XML 419 R193.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Financial instruments and risk management - Summary of changes in market price relevant to alumina purchase price swaps outstanding (Detail) - Commodity price risk [Member] - Aluminium [Member] - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Disclosure of detailed information about financial instruments [line items] |  |
Percentage increase in market price change | 10.00% |
Percentage decrease in market price change | (10.00%) |
Increase in market prices, effect on earnings | $ (28) | $ (102)
Decrease in market prices, effect on earnings | 27 | 35
Increase in market prices, effect on equity | 97 | 101
Decrease in market prices, effect on equity | $ 101 | $ 103

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 Change in Commodity Price, Decrease, Effect on Equity + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceDecreaseEffectonEquity
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Change in Commodity Price, Decrease, Effect on Net Earnings Amount + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceDecreaseEffectonNetEarningsAmount
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Change in Commodity Price, Decrease, Percent + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceDecreasePercent
Namespace Prefix: | rio_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Change in Commodity Price, Increase, Effect on Equity + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceIncreaseEffectonEquity
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Change in Commodity Price, Increase, Effect on Net Earnings Amount + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceIncreaseEffectonNetEarningsAmount
Namespace Prefix: | rio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Change in Commodity Price, Increase, Percent + References No definition available. + Details
Name: | rio_ChangeinCommodityPriceIncreasePercent
Namespace Prefix: | rio_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | ifrs-full_ProductsAndServicesAxis=rio_AluminiumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |