XML 160 R85.htm IDEA: XBRL DOCUMENT
v3.19.3

Financial Risk Management - Commodity Price Sensitivity (Details) - ZAR (R) R in Millions |  | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2019 | Jun. 30, 2018
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Limit of gold production hedged (as a percent) |  | 20.00% |
Gold production period hedged (in months) |  | 24 months |
Temporary maximum gold production hedged, as a percent | 24.00% |  |
Limit of silver production hedged (as a percent) |  | 50.00% |
Silver production period hedged (in months) |  | 24 months |
Commodity price risk |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible change in risk variable percent |  | 10.00% | 10.00%
Commodity price risk | Bottom of range |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible change in risk variable percent |  | 10.00% | 10.00%
Commodity price risk | Top of range |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible change in risk variable percent |  | 20.00% | 20.00%
Commodity price risk | Rand gold derivatives |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible increase in risk variable percent |  | 10.00% | 10.00%
Reasonably possible decrease in risk variable percent |  | 10.00% | 10.00%
Increase by 10%, impact on earnings |  | R (76) | R 0
Decrease by 10%, impact on earnings |  | R 79 | R 0
Commodity price risk | US$ gold derivatives |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible increase in risk variable percent |  | 10.00% | 10.00%
Reasonably possible decrease in risk variable percent |  | 10.00% | 10.00%
Increase by 10%, impact on earnings |  | R (20) | R (166)
Decrease by 10%, impact on earnings |  | R 20 | R 167
Commodity price risk | US$ silver derivatives |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible increase in risk variable percent |  | 10.00% | 10.00%
Reasonably possible decrease in risk variable percent |  | 10.00% | 10.00%
Increase by 10%, impact on earnings |  | R 0 | R (14)
Decrease by 10%, impact on earnings |  | R 4 | R 15
Cash flow hedges | Commodity price risk | Rand gold derivatives |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible increase in risk variable percent |  | 10.00% | 10.00%
Reasonably possible decrease in risk variable percent |  | 10.00% | 10.00%
Increase by 10%, impact on other comprehensive income |  | R (1,162) | R (522)
Decrease by 10%, impact on other comprehensive income |  | R 1,174 | R 515
Cash flow hedges | Commodity price risk | US$ gold derivatives |  |  |
Disclosure of nature and extent of risks arising from financial instruments [line items] |  |  |
Reasonably possible increase in risk variable percent |  | 10.00% | 10.00%
Reasonably possible decrease in risk variable percent |  | 10.00% | 10.00%
Increase by 10%, impact on other comprehensive income |  | R (110) | R 0
Decrease by 10%, impact on other comprehensive income |  | R 113 | R 0

X
- Definition Gold Production Period Hedged + References No definition available. + Details
Name: | hmy_GoldProductionPeriodHedged
Namespace Prefix: | hmy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum Gold Production Hedged, as a Percent + References No definition available. + Details
Name: | hmy_MaximumGoldProductionHedgedasaPercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum Silver Production Hedged, Percent + References No definition available. + Details
Name: | hmy_MaximumSilverProductionHedgedPercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Change In Risk Variable, Percent + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleChangeInRiskVariablePercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Other Comprehensive Income + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnOtherComprehensiveIncome
Namespace Prefix: | hmy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Pre-Tax Earnings + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnPreTaxEarnings
Namespace Prefix: | hmy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Percent + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariablePercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Other Comprehensive Income + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnOtherComprehensiveIncome
Namespace Prefix: | hmy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Pre-Tax Earnings + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnPreTaxEarnings
Namespace Prefix: | hmy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Percent + References No definition available. + Details
Name: | hmy_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariablePercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Silver Production Period Hedged + References No definition available. + Details
Name: | hmy_SilverProductionPeriodHedged
Namespace Prefix: | hmy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Temporary Maximum Gold Production Hedged, As A Percent + References No definition available. + Details
Name: | hmy_TemporaryMaximumGoldProductionHedgedAsAPercent
Namespace Prefix: | hmy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfNatureAndExtentOfRisksArisingFromFinancialInstrumentsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CommodityPriceRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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_ClassesOfFinancialInstrumentsAxis=hmy_RandGoldHedgingContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=hmy_USGoldDerivativeContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=hmy_USSilverDerivativeContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfHedgesAxis=ifrs-full_CashFlowHedgesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=hmy_RandGoldHedgingContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=hmy_USGoldDerivativeContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |