XML 110 R79.htm IDEA: XBRL DOCUMENT
v3.19.1

Income and other taxes - Narrative (Details) - USD ($) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Aug. 08, 2018 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |  |
Unrecognized deferred tax assets |  | $ 172,954 | $ 135,905
Income taxes paid |  | 50,000 | 12,000
Canada | Capital Losses |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |  |
Unrecognized deferred tax assets |  | 423,000 |
Fekola SA | Non-participating Share Capital |  |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |  |
Income tax relating to priority dividend |  | $ 18,000 | $ 2,000
Priority dividend rate to non-controlling interest | 10.00% | 10.00% |

X
- Definition Income Tax Relating To Priority Dividend + References No definition available. + Details
Name: | btg_IncomeTaxRelatingToPriorityDividend
Namespace Prefix: | btg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Priority Dividend Rate, Non-Controlling Interest + References No definition available. + Details
Name: | btg_PriorityDividendRateNonControllingInterest
Namespace Prefix: | btg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of deductible temporary differences for which no deferred tax asset is recognised in the statement of financial position. [Refer: Temporary differences [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2017-01-01 -Paragraph 81 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2017-03-01&anchor=para_81_e&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition The cash flows from income taxes paid or refunded. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 7 -IssueDate 2017-01-01 -Paragraph 35 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_35&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_IncomeTaxesPaidRefund
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis=btg_CapitalLossesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=btg_FekolaSAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=btg_NonparticipatingShareCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |