses		0.6
Deductions/Applications	(0.6)	0.2	0.2
Balance at end of period	0.5	1.1	0.7
Notes issued under par
Valuation and Qualifying Accounts and Reserves
Balance at beginning of period	60.5	62.2	63.8
Charged to costs and expenses	1.7	1.7	1.6
Balance at end of period	58.8	60.5	$ 62.2
Valuation allowance
Valuation and Qualifying Accounts and Reserves
Balance at beginning of period	619.6
Charged to costs and expenses	199.5	619.6
Balance at end of period	$ 819.1	$ 619.6