XML 91 R64.htm IDEA: XBRL DOCUMENT
v2.4.1.9

BENEFIT PLANS: (Details 2) (USD $) In Millions, except Per Share data, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Post retirement defined benefit plan | Expatriate Plan |  |  |
Benefit plans |  |  |
Net asset value (in dollars per share) | $ 1.00 scco_NetAssetValuePerShare / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Discount rate (as a percent) | 3.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 4.25%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 3.35%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember
Expected long-term rate of return on plan asset (as a percent) | 4.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 4.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 4.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember
Post retirement defined benefit plan | Mexican Health Plan |  |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Discount rate (as a percent) | 6.70%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 7.10%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 6.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember
Expected long-term rate of return on plan asset (as a percent) | 6.70%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 7.10%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 6.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember
Number of financial institutions managing plan assets | 3 scco_DefinedBenefitPlanNumberOfFinancialInstitutionsManagingPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |  |
Plan obligations as a percentage of benefit obligation | 30.00%scco_DefinedBenefitPlanPlanObligationAsPercentageOfBenefitObligation / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |  |
Asset allocation (as a percent) | 100.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 100.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |
Expected employer contribution in next fiscal year | $ 6.3 us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |  |
Pending payments to former Buenavista workers | $ 3.4 scco_DefinedBenefitPlanBuyoutPaymentsOutstandingToWorkers / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |  |
Post retirement defined benefit plan | Parent Company (Grupo Mexico) common shares | Mexican Health Plan |  |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Asset allocation (as a percent) | 73.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / dei_LegalEntityAxis = us-gaap_ParentCompanyMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |  |
Post retirement defined benefit plan | Equity securities | Mexican Health Plan |  |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Asset allocation (as a percent) | 73.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_EquitySecuritiesMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 74.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_EquitySecuritiesMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |
Post retirement defined benefit plan | Treasury bills | Mexican Health Plan |  |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Asset allocation (as a percent) | 27.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = scco_MexicanTreasuryBillSecuritiesMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember | 26.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = scco_MexicanTreasuryBillSecuritiesMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember / us-gaap_PlanNameAxis = scco_MexicanPlanMember |
Post-retirement Health Care Plan | Expatriate Plan |  |  |
Assumptions used to determine the pension obligation and seniority premiums as of year-end and the net cost in the ensuing year |  |  |
Discount rate (as a percent) | 3.50%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = scco_DefinedBenefitPostretirementHealthCarePlanMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 4.25%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = scco_DefinedBenefitPostretirementHealthCarePlanMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember | 4.25%scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = scco_DefinedBenefitPostretirementHealthCarePlanMember / us-gaap_PlanNameAxis = scco_ExpatriatePlanMember

X
- Definition Represents the interest rate used to adjust for the time value of money assumed to determine the pension obligation and seniority premiums as of the year-end and the net cost. + References No definition available. + Details
Name: | scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostDiscountRate
Namespace Prefix: | scco_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to determine the pension obligation and seniority premiums as of year-end and the net cost. + References No definition available. + Details
Name: | scco_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostExpectedLongTermReturnOnAssets
Namespace Prefix: | scco_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the buyout payments outstanding to workers under defined benefit plans. + References No definition available. + Details
Name: | scco_DefinedBenefitPlanBuyoutPaymentsOutstandingToWorkers
Namespace Prefix: | scco_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the number of financial institutions managing the plan assets. + References No definition available. + Details
Name: | scco_DefinedBenefitPlanNumberOfFinancialInstitutionsManagingPlanAssets
Namespace Prefix: | scco_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the plan obligation as a percentage of the entity's aggregate defined benefit obligation. + References No definition available. + Details
Name: | scco_DefinedBenefitPlanPlanObligationAsPercentageOfBenefitObligation
Namespace Prefix: | scco_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | scco_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAndNetPeriodicBenefitCostAbstract
Namespace Prefix: | scco_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the company's net asset value per share. + References No definition available. + Details
Name: | scco_NetAssetValuePerShare
Namespace Prefix: | scco_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=scco_DefinedBenefitPostretirementHealthCarePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |