XML 104 R81.htm IDEA: XBRL DOCUMENT
v3.21.1

Note 5 - Significant Accounting Policies (Details Textual) |  |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jan. 08, 2021 | May 26, 2020 | Nov. 12, 2018 | Oct. 01, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Statement Line Items [Line Items] |  |  |  |  |  |  |
Closing foreign exchange rate |  |  |  |  | 81.79 | 16.77 | 1
Foreign currency allocation, percentage |  | 70.00% | 55.00% | 30.00% |  |  |
Bottom of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Right of use assets, useful life (Year) |  |  |  |  | 3 years | 3 years | 3 years
Top of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Right of use assets, useful life (Year) |  |  |  |  | 6 years | 6 years | 6 years
Buildings [member] | Bottom of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 10 years | 10 years | 10 years
Buildings [member] | Top of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 15 years | 15 years | 15 years
Machinery [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 10 years | 10 years | 10 years
Fixtures and fittings [member] | Bottom of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 4 years | 4 years | 4 years
Fixtures and fittings [member] | Top of range [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 10 years | 10 years | 10 years
Motor vehicles [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Property, plant, and equipment, useful life (Year) |  |  |  |  | 4 years | 4 years | 4 years
Changes in foreign currency allocation [member] |  |  |  |  |  |  |
Statement Line Items [Line Items] |  |  |  |  |  |  |
Foreign currency allocation, percentage | 60.00% |  |  |  |  |  |

X
- Definition The percentage of proceeds to be received in foreign currency. + References No definition available. + Details
Name: | cmcl_ForeignCurrencyAllocationPercentage
Namespace Prefix: | cmcl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The useful lives used for property, plant and equipment. + References No definition available. + Details
Name: | cmcl_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | cmcl_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The duration term for the useful life of right of use assets. + References No definition available. + Details
Name: | cmcl_RightOfUseAssetsUsefulLife
Namespace Prefix: | cmcl_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | cmcl_StatementLineItems
Namespace Prefix: | cmcl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ClosingForeignExchangeRate
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_BuildingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_MachineryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_FixturesAndFittingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_MotorVehiclesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=cmcl_ChangesInForeignCurrencyAllocationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |