The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the cash inflow during the period from the sale of a component of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the back in right percentage granting entity the right to assume a specified non-carried interest in an underground project if counterparty in option agreement decides to develop an underground mine.

+ References

No definition available.

+ Details

Name:	vgz_BackInRightPercentage
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the gold price per ounce.

+ References

No definition available.

+ Details

Name:	vgz_GoldPrice
Namespace Prefix:	vgz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The number of successive payments per option agreement.

+ References

No definition available.

+ Details

Name:	vgz_NumberOfSuccessivePayments
Namespace Prefix:	vgz_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of interest in project that the counterparty has the exclusive right and option right to earn per the option agreement.

+ References

No definition available.

+ Details

Name:	vgz_PercentageOfInterestPerOptionAgreement
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of net smelter return royalty on any future productions from specified claims.

+ References

No definition available.

+ Details

Name:	vgz_PercentageOfNetSmelterReturnRoyalty
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership interest if terms of option agreement are not fulfilled.

+ References

No definition available.

+ Details

Name:	vgz_PercentageOfOwnershipInterestIfTermsOfOptionAgreementNotFulfilled
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership to be transferred to counterparty upon timely making all option payments and fulfilling other obligations with respect to Option Agreement.

+ References

No definition available.

+ Details

Name:	vgz_PercentageOfOwnershipToBeTransferred
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the aggregate amount of royalty payments to be received.

+ References

No definition available.

+ Details

Name:	vgz_RoyaltyPaymentsToBeReceived
Namespace Prefix:	vgz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Sale price of gold/silver project.

+ References

No definition available.

+ Details

Name:	vgz_SalePriceOfGoldProject
Namespace Prefix:	vgz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of the carrying value for the remaining option payment proceeds to be recognized as a contract liability until the title has been transferred to the buyer or the option agreement has been terminated.

+ References

No definition available.

+ Details

Name:	vgz_ValueOfCarryingValueForOptionPaymentProceedsToBeRecognizedAsContractLiability
Namespace Prefix:	vgz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=vgz_GuadalupeDeLosReyesMexicoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TransactionTypeAxis=vgz_OptionAgreementTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=vgz_ExecutionOfOptionAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=vgz_OneYearAnniversaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=vgz_TwoYearAnniversaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=vgz_BeforeFourYearAnniversaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=vgz_OpenPitMiningMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=vgz_UndergroundMiningMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Mineral Properties, Guadalupe (Details)	1 Months Ended	6 Months Ended
Mineral Properties, Guadalupe (Details)	Oct. 31, 2017 USD ($) item	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Property, Plant and Equipment [Line Items]
Proceeds from sale			$ 358,000
Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Interest has right to earn (as a percent)	100.00%
Sale price of gold/silver project	$ 6,000,000
Number of successive payments \| item	2
Back in Right (as a percent)	49.00%
Ownership interest if terms of option agreement not fulfilled (as a percent)	0.00%
Ownership to be transferred (as a percent)	100.00%
Ownership interest (as a percent)	100.00%
Proceeds from sale	$ 1,500,000
Value of carrying value for option payment proceeds to be recognized as contract liability		$ 0
Guadalupe De Los Reyes, Mexico [Member] \| Execution of Option Agreement [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Sale price of gold/silver project	1,500,000
Guadalupe De Los Reyes, Mexico [Member] \| One Year Anniversary [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Sale price of gold/silver project	1,500,000
Guadalupe De Los Reyes, Mexico [Member] \| Two Year Anniversary [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Sale price of gold/silver project	1,500,000
Guadalupe De Los Reyes, Mexico [Member] \| Before Four Year Anniversary [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Sale price of gold/silver project	1,500,000
Open Pit Mining [Member] \| Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Aggregate royalty payments to be received	$ 2,000,000
Open Pit Mining [Member] \| Minimum [Member] \| Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Net smelter return royalty (as a percent)	1.00%
Gold price (USD per ounce)	$ 1,600
Open Pit Mining [Member] \| Maximum [Member] \| Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Net smelter return royalty (as a percent)	2.00%
Gold price (USD per ounce)	$ 1,400
Underground Mining [Member] \| Minimum [Member] \| Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Net smelter return royalty (as a percent)	1.00%
Gold price (USD per ounce)	$ 1,600
Underground Mining [Member] \| Maximum [Member] \| Guadalupe De Los Reyes, Mexico [Member] \| Option Agreement Two [Member]
Property, Plant and Equipment [Line Items]
Net smelter return royalty (as a percent)	2.00%
Gold price (USD per ounce)	$ 1,400