Estimated mineral price for measurement of fair value less costs Of disposal

No definition available.

Name:	abx_EstimatedMineralPriceForMeasurementOfFairValueLessCostsOfDisposal
Namespace Prefix:	abx_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss (gain) on assignment of shareholder loans

+ References

No definition available.

+ Details

Name:	abx_LossGainOnAssignmentOfShareholderLoans
Namespace Prefix:	abx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Net assets value multiple used to determine the fair value less cost to dispose

+ References

No definition available.

+ Details

Name:	abx_Netassetsvaluemultiple
Namespace Prefix:	abx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted average cost of capital used as a significant Level 3 unobservable input for assets. [Refer: Level 3 of fair value hierarchy [member]]

+ References

No definition available.

+ Details

Name:	abx_WeightedAverageCostOfCapitalSignificantUnobservableInputsAssets
Namespace Prefix:	abx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of consideration paid or received in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2020-01-01
-Paragraph 40
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_40_a&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfInformationForEachMaterialImpairmentLossRecognisedOrReversedForIndividualAssetOrCashgeneratingUnitAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of impairment loss, impairment gain or reversal of impairment loss that is recognised in profit or loss in accordance with paragraph 5.5.8 of IFRS 9 and that arises from applying the impairment requirements in Section 5.5 of IFRS 9.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 82
-Subparagraph ba
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_82_ba&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The increase (decrease) in equity through changes in ownership interests in subsidiaries that do not result in loss of control. [Refer: Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 106
-Subparagraph d
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_106_d_iii&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

The proportion of ownership interest in a joint venture attributable to the entity. [Refer: Joint ventures [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2020-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2020-en-r&anchor=para_17_b_iii&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2020-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2020-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2020-01-01

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2020-01-01
-Paragraph 21
-Subparagraph a
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_21_a_iv&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ProportionOfOwnershipInterestInJointVenture
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The proportion of ownership interests in a subsidiary held by non-controlling interests. [Refer: Subsidiaries [member]; Non-controlling interests]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2020-01-01
-Paragraph 12
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_12_c&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ProportionOfOwnershipInterestsHeldByNoncontrollingInterests
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The higher of an asset’s (or cash-generating unit’s) fair value less costs of disposal and its value in use. [Refer: Cash-generating units [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2020-01-01
-Paragraph 130
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2020-en-r&anchor=para_130_e&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_RecoverableAmountOfAssetOrCashgeneratingUnit
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=abx_TanzaniaMinesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	ifrs-full_SegmentsAxis=abx_LagunasNorteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=abx_PorgeraMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=abx_TanzaniaMinesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	ifrs-full_IndividualAssetsOrCashgeneratingUnitsAxis=ifrs-full_IndividualAssetsOrCashgeneratingUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MeasurementAxis=ifrs-full_AtFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=abx_BulyanhuluMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=abx_NorthMaraMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=abx_BuzwagiMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

IMPAIRMENT OF GOODWILL AND OTHER ASSETS Narrative (Details)				3 Months Ended				6 Months Ended
	Mar. 31, 2021 USD ($)	Jan. 24, 2020 USD ($)	Jan. 01, 2020	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)				$ (2,000,000)		$ (23,000,000)		$ 87,000,000	$ 313,000,000
Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity									238,000,000
Tanzania Mines [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Proportion of ownership interests held by non-controlling interests								16.00%
Non-controlling interests
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity									238,000,000
Lagunas Norte [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)					$ 86,000,000
Porgera
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Proportion of ownership interest in joint venture								95.00%
Tanzania Mines [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)									$ 332,000,000
Proportion of ownership interests held by non-controlling interests			16.00%				16.00%
Loss (gain) on assignment of shareholder loans							$ 167,000,000
Tanzania Mines [Member] \| Minimum [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Net assets value multiple		$ 1.1
Weighted average cost of capital, significant unobservable inputs, assets		5.40%
Tanzania Mines [Member] \| Maximum [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Net assets value multiple		$ 1.3
Weighted average cost of capital, significant unobservable inputs, assets		6.20%
Tanzania Mines [Member] \| Short-term [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Estimated Mineral Price For Measurement Of Fair Value Less Costs Of Disposal		1,350
Tanzania Mines [Member] \| Long-term [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Estimated Mineral Price For Measurement Of Fair Value Less Costs Of Disposal		1,300
Individual assets or cash-generating units [member] \| Lagunas Norte [Member] \| At fair value [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Consideration paid (received)	$ (63,000,000)
Individual assets or cash-generating units [member] \| Porgera
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)								$ 0
Individual assets or cash-generating units [member] \| Bulyanhulu [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)							649,000,000
Recoverable amount of asset or cash-generating unit							1,237,000,000
Individual assets or cash-generating units [member] \| North Mara [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)							88,000,000
Recoverable amount of asset or cash-generating unit							967,000,000
Individual assets or cash-generating units [member] \| Buzwagi [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [abstract]
Impairment reversals (charges)							$ 0