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v2.4.1.9

Supplemental Cash Flow Information and Material Non-Cash Transactions (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jul. 31, 2012 | Dec. 31, 2014
Compensation Options Issued to Underwriters | 166,667 vgz_CompensationOptionsIssuedToUnderwriters |
Gold Production Volume Second Tier For Royalty Calculation |  | $ 1,250 vgz_GoldProductionVolumeSecondTierForRoyaltyCalculation
Royalty Percentage On Second Tier Volume Production |  | 2.50%vgz_RoyaltyPercentageOnSecondTierVolumeProduction
Gold Production Volume First Tier For Royalty Calculation |  | $ 1,250 vgz_GoldProductionVolumeFirstTierForRoyaltyCalculation
Royalty Percentage On First Tier Volume Production |  | 2.00%vgz_RoyaltyPercentageOnFirstTierVolumeProduction
Percentage Of Ownership Under Purchase Agreement |  | 100.00%vgz_PercentageOfOwnershipUnderPurchaseAgreement
Two Thousand Thirteen Facility [Member] |  |
Number of shares issued in transaction, (Shares) |  | 612,180 us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction / us-gaap_DebtInstrumentAxis = vgz_TwoThousandThirteenFacilityMember
Compensation Warrants [Member] |  |
Warrants issued (in shares) | 166,667 vgz_NonOptionEquityInstrumentsIssued / dei_LegalEntityAxis = vgz_CompensationWarrantsMember |

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of compensation options issued to underwriters as part of an equity placement. + References No definition available. + Details
Name: | vgz_CompensationOptionsIssuedToUnderwriters
Namespace Prefix: | vgz_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gold Production Volume First Tier For Royalty Calculation + References No definition available. + Details
Name: | vgz_GoldProductionVolumeFirstTierForRoyaltyCalculation
Namespace Prefix: | vgz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Gold Production Volume Second Tier For Royalty Calculation + References No definition available. + Details
Name: | vgz_GoldProductionVolumeSecondTierForRoyaltyCalculation
Namespace Prefix: | vgz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of non-option equity instruments issued. + References No definition available. + Details
Name: | vgz_NonOptionEquityInstrumentsIssued
Namespace Prefix: | vgz_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage Of Ownership Under Purchase Agreement + References No definition available. + Details
Name: | vgz_PercentageOfOwnershipUnderPurchaseAgreement
Namespace Prefix: | vgz_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Royalty Percentage On First Tier Volume Production + References No definition available. + Details
Name: | vgz_RoyaltyPercentageOnFirstTierVolumeProduction
Namespace Prefix: | vgz_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Royalty Percentage On Second Tier Volume Production + References No definition available. + Details
Name: | vgz_RoyaltyPercentageOnSecondTierVolumeProduction
Namespace Prefix: | vgz_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=vgz_CompensationWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=vgz_TwoThousandThirteenFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |