The amount of dividends proposed or declared after the reporting period but before financial statements are authorised for issue. Such dividends are not recognised as a liability at the end of the reporting period because no obligation exists at that time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 137
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_137_a&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 10
-IssueDate 2020-01-01
-Paragraph 13
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=10&code=ifrs-tx-2020-en-r&anchor=para_13&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwners
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount, per share, of dividends proposed or declared before financial statements were authorised for issue but not recognised as distribution to owners.

+ References

+ Details

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwnersPerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of shares in the entity held by the entity or by its subsidiaries or associates. [Refer: Associates [member]; Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 79
-Subparagraph a
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_79_a_vi&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_SharesInEntityHeldByEntityOrByItsSubsidiariesOrAssociates
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Disclosure of Dividends [Line Items]

+ References

No definition available.

+ Details

Name:	rio_DisclosureOfDividendsLineItems
Namespace Prefix:	rio_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of dividendsper share relating to the current year, recognised as distributions to owners of the parent.

+ References

No definition available.

+ Details

Name:	rio_DividendsPerShareAsDistributionsToOwnersOfParentRelatingToCurrentYear
Namespace Prefix:	rio_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of dividends per share relating to prior years, recognised as distributions to owners of the parent.

+ References

No definition available.

+ Details

Name:	rio_DividendsPerShareAsDistributionsToOwnersOfParentRelatingToPriorYears
Namespace Prefix:	rio_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of share excluded from final dividend calculation.

+ References

No definition available.

+ Details

Name:	rio_NumberOfShareExcludedFromFinalDividendCalculation
Namespace Prefix:	rio_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of share excluded from interim dividend calculation.

+ References

No definition available.

+ Details

Name:	rio_NumberOfShareExcludedFromInterimDividendCalculation
Namespace Prefix:	rio_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Retained Profits And Reserves That Could Be Distributed As Fully Franked Dividends

+ References

No definition available.

+ Details

Name:	rio_RetainedProfitsAndReservesThatCouldBeDistributedAsFullyFrankedDividends
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	rio_DividendTypeAxis=rio_FinalDividendsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	rio_DividendTypeAxis=rio_SpecialDividendsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=ifrs-full_PotentialOrdinaryShareTransactionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=rio_RioTintoPlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfShareCapitalAxis=ifrs-full_OrdinarySharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfShareCapitalAxis=rio_AmericanDepositoryReceiptsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=rio_RioTintoLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Dividends - Additional information (Detail) $ / shares in Units, $ in Millions		12 Months Ended
	Feb. 17, 2021 USD ($) $ / shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) £ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) £ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) £ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Disclosure of Dividends [Line Items]
Number of shares held (in shares) \| shares		0	0	0	0	0	0	0	0	0
Final Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) \| $ / shares		$ 3.090			$ 2.310			$ 1.800
Special Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) \| $ / shares		0.930			0			2.430
Potential ordinary share transactions
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) \| $ / shares	$ 3.090
Dividends payment proposed in the announcement of the results for the year \| $	$ 6,500
Potential ordinary share transactions \| Special Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) \| $ / shares	$ 0.930
Rio Tinto plc \| Final Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) \| (per share)		2.310	£ 1.7747		1.800	£ 1.3596		1.800	£ 1.2943
Interim dividend per share (in usd per share) \| (per share)		$ 1.550	1.1974		1.510	1.2332		1.270	0.9682
Rio Tinto plc \| Special Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) \| (per share)			0		2.430	1.8355		$ 0
Interim dividend per share (in usd per share) \| (per share)			£ 0		$ 0.610	£ 0.4982			£ 0
Rio Tinto plc \| Ordinary
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) \| shares		258,779	258,779	258,779	852,283	852,283	852,283	132,294	132,294	132,294
Number of share excluded from interim dividend calculation (in shares) \| shares		171,213	171,213	171,213	564,099	564,099	564,099	314,529	314,529	314,529
Rio Tinto plc \| American depository receipts
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) \| shares		28,743	28,743	28,743	37,678	37,678	37,678	22,824	22,824	22,824
Number of share excluded from interim dividend calculation (in shares) \| shares		29,634	29,634	29,634	47,674	47,674	47,674	36,321	36,321	36,321
Rio Tinto Limited
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) \| shares		98,065	98,065	98,065	628,566	628,566	628,566	130,129	130,129	130,129
Number of share excluded from interim dividend calculation (in shares) \| shares		84,377	84,377	84,377	342,062	342,062	342,062	251,394	251,394	251,394
Number of shares held (in shares) \| shares		828,338	828,338	828,338
Retained profits and reserves distributed as dividends \| $		$ 11,014	£ 11,014	$ 11,014	$ 8,599	£ 8,599	$ 8,599	$ 6,178	£ 6,178	$ 6,178
Rio Tinto Limited \| Final Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) \| $ / shares				$ 3.4974			$ 2.5089			$ 2.2853
Interim dividend per share (in usd per share) \| $ / shares				2.1647			2.1908			1.7084
Rio Tinto Limited \| Special Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) \| $ / shares				0			3.3870			0
Interim dividend per share (in usd per share) \| $ / shares				$ 0			$ 0.8850			$ 0