The amount of future minimum lease payments payable under non-cancellable operating leases. Minimum lease payments are payments over the lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with: (a) for a lessee, any amounts guaranteed by the lessee or by a party related to the lessee; or (b) for a lessor, any residual value guaranteed to the lessor by: (i) the lessee; (ii) a party related to the lessee; or (iii) a third party unrelated to the lessor that is financially capable of discharging the obligations under the guarantee.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2017-01-01
-Paragraph 35
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2017-03-02&anchor=para_35_a&doctype=Standard&book=B
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_MinimumLeasePaymentsPayableUnderNoncancellableOperatingLease
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The income arising in the course of an entity's ordinary activities. Income is increases in economic benefits during the accounting period in the form of inflows or enhancements of assets or decreases of liabilities that result in an increase in equity, other than those relating to contributions from equity participants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 28
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_28_a&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 23
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_23_a&doctype=Standard
-URIDate 2017-03-09

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 32
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_32&doctype=Standard
-URIDate 2017-03-09

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 33
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_33_a&doctype=Standard
-URIDate 2017-03-09

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2017-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2017-03-01&anchor=para_34&doctype=Standard
-URIDate 2017-03-09

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 82
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_82_a&doctype=Standard
-URIDate 2017-03-09

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 103
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_103&doctype=Standard
-URIDate 2017-03-09

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IAS
-Number 18
-IssueDate 2017-01-01
-Paragraph 35
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=18&date=2017-03-02&anchor=para_35_b&doctype=Standard&book=B
-URIDate 2017-03-09

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 102
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_102&doctype=Standard
-URIDate 2017-03-09

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2017-01-01
-Paragraph B12
-Subparagraph b
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2017-03-01&anchor=para_B12_b_v&doctype=Appendix&seq=2
-URIDate 2017-03-09

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 12
-IssueDate 2017-01-01
-Paragraph B10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2017-03-01&anchor=para_B10_b&doctype=Appendix&seq=2
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_Revenue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Basis of presentation.

+ References

No definition available.

+ Details

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

- Definition

Expected period to determine final prices for copper.

+ References

No definition available.

+ Details

Name:	rio_ExpectedPeriodToDetermineFinalPricesForCopper
Namespace Prefix:	rio_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Impairment provision resulting from application of ECL model pre-tax.

+ References

No definition available.

+ Details

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

- Definition

Money market funds.

+ References

No definition available.

+ Details

Name:	rio_MoneyMarketFunds
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reclassification of cash flow hedge reserve to cost of hedging reserve first application of IFRS9.

+ References

No definition available.

+ Details

Name:	rio_ReclassificationOfCashFlowHedgeReserveToCostOfHedgingReserveFirstApplicationOfIFRS9
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reclassification of retained earnings to cost of hedging reserve first application of IFRS9.

+ References

No definition available.

+ Details

Name:	rio_ReclassificationOfRetainedEarningsToCostOfHedgingReserveFirstApplicationOfIFRS9
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reclassification of trade and other receivables from amortised cost to FVPL.

+ References

No definition available.

+ Details

Name:	rio_ReclassificationOfTradeAndOtherReceivablesFromAmortisedCostToFVPL
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The transition adjustment relates to an ‘uplift’ arrangement with a partner in a joint operation whereby sales revenue was recognised under IAS 18 when the Group sold product from other operations to its partner to allow it to meet its contractual obligations when insufficient product was available in the jointly owned operation. The Group recognised an asset for product which will be receivable from the partner out of the partner’s share of future production of the joint operation. Under IFRS 15, such transactions with partners in joint operations cannot be recognised as sales revenue.

+ References

No definition available.

+ Details

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

- Definition

Transition adjustment reduction in deferred tax liabilities.

+ References

No definition available.

+ Details

Name:	rio_TransitionAdjustmentReductionInDeferredTaxLiabilities
Namespace Prefix:	rio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Transition adjustment reduction in trade and other receivables.

+ References

No definition available.

+ Details

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

- Details

Name:	ifrs-full_RetrospectiveApplicationAndRetrospectiveRestatementAxis=ifrs-full_IncreaseDecreaseDueToChangesInAccountingPolicyRequiredByIFRSsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ComponentsOfEquityAxis=ifrs-full_RetainedEarningsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_EffectOfOverlayApproachReclassificationAxis=ifrs-full_EffectOfOverlayApproachReclassificationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Basis of Preparation - Additional information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018
Basis Of Presentation [Line Items]
Non-cancellable operating lease commitments	$ 1,800
Money market funds			$ 7,800
Reclassification of trade and other receivables from amortised cost to FVPL			1,316
Reclassification of retained earnings to cost of hedging reserve	22
Reclassification of cash flow hedge reserve to cost of hedging reserve	4
Transition adjustment reduction in trade and other receivables			235
Transition adjustment reduction in deferred tax liabilities			71
Consolidated sales revenue	19,914	$ 19,319
Increase (decrease) due to changes in accounting policy required by IFRSs [Member]
Basis Of Presentation [Line Items]
Consolidated sales revenue	$ (10)
Retained earnings [Member]
Basis Of Presentation [Line Items]
De-recognition of receivable arising from uplift transaction			164
Transition adjustment reduction in trade and other receivables			235
Bottom of range [Member]
Basis Of Presentation [Line Items]
Period to determine final prices for copper concentrate	30 days
Top Of Range [Member]
Basis Of Presentation [Line Items]
Period to determine final prices for copper concentrate	180 days
IFRS 9 [Member]
Basis Of Presentation [Line Items]
Impairment provision resulting from the application of the ECL model			$ 7