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: