BENEFIT PLANS: - Post retirement (Details) - Post retirement defined benefit plans and defined contribution plan $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) entity $ / shares	Dec. 31, 2017
Expatriate Plan
Benefit plans
Net asset value (in dollars per share) \| $ / shares	$ 1.00
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%

Represents the buyout payments outstanding to workers under defined benefit plans.

No definition available.

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Namespace Prefix:	scco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the number of financial institutions managing the plan assets.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Represents the plan obligation as a percentage of the entity's aggregate defined benefit obligation.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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Balance Type:	debit
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- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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Period Type:	instant

- Definition

Net asset value per share or per unit of investments in certain entities that calculate net asset value per share. Includes, but is not limited to, by unit, membership interest, or other ownership interest. Investment includes, but is not limited to, investment in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds. Excludes fair value disclosure.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 35
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- Details

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- Details

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- Details

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- Details

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- Details

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