XML 94 R63.htm IDEA: XBRL DOCUMENT v3.19.1

Mine restoration provisions - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure of fair value measurement of assets [line items]
Inflation rate	2.10%
Current estimate to settle mine restoration provisions	$ 126	$ 102
Bottom of range
Disclosure of fair value measurement of assets [line items]
Discount rate	2.50%
Top of range
Disclosure of fair value measurement of assets [line items]
Discount rate	2.81%

X

- Definition

Inflation Rate, Significant Unobservable Inputs, Liabilities

+ References

No definition available.

+ Details

Name:	btg_InflationRateSignificantUnobservableInputsLiabilities
Namespace Prefix:	btg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

A current estimate using the entity's own data about the future cash outflows to be paid to fulfil an obligation if there is no reasonably available information that indicates that market participants would use different assumptions. This is used as a significant Level 3 unobservable input for liabilities. [Refer: Level 3 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 13
-IssueDate 2017-01-01
-Paragraph B36
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2017-03-01&anchor=para_B36_d&doctype=Appendix&seq=2
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_CurrentEstimateOfFutureCashOutflowsToBePaidToFulfilObligationSignificantUnobservableInputsLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
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_DisclosureOfFairValueMeasurementOfAssetsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Interest rate used as a significant Level 3 unobservable input for liabilities. [Refer: Level 3 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 13
-IssueDate 2017-01-01
-Paragraph B36
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2017-03-01&anchor=para_B36_a&doctype=Appendix&seq=2
-URIDate 2017-03-09

+ Details

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

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: