XML 210 R196.htm IDEA: XBRL DOCUMENT
v3.19.1

Finance costs and finance revenues (Details 2) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Disclosure of business combination [Line Items] |  |
Annual average of future sales of mineral | $ 196,801 | $ 193,588
Useful life of mining properties | 13 years | 13 years
Pre-tax Discount rate (%) | 10.00% | 10.00%

X
- References No definition available. + Details
Name: | cik0001013131_DisclosureOfBusinessCombinationLineItems
Namespace Prefix: | cik0001013131_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The annual average future sales of mineral in significant unobservable valuation inputs. + References No definition available. + Details
Name: | cik0001013131_SignificantUnobservableValuationInputsAnnualAverageOfFutureSalesOfMineral
Namespace Prefix: | cik0001013131_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Discount rate in significant unobservable valuation. + References No definition available. + Details
Name: | cik0001013131_SignificantUnobservableValuationInputsdiscountRate
Namespace Prefix: | cik0001013131_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The useful life of mining properties in significant unobservable valuation inputs. + References No definition available. + Details
Name: | cik0001013131_SignificantUnobservableValuationInputsusefulLifeOfMiningProperties
Namespace Prefix: | cik0001013131_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration