SIGNIFICANT ACCOUNTING POLICIES - Stock-Based Compensation (Details) - 12 months ended Dec. 31, 2018	CAD ($)	USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Employee Share Purchase Plan, Employer Matching Contribution, Percent Match	50.00%	50.00%
Barrick Share Purchase Plan, Employer Matching Contribution, Percent Match	100.00%	100.00%
Stock options
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period	4 years	4 years
RSUs
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period	3 years	3 years
RSUs \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period	2 years 6 months	2 years 6 months
RSUs \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period	3 years	3 years
DSUs
Disclosure of terms and conditions of share-based payment arrangement [line items]
Minimum required annual retainer (as percent)	75.00%	75.00%
PRSUs
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period	3 years	3 years
PRSUs \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage (as percent)	0.00%	0.00%
PRSUs \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage (as percent)	200.00%	200.00%
PGSUs \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage (as percent)	100.00%	100.00%
PGSUs \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage (as percent)	600.00%	600.00%
ESPP \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Annual contributions per employee (as percent)	1.00%	1.00%
ESPP \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Annual contributions per employee (as percent)	6.00%	6.00%
BSPP \| Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Annual contributions per employee (as percent)	1.00%	1.00%
BSPP \| Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Annual contributions per employee (as percent)	10.00%	10.00%
Canada, Dollars \| ESPP
Disclosure of terms and conditions of share-based payment arrangement [line items]
Maximum employer contribution	$ 5,000
Canada, Dollars \| BSPP
Disclosure of terms and conditions of share-based payment arrangement [line items]
Maximum employer contribution		$ 5,000
United States of America, Dollars \| BSPP
Disclosure of terms and conditions of share-based payment arrangement [line items]
Maximum employer contribution		$ 4,000

Barrick Share Purchase Plan, Employer Matching Contribution, Percent Match

No definition available.

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

- Definition

Employee Share Purchase Plan, Employer Matching Contribution, Percent Match

+ References

No definition available.

+ Details

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

- Definition

Share-based compensation arrangement by share-based payment award, minimum amount of required annual retainer available for election

+ References

No definition available.

+ Details

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

- Definition

Share-based payment arrangement, annual contributions per employee, percent

+ References

No definition available.

+ Details

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

- Definition

Share-based payment arrangement, employer matching contribution, maximum amount of match

+ References

No definition available.

+ Details

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

- Definition

Vesting percentage for share-based payment arrangement

+ References

No definition available.

+ Details

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

- Definition

Vesting requirements for share-based Ppment arrangement

+ References

No definition available.

+ Details

Name:	abx_VestingRequirementsForSharebasedPaymentArrangement
Namespace Prefix:	abx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_StockOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_RestrictedShareUnitsMember
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_TypesOfSharebasedPaymentArrangementsAxis=abx_DeferredShareUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_PerformanceRestrictedShareUnitsPRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_PerformanceGrantedShareUnitsPGSUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_EmployeeSharePurchasePlanESPPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=abx_BarrickSharePurchasePlanBSPPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	abx_ContributionLimitCurrencyAxis=currency_CAD
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	abx_ContributionLimitCurrencyAxis=currency_USD
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: