XML 151 R144.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Intangible assets - Summary of intangible assets (Parenthetical) (Detail) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Intangible assets | $ 3,119 | $ 3,279 | $ 3,336
Disposals, transfers and other movements | $ 36 | $ 82 |
Quebec smelters [member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Fair value less costs of disposal, post-tax discount rate | 6.70% | 7.00% |
Description of recoverable amount of asset is fair value less costs of disposal or value in use | the Quebec smelters cash-generating unit. The Quebec smelters cash-generating unit was tested for impairment by reference to FVLCD using discounted cash flows, which is in line with the policy set out in note 1(i). The recoverable amount of the Quebec smelters is classified as level 3 under the fair value hierarchy |  |
Description of level of fair value hierarchy within which fair value measurement is categorized | level 3 |  |
Water rights [member] | Quebec smelters [member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Intangible assets | $ 1,824 |  |
Trademarks [member] | Bottom of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 14 years |  |
Trademarks [member] | Top of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 20 years |  |
Patented and non-patented technology [member] | Bottom of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | ten years |  |
Patented and non-patented technology [member] | Top of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 20 years |  |
Power contracts water rights [member] | Bottom of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | two years |  |
Power contracts water rights [member] | Top of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 45 years |  |
Other purchase and customer contracts [member] | Bottom of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | five years |  |
Other purchase and customer contracts [member] | Top of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 15 years |  |
Computer software [Member] | Bottom of range [Member] | Internally generated [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | two years |  |
Computer software [Member] | Top of range [Member] | Internally generated [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | five years |  |
Other intangible assets [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Intangible assets | $ 463 | $ 387 | 398
Disposals, transfers and other movements | $ 79 | 94 |
Other intangible assets [Member] | Bottom of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | two years |  |
Other intangible assets [Member] | Top of range [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Finite life intangible assets, useful lives | 20 years |  |
Exploration and evaluation [member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Intangible assets | $ 393 | 711 | $ 706
Disposals, transfers and other movements | (45) | $ (17) |
Exploration and evaluation [member] | Kemano Tunnel Project [Member] |  |  |
Disclosure of detailed information about intangible assets [Line Items] |  |  |
Disposals, transfers and other movements | $ 34 |  |

X
- Definition The description of the level of the fair value hierarchy within which the fair value measurement is categorised in its entirety (without giving regard to the observability of 'costs of disposal') for a cash-generating unit (group of units'). [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2016-01-13 -Paragraph 134 -Subparagraph e -Clause iiA -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2016-03-30&anchor=para_134_e_iiA&doctype=Standard -URIDate 2016-03-31 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2016-01-13 -Paragraph 130 -Subparagraph f -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2016-03-30&anchor=para_130_f_i&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_DescriptionOfLevelOfFairValueHierarchyWithinWhichFairValueMeasurementIsCategorised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition The discount rate used in the current measurement of fair value less costs of disposal. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2016-01-13 -Paragraph 130 -Subparagraph f -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2016-03-30&anchor=para_130_f_iii&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_DiscountRateUsedInCurrentMeasurementOfFairValueLessCostsOfDisposal
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The decrease in intangible assets other than goodwill resulting from disposals. [Refer: Intangible assets other than goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2016-01-13 -Paragraph 118 -Subparagraph e -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2016-03-30&anchor=para_118_e_ii&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_DisposalsIntangibleAssetsOtherThanGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Information about whether the recoverable amount of an asset (cash-generating unit) is its fair value less costs of disposal or its value in use. [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2016-01-13 -Paragraph 130 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2016-03-30&anchor=para_130_e&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_InformationWhetherRecoverableAmountOfAssetIsFairValueLessCostsToSellOrValueInUse
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of identifiable non-monetary assets without physical substance. This amount does not include goodwill. [Refer: Goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2016-01-13 -Paragraph 118 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2016-03-30&anchor=para_118_e&doctype=Standard -URIDate 2016-03-31 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 54 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_54_c&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_IntangibleAssetsOtherThanGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The useful lives or amortisation rates used for intangible assets other than goodwill. [Refer: Intangible assets other than goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2016-01-13 -Paragraph 118 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2016-03-30&anchor=para_118_a&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_UsefulLivesOrAmortisationRatesIntangibleAssetsOtherThanGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_IndividualAssetsOrCashgeneratingUnitsAxis=rio_QuebecSmeltersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=rio_WaterRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=rio_TrademarkMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=rio_PatentedAndNonpatentedTechnologyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=rio_PowerContractsWaterRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=rio_OtherPurchaseAndCustomerContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=ifrs-full_ComputerSoftwareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MethodsOfGenerationAxis=ifrs-full_InternallyGeneratedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=ifrs-full_OtherIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=ifrs-full_IntangibleExplorationAndEvaluationAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_IndividualAssetsOrCashgeneratingUnitsAxis=rio_KemanoTunnelProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |