XML 56 R47.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Financial instruments disclosures - Additional information (Detail) - Level 3 [member] - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2018 | Dec. 31, 2017
Disclosure Of Financial Instruments [Line Items] |  |
Percentage of change in London metal exchange | 10.00% |
Period of London metal exchange curve | 10 year |
Decrease in carrying value of forward contract due to long-term metal pricing assumptions | $ 16 | $ 41
Increase in carrying value of forward contract due to long-term metal pricing assumptions | $ 38 | $ 22

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_DisclosureOfFinancialInstrumentsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Decrease in carrying value of forward contract due to long-term metal pricing assumptions. + References No definition available. + Details
Name: | rio_DecreaseInCarryingValueOfForwardContractDueToLongTermMetalPricingAssumptions
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Increase in carrying value of forward contract due to long-term metal pricing assumptions. + References No definition available. + Details
Name: | rio_IncreaseInCarryingValueOfForwardContractDueToLongTermMetalPricingAssumptions
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of change in london metal exchange. + References No definition available. + Details
Name: | rio_PercentageOfChangeInLondonMetalExchange
Namespace Prefix: | rio_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of London metal exchange curve. + References No definition available. + Details
Name: | rio_PeriodOfLondonMetalExchangeCurve
Namespace Prefix: | rio_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |